THE
GEOLOGICAL MAGAZINE.
DECADE II. VOL. VI.

JANUARY—DECEMBER. 1879,

THE

GEOLOGICAL MAGAZINE:

OR,

Monthly Journal of Geology:

WITH WHICH IS INCORPORATED

“THE GEOLOGIST.”

NOS. CLXXV. TO CLXXXVI.

EDITED BY
HENRY WOODWARD, LL.D., F.B.S., F.G.S., F.Z.S.,
VICE-PRESIDENT OF THE GEOLOGISTS’ ASSOCIATION ;
MEMBER OF THE AMERICAN PHILOSOPHICAL SOCIETY, PHILADELPHIA 5
HONORARY MEMBER OF THE YORKSHIRE PHILOSOPHICAL SOCIETY; OF THE GEOLOGICAL SOCIETIES
OF EDINBURGH, GLASGOW, AND NORWICH; CORRESPONDING MEMBER OF THE GEOLOGICAL

SOCIETY OF BELGIUM; OF THE NATURAL HISTORY SOCIETY OF MONTREAL; AND
OF THE LYCEUM OF NATURAL HISTORY, NEW YORK.

ASSISTED BY

PROFESSOR JOHN MORRIS, M.A, F.GS., &., &c.,

AND

ROBERT ETHERIDGE, F.R.S.L. & E., F.G.8S., &c.

NEW SERIES. DECADE II, VOL. VI.
JANUARY—DECEMBER, 1879.

LONDON:

TRUBNER & Co., 57 ann 59, LUDGATE HILL.
F. SAVY, 77, BOULEVART ST.-GERMAIN, PARIS.
¢ 1879.

HERTFORD:

PRINTED BY STEPHEN AUSTIN AND SONS,

PLATES.

*XIII.
& XIV.
XN.

LIST OF PLATES.

. Bird’s-eye View of Barren Island, Lat. 12° 17’ N. Long, 93° 54’ E.
. Map of Land’s End and Scilly Isles cee see cee sees
. Map of Geology of Lake District 0.0... cece cece tee ste te
. Protophasma Dumasii, Brong., Coal-measures, France ..... .....

. Eurypterus Scoulert, Hibbert 20.0. ce cee ee vee mate ice
. Ramipora Hochstetteri, var. carinata, R. Eth., Junr. _ ..... ieee
Ba COlandachonisman due01070100 7001, Cage amr ee
. Emys lutaria, Merr., Mundesley, Norfolk 2... es
> Miley) Git Uriah SIE INGS, | So, deeo | eae Jomo) Gam Vem Ge vee) ec
> fiumalneam, Ios! SINC coos cece oan bows comm san comee ed Ges
= Sumatran Lertiany shellsyandyCoralsy yes es sane ee

> (Sidumenran Cuearineny IOS ex | een eee cece

Sumatran ie nti asa Site) laa ieee eae ee ee ee
Ditto GUNG RD sey Ne aN aetna ued ais ae leet sedey
Ditto CORTON ag meas et crsien emertad every ica per eoeealerest es

PAGE

Ase
ay

LIST OF WOODCUTS.

PAGE
Three sections to illustrate Physical Geology of Lake District... 00 ... 54
Sections showing Breaks in Rocksof “ Old Red Sandstone Formation,’’ Ireland 68
Osmunda bromeliefolia of Philippine Isles ..... cc, cess see cesses cette arene sete 153
Coast towards Rosemullion Head, showing Rock Platforms and Cliffs com-

posed of Head upon Raised Beach sae sess sssse cere sees cree ets atte 168
Section, Cape Cornwall) om north side tig) asus) crc cece neeee een cree) ee cess 171
Trigonia Elise, Cornet and Briart, Bracquegnies, Belgium... sae eee oes 196
JRO SHO NEUE, cers ce oe om 197
Seanion mene Cramer, Coranyiilee as ceo deo orm am aon Gm Ge 204
Section, Godrevy, Cornwall .... DAS DN ee N Ae ARR ONE Ee 205
Cotrany edn, Coatiwalle ous cee no ty oc ce ee 205
Section of Head, concealing a Raised Beach, resting upon Slate, above sea-

Nene leavers Ak Cos ceieeG ferme htasetiecsssvies vatncel Ausist (Gasca Teteeat P cseetely canane) Al esgechac Tene 211
Syningolates) Lcronensts, ELINGC)) eer | cere este) ccs) erst) cesesy | eeree) errr cere) eae 245
See tonwote Coralaree tems water piece mary iiacsatiesr. Wily oesesiud reset erro ee 297
Diagrammatic section showing relation between Rocks N. and 8. Dingle Bay 391
Relation of Serpentine and Sedimentary Rocks near Figline .. 0... ee 369
Section about a mile N. of Bridlington Harbour 2. wk cece see wee 898
Columnar Sandstone in a quarry at Gorischstein W. Schandau, “Saxon 438

Switzerland”’ ..... Seana pets atten Nonesaes atassyll sens) (oepased! Case che lettlaye Urata yee 438
Single Column of Columnar Sandstone 0, o ceee tees cere cee nee 438
Section at Reedy Creek, also at Two-mile-flat, New South Wales... ... 450
Branchiosaurus salamandroides, Fritsch, dorsal view, Gas-coal, Bohemia ..... 523

Ditto ditto twice natural size ditto ditton nye 524

Ditto ditto upper side of skull _ ditto ditto O20

Ditto ditto under side of skull ditto ditto —..... 525
Dawsonia polydens, Fritsch, under side of skull ditto ditto 527
Diagram-pproilevot Parallel Roads of Glen Royeeny cy) erry enone) eee ee: 530

Spine of Ctenacanthus minor, Davis, Lower Coal-measures, Dudley Hill, near
Bradford .....

Geese eeeny = penne sense ane

en i

MS EAT

Pll) jCutl

THE

GEOLOGICAL MAGAZINE.

NEW “SERIES; DECADE lly ‘VOLE? VI:
No. I—JANUARY, 1879.

Om EGAN A, Auk ECGS.

—>__

J.—On tHE TRIPARTITE CLASSIFICATION OF THE LOWER
Patzozor1c Rooks.

By Cuartzes Lapwortn, F.G.S.

Y those accustomed to the hopeless confusion of the Greywacké
of the earlier geologists, the publication of Murchison’s grand
work on the “Silurian System” was hailed with feelings of the
most profound relief and satisfaction. His clear and brilliant pre-
sentation of the physical and paleontological proofs of an orderly
sequence among the Paleozoic Rocks below the Old Red Sandstone,
as originally set forth in all their force and harmony in his magni-
ficent volumes, naturally astonished and dazzled the majority of
his scientific contemporaries, and secured for his nomenclature of
these ancient deposits an almost universal acceptance. His subse-
quent abuse of this advantage to strengthen and consolidate his own
system at the expense of that of his equally-illustrious co-worker—
the less fortunate but more cautious Sedgwick—was a gallant but
unscrupulous defence of this original nomenclature, which by that
time he must have felt himself almost powerless to disturb. His
later extension downward of the limits of his System, till it
embraced all the rocks between the supposed Azoics and the Old Red
Sandstone—though, in a measure, forced upon him from without—
ought perhaps to be regarded in part as a very natural return to
the ideas of his early teachers, who had always held the practical
unity of the rocks of the Transitional period. In this way, however,
Murchison unwittingly destroyed many of the most beneficial results
of his own labours ; in a sense, spending his old age in the attempted
re-erection of the very edifice it had been the pride of his manhood
to destroy—the early years of his scientific career being devoted to
the worthy task of proving the marvellous variety of the Lower
Paleeozoics ; his later years to demonstrating their integrity, unity,
and indivisibility.

At the present day it would be wholly superfluous to enter upon
the discussion of the vexed question of the respective claims of
Sedgwick and Murchison to the Middle and Lowest Divisions of the
Lower Palzozoic Rocks. We may, however, without fear of contra-
diction, concede to Sedgwick the credit of having been the first to

DECADE II.—VOL. VI.—NO. I. 1

rs

2 C. Lapworth—Classification of the Lower Paleozoic Rocks.

determine the limits and sequence of their larger subdivisions, and
to Murchison and his followers the honour of having been the first to
assion them their distinctive fossils. Sedgwick worked out single-
handed the true stratigraphical arrangement of the rocks of the Lower
Palzeozoics of Wales, from the Bangor Beds to the summit of the Bala
Series, and divided them into several successive groups, the propriety
and convenience of which subsequent research has served only to
make more distinctly apparent. The unavoidable—but none the
less vital—defect in his earlier work lay in his not publishing the
characteristic fossils of these subdivisions, until after the appearance
of the great work of his rival, in which the most conspicuous forms
appear as characteristic of the subdivisions of a supposed overlying
system. Murchison’s work, on the other hand, depended not only
upon mineralogical characters and sequence of formations, but also
upon paleontological peculiarities. He failed signally, however, in
strictly and correctly defining his lower groups, and in correlating
some of his most typical beds, with the result of greatly confusing
his lists of characteristic fossils.

The rigid conservatism of Murchison in his old age, and his
systematic disregard of the facts and arguments adduced in support
of the Cambrian System, brought about its inevitable re-action after
his death. 'The campaign against the Murchisonian nomenclature, so
brilliantly opened by Professor Sterry Hunt, in his masterly paper
on the “ History of the Names Cambrian and Silurian in Geology,”
has since assumed extraordinary proportions. The Cambridge School,
headed by Professor Hughes, the present talented occupant of the
Woodwardian Chair, supported by several earnest and industrious
adherents, has revived the claims of Sedgwick in all their entirety ;
and presses them on the attention of geologists with an energy and
persistence that threatens to lead to the formation of a body of
workers, determined to force from posterity, in honour of the memory
of Sedgwick, the rights he demanded, but of which during his life-
time he was so unfairly deprived.

But, on the other hand, the Murchisonian nomenclature is embodied
in the maps and publications of the National Survey. It is embalmed
in the classic memoirs of the illustrious Barrande, and in the numerous
works of the best-known geologists of Europe and America. It is
still held, almost in its widest sense, by the more influential officers
of the Geological Survey, and is taught to their students and sub-
ordinates with that complacent pride which has naturally been engen-
dered by a quarter of a century of uninterrupted success. Even yet,
its advocates have such an unfaltering faith in its intrinsic propriety
and consequent impregnability, that the fact of the daily increasing
number and ability of their opponents is either contemptuously
ignored, or, at most, is deemed unworthy of a more respectful
recognition than a passing smile.

The utter impossibility of reconciling the antagonistic claims of
these opposing schools has led, of late years, to the formation of a
third party, in which the best-known names are those of the late
Sir Charles Lyell, and of Dr. Henry Hicks. These concede the

C. Lapworth— Classification of the Lower Paleozoic Rocks. 3

light of Murchison to all the strata between the base of the Arenig
and the summit of the Ludlow, but emphatically assign the Lingula
Flags and Paradoxides Beds to the Cambrian. This school—if
school it may be called—has been greatly aided by the wide publicity
given to their views in the numerous memoirs in which they record
their steady and cautious advance in working out the natural
Succession among the subordinate members of the Lower Palaeozoic
Rocks. It is just possible that, owing to the modesty of the claims
it makes for Sedgwick, and to its retention of such a large proportion
of the prevalent nomenclature, this view might gradually and
insensibly have taken possession of much of the field, were it not for
the persistent exertions of the Cambridge School, smarting under a
sense of injustice, and determined to rest satisfied with nothing less
than a complete redress of those historic grievances, which their
affection for the honoured name of Sedgwick has led them to regard
as little less than personal to themselves.

But the partial success that has already attended the earnest con-
scientiousness and perseverance of the members of the Sedgwickian
party has, in truth, hastened the evil day. The result that their
efforts have had in calling the attention of geologists to the salient
points of the question at issue, is as fatal in its effects upon their
own theory, as it is upon that of their opponents. By their recent
adoption of the Lyell-Hicks line of demarcation at the base of the
Lower Llandovery, they furnish, indeed, a thorough demonstration of
the almost perfect palzeontological) distinctness of the faunas of the
so-called Lower Silurian formations, and those of the true or Upper
Silurian, and the consequent impossibility of combining them philo-
sophically in one and the same system. But, in spite of all that is
implied to the contrary, this course is, in effect, a distinct abandon-
ment of Sedgwick’s fundamental argument that these systems were
necessarily distinct, from the fact that in the typical areas their beds
were stratigraphically discordant. Jt amounts, on the other hand,
to an implicit adoption of the only safe principle, that we have no
reliable chronological scale in geology but such as is afforded by the
relative magnitude of zoological change—in other words, that the
geological duration and importance of any system is in strict pro-
portion to the comparative magnitude and distinctness of its collective
fauna. It appears to me that it is impossible for them to rest here,
but that their next and inevitable step will be the further admission
that the Lyell-Hicks division of Cambrian and Lower Silurian are as
rightly entitled to the rank of separate systems as the true or Upper
Silurian itself; and that, eventually, their rigid sense of fairness
and justice will lead them so to discriminate them.

For, amid all the confusion incident to this controversy, one grand
fact stands out clear and patent to the most superficial student of
Paleozoic geology — namely :—the strata included between the
horizon marking the advent of Paradozides, and the provisional
line presently drawn at the summit of the Ludlow, imbed three
distinct faunas, as broadly marked in their characteristic features as
any of those typical of the accepted systems of a later age.

4 C. Lapworth—Classification of the Lower Paleozoic Rocks.

The necessity for a tripartite grouping of the Lower Paleozoic
Rocks and Fossils, in partial accordance with this fact, has been
very generally acknowledged for the last thirty years. The keen-
eyed and philosophic Barrande was the first to recognize this truth,
and his addition of the “ Primordial” to the First and Second Faunas
of Murchison’s original Silurian marked a geologic era equal in
importance to the establishment of a new system. How keenly its
enthusiastic discoverer watched over, and how zealously he pro-
moted and encouraged, the gradual detection and elimination of his
«“ Primordial” Fauna in Kurope and America, are matters familiar
and delightful to all earnest students of the history of discovery
among the Lower Paleozoic Rocks. How the facts obtained by
Phillips, Salter, and Hicks in Britain, foreed even Murchison himself
to adopt Barrande’s views, and in his later years to become their
keenest and most unsparing advocate, is equally well known. The
subsequent development of the “ Primordial” Fauna in Britain by
Hicks, Salter, Belt, and others; in Sweden by Angelin, Nathorst
Linnarsson, and Sjogren; and in America by Billings, Emmons, Hall,
and Hartt, has progressed with marvellous rapidity. very system-
atic geologist worthy of the name has, in his turn, been compelled
to acknowledge the distinctness and first-rate importance of the
« Primordial” Fauna.

Under one form or another, also, the difference in the facies of
the more recent First and Second Faunas of Murchison has been
universally admitted from the first, and the rock-groups formed by
their including strata have been separated—at least as distinct sub-
systems—in all parts of the world. It is indeed true that there have
been, perhaps, as many diverse views held with respect to the
proper position of the line of demarcation between them, as there
have been separate areas of investigation; and it is only of late that
geologists have reached something like a concensus of opinion in draw-
ing it with Hicks at the base of the Lower Llandovery. Nevertheless,
no honest investigator, either British or foreign, has ever dreamt of
disputing the grand fact of the distinctness of these two faunas and
the consequent need for the separation of their containing rock-
groups in any natural and workable plan of classification.

Thus, it is hardly possible that any geologist, who is familiar with
the rocks and fossils of the Lower Palzeozoics, or who is even fairly
versed in the literature of the subject, would at present venture to
deny the proposition that between the base of the known fossiliferous
series and that of the Old Red Sandstone there lie three successive
rock-groups—each of which is characterized by a special fauna of
first-rate geologic importance.

Further insistence upon this point is probably needless. But if
the fact be once admitted, it follows of necessity that the interests of
science demand that these three successive rock-systems shall be dis-
tinguished by three separate and unmistakable titles.

At this stage, however, we plunge into the very midst of the
conflict of the schools. Friends, foes, and spectators, seem all fairly
agreed as to the advisability of a triple division of the sediments.

C. Lapworth—Classification of the Lower Paleozoic Rocks. 5

The points around which the strife is at its keenest bear upon the
question as to whether these three divisions are of equal classificatory
value, and if so, which party has the best right to give them their
names.

The strict Murchisonian of the present day claims for the Silurian
all the fossiliferous strata that lie between the Archean and the
Devonian, and arranges them in his three sub-systems of the
Primordial, Lower, and Upper Silurian. If he is a paleon-
tologist, he seizes at once upon the indisputable fact that
the general facies of the fossils of these three divisions, when
viewed in their collective aspect, has a marked character of
its own, wholly distinct from that of the faunas of the overlying
rock-groups. Profoundly impressed by this distinction, the less
striking differences between the faunas of the three members of
the Lower Paleozoic itself dwindle in his eyes into utter insig-
nificance, and the slightest party bias is sufficient to lead him to
regard them with Barrande as forming “one grand and indivisible
triad which is the Silurian System.” As discovery progresses,
gradually demonstrating the former presence of organic existences
in strata far below the base-line laid down by the founder of his
system, departing gradually in facies from his typical fauna (but,
nevertheless, connected therewith by almost imperceptible grada-
tions), his former admission, and the traditions of his school, compel
him to keep pace with it, extending his system and fauna down-
wards step by step. The result is, that if he is consistent, he is at
last driven to demand also, with Barrande, the inclusion of the beds
which Murchison, even in his latest years, acknowledged to be the
very basement rocks of a pre-Silurian system.

If, on the other hand, he is a stratigraphist, he instances the fact
that in Britain and America no general stratigraphical discordance
interrupts the vertical succession of formations between the Archean
and the Carboniferous. He points to the Llandovery beds of Britain,
and shows that the grandest stratigraphical break in the entire series
in the typical area occurs in the heart of a group of beds that the
founder of his school placed partly in one sub-system and partly in
the other ; but which he, in common with all scrupulous geologists,
included in a single formation, whose essential unity he fearlessly
challenges his opponents to deny. He calls attention to the Colonies
of Bohemia to show that even where the paleontological distinction
between the sub-systems is most abrupt, yet, according to the
greatest of Silurian paleontologists, there is actually an alternation
of the two faunas in the beds of passage. Or, he points triumphantly
to the succession in Scandinavia, where the Lower Paleozoics are
reduced to a collective thickness of a few hundreds of feet, and are
occasionally folded up and entangled almost inextricably together in
a single section, and asks how is it possible to doubt the unity of a
System whose members are individually of such insignificant dimen-
sions, and, physically, are so indissolubly united !

The moving principle of the Sedgwickian, on the contrary, is the
demand for historic justice. With true British instinct, he recognizes

6 CO. Lapworth—Classification of the Lower Paleozoic Rocks.

the fact that the revered founder of his school was unfairly deprived
of the natural fruits of the labours of a lifetime by the overwhelming
forces of influence and circumstance; and he chivalrously devotes
all his energies to the task of overturning history to the extent of
bringing back matters to the point they would have reached, had
the relative position of Sedgwick and Murchison been reversed. To
this paramount consideration everything else is sacrificed. The
Silurian is cut down so as to include the Upper Division only of
Murchison’s original System ; while all the fossiliferous beds below
are assigned to the Cambrian. That in this way he commits pre-
cisely the same scientific error as the Murchisonian, never seems to
occur to his imagination. That every fact adduced in support of
Sedgwick’s claim to the rocks of the Second fauna can be met by one
in Murchison’s favour equally cogent, is forgotten. That every error
committed by the latter to the destruction of his claims can be
paralleled by one equally fatal to those of his opponent, is similarly
ignored. He has long sinve convinced himself of the fact that the
Silurian, as he restricts it, is quite large enough to form a system by
itself, and that its fauna is grand enough and special enough to
characterize one; but we never find him carry out this argument to
its legitimate conclusion—that, if so, his own Cambrian is not one,
but two systems, whose individuality he is, by his own principles,
equally compelled to recognize. He seeks in all kinds of out-of-the-
way spots for evidences of local unconformities between the Balas
and the Llandoveries to satisfy his stratigraphical conscience that
there is sometimes an actual physical break between them; when,
without leaving his closet, he could assure himself of the fact that
the two systems of the so-called Lower and Upper Silurian are
already known to be stratigraphically concordant nearly all over th

world. Where this argument fails, we find him insisting upon th

presence of conglomerates and upon the sudden change in the cha-
racter of the organic remains. But each and all the principles of
classification implied in these distinctions are violated in his own
procedure. The grandest zoological breaks in the whole Lower
Paleozoic Series (those between the Olenus beds and the Arenigs
of Britain, and between the Canadian and Trentonian of North
America), and the thickest and most persistent conglomerates that
antedate those of the Old Red Sandstone (viz. those of the Lower
Girvan and Quebee Groups), all occur in the very heart of his own
Cambrian System. Yet of these we hear little or nothing, but all
the strata between the Archean and the Llandovery are piled up into
a single system, for the sole reason that they happen to occur in
association in the mountain-area of North Wales, and were very
naturally lumped together by the first scientific man who con-
scientiously studied them.

The Lyellian is certainly more politic than his excited neighbours,
but, from a common-sense point of view, his disinterested procedure
is equally unfair. To him, the fact that Murchison described the
Upper and Lower Silurian Rocks in his original Silurian System in
such a way that they can, to a certain extent, be recognized and

C. Lapworth— Classification of the Lower Palwozoic Rocks. 7

identified in Europe and America, is all-weighty. He calls special
attention to the fact that Sedgwick’s Upper Cambrian was ultimately
found to possess the fossils of Murchison’s Lower Silurian, but he
forgets to add that it was Sedgwick, and not Murchison, who first
_gave the natural divisions of this group, placing them in their proper
relations to each other, and defining their true limits above and
below. He points out with emphasis the grand distinctions between
the Primordial and Second Faunas, and the consequent impossibility
of uniting the rocks they characterize in one and the same system ;
but the fact of the stratigraphical break at the base of the Mayhill
Sandstone is, however, contemptuously dismissed as of no special
classificatory value, and the two Llandoveries are joined in a single
formation. Thus, in one stroke, Sedgwick is deprived of his grand
argument of a physical break between his own and the overlying
rocks ; and the Second and Third Faunas are re-united to form what
is termed the Silurian System. In effect, Murchison receives the
lion’s share, simply on the ground of possession; while Sedgwick is
deprived of half his system because he had the misfortune, in the
earlier stages of the controversy, not to command so numerous and
influential a following as his more socially fortunate opponent.

At irregular intervals, also, we catch a momentary glimpse of a
stray individual who refuses to identify himself with either of these
great parties ; preferring rather to temporize by definitively assigning
the rocks of the Middle Fauna to neither claimant in particular. He
refers to them under such makeshift titles as the Cambro-Silurian or
Siluro-Cambrian, according as his otherwise unexpressed personal
bias inclines him to one or other of the contending parties. Occasion-
ally, indeed, we do find him possessed of a true estimate of the grand
importance of the group, but he often leaves it to be understood that
he regards it as forming a transitional series of second-rate geologic
significance; and, in effect, belonging properly to both Cambrian
and Silurian at once. He is at the same time so fully impressed
with the consciousness of his own forlorn and isolated condition, as
well as of the hopelessness of stemming the current of vulgar use
and wont, that he generally contents himself with simply recording
his protest in this manner, and timidly guards himself against possible
ambiguity and misconception by prefixing the qualifying term True
or Upper when he comes to speak of the undisputed Silurian.

But, in addition to the foregoing, there are innumerable outsiders
like myself, who care nothing for schools, but everything for the
facts. There is that great and ever-increasing body of students who
are attracted to the study of geology because of the flood of light it
casts upon the mysterious problems of life and its distribution.
Above all, there are those foreign geologists, who naturally expect
from British investigators an authoritative and unmistakable geologic
scale to which to refer the results of their own researches. To all
these the erying scandal of this interminable dispute is an annoyance
and a positive encumbrance.

But whose procedure shall we follow? Shall we adopt the
Murchisonian’s convenient plan of carrying down the base-line for

8 C. Lapworth—Classification of the Lower Paleozoic Rocks.

the Silurian System as far as a Trilobite has yet been detected, sinking
it deeper and deeper into the earth as the progress of discovery
reveals the evidence of the former presence of organisms in strata of
yet older and older date, at the same time extending its highest
boundary upwards into the supra-Ludlow formations as we detect |
the presence of an occasional fossil of a Ludlow type yet higher and
higher in the more rapidly accumulated Red Sandstones above the
Bone beds, till our unwieldy system includes half the fossiliferous
sediments of the globe, and its very subdivisions are almost equal in
classificatory importance to the accepted systems of a later date ?

Or shall we adopt the methods of the traditional followers of
Sedgwick, and, drawing a rigid line of demarcation at the base of
the Lower Llandovery, imitate our opponents to the extent of erecting
all the anterior fossiliferous strata into a gigantic system, on the
ground that they were so combined by its founder, and in the delusive
hope that we shall find at its base a universal unconformability, so
that the name Pre-Cambrian will ever remain a synonym of the
metamorphic and possibly azoic formations ?

Or, with Lyell, shall we condone the past, and give a double share
to the stronger party; consoling ourselves with the reflection that,
after all, the question is merely a question of names, and not of
principle; arguing that the injustice we tolerate did not originate
with us, and is less the crime of a party than the inevitable result
of untoward circumstance ; and justifying our procedure in the eyes
of the world by the implication that the general adoption of the
larger portion of the Murchisonian nomenclature is already an ac-
complished fact, upon which it would be ridiculous to expect that
any feeble efforts of ours would ever have the slightest influence ?

Or, ought we rather to cast in our lot with the few who employ
the term Cambro-Silurian or Siluro-Cambrian for the rocks of
the Second Fauna, and try once again the oft-repeated and as oft-
defeated experiment of reconciling the claims of both parties by
allying the strata in dispute to two systems at once, in the use
of titles which their very founders themselves abandoned as incon-
venient and absurd ?

Or, finally, standing aloof from all parties, shall we, in the name
of science, claim the right of fully recognizing the systematic
equality of the three Lower Paleozoic Faunas, by regarding the
three successive rock-groups which contain them as individually
entitled to the rank and denomination of a complete system ?

It seems to me that to every unprejudiced mind it will be
apparent that the adoption of this last course has now become an
absolute necessity. Geologic truth and convenience imperatively
demand a separate place and name for each of these systems. It
only remains for us so to arrange their titles that no real injustice
shall be committed.

Dr. Hicks’s definition of the Cambrian system as including the
Paradoxides- and Olenus-bearing beds, from the base of the Harlech
Grits to the summit of the Lower Tremadoce is by far the best that
has hitherto been proposed. Thus restricted, the title is synonymous

0. Lapworth— Classification of the Lower Paleozoic Rocks. 9

with that of the Rocks of the First or Primordial Fauna of Barrande,
and is certain to be ultimately accepted everywhere among geologists,
from its naturalness, geologic distinctness and convenience of appli-
cation, not only in Britain and Western Hurope generally, but also
among the ancient rocks of the continent of America.

In the same way the general restriction of the title Silurian to the
strata that are comprehended between the line marking the base of
the Lower Llandovery, and that denoting the commencement of the
brackish or fresh-water conditions of the typical Old Red Sandstone,
appears equally inevitable. It covers the whole of the rocks of
Barrande’s Third Fauna, which, as we have seen, must be erected into
a separate system as a matter of geologic convenience. It is
fortunate that the application of Murchison’s title to them has never
been disputed, even by his bitterest opponent.

The various titles at present in use for the intermediate system are
all certain to be discarded by the geologist of the future. They are
all more or less erroneous, ambiguous, or inconvenient. The re-
tention of the designation Lower Silurian would be as systematically
erroneous as it is historically unjust. To call it Upper Cambrian
would be to allow the followers of Sedgwick to commit the very
error they so emphatically condemn in the procedure of their oppo-
nents. The perpetuation of the Sedgwick-Murchison controversy,
by the general adoption of such a title as the Cambro-Silurian or
Siluro-Cambrian—even were it possible—would be, to say the least
of it, excessively unwise. Neither party is likely to forego its
claims when the object of contention is so conspicuously labelled
with the names of both.

Before, however, we can take a single step to free ourselves from
the present difficulty, we must dispose of two formidable objections,
which, under the guise of universally accepted scientific principles,
have grown grey in the service of prolonging this unfortunate con-
troversy, and have, as yet, stubbornly barred the way to anything
like a peaceful solution. 5

By those who still retain the Silurian System of the later days of
Murchison in allits magnitude, the argument of their founder that there
is no universal stratigraphical break to be detected among the Lower
Paleozoics, at least as far down as the base of the Lingula Flags, is
held to be an overwhelming reply to all objectors. Similarly, it has
been the habit for their opponents, in their turn, to point triumphantly
to the local breaks in Britain between the Mayhill and Bala beds, as
affording in themselves a positive demonstration of the truth of their
own view that these formations belong to wholly distinct systems.
For a corresponding reason, also, the latter party claims for the
Cambrian all the fossiliferous strata that underlie the Llandovery,
from the fact that the physical succession among them is uninterrupted
by a general physical break. Of such pre-eminent value is this
principle considered, even by those who profess to stand aloof from
this controversy, that a strong tendency is abroad to sacrifice in
its favour the Old Red Sandstone itself.

To the field-geologist, pure and simple, who desires, above all

10 C. Lapworth—Classification of the Lower Palwozoie Rocks.

things, an unmistakable base-line for his system, capable of being
rigidly defined upon his maps and sections, the presence of a decided
unconformability affords the very thing of which he stands most in
need. The grouping founded upon stratigraphical breaks com-
mends itself to his mind with a force that is practically irresistible.
But it is far otherwise with the cautious systematist, who endeayours
to found his systems in accordance with those of Nature herself,
upon principles, not of local, but of universal application. Though
fully cognizant of the value of an unconformability as affording him
a fairly reliable horizon within a limited area, he soon learns that it
is of all things most untrustworthy when it extends over regions of
large diameter. It is at most a local phenomenon, wholly misleading
except in local application.

It is surely a work of supererogation in these days to point out
how the tendency of the entire course of geological discovery for
the last fifty years has been to reduce to a mere shadow the magni-
tude of the miraculous and world-wide stratigraphical breaks that
bounded the geologic systems of our forefathers. The doctrine of
universal convulsion and the simultaneous destruction of all the life
upon the earth at the end of each great epoch has so long since
passed into the limbo of exploded hypotheses, that it would be highly
amusing, were it not so painful, to see its degenerate and impoverished
survival—the dogma of the necessity for general stratigraphical and
palzontological breaks between our modern systems—drageging out
its miserable and ridiculous existence, even in our midst, and claiming
allegiance from men of standing in the science.

One concession, and one only, appears to be all that is needful to
meet the real facts of the case. As a general rule, our British
systems have been founded, less upon paleeontological than upon
mineralogical considerations, and it is more of the nature of a series
of happy accidents, than a geologic necessity, that they happen to
possess such distinctive faunas. In all cases, however, it is clear,
both here and elsewhere, that the faunas that characterize our
accepted rock-systems owe their distinctness—such as it is—to the
fact that in the more typical areas there happened to be an absence
of fossiliferous strata to unite them. Whether the time thus zoo-
logically unrepresented was occupied in the upheaval and partial
denudation of the rocks of the preceding system (as locally between
the so-called Lower and Upper Silurians of Britain), or whether, on
the other hand, it was filled by the deposition of barren strata (as
between the corresponding systems of the United States), the result
is precisely the same. The faunas of the consecutive systems differ
to the extent of the progress made in the locally unrepresented
interval ; and the group of rocks holding each fauna forms for the
geologist a convenient Procrustean bed to which to fit the tolerably
synchronous deposits of other lands. The unconformability argu-
ment is worthless except from the point of view that the faunas of
our typical British systems are likely to be the more distinct the
longer these separating interregenums lasted. It is best, that is,
simply as a matter of convenience and clearness of definition, to

C. Lapworth—Classification of the Lower Paleozoic Rocks. 11

choose, if possible, the longest non-fossiliferous periods to divide
them, and these are almost certain to occur where there is the greatest
appearance of unconformability.

Nevertheless, the same effect may be owing to acause in its nature
diametrically opposite—the required paleontological break being due
to a more than ordinary depression of the sea-bed, and the conse-
quent cessation of almost all deposition in that area—a circumstance
to my mind of equal importance from a classificatory point of view
with an unconformability itself. An extraordinary regional depres-
sion of this character seems to have been the actual cause of the appa-
rently sudden change in the facies of the Paleozoic fauna at the
commencement of the Arenig period, both in Britain and Scandinavia,
and when fully worked out will, in all probability, enable us to lay
down a paleontological line of demarcation far more strictly syn-
chronous throughout its geographical range than that which we shall
be compelled to adopt at the base of the Lower Llandovery.

Nor is the venerable objection—that, owing to the established laws
of scientific nomenclature, a moral obligation is binding upon us to
adhere rigidly to the limits of each system as originally laid down
by its founder—worthy of a whit more respect.

This is a claim whose absurdity verges upon the ridiculous when
it is advanced by the Murchisonian in support of his contention that
the Paradoxides and Olenus beds appertain to the Silurian, for they
actually antedate all the strata of Murchison’s original Silurian
System. It is, therefore, only occasionally employed by him in a
restricted sense in defence of his retention of the strata of the Second
Fauna.

It crops up continually, however, in the writings and arguments
of those belonging to the opposite party. It is urged again and
again with a wearisome iteration, as if this conservative rule in
geologic nomenclature were necessarily to over-ride every other
scientific canon whatsoever. But even if we grant that Sedgwick,
and not Murchison, first correctly defined and characterized the rock-
group which yields the Second Fauna, this rule is equally inoperative
in the face of our present recognition of the grand geological impor-
tance and distinctness of this Fauna. Of this fact Sedgwick was
originally wholly unaware; nor does he ever appear to have
estimated it at its true value. To us, however, who have watched
the gradual elimination of the Primordial Fauna, the grand distinct-
ness of the Second Fauna is so glaringly apparent, that it is impossible
for us to conceive of the rock-group which it characterizes as a mere
subdivision of the Cambrian.

It is all very well to plead for historic justice, and to demand, out of
respect to the memory of a genius, the adoption of the nomenclature
which the general geological world was, in a sense, deprived of the
opportunity of accepting during his lifetime. But time and geolo-
gical convenience will soon make short work of any scheme of
nomenclature, however historically just, if it be not in all its parts
the natural expression of the inter-relationships and mutual subor-
dination of the facts it is its special aim to associate and systematize.

12 OC. Lapworth—Classification of the Lower Paleozoic Rocks.

No amount of enthusiastic regard for the memory of a martyr will
bolster up an unwieldy system for ever. The giant size upon which
its weaker advocates pride themselves must in the end be the main
cause of its inevitable dismemberment. We shall best promote the
interest of the man whose memory we venerate, by modestly claiming
for him as much, and no more, than truth and geological convenience
will allow.

Thus, however reluctant we may be to interfere with the schemes
of classification propounded by our great masters in the science, it
appears to me that the time has now arrived when we can no longer
be accused of disrespect or disloyalty in endeavouring to emancipate
ourselves from the inconveniences due to our superstitious adherence
to an effete and unworkable nomenclature. The present needs of
our science demand, with a unanimous voice that partizanship can no
longer silence, a distinct title for the rocks of the Second Fauna. The
experiment of naming them in such a way as to recognize the claims
of both Murchison and Sedgwick has been tried again and again
with the same result. It has invariably ended in prolonging and
greatly intensifying the original controversy. But one course
remains to us. We must give it a new title, which, though it might
have been originally suggested by either party, shall contain no
element of future discussion.

So long as present systems of nomenclature survive, nothing can
disturb the application of the title of Cambrian to the rocks of the
Primordial Series, and that of Silurian to the strata of the Third
Fauna. In these systems, as thus restricted, the most perversely
Ingenious partisan could scarcely find room for controversy. Within
these limits the labours of their respective founders were compa-
ratively perfect and complete, and the propriety and harmony of
their original classifications, though slightly modified in detail by
subsequent research, has never been impugned, either by friend or
foe. It is vastly. different, however, as we have seen, with the
intermediate system. From the day it was recognized until now,
it has been the object of incessant disputes. Its co-discoverers both
committed the gravest of errors regarding either its proper limits, its
relationships, or the sequence and fossils of its component formations.
It has been the subject of almost as much passionate argument as
the Wernerian theory itself; and the whole subject is a disgrace to
modern science, and an obstacle to its progress that must be got rid
of—whatever the sacrifice.

Time has already done justice to the value of the discoveries of
both Murchison and Sedgwick, by assigning them each a system in
which their labours were accurate and complete. We shall do their
memories the greatest service by giving the system in which their
work appears to our eyes—in the light of later discovery—to have
been more or less inaccurate or deficient, a title which shall bear no
personal reference to either.

Sedgwick, with his well-balanced and philosophic mind, named
his system after the entire Principality in which his rocks were
typically developed. His title of Cambrian is thus comprehensive

CO. Lapworth—Classification of the Lower Paleozoie Rocks. 13

enough to embrace the whole of the Lower Paleozoics. It not only
calls up before the imagination the majestic mountains where they
may be studied under their most typical aspect, but it reminds us
that they formed the fortress-homes of the early Britons—those
proud old savages, who, like the Greywackés upon which they trod,
were the last to succumb to the irresistible march of conquest.

Murchison, on the other hand, with his military proclivities, and a
keener instinct for locality, had already made choice of the term
Silurian; associating the rocks of his system with that classic
Cambrian tribe, the Silures, whose indomitable struggles for liberty
had hallowed the very hills upon which he sought his types; and
thus, in a measure, he may be said to have erected an everlasting
monument to British valour and love of freedom.

But, as has been more than once pointed out elsewhere, the Silures
were a nation inhabiting the southern parts of Wales, and Murchison
distinctly availed himself of the privileges of genius in thus extend-
ing their rule into Shropshire and the regions to the north.

North Wales itself—at all events the whole of the great Bala
district where Sedgwick first worked out the physical succession
among the rocks of the intermediate or so-called Upper Cambrian
or Lower Silurian system; and in all probability much of the
Shelve and the Caradoc area, whence Murchison first published its
distinctive fossils—lay within the territory of the Ordovices; a tribe
as undaunted in its resistance to the Romans as the Silures. It was
indeed the lasé of the old British tribes to yield to their invincible
legions; and it is consequently quite as well worthy of scientific
commemoration as the Silures themselves.

Camden thus refers to the Ordovices:' ‘‘'Those countries of the
Silures and Dimete, which we have last surveyed, were in after-
times, when Wales came to be divided into three Principalities, called
by the natives Deheubarth (or the Right-hand part), and in English,
as we have already observed, South Wales. ‘The other two Princi-
palities (which they call Gwynedh and Powys, and we North Wales
and Powisland) were inhabited by the Ordovices, called also
Ordevices, and Ordovice, and in some authors, though corruptly,
Orduluce. A courageous and puissant Nation these were, as being
inhabitants of a mountainous country; and receiving vigour from
native soil; and who continued, the longest of any, unconquered
either by Romans or English. For they were not subdued by the
Romans till the time of the Emperor Domitian ; when Julius
Agricola subdued almost the whole nation. Nor were they sub-
jected by the English, before the reign of Edward the First. Fora
long time they enjoyed their liberty, confiding as well in their own
strength and courage, as in the roughness and difficult situation of
their country, which seems to be laid out by Nature for ambuscades
and the prolongation of war. ‘To determine the limits of these
Ordevices is no hard task, but to give a true reason of the name
seems very difficult. However, I have entertained a notion, that,
seeing they were seated upon the two rivers of Devi, which springing

1 Camden’s Britannia, Dr. Gibson’s Translation, second edition, p. 778.

14 ©. Lapworth—Olassification of the Lower Paleozoic Rocks.

not far asunder, take their course different ways, and that Oardewi
(Read Ar-dhyvi—tTransl.) in the British language signifies—Upon
the rivers of Devi—they have been thence called Ordevices. To
the Ordovices belonged those countries which are now called in
English by new names—Montgomeryshire, Merionethshire, Caer-
narvonshire, Denbighshire, and Flintshire.”

Here, then, have we the hint for the appropriate title for the
central system of the Lower Paleozoics. It should be called the
Orpovicran System, after the name of this old British tribe.

Whatever arguments may be adduced in support of the term
Silurian will apply equally well, or even with greater force, to this
new title. Like the term Silurian, it is classic in origin, but at the
same time thoroughly British. It is equally euphonious, and far
more strictly significant of the geographical area where its strata are
typically developed. Indeed, the employment of the one title
almost of itself necessitates the adoption of the other; for only in
this way is it possible to recognize the systematic equality of the two
systems in their very designations—the one receiving its name from
the ruling tribe in the south of Wales, the other from the dominant
tribe in the north. If there is anything specially becoming in com-
memorating the warlike tribe of the Silures in the name of a geologic
system, how strikingly appropriate is the title of Ordovician in
erecting a similar scientific monument to the last and most valiant of
the old Cambrian tribes.

On this arrangement the Lower Paleozoic Rocks of Britain stand
as follows :—

(c) Srturtan System :—Strata comprehended between the base of

the Old Red Sandstone and that of the Lower Llandovery.

(b) Orpovicran System :—Strata included between the base of

the Lower Llandovery formation and that of the Lower Arenig.

(a) Camprian System :—Strata included between the base of the

Lower Arenig formation and that of the Harlech Grits.

That our attempt to cut in this way the knot which all the schools
have already convinced both themselves and others of the utter
impossibility of untying, will do much more than draw the attention
of geologists in general to what we believe to be the more striking
aspects of the question, can hardly be expected. It is almost certain
that any suggestion that might have been made by either of the
schools with the object of freeing this section of the science from the
present dead-lock, would, as a matter of course, be opposed to the
utmost by the others. How much worse is it when the hint is given
from without. The great mass of the most influential of our living
geologists have so long since given in their adhesion to one or other
of the contending parties, that it is not improbable that our well-
meant interference will be stigmatized by all as a most unwarranted
and impertinent intrusion.

By those, however, who are weary of the interminable discussion,
and who feel the necessity for some scheme of classification which,
while it systematizes the known facts, holds the balance true with
reference to the opposing claims of the two great pioneers in the

CO. Lapworth—COlassification of the Lower Paleozoic Rocks. 15

study of the Lower Paleozoics, our suggestion may be tolerated now,
and adopted later on, when the necessity for this course has become
more strikingly apparent. To those who interest themselves in the
attempted correlation of the Lower Paleeozoic Rocks of the Northern
Hemisphere, and who are continually hampered by the want of some
clear and unmistakable generic terms expressive of the general
parallelism among these widely-separated deposits, the ease and
comfort of a classification which imitates Nature herself in placing
the three grand members of the Lower Paleozoic Rocks upon an
equal footing, is an advantage of which they are certain in time to
avail themselves to the full. Those again, who feel how vain is the
endeavour to parallel the special formations and minor stages of our
British Lower Paleeozoics with those of other areas, will hail with some
approach to satisfaction the release of such convenient sub-generic
terms as Lower and Upper Cambrian, and Lower, Middle, and Upper
Silurian, with the list completed by the addition of Lower and Upper
Ordovician ;—terms all of easy and immediate application, and all
expressive of epochs, which, so far as our present knowledge enables
us to judge, embrace tolerably equal periods of geological time.

No earnest student of the history of discovery among the Lower
Paleeozoic Rocks, whose opinions are the natural outcome of his own
careful generalization of presently known facts, and not the petrified
remains of the views he so enthusiastically adopted a quarter of a
century ago, can fail to perceive that the ideas of the extreme party
which claims all the Lower Palzozoics for the Silurian are fated soon
to become wholly extinct. The wave of backward opinion which
led this party to revert in substance to the ideas of their predecessors
was inevitable. We are now witnessing the as-inevitable return of
the tide. Here and there this application of the term may linger on
for a time, as in Bohemia, and possibly in Scandinavia, kept alive
by the very principle that must in the end prove fatal to it, when
local conveniences become superseded by cosmopolitan necessities.

A single glance at the magnificent development of the Lower
Paleeozoics on the continent of North America is enough to convince
every unbiassed investigator how much we have yet to learn
regarding their British prototypes, and how ridiculously inadequate
is our present estimate of their grand importance in the geological
series. As this knowledge dawns upon us as the result of our
discoveries in the future, some such classification as is here pro-
posed will perforce be adopted by all; and the systematist will then
be left free to work out his generalizations untrammelled by the
defects of a cramped and unnatural nomenclature. Our British
strata can in the end return but one answer to the most extended
appeal. Every geologist will at last be driven to the same con-
clusion that Nature has distributed our Lower Paleozoic Rocks in
three sub-equal systems, and that history, circumstance, and geologic
convenience, have so arranged matters that the title here proposed
for the central system is the only one possible.

16 V. Ball—Volcanos of the Bay of Bengal.

T].—On tHE VoLcanos OF THE Bay or BENGAL.

By V. Batt, M.A., F.G.S. ;
of the Geological Survey of India.

(PLATE I.)

URING the year 1873, it was my good fortune to be one of a
party who, in the course of an exploration of the Andaman
and Nicobar Islands, were enabled to spend a few hours on the
detached volcanic islands of the Bay of Bengal, which are known
respectively as Barren Island and Narkondam. The time at our
disposal did not admit of our making as thorough an examination as
we should have wished, but there was sufficient opportunity for
testing the accuracy of the statements regarding the islands which
had been previously published, and also for making a few original
observations.

The information upon which the accounts of Barren Island, given
in geological manuals and other works, have been founded, is
exceedingly faulty. Dr. Liebig’s paper, which contains the fullest
and most accurate description of the island, does not appear to
have reached the hands of several authors, who have since its
publication tenaciously clung to old statements which should have
been long since expunged.

In presenting this account to the readers of the GroLocicaL
MaGazing, it is necessary for me to premise that in substance it has
already been published in the Records of the Geological Survey of
India.!. The present edition differs from the original in being
illustrated by the accompanying sketches of the islands, and in
sundry small alterations and additions to the text.

The wide circulation of the Groxtocican MacGazinE among
geologists throughout the world affords an unequalled opportunity
for stamping out errors like those which are exposed in the follow-
ing pages. It is hoped that in future works and editions of works on
Geology or Volcanos there will be no repetition of the old statements
or old illustrations which have served to give such incorrect ideas
as to the physical features of these remarkable islands.

Barren Island and Narkondam are two volcanic islands situated
in the Bay of Bengal at a distance of seventy miles from one another
on a north-by-east, south-by-west line. They constitute links which
connect what is known as the Molucca band with the volcanic region
of Arracan and Chittagong. This has been pointed out by several
physical geographers, one of whom? has written :—

‘One of the most terribly active groups of volcanos in the world
begins with the Banda groups of islands, and extends through the
Sunda groups of Timor, Sumbawa, Bali, Java, and Sumatra,
separated only by narrow channels, and altogether forming a gently
curved line 2,000 miles long; but as the volcanic zone is continued
through Barren Island and Narkondam in the Bay of Bengal, and

1 Calcutta, No. 4, 1873. 2 Mrs. Somerville.

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ses

V. Ball— Volcanos of the Bay of Bengal. 17

northward along the Coast of Arracan,’ the entire length of the
volcanic range is a great deal more.”

Dr. Hochstetter carries the line of elevations which accompanies
the zone of volcanic action still further, in an oblique S form,
through New Guinea to the north of the Australian continent. “It
forms in New Ireland, the Solomon Islands, New Hebrides, and
New Zealand, a curve, concave towards the west, the small group
of the Macquarie Islands being possibly considered as the extreme
southern end of this curve.”

So far as is known, there are no volcanos in either the Nicobar
or Andaman Islands. It has been by some supposed that the hill
on Bompoka in the Nicobars, and some of the high ground in the
Great Nicobar, might be volcanic, but the evidence is rather against
than in favour of this view. Igneous rocks (diorite and gabbro)
not unfrequently occur, however, in both groups of islands. A
statement made in an old account of the Cocos, that the little Coco
is formed of volcanic rocks, is, I believe, quite without foundation.
The only rocks I observed there were Tertiary sandstones and shales.

Barren Istanp, Lat. 12°17’ N.; Long. 93° 54’ E.

History of the Island derived from Previous Notices.—In the table
appended I have given a précis of all that has been published on the
subject of Barren Island; but a few additional remarks, tracing out
the way in which certain inaccuracies have arisen, seem to be
desirable.

The first published account was by Captain Blair, in his report
on the Andaman Islands, dated 1789. I have not seen the original
document, but the account was extracted and reprinted by Lieutenant
Colebrooke in the Asiatic Researches.

Captain Blair gave the height of the central cone at “nearly
1,800 feet.” Were it not also stated, however, that the cone was
equal in height to the outer walls of the surrounding part of the
island, we might, in consequence of Blair’s oft-proved accuracy as
an observer, be disposed to believe that at the time of his observa-
tion the cone was nearly double its present height. That there has
not been a general subsidence of the island to the extent of 800
feet is proved by the fact that the base of the cone was then, as it is
now, but little raised above the sea-level. Blair himself states that
the island may be seen at a distance of twelve leagues in clear
weather, which would only require an elevation of about 920 feet.
I can only suppose, as an explanation of the difficulty, that Blair
took several heights which varied between 800 and 1,000 feet, and
that these, by some error, came to be written together as 1,800.

The angle of inclination of the sides of the cone is stated by Blair
to be 82° 17’.

The sketch by Lieutenant Wales given in Lieutenant Colebrooke’s
paper, save that it represents an inclination of about 60° for the
sides of the cone, conveys the best idea of the island of any of the

_/ A very full account of the mud volcanos on this coast has recently been pub-
lished by Mr. F. R. Mallet, F.G.S., Rec. Geol. Survey of India, vol. xi. part ii. p. 188.

DECADE II.—VOL. VI.—NO. I. 2

18 V. Balli—Volcanos of the Bay of Bengal.

numerous figures which have been published. It was reproduced
by Von Buch, and copied from him by Sir Charles Lyell, Dr.
Daubeny, Dr. Buist, Von Cotta, ete. Von Buch, in his “ Memoir
on the Canary Islands,” gives the height of the cone at 1,690 Paris
feet. His account, though apparently derived from Lieutenant Cole-
brooke’s paper alone, contains the statement that the sea penetrates
into the circle at the base of the cone. This can only have been due
to some misapprehension of the meaning of Blair’s words, which
were as follow :—‘ The base of the cone is the lowest part of the
island, and very little higher than the level of the sea.”

Sir Charles Lyell, in the earlier editions of the ‘ Principles,”
framed his account from Von Buch’s. In the changes from English
into French, and back again into English, the elevation of the cone
became increased by 48 feet, standing in the seventh edition of the
“Principles” (1847) at 1,848 feet. It is also there stated that the
circular basin inside is filled with the waters of the sea. In the
ninth edition (1853), Captain Miller’s estimated elevation of 500
feet is adopted instead of the former one; but the statement regard-
ing the sea inside still remains. In the tenth edition (1868) Captain
Miller’s estimate of 500 feet, as the height in 1834, is retained; but
it is stated that according to Von Liebig in 1857, both the cone and
outer crater were about 1,000 feet high, and in reference to the sea
we find the following :—“ In some of the older accounts the sea is
described as entering the inner basin, but Von Liebig says it was
excluded at the time of his visit.” I believe this statement regard-
ing the sea to have arisen solely in the way I have pointed out. It
is important that there should be a clear representation of the case,
as otherwise it might be concluded that we have direct evidence of
the rising of the island within the historical period.

The next account to that by Blair is by Horsburgh, about which
there is nothing particular to remark here, save that he asserts that
in 18038 the volcano was very active (see table).

Dr. J. Adam’s account is derived from information and specimens
received from a friend who had landed on the island in 1832. He
speaks of the stones on shore hissing and smoking, and the water
bubbling all round them. ‘The statement has apparently been
understood by one writer to indicate that the lava at the surface
had not then cooled down. But the hot spring was probably quite
sufficient to account for the phenomena observed. ‘This is the first
mention made of the hot spring. The author supposes that the
volcano is only active in the south-west monsoon,’ i.e. requires
water to bring it into a state of activity. Apart from other considera-
tions, it is only necessary to say that the only authentic account of it
in a really violent state of eruption is by Blair, who saw it on the
21st of March, and therefore not during the south-west monsoon.

Captain Miller’s account is very inaccurate in several respects.
He has given the height at 500 feet, and the angle at which the cone

1 Curiously enough Mr. Mallet (/.c.) mentions that a similar belief is held by the
islanders with regard to the activity of the mud voleanos of Ramri and Cheduba,
but he points out that the recorded dates of eruption do not support this view.

V. Ball—Volcanos of the Bay of Bengal. 19

rises at 45° or even more. If the elevation of the cone in his time
were only so much, then, since he states that this was also the
elevation of the outer walls or amphitheatre, both must have in-
creased pari passu. ‘This view is of course untenable, and we are
forced to believe that Captain Miller only gave a rough guess. His
remarks on the vegetation are quite inconsistent with one another,
for he says,—‘“There is no vegetation of any kind within the
amphitheatre, but a few small trees are found on other parts of the
island, which, however barren it may have been at one time, is now
well wooded.”

Dr. Daubeny, in his description of Barren Island, though quoting
from Lieutenant Colebrooke, gives the elevation of the cone at
4,000 feet, which must, I think, have been due to a clerical error.
A somewhat modified reproduction of the original sketch is given.

Mr. Scrope, in his work on Volcanos (2nd edition, Lond., 1862),
writes regarding Barren Island: ‘This permanently active volcano
is a eone about 4,000 feet high, rising in the centre of a circular
cliff range, which entirely surrounds it except at one point where
the sea has broken in.” Though the authority is not given, it seems
probable that this account is derived from Dr. Daubeney’s, as the
elevation is not given at 4,000 feet in any other work.

In 1846 the island appears to have been visited by the Danish
corvette Galathea, but the only record of the fact is said to be an
inscription on a rock on the island—‘“‘ GALATHEA, 1846.” This we
failed to observe.

In the Bombay Times for July, 1852, on the authority of Dr. Buist,
it is stated that the volcano was then very active, but I have not
been able to refer to the original account.

The chief points in the “accounts subsequent to the ‘above will
be found incorporated below (see the table on pp. 20,21). Dr.
Playfair, Von Liebig, and the Andaman Committee agree in es-
timating the angle of the cone at 40° to 45°, and the elevation at
from 975 to 980 feet.

From the preceding records we may gather the following. The
volcano has probably not been in violent eruption since the years
which closed the last and commenced the present century.' The
lava-flow which stretches from the entrance open to the sea to the base
of the cone was probably poured out during this period, and raised
the level of the encircling valley some 40 feet above its elevation
in 1789, when Blair saw it. He makes no mention of a lava-stream
in his time. If it did not exist then, it cannot—as has been supposed
by some—have been instrumental in the formation of the entrance.
That this fissure was probably due to other causes we shall presently
see.

From Lieutenant Wales’ figure it is apparent that no material
change has taken place in the general configuration, and as it has been
shown that 1,800 feet cannot have been the true height, and about
920 probably was, no great alteration in the elevation is likely to
have taken place.

1 The statement ‘“‘ very active”’ from the Bombay Times is too vague for reliance.

V. Ball— Volcanos of the Bay of Bengal.

20

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21

V. Bali— Volcanos of the Bay of Bengal.

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General Description of Barren Island.—Seen from any side but the
north-west, Barren Island appears as a nearly flat-topped hill with
numerous spurs running down into the sea. From some aspects,
however, the top of a central cone with a column of smoke rising
from it is discernible.

As the north-west side opens up to view, it is first realized that
the island consists of a circular ridge forming a huge amphitheatre,
which is broken down at one side for a distance of perhaps 150
yards to the level of the sea. The view obtainable through this
entrance discloses a bare cone which rises from the centre of the
island. Except at a sort of shoulder not far from the top, and at
two peaks close to the summit, no rocks are seen on this cone, its
smooth sides being covered with grey ash and occasional strings of
shingle. ‘Towards the top some whitish patches are seen, these are
due to the presence of gypsum mixed with the ash.

The accompanying illustration, it will be observed, is somewhat
diagrammatic in its character, being rather of the nature of a bird’s-
eye view, than a representation taken from an actual point of view.

The total diameter of the island is, on the authority of Lieutenant
Heathcote, 2,970 yards. The circuit of the island, from the time it
took us to row round, I estimated at about six miles.

The high encircling ridge is formed of somewhat irregularly de-
posited layers of lava, ash, and conglomerate, which dip away from
the centre. A section of these may be seen on the left hand of the
gap or entrance, and others at various points on the sea-face, no two
of them corresponding exactly in character.

These beds or layers generally dip at angles of 35° to 40°, which
inclination appears to be continued steadily under the sea, as bottom,
except at one place, has not been found with a line of 150 fathoms
at one-quarter of a mile from the shore. This steepness has been
unfavourable to the formation of a fringing reef of coral of any
magnitude, such as we find surrounding some of the islands of the
Andaman and Nicobar groups. The elevation of this outer ridge
varies somewhat in places, but it probably nowhere is much in
excess of 1,000 feet. Its highest points are towards the south and
west.

The appearance presented by the inner scarped face of this amphi-
theatre is very peculiar. In several places cornice lines mark the
position of particular beds, but a purplish grey, or in places brownish,
ash spreads over the steep slopes, except towards the south-west and
west, where there are some trees and shrubby vegetation. To the
north, south, and east a few tufts of grass—generally arranged in
long vertical lines, the first being a sort of protection to those below
it—are the only plants which have managed to establish a footing in
the loose ash. The outer slopes facing the sea are for the most part
covered with a luxuriant vegetation, in which large forest trees may
be discerned. These latter attract considerable numbers of fruit-
eating pigeons (Carpophaga bicolor).

From its composition and character, it is evident that this ring of
cliffs is the remnant of the original cone which gradually rises from

V. Ball— Volcanos of the Bay of Bengal. 23

below the sea. Its top and a portion of the side were, no doubt,
blown off by a violent eruption, and the present cone was sub-
sequently formed inside. The gap or fissure in the surrounding walls
bears about north-west-by-west from the centre of the island. It is
the only place where an entrance can be obtained to the central
valley.

For a long time Barren Island was considered by Von Buch and
others of his school as a most favourable example of his elevation
theory of craters. Since, however, the island is in reality only
formed of volcanic materials elevated above the sea without a trace
of any pre-existing rocks, it is evident that its peculiar form gives
no support to that now exploded hypothesis.

Hot Spring.—Close to the landing-place, there is a hot spring
which has been mentioned in several of the accounts of the island.
Dr. Playfair found the temperature to exceed 140°,—the limit of his
thermometer. Dr. Liebig’s thermometer was only ¢ eraduated up to
104°, but judging from the feel to the hands, he egcmatied it to be
near the boiling-point. The Andaman Committee record it at from
158° to 163°. At the time of our visit the highest temperature of
the water where it bubbled out of the rocks, close to high-water
mark, was 130° F. We therefore failed to boil some eggs in it
which we had brought with us for the purpose. The water is
perfectly clear and sweet,’ and there was no trace of sulphurous
vapours. Strange to say, where, though mingled with the sea, it
was still too hot for the hand to be retained in it with comfort,
there were a number of brilliantly-coloured fish swimming about.

Facing the landing-place is the termination of a flow of lava
which extends backwards for about a mile to the base of the cone,
round which it laps for perhaps # of the circumference. The height
or thickness of this flow of lava is about 10 feet at first, gradually
rising to about 50 feet where it emerges from the base of the cone.
The upper surface is deeply cleft and covered over with blocks
of black cellular lava which rest upon one another in confused
piles. Sometimes they are poised so insecurely one upon another
that it is a matter of no little risk to attempt scrambling over them.
Towards the base of the flow the rock from its slower cooling
is more compact and less cellular. In places it contains white
crystals of a mineral resembling leucite. In others it is a true
basalt with numerous crystals of olivine.

As pointed out by Dr. Liebig, the older lava seen in the section of
the ridge differs from this; ‘it consists of a reddish matrix with
crystals of felspar (probably sanidine), olivine, and augite. A
somewhat similar rock occurs on Narkondam.

On our way to the central cone from the landing-place, we at first
endeavoured to avoid the rough surface of the lava-flow by keeping
on the slope of the gap; but after a short distance the bushes and
unevenness of the ground compelled us to strike down on the lava,
when we found, to our astonishment, a sort of path which must have

1 The Andaman Committee do not appear to have realized this fact, as they spent
no little time and trouble in excavating a well without finding a trace of water.

24 V. Ball— Volcanos of the Bay of Bengal.

been made by the committee sent from Port Blair to report upon the
supply of grass. Arrived at the foot of the cone, we commenced
the ascent from the west. The loose ashes and shingle rendered it
somewhat toilsome work; and those in front found it difficult to
avoid loosening fragments of lava which bounded down the hill in
a most unpleasant way for those who were following. Dr. Liebig
appears to have ascended from the north side, where it seems to
have been equally difficult. About 1 of the way from the top
there is a shoulder of rock which shows very well in the photo-
graph. This probably marks the position of an old vent. There is
a good deal of firm ‘ground about it. The summit of the cone is
truncated, and contains an oval-shaped depression, one-half of which
is partly filled with débris, and the other, some 20 yards in diameter
and 50 feet deep, has a circular bottom, which is filled with sand.
This appears to have been the last crater formed on the island.

The two principal edges of the depression strike to north-west,
south-east; they consist of ash permeated with fibrous gypsum
(selenite) ; numerous cracks and fissures occur in this part of the
hill, and the ground is hot. On turning over the surface, the sides
of these cracks are found to be encrusted with sulphur, resting upon
the rugosities of which small detached crystals of the same mineral
were not uncommon. From the highest point on the northern edge
a thin column of white vapour and sulphurous fumes is slowly
poured forth. Even when standing in its midst, the fumes did not
prove so irritating as might have been expected. On the southern
side of the crater solid lava is seen in siti, and on the west there
is a peculiarly-shaped mass which forms a conspicuous object from
below. Portions of the lava here have a reddish matrix and are
somewhat vesicular. I also found some basalt, the outer surface of
which was weathered into a white crust. It seems probable that
the nucleus of the cone is solid rock to a considerable extent, the
ashes seen at the surface being only superficial. By following water
channels when they were to be found, and glissading over the ashes,
the return to the base of the cone was effected speedily and without
much difficulty.

By a small watch-aneroid supplied with a Vernier scale for feet,
the height of the cone appeared to be 950 feet; but as one heavy
storm of rain had passed, and clouds portended another, I am willing
to believe that owing to the atmospheric disturbance the observation
was not trustworthy, and that from 975 to 980 feet, given by Lieu-
tenant Heathcote, Dr. Liebig and others, is the true elevation. The
temperature on the top was 83°.

The diameter of the base of the cone is 2,170 feet according
to Lieutenant Heathcote. The slopes of the cone incline, according
to my observation, at angles varying between 30° and 35°. Blair,
as already stated, gave it at 32° 17’, or about the mean of these two.
Other observers say 40° to 45°, but a photograph of the cone, which
I possess, shows that the former are correct.

Dr. Liebig has discussed the question of the amount of sulphur
obtainable on the island. Heé seems to think the chances of finding

V. Ball—Voleanos of the Bay of Bengal. 25

a permanent supply very doubtful, but recommends a preliminary
trial.

Jonsidering the great expense which keeping up constant commu-
nication with the Andamans and the superintendence of convict
labour would involve, I cannot see that there is any prospect of the
collection and refining of the sulphur being made to pay. So far as
is known, the substance occurs only at the summit of the cone,
though doubtless, if the right places could be found, it does also
occur lower down. But in such places, it could only be as an old
deposit which, on being worked out, would not be replaced again.
On the summit, deposition, so far as I could see, proceeds very
slowly, certainly not with sufficient rapidity to keep labourers con-
stantly employed.

Narxonpam, Lat. 138° 24’ N.; Long. 94° 12’ E.

History and Previous Notices.—So little has been published regard-
ing this island that a few lines will suffice to dispose of all that has
ever been recorded regarding it.

In 1795 it was passed by Colonel Symes! when on his voyage to
Rangoon, whence he started on his embassy to Ava. He speaks of
it as “a barren rock rising abruptly out of the sea and seemingly
destitute of vegetation.”

Dr. McClelland, writing in 1838,? says:—‘It is a volcanic cone
raised to the height of from 700 to 800 feet.” He gives a sketch
showing the figure of the cone, “the upper part of which is quite
naked, presenting lines such as were doubtless formed by lava
currents descending from the crater to the base, which last is
covered with vegetation.” No soundings are to be found at the
distance of half a mile from the shore. This account is reproduced
by Mrs. Somerville, Dr. Daubeny, Dr. Buist, and Mr. Scrope.

Horsburgh*® says:—“ Narkondam may be seen about fourteen or
fifteen leagues from the deck, and appears in the form of a cone or
pyramid with its summit broken off; it is bold and safe to approach
all round.”

Mr. §. Kurz, in his report on the vegetation of the Andaman
Islands, writes :—‘‘ Narkondam Island has an extinct volcano
remarkable for the great height of its cone, being twice as high as
its outer wall. Owing to the great height of the cone (perhaps
2,000 feet) in proportion to the surrounding wall, this island must
have sunk very much, or the volcano must have been formed from a
considerable depth in the sea.” Mr. Kurz gives an outline sketch
of the island as it appeared to him from a distance of twenty miles.

In a paper on the geology of the neighbourhood of Port Blair,* I
made a few remarks on the appearance of Narkondam as seen from
a few miles distance. I then accepted the height of the cone, 2,150

1 Embassy to Ava, vol. i. 1827, p. 167.

2 On the Difference of Level in Indian Coal-fields, J. A. S. B. vol. vii. Also in
the Coal Committee’s Report, and in Corbyn’s Indian Review.

3 Indian Directory, fifth edition, vol. ii. 1843, p. 5d.

4 J. A. S. B. vol. xxxix. part 1. 1870, p. 231.

26 V. Ball—Volcanos of the Bay of Bengal.

feet, given on the chart, as authentic. This, it will be seen by the
sequel, I do not now adopt as correct. In the Jndian Observer for
the 10th of May, 1873, a short account of the present visit will be
found.

General Description of Narkondam.—Viewed from the north-west
at a distance of about four or five miles, the island of Narkondam
appears to consist of a tolerably regular cone which rises from an
interrupted ring of irregularly piled masses. The apex is some-
what truncated, but has three distinct peaks. On the occasion in
1869 when I first saw the island, a dense mass of cloud rested on
the top, as is indicated in the accompanying illustration. I was
then unable to make out the character of the summit. But when
subsequently seen, it was observed that there were three peaks as
represented in the rough sketches published by Mr. Kurz and Dr.
McClelland. The upper parts of the cone, and the sides for more
than half-way down, are deeply furrowed by ravines, and what
appears to be a low scrub jungle spreads uniformly over the island
Save upon some vertical scarped faces.

With the observers above mentioned, who did not land, the conical
form alone seems to have been accepted as sufficient proof of the
volcanic character of the island. Dr. McClelland, as noted above,
speaks of the lined appearance being “doubtless formed by lava-
currents descending from the crater to the base.” These lines are,
however, simply the result of erosion, and mark the position of the
watercourses.

The elevation of the summit of the cone has been variously
estimated at from 700 to 2,150 feet. Since, however, according to
Horsburgh, the island first becomes visible from the deck of a
steamer at a distance of from fourteen to fifteen leagues, it is
probable that about 1,800 feet would be nearer the true altitude, and
such indeed, judging by the eye, appears to be a very fair estimate.

Those who have seen Stromboli from the north-east, can scarcely
fail to be struck with the extraordinary resemblance between it and
Narkondam as represented in the accompanying illustration.

On the occasion of our visit in March, 1873, we landed in a small
bay on the north-west side of the island. At about 100 yards
distance from the beach the water became so shoal, owing to a coral
reef, that we were compelled to land on a raft. We soon found that
the jungle, which in the distant view appeared to consist mainly of
low scrub, was really composed of large forest trees with a thick
undergrowth. So dense was this, just above high-water mark, that
at first it seemed probable that it would be impossible to penetrate
it. Added to the natural density of the jungle, another obstacle
was presented by the prostrate condition of many of the trees, which
in their fall had carried down tangled masses of creepers and the
lower vegetation. It soon became apparent that at no very distant
period a violent hurricane or cyclone must have swept across the
island. An entrance was at last found, and for three hours, cutting
our way and making constant detours to avoid fallen trees, we
endeavoured to force onwards to the summit, but were at length

W. A. E. Ussher—Historical Geology of Cornwall. 26

compelled to give up all hope of succeeding, and returned to the
beach. Further evidence of the hurricane was there afforded by
numerous fragments of a wreck which had been thrown up on the
sand. Subsequently this storm was identified with one which took
place on the 26th of October, 1872, and did much damage in the
Cocos Islands and other parts of the Bay.

The only rock seen where we landed was a conglomerate, or
boulder-bed, some 50 feet thick. The boulders consisted of a trachytic
porphyry which contained sanidine, augite, and mica, in grey or
pinkish matrices. We discovered no evidence whatever of recent
lava or basalt occurring, though either or both may exist, as our
observations were confined to one small bay. There is no historical
record, so far as I am aware, of smoke ever having been observed to
issue from Narkondam. It has, therefore, long been dormant, if not
absolutely extinct.

Notwithstanding the luxuriance of the jungle, which included
species of Ficus, Palms (Caryota), Acacia, Calosanthes, etc., no fresh
water was discovered.

Much remains to be done in the exploration of this most interest-
ing volcanic island. It is particularly desirable to ascertain whether
there is really a crater at the summit, and whether there are any
traces of recent lavas.

Future visitors would do well to provide themselves with some
wood-cutters. They should land near the northern spur, and getting
then on the steady rise, they will probably find no insuperable
obstacle on their way up.

Owing to the fact of the physical geology of the Andaman and
Nicobar Islands being, as yet, imperfectly known, I have not here
discussed the connexion which in all probability exists between their
elevation and this adjacent line of volcanic activity.

III.—Historitcat Grotocy or CoRNWALL.*
By W. A. E. Ussuer, F.G.S.
O ascertain the most recent movement to which a country has
been subjected, and by careful comparison with the past to
discover what insensible changes are now progressing, is of the
utmost importance in approaching its Quaternary History.

By a recourse to such occasional observations as have been re-
corded by historians or monkish chroniclers, gleaned perhaps in
few cases from actual investigation, and exaggerated, no doubt,
in an age delighting in the marvellous. some information may be
gained; but when we consider that these notes were made rather
for the gratification of the curious than with a view to ascertain
their causes or to forecast their effects, and that the facts of one
century may become the legends of the next, it behoves us to
sift the evidence, retaining only such bare and unvarnished state-
ments as by incidental mention and simple relation appear most

1 The Chart to accompany this paper, of the soundings around the coast of

Cornwall, not being executed in time, will appear in next month’s number with
the concluding historical part of this article —Eprr. Grou. Mac.

28 W. A. E. Ussher—Historical Geology of Corneeall.

worthy of credence, especially when the accounts are corroborated
by independent writers.

It has ever been the characteristic of the ignorant and unin-
quiring peasantry to ascribe the occurrence of great boulders of
rock dissimilar to any in the neighbourhood, the fantastic shape,
so frequently effected by weathering in rocks of unequal durability
and such-like remarkable objects, to the agency of fabulous beings
endowed with enormous strength and gigantic proportions; and so
names are given to phenomena of unusual occurrence, and are
retained by a less credulous posterity even when the legends which
suggested them have almost entirely passed away. Many such names
are to be met with in Cornwall.

Again, traditions of a more extensive coast-line, of lands now
Swept away, have been handed down, doubtless magnifying the
extent of the ancient land, as the account passed through succeeding
generations.

Our familiarity with the causes producing such phenomena as
earthquakes, comets, eclipses, and the like, however seldom some
of them have been experienced in a lifetime, renders the obser-
vations of the present age more accurate and less liable to exaggera-
tion than those of preceding centuries, when anything of infrequent .
occurrence in the experienced operations of nature was regarded
as cataclysmal, resulting from direct interposition in an unvarying
state of things. The rapid advance and more general cultivation of
scientific research, no longer fettered by ignorance and superstition,
embraces in an ever-extending chain of cause and effect phenomena
which our ancestors regarded as supernatural.

It is however curious to note how some amongst the ancients,
by the acuteness of their perceptions, grasped an occasional scientific
truth which has been corroborated in the present day. Thus, it is
remarkable that Ovid, Pythagoras, Pliny, and Aristotle should have
believed the sea to be less changeable than the land.! Strabo, in
opposing the opinions of Eratosthenes and Xanthus as to the cause
of shells being found at great elevations and distances from the
sea, says: “It is not because the lands covered by the seas were
originally at different altitudes that the waters have arisen or
subsided or receded from some parts and inundated others. But
the reason is that the same land is sometimes raised up or depressed,
so that it either overflows or returns to its own place again. We
must therefore ascribe the cause to the ground, either to that ground
which is under the sea or to that which becomes flooded by it, but
rather to that which lies beneath the sea, for this is more movable.”

The historical evidence may be classified under three heads :—

Firstly, accounts of unusual disturbances of the sea by contem-
porary observers.

Secondly, records of disastrous inundations preserved in old
chronicles.

Thirdly, traditions of the Lyonesse and probable references of the
ancient geographers and historians to the Scilly Isles.

1 Stoddart, Proc. Brist. Nat. Soc. for 1870, vol. v. p. 48.

W. A. EH. Ossher—Historical Geology of Cornwall. 29

Fourthly, the insulation of St. Michael’s Mount and the identifi-

cation of Ictis.
Part 1.—Contemporary Observations.

These have been taken exclusively from papers by Mr. Edmonds.
In Edin. New Phil. Journ. he mentions an influx and reflux of the
sea, varying from three to above five feet, in Mounts Bay, at five p.m.,
on March 25rd, 1847; the double movement taking from fifteen to
twenty minutes. During the most part of the day the water, from
the mouth of the Catwater to within Sutton Pool, at Plymouth,
was constantly agitated by flux and reflux.

In Falmouth Harbour, and on the shores of the Scilly Isles,
similar oscillations took place, whilst in St. Ives Bay nothing un-
usual was remarked.

At Newlyn four fluxes and refluxes of the sea occurred in an hour
and a half. In the shallow water between Marazion and Penzance
no agitation was perceptible. The limits of the disturbance, so far
as observed, were from Mousehole on the west to Porthleven on the
east, a distance of ten miles.

On October 30th of the same year, at five p.m., a rise of the sea,
coming from the south-west, and reaching five feet, took place at
Penzance.

Three similar fluxes and refluxes occurred at Plymouth in forty
minutes.

Four whirlwinds, accompanied by shocks, passed through the
parish of St. Just, on December 12th, 1846.

The same writer’ mentions an earthquake felt over 100 miles,
from the Scilly Isles through Cornwall as far as Plymouth, in
July, 1757. .

A disturbance of the sea took place in Mounts Bay at four hours
and a quarter after the great earthquake at Lisbon in 1755, when
the sea suddenly rose to the height of six feet at St. Michael’s
Mount, coming in from the §.H.; and to eight feet at Penzance
Pier, coming in from the 8.H. and §.S.H. At Newlyn Pier-and
Mousehole the sea coming in from the south rose and fell ten feet.
Toward the decline of the commotion, the sea was found to be
running at seven miles an hour in Guavas Lake.

If the observation recorded in the following extract be not mag-
nified in transmission from the original observer, it shows the care
necessary in ascribing the occurrence of some isolated pebbles and
boulders above the reach of the highest spring tides to changes
in the relation of sea and land: “I have been informed by two
descendants of an eye-witness that at Lamorna Cove, which is on
the south-east part of Mounts Bay, the sea on this occasion rushed
suddenly towards the shore in vast waves with such impetuosity
that large rounded blocks of granite from below low-water mark
were swept along like pebbles, and many were deposited far above
high-water mark. One of seven or eight tons weight was rolled
to and fro several feet above high-tide level.”

IT R. Ges. Corn:

30 W. A. E. Ussher—Historical Geology of Cornwall.

Whether the size of the boulders be exaggerated or not, it is
evident that the disturbance described was sufficiently powerful
to shift large stones from the existing beach to a point about the
average height of the Cornish raised beaches above high-water
mark, even allowing for an exaggeration of five feet in the height
to which the large boulder was said to be moved. At Polkerris,
near the Par estuary, “ Raised Beach” has been engraved on the
map, apparently on the strength of the occurrence of isolated quartz
pebbles amid sandy debris on a small promontory some twenty feet
above the adjacent beach, which is composed of exactly similar quartz
pebbles. This phenomenon is much more likely to have been
produced by exceptional gales, or such disturbances as have been
described, than to be the relics of a raised beach, the lighter
materials of which had been dissipated by spray and rain, for the
raised beaches are usually too much consolidated to allow of such
facile dissipation.

In February, 1759, Mr. Edmonds records a slight shock felt
at Liskeard for fifteen minutes, accompanied by blood-red rays.

In March, 1761, on the day of the second earthquake at Lisbon,
the sea advanced and retreated five times four hours and a quarter
after ebb-tide, at five p.m., in Mounts Bay, rising six feet at
Penzance and Newlyn, and four feet at St. Michael’s Mount. At
the Scilly Isles the agitation continued for more than two hours.

In July, 1761, fluxes and refluxes occurred in Mounts Bay, and
at Falmouth, Fowey, and Plymouth.

In 1789 fluxes and refluxes of the sea were observed at Penzance
and St. Michael’s Mount. Tarth shocks were felt on December
30th, 1852.

In 1886 a slight disturbance of the earth was felt in the parishes
of Budock and Stithians.

On October 20th, 1837, a slight shock is said to have been felt in
the Scilly Isles.

On February 17th, 1842, an earthquake was felt between the
hours of eight and nine a.m., from Manaccan on the south to St.
-Cubert on the north, a distance of twenty-five miles; and from
Falmouth on the east to St. Hilary on the west, a distance of
eighteen miles.

On July 5th, 1848, the sea was much agitated within Porthleven
Harbour. Three hundred yards from the north shore of the harbour
nothing unusual was observed. At one p.m. the sea rushed in
for fifty yards, reaching a height of four or five feet at Marazion.
At Penzance an agitation accompanied by strange currents was
observed.

The effects of the disturbances above cited are eminently tran-
sient, except in abnormal shifting of detritus to higher levels, but
when we find that within the short space of a century Cornwall
has felt the spent force of earthquakes propagated from distant
centres of internal or eruptive motion, the probability of similar
disturbances emanating from much nearer sources, and productive of
considerable if not permanent effects, is at once suggested. Whilst

W. A. E. Ussher—Historical Geology of Cornwall. 3l

the record of such cataclysms in early historic or medieval times
would refer to their disastrous effects, want of knowledge and
observation leaving the causes unknown, the recent prehistoric
geological period conceals them in an impenetrable veil.

Part 2.—Records of Disastrous Inundations.

I quote the following from Mr. Peacock’s book (On Vast Sinkings
of Land, etc.) :—

p- 116. “Dr. Barham quotes from the Saxon Chronicle, par-
ticulars of the inundation of Nov. 11th, 1099; and of another on
the same authority in 1014. This year (1014) on Michaelmas Eve,
Sept. 28th, came the great sea-flood which spread over this land,
and ran up as far as it never did before, overwhelming many towns
and an innumerable multitude of people.”

p- 115. An account of a destructive inundation 13 years after
the Domesday Survey, by Fiorence of Worcester; “On the 3rd day
of the Nones of November 1099, the sea came out upon the shore,
and buried towns and men very many, and oxen and _ sheep
innumerable.” From the Saxon Chronicle for that year, “On St.
Martin’s mass day, the 11th Nov., sprung up so much of the sea-
flood, and so myckle harm did, as no man minded that it ever afore
did, and there was the ilk day anew moon.” “Whence,” says Mr.
Peacock, ‘“‘the catastrophes cannot be referred to the great height
of the tide, for the highest spring-tides do not occur until several
tides after the new moon, and the llth of November is several
weeks after the equinox.”

p- 188. Mr. Peacock accounts for Geoffery of Monmouth’s
omission of the mention of the inundations of 1014 and 1099, on
the ground that the chroniclers very often omitted to record the
actual disappearances of lands.

In p. 140 he quotes from Mr. Pengelly’s paper on the Antiquity
of Man in the South-West of England: ‘Leland (1533-1540) says,
‘Ther hath been much land devourid betwixt Pensandes and Mouse-
hole. Ther is an old legend..... a Tounlet in this Part (now
defaced and) lying under the water.’ ”’

In p. 141 he gives a reference to Mounts Bay from Magna
Britannia published anonymously in 1722 (vol. i. p. 808): “’Tis a
tradition among the people here, that the ocean breaking in violently,
drowned that part of the country which now is the Bay.” Mr.
Peacock disposes of the idea that the catastrophes of 1014 and
1099 might have been the result of similar movements to those
“which occurred on the South Coast of England in 1817, 1824, and
1859, at a considerable distance of time from either equinox,” on
account of the unprecedented harm done by them, and the in-
adequacy of such high tides as those mentioned to produce com-
mensurate effects.

Notwithstanding, I am inclined to differ from Mr. Peacock in this
conclusion for the following reasons :—

Firstly. Such traditional accounts as those of Leland and the
Magna Britannia, and the statement of Vice-Admiral Thevenard in

32 W. A. HE. Ussher—Historical Geology of Cormeall.

Mem. relatifs 4 la Marine (a.p. 1800), “La submersion du terrain
. .. et de la pointe ouest de PAngleterre. rx.” (commencement of
ninth century), quoted by Mr. Peacock in p. 88 of his book, must be
laid out of the question.

Secondly. All statements made by writers who lived long after the
occurrences they describe must be accepted with reservation, as they
may have been derived from the contemporary record of the
occurrence, and cannot, therefore, be said to furnish additional
evidence. Thus with Florence of Worcester, who wrote in the
thirteenth century.

Thirdly. Taking the Saxon Chronicle as the only direct con-
temporary account of the inundations of the eleventh century, one
would like to know whether the descriptions there given were penned
by an eye-witness of the catastrophe, or inserted from rumours which
would doubtless have magnified the disaster ere they reached the
chronicler.

Fourthly. Admitting Mr. Peacock’s reason for the omission of
remarkable events here and there by the chroniclers generally, I
cannot see their particular application to Geoffery of Monmouth,
who flourished in the twelfth century, and would therefore have less
excuse for omitting to mention events, which had been witnessed
by the generations immediately preceding him, than Florence of
Worcester, who lived more than three centuries after they had occurred.
For these reasons I am disinclined to believe in sudden elevations or
depressions of land, and to consider that, owing to some such dis-
turbances as I have quoted from Mr. Edmonds, though perhaps of
greater magnitude, lives may have been lost and lands devastated by
the influx of waves propagated by earthquake shocks, and by seasons
of unprecedented flood. That the effects produced would be partial
or transient, whilst the story of the disaster for which men could
assign no cause would be magnified as it passed from the eye-
witnesses of the catastrophe to their descendants, and finally, with
many interpolations and distortions, live as a local tradition with
perhaps very little of its original significance remaining.

Part 3.—Traditions of the Lyonesse, éc.

The following information is chiefly extracted from Mr. Peacock’s
book :—

“Tt is said that in Camden’s time the inhabitants of Cornwall
were of opinion that the Land’s End did once extend further to the
west, which the seamen positively conclude from the rubbish
they draw up, and that the land there drowned by the incursions of
the sea was called Lionesse. That a place within the Seven Stones
is called by the Cornish people Trevga (i.e. a dwelling), and that
windows and other such stuff have been brought up from the bottom
there with fish-hooks, for it is the best place for fishing. That at
the time of inundation supposed Trevelyan swam from thence (at
least 15 nautical miles to the nearest part of the mainland) and in
memory thereof bears Gules, an horse Argent issuing out of the sea
proper.” (Vide Note A.)

W. A. E. Ussher—Historical Geology of Cornwall. 33

“Tf the Lyonesse country really existed in Ptolemy’s time
(a.p. 117 to 161), it cannot have extended as far westwards as is
shown on the map in the Churchman’s Magazine (for July, 1863,
p- 89), from Land’s End and Lizard Point to and comprising the
Scilly Isles. Because Strabo, who flourished at least a century
before Ptolemy, quoting Posidonius, who was still older, mentions
those islands as then existing under the name of Cassiterides (book iii.
cap. li. § 9), and that they were ten in number (Ibid. cap. v. § 11).”

“Dr. Paris, in his ‘Guide to Mounts Bay and the Land’s End,’
p- 91, mentions Camden’s tradition of the Lyonesse (the Silurian
Lyonois), said to have contained 140 parish churches, all of which
were swept away by the ocean.” He says further that the Scilly
Isles are now 140 in number, though only six are inhabited.

Camden (Britannia, edit. 1722) says, “ The Scilly Isles are called
by Antoninus, Sigdeles; by Sulpitius Severus (died a.p. 420),
Sillinz ; by Solinus, Silures; by Dionysius Alexandrinus, Hesperides ;
by Festus Avienus (latter part of fourth century), Ostrymnides; by
several Greek writers, including Diodorus, and by Pliny the Elder,
Cassiterides.”’ ?

Dr. Borlase,” in a letter to the Rev. J. Birch on the Scilly Isles, says
that the present inhabitants are new comers, having no connexion
with the old race, as all the antiquities found in the islands belong
to the rudest Druidic times.

In isles now uninhabited and not used for pasturage, rude stone
pillars, erect circles of stone, kistvaens, innumerable rock basins,
and tolmens,® are found, whilst the small islands, tenements, and
creeks, are called by British names.

Within the three years previous to 1753, he states that the ad-
vance of the sea in the Scilly Isles has been very considerable; this
advance being, in his opinion, due to subsidence for the following
reasons: Strabo’s opinion as to their number (vide supra) and as to
one only being desert and uninhabited; the fact that the Isle of
Scilly, which gives its name to the group, is now a high barren
rock, a furlong across, with cliffs to which only sea-birds can obtain
access.

The flats which stretch from one island to another are plain
evidences of a former union between many now distinct islands.
The flats between the islands of Trescan, Brehar, and Sampson, are
left quite dry at a spring-tide low-water, when walls and ruins have
frequently been seen through the shifting sands, covered by 10 to 20
feet of water at high tide. As these foundations were probably at
one time six feet at least above high-water mark, the advance of the
sea by denuding action alone would be insufficient to account for
their present position, “ten feet below high-water.” Whence he
considers that ‘a subsidence amounting to 16 feet at least has taken

1 Peacock, p. 109.

2 Phil. Trans. for 1753, vol. 48, p. 326.

3 Tolmens.—Oval or spheroidal rocks, when resting on two others, with a cavity
between, are called by Dr. Borlase tolmens (stones with holes), and are supposed by

him to have been rock deities (Carne on the Scilly Isles).—T.R G.S. Corn. vol. vil.
p. 144.

DECADE II,— VOL. VI.—NO. I. 3

34 W. A. E. Ussher—Historical Geology of Cornwall.

place, which caused the desertion of the islands by their terrified
aboriginal inhabitants. These original inhabitants carried on a trade
in tin with the Phcenicians, Greeks, and Romans” (for this opinion
he cites Diodorus Siculus, lib. v. cap. 1. and Strabo, Geog. lib. iii.).
“Whilst only one inconsiderable vein of tin occurs in Tresco
Island, and that betrays no sign of ancient working, nor are any old
workings now visible sufficient to have maintained a trade in tin.”
He says further, ‘‘ But though there are no evidences to be depended
on of any ancient connexion of the Land’s End and Scilly, yet that
the cause of that inundation which destroyed much of these islands
might reach also to the Cornish shores, is extremely probable, there
being several evidences of a like subsidence of the lands in Mounts
Bay.”

Dr. Borlase, in his Natural History of Cornwall, says, ‘The supply
of tin from Gades and Spain being too small to supply the vast trade
as far as India, they must have got it to the east of the Damnonii.”

The Chaldeans and Arabians call tin by a name similar to the
Greek kacovtepov. The Scilly Isles were called Cassiterides
long before the Greeks knew of their position, for Herodotus
(BC. 400) says, Ovte vncas oda Kacoutepibas exoas ex Tov oO
KATGITEPOS HuLy Porta.

Solinus calls them Insule Silurum or Insula Silura, perhaps in
mistake for islands off the Welsh coast.

Tacitus? says the Silures were opposite to Spain, which would
point to the Scilly Isles. It is probable that the Phcenicians re-
garded West Cornwall as an island, and one of the Cassiterides, as
the Scilly Isles alone would have been totally insufficient to afford
the supply.

“ Ortelius,’ therefore, not without reason, makes the Cassiterides
to include, not only the Scilly Isles, but also Devonshire and
Cornwall.”

‘“‘Tin was also anciently found in Lusitania and Gallicia.

Mr. H. Boase® quotes Carew ® as follows :—“ The encroaching sea
hath ravined from it the whole country of Lionnesse, together with
divers other parcels of no little circuit, and that such a Lionnesse
there was, these proofs are yet remaining. The space between the
Land’s End and the Isles of Scilly, being about 30 miles, to this day
retaineth that name, in Cornish, Lethowsow, and carrieth an equal
depth of 40 or 60 fathoms, save that about midway there leth
a rock which at low water discovereth its head. They term it the
Gulf, suiting thereby the other name of Scilla. Fishermen also
casting their hooks thereabouts, have drawn up pieces of doors and
windows.” After touching on Dr. Borlase’s views, Mr. Boase’ pro-
ceeds to say, “The arguments adduced by our old historians in
proof of the tradition, refute themselves. In the first place, the sea
is no shallower between the Land’s End and Scilly, than at equal
distances from land, on other parts of the coast; and the midway

294

1 p. 29. 2 Ib. p. 3 3 1527-1593. 4 Ib. p. 29.
> T.R.G.S. Corn. vol. ii. pp. i30, 181. 6 Carew, p. 3. 7 Op. cit. p. 132,

W. A. E. Ussher—Historical Geology of Cornwall. 30

gulf or Wolf-rock, happens not to be in that channel at all. but con-
siderably to the south of it; and as to the stories of fishing up
pieces of doors and windows, and seeing tops of buildings, etc., had
all the buildings, doors, and windows of Cornwall, been placed
there, the first tempest would have swept them all away, as pebbles
before a torrent. The truth is, that no such relics were ever dis-
covered, or could have remained for discovery, in that boisterous
channel of the Atlantic Ocean.”

With the above opinion I entirely agree, for the very mention of
windows dredged up is sufficient to refute any testimony of an
historical connexion of the Land’s End with the Scilly Isles based
upon it. Except as fragments of wreck, it is impossible to conceive
the occurrence of such material in the places specified.

(Peacock p. 140.) The tradition of the loss of area on the
West of Land’s End is thus mentioned by Harrison (An Historical
Description of the Island of Britaine, by W. Harrison, prefixed to
Hollingshed’s Chronicles, 1586, vol. i. lib. ii. ch. 10, p. 897): “A
remarkable corroboration of Ptolemy’s positions of the promontories
Belerium and Ocrinum,”! as Mr. Peacock thinks, “It doth apeere
yet by good record, that whereas now there is a great distance
betweene the Syllan Isles and point of the Land’s End, there was of
late years, to speke of scarslie a brooke or drain of one fadam water
betweene them, if so much, as these evidences appeereth and are yet
to be seene in the hands of the lord and chiefe owner of those Isles.”

Dr. Paris and Mr. Carne? considered that St. Just in the Land’s
End district might have been meant by the word Cassiterides, owing
to the traces of tin in the Scilly Isles being insufficient to justify that
appellation. Mr. Carne,’ speaking of Piper’s Hole, in Tresco Island,
as a supposed adit of the ancient tin works, objected that as it 1s
above high-water, it is just such a site as would be selected now.
He further considers that, if any mines had ever been productive in
the Scilly Isles, some traces of diluvial tin ore would even now be
found from time to time in the low-lying tracts in St. Mary’s, and on
the south-eastern side of Tresco.

Mr. Peacock* quotes Diodorus Siculus as follows :—“ Far beyond
Lusitania (Portugal) very much tin is dug out of the islands in the
ocean nearest to Iberia (Spain), which from the tin are named
Cassiterides.”

D. P. Alexandrinus, who flourished in the time of Augustus, says
in his Geography, line 599, etc. : “« But beyond the Sacred Promontory
(Cape St. Vincent), which they affirm is the extremity of Hurope, in
the islands Hesperides, where the source of tin is, the rich children
of the illustrious Iberi dwell.” Mr. Peacock thinks that the Scilly
Isles are here alluded to under the name Hesperides.

Strabo has told us that Publius Crassus saw that the metals were

1 Peacock, p. 109. ,

2 Mr. Carne (T.R.G.S. Corn. vol. ii. p. 354) says, “It is exceedingly probable
that the western extremity of England, of which St. Just forms a prominent part,
constituted the principal portion of what was formerly known under the name of the

Cassiterides.””
3 T.R.G.S. Corn. vol. vii. p. 158. * Peacock, p. 106.

36 Notices of Memoirs—F’. Toula, The West Balkan.

dug out at a little depth in the Cassiterides (book ii. cap. v. § 15) ;
this was about 57 B.c.

Strabo further describes the Cassiterides as ‘“‘islandsin the high
seas just under the same latitude as Britain, northward and opposite
to the Artabri.” }

(To be continued in our next Number.)

INA @MRAROAES) Olgy IM mae wes

—_»>——_

On THE Grotocy oF THE West Barkan.’ By Fr. Touna. (Proceed.
Imper. Acad. Vienna, March 14, 1878.)

HE southern margin of the Berkowiza-Balkan is composed of
Tithonian coral-limestones. Beneath these lie Middle-Liassic
strata, with Belemnites paxillosus, Spiriferina verrucosa, Rhynchonella
(near curviceps), and Gryphea (near cymbium). Beneath these are dark-
tinted limestones with Crinoids, small Gasteropods, Lima radiata,
and Retzia trigonella (Recoaro Limestones), resting on red sandstones
of the Werfen Schists, which in their turn rest on argillaceous
schists of the Carboniferous (Culm) Formation. The Lower Triassic
Limestones stretch out wide above Pecenoberols, and upwards to the
summit of the defile, where they are seen to rest on intensely yellow
sandstones containing Myophoria costata. Near Ginci-Han Liassic
beds appearagain. Their organic remains are—Belemnites paaillosus,
Schlth., Pleurotomaria (near expansa, Sow.), Rhynchonella acuta,
Sow., Sprriferina rostrata, Schlth., Lyonsia untoides, Gldf., Pecten
liasinus, Nyst, Pect. sublevis, Phill., Plicatula (near spinosa, Sow.),
Gryphea (near fasciata, Tietze). The steep northern slope is
formed of granite, intersected by many veins of andesite. Farther
off, crystalline schists extend to beyond Berkovac. On the whole,
the Berkoviza-Balkan is an independent portion of the Balkan chain.
Cretaceous deposits are wanting throughout the section, except that
perhaps the coral-limestones on the southern side may possibly be
Lower Cretaceous, if not Tithonian.

The crystalline schists past the lme Berkovaz-Vraza are succeeded
by Paleozoic argillaceous schists and conglomerates, overlain by red
sandstones and light-coloured limestones. Mighty masses of these
limestones, locally abounding with organic remains (Thamnasirea,
Actinarea, Reptomulticava, Chetetes Coquandi, Mich., Lithodomus,
Caprotina Lonsdale, d’Orb.), rise above the Lower Triassic deposits.
Near Vraza, sandy limestones and marls, characterized by the presence
of Orbitolince, appear on the northern base of the Caprotina-lime-
stones. Several of their beds abound with fossils, as,—Ositrea
Vrazaénsis, sp. nova, Rhynchonella (near lata, d’Orb.), Terebratula,
Waldheimia, Cerithium Forbesianum, Turbo, <Astarte numismalis,
OCyrena (?) lentiformis, Reem., Cardium (near Ibbetsoni), Pecten,
Areopagia gracilis, sp. nova, Terebratula, and Rhynchonella lata.

1 Peacock, p. 107.
2 Notes on the seeey of other parts of the Balkan, by M. Toula, are given
in the Gzou. Mag. Dec. IL. Vol. IV. p. 518.

Reviews—Kinahan’s Geology of Ireland. Oo”

The organic remains in the Inoceramus-limestone between Vraza
and Ljutiobrod are,—Galerites (vulgaris ?), Ananchytes ovatus, Car-
diaster pilula, C. ananchytis, Inoceramus (near Crippsi and Cuvieri),
Terebratula (near Hebertina), Trochus, Ammonites (Harpoceras),
Hamites. Beneath these strata lie sandy limestones, abounding with
Orbitoline, resting on Bryozoan limestones. These contain Repto-
multicava micropora, Ceriocava subnodosa, Multicrescis Michelini,
etc., together with spines of Cidarites, Nucleolites (near Olfersi),
Terebratula, Ostrea (near Boussingaulti), Lima Tornbeckiana, and
Serpula filiciformis. Caprotina-limestones appear farther southward.
The whole series reminds one of the three subdivisions of the
“ Schratten Limestones”’ in the Northern Alps, resting to the south
on red sandstones and conglomerates. Lower Triassic red sand-
stones, resting on quartzite schists, and overlain by Lower Triassic
limestones, are amply developed between Cerepis and Obletnja.
Melaphyres and diorite are widespread. Granite appears at two
places. At one spot on the banks of the River Isker the Triassic
limestones contain Natica, Pecten Alberti, Modiola triquetra, Gervillia
socialis, G. mytiloides, Leda, Myophoria costata, M. levigata, M.
elegans, Myoconcha gastrochena, Anoplophora (near musculoides), etc.
Argillaceous schists of the Carboniferous formation (Culm), crop-
ping out from beneath red sandstones, prevail in one part of the
Isker Valley, striking N.—S. Some intercalated sandstones yield
vegetable remains, as Archceocalamites radiatus, Cardiopteris poly-
morpha, Neuropteris antecedens, Stigmaria inequalis, and Lepido-
dendron Veltheimianum. The Culm schists continue as far as Ronca,
where red conglomerates and sandstones appear again, forming the
narrow defile through which the River Isker enters the gorges of
the Balkan. Count M.

REVIEWS.

T.—Manvat or THE Groutocy or Iretanp. By G. Henry Krinanan.
8vo., pp. 444, Map, 8 Plates, and 26 Woodcuts. (London,
Kegan Paul & Co., 1878.)

PWARDS of twelve years ago Lyell observed how increasingly
difficult he felt it to keep up with the progress of geology.

And every student of the science must continually be impressed

with this difficulty. The grand work of our American brethren is

in itself an immense study, and so important is the light it has
thrown on every branch of geology, that it possesses a world-wide
interest. But while the Guonogicat Macazine and the Geological

Record announce to us periodically what has been done, and what

is being done, the number of isolated works is too great, and access

to them often too difficult, for those who wish to glean the sum and
substance yielded by minute observation.

And in the British Islands, as has been often remarked, the
increase in our knowledge becomes every year more and more a
matter of local detail, supplementing and illustrating the work and
conclusions of those who sketched out the main features in their

38 Reviews—Kinahan’s Geology of Ireland.

geology. Hence the work of summarizing the labours of all becomes
a desideratum, and it is somewhat surprising that until the past
year no epitome of the Geology of Ireland had appeared.

Two works have however now been given to us; but while both
aim at illustrating the geology of the sister isle, in no sense can they
be considered as rivals—the one supplements the other.

Professor Hull’s work, to which attention was lately directed,
gives in outline the chief features in the Geology of Ireland, and
dwells more especially upon the physical history of the rocks, and
the sculpturing of the scenery. Mr. Kinahan’s work, now before
us, aims to give a more detailed account of the strata, and of the
facts to be observed in the field, thus acting as a guide to the geolo-
gist in his explorations.

As the general features of the Geology of Ireland were pointed
out at some length in the notice of Prof. Hull’s book (see Gzot.
Mac. March and April, 1878), and as Dr. Evans again alluded to
them in his Address to the Geological Section of the British Asso-
ciation at the Dublin Meeting (see Guou. Mag. Sept. 1878), it will
be unnecessary to go over the same ground again.

After a brief and concise introduction, Mr. Kinahan proceeds at
once to the description of the stratified: rocks, which take up the
first section of the book.

The oldest Paleozoic rocks are grouped as Cambrian (Sedgwick),
Cambro-Silurian (Phillips), and Silurian (Jukes). In the case of
the term Silurian, although, as we think rightly, the author does not
include all the beds embraced under that denomination by Murchi-
son, yet we think the name of the author of the Silurian system
should certainly have been bracketed to it.

The separate subdivisions are described under local geographical
names, and their probable English equivalents are given in a table.

Much interest attaches to the Dingle beds or Glengariff grits,
which overlie true Silurian (Ludlow) rocks, with apparent con-
formity, in the Dingle promontory.

In this promontory the beds are described as consisting “of green
and purple grits and slates which pass up into beds of coarse thick
sandstones and grits of greenish and reddish tints, like those in
the neighbourhood of Glengariff, County Cork, and interstratified
similarly with purple slates.” No fossils proper to the group have
been found in them. But in the Iveragh and Dunkerron pro-
montory ‘there is a conformable sequence extending upwards into
the Carboniferous slate and limestone.” In the Glengariff grits,
south and south-east of Dingle Bay, obscure tracks and plant-like
markings have been met with in the beds.

Professor Hull remarks that the Dingle Beds “are overlaid in a
highly discordant manner by the red sandstones and conglomerates
of the Old Red Sandstone formation.” Nevertheless, as he adds,
“they have been placed by the Government Surveyors in a kind of
neutral territory, and are provisionally unattached to either of the
formations with which they are in contact.”

Mr. Kinahan places the Dingle Beds, as does Professor Hull, rather

Reviews—Kinahan’s Geology of Ireland. 39

with the Silurian ; but his section (p. 54) to show the unconformable
overlie of the Lower Carboniferous sandstones and shales (=Old
Red Sandstone, etc.) is not quite clear, for it is suggestive of a
fault between what he there marks as “Old Red Sandstone,” and
the Dingle or Glengariff grits. Jukes, it should be observed,
thought it expedient to join the Dingle or Glengariff grits to the
overlying rocks rather than to the Silurians.

As even Professor Hull links these beds doubtfully with the
Silurians, one would have been glad to have been furnished with
sections showing more clearly the actual facts, inasmuch as the
question is of much importance in its bearing upon the relations of
the Silurian and Old Red Sandstone, and of the Devonian and
Carboniferous strata.

It may be well to bear in mind that in the south-west of England
and South Wales, De la Beche found great difficulty in drawing a
hard line between the Silurian and Old Red Sandstone, while in
Gloucestershire and Somersetshire the Old Red Sandstone passes up
most gradually into the Lower Carboniferous Rocks.

Hence, when Mr. Kinahan includes the Old Red Sandstone of
Treland in the Carboniferous formation, ‘“‘ because in no place in
Treland has it a defined upper boundary, one group graduating into
the other,” we feel that, while he may be right in theory, the practice
will be found a very inconvenient one, and inconsistent with the
classification elsewhere adopted. It is only right to add, what he
tells us further on, that “only in Munster and in the hills between
Lough Erne and Pomeroy, counties of Fermanagh and Tyrone, is
the Old Red Sandstone at the absolute base of the Carboniferous
formation ; as in all other places the rocks so called and described
are on different geological horizons, ranging up to the base of the
Coal-measures.”” And he shows that this is due to the repetition of
sandstones or ‘‘shore-beds” throughout the Lower Carboniferous
series. The diagram fig. 5, illustrating the changes from the shore-
beds into the Carboniferous Limestone, might, we think, have been
drawn a little more naturally, without interfering with its object.

The following table shows the general grouping of the Carbon-
iferous rocks adopted by Mr. Kinahan :—

{ Coal-measures.
| Carboniferous Slate, including the Coomhoola Grits, and
CaRBONIFEROUS< _ the Carboniferous Limestone.

Yellow Sandstone Lower Carboniferous Sandstone
Old Red Sandstone and Shales.

The interchange of sedimentary conditions exhibited in this series,
forms a very interesting study, and one with which all students of
the Devonian rocks must make themselves acquainted, in picturing
the physical history of those deposits.

Detailed accounts of the Coal-measures are given, with records of
the organic remains, and of the Coal-seams in the several Coal-fields.

The Permian rocks are bracketed with the Mesozoic division, and
Mr. Kinahan observes that in Ireland all the undoubted Permian
rocks seem to be intimately connected with the associated Triassic

40 Reviews—Kinahan’s Geology of Ireland.

rocks, while the Rheetic beds above seem to graduate from them
into the Jurassic rocks, as they do in England.

The Lower Lias is next described, and the alteration of the Port-
rush Lias into Hornstone is attributed to the intrusion of the granitic
rocks of the district, and the metamorphic influence of steam or heated
water.

Accounts of the Greensand, Chalk, and Miocene strata are given,
including the Miocene Iron-ore measures.

A description of the Pliocene Clays of Lough Neagh completes
the first section of the book.

Section 2 is devoted to the Metamorphic and Hruptive rocks, and
here we are introduced to some new terms. Thus Metamorphic
action is described as in some cases Regional, extending over large
areas, and due to “the influence of intensely heated water or steam,
which, as it were, stewed them [the rocks], from which the action
may be called Mrrarnpsts.” In other cases the Metamorphism may
be Local, adjoining intruded masses of rock, etc., which give the
strata a baked appearance ; hence this change is termed Paroprests.
A third kind of Metamorphism, due to the introduction and action of
chemical substances from without, is called Muruynosts. It may be
questioned whether the introduction of these words is a benefit to
the student, who would no doubt be satisfied with the terms Regional
and Local Metamorphism. But Mr. Kinahan is not altogether un-
known for the introduction of peculiar terms, and in his Introduc-
tion speaks of the Hruptive rocks as Granitic or Catogene, that is
rocks formed beneath the surface of the earth at greater or less
depths; and as Anogene, or rocks formed on or close to the surface
of the earth.

Section 3 is devoted to the Superficial Accumulations, Glacial and
Aqueous Drifts, and Meteoric Drift ((Molian or wind-formed drift) ;
the subjects of Glaciation, Hrratic Blocks, Raised Beaches, and Sub-
merged Land and Forests, Peat-Bogs and Pre-historic Remains,
Soils, ete.

Section 4 contains an account of the Physical Features, Escarp-
ments, Cliffs, Hills, and Cooms, of the Valleys and Subterranean
Rivers, the Bays, Lagoons, Lakes, and Islands.

Speaking of the Valleys, Mr. Kinahan says, ‘It is a popular belief
that Rivers and Streams have excavated the valleys in which they
flow. This may be the case in reference to some valleys no doubt,
but in Ireland in general, the rivers are due to the valleys, not the
valleys to the rivers; the valleys occupying dykes of fault-rock or
lines of breaks or other skrinkage fissures in the strata or accumu-
lations in which they are situated.” This statement, which forms
the opening paragraph to Chapter XIX., is well calculated to evoke
criticism. We are quite prepared to acknowledge that Faults,
Fissures, and Joints have had great influence in originating or modi-
fying the courses of rivers, but clearly the rivers in most cases have
carved out the valleys. Indeed, Mr. Kinahan himself speaks of the
Ovoca and its tributaries as occupying deep narrow valleys excavated
along lines of faults.

Reviews—Benecke’s and Cohen’s Geology of Heidelberg. 41

Section 5 embraces the subjects of Economic importance, Mines
and Minerals, with a list of Mineral Localities, Stones, Quarries, and
Mineral Manures, and Water Supply. An Appendix gives a glossary
of Geological and Celtic terms.

In conclusion we can only speak in the highest terms of the
appearance of the book, which is exceedingly well printed and
bound. The geological illustrations are diagrammatic and pictorial,
but the figures of fossils by Mr. W. H. Baily scarcely do justice to
the author of “Figures of Characteristic British Fossils.” The map
on a scale of 27 miles to one inch is very nicely executed, and
shows at a glance the chief features of the Geology of Ireland.
We can cordially recommend Mr. Kinahan’s book to every student
of British geology, and especially to those who desire to go into the
field and observe for themselves.

GrontocgicaL Mae or HEIpELBERG.

TI.—Guogrostiscuz Karte per UmaGrcenp von HEIDELBERG.
BeEARBEITET VON Dr. HE. W. Benecke unp Dr. E. Conen. Mit
Unterstiitzung des Grossh. Badischen Handelsministeriums.
(Blatt I., Heidelberg.) (Strassburg, 1877: Karl J. Triibner ;
London, Triibner & Co.)

OUR years since! we had the pleasure of directing the attention
of our readers to the publication of a sheet (Sinsheim) of
a geological map of a portion of the Grand-Duchy of Baden, in
which the authors proposed to have incorporated the results of a
lengthened study of the area immediately surrounding Heidelberg.
The sheet then issued, the southern half of the projected map,
showed the district lying south of the Neckar Valley, and east of
the railway running south from Heidelberg. The present sheet,
which, though the last issued, is numbered “ Blatt I.,” embraces the
area lying east of the University town as far up the Neckar Valley
as Hirschhorn, with a smaller map of Eberbach, and its curious out-
crops of nephelinite, and extending as far north along the Bergstrasse
as Weinheim. Over this area granite, often containing hornblende, and
deposits of barytes distinguish it from the region lying further south,
where Trias beds cover a great portion of the surface. The sub-
divisions of the sedimentary and the varieties of the igneous rocks are
carefully indicated in colour, and the contours are given in great
detail. The map is a production of which the authors have good
cause to feel proud, and as a specimen of colour-printing it is every-
thing that could be desired. The scale of the map is 1: 50000.

It is to be regretted that the explanatory text, which the authors
stated, at the time they issued the first sheet, should accompany the
publication of the present one, has not yet been provided. It would
prove of great benefit to those geologists who may desire to use the
map in the field, and should not have been withheld.

1 Grou. Mac. 1874, Decade II., Vol. I. p. 326,

42 Reports and Proceedings—

d5v 1508 OSs tse NID) IS asOle ssa DAN ters
Ny Ses

Tur GrorocicaL Socirry or Lonpon.—I.—November 6, 1878.—
Henry Clifton Sorby, Hsq., F.R.S., President, in the Chair,

The following communications were read :—

1. “On the Range of the Mammoth in Space and Time.” By
Prof. W. Boyd Dawkins, M.A., F.R.S., F.G.S.

The author expressed his opinion that the result of the evidence
collected since the death of Dr. Falconer has been to establish the
view of that paleontologist as to the Mammoth having appeared in
Britain before the Glacial epoch. The evidence as to the occurrence
of the Mammoth in the south of England was first examined. The
remains found beneath the bed of erratics near Pagham belonged,
not to Hlephas primigenius, but to H. antiquus. But in 1858 re-
mains belonging to the former were found by Prof. Prestwich under
Boulder-clay in Hertfordshire. In Scotland remains of E. primi-
genius have been found under Boulder-clay; but whether under the
oldest Boulder-clay is uncertain. In 1878 a portion of a molar was
brought up from a depth of 65 feet near Northwich. It was ina
sand beneath Boulder-clay, which the author considered to be un-
doubtedly the older Boulder-clay. The author now assents to Dr.
Falconer’s opinion (which he formerly doubted) that H. primigenius
was a member of the Cromer Forest-bed fauna. It is also clear
that it was living in the southern and central parts of England in
Postglacial times. It has not been found north of Yorkshire on the
east, and Holyhead on the west, probably because Scotland and
North-west England were long occupied by glaciers. Its remains
have been found on the continent as far south as Naples and as far
north as Hamburgh, but not in Scandinavia. Its remains, as is well
known, abound in Siberia, and it ranged over North America from
Eschscholtz Bay to the Isthmus of Darien, E. columbi, E. americanus,
and H. Jacksoni being only varieties. The author then discussed
the relations of E. primigenius to E. columbi, E. armeniacus, and E.
Indicus, and came to the conclusion that it is the ancestor of the last.

2. “The Mammoth in Siberia.” By H. H. Howorth, Hsq., F.S.A.
Communicated by J. Evans, Esq., LL.D., F.R.S.. V.P.G.S.

The author gave reasons for considering that the “ griffon’s claw ”
sent by Harun-al-Rashed to Charlemagne was the horn of a fossil
Rhinoceros, so that the extinct mammals coeval with the Mammoth
were known in Europe at an early date. They were probably
known even in the days of Heredotus. Other evidence, such as the
Christy Collection, shows that the Siberian deposits were known at
a very early time. There is evidence, too, to show that fossil ivory
was known to the Chinese, who asserted that the animals were still
living underground. The author described several cases of the dis-
covery of well-preserved bodies of Mammoths in historic times.
They have occurred in widely separated places, from the eastern
watershed of the Obi to the peninsula of the Tschuksi. Bones also
have been found over the whole length of Siberia, the Brai Islands,
and the islands of New Siberia.

Geological Society of London. 43

The author further discussed the theories which account for their
presence :—1. That the animals lived much further south, and were
carried down by rivers to where they now lie. 2. That they lived
on the spot. As there are physical difficulties in the way of the
transport theory, as the Mammoth was covered with dense hair, and
fed on plants growing on the spot, and as the remains are not
confined to the vicinity of rivers, it is probable that the second view
is the correct one.

There are, however, some points connected with it requiring
further consideration. It being proved that the Mammoth only
required a temperate climate, it must not be hastily assumed that it
could endure that of Siberia. Where the Mammoths are now found
the ground at two or three feet below the surface is permanently
frozen all the year round, vegetation does not appear till June, the
summer is very short, the winter proportionately long, vegetation
poor and stanted, the temperature in January is as low as —65° F.,
and no tree will now grow in the greater part of North Siberia.
How then could Elephas primigenius and Rhinoceros tichorhinus
obtain food on such ground? The only alternative seems to be,
either to suppose a great migration N. and S., or a change of
climate. The author is of opinion that in Siberia such a migration
is not possible. It seems therefore more probable that the climate
of Siberia has become more severe. The plants found in the
fissures of the Rhincceros-teeth are those now living in South
Siberia. The plant-remains associated with the Mammoth (not
floated from a distance, but of the locality) show the same thing,
larch, birch, and other trees of good size being found. Freshwater
and land shells are also found, not now living. Hence it seems
reasonable to conclude that the climate has become more severe, and
that of the north in the days of the Mammoth resembled that of
the south at the present time. The author then considered the
cause of the Mammoth’s extinction. This he held to have been
sudden. The remains must have been preserved soon after death.
He therefore maintains that they were destroyed by a flood due to
some sudden convulsion which also changed the climate.

3. “On the Association of Dwarf Crocodiles (Nannosuchus and
Theriosuchus pusillus, e.g.) with the diminutive Mammals of the
Purbeck Series.” By Prof. R. Owen, C.B., F.RB.S., F.G.S.

The author noticed an objection which had been raised to his
view of the origin of the differences between the Mesozoic and
Neozoic Crocodiles by the adaptation of the latter to the destruction
by drowning of large mammalia (Q. J. G. S. xxxiv. p. 422), namely
that mammals were coexistent with the Mesozoic forms, and re-
marked that from their small size they would hardly constitute a
suitable prey for the Crocodiles to which he then specially referred,
but would be more likely to perform the same part as the Ich-
neumons of the present day, which check the increase of Crocodiles
by destroying their eggs and newly hatched young. He stated,
however, that in some slabs of “ feather-bed’’? marl which accom-
panied the Becklesian Purbeck Collection to the British Museum,

44 Reports and Proceedings— Geol. Soc. Lond.

the remains of small Crocodiles were detected in considerable abun-
dance; and he gave a description of these, and especially of one
which he named Theriosuchus pusillus. This reptile, which is esti-
mated to have been about 18 inches long, had scutes presenting the
“neg and groove” character of those of Goniopholis, with which
genus it further agreed by having the antorbital part of the skull of
the broad-faced Alligator type. In the dentition it resembled the
Triassic Theriodonts more than any other Crocodiles. The vertebree
are amphiplatyan. In conclusion, the author indicated the con-
ditions which have to be fulfilied in the case of recent Crocodiles to
enable them to drown a large mammal without inconvenience to
themselves, and showed that these conditions were realized also in
the Neozoic forms, whilst there was no reason to suppose that any
Mesozoic Crocodiles possessed the adaptations in question.

II.—Nov. 20, 1878.—R. Etheridge, Esq., F.R.S., Vice-President,
in the Chair.—The following communications were read :—

1. “On the Upper-Greensand Coral Fauna of Haldon, Devon-
shire.” By Prof. P. Martin Duncan, M.B. Lond., F.R.S., F.G.S8., ete.

The author in this paper stated that since the publication of his
supplement to the British Fossil Corals, published by the Paleeonto-
graphical Society, several new corals have been obtained at Haldon by
Mr. Vicary, of Exeter. Twelve additional species were noticed, of which
ten were new. This brings the total number of species in the Haldon
Greensand up to twenty-one. The new species are thus distributed :
—Aporosa: Oculinidee (1), Astreidee (3), Fungide (5); Perforata:
Turbinarie (2); Tabulata (1). The paper concluded with remarks
on the genera and species represented, from which it appeared that
the Coral fauna of Haldon is the northern expression of that of the
French and Central European deposits, which are the equivalents of
the British Upper Greensand. The Haldon deposit was formed in
shallow water, and the corals grew upon the rolled débris of the age.

2. “Notes on Pleurodon affinis, sp. ined., Agassiz, and description
of three spines of Cestracionts from the Lower Coal-measures.” By
J. W. Davis, Esq., F.G.S.

The author described some fossil remains of fish obtained from
the bone-bed immediately above the “ Better-bed Coal” referred to
by him in a former paper (see Q. J. G. 8. vol. xxxii. p. 332). The
fossils described included Ichthyodorulites belonging to 4 species,
namely :—Pleurodus affinis, a species named, but not described or
figured, by Agassiz; Hoplonchus elegans, gen. et sp. nov.; Ctena-
canthus cequistriatus, sp. nov.; and Phricacanthus biserialis, gen. et
sp. nov. ‘Teeth, believed to be those of Pleurodus affinis, were also
described.

Specimens anything like perfect are very rare. He suggested
that the coal, after having been formed on land, probably became the
bed of a lake or an open shore-line. He remarked that this thin
bed extended uniformly over a very considerable area. In reply
to Prof. Morris, he stated that the Geological Survey had adopted
a different line of division between the Middle and Lower Coal-

Correspondence—Prof. E. Hull. 45

measures from that formerly suggested by Prof. Phillips. He
pointed out that marine and freshwater species of fish appeared to
co-exist in the Carboniferous beds, and compared this with the
analogous case of the Lake of Nicaragua, as described by the late
Mr. Belt. Freshwater forms of sharks are not unknown in the
Ganges and other rivers.

3. “On the Distribution of Boulders by other Agencies than that
of Icebergs.” By C. H. Austin, Esq. ,C.E., ¥.G.S. (a theoretical paper).

CORRESPONDENCE.

ADDITIONAL NOTES ON THE NORTH DEVON SECTION.

Str,—Permit me to make one or two additional notes to those
contained in the Gronogicat Macazrne for December on the North
Devon Section.t Since they were written, the volume of Proceedings
of the British Association for 1877 has come to hand, containing
a short paper by Prof. G. Dewalque, ‘‘On the Devonian System in
England and in Belgium,” * which is of much interest at the present
time, as coming from so high an authority on the Devonian question
as regards Belgium and its borders. M. Dewalque comes to the
conclusion (1) that the North Devon series is perfectly continuous from
Barnstaple to Linton; and (2) that “ nowhere is there a reappearance
of such identical rocks as to prove, by repetition of the series, the exist-
ence of a fault,” so that Mr. Etheridge’s views and those of observers
who agree with him receive an important confirmation on this point.

M. Dewalque also concurs in the view that the Pilton and
Barnstaple Beds are of Lower Carboniferous age, in fact repre-
sentatives of the Carboniferous Limestone, in which case the
underlying ‘“‘ Baggy and Marwood slates,” with Cucullea, must
be the representatives of the Lower Carboniferous slate and Coom-
hola Grit of the South of Ireland. I have just discovered that
this view was for the first time advocated by the Rev. Professor
Haughton, F.R.S., in a valuable paper on “The Evidence afforded
by Fossil Plants as to the Boundary-Line between the Devonian
and Carboniferous Rocks,” published in 1856.3 The concurrence,
therefore, of evidence and opinion on the age of these beds may,
I think, be considered to have completely established the Carbon-
iferous age of those beds hitherto generally considered as ‘“ Upper
Devonian.” *

On the other hand, the opinion of Professor Dewalque on the
marine origin of the “Cornstone Group” of Hereford, will afford
surprise in some quarters. .

In conclusion, allow me to make a correction of a clerical error
in my paper. For “it,” p. 531, line 11 from top, read “this
division.” Epwarp Hutt.

Dustin, Dec. 14, 1878.

1 “« Possible Explanation of the North Devon Section,” by Prof. E. Hull, Gzot.
Mage. December, 1878, p. 529.

2 Brit. Assoc. Rep. 1877, Trans. of Sections, p. 69.

3 Journ. Geol. Soc. Dublin, vol. vi. p. 227.

4 “Siluria,” 4th edit. p. 272. H. B. Woodward, “Geology of England and
Wales,” p. 69.

46 Correspondence—Mr. J. R. Dakyns.

THE CALDER VALLEY.

Srr,—Mr. Davis’s paper on the Valley of the Calder, in the
number of the Guo. Mac. for November, 1878, is sure to be widely
read; but I fear that some points in it are likely to be misunder-
stood by beginners in the study of geology. This must be my
excuse for troubling you with any remarks on it, and I trust
that my friend, the author, will for the same reason forgive any
criticisms of mine.

Take the following sentences with reference to the Pennine Anti-
clinal and Blackstone Edge, viz.: “The thick beds of gritstone and
shales were crumpled up like the leaves of a book, but being of a
hard and very inelastic nature, the grit rocks were broken asunder,
and we have the two faces of the separated rock considerably apart,
in some instances the distance has to be reckoned by miles; ” and
again, ‘‘As the strata were successively strained and broken, they
would gape wide apart at the centre of the arch; each bed of sand-
stone or shale, as it became elevated to the surface, would carry those
which had preceded it further and further from the centre of rupture.”

I think that these remarks are very apt, as they stand, to mislead
young students into thinking that the opposing escarpments of each
bed of grit, etc., as shown in the diagram, once touched each other
along their present faces; and that the vacant spaces represent a
gaping fissure instead of so much material removed by denudation.
Of course, Mr. Davis does not mean this, but I fear that many
readers will think he does.

Again, with reference to Stainmoor and the transport of granite
boulders, we read that a branch of the great glacier “‘ passed over
Stainmoor into Wensleydale.” Now, the pass of Stainmoor does not
lead into Wensleydale, but into Teesdale. Wensleydale must have
been written by mistake for Teesdale. But further, there are no
granite boulders in Wensleydale. The whole discussion as to the
transport of Shap granite boulders into Hast Yorkshire turns upon
the fact that they did not travel by way of Wensleydale, but crossed
over the lofty pass of Stainmoor, and that at such an elevation that
there was nothing to prevent their also getting into Arkendale, and so
into Swaledale, had they gone over on floating ice, as so many
geologists have maintained. With reference to this I would refer to
Mr. Goodchild’s map and paper on the “ Glacial Phenomena of the
Eden Valley” (Quart. Journ. Geol. Soc. 1875, vol. xxxi. p. 55).

I do not know what river base Mr. Davis refers to as being “not far
distant’ from the Calder Valley; but, as to the latter valley having
been submerged when the erratics found in its gravel, were trans-
ported thither, I wish Mr. Davis would give us his reasons for so thinking.

It would be a very interesting fact were it established or even
rendered probable that the Calder Valley was submerged when its
gravels were deposited; but I should like to hear the reasons for it
before accepting it. The said gravels did not appear to me, when I
was working in that country, to differ from ordinary river gravels; nor
do I think it at all necessary to introduce the sea to account for the
erratics found in those gravels; for the glacial drift with erratics

Oorrespondence—Ur. A. J. Jukes Browne. 47

lies on the Lancashire side so high on the hills close up to the water-
shed, and so much above the summit level of the low pass between
Todmorden and Rochdale, that I think erratics may very well have
been washed down out of the glacial beds into the Calder Valley by
ordinary rain and river action.

Iam also puzzled by the statement, ‘ You may always be sure
that, wherever heather and peat occur, the rock below the surface is
sandstone. You will never find the heather growing on a bed of
limestone, or shale, or clay, but always on sandstone.” I have
myself noticed that peat is very often, not to say generally, under-
lain by a bed of yellowish clay, which forcibly reminded me of the
underclay of a coal-seam. J. R. Daxyns.

H. M. Grorocican Survey, BripuineTon Quay.

CHLORITIC MARL AND UPPER GREENSAND.

Srr,—Will you allow me to make a few observations in reply to
Mr. C. J. A. Meyer’s “ Notes respecting Chloritic Marl and Upper
Greensand,” which appeared in the GrotoercaAL Magazine for
December, 1878.

Let me in the first place thank Mr. Meyer for pointing out the
probability that Captain Ibbetson included two distinct beds “in
actual contact, but widely separated in age,” under the term Chloritic
Marl. The idea had not occurred to me, and I have not had an
opportunity of refreshing my recollection of the Isle of Wight
sections since I took up the question of the Chloritic Marl; it would
seem, however, to be a very probable supposition, but assuming it
to be correct, I fail to see how it improves Mr. Meyer’s position. On
the contrary, it appears in my opinion to form a still greater objec-
tion to the classification proposed in his paper “on the Cretaceous
Rocks of Beer Head.

Mr. Meyer maintains that he was correct in correlating beds 10
to 12 of that section with Ibbetson’s Chloritic Marl, i.e. with what
he himself defines as embracing “the (local) top of the Upper Green-
sand and the (local) bottom of the Chalk Marl of the Isle of Wight.”
Now, granting for the moment the correctness of this correlation, he
has surely committed himself to a classification that cannot possibly
be retained. If, indeed, these are the beds which were originally
united under the name Chloritic Marl, it becomes very clear that
such an application of the term cannot any longer be admitted, and
with it, therefore, must fall also Mr. Meyer’s nomenclature.

Whatever was the original signification of Chloritic Marl (and I
think the question is likely to remain rather obscure), I still believe
that it was the glauconitic base of the Chalk Marl only to which the
term was applied by most subsequent observers. Mr. Meyer must
excuse me for pointing out that the instance he gives to the contrary
hardly goes for much, since Forbes was associated with Ibbetson in
the original description of Chloritic Marl, and the memoir referred
to was written by Forbes in 1850, a year only after the publication
of Captain Ibbetson’s Notes. It is possible, however, that the
Chloritic Marl of the Geological Survey Memoirs, issued in 1862,

48 Correspondence—Mr. A. J. Jukes Browne.

was the same as that of Captain Ibbetson, but more recent writers
have certainly taken it in the more limited sense.

Again, Mr. Meyer asks, “was I wrong then in suggesting the
separation of beds 10 to 12 from the Upper Greensand, and applying
to them the term Warminster Beds?” Now, there are two questions
involved in this sentence which should be carefully distinguished.
These are—

(1). The separation of the said beds from the rest of the Upper
Greensand.

(2). Their separation from or inclusion in the formation usually
known as the Upper Greensand.

As regards the desirability of the first, we are all agreed, and Mr.
Meyer has been duly credited with being the first to recognize the
distinctness of the fauna.

With respect to the second point, it depends of course on the
application and definition of the term “‘ Upper Greensand,” and I
confess that I do not see the force of Mr. MeYer’s reasoning on this head.

Surely, if we are to retain the name Upper Greensand at all, it
should include all the strata which follow, in unbroken succession,
from the top of the Gault (wherever that line is drawn) to the base
of the Chalk Marl, where there is a distinct break in the series.
This was its original application, and if we have eventually to
recognize more life-zones than those at present indicated, why may
they not all be included under the one comprehensive term ?

Mr. Meyer distinctly limits the “true Upper Greensand” to the
strata between the Blackdown and the Warminster Beds, thus
reducing it to mere zonal importance. I contend, on the other hand,
that it is better to retain the name in its original signification, and to
give it the rank of’a divisional formation.

The answer to Mr. MeyYer’s second question is, I think, contained
in his own ‘“ Notes.” He asks, where is there a Warminster fauna
in the Upper Greensand? The answer is given at the bottom of
the same page; speaking of the conglomerate occurring on the line
of division between the Upper Greensand and Chalk Marl, near St.
Catharine’s Down, he rightly says that it divides two faunas, “the
lower of which includes Pecten asper, Terebratella pectita, Catopygus
columbarius, Galerites castaneus, and various other Echinoderms.”
Is not this a Warminster fauna, and is it not in the “local top of the
Upper Greensand,” whatever the bed might formerly have been called ?

Having now replied to Mr. Meyer’s queries, I should like to ask
him two questions in return. (1). Why has he changed his mind
regarding bed 13, and why does he not identify it with the zone of
Belemnites plenus? (2). What does he mean in saying that he was
therefore wrong in giving Holaster subglobosus so wide a range in his
tables of fossils? Is it not found in the beds where he marks it as
occurring ?

Finally, I may express my satisfaction at finding that Mr. Meyer
admits “that the term Chloritic Marl is and always has been a bad
one,” and I hope he will ultimately agree with Mr. Whitaker and
myself in advocating the entire abandonment of the name.

Dec. 16th, 1878. _ <A. J, JuKES BROWNE.

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THE

GEOLOGICAL MAGAZINE.

NEW RSERIES- i) DECADE wils) VORP VI:

No. II—FEBRUARY, 1879.

(svi SEIN (YNIB JAS abe Gals S

——>—__

I.—On tue Puysican History or tHE Encuise Laker District.
Wire Norss on THE PossipLE SUBDIVISIONS OF THE SKIDDAW
SLATES.

By the Rey. J. Currron Warp, F.G.S., F.R.M.S.
(PLATE II.)

Introduction.—In previous papers upon the Geology of the English
Lake District, which I have had the honour of laying before the
Geological Society, special considerations of theoretic significance
have been dwelt upon, and in the official memoir upon the Geology
of the northern part of the English Lake District, detailed facts
have been brought forward and a sketch given (in chap. xii.) of the
original relation of the formations to each other, and their physical
history. J yet venture to think, however, that there is need of a
general summary of the facts relating to Physical History which may
reach a wider circle of readers than do the official memoirs, and
which may stimulate further inquiries into this deeply-interesting
subject. The following pages may therefore be regarded as a sequel
to my former papers on the district, and in some measure as a last
chapter to the story told thus far."

AGE oF THE DistRIOT.

Our first inquiry is naturally—What is the age of this small
mountain district of Cumbria? Do Scafell, Helvellyn, and Skiddaw
stand up as modern products of the world’s evolution, or are they
very ancient monuments, bearing many hieroglyphics written by the
finger of time? First then, if we sum up the rocky volumes at our
disposal, we find the following geological formations represented :—

(d) Carboniferous and Basement Conglomerate.

(c) Upper Silurian and Coniston Limestone Series.

(6) Volcanic Series of Borrowdale.

(a) Skiddaw Slates.

Hach of these series stands by itself, and is either separated from
its neighbour by a long period of time, as is markedly the case
between (d) and (c), and less so between (c) and (6), or by a decided
change in physical conditions, as between (a) and (6).

1 For a list of the author’s papers on the district see Appendix at the close of this
memoir.

DECADE II.—VOL. VI.—NO. II. : 4

50 ~=©Rev. J. Clifton Ward—Geology of the Lake District.

About the Carboniferous and Upper Silurian! we know sufficient
to be sure of their age as compared with the corresponding rocks of
other areas; but it is doubtful whether we are right in assigning,
unhesitatingly, certain definite ages to the series (b) and (a), and
that, too, mainly on the strength of the occurrence in the latter of
certain groups of Graptolites. The Skiddaw Slates may be con-
sidered to be of Lower Llandeilo age, as long ago surmised by Mr.
Salter and believed by Professor Nicholson; but they may represent
several of the subdivisions of the Welsh Lower Silurian, and I shall
presently bring forward some physical evidence to show the possi-
bility of this latter surmise. At any rate, this much is evident, that
the mountain district of Cumbria is made up of rocks of great age,
and we may consider all the material that now enters into the
formation of our Lake District Mountains to have been formed ere
the lowest beds of the great Carboniferous System were laid down,
and at the present day the beds of Carboniferous Basement Con-
glomerate and overlying limestones, sandstones, and shales form a
rough circular framework to the older and mountain-forming rocks
of Silurian (or Silurian and Cambrian) age, as shown in the Sketch-
Map (Plate II.). We will now consider in succession the physical
conditions which probably prevailed during each succeeding period
of the history of Cumbria, giving first the leading facts in short
abstract, and then dwelling on the conditions which those facts
indicate.

Part J.—Puysitcat Conpitions oF EACH PERIOD.
A.—Skiddaw Slate Period.

As the name indicates, many of the rocks formed during this period
have now a slaty character. The total thickness of the whole series
we do not know, for no defined base is met with; but there must, I
think, be at least a thickness of 10,000 or 12,000 feet of beds
included under the head of Skiddaw Slates. We will return to the
consideration of possible subdivisions of this formation, later on.

Cleavage is undoubtedly a characteristic feature among the rocks
of this series, and is best exhibited among the fine black slates of the
west and south side of Skiddaw. In such slates it is sometimes
exceedingly difficult to determine the original bedding, and where,
as in many cases, a system of close jointage, and sometimes a species
of secondary cleavage, occur, the task is made still more difficult, or
quite impossible. These slates, representing old marine muds, are
those beds which most frequently contain fossils—as Graptolites, a
few Trilobites, Phyllopod Crustacea, etc. Sometimes interstratified
with the black slates, and sometimes forming thick masses by them-
selves, occur bands and beds of sandy mudstone, sandstone, and
coarse grit. The flags are frequently ripple-marked, and show worm
tracks. The grit occasionally passes into a true conglomerate, with

1 In conformity with Survey nomenclature used in previous work, I here call the
series above the Coniston Limestone, Upper Silurian, and when speaking generally
of the physical relations of one group "to another, I use the term to include all under
the head of (c).

Rev. J. Clifton Ward—Geology of the Lake District. 651.

pebbles of quartz, and fragments of black slate, accompanied some-
times by felspathic portions, giving it a somewhat ashy appearance.
These conglomeratic characters more particularly prevail in a bed
occurring high up in the Skiddaw Series, to be referred to hereafter
(see large-dotted band in Map). Again, in the lower part of the
series, gritty beds very largely prevail, as in Whiteside and Grasmoor
(Hor. Sect. No. 2, a, p. 54), where there are some thousands of feet of
such beds. Fossils are not abundant in the sandy or gritty beds, and
indeed, with the exception of worm tracks, and some doubtful Grap-
tolites in the flaggy parts, and a single obscure shell in the upper
grit of Latterbarrow, none have been found.

Physical Conditions indicated.—In this 10,000 or 12, 000 feet of
deposits, we meet with no indications of deep- sea conditions, rather
throughout of shallow-water and shore conditions. Judging from
the way in which, generally speaking, the sandy and gritty beds
thicken westwards, one would be inclined to infer that the current
drift was from the west, and continental land not far off in that
direction. To allow of such a thickness of shallow-water deposits,
there must have been continual depression of the area of deposition,
and the greatest thickness of gritty beds occurring in the lower part
of the series accords well with the idea of such a slow depression
taking place, and causing the gradual submergence of the neighbour-
ing land, whence the coarser sediments may have been derived.
The presence of the bed of grit high up in the series may have been
the result of a special set of currents lasting for a short time, and
distributing the current-borne material very irregularly, as is,
indeed, clearly shown by the great variations in thickness of the bed.
It is quite possible that this bed of grit may indicate either a cessation
of depression and slight denudation of the previously formed deposits,
or even a partial elevation accompanied by denudation. There is
little or nothing, however, in the general course of this grit to
indicate the presence of a marked unconformity, rather would it seem
to point to some slight change of conditions in the depths of the area
of deposition. In the south-west of the district, about Lank Rigg,
and Latterbarrow, this grit is succeeded at once by volcanic deposits,
the black slates of the summit of Skiddaw being entirely absent.
This would seem to show that the volcanic forces came into play
earlier in this direction than about Keswick, and as volcanic action is
generally connected—in the first place at any rate—with movements
of elevation, it may well have been that some such movements
preceded and prepared the way for the deposition of the grit. The
volcanic ashes laid down upon the grit of Lank Rigg and Latter-
barrow contain many rolled pebbles of that grit, and the character
of these early ashy beds is clearly such as to indicate submarine
volcanic deposits. On the other hand, the very presence of rolled
pebbles of the grit proves that sufficient time must have elapsed for
the consolidation of the gritty deposit ere the volcanic beds were laid
down. This leads us naturally and without break into the next
period—that of great and long-continued volcanic activity.

. 92 Rev. J. Clifton Ward—Geology of the Lake District.

B.—Volcanic Period.

The rocks deposited in the present area of the Lake District during
the period coming between that of the Skiddaw Slates and that of
the Upper Silurian are almost exclusively of Volcanic origin. They
may represent a total thickness of about 12,000 feet. At the base of
the volcanic series only are there intermixtures with rocks of an
ordinary sedimentary character; here, where the junction beds are
exposed, occur alternations of Skiddaw Slate and submarine volcanic
deposits. The rest of the series consists of beds of volcanic ash and
breccia with lava flows. The finer ash deposits are frequently
well stratified and false-bedded. The breccia is of all degrees of
coarseness, from a rock made up of fragments having the size of a
sixpence or shilling to one containing blocks several yards in
diameter. Conglomeratic ash occurs in one or two beds near the base
of the series. Much of the variation in appearance among the beds
of the ashy series is due to subsequent alteration, metamorphic
action producing diverse changes, dependent, oftentimes, upon slight
original differences in texture and composition—examples of selective
metamorphism. 'The lava-flows are either good dolerites and basalts,
or belong to a class more or less mediate between these and the more
acidic group of lavas. As is generally the case among volcanic
deposits, the various beds are more or less irregular in their range,
showing instances of rapid thickening and thinning.

Physical Conditions indicated.—The presence of ordinary sedi-
mentary beds interstratified among the volcanic deposits near their
base; the occasional occurrence in this lower part also of con-
glomeratic ash ; and the absence of both these peculiarities in the
great bulk of the volcanic series, together with that of fossils in
the bedded ashes,—all point to volcanic action commencing at the
close of the so-called Skiddaw Slate period beneath the waters
of the Skiddaw Slate sea, and the gradual passage from sub-
marine voleanic conditions to those of terrestrial and wholly sub-
aerial volcanos. At first sight it might seem that the regularly-
bedded ashes running at intervals throughout the series, pointed to
subaqueous deposition, but no one can ramble much around modern
terrestrial volcanos without being struck by the frequent cases of
fine stratification shown by the ash scattered around, whether de-
posited in the wet or dry state, and by the not infrequent cases of
false-bedding. It may sometimes have happened also that extensive
deposits of ashy material were laid down in large crater-lakes.

The centres of eruption are difficult to fix upon, as might be
expected amongst volcanic remains of such antiquity. The boss of
Castle Head, Keswick, almost certainly represents one such centre,
and the best developments of lava-flows are all found occurring
within an easy distance. It may be further remarked that since the
lower part of the series contains the greatest thickness of lava-flows,
it would seem that the chief emissions of lava were followed by
long and continued ejections of ashy material. What the height of
the old Cumbrian volcano or volcanos may have been, it is difficult
to estimate; but volcanic deposits were accumulated to a thickness, in

Rev. J. Clifton Ward—Geology of the Lake District. 58

parts, of at least 12,000 feet, and the highest beds known (the fine,
altered, almost flint-like ash of Great End, Esk Pike, and Allen
Crags) are unsucceeded by any conformable series of sedimentary
rocks; hence we know not how much of the products of the old
voleano has been lost, and, for aught we know to the contrary, an
Etna in size may have once stood where now are the resting-places
of quiet lakes. In this connexion it is interesting to remember how
little of our miniature mountain district would be uncovered, could
we transplant Etna bodily with its surrounding volcanic ejecta to the
site of the present Lake District.

Note.—In my previous papers, read before the Geological Society,
and in the Survey Memoir, I have given my reasons for believing
that the several granitic areas of the district were not connected
with the volcanic deposits as cause with effect. It may well be
that one or more large centres of eruption now lie hid beneath
the unconformable overlap of Upper Silurian and Carboniferous
rocks.

Bb.—Unrepresented Period.

Between the periods indicated by B and C, there comes an
interval of unknown duration which we may represent by Bb.
This was a time of which we have no records left, but the duration
of which is made clearly evident by records abstracted. It is as if
the latter part of volume B was torn away, and hence we infer
a denuding action subsequent to its completion.

Our Cumbrian Etna had ceased its activity, and, as so frequently
happens, a subsidence of the volcanic region ensued, accompanied
doubtless by much waste of the volcanic material through the agency
of atmospheric denudation. Subsidence, however, continued until
the old volcano came within the planing power of marine coast-
action, and at last there was probably but little of the old terrestrial
voleano lett above the level of the sea.

For Cumbria, this is undoubtedly the point at which one would
draw the line between Lower and Upper Silurian. Here is a great
physical break, and the deposits accumulated above the Volcanic
Series are markedly transgressive in their strike to those of that
series, though, undoubtedly, for a certain distance east of Coniston,
the strikes do more or less correspond. West of Coniston, however,
nothing can be clearer than the successive curving round in strike
of the divisions of the Volcanic Series and their abutment at right
angles against the outcrop of the Coniston Limestone and Upper
Silurians.

The period unrepresented by deposition, but made clear through
denudation, was brought to a close by the formation on the bed of
that Mid-Silurian sea of a deposit of limestone (the Coniston), rich
in the remains of marine life. But here we meet with evidence of
a slight return of volcanic conditions, and mingling with the
calcareous deposit a bed or beds of lava were poured out. This
time, however, the lava belongs decidedly to the more highly silicated
group, and the felstone now associated with the Coniston Limestone

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Rev. J. Clifton Ward—Geology of the Lake District. 59

probably represents an ancient quartz-trachyte. With this slight
indication of dying volcanic power over the tract under description,
commences another great series of marine depositions quite unaccom-
panied by volcanic phenomena.

C.— Upper Silurian Period.

Under this heading I will also include the time during which the
Coniston Limestone and associated beds were being formed; phy-
sically, in this district, these deposits belong to. the Upper Silurian,
although, palwontologically, they may be the equivalents of Welsh
Lower Silurian divisions.

According to Mr. Aveline’s determinations, in the Kendal district
the total thickness of these Upper Silurian beds cannot be less than
14,000 feet. At the base of this great series lies the only limestone
bed—that of Coniston—and throughout are alternations of clayey and
sandy deposits, the former much cleaved and folded, and the latter
occurring as flags, sandstones, or grits.

Whether there be a slight unconformity or not between the
Coniston Limestone Series and the great overlying group of Coniston
Flags, practically the whole forms one continuous succession of
sedimentary deposits.

Although no Upper Silurian beds are found north of their Coniston
and Windermere outcrop, there is every reason to believe that the
whole series once extended over the now exposed volcanic rocks, for
there is nothing in the deposits themselves to indicate a land margin
near their present outcrop.

Physical Oonditions indicated.—Such a thickness of beds as that
just described implies a continued slow subsidence of the sea-bed
during the whole period of deposition. The character of many of
the strata decidedly points to shallow-water formation, though it is
hard to say from what direction the material was derived. The
conditions correspond in great measure to those prevailing during
the Skiddaw Slate period; when, however, the uppermost Silurian
beds had been deposited, the Skiddaw Slates must have been buried
some 20,000 to 25,000 feet deep, beneath the piled-up volcanic series
and the great accumulation of Upper Silurian strata.

Ce.—Unrepresented Period (Old Red).

Again we come upon a period of time unrepresented by written
records, but clearly evidenced by the destruction of the records of
the previous periods. This destruction by denudation was carried
on to an enormous extent, being accompanied, or rather rendered
possible, by great movements of upheaval over the whole tract, which
movements were probably most intense along a N.E. and S.W. axis.
running through the heart of the present mountain district. If we
pile up black cloth in layers to a thickness of ten inches, red cloth
upon this to a thickness of twelve inches, and blue cloth upon the red
fourteen inches thick, then by bringing some powerful force to bear
upon the two ends of the pile, the whole may be thrown into curves
and contortions by the lateral pressure, and the centre portions
consequently raised above the level of the ends. Imagine, then, a

o6 Rev. J. Clifton Ward—Geology of the Lake District.

large pair of shears brought forward which shall cut off or pare
down all the upraised central portion; in this way the uppermost
blue cioth may be removed altogether from the centre of the low
arch, a less amount of the red cloth layers would be removed, while,
perhaps only a few topmost inches of black cloth would be touched,
but the consequence would be that, at the centre of the cloth dome,
an arch of black cloth would appear, on either side of this would lie
inclined layers of red cloth, to be flanked in their turn by similarly
inclined strata of blue cloth. Suppose. now, the ten inches of black
cloth to represent 10,000 feet of Skiddaw Slates, the twelve inches of
red cloth 12,000 feet of Volcanic Deposits, and the fourteen inches of
blue cloth 14,000 feet of Upper Silurian strata; suppose, moreover,
the lateral pressure applied at either end of the cloth to signify a
probable depression of extensive tracts on either side of that over
which these formations are upraised, and the gnawing and planing
action of the sea alone the coast-line of rising land, aided by the
powers of the atmosphere, to be represented by the great shears,
then, when the elevation and crumpling had done their work, and
brought the pile of 36,000 feet of strata conveniently under the
denuding agents, some of the outer coats of this dome must have
been pared away, and Upper Silurian and Volcanic deposits beg
both removed over the central dome, the Skiddaw Slates themselves
would be once more exposed to view (see Plate II., Fig. 2). Such a
denudation must mean the removal of 20,000 to 25,000 feet of strata,
unless we suppose that within the distance of a few miles (twelve or
fourteen) the thickness of the Upper Silurian beds was much reduced.
To this amount of removed material we must add a considerable
thickness of Skiddaw Slates, themselves cut from the dome top.
Surely such an action must represent a very great length of
time, yet do we find that it all transpired in the interval between the
close of the Upper Silurian and the deposition of the Red Conglo-
merate of Mell Fell, ushering in the great Carboniferous Period.
For these Lower Carboniferous rocks (Mell Fell Conglomerate, etc.)
are deposited across the denuded edges of all the older formations ;
at one place they lie upon Upper Silurian, at another upon rocks
of the Volcanic Series, and at yet another upon the Skiddaw Slates.
Thus there cannot be the shadow of a doubt as to the length of time
which must have elapsed between the close of the Upper Silurian
and the commencement of the Carboniferous Period, and of the
greatness of the work accomplished in that time.

It is to the earlier part of this lengthy period, when the Skiddaw
Slates were buried at their deepest, and internal commotions began
to be displayed, that I would assign the formation of the various
granitic centres. In an earlier paper I have treated of the probable
pressure under which they were respectively formed, and called
attention to the fact—in the Survey Memoir (p. 74)—that an axial
line of most intense metamorphism runs parallel with the main axis of
upheaval. That there was a disposition at this period towards
volcanic outburst I do not doubt, and that the mass of the Shap
Granite came nearest to establishing a volcanic connexion with the

Rev. J. Clifton Ward—Geology of the Lake District. 57

surface I have hinted before; but we have no evidence that the
granitic roots were ever continuous, in this district, with volcanic
vents, though, having no deposits of the true Old Red age (Lower
Old Red) in the district, it would be unsafe positively to say that
there were not volcanic eruptions within this area in Old Red times,
or that the Shap Granite, for example, does not represent the root of
such an Old Red volcano. Of the three principal granitic centres
(see Sketch-Map, Plate II.) the Skiddaw granite occurs only in con-
nexion with the Skiddaw Slate, which is extensively metamorphosed
around, but the granite, where we now see it, is undoubtedly intrusive ;
the Eskdale Granite ranges for a distance of more than fourteen
miles through the Volcanic Series, and is surrounded by an extensive
zone of altered volcanic rocks; while the Shap Granite has altered
both volcanic rocks and the Coniston series. We have, in fact, in
these three masses, granite consolidated at various depths, or the
potential roots of volcanos exposed at different stages.

We shall return to consider the probable length of time repre-
sented by the effects of denudation during this period, when the
chronology of the district is discussed.

D.—Carboniferous Period.

Under the head of Carboniferous I include the beds in this distriet
formerly classified as Old Red, but which have been shown to be
but the Basement Conglomerates of the Carboniferous. These con-
glomerates are particularly well developed in Mell Fell (1760 ft.
high), and the range of hills extending eastwards from that mountain
to the foot of Ullswater (see Sketch-Map). Their general character
is that of a loose sandy matrix containing pebbles of all sizes and
occasional large and more angular blocks as much as three feet in
length. In parts the larger pebbles are absent, and the beds take
on the character of a coarse grit, always much false-bedded. The
peculiarity of this conglomerate consists, however, in the composition
of its pebbles. In Mell Fell they all seem to belong to sedimentary
rocks, and are composed of gritty and micaceous sandstone similar to
that so largely occurring in the Upper Silurians (Ludlows) of the
Kendal district. Although Mell Fell, rising to a height of 1760 ft.,
stands partly on Volcanic ground and partly on Skiddaw Slate, and
must have once extended much further to the west and even nearer
to the mountains formed of volcanic rocks, yet I have failed to detect
one undoubted instance in the conglomerate of this hill of a pebble
made from these rocks. At Pooley Bridge (foot of Ullswater) a
few cases occur of ash and trap pebbles, though those of sandstone
and grit largely predominate. At Hutton, however, two miles to the
east of Mell Fell, there are many pebbles of ash and trap and of
altered Skiddaw Slate, occurring with those of sandstone. It is
worthy of remark that the pebbles of trap at Hutton most resemble
the lava flows of Eycott Hill two or three miles to the north-west
(just N. of the railway line). In most cases the pebbles, and even
the large angular blocks, lie with their long axes in the direction of
the bedding. The pebbles are frequently rather elongated and often

58 = Rev. J. Clifton Ward—Geology of the Lake District.

flattened at the sides. In some few cases these flattened sides seem
to bear scratches like those left by glacial action. Such are the
chief facts with regard to this Basement Conglomerate, their possible
meaning will be considered directly.

The various beds of limestone, shale, and sandstone which go to
form the Carboniferous framework of the district come in above this
very irregularly distributed conglomerate. Some of the lower beds
of limestone contain quartz grains and small pebbles. Generally
speaking, there are very frequent alternations of limestones and sand-
stone, with occasional shale bands and thin coal-seams. The lime-
stones are often highly fossiliferous and largely made up of corals.

No volcanic ashes or lavas are found in connexion with the
Carboniferous rocks immediately surrounding the mountain district.
Lavas, basaltic in character, and often highly vesicular, occur beneath
the limestone all round the northern side of the framework, from
Cockermouth to Eycott Hill (see Sketch-Map), and could one not
prove by fairly conclusive evidence that they belong to the northern
extension of the Borrowdale Volcanic Series (on the N. side of the
anticlinal), they might readily be taken for Carboniferous basalts,
such as occur among the Carboniferous rocks in plenty upon the
other side of the border.

‘In one case only do igneous intrusions occur among Carboniferous
rocks immediately skirting the district, and that case is among the
basement conglomerates just east of Little Mell Fell. Four very
small bosses of basalt, wrapped round by hardened conglomerate,
and showing vesicular margins, may be seen close to Mell Fell farm.
That they are intrusions there can be no doubt, and microscopic
examination reveals their likeness to the basaltic dykes of the Pennine
range—a likeness which is also sufficiently evident in hand
specimens.

Physical Conditions indicated.—What was the condition of our
present mountain tract during the great Carboniferous period? Was
it wholly submerged after the elevation and denudation to which we
have already seen it subject, or was there always a nucleus of dry land
—an embryo of Cumbria—around which the Carboniferous deposits
were laid down? JI do not think this is a question that can ever be
decidedly answered. Long ago it was remarked by Prof. Sedgwick,
that ‘had our island been laid dry immediately after the Carboni-
ferous period, without any change of relative position among the
great formations, the Cumbrian mountains would have appeared as
a cluster of ancient rocks rising out of a great Carboniferous
plain.”* That the limestone beds extended much farther than
their present outcrops, cannot be doubted ; but whether the elevated
and denuded block of Silurian strata was ever completely smothered
under Carboniferous deposits, may fairly be questioned. At first
sight one would naturally suppose that the existence of thick
masses of Basement Conglomerate would clearly point to shore

1 Some such apparent ice-scratched stones from Mell Fell have been deposited in

the Jermyn Street Museum.
2 Trans. Geol. Soc., second series, vol. iv. p. 47.

Rev. J. Clifton Ward—Geology of the Lake District. 59

action; but while these beds do thus indicate shallow-water con-
ditions, and the presence of powerful currents around some land,
yet the material—in the case of Mell Fell,} etc.—is not derived
from the neighbouring Lower Silurians, but won from Upper
Silurian strata, which in the area around Mell Fell must have been
denuded away long since, for, be it remembered, these conglomerates
are laid down partly upon Volcanic rocks and partly on Skiddaw
Slate (see Map), and the latter could not have been exposed until
long ages after the Upper Silurians had been removed.

Since the Mell Fell Conglomerate must have had at one time a
much greater westerly extension, and since it now occurs up to a
height of 1760 ft., the Cumbrian nucleus must have been small,
though to what height it attained cannot be estimated. But what
could cause the peculiar composition of the conglomerate? Why
should it not be made up of stones worn from the neighbouring
land? This is a puzzle. Was there no such neighbouring land
formed of Lower Silurian rocks? Then why should there be
exposed Upper Silurian beds—whence the pebbles were worn—laid
bare at some point which one would infer, from the facts of denuda-
tion previously discussed, to be at a distance from the principal centre
of upheaval —farther from the axis of elevation and disturbance
(Plate II. Fig. 2). If Upper Silurian beds, forming the sides of
the anticlinal, were exposed, surely there is every probability that
some land existed nearer to the centre of upheaval. This anomalous
distribution of the material of the Conglomerate led me at one time
to speculate on the possibility of the Upper Silurian sandstone
pebbles having been drifted by current action “around the skirts of
a tract of high land, which, not rising in any lofty peaks, was
effectually protected from marine and subaerial denudation, at that
particular time, by an icy covering, leaving few or no rocks exposed
above its surface.” Even then it is hard to understand how ice-
borne scratched stones from the Lower Silurian high ground did not
freely mingle with the current-drifted pebbles of sandstone. Again,
how is the great development of conglomerate between Mell Fell
and Pooley Bridge to be accounted for? It would seem to thin away
very rapidly, both north and south, but especially to disappear
northwards. Can it have accumulated in an old valley ® or fiord, or
in a narrow channel? If in the former, how came it to be filled
with material foreign to the surrounding land? If in the latter—a
channel or strait—may not the Mell Fell deposits occupy the site of
the eastern end of a strait, which at that early period had been
sketched out as the future great valley separating the Skiddaw and
Blencathra group of mountains from the more southern mass of
land.* Jn this case one might understand the banking up of shingle

1 Mell Fell is a mountain of rounded form at the west end of the long patch of
Conglomerate marked on the Sketch-Map, Plate il.

* Survey Memoir, p. 76.

3 Prof. Phillips long ago suggested that the Old Red—so-called—may have been
accumulated in old valleys.—Geology of Yorkshire, vol. ii. p 14.

4 The east and west line of railway on the Map may be taken as the axis of this
now much-deepened channel.

60 Rev. J. Clifton Ward—Ceology of the Lake District.

against the eastern end of the channel, and much of it might have
been rolled well into or through the strait. The subsequent great
deepening and widening of this channel to form the present broad
valley may easily have removed all traces of the further westerly
extension of the conglomerate. (The base of the conglomerate at
Mell Fell stands at about the 1000 ft. level.) This might account
for the great local thickening of the conglomerate along an east and
west line, although of course its present distribution in the form of
a band, two miles wide and some five in length, is due partly to the
overlap of the limestone on the north and east, and in the south its
boundary appears to be mostly a faulted one.

I should be inclined to think that on the whole it was most likely
that the drift of Upper Silurian pebbles was from the south, round
the skirts of the land-nucleus by Shap and Bampton, until, the
current being deflected up the eastern end of the early Keswick Vale
strait, the material might be there banked up and prevented from
being carried further north, partly by the set westwards up channel,
and partly, perhaps, by more or less of a bank on the north side of
the mouth of the strait. Certain it is that north of the present line
of railway (between Keswick and Penrith) the conglomerate is
almost entirely absent.

My former supposition as to the land-nucleus being covered with an
ice-sheet I regard as very doubtful, but one cannot but be surprised at
the scarcity of pebbles derived from the Volcanic series, although, as
I have remarked, they are more numerous at some spots than others.
It may have been that cold conditions prevailed, as rather indicated
by the character of some of the stones in the conglomerate (the
apparently flattened and scratched stones, and the large and more
angular blocks) ; but if cold prevailed, and ice and snow were at
work upon the land, one might have expected to see more indications
of their action in the shore deposits. There is, however, another
fact which rather strongly militates against the idea of a glacial
climate having prevailed at this time. North of Carlisle, all along
and over the border, there occurs a great development of the
Calciferous Sandstone Series, consisting of many thousands of feet
of beds below the true Limestone Series of Cumberland, as
developed east of the Lake District. This great thickness, gritty
sandstones in the upper part, and thin limestones and shales with
occasional coal-seams in the lower part, must, one would suppose,
have been in course of deposition during the period of formation of
the so-called Basement Conglomerate, and, perhaps, long anterior to
the commencement of its formation. Now these beds show no signs
of glacial conditions, the lower part (thin limestones—with ordinary
Carboniferous Limestone fossils,—shales, and a few coals) indicates
similar conditions to those prevailing during the rest of the Carboni-
ferous—sometimes marine, sometimes fresh-water, sometimes terres-
trial—and the upper part consists mostly of thick gritty sandstones
containing thin calcareous bands, and occasional coal-seams with shale.
Hence we must suppose either that (1) previous to and during the for-
mation of the Mell Fell Conglomerate, rocks of a Carboniferous type

Rev. J. Clifton Ward—Geology of the Lake District. 61

were being deposited in the border-area under ordinary Carboniferous
climatal conditions; or (2) that the Conglomerate was deposited
when glacial conditions prevailed, and that a long period elapsed
between its formation and that of the true Limestone. Series, during
which period the Lower Carboniferous of the border-land and of
Scotland was formed under warmer conditions. Now against this
latter supposition is the tact that there are often indications of a true
conformable junction between the upper part of the basement-beds
and the overlying limestones; therefore, if there is no break
between the Basement Conglomerate and the Limestone series, and
no break between the Lower Carboniferous Calciferous Sandstone
series and the same Limestone series, the Conglomerate and the
Calciferous Sandstone series must be considered as more or less
contemporaneous formations, and the doubtful glacial indications
among the Conglomerate are negatived by the general Carboniferous
facies of the climate indicated among the Calciferous Sandstone
series.

All that has now been said about the origin and formation of the
Mell Fell Conglomerate inclines me to think that, at all events
during the early part of the Carboniferous Period, there must have
been a land-nucleus, a Cumbria in embryo; but whether this early
centre was or was not covered over during the later part of the Car-
boniferous Period by deposits of limestones, sandstones, and shales,
is one which must be left open. Certainly, the general absence from
the limestone series immediately surrounding the district of material
such as would have been derived from a tract of land formed of the
Lower Silurian rocks, is in favour of a complete submergence during
the latter half of the Carboniferous Period. Surely, if the present
outcrop of the limestones, etc., immediately around the Lake Dis-
trict, be not far removed from their termination along a shore-line,
one would expect, at any rate, to find water-worn débris won from
the hard rocks of the Volcanic Series. May we not, therefore, rather
believe that after the great elevation and denudation of the Silurians
of the district which took place in Old Red times proper, the
Mell Fell Conglomerate was formed at the mouth of an inlet or
strait running into or through the northern portion of the early land,
and that subsequently that early land was wholly or almost wholly
covered up by Carboniferous deposits as it once more slowly sank
beneath the waters of the sea. The close of the Carboniferous Period
was probably marked by an upward movement over the area of the
present Lake District, a movement during which the denuding
powers must have largely stripped off the outer Carboniferous skin,
laying the old Silurian nucleus bare, never again to be covered up
by unconformable measures. This elevatory movement was probably
coincident with that great east and west one forming the Pendle
Anticlinal.

(Zo be Continued.)

62 W. Swanston—Clays overlying Basalt, Lough Neagh.

I7.—On Svprosey Fossttirerous Priocenr Cnays OVERLYING
Basalt, NEAR THE SHORE oF LovucH NwaaGu.

By Witu1am Swanston, F.G.S., Belfast.

N the Geonocrcan Macazine for December, 1876, appeared a
short paper on certain clay beds near the south-eastern shores of
Lough Neagh. The paper is intended to supplement a more extended
communication entitled, “On the Age and Mode of Formation of
Lough Neagh,” read by the same author—Edward T. Hardman,
Hsq., F.C.S., H. M. Geol. Survey of Ireland—before the British
Association in 1874,’ and also read before the Royal Geological
Society of Ireland in January, 1875.2 The beds in question are
described “as a very extensive and important deposit, spreading
(under water and on shore) over an area that cannot be less
than 180 square miles in extent, and probably in some places 500
feet thick. ‘They repose on the basalt, and are covered by drift.
All the evidence we have points to their being of Pliocene age.”
The author, after giving a sketch of the Geology and Physical
Geography of the district, proceeds with a description of the clay
beds and associated lignites, and gives abstracts of numerous borings
ranging in depth from a few feet to 192 feet, which have been made
over this area. These borings disclosed a series of light-grey and
variously-coloured plastic clays, containing hard nodules of clay-
ironstone inclosing leaf and other plant-remains, also large quantities
of black lignite, occurring frequently in masses throughout the beds,
but sometimes bedded.

From the fact that no visible junction was known between the
clays and the rocks upon which they repose, much elaborate argument
was brought forward to prove that the former were of later date than
Miocene, and rested on the surrounding basalt of that age. Hitherto
no fossils except plant-remains had been found in them, and, in the
absence of more direct evidence, they were considered to be of
Pliocene date. The subsequent discovery* of fossil shells in a clay
band on the banks of the Crumlin River, and which clay band was
supposed to rest in this place directly on the basalt, seems to have
proved to the satisfaction of the author of the paper, and to Professor
Hull, F.R.S., who examined the section at the same time, that the
beds were undoubtedly of Pliocene age.

Owing to the extremely delicate structure of the shells, and the
friable nature of the bed in which they occur, it is most difficult to
obtain good specimens; those procured by Mr. Hardman were
admittedly in so bad preservation that Mr. W. H. Baily, F.G.S., to
whom they were submitted, would not do more than express an
opinion regarding them, than that they may possibly belong to a new
species. The author, however, seemed to be convinced that they
belonged to a species of Unio, not unlike Unio Solanderi of the
Upper Hocene of Hordwell Cliff, Hampshire; and is so far satisfied

1 British Assoc., Trans. of Sections, p. 79.

2 Journ. Royal Geol. Soc. of Ireland, vol. iv. part ili. new series, p. 170.
3 GEoLogicaL Magazine, December, 1876, Decade II. Vol. III. p. 556.

W. Swanston—Clays overlying Basalt, Lough Neagh. 63

regarding their character, and the age of the containing beds, that
he concludes his paper by remarking, in the absence of better speci-
mens, that, “In the meantime it is right to place the matter on
record—seeing that this place is, so far as I know of, the only
locality in the British Isles yielding lacustrine fauna of Pliocene date.”

During the past summer, in company with a few other amateurs,
I made frequent visits to the Crumlin River, and succeeded in pro-
curing better examples from the same clay beds than had apparently
been obtained before. As the opinion formed from the inspection of
the fossils on the spot, and from other independent evidence, is
entirely different from the conclusions arrived at by Mr. Hardman,
not only as regards the shells, but also respecting the age of the
beds; and as considerable importance has been attached to the
determination of the shells as indicative of a Pliocene lacustrine
fauna in Britain; I had a good series of them prepared and sent to
Dr. J. Gwyn Jeffreys, F.R.S., for his opinion regarding them.
That gentleman, with his usual kindness, states, ‘“ I can come to no
other conclusion than that they are certainly not any species of Unio,
but belong to our common mussel (Mytilus edulis).* which occurs in
all the newer tertiaries. The structure, composition and colour
agree (See British Conchology, vol. 1. p. 103.)”

A quantity of the material from the same shell-bed was submitted
to Joseph Wright, Hsq., F.G.S., of Belfast, for microscopic exami-
nation. Mr. Wright reported that the only microzoa that he was
able to detect in the clay were a few foraminifera, referable to four
species, namely :—

Globigerina bulloides, D’Orb.—very rare.
Textularia variabilis, Will.—small, and very rare.
Discorbina globularis, D’Orb.—rare.

Nonionina depressula, W. and J.—common.

The foraminifera above enumerated are all found living and in
abundance on our coasts, and are also species which are of frequent
occurrence in our Drift-beds; the last mentioned, especially, is a
very common Boulder-clay form.

The coarse material left after the examination for microzoa, consists
for the most part of small round pieces of clay, which were too hard
to dissolve in the washing. There were also a good many fragments
of lignite, and one piece of silicified wood about an inch in length.

An examination of the stratigraphical position of these fossiliferous
clay-beds proves that they repose upon a deposit of true Boulder-
clay, the position of which is accurately represented in the section
illustrating Mr. Hardman’s paper,’ and is there described as follows :
““m. Coarse gravelly clay—pebbles of quartz and basalt—resting in
pockets and erosions of basalt = 3 feet.” This coarse gravelly clay
is of a dark brown colour, extremely compact, and full of large

' This confirms the opinion expressed by the Editor of the Grou. Mae., that the
fossils shown him by Mr. Hardman indicate rather a Mytilus or Modiola-like shell
than a Unio.—See Grou. Mac., December, 1876, foot-note, p. 557.

2 Gxou. Mac. 1876, Decade II. Vol. III. Pl. XXII. Fig. 1; and Journ. Royal
Geol. Soc. of Ireland, vol. iv. part iii. new series, pl. xii. fig. 1, ete.

64 W. Swanston—Clays overlying Basalt, Lough Neagh.

stones and pebbles; so compact is it, that it is with difficulty the
larger stones can be removed, but when taken out they almost all
exhibit the well-known form of glacial pebbles, and very many of
them retain quite distinctly the characteristic scratching and polishing
due to ice action. The miscellaneous character of the stones and
pebbles is also worthy of note. The following were noticed,
beginning with the most numerous and proceeding in the order of
their relative abundance :—Basalt (local), chalk and flint (Antrim),
sandstone and clay nodules (New Red Marls ?), quartz, mica-schist,
granite (red), etc. There is also a great abundance of lignite, in
pieces from several inches in length to mere particles, scattered
irregularly through the bed, and I was fortunate enough to find a
piece of grey siliceous sandstone containing plant-remains, principally
dicotyledonous leaves resembling those of the beech and willow, and
closely agreeing in character with the siliceous nodules which occur
in the plastic clay of Lough Neagh.

The only conclusion that can be drawn from the foregoing is,—
that the beds in question containing Mytilus edulis and Foraminifera
are of marine, or, at least, of brackish-water origin. The common
mussel is at present found living from high-water to a few fathoms
in depth, and it is also found in tidal rivers, but never entirely out of
reach of the sea. Judging from the appearance of the fossils in the
clays, I am of the opinion that the animals lived and died where we
now find their remains; or that they have, at least, suffered very
little disturbance. In many of them the valves are united and the
epidermis still preserved. Foraminifera are essentially marine
organisms; a few only are known to inhabit brackish water. The
species detected in the clays in question indicate a depth of at least
a few fathoms, and may be found in almost every haul of the dredge
on suitable ground around our coast at moderate depths.

The fact that the fossiliferous deposit reposes upon true Boulder-
clay containing well-marked glacial pebbles, at once proves that it is
not of Pliocene age, but either a Glacial or a Post-Glacial deposit. The
settling of this question would require further investigation than has
yet been given to the subject. The error into which Mr. Hardman
seems to have fallen, was, in hastily concluding that the Crumlin
River beds were identical with the beds of white clay, lignite, etc.,
which occur along the southern shores of Lough Neagh, whereas
the latter beds do not seem to extend to within half a mile of the spot
where the fossils occur, nor do they in any way resemble them in
lithological character.

What then is the age of the Lough Neagh clays and their associated
lignites, which are estimated as covering an area of 180 square
miles and to be in some places probably 500 feet thick ?

Granted that they may repose upon the basalts—they may be of
any age between that to which the lower sheets of the Miocene beds
of the neighbourhood belong, and the clays of the Glacial epoch with
which the upper beds are undoubtedly associated. In all probability
they span the entire period, and are in part contemporaneous with
the lacustrine iron-ores, beauxite, and lithomarge of the Antrim

G. H. Kinahan—The Silurian Rocks of Ireland. 65

Hills, which also rest on the same basalts, and contain plant-remains
similar in general character to those in the Lough Neagh clays. In
the absence, however, of full lists of the flora of both beds, nothing
more definite can at present be stated regarding their identity.
Should subsequent researches prove them to be the same, it may
safely be inferred, that one reason why the Lough Neagh beds still
retain their clayey character is owing to the simple fact that the
later outflows of Miocene basalt did not reach them, and convert
- them into iron-ores, etc., similar to those so largely developed to the
east and north of County Antrim.

Although not strictly connected with the subject, I may be allowed
to refer to the much-vexed question of the origin of the silicified
wood of Lough Neagh. Dr. Barton was most probably right in his
statement, made in 1751,! that the celebrated fossil-wood was found
in association with the black lignites. His descriptions of over a
hundred specimens—many of them figured in his work, most of
which were part wood and part stone—cannot be ignored; and
although only a few of these were obtained direct from what seemed
to be the true Lough Neagh beds, yet many were so intimately
associated with the lignite, the origin of which is not disputed, that
considerable weight still attaches to his quaint descriptions.

I have in my possession specimens, portions of which still retain
their woody character, in no way different from the more solid pieces
of lignite. One piece was found intimately associated with the
lignite and white-clay beds; and in the same place was also found
one of the numerous ironstone nodules, derived from the same clays,
which contained a piece of silicified wood and other plant-remains.
Scattered through the Boulder-clays of the district for miles around
may be found pieces of the lignite, which testify to the vast amount
of denudation which the older beds have suffered. Associated with
them, but much less abundant, may be picked up the silicified speci-
mens, the angles of which are quite sharp, and showing no evidence
of distant origin.

IjJ.—TuHe Srnurtan Rocks or IRELAND AND THEIR RELATION TO
THE OLp RED SANDSTONE.’

By G. H. Kinauan, M.R.1.A., ete.

A QUARTER of a century ago it was a disputed question whether
the Old Red Sandstone was a separate formation or not.

About that time, or a few years later, the subject engaged the

attention of the Geological Section of the British Association.

When I joined the Geological Survey, Sir R. Griffith had mapped
the older rocks in West Cork as of Silurian* age, while Jukes was
inclined to class them as Old Red Sandstone. Plant-remains
were found in rocks of the same series in the Killarney district by
Du Noyer in the summer of 1855, and near Valencia by myself in

' Dr. Barton’s Lectures on Natural Philosophy ; Lecture 3, Metamorphoses, p. 51.

2 Read Nov. 18th, 1878, before the Royal Geological Society of Ireland.

°'In this paper Jukes’ nomenclature is followed; the formations. being called
Silurian and Cambro-Silurian instead of Upper and Lower.

DECADE II.—VOL. VI.—NO. II. ; 5)

66 G. H. Kinahan—The Silurian Rocks of Ireland.

the following year. When the plants were pronounced by Salter to
be of Carboniferous types,’ Jukes considered the question to be finally
settled; Griffith however said, “ Wait till the Dingle district is
examined, and you will find, that although the plants are of
Carboniferous types, the rocks are Silurians.”

When the Dingle peninsula was examined by Du Noyer, Foot,
and Wynne, it was found that while there was a great unconform-
ability between the lower and upper divisions of the strata called .
Old Red Sandstone, a complete conformability extended from the
lower division downwards into fossiliferous Silurians, and from the
upper division upwards into the Carboniferous Limestone and the
Coal-measures. In the lower division, however, no fossils could be
found,’ and these strata were called “Dingle beds,’—a title which
involved no assumption as to their age. To this lower division,
according to both Griffith and Jukes, the above-mentioned rocks near
Killarney, near Valencia, and in West Cork, belong

Subsequently these rocks were examined conjointly by Griffith,
Murchison, and Jukes; and some of the party visited not only Cork
and Kerry, but also Galway and Mayo. After this exploration
Murchison was inclined to side with Griffith; but the plants were a
stumbling-block. Furthermore the late Mr. John Kelly showed
that the Dingle beds have the same stratigraphical position as the
rocks mapped as Old Red Sandstone in the Curlew Mountains (cos.
Sligo and Roscommon) and about Fintona (cos. Fermanagh and
Tyrone) ; while the Curlew and Fintona rocks are lithologically
similar to the Old Red Sandstone of the Commeragh, Galtee, and
Knockmeeldown Mountains; the classification of the just-mentioned
Cork and Kerry rocks therefore was left an open question until the
rocks in Mayo, Roscommon, Sligo, Fermanagh, and Tyrone,
suggested by Griffith to be of the same age as the Dingle beds, were
examined.

The question remained in abeyance while the officers of the
Geological Survey were examining the rocks of North-east Munster ;
until about 1864, when Foot declared that he suspected the rocks of
the Curlew Mountains to be “Dingle Beds.” The following year
Jukes examined those rocks for himself, and subsequently announced
his belief that the lower portion of the so-styled Old Red Sandstone,
near Ballaghaderreen, to the west of the Curlews, was probably of
the same age as the “ Dingle Beds,” as it seemed to lie conformably
on similar fossiliferous Silurians, as previously stated by Kelly,
while it was similarly capped unconformably by what all would
regard as true Old Red Sandstone (Carboniferous). Still it was
premature to say what its age might be until it and all the tracts
mentioned by Griffith had been systematically examined.

At this time I began the work in West Galway and Mayo, and,
after seven years’ careful examination, I came to the conclusion that

1 Mr. W. H. Baily has recently examined the plants from these localities in the
Glengariff Grits.

* I have since learned from Mr. O’ Kelly that fossils, like plant-stems, were subse-
quently found in the Dingle beds.

G. H. Kinahan—The Silurian Rocks of Ireland. 67

the oldest rocks there are Cambrians. These are partially covered,
as it would seem conformably, by Cambro-Silurians. Resting un-
conformably on both of these are newer rocks, some of which years
ago were proved by their fossils to be Silurians, but others for a
time were considered to be Old Red Sandstone. All of these are
capped unconformably by acknowledged (Carboniferous) Old Red
Sandstone.

The rocks extending from Loughs Corrib and Mask by Maum to
the Atlantic on the south of Killary Harbour had for years been
known to be Silurians; but the rocks between Toormakeady on
Lough Mask and Mweelrea north of the mouth of Killary Harbour,
as also an isolated tract further north near Louisburgh, were at one
time supposed, on account of their lithological character, to be Old
Red Sandstone. Griffith, however, found Silurian fossils at Toor-
makeady, while subsequently I also found them in somewhat similar
rocks in the Mweelrea Mountains. It was either during the ex-
ploration in which Griffith found the fossils at Tocrmakeady, or on
a subsequent occasion, that he came to the conclusion that all
were of Silurian age; the Louisburgh beds being the newest, and
the representatives of a portion of the Dingle Beds.

To the northward of Toormakeady, in the neighbourhood of
Croaghmoyle, there is a large tract of rocks, that Jukes, Symes, and
myself were convinced to be of about the same age as the Toor-
makeady conglomerates, although it was marked on Griffith’s map
as Old Red Sandstone. This led me to seek for an explanation, and
when my maps and sections were so far complete as to be intelligible,
they were carefully examined and considered by Griffith. Subse-
quently I waited on him, by appointment, and in our conversation
I learned that the marking of that district, as also of others, on his
map, as Old Red Sandstone, was done in compliance rather with
received opinions, than with his own conviction. That. in the so-
called “ Old Red Formation ” in Ireland, there was a marked uncon-
formability,—part of it extending downwards conformably into the
Silurian, and part of it upwards into the overlying Carboniferous
rocks. That the rocks of West Cork, and adjoining portions of
Kerry, of Dingle, of Toormakeady, of Mweelrea, of Louisburgh, of
Croaghmoyle, of the Curlew and Fintona Mountains, he believed to
be of nearly similar Silurian age. Those in the West Cork and
Kerry, Dingle, Toormakeady, Mweelrea and Louisburgh, he had had
time to examine properly, and had mapped them as Silurians,
while the rest he had not so carefully examined. But in deference
to Portlock’s authority, and also because they were lithologically
more or less similar to the Old Red Sandstone (Carboniferous) of
the Knockmeeldown, the Galtee, and Commeragh Mountains, he
left them as Old Red Sandstone. At the same time, he pointed
out—‘ The Toormakeady Conglomerates are also similar, yet I found
Silurian fossils in them.”! In this conversation he also stated:

1 Strictly, these fossils are not in the Conglomerates, but in the beds de/ow them.
As yet, in no place above the Toormakeady Conglomerates have fossils been found,

except, perhaps, in the green tuff at Mount Partry—its position, however, is
uncertain,

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G. H. Kinahan—The Silurian Rocks of Ireland. 69

«None of my work is guesswork; all my conclusions are from
personal examination. I cannot now work out these rocks, and my
map must remain as itis; the Geological Survey must complete the
examination,” or words to this effect.

After this interview, I paid more special attention to this subject,"
and an epitome of my researches (except in respect to the equiva-
lents of the Dingle Beds) appears in my recently-published “ Manual
of the Geology of Ireland.” In that book I only hint at the age of
the equivalent of the “Dingle beds,” because at the time it was
being written, more than a year ago, I was aware some of my
colleagues were engaged working out the disputed rocks of the
Curlew and Fintona Mountains, and I supposed they would have
given attention to the question as to their age. It was not till the
book was in print.that I learned that the dispute had been ignored ;
although Mr. Berdoe-Wikinson’s work proved that Jukes’ and
Foot’s surmises in respect to the classification of the rocks of the
Curlew Mountains were correct. Then, when I felt at liberty to
express my opinion, it was too late to do so, except in the preface of
the book. ~

The accompanying sections (Figs. 1 and 2) show the relations of
the lower and upper divisions of the Old Red Sandstone to the
Silurian and to the Carboniferous. In one table are given the
sections of the Old Red Sandstone of Silurian age, and in the other
most of the type sections of the true or Carboniferous Old Red
Sandstone.

In the Ballycastle Coal-field, to the north-east of Antrim, Old
Red Sandstone occurs interstratified in the Coal-bearing Calp.
This is also the case near Draperstown, county Derry, where the
Calp is very similar to that of Antrim, except that no workable
coals have been found there; while in Armagh the Old Red Sandstone
is interstratified with the Burren limestone. These three districts
are grouped together, as in the rocks associated with the Old Red
Sandstone are found fish-remains, more or less similar among
themselves, and also to the fish-remains met with at Burdie House,
Scotland.

To the north of the county of Dublin conglomerates occur close
under the base of the Coal-measures, while in the rest of Dublin,
Kildare, and Carlow, small patches of red conglomerate have been
discovered, seemingly on different geological horizons. These appear
to be only shore-beds, margining ancient lands; but in the county of
Kilkenny, to the north-east of Thomastown, the Old Red Sandstone
comes in as a distinct subdivision at the base of the Carboniferous
Limestone formation, and increases in thickness as it is followed
to the south-west. In this place, as also in the country between
Knocktopher and Waterford, and in Slievenaman, the rocks are of
the ordinary Central Ireland type (red and yellow shales, clay-
rocks, sandstones, and conglomerates; the pebbles in the conglo-

' Foot and myself, in about 1864, wrote a paper to show that the Munster Old

Red Sandstone was in part Silurian and in part Carboniferous; the paper, however,
was not published, as Jukes considered it to be premature.

70 G. H. Kinahan—The Silurian Rocks of Ireland.

merates are usually small, and of white quartz, with some of red
jasper) ; but south-west of the valley of the Suir, in the Commeragh,
Galtee, and Knockmeeldown ranges, the type changes, the rocks
being massive purplish conglomerates, interstratified with slaty grits
or gritty slates. ‘The pebbles in these conglomerates are often very
large, while the maximum thickness of the subdivision seems to be
considerable. The upper portion of the subdivision (called Upper
Old Red Sandstone on the Geological Survey Maps, and Yellow
Sandstone by Griffith), however, is still very like the Central Ireland
type, except that the conglomerates are few or altogether absent.
North of the Galtees, in Slieve Phelim, Kimalta, Slieve Arra, Slieve
Bernagh, and Slieve Aughta (counties Tipperary, Limerick, Clare,
and Galway), the rocks are for the most part of the Central Ireland
type, although in places there are massive conglomerates; while
in Slieve Bloom (King’s and Queen’s counties), the rocks are more
like the Commeragh type.

South of the valley, between Dungarvan and Dingle Bay, there is
a very complete change in all the rocks; from the base of the Coal-
measures downwards, they assume peculiar types. ‘The Cork type
of the Old Red Sandstone has below massive, although generally
cleaved, purplish and dark grey grits and slates (Old Red Sandstone) ;
and above, when typical, yellow and greenish grits and shales,
over variagated green, red, liver-coloured, and rarely purple slates
(Upper Old Red or Yellow Sandstone).

The Old Red Sandstone is very constant in its characters, but the
Yellow Sandstone changes considerably in the east and west direction,
To the eastward, where it is overlaid by the Lower Limestone Shale
and limestones, the Yellow Sandstone partakes in part of the Central
Ireland Type, and contains more or less red beds; but towards the
westward, where it is overlaid by the Carboniferous Slate, the red
rocks die out, and the sandstones are replaced by grits. The greatest
and most sudden change that I have observed is in the neighbourhood
of the bay called Kenmare River. On the north and south sides of
this bay, in the neighbourhoods of Sneem and Ardgroom, are tracts
of Carboniferous Slate lying on Yellow Sandstone. ‘Those to the
eastward are cut off by faults with downthrows to the west, and
further east, at Kenmare, are limestones and the Lower Limestone
Shale resting on bright red rocks, the latter lying conformably on
the Old Red Sandstone. These bright red rocks are evidently on
the same geological horizon as the Yellow Sandstone to the westward
of them, although so totally different. The Old Red Sandstone
extends conformably downwards into the Glengariff Grits, which, as
previously stated, are considered both by Griffith and Jukes to be the
equivalents of the Dingle Beds, and by the first to belong to the
Silurian formation.

On the north of Dingle Bay the Old Red Sandstone belonging: to
the Carboniferous is nearly similar to that in Cork, but in places it
contains conglomerates. It has a great thickness (over 5000 feet),
and its upper portion is somewhat like the Yellow Sandstone of Cork,
but contains more red beds. Farther east, in the county Limerick,

G. H. Kinahan—The Silurian Rocks of Ireland. vo

this Old Red Sandstone is like the Yellow Sandstone of North Kerry,
but it is apparently much thinner; while still farther east are the
already-mentioned rocks of Slieve Phelim. In Connaught, except in
Slieve Aughta, south-east Galway, also in the north-west of Leinster,
the Old Red Sandstone is evidently a shore formation at different
horizons in the Limestones; but in Fermanagh and Tyrone it seems
to be at the base of the Carboniferous. The rocks are more or less
similar to the Central Ireland type.

We have now given a short résumé of the Old Red Sandstone
adjuncts of the Carboniferous, and may now proceed to explain the
sections of the Silurian portion of the Old Red Sandstone. We have
mentioned that the Dingle Beds on the north of Dingle Bay, which
are capped unconformably by Carboniferous Old Red Sandstone,
are considered by such competent authorities as both Griffith and
Jukes to be the equivalents of the Glengariff Grits, which in the
Killarney district and in West Cork extend conformably upwards
into the Carboniferous rocks. The authority of these geologists is
scarcely to be questioned; we therefore take it as proved, and
proceed to the next section.

At Toormakeady, county Mayo, are conglomerates lithologically
somewhat similar to the Commeragh Old Red Conglomerates, but in
the beds at the base of the Toormakeady Conglomerates are Silurian
fossils; and further westward, in the very similar rocks of the
Mweelrea Mountains, Silurian fossils also occur. On these rocks the
Carboniferous strata lie unconformably.

North of the Mweelrea rocks are the Louisburgh Beds. In them no
typical Silurian fossils have been found, but lithologically they are
similar, in part to the Mweelrea pebbly grits, and in part to the Salrock
slates; the latter being the highest beds in the Galway Silurians.

To the north of the Toormakeady Conglomerates, east and north-
east of Clew Bay, are the Croaghmoyle Conglomerates. No typical
fossil have been found in them, but lithologically they are similar
to the Toormakeady rocks, also to those to the north-east, in the
Curlew Mountains; while they are capped unconformably by the
Carboniferous rocks.

The Curlew Mountain rocks are lithologically more or less similar
to those already mentioned. They extend downwards conformably
into Silurians, having fossils similar to those in the Silurians that,
in the county Kerry, underlie the Dingle beds; while upwards,
similar to the Kerry rocks, they are cut off and are capped uncon-
formably by the Carboniferous beds.

The rocks of the Fintona district are lithologically similar to those
of the Curlew Mountains, and are also capped unconformably by the
Carboniferous series. Of these Portlock states that in one place they
seem to lie conformably on the Cambro-Silurians. Griffith, however,
in conversation, stated that he suspected there was a sequence of
rocks somewhat similar to that near Ballaghaderreen, and that
Silurian fossils occurred in them similar to those at Toormakeady.
This supposition rests solely upon information which I have not
had an opportunity of working out.

72 G. H. Kinahan—The Silurian Rocks of Ireland.

Let it be clearly understood that, in no place in the above-discussed
rocks—of Cork, Dingle, Toormakeady, Louisburgh, Croaghmoyle,
Curlew Mountains, or the Fintona districts, have fossils been found
to prove distinctly that they are of Silurian age. The only indirect
evidence of that kind which can be produced being the fossils in the
Mweelrea beds; which may perhaps be on the same geological horizon
as the unfossiliferous rocks of Toormakeady, Louisburgh, Croagh-
moyle, and the Curlew and Fintona districts; while on the other
hand there are plants of Carboniferous types found in the Dingle and
Glengariff beds. Therefore it is no doubt possible, that (if there is
such a distinct formation as the Old Red Sandstone) these rocks may
belong to it. It is evident, however, that they all are of one and
the same age,' and it is the height of absurdity to class’ the Dingle
beds,’ with plants of a Carboniferous type, among the Silurians,
while the Curlew and Fintona rocks are put in a separate formation
and called Old Red Sandstone. That the Old Red Sandstone forma-
tion is the Sick Man of Geology seems proved ; as its supporters are
reduced to suggesting the existence of extraordinary unconform-
abilities to allow of its existence ; or to distorting the different rock
sections and representing the rocks, not as they really are, but as
they ought to be in the opinion of these different observers. The
title of Old Red Sandstone to be ranked as a distinct formation
seems to depend on the meaning given to the expression a Geologicat
Formation. The generally accepted meaning seems to be—a series
of strata with a more or less well-defined beginning and ending, its
distinctness being marked paleontologically and (almost always)
stratigraphically ;—these characteristics the Old Red Sandstone does
not seem to possess.

In South-west Ireland, indeed, there is a vast continuous unbroken
series of reddish, purplish, and greenish arenaceous and argillaceous
rocks, over 20,000 feet thick, that extend upward from the typical
marine Silurians of Dingle to the typical marine Carboniferous of
Cork. These must represent the time during which the Old Red
Sandstone accumulated, in Ireland or elsewhere. In this series,
except in the upper 1000 or 2000 feet, (Yellow Sandstone) fossils
occur at rare intervals, and are principally plants allied to Carbon-
iferous types. In the Yellow Sandstone terrestrial fossils are
much more common; while in the lower beds of the overlying
Carboniferous Slate, strata containing terrestrial and marine fossils
alternate with each other.2 In South-west Ireland the rocks,

1 In the Dingle Silurians, in the Toormakeady conglomerates, in the Mweelrea
beds, in the Curlew rocks, and in the Fintona rocks, there are peculiar and
characteristic felstones and traps that seem to be of the same age.

2 As the Continental and American geologists have found plants like Carboniferous
in the Silurians, this evidence against the Silurian age of the Dingle and Glengariff
beds may be considered in part at least as done away with.

3 It has been suggested that there is an unconformable overlap of the Carbon-
iferous Slate on the Yellow Sandstone. This, however, is perfectly impossible, for
such an overlap could not exist without, in places, adding rapidly to the thickness of
the Carboniferous Slate, which nowhere happens; furthermore, the Carboniferous

Slate everywhere graduates downwards into the Yellow Sandstone, and the latter
into the Old Red of the Cork type.

~G. H. Kinahan—The Silurian Rocks of Ireland. 73

including the Yellow Sandstone, the Old Red, and the Glengariff
Grits, might possibly be called a formation ; if it were not that north
of Dingle Bay there is a great break in the sequence, the upper
5000 or 6000 feet, only, extending continuously into the Carbon-
iferous rocks. Stratigraphically and paleontologically this upper
portion belongs to the Carboniferous formation; while the lower
portion, over 10,000 feet in thickness, stratigraphically belongs to
the Silurians, but paleeontologically to the Carboniferous.

It has been suggested that the Old Red Sandstone (Carboniferous)
of the Dingle promontory (2, Fig. 2) cannot be the same as the
Old Red Sandstone (Carboniferous) of West Cork (1, Fig. 2), as
such a change in their positions could not take place in so small a
distance as the width of Dingle Bay. This suggestion, however, is
not borne out by facts, as extending along Dingle Bay there is a
great fault with a downthrow to the northward, which, to the
eastward of the bay, brings down the Coal-measures against the
Old Red of the Cork type, and cuts out a thickness of strata more
than sufficient to account for a greater change. Hlsewhere in
Ireland, as shown in the sections (Fig. 2), rocks having the Old Red
Sandstone characteristics, and, like it, graduating into the Lower
Limestone Shale, occur on different geological horizons.’

Nore in Press.—Since this paper was read, Prof. Hull, in the
Gerotoeicat Magazine, November Ist, 1878, published ‘‘ A Possible
Explanation of the North Devon Section.” Unfortunately for the
suggestions contained in it, there are various errors in reference
to the Irish rocks.

All the Irish geologists who have studied the Dingle and Glengariff
Grits came to one conclusion about them, that is, that they belong to
one group, and Prof. Hull has now arrived at the same conclusion.
If this is allowed, we have a vast continuous series of rocks which
represents ALL THE TIME intervening between the accumulation of the
typical Silurian of Dingle and the typical Carboniferous of Cork. This
necessitates some portion of this series of rocks being the equivalent
of the Old Red Sandstone or the Devonian rocks. Those that are
acquainted with the Old Red Sandstone (Griffith and Jukes) in the
country south of Dingle Bay are aware that it contains fossil plants
said by Baily to be also found at Kiltorcan, county Kilkenny, while
farther southward, near Toe Head, county Cork, and in the county
Waterford, the Kiltorcan fossils are well represented. The rocks
containing these fossils lie conformably on the Glengariff Grits,
while the latter also contain plants said by Baily to be of the same
type as some of the fossils of Kiltorcan. Thus these Old Red Rocks,
also the Glengariff Grits, according to Prof. Hull’s reasoning, should
be of the same age as the Kiltorcan beds, and consequently Old Red
Sandstone. Yet this authority states that the Glengariff Grits are
certainly Silurians.

An unconformability in the Cork rocks between the Carboniferous

' Its uncertain position induced the Rev. Dr. Haughton, in the year 1863, to
designate it a ‘“‘ Phantom formation.’’—Journal Geol. Soc. Dublin, 1863.

74 W. A, £. Ua terccent Geology of Cornwall.

Slate and the Glengariff Grits is an impossibility, on account of the
universal parallelism between the strike of the beds in the first with
those in the underlying Yellow Sandstone, Old Red Sandstone, and
Glengariff Grits. The question of the age of the Glengariff and
Dingle Beds, so far as their relative positions are concerned, remains
nearly as undecided as in Jukes’s time. Jukes found that strati-
graphically these rocks were allied to the Silurians, but Salter insisted
that the fossils were Carboniferous, and that the rocks should be
similarly classed; at the present time Baily reiterates Salter’s
opinion.

Are the Dingle or Glengariff Beds Silurian or Old Red Sandstone ?
—The answer to this question depends on the relative values of,—
stratigraphical position and fossil evidence. If the first is most
important, then the rocks belong to the Silurian; but if the second,
then they are of Old Red Sandstone age, a group of rocks that form
passage-beds from the Silurian into the Carboniferous. It seems
remarkable that Prof. Hull should class the Dingle and Glengariff
Beds as Silurians, while he has mapped the rocks of the Curlew
Mountains, which are siratigraphically similar, as Old Red Sandstone.

It is unnecessary to enter into Devonian geology further than to
point out that Jukes’ fault has not been disproved, while the Irish
geologists who have been in Devon believe in its existence; also the
fossil evidence, so much relied on, seems not to be of much geological
value, inasmuch as the species have been collected without that
care and precision which can alone render them of use in marking
horizons. The localities assigned to the specimens, in the collections
chiefly relied upon, are such as Torquay, Chudleigh, etc. ; where two,
if not more, distinct groups of rocks are developed.

TV.—Hisrorican GEoLoGY oF CoRNWALL.
By W. A. E. Ussuer, F.G.S.
(Continued from the January Number, p. 36.)
(PLATE III.)

Part 4,—St. Michael’s Mount.

HE best description of St. Michael’s Mount, as it now exists, that I

can find, is by Mr. Wm. Pengelly, F.R.S.,' as follows: “The Mount
is an isulated mass of granite measuring about five furlongs in peri-
meterat its base. At high-water it plunges abruptly into the sea, except
on the northern or landward side, where the granite comes in contact
with the slate, into which it sends veins and dykes, as may be well
seen on each side of the harbour. Here there is a small plain
occupied by a village, adjacent to which is the harbour, built in
1726-7, and, as Mr. Johns, the harbour-master, has been good enough
to write me, capable of receiving ships of 500 tons burthen.” Its
situation is described as follows: ‘“‘The distance between the nearest
point of Marazion Cliff and spring-tide high-water mark on the
Mount is 1680 feet. A tidal isthmus (Hogus) of highly inclined
Devonian slate and associated rocks, in most cases covered with a

1 Journ. Roy. Inst, Corn. for 1878, p. 12.

W. A. E. Ussher—Historical Geology of Cornwall. 79

thin layer of gravel or sand, is at spring-tide high-water, in still
weather, 12 feet below ; and at low-water 6 feet above the sea-level.
This ridge is dry in fine weather from four to five hours every tide,
but occasionally during storms and neap tides it is not passable for two
or three days.”

“« St. Michael’s Mount! was named in Cornish, as Carew informs us
‘Caraclowse in Cowse, in English, the hoare rock in the wood:
which now is at every flood encompassed by the sea, and yet at
some low ebbs, roots of mighty trees are descried in the sands
about it.” 3. 6. Florence of Worcester expressly asserts that it
was formerly five or six miles from the sea and enclosed with a very
thick wood; and therefore called in British, Carrey lug en Kug,
“Le Hore Rok in the wodd.’ ”

The above is said to have been corrected by Florence of Worcester
in a letter to William of Worcester, 1478.?

Mr. Peacock * thinks that we need not go back further than the
time of the Domesday Book for the origin of the Cornish name of
St. Michael’s Mount, “ Carreg coedh yn clos,” i.e. ‘“‘ Rock of the wood
in the enclosure,” as William Camden (1550-1623) “proves that
the Cornish language had not become quite extinct even so lately as
his time.”

“Dr. Gibson,‘ the editor of Camden’s Britannia, says that St.
Michael’s Mount is called Careg Cowse in Clowse. Careg is, doubt-
less, the origin of the English word crag; and cowse is said to mean
cana, white; and clowse obviously means a close or enclosure.”

“Mr. Metivier says that St. Michael’s Mount was ‘Carreg Coed
yn Clos,’ rock of the wood in the enclosure.”

Mr. Peacock*® says that “the earliest period at which the Saxon
name Mychel Stop, or Michael’s Step, could have been given to the
Mount, was after the landing of Hengist and Horsa in 449.”

The Mount received its present name in 1085, from the Monastery
of St. Michael, of which it then became an appanage ; before that
time it was called Dinsol.°

‘In Milner’s Gallery of Nature, p. 387, it is stated that in the
time of Edward the Confessor, 1044, the rock of St. Michael’s
Mount was the site of a monastery described as being near the sea,
‘juxta mare’ (interpreted by Barham, ‘by the sea’).”

“The ancient designation,” says Mr. Pengelly, ‘‘betokens a change
in the geography of the district—a change, not only within the human
period, but since Cornwall was occupied by a people who spoke the
language which was tardily supplanted by the Anglo-Saxon.”

Mr. Pengelly refers the name “ Hogus,” now applied to the rocky
ledge between Marazion and the Mount, to an old Scandinavian
derivation, meaning “a rock in or near a wood adjacent to water,
and used for sacrificial purposes.”

Mr. Peacock’ takes exception to this determination on the ground
that Hogus (in Guernsey hougue, French hogue, neo-Latin hoga)

pyle Ren Gr Sel COrnenyOly ii pal 34.

? Pengelly on Submerged Forests in Torbay. 3 Peacock, p. 110.
4 Ibid. p. 89. PS neelite 6 Ibid. p. 112. 7 Peacock, p. 107.

76 W. A. HE. Ussher—Historical Geology of Cornwall.

sometimes denotes a quarriable knoll, of which he gives examples.
From this Mr. Peacock infers that the term Hogus only carries us
to the middle ages, and not to the time of Diodorus.

Mr. Peacock! quotes Diodorus Siculus (about 44 B.c.) as follows:
“They who inhabit the promontory Belerium are exceedingly
hospitable, and on account of the merchants being their guests are
civilized by custom in their mode of life. They procure the tin by
ingeniously working the earth producing it, which, being rocky, has
earthy veins, in which working a passage and melting (the ore) they
extract [the tin]. Forging it into masses like Astragals, they carry it
into an Island situate before Britain, called Ictis. For the middle
space being dried by the ebb they carry the tin into this (island) in
abundance in carts. (But a certain peculiar thing happens con-
cerning the neighbouring islands lying in the middle (weraév)
between Europe and Britain, for at full sea they appear to be
islands, but by the reciprocation of the ebb of the sea, and a large
space being dried, they appear peninsulas.) Hence the merchants
buy [the tin] from the inhabitants and export it into Gaul.”

Taking wetaév to mean “in the middle,’ Mr. Peacock considers
that the Northern Channel Islands were alluded to in the above
passages, being of opinion that the Northern Channel Islands were
then only insulated at high-water, and that they are called neigh-
bouring islands to distinguish them from the more remote islands in
the Bay of Biscay.

Mr. Pengelly* observes that, according to Leland, St. Michael’s
Mount in 1533 was no larger than at present; that William of
Worcester’s estimation of its distance from the mainland differs but
little from its present site: that “Bishop Lacy’s encouragement to
the Faithful in 1425 to complete a causeway between Marazion and
the Mount, for the protection of life and shipping, denotes that the
exposure was as great as in our day; and as the Confessor’s Charter
in 1044 describes the Mount as ‘juxta mare,’ * next or by the sea, it
may be safely concluded that the insulation of the Mount had taken
place more than eight centuries ago.”

After a passing allusion to other competitors for the Ictis of
Diodorus, he says, ‘It is perhaps worthy of remark, that those who
have studied the Geology of Cornwall, espoused the cause of the
Mount; while those who fail to do so, appear to have come to the
question with their minds imbued with a belief in William of
Worcester’s statement, that there were 140 parish churches sub-
merged between the Mount and Scilly, and accordingly hold that
the submergence took place not only since the time of Diodorus, but
since the introduction of the parochial system into Cornwall.”

Mr. Pengelly quotes Sir George Cornewall Lewis (An Historical
Survey of the Astronomy of the Ancients) as follows: “'Timzus
mentions an island of Mictis within six days’ sail of Britain which
produced tin, and to which the natives of Britain sailed in coracles.”
He regarded Mictis and Ictis as variations of Vectis.

1 Peacock, p. 86. 2 Journ. Roy. Inst. Corn, for 1873, p. 181.
3 “Sanctum Michaelum qui est juxta mare.”

W. A. E. Ussher—Historical Geology of Cornwall. 77

From Mr. Pengelly’s statement that the Mount 1900 years ago
possessed a harbour, Mr. Peacock dissents on the ground that “if
the coast had remained unaltered ever since Diodorus’s time, the
Roman tin-transporting ships need not by any means have been
confined to St. Michael’s Mount as a harbour, because, as the Rev.
W. Borlase! well observes, Guavas Lake is the principal anchoring
place.” Whence he considers that the chief export of tin could not
have taken place from St. Michael’s Mount, and does not favour the
belief in its identification as the Ictis of Diodorus. He says further :*
«The ancient block of tin which was dredged up about 1823 in
Falmouth Harbour (Lyell’s Principles of Geology, 1867, p. 451), if
we suppose it to have been dropped during its transit to the Isle of
Ictis, would seem to place Ictis opposite Falmouth harbour, and
therefore twenty miles east of St. Michael’s Mount.”

Mr. Pengelly, in a lecture at the Royal Institution,’ says, “The
Mount is by no means a solitary rock of its kind. Within seventy
miles east of it there are certainly four that actually are or probably
were, within the last 1900 years, precisely similar though slightly
larger islands—Looe Island, St. Nicholas Island, the Mewstone, and
Borough Island.”

Mr. Peacock cherishes the idea that the Mounts Bay forest was
submerged in the historic period, and is sufficient confirmation of the
“tradition of these parts that St. Michael’s Mount, now enclosed half
a mile with the sea, when the tide is in, stood formerly in a wood.”

He quotes the following note from Carew (1602) :* “Tradition
tells us that in former ages the Mount was part of the insular
continent in Britain, and disjoimed from it by an inundation or en-
croachment of the sea, some earthquake or terrestrial concussion.”

“Tf,” says Mr. Peacock,® “the storm of 1099 and Dr. Borlase’s
submersion® in the ninth century be true, St. Michael’s Mount
cannot have been the ancient isle of Ictis, because must we not
suppose that the Mount only became an island at one of these
submersions.” Mr. Peacock strengthens his position by the following
quotation’? from page 2 of the Domesday Book: “The land of
Michael . . . there are two hides which never paid the Danish tax
(nunquam geldaverunt). The land is eight caracutes.”

The hide is generally supposed to be equal to 120 acres.* Sir. H.
Ellis says that the measure of a hide varied in different places at
different times. ‘The carucate was as much arable land as could be
managed with one plough and the beasts belonging thereto in a year;
having meadow, pasture, and houses for the householders and cattle
belonging to it.”

Taking the smallest estimate of a “hide” from the five different
measures of it in the reigns of Richard I., Edward I., and Edward II.,

1 Phil. Trans. vol. 48. 2 Peacock, p. 118.

3 Quoted by Peacock, p. 139. 4 p. 140. 5 Peacock, p. 88.

6 Dr. Borlase was inclined to refer the submersion of St. Michael’s Wood to the
inundation of the year 830, mentioned in Irish Annals. Mr. Whitaker ascribed it to
that mentioned by the Saxon Chronicle and Florence of Worcester as occurring in

1099. Vide T. R. G. 8S. Corn., vol. i: p. 139.

7 Ib. p. 187. 8 Ib. p, 113.

78 W. A. E. Ussher—Historical Geology of Cornwall.

which vary from 60 to 180 acres, Mr. Peacock says that eight
carucates would have amounted to 490 acres, whilst’ the present
dimensions of the Mount, measured from the Ordnance Map, “are
found to average 22 x 14 chains; the area therefore is 30:8 acres; *
and it is quite clear that, so far from there being eight carucates of
arable land, there can hardly be a single acre capable of being
ploughed, because the ground is too steep and rocky.”

Mr. Peacock * believes that at the date of this description in the
Domesday Book (in the year 1086), St. Michael’s Mount was not an
island, for the following reasons: Firstly, because neither the
Domesday Book nor the Saxon name Michael Stop give any reason
for such a conclusion. Secondly, because it is the custom in the
Domesday Book, “‘ when a place is an island, to call itso.” Of this he
gives examples. Thirdly, on account of its then containing at least
eight times as much land as at present.

Of the several remaining competitors for the Ictis of Diodorus, Mr.
Peacock disposes as follows :—

As the Scilly Isles do not lie between Europe and Britain, and as
there is a 43-fathom sounding between them and the Land’s End,
none of them would answer to the description of Ictis.

As to the Isle of Portland or the Isle of Wight, so accurate an
observer as Diodorus would not have failed in distinguishing their
position definitely as ‘‘near the south coast of Britain, nor are there
any grounds for the supposition that the relations of either locality
to the mainland were different in Diodorus’s time from the present.”

With respect to the claims of Mont St. Michel, he considers that the
space between it and the Continent was the Forest of Scisy and not
sea until seven centuries and a half after Diodorus’s time.

As alternatives, Mr. Peacock proposes the Wolf Rock (which would
be opposite Britain if a westerly and north-westerly extension of
the Cornish cvast be conceded) ; the Seven Stones; or some island
now totally lost. He considers, however, that the identification of
Ictis is “‘ both impossible and unimportant.”

Mr. Claypole* gives an estimate of the uniform rate of depression
of Mounts Bay on assuming the identity of St. Michael’s Mount
with the Ictis of Diodorus and the Ocrinum of Ptolemy. He says:
“Tt must then have been an island as now at high-water only. In
the time of Diodorus the isthmus must have been below high-water
mark. So depression must be restricted to limits allowing the
isthmus to have been below the upper limit of 20-foot tide, 1800
years ago, and above its lower limit now: so that it would not have
exceeded 6 feet, therefore the rate of depression would be 4 inches
per century, which would be 6 feet in 12,600 years.”

Mr. Pengelly,> commenting on the evidence furnished by the
caverns of Devon, gives the following general note, which may not
be out of place here: ‘In order to obtain the whole, we must add
to this part the time represented by the lodgement of the Blue

1 Peacock, p. 136. 2 Tb. p. 114. 3 Tb. pp. 112, 113.

4 Proc. Brist. Nat. Soc. 1870, vol. v. p. 35.
5 Journ. Royal Instit. Corn. for 18738.

W. A. E. Ussher—Historical Geology of Cornwall. 79

Forest Clay of Devon on the tin ground of Cornwall; to this again
must be added the period in which the forests grew ; to this a further
addition must be made of the time during which the entire country
was carried down at least 70 feet vertically by a subsidence so slow
and tranquil and uniform that it nowhere throughout the area of
Western Europe and the British Islands disturbed the horizontality
of the old forest soil; and finally we must also add the time which
has elapsed since—a time which of itself, thanks to the description of
St. Michael’s Mount by Diodorus Siculus, we know certainly ex-
ceeded 2000 years, and which the volume of the stratified deposits
overlying the forests, as well as the amplitude of the existing fore-
shore, warrants our believing exceeded it by a very large amount.”

Conclusion.—If the word Cassiterides, in the writings of Strabo,
Posidonius, and Diodorus, refers to the Scilly Isles, and if they have
also been mentioned by Dionysius Alexandrinus under the name of
Hesperides, the quotations from these authors would imply the
following consequences.

First,—That tin must have been obtained in the Scilly Isles as
they then existed.

Secondly,—That, as no productive tin veins or signs of old work-
ings are found on these islands, such workings must have been
carried on in districts now submerged, at a time when the number
of the islands (allowing a considerable margin on the score of
insignificance in Strabo’s account) was much less than at present,
and when the flats between the islands of Tresco, St. Mary, and St.
Martin (as may reasonably be inferred from Dr. Borlase’s descrip-
tion), were dry land at high-water and above the level of spring-
tides.

Thirdly,—That the Channel Islands were not insulated in Diodorus’
time; for, if they were, he would hardly have alluded to the Scilly
Isles as nearest to Iberia. This accords with Mr. Peacock’s views as
to their more recent insulation.

Fourthly,—From Alexandrinus’ account, must we not suppose
that the inhabitants of the islands were a colony from Spain in his
time, and either supplanted the original inhabitants alluded to by
Dr. Borlase, or were themselves succeeded by a British race,
addicted to Druidic rites ?

Notwithstanding, I am inclined to think that the word “ Cassi-
terides” was indiscriminately used for the Scilly Isles and Land’s
End District, owing to the imperfect navigation of those early days
of naval commerce.

Diodorus’s description of the inhabitants and mineral wealth of
Belerium would apply rather to a district of that name than to an
individual promontory, and it does not seem improbable that the
name of one of its most important headlands should be indiscrimi-
nately applied to the whole stanniferous district of the Land’s End.
If, as Mr. Peacock supposes, the Northern Channel Islands are
spoken of by Diodorus as neighbouring islands with reference to
Ictis, one can scarcely agree with him in disposing of the claims of

1 T. R. G8. Corn. vol. vii. p. 153.

80 W. A. E. Ussher—Historical Geology of Cornwall.

the Isle of Wight to the appellation of Ictis on the ground of the
accuracy of that historian’s descriptions. Jf the name Vectis’ applied
exclusively to the Isle of Wight, Pliny’s mention of it as lying
between Ireland and Britain would prevent one from putting too
much faith in the latitudes and longitudes of ancient geographers.
(Vide Note B.)

To revert to more recent records. As the description of St.
Michael’s Mount in the Domesday Book is so indefinite, and, from
the nature of the record, rather applicable to the lands belonging
thereto than to the geographical position of the Mount itself, there
appears to be little reason why the eight carucates mentioned in the
passage should not be regarded as arable lands on the adjacent
mainland belonging to the monastery. The submergence of the
Mounts Bay forest seems to have occurred considerably anterior to
any inundation on record, for the following reasons.

First,—Mr. Carne? mentions the extension of the old forest ground
seaward, traced to a depth of from twenty to thirty feet below spring-
tide level.

Secondly,—There is every reason to conclude, with Mr. Carne, that
the forest bed met with in a pit at Huel Darlington mine, under
12 feet of marine sediment, four feet of peat, and eight feet of river
wash, is continuous with the forest bed on the beach.

Thirdly,— Whilst the entombment of the forests in marine sedi-
ments indicates subsiding movements, the peat and overlying gravel in
Marazion Marsh, and the present positions of rock plattorms slightly
higher than spring-tide at high-water, and of estuarine deposits,
seem to point to a slight subsequent elevation, not yet counteracted.
The changes which took place after the submersion of the old forest
ground can hardly have been comprised in eight centuries, and were
more probably operating during a period of more than 2000 years.
A belief in the pre-historic ’® submergence of the Mounts Bay forest
is by no means contrary to the identification of St. Michael’s Mount
with the Ictis of Diodorus; for, although the land may have been
at a slightly lower level in the time of Diodorus than at present,
the rapid disappearance of thirty-six acres of pasturage from the
West Green sand-banks*‘ since Charles the Second’s time, mentioned
by Dr. Boase (T.R.G.S. Corn. vol. iii. p. 181), leaves one free to infer
that prior to that time the bank was of still greater extent, so that
its eastward portion may have facilitated the passage to the Mount
by affording a ridge or causeway of sand covering the rocky isthmus
and passable in most conditions of the tides. The Wolf Rock and
the Seven Stones can scarcely be regarded as possible competitors for
the Ictis of Diodorus; their admission would entail a subsidence of
at least 200 feet within 2000 years, as the former is seven miles to
the south-west of Guethenbras Point (Land’s End district), with

1 (Peacock, p. 183.) Pliny, Nat. Hist. lib. iv. § 80: “Sunt autem xl Orcades
modicis inter se discrete spatiis. Septem Acmode, et xxx Hebrides; et inter
Hiberniam ac Britanniam, Mona, Monapia, Ricina, Vectis,”’ etc.

2 T. R. G. S. Corn. vol. vi. p. 280, etc. 3 As far as Britain is concerned.

4 The banks are now only two or three acres in extent,

Notices of Memoirs—Prof. Owen on Wingless Birds. 81

intervening depths of from twenty-one to thirty-eight fathoms; and
the latter are fourteen miles west from the Land’s Hnd, with depths
of thirty-two to forty fathoms between them and the Longships.
St. Michael’s Mount appears better to accord with the description of
Diodorus than any other island on the Cornish coast, on account of,
firstly, its vicinity to tin-producing districts; secondly, the facility
with which carts laden with the ore could have reached it, either
on the supposition of an elevation of a few feet, or allowing the
extension of the sand-bank from the mainland or the existence of a
sand spit concealing the isthmus.

APPENDIX.

Nore A.—A rock near the Land’s End bears the name of “the Armed Knight.”’
Though this appellation may have been bestowed on it through a fancied resemblance
in outline, the existence of the tradition respecting Trevelyan’s adventure appears to
furnish a more likely reason for the name. :

Nort B.—In Speed’s Map of Cornwall, 1610, no dependence can be placed upon the
latitudes, as may be seen by placing a tracing of a reduced Ordnance Map of the
same scale (about 1 inch to 4 miles) over it, when the Land’s End district will be
found to occupy entirely different positions scarcely overlapping in any place, and
the shape of the Lizard district to be quite dissimilar.

Another map without date, but probably as old as Speed’s, was shown to me by
Mr. Parfitt, of the Devon and Exeter Literary Institute ; the same discrepancies were
visible in it.

Now when we find discrepancies of latitude equal to 10’, and the shapes of pro-
montories entirely misrepresented in maps of their own country produced by
geographers 300 years ago, how can we expect to find even as great accuracy in the
geographical descriptions of Roman or Greek historians, more especially when
relating to coasts with which they must at best have been very slightly acquainted ?

IMNGnEChne| | Guan WnsaVeonSS

On tHe Extinct Winexess Brrps or New Zeatanp. By Ricwarp
Owen, O.B., F.R.S., erc. (London: John Van Voorst, 1,
Paternoster Row.)

ARON CUVIBER, in the “ Avertissement” to the First Hdition
of the ‘ Recherches sur les Ossemens Fossiles des Quadrupédes, ’?
assigns as a reason for reprinting, with additional matter, his

““morceaux détachés dans les ‘Archives du Muséum d Histoire

Naturelle,’ ”’ the facility which would thereby be afforded to students

of fossil remains in their comparisons with the text and plates of

such Work.

A like motive has led the Author to collect his detached Memoirs
on the Fossil Bones of the Birds of New Zealand, which have
appeared in successive Parts of the ‘Transactions of the Zoological
Society of London’ since the year 1838, and to similarly combine
them with additional matter and general remarks in the two volumes
now issued.

His purpose, long entertained, was strengthened by the appearance
and favourable reception of an excellent and comprehensive Work
on the existing Birds of New Zealand,” to which the present Volumes
may be deemed complementary.

1 4to. 3 vols., 1812.

2 “A History of the Birds of New Zealand,’ by Walter Lowry Buller, Sc.D.,
F.L.S., ete. 4to. (London, John Van Voorst, 1872.)

DECADE II.— VOL. VI.—NO. II. 6

82 Reviews—Skertchly’s Physical System of the Universe.

They comprise an Introductory Notice of the circumstances which
led to the discovery and restoration of the extinct Avifauna of New
Zealand. 'The descriptions are accompanied by Illustrations of the
natural size of the fossils, and reduced views of the restored skeletons
on which the several genera and species have been founded. The
whole is preceded by an illustrated Anatomy of the existing wingless
bird (Apteryx australis) which is the nearest ally of the extinct
Dinornis ; and is followed by notices of the food, footprints, nests,
and eggs of the Moas, the Maori traditions relating to those gigantic
birds, the causes and probable period of their extirpation, and a
speculation on the conditions influencing the atrophy of the wings in
flightless birds.

The latter topic has led the Author to append Supplementary
Memoirs on the Dodo, Solitaire, Great Auk, and some evidences of
gigantic extinct Birds of Australia and Great Britain.

His advanced age has led him to issue the present Work entire, in
preference to a publication in Parts. It consists of a Quarto Volume
of Text (512 pp.), and a similar Volume of 130 Plates, several of
which, from the size of their subjects, are in folio. With the Text
are intercalated Woodcuts.1 Dr. Hector’s Geological Map of New
Zealand, giving the localities of the discovered fossils, is annexed.

RAVI WwW SS.
—>——_
I.—Tuer Puystcan System oF THE UNiverse. AN OUTLINE OF
PuystograPHy. By Sypnry B. J. Sxertouty, F.G.S8. 8vo.,
pp. 885. (London, Daldy, Isbister & Co., 1878.)

INCE the Science and Art Department determined to hold an
Examination in Physiography we have been presented with
various text-books on the subject. Professor Huxley, the Rev.
Alexander Mackay, Professor Ansted, and more recently Mr.
Skertchly, have come into the field; while in late numbers of “ Good
Words”? Mr. Norman Lockyer has contributed a series of physio-
graphical sketches on “The Harth’s Place in Nature.”

This subject—which, at South Kensington, seems to have sup-
planted Physical Geography, ought, however, in no sense to interfere
with it. Physical Geography deals with the configuration of the
earth’s surface, and with the distribution of its various forms of life ;
it is, in fact, the geology of the present day, and must always retain
more or less of an individuality so far as any study can do so.

Physiography, on the other hand, endeavours to knit together the
sum and substance of all that is known of the physical history of
the universe—it is, in fact, a Cosmogony—though its chief aim is
to develope the intimate connexion between all sciences, and to illus-
trate the Unity of Creation.

It is only within the past few years that Physiography has assumed
its present comprehensiveness. The term has not unfrequently been
in use to designate the physical aspect or contour of any tract on
the earth’s surface. Nor has the connexion of various sciences been

1 The price of the Work is £6 6s.

Reviews—Shkertchly’s Physical System of the Universe. 83

lost sight of, for as early as 1849 a little work entitled ‘“‘' The Unity
of Nature,” by John Warren Howell (edited by Charles Pooley), was
published; a work whose object was to show the relation of the
sciences one to another. But recent spectroscopic observations have
especially led to the conclusion that all the heavenly bodies “are
but parts of one stupendous whole.”

In the work now before us, Mr. Skertchly gives us an outline of
physiography, embracing all the latest work in astronomy and
physical science which bears upon the history of the universe. It is,
we must premise, a work which contains a good deal of hard reading,
and perhaps too many technical terms to please an ordinary
reader. In the introductory chapter the author briefly sketches the
plan of his work, and shows that the past and present state of the
globe are the result of the action of heat upon solid, liquid, and gaseous
matter. Chapter 2 deals with Matter and Motion, and it is pointed
out that the earth is not an isolated fragment in space, but part of
one great machine. Chapter 8 treats of Light and its Revelations,
and it is shown that the sun, stars, etc., contain the same elements
known to us on earth. Chapter 4 is devoted to the Sidereal System
—a term applied to the whole of the visible universe, with its hosts of
stars, nebula, etc., and it is pointed out that not only is it composed
of the same kind of matter, but this is acted upon by the same laws
as terrestrial matter. In Chapters 5, 6, and 7, the Solar System
is treated; the motions, reactions, and influences of the bodies are
dwelt upon, also the origin and movements of meteors and comets.
Chapter 8 is devoted to the Sun, and all that is known of it—the
influence of the cycle of its spots on terrestrial magnetism, tempe-
rature, rainfall, and other phenomena. Chapter 9 deals with the
Earth’s Internal Heat, in which it is concluded that the interior is
probably metallic; that, as a whole, the earth is very rigid, and
cannot be molten in the interior; that it contains great cavernous
spaces more or less full of liquid rock; and that volcanic action has
been far more extensive than it is at present. The effects of In-
ternal Heat and influence on the production of faults and contortions,
upheavals and depressions, and in the sketching out of the broad
features of the continents are noticed in Chapter 10. The effects of the
Karth’s External Heat are pointed out in Chapter 11, where various
climatic conditions are shown to result from Solar Heat. Chapter
12 continues this subject in its bearing on Earth Sculpture, where the
influence of Subaérial Denudation is noted as the most prominent. In
Chapter 13 the subject of Climate is again dealt with, also the causes
of great variations in past periods. The conclusions being that cold
and warm periods alternated in comparatively rapid succession during
the Glacial period; and that they are due to the indirect results of a
high excentricity, combined with the position of the solstitial points
in aphelion and perihelion. Chapter 14 deals briefly with Life,
and it is shown how dependent the forms and their distribution are
upon climatic change. The concluding chapter discusses the Nebular
Hypothesis, which, while it is stated to be the naturai explanation
of the Solar system, yet is not supported by what is known of exist-

84 Reviews—Geéologie pour les Années 1876 et 1877.

ing nebule; they do not contain the spectra of all the known
elements, and hence it might be inferred that none of them could
condense into a system like ours. To this, Mr. Skertchly replies
that, “It may be that at excessively high temperatures most of the
vibrations are too rapid to emit light, and hence, even if our
elements are truly such, they might fail to yield a spectrum under
nebular conditions.”

In concluding this outline of Mr. Skertchly’s work, we cannot
refrain from complimenting him upon the care he has bestowed upon
this subject, and from expressing our belief that he has formed a
very solid nucleus from the nebulous matter that is scattered through
a wide range of knowledge. H. B. W.

IIl.—Revvur DE GéOLOGIE PouR LES ANNEES 1876 ET 1877. Par
M. Detessse et M. De Laprarent. (Paris: F. Savy, 1879.)

HE onward progress of geology is fully evidenced by the
numerous works which of late years have been published
bearing on that science. Distributed as separate treatises, or as
memoirs and papers in various scientific journals, or in proceedings
of societies, and in different languages—the majority of them might
be comparatively unknown to many geologists, without some general
record of their place of publication. This desideratum has been
fulfilled by the “Revue de Géologie” of MM. Delesse and De
Lapparent, of which fifteen volumes have now appeared, and to
which object the ‘Geological Record” and ‘Revue Géologique
Suisse” have also contributed. With the fifteenth volume of the
“Revue de Géologie,” the Editors have brought their French record
of geological literature up to 1877. Commencing in 1860, the series
now published contains a vast amount of useful information with
regard to the various publications issued during the period, and so
arranged as to be easily referred to. The subjects in this, as in the
preceding nine volumes, are classed under the chief divisions adopted
by Prof. Dana in his Manual of Geology,—physiographical, litho-
logical, historical, geographical, and dynamical geology. As in
preceding years, the authors have endeavoured to present a concise
but faithful and methodical analysis of the various memoirs which
have contributed to the advancement of geological science during
the years 1876-77. J. M.

I1I.—Conrrisutions To THE KNOWLEDGE OF THE HRuPtTIvE Rocks
IN THE DisTRICTOF SAAR AND MoseLLe.—“ BertRAGE ZUR KENTNISS
prR ERUPTIVGESTEINE IM GEBIETE von SaaR wunD Mosst.”
Von Prof. Dr. A. von Lasautx. pp. 76, with 2 coloured plates.
(Bonn, 1878.)

N this treatise the author describes the mode of occurrence, the
megascopic, and the microscopic characters of a number of
eruptive rocks which have hitherto been, with a few exceptions,
designated Greenstones. The rock first described is the Diabase-

Diorite of Kiirenz, near Trier. Then follow descriptions of an

Reports and Proceedings—Greological Society of London. 85

Amphibolite from Olmuth ; Diorites from Wilmerich, from Winkel-
hornfloss, near Schillingen, from the Grinburg, near Wadrill, and
from Paschel, near Zerf. A decomposed dioritic rock from Schoden
on the Saar is also described. Diabases from Kellenbach, Forstel-
bach, Hockweiler, near Trier, Saarburg and other localities, are
likewise treated of at some length. Descriptions of numerous
Melaphyres from different localities are followed by an account of
what is headed as a Porphyry, from Rhaunew, which is shown to be
a fine-grained granitic rock with porphyritic felspar crystals.

The descriptions are clear, and the drawings at the end of the
treatise are well calculated to explain those portions of the text
which need illustration, as they are rendered in the slightly diagram-
matic manner which characterizes the microscopic drawings of many
of the leading continental petrologists.

IV.—Tse American QuarterRLty MicroscopicaL JouRNAL. Con-
taining the Transactions of the New York Microscopical
Society. No. I. (New York, October, 1878.)

E heartily wish Mr. Romyn Hitchcock, the Editor of the
above, all possible success in his arduous but much needed
undertaking.

That the United States should have been hitherto without a
journal of Microscopy is certainly an anomaly, considering the
numberless other scientific publications of which it can proudly
boast, and the immense field there open for all comers to work in.

We trust, therefore, that this attempt to supply a known defect
may meet with a fate quite the reverse of that which attended its
predecessor the “‘ Lens.”

The part before us is got up somewhat in the style of our lately
defunct “Monthly Microscopical Journal,” but printed on better
paper, and illustrated with, we venture to add, still more excellent

lates.

Though the present number does not\contain any papers of special
interest to the geologist, still we nevertheless trust that from time
to time we may see, and be able to record as occurring in its pages,
articles on Microscopic Geology. B. B. W.

REPORTS AND PROCHHE DINGS.
MS

GEOLOGICAL Society oF Lonpon.—I.—December 4, 1878.—Henry
Clifton Sorby, Hsq., F.R.S., President, in the Chair.—The following
communications were read :—

1. “On some Mica-Traps from the Kendal and Sedbergh Districts.”
By Prof. T. G. Bonney, M.A., F.R.S., F.G.S., and F. T. 8. Houghton,
Hsq., B.A.

The rocks described by the authors are mapped by the Geological
Survey on Quarter Sheets 98 N.H., 98 S.E., and 97 N.W., and in
parts briefly mentioned in the accompanying memoirs, under the
generic name mica-trap. Seventeen examples are described macro-

86 Reports and Proceedings—

scopically and microscopically, and of eight chemical analyses are
given. It appears better to call one a porphyrite and two diorites
(micaceous varieties). The remainder are all characterized by
abundance of mica (biotite). Augite also appears to have been
generally a constituent; but it has almost invariably been replaced
by secondary products, calcite, dolomite, viridite, etc. Three are
crystalline in structure; one of these is named minette, the others
kersantite. The remaining eleven show a microcrystalline or crypto-
crystalline base. It is proposed to call eight of them minette-
felsite, the rest kersantite-porphyrite. ‘These rocks commonly occur
in rather narrow dykes; they are intrusive in Silurian strata, and,
in the authors’ opinion, are undoubtedly true igneous rocks.

2. “ Pleistocene Notes on the Cornish Coast near Padstow.” By
W. A. E. Ussher, Hsq., F.G.S.

In this paper the author described certain deposits seen in a small
bay near St. Enodock’s chapel, and known as Daymer Bay, and in
section at Greenway cliffs. The former included a portion of raised
beach, and a reef of consolidated old beach and a peaty deposit below
high-water mark, the raised beach indicating a depression of from
5 to 10 feet and a subsequent elevation of more than that amount,
during a pause in which the lower beach was formed. The further
elevation of the coast was sufficient to favour the growth of forests
furnishing the peaty bed, which a subsequent subsidence has brought
down to its present level. Greenway cliffs consist of grey slates,
resting against which, in two places, are old consolidated blown
sands; about 5 feet above high-water mark is a raised beach, near
which the face of the cliff consists of “head” capped by gravel.
The author discussed the relative ages of these deposits, and inclined
to regard the gravel as a fluviatile deposit, and the stony loam or
“head” as an ancient talus or flood-gravel, both deposited before
the raised beach.

3. ‘The Pleistocene History of Cornwall.” By W. A. E. Ussher,
Ksq., F.G.S.

In the first part of this paper the author, from his own observa-
tions and the writings of other geologists, gave detailed descriptions
of the various superficial deposits of Cornwall as exposed in nume-
rous coast-sections.

In the second part he discussed the relative ages of these deposits,
for which he proposed the following classification :—

1. The oldest beds described are patches of quartzose gravel,
found up to 400 feet above the present sea-level; these are regarded
by the author as of fluviatile origin, and as being possibly rede-
posited Tertiary beds. | Their age may be any thing between Cre-
taceous and Glacial.

2. Boulder-gravels, from 40 to 50 feet above sea-level.

3. Raised beaches, up to 15 feet above sea-level.

4. Old blown sand closely associated with the raised beaches.

5. “Head” or talus of angular fragments lying upon the raised
beaches, and therefore of younger date than the latter.

6. Stream tin-gravels, evidently older than the forest stratum.

Geological Society of London. 87

7. Submerged forests, evidently occupying a long period subse-
quent to the deposition of the stream tin-gravels.

8. Recent marine and fluviatile deposits.

In conclusion he remarked on the paucity of superficial deposits
in Cornwall, the absence of evidence of glacial conditions, and the
proofs of great changes in the level of the area.

IJ.—December 18, 1878.—1. “On Remains of Mastodon and
other Vertebrata from the Miocene Beds of the Maltese Islands.” By
Prof. A. Leith Adams, M.B., F.R.S., F.G.S. The author recognized
the following Maltese formations :—

Upper Limestone.—Maximum thickness over 250 feet, passing
into a sandy rock, and that into a hard red limestone. Fossiliferous,
containing 4 Brachiopoda, several Lamellibranchs and Gasteropods,
and 25 Echinodermata (10 being peculiar).

Sand Bed.—Maximum thickness about 60 feet, variable in
character, characterized by vast abundance of Heterostegina depressa ;
‘15 Vertebrata.

The Marl Bed.—Maximum thickness over 100 feet, but sometimes
almost wholly thinned out. Organic remains rarer than in the
Sand Bed.

The Calcareous Sandstone.—Maximum thickness rather over 200
feet, Contains bands of nodules, of which the second is rich in
organic remains. Hence come the noted teeth of Squalide. Among
its invertebrate fauna are many Pectens, with other Lamellibranchs,
Gasteropods, and Brachiopods. Also 22 species of Echinodermata.

The Lower Limestone.—Maximum thickness over 400 feet. Scutella
subrotunda and Orbitoides despansus are abundant in the upper part,
and it is generally fossiliferous.

In a nodule-seam in the Calcareous Sandstone in the Island of Gozo
two rather imperfect teeth of a Mastodon have been found. Both
are penultimate molars. They agree most nearly with the teeth of
Mastodon angustidens, but the characters are not sufficiently well
preserved to differentiate the species with certainty.

The same formation has furnished teeth of a Phoca to which the
specific name rugosidens has been given by Prof. Owen. Large
teeth referable to the Phocide are found in the nodule-seams of the
Calcareous Sandstone and in the Sand Bed; the Marl Bed has also
furnished a portion of a jaw.

The Woodwardian Museum contains a part of a jaw of Squalodon,
evidently from a nodule-seam of the Calcareous Sandstone (found by
Scilla cire. 1670). The Sand Bed and Calcareous Sandstone have
furnished remains of more than one species of Delphinus, and large-
sized Cetacean vertebra are found in nearly all the beds, especially
the Sand Bed. Halitherium has been obtained from the Sand Bed,
Marl Bed, Calcareous Sandstone, Lower Limestone, and (?) Upper
Limestone.

One specimen of Ichthyosaurus gaudensis, Hulke, has been
furnished by the Calcareous Sandstone; the same has also furnished
Melitosaurus champsoides, Crocodilus gaudensis, and Sterrodus meli-
tensis. Myliobates toliapicus and allied species have come from all

88 Reports and Proceedings—

the deposits except the Upper Limestone. Aitobates subconversus
from the Sand Bed and Marl. The Squalide are abundant from all
the deposits except the first. There are ten species belonging to
the following genera:—Carcharodon, Carcharias, Oxyrhina, Hemi-
pristis, Coraz, Odontaspis, Lamna. Remains of Notidanus, Plataa,
and Diodon have also been found.

2. “ Dinosauria of the Cambridge Greensand.” Parts I.—VII.
By Prof. H. G. Seeley, F.L.8., F.G.S.

The author stated that this paper was founded upon the collection
of more than 500 Dinosaurian bones preserved in the Woodwardian
Museum, for the opportunity of studying of which he was indebted
to the kindness of Prof. T. McKenny Hughes. He described the
conditions under which the specimens occur, and accounted for the
apparently worn state of the bones as the results of exposure to the
air, and subsequent maceration.

J. ‘Note on the Axis of a Dinosaur from the Cambridge Green-
sand.” This bone was said to be very similar to the axis from the.
Wealden previously described by the author (Q.J.G.S. vol. xxxi.
p. 461), but differed in the neural arch being supported on pedicels
of the centrum, in both articulations for the rib being on the
centrum, in the compressed form of the odontoid process, and in
the subhexagonal form of the oblique posterior articular surface of
the centrum. There is no indication of a wedge-bone beneath the
anterior articulation. The condition of the axis in other Dinosaurs,
such as Zanclodon, was indicated, and reasons given for regarding
the structure of the bone as a modification of the Crocodilian type.

II. “On the Vertebral Characters of <Acanthopholis horridus,
Huxley, from the base of the Chalk-Marl near Folkestone.” The
author stated that only dorsal and caudal vertebree of Acanthopholis
are at present known. The dorsal vertebre have the visceral
surface well rounded, the articular ends subovate, and the centra
laterally compressed. The early caudal vertebrae are deep, with
strong compressed transverse processes, zygapophyses directed well
forward, and the neural spine directed upward and backward. The
centrum is inclined obliquely forward; the facets for the chevron
bone large, and the anterior articulation circular. The later caudals
have nearly the same absolute length of centrum, and the transverse
process is first reduced to a tubercle, and afterwards disappears
entirely. A deep channel is developed on the underside of the
centrum, and two more or less marked ridges run along each side
of the centrum, making the articular ends subhexagonal.

Ill. “On the Skeleton of Anoplosaurus curtonotus, Seeley.” This
genus and species are founded upon an associated series of about 80
bones from near Reach. The remains include a portion of the left
ramus of the lower jaw, 5 cervical (axis and atlas missing), 13
dorsal, 6 sacral, and 8 caudal vertebree (the tail being imperfect),
the coracoids (one imperfect), the proximal end of the scapula, the
proximal and distal ends of the humerus, the proximal and distal
ends of the femur, a small fragment of the ilium, small portions of
ribs, and fragments of the metatarsals and phalanges. The teeth

Geological Society of London. 89

were placed close together in sockets, 13 occurring in a space of 2}
inches. The general form of the vertebral centra indicates a convex
curve in the back and sacrum, and a concave curve in the neck and
tail, rendering it probable, in conjunction with the great develop-
ment of the sacrum, that the animal affected a semierect attitude.
The sacral vertebrae, as preserved, are all separate. The scapula is
remarkably thick, with a strong spinous or acromioid process. The
femur shows distinctive Dinosaurian features, but presents a form
that has not previously been described. The vertebral centra
indicate a near affinity to Acanthopholis; but no dermal armour has
been met with, and the caudal vertebrae present differences which
seem to justify its location in a distinct genus.

IV. “On the Axial Skeleton of Hucercosaurus tanyspondylus, Seeley.”

This genus is founded on an associated series of 19 vertebrae and a
neural arch from Trumpington. Four dorsal vertebre are preserved,
which considerably enlarge towards the sacral region, so that
probably the vertebral column was carried in a more than usually
erect position. The underside of the centrum in the early part of
the series has an angular or squeezed form; but this appearance is
lost in the hinder centra. The sacral region is represented by 3
vertebra; there were probably, in all, 5 or 6. Twelve early caudal
vertebra are preserved; these become unusually elongated and
prismatic posteriorly. The chevron bones were at first very large,
but are small when the articular face of the centrum has acquired
the hexagonal outline. The neural arch in the caudal region was
very depressed. This genus was considered to be closely related to
Acanthopholis, though the vertebree differed so greatly in form.
_ Y. “On the Skeleton of Syngonosaurus macrocercus, Seeley.” This
genus is founded on a series of 19 vertebrae, representing the neck,
back, sacrum, and tail. It shows affinities to several Dinosaurian
types, especially Hucercosaurus and Iguanodon. The early dorsal
vertebrae are remarkably compressed, and the neural arches are
entirely united to the bodies of the vertebra throughout the series.
In the lower dorsal region the ridge on the visceral surface dis-
appears, and the centrum becomes deep. The visceral ridge re-
appears in the sacrum. The caudal vertebre are at first compressed,
and have the articular faces oblique and slightly proccelous; the
chevron bones have a large single facet united by suture to the lower
half of the articulation. In these vertebrae the visceral surface is
rounded and narrow. The proximal end of a humerus and distal
ends of both humeri were obtained ; they are of small size. Several
metatarsal bones and phalanges have also occurred, and are large in
proportion to the other remains. In doubtful association with these
bones were 11 pieces of dermal armour, closely resembling that of
Acanthopholis.

VI. “On the Dorsal and Caudal Vertebree of Acanthopholis stereo-
cercus, Seeley.” This species was founded on a small associated
series of vertebree, one of which is an imperfect cervical, 2 dorsal,
and 8 caudal. The species differs from A. horridus, Huxley, in the
form of the centrum, in the different character of the facets for the

90 Reports and Proceedings—Geol. Soc. Lond.

chevron bones, and in the deeper median channel of the visceral
surface. The caudal vertebre slightly decrease in length posteriorly.

VII. “On a small series of Caudal Vertebre of a Dinosaur, Acan-
thopholis eucercus, Seeley.” This species was founded on an associated
series of 6 caudal vertebrae, which differed from those in the tail of
A. horridus, in the centrum being more elongated and constricted,
and in the rapid diminution in length of the centra posteriorly. The
species is slightly larger.

III.—January 8, 1879.—1. “On some Tin-deposits of the Malayan
Peninsula.” By Patrick Doyle, Hsq., C.E. (Communicated by the
Rev. T. Wiltshire, M.A., F.L.S., F.G.S.)

The tin-ore of the Malayan Peninsula is obtained from “stream-
works” in an alluvial plain extending between a range of granitic
mountains and the sea. The author describes the mines of the
district of Larut Perak. The ore is got in open workings at an
average depth of about 10 feet. The tin-bearing stratum has an
average thickness of 4°87 feet; it is overlain by stratified sand and
clay, and rests upon either porcelain clay or, sometimes, a sandstone.
The ore varies from a fine sand, near the sea, to a coarse gravel,
near the mountains, and is mixed with quartz, felspar, mica, and
schorl. The author is of opinion that the stratum of ore has been
derived from the granite of the mountain range, in which it still
occurs in veins, by denudation, and under conditions which still
exist, though in a modified form.

2. “Description of Fragmentary Indications of a huge kind of
Theriodont Reptile (Titanosuchus ferox, Owen), from Beaufort West,
Gough Tract, Cape of Good Hope.” By Prof. R. Owen, O.B., F.R.S.

The author stated that among the fossils recently sent to the
British Museum from the Cape of Good Hope by Mr. T. Bain, there
were two boxes containing specimens of a most unpromising cha-
racter, there being in them no entire bones, but only numerous more
or less water-worn fragments. Among these was found a portion
of a maxillary showing some traces of teeth; and sections having
been made of this bone, the remains of several teeth were displayed,
inclitding a canine, the preserved portion of the socket of which was
44 inches long. From the number and mode of implantation of the
teeth, the author concluded that the animal to which they belonged
resembled the Theriodont genera Galesaurus and Galenops. The
anterior portion of the left ramus of the lower jaw, measuring
74 inches in length, showed teeth presenting close analogies with
those of Theriodonts, and this alliance was confirmed by the study
of other fragments. Some of the characters presented by these
remains seem to suggest affinities with the carnivorous mammalia,
such as have been already indicated by the humeri of Theriodonts
and Carnivores.

The canine tooth of the new South-African reptile, which the
author proposes to name Titanosuchus ferox, was six times as long
as that of the allied form Lycosaurus ; and we have in Titanosuchus
evidence of a carnivorous reptile of more carnassial type than

Oorrespondence—Rev. Professor S. Haughton. 91

Machairodus and other Felines. The author suggests that Titano-
suchus found its prey in the contemporary Pareiosauri, Oudenodonts,
and Tapinocephalans of the same locality.

3. “Notes on the Consolidated Beach at Pernambuco.” By J. C.
Hawkshaw, Esq., M.A., F.G.S.

The consolidated beach at Pernambuco, which has already at-
tracted considerable notice, is a ridge of sandstone from 25 to 75
yards wide, and, as shown by borings made under the author’s
direction, from 10 to 13 feet thick. The landward or higher edge
is nearly at the spring-tide high-water level, and it slopes seaward ;
the river (with a depth of 28 feet at low water 60 feet from the
rock) flowing along the former face. The rise and fall of spring
tides is 7 feet. Beneath the above rock is a stratum of sand with
shells and stones about 8 feet thick, and then a second layer of
sandstone rock. :

The consolidated beach is cemented by carbonate of lime, which
the author considers to have been deposited by the action of water
percolating through the rock, probably when the level of the land
differed somewhat from what it is at present. He thinks it possible
that this and other similar beaches on the Brazilian coast may mark
periods of repose in the slow vertical movements which the coast
has undergone.

CORRESPONDENCE.

ON THE FORMER CLIMATE OF THE POLAR REGIONS,

Str,—In the Grotocican Macazine for December, 1878, page
552, in a paper by the Rev. O. Fisher, M.A., on “The Possibility
of Changes in the Latitudes of Places on the EHarth’s Surface,”
the following passage occurs in reference to the question of the
possibility of the crust of the earth slipping over a fluid substratum,
thereby causing changes of latitude :—‘‘That theory belongs to
Dr. Evans; and he has ably defended it against Dr. Haughton’s
somewhat formidable objections in his recent address to the British
Association at Dublin. The supposition alternative to Dr. Evans’,
by which Dr. Haughton would account for a former warm climate at
the Pole through residual heat in the earth, has, J think, been
disposed of by anticipation in Sir W. Thomson’s paper on the Secular
Cooling.”

Iam not at all prepared to admit either horn of the foregoing
dilemma, but shall confine myself at present to the first.

Dr. Evans’ address was delivered at the opening of the Geological
Section of the Association Meeting, and my paper, showing the
impossibility of accounting for the Tertiary plant-remains in the
Arctic Regions by any change in the position at the Pole, was the
last paper read before the Geological Section of that meeting.

I believe that I am correct in stating that neither the President,
Dr. Evans, nor any geologist present, gave anything like a satisfactory
answer to what the Rev. O. Fisher has called my “somewhat for-
midable objections.”

92 Correspondence—Rev. Professor S. Haughton.

My contention, in brief, was this, that the Tertiary plant-remains
indicating a climate similar to that of Lombardy (so far as heat is
concerned) are so situated round the North Pole that no possible
change in the position of that Pole (even were such permitted by
mechanical considerations) would give them the climatic conditions
as to temperature which they require. It was urged at the meeting,
as an objection to my view, that the presence of evergreens among
the Arctic Tertiary plants was inconsistent with the prolonged
absence of light, which they must have sustained if the Pole were in
its present position. To this, my reply was the following statement
by Professor W. R. McNab, M.D., of the Royal College of Science :—

“4, VERNON ParapE, CLonTarr, 7th April, 1878.

“Dear Dr. Havewron,—I fear I cannot give you a direct answer to your
question, and I have not found any papers on the subject in the ‘ Botanischer
Jahrsbericht,’ Sachs’ ‘Lehrbuch der Botanik,’ in Sachs’ ‘Handbuch der Experi-
mental-Physiologie der Pflanzen.’ The general facts of the case can, however, be
very readily stated.

“ Plants containing green chlorophyll grains, when placed in darkness, partial or
complete, change colour from the destruction of the chlorophyll. Sachs says (Text-
book of Botany, page 669) that in the leaves of rapidly-growing Angiosperms the
absorption and disappearance of the chlorophyll takes place in a few days if the
temperature be high. He adds, Cactus stems with slow growth, and the shoots of
Selaginella, remain green for months in the dark. It is probably true also of
Conifers, as I have seen them kept in the dark during the winter months without
injury. This I saw in Berlin. Large plants requiring protection from the cold were
laid on their sides, and a covering of mats and leaves on a wooden frame placed
over them.

“The evergreens in your list are all Conifers, and I am of opinion that the
absence of light for a considerable period would not injure them.

“Tt is well known that cold alters the colour of the leaves of many Conifers at
once, but in your paper you state the temperature at 48° F., a temperature much too
high to influence the colour.

‘Your question places an isolated physiological fact in a very important light, at
least it appears to do so to me. I give it in Sachs’ words (Text-book, page 665) :
‘If the temperature is sufficiently high, the green colouring substance is found in
the cotyledons of Conifers and in the leaves of Ferns, in complete darkness as well as
under the influence of light. . . . Provided, therefore, that the temperature is
favourable, the chlorophyll in the cotyledons of Conifers and the leaves of Ferns does
not require light in order to assume its green colour, while that in Angiosperms does
require it, and in both cases the change does not take place at low temperature.’

‘‘ My answer to the objection that has been made to your paper is this: ‘ Grant
that the evergreens cannot stand prolonged absence of light—that refers to Angio-
spermous forms. Here all the forms are Coniferous; and Coniferous plants with
Ferns have the peculiar property of forming green chlorophyll grains in the dark.

““T think a few evergreens do stand prolonged darkness, as I have certainly seen
myrtles and rhododendrons placed during the winter in very dark sheds.

“‘ As I can only refer to the books in my own library to-day, I shall try to find out
some reference to the St. Petersburg observations, and let you know the result in
due course.—I am, very truly yours,

(Signed) W. R. McNas.”

‘Rey. Prof, Haughton, F.R.S., etc., etc.”

During the discussion on my paper in the Geological Section, it
was observed by Mr. Pengelly that ‘‘ magnolias’’ are mentioned by
Professor Heer as occurring among the Greenland Tertiary plants.
To this my reply was, that although some of the magnolias are ever-
greens, some of them also have deciduous leaves, and that the
occurrence of plants or trees having deciduous leaves should cause us

Oorrespondence—Ur. W. A. E. Ussher. 93

no surprise in the Arctic Regions, provided a suitable temperature
were provided for them.*

I cannot give here all the details explained in my paper, but I
claim to have surrounded the North Pole with such a network of
Lombardic plants, requiring Lombardic heat, but not Lombardic
light, as to render the escape of the Pole from its present position as
difficult as that of a ‘“‘rat in a trap surrounded by terriers.”

If the Lombardic light as well as heat were present in these
Tertiary times, it would be difficult to explain the absence of a
multitude of evergreen plants which require light to develope
chlorophyll grains. Such evergreen plants ought to have migrated
from North America and Europe into Greenland as easily and as
rapidly as the peculiar groups of evergreens found there in Tertiary
times.

In my opinion, the natural selection in the Tertiary Flora of
Greenland of such evergreens only as require Lombardic heat, but
can dispense with Lombardic light, is a fact which my opponents in
the Geological Section not only did not answer, but entirely failed
even to see the force of. S. Haveurton.

Trrity CoLttece, Dus, 17th January, 1879.

FACTA NON VERBA.

Str,—The Devonian question being already hampered with so
much theory, I venture to hope that you will insert the following
facts, arrived at after a series of traverses by almost all the river-
courses in North Devon. Prof. Hull’s description of the rocks of
this county and West Somerset contains serious errors, into which I
am sure he would not have fallen had he been acquainted with the
area.

Firstly. The Pilton beds consist of bluish grey and grey schistose
and slaty rocks, with local developments of grey and brownish grit.
The calcareous element is represented by thin, trivial, and impersis-
tent beds of limestone.

Secondly. The Baggy Sandstones are buff-grey and brown,
apparently confined to a definite horizon, but by no means equally
developed thereon ; they rest upon olive slates. For stratigraphical
survey lines these may be included in the Pilton beds, from which
they cannot, in disturbed districts, be readily distinguished.

Thirdly. The Pickwell Down beds are strangely mixed up with
the Morthoe Slates in Prof. Hull’s table, which would be fatal to the
supposition of unconformity between them (vide Grou. Mac., 1878,

. d01, lines 18 and 19). The Pickwell Down series is distin-
guishable through North Devon by its characteristic interstratification
of slates, not shales; these are almost invariably lilac or purple, and
toward the base of the division seem to pass into the Morte group by
intercalation with buff and greenish slates, especially on Exmoor.

Fourthly. The Mortehoe slates are simply an unfossiliferous upper
portion of the Ilfracombe group; the former being greenish and
glossy ; the latter grey, bluish, steel grey, and silvery, with local

1 So far as I can understand, it would be difficult, if not impossible, to distinguish
between evergreen magnolias and those with deciduous leaves, in fossil remains,

94 Correspondence—Mr. Townshend M. Hail.

developments of limestone bands near Ilfracombe and in West
Somerset. It is impossible to fix any definite boundary between them.

Fifthly. The upper beds of the Hangman group are very coarse
and siliceous, silvery red-stained shales being sometimes intercalated ;
the lower beds are generally flaggy and of a grey colour.

Sixthly. The Lynton zone is represented by grits, generally
breaking in even tabular layers, schists, schistose grits, and slates,
of a uniform warm grey tint.

Seventhly. The Foreland grits are generally fine, flagey, cream-
coloured, dull-grey, brown, reddish or greenish grits, with beds of
red grit, sometimes massive ; they very seldom contain slates.

Throughout the series conglomerate is conspicuous by its absence.
The Drayton and Slade group, if not another name for the olive
slates which form the base of the Pilton beds, below the Cucullea
zone, has no existence; and if the Cucullea and olive slates are to
be regarded as a separate division, the term Marwood used by Prof.
Hull is much the most suitable, owing to the presence of the Hang-
man lower down. W. A. E. Ussuer.

Brar STREET, BARNSTAPLE, Dec. 1878.

THE NORTH DEVON SECTION.

Srr,—Professor Hull, having depended on the writings of others
for his knowledge of the North Devon rocks, has obtained the result
which usually follows this method of inquiry. His proposed classi-
fication looks, no doubt, very well in print, but there are two or three
points to which any one knowing the locality must take exception.

At page 531 it is suggested that ‘it will probably be found on a
careful re-survey of North Devon, that the Pickwell Down Sand-
stones are somewhat unconformable to the underlying beds.” Now,
as a matter of fact, so far from this being the case, there is a gradual
passage from the slates to the sandstones; first slates alone, then
slates with layers of sandstone; next, sandstones with layers of
slate, and finally the Pickwell Down Sandstone itself. With regard
to a re-survey of this district, it must be remembered that the present
map was constructed, not by the Geological Survey, but by De la
Beche, working as an amateur; and the only boundary-line shown
on it is that separating the Devonian and the Carboniferous. In
1865 I laid down for the first time, on the one-inch scale, the
various subdivisions of the North Devon series from personal obser-
vations made during the preceding three years. The nomenclature I
then published I had occasion to alter shortly afterwards by the
substitution of Cuculleea zone for Marwood zone,’ and the adoption
of “ Pickwell Down Sandstone” for the upper portion of the Morthoe
group. Mr. W. A. E. Ussher, F.G.S., of the Geological Survey, who
has now been engaged for some months in mapping the river valleys,
informs me that, after going carefully over the ground, he has not
only adopted these subdivisions, but also the general horizons as
shown on my map.

As far as the Drayton and Slade beds are concerned, they have
been placed by Professor Hull in a most convenient position in his

1 For reasons see Quart. Journ. Geol. Soc., vol. xxii. p. 374.

Correspondence—Mr. J. Gunn. 95

classification, as passage-beds between the Baggy or Marwood bed
and the Pickwell Down Sandstone; though to do this they must be
transported bodily at least one mile to the south. I may also notice
the misapplication of the term Baggy and Marwood slates—this bed
consisting principally of sandstone; the thin intercalated beds of
olive slates and shale being the exception.

_ In the Morthoe group I am not aware of any “ purplish”’ slates.
Their real colour is a silvery grey. The purplish slates included by
Professor Phillips in the then undivided Morthoe group le above the
Pickwell Down Sandstone, and form the passage between it and the
Cucullea zone.

The suggestion as to the Foreland Sandstone being Upper Silurian
must be taken for what it is worth; as with a few most indefinite
traces, which may be attributed to organic remains, it is impossible
to fall back upon paleontological evidence.

Another objection to Professor Hull’s explanation of the North
Devon section is, that he seems to ignore altogether the existence of
Upper Devonian fossils. The Ilfracombe group with its limestones
undoubtedly belongs to Middle Devonian age, and if both the Pilton
beds and the Cucullea zone are transferred to the Lower Carbon-
iferous, he leaves no fossiliferous bed whatsoever of Upper Devonian
age; but has evidently trusted that “Drayton and Slade” might
serve to fill up the gap, or that an unconformity might exist at the
base of Pickwell Down to account for it.

Pinton, BarnstTapLe, Dec. 16, 1878. TownsHEenD M. Hatt.

MIOCENE FLORA IN ARCTIC REGIONS.

Str,—Voluminous and elaborate writings have issued from the
press, in almost every possible form, to account for the existence of
a Miocene flora in Arctic regions, without, I need scarcely say, any
satisfactory result. I venture in a few lines to suggest an element of
change, or rather a new application of one, which seems to have
escaped notice. It consists in the transfer of water by the Gulf
Stream from Equatorial to Polar Regions. This is incessantly in
progress, and it would be difficult to ascertain the immensity of the
volume of water which is thus transferred, simply through the
agency of the sun. It would be equally difficult to ascertain the
enormous quantity of ice which is amassed annually by the congela-
tion of this water. It is the fact of its being so warmed which leads
to its being conveyed nearer to the North Pole than it could be under
other known causes, but the point must be reached when its fluidity,
in great part at least, must cease.

Now, it appears to me, that, owing to this cause, there must be such
an accumulation of ice as would tend, if the pressure were equably
circumpolar, to depress the Equator: and, if it were lateral, as
under circumstances it must be, to produce an obliquity of poles, in
proportion to the bulk of the ice and its nearness to the Pole. With
reference to this obliquity, I might merely add Q. E. D., and submit
the problem to the public in the naked simplicity of truth, reserving
to myself the privilege of defence or explanation as occasion may

96 Correspondence—Mr. Dakyns.—Obituary—T. Sopwith.

require. I will only remark that an interesting analogy may be
traced between the evaporation of the water of the ocean and the
impulsive motion of the Gulf Stream, both alike due to solar heat ;
only the vapour is liable to be converted into snow much nearer
home ; but the Gulf Stream rolls on till its heat is expended and it
is converted into ice, and so its function in the economy of Nature is
discharged, which may not at present have been fully appreciated.

26, TBraaol or Wares Roap, Norwicu, JoHN GUNN.
January 15, 1879.

THE HITCHING STONE.

Srr,—In the British Association Report for 1874, page 196, the
“ Hitching Stone” on Sutton Moor, near Keighley, is described as a
boulder. As I surveyed that country, I may perhaps be allowed to
say that in my opinion the Hitching Stone is not a boulder. It is
simply a. block of Millstone Grit, weathered in place, the rest of the
layer having, in the immediate neighbourhood, been removed by
denudation. Ina broad sense, it forms part of the massive grit of
which Hitching Stone Hill is composed. The stone stands on the
escarpment of this grit, the base of which is marked by Hitching
Stone Spring, about 30 feet below. This bed of grit is considered by
my colleagues and myself, on stratigraphical grounds, to be a
portion of the Rough Rock. Hanging Stone Quarry is in the grit of
Harl Crag, which is the principal bed of the Third Grit Series.

The most remarkable thing about the Hitching Stone is that it is
perforated by a large hole, out of which a tree, a Lepidodendron as
far as I remember, has weathered. A vertical section across the
hole is of an oval shape, measuring 15} inches Be the longer
axis horizontal or rather along the bedding plane: thus we see the
flattening produced by the weight of the overlying sand on the
decaying trunk ; and we also see that the stone is standing in its
original position in the bed of grit of which it formed a part.

BRIDLINGTON Quay. J. R. Daxyys.

renee Awe wae

THOMAS SOPWITH, M.A., F.R.S., F.G.S.
Born 1803. Diep 1879.

Wz regret to announce the death of Mr. Thomas Sopwith, F.R.S.,
at Westminster, on the 16th January last. He was born in 1803,
at Newcastle-on-Tyne, and was for nearly 50 years extensively
engaged as a civil engineer in mining, railway, and other works,
both in this country and on the Continent, and was the author of
several works on architecture, isometrical drawing, and mining. In
1838 he was appointed Commissioner for the Crown under the Dean
Forest Mining Act, and in the same year a communication made by
him to the British Association led to the establishment of the
Mining Record Office. He was a member of many of the leading
scientific societies, and one of the early members of the Institution
of Civil Engineers.—Daily News, Jan. 17, 1879.

Erratum. In Mr. Dakyns’ letter in the Guot. Mac. January, 1879, p. 46,
line 11 from bottom, the words river base should have been river Ouse.

oe

~

CEOL :MAG.1879.

GM. Woodward det.

DECADE 11VOLV1.PLATE. Iv.

| ty ‘ West New men Co. imp.
Protophasma Dumasii,Brong.Coal MeasuresFrance.

(To face .97°)

THE

GEOLOGICAL MAGAZINE.

NEW SERIES. DECADE II. VOL. VI.

No. IIIL—MARCH, 1879.

@ne Gales N Ae eae ee aes

————

J.—On a New Genus or OrtHopterovus INSECTS OF THE FAMILY
Puasmipm (ProropuHasma Dvuuasii), From THE Uprrr Coat-
MEASURES OF ComMENTRY, Dept. ALLIER, FRANCE!

By M. Cuaries Bronenrart,
of the Museum of Natural History, Jardin des Plantes.

(PLATE IY.)

We possess only a few elements of the Insects of the Coal

Period—Articulata are rare in these beds, and it is only
after long research that we are able to collect sufficient materials
for a special work on the Entomology of this epoch.

Prof. Goldenberg has made us acquainted with the fauna of the
Coal-measures of Saarbriick, and has quite recently (1877) published
the second part of his work, entitled ‘‘ Fauna Sarepontana Fossilis,”
in which he describes fairly preserved wings of Neuroptera and
Orthoptera, one of which (Hugereon Boeckingii) also exhibits the
remains of the body.’

In America, Mr. Samuel H. Scudder has ardently studied the
Insect-remains from the Coal-measures of the United States. Lastly,
Dr. H. Woodward has published several works on the fossil
Articulata, and amongst others, in 1876, an interesting note on a
very complete Orthopter from the Coal-measures of Scotland
(Lithomantis carbonarius) .*

The insect-remains found in the Coal-measures belong principally
to the running Orthoptera, such as the Buarripm, some species of
Manrip#, and some NeuropreEra, such as Termites and Hemerobius.

Prof. Goldenberg has given the name of Fu/gurina to certain
insects, which would indicate the presence of HemiprEera in the
Coal epoch.*

1 Translated from the ‘‘ Annales des Sciences Naturelle,’ 6¢ Série, 1878, Zoologie,
Tome vii. Art. No. 4, by A. P. Wilson, Esq.

2 See papers by Dr. Anton Dohrn on Z#. Boeckingii, Paleontographica, 1866, Bd.
Xill. p. 333, taf. xli. and 1869, Bd. xvi. p. 129, taf. viii.

3 See Quart. Journ. Geol. Soc. 1876, vol. xxxii. p. 60, pl. ix. fig. 1.

4 I possess some wings of insects very like those figured and described by
M. Goldenberg, but more complete, and showing the reticulations of the wing, but

DECADE II.—VOL. VI.—NO. III. 7

98 Ch. Brongniart—New Fossil Insect from the Coal-Measures.

I am indebted to my friend, M. Grand’Hury, for the oppor-
tunity of adding a new form to the running Orthoptera hitherto
described.?

It was obtained from the Upper Coal-measures of Commentry,
Allier.

I ought at the same time to describe several other fossil Articulata
from St. -Htienne, which this able paleontologist has procured for
me, but the very perfect state of preservation in which this fossil
has been found, and the interest of its zoological affinities, induces
me to make it known immediately.

The fossil is sufficiently well preserved to be seen, as represented
in our Plate, without the aid of a magnifying glass, and we at once
recognize an Orthopterous insect allied to the Phasmide, from which
it differs, however, by certain characters to be presently referred to.

It is the first example of this family which has been obtained in
a fossil state. On the intaglio one observes a brownish matter,
which is darker in some places, and probably represents the sub-
stance of the integument.”

This magnificent Orthopter is preserved in profile lying on its
right side, and every portion of its body except the abdomen is
preserved. One can see (even with the naked eye) the limbs with
their serrated margins; the head, the eye, the antenne, and the
palpi, lastly the elytra, of which one is very well preserved, and
the fine second pair of wings, both of which are almost entire.

The Phasmide have been carefully studied by MM. Audinet-
Serville, Westwood, and Gray. The last of these authors divides
the ‘‘ Spectres” into two great groups; the Apterophasmina, or wing-
less Phasmians, and the Pterophasmina, or winged Phasmians.

The Orthoptera included in the family of the Poasmrp= have very
different forms. Some have the antennz very long, and very slender
(Phasma); others have them on the contrary short and very robust
(Cyphocrana). One has the prothorax very short (Phasma) ; with
others it is longer (Prisopus). Lastly, certain genera have the legs
smooth and destitute of spines (Phasma) ; in others, on the contrary,
they are very angular and serrated (Diura, Gray, Cyphocrana).

I shall not speak of the other genera, as they have no points of
resemblance with our fossil, but proceed to compare it with the
groups above cited in the latter part of my report.

I dedicate this beautiful Orthopter to my uncle, M. J. B. Dumas,
Member of the Academy of France, and Perpetual Secretary of the
Academy of Sciences.

they have no relations to the Hemrprera. They are, I believe, the wings of |

Nevroptera, which probably belong to the genus Chauwliodes, of Westwood. ” (See
J. O. Westwood, “ Oriental Entomology,” Chauliodes subfasciatus, p- 70, pl. 34,
Fig. 5.

r Tis fossil was discovered by M. Fayol, Engineer, in a bed of compact
micaceous shale of the Upper Coal-measures of Commentry (Allier), in the Forest-
pit, at 5 métres 50 from the top of the great Coal.

2 An analogous observation has been made on fossil plants; one has noticed the
impressions of leaves in the Coal-measures, in particular the leaves of Ferns which
could be detached from the surface of the shale and examined separately.

Ch. Brongniart—New Fossil Insect from the Coal-Measures. 99

PROTOPHASMA, Nov. gen.
Protophasma Dumasii,’ Ch. Brong. (Plate IV. Fig. 1.)

LENGTH. BREADTH.

Pa pr aos ee ls 4 mill. 3 mill.
PAMNONM EDs ied Shee See aee ne RCAC EL eet ae Qe is; ayes
FTG adh yas sesh Sek eat LU eee cee ae Oe a. 6) oie
Pro th ora yaaa tee eect een 12 5 6°50 ,,
WMfesothoraimun. wy siee ste atreeatenake ene Tele HO 5
ie tabhorance mettre eterna Tee gags 323
PAVoG Orn erie eee een ees PPS PE kD 55 8 ,, at the base.
MOTE corceeertrecee WG 5 Ob ass
Ist pair tba 1S 5. DF setae
LEAT SUES eeseeesteseeee OM. 1 Fe
{ femur, Seo. Ges. BV 55
Limbs .....¢ 2nd pair THVOND, rome Nl ee 2 fas
uLarSUSieeeeee oes ‘Siapss 1 =
MIGTENETE Sereeerrere OD ee ANN Na
érd pair tilbtay wowcee 22 2°50 ,,
LEVESON ceed Ae NY. 96 NN as5
TON h yng) eee yee hears One ere ete oe Cae Oe 183 55 (fee ee
|Whinorsis sneer Fete a eke te weed 85 32

)

The head of Protophasma, like the rest of the body, is seen in
profile, and is of an oval form; it is longer than broad. Only one
of the eyes is visible ; it is rather long and prominent. The antennz
are attached to the front of the head in the centre; they are short, being
only 21 mm. long. This character of the antennz distinguishes the
fossil from the Phasmide, properly so-called, and relates it to the
genus Cyphocrana. The first joint is small and round; the second
is larger, rather long, and increases in size at its distal end. I
cannot clearly define all the other articuli, but those which can be
seen distinctly are long, slender, and smooth.

The two palpi are well preserved; they are composed of four
articulations almost of the same length; but the last is smaller than
the others. One sees the upper labrum and one mandible; but the
details cannot be clearly made out. The left mandible, which is
alone visible on the surface of the matrix, is broad at its lower part.

Amongst the insects of this family the thorax is divided into three
portions, the prothorax, the mesothorax, and the metathorax; and
to each portion a pair of legs is articulated. In the living forms
(Phasma) the prothorax is usually short, and it seldom in any case
exceeds the length of the mesothorax (Prisopus). In Protophasma
this section is longer than the mesothorax, in which character it
resembles Prisopus.

The prothorax is cylindrical, and expands near the head so as to
form a collar. It is the only part of the thorax which can be clearly
seen; the other divisions are not so well preserved.

The abdomen, as already stated, is wanting in the fossil, but I am
enabled approximately to estimate its probable length.’ In order

1 From mpértov ‘ first’ and gacpa ‘a spectre.’

* For example :—Total length in millimétres Length of Length of
of living forms. the thorax. the abdomen.
10 3
20 6 13°50
16 4-50 10
NG) Wicket eeccrs 5°50 11

100 Ch. Brongniart—New Fossil Insect from the Coal-Measures.

that these insects may maintain their equilibrium, the weight of the
abdomen must at least be equal to that of the head and thorax; this
relative proportion is constant in the living species; indeed, the
abdomen generally exceeds the wings in length by one or two
centimétres.'. I am supported in this conclusion by a number of
examples. For instance, in a Phasmian which has a total length
of 16 centimetres, the head and thorax are 54 centimétres, and the
abdomen 11 centimetres long. We see that the abdomen is twice
as long as the head and thorax together.

In the fossil, this part, the head and thorax, measures 44 centi-
métres, the wings 8} centimétres; therefore, for the insect to be
in a state of equilibrium, the abdomen must have been about 10
centimétres in length. I make this statement with all reserve.
Another specimen of this insect. in a more perfect state, must be
discovered in order to justify this conclusion.

The legs are perfectly preserved. The first two pairs are almost
of equal length, but shorter than the third pair. They are all
angular, and serrated, and in this respect they resemble those of
Cyphocrana, and differ from those of PHasmipm.

The trochanter is robust and short in the three pairs; in the first
two pairs the femur is triangular, and is finely serrated along its
inferior margin. The tibia is also angular and serrated, and is
contracted near the proximal end; it terminates in two points at the
distal end. The tarsi are alike in all the three pairs of feet, and are
divided into 5 joints, of which the first is the longest; the last is
provided with a pair of recurved, pointed, and widely-divergent
claws, separated by a small rounded pad. The terminal articulation
of the tarsus is broadest at its distal end; the three middle joints
are of equal length. The third pair of legs are the longest. The
femur is more robust and less angular than in the two other pairs,
and is armed with seven sharp spines along its lower margin.

The tibia is angular, and bordered with fine denticulations, nine of
which are larger than the rest, and placed at regular intervals apart.

The elytra of Protophasma do not offer any special characters,
and are of moderate size, measuring about one centimétre in length.
A stout longitudinal nerve marks the mesial line.

The true wings, or the second pair, are quite distinct, but are
neither of them quite complete. Fortunately, what is wanting in one
is preserved in the other, so that I] have been enabled to reconstruct
them, as seen in the accompanying plate (Pl. 1V. Fig. 2). In the
existing Phasmians, the wing is divided into two parts; the anterior
portion supported by three or four straight nerves, which reach to
the extremity of the wing, and united by irregular polygonal reticu-
lations; the posterior portion traversed by slender and _ straight
nerves, which radiate, fanwise, from the base of the wing, and |
which are united together by finely reticulating cross-nerves.

The wings of Protophasma differ from those of the living
Phasmians. In the fossil form, the division between the anterior and
posterior portions of the wing is not so well marked as in the living

1 Except certain species which have very short wings.

Oh. Brongniart—New Fossil Insect from the Coal-Measures. 101

species. In both, however, the posterior portion of the wing is the

largest. To facilitate the description of the neuration, we will
divide the wing into parts, as in the living species. The total length
is 85 mm., and the breadth, near the middle of the wing, 32 mm.
The upper marginal nerve (a) is a little curved towards the middle
of the wing (Fig. 2a); the upper sub-marginal (0b) is parallel to the
marginal (a), but straighter, and at the broadest portion they are
6 mm. apart. The externo-median (c) is 1 mm. from the upper
sub-marginal (b), and at the extremity of the wing it is distant mm.
from it. The median (d) follows the same direction as the preceding
one, but it is more curved.

A branch formed by the union of the reticulations, and which
becomes a true nerve, divides into two branches near the extremity
of the wing. The interno-median (e) is one mm. from the median
nervure, and at a distance of 13 mm. from the base of the wing it
dichotomises ; the upper branch, at 14 mm. from the margin of the
wing, is divided into two branches. The second branch of the
internal median, which is given off from the principal trunk at
14 mm. from the edge of the wing, separates into two branches,
the upper one of which alone dichotomises. The lower sub-marginal
(f), which is 2 mm. from the preceding one, divides into two
branches, the upper one of which subdivides again into two. The
anal nerve (g) is very short, and splits up almost immediately
into two branches; then, at a distance of 7 mm. from the base of the
wing, we see 14 straight and slender nerves, which alternately
subdivide into two branches near the ventral margin. All these
nerves are united by numerous straight and delicate reticulations.

The wings of the existing species of Phasmians are generally
covered with colour-bands, either brown or blue, on a ground of
a lighter hue; this was evidently the case in Protophasma also.
We see, in fact, with the naked eye, darker bands which traverse
the wings transversely to the general direction of the nerves. In
the neuration and coloration of the wings, the fossil form resembles
most nearly the Phasma variegatum, Stoll.

The habits of the Phasmians are but little known, but they are
vegetable feeders, whereas the Mantipm are carnivorous. These
insects crawl sluggishly on plants, and feed upon the young shoots
of resinous trees, their habits are generally solitary.

In the Carboniferous period we find evidence of the existence of
numerous trees of the family Coniferee (and Lycopodiacez), such as
Sigillaria, Calamodendron, Arthrophytis, Cordaites, etc., all resinous
trees suitable for Protophasma.

It is remarkable that the insects of the Carboniferous epoch appear
to differ but little from those which exist at the present day; but it
is not in France, nor even in Europe, that we must look for insects
like those which existed at the epoch of the Coal-formation. It is
in the hot regions of America, Asia, Africa, and Australia, that we
find their homologues; and the Orthopter which we have just
described adds another example in support of this assertion. All
that we know of the Flora and Fauna of the Coal-period, proves

102 W.A. H, Ussher—Post- Tertiary Geology of Cornwall.

to us that the Earth was covered with a sheet of water of little
depth, from which numerous islands emerged, over which a
luxuriant vegetation spread. There, in the water, lived the
Palgocypris and the Palgoniscus, on the banks of the water, upon
the Sigillarias, lived the Phasmide and Mantidz, of which several
species have been discovered. In the interior of these islands, in
the earth formed of leaves, stems, and branches of plants, lived a
great number of Blattide.

The knowledge we possess of the Carboniferous period, that is to
say, of the plants and animals, proves to us that there was at this
epoch a higher temperature and intense sunlight. ‘The presence of
these two insects supports this conclusion, since all the existing
representatives of these groups live in the open sunlight in the
hotter and more humid regions of the globe.

EXPLANATION OF PLATE IV.

Fie. 1. Protophasma Dumasii, Ch. Brong. a, head; 6, antenne; ¢, eye; d, palpi;
e, prothorax; 7, first pair of legs; gg, elytra; hh, second pair of legs ;
Jj, third pair of legs; &, abdomen, restored; ™, wing folded on itself;
m, wing border of the second pair, restored ; 77, wings of second pair.

. Wing of the second pair, restored (the letters are explained at p. 101).

. Part of Fig. 2, twice natural size. Fic. 4. Elytron.

. Wing and Elytron of Diura Japetus, Gray. a, upper portion of wing with
straight nerves; 4, lower portion with nerves radiating from base of wing ;
e, elytron.

» 6. Head of P. Dumasii, twice natural size; a, prothorax; 6, head; d, palpi;

e, labrum; f, eye; g, mandibles; h, antennze.
» @. Head of Diura Japetus, Gray. Fra. 8. Half of same, twice natural size.
», 9. One of the third pair of legs of P. Dumasii, twice natural size.

Qi co to

I1.—Post-Trrtiary GHoLtocy or Cornwatt.?
By W. A. E. Ussuzr, F.G.S.

Part JJ.—Puurstocene Purrtiop.
HE materials for a classification of the later Pleistocene deposits
of Cornwall are so voluminous that it was found impossible to
embody them in a single paper. Having submitted to the Geological
Society a general classification with such notices of the deposits as
seemed necessary to show the grounds whereon it was based, I
purpose in the following paper to complete the notices of deposits.
As an apology for the amount of compilation thus rendered neces-
sary, | must plead the object of the papers, viz. to place in one view
all that has been written on the subject, as references alone would
entail more time and trouble in looking up than many readers would
be disposed to concede.

The paper is divided into the following sections :—

1. Oldest superficial deposits; 2. (a) Boulder Gravels, (6) Raised
Beaches, and (c) ‘‘ Head.” 38. Submerged Forests and Stream-Tin
Gravels. 4. Recent Marine and Blown Sands.

Oldest Superficial Deposits——From their isolated positions, and
evident relations to an entirely different surface configuration, the
gravels of Crousa Down and Crowan, and the sands and clays of St.

1 Continued from the February Number, p. 81.

W. A. E. Ussher—Post-Tertiary Geology of Cornwall. 103

Agnes, must be regarded as the earliest traces of superficial deposits
as yet observed in Cornwall.

Gravels of Crousa Down and Crowan.—On Crousa Downs, Lizard
District, a patch of rounded and subangular quartz gravel “ occupies
an area of about half a square mile at a height of about 360 feet
above the sea” (Report on Geol. Corn. and Dev. p. 396).

The Rev. E. Budge (Trans. R. G. 8. Corn. vol. vi. pp. 1 and 91)
describes the deposits, generally, as extended layers of fine yellow
gravel, with a quantity of quartz pebbles, exposed in pits 10 to 12
feet deep in places, near the road leading to Coverack. The
character of the sections is given thus—Black peaty soil containing
small angular quartz stones about 6 inches thick, upon layers of fine
and very coarse gravel alternating in no very determinate order,
containing quartz pebbles of very irregular form, some as large as a
man’s head, but for the most part not exceeding 2 to 3 inches in
length. The Crousa Down gravel rests on Diallage rocks.

A similar occurrence was noticed by Mr. Tyack (62nd Ann. R. Geol.
Soe. Corn. p. 176, etc.) at Blue Pool in Crowan. The pebbles covered
an area of 800 yards from north to south, and 500 from EK. to W.
They are scattered over the surface, are well worn, and vary in size
from large boulders to the dimensions of hazel nuts. The gravel is
400 feet above the sea, it rests on yellow clay. As at Crousa Down
the quartz is such as would be furnished by veins in the Killas, the
pebbles of schorl being very few, and the occasional granite frag-
ments angular; yet the Killas districts near Crowan are at a much
lower elevation than the granite on which the pebbles are found.

These quartz gravels appear to have been derived from quartz-
iferous Killas, either by direct transport of aqueous agencies suffi-
ciently protracted in their operation to allow of the comminution of
the slaty matter, or indirectly by the disintegration and redeposition
of a quartz conglomerate rock of Paleozoic age. Referring to the
derivation of the Crousa Down Gravel, the Rev. EH. Budge illustrates
the prevalence of quartz veins in the Killas to the north by citing
the occurrence of masses of quartz in the slates near Nare Point,
whence they can be traced for some miles along the line of strike;
and of a quartz vein 10 feet wide on the south-west of Carne, in St.
Anthony parish.

Between the Loo Pool and Marazion, on the top of the cliffs, near
Trewavas Head, small flint and quartz pebbles occur in the soil, and
do not appear to extend more than a few paces inland. As their
height above the sea and the adjacent configuration preclude the
possibility of their being the relics of a raised beach, I am forced to
conclude that they are either traces of gravels somewhat similarly
situated to those of Crousa Down and Crowan, or that during
exceptionally severe gales some of the smaller pebbles of the beach
below had been from time to time carried upward in the spray and
landed on the top of the cliff.

Deposits of St. Agnes.—(Report, etc., p. 258). De la Beche was
disposed to regard the sands and clays which nearly encircle the
higher parts of St. Agnes Beacon as “the remnant of some supra-

104 W.A. E. Ussher—Post-Tertiary Geology of Cornwall.

cretaceous deposit.” “They occur at an elevation of between 300
and 400 feet above the level of the sea, resting upon the slates of
the hill, and partly also on a small portion of the granite rock which
there occurs; the granitic rock and slates being traversed by several
tin lodes.” “This isolated deposit has not hitherto been found to
contain organic remains, with the exception of some traces of plants
that have the appearance of Fucoids.”

The following sections are given by De la Beche (Report, p. 259) ;
Hawkins (Trans. Roy. Geol. Soc. Corn., vol. iv. p. 1385, etc.) ; Hen-
wood (op. cit. vol. v.); respectively—on the North-east of the Beacon.
Numbers affixed for reference :

(1) Head of rubble from hill above or Cobb ... ... «+ Sf. Oin.

MellOw Sand Aas sent ugha MMe ere 0a) ch abo Re eae te = 2ft. Oin.
Brownish sand with numerous planes dipping at 45° (apparent

PARES) Corl igs' oc) cg Ee aa ee litt. Oin.
ihight-colonredsmininetcl aye yes ul ee ipsa acon hssn a eeien 2 tLe UH
Bluexclayzcparen i meee = een onl esi (aso evs s aeaei gitere MpaO LUO.
Mellow:cand@ieaaee mere acetone hl ea Ch nN Lacerta mun ae Um OETL.
Wihite\sand)imhtcmay, Uhre) edi Db icc Wee Micke vase St alk e Meath etetten uOUDE
Yellow sand ... A. ... éft. Qin.

Pebbles resting upon an uneven surface of slate—thiekness variable.
(2) Near Trevaunance—
Yellow Cobb with Killas rubble...

Hire niclay aires cack aiece Re tate naw deren esee gaouuesHOnts
Chlayy anal cama’: dyoo aber esd ona reat Gob acd a eco cH OM
Fine white gritty sand—depth not ascertained.
(3) Half a mile from the Beacon—
Surface 383 feet above high water.
CET ape Rake esael Lene das: di GAs ido. tba -soo hungs caus | Orin.
Yellow sand, 7 feet below the surface. .. St. Qin.

The overburden not mentioned would seem to be 5 feet thick.
The following sections given by Messrs. Kitto and Davies lie
toward the North-east of the Beacon (Trans. R. G. Soc. Corn., vol. ix.) :
(4) Near the outer margin of the deposit—

Head: ths. SeeeY ote, eRe Te ee Lotte Cine
Mellowssands.2) tesst scenes gion Wesmeeces: Neasialdeondpw2tt., Oi
WRedisand eree vi iecay Wich secs Beaeen Com pecs dees bees ie eta) MOI
White sand... . sas goo Gata Onin

Pebbles in sand not gone ‘through. ji
Sections near the above on N.W. and S.W.

(S)OnUNEWe— Heady tecniescy venstrecaicre Meares, wees) Ueeep oc. ge Olt ame Olle
Clayawath¥atew pebbles resi neem ese pssst i ecee eet same ORT
Sanders ambi icerhy ARG E We sages Read eee 12ft. Oin.
Sandstone ... . pte Waco, ota “Obes

Sand with pebbles not gone through.

(6) On S.W.—Very sandy overburden, with numerous quartz pebbles from the
size of a marble to that of a walnut, beneath which clay only is raised
varying from 6 to 12 feet in thickness.

On the inner margin of the deposit to the west of the above,
‘mining operations in 1865 exposed a cliff facing North, 16 feet in
height, and 15 feet below the surface,” nearly perpendicular,
“‘ smoothed and polished” and worn ‘into caves and hollows.” An
adit cut through to the sand on the other side proved this to have
been in all probability a projection from a main cliff face, which old

W. A. E. Ussher—Post-Tertiary Geology of Cornwall. 105

miners state to occur facing eastward for some distance to the south-
ward, and to be worn into numerous hollows. The sand in this
part of the deposit “contained very large pebbles and boulders and
angular” stones.

Compare the section given by De la Beche (op. cit.) with the fol-
lowing by Hawkins on the North side of the Beacon (op. cit.), and
by Henwood, locality not specified (op. cit.) :

(7) Yellow Cobb with rubble of Killas stones... .. eect 2k) GIN.
Brown sand with sedimentary divisions dipping S. at 45°... 9ft, Oin.
White Clay ... 4in. to din.
Brown an bluish-grey ‘clay (with a "slight admixture of f
Carbonaceous matter) ica see) ers leroh) eas esa cas Sibson Ont.euOim.
Gritty sand ... ... ... Beem tes nue) ccohe Olbs OL ku ee OLD.
(8) Loose stones and earth, up i ee 6ft. or 8ft. Oin.
Pink, yellowish, and ’ prownish sand, in ‘layers dipping
southward. ... 2ft. to 10ft. Oin.

(In the lower portions small ferruginous crusts and masses
of conglomerate in a sand or “clayey matrix are some-
times found in various pits.)
Stiff blue clay... Bees esse dt testOplitag ©
Milk-white sand occasionally clayey i in the upper part.
Bed of pebbles in which stream-tin is said occasionally to occur.
The following section on the North of the Beacon is given by Dr.
Boase (Trans. R. Geol. Soc. Corn. vol. iv. p. 296):
(9) 1. Subsoil—earth with angular stones... ... lft. to 2ft. in.
2. Yellow and white sand, with minute particles of schorl
3. Dark ochreous-coloured sand, with a minute Ce
of clay between the grains... 2ft. Oin.
4. Soft and greasy, tough, adhesive blue clay, with an
oily rancid smell, as if from impregnation of

=

Nn.

animal matter ... 1ft. Oin.
5. Clay (called Furnace clay), white and Plastic, emitting

anwarcillaccouss Odour eit ice! iccetnteest mesel) eee 3ft. Oin.
6. Sand, nearly pure white... ... 20 7it. Qin.

7. Loose rubbly layer, like (1), said to rest on solid rock.

(10) Quoted by Mr. Henwood (op. cit.) from the Mining Review,
paper by Mr. Thomas :—Section on the North of the Beacon, half a
mile from it, near Wheal Kind. Surface 383 feet above high water.
Hight feet sunk in white sand (7 feet below the surface).

(11) Mr. Henwood quotes (op. cit.) the following :—N.W. from
the Beacon. Surface at 377 feet above high water. Sand met with
at 3 feet below the surface ; 15 feet sunk through yellow sand.

(12) Messrs. Kitto and Davies give the following section to
N.W. of the Beacon :

Soil and Head... .. tins: | Geb Bodh eal elias
Blue fire clay (coarse, through ‘admixture of f sand) cca’ 60 con. Chilis Onn
Candle clay, adhesive and very tough ... ... ... soo coo eo 2ft. Oi.
Sand resting on Killas .. ... sce noo, Udit | Ui

(18) Mr. Flaw eine (op. cit.) pee ce Hollowine section on the
East of the Beacon :
Depth of the atts 24 feet in all.
Yellow Cobb under vegetable mould... ... ... ... « 2ft. to 3ft. in.

Yellow sand . ee Peis tur coe ton ieahienen ort. to) Atta Ome
Mimi neae ayant at eR Ny eget lft. Qin.
White sand ... .. 43ft.todft. Oim.

A few flattish pebbles i in black mud (local name) i Gl 28h to oft: \Oim:

106 W.A. HE. Ussher—Post-Tertiary Geology of Cornwall.

(14) Messrs. Kitto and Davies give the following section on the
east of the Beacon (op. cit.) :
Head ... ned! Geo RSA ned goo) cos cae), Gea Dini,

White candle clay ool VAdS MESOMCRO cca Ss: “dao hen Gham Me Oia,
Gravel... .. Bence) was", ieselll ec uae eeemenec omy mnt tax OuIe
White candle clay aa6 Boo) aban |, gy eine rbials

Yellow and whitish sand not gone through.
The following sections were taken in the isolated part of the
deposit on granite to the West of the Beacon :
(15) Hawkins (op, cit.)—
WellowaC ODD imecsfersemitical lesan acelu esen ase 4ft. Qin.

Clay ... 009 aco cD 00 6ft. Oin.
Puddle sand (local name)... 550) Seo fees) cou) RE Ho Bi Cham,

(16) Henwood, quoted from Mining Raia (op. cit.) :—Surface
418 feet above high water. Sand met with at 9 feet below the
surface; 12 feet sina through yellow sand of a lighter tint at the
base.

(17) Messrs. Kitto and Davies (ep. ne

Head ee deal ecle.! Wee) IE NO FG Sinem:
Candle clay UM EATS uaa UN arab or MBs aa oADintn | Orin;
Dark red sand ,. Be MSR eG Mie AEE UE ASS eae Ot mous
Yellowish sand | be ee ee thee Ome

Gravel, pebbles, boulders, and sand resting ¢ on granite 93ft. Qin.

34ft 3in.

I observed four pits, all in the main deposit, and lying to the
northward of the Beacon, varying from seven to eleven feet in
depth ; the very impersistent nature of the clay and of the colours
in the sands was very noticeable.

From the map and sections accompanying the paper by Messrs.
Kitto and Davies (op. cit.), it will be seen—that the clays are in no
place coextensive with the sands, although in parts their boundary
approaches very near to the limits of the deposit; that they are the
thickest in the isolated patch on the granite (17), which lies in a
basin ; that the coarse detritus is of exceptionally local character
in the different sections, tin stone pebbles being confined to the
immediate vicinity of lodes. The appearances of bedding in the sand,
and the relative positions of the sands and clays in sections (1),
(7), and (8), are indications of a continuity of deposit, which the
variability of the other sections given shows to be abnormal. The
occurrence of quartz pebbles in exceptionally sandy overburden
(section 6), is worthy of note, and suggests the former overspread of
gravelly detritus, similar to the gravels of Crousa Down and
Crowan.

The Head, as far as I observed it, consists of brown loam, with
angular fragments of local rocks derived from the hill above,
resembling, according to Messrs. Kitto and Davies, ‘“The soil and
subsoil found upon the Killas of Cornwall, except that it is some-
what sandy in parts and occasionally contains washed pebbles.”
This Head, Overburden, or Cobb, is of like nature, and probably
roughly contemporaneous with the accumulations of stony loam on
the coasts hereafter to be noticed. The preservation of the deposits

W. A. E. Ussher—Post- Tertiary Geology of Cornwall. 107

in their present form is probably largely due to this protecting
envelope of talus shed from the adjacent Beacon hill, which ex-
ceeds 600 feet in height.

From such local materials as the granite on the west of the
Beacon, the Elvan Course to the north of it, and the Killas, the
sands and clays seem to have been formed.

The position of the deposits with reference to the present coasts,
and to the high land of the Beacon, and the cliff-like sections and
waterworn hollows noticed in some parts, would seem, “as De la
Beche suggests,” to justify a marine origin, but with them “the
resemblance to the raised beaches appears to terminate” (Report,
page 258.) The interchangeable characters of the sands and clays
are more in accordance with the irregular deposition of a stream,
subject to fluctuations attendant on meteorological changes, than with
the more uniform sorting action of a coast-fringing sea. The very
local character of the basement gravels is also against the admission
of a marine origin. As an entirely new system of drainage has
been moulded since the deposits were thrown down, proximity to
the present coast-line is no argument in favour of marine origin or
former proximity to the sea.

Fluviatile agencies, which have produced similar effects in wear-
ing the surface of the shelf in stream-tin sections, coupled with the
weathering and water-wear of a vertical face, slickenside, or joint,
might, in the absence of further evidence, explain the phenomena
of the smoothed surfaces, water-worn hollows, and old cliff face
mentioned by Messrs. Kitto and Davies. Had such action pre-
vailed for a long period in an old line of drainage down which the
coarser detritus had been swept, the damming up of the old
stream course and selection of a new one above the present site of
the deposits, would tend to the formation of a lake in whose quiet
waters the finer debris of the adjacent land borne down by rills and
streamlets would have been filtered, and have settled down in the
form of sand and clay.

The isolated positions of the deposits of Crousa Down, Crowan,
and St. Agnes, afford no clue as to their relative ages. Yet this
isolation justifies me in classifying them together as the oldest super-
ficial deposits as yet noticed in Cornwall. An entire bouleversement
of the levels of their respective districts has taken place since their
formation, and all traces of synchronous deposition have been swept
away in the elaboration of the present drainage system. As they
can only be regarded as relics of much more widespread deposits,
the possibility presents itself that we may have in them the traces,
im situ, or re-distributed, of Tertiary or even late Cretaceous deposits,
presenting a different aspect to that in other areas through de-
pendence on local sources of supply. During the vast period that
intervened between the Culm-measure rocks and the Pleistocene
Age, it is unreasonable to argue from the absence of deposits of
intermediate age that Cornwall was never invaded by Secondary or
Tertiary seas.

On the Occurrence of Flints in Cornwall.—De la Beche (Report,

108 W.A. #. Ussher—Post- Tertiary Geology of Cornwall.

p: £29) commented on the abundance of rolled Chalk flints in the
recent as well as the Raised beaches on the Cornish coast; he
suggested the existence of a race making use of flint implements
prior to the raising of the beaches, and that these flints in trans-
port from the localities whence they were derived, might have been
dropped, and, in unlading, have been lost and rolled with the beach
pebbles. This theory may be dismissed as untenable both on
account of the absence, in inland localities, of relics of such a race
as that invoked, and on account of the number of natural flints and
the absence of signs of manufacture.

Mr. Peach notices (T.R.G.S. Corn. vol. v. p. 55) the abundance of
flints in some of the coves at Gorran, and suggests their derivation
from the Chalk of “‘ No Rest,” off the Dodman Point, ‘a name given
to some submarine rocks by the fishermen, owing to their trawls
becoming hitched in the rough ground.”

It is scarcely credible that such observers as De la Beche, Borlase,
Boase, Carne, Henwood, etc., could have failed to notice the
existence of Cretaceous rocks off the Cornish coast, and, if known
to them, they would certainly have commented upon them. 'There-
fore, in the absence of further particulars, it is safer to regard the
“Chalk of No Rest” as a local epithet without any geological
significance.

De la Beche, quoting Borlase (Nat. Hist. p. 106, in Report, p. 646),
says: “In the low lands of the parish of Ludgvan, in a place called
Vorlas, there is a bed of clay, about three feet under the grass, in
which numbers of chalk flints are found, with pebbles of quartz
and some shingle, with pieces of angular slate.” I was unable to
find the locality indicated, the present rector of Ludgvan being
ignorant of the name. Thinking, however, that Vorlas might be a
misprint for Crowlas, a small village on the flats near Ludgvan, I
made inquiries there, but failed to elicit any information respecting
the occurrence of flints in the neighbourhood.

Mr. Henwood (Journ. R. Inst. Corn. vol. iv. p. 214) mentioned
the occurrence of flints of considerable size in the tin ground at
Lower Creamy, a part of Red Moor, in Lanlivery, N. of St. Austell.
He also stated that a few flints have been very rarely found in a
peat bed, containing remains of furze, alder, oak, and hazel, in the
stream works of Pendelow, as shown in 1873 (op. cit. p. 218).

Mr. Higgs (T. R. G. 8. Corn. vol. vii. p. 449) gives a short notice
of the discovery of a substance resembling a chalk flint in a cavity
in a lode in Balleswhidden Mine.

If the above are Cretaceous flints, and not fragments of slate or
fine grit, to which contact with igneous matter had imparted a
cherty character, they would seem to indicate the destruction of
Cretaceous material, or of deposits of a later date, resulting in part
from the waste of Chalk.

Mr. A. Smith (T. R. G. 8. Corn. vol. vii. p. 343) mentioned the
occurrence of comparatively unworn chalk flints, and fragments of
Greensand rock more worn, on Castle Down, in Tresco, one of the
Scilly Group.

W. A. E. Ussher—Post-Tertiary Geology of Cornwall. 109

Mr. Spence Bate (Trans. Dev. Assoc. for 1866) alludes to the
occurrence of flints in moorland around Dosmare Pool, Curza
(2? Crousa) Down, on the top of Maen rock, at Constantine, and on
Trevose Head.

The flints occurring in the Raised Beaches will be noticed in the
section devoted to the latter further on.

As the present drift of shingle from W. to EH. is the reverse of
that which the presence of chalk flints in the recent beaches would
lead us to expect, we may conclude that they were obtained by the
destruction of the raised beaches, and explain their occurrence in the
latter by either of the following hypotheses: first, that the set of
the wind-waves during the formation of the Raised Beaches was the
reverse of the present, as Mr. Godwin-Austen suggests (Q.J.G.S.
vol. vi. p. 87); or, secondly, that during the Pliocene or part of
the Pleistocene Period, prior to the formation of the raised beaches,
the land stood at a much greater elevation, and the English Channel
valley as dry land “served to connect the British Islands with
France, etc.” (Godwin-Austen, op. cit.); that a large part of its area
was drained by rivers and streams flowing westward, and carrying
Cretaceous and other easterly derived detritus in that direction,
which detritus, on the submergence of the valley, was incorporated
by the Pleistocene sea in the beaches then successively marking its
advance, till the culmination of the subsidence at levels marked by
the Raised Beaches.

Notes on Glacial Hypotheses.

Although the Glacial epoch has left no direct evidences of its
changes in Devon and Cornwall, it is scarcely possible that either
county remained uninfluenced by them. The very fragmentary
relics of deposits formed during the existence of a previous and very
different configuration seems to call for some such powerful denuding
agencies as torrential surface waters, consequent on the termination
of rigorous conditions of climate.

The Rev. O. Fisher (Grou. Mac. 1873, Vol. X. p. 163) ascribes the
reversal of lamine in schorlaceous granite, in Carclaze Mine, to the
passage of ice over them. But such phenomena, as I have elsewhere
(Q J.G.S. 1878, vol. xxxiv. p. 49) endeavoured to show, furnish no
proofs of ice-action in the South-west of England. Striez or
moutonnéed surfaces have not been detected in Devon or Cornwall.
The grooved face of rock near Barlynen Abbey, North Devon,
ascribed by Prof. Jukes to ice-action (Guot. Mag. Vol. IV. p. 41;
vide Whitley, 32nd Ann. Rep. R. Inst. Corn.), is merely a voluted
bedding plane, a structure not unfrequently met with in Devonian
and Culm-measure rocks, and exhibited by some beds in an adjacent
quarry.

If Cornwall was at any time subject to extreme glacial conditions,
its highlands were not submerged during the Glacial epoch, nor
were its borders invaded by a foreign ice-sheet; for traces of
submergence would be found in the one case, and foreign ice-borne
materials in the other. Positive evidences of local glaciation are

110) = Rev. J. Clifton Ward—Geology of the Lake District.

also wanting, unless we regard the presence of large boulders at
high levels, as the diallage blocks of Crousa Down for instance, as
the unremovable débris of an old glacier system, and ascribe the
presence of large boulders, at some distance from their parent rocks,
in river gravels, to the relics of moraine, carried down to successively
lower levels in the excavation or deepening of the present lines of
drainage. However, if, as I agree with Mr. Godwin-Austen in
thinking (op. cit.), the land stood at a much greater elevation during
the Glacial epoch, a great and constant snowfall may have given
rise to local glacier systems; and as the present area of the
county would offer little more than the generative sources of the
(imaginary) glaciers, all traces of pre-existent deposits and of
moraine matter, except very large boulders, would be swept down
by the flood waters of the succeeding period of subsidence to levels
now submerged. But as all such glacial theories are purely
hypothetical, it behoves one to fall back on the probability that
Cornwall, during the Glacial epoch, stood at a much greater
elevation, and that its highlands were crowned with constant snows,
the melting of which during the succeeding amelioration, accom-
panied by subsidence, caused the liberation of great quantities of
surface water with torrential power carrying off the pre-existing
detritus to lower lands, now submerged.
(Zo be continued in our next Number.)

I beg leave to correct the following errata in Part I. of my paper. On p. 33,
line 40, for “10 to 20” read ‘10 to 12;” on p. 34, line 20, for “‘B.c. 400” read
“p.c. 440,” and for “exoas’’ read “ éovoas,” also for “vnoas” read ‘‘ynoous;”’
and on p. 79, line 1, for ‘‘on”’ read ‘‘ or.’ —W. A. E. U.

IIJ.—On tur Prysicat Hisrory or tHe Enerise Lake Disrricr.
Wir Norss on THE PossiBLe SUBDIVISIONS OF THE SKIDDAW
SLaTEs.}

By the Rev. J. Currron Warp, F.G.S., F.R.M.S.
Post- Carboniferous Periods.

As the Carboniferous rocks form a framework around the Silurian
mountain country, so do the Permian rocks for considerable
distances lie as an outer flat and bevelled edge to the slightly raised
Carboniferous frame, the edge indeed overlapping the frame itself
along the west coast-line between St. Bee’s Head and the Duddon
Estuary.

It is not purposed to give a detailed description of any Post-
Carboniferous formations lying outside the mountain district. The
two thick Permian sandstones (the Penrith and St. Bees), separated
by a set of shales and marls, are believed by some to indicate the
conditions of an inland sea, and the formation in some parts of its
English development to suggest cold or glacial conditions. How-
ever this may be, it seems more than probable that during the whole
of the Permian Period the present Lake District was dry land, and
undergoing that subaerial waste which, long continued, was to give

1 Concluded from the February Number, p. 61.

Rev. J. Clifton Ward—Geology of the Lake District. 111

rise to the present beautiful forms of mountain and valley. If the
Permian were partly a cold period, then an early set of glaciers may
have found their home among the early Cumbrian mountains, and
any amount of ice-smoothing and polishing of the rocky surface
then produced must, to a certain degree, have hindered the work of
denudation for a long period afterwards. Indeed, it is more than
likely that the very large amount of denudation produced by glacial
means during a glacial period is more than counterbalanced by the
retarded action of subaerial forces working upon a generally
smoothed and rounded surface. In post-Permian times, when
extensive north and south movements and dislocations occurred (as
along the foot of Cross Fell range, and the Pennine Anticlinal), sym-
pathetic movements may have taken place in the mountain nucleus,
and very likely the majority of the N. and 8. faults ranging through
the Silurians, and frequently shifting the previously formed E. and W.
ones, were produced at this period.

As we pass in review the periods succeeding the Permian, nothing
more can be said with regard to the history of the Lake District
than that in all probability the Cumbrian centre remained an area of
dry land, more or less lofty, though slowly being eaten down and
into by the forces of denudation. From the mountains as they then
existed one could have looked northwards and southwards into
areas of water beneath which the New Red deposits were being
formed. Subsequently the Liassic sea with its marine monsters
probably skirted the mountain district at no great distance.

Onwards in time through the Jurassic Period, with its Australian-
’ like climate, during which the Cumbrian mountains may have
experienced many a storm of semi-tropic violence, through the long
Cretaceous Epoch and Tertiary times must the District have been
suffering wear and tear, at times doubtless nearly or quite united to
the neighbouring high ground of the Pennine Range and of Wales.
No wonder so much has been carried away by apparently weak sub-
aerial powers of denudation, rather the wonder is that the mountains
should have been preserved at all, instead of all being levelled to
the sea. This will again be commented on in following pages, when
the question of the numerical equivalents of periods will be dis-
cussed. ‘That the District experienced many vicissitudes of climate
throughout this enormous length of time seems certain—now tempe-
rate, now semi-tropic, and now again probably glacial, and the last
“marked geological change which it underwent was during the so-
called Glacial Period proper.

Glacial Period.

This period having been treated of in full, as regards the Lake
District, in my former Papers, and in much detail in the Survey
Memoir, chap. xiii., nothing but a mere necessary outline will be
now given.

The glacial phenomena of the district are as follows :—Till,
mainly the product of a confluent glacier-sheet. Drift gravel, and
Stratified sand and gravel, often occurring in the form of eskers, due

112. Rev. J. Clifton Ward— Geology of the Lake District.

principally to marine action. Boulders carried far from the parent-
rock by glacier-ice at one time, and floating-ice at another. Glacial
scratches partly produced by a confluent glacier-sheet, partly by
small separate glaciers; also occasionally made by floating-ice during
the period of submergence. Moraines left by an early set of glaciers,
much modified by subsequent aqueous action; and more perfect
moraines left by the most recent local glaciers. Many years study
of these phenomena has led me to draw the following general
conclusions, which I take in part from my Survey Memoir, p. 97:

“‘ At the commencement of the cold period small glaciers occupied
the heads of the various valleys, and, as the cold continued and
increased, they became larger and larger, until, in many cases, they
united, overlapping the lower ridges parting valley from valley, and
forming one great confluent ice-sheet, the movement of which was
determined to the north and to the south, or east and west—as the
case might be, in different parts of the district—by the main water-
parting lines. A great quantity of rocky débris was moved onwards
and left scattered over the country, partly by the first formed
moraines being pushed forward, and partly by the ice overriding the
same and dragging on and triturating the fragments beneath it. In
this way the Till was formed, sometimes left in rock-sheltered
upland hollows, but most largely deposited on the lower and less
inclined ground.

‘‘Whether this first land-glaciation was interrupted by one or
more mild periods, the deposits in this district do not prove.
As the final close of this epoch of intense glaciation drew on,
moraines were left by the retreating glaciers plentifully scattered in
every valley, but the glacial streams and rivers must have made
much havoc amongst them, cutting them up and bearing away their
material to lower levels.

«Then, when the cold had disappeared, began a submergence of the
district to a very considerable extent. As the land sank, the old
moraine material was sifted, sorted, and partly rounded. At the
ends of some of the fiords or straits, sand-bars were formed ; but,
as there was no floating-ice during the earlier stages of submergence,
these sand and gravel deposits enclosed no large boulders. The
district became gradually converted into an archipelago, and currents
circulated among the islands. When depression had gone on to the
amount of 1,000 feet or less, the cold returned and ice-rafts bore
blocks from one part to another.' In many cases the direction in
which currents swept the floating-ice was the same as that of the
old glaciers, and thus boulders were transported along the same
course at different periods and by different means. Sometimes,
however, or at certain parts, marine currents bore floating ice, with
its boulders, in directions opposed to, or much at variance with, the
old glacier courses. Thus, when the land stood about 1,200 feet
lower than at present, a current, sweeping the north-western out-

1 For maps showing probable form of land at different stages of submergence, see

papers by the author on “Lake District Glaciation,’ Quart. Journ. Geol. Soc., vol.
Xxix. p. 422, and vol. xxxi. p. 162.

’

Rev. J. Clifton Ward—Geology of the Lake District. 113

skirts of the district, carried boulders from Sale Fell southwards on
to Broom Fell. Not until the submergence reached over 1,500 feet
was there any direct communication between the northern and
southern halves of the Lake District, except by the straits of Dunmail
Raise. Under such conditions a current very probably ran through
those straits from south to north, turning mainly to the east on
reaching Keswick Vale, though probably sending a branch off to the
west ; while other currents may have set through the straits between
Skiddaw and Blencathra. The case mentioned of an ash boulder at
the upper sources of the Caldew would seem to point to a current
having at one time passed from south to north, up the Glenderaterra
Valley and down through that of the Caldew. The block could not
have reached its present situation from any of the volcanic deposits
lying north of Carrock and Comb Height, and is scarcely likely to
have come from the very limited ask exposures of Hycott Hill, to
the south-east of the Caldew at Mosedale. It is not likely that this
boulder could have been transported by glacier-ice or any form of
ice-sheet, because it is in the very midst of lofty mountains which
would have produced sufficient ice to have filled the valleys between
them and kept out any ice-sheet foreign to this group. Hence, I am
inclined to consider this case as a proof of submergence to the height
of at least 1,300 feet, and of the existence of marine currents passing
through the Skiddaw mountain group.

“The submergence continued until the land must have sunk more
than 2,000 feet below its present level, as the position of boulders
in many parts of the district seem to show, and notably those on
Starling Dodd (see page 93, also Quart. Journ. Geol. Soc. vol. xxix.
p. 4387, and vol. xxx. p. 96). Then the whole district was repre-
sented merely by scattered islands clad in snow and ice, each a little
nursery of icebergs.

“As the land was re-elevated, the glaciers crept down to the level
of the sea, sometimes forming moraines just at the sea-margin, as
was the case beneath Wolf Crag, Matterdale Common, when the
land stood 1,400 feet below its present level. During all this time
numerous boulders were let fall upon the early-formed mounds of
sand and gravel, and as the sea shallowed, more of such mounds were
deposited, now, however, frequently containing ice-borne blocks.

“ Finally, when the land had regained its former height above the
sea, glaciers still lingered in the recesses of the mountains, but this
second set of glaciers at no time equalled the first in size. Some, in
Borrowdale, were sufficiently large to creep down probably as far as
Rosthwaite, and the more or less perfect moraines in every upland
valley remain as the last traces of the Glacial Period.

“JT think too that the immediate cause of the numerous lake-
hollows, many of which are now completely filled with stream-
borne detritus, was the onward movement of the glacier-ice when at
its thickest, as suggested by Professor Ramsay’s theory; for not
only are these lake-basins extremely shallow when compared with
the heights of the mountains and the thickness of the former ice-
sheet, but in most cases the agreement is remarkable between the

DECADE II.—VOL. VI.—NO. III. 8

114 Rev. J. Clifton Ward—Geology of the Lake District.

spots at which the greatest depth of water occurs and those points
where, from the confluence of several ice-streams or from a narrow-
ing of the valley, the onward pressure of the ice must have been
greatest.’

“‘T have sometimes been asked whether the glaciation described in
my papers on this district was not wholly belonging to the close of
the Glacial Period, and whether previously the whole mountain
district had not been overridden by a great ice-sheet from the
north? To this I answer that, so far as J am able to speak, there is
no evidence in the district of such a mountain- and valley-ignoring
sheet, and not one boulder of foreign northern rocks to be found
among the mountains. Therefore the burden of proof lies with those
who advocate this theory.”

Post-Glacial Period.

With times subsequent to the Glacial Period we have here but
little to do, though a few remarks may not be out of place.

I have often been struck with the scarcity of delicately poised
perched boulders, and cannot but think that this may be partly due
to shocks of earthquake in post-Glacial times, of sufficient severity to
dislodge any such. The country is so thoroughly glaciated, that
their absence is all the more conspicuous. But I fancy there are
also other indications of earth-movements. There are several cases
of fissuring upon mountain summits, and even of fissures crossing
mountain ridges, which would appear to be the work of earth-move-
ments more general than the slips so often occurring upon mountain
slopes. Thus, on the summit of the Screes Mountain, and Kirk
Fell, Wastdale; upon and distinctly crossing the narrow ridge of
High Stile, between Buttermere and Ennerdale: at Rosthwaite
Cam, Borrowdale, and Helm Crag, Grasmere, are instances of
fissures, many of them deep, long, and more or less parallel to
one another. In some of these cases there is no appearance of
slipping upon the mountain flanks, and J cannot but think that at
least some of them are the result of the passage of earthquake
waves.

Since the close of the Glacial Period, the atmospheric denuding
agents have been much occupied over many areas in the work of
clearing away glacial débris, such as once ayain opening out valleys
partly choked by glacial drift—example, the valley between Threl-
keld and Keswick. In other parts the denuding agents have had
even harder work in roughening the ice-smoothed surface, and one
may confidently say that the general contour of the country as we
now see it can be but very little different from that which prevailed
immediately anterior to the Glacial period.

«« Stone implements of two kinds have been found in the mountain
district ; some are of the smooth and polished neolithic type similar
to the stone axes from Ireland, figured in Sir J. Lubbock’s Pre-
Historic Times, at page 88 (2nd edit.) ; others are generally longer,
more narrow in proportion to their length, and have a roughly

1 See papers by the author.

Rev. J. Clifton Ward—Geology of the Lake District. 115

chipped surface. One of the latter kind was found near the so-
called Druid’s Circle, Keswick, and another by the side of Loughrige
Tarn. The latter is 11 ins. long, 34 ins. broad, and 2 ins. deep; two
beautiful photographs, giving a front and side view of this splendid
specimen, have been presented to the Keswick Museum by Wheatley
Balme, Esq.; the side view at once indicates the end used as a
handle, the presence of which would seem to show that this was
not merely an unfinished implement of the polished class, but was
used in its present chipped form; and, indeed, the general shape of
the two kinds is tolerably distinct. Several of these old stone
implements of the district, and others of bronze, may be seen in the
Keswick Museum.!

“These celts are mostly formed of the highly altered, felstone-like
or flinty ash, which occurs so plentifully about Scafell. Rude stone
circles, and many remains of what appear to be stone pit-dwellings
occur (?).?. The lakes, although examined in some cases at a very low
state of the water, have not yet yielded any relics of ancient pile-
dwellings. In later times the Roman occupation left its traces in
roads over lofty mountains, and scattered camps and settlements.” ®

Part I].—Curononocy or tHe LaKke District.

I wish now to make an experiment, namely, to try whether, by
using the most reliable estimates yet made, (1) upon the rate of
deposition, (2) upon the rate of denudation, it be possible to draw up
a Chronology of the Lake District to place beside the ascertained
facts of History. I am sensible how uncertain are many of the
data, yet it is well for the geologist occasionally to take stock of
time, so far as he is able—that element in which he deals oftentimes
so freely, and at times even recklessly.

For my purpose I shall avail myself of my friend Mr. Lloyd
Morgan’s article upon ‘Geological Time” (Gzotocican Magazine,
1878, p. 199), in which he has conveniently brought together
the estimates of various eminent geologists as to rates of deposition
and denudation.

Skiddaw Slate Period.—The deposits of this period, if not alto-
gether deltaic, are not far removed in character from such. We
have seen how large a proportion of them must have been laid down
in shallow water. If then we take ;'5 of an inch per annum as the
average rate of deposition for deltaic sediments, and allow that

1 T may here mention that this museum has been started with the hope of illus-
trating, as completely as possible, the Natural History of the district. Any help
from naturalists visiting the country would be most gladly received, as the working
resources are somewhat limited.

* T have placed in the Keswick Museum of Local Natural History a map of the
District on the 1-inch scale, upon which are marked in different colours and patterns
(1) all pre-historic remains, (2) Roman remains, (8) camps, etc., of uncertain age ;
and a detailed account of these will be found in a paper entitled “‘ Notes on
Archeological Remains in the Lake District,’ published in the Transactions of
the Cumberland and Westmoreland Antiquarian and Archeological Society,
1878, p. 241.

3 Geology of the Northern Parts of the English Lake District, by the Author.

116 = Rev. J. Clifton Ward—Geology of the Lake District.

distance from the actual area of a delta means a decreased rate of
deposition, we may assume perhaps that the 10,000 feet of Skiddaw
Slates were laid down at the rate of +4; of an tae per annum, and
this would give a period of six million years for the formation of
the whole series. If, however, we take the rate at > instead of ~4,
the period is reduced to less than 14 million.

Volcanic Period.—No reliable estimate can be made of the rate of
deposition of volcanic material. The length of the periods of repose
between successive eruptions appears to be very variable. In this
particular case, however, there is nothing to lead one to suppose that
the eruptions were not tolerably continuous. There seem to be no
great breaks in the series, and, for aught we know to the contrary,
the whole thickness of some 12,000 feet may represent continuous
and violent action. Hence I am inclined to put the rate of accumu-
lation at not less than 535 of an inch per annum, which gives a period
of 14 million years. If we take + as the rate—as Mr. Morgan has
assumed in the case of Htna—the length of the whole period is
reduced to 720,000 years. The gap between this and the next
period might be put down at 4 a million of years, perhaps some 500
feet having been removed at the rate of 1 foot in every thousand
years, the denudation acting upon a sinking area.

Upper Silurians of Lake District.—The same remarks may be
made on this series of sedimentary deposits as on those of the
Skiddaw Slates. Although in great part they must have been
formed in tolerably shallow water, yet might the deposition have
gone on more or less outside the limits of a delta proper. Taking
therefore the rate of deposition at 5 of an inch per annum, a Pnlele
ness of some 14,000 feet of beds may represent a period of about
84 million years.

Old Red Period.mHere we have not facts of deposition to calculate
from in this district, but those of denudation. What length of time
must have elapsed between the close of the Upper Silurian and the
commencement of the Carboniferous, to allow of the removal of
probably more than 20,000 feet of rock, so that the Mell Fell con-
glomerate could be deposited transgressively upon both Volcanic
Rocks and Skiddaw Slates? The length of time must have been
great indeed, for the extensive denudation necessitates also a great
amount of continued elevation to allow of the deeply buried strata
coming within the range of the denuding powers. A planing action is
required to cut off the rising land along the main axis of upheaval;
and the sea alone can supply us with this. The work, in fact, would
be most efficiently done if we could suppose the elevation to be going
on but very little faster than the sea could gnaw and eat the land
down. Now are we warranted in assuming that the rate of denu-
dation under such circumstances would be greater than in the case
of a tract of country lowered mainly by subaerial agencies? I
think we are. Prof. Geikie has calculated that the area of country
drained by the Mississippi is being lowered at the rate of one foot in
6000 years, while that drained by the Po is being lowered at one
foot in 729 years; the Ganges, Hoang Ho, Rhine, Danube, and Nith

Rev. J. Clifton Ward—Geology of the Lake District. 117

are each lowering their basins at rates intermediate between these
extremes. We might, I think, assume that the sea acting as a great
planing agent, aided by the atmospheric forces working on those
parts well above water, might denude at the rate of one foot in 750
years, the elevation along the main axis going on at about the same,
or but little more than the same rate. But even this comparatively
high rate of denudation would require 15 millions of years to do the
work which was effected.

There can be no doubt that the Old Red Period (i.e. all the time
between the close of the Upper Silurian and the commencement of
the Carboniferous, as shown by the deposition of the basement beds)
was one of great duration. Paleontological facts demand a great
length of time, and the facts of physical geology, not only in
England, but markedly in Scotland, demand the same. Still, it is
with some little compunction that one draws on Time’s bank as
large a draft as 15 million years.

Carboniferous Period.—A large proportion of the thickness of
Carboniferous rocks is undoubtedly deltaic in character. If we
allow the British Carboniferous to have a thickness of some 20,000
feet at the outside, then taking 12,000 feet as delta deposits, and
8000 feet as limestone and extra-deltaic, we arrive at the following
conclusion :—

12,000 feet at rate of 35 of an inch per annum=1,440,000 years

8,000 feet zm ss Fe - =4,800,000 _,,
100 feet of Coal ,, sis 4 oH = 120,000 ,,
6,360,000 years,

or, in round numbers, we will say 64 million years. If the whole
thickness be taken at the rate of 5 of an inch per annum, the period
indicated is 12 million years.

Post- Carboniferous Periods.—In England the various Post-Carbon-
iferous formations do not amount in total thickness to more than
20,000 feet; but when we consider the large development of some of
these formations abroad—example, the Hocene and Miocene—it is
necessary in any calculations of total length of time to make a
greater estimate than 20,000 feet. Accordingly I will take 40,000
feet—almost certainly an over-estimate—of rock deposited at the
uniform rate of 35 of an inch per annum. ‘This represents a period
of 24 million years.

Glacial Period.—For this last episode of geological history it is
difficult to find data either of deposition or denudation to go upon.
According to Mr. Croll’s theory, the epoch commenced some 250,000
years ago, and ended about 80,000 years back. I have already
stated that I believe there is evidence in the Lake District of a
submergence to the amount of 2,000 feet, and Professor Ramsay long
since stated that he believed there was like evidence in Wales. But
although I see no other way of accounting for the facts, yet do I
fully acknowledge the difficulty of the supposition. I am supposing
that the Lake District group of mountains, which for so many
geologic ages were being elaborated under subaerial agencies, now

118 = Rev. J. Clifton Ward—Geology of the Lake District.

within the last million of years sank deeply beneath the sea, and
was re-elevated without, apparently, any long periods of rest, and
therefore without having left upon it many well-marked lines of
marine action. Moreover, supposing Mr. Croll’s theory to be the
right one as to the cause of the Glacial Period, and taking the
time indicated by that theory, this submergence and re-elevation
must have taken place in some 200,000 years. Now, from what we
know of such movements at the present day, the rate of two feet per
century would appear high, and this rate would allow of no halt.
There might be plenty of time for the District first to become
shrouded in confluent glacier-ice, and then to be depressed and re-
elevated under changing climatal conditions ; but I must acknowledge
that the submergence to such an amount is somewhat embarrassing.

Post-Glacial Period.—According to Mr. Croll, about 13 feet may
have been removed from the general surface of the country since
the close of the Glacial Period (7.e. in 80,000 years). I doubt very
much whether, taken all round, more than six feet has been thus
removed in the same period over the area of the Lake District
mountains, and this would be at the rate of one foot in every 13,000
years. The ice-action is yet so evident over large tracts, that I
question whether even this may not be too high an average. The
Skiddaw Slate mountains with their greater softness may, however,
more than make up for the unyielding nature of the hard ice-
smoothed volcanic rocks.

General rate of subaerial denudation in the Lake District—The
low rate of denudation just now assumed for the period since the
close of the Glacial may be partly put down as resulting from the
polished state of the country, but that the general rate over so small
a mountain district must have been low is, I think, very probable.
If an accurate model of the Lake District be examined, it will be
seen that more material has been removed in the formation of the
valleys than has been left to form the mountains. The mountain
district might, indeed, as well be described as a valley district, so
close to one another are the several valleys, and so narrow the
mountain ridges separating them.

The question then arises, at what average rate has denudation
been carried on since Carboniferous times? Is the amount of
denudation effected ridiculously small for the amount of time sup-
posed to have been spent upon it? or the reverse ?

At the close of the Carboniferous Period we must, I think, believe
the area under description to have been elevated as a more or less
lofty table-land, constituting the rough-hewn block out of which
such a valley-system as that we now see has been carved. The
height of that table-land we cannot indeed accurately estimate, but
it may well have been higher than the height of the highest
mountains as they now stand. This is not, however, a necessity,
for much denudation may have been effected, ere, in times long after
the close of the Carboniferous, the base of the country, so to speak,
had been raised to its highest level, or, in other words, ere the move-
ment of elevation had finally ceased. Still, I think we may assume,

Rev. J. Clifton Ward—Geology of the Lake District. 119

without much affecting the result, that at the close of the Carbon-
iferous Period, the Cumbrian nucleus was elevated to its greatest
height as a table-land with slight ridges and furrows, the early
promise of mountain and valley. Uniting the summits of the chief
mountains by means ofa plane, we restore some such plateau; butas
it is certain that the denuding agents would lower the country
generally as well as along certain lines of valley, we must place the
original plateau at a higher level than any plane now joining the
mountain tops. Now the highest mountain, Scafell Pikes, is a little
above 3,200 feet in height, and there are several others over 3,000
feet. Might we not suppose that the original plateau stood at
300 to 500 feet higher than the present highest point? If so,
and we can form an idea of the present mean level, we get the
thickness of rock removed over the area of the district in the work
of scenic elaboration. If we take the Keswick one-inch sheet, we
find that of a list of 47 mountain summits in this sheet, there are 34
above 2000 feet in height, and 18 above 2,500 feet. Probably the
mean level is not less than 1,500 feet, and not much greater than
1,800 feet. Hence, if we assume the height of the original plateau
to have been 3,500 feet (which may very likely be under the
mark), and the present mean level to be 1,500 feet, we have to
account for the removal over the area in question of some 2,000 feet
of rock by purely subaerial agents. It should be borne in mind
that none of the rocks thus removed are calcareous to any degree,
and therefore they are not readily soluble in water; still the
wonder remains that, if the original plateau did not much exceed
300 feet above the present highest point, more has not been effected
by denudation during that long period from the close of the Carbon-
iferous to the present, for the actual amount denuded seems insig-
nificant indeed in comparison with that removed from the same
district during the Old Red Period. Still, the changed conditions
may make all the difference; in the latter case—that of the Old
Red—conditions the most favourable for denudation may have pre-
vailed—land rising scarcely faster than the rate at which the sea
could plane it down; while in the case of Post-Carboniferous ages, the
conditions are those of a small tract of only moderately high ground
containing no soluble rock material, and eaten down and into by sub-
aerial agencies. If the basin of the Mississippi be lowered by such
agencies one foot in every 6,000 years, are we likely to err much if
we assume that this small mountain area was denuded at the rate of
one foot in every 10,000 years? Calculating on this supposition,
the 2,000 feet removed, in the formation of mountain and valley out of
the rough-hewn block provided at the close of the Carboniferous epoch,
would represent a period of some 20 million years. In our former
ealculation of the length of time represented by the formation of
of 4C,000 feet of Post-Carboniferous strata, we arrived at a period
of 24 millions of years.

Summary. — The foregoing time-estimates may now be placed
together in one column, and in parallel columns the rates of deposi-
tion or denudation which have been assumed.

120 = Rev. J. Clifton Ward—Geology of the Lake District.

CHRONOLOGICAL SUMMARY.

steee Rate of Deposition. Rate of Denudation.
Skiddaw Slate Period..... 6 Tins DACA |W GN Ses
Volcanic Period ............... 13 ae Ts JOSE CVU eee
Possible Gap. ......... Yad es chilis a ee 1ft. in 1,000 years
peer allman ci bets | 83 Sw MNS [OTE CHAT ae ees

IDistrictepe eee f
@ldeRedsPeriod ee ees LLG») Gl READ pert NIV Mee a ma RE 1 ft. in 750 years.
T27000Tt: @ =o mm. per ann: |) ea

8,500f. @ asin. ,, We Oh

BOM ATG ae ce

Q
ty)
i=
ion
(=)
i=}
(=
lourd
(q>)
fa
fo}
a
es
tae)
@
4
J
is)
Q
lor)
wile
——S

Post - Carboniferous \
Periods! ween tence J A

The above result may, after all, in itself be of little value; but if
it helps to make one realize the respective magnitude of the various
operations which the Lake District has undergone in the course of
its long history, one main purpose will have been served. Whether
the Old Red Period was one of such duration as here indicated or
not, its length, in respect to the other formations, is probably shown
with some degree of truth. Whether 60 millions of years have
elapsed since the beginning of the Skiddaw Slate Period or not,
it is more than likely that the time which elapsed between the first
laying of the foundations in the early Skiddaw Slate sea and that
time when the roughly-hewn block of country was turned out at
the close of the Carboniferous epoch, for the tracing of scenic
details upon it, was greater than the time consumed in the actual
formation of our present mountain and valley system by subaerial
denudation.

Part III.—Nores on tHE PosstsiE SuBDIVISIONS OF THE SKIDDAW
SLATES.

Introduction.—In making some observations upon the correlation
of the Skiddaw Slates with the Silurian rocks of Wales, I wish to
bear in mind the following axioms. (1). Physical evidence, such as
character and thickness of deposits, can be taken as no absolute
guide in the correlation of distinct groups of strata separated from
one another by considerable distances. (2). A general sequence of
similar deposits in two distinct but not widely separated areas may
be held to indicate a succession of similar conditions prevailing at or
near the same period of time. (8). The evidence of fossils as to the
age of a deposit is generally trustworthy when it is grounded upon
assemblages of life, and when corroborating evidence is to be gathered
from the formations above and below. (4). In determining the age
of a formation due weight should be given to both physical and
paleeontological evidence, but neither should be relied on exclusively.

Applying these axioms to the case of the Skiddaw Slates, I wish
to see whether the paleontological dictum as to their Lower Llan-
deilo or Arenig age can be unhesitatingly supported.

Rev. J. Clifton Ward—Geology of the Lake District. 121

First, I would remark that this name—indicating the supposed
age and the equivalent in Wales—has been given to the whole
thickness of some 10,000 feet. Second, that this opinion is founded
almost entirely upon the presence of certain groups of Graptolites.
Third, that Graptolites are notably capricious in their distribution—
witness in the Lower Silurians of Scotland the immense thickness of
non-graptolite bearing and unfossiliferous strata associated with the
one or two black shale bands bearing Graptolites. Fourth, that in
the Skiddaw Slate Series as a whole there are several alternations of
deposits varying much in character—an upper black slate series, a
marked grit or gritty series, again a black and irony series of slates,
passing down into a great thickness of sandy and gritty beds.
Fifth, that the majority of the Graptolites have been found in beds
above the upper grit, but that they also occur in those below the grit,
where the sediment seems to have been favourable for their existence ;
while there are a few cases apparently of their occurrence even
among some of the flaggy beds of the lower sandy and gritty series.
With these preliminary remarks, I will pass, first, to the consider-
ation of physical evidence as to subdivisions and their possible
equivalency to Welsh Lower Silurians.

Points of Physical Evidence.—I had been working for some years
upon the Lake District rocks, when Prof. Ramsay called me into
Wales to trace a base to the Arenig series marked by a thin grit.
In carrying out this work, I was often struck by the general resem-
blance in sequence of the deposits both above and below the grit to
that of a like series in Cumbria, and on returning to the Lake
country examined more closely the characteristics of the various
parts of the Skiddaw Slates. The resemblance in physical character
between the Arenig grit of Wales and the upper grit of the Skiddaw
Series is perfect. With one or two local exceptions, the Cumbrian
upper grit is thicker than the Welsh Arenig, but both are made up
of similar materials, both vary much in coarseness, though almost
always presenting some coarse gritty or conglomeratic portion, and
both are much traversed by quartz strings. The constancy of the
Arenig grit in N. Wales, though often not exceeding 12 or 20 feet,
is surprising, and the fact is at any rate worth recording that among
strata of somewhat parallel age in Cumbria there occurs a like grit.
Moreover, in Wales the Arenig slates above the grit soon become
mixed with volcanic deposits, submarine volcanic ejecta, and in
Cumberland we have in the northern or Skiddaw district a consider-
able thickness of black Graptolite-bearing slates succeeded by a
Volcanic Series, and in the south-western part, at Lank Rigg and
Latterbarrow, the same Volcanic Series lying directly upon the grit.
(See also previous remarks on this subject, page 51.)

Turning to the beds below the grit, we have in Wales the iron-
stained Tremadoc Slates underlaid by a great thickness of flaggy,
sandy, and gritty beds, the Lingula Flags. In Cumbria there is a
like physical sequence; beneath the grit come black iron-stained
slates, often quite indistinguishable from the Tremadocs of North
Wales, underlaid by agreat but unknown thickness of flaggy, sandy,

122 Rev. J. Clifton Ward—Greology of the Lake District.

and gritty beds. If reference will be made to the Horizontal
Section through the Skiddaw Slate Series, No. 2, page 54, the course
of which is marked in the accompanying Sketch-map, the sequence
and lie of these subdivisions will be clearly seen. The central range
of high mountains along this section shows the lower sandy series
in their fullest development, the physical equivalents—as it would
appear from above—of the Lingula Flags; and the black slates
beneath the grit at either end of the section (shaded more darkly)—
physical equivalents of Tremadocs—come in as a faulted synclinal
in the valley between Whiteside and Grasmoor, the latter mountain
presenting a very exceptional example of a summit formed by an
anticline.’

Referring to Horizontal Section No. 1, page 54, it will be seen that
the grit of Great Cockup dips southwards under the mass of Skiddaw
(see also Map), and only reappears in an anticlinal fold on the south
side of that mountain. Thus, the area of Skiddaw and surrounding
mountains is mostly made up of the slates above the grit, the phy-
sical equivalents—and in this case the paleontological equivalents
also—of the Welsh Arenigs or Lower Llandeilo. Ina set of rocks
so highly contorted as are those of the Skiddaw Slates, taken as a
whole, it is often impossible to detect and trace the faults; butif my
reading of the district be at all correct, there must, I think, be some
large N. and §. fault or series of faults separating the tract of
Skiddaw, etc., from that W. and S.W. of Derwentwater and
Bassenthwaite Lake. This I have indicated in the Sketch-Map.
That there are many such N. and S$. faults of great size is proved
by the frequent shiftings of the grit west of Great Cockup. In
Hor. Sect. No. 1, page 54, a large strike-fault throws down the Vol-
canic Series against beds far below the grit, and while this is very
generally the case for many miles west of Carrock Fell, yet is there
clear evidence at several points of the passage upwards into the
Volcanic Series of the higher beds of the slates above the grit. To
sum up the physical evidence : while fully acknowledging the fre-
quent inconstancy of physical characters, there does seem to be in
this case of Cumbria and Cambria, some 60 to 80 miles distant from
one another, a striking sequence of similar deposits, such, indeed, as
to lead me to infer, so far as physical evidence can do so, that in
Cumbria we have the following groups represented which are more
or less equivalent to those of Wales.

Arenig Slates—True Skiddaw Slates.
Arenig Grit.

Tremadoc Slates.

Lingula Flags.

It is impossible everywhere to define the limits of these groups, so
contorted and faulted is the District; but that they exist as generally
definable subdivisions I have myself no doubt. It would seem—-
as already called attention to in the Survey Memoir—that the lowest

1 This may be well seen looking up on to Grasmoor End from Crummock Water.

In Horizontal Section No. 2, the upper black slate should have been represented as
conformable to the underlying grit of Elva Hill.

Rev. J. Clifton Ward—Greology of the Lake District. 128

sandy series of beds so largely developed in Grasmoor and Whiteside,
either thin eastwards or have their place taken by less sandy and
more slaty deposits in this direction; this, combined with excessive
faulting, and the difficulty in tracing the faults, owing to contortion
and cleavage, makes it exceedingly hard to draw the actual
boundaries of these groups in many places.

Points of Paleontological Evidence.—In assigning the whole thick-
ness of the Skiddaw Slates to the Lower Llandeilo, and that mainly
on the strength of the Graptolite fauna, Axiom (38) is distinctly
transgressed in both its clauses, for the Graptolite family cannot be
taken as a characteristic assemblage of life in general, and the forma-
tion above (the Volcanic Series) is unfossiliferous, while nothing is
known of that below. Still, the group of Graptolites being such as
is known to be characteristic of rocks of Lower Llandeilo age else-
where, is evidence of considerable value, though not to be too
exclusively relied on; but when the paleontologist says further that
the whole of this Skiddaw Slate Series must be L. Llandeilo because
Graptolites do occur throughout, or nearly so, I for one am inclined
to demur. Coulda L. Llandeilo assemblage of fossils be shown to
prevail throughout the series, the case would be different. But it so
happens that among the Trilobites there are several Tremadoc forms
—see notes by Mr. Etheridge, F.R.S., at the end of the Survey
Memoir—and with them a species of Cybele hitherto only represented
by species not occurring below the Caradoc rocks. Certainly the
scanty evidence to be derived from the group of Trilobites is con-
flicting, and besides Trilobites and Graptolites, we have but a few
doubtful plant-remains, carapaces of Phyllopod crustacea, a Lingula
(brevis), and doubtful Discina, and worm-tracks. Under these
circumstances no wonder that the Graptolites are referred to as the
most important. Hence we have the evidence of this group in
favour of the L. Llandeilo age of the Skiddaw Slates, and the
evidence of at least part of the Trilobite fauna in favour of the
Tremadoc age of portions of the series. 'The question arises, are we
justified in saying that such and such beds below a certain horizon
cannot be of Tremadoc age because beds believed to be of that age
in Wales do not contain Graptolites ? A thin grit in Wales separates
black slates above, containing Graptolites, from black slates below
not containing them; the upper are called Arenig, the Lower
Tremadoc: are we to assert from this that, such being the case in
Wales, so far as our experience goes, no black slates, whatever their
physical position, which contain Graptolites, can be of Tremadoc
age? Surely not. In Cumbria we have a grit, similar to the
Arenig grit of Wales, with black slates above containing Arenig
Graptolites, but in this case the black slates below also contain
them ; therefore the paleontologist says these cannot be Tremadocs,
and yet there may be but 50 feet or less of grit separating the two
series. For my own part, while ready enough to accept the evidence
of paleontology when it is presented in the form of life assemblages,
I do decline to pin my faith as to the succession and equivalence
of rock-groups to the evidence afforded by the finding of a few

124 Rev. J. Clifton Ward— Geology of the Lake District.

Graptolites below a certain horizon, such an horizon not necessarily
indicating any long break.

Among rocks in which there so frequently occur great thicknesses
of wholly unfossiliferous beds, the mere absence of a particular fossil
or group of fossils cannot go for much. Thus, over large tracts of
the Lingula Flags in Wales, no Lingulas or other fossils occur, while
in some spots they may be plentiful enough. Hence, although no
Lingula Davisii has been found in the lower sandy series of White-
side and Grasmoor, this cannot be used as evidence against the
Lingula Flag age of these beds if that be supported on general
physical grounds.

Summary of Hwvidence-—The Physical evidence inclines one to
believe that the Skiddaw Slates include the Arenig Slates, the Arenig
Grit, the Tremadoc Slates, and the Lingula Flags. The Paleeon-
tological evidence, based on no complete assemblage of life, and
having no fossiliferous formations to which to refer above and below,
suggests an Arenig age for the whole series on one score, and a
possible Tremadoc age for portions of it upon another score. Hence,
may we not conclude it to be at all events very possible that in
Cumbria we have the equivalents of the Welsh rocks down to the
Lingula Flags ?

If we consider the Lingula Flags and Tremadoc Slates as
Cambrian, all that portion of the small Sketch-map denoted by
broken vertical lines will represent the Cambrian, and that above
the Grit the Silurian.

Expianation or SKETCH-MAP, Prats II. (Gzou. Mac. Feb. 1879, p. 49.)

Fie. 1. Diagrammatic Section, from N. to 8., to show general structure of District.
Fic. 2, Diagram to show plateau of marine denudation, at the close of the Old Red
period. The pattern used to denote the Upper Silurians is not meant to
indicate that the strata are vertical, though they are generally highly inclined.
Sketch-map of the Geology of the Lake District. The lines along which the
Horizontal Sections on p. 54 are drawn are indicated in the Sketch-map.

APPENDIX.

List oF ParErs, By THE AuTHOR, ON Lake District GEOLOGY, TO BE
REFERRED TO IN CONNEXION WITH THIS PAPER.

Notes on the Microscopic Structure of some Ancient and Modern Volcanic Rocks.
Quart. Journ. Geol. Soc. vol. xxxi. p. 388.
On the Granitic, Granitoid, and associated Metamorphic Rocks of the Lake
District. bid. vol. xxxi. p. 568, and vol. xxxii. p. 1.
Part I.—On the Liquid Cavities in the Quartz-bearing Rocks of the Lake
District.
Part II.—On the Eskdale and Shap Granites, with their associated Metamor-
phic Rocks.
Part III.—On the Skiddaw Granite, and its associated Metamorphic Rocks.
Part IV.—On the Quartz-Felsite, Syenitic, and associated Metamorphic
Rocks.
Part V.—General Summary.
The Geology of the Northern Part of the English Lake District. Memoirs of the
Geological Survey. Longmans & Co., and E. Stanford.
Notes on the Occurrence of Chlorite among the Lower Silurian Voleanic Rocks of
the Lake District. Mineralogical Mag. No. 4.
_ On the Lower Silurian Layas of Eycott Hill, Cumberland. Monthly Microscop.
Journ. 1877, p. 239.

A. Champernowne—The Devonian Question. 125

* Glaciation of the Northern Part of the English Lake District. Quart. Journ.
Geol. Soc. vol. xxix. p. 422.

On the Origin of some of the Lake Basins of Cumberland. did. vol. xxx. p. 96.

The Glaciation of the Southern Part of the Lake District, and the Glacial Origin
of the Lakes of Cumberland and Westmoreland. Second Paper. Jdid. vol.
xxxi. p. 152.

Notes on the Archeological Remains of the Lake District. Trans. of the Cumb.
and West. Ant. and Arch. Soe. part il. vol. iii. p. 241.

IV.—Tuet DEVONIAN QUESTION.
By A. CHAMPERNOWNE, M.A., F.G.S.

N last month’s Grotocican Macazine there is much (by three

writers) that bears upon the Devonian Question, and I would

now add a few words on the same subject, which is of the greatest
interest to me.

In the first place, notwithstanding that two of the writers are
my personal friends, ] think that the united criticisms upon Prof.
Hull’s proposed classification exceed what the nature of the case
calls for, as that scheme contains the most essential elements of
truth. I have myself been in North Devon during the last autumn
with Mr. Ussher, and we hope to give a further account of our work
and the conclusions arrived at. My chief object in going there
was to test certain opinions I had before expressed with great confi-
dence (in these pages and elsewhere), and, as a result, I have proved
to my satisfaction that those opinions were wrong.

Neither by fault, nor inverted junction along the line indicated by
Jukes, is there any wholesale reduplication of the North Devon
Series. The fault I had already taken to be disproved by Mr.
Etheridge’s paper (Q. J. G. 8. 1867). In the last paragraph of
Mr. Kinahan’s paper he observes, that ‘Jukes’ fault has not been
disproved, and that the Irish geologists who have been in Devon
believe in its existence.” This, however, from Prof. Hull’s classifi-
cation, is evidently not his opinion, as he places the Ilfracombe and
Morte slates beneath the Pickwell or (Upper) Old Red Sandstone,
but he suggests an unconformity at the base of the latter, of which
there is no evidence.

Regarding the Pickwell as what Mr. Kinahan aptly calls the
Carboniferous Old Red, I will venture to say that in nine out of ten
Western Huropean areas a break! might be expected at a corre-
sponding horizon, but the North Devon marine sequence is almost
unique in its completeness. My former belief in an inverted passage
assumed perfect conformity at that junction, and of this conformity
there are indisputable proofs.

1 Of all areas in which rocks belonging to the Siluro-Carboniferous interval are
developed, that of the Welsh border counties, although geographically the nearest, is
perhaps the least comparable of any to the North Devon area, and the greatest
stumbling-block to a would-be ‘‘ Devonian”’ disciple. In vain may be the search
there for a break of any magnitude to be filled in from the latter area. Lacustrine
conditions may have prevailed more or less, from the final retreat of the Ludlow
types, until the waters of the Lower Limestone Shale united the “ Welsh Lake” (see
Prof. Geikie’s Lectures on the Old Red Sandstone) with the ocean. In South Ireland

and Devonshire, on the other hand, there are plain indications of an open sea to the
South and Hast, extending into the Rhine country.

126 A. Champernowne—The Devonian Question.

The absence of a ‘‘ Middle Devonian” (with its peculiar forms of
life) anywhere in the United Kingdom, save North and South Devon
only, was enough to stagger one and shake one’s faith in fossils ;
and no unconformity in the heart of the Old Red Sandstone
districts appeared originally to me to be sufficiently significant to
explain its absence. Nevertheless, the rock groups north of the
Pickwell Series are unquestionably distinct from those south of it.

With regard to Mr. Hall’s expostulation as to there being no
fossiliferous ‘“‘ Upper Devonian” in Prof. Hull’s scheme, that surely
is a question of nomenclature, and, expressive as the local names
‘Marwood’ and ‘ Pilton,’ ‘ Baggy,’ ‘Cucullea zone,’ certainly are, I
think that the only philosophical classification ultimately attainable
will be to drop the term ‘‘ Upper Devonian” as applied to these beds
altogether, or regard it simply as a synonym for Lower Carbon-
iferous, in cases where that period is not represented by good
Carboniferous Limestone. In this respect I still think Jukes was
undoubtedly right. Therefore I would apply the term Devonian
as high as Prof. Hull applies it, regarding the Pickwell as the
conformable base of the Carboniferous. This will still leave us the
great Ilfracombe-Morte Series as Devonian, and the Linton grey
beds as a lower fossiliferous Devonian.

The presence of land-plants of Carboniferous genera in the Mar-
wood beds would be in harmony with this view, and the great
profusion of a Productus in the gritty beds of the Pilton Series at
Croyde Bay, etc., would make it probable that they represent (in
time) the lower parts of the Carboniferous Limestone.

There are not wanting signs that Prof. Hull’s suggestion about
the Silurian affinities of the Foreland Sandstones is worth a great deal.
In the red and variegated beds of the Lincombe Hill, etc., exposed
along the New Cut at Torquay, Mr. Lee and I found many portions
of Homalonotus armatus, Burmeister. The genus Homalonotus being
essentially Cambro-Silurian and Silurian, suggests at least that these
beds, which contain also Chonetes, Holopella and a small Myalina,
may have some Silurian affinities, and may be as low as the lowest
North Devon beds. At the same time there are among them some
grey red-speckled siliceous grits with superficial raddling, which
resemble those of the Hangman Series, and as the South Devonian
rocks are not nearly so complete as those of North Devon, it is quite
possible either that the true Hangman Grits may be absent, or that
beds belonging to the three lower groups of the North, Foreland,
Linton, and Hangman, may be somewhat inseparable in the South ;
the Meadfoot grey and brownish grits and schistose beds might well
represent the Linton. Great N.W. and S8.E. faults, shifting an
earlier set of fissures, cut out parts of the series in the Torquay
Promontory.

As a matter of pure speculation, I see no reason why the Homa-
lonotus red flagstones of the Hifel district should not prove to be a
Silurian rock rising from below the Coblentzien (Lower Devonian)
of Daun, Priim, etc.

To resume then: I believe Sir Roderick Murchison! was right as

1 Siluria, 4th edition, p. 282,

Prof. E. Hull—Reply to Mr. Kinahan. Ie

to the comparative structure of South Ireland and North Devon, and
that the great unconformity shown in the centre of Mr. Kinahan’s
woodcut (Guon. Mac. 1879, February No. p. 68, Fig. 1), represents
the missing Hifelian system; missing in South Ireland, not from
denudation, but from having never been deposited in that region.
The Glengariff and Dingle Grits would therefore have been upturned
and denuded, and remained land or shoal water during the time that
the Ilfracombe-Morte Series was accumulating in a steadily subsiding
area, which is now North Devon and West Somerset.

I have crossed the mountainous country from Macroom to Killarney,
which route affords grand sections of these massive grits, so that
their characters are somewhat known to me, and I know them also
on the Upper Lake of Killarney, and at the Gap of Dunloe.

Taking all into consideration, the conclusions of Prof. Hull appear
to be in the main legitimate deductions from the facts, and not mere
theory.

Dartineton Hatt, Totnes, DEvon.

V.—TuEr DeEvontaAN QuEsTION: Repty Tro Mr. Krnanan’s Norte.
By Professor K. Hurt, M.A., F.R.S., etc., ete.

N the Gro.octcan Magazine for February will be found a “Note
in Press,’ appended by Mr. Kinahan to his paper on the
“Silurian Rocks of Ireland,” read some time ago before the Royal
Geological Society of Ireland, and which I had an opportunity of
hearing and replying to. On that occasion I pointed out some of
the numerous defects and erroneous views which this paper contains ;
and I could have wished that the matter had rested here, because I
consider it highly unbecoming that the Director of the Survey should
enter into a public controversy with one of his staff on points
connected with the geological structure of the country which has
been entrusted to him for elucidation. On the English and Scotch
Surveys such conduct is happily unknown, and however the field
surveyors may differ amongst themselves, and maintain their opinions
in print, there has always existed a sufficient feeling of respect for
the heads of the Survey, as well as a just consideration of the interest
and credit of the Survey itself, to prevent open controversies with
the heads of the Survey in the public prints. To this rule Mr.
Kinahan presents the solitary exception. I cannot take blame to
myself for having provoked the “Note in Press” to which I have
referred, because there is nothing in my paper. published in the
GronocicaL Magazine, Decade Ii. Vol. V. 1878, p. 529, to call
forth the statement on the part of Mr. Kinahan that I had made
“ various errors in reference to the Irish rocks.”

If, then, I depart from the rule I have followed for several years
in reference to Mr. Kinahan, of passing over his unseemly language
in silence, it is with the understanding that this rule will be adhered
to on all similar occasions, and that my silence in the future must
not be construed into acquiescence, either in his statements of
supposed facts, or his conclusions.

128 Prof. E. Hull—Reply to Mr. Kinahan.

I shall now touch briefly upon his points seriatim, as stated in his
‘“‘ Note in Press” (p. 73), which seem to call for reply.

First.— Mr. Kinahan says: “If this be allowed” (7.e. the Silurian
age of the Dingle and Glengarriff Grits in which “all Irish geologists
who have studied them agree’’), ‘‘ we have a vast continuous series of
rocks which represents ALL THE TIME intervening between the accu-
mulation of the typical Silurian (beds) of Dingle and the typical
Carboniferous (beds) of Cork.” }

This is a remarkable statement in the face of the fact—that in the
Dingle Promontory there exists between the “Upper Silurian” Dingle
beds and the Old Red Sandstone (and consequently the overlying
Carboniferous beds) an unconformity scarcely exceeded in amount
by that between any two sets of rocks in the British Islands—by
which the Old Red Sandstone rests on beds in some places 12,000 or
15,000 feet higher or lower than in others. If this is Mr. Kinahan’s'
idea of a ‘“‘ continuous series ” representing all the time between the
Silurian and Carboniferous, his notions are special and peculiar. In
my paper (Grou. Mac. Nov. 1878) I suggested that this great gap
in the Irish series is filled up by the Marine Devonian beds of IIfra-
combe and Mortehoe—a suggestion which seems to bring the Irish
beds into remarkable harmony with the Devonshire series.

Mr. Kinahan next attempts to commit me to the following
absurdity. Because certain plant-remains (which J have seen) are
stated on somewhat doubtful authority to have been found in the
Glengarriff Grits south of Dingle Bay—and are also “said by Baily ”
to be found at Kiltorcan in the Upper Old Red Sandstone—there-
fore he supposes I have stated that the Glengarriff Grits are at one
place Upper Silurian, and at another Old Red Sandstone !

This process of reasoning, besides being a little amusing, involves
several postulates which I do not admit.

First, from the appearance of the plant-remains found in Kerry,
I strongly suspect they have been got out of the Lower Carbonifer-
ous Slate and Coomhola Grit Series rather than out of the Glengarriff
beds. If Mr. Kinahan had been a little more candid, he would
have admitted that when we examined these plant-remains the
other day in this Office, great doubts were expressed by others, as
well as by myself, of their having been found in the Glengarriff
Grit Series at all.

I also distinctly deny the supposed conformity in the sense of con-
tinuity of the Carboniferous and Upper Old Red to the Glengarriff
Grit Series; and of this I hope to give sufficient proof in a paper
now in the hands of the Secretary of the Geological Society of
London, but not yet brought before the Society. On the contrary ;
the wide lapse of geological time represented by the great dis-
cordance in the beds north of Dingle Bay is represented also by at
least as great a break in continuity south of Dingle Bay—where the
Lower Carboniferous Slates and Grits come directly in contact with
the Glengarriff Grit Series (as at Kenmare, Sneem, Glengarriff, etc.),
without the intervention of the true Old Red Sandstone of Dingle,

1 The italics are Mr. Kinahan’s own.

Prof. E. Hull—Reply to Mr. Kinahan. 129

Tralee, ete., a fact which Mr. Kinahan, with all his experience,
has failed to discover for himself.

For my part, I cannot be guilty of the absurdity of supposing that
beds separated by a gap (represented by 12,000 feet of strata) on
one side of a small bay, that of Dingle, can be in a position of con-
tinuous sequence on the other side; yet this view appears to be held
by Mr. Kinahan (“ Geology of Ireland,” p. 52, etc.).

As regards the beds of the Curlew Mountains, which are shown
on the maps of the Geological Survey as Old Red Sandstone, Mr.
Kinahan considers them to be “ stratigraphically similar” to those
of the Glengarriff Grit Series. This is a view peculiar to Mr. Kinahan
himself, who can have but little personal knowledge of these beds,
and different from that entertained by the officers of the Survey who
surveyed the ground. Professor Jukes calls these beds ‘‘Old Red
Sandstone” in his paper “On the Felstones of the Curlew Hills”
(Journ. Geol. Soc. Ireland, vol. i.); they were so denominated by the
late Mr. Foot, and by Mr. Cruise, who surveyed the ground; as also
by Sir R. Griffith in his Geological Map of Ireland (1855), who
places these beds (Fc) on quite a different geological horizon from
the Dingle Beds and Glengarriff Grits (which are marked He). I
am not surprised at this unanimity of opinion, in which I entirely
concur, as the beds of the Curlew Hills, consisting of dark red and
purple sandstones and conglomerates, bear little resemblance to the
hard green grits and purple slates of the Glengarriff Series.

Mr. Kinahan proposes to abolish the Old Red Sandstone from the
Geological Map of the South of Ireland—entirely ignoring the fossil
evidence, which is of a very striking kind. There is, first, the pre-
sence of the fresh-water bivalve Anodonta Jukesii; then the remains
of Old Red fishes, such as Ooccosteus, Pterichthys, etc.; and plants
like the noble Adiantites (Paleopteris) Hibernicus, not found in the
overlying Carboniferous beds. Now, while these beds, lying at the
top of the true Old Red of the South of Ireland, thus indicate
freshwater conditions, those of the succeeding Carboniferous Slate
show only marine conditions, as indicated by numerous species of
Mollusca.

As Mr. Kinahan has done me the honour to point out my
“errors”? in reference to Irish rocks, he cannot, therefore, object
to a similar piece of service on my part. I might enumerate many,
but will content myself with two instances.

In his paper already referred to (Guou. Mac. Feb. p. 69) he says:
“Tn the Ballycastle Coal-field, to the north-east of Antrim, Old
Red Sandstone occurs interstratified in the Coal-bearing Calp.”
Now, ‘‘Calp” is the term used in Ireland to denote the middle earthy
beds of the Carboniferous Limestone. Thus, while Mr. Kinahan
would obliterate the Old Red Sandstone lying at the base of the
Carboniferous beds, with its fresh-water shells, its peculiar fish, and
remarkable flora, from the South of Ireland, he would introduce it
amongst the Coal-bearing beds of county Antrim. ‘This is, to say
the least, a novel position for the Old Red Sandstone.

The beds referred to are red sandstones with a conglomerate base

DECADE II.—VOL. VI.—NO. III. 9

130 Prof. E. Hull—Reply to Mr. Kinahan.

which occur in the lower portion of the Ballycastle Coal-field. Some
years ago I pointed out, in a paper published in the Trans. Roy. Geol.
Soc. Ireland, vol. ii. (1871), and therefore accessible to Mr. Kinahan,
the analogy between the beds of the Ballycastle Coal-field and those
of the Lower Coal-formation and underlying Calciferous Sandstone
Series of Scotland—referring the beds to a similar geological horizon.
On the publication of the paper, Professor Geikie expressed his
concurrence in my views. According to Mr. Kinahan, however, we
have an intercalation of Old Red and Carboniferous rocks, unknown
elsewhere amongst British formations.

Mr. Kinahan seems to deny the existence of Permian beds near
the City of Armagh,’ as coloured and described in the Survey
publications, and for the purpose of doing so, deliberately mis-states
the position of the beds at this spot, notwithstanding clear and ex-
plicit descriptions given in at least two publications,*® accompanied
by sections, showing the position of the Permian beds with reference
to the Carboniferous Limestone. ‘These beds consist of sandstones,
breccias, and conglomerates, resting on the marble beds of the Car-
boniferous Limestone, and after I had (in 1872) identified them as
Permian beds, they were visited by Prof. Ramsay, who concurred in
my view, recalling as they did to his mind the ‘“‘brockram” of the
Vale of the Eden. Mr. Kinahan, however, dissents from the views
of Professor Ramsay and myself, which he is at perfect liberty to
do ; but in order to justify his dissent, makes a statement which is
entirely erroneous, namely, that Mr. Egan, who surveyed the ground,
has proved that the supposed Permian beds are “ interstratified ”
with limestones with fish-remains;* and secondly, that the limestones
of Armagh belong to the upper division of the Carboniferous Lime-
stone Series. If this is so, then the maps of Sir R. Griffith and of
the Geological Survey, which represent the beds near Armagh as
Lower Limestone, are altogether wrong.

Mr. Kinahan has been commended for his disregard of “ authority,”
and unquestionably independence of opinion is a high quality in a
man, provided it be accompanied by candour in stating the case as
against himself, and weighing the views of others. ‘The instances
T have given will suffice to enable the reader to form his own con-
clusions on this question.

I have now done with Mr. Kinahan’s views; nor shall I again be
tempted to notice them. Except for the discredit they are calculated
to bring on that branch of the public service to which he belongs,
they might well be passed over in silence. Perhaps, after all, even
this apprehension is groundless.

GroLogicaL SurvEY Orricr, Dustin,
12th February, 1879.

1 “ Geology of Ireland,” p. 133.

2 Quart. Journ. Geol. Soc. Lond. vol. xxix. p. 402, and Explan. Memoir to Sheet
47, by F. W. Egan, p. 11 (1873).

3 There is no reference given for this statement, and Mr. Egan, in a letter in my
possession, says: ‘‘In reply to your letter of yesterday, I fail to see where I have
proved that the red and other coloured sandstones (considered by you to be of Permian
age at Armagh) are interstratified with limestones.”

Notices of Memoirs—Prof. Heim on Formation of Mountains. 131

INT QuosteamS) (slr AVA Wis mesS

Notice or Pror. A. Hetm’s work on THE MECHANISM OF THE
Formation oF Mounrains.! By Pror. EH. REN»EVIER.

HIS work is an important one, not only from its being a con-
scientious study of a very interesting Alpine region, but also
from its containing the result of the author’s systematic researches
on the mode of formation of the Alps and of mountain chains in
general.
Prof. Albert Heim, former pupil of the late Escher von der Linth,
replaced the latter on his lamented decease in the Chair of Geology
at the University of Zurich and at the Federal Polytechnic School.
He has profited not only by all the experience of his master, but
has had the use of all his manuscript and unpublished notes. Be-
sides having often traversed the Glarus Alps with our regretted
colleague, he has studied them more in detail for a number of years.
In these explorations—as well as in his numerous travels across
Europe, from Sicily in the south to Norway in the north—he has
fixed his attention especially on the different alterations and dislo-
cations of rocks, and on the physical causes to which they have been
subject. This is also the dominant point of view in the work to
which we have the pleasure to point, and it is this which the author
has wished to signify by the phrase, ‘‘ Mechanism of the Formation
of Mountains.” From the wide generalizations in which Prof.
Heim’s book is very rich, it commends itself not only to the notice
of Swiss geologists, but also to those in other countries who are
interested in the physical laws which govern our world.

The work consists of two 4to. volumes, accompanied with a
magnificent atlas of 17 large folio plates, of which 14 are chromo-
lithographs. The first two are geological maps, one on the scale of
rovsos Of the mass of the Tcedi and its environs, the other on the
scale of =ss505 representing the Glarus Alps and chain of the
Grisons to the north-west of the Rhine. The plates following con-
tain geological sections to true scale, without exaggeration of heights,
also drawings and sketches, done with the hand of a master—exact
execution being guaranteed, since they have been put on stone by the
author himself.

Vol. i. 8350 pages, contains the geology of the Tcedi mass, whilst
the second, of 250 pages, is devoted to the discussion of general
orographical principles applicable to all mountain regions. They
are complementary of each other and form one inseparable whole.

The Tcedi-Windgelle group of mountains is at the eastern ex-
tremity of the Finsteraarhorn mass of crystalline rocks. The Reuss,
Linth, and Hinder Rhine have their sources in this district. We
find there rocks of very different age, protogine occurring at a short
distance from Hocene beds.

The first volume is divided into five parts, of which the first is
devoted to the description of the crystalline rocks which form the

" Mechanismus der Gebirgsbildung im Anschluss an die geologische Monographie
der Tcedi-Windgzllen-Gruppe. 2 vols. 4to. with Plates. (Bale, 1878.)

182 Notices of Memiors— Prof. Heim on Formation of Mountains.

central nucleus of the mass. The granite of Puntaiglas, the por-
phyry of the Windgelle, have a special interest. The various
schists of the central mass are repeated in the transverse section
making the anticlinal and synclinal folds. The central mass itself
contains Verrucano and Carboniferous beds—part of the Verrucano
being contemporaneous with the latter formation.

The second part treats of the beds which form almost a complete
series from the Carboniferous to the Eocene. Fossils are in general
scarce enough ; they are sufficient, however, to prove the existence of
the Liassic, Jurassic, and Cretaceous formations. The author notices
among others Ammonites raricostatus found for the first time in the
Central Alps.

But that which gives the principal interest to this region is the
gigantic foldings of the crust, of an intensity and extent the like
to which has not been observed elsewhere. The reversals are so
considerable that they surpass in extent and interest even the
very curious case of the Dent de Morcles, which I noticed on a
former occasion.

The third part of the volume is occupied by a description of
these complicated foldings. One enormous fold, bent over towards
the north, borders the northern margin of the central mass; by this
reversal the Jurassic, Verrucano, Porphyry, and even the Gneiss,
are piled up on the Nummulitic. In the direction of the Windgeelle,
to the lower Landalp, this fold breaks up into a large number of
minor ones. At the southern border of the central mass, we find
that the chain of the Piz Tumbif is formed by a fold which is again
folded—a compound fold. The middle zone, consisting of calcareous
sediments, which is elevated on the back of the crystalline mass,
penetrates, in some places, into this, forming very much compressed
synclinals. The Tcedi itself is an enormous block of Jurassic
Limestone, which has been separated from the surrounding masses
of similar nature by prodigious denudation. At the top of the
Bifertenstock are seen the Nummulitic Limestones, at a height of
11,300 feet. Many of the most remarkable folds of this region had
remained unknown hitherto.

The fourth part of vol. i. contains a description of the well-known
double fold which passes by the name of the Glarner Doppelfalte.
Escher von der Linth was the first to discover this feature, which
reverses absolutely the position of the beds over an extent of 454
square miles. Several geologists maintained that a reversal of such
an extent was impossible, inadmissible! Such an opinion had for its
excuse an incomplete knowledge of the locality. The present work
is the first which gives an account of the phenomena over the whole
of the reversed area. The mechanical explanation which Escher had
broached we find here confirmed and developed in all its details.

Apropos of this, already in the first volume are a number of
general researches, among others, on the theory and formation of
reversed folds. Wealso find there suggestions for a uniform mode of
indicating the different parts of a fold, ete. Finally, the author

1 Archives des Sciences physiques et naturelles, 1877, May number. [Geneva.]

Notices of Memoirs—Prof. Heim on Formation of Mountains. 133

shows that the Glarus double fold is the mechanical continuation of
the central mass of the Finsteraarhorn —that the latter is also formed
by lateral displacement—that these different mountains are of the
same age, and must have been produced during the Miocene or
Pliocene epoch. |

The last part of the first volume treats of the form of the surface ;
and in different chapters are considered successively—glaciers, the
effects of Quaternary glaciers in the district, avalanches, springs, and
specially the relations of erosion to the present configuration of the
surface. Denudation has destroyed absolutely the original shapes
which would correspond to the internal structure of the mountains.
The Alps in our day have no longer half their pristine mass, more
than half has been removed by erosion. We recognize in the form
of terraces, on the sides and floors of valleys, the remains of old
beds up to a height of 6,500 feet above the level of the present
bed. These terraces are entirely independent of the structure of
the mountain, but they correspond with those of the confluents of
the same river, and differ in the valleys formed by the different
main rivers.

Professor Heim thinks that the necessary conclusion from these
facts, is that the valleys of the Alps are due entirely to erosion. If
fissures or synclinal lines have in the first place fixed the direction,
this must have been far above the present peaks and actual crests
and in rock which has long disappeared. Many of the large rivers
existed before the mountains which now surround them. EHrosion
acts from the mouth of a valley upwards, the valleys eat more and
more back into the hills, and are often intersected. In a special
résumé the author enumerates the arguments with which he meets
those geologists who assume that mountain-valleys are ruptures of
the earth’s crust.

In the second volume the first part is entitled ‘Mechanical dis-
tortion of rocks by the elevation of mountains.” The phenomena of
folding, rupture, cleavage, etc., are examined as to their physical
relations. The outcome is, that distortion without fracture can be
produced in rocks which had already acquired their present hardness.
The new observations belonging to these phenomena are grouped
under sixteen laws. The author developes the result of an examina-
tion by the microscope of rocks crushed by pressure—this can even
produce chemical changes. The following chapter contains the
physical explanation of these phenomena—it may be stated shortly
thus: Ata certain distance below the surface rocks are found under
a pressure much greater than their power of resistance ; this pressure
spreads in all directions as in a liquid. Rocks are thus reduced to a
latent plastic state. Directly that a new force like lateral pressure—
such as causes the elevation of mountains—acts on the mass, a
homogeneous change of form results. Neighbouring surface rocks
are distorted in yielding. The thrusts which have acted during
crumpling of the Alps are in accordance with theory and experience.

A second part of the volume is devoted to the central masses of the
Alps. Some geologists imagine that these crystalline centres play

134 Notices of Memoirs—Prof. Heim on Formation of Mountains.

the part of active eruptive rocks, and have elevated the Alps in
thrusting off the sedimentary masses to the right and left. Messrs.
Favre, Suess, etc., on the contrary, regard the central masses as
formed within folds. Prof. Heim is of the same opinion; he shows
that all the eruptive rocks of the Alps are much older than the eleva-
tion of the chain, which proves that they have merely played a
passive part, like the sedimentary rocks themselves, during the eleva-
tion. Certain central masses, like that of the Simplon, form large
and well-preserved anticlinals. All intermediate conditions are found
between this regular form and the fan-structure, which is nothing
but an excessive folding. There is no definite separation between
the crystalline schists of the central mass and the sedimentary rocks
associated with them in the interior of the mass. While the crys-
talline schists have ordinarily a high dip, we see them in some
places but slightly inclined, and absolutely parallel to the limestones.
The unconformities which exist between the two groups of rocks
are often not original; they are produced neither by cooling effects
nor by a former elevation, but simply by a difference of movement
during the uplift of the Alps. According to Prof. Heim the clearest
proof of the inactivity of the crystalline rocks is given by the
repeated demonstration—amply detailed in the volume—that the
central mass itself has undergone an enormous lateral compression,
which by crumpling has reduced this zone of the crust to half its
original width. The central masses are then zones of folding of the
crust, of a “mechanical facies,” only a little different from what is
frequently seen in calcareous formations. The difference is perfectly
explained by that of the weight which acted on one and the other
group of rocks during the lateral displacement.

The last part of the work is headed “On the structure and
formation of mountain chains.” The author groups here the results
of preceding researches. After an historical account of different
views successively put forth on the elevation of mountains, Prof.
Heim describes in a general manner different phenomena of
dislocation in their interior. The lateral displacement, which he
recognizes as sole cause of the formation of chains, can be measured
on horizontal sections in stretching out the folded beds. A contrac-
tion only of 33> of the earth’s circumference would have sufficed to
fold the crust in a way to form all the mountains found on the
meridian crossing the Alps.

The remaining chapters contain researches on the distribution of
lateral displacement on the surface of the globe, on the relation of
different sorts of mountains between themselves and continents, as
well as on the proximate causes of their formation. The author,
in conclusion, attributes foldings of the crust to the diminution of the
diameter of the globe, resulting from contraction by cooling of the
internal mass. Prof. Heim estimates at 50,000 metres the diminution
of the earth’s radius, and thinks that the result would be the same
under either hypothesis of the fluidity or solidity of the internal
nucleus.

The analysis above given of this important work is in large part

Reviews — Nicholson and Etheridge—Fossils of Girvan District. 135

due to the author himself, who has furnished the materials as far
as the essential ideas of his book are concerned. The work is
one which will certainly become classical.

Lausanne, 1878.

[Translated by EH. B. T., from the ‘‘ Archives des Sciences physiques et naturelles,”
1878, November number. |

d5u) 02h WF Jb ay WAS

—_»>—_—_

J.—A MonocrarpH oF THE SriLuRIAN Fosstns oF THE GIRVAN
District, IN AYRSHIRE, WITH SPECIAL REFERENCE TO THOSE
CONTAINED IN THE “GRAY CouuEection.” By Professor H.
AtLEyNE Nicuonson, M.D., D.Sc., etc., and Rospert Eran-
RIDGE, JUN., F'.G.S8., etc. Fasciculus I. Rutzopopa, Acrinozoa,
Trrtopita. Svo. 135 pages and 9 plates. (Blackwood and
Sons, Edinburgh and London, 1878.)

OON after fossils were first collected and brought to notice in
the district referred to, Sir Roderick Murchison devoted a
large portion of a Memoir on the Silurian rocks of Scotland (in the
Quart. Journ. Geol. Soc. London, vol. xvi. 1851) to the elucidation
of the contorted and dislocated strata in which they had been
discovered. He writes: ‘‘The most fossiliferous Silurian rocks
yet discovered in Scotland lie directly to the Hast of Ailsa Crag,
and to the north and south of the port of Girvan. . . . The rocks
constituting the Silurian series of Ayrshire consist of (8) schists
and limestones, (2) shelly greywackes, sandstone with conglomerates,
and (1) limestone and schists,” in ascending order. ‘“ These ridges
are composed of strata which strike from W.S.W. to E.N.E., or
parallel to the general direction of the Silurian rocks of the South of
Scotland. The Girvan Water and the Stinchar flow in longitudinal
depressions or fissures,’ which are also coincident with the strike of
the rocks” (pp. 141-3). Not only the recognition of the Girvan
fossils (mostly collected in those days, we believe, by John Carrick
Moore and Alexander M‘Cullum) as Silurian, but the discovery
that the old Silures had inhabited this part of Ayrshire, was a source
of great gratification to Murchison ; and he urged the further collec-
tion of the organic remains, and induced Mr. J. W. Salter to
enumerate and describe those already in hand (op. cié. p. 170, etc.).
Sedgwick and M‘Coy also had already taken a similar interest
in this Paleeozoic locality, and had studied some of its fossils (Rep.
Brit. Assoc. 1850, etc.).

With the progress of the Geological Survey the Silurians of
Ayrshire became still better known (Explan. Sheets 7, 18, 14, and
15) ; and the importance of having their fossils definitely determined,
and fully compared with those of Wales and elsewhere, was so
strongly felt that a Government grant of £75 was obtained through
the good oftices of the Royal Society towards the work ; and Robert

1 The Geological Surveyors, however, did not find a general concordance of the

lines of valleys with faults in this district, though the strike of the beds has certainly
an influence on them. See ‘‘ Explan. of Sheet 7, Mem. Geol. Surv. Scotland, 1869.”

186 Reviews—WNicholson and Etheridge—Fossils of Girvan District.

Gray, Esq., F.R.S.E., most liberally gave further means for the
purpose. Mrs. Robert Gray’s collection of the Girvan fossils is the
most complete extant, and has been carefully studied. The authors,
Mr. Lapworth, and the Geological Surveyors, have also had fossils
collected for examination.

The first part of the proposed Monograph is handsomely produced,
with good printing and paper, and with nine excellent plates,
lithographed by C. Berjeau, F.L.S.

Among the Protozoa (and at page 10, among the Rhizopoda) are
enumerated the obscure Nidulites and Ischadites, the better known
Saccammina of H. B. Brady, and the less determinate Girvanella of
N. and Eth. The remarks on the possible affinities of the first two
are painstaking, and, though inconclusive, are useful in view of
further inquiries. The Silurian age of Saccammina, a real Rhizopod,
known also in both Carboniferous Limestone and recent seas, is
very interesting ; but not so wonderful as it would be did we not
know of the persistency of low organic existences. Principal
Dawson has enumerated several Silurian and pre-Silurian Rhizopods.
The Rev. J. F. Blake has noted a Lower-Silurian Dentalina’ at
Aberystwyth; and the Zozoén is still unaccounted for by some
mineralogists, and accepted by most Rhizopodists. The Girvanella,
though obscure, has its analogues in Chalk flints, and in recent
abyssal ooze.

The Corals, though numerous, are not well preserved. They have
been very carefully and judiciously dealt with; and have yielded
about 21 species in 15 genera. Those of the Craighead Limestone
have Lower-Silurian characters; from the other localities they
indicate Upper-Silurian age. Chetetes and Fistulipora are here
included in the Actinozoa for convenience, though belonging possibly
to the Polyzoa. In naming a new genus of Corals after Lindstrom,
the authors should have written Lindstremia, instead of retaining
the Swedish form of the diphthong. Though the German and some
other printers abroad have not the necessary type, we have it, and
should use it in Latinized words, such also as Lindstremi and
Keenigi, elsewhere in the Monograph.

Several of the Trilobites are described and figured in this
Fasciculus. Great care has been taken both with descriptions and
figures; also with synonyms, and the references to other writers
and observers. This indeed holds good with the descriptions of the
fossils throughout. We must remark that no reason is given why
the Trilobites are retained among the “ Entomostraca.” Advanced
Carcinology (as represented by Henry Woodward’s “Catal. Brit.
Crustacea,” Brit. Mus. 1877) gives them a higher place, between
the Isopoda and the Amphipoda.

A Bibliography of the Silurian Fossils of the Girvan District, from
1849 to 1878, occupies pages 1-6; and a list of definite localities
of the fossils fills page 7. Everything promises well for future
Fasciculi of this Monograph, so well begun ; its good appearance and
trustworthy contents are the praiseworthy results of careful printers

1 Gzou. Mag. Dee. II. Vol. ILI. p. 134.

Reviews—Rev. T. Wiltshire—History of Coal. 137

and lithographers, of enthusiastic and experienced authors, working
for love alone, and of liberal promoters. We sincerely trust that
generous support will be given to this publication, so useful to
geological science. Ate te dlc

I].—Tue History or Coat. By the Rev. Tuomas Witrtsuirg, M.A.,
F'.G.S., etc. Svo. 36 pages. (Spon, London and New York.)
IVEN as an Introductory Lecture to the Evening Classes at

King’s College Winter Session of 1878, this concise, and
yet elaborate history of the use of coal is remarkably well adapted
to supply much-required information on a subject interesting to the
thinking public. It will also excite a wholesome desire to learn all
that can be learned about the nature, origin, and economic applica-
tion of the valuable varieties of fossil fuel.

After two or three pages on the geological relations of coal to our
own and other countries, also some remarks on the probable ignor-
ance of the use of coal in pre-historic times, and on the general
use of charcoal in early historic times, Mr. Wiltshire refers to
the early mention of fossil fuel in Liguria and Elis, the former
district still supplying lignite at Cadibona. The terms anthraces,
bitumen, Thracius lapis, obsidianus lapis, ampelites, and gagates, as
applied to lignite, mineral pitch, jet, and coal by ancient authors, and
the supposed benefits derived from the various uses of these sub-
stances in early times, are learnedly discussed.

The more definite use of coal as fuel by the Romans in Britain, and
possibly by the earlier inhabitants, is well worked out at p. 14, etc.
At page 19 we enter on a later period, when, about a.p. 850, the
monasteries appear to have recognized the value of coal (unless,
indeed, charcoal is the substance referred to in their documents). In
deeds and charters of a.p. 1190, however, the digging of coal is
definitely referred to in the North of England and soon after in
Scotland. The Newcastle Coal-field soon sent its minerals by sea
along the south coast, and “sea-coal” became a household word in
London, little as its use was approved of in town and country by
old-fashioned people, and by those who for various reasons preferred
wood fires and open hearths. The old colliery laws, often hard and
arbitrary, the gradual introduction of sea-coal in London houses, in
spite of prejudice and Royal decrees, and the gradual growth of the
word “coal” from its olden forms, are fully treated. The introduc-
tion of steam pumping engines, and the invention of safety-lamps,
to facilitate the working of mines, and then the increased demand
for coal in the manufactures, arts, locomotion, and domestic use,
brought about the changes which have so greatly influenced affairs
among all classes and conditions of modern life.

The Appendices, including a Map, illustrate the relative supply
of coal obtained from different countries; and especially the
increasing quantity taken year by year from the British Coal-fields.
Nearly 135 million tons of coal are raised every year in the United
Kingdom and Ireland. In 1877 more than eight million and a half
tons of coal came into the London District alone, sufficient to make

138 Reports and Proceedings—

a wall, thirty feet high and thirty feet wide, reaching from London
to Brighton. The coal removed from our mines since the year 1800
would form a mass nearly a cubic mile in dimensions.

This enormous and increasing consumption of coal must have its
limit before long. Were the rate to continue as now, and could coal
be got from 4000 feet depth, we might look forward to England
having 1000 years before her with coal at hand. Bnt the lavish use
of this fossil fuel increases every year; and if the digging be
practically limited to 3000 feet (as is most feasible), our combustible
treasure can last for only 300 years! MU, ke dj.

I1J.—Journan or tue Royvat Microscoprcat SocretTy, CONTAINING
ITS TRANSACTIONS AND PROCEEDINGS, WITH OTHER MicroscoPIcaL
AND BronoercaL Inrormation. Edited by Frank Crisp, LL.B.,
F.L.S., ete. Vol. II. No. 1, February, 1879. 8vo. (London:
Williams & Norgate.)

Ne life has been infused into this Journal through the energy
and ability of its present Editor, Mr. Frank Crisp, who seems
determined to make it a thoroughly useful and successful scientific
periodical. The part just issued has a far richer complement of
varied biological information relating to histology, than the former
ones, inasmuch as notices of foreign discoveries are especially cared
for; there is a full catalogue of books and journals, and of their
contained memoirs, treating of microscopical research. The Trans-
actions of the Society furnish eight illustrated memoirs to this
Journal; and of the notes and memoranda there are fifty and more.
There is little that bears on Geology in this February Number,
except a notice of Prof. Verrill’s discovery of Cliona sulphurea freely
penetrating some marble blocks wrecked off Long Island in 1871.
ANS Ie os

ISJAIpAOisvayS) /AINTID) 1SAs(OCisIaI DIAN ES

——_

GroLocicaL Society or Lonpon.—I.—January 22, 1879.—Henry
Clifton Sorby, Hsq., F.R.S., President, in the Chair.—The following
communications were read :—

1. “On Community of Structure in Rocks of Dissimilar Origin.”
By Frank Rutley, Esq., F.G.S.

After alluding to the community in mineral constitution of certain
rocks to which different names have been applied, and indicating
the advisability of retaining some old terms in a provisional
sense, questions relating to the causes of the angular and rounded
characters of certain rock-constituents were discussed. The author
then described some of the more common structural peculiarities met
with in rocks of various origin, especial attention being directed to
those in which micro-crystalline, crypto-crystalline, or micro-felsitic
conditions have been either normally developed or superinduced ;
while other rocks were described in which corresponding structure,
sometimes coupled with a similar mineral constitution, may be met

Geological Society of London. 139

with. Difficulties attending the determination of the origin of some
clastic rocks were also pointed out, and the value of certain structural
characters in their diagnosis were mentioned. Assumptions as
to the origin of some fragmentary rocks were shown to be un-
demonstrable in certain cases, although such assumptions often
earried much probability with them. The resemblances presented
by devitrified rhyolitic rocks, felstones, and felspathic grits were
dwelt upon at some length. The paper included a short structural
classification of the constituents of rocks.

2. “Distribution of the Serpentine and associated Rocks, with
their Metallic Ores, in Newfoundland.” By Alexander Murray, Hsq.,
C.M.G., F.G.8.

The author stated that no extensive display of serpentine is known
in the Laurentian series in Newfoundland; nor is the existence of
crystalline limestone of that age, with which serpentine is often
associated, as yet well established. The Intermediate or Huronian
system is singularly barren in lime, magnesian minerals, and mica;
lime occurring almost exclusively as intersecting calcareous veins.
Over all the known area of the system no masses of serpentine have
been observed, and only one instance of the presence of a serpen-
tinous mineral, which occurs in an intrusive mass intersecting the
Intermediate system, and disturbing the outcrop of the sandstones
of the Primordial Silurian (Lingula Flags) at a place called ‘The
Broad” of Tickel Harbour, Trinity Bay, where some steatite with
some seams of asbestos were seen near the contact. Wherever a
typical fossiliferous horizon could be established, the stratigraphical
position of the fossils placed those of the Lévis age, or older, below
the serpentines ; while in all cases, where the types were of Hudson-
River or newer date, they as invariably succeeded unconformably
above. Instances of this unconformable relation were mentioned in
which the upper formation was as late as the Devonian age. The
stratigraphical and paleontological break between the Lévis and
Trenton groups is here filled up by a metamorphic mass which, in
part at least, may possibly represent the horizon of the Chazy group ;
and the great intrusive masses have been connected with, or the
cause of, the metamorphic phenomena displayed.

I.— February 5, 1879.—The President announced the receipt of
a legacy of £1000, bequeathed to the Society by the late Sydney
Ellis, Esq., of The Park, Nottingham.

The following communications were read :—

1. ‘On the Occurrence of Pebbles with Upper-Ludlow Fossils in
the Lower Carboniferous Conglomerates of North Wales.” By Aubrey
Strahan, Esq., M.A., F.G.S., and Alfred O. Walker, Hsq., F.L.S.

The authors described the mode of occurrence near Abergele of
certain Lower Carboniferous conglomerates, best exposed in Ffernant
Dingle, and especially of one containing numerous red and green
sandstone pebbles, which inclose fossils of Upper-Ludlow forms,
and lying above the so-called “ Bastard Limestone.” From the ar-
rangement of the beds the authors believe that they may have been

140 Reports and Proceedings—

deposited against a bank or sloping surface of Wenlock shale ; and
they state that the great majority of the pebbles in the conglomerate
are quite unlike any rock known in the district, but closely resemble
the Upper-Ludlow beds of Kendal and Central Wales. The authors
discuss the origin of the pebbles, and suggest ‘‘ the probable exten-
sion of the Ludlow beds under Lancashire as the most likely source
from which they can have been derived.”

2. “On a New Group of Pre-Cambrian Rocks (the Arvonian) in
Pembrokeshire.” By Henry Hicks, M.D., F.G.S. With an Ap-
pendix on their Microscopic Structure by T. Davies, Esq., F.G.S.

In some new areas of Pre-Cambrian rocks discovered by the
author last summer in Pembrokeshire, some rocks of a character
hitherto unrecognized in this country were made out. As they were
found to hold there, and-subsequently also in other areas, a very
definite stratigraphical position, with a vertical thickness of several
thousand feet, they have been separated by the author from the
other Pre-Cambrian groups under the distinctive name of Arvonian.
They were also found to occupy an intermediate position between
the Dimetian and Pebidian formations, and at all points, so far as
could be made out, appeared to be separated from each of those
formations by stratigraphical breaks. The new areas where they
are chiefly exposed are situated some few miles to the north of
Haverfordwest, where they form ridges running in a direction from
N.E. to 8.W. They occupy an average width ‘of about a mile, at-
tain at some points to a height of nearly 600 feet, and together
have a length of over nine miles. The rocks are flanked by Pebi-
dian and Cambrian beds along their N.W. borders, and on the S.E.
Silurian rocks have been brought against them by faults. In general
appearance, as well as in their more minute lithological characters,
they are easily distinguished from any of the rocks hitherto de-
scribed by the author as characteristic of the Dimetian and Pebidian »
groups in Pembrokeshire. They are, however, so closely allied to
some of the true “ halleflinta’”’ rocks of Sweden, that it seems to the
author and Mr. Davies that this is the name that should be applied
to them in a petrological sense. In external aspect and in their
splintery fracture they resemble a hornstone. Under the microscope
they are seen to consist mainly of a crypto-crystalline ground-mass,
which, when examined with a high objective, is resolved into grains
of quartz, with an interstitial ingredient having but little action
on polarized light, but which presumably is felsite. There are also
numerous nests and fissure-like groups of quartz-grains disseminated
throughout, and sometimes angular fragments, distinct in size and
shape, are enclosed. These nests and fissure-like groupings are
frequently encircled also with bands of fibrous, chalcedony, the
structure of which is well exhibited with polarized light, and a
rude parallelism, suggestive either of an incipient foliation or of
stratification, is thereby given to the rock. The author and Mr.
Davies believe the origin of the rock to have been a sedimentary one.

3. On’ the Pre-Cambrian (Dimetian, Arvonian, and Pebidian)
Rocks of Caernarvonshire and Anglesey.” By Henry Hicks, M.D.,

Geological Society of London. 141

F.G.S. With an Appendix on their Microscopic Structure by the
Rev. Prof. T. G. Bonney, M.A., F.R.S., F.G.S.

In this paper the author gave the results of some further re-
searches made in Caernarvonshire and Anglesey since his previous
communication to the Society on Dec. 5, 1877. <A brief statement
of some of the results was read at the last meeting of the British
Association in Dublin; but much additional evidence was now
brought forward, besides many important facts obtained since by
microscopical examination of the rocks. Concerning the areas de-
scribed in his former paper much additional information was given,
and the boundary in one case greatly extended. This new area lies
to the west of Moel Tryfaen, and includes now, in addition to the
central or quartz-felsite ridge, the whole of the rocks marked in the
Survey maps as altered Cambrian, extending as far west as Glynllifen.
Many of the large masses in south-west Caernarvonshire and the
Llyn promontory, hitherto supposed to be intrusive rocks of Silurian
or Post-Silurian age, were discovered, during these researches, to be
of Pre-Cambrian age, and conclusive evidence obtained that the so-
called altered Cambrian rocks there, and in Anglesey, were also of
that age. In these various areas the three Pre-Cambrian formations
found in Pembrokeshire were recognized by having similar litholo-
gical characters, and in holding almost identical stratigraphical
positions in their relations to one another. Dimetian rocks were
recognized at Twt Hill, Rhos Hirwani, near Ffestiniog, and in
the so-called granitic ridge in Anglesey. Arvonian rocks between
Caernarvon and Menai Bridge, in the Hifl Range, Nevin Mountain,
and near Ty Croes, in Anglesey, etc., etc. Pebidian rocks to the
east of Glynllifen, Bangor, at the lower part of the Lynn promon-
tory, and in many places in Anglesey. Some notes on the section
near Ty Croes by Prof. Bonney accompanied the paper, in addition
to an appendix by him on the microscopic examination of rock-
specimens from each of the areas examined.

4. “On the Quartz-felsite and Associated Rocks at the Base of
the Cambrian Series in North-western Caernarvonshire.” By the
Rev. Prof. T. G. Bonney, M.A., F.R.S., F.G.S.

The great masses of quartz-felsite (or quartz-porphyry) which
occur in the vicinity of Bangor, Caernarvon, and Llyn Padarn, are
coloured in the Survey map as intrusive, and in the memoir reyarded
as most probably the result of an extreme metamorphosis of the
lower beds of the Cambrian series.

The author showed that these quartz-felsites exhibited, in places,
all the characteristics of true igneous rocks—flow-structure, fissile
structure, and the more ordinary structure of rhyolitic rocks; that
they were, in one place, at least, associated with masses of agglo-
merate, and in another parted by a band of comparatively unaltered
Slate. He also showed that in several places there succeeded a grit
formed of fragments of it, that larger fragments of perfectly
characteristic structure, associated with others of a more slaggy and
Scoriaceous type, occurred repeatedly in the overlying beds up to the
base of the Cambrian, described by Prof. Hughes and Dr. Hicks, the

142 Correspondence—Mr. C. Callaway.

felsite pebbles in which come from the same source. Lastly, he showed
that the signs of the metamorphism and apparent “ melting down ”
asserted to be visible on the sides of Llyn Padarn, proved, on micro-
scopic examination, to be mainly superficial. Hence, he maintained
that these rocks were rhyolitic lava-flows of Pre-Cambrian age.

5. “On the Metamorphic Series between Twt Hill, Caernarvon,
and Port Dinorwic.” By the Rev. Prof. T. G. Bonney, M.A., F.R.S.,
F.G.S., and F. T. 8. Houghton, HEsq., B.A.

In the Geological Survey Map this district is coloured as “ intru-
sive felsite,” together with those spoken of in the last paper. It
was asserted to be probably metamorphic rock by Prof. Hughes and
Dr. Hicks in a communication made to the Society last year, and
the first author confirmed that view by microscopic examination of
a specimen collected by them. The authors had during the past
autumn more minutely examined the district, and found :—(1) that
the general character of the series was that of a metamorphic one;
(2) that the rocks of granitoid aspect were associated with well-
marked beds of conglomerate; (3) that this series extended up to a
little beyond Port Dinorwic, where the quartz-felsite set in. The
paper described the microscopic structure of some of the rocks, and
the authors expressed the opinion that the more granitoid specimens
were probably the results of alterations of felspathic grits.

CORRESPONDENCE.

GLUT
THE TRIPARTITE DIVISION OF THE SILURIAN AND CAMBRIAN
FORMATIONS.! :

Str,—Will you allow a still small voice from the frontiers of
Siluria to say a word on Mr. Lapworth’s proposal to call the rocks
of the Second Fauna Ordovician? The lines have fallen to me in
the pleasant places of South Shropshire, amidst the monuments of
Murchison’s genius. But Murchison is gone, the surveyors are
gone (it is to be hoped they will come back again), and I am left
almost alone to represent Caer Caradoc and Wenlock Hdge. By the
names of Murchison and Sedgwick (now, perhaps, in still happier
hunting-grounds, recounting their old exploits, and wondering at
their ancient squabbles), I implore the rival schools to accept the
olive-branch! He who holds it is worthy to propose the compromise.
Moffat and Girvan have witnessed his renown. Scores of faults and
flexures testify to his skill. He has won an Ordovicia in the Scottish
Uplands. Let true scientific frontiers be established! Let Barrande
and Hughes meet together ; let Cambria and Siluria recede from each
other !

I am bound to record my humbie protest against the present
imbroglio. The want of a proper name for the rocks of the second
fauna is most embarrassing. I have used “ Lower Silurian” under
protest, and “Cambro-Silurian ” with dissatisfaction. Working some
time ago amongst the Upper Cambrians of Salop, and being anxious

1 This and the two following letters have been unintentionally delayed in
publication. —Hprr. Grou. Mac.

Correspondence—MUr. C. J. A. Meyer.—Mr. Jukes-Browne. 148

for all information on the subject, I eagerly waited for a paper
announced for the Geological Society on a new “Cambrian” find in
North Wales. The paper appeared, and the “Cambrian” turned out
to be Arenig. The author, of course, was a student of the Cambridge
School. Those of us who are simply workers, and not sectarians,
should not have our tools broken by the worshippers of great
names. CHARLES CALLAWAY.
WELLINGTON, SALop, January 6th, 1878.

CHLORITIC MARL AND UPPER GREENSAND.

Sir,—I beg the favour of space for a brief reply to Mr. A. J.
Jukes-Browne’s questions which appeared in the GroLoctcaL
Magazine for January, 1879. Mr. Jukes-Browne asks:

(1). “ Why has he (Meyer) changed his mind regarding bed 13
(of the Beer Head Sections), and why does he not identify it with
the zone of Belemnites plenus ?”

(2). “ What does he mean in saying that he was therefore wrong
in giving Holaster subglobosus so wide a range in his tables of
fossils? Is it not found in the beds where he marks it as
occurring ?”

In reply to question (1): It would be hardly correct to say that I
have changed my mind regarding bed 13. In 1874 I described it
as representing Chalk Marl. More recent examination has convinced
me that I am right in placing it above the Chloritic Marl, and I now
identify it with the zone of Belemnites plenus.

To question (2) I can but repeat my acknowledgment (in Gro.
Mag. for Dec. 1878) of error in my tables of fossils of the Beer
Head Sections.

For the rest I shall be happy to continue this discussion so soon
as Mr. Jukes-Browne may have found “an opportunity of refresh-
ing his recollection of the Isle of Wight sections,” by reference to
the disputed rocks and fossils in situ. By such time perhaps some
acceptable term may have suggested itself which may replace that
of Chloritie Marl. C. J. A. Meyer.

January 6th, 1879.

Sir,—Having informed Mr. Meyer of the typographical error
which occurred in my last letter,’ he has been good enough to send
me fuller particulars, in answer to my questions, than are contained
in his reply sent to you for insertion in the GrotocgicaL Magazine.
I gladly avail myself of his permission to transmit them to you for
publication, as they contain fresh evidence regarding the zones in
the Devon cliffs. Mr. Meyer writes to me as follows :—

“You may remember that in my description of bed 18 in
1874, I referred it to the base-bed of the Chalk Marl. That
is to say, I considered it then as the lowest representative of
the Chalk Marl of that particular district. I described it as
distinct from the Chloritic Marl, because it even then appeared
to me to represent Chalk Marl as to its matrix and older beds

1 At p. 48, line 9 from foot of page, for ‘‘ not” read ‘‘ now.”

144 Correspondence—Mr. G. H. Kinahan.—Mr. O, Fisher.

only as to its remanié fossils. J had at the time no clear evidence
of the horizon of the bed next above, not having then elsewhere
sufficiently studied the fauna of the passage-beds from Chalk Marl
to Chalk. In 1876, Barrois, as you know, referred bed 13 to
Chloritic Marl. In 1877, and again in 1878, I re-examined the
Devon cliffs, obtained much additional information, and _ satisfied
myself that bed 13 belonged to a higher horizon than I had at first
supposed. I found that bed 13 itself contained Belemnites plenus.
That the bed next above it (bed 14) contained Inoceramus labiatus.
That Holaster subglobosus, in some sections wholly absent, abounded
here and there only in the top of bed 12, was to be found very rarely
im the lower part of bed 13, but was not present in any of the other
beds. In my tables of fossils of 1874 I had most unluckily included
amongst supposed specimens of Holaster subglobosus the Holaster
nodulosus of Hebert and H. carinatus, Ag., which are present in beds
11, 12, and probably also flattened specimens (seen only in situ) of
Echinoconus, which occur rarely in beds 14 to 17. The result of my
researches since 1874 in these particular sections amounts broadly
to this—that I find reason for placing beds 13, 14, respectively a
stage higher in the Cretaceous series than I had at first supposed.”
I hope Mr. Meyer will soon be able to publish the results of his
recent researches in greater detail, as the zone of Bel. plenus appears
likely to become an important divisional line in the Cretaceous series.
Jan, 8, 1879. A. J. JUKES-BRrowne.

SIR R. GRIFFITH AND THE OLD RED SANDSTONE.

Sir,—I find I have misrepresented Sir R. Griffith ; from my
conversation with him I imagined his statements in reference to
the Fintona, Curlew Mountain and Croagh Moyle rocks had not been
published ; while now I learn they had been published in 18438,
during the meeting of the British Association at Cork. For this
correction J am indebted to the Rev. M. H. Close, President of the
Royal Geological Society of Ireland. As that gentleman has in pre-
paration a history of Griffith’s Map, it is unnecessary to say more
on the subject at present. G. Henry Kinanan.

Ovoca, February 7th, 1879.

ON THE FORMER CLIMATE IN THE POLAR REGIONS.

Sir,—Dr. Haughton’s letter makes it look as if I had committed
an anachronism in saying that Dr. J. Evans had, in his opening
Presidential Address, defended his theory about changes of latitude
against arguments subsequently brought forward in the Section by
the Professor. It was, however, to a paper read by Dr. Haughton,
in April, 1878, at the Royal Society, to which I referred.

O. FisnEr.

ERRATA AND Omissions.—In Mr. Lapworth’s paper on the Tripartite Classifica-
tion of the Lower Paleozoic Rocks, Grou. Mac., January, 1879.
After title insert-—(Read before Edinburgh Geological Society, Dec. 19, 1878.)
p- 3, line 1, for “ight read right.
p. 3, line 40, for division read divisions.
p- 12, line 20, for ¢¢ read them.

THE

GEOLOGICAL MAGAZINE.

NEW SERIES: DECADE JI. VOLE. VI.

No. IV.—APRIL, 1879.

(@pStahS AEN (ASE) Pe NaS Oe bass

— ;

T.— On some Fish Exuvia From THE CHALK, GENERALLY REFERRED
to DERCETIS ELONGATUS, AG.; AND ON A New SpecizEs or Fossin
ANNELIDE, T2REBELLA LEWESIENSIS.

By Wituram Davizs, F.G.S.,
of the British Museum.

NOT uncommon fossil of the Chalk, in both the upper and lower
divisions, is an elongated, and more or less undulating body,
composed of the scales and bones of fishes confusedly mingled one
with another, and known to the quarrymen as “ Petrified Hels.”
Dr. Mantell was the first to discover and describe these singular
objects; he says, “A long cylindrical fish, of which neither the
fins nor the extremities have been discovered, is one of the most
frequent, but most imperfect of the Sussex ichthyolites. The
specimens are of a subcylindrical form, rather flattened by com-
pression, from six inches to two feet in length, and about one inch
wide. They occur abundantly in the Upper Chalk, and occasionally
in the siliceous nodules. They are, for the most part, perfectly
straight; but some specimens are undulated, as if the fish had been
suddenly enveloped in the Chalk while in a state of motion. The
surface is covered with small delicate smooth scales, confusedly
mixed together; not one instance having been noticed in which they
are disposed with any degree of regularity.”

“Until more illustrative specimens shall be discovered, our con-
jectures concerning the recent animal must be vague and unsatisfac-
tory. That the remains in question are referable to a fish of the Order
Apodes cannot, however, be questioned, and they certainly appear to
be more intimately related to the genus Murena, than to any other
with which we are acquainted.”! And he accordingly names them
Murena? Lewesiensis. In subsequent works? he refers them to
Dercetis elongatus, Agassiz; probably from two small fragments in
his collection, and figured in the work above quoted (tab. 34, figs.
10 and 11), regarding which specimens he says fig. 11 “is the only
example” of Murena Lewesiensis “that retains the slightest indica-
tion of a fin,” whilst that of fig. 10 “shows vestiges of the tail,
and of one fin, but no conjecture can be formed of the genus of the

| Fossils of the South Downs, 1822, p. 282, tab. 34, fig. 10, tab. 40, fig. 2.

* Medals of Creation, 1844, vol. ii. p. 658; Petrifactions and their Teachings,
1851, p. 438.

DECADE Il.—yVOL. VI.—NO. IV. 10

146 William Davies—On Dercetis elongatus, Agassiz, etc.

original” (p. 133). Yet these same fragments were subsequently
figured by Agassiz, who, without hesitation, refers them to his
Dercetis elongatus, as respectively anterior and posterior portions
of the body;* an inexplicable allocation by either author; seeing
that the specimens are each too obscure and fragmentary for certain
identification, being mainly composed of rounded scales ‘‘ confusedly
mixed” with bones and fin-rays, and do not contain a fragment of
a Dercetis scute. Whereas the species was actually founded upon
two other specimens in good preservation in Dr. Mantell’s possession;
one containing the head and a large portion of the body with the
characteristic dermal scutes in situ, and the other consisting of a
portion of the vertebral column of a larger individual, also ac-
companied with the dermal plates, but in neither specimen are there
any indications of scales.”

Moreover, by the aid of these two specimens Dr. Mantell designed
and published a restoration in outline of this extinct fish,? in which
no scales are represented. Nor does Prof. Agassiz in his diagnosis
of either the genus or species mention other scales besides the scutes;
and I may also add that I have examined many well-preserved
specimens of Dercetis, and have not met with any trace of such a
dermal covering. However, Dr. Mantell’s determination has been
generally adopted for these remains, though some collectors refer
them to coprolites, and others to intestines of fishes. To the accept-
ance of either of the above views of their origin I have long been
convinced that there are grave objections, founded upon an examina-
tion of numerous examples. That they are not the bodies of a
species of fish, as confidently asserted by Dr. Mantell, is evident by
the fact that they are collectively composed of debris of several
species, and also, that scales of more than one species may frequently
be detected upon the same specimen, the scutes of Dercetis being
rare: neither are they coprolites, else they would occur in compact
and less lengthened masses; and much less, from physiological
reasons, can they be considered as intestinal. But the form and
structure is highly suggestive of their being the remains of mem-
branous tubes of large soft-bodied Annelides, of solitary habits,
that collected and agglutinated, either for protection or disguise,
the scales and bones of fishes to the exterior surface of their tubes ;
as some recent Annelides collect and attach by agglutination
fragments of shells, grains of sand, and other substances to their
dwellings. That they were tubular is shown by transverse sections
of specimens which have been filled with chalk, and sometimes with
flint, having the thin walls of the tube preserved entire; but this
is of rare occurrence, owing to the extreme thinness of the mem-
branous substance of which it was composed. And that they were

1 Poiss. Foss. tom. il. pt. i. p. 259, tab. 66a, figs. 3, 4. Figure 3 is drawn as
having a series of seven consecutive vertebree; these had no existence save in the
imagination of the artist, none being present upon the specimen; this and the other
type-specimens of Dercetis figured by Agassiz are preserved in the National Collec-
tion, and each are as intact as when drawn for his work.

2 Op. cit. tab. 66a, figs. 1, 2, and 5.
3 Wonders of Geology, 1838, p. 309, fig. 39, and subsequent editions.

Wiliam Davies—On Dercetis elongatus, Agassiz, etc. 147

not burrowers, but lived and extended their dwellings upon the
ooze of the sea-bottom, may be assumed from the covering of
extraneous matter, their comparative straightness, position in the
Chalk, and the great length they attained—Dr. Mantell says “from
six inches to two feet,” but this can only apply to lengths that have
been extracted from the quarry, and which were originally longer,
as no specimen with the extremities entire has yet been discovered.
This prone habit is further confirmed by the fact that only in a
few instances have I been able to trace the agglutinated debris
completely surrounding the tube, as if, after the animal’s death,
it had been removed by the action of the waves from as much
of the surface as was above the ocean-floor; or it might be that the
animal did not in all cases agglutinate debris to the whole or to
the inferior surface of its structure, for two casts from a quarry
near Guildford, which admirably show by impression the mem-
branous or horny structure of the tube, bear no indication of the
attachment of any foreign substance, but, nevertheless, may be
referred to the same species upon the evidence of a third fragment
from the same quarry, which has precisely the same surface structure,
but has also some scales attached and faint impressions of others.
That the affixed debris left permanent impressions upon the
substance of the tube is well displayed upon another cast which
has been completely denuded of its covering, but retains deep
imprints of the lost scales and bones. The above-mentioned
specimens, and other interesting examples of this fossil, form part
of the collection of J. R. Capron, Esq., of Guildford, which has
recently been acquired for the British Museum.

Besides their irregular disposition, there are diverse individual
variations in regard to the affixed substances: whilst some speci-
mens are constructed of small and delicate scales intermixed with
few or no bones, others are formed either of large or small scales
associated with numerous small bones pointing in every direction
along the membranous surface of the tube, but not extending beyond
it, vertebree being comparatively rare and of small size; long fin-
rays, ranging from one inch to two and a half inches in length, enter
largely into the composition of others, and are arranged fairly in the
direction of the long axis of the specimen. An example of this
variety is represented in Dixon’s Fossils of Sussex, pl. 34, fig. 5;
and there is a specimen in the British Museum, fourteen inches long,
on which the appropriated rays exceed two inches in length.

I have detected scales of small specimens of Beryx ornatus, Bery-
copsis, and Osmeroides Lewesiensis; but most of the scales are too
imperfect for identification. .

That the animals that formed these dwellings (the only evidence
known to us of their past existence) were solitary in their habits, is
inferred from the circumstance that in no instance have two
specimens been found in juxtaposition. And, imperfect as is ‘the
evidence respecting their natural position, I think we may, never-
theless, assume that they were branchiferous Annelides of the Order
Tubicola ; with affinities to one or other of the genera which con-

148 J. 8S. Gardner—Correlation of the Tertiary Series.

struct their dwellings of sand or small stones, rather than to Serpula,
or other recorded fossil genera that form calcareous tubes, and are,
also, more or less gregarious. ‘The recent genus Sabella, which
belongs to the former division, contains species which construct
calcareous dwellings; and Prof. M‘Coy has described a species of
this group (S. antiqua) 1 as occurring in the Carboniferous rocks of
Ireland. But generic identifications founded upon such remains are
necessarily conjectural and doubtful, as they yield no information
regarding the anatomical structure of their former inhabitants; yet are
nevertheless useful, in default of more precise knowledge, as aids to
classification. With this view, and having regard also to the mem-
branous tube, solitary life and habit of collecting organic debris for
affixing to their domiciles, I am disposed to refer the makers of these
dwellings to the genus Terebella, which includes one species, having
analogous habits, the well-known shell-collecting Terebella conchilega.
* Though Dr. Mantell failed in his interpretation of the natural
position, and abandoned the name he first gave to these remains ;
yet his description of them is so clear and concise that the specific
name he originally proposed must be retained, although objectionable
as regards objects so generally distributed in the Chalk. I therefore
propose that they be designated Terebella Lewesiensis, Mant. sp.,
until more authentic information regarding their origin is obtained.

IJ.—On tHe Correnation oF THE BournemouTH Marine SERIES
WITH THE BrackLESHAM Beps, THE Upper anpD Mippie Bagsnor
Brps oF THE Lonpon Basin, anD THE Bovey Tracry Bens.

By Joun Srarxiz Garpner, F.G.S., M.G.S. of France, etc.

1 the spring of the year 1878 I brought under the notice of the

Geological Society a paper describing for the first time as Marine,
the Upper Series of the Bournemouth strata, present in thickness to
the east of Bournemouth Pier. The publication has been delayed,
but the present sketch will only to a very slight extent forestall it,
and is written simply with a view to make clear the synchrony of
the Bournemouth Marine Beds with the lower part of the Brackle-
sham Beds of the Hampshire Basin, the Middle and so-called Upper
Bagshot Beds of the London Basin, and the Bovey Tracey Beds, the
true position of the latter, especially, being more clear at the present
moment than it was a few months ago. I propose first to describe
briefly the Bournemouth Marine Strata, and then the other formations
with which I have correlated them, in the order in which they are
mentioned above.

Tue Marine Bovurnemourn Brps.—I have in the paper read
before the Geological Society, pointed out the exact equivalents of
each of the beds composing the series in the Alum Bay section.
The marine or rather brackish-water beds first appear in a landslip
almost under the Meyrick Road, a point some half mile east of
Bournemouth Pier. From this point to Hordwell Cliff none of the

' 1 Carb. Foss. of Ireland, p. 171, pl. 4, fig. 11.

J. S. Gardner—Correlation of the Tertiary Series. 149

strata. appear due to purely freshwater action. Before I proceed
further, I may as well at once meet an objection that may be urged
against the purely freshwater origin of the Lower Bournemouth
Series, that is, the occasional presence of Teredo-bored wood in it.
This isolated fact for some time presented a grave difficulty, but in
addition to the evidence recapitulated in Dr. J. Gwyn Jeffreys’ account
of the occurrence of similarly bored logs 300 hundred miles up the
river Gambia, and his distinct statement, to which I have before
alluded,! that there is a species which lives in fresh-water; the
mention of the subject elicited letters containing even stronger testi-
mony as to the fresh-water habits of the ship-worm. In one of
these? Arthur Nicols states that Teredo navalis is certainly able to
endure a long continuance of fresh water, being found at Brisbane,
where the river is subject to long-continued freshets. One of these
lasted ten days, during which the flood was so powerful that ocean
steamers could not get up, yet although the river at ebb-tide is more
fresh than salt, the piles have to be protected. In the previous letter®
a correspondent states that in the Delta of the Irawadi, where for
eight months in the year the waters are only slightly brackish or
even potable, the large canoes which traverse them are infested with
ship-worm, and have to be fired to get rid of them.

This difficulty may, therefore, be regarded as finally removed.

The Lower Marine Beds are black sandy clays, and contain oysters
and leaves, covered with Polyzoa, and a variety of casts of shells,
apparently referable to Bracklesham species; Callianassa is also
abundant in them, and shore-crabs are met with. These dark beds
can be traced from this point for about five miles, where they dip
under the beach. They change over and over again, occasionally
very abruptly, within short distances, from dark sandy clay to buff
or yellow or white sand. Sometimes the dark clay suddenly thins
to a mere layer, or is still more frequently only represented by
small lenticular patches. The junction between the dark beds and
those which overlie them can nearly always be traced by a line
of wet which darkens the lower series, even if they also happen
to be of white sand. Above these are the Upper Marine Beds,
generally of pure white, sometimes slightly yellow sand, and
inclosing masses of well-rolled shingle. The pebbles are sometimes
large, but, of whatever size, they always have a thick white coating.’
so much so, that frequently only a nucleus of black flint, or not even
that, remains. These Hocene pebbles cannot be mistaken for those
of the overlying gravel, being far more worn, and well rounded.

These Lower Marine Beds contain plant-remains of great interest.
Going back to the Fern Beds,’ which are high in the cliffs, the greatest
difficulty is experienced in ascertaining how the freshwater beds
came to be so completely replaced, within only 100 yards, and upon
the same horizon, by marine beds. The frequent landslips, indeed,

1 Proc. Geol. Association, vol. v. p. 55.

2 “ Nature,’ May 3rd, 1877. 3 “ Nature,’ April 19th, 1877.

4 As the Bracklesham flint-pebbles are usually encrusted with Litharea Websteri,

probably this may explain the “ white coating.’’—Epir. Grou. Mac.
° The uppermost of the Bournemouth freshwater series.

150 =o. S. Gardner—Correlation of the Tertiary Series.

that take place here, very seldom allow the section to be seen at all.
With difficulty it was cleared, and with the help of Mr. De Wilde,
drawings and photographs were taken. The Fern Beds and those
below them were seen to contract and become very distorted, and to
be finally pushed upward and end in a point. A wedge of hardened
sand displaces them, and this rapidly thickens or fans out, and forms
a cliff 40 feet high, nearly perpendicular, and filled with lumps of
clay, the débris of broken-up leaf-beds. Under the thin end of this
wedge is a mass of whitish sand, belonging to the freshwater beds,
and stretching a long way west. The transition does not appear to
have been violent or sudden, but rather to mark tidal action. Under
this cliff a small ledge contains compressed seeds and carbonised
leaf-remains of many kinds—identical with those of Bovey Tracey.
Beyond a second landslip, the first cliffs that rise from the beach
contain a small patch of beautifully preserved fruits and seeds,
which are of great interest. The exact spot is marked by a stream-
let, falling over the commencement of the cliff, where it is only
about 8 feet high. I mention this stream, as it has been persistent
for many years.

At the east corner of Boscombe Chine, about 6 feet above the
beach, there is a bed containing branchlets with leaves attached of
Dryandra, and of a Sequoia-like Conifer. One of the most interesting
spots, as well as the most picturesque, perhaps, along the whole
coast, is the Honey-Comb Chine.! The dark beds near their base are
in places so full of the fruit known as Nipadites, that after rain a
small hand-basket full may be collected in an hour. I also found
the base of a magnificently preserved palm-siem, its roots entangling
white pipe-clay, inclosed in a bed of sand. The wood was apparently |
so fresh as to cut easily into slices with a knife, and the fibres
separated readily.

One other patch, among many, only need be noticed for its flora,
and it occurs but a short distance further on, again being identified
by astreamlet. The bed is close to the beach, and is of a cigar-
ash colour. It contains, besides much bored-wood, limbs of all sizes
of an American Cactus, with the spines adhering, and splendidly
preserved branches of a Conifer, common to most beds east of the -
Pier. With these was a shark’s tooth. Other patches contain in-
distinct leaf-impressions, seeds and pods, casts of Oysters, bored
wood, ete.

From this point the cliffs go on with varying strata, and become
lower and lower towards the neck of land which connects the
promontory of Hengistbury Head with the main land. On the neck
itself all the sand has been washed away, and rolled Hocene flints
are mixed with the more angular gravel in one shingly mass.

The Upper Marine Series is unfossiliferous.

1 Trespassers are warned off, but the beds are nevertheless well worth examination.
The sides, upwards of 100 feet high, are white as sugar, and worn into trellis-like
patterns by rain. The ridge separating them, deprived of its gravel capping, and
formed of snow-white sand, looks quite Alpine with its sharply-cut peaks and water-
worn gulleys, easily magnified by a vivid imagination into chasms and crevasses.

J. S. Gardner—Correlation of the Tertiary Series. 161

The Head itself contains a separate sequence, the Hengistbury
Head beds. The uppermost layer is white sand with an orange
clay layer at the base. The main mass of the Head is composed of
brown clay, to which it owes its preservation. ‘This stiff clay has
resisted denudation and the layers of ironstone which it contains,
falling into the sea, have formed a protecting barrier... Below
the clay is a green sand bed, and lastly we find black, chocolate-
coloured, and white sands, belonging to the same Upper Marine
Series which we haye seen capping the Boscombe Cliff.

The highest beds, above alluded to, I have traced across to the
base of High Cliff, where they had already a place assigned to them
in the Bracklesham Series.”

Tue BrackLesHam Bups.—lt is difficult to distinguish these at
Alum Bay from the overlying Barton Series. Prof. Prestwich indeed
grouped both in one bed, No. 29, but Mr. Fisher* has shown that
the lower 48 feet form a portion of the Bracklesham Series. ‘The
most complete section is at Whitecliff Bay, where almost every
bed that has been met with on the main land is represented. The
whole group consists of alternations of sand and sandy clay, the clays
being more prevalent in the highest member, the sands in the
lower. Green grains abound in all the beds. Many of the beds
are laminated, being formed of alternations of very thin bands of
clay, separated by sandy layers, and contain vegetable matter. The
best known localities, and those from whence celebrated collections
of fossils have been procured, are Bracklesham or Selsey, Stubbing-
ton, and near Bramshaw in the New Forest. At Highcliff, the
junction between the Bracklesham and Barton beds is placed by
Fisher at the Nummulina Prestwichiana bed, 35 feet above the white
Hengistbury Head Sand at the base of the cliff. As the Bracklesham
Series are at Whitecliff Bay 530 feet thick, we see that there is a
probability that the whole of the Marine Series of Bournemouth,
with the Hengistbury Head Beds, may be contemporary with them.

The MippuxE and so-called Upper Bacsnot Bens of the London
Basin.—The Middle Bagshots, representing the Bournemouth and
Bracklesham beds, have no great extension in the London Basin,
and do not exceed forty to sixty feet in thickness. They more resem-
ble the Bournemouth beds than the true Bracklesham series. Their
principal development is round Chertsey and Addlestone. They are
easily recognized by their sands and clays with green grains, which
also distinguish them from the Lower Bagshot beds. They seldom
contain fossils, but enough have been found to identify them with
Bracklesham.

It appears to me that there is not the slightest reason to suppose
that any Upper Bagshot beds are present in the London Basin. The
absence of Barton clay, and the identical character of the beds with
the Upper Marine beds of Bournemouth, renders it unlikely that

* I have made frequent but unavailing search for the leaves marked on the Geol.
Survey Map as occurring here, but I have found leaves in the same beds in a
brick-pit inland.

* Rey. O. Fisher, Q. J. G. 8., 1862, vol. xviii. p.67. 3 Q.J.G.S., 1862, vol. xviii. p.84.

152 =o J. S. Gardner—Correlation of the Tertiary Series.

there is the gap in the sequence there which their present reference
to Upper Bagshot implies."

The Bracklesham beds have a very considerable extension in the
Paris area, where they are universally admitted to be represented
by the well-known and important Calcaire-Grossier formation. It
is quite otherwise with the supposed Belgian equivalents—the
Bruxellien system. In this it is a question of averages, and out of
the list of twenty-seven of the most characteristic species cited
by Prestwich? to support the correlation, twelve, a very large
proportion, are Barton; and the Mollusca, as a group, is not
sufficiently or purely Bracklesham to warrant belief in so northern
a spread of that formation.

Tue Bovey Traczty Breps.—So ample an account of these and
their bibliography is to be found in the reprint from the Philosophical
Transactions, part iii. 1862, of the work upon them by Pengelly and
Heer, that little can now be added. The peculiarities in the biblio-
graphical history of these deposits are, first, that they were
frequently under the notice of scientific men for more than a
century, without any distinct vegetable-remains other than wood
being found in them; and, secondly, that the fact of Pleistocene
deposits overlying them led all writers to presuppose that they were
of very recent age. Before, however, Heer and Pengelly had
commenced work, Dr. Falconer “made several visits to Bovey,’* in
some of which he was accompanied by other geologists. “The result
was a strong impression that the deposit would be found to belong
to the Miocene period.” ‘This impression was fully shared in by
Pengelly, who was gratified to find it borne out by Heer, when, upon
the determination of forty-one species, twenty-two of them new to
science, he pronounced the formation to be “decidedly of the Lower
Miocene age.” * 'Time has, however, completely refuted upon plant
evidence the theory that the Bovey beds are Miocene, and unmis-
takably identified them with the Middle Bagshot of Bournemouth.
Upon geological evidence, also, the improbability is apparent of such
great deposits being accumulated in a Devonshire valley without
any trace of them existing elsewhere; and a theory which brings
them into a defined position in the consecutive formations of the
country should be a welcome one.

Pengelly’s principal section shows a series of beds 115 feet thick,
allowing 10 feet for newer deposits, and at p. 14 we find that there
are at least 130 feet of underlying beds of the same age (99 feet
by actual section, and about 40 feet by estimate, less 10 feet for
surface Head or Pleistocene deposits) ; and we thus have a thickness
of some 240 feet. This by no means represents the total thickness,
for the bottom has never been reached, and there is also evidence
of great denudation. There is besides, a fault, which Pengelly
considers to show a vertical displacement of 100 feet, but which
may indicate more, to judge from a section on the east side of it, pos-
sessing, as it does, only an aggregate of 2 inches of coal instead of
36 feet in a similar depth, so that a great gap may exist between

1 Mem. Geol. Surv. vol. vi. 1871, p. 333. 2 Q. J. G. 8. vol. xiii. p. 106.
3 Phil. Trans. part iii. 1862, p. 3. ANcupulos

J. 8. Gardner—Oorrelation of the Tertiary Series. 158

the two. I by no means, however, endorse Pengelly’s idea that the
coal is in extensive layers, but should expect to find it only in local
patches, of greater or less extent. It is rather difficult to make out
what Pengelly believes to be the total thickness of the Bovey Tracey
Beds proper. He says, however, that 210 feet is its aggregate thick-
ness, exclusive of Mr. Divett’s section, showing, as corroborated by
Pengelly, 130 feet of underlying deposit, and of the fault showing
at least 100 feet of higher beds. We have thus a total of 440 feet,
yet the bottom has never been reached, and much has been denuded.
Forbes, in speaking of them, says:'—“The present geographical
limits of the deposit may have scarcely any relation to its original
extension. It is interrupted by considerable faults; and the beds are
occasionally disposed at high angles, which -have no relation to the
present surface-contour; and it seems probable that they may be
but a remnant of the original formation, which has been protected
from denudation in the Bovey Valley.”

The paleontological evidence upon which the
Miocene age of these beds has been determined,
proves conclusively that they are Middle Eocene
and on the same horizon as the beds at Bourne-

mouth, only 80 miles distant. The Oaks, the \

Laurels, the Figs, apparently all the dicotyledonous x

leaves, are identical. The Cinnamons of Bovey, NA
thought to be especially characteristic of Miocene, NZ
are abundant at Bournemouth. The fruits are so NA
similar that handfuls of Anona from each place, if WA
once mixed, could not again be separated. Two SS ;

Ferns out of three are common to Bournemouth
and Bovey, and of these the most characteristic
is found equally abundantly at both, and in pre-
cisely similar positions. The pinnz of Osmunda
lignita are found in blackish shaly clay, spread
in layers and mingled with Cactus spines ( Palma-
cites Demonorops, Heer) and Sequoia. On the
other hand, the three small seeds which are sup-
posed to link Bovey with Hempstead are insigni-
ficant, and indeed are not confined to the Hemp-
stead Beds. If the Bovey Beds are Miocene, the
Bournemouth Beds must also be Miocene.

Having so much reason to believe that the
Series is contemporaneous with the Hocene at
Bournemouth, we see that this silted-up lake lies
in the direction whence the Great Eocene river
came, and must either have been in its direct mys
course, or in that of one of its affluents. Lyell’s Osa ibromelicy ela
account of the imbedding of plant-remains in the of the | Myo ee

5 . 2° Indistinguishable from

Slave Lake is so curiously like what must have O. lignita.
happened here, that parts of it are extracted.

DL,

AN

Saas
me

Vo
W

We.

1 Quart. Journ. Geol. Soe. vol. ix.
2 From the Royal Herbarium, Kew. Plenasiwm bromeliefolium, Presl., Kitings-
hausen’s Farnkrauter der Jetztwelt, p. 152, fig. 66, 67; pl. 80, fig. 1. Isle of Luzon.

154 J. Nolan—NMetamorphic and Intrusive Rocks of Tyrone.

“In Slave Lake, in particular, which is 200 miles long, the
quantity of drift timber brought down annually is enormous.” The
trees become water-logged and sink, and “the trunks gradually
decay, until they are converted into a blackish-brown substance
resembling peat, but which still retains more or less of the fibrous
structure of the wood; and layers of this often alternate with layers
of clay and sand.” The banks have ‘a remarkable horizontal
slaty structure,” and along the Mackenzie “display almost every-
where horizontal beds of woody coal, alternating with bituminous
clay, gravel, sand, and friable sandstone.” ... “The Slave Lake
itself must, in process of time, be filled up by the matters daily
conveyed into it by the Slave River.” [Principles of Geology, 1868,
10th edit., vol. ii. p. 526. ]

To believe that this huge fragment of a large deposit belongs to
the Miocene, we have to suppose that it was deposited and all, ex-
cept this patch, denuded at a period when we have no record of
agents existing in our country capable of doing the one or the other,
and this in spite of lithological and paleontological evidence which
directly connects them with a similar mass of strata not 80 miles
distant.

IIJ.—On tHe Meramorruic anp Intrusive Rooks or Tyrone.!

By J. Nouan, M.R.I.A., etc.;
of H.M. Geological Survey of Ireland.

HE rocks I propose to describe in this paper belong to that
great metamorphic series which occupies so large a portion of
the north of Ireland, extending over most of the counties Tyrone,
Londonderry, and Donegal. For the present I shall confine my
observations principally to that portion of them situated about the
central parts of Tyrone, from the vicinity of Omagh eastwards and
north-eastwards towards Slieve Gallion. This district has been
already ably described by General Portlock in his “ Geological
Report on Londonderry and parts of Tyrone and Fermanagh” ; but
as, during the progress of my work for the Geological Survey, I have
had opportunities for a very detailed examination of it, I beg,
briefly, to offer some further remarks and conclusions.
The rocks in the district may be thus classified :—

First.—Schist and Gneiss.

Secondly.—Green metamorphic rock, generally hornblendic or
pyroxenic, passing in some parts into schist, and in others
into granite.

Thirdly.—Quartz Porphyry and Granite — metamorphic and
intrusive.

First.—Schist and Gneiss.—Little requires to be noticed of these
rocks, as in this district they present but few special characteristics.
They occupy a hilly tract of country, extending from near Carrick-

! This paper is published by permission of the Director of the Geological Survey
of Ireland, and of the Director-General. It was read before the British Asso-
ciation in Dublin, August, 1878.

J. Nolan—WMetamorphic and Intrusive Rocks of Tyrone. 155

more north-eastwards to Fir Mountain, having a width of from
three to four miles at the greatest, and terminating at both ends
among the green metamorphic rocks presently to be described, in
which, indeed, they may be considered as forming a huge lenticular
mass. The prevailing character is a coarse massive gneiss passing
into schist, generally micaceous, and often containing some horn-
blende. Close to the junction with the green metamorphic rocks
just alluded to, the foliation is less strongly marked, while the
texture is more crystalline, and much hornblende appears, as if
passing gradually into that rock. Remarkable examples of this may
be seen at Fir Mountain, and at Lissan, in the stream forming the
county boundary. In the former locality, we find at the base of
the hill, micaceous schists and well-foliated gneiss, succeeded by a
coarser quality, till at the summit we have massive rocks, in which
all traces of foliation seem nearly obliterated, approaching so closely
to the hornblendic type that no exact line of division is at all
possible. The stream section, north of Lissan demesne, exposes
similar rocks, which are more quartzose, and change into granite and
syenite. From these observations it would appear that the schistose
and amorphous green rocks are but parts of one system, the varieties
being due either to differences in the chemical composition of the
original rocks, aided, probably, by conditions of greater intensity of
heat and pressure, or perhaps, that the more crystalline parts were
the result of re-emetamorphism. That some such action has taken
place over that part of the district at least, I shall endeavour to
show subsequently.

Secondly.—Green metamorphic rocks, generally hornblendic or
pyroxenic.—These, as has been remarked, occupy the country around
the gneiss series just described. The most prevailing kind consists
of an aggregate of plagioclase felspar, which is often labradorite,
with hornblende, or pyroxene, or both, developing in some places
into largely crystalline hypersthenite, in others becoming more
finely crystalline, passing into a compact greenish or bluish variety.
Free quartz, too, often occurs, sometimes in grains scarcely perceptible,
but in other places developing into great crystalline blebs, converting
the rock into a coarse syenite.| Examples of this may be observed
in the hills north of Pomeroy, where, at the base, the hornblendic
rock with a little quartz is seen, which mineral increases in the
space of a few yards to great crystals, that weather out in warty
excrescences, giving to the rock, as Portlock remarks, “‘a peculiar
mechanical aspect.”

In other localities the compact varieties become highly felspathic,
and pink felspar (orthoclase) appears, with quartz, until a corase
elvanite or quartz porphyry is produced, which usually contains
mica and passes into granite, or syenitic granite by the addition of
hornblende.

That the green metamorphic rocks thus pass gradually into granite,

1 T use the term syenite in the same sense as it is used in Jukes’s Student’s

Manual of Geology, viz. “A crystalline granular aggregate of felspar, hornblende,
and quartz.”

156 J. Nolan—Metamorphic and Intrusive Rocks of Tyrone.

appears to have been the opinion of the late Sir Richard Griffith
and General Portlock. Thus, at p. 60 of his “Geological Report,
etc.,” we find the latter author quoting the former—<“Slieve Gallion
mountain is composed of granite, syenitic granite, syenitic green-
stone, and greenstone, and the same varieties of rock, apparently
graduating into each other, occupy the parishes of Lissan and
Kildress”; and at p. 94, he himself states that “there are so many
gradations of change, from the rock which appears decidedly granitic
into hornblendic rocks on the one hand, and into others which are
little more than schists, in which the constituents have been blended
together and the stratification obliterated, that the mind seems forced
to consider the whole, even to the granite, as metamorphic.”

In other parts of the green rock basic minerals prevail, and it
becomes coarse diorite, diallage, or hypersthenite. One of the best
localities where these changes may be seen is at Termon Rock, near
Carrickmore. The massive crags which rise abruptly over the flat
through which the railway runs are diorites, traversed in every
direction by veins of epidote; and at the Glebe of Athenree, one
mile to the east, the diorite is replaced by diallage or hypersthenite ;
while at the “Scalp,” two miles to the north-east, a more largely
crystalline variety occurs. At all these places the felspar is, as we
might expect, labradorite, yet at Oritor, near Cookstown, there is a
massive rock in which hypersthene is associated with orthoclase.

In close proximity even to the largely crystalline rocks sudden
variations in texture are not uncommon. ‘These are well shown at
the locality just mentioned, where, in the same mass, one part is
compact, while the rest is crystalline often to a great degree. In
some cases, too, hypersthene appears in one part of the mass, while
the rest is compact, and traversed by veins consisting of a mixture
of quartz and orthoclase. Again, the compact variety often presents
the appearance of a dyke traversing the more crystalline portion.
In one case of this kind a lenticular dyke-like rock was traced over
a distance of thirty yards, and looked very much like basalt. In it,
however, white crystals of orthoclase were observed.

These compact dykes and veins traversing the more crystalline
portions seem to be analogous to those of fine-grained granite rock
which may be seen cutting across the granite in the neighbourhood
of Dublin, and have been called eurites by the late Professor Jukes.
Such veins he regards as portions of the same magma as the granite,
proceeding from the parts still in fusion, and forced into cracks or
fissures in the partially consolidated upper portions, and the same
explanation may answer as well for the compact dyke-like veins just
described.

Another variety of these compact and finely-crystalline rocks is
one full of cells, usually filled with calcite, or, though rarely,
chalcedony. These may be seen at Slieve Gallion, at Drumnakilly
near Omagh, and at several intermediate localities. Some parts,
from the number and size of the cells, suggesting great disengage-
ment of elastic fluids, present such appearances of a volcanic nature
that one is at first inclined to consider them as such, yet, on further

J. Nolan—Metamorphic and Intrusive Rocks of Tyrone. 157

examination, there is no evidence of extrusion, the rock changing by
the gradual disappearance of the cavities into the ordinary horn-
blendic close-grained variety.

The passages from these varieties into schistose rocks are also very
remarkable. They not only occur in the vicinity of the schist series,
but everywhere throughout the mass, no considerable tract of which,
indeed, is without some trace of foliation. Thus, at Termon Rock,
which is mostly composed of coarse diorite, foliation was observed
in the more finely crystalline portions, associated with a variety,
which, from its close texture, has much the look of an indurated
or highly altered slate, full of strings and ramifying veins of
serpentine; and to the north-east of Omagh, west of the road to
Mountfield, similar schistoid rocks, also abounding with serpentine,
may be seen.

A very interesting series is met with at Beaghbeg, some six miles
north of Pomeroy. Here, within a small area, are diallage and
quartz-porphyry, having between them finely crystalline and com-
pact rocks. Some of these latter have minute scattered prisms of
hornblende in a felspathic-looking base, and change into partially
foliated rocks of porcelainic appearance, with numerous strings and
veins of quartz. Close to this, on the north-west, are chloritic aud
taleose schists, and schist breccias, containing pieces of red iron
jasper and green flinty-looking rocks with quartz grains like altered
felstones, or perhaps very quartzose grits. These latter were again
noticed at Creggan, four miles to the south-west, but among the
finely-crystalline hornblendic series.. They have all the appearance
of metamorphosed conglomerates, and still further confirm the
evidence as to the original sedimentary character of these rocks.

Thirdly.— Quartz, Porphyry, Granite, and Syenite—It has been
before remarked, that the compact varieties of the green metamorphic
rock frequently lose all trace of hornblende, and become felspathic.
The base in these cases is usually of a light green or bluish, changing
to a pink or reddish grey colour. This occurs very gradually—first
there appear a few spots of a pink or reddish shade, these then
extend and form the prevailing tint of the base, and some quartz
appears. Crystals of flesh-coloured orthoclase and a light olive-
green felspar that seems to be oligoclase, are now observed, the
blebs of quartz increasing in size and quantity, with an admixture
of dark green mica of resinous lustre occurring in hexagonal plates.
We thus get a quartz-porphyry—a rock having all the constituents
of granite, differing only in the disposition of the silica, which, as
just remarked, is in individual crystals, and does not form the base.
It is easy to see that a rock of this kind can readily pass into true
granite, requiring but such an increase in temperature as to keep
the silica in solution while the other minerals have crystallized out,
and, accordingly, we find that in many parts of this district the
quartz-porphyry does pass into granite. A very remarkable example
may be seen at Mullanamore Bridge, north of Carrickmore. The
porphyry was observed in the stream a little above the bridge, close
to it is a rock which it is impossible to refer with certainty to either

158 J. Nolan—WMetamorphic and Intrusive Rocks of Tyrone.

class, while immediately at the bridge is typical granite. At all
these places the rock has the same general character of a coarse
quartzose mass with pink felspar and green mica, except that to the
north the base is felspathic, while to the south it is siliceous, and
has the granular character of granite. Similar observations were
made in a quarry a little east of this, and in some other localities,
particularly at Slieve Gallion, where several sections exhibit this
change from porphyry into granite.

At the summit of Glenarudden Mountain, the porphyry is
succeeded by a rock having a compact base of a greenish or greyish
colour, with, occasionally, spots of red or flesh-coloured felspar, and
a little diffused hornblende. ‘Towards the north this latter mineral
increases in quantity, and quartz appears; giving place, however, to a
rock devoid of that mineral, and in which the hornblende is replaced
by pyroxene, with some serpentine. This, again, is succeeded by and
passes into the same kind of compact felspathic green rock, and
ultimately into the porphyry. In the vicinity, at a stream called the
White Water, the latter rock has a decided schistose character,
approximating it more closely to the nature of a metamorphic than
of an intrusive igneous rock.

Another remarkable variety may be seen at Carrickmore, at the
Glebe of Athenree, and at some other localities in the adjoining
little glen of Tremogue. This is a finely-crystalline mixture of
quartz and felspar, with a small proportion of mica, some of which
is talcose-looking, though for the most part it occurs in small white
silvery scales, probably lepidolite. It is described by Portlock as a
granite, though it may perhaps be more properly classed among
the elvanites. As the exposures of this rock occur on a regular
line bearing north-eastwards, it might at first appear to be an
intrusive dyke in the metamorphic rocks, but this view is not borne
out by an examination of its relations to those rocks. At the
several localities where sections were observed, they seem to
graduate into each other, the dark-green micro-crystalline horn-
blendic rock becoming felspathic and light-coloured, in the vicinity
of the elvanite, passing insensibly into it, though in one place it
seems to penetrate it as a dyke. It is impossible to say whether the
elvanite might not have been originally a bed of fine quartzose grit,
or perhaps an intrusive dyke in the old sedimentary rocks, fused in
with them when the whole series were metamorphosed.

The granite of this district is very variable in composition. In
general, it contains the same minerals as the porphyry, but in some
places the mica is replaced by tale or chlorite. Of secondary
minerals, carbonate of lime is the most prevalent, and at Limehill,
near Pomeroy, it occurs in such quantity, that in one part the
quartz altogether disappears, and the resultant is a curious mixture
of pink felspar and carbonate of lime; so that it has been burned,
though with little success, for agricultural purposes.

Changes from the granite into the green hornblendic rocks,
through syenite, have already been noticed. Hornblende, indeed,
is pretty generally disseminated through the granite, and in some

J. Nolan—Metamorphic and Intrusive Rocks of Tyrone. 159

parts is in about equal proportion with the mica, forming hornblendic
or syenitic granite. This again passes into a variety devoid of
mica, the felspar changing to a greenish colour, and ultimately into
the quartzless hornblendic rock. These changes, as before men-
tioned, are well seen at Slieve Gallion, and also at the hills called
Bardahessiagh, and Craighballyharky, north of Pomeroy, where
instances occur, in which the granitic and hornblendic varieties are
so blended in the same rock-mass, that it is quite impossible to
distinguish them.

Granite as an Eruptive Rock.—When the maximum of metamor-
phism is reached in the complete fusion of rock and conversion into
crystalline granite, we may expect to find that at some places such a
mass has been intrusive, and, accordingly, there are few areas occu-
pied by metamorphic granite, in which it has not been evidently
intrusive at some parts. Thus, in the granite of Newry, the great
mass of which I believe to be of metamorphic origin, parts are
certainly intrusive, instances of which will be found detailed in the
Geological Survey Memoirs descriptive of that part of the country.
So, in this district too, the granite has all the appearance of having
been intrusive at some parts. Thus, at Drumduff, near Beragh,
close to the margin of that rock, the sandstones are indurated, and
have an unusually high dip; but by far the best evidence is to be
seen at Aghnagreggan Bridge, near Carrickmore. There the sand-
stones can be observed in actual contact with the granite, they are
highly disturbed and semi-vitrified, being converted into yellowish
quartzite, leaving little room for doubt but that the granite has
been intruded through them. It cannot be regarded as being due
to metamorphism of the sandstone, for in the immediate vicinity
beds were found quite unaltered. This could not be the case if this
part of the Old Red Sandstone had undergone so complete a change
as a conversion into granite. A great extent of rock would be
indurated, then foliated and altered into coarse gneiss, which,
becoming more massive and crystalline, would ultimately pass into
granite. As no such gradation was anywhere observed in this
district, no change in the sandstones being effected, except on those
in contact, which, as just now remarked, have been partially
vitrified and altered in colour, as happens where masses of molten
rock have been protruded through sedimentary strata, we may
justly conclude that a similar action has taken place here, and that
some of the granite has been intrusive. If this be so, then, we have
proof that the granite is newer than the earlier part of the Old Red
Sandstone period, while the mass of the schists and other metamor-
phic rocks with which it is associated, and into which it appears
to graduate, are certainly older, being probably of Lower Silurian age,
coeval with those in the West of Ireland. This apparent difficulty
is, however, easily explained, if we suppose the granite, and perhaps
some of the other highly crystalline rocks, to be the result of
re-metamorphism. The depression, which took place during the
period when the great series of sandstones and conglomerates—
which even now have a thickness of upwards of 10,000 feet—were

160 J. Nolan—WMetamorphie and Intrusive Rocks of Tyrone.

deposited, must have sunk the underlying metamorphic rocks to
such an immense depth that their lowest portions were completely
fused and became intrusive. This latter action must have taken
place prior to the commencement of the Carboniferous period, as, at
Slieve Gallion, the basal beds of that formation rest upon the
granite, and are, in fact, almost altogether made up of its debris.

That metamorphic action continued to affect the rocks of this
district at various periods up to that of the Upper Old Red Sandstone,
seems to have been the opinion of General Portlock, and he regards
the granite as a result of the metamorphism of rocks of the latter
formation. Indeed, if his view be correct, the formation of the
granite should be regarded as of post-Carboniferous age, as it is
really the lowest beds of that formation—the red sandstones and
quartzose conglomerates—that he calls Upper Old Red Sandstone.
The sections he describes at Slieve Gallion, as exhibiting changes
from red sandstone through partially altered rocks containing
felspar, into granite, have been just referred to, and it has been
shown that these appearances are due to the fact, that the sandstones
in proximity to the granite are almost altogether made up of its
fragments, in many cases, too, of crystals that have undergone but
slight attrition, so that the distinction between the crystalline and
the derivate rock is often a matter of considerable difficulty.

On the whole, therefore, there appear to be good grounds to
establish the conclusion, that we have in Ireland an intrusive granite
of Old Red Sandstone age. Hitherto most of the granite of this
country has been considered to be of older date except that of
Mourne and the elvanites of Carlingford, which are post-Carbon-
iferous.| The discovery of granite of an intermediate period is,
however, but what we might expect, as we have no reason to
suppose but that it was formed during every period, even at the
present day, when, as Professor Jukes remarks—“ Granite must be
forming now wherever molten rock of the proper chemical com-
position is cooling under the requisite physical conditions ;” and we
may expect that the further investigation is extended, the better
will we be able to assign to their respective ages in the history of
our earth, a class of rocks, which, not very long since, were believed
to be essentially primeval and antecedent to all others.

Nore.—Since the above was written, Mr. Kinahan’s book on the
“Geology of Ireland” has appeared, in which the rocks here
described as Old Red Sandstone are classed with the Silurian
system. Without expressing any opinion on this question, I may
remark that it does not at all alter the geological position of these
beds, as they are referred to a later age than any of the generally
recognized Upper Silurian rocks—while the era of intrusion of the
granite must still be regarded as of post-Silurian and pre-Carbon-
iferous age.

1 Mr. Symes describes an intrusive granite near Westport as “ of older date than

the Upper Silurian period,” but there does not seem to be any evidence to fix its
age more definitely. See Geol. Survey Memoir to accompany Sheets 83 and 84.

R. Etheridge, jun.—Notes on the Gilbertson Collection. 161

ITV.—Notrs oN THE BIVALVES CONTAINED IN THE GILBERTSON
Coutuecrion, British Musrum, anp Ficgurep In Pui.uirs’s
““GEOLOGY OF YORKSHIRE.”

By R. Eruerines, Jun., F.G.S. ;
of the British Museum.

Y far the larger proportion of the Carboniferous fossils described
and figured by the late Professor John Phillips, F.R.S., in the
second volume of his “Illustrations of the Geology of Yorkshire,”
and published in 1836, are contained in the collection of the late
Mr. Gilbertson, of Clitheroe, now deposited in the Geological
Department of the British Museum. The early date of publication
of this work renders the collection described in it one of the most
important, next to those of Sowerby, Ure, Martin, and one or two
others, to students not only of British, but equally so of Continental
Carboniferous Paleontology. Unfortunately the descriptions of Prof.
Phillips are so abbreviated and unsatisfactory, and the figures in
many instances so meagre, that it is with great difficulty anything
like an accurate determination of a species can be made by the aid
of them. Under these circumstances the following notes made
directly from the type specimens will probably be found of use; it
would, however, be far more satisfactory to have the specimens
refigured. For convenience sake I shall commence with those
composing plate vi., and then take the others composing plate v.

1. Pinna inflata, Phillips sp. (p. 211, t. 6, f. 1).

This, as already pointed out by Mr. Davidson,! is Productus striatus, Fischer. The
Gilbertson Collection contains three specimens, but not the figured one, so far as we
can ascertain, although it is so stated by Prof. Phillips.

2. Pinna costata, Phillips sp. (p. 211, t. 6, f. 2).

T can see little or no difference between this and the ordinary Pinna flabelliformis,
Martin; indeed this appears to have struck the author himself, for he says, “ This is
probably the species figured by Martin under the name of Pinna flabelliformis, and
P. nuda.” Prof. M‘Coy has so placed it with a note of interrogation.?

3. Inoceramus vetustus, Sowerby (Phillips, p. 211, t. 6, f. 3).

The Gilbertson Collection possesses a specimen which may be one of the types of
this species, it is larger than fig. 3, and is not in quite such a perfect state of pre-
servation as that is represented, but unless there is a specimen in the Collection of
the Yorkshire Philosophical Society bearing a greater resemblance, this must be the
figured form. ‘The original of fig. 4 I cannot trace.

4. Avicula cycloptera, Phillips sp. (p. 211, t. 6, f. 5).

A peculiar and well-marked species. The type is the only example in the Collection.
It is on a weathered limestone surface, and is scarcely so well preserved as the figure
represents.

5. Avicula tessellata, Phillips sp. (p. 211, t. 6, f. 6).

This species is referred by Professor John Morris? to the genus Aviculopecten. I
have not seen the characters of the hinge. The Gilbertson Collection contains only
the figured example.

6. Pecten granosus, Sowerby (Phillips, p. 213, t. 6, f. 7).

This specimen is not in the Gilbertson Collection.

* Mon. Brit. Carb. Brachiopoda, 1861, pt. 5, p. 139.
* Brit. Pal. Foss. p. 498. + Catalogue, 2nd ed., 1854, p. 166.

DECADE II.— VOL. VI.—NO. IV. 11

162 R. Etheridge, jun.—Notes on the Gilbertson Collection.
7. Avicula radiata, Phillips sp. (p. 211, t. 6, f. 8).

The figure of this species in no way does the specimen justice. The number of
radiating ribs, which are numerous, are not distinctly shown, neither is the full
extent of the shell. The posterior wing appears characteristic. By Morris it is
placed in Aviculopecten.

8. Gervillia squamosa, Phillips sp. (p. 212, t. 6, f. 9).

The broad squamose ridges render this species a particularly well-marked form.
The vacant space within outline on the left of the figure should represent the
internal cast from which the shell has been removed. The lower vacuity is matrix
covering up the ventral portions of the valve. It isthe Avicula sguamosa of Morris.?

9. Gervillia laminosa, Phillips sp. (p. 212, t. 6, f. 10 and 11).

Here, again, the figure does not fully represent the original. The shell is in form
quite a Pteronites, only the umbonal slope is too pronounced. There is not that great
declivity between the body of the shell and the posterior and anterior wings shown
in the figure. Prof. Morris refers the species to Avicula.?

10. Gervillia lunulata, Phillips sp. (p. 211, t. 6, f. 12).

The type is a beautifully preserved shell in limestone. Prof. Phillips’s figure has
been a little restored about the beaks and posterior margin. There is another large
example, without any trace of shell remaining, measuring as much as four inches and
a half in its longest diameter by two and a half. And yet another specimen nearly
as large. The species is placed in Avicula by Prof. Morris.*

11. Gervillia inconspicua, Phillips sp. (p. 212, t. 6, f. 18).

Not in the Gilbertson Collection.

12. Perna? Phillips sp. (t. 6, f. 14).

This is the internal cast of a Myaliniform shell in limestone, without any
characters whatever by which it can be identified.

13. Pecten ellipticus, Phillips sp. (p. 212, t. 6, f. 15).

The hinge characters are exceedingly well shown in this cast, although not
illustrated in the figure. It is an Hxtoliwm, and not very far removed from £,
Sowerbii, M‘Coy. It is the Aviculopecten ellipticus of Morris.+

14. Pecten hemisphericus, Phillips sp. (p. 212, t. 6, f. 16).

The shell which is marked in the Collection as the type of this species has either
been injured since the figure was drawn, or the latter was somewhat restored. It is
deficient around the ventral margin.

15. Pecten dissimilis, Phillips sp. (p. 212, t. 6, f. 17 and 19).

I am only able to satisfactorily recognize the specimen from which fig. 17 has
been taken, and I must for the present refrain from expressing any opinion on the
identity, or otherwise, of Aviculopecten dissimilis, Fleming, and A. dissimilis, Phill.
The subject of fig. 17 has remarkably close and concentric lines covering the whole
surface of the valve.

16. Pecten stellaris, Phillips sp. (p. 212, t. 6, f. 18).

The ribs in the type are of a much less prominent nature than shown in Phillips’s
figure, and there are three distant concentric lamella. This and the Avicula tessellata
are very much alike in the nature of the ribbing, only in P. sted/aris the ribs are
much more numerous, the anterior ear is divided off from the body of the shell, and
there is no obliquity, as in Avicula tessellata.

17. Pecten arenosus, Phillips sp. (p. 212, t. 6, f. 20).
There is no shell at all resembling this figure in the Gilbertson Collection. From
the appearance of the figure I should imagine it represents an imperfect shell.

18. Pecten plicatus, J. de C. Sowerby (Phillips, p. 212, t. 6, f. 21).
T have compared this with Sowerby’s type and find that it corresponds in every
particular, except that in the type the ribs are finer and more numerous. In the
Phillipsian shell the posterior wing is deficient, it really runs out to an extended

1 Cat. Brit. Foss. 2nd ed. p. 165. 2 Thid, p. 162. 3 Tbhid, p. 162.
4 Ibid, p. 162. 5 Catalogue, 2nd ed. 1854, p. 164.

R. Etheridge, jun.—WNotes on the Gilbertson Collection. 163

point when the valve is perfect. Phillips described his shell as, ‘‘ Kars without
radiating ribs?” I find, however, that this doubt on Prof. Phillips's part arose from
the decorticated nature of the ear-surface of his specimen ; there are distinct traces
of radiating ridges. Sowerby, in his description, says, ‘‘ smooth striz,”’ ! and Phillips,
“nearly smooth radiating ribs,” but there can be no doubt, on a careful examination,
that both Sowerby’s original, and the specimen referred to this species by Phillips,
were minutely and strongly decussated by close, concentric, frilled imbrications, now
in a great measure worn off.

19. Pecten anisotus, Phillips sp. (p. 212, t. 6, f. 22).

I have compared the type of this species with the specimens upon which I founded
the provisional species of Aviculopecten subanisotus,* and I find, as I then antici-
pated, that they are one and the same. The posterior ear as represented in Phillips’s
figure is incorrect; in the specimen it is broken away, in the perfect shell the valve
expands gradually into it, and there is no notch as shown in the figure referred to.

20. Plagiostoma (Phillips, t. 6, f. 23).

Probably an Aviculopecten, although I cannot find the specimen.

21. Pecten interstitialis, Phillips sp. (p. 212, t. 6, f. 24).

The figured specimen is not in the Gilbertson Collection, although there are
several specimens so labelled, with very few and coarse ribs, resembling in this
respect Aviculopecten Murchisoni, M‘Coy.3

22. Avicula sublobata, Phillips sp. (p. 211, t. 6, f. 25).

The type is not in the Gilbertson Collection. I cannot therefore institute a direct
comparison with those shells I described* some time ago, under this name, showing
colour bands.

23. Pecten deornatus, Phillips sp. (p. 218, t. 6, f. 26).
Not in the Gilbertson Collection.

24. Pecten simplex, Phillips sp. (p. 212, t. 6, f. 27).

The specimen appears to have been mislaid.

25. Pecten fimbriatus, Phillips sp. (p. 218, t. 6, f. 28).

The type is not in the Gilbertson Collection.

26. Corbula? senilis, Phillips sp. (p. 209, t. 5, f. 1).

Not in the Gilbertson Collection.

27. Sanguinolaria ? angustata, Phillips sp. (p. 208, t. 5, f. 2).

In a very imperfect state of preservation. This was made by M‘Coy the type of
his genus Sanguinolites,® but the specimen is utterly useless for type-purposes.

28-32. Sanguinolaria tumida, Phillips sp. (p. 209, t. 5, f. 3).

S. arcuata, Phill. (p. 209, t. 5, f. 4), S. sudeata, Phillips sp. (p. 209, t. 5, f. 5),
Solemya primeva, Phillips sp. (p. 209, t. 5, f. 6), and Venus elliptica, Phillips sp.
(p. 209, t. 5, f. 7), are in other collections. ; :

33. Venus parallela, Phillips sp. (p. 209, t. 5, f. 8).

A much worn little shell, but possessing strong concentric prominent ridges when
in the perfect condition. It is placed in the genus Cypricardia by Prot. L. G, de
Koninck.®

34. Isocardia oblonga, J. de C. Sowerby (Phillips, p. 209, t. 5, f. 9).

A very good example with the outer shelly layer removed. The valves are in
apposition, the left moved a little out of place. I have compared this with
Sowerby’s type, and find that it agrees intimately.

35. Oypricardia rhombea, Phillips sp. (p. 209, t. 5, f. 10).

The type of this species does not correspond with the shell I have been in the
habit of calling by this name, or have usually seen so labelled in collections.

1’ Min. Con. vol. vi. p. 144.

2 Mems. Geol. Survey Scot., Expl. 31.

3 Synopsis Carb. Limestone Foss. Ireland, 1844, t. 18, f. 3.
4 Grou. Mae. 1876, Dec. Il. Vol. Ili. p. 151.

> Synop. Carb. Limestone Foss. Ireland, p. 48.

5 Descrip. Anim. Foss. Tert. Carb. Belgique, p. 97,

164 &. Etheridge, jun.—Notes on the Gilbertson Collection.

Phillips’s species is a somewhat elongated shell, and has been fairly portrayed, so far
as the general characters go, by Prof. de Koninck.!

36. Nucula luciniformis, Phillips sp. (p. 210, t. 5, f. 11).

The concentric strie are exceedingly fine in this species, the beaks quite close
together, and the escutcheon linear, and little developed.

37. Nucula brevirostris, Phillips sp. (p. 210, t. 5, f. 11a).
Not in the Gilbertson Collection.

38. Lucina ? laminata, Phillips sp. (p. 209, t. 5, f. 12).

This is an Edmondia-like shell with close concentric imbricating lamine. I cannot
conceive what has led Prof. de Koninck? to unite this species with Modiola
squamifera, Phillips, for there could not be two more dissimilar shells, more especially
as he had previously placed* Z. 2? daminata in the genus Cardinia.

89. Isocardia ? axiniformis, Phillips sp. (p. 209, t. 5, f 18).
Not in the Gilbertson Collection.

40. Nucula cuneata, Phillips sp. (p. 210, t. 5, f. 14).

The figure of this species is much enlarged. It has no appearance of a Nucula,
but I suspect itis very much more nearly allied to Pleurophorus, King. The posterior
radiating strize are quite apparent.

41. Nucula tumida, Phillips sp. (p. 210, t. 5, f. 15).

As pointed out by Prof. M‘Coy,‘ this is the WV. gibbosa, Fleming, under which
name the shell is now universally known.

42. Nucula undulata, Phillips sp. (p. 210, t. 5, f. 16).

The posterior end of this shell is produced, and when perfect is obtusely pointed.
In the figure it is too rounded and should have been represented as broken off. It
belongs to the same group of Paleozoic Nuculidee as V. devirostrum, Portlock.

43. Nucula claviformis, Phillips, non Sow. (p. 210, t. 5, f. 17).

Identical with Leda or Nuculana attenuata, Fleming. The specimens with which
Phillips worked were contained in the Collection of the Yorkshire Philosophical
Society, the Gilbertson Collection, and that of the Natural History Society of
Neweastle. Phillips usually appears to have first indicated after the name of each
species that collection in which his type was placed, and following that rule, the type
of this species would be in the Cabinet of the Yorkshire Society, but the Gilbertson
Collection contains one so like the figure that I cannot but regard it as the original
of his WV. elaviformis.

44, Isocardia ? unioniformis, Phillips sp. (p. 209, t. 5, f. 18).
The original specimen is in a very bad state of preservation. The species is the
type of Prof. de Koninck’s genus Hdmondia.®

45. Cucullea obtusa, Phillips sp. (p. 210, t. 5, f. 19).
Although marked in the usual way by Phillips as being in the Gilbertson
Collection, I am unable to find the type.

46. Cucullea arguta, Phillips sp. (p. 210, t. 5, f. 20).

Phillips remarks that his shell is restored at the ends, and there is in the collection
such a specimen wanting a portion of the posterior end, otherwise it is in a very good
state of preservation, and is clearly the specimen from which Phillips’s figure was
drawn. By the latter the species was referred to Cucul/ea, and by Prof. de Koninck
to Arca,® but whatever may be the character of the shell to which Prof. de Koninck
has applied this name, that figured in the “Geology of Yorkshire” belongs to
neither of these genera, but possesses the prominent concentric ridges, split on the
anterior end, the anterior sinus, and well-developed posterior slope of that group of
shells to which Prof. M‘Coy, in 1852, applied his previously enunciated name of
Leptodomus. Accepting the specimen in question in the Gilbertson Collection as the
type, I feel sure that it is to this group it will have to be referred, and neither to
Cucullea nor Arca.

1 Descrip. Anim. Foss. Tert. Carb. Belgique, Atlas, t. 1, f. 15, a. ¢.
2 Ie, Citi {0s Pe 3 Tbid, p. 78. 4 Brit. Pal. Foss. p. 512.
> Descrip. Anim. Foss. Terr. Carb. Belgique, p. 66. § Loc. cit. p. 116.

R. Etheridge, jun.—Notes on the Gilbertson Collection. 165

47. Modiola lingualis, Phillips sp. (p. 209, t. 5, f. 21).

The type of this species is not preserved in the Gilbertson Collection, but there
are specimens of the shell to which I gave the name of Modiola lithodomoides, which
may be only the full-grown condition of M. lingualis.

48. Modiola squamifera, Phillips sp. (p. 209, t. 5, f. 22).

An exceedingly well-marked shell, distinguished by its broad flat lamellze; the
posterior wing is small, although it is not entirely preserved, and the dorsal margin
in Phillips’s figure is too decidedly marked. This species belongs to a peculiar group
of Carboniferous Mytiliform shells of the hinge character of which we at present
know little. By Prof. de Koninck it has been identified! with a Belgian shell,
which he places in the genus Cypricardia; but judging from the respective figures, I
should be inclined to pause before uniting the two.

49. Modiola granulosa, Phillips sp. (p. 210, t. 5, f. 23).

Not in the Gilbertson Collection. ;

50. Modiola elongata, Phillips sp. (p. 210, t. 5, f. 24).

If the figure is a correct representation of the original, the specimen is not in the
Collection.

51. Cypricardia glabrata, Phillips sp. (p. 209, t. 5, f. 25).

Not in the Gilbertson Collection.

52. Pleurorhynchus Hibernicus, J. Sowerby (Phillips, p. 210, t. 5,
i 20).

Phillips’s type of this species is not in the Gilbertson Collection.

08. Pleurorhynchus minax, Phillips (p. 210, t. 5, f. 27).

Phillips remarks that the lower figure of Sowerby’s Cardium aliforme? is pro-
bably his species, and this view has been adopted by Prof. Morris. On the other
hand, Professors de Koninck* and M*Coy® wholly unite P. aliforme and P. minax.
After a very careful and lengthened comparison of the types of both Sowerby and
Phillips, I have to express my complete adherence to the views of these authors so
far, leaving out of the question, for the present, the question of the Devonian
P. minaz.® Extreme care should be taken in describing the surface characters in
this group of shells, for I find that the shelly matter was of considerable thickness,
and the various layers each possessed its own style of ornament. This has been
noticed to a certain extent by Prof. M‘Coy;’ when perfect, Conocardium (Pleuro-
rhynchus) aliforme has the valleys between the radiating ribs crowded with close
undulating laminze resembling those seen on the surface ot Spiriferina laminosa.

54. Plewrorhynchus elongatus, J. Sowerby (Phillips, p. 211, t. 6,
£ 28).

An exceedingly well-marked and distinct form; it has been shown by Prof. de
Koninck, who is followed by M‘Coy, to be only a synonym of Conocardiwm rostratum,

Martin.’ I have compared Sowerby’s figured specimen, which was given to him by
Mr. Martin, with Phillips’s shell, and find them to agree.

00. Pleurorhynchus armatus, Phillips sp. (p. 211, t. 5, f. 29).

This specimen is not in the Gilbertson Collection, but I have little doubt that
Prof. de Koninck is correct in referring? it to Conocardium (Pi.) aliforme, Sow.

06. Pleurorhynchus trigonalis, Phillips sp. (p. 211, t. 5, f. 80-32).

I have examined in detail the only specimen of this species in the Gilbertson
Collection, and which represents figs. 30 and 32 of the above plate, but somewhat
on an enlarged scale. Prof. de Koninck has referred 1° this species to C. Hibernicum,
Rowerby 5 in this I agree with him, as I believe it to be only the young form of the
atter.

d7. Unknown genus, Phillips (t. 5, f. 33).

Not in the Gilbertson Collection.

TY Loe: cit. p: 92, t. 3, f. 11. 2 Min.:Con. t. 552.

3 Catalogue, 2nd ed. p. 195. 4 Loe. cit. p. 88.

° Brit. Pal. Foss. p. 516. § Pal. Foss. Cornwall and Devon.
7 Loe. cit. p. 517. 8 Arcites, Pet. Derb. t. 44, f. 6.

° Loe. cit. p. 83. 10 Thid, p. 85.

166 W. A. E. Ussher—Post-Tertiary Geology of Cornwall.

V.—Post-Tertiary GEOLOGY oF CoRNWALL.!
By W. A. E. Ussuer, F.G.S.

Part JIJ.—Tuse Rarisep Beacnes anp AssocrIATED DrEposits oF
THE CorwnisH COAST.

HE following observations of the Cornish Cliffs are given in
order, proceeding round the coast from Plymouth. The num-
bers and letters have been prefixed to facilitate subsequent reference.

1. Mount Edgecombe, near Plymouth.

a. De la Beche (Geological Manual, p. 159) mentions the occur-
rence of rolled shingles, covered by fragments of slate and red
sandstone near Redding Point ; the height of the deposit is not given.

b. Near Mount Edgecumbe Obelisk I noticed brown and reddish
coarse-grained sand filling an inequality in the limestone at about
30 feet above the river; this is probably a trace of contemporaneous
deposition with the Hoe Raised Beach.

2. Looe Island. Mr. Pengelly (Trans. R. G. 8. Corn. vol. vii. p.
118) noticed the occurrence of layers of comminuted, and somewhat
rounded, yellowish matter containing rather large rounded slate
fragments and ordinary pebbles, on the northern cliffs of the island.
Height above high water not given.

3. St. Austell’s s Bay.

a. A point at which Raised Beach is engraved on the map, at Pol-
kerris, is capped by 8 feet of Head of small angular killas fragments,
occasional quartz pebbles were found, being either the relics of a
raised beach, or hurled to a height of 30 feet. above high-water
mark by storm waves from the beach below. This point is joined to
the main cliff by a very narrow ridge of rock.

b. Near Polmere the Head rests upon micaceous slates, and in
places presents a rudely stratified appearance.

c. Near the Par Inn, a stratified gravel of subangular grit, quartz,
slate, and granite stones, and occasional boulders, 4 to 5 feet in
thickness, occurs at about 20 feet above high water.

d. On the south side of Spit Point, fine gravel with pebbles of
quartz and boulders (one flint pebble found and a fragment of Car-
dium, ? im sitéi) 8 feet in thickness, and at base 5 feet above high
water, occurs on the low cliffs.

e. Near the above the base of the raised beach is 10 feet above
high water, it consists of fine gravel alternating with greyish sand
upon large pebbles and unworn blocks of the subjacent rock. The
deposit is 10 feet in thickness, the layers appear to dip seaward.

4. Gerran’s Bay.

a. On the eastward side of the beach the section consists of—

Brown soil with angular stones... sao co tis | Onn
Brown loam with angular fragments of slate and ‘quartz ..- lOft. Oin.
Beds of consolidated black sand and quartz gravel, lying

unevenly on the Sy rock at about five feet above

LV VyyALESI Ge Geni Be .. 4ft. 6in.

De la Beche (Report, p. 430) mentions the consolidation of portions
1 Continued from the March Number, p. 110.

W. A. E. Ussher—Post-Tertiary Geology of Cornwall. 167

of the raised beach in Gerran’s Bay by oxide of iron. Near Pen-
dowa the beach is absent, and the Head rests directly on the slates.

b. Mr. Trist (T. R. G. S. Corn. vol. i. p. 111) described the raised
beach as a flat stratum of sand and pebbles, sometimes occurring as
a black sandstone 2 feet in thickness, sometimes as a conglomerate
of sand and pebbles 10 feet thick, resting on limestones and argil-
laceous schists abounding in manganese, and capped by an argilla-
ceous friable earth.

c. Near Pendover (? Pendowa) beach, Mr. Trist noticed quartz
boulders at the Carnes, wholly insulated, and of a different nature
from the substratum (vide T. R.G.S. Corn. vol. vi. p. 91. Budge.)

d. Dr. Boase (T. R. G.S. Corn. vol. iv. pp. 270, 273) mentions the
occurrence of “layers of different substances” in the cliffs to the
east of Porthscatho and in Gerran’s Bay, the inferior 10 feet being
much consolidated. One ferruginous layer resembled pudding-stone.
The pebbles diminish upwards into pure sand, reddish brown and
friable, in layers 8 or 9 inches thick.

e. (op. cit. p. 275.) At Porth, one mile east of St. Anthony, Dr.
Boase noticed beds of sand and gravel ; Porth farmhouses being built
on diluvium of regular beds of sand and pebbles, the latter below ;
shells, chiefly marine univalves, were found in parallel layers in the
sand. The height above high water is not given.

5. Falmouth.

a. Coast-section on the N.E. of Pendennis Castle. Head of angular
fragments of slate and quartz with a tolerably regular horizontal lie,
40 to 50 feet in thickness, contains here and there a few pebbles at
its base, which is from 5 to 10 feet above high water. Mr. Godwin-
Austen mentioned (Q. J. G.S. vol. vii. p. 121) the occurrence of 30
feet of Head on the west of Pendennis Point.

b. Near Cove Battery the Head is of a greyish colour in the upper
part, brownish below; a line of larger fragments and a band of loam
without stones occur in it.

c. Mr. R. W. Fox (Phil. Mag. and Journ. Science, ser. 3, vol. i. for
1832, p. 471) describes the Falmouth raised beach as a horizontal
bed of rolled quartz pebbles, gravel and sand (like the present
beach), from 1 to 3 feet in thickness, and generally from 9 to 12 feet
above the highest spring tides. The Head upon the old beach is
described as earth, stones, and detached pieces of rock. The cliffs
are from 80 to 60 feet in height. The old beach does not extend far
from the cliff face, it was observed in one place at 8, in another at
20 feet, within it. Between the parishes of Budock and Mawnan
the pebbles appeared to be cemented into a conglomerate, in places,
_by the oxides of iron and manganese.

d. Mr. Godwin-Austen (T. G.S. ser. 2, vol. vi.) describes the old
beach and overlying Head at Swanpool as purely marine beds pass-
ing up into fluvio-marine and fluviatile accumulations.

e. Between Pennance Point and Maen Porth (Fig. 1), a bed of
pebbles, chiefly quartz, with slate boulders, is visible, under Head of
angular fragments in loam, at intervals. In one place the beach
consists of quartz pebbles in grey and reddish brown sand, with

168 W. A. E. Ussher—Post-Tertiary Geology of Cornwall.

large worn blocks of slaty rocks; 38ft. 6in. thick, and about 4 feet
above high water at its base. Rock platforms are noticeable at
about the level of spring tide high water.

ae
f i

NMEA ANY (Vy
WANN

SAILS
4 /} NT

Fic. 1.—The Coast toward Rosemullion Head; showing Rock Platforms and Cliffs
composed of Head upon Raised Beach.

6. South of the R. Helford.

a. At Ligwrath, between Nare Point and Porthalla, the Head con-
sists of brown earth with angular stones, pebbles are met with in
places at its base, at about 5 feet above high water. Boulders com-
pose the present beach.

b. South of the above, traces of a raised beach consisting of beds
of coarse black and brown sand, with grit, slate, igneous rock, and
small quartz pebbles, in places 2 to 3 feet thick, and at base about
8 feet above high water, are visible here and there under Head of
grey and brown loam with angular stones.

c. De ‘la Beche (Report, p. 481) figures part of a consolidated
raised beach forming the roof of a cavern in the slates on which it
rests, and supporting a Head of angular fragments, between Port-
halla and the Nare Point. He also gives a sketch of the old beach
at Nelly’s Cove and between Rosemullion Head and Mainporth (op.
cit. p. 452).

d. The Rev. H. Budge (T. R. G.S. Corn. vol. vi. p. 1) mentions
the occurrence of a raised beach, about 5 feet above high water, con-
tinuing for some hundreds of yards from Nelly’s Cove (4 mile from
Porthalla), and accessible only at low water; he observed traces of
the old beach on steep rock ledges now overflowed by the tide. On
the north of Nare Point, 8 to 10 feet of angular debris rested on the
old beach.

7. Coverack Cove.

a. The low cliffs to the east of Carnsullan are about 15 feet in
height, and composed of brown earth with angular and subangular
stones and boulders.

b. The Rev. H. Budge (op. cit.) describes the cliff-section on the
north side of the Cove as—Reddish-coloured marl or rubble upon a
thick bed (12 feet) of fine ferruginous sand, consolidated in places,

W. A. E. Ussher—Post-Tertiary Geology of Cornwall. 169

upon large rolled pebbles arranged in regular lines and about 0 feet
above high water at their base.

c. The same observer says that the whole of the outer portion of
the Lowlands in St. Keverne parish (a flattish tract of 60 acres in
extent) is formed of very fine sand (valued for constructing moulds
for brass casting), so similar to that overlying the Coverack raised
beach that he considered them contemporaneous. At and near the
coast-line pebbles were occasionally met with in the sand.

d. Mr. Budge mentions a rampart of large diallage pebbles round
a low fortress of sand upon the present beach at Coverack.

e. Dr. Boase (T. R. G.S. Corn. vol. iv. p. 3829) mentions the occur-
rence of diluvium of an ochreous colour consolidated toward its base,
and containing small pebbles of quartz, compact felspar, and serpen-
tine, resting on serpentine, near Coverack Quay.

f. De la Beche (Report, p. 129) and Godwin-Austen (Q. J. G. 8.
vol. vii. p. 121), comment on flints occurring in the Coverack raised
beach. Flints also occur in the present beach at Porthbeer Cove,
south of Coverack.

8. Gunwalloe. The cliffs are capped in places by a Head of light
brown loam with angular stones.

The Lizard District south of a line between Porthbeer Cove and
Mullion was not observed by me, nor can I find any descriptions of
Pleistocene phenomena on its sea-board. The low cliffs to the south
of the Loo bar are capped by about 5 feet of brown loam with
angular fragments of quartz, etc., under coarse brownish blown sand.

9. Coast from Loo Pool to Marazion.

a. De la Beche (Report, p. 430) figures part of a raised beach be-
tween the Loo Pool and Cove village, stained by black oxide of iron,
and containing strings of the same substance, the prevalence of which
in the rocks of South Cornwall is pointed out.

b. Mr. Henwood (T. BR. G.S. Corn. vol. v. p. 54) noticed patches
of granite and slate pebbles, from the size of a nut to a foot in
diameter, in Tremearne Cliff. The deposits rested on slates at 14 feet
above the present beach, in one spot, and at 30 feet in another, going
eastward.

c. (op. cit.) ‘At Wheal Trewavas, where the rock is wholly com-
posed of granite, it is covered by a thick bed of transported frag-
ments of micaceous slate.”

d. On the west of Pra Sands, Mr. Henwood (op. cit.) noticed a
bed of granite, elvan, and slate pebbles, at about 6 feet above the
present beach, and covered by “a high bank of rubbish,” the debris
of the adjacent rocks.

e. Between Cuddan Point and Trevean Cove, the Head consists
of dark grey loam with angular (local) fragments.

f. The Perran Sands are bounded by cliffs from 5 to 20 feet high,
partly composed of brown loam with angular stones and blocks of
greenstone.

_ g. In a cove west of Perran Sands and south of Perranuthno; in
one part—

170 W.A. E. Ussher—Post-Tertiary Geology of Cornwall.

Brown earth with large and small angular stones... ... ... 10ft. to 15ft.
upon—large pebbles and subangular fragments of quartz and
greenstone... lft.

upon—brown loam with small angular quartz stones and large
angular greenstone boulders.

g. In another place—

Soil ... wie baht ewe ait. tovertts
Brown loam with ‘angular ¢ greenstone fragments Bog asp ag iis WO) (i:
As above, fragments fewer, and, asarule, smaller ... ... 10ft. to 1dft.
Pebbles, and “occasionally subangular fragments, of ‘quartz

and greenstone ... ... . .. 2ft. (about).

resting unevenly upon greenstone), ab from 8 to 12 feet above high
water.

h. Toward Marazion the cliffs average 20 feet in height, and are
composed of a Head of angular slate, quartz, and greenstone frag-
ments in brown loam.

10. South of Penzance.

a. Mr. Carne (T. R. G. 8. Corn. vol. iii. p. 229) observed layers of
pebbles and boulders from 3 to 6 feet thick, and 40 feet in length, at
the junction of the slate and granite at Mousehole. Mr. Henwood
gives the height of the above as a little above high-water mark.
(Ibid. vol. v. p. 110.)

The following are from Mr. Carne’s paper (op. cit.).

b. At Carn Silver, boulders and pebbles were found in the end of
a cavern, 8 feet wide and 12 feet high, once probably filled with
them.

c. In St. Loy Cove, under 30 feet of Head of granitic stones in
clay, pebbles and boulders were observed, 4 to 8 feet in thickness,
150 feet in length, and at their base at high-water mark. (Present
beach composed of granite boulders.—W.U.)

d. Boulders were also observed at Polwarnon (? Polguaruon) Cove,
Lean Scath, Pednvounder Cove (near the Logan rock), and at the
Land’s End Hole, but their height above the sea is not given.

e. Near Penberth on the east, I noticed a small patch of Head
composed of brown loam with angular stones and angular and sub-
angular boulders.

11. Land’s End.

a. In Whitesand Bay, near Carn Aire, the Head consists of angular
and subangular fragments and boulders of granite in coarse light buff-
brown granitic debris (growan), becoming browner and more loamy
near the base. The present beach is composed of granite boulders.

b. Between Creagle and Aire Points, Mr. Carne (op. cit.) observed
6 feet of boulders and pebbles under 80 feet of clay with granitic
fragments. Base of boulder bed at about spring tide high water.

ce. On the south of the Nanjulian River (Carne, op. cit.) boulders
and pebbles occur at 15 feet above high water.

d. On the south of Pol Pry (op. cit.), a thin bed of boulders at 20
feet above high water.

e. In an iron vein at Huel Oak Point (op. ct.) boulders were
found at 8 feet above high water.

12. Pornanvon and Porth Just.

W. A. E. Ussher—Post-Tertiary Geology of Cornwall. ii

a. In Pornanvon Cove Mr. Carne (op. cit.) noticed 2 boulder beds
(in a matrix of calcareous sand, granitic gravel and clay), separated
by a mass of solid granite. The westernmost bed being 4 chains
long, 10 feet thick, and overlain by 60 feet of granitic debris ; that
on the east was found to be 9 chains long, 20 feet in maximum thick-
ness, and surmounted by 20 to 50 feet of granitic debris. The
boulders vary in size from that of a hazel nut to 3 feet in diameter ;
no large slate boulders were noticed. The base of the deposit is
about the level of very high spring tides. At Porth Just Mr. Carne
found boulders at 15 feet above high-water mark.

b. Mr. Henwood (T. R. G.S. Corn. vol. v. p. 18) mentioned the oc-
currence of rounded stones of granite, from the size of a nut to 2 or
8 feet in diameter, with a few slate pebbles, and with granitic sand
filling the interstices, at from 15 to 20 feet above high water, at
Porth Just and Pornanvon. He says that an adit at Wheal Besans
Lode, Little Bounds Mine, was driven for several fathoms through
one of these beds, which was found to be from 60 to 70 feet in
thickness. (In this estimate the overlying Head was probably
included.—W.U.)

c. Miss Carne (T. R. G. 8. Corn. vol. vii. p. 371) stated that the
adit of a mine south of Kennal Point enters the cliffs under a mass
of pebbles and boulders.

13. Cape Cornwall.

a. In the south part of Priest Cove I noticed a few pebbles and
subangular stones (one of granite), in olive-brown loam, and, occa-
sionally, greyish sand, under 5() to 60 feet of Head, which presents
a stratiform appearance through unequal distribution of fragments,
and different tints.

b. In a little cove just north of Cape Cornwall I observed the
following section (Fig. 2) :—

i PRAM LALAD AY ATT

he
p
)

CSEOTS Raised beach.

Fie. 2.—Cape Cornwall on the North side.
1 Inch=24 Feet.

Head, brown loam with numerous angular stones,containing

larger fragments in the lower 5 feet, with pebbles here

and there atand near the base... ..< ..- ss, --- -.- Leit. Qin.
upon—gravel of pebbles and subangular fragments of slate

(altered), quartz, greenstone, a few of flint, and rounded

and subangular granite boulders, in coarse brown and black

loamy, SANG Att MT scelP psi ween Yi encPacecrsont ccot ees snOkve) MOIS

172 Notices of Memoirs—Dr. O. Lenze—Geology of W. Africa.

Base of the deposit about 6 feet above high water. Boulders on the
present beach. Rock platforms are visible at about high-water mark.

c. In Porthleden Cove the following section was taken :—

Head, brown loam with small angular pieces of quartz, containing
small fragments of slate, and, occasionally, granite, 12 feet thick ;
upon yellowish-brown and brown loam with a few angular frag-
ments; upon well-worn and subangular boulders with a few large
pebbles, a few feet above high water.

d. Mr. Godwin-Austen (Q. J. G.8. vol. vii. p. 121) notices the oc-
currence of granite pebbles, under yellowish clay, with large and
small angular stones, and from 5 to 20 feet in thickness, at Creek
Tor, in the parish of St. Just, Penrith.

e. On the north of Cape Cornwall, Mr. Carne (T. R. G.S. Corn.
vol. iii. p. 229) noticed a bed of slate boulders, 2 feet thick, and a
chain in length, on greenstone at 10 feet above high water. The
boulders were imbedded in clay and sand with small slate particles.

14. Pendeen Cove (op. cit.). Mr. Carne observed 3 feet of small
pebbles in sand, made up of comminuted marine shells and pulverized
granite, in one place capped by a bed of sand, overlain by 60 feet of
Head. The base of the deposit is at about the level of spring-tide
high water. The sand is in process of consolidation by iron oxide ;
it appears to have been blown from the beach into the interstices of
the gravel.

(To be continued in our next Number.)

IN(@ Abe eS) (Olay ViaeVE@ re Se

I.—Gzronocican Norrs on Western Arrica. By Dr. O. Lenz.!
{Communicated by Count Marscuatt, F.C.G.S.]

1. The Gabbro of Monrovia.—Gabbro appears near Monrovia in
the form of irregularly fissured, isolated massives, rising above hills
covered with the richest tropical vegetation. In its fresh condition it
is dark green, distinctly granular, without any traces of schistose or
porphyritic texture. Microscopical investigation proves a light-grey
plagioclase to be its chief component, together with light-yellow
tabular crystals of diallage, and interspersed particles of titanate of
iron. ‘The presence of serpentine also is probable, although not
ascertained by positive observation.

2. Polished Rocks in the Beds of Rivers.—Several of the West-
African Rivers, opening into the Atlantic, force the lower portion of
their course through a low and long chain of crystalline schists and
quartzites, striking N.-S. Violent rapids, cataracts, and cascades,
especially in the Congo and Ogowe, are serious obstacles to navi-
gation. The rocks in the bed and on both banks, as far as they
come in contact with the waters, are covered with a thin dark-
brown varnish-like crust of extremely thin lamellee of oxyd of iron,
whose uppermost surface, continually exposed to the action of water,

1 [Proceed. Imper. Geol. Instit. Vienna, January, February, and March, 1878. ]
See also Grou. Mac. Dee. II., Vol. IV. p, 27, and Vol. V. p, 312.

Notices of Memoirs—Dr. O. Lenze—Geology of W. Africa. 173

‘assumes a metallic brightness. The crust is most conspicuous on
the gneisses and on the mica-schists with garnets in the Apinshi region.
It is absent as well on the portions above the contact of water as on
the rocks along the banks where the water flows quietly.

Similar facts have been ascertained on the Rapids of the Nile,
on the Cataracts of the Congo (by Captain Tuckey), and on the
syenite rocks along the Orinoco (by Alex. von Humboldt). Dr.
Darwin observed a black crust, similar in appearance to graphite,
on the banks of several Brazilian rivers which open into the
Atlantic. Berzelius found this crust to be composed of oxyds of
iron and manganese.

The older crystalline rocks of North-west Africa are everywhere
overlain by a (probably Diluvial) deposit of intensely yellow, loamy,
and highly ferruginous sands, including large blocks of brown
hydroxyd of iron. These blocks are aggregated concretions of the
size of beans or peas, similar to the pisiform iron-ore of Europe.
When such blocks are decomposed, the concretions, bearing distinct
marks of having been rolled, are spread over an extensive surface.
The rivers carry with them enormous quantities of fine white quartz
sand, with flakes of mica, which every year during low water are
deposited in enormous sand-banks, rising several métres above the
sea-level. The waters, whirling violently against the rocks, keep
in suspension the quartz grains and the concretions of iron-oxyd,
and the last material, comminuted by the friction of the hard sand,
is deposited on the surface of the rocks in the form of a thin crust.

3. Geology of the Gold Coast, Guinea.—The gold here appears in
the shape of dust or granules, seldom of the size of a pea. The
natives wash it out of the clays and sands in a most primitive way ;
and they frequently adulterate it, by boring holes into the granules,
filling up the cavities with copper or brass, and carefully closing them
again. The primary locality of the gold is still unknown.

It is washed everywhere also in the region of the Senegal and
Gambia Rivers, as near Cape Palmas, out of a red clay, of probably
comparatively recent origin, including layers of rolled ferruginous
fragments. Near Accra, close to the sea-shore, there is a coarse-
grained, intensely red, and somewhat argillaceous sandstone, with
intercalated layers of large rolled fragments of quartz, and without
any traces of organic remains. At first view it has a resemblance
to some of the Triassic beds of Germany. Further inland are
gneisses and granites; and in the Ashanti region and along the river
Volta there are fine black amphibolic schists, abounding with
garnets, locally of rather large size. Possibly, as in the Ural, these
schists may be the primary locality of the gold.

4, Ttabirite (Iron mica-schist) of the Okande Region.—The Okande
region is situated some sixty geographical miles inland, amidst the
rapids of the Ogowe. This river breaks its way westward through
a chain of schistose rocks, with a main strike N.-S., and with a very
steep dip from W. to HE. The Itabirite rests on a very thick stratum
of white and red quartz, the same which appears, at a lower horizon,
intercalated among the mica-schists with garnets of the Apinshi
region, In its upper horizons it passes gradually into quartz.

174 Notices of Memoirs—Dr. O. Lenz—Geology of W. Africa.

The Okande Itabirite is hard and heavy, its colour is reddish-
purple; its texture granular-schistose ; its components are quartz,
specular oxyd of iron, and magnetic iron. The quartz is con-
spicuously prevalent, in the form of whitish-grey granules, in
coherent parallel layers. The specular iron-ore appears in bright
black lamelle, scattered in the quartz, and frequently bearing a
crust of red oxyd of iron. This oxyd appears, likewise, in coherent
layers, parallel to those of quartz, and alternating with them. Thus
a tranverse fracture offers an alternation of rather broad red and
white stripes, interspersed with bright lamelle of iron-ore.
Magnetic iron-oxyd is scattered in minute particles throughout the
whole, so that large specimens of this rock cause a marked irritation
of the magnetic needle. Atmospheric agents give rise to a thin out-
ward crust of hydroxyd of iron, and make the surface irreguiarly
rough, the quartz offering a greater resistance to these agents than
the portions impregnated with oxyd of iron.

The Itabirite of Okande differs from that of Brazil by not including
such accessory minerals as gold, talc, chlorite, iron-pyrites, and
actinote. Itabirite and analogous rocks, associated with Itacolumnite,
were first found in the Schist-formation of Brazil, subsequently in
South Carolina, the South-east of France (Département du Var),
Portugal (Tras os Montes), and Germany (Soonwald).

The Okande Itabirite is a normal and important constituent of the
West-African Schist-formation. It assumes generally the shape of
low and ragged cliffs in the river-courses. In the plain of Lope it
disappears, almost entirely, beneath beds of Diluvial loam of com-
paratively recent origin.

5. Geology of West Africa.—The islands in Corisco Bay, some-
what north of the Equator, rise about ten métres above the sea, and
are composed of a light-coloured calcareous sandstone, in horizontal
strata, overlain with vegetable soil, and extending eastward as far as
the mainland at the mouths of the Rivers Muni and Munda. These
strata contain many casts of very large, inflated, knotted, and
carinated Ammonites, closely allied to Ammonites inflatus, a character-
istic fossil of the Upper Gault. A well-preserved fragment of this
species has been found farther south, in Fish Bay (Benguela).
Small, badly preserved Bivalves are of rare occurrence: and car-
bonized stems of indeterminable plants are frequent. Numerous
fissures in every direction are filled up with an uncommonly hard
and solid ferruginous sandstone, occasionally also with oxide of
iron.

Near Gaboon, white limestones, about two métres thick, with
many veins of calcite, and with local accumulations of Gasteropods,
Bivalves, fragments of Crustacea, Hchinida, etc., rest on Cretaceous
Sandstones. The above-mentioned deposits bear an Eocene facies,
and are strictly local.

The horizontal Tertiaries of the Loango Coast are overlain by an
unstratified deep yellow loam, with nodules of white marl and
hollow concretions of hydroxyd of iron, thus nearly resembling
Loess. This loam, destitute of organic remains, extends along the

Notices of Memoirs—Dr. O. Lenz—Geology of W. Africa. 175

coast of Gaboon, on both banks of the Ogowe, even to the outposts
of the West-African Schist-formation. Its surface is covered with
innumerable granules of pisiform iron-ore, resulting from disaggre-
gation of the concretions of hydroxydated iron. The whole deposit
may be compared with what is generally called Diluvium, and may
be coeval with the origin of the Ogowe Lakes, on the withdrawal
of the waters into their existing beds. Still, a number of larger
and smaller lakes exist on both sides of the Ogowe, connected with
it by channels, a narrow wall of loam, at most ten to fifteen métres
in height, standing between lake and river. Many blocks of schis-
tose rocks, probably transported by the waters once filling up the
whole region from Gaboon to Neomi (Kamma), are spread over the
surface of these natural dykes. The analogy of this loam with the
Laterite of East India is conspicuous. At present the Ogowe, in its
whole course, down to a few miles above its mouth, carries and
deposits only enormous quantities of purest quartz sand, without
any trace of loam; while the adjacent loam dykes are completely
devoid of arenaceous beds.

The foremost chains of an extensive range of crystalline schists,
spreading from the inmost corner of the Gulf of Guinea, Southward
to Angola, appear in the Okota region about forty miles inland.
The range is composed of many parallel chains, dipping eastward
with a steep angle. ‘The lowermost horizon (Okota) has a group of
thin-bedded, light-coloured, fine-grained schists, with some mica,
locally talcose, and in one place containing a great lenticular inter-
calation of steatite. Subordinate beds of red and white quartz are
not rare, both in the schists, and in the typical granatiferous mica-
schists.. A ferruginous schist, closely resembling the Itabirite of
Brazil, exists along the frontier of the Okande region. Great beds
of black siliceous schists extend from the River Okne to the Cataracts
of Ndume, at the commencement of the inner plain. Granite, in
fine varieties, appears only in large erratic blocks, brought probably
from the interior when the Ogowe had a far larger bed.

The massif here described appears on the maps as Sierra Complida
and Sierra do Crystall, and may be conveniently designated as the
West-African Schist Mountains. Globular segregations, including
fine crystals of yellow and reddish quartz, and covered on their
surface with a peculiar network much resembling honeycomb, are
found in both original and derivative situations, in the latter case
having probably been transported out of the black siliceous schists
mentioned above. The volcanic region of the Cameroon and Rumbi
Mountains extends over more than 100 German miles; its highest
summits, ascended by MM. Burton and Mann, exceed 13,000 feet.
The existence of twenty-eight craters has been ascertained. All the
lava-currents have gone southward; and, in this direction, the
marginal ashes and slags of the craters are lower and are cut
through. Emanations of smoke prove all this region to be still in
the condition of a Solfatara. An eruption is said to have taken place
between 1830 and 1840; details, however, are wanting. This region
is south-westward of the volcanic islands of Fernando Po, Principe

176 =Notices of Memoirs—Dr. A. Nehring—Origin of Loess.

Thomé, and Anobon; and a prolongation of the line connecting
these islands reaches St. Helena.

The Clarence Peak on Fernando Po has a height of above 10,000
feet ; smoke and fire are said to have been occasionally observed on
it. The small island of Anobon seems to have been a single volcano,
whose crater has become a lake. Dr. Pechsel-Lésche found on the
coast of Loando (8° to 5° §. Latitude) a dark-brown very argilla-
ceous rock of loose oolitic texture, containing Corals and many
specimens of Leda, Mactra, Tellina, and Cardium. Near Landana,
well-preserved remains of Fishes (among them the vertebral column
and head of a large individual), teeth of Raize, palatal teeth, fin-
spines, the tooth of a Crocodile, and a coprolite, were found, together
with a large Nautilus, some small Gasteropods, and Bivalves. A
light-coloured limestone along the coast south of Congo has abundant
shells of Ostrea.

Very little is known of the Geology of Angola and Benguela.
Granites, schists with abundant copper-ores, volcanic rocks, rock-
salt, and asphalt are said to occur there. _Limestones, in horizontal
beds, possibly connected with those along the south coast, and
prismatic basalt near Old Calabar, have been observed. The natives
Oppose any approach of foreigners to the rock-salt deposits.

IJ.—On THe QuaTERNARY Deposits AT WESTEREGELN AND THIEDE,
NEAR BRUNSWICK ; IN ILLUSTRATION OF THE SUBAERIAL ORIGIN
or Lorss. By Dr. A. Neurtne.'

[Communicated by Count Marscuatu, F.C.G.S.]

I. Westeregeln.—The Quaternary Fauna of this locality is cha-
racterized as a “Steppe” fauna by the presence of remains of
Alaktaga Jaculus, Spermophilus Altaicus, Sp. guttatus ; Arctomys
Bobak, Lagomys jpusillus, several Hastern-EKuropean burrowing
Muride, and Wild Horses, all of them having, apparently, lived in
the locality where their remains are now met with. This is shown
by the number of both young and adult individuals, and by their
good state of preservation. Other species associated with the fore-
going offer no objection to the “Steppe” character. Cheiroptera,
Wolves, Badgers, Hares, Bustards, Ducks, Larks, Finches, Swallows,
Frogs, and Toads are not of rare occurrence in the Steppes of Hast
Kurope and Asia. Pelobates fuscus is said to be frequent around
Sarepta and other parts of the Steppes along the lower course of the
Volga; and the Pike abounds in the waters of the Steppes. Similar
animals have left their remains in the Quaternary deposits under
notice. The local Fauna, like that now existing in the South
Siberian Steppes, has mixed with it occasional visitors, such as came
in summer from Central and South Germany, as Hyenas and Lions,
or in winter from northern regions, as Reindeer, Arctic Foxes, and
Lemmings. The presence of these last three indicates that the
vicinity of what is now Westeregeln was not covered with forests.
As to the extinct forms, such as Hlephas primigenius, Rhinoceros

1 Imper. Geolog. Institute of Vienna, Report of Meeting, July 31, 1878.

Notices of Memoirs—Dr. A. Nehring—Origin of Loess. 177

tichorhinus, and Bos primigenius, they (with habits similar to those of
their living congeners) may have visited the Steppes in those seasons
when vegetation had come to its full development there.

Il. Thiede——The Quaternary deposits of this locality may be
divided into three horizons. The uppermost, about 14ft. thick,
begins immediately beneath the vegetable soil, and has the aspect of
a Diluvial loam (Loess). From 1 to 9 feet downwards it is more or
less dark-coloured by the admixture of carbonaceous substances, and
most of its lime has been washed away by percolating waters. Fossil
bones are scarce. Remains of a large species of Bos have been found
at a depth of about 7 or 8 feet; and the remains of Mammoth at
10 feet, close to where the skeleton of a Lion was met with, at a depth
of 12 feet, some years ago. At about 12 feet the loam is very calca-
reous, clear-yellow, fine-grained, and of tubular structure, without any
trace of stratification or of plasticity. Not unfrequently it here con-
tains Loess shells, as Pupa muscorum, Succinea oblonga, and species
of Helix. This uppermost deposit is so situated that the nearest
river (the Ocker) could reach it only when swollen exceptionally
high ; and wind-action must have been essential to its formation,
with occasional local floods after heavy rainfalls.

In the second horizon, from about 14 to 22 feet depth, the material
is, for the most part, a highly calcareous Diluvial marl. This in-
cludes an abundance of flint pebbles, with both rolled and angular
fragments of siliceous schist, Pliner limestone, granite, and quartz.
A block of granite weighing about 20lbs. has been found at 16 feet
depth,—a subangular fragment of Beyrichia limestone, bearing a
distinct impression of Rhynchonella plicatella (Kloeden),—an Ostrea,
possibly from the White Jura north of the Hartz,—and a number of
small Belemnites (B. ultimus or B. minimus), much worn, are met
with among these fragments. Most probably all these objects have
been brought to their present situation, together with the flint imple-
ments and fragments of charcoal,' by the swollen waters of the River
Ocker. The rolled and angular fragments are derived from northern
Diluvials, and in part from the Hartz and its outposts. The second
horizon may be palzontologically designated as a “ Mammoth-deposit,”
from the frequency of generally well-preserved remains of Hlephas
primigenius. ‘These and the bones of Rhinoceros tichorhinus are fre-
quently incrusted or agglutinated with calcareous concretions.
Remains of Hyena spelea and of Cervus tarandus are scarcer than
those of Equus caballus and of a species of Bos.

The third horizon, called the “ Lemming-deposit,” from the preva-
lence of the remains of this Rodent, reaches from 22 feet depth down
to the clefts filled with gypsum, 30 to 35 feet, and at places 40 feet
deep. The second and third horizons are connected by paleontological
transitions. The prevalent fossil forms are Lemmings; in the upper
portion Myodes lemmus, and in the lower part less frequently I/yodes
torquatus. Arvicola gregalis is rather common. Bones of Reindeer

1 Rough stone axes under the soil, and flint implements and charcoal in the lower

part of the Loess, were found at Thiede by Dr. Nehring, who also met with flint
flakes, bits of charcoal, and split bones at Westeregeln.

DECADE II.—VOL. VI.—NO. IV. ; 12

178 =Reviews—Geological Survey of England and Wales.

and Arctic Foxes, both young and adult, are not rare, but much
scattered. Remains of Equus, Arvicola ratticeps, A. amphibia (or
Myodes Obensis), Lagomys sp., Lepus sp., Spermophilus sp., and of a
species of Bat, seem to exclusively belong to the upper portion. The
loam of this horizon contains a notable proportion of sand, and is
divided into distinct horizontal strata, two to three centimétres thick,
layers with coarse-grained sand generally alternating with beds either
containing fine-grained sand, or quite loamy. Here and there large
pebbles, up to the weight of 200 grammes, are found, but not so
large nor so abundant as in the “Mammoth horizon.” The pro-
portion of lime is rather considerable, and calcareous concretions are
not of rare occurrence, especially in connexion with the fossil bones.

III. Conclusions.—The ossiferous deposits of Thiede are essentially
the result of violent currents of flood-waters. During the intervals
between two inundations, winds, more frequent in the dry summer
months, may have brought a considerable amount of sand and dust
over this the exposed region, depositing these substances among the
gypsum cliffs of Thiede. The effects of atmospheric currents are
chiefly conspicuous in the upper horizon, less distinct in the lower-
most, and not at all perceivable in the middle horizon. This assertion
is proved, first, by. their high level above the present level of the
nearest river ; secondly, by their petrographical constitution; thirdly,
by their organic remains belonging nearly all to land-animals, and
mostly to forms proper to Steppes, which are continually subject
to subaérial accumulations of sand and dust, such as Von Richthofen
has observed on a very large scale in the undrained Steppe-regions of
Central Asia. The few traces of water-action may be explained by
local inundations, in consequence of occasional heavy rains. If we
suppose the “Lemming deposits” of Thiede to belong to the Glacial
(and, if we admit two such periods, to the Second Glacial period),
the middle and upper horizons at Thiede, as also the whole of the
deposits at Westeregeln, should be ranked among those of the Post-
_ glacial period, when Western and Central Europe had taken a more
ue form, and certain regions were subjected to a dry Steppe-
climate.

d5% dah WE 26 IE WW SS -

—_—_~>—_—_.
I.—Tue GrotocicaL SurvrEy oF ENGLAND AND WALES.

Tur Grotocy or THE N.W. Part or Essex, anp tHE N.B. Parr
or Herts, with Parts oF CAMBRIDGESHIRE AND SurrFoLK. [ Ex-
planation of Sheet 47 of the Geological Survey Map of England
and Wales.| By W. Wuiraxer, W. H. Pennine, W. H. Datrton,
and F. J. Bennett. 8vo. pp. 92. (London, 1878.)

HE Geological Survey is gradually extending its labours over

the northern and eastern counties; and there now remains not

an English county which has not been partially surveyed, nor one

of which some account has not been published “by order of the
Lords Commissioners of Her Majesty’s Treasury.”

Reviews—Geological Survey of England and Wales. 179

Two years ago we called attention (Gror. Mac. April, 1877) to
a short memoir on the Geology of the eastern end of Hssex, by
Mr. Whitaker ; we have now the pleasure of announcing the publi-
cation of the above-mentioned work, by the same geologist, in
conjunction with three colleagues. Most of the field-survey was
done (we are told) by Mr. Penning; while Mr. Whitaker himself
has performed the duties of editor, in his invariably careful and
systematic style.

' Much of the country described is comparatively little known
to geologists. It lies chiefly in Essex, including the towns of
Braintree, Coggeshall, Dunmow, Halstead, Saffron Walden, Harlow,
Thaxted, and Witham. In Hertfordshire is included the country
around Bishop’s Stortford, Buntingford, Hertford, and Ware; in
Cambridgshire, that around Linton and Royston; and in Suffolk,
that around Haverhill, Long Melford, and Sudbury. The previous
observers include the late Rev. W. B. Clarke, John Brown, of
Stanway, J. Mitchell, Prof. Prestwich, and Mr. 8. V. Wood, Jun.

Geologically the area consists of a great plain of Chalky Boulder-
clay, beneath which, in the valleys, are exposed glacial sands and
gravels, Tertiary deposits, and Chalk. In the north-western corner
of the area a trace of Gault is exposed, and bordering this, near
Royston, the Chalk stands out in comparatively bold hills: rising
even to 550 feet above the sea-level at Tharfield, where capped by
the Boulder-clay.

About half the area beneath the Drift is occupied by Chalk, and
nearly half by the London Clay, between which a belt of the Lower
London Tertiaries, comprising Reading and Thanet Beds, has been
traced, and not without considerable difficulty, owing to the covering
of Drift.

A detailed description of the various rocks in the numerous pits
and cuttings examined, forms the main feature of this work; the
initials of each observer being appended to his statements.

Some disturbances in the Chalk are figured, in one of which cases
the beds are tilted at an angle of 60°. Lists of fossils from the
various pits are given on the authority of Mr. Etheridge. The
account of the Reading Beds is partly re-printed from Mr.
Whitaker’s Memoir on the London Basin. The description of the
Thanet Beds is new, as they were only discovered in this area in
1878, during the progress of the Geological Survey. In the same
year Mr. Whitaker also discovered traces of the Red Crag at Sudbury.
A short description of these is given, with a list of the organic
remains which were in the state of casts or impressions.

Descriptions of the glacial deposits occupy about a third of the
work. We should gladly have seen some more definite scheme of
classification adopted for these beds, but we are told that “until the
work of the Geological Survey in Norfolk and Suffolk is in a more
advanced state, it is better for us not to commit ourselves to a
scheme of classification, and to be content with the detailed mapping
of the beds and their lithological description.”

Such being the case, the work cannot possess so much interest for

180 Reviews—The Paleontographical Society’s Monographs.

the general reader, but it comprises a valuable store of facts,

supplemented in an Appendix with the record of a number of well-
sections and borings; and these will be of both practical and
scientific value to many living in the district, while they must also
aid the theorist in his efforts to account for the formation of the
deposits, more especially those belonging to the Glacial period. It
will be remembered that in his Memoir on the Geology of the
Fenland, Mr. Skertchly spoke with some confidence as to the
classification of the Glacial deposits, and of the land-origin of the
Chalky Boulder-clay. But we are not treated here to theoretical
views. Mr. Penning tells us in regard to the Boulder-clay that it
was evidently formed in one continuous sheet, that it rarely presents
any signs of stratification, and that its main substance consists of
material derived from the rocks at no great distance from the poimt
where it may be observed—facts which coincide with those observed
by Mr. Skertchly, and upon which, in part, he based his conclusions.

TI.—MonoGRAPHS PUBLISHED BY THE PALHONTOGRAPHICAL SOCIETY.
Ato. vols. xxxi. and xxxii. 1877-8.

N 1877 Mr. 8. V. Wood supplemented the Monograph of the
Eocene Bivalve Molluscs, written by the late Mr. F. H.
Edwards and himself, with valuable figures and descriptions, chiefly
of Cyrene and Cyclades, so important in the history of the Woolwich
and Reading beds. He also’added an instalment, unfortunately
the last that he feels able to contribute, to the Monograph of the
Hocene Gasteropods, commenced by the late Mr. Edwards, and
continued by himself. Species of the genera Helix, Cyclostoma,
Bulimus, Succinea, Bythinia, Planorbis, Limnea, Neritina, and Nerita,
are the chief subjects of this memoir and its plate, which last has
been well and characteristically drawn by Mr. G. B. Sowerby.

Dr. Lycett continued his exhaustive Monograph on the Trigonie
in 1877. Many of the Costate, and one of the Byssifere, together
with several supplemental species, only lately come to hand, are
described and beautifully figured in this part iv. Two specimens
from Australia and Lebanon are given in woodcuts for comparison.
The lithograph plates, by Lichtenbauer, are beautifully drawn, but
give an unnaturally clean and smooth surface to the fossils.

Dr. Traquair’s Monograph of the Carboniferous Fishes begins
with the Palgoniscide for part i. (1877). It has an instructive
Introduction, both geological and zoological; and treats of Cosmo-
plychius striatus (Ag.); Elonichthys semistriatus, 'Traq.; HE. caudalis,
Traq.; H. oblongus, Traq., and E. striolatus (Ag.) ; with seven most
teaching and illustrative plates, lithographed from drawings made
by Dr. and Mrs. Traquair.

Professor Owen in 1877 enriched paleontology with a concise
and masterly account of a great carpal spur or spine of the gigantic
Omosaurus hastiger, from the Kimmeridge Clay, illustrated with
large drawings ; and in 1878 he continued his Monograph on the
Wealden and Purbeck Reptiles, with descriptions and numerous

Reviews—The Paleontographical Society’s Monographs. 181

fine figures of remains of the Crocodilian genera Goniopholis,
Petrosuchus, and Suchosaurus.

' Prof. A. Leith Adams supplied in 1877 the first portion of a
much-wanted Monograph of the British Fossil Elephants. It
consists of descriptions of the dentition and osteology of Elephas
antiquus, Falconer; with a useful Introduction, and five excellent
plates, by Griesbach.

In 1878 Dr. T. Wright gave part viii. of his Monograph of the
British Cretaceous Echinodermata, describing and figuring many
species of Hpiaster, Micraster, Echinospatagus, Enalluster, and Car-
diaster. Several of these are among our most common fossils, and
have received so many dubious names and synonyms that both
collector and student will now be delighted to have a definite system
of nomenclature for use. The many figures in the eight plates are
exquisitely, almost too delicately, rendered ; they were the last work
of the lamented C. R. Bone.

The Introduction, Index, and Title-page of Vol. I. of Dr. Wright’s
Monograph of British Oolitic Echinoderms, began in 1857, also were
issued in 1878.

The completion of Dr. H. Woodward’s Monograph of the British
Fossil Merostomata, in 1878, is a subject of congratulation to the
_ Society, to the author, and to paleontologists. The comparatively
rare occurrence of Pterygotus, Slimonia, Stylonurus, and Hurypterus,
of their Limuioid allies, Bellinurus, Prestwichia, and Neolimulus, and
of their obscure relation the Cyclus, all of Upper Paleozoic age,
has been counterbalanced by the rather abundant specimens of
distinctive fragments and even individuals of some of the species. ©
These precious evidences of extinct life happily attracted the
attention of a Carcinologist who had opportunities and the will to
study everything that had already been written on these fossils, and
‘to think and work anew among the increasing store of specimens
brought under his notice, both in public collections, and by the courtesy
and consideration of friends and fellow-workers. How freely some
have helped, and how judiciously the author has availed himself of
previous useful discoveries and labours, his Monograph clearly
shows throughout; but more especially in the treatment and illus-
trations of the larval Trilobites, after Barrande,—the larval Limulus,
after Packard and Dohrn,—and the anatomy of Limulus, at large, after
Owen. With this work off his mind, enriched with experience, and
lightened with the pleasant thought of well-spent labour, Dr. H.
Woodward will soon, we trust, contribute further Monographs on
legions of Crustacean Fossils to the Paleeontographical Society. The
willing concurrence of geologists in helping on the work of the
Palzeontographical Society, so well shown, as above mentioned, in
this Monograph, is equally apparent throughout all the Monographs
yet published.

The commencement of Prof. L. C. Miall’s Monograph of the Sirenoid
and Crossopterygian Ganoids, in 1878, with 32 pages and six plates,
Opens another pleasant vista to palichthyological students, like
that promised by Dr. Traquair’s Monograph. The Introduction treats

182 Reviews—Dr. C. W. Giimbel’s Alpine Geology.

of the real Ganoid Fishes, lucidly and systematically. The recent
Lepidosiren and Protopterus are then described clearly and concisely.
The study of the genus Ceratodus is taken up at page 18; and, after
an illustrated account of the recent form, the fossil teeth from the
Trias (one), Rheetic, and Great Oolite (one), (the plates for which
hardly do justice to the specimens), are fully described and figured.

Another valuable and longed-for Monograph had its commence-
ment in 1878, namely, that on the Ammonites of the British Lias by
Dr. T. Wright. Hight excellent plates of good specimens of the
Ammonites, by A. Gawan, are published with this portion of the
Monograph; but the text forms part only of the Geological Intro-
duction, describing the succession and characters of the several strata,
from the Rhzetic upwards. The Ammonites are referred to under
the new generic names of Algoceras, Arietites, etc.; and the Lias is
described according to its successional zones, as characterized by
Ammonitic species, namely, Planorbis-zone, Angulatum-zone, Buck-
landi-zone, Turneri-zone, etc. The Continental Lias is throughout
carefully brought into comparison with that of Britain, and thus a
vast amount of geological information is afforded.

Additional Jurassic Brachiopoda have still turned up, and new
observations on species already described have had to be made, so
that the persistent energy and cultivated experience of our friend
T. Davidson, F.R.S., had abundant matter at hand for the Sup-
plement to his magnificent Monograph of British Brachiopoda ; and
we have No. 2 of part ii. of vol. iv., with nearly 100 pages and 13
plates, in 1878. An elaborate Table (of nine pages) shows the dis-
tribution of Triassic, Liassic, and Oolitic Brachiopoda in Britain ;
and serves also as an Index to the Supplement, and in some measure
to the Monograph also. These plates, like those already given, have
been drawn by the accomplished author himself.

“A Preliminary Treatise on the Relation of the Pleistocene
Mammalia to those now living in Europe,” by Professor W. Boyd
Dawkins, was published in 1878, as “ Part A” of the Monograph on
the Pleistocene Mammalia of Britain, but a considerable part of it
had been written in 1872. It is of very great interest, as well to the
general reader as to the geologist. Chapter i. gives the definition of
the successive ages, from the Historic back to the divisions of the
Tertiary Period. Chapter ii. treats of the Wild and Domestic
Animals of Great Britain and Ireland in Historic Times, especially
the Cattle, and the effects made upon the inhabitants by changes in
land, marsh, forest, etc.; a list of these Historic Mammalia is added.
Chapter iii. notices the wild and domestic animals of the Continent
during Historic Time, climatal changes, and conclusions.—T. R. J.

JII.—A Snort Inrropuction to Aupinr Guronoey. By Professor
Dr. C. W. Gimset, etc., etc. With numerous Illustrations.
small 8vo. [Kurze Anleitung zu geologischen Beobachtungen
in den Alpen; etc., etc. ]

HIS very concise, clear, and yet fully expressive account of
Alpine geology is really an admirable little geological manual,
based on the structure and physical geography of the Alps. It is

Reviews—Zittel’s and Schimper’s Paleontology. 183

the geological portion of the “Introduction to Scientific Observation
in Alpine Journeys,” published by the German and Austrian
Alpine Society. How to observe is the first thing taught, both as
to rock-materials and the arrangement of strata in general, with
their mineral veins, faults, and foldings, and their normal and
abnormal successions. The relations of strata to the surface, the origin
of springs, also glaciers, caves, etc., are duly noticed or referred to.
Alpine structure is then entered upon; and the constituent groups
of strata, from the “ primitive” or “archeolithic” upwards, with
their chief characters and their leading fossils, are excellently well
noted and illustrated. The specialities of Alpine rocks, strata, and
fossils are next treated of, and shown by sections, etc., in order of
stratal sequence from below upwards; so that nothing which a
beginner, or even an advanced student, in geology ought to observe
or look for, is omitted in this masterly résumé. We know that it
is the work of an accomplished geological surveyor and experienced
Alpine explorer. AW, Jt. Ue

I1V.—Hanpsucu Der Patzontouociz. By Karl A. Zirren, Professor
of Paleontology in the University of Munich, in conjunction
with W. Ph. Scumpsr, Professor at the University of Strassburg,
8vo. vol. i. part ii. pp. 129-307, with 155 wood-engravings.
(Munich, 1879.)

r [ge second part of this excellent Manual of Paleontology will be
welcomed by all students of the science, and the long delay

in its appearance can be well forgiven when its cause is understood.

The first part, dealing with the general principles of Paleontology,

with the Foraminifera and with the Radiolaria, was issued in 1876,

and there is thus an interval of between two and three years

between the dates of publication of the first and second instalments
of the work. The obstacle which gave rise to this apparently long
delay is to be found in the fossil Sponges. When Prof. Zittel came
to grapple with this portion of his subject, he found that it would
be necessary either to content himself with a simple compilation of
the known paleontological literature dealing with these organisms,
or to attack this difficult group of fossils for himself, keeping his
mind free from previous prejudices, and starting afresh upon a new
basis of investigation. This latter alternative, fortunately for science,
was the one finally adopted; and the re8ult is that the chaotic
crowd of fossil sponges now stands ranked in regular series, their
intimate structure more or less fully understood, and their relations
‘with living forms in many cases completely demonstrated. All
zoologists will find cause, therefore, to rejoice that Prof. Zittel
should have wisely decided rather to delay his work than to leave
the sponges in the unsatisfactory condition in which he found them.

From another point of view, it is interesting to note, as evidence

of the rapid progress that Paleontology is making, that the author

recognizes that the delay which has occurred has already rendered
considerable alterations in the first part of the work a matter of
necessity. Some of these alterations, such as those necessitated by

184 Reviews—Zittel’s and Schimper’s Paleontology.

the appearance of Mr. H. B. Brady’s admirable monograph of the.
Carboniferous and Permian Foraminifera, are so obvious as to call
for no comment; but one might doubt the propriety of some of the
others, in a work essentially professing to give only the generally
accepted and settled facts of the science. One might doubt, for
example, if Munier-Chalmas can be considered as having finally
proved that Dactylopora, Gyroporella, and Acicularia, are really Alge;
or if the researches of Mébius have conclusively demonstrated the
mineral nature of Hozoén. There are, at any rate, very high authori-
ties who would still be prepared to dispute both of these conclusions.

The general plan of the present instalment of the work is pre-
cisely the same as that adopted in the first part. Each group is
considered first as regards its general characters ; then the classifica-
tion and taxonomic divisions of the series are dealt with, all the
genera being briefly but clearly defined, where their characters are
thoroughly understood; and, finally, a short section is devoted to the
subjects of geological range and phylogeny. No plan could be
devised which would so largely meet the many wants of those who
desire to enter upon a really scientific study of fossil organisms, and
the manner in which it has been executed, as a rule, deserves the
highest praise. The illustrations, without exception wood - en-
gravings, are all good, and many wholly original ; and though some
may miss the oveater delicacy and finish afforded by lithographs,
most will appreciate the immense convenience of having the picture
of the fossil side by side with its description in the text, and of thus
being spared the labour of hunting up the figure in a remote series
of plates at the end of the volume.

The groups treated of in Part II. are the Sponges, the Corals, and
the Hydrozoa. As regards the first of these, nothing need be said
here, as all students of Zoology and Palzontology are already
familiar with the beautifully illustrated memoirs on this group,
which Professor Zittel has published in the Transactions of the
Bavarian Academy of Sciences and the ‘Neues Jahrbuch fir
Mineralogie”; and they know therefore how greatly they are in-
debted to the author. Nor need much be said as regards the Corals ;
the general treatment of which is in many respects greatly superior
to anything to be found in previous manuals of Paleontology, and
which has the merit of giving the student the most recent researches
upon this subject in a condensed and readily available form. One
cannot help recognizing, of course, that Professor Zittel is here not
upon ground so thoroughly familiar to him as was the case with the
fossil Sponges: and one may feel regret that in the laudable desire to
embody the latest information in his work, he should sometimes’
have so implicitly relied upon writers whose investigations have not
yet met with the general approval of their fellow-workers. One
may, for example, doubt the propriety of admitting into a systematic
work for general students the classification of the Rugose Corals
proposed by Dybowski; while the total and absolute abolition of
the old division of the Tabulata is certainly premature; and it
would probably be difficult to bring forward any direct and positive
scientific evidence in support of the definite reference of Syringopora,

Reviews—Zittel’s and Schimper’s Paleontology. 185

Halysites, Aulopora, etc., to the Alcyonaria, and still less so if that
reference places them in the Tubiporide. At the same time, it is
quite unreasonable to expect that any writer of a systematic treatise
on Paleontology should, now-a-days, possess an equal, detailed,
personal knowledge of all the departments of the science, and with
this consideration in one’s mind, it is impossible to refuse high
commendation to the section of his work which Professor Zittel has
devoted to the Corals. What has been said above as to the Corals
will apply with equal cogency to the portion of the volume which
deals with the Hydrozoa. The general treatment of the subject is
excellent; and even an ill-natured critic would find it difficult to
detect other fault than that the author, in accepting the results of the
latest investigations, does not, perhaps, sufficiently indicate to the
student that these investigations have by no means always received
the general endorsement of other high authorities in the same field.
For instance, it can hardly be said that Parkeria has been proved to
be really of calcareous composition, and of Hydrozoal affinities. It
is probable, at any rate, that well-known names could still be cited
in support of an entirely opposite view; and in cases which no
one but a specialist can decide, it would seem advisable to indicate
that divergences of opinion still exist, and that the question ought
to be looked upon by the student as one not yet finally solved.
Again, the reference of the Stromatoporoids to the Hydrocoralline,
in close association with Millepora, might have been more clearly
indicated as a purely provisional arrangement, rendered unavoidable
by the absolute necessity of placing extinct groups somewhere in the
zoological series. No one, probably, would be more ready than the
accomplished author to admit that, in spite of what has been done
of late years, the entire subject of the structure and affinities of
these obscure and difficult fossils has yet to be worked out to a fully
satisfactory conclusion; and it would perhaps have been better if
this admission had been explicitly made.

Upon these and many other points of a like nature, wide differences
of opinion will, and ought, to exist for a long time to come; and it
is not altogether unreasonable to think that these differences might
with advantage have been more fully recognized in the work before
us. No impartial critic, however, can refuse his tribute of admira-
tion in dealing with the work as a whole. It is only as a whole
that a treatise of this kind ought to be judged, and from this point
of view it would be difficult to award too great praise to the manner
in which Professor Zittel has so far carried out his portion of the
work. It will be, when completed, incontestably, the best systematic
treatise on Paleontology, of its kind, in existence; and no paleon-
tological or zoological student can afford to be without it, if he
should wish to enter upon any serious investigation into his subject.
From a patriotic point of view, one can only regret that the time
has not yet come at which it would be possible to induce any British
publisher, with any reasonable expectation of pecuniary profit, to
undertake the publication of a similar work. EE AG Ne

186 Reports and Proceedings—The Geological Congress.

ARIES OVSyeuS) ANAND) IS IsyO(Gsaapapo aes r=

———SSSS

].—Tue InTERNATIONAL GronocicaL Coneress, Paris, 1878.

HE International Congress of Geologists held in Paris during the
month of September last seems not to have attracted the amount
of attention in England that it deserved ; the proceedings of the
Congress were by no means devoid of interest, and, indeed, were of
some considerable importance, inasmuch as several very valuable
papers were read and discussed ; attention was also directed to cer-
tain lines of geological inquiry now urgently requiring the earnest
study and consideration of all geologists.

On the whole, the Conference was very successful, and arrange-
ments were made for holding such gatherings triennially, a great
number of the members present pledging themselves to work at
certain questions and to present reports embodying the results of
their labours at the next Conference, which it was decided should be
held at Bologna in October, 1881.

The small amount of notice which the Congress here attracted
was probably mainly due to the fact that it took place almost imme-
diately after the meeting of the British Association, and at a time
when many other gatherings of a somewhat similar nature were
being held; many persons were doubtless surfeited with scientific
picnics, and others were, at that time, compelled to start for their
real holiday excursions, if they wished to take advantage of the short
amount of autumn weather then remaining to them.

The Congress was opened at the palace of the Trocadero on Thurs-
day, August 29, under the Presidency of M. Bardoux, Minister for
Public Instruction; there were from 350 to 400 persons present,
including amongst their number many of the leading geologists from
all parts of Europe and America; at this meeting the Council of
Management was elected, with this was incorporated the members
of the original committee, appointed at the Philadelphia Exhibition
in 1876, viz. Messrs. E. De Baumhuer, J. W. Dawson, James Hall,
C. H. Hitchcock, Sterry Hunt, T. H. Huxley, Lesley, J.S. Newberry,
R. Pumpelly, W. B. Rogers, and Otto Torell.

The following Members of the Congress, who were all present,
with the exception of the English representative, were elected to
serve on the Council, viz. :

President:
Pror. M. HEBERT, Parts.

Vice-Presidents :

For England ..» « Mr. THos. Davipson, F.R.S., Brighton.
», Australasia ... ... Prof. Liversipex, Sydney.
» Belgium... ... ... Prof. Dz Koninox, Liége.
» Canada... ... .. Dr. Srerry Hunt, F.R.S., Boston.
», Denmark ... ... Dr. J. SrEENstRUP, Copenhagen.
9» Spain ... ... «. Prof. Vintanoya, Madrid,
», United States ... Prof. J. Hatt, New York.

», France ... ... .«. Prof. DavBréxz, Ecole des Mines, Paris.

Reports and Proceedings—The Geological Congress. 187

For France see ace Prof. A. GAupry, Mus. d’histoire Naturelle, Paris.
» Hungary ... ... Prof. Szaso, Buda Pesth.
» ltaly ... ... ... Prof. Carezyini, Bologna.

» Netherlands ... ... M. van Baumuauer, Haarlem.

», Portugal see eee M. Riperro, Lisbon.

», Roumania ... ... Prof. SrepHanEsco, Bucharest.

», Russia ... ... ... Prof. Dz Moruuer, St. Petersburg.
», Sweden and Norway Dr. Orro Toretx, Stockholm.

» Switzerland ... ... Prof. Favre, Geneva.

Council :
Messrs. BARRANDE, J., Prague, Bohemia.
Briart, M.A., Pres. of the Geological Society of Brussels.
CHAMBERLAIN, Dir. of the Geol. Survey of Wisconsin, U.S.A.
Coox, G. H., Dir. Geol. Survey of New Jersey.
DewatavE, Prof. of Geology, Liége.
Drevrarait, Prof. of Geology, Marseilles.
Duvont, Dir. Natural History Museum, Brussels.
GossELET, Prof. of Geology, Lille.
Hanxs, J., San Francisco.
» Hantxen, Dir. Geol. Institute, Hungary.
Hetuanp, Delegate from Norway.
Inostranzorr, Prof. of Geology, St. Petersburg.
JaccarD, Prof. of Geology, Newfchatel.
Grorpano, Inspector General of Mines, Italy.
Lenntrer, Dir. of the Museum, Havre.
Lorton, Geneva.
Lory, Prof. of Geology, Grenoble.
LunpeRren, Prof., University of Lund.
Mataiss, Delegate from the Royal Academy of Sciences, Brussels.
Martueron, Marseilles.
Maver, Prof., University of Zurich.
Monrimre, Prof. of Geology, Caen.
Pixar, Prof. of Geology, University of Agram.
Prrona, Delegate from the Institute of Venice.
ReEneEvIER, Prof. of Geology, Lausanne.
Saporta (Comte de), Corr. Member of the Institute of France.
Sea, late Minister for Public Works, Italy.
Sretwyn, A., F.R.S., Dir. of the Geological Survey of Canada.
Strovor, Prof. of Geology, Rennes.
Wrykter, Dr. T. C., Haarlem.

Secretaries—Messrs. Broccu1, DELAIRE, SAUVAGE, and VELAIN.
Treaswrer—A. BIOcHE.
General Secretary—A. JANNETTAZ.

The propositions specially laid down, and previously published
in the programme, for the consideration of the Congress, were the
following :—

1. The unification of geological signs (é.e. colours and con-
ventional signs).

2. The discussion of various questions relative to the limits and
characters of certain formations.

3. The representation of faults and veins.

4, The respective values of the fauna and flora in defining beds.

5. On the value of the mineral composition and texture of rocks
in determining their origin and age.

Some thirty and odd papers bearing more or less closely upon the
above propositions were read and discussed.

188 Reports and Proceedings—The Geological Congress.

At the last meeting international commissions were appointed
to consider certain propositions, and to report upon them at the
meeting to be held at Bologna in 1881. Two of them are matters of
the utmost importance to geologists, and if they be well and honestly
worked out, the results should prove of the greatest use and benefit
to Science.

1. An International Committee for the Unification of Geological
Signs, composed as follows :—

For England ..- w.» Prof. T. McKenny Hucuss, Cambridge.

» Australasia ... ... Prof. Lryersipez, University of Sydney.
» Belgium... ... ... M. Duponz, Dir. of Nat. Hist. Mus., Brussels.
5 Camack, ... Mr. Setwyn, F.R.S., Dir. Geol. Survey, Canada.

» Spain and Portugal M. Rreerro, Dir. of the Geol. Survey of Portugal.
», United States ... Mr. Lestey, Dir. Geol. Survey of Pennsylvania.
» France ... ... .. M.D Cuancourrors, Ecole des Mines, Paris.

», Hungary .- eo M. Dr Hanrxen, Dir. Geol. Inst. Hungary.

» Italy ... ... ... M. Grorpana, Rome.

» Russia ... ... .. M.D Moztusr, University of St. Petersburg.

» Scandinavia ... .. M. Orro Torztt, Dir. Geol. Survey of Sweden.
5, switzerland ... ... Prof. Renrvrer, Lausanne.

2. The Committee for the Unification of Geological Nomenclature
is as follows :—

For England... ...... Prof. T. McKenny Hueuss, Cambridge.

», Australasia ... ... Prof. Liversipex, Sydney.

», Canada ... ... .. Dr. Srerry Hunv, Boston, U.S.
», Spain and Portugal Prof. Viruanova, Madrid.

», United States ... Prof. J. Haut, New Jersey.

» France ... ... .. M. Hisert, Paris.

», Hungary we ae Prof, Szaso, Buda Pesth.

A italy fie ee eee a ecot CO keEnEiny wholosma:

>», Roumania ... ... Prof. SrepHanzEsco, Bucharest.

» Russia ... 2. «. Prof. INosrranzorr, St. Petersburg.
», Scandinavia ... ... Prof. LunpGren, Lund.

», Switzerland ... ... Prof. A. Favre, Geneva.

The members of these international commissions are charged with
the formation of local committees in their respective countries ; each
committee is to have the power to choose its own president and
secretaries.

The reports of the committees are to be forwarded to the central
committee at Bologna by January 1st, 1881, which is charged with
the duty of printing and distributing the same before the opening of
the Congress in the October of that year.

The French Government has undertaken to print the Proceedings
and Papers of the first session of the Geological and other Congresses
(some 30 in number) held during the Paris Exhibition.

The Geological Society of France threw open its rooms to the
Members of the Congress, not only during the actual week of the
meeting, but for some time both before and after. Arrangements
were made also for several very interesting geological excursions,
which were well attended, and went off very pleasantly and suc-
cessfully.

A very notable and useful feature in the arrangements for the
Congress was the publication and gratuitous distribution of a very
full and valuable “ Guide” to the Geological and Mineralogical Col-

Reports and Proceedings—Geological Society of London. 189

lections at the Exhibition, and to the various public and private col-
lections in Paris ; this book, consisting of about 160 pages, described
the principal features of the different collections—the plan that ac-
companies it indicated the positions of the geological exhibits in the
building; without this “Guide” many of the collections scattered
over the vast building on the Champs de Mars might easily have
been overlooked even by the most careful. The book is divided
into three parts,—the first part treats of the geological collections
according to their range in time, or as it is headed—“ Stratigraphical
Geology ;” the second part treats of the collections according to the
countries from which they were sent ; whilst the third division of the
book is devoted to the mineral collections and mineralogical apparatus. .

The Organizing Committee for the next meeting at Bologna in
1881 is composed as follows :

Patron—His Masesty tHE Kine or I[taty.
Honorary President—M. Suwa, President of the Academy, Rome.

Messrs. Caprtuini1, The Museum, Bologna.
Gastatp1, Prof. of Geology, Turin.
TaRAMELLI, Prof. of Geology, Pavia.
Ompont, Prof. of Geology, Padua.
Meneeurnt, Prof. of Geology, Pisa.

Ponzi, Prof. of Geology, Rome.

Giorpana, Chief Engineer of Mines, Rome.
Guiscarp1, Prof. of Geology, Naples.
GrEMMELLARO, Prof. of Geology, Palermo.
Dz Prrona, Prof. of Geology, Venice.

The Italian Government and the Municipality of Bologna have
offered their assistance in making arrangements for the reception

and convenience of the members of the Congress during their stay
in Bologna.

II. Gzoroeicar Socrery or Lonpon.—I.—Annual General Meeting.
February 21st, 1879.

Henry Clifton Sorby, Hsq., F.R.S., President, in the Chair.

The Reports of the Council and of the Library and Museum
Committees for the year 1878 were read and ordered to be printed.

The Wottasron Gold Medal was awarded by the Council to Prof.
Bernard Studer, F'.M.G.S., “the father of Swiss Geology.”

The Murcuitson Bronze Medal to Prof. M‘Coy, of Melbourne
University.

The Lyrtt Gold Medal was awarded to Prof. E. Hébert, of Paris,
for his investigations of the Cretaceous formation, ete.

The Brespy Gold Medal to Prof. E. D. Cope, of Philadelphia.

The “ Wollaston Donation Fund” was awarded to Mr. Samuel
Allport, F.G.S., of Birmingham, in aid of his researches in the
Microscopical Structure of Rocks.

The ‘Murchison Geological Fund” was awarded to Mr. J. W.
Kirkby, of Leven, Fife, N.B., in aid of his researches in the faunas
of the Magnesian Limestone and the Carboniferous strata.

The “Lyell Fund” was awarded in equal moieties to Prof. H.
Alleyne Nicholson, M.D., F.G.S., of St. Andrews, for his various

190 Reports and Proceedings—Geological Society of London.

and important researches in Paleozoic Paleontology : and to Dr. H.
Woodward, F.R.S8., in recognition of his work on Fossil Crustacea,
ete.

The President then proceeded to read his Anniversary Address,
which was devoted to the examination of the structure of limestones,
and the means presented, especially by optical investigation, for
determining the origin of their constituent particles.

II.—February 26, 1879.—Henry Clifton Sorby, Hsq., F.R.S.,
President, in the Chair.— The following communications were
read :—

1. A copy of a Letter from the late Acting Governor of the
Falkland Islands, relating to the overflow of a peat-bog near Port
Stanley, in Hast Falkland. Communicated by H.M. Secretary of
State for the Colonies.

2. “Note on Poitkilopleuron Bucklandi, of Kudes Deslongchamps
(pere), identifying it with Megalosaurus Buckland.” By J. W.
Hulke, Esq., F.R.S., F.G.S.

The author stated that the genus Potkilopleuron was founded by
Deslongchamps, after much hesitation, to receive some Megalosauroid
fossils found in a quarry near Caen; and that he gave them the
specific name “‘ Bucklandi”’ with the view of facilitating the union
of the two genera, should this be found necessary. ‘The author
reviewed the evidence on which the genus Pozkilopleuron rests,
indicating the close resemblance of the remains to those of
Megalosaurus, and showing that a medullary cavity exists in the
vertebre of the latter, thus getting rid of the most important
difference between the two supposed genera. The author’s con-
clusion was that Poikilopleuron and Megalosaurus Bucklandi were
identical.

2. “Note on a Femur and a Humerus of a small Mammal from
the Stonesfield Slate.” By H. G. Seeley, Hsq., F.L.8., F.G.S.,
Professor of Geography in King’s College, London.

The author described a small femur and humerus preserved in
slabs of Stonesfield Slate in the collection of the British Museum,
to which they were presented many years ago by Mr. Pease Pratt.
The bones nearly correspond in size, and, in the absence of evidence
to the contrary, the author preferred to regard them as possibly be-
longing to the same animal. From their characters the author was
inclined to associate them with the jaw known as Phascolotherium,
and to believe that they represented a special, probably insectivorous,
monotreme type, with indications of marsupial tendencies, such as,
on the hypothesis of evolution, might well be expected to occur early
in the development of the Mammalia.

3. “A Review of the British Carboniferous Fenestellide.” By
G. W. Shrubsole, Esq., F.G.S.

In this paper the author gave the results of his investigation of
the Fenestellide from the upper beds of the Carboniferous Lime-
stone on Halkin Mountain, in Flintshire. He stated that the de-
scribed Carboniferous species of Fenestella now number 24, of which

Correspondence—Mr. James W. Davis. 191

he has been able to examine 19, and finds that they have been
needlessly multiplied, owing especially to the neglect on the part of
describers to allow for difference in the structure at various stages
of growth and in different parts of the polyzoarium. His investiga-
tions led him to refer the forms known to him to only 5 species,
namely, Fenestella plebeia, M‘Coy, F. crassa, M‘Coy, F. polyporata,
Phill., F. nodulosa, Phill., and F. membranacea, Phill,

CORRES PONDHNCE.

—

THE CALDER VALLEY.

Sir,—Will you permit me to thank my friend Mr. Dakyns for
drawing the attention of your readers to two or three particulars
having reference to the physical forces which have caused the con-
figuration of the Valley of the Calder. He is puzzled by the
statement that heather and peat are found above sandstones, and that
the heather does not grow on limestones or shale or clay, further
observing that he has generally noticed the peat underlain by a bed
of yellowish clay, very similar to the underclay of a coal-seam. Of
course, Mr. Dakyns is correct. I do not suppose any one would
expect to find any plants, except lichens, growing on a bare mass of
rock. The disintegration of the sandstone by atmospherical agencies,
and the decay of organic matter, will tend to form a soil in which
the heather can take root, and which may eventually assume the
appearance indicated by Mr. Dakyns. Taking the facts, however,
in the broad sense which I intended in the paper, we do find that
the heather grows only on the moorlands constituted of sand or
gritstone. I-could quote numerous instances where a sharp line can
be drawn between the sandstones and shales which form the surface
stratum, by the occurrence or otherwise of heather growing above it,
and I am sure it is unnecessary to remark that heather is not a
characteristic plant on limestones.

I did not intend that any geological beginner should imagine that
the present faces of the corresponding escarpments of the Yorkshire
and Lancashire grits were ever in contact, and I venture to think
that the purport of the paper will show that a constant change of
form is in progress, and that the rock escarpments are always subject
to the disintegrating action of water or frost. There can be little
doubt, also, that the original faces of the rocks would be borne
further and further from the centre of operations at the time that
the elevation took place, and that some part of the distance by which
the opposing escarpments are separated at present is due to this
cause.

I am afraid my reasons for considering that the drift or gravels in
the Valley of the Calder have been transported to their present
position during a period of submergence would occupy more space
than could be devoted to a letter, and with your kind permission I
_ will defer stating them to some future time.

Cuzvinepce, Hauirax, February 19th, 1879. James W. Davis.

192 Correspondence—Prof. Edward Hull.

THE DEVONIAN QUESTION.

Sir,—It is with much pleasure I have read Mr. Champernowne’s
communication on “The Devonian Question” (Gro. Macazine,
March, p. 125). Knowing how sedulously he has been studying
the Devonshire rocks for some years past, 1 regard his opinion as of
great value; and, therefore, when I find it to be confirmatory of the
views I ventured to suggest, J am strengthened in the belief that
they are (to use Mr. Champernowne’s own words) “in the main
legitimate deductions from the facts, and not mere theory.” The
evidence which Mr. Champernowne has adduced of the Silurian
affinities of the Foreland Sandstones is of much importance at the
present time—because it bears by a reflex process of reasoning on
the question of the age of the supposed representative beds—those
of the Glengarriff and Dingle series in the South of Ireland; a
question which is still sub judice.

As regards the suggested unconformity at the base of the Pickwell
Down Sandstone, it is in no way necessary to my argument; and
I am quite content to abandon the idea on the statements of two of
my friendly critics. But I would suggest to Mr. Champernowne,
in reference to the difficulty he feels regarding the S. Wales district
(Professor Geikie’s ‘“ Welsh Lake’), whether there may not be a
break between the “Pebbly beds and Conglomerate” and the
«‘ Cornstone ” series, etc., of Monmouthshire (‘“Siluria,” 4th edit.
p- 245), the former of which I cannot but regard as the equivalent
of the Pickwell Down Sandstone.

As Mr. Champernowne has anticipated my reply to Mr. Hall and
Mr. Ussher (though probably the latter has by this time discovered
that he had entirely misunderstood the purport of my paper), it is
scarcely necessary that I should add anything to his statements. I
will, therefore, only ask him in conclusion to weigh the evidence I
have adduced in the same number of the Gron~ogicaL MaAGaziInE,
p- 129, for believing that the Red Sandstone and Conglomerate of
the South of Ireland, which passes up into Griffith’s “‘ Yellow
Sandstone,” is really the representative of the true “Old Red
Sandstone” of other districts, and not merely the base of the Car-
boniferous Series. Epwarp Hutt.

Dus, 10th March, 1879.

MIiISCHiIDAN HOUS.

—~+.__—_

Fosstts FRoM THE Diamond Freips, Sourn Arrica.—Mr. George J. Lee, of
Kimberly, Griqua-land West, has forwarded, through His Excellency Colonel
Lanyon, the Governor of the Colony, to Sir Joseph D. Hooker, C.B., for presenta;
tion to the British Museum, part of a carbonized! branch of a Coniferous tree
(found 195 feet below the surface in Claim 196); a fragment of a fossil fish
(Paleoniscus) of Triassic age; and four casts of portions of the vertebral columns
and ribs, and a foot of small Dicynodont reptiles, preserved as hollow moulds, in
finely laminated and friable shale. Also numerous pyritised bodies, possibly replacing
some organism. The Reptilian remains have been submitted to Prof. Owen, C.B.,
who will notice them more fully hereafter. ‘The fossil wood will be examined by |
Mr. W. Carruthers, F.R.S.

1 Resembling charcoal in its mineral condition.

THE

GEOLOGICAL MAGAZINE.

NEW SERIES. DECADE II. VOL. VI.

No. V.—MAY, 1879.

(Disa MCIN (Ya, Sy any Galas

ed

T.—On tHe Discovery oF A SPECIES OF JGUANODON IN THE
KIMMERIDGE CLAY NEAR OXFORD; AND A NOTICE OF A VERY
FosstLtirERous BanD OF THE SHOTOVER SANDS.

By Prof. Prestwicu, M.A., F.R.S., V.P.G.S., ete.

N interesting discovery has just been made in this district. A
i short time since some workmen from Cumnor brought to the
Museum a basketful of bones which they said they had found in
digging the clay at the brick works, now in course of large exten-
sion, at Cumnor Hurst, three miles west of Oxford. On cleaning
the specimens, the characteristic vertebre and teeth of Iquanodon
were recognized. A large number of the vertebre are entire, but
the jaw is in fragments, with many teeth, however, in position. The
skull is wanting, except a small fragment. One of the feet, with
the claws, is almost complete. The larger bones are almost all
broken, but we hope to be able to reunite many of the fragments,
as there is reason to believe that the skeleton was entire or nearly so.
The smaller bones and the extremities of the larger bones are in a
beautiful state of preservation. It is a smaller animal than the
Wealden Iguanodon Mantelli, but whether owing to age or difference
of species remains to be determined. It seems to me to indicate a
different species, with smaller and more delicately-formed bones.!

On visiting the place, I found that the specimens had been met with
in driving a tramway into the side of the hill, where new pits are
being opened out. Consequently a cutting only a few feet wide was
made, and which, at the spot where the bones were found, was about
seven feet deep. The clay was bare at the top, though a little dis-
turbed. ‘The bones were found at a depth of about four feet, in a
thin seam, two or three inches thick, of yellow sandy clay, and
they had extended part of the way across the cutting. A further
portion of the skeleton may therefore remain in the undisturbed
beds on one side. There is reason to believe that some portion of
the bones were carted away, but I hope these may yet be traced ;
while, with the obliging assistance of the manager of the works, a
watch will be kept on the clay at the sides when it has to be removed.

1 The Scelidosaurus Harrisoni, Owen, from the Lias of Lyme Regis, is closely
allied to Iguanodon, but is much smaller; so also is the Acanthopholis horridus,
Huxley, from the Grey Chalk of Dover.

DECADE II.—VOL. VI.—NO. V.. 13

194 Prof. Prestwich—Discovery of Iguanodon in Kimmeridge Clay.

The thin sandy seam, being very conspicuous in the dark clay,
can be traced on the side of the cutting (which deepens gradually as
it proceeds further into the side of the hill) in a position nearly
horizontal but slightly waved, until it is lost under about ten feet of
the clay. In the part over the bone seam, where the men are now
digging, I found a few perfectly characteristic shells of the Kimmer-
idge Clay, such as Ewxogyra virgula, Cardium striatulum, Thracia
depressa, Ammonites biplex, together with Lima pectiniformis, and
Serpule. A pit a few yards further on showed an additional six feet
of clay, overlaid by the ferruginous sands, the equivalent of the
Shotover beds, but without any organic remains.

There can be no doubt, therefore, of the position of this remark-
able fossil, which shows that the Iguanodon, or some closely allied
Dinosaur, was not confined to the Lower Cretaceous and Wealden
beds, but existed during the period of the Kimmeridge Clay.
Nothing else besides a few fragments of drifted wood indicates the
neighbourhood of dry land, unless the thinning off of this formation
to less than 100 feet in this district be due to the approach to an
old shore-line, and not to the removal of higher beds by denudation.
With the later setting in of the Shotover sands, with their shells
(Unio, Paludina, Cyrena) and plants (ferns and numerous remains of
reeds and grasses), we pass into well-marked land and freshwater
conditions, but at Shotover the sands of the Portland series inter-
vene between the two. It is probable, however, that the same old
land surface, indicated by the latter, was, during the Kimmeridge
period. only a short distance further off, and that its gradual rise
finally displaced the Portland sea in the Oxford area. We might
therefore have had continuity of land conditions and consequently of
the land fauna from the Kimmeridge to the Lower Greensand period.

I may take this opportunity to mention, for the information of any
geologists who may be visiting the classical district of Shotover Hill,
that the above-named freshwater mollusca, which are so rare in
the old pits above Headington at the west.end of the hill, occur
abundantly at the east end of the hill near Wheatley. About three
years since, a pit was opened for the extraction of yellow ochre and
iron ore, some 200 or 300 yards west of Wheatley windmill. It
was twelve feet deep, and consisted of beds of rubbly iron sandstone,
impure limonite, and yellow ochre. At the depth of about seven or
eight feet a thin seam of iron sandstone, at the base of the main bed,
six to eight inches thick, was literally full of casts and impressions of »
these shells—chiefly Cyrena and Paludina; while another thin band ~
was covered with ripple markings and matted with indeterminable
plant impressions. Soon afterwards, however, owing to the fall
in the value of iron and the other products, the pit was, unfortu-
nately for geologists, closed, and has since been filled in; but there
still remains on the opposite side of the lane an old pit in which the
same shelly seam may be found, though not so well developed and
continuous. The only addition to the fauna of these Shotover Sands
made since the publication of Prof. Phillips’ “ Geology of the Neigh-

Dr. Lycett—On Trigonia Elise, from the Greensand. 195

bourhood of Oxford,” etc., is by Prof. Rupert Jones, F.R.S., who found
inasmall slab of the Ironstone a few bivalved Entomostraca, which he
refers to a species of Candona, and four species of Cypridea. They
are described in the Grou. Mac., 1878, Decade II. Vol. V. pp. 100
and 277. They are Wealden species.

P.S.—Since writing the above, I have taken a few of the remains
up to the British Museum, where they have been submitted to ex-
amination and comparison by Mr. William Davies, F.G.S., who has
kindly pointed out to me that there are, among these, portions of
jaws with successional teeth; dorsal, sacral, and caudal vertebra,
scapula, humeri, pelvic bones, portions of femora, fibule, astragalus,
phalanges; and other bones not yet determined. Mr. Davies has no
doubt that the remains are those of a young Iguanodon, the epiphyses
of the limb-bones being unanchylosed.—J.P.

If.—On Teiconia Etis%z#—Cornet AnD Briart.!
By Dr. Lycert.

HE Whetstones (Meule) of Bracquegnies, Belgium, are upon the _
same geological horizon (zone of Ammonites inflatus, Sow.) and

are identical lithologically with the well-known Whetstones of
Blackdown ; like to the latter deposits they are characterized by the
prevalence of Trigonie which are allied to, but are for the most part
not strictly identical with the species of Devonshire. The Trigonia
Hlisg, Cornet and Briart, herewith figured, is allied to and equals in

Trigonia Elise, Cornet and Briart.—Greensand, Bracquegnies, Belgium.

i {ape
sah

pobrite

Fic. 1. Side view. Fic. 2. Umbonal view.

abundance the well-known T. aliformis, Park., of Blackdown, and is
the Belgian representative of that group of Trigonig. Like the
Devon species it is remarkable for the great length of the hinge-
border, and the produced, attenuated posterior side, with its short
siphonal border; but is without the anteal inflation of the valves
and the peculiarities of the eoste which distinguish T. aliformis,
Park. For the latter, see Monograph of British Fossil Trigoniz,
Palzontographical Society, 1877, pl. 28, figs. 5, 5a. :
Another abundant Trigonia at Bracquegnies is the T. dedalea of
Cornet and Briart. This differs from the well-known common

1 Cornet and Briart, Description de la Meule de Bracquegnies, Mémoires
Couronnes et Mem. des savant Etrangers, Acad. Royal de Belgique, t. xxxiv. 1868.

196 Dr. H. Woodward—On Eurypterus Scouleri, Hibbert.

Blackdown form bearing the same name, but is identical with a
large variety of that species which has occurred rarely in the Whet-
stones of Little Haldon, figured as T. dedalea, var. confusa, in the
Monograph above quoted, pl. 23, fig. 1. Fine examples of the
latter form are exhibited upon the tablets of the British Museum as
T. dedalea, Park. Other Trigonie occur in the Belgian beds, but
the two here alluded to are the most abundant and characteristic
species.

III.—Norers on Patmozoro Crustacea.
Euryerervs ScouLeri, HiBBErt.
By Henry Woopwarp, LL.D., F.R.S., etc.
(PLATE YV.)
MONG the many relics of Paleozoic life-forms which the
Carboniferous formation has yielded to the palontologist,
none is more remarkable than ‘“Scouler’s Hidothea,” or the Hury-
pterus Scouleri of Hibbert.

This fossil Crustacean is of itself sufficiently bizarre in aspect to
arrest the notice of even the most casual observer, whilst its geo-
logical history is equally curious.

The Carboniferous epoch, however, is rich in interest; for it is,
above all others, that, at which the ideal boundary-line for the
Biologist should be drawn, which marks more clearly than any
other the incoming of the recent, and the outgoing of the extinct
faunas of our globe.

As we scan the record of these old Carboniferous rocks, so rich in
organic remains, we seem to stand on some lofty beacon-hill, whence |
we can cast our glance upwards and downwards along the stream
of Time.

Beneath our feet lie buried the last representatives of those
aboriginal races, now quite extinct, the Trilobita and the Eurypterida,
whose ancient hosts peopled the seas of the Devonian and Silurian
ages, and reached far away into the Cambrian epoch. Beside them
lie the earliest representatives known of our modern Decapoda,
Stomapoda, and Isopoda, then but few and feeble, but now the
dominant races of the Crustacean class.

Eurypterus Scouleri is the last representative of the extinct Eury-
pterida—probably the only order in the class Crustacea which have
really died out. For the modification necessary to convert the
extinct order Trilobita into its modern representative order, the
Tsopoda, seems a far lesser metamorphosis of organs than that needed
to transform the aquatic branchiated order Eurypterida into the .
terrestrial pulmonated Arachnida (Scorpionide) ; yet not only these,
but many other similar modifications, resulting in the extinction of
the older type and the extension of the newer form, have doubtless
taken place since the Carboniferous epoch.

This last species of Hurypterus, of which our plate affords an at-
tempted restoration, has been fully described, so far as the materials
existing admitted, in a Monograph on the Merostomata, by the writer.

(See Pal. Soc. Mons. 1866-78. Part IV. 1872, pp. 133-189.)

GEOL. MAG. 1879. New SERIES. Dec. II. Vou. VI. Pl. V.

NSS
ss

Hurypterus Scoulert, Hibbert, 1836.

(Restored.)
Lower Carboniferous Freshwater Limestone.
KIRKTON, NEAR BATHGATE, WEST LOTHIAN.

Fig. 1. Dorsal view. Fig. 2. Side view.

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Dr. H. Woodward—On Eurypterus Scouleri, Hibbert. 197

Fic. 3. Euryprerus Scoutert, Hibbert, 1836.
(Under side restored.)

Fig. 2. Antenne. 3. Mandibles. 4. Ist Maxille. 5. 2nd Maxille.
6. Maxillipeds; serving in this order as the chief locomotory organs. m. The
metastoma or post-oral plate. 7. The thoracic plate or operculum, covering the
branchie. Figs. i-vii. The head-shield.! Figs. viii. and ix. are concealed by
the operculum. Figs. x.—xix. Thoracico-abdominal somites destitute of any
appendages. Fig. xx. The telson; or tail-spine. For dorsal view, see Pl. V.

1 As the antennules in the Eurypterida are, theoretically, considered to be aborted, the head-
shield would be really composed of the 7 cephalic and the Ist thoracic somites; but the Roman
numerals only indicate the number of somites coalesced in the head-shield which are actually
represented by paired appendages, reckoning the optic segment as the first, and the thoracic
plate or operculum as the seventh,

198 Dr. H. Woodward—On Eurypterus Scouleri, Hibbert.

It was pointed out at that time (1872) that this singular species:

“presents many anomalies and considerable divergence from the

type-form of Eurypterus remipes,” De Kay, from the U. Silurian of

New York.

“Tn the curious form of the eyes, elevated above the carapace,
upon a round base or peduncle, and in the singular bifurcating
median ridges, or crests between the eyes, we are reminded of
Stylonurus Scoticus; but the rounded, almost hemispherical head-
shield, finds its analogue alone in the carapace of the modern
Limulus. In point of size, HE. Scouleré claims a place among the
largest of the Meroestomata.” (op. cit. p. 138.) :

Our restoration is based upon an acquaintance with two separate
heads—one of which is almost completely perfect, and has the two
most anterior segments attached to it; and a body, made up of the
eight hindmost body-rings, all duly united and showing both upper
‘and lower surface entire, and preserved in the round. Of the mouth
organs we only know the basal joints imperfectly, from a specimen
of a head in Mr. James Powrie’s collection, which we were permitted
to develope upon the under side; but from the entire absence of
appendages to the body-segments, we are justified in concluding that
its mouth organs also subserved the office of locomotory appendages,
as in the rest of this singular order.

From the form of its body there can be little doubt that its habit
was aquatic and not terrestrial, for we have detected the thoracic
plate which must have covered the branchiz, and there is no evidence
of trachzeal openings in the body-segments. But, on the other hand,
there seems good geological evidence for concluding that Hurypterus
Scoulert was an inhabitant of freshwater.

The following description of the locality whence it was derived is
most suggestive :—

The specimens are from a quarry at Kirkton, near Bathgate, West
Lothian, which, it would appear, is not in the Coal-measures proper,
but in the Carboniferous Limestone. The bed is described in a
Memoir by Dr. Hibbert, upon certain freshwater limestones (Trans.
Roy. Soc. Edinb., vol. xiii. 1836).

‘“‘ A mile or two to the east of Bathgate, at Kirkton, we find that a
very considerable outbreak of Greenstone has occurred. Close to it
on the west appears the limestone of Kirkton. By this contiguity,
we are assured that the limestone must have been elaborated within
_ the immediate sphere and influence of an extensive volcanic eruption.
The consequence has been that one of the most unique formations of
which Great Britain can boast has been formed, indicative of thermal
waters, belonging to the Carboniferous epoch.

“A decidedly freshwater formation is thus exposed, which is
characterized by the absence of all marine shells, corallines, etc., and
the presence of the well-known vegetable-remains of the Coal forma-
tion.

“ But the remarkable circumstance in this limestone is its minera-
logical character, indicative of the very powerful chemical action
under which it was elaborated. This chemical action appears to

Prof. T. G. Bonney—On Dana’s Classification of Rocks. 199

have been so energetic, as to have caused such miscellaneous earthy
matters as are found to enter into the composition of an impure
limestone, like that of Kirkton, to separate into laminz, and to
assume a sort of striped disposition (rubané as it is also named),
resembling what I have occasionally noticed in Auvergne, where
Tertiary strata have come into contact with volcanic rocks. The
strata, for instance, of Kirkton quarry, are composed of distinct and
alternating thin laminz, some of them being of remarkable tenuity,
variously consisting either of pure calcareous matter, of translucent
silex, resembling common flint, or of a mixed argillaceous substance,
which approaches to the character of porcellanite, or of ferruginous,
or even of bituminous layers, originating probably from vegetable
matter. |

“Upon one of these very thin aluminous folia, which I have
compared to porcellanite, I observed the impression of a Fern,
apparently of a Pecopteris, which was delineated upon it like a
painting upon porcelain.”

This fern, which has been named Sphenopteris affinis by Lindley,
is associated with stems, leaves, and fruits of Lepidodendron,
Calamites, and many other plants. Entomostraca are also abundant.

Our restoration of the appendages made (in 1872) after the
American species, H. remipes, figured by Prof. James Hall, may
possibly need modification when more materials for their better
reconstruction are available. Meantime we venture to draw the
attention of Scottish geologists to this very interesting and classical
locality in the hope that new light may be afforded thereby as to the
nature and affinities of this singular Freshwater Crustacean.

IV.—On Proressor Dana’s CLASSIFICATION OF Rocks.
By Professor T. G. Bonnry, M.A., F.R.S.

HE two important papers by this accomplished veteran of
science, which have appeared in the American Journal of
Science (vol. xvi. November and December, 1878) [noticed in this
present number of the GroLtogican Macazine pp. 222-225], though,
as might be expected, of the highest value, are in one or two
respects, as it seems to me, open to question. Professor Dana
approaches the subject as a chemical mineralogist: I venture to
criticize as a field geologist who checks his conclusions by using the
microscope.

There is, however, one point on which I would first venture to
express my hearty concurrence with his remarks—namely, upon the
impossibility of drawing hard and fast lines of distinction between
rocks belonging to different geological ages. Lapse of time of course
will bring about certain mineralogical changes, such as the forma-
tion of epidote, viridite, chloritic minerals, and various carbonates,
or of hornblende in augitic rocks; or again, under certain circum-
stances, the production of tourmaline, lithia mica, etc. ‘ In short, the
present condition of a rock may be said to be the result of two inde-
pendent variables—external agents and time—and (within limits)
the same result may come from either of these being large in com-

200 Prof. T. G. Bonney—On Dana’s Classification of Rocks.

parison with the other. For instance, I have examined rhyolites,
felsites, basalts and serpentines of very different geological ages, and
have found it impossible to draw any important lines of distinction
between them.

Still, while granting this, there may be advantages in retaining
such a term as diabase, though we admit the rock’s former identity
with dolerite, and cannot draw a hard and fast line between the two.
The latter difficulty does not meet us here only in Lithology, and it
is convenient to have a term to denote varieties which have under-
gone marked alteration. Some geologists, I have observed, seem to
forget that igneous rocks, as well as sedimentary, have their meta-
morphic representatives, and as a rule text-books do not sufficiently
call the student’s attention to this point.

With reference to Professor Dana’s remarks on trachyte and
felsite, it seems to me that, while admitting the chemical identity
and common origin of both, we may conveniently take the presence
of a glassy base as characteristic of the one, and of a micro- or
crypto-crystalline ground-mass of the other. It is true that the latter
may have resulted from subsequent devitrification, and a rock once
glassy may have become cryptocrystalline. In that case, however,
where we are convinced of the fact, we may either call the rock a
devitrified rhyolite, and place it among the metamorphosed igneous
division, or coin a single name to express the fact of change.

Professor Dana criticizes the use of the term ‘gabbro.’ It is quite
true that there has been some uncertainty in this, and that the Italian
petrologists call ‘granitone’ the rock to which the Germans apply the
name gabbro. It is also true that gabbro is closely allied to dolerite,
and that diallage is only a variety of augite; still, as this gabbro is a
rock of a very definite appearance in the field, and seems to be of
rather a different habit from dolerite,! which shades off through
anamesite into the finer crystalline basalts (I think a revision of
terminology needed here), the name appears to be useful. As regards
euphotide and the so-called saussurite, I cannot altogether agree with
Prof. Dana. I have examined a good deal of this rock in the field
and microscopically, and have no doubt the mineral is only an altera-
tion product from labradorite or anorthite, and the rock simply an
altered gabbro. In the field (and under the microscope) the felspar
may be seen gradually altering into saussurite, and the pyroxenic
constituent into some form of hornblende. It seems, then, to me
that gabbro may conveniently be retained for the name of a rock
closely related to dolerite, and euphotide applied to the metamor-
phosed variety.

Professor Dana is very severe on geologists (especially micro-
scopists) for their use of the term plagioclase. I venture to think
we have a defence. Doubtless plagioclase is only a synonym for
triclinic felspar, but I think that its correspondence in form with
orthoclase renders it a more convenient term. We do not regard a

1 | have never seen gabbro except under circumstances which suggested deep-seated
intrusion ; it seems to be the analogue of granite.

Prof. T. G. Bonney—On Dana’s Classification of Rocks. 201

rock as perfectly defined when we say it consists of “ plagioclase
and augite,” and so forth; but we not seldom find that we must be
satisfied with this; because even Professor Dana himself could give
us no better definition. Let us grant that there be a typical albite,
oligoclase, labradorite, and anorthite ; that there may be rocks in
which each one of these felspars alone occurs ; still 1 maintain that
they have a frequent habit of intergrowth, as in perthite, bytownite,
microcline with albite, etc., and that in many cases they thus occur
in rocks. Examination also of the analyses given by Professor
Dana himself! shows that even among the type felspars there is
great variety; and that when a felspar is a rock constituent we have
no security against variation or intermixture of species; while in
many cases the felspars occurring in rocks are so minute that it
would be impossible for the chemist to separate them for analysis.
Analysis of the rock as a whole often fails to give the desired
response, because the chemical constituents which it reveals may
enter into the composition of more than one of the minerals already
known to be present; so that the investigator is in the position of a
mathematician who is asked to solve an indeterminate equation.
Under certain circumstances we can, indeed, feel sure that the
plagioclase is either albite or oligoclase or both, under others that it
is labradorite or anorthite or both; and it would perhaps be expe-
dient to add after the term “doubtless a or b or a mixture of them,”
but we may be pardoned for avoiding the monotony of this constant
repetition, and leaving this to be supplied by the intelligent reader.

Our position then, as workers with the microscope, is that while
thankfully acknowledging the aid of chemical analysis, we do not
feel bound to spend much time or money in determining the precise
character of the felspar in every case, because we know from experi-
ence that not seldom the oracle gives an ambiguous response, or at
best leaves us very nearly where it found us.

Accordingly we use the term plagioclase” (with the understood
limitation) as the most definite permitted by the present state of
science. It may be that ultimately we shall be able to form a rock
group correspondent with each of the species of plagioclastic felspar ;
but I doubt it, and expect that we shall not do more than separate
those containing albite and oligoclase from those containing labra-
dorite and anorthite; though even then it is not impossible that the
second and third of these may sometimes be associated.

My most essential difference, however, from Professor Dana relates
to his proposed classification of rocks. In this he passes over the
question of the origin of the rock, by adopting a purely chemical or
mineralogical basis, and grouping metamorphic clastic with true igne-
ous rocks. He also justifies this method of classification by pointing
out that true massive crystalline rocks need not necessarily be igneous,

1 A System of Mineralogy, pp. 337-361 (ed. 1868).

2 It is no doubt inconvenient that the species microcline has been discovered since
the adoption of the term plagioclase; but we may avoid this difficulty by agreeing
that the term plagioclase shall be used as a symbol for the group of soda and lime

felspars—the character of the other species being so exceptional, and its relations to
orthoclase being in most respects close.

202 Prof. T. G. Bonney—On Dana’s Classification of Rocks.

and schistose rocks not necessarily metamorphic clastic. Within’
limits there is truth in this statement; but the qualification is all-
important. I venture then to inquire whether Professor Dana has
carefully studied the microseopic structure of these two groups and
found that there is no difference in this respect between massive
igneous and massive metamorphic clastic rocks, or between schistose
igneous and schistose clastic rocks. This is a question to the study
of which I have devoted much time both in the field and with the
microscope; and mostly with this result—that in the former case
not seldom the distinction was plain enough when sufficient pains
were taken in looking for it; in the latter it was usually very marked.
Hence, notwithstanding the weight of Professor Dana’s authority, I
venture to protest against any system of classification which sets at:
naught the distinction between a sedimentary and an igneous rock.
There may be cases where metamorphism has been carried so far that
the distinctive characters of the former rock are lost, but the
evidence in favour of this is certainly far less satisfactory than it is
commonly asserted to be, and (in the present state of our know-
ledge) to assume that such cases exist will, I think, encourage
sloth in research and be a backward rather than a forward step in
science.

There is also, from his own point of view, another serious objection
to Professor Dana’s classification. He draws a very marked dis-
tinction between the potash-felspar series (including leucite) and the
soda-felspar (including nepheline). But while not denying the
utility of this, in part, we must remember that there are few potash-
felspar rocks in which there is not some soda-felspar (including
oligoclase), and that cases are not uncommon in which the one about
equals the other in quantity. Hven Professor Dana, by his remark
on the nepheline rocks (phonolites, etc.), virtually admits that the
distinction can hardly be maintained ; and further, what are we to say
of the association of leucite and nepheline, and of the occurrence of
these minerals with both orthoclastic and plagioclastic felspars ?
Again in Professor Dana’s classification we have lherzolite grouped
with eclogite, and serpentine with chlorite schist; simply because
they contain no felspar, notwithstanding their great mineralogical and
chemical differences.”

1 It is not seldom hard to say (even after chemical analysis) whether a rock
should be called a syenite or a diorite, a minette or a kersantite.

2 Analysis of eclogite (garnet and omphacite, with quartz, disthene and mica) from
Eppenreuth. Si 02=57:10 Al, 03=11:66 Fe, O,=2°84 FeO=3:22 MnO=0-°31
Mg 0=637 Ca O=13'80 K, O=0°81 Na, O=2'21 H2 O=0°54. Analysis of
lherzolite (olivine, enstatite and diopside with picotite) from Kalohelmen. $i O2=37-42
Al, O,=0:°10 Mg O=48:22 Fe O=888 MnO=0°17 NiO=0:23 H, O=0°71.
(Von Lasaulx, Elem. der Petrog.) Analysis of Serpentine (from Cornwall). Si 0,=
38°50 Al, O3=1:02 Mg O=36°40 CaO =1:97 Fe, 0;=4:66 Fe 0 =3-31 NiO =0°59
Hz O=12°35 Fe S=0'41. Undecomposed residue =1:37. (Q.J.G.S. xxxiii. 925).
Analyses of Chlorite schist variable; these are two given by Zirkel (Petrog.
i. 311) (1) Si02=31-54 Al,0,=544 Fe,03=10:18 Mg 0=41:54 H,0=9°32
(2) Si 0,=4208 Al,O3=3°57 Fe 0=26'85 Mn O=0-59 Ca O=1:04 MgO=
17:10 Hz O=11:24. In such a grouping, even chemistry, as it seems to me, is
fairly thrown overboard.

W. A. E. Ussher—Post-Tertiary Geology of Cornwall. 203

In short, as it seems to me, the classification of rocks must not be
attempted by relying on evidence obtained in the field, with the micro-
scope, or from the laboratory alone. Sometimes, it is true, the first
will teach all that it is really important to know; commonly, however,
we shall have to appeal to the second source of information, and not
seldom we shall obtain from the third the solution of a difficulty
which the other methods have failed to answer; but this last is
rather a court of appeal than a court of first instance, and one which
will not so much reverse the judgments of its predecessor as decide
points which had been of necessity reserved. Or, to put it other-
wise, and perhaps more accurately, the chemist is called in, like an
expert, to settle certain questions, but there are many others with
which he is not competent to deal. Professor Dana, as I venture
to think, notwithstanding his own extensive learning as a geologist,
places too much reliance on chemical evidence; and thus, while
aiding in the destruction of certain idols which have a detrimental
effect in Science, has set up others in their stead which would be
as hurtful to its progress.

V.—Post-Trrtiary GEOLOGY oF CoRNWALL.!
By W. A. E. Ussusr, F.G.S.
' (Part III.—Continued.)

Tur RaiseD Bracues AND AssoctaTED Dsposits oF THE CoRNISH
Coast.

15. St. Ives.

a. On the east of Carrack Olu Point, a bed of pebbles, 1 foot thick,
is shown under Head, at from 2 to 5 feet above high water. The
greenstone composing the Point is capped by a Head of yellowish-
brown loam with angular fragments of greenstone.

b. In the bay east of the above, near the north part of St. Ives,
the section is as follows :—

Head, with large angular fragments ... ... ... -. «. Off. Oin.

Impersistent strip of yellowish-brown loam.

Head, loam with a tew subangular fragments, and boulders
tomjardythebasel sis.) Wissel Mal: ou Nesstilidesy biswiod fant .2ech iSite, aa,0im.

Olive and yellowish sand with occasional pebbles... ... ... 10ft. Oin.

At base about 5 feet above high water; resting upon dark bluish
slaty grit with numerous joints.

c. On the north part of St. Ives Island, the greenstone is capped
by a Head of angular greenstone fragments from 10 to 16 feet in
thickness.

d. Mr. Whitley (Journ. R. Inst. Corn. No. 11, p. 184) gives the
following section of the raised beach in Porthgwidden Cove, St. Ives :

Greenstone soil, upon Head of large angular blocks of hornblendic \
: 5 2 About
rock. Fine sand and loam ; upon pebbles of hornblendic rock, { 56 foot

quartz, granite, and a few worn flints, mixed with sand, and( 44-4
containing layers of fine brown sand coo eco cad ga0” 6c0 ;

The base of the deposit is given as 5 feet above high water.

1 Continued from the April Number, p. 172.

204 W.A. HE. Ussher—Post-Tertiary Geology of Cornwall.

16. Gwythian and Godrevy.

a. Near the southern end of Black Cliffs the slates are capped by
a Head of brown clay with angular stones, and a few quartz pebbles
at its base.

b. South of Ceres Rock, greenish grey slates are capped by a Head
of greenish grey clay, probably resulting from their decomposition.

c. West of Gwythian ; cliff-section—

ROSSOW

q UNICSISIR
WIAD Le
a 2

\

5 ag A eae Nexo
Er wOeCO VG 6 5 SS
> \
OM tes inhe:

So o .c

—_

<—— (OnE
°) SABES eoSe
of-= ———— ————
DUET TL fa:
MIATA]
Fie. 3.—Near Gwythian. Vertical scale 1 inch = 12 feet.
Lo ABO an BEI! Go cody cop sg 000 005, 0G) c0o, coc. cad Ah Oia,
2. Brownish loam with angular slate fragments ... ... ... ft. in.
3. Agglomerate of angular slate and quartz stones in a con-
solidated matrix of small angular pieces of slate ... ... 3ft. Oin.
4. Fine brownish sand, consolidated in places, containing a
few pebbles abl Nebel, Coeet Gas (eROS eae eee sad ce enOits One
5. Three beds of pebbles and subangular stones of slate and

quartz, with occasional pieces of flint in the lower bed.
The beds are 4in., 1ft., and 2ft. in thickness, respectively 3ft. 4in.

d. Near the above, the Head consists of grey loam with angular
slate stones of small and average size. The pebble deposits occur in
two layers, separated by a seam of brown sand. The base of the
gravel is about 5ft. above high water.

The following observations of the Cliffs of Godrevy commence at
a point about three-quarters of a mile to the south of Godrevy Island.

e. The section, partially obscured by sandy debris, consists of —

Head, yellowish and grey loam with small angular stones, and
occasional large angular quartz fragments, resting unevenly oe to 20ft
it.

upon——tinexolive) brown sand gis -mieee tee ene ace aanece
Coarse grey sand with pebbles and subangular fragments of

slate and quartz, the former sometimes large ... ... ... oft.
Consolidated coarse blackish sand with small pebbles and
subangular fragments, and a few large pebbles... ... ... variable.

At base 5 to 8 feet above high water.

jf. The pebble band is stained blackish, it is from 6 inches to 1 ft.
thick, and about 6 feet above high water. At this point angular and
subangular fragments, some large, are associated with the pebbles in
a coarse impure sand matrix.

g. ‘Two beds of coarse blackish and reddish-brown consolidated
sand, containing pebbles, etc., of slate and quartz, 3 feet in maximum
thickness, and 6 feet above high water at their base, are capped by

W. A. E. Ussher—Post-Tertiary Geology of Cornwall. 205

angular Head. The upper bed forms the roof of a cavern in the
slates. (Fig. 4.)

SA IO ay,

uy avs we
Se

~ a 220 S = Raised Beach.

A AM

Fic. 4.—Godrevy. Vertical scale—1 inch = 2¢ feet.

h. A portion of the consolidated raised beach is visible on the fore-
shore resting upon two bosses of a waterworn slate reef. The denu-
dation of the reef has scarcely affected the unsupported part of de
under surface of the beach. (Fig. 5.)

SSS

Fie. 5.—Godrevy Beach.
Portion of Raised Beach resting on bosses of Slate isolated from the main cliff.

i. Toward Godrevy Island the beach consists of coarse blackish
consolidated sand with pebbles, more gravelly at the base, 4 feet thick,
under thick beds of consolidated buff and grey sand with pebbles
disseminated through the lower parts.

j- Dr. Paris (T. R. G.S. Corn. vol. i. p. 7). noticed a mass of sand
near Godrevy Island, containing whole shells and slate fragments,
12 to 20 feet thick, and 100 feet in length.

k. Dr. Boase (T. R. G.S. Corn. vol. iv. p. 469) described a bed of
pebbles above high water, at Godrevy Point and around Fistral Bay,
overlain by a bed of testaceous sand ; under ‘transported but un-
altered debris,” in one place (op. cit. p. 809) described as 20 feet of
ferruginous clay with angular fragments (local), thinning out land-
wards as the ground rises.

1. Mr. Whitley (Journ. R. Inst. Corn. No. 11, p. 184) gives a sec-
tion of the cliffs under Godrevy Farm from top to base.

Brown loam soil... Secor SOl a LOmMonne

Clay and loam with numerous ‘angular fragments ‘of quartz... 6ft. to 16ft.
Sandy loam mixed with siliceous sand, and portions of a bed

206 W.A.E. Ussher—Post-Tertiary Geology of Cornwall.

of contorted slate (believed by Mr. ianiley to have been
pressed into the bed by ice). fs
Red and white siliceous sand, of quartz grains "partially younded.
Boulders of blue grit, granite, quartz, ‘vesicular trap (as at
St. Minver).
Slate and a few worn flints in sand cemented by the oxides
of iron and manganese.

m. De la Beche notices (Report, p. 426) the old dunes of consoli-
dated sand, between Gwythian and Godrevy Head, which he distin-
guished from the underlying raised beach.

17. Observations of the Fistral Bay Cliffs made here and there
proceeding northward.

a. South end of the Bay (section obscured in places). Coarse brown
semi-consolidated sand, with planes resembling bedding and false
bedding, containing occasional lines of small angular slate and quartz
fragments, 20 feet thick, seems to underlie Head, shown in a reced-
ing part of the cliff. At the base of this old blown sand, a trace of
blackish coarse consolidated sand binding pebbles of slate and quartz
is visible at from 4 to 5 feet above high water.

b. The basement beds consist of gravel of small quartz pebbles,
with fair-sized quartz and slate pebbles, and large subangular slate
fragments in blackish sand, 1 foot to 18 inches thick, with few peb-
bles and of a brick-red colour in places ; overlain by fine blackish and
reddish brown sand with a few pebbles through it, from 2 to 3 feet
in thickness.

c. The basement beds are represented by two beds of small quartz
and slate pebbles and subangular stones, 6 inches and from 6 inches
to a foot thick, respectively, separated by 18 inches of coarse blackish
sand.

d. Coarse consolidated sand of slate and quartz and comminuted
shells rests on a pebble bed 2 feet thick, and at base 5 feet above
high water. The pebbles are of slate, quartz, and occasionally flint ;
quartz predominates ; the matrix is coarse grey sand.

e. Cliff-section toward the north of the Bay—

Recent blown sand ... boo") Geb), can) con. Gully | Oning
Sandy soil with angular fragments OE lated yk eel eee nosy
Buff loam with angular stones and boulders... ... ... .. 2. Oin,
Buffsand ... ... lft. Qin.
Coarse and fine gravel of quartz, dark srey sri slate and
occasionally flint ... ... .. 4ft. in.

f. Near the above old blown sand is shown consisting of brown
consolidated sand in laminz about one-eighth of an inch | thick, con-
taining pebbles for 4 feet upwards from its base, which is about 10
feet above high water.

g. About 100 yards from the above a trace of consolidated sand
binds pebbles at about a foot above high water. Old consolidated
blown sand is shown in the cliff above; overlain by Head, capped
by recent blown sand. ‘Two whole shells of Patella were found
near the base of the old blown sand, which forms a tough, bedded
rock, hardening on exposure to the weather.

h. Dr. Paris (i. R. G. 8. Corn. vol. i. p. 7) described the old beaches
of Fistral Bay and New Quay as a horizontal bed of pebbles, 10 to

W. A. E. Ussher—Post-Tertiary Geology of Cornwall. 207

12 feet thick, containing whole shells and slate fragments cemented in
sand, resting on slates, and supporting immense heaps of drifted sand.

i. De la Beche (Report, p. 427) describes the Fistral raised beach as
rolled pebbles, often large, mixed with smaller gravel and sand,
overlain by alternations of fine gravel and sand (the layers being
unequally consolidated), capped by sand, becoming mingled with
rock fragments, near the extremity of the dunes on the north and
south.

j. Mr. Pattison (T. R. G.S. Corn. vol. vii. p. 50) mentions the inter-
section of the Fistral raised beach by a lead lode, in the middle of
the Bay. He describes the present beach as ‘fine sand and an
abundance of shells; it exhibits no pebbles save those derived from
the ancient beach.”

18. New Quay.

a. On the east side of Towan Head, a trace of black consolidated
sand with pebbles is visible at about 6 feet above high water.

b. On the west of New Quay Pier, the section consists of coarse
yellowish-brown consolidated sand, chiefly made up of comminuted
shells, with a few shells of Helix, containing angular, subangular,
and rounded stones and boulders of quartz and slate (a granitoid
fragment was found) at the base; upon coarser sand with well-
rounded fragments resting on a narrow rocky platform 6 feet above
high-water mark.

c. Dr. Boase (T. R. G. 8. Corn. vol. iv. p. 259) noticed a bed of
shelly sandstone, on the north of New Quay signal station, contain-
ing fewer shells than at Fistral Bay ; the lower part, just above high-
water mark, being consolidated into a conglomerate.

d. De la Beche (Report, p. 427) gives a section on the east of
Look-Out Hill, New Quay, of an ancient beach of rounded slate
pebbles agglutinated by consolidated sand, some feet above the sea-
level; capped by layers of sand of comminuted sea-shells con-
solidated in the lower parts; under a Head of angular fragments
from the rocks of the hill above.

19. Between New Quay and Padstow.

a. A thin capping of Head visible on part of Trevelga Head Island.

b. To the west of Tregurrian, Head of angular and subangular
slate and quartz stones is shown in the cliffs, under greyish sandy soil.

c. West of Trenance (N. of Mawgan Porth) the Head consists of
brown loamy clay with large quartz boulders, and small slate and
grit stones.

d. At the north end of Treyarnon Bay the low cliffs are capped
by 6 inches of angular quartz and slate stones, under brown clay,
one foot thick.

e. The cliffs bounding Constantine Bay, for about three-quarters
of a mile, seldom exceed 7 feet in height. Opposite Constantine
Island the cliff is composed of—

Blown sand with a layer of broken Mytili, and whole Patella,
finer in the lower part, and containing angular pieces of
slate, and fragments of shells, as above rae aie a A a hsy de Oe
upon—coarse quartzose sand with rounded grains ... ... Lft. to 2ft.
resting on slates at 6 feet above high water.

208 W. A. HE. Ussher—Post-Tertiary Geology of Cornwall.

jf. Near the centre of Perleze Bay a few quartz and slate pebbles
are present, under blown sand, at about five feet above high water.

g- The cliffs of the cove north of Trevone (2 miles west of Pad-
stow) are from 5 to 15 feet high, and occasionally capped by coarse
brownish sand, giving place to dark brown clay with angular slate
fragments, and an occasional quartz pebble. The ground slopes
upward for a quarter of a mile very gradually.

20. Between Padstow and Tintagel.

a. On the cliffs of Bray Hill, near St. Enodock, yellowish and
grey, thin bedded, consolidated sand of comminuted shells, con-
taining shells of Helices, is visible, at base 5 feet above high water.

b. In one place the following section occurs under 2 feet of
recent blown sand:

Consolidated sand... 6in.
Dark brown loam, containing angular f ‘fragments of quartz,
slate and grit ets Seo) o00 0g. Ali, a) Bhs

Upon greenish grey slates with quar rtz veins.

c. Near the mouth of the St. Enodock Valley, a bed of consolidated
sand, one foot thick, containing land shells and angular fragments
of slate, is capped by recent blown sand, and rests on red and green
banded slates at 8 feet above the present beach.

d. At the stream mouth between Porteath and Trefan Head,
Head, of angular stones in brown and yellowish loam, has a stratified
appearance in the distance, owing to the sizes and dispersion of the
fragments and their partial absence in places. The stream has cut
a steep bank at the mouth of its gorge, which exposes 20 feet of
Head—brown loam with angular slate and quartz stones, roughly
horizontal in arrangement.

e. By the mouth of the stream west of Port Isaac, between
Roscarrock and Lobber Rock, 20 feet of Head is shown, consisting
of angular fragments of slate and quartz in brown loam.

f. Near Chapel Rock the slates have been cut into reef platforms
or shelves, in places, at about high-water level.

g. At the mouth of the stream gorge west of Dannon Chapel, 10
feet of Head is shown, consisting of brown loam with angular slate
and quartz stones.

21. The Scilly Isles.

Mr. Carne (Trans. R. G. 8. Corn. vol. vii. p. 140) mentions the
occurrence of redistributed granitic matter, called “secondary
granite,’ on Rat Island, at Piper’s Hole in Tresco, and Piper's
Hole in St. Mary; in both the latter caverns it forms the principal
part of the roof, and contains boulders or rounded masses of
perfect granite, some rather large.

GuNERAL CoNCLUSIONS.

Head.—The position of the stony loam or Head in sites where no
modern talus could rest; the denudation it has undergone, and its
frequent presence on the cliffs; prove its accumulation to have
taken place subsequent to the formation of the raised beaches, yet
considerably anterior to the prevalence of the present climatal con-
ditions. It marks, as Mr. Godwin-Austen (Q.J.G.S8. vol. vil. p. 122)

W. A. E. Ussher—Post-Tertiary Geology of Cornwall. 209

says, “A time when the degradation of the surface proceeded much
more rapidly, and when fragments of rock far exceeding the motive
power of any rainfall were conveyed down slopes along which only
the minutest particles of matter are now carried” (vide 9c). Such
conditions of long-continued subaerial waste are likely to have
prevailed, as Mr. Godwin-Austen suggests (Q.J.G.S. vol. vi. p. 93,
etc.), during a greater elevation of the (South) West of England.

The rough appearance of stratification sometimes noticeable in the
Head [(1) through the horizontal lie and apparent regard to gravity
in distribution of its contained fragments, vide 3b; 5b; lda; 20d;
(2) through strips of loam or clay without stones. as in the higher
cliffs bordering Pra Sands, and 156; (8) through percolation of
water carrying down overlying substances to a certain horizon, as
17 e; (4) through distribution of colouring matter, as 5 b, 18 a] may
in many cases be due to fluviatile deposition, to which Mr. Godwin-
Austen referred the Head at Swanpool (5 d) and other places.

We cannot suppose that no fluviatile deposits were formed during
this period of subaerial waste; judging from the pell-mell distribu-
tion of angular fragments in the torrential gravels of the present
streams, in their higher reaches, it is only reasonable to expect that
similar deposition would then have taken place on a much larger
scale, and that its traces would be found in the present area of the
county which would only represent the highlands of its former
extension.

Raised Beaches.—The general consolidation of the old beach mate-
rials, occasionally into a very hard rock (vide 6c; 169, h; 18), renders
their detection, even as fragments on a level with the surface of the
present beach, comparatively easy ; where, however, the process of
consolidation was interfered with by the accumulation of the Head,
the beach material seems to have been swept away, and in some
cases to have left traces in occasional pebbles at or near the base of
the Head (vide 5a; 6a; 164; and perhaps 19g). Even where the
raised beach is well developed, the upper part has been sometimes
mingled with the base of the overlying talus (186). Angular frag-
ments are occasionally found in the raised beaches (16/). The
above observations serve to explain the appearance of beach material
on Head, S. of Perranuthno (9 g), as, in an adjacent section (9 9’),
the Head is represented by pebbles and subangular fragments. On
Bray Hill (20 6), 6 inches of consolidated sand rests on 2 to 3 feet of
Head; but the latter is represented in an adjacent spot by con-
solidated sand with angular fragments of slate, and land shells (20 ¢) ;
so that the old sand drift may have taken place on the beach plat-
form after a little talus had been shed upon it during the earliest
symptoms of elevation.

It is often difficult, where old consolidated blown sands occur, to
distinguish their junction with underlying raised beaches, as pebbles
and fragments of Mytili, Patelle, etc. (167; 17f,g; 18) may
have been cast upon the dunes by storm waves; for their presence
and linear arrangement in recent blown sand (19 e) would seem to
be due to protracted gales from the same quarter.

DECADE I1.— VoL. VI.—NO. V. 14

210 W. A. EH. Ussher—Post-Tertiary Geology of Cornwall.

Being chiefly composed of comminuted shells, the percolation of
water through the old dunes would best explain their consolidation.
Dr. Paris (T.R.G.S. Corn. vol. i. p. 7), in addition to this, gives two
other possible modes of consolidation, viz., by water charged with
pyritical substances, or by ferruginous infiltration.

The absence of organic remains in the majority of the Cornish
raised beaches has been ascribed to Arctic currents (Godwin-Austen,
Q.J.G.S. vol. vi. p. 87), which I think very probable. It also
suggests the possibility that many of them may have been deposited
by rivers, or in estuaries, whose seaward banks have been swept
away. Some of the boulder beds mentioned by Messrs. Carne and
Henwood are at too great heights to be regarded as raised beaches,
and may more reasonably be referred to far older fluviatile deposi-
tion. If the adit mentioned by Mr. Henwood (12 6) cut through
a continuation of the worn boulder beds of Porth Just and
Pornanvon to a thickness of 60 feet, the boulder beaches of these
localities must be regarded as anterior to the raised beaches. In the
formation of the old beach cliffs at the termination of a long period
of subsidence, fluviatile deposits (thrown down before, and during,
the initiation of the present lines of drainage) would have been
truncated, so to speak, and exposed at different heights upon the
cliffs, just as we find old river gravels exposed on the secondary
cliff-line of Devon.

Again, during the elevation of the old beaches, the existing river
channels would have been deepened, and river deposits formed in
the breaches of the old cliff-line, to be redistributed by the sea in
its recent advance. How far boulder gravels and unfossiliferous
raised beaches (provisionally so called) may be referred to either of
these periods of fluviatile action it is impossible to say, without a
searching investigation of each particular deposit with references to
its surroundings.

The local elevation of the raised beaches cannot be correctly
measured by the height above high water of their remains. For
such an estimate ignores the original thickness of the beaches, and
postulates an identity in the local rise of tide during the raised
beach formation and at present. The latter supposition is im-
probable when we take into account—

Istly. The destruction by the sea during elevation (of the old
beaches) of such inequalities as may have proved obstacles to the
stream of tide.

2ndly. The modification the raised sea-bed would have undergone
through subaerial agencies.

3rdly. The probably different relations of land and sea in other
parts of England, and on neighbouring coasts during the formation
of raised beaches in the 8.W. counties.

4thly. The subsequent modification of the old coast-line.

Mr. Pengelly (Trans. Dev. Assoc. part v. p. 103) points out the
fallacy of supposing—that all contemporary raised beaches are on
the same level, and the converse—that raised beaches on the same
level are necessarily contemporaneous. The cautions given show

G. H. Morton—Geology of the Isle of Man. 211

the danger of laying stress upon individual observations which
may be taken where the beach was left very thin, or at different
parts of its seaward slope.

The base of the Cornish raised beaches above high-water is shown
by observations to average 5 feet: such cases as Pendeen Cove
(14); Tremearne (9 6); Nanjulian (11 ¢); Porth Just (12 a); being
exceptional. ‘Taking the thickness of the old beaches at 15 feet as a
maximum, the average subsidence indicated by them would be from
12 to 20 feet below high water.

De la Beche (Geological Manual, p. 157) gives a section of the
successive faces (indicated by dotted lines) that the degradation of a
cliff composed of Head upon raised beach would be likely to exhibit
(see Fig. 6).

Sea-level.

Fie. 6.—H, Head, concealing a raised beach, resting upon slate, S, above the

sea level.

The raised beach platform has been cut too far back to allow
of such cliff faces as 1 and 2. Exceptions to this rule may be
furnished by the low tract at Spit Point near Par; the lowlands of
St. Keverne (7c); the flattish tract covered by blown sand between
Constantine and Perleze Bays, if the waterworn sand (in 19 e) isa
trace of raised beach, or rests. on an old beach platform ; the gently
sloping tract bordering the coast near Trevone (19 g).

The cliffs bordering a part of Pra Sands are wholly composed
of Head to a height of 60 feet from the present beach; but as Head
rests on a portion of raised beach on an adjacent promontory, on a
platform 5 feet above high water, the old beach platform may in
this instance have been broken up by fluviatile agencies prior to or
during the accumulation of the Head; or the original surface of the
platform must have been most irregular. Such cliffs as Nos. 3 and 4
are by far the most general sections on the Cornish coast, which has
been in very many places cut too far back to show either raised beach

or Head.

(To be continued in our next Number.)

VI.—Grotocy or THE Is~e or May.
By G. H. Morton, F.G.S.

N the Gxotoercan Macazine for 1877, Dee. II. Vol. IV., pp. 410,
456, there is an article on the ‘‘ Geology of the Isle of Man.”

by Mr. Henry H. Howorth, to which I desire to call attention. Most
geologists are aware that the late Rev. Joseph G. Cumming, M.A.,
F.G.S8., wrote a work entitled ‘The Isle of Man,” in 1848, and that
it contains a geological description of the island. In this work, and

4

212 G H. Morton—Geology of the Isle of Man.

in a paper by the same author, published in the “Journal of the
Geological Society” for 1846, vol. ii. p. 317, there is a minute
description of the Carboniferous formation developed at the south
of the island, near Castleton, illustrated by maps and sections. Mr.
Cumming gives the order in which the subdivisions occur from the
top downwards as follows :—

Posidonian Schists.

Poolvash Limestone.

Lower Limestone.

Old Red Conglomerate.

He describes each of these subdivisions, the volcanic ash inter-
stratified with the Poolvash Limestone, and gives a list of 222
fossils found by him in the Carboniferous Limestone, showing the
range of each species. The Old Red Conglomerate at the base of
the limestone is minutely described, and the area it covers is shown
on the geological maps. Several papers have since appeared on the
geology of the island, but one entitled, ‘‘A Sketch of the Geology of
the Isle of Man,” by Mr. John Horne, F.G.S., of the Geological Survey
of Scotland,! includes a concise account of the Carboniferous Lime-
stone, and confirms the arrangement of the subdivisions adopted
by Mr. Cumming; indeed, no one, excepting Mr. Howorth, has
challenged the correctness of his conclusions, which have the appear-
ance of being the result of long-continued and careful observations.

Mr. Howorth states that he spent three long days in examining the
deposits in the south of the island, but principally the Old Red Con-
glomerate. That Mr. Cumming was “‘entirely erroneous,” and that the
Old Red Conglomerate does not underlie the Carboniferous Limestone,
but is simply an overlying deposit of Boulder-clay, and remarks that
« A conglomerate consisting almost entirely of limestone boulders,
imbedded in a matrix of pulverized limestone, lying immediately in
contact with beds of limestone, cannot well by any process of
reasoning be made into an Old Red Conglomerate.” Mr. Howorth |
searched carefully the various points where the deposit occurs at
Langness, but could find no evidence of it being overlain by the
limestone; and at Cushnahavin he says he actually saw the latter
reposing on the underlying Silurian strata. He concludes the con-
glomerate to be a consolidated Boulder-clay, and that the trap-dykes
with the volcanic vent at Scarlet Point were posterior to the Con-
elomerate, and finally remarks that ‘“‘ We thus add another. remark-
able example to the list of volcanos active within the British seas in
Post-Tertiary times.”

During last summer, I, like Mr. Howorth, had three days in the
Isle of Man, which JI devoted to the examination of the Carboniferous
Limestone and the Conglomerate at its base. Having read Mr.
Howorth’s paper in the Grou. Macazine, I at once endeavoured to
ascertain the stratigraphical position of the Conglomerate, and I
found the difficulty of doing so somewhat over-estimated, although
the shore along the outcrop is only exposed at low water and some-

1 Trans. Edin. Geol. Soc., vol. ii. pt. 3, 1874.

G. H. Morton—Geology of the Isle of Man. 213

what obscured by stones and sea-weed. I, however, found without
difficulty a spot on the shore, north of the copper mine, where the
Old Red Conglomerate clearly dips below the Carboniferous Lime-
stone, and trap-dykes traversing both alike. I found the boulders
and pebbles in the Conglomerate to be quartzite instead of limestone
—at least all I could find were quartzite, and many I tried with acid
so as to be perfectly sure about them. In colour they certainly
resemble the limestone in the vicinity, but they still more nearly
resemble the quartzite interstratified with the Silurian in close
proximity.

Mr. Howorth says he found no Old Red Conglomerate, but the
limestone resting directly on the Silurian at Cushnahavin, but Mr.
Cumming describes how the limestone is faulted against the Silurian
at that place so that the appearance may easily be explained, and he
states that the Conglomerate occurs at a little distance, about 10 feet
below high-water mark. I found the top of it under the limestone
just as described, and have great confidence in the correctness of Mr.
Cumming’s sections, though I had not time to follow them across
the whole area. I need scarcely remark on the improbability of
trap-dykes intersecting Boulder-clay, and volcanic vents in the
British Seas in Post-Tertiary times.

Mr. Howorth says he was not at Peel, and that his arguments only
apply to the south of the island; but I visited that locality and found the
Old Red Sandstone to be interstratified with a conglomerate in steep
cliffs dipping towards the sea at a considerable angle. Mr. Cumming
refers to numerous blocks of limestone thrown up by the waves along
the shore, and concludes that there are beds of it on the dip at no great
distance from the land. He also states that limestone was formerly
obtained and burnt in kilns, though unable to determine whether it was
an interbedded, cornstone or an overlying limestone. However, there
seems no doubt that the Red Sandstone with conglomerate at Peel is
of the same age as the Conglomerate about Castleton. Mr. Howorth
states that he is only an amateur geologist, and had only three days
in the district ; but Mr. Cumming resided in the island, being Vice-
Principal of St. John’s College—within gun-shot from the Old Red
Conglomerate—and it is very improbable that he made any mistake
in its geological position—however nearly it may resemble some local
Boulder-clay. It is surprising that Mr. Howorth’s paper has not
been noticed; for, being the most recent communication on the
subject, it tends to throw doubt on the stratigraphical order of the
Carboniferous series in the Isle of Man—and the Old Red Con-
glomerate must be considered to be the base of it.

In conclusion, I recommend those interested in the subject to read
Mr. Horne’s paper, for he very fully describes the Old Red Sandstone
of Mr. Cumming, which he considers to represent the Calciferous
Sandstone series of Scotland, and consequently can entertain no
doubt as to its position being beneath the Carboniferous Limestone.

Liverpoou Gzot. Soc., Fd. 10, 1879.

214 #. T. Hardman—Fossiliferous Beds of Lough Neagh.

VIl.—Tur Fossinrrerous Cray Bens overtyine Basar, Loucu
NEAGH, AND THE GrEoLoGICAL AGE oF THAT LAKE,

By Epwarp T. Harpman, F.C.S., etc.

REGRET that I have not had an earlier opportunity of replying

to a paper in the GroLocicaL Magazine for February, p. 62, by

Mr. William Swanston, F.G.S., on the above subject. I shall now try
to compress my remarks into the smallest possible space.

1. With regard to the Fossiliferous Clays in the Crumlin River :—
Mr. Swanston is mistaken in supposing that the discovery of shells
in these beds “ proved to the satisfaction of the author (myself) and
Professor Hull, F.R.S.,,. . . that the beds were undoubtedly of
Pliocene age.” Here Mr. Swanston has reversed matters. On the
contrary, this conclusion had been arrived at two years before, and
at the Belfast Meeting of the British Association I stated my con-
viction, chiefly from stratigraphical evidence, that the Lough Neagh
Clays were of Pliocene age, and the similarity of the beds led us to
the conclusion that the shells nught be of Pliocene age.

2. I never led it to be believed that I was “convinced” that the
shells in question ‘“ belonged to a species of Unio.” And even before
suggesting that “they appear to belong,” etc., I had consulted Mr.
W. H. Baily, F.G.S., whose authority as a Paleontologist I need not
here enlarge upon. Moreover, not being convinced by the examina-
tion of a few mutilated specimens, I even pointed out the necessity
for a thorough examination of the specimens on the spot, to which
hint doubtless Mr. Swanston is indebted for his collection.

3. I am ata loss to know if the opinion of Dr. Gwyn Jeffreys,
F.R.S., is positive or conjectural. Such a phrase as “‘I can come to
no other conclusion” is somewhat ambiguous. There could be but
little difficulty in determining absolutely the common mussel as it
occurs in drift.

4. Here it occurs to me: Can Mr. Swanston and I be referring
to exactly the same locality ? In the section I described there occurs
positively no Boulder-clay whatever; though there is abundance of
it both higher up and lower down the river, from which Mr.
Swanston may have obtained his shells. But the clays resembled
in every respect many of the beds of undoubted lacustrine clay of
Lough Neagh, and were perfectly similar to those found not far
distant on the Glenavy River; and also to many of the beds used
for pottery manufacture to the south of the lake. Furthermore, the
shells I noticed are extremely thin and fragile, hardly thicker than
a piece of notepaper. They appear in every way suited for the
quiet waters of a lake, but seem ill-fitted to resist the stormy
buffetings of a sea-shore. The clays in which they occur are deposits
‘clearly formed on the ancient margin of the lake, as denoted by old
shore-cliffs of basalt close by. Even granting that the shells be
Mytilus, it would not be outside the bounds of possibility that the
lake might formerly have communicated with the sea, as it is now
only 48 feet higher; thus the shells might be true lacustrine fossils
deposited before the Glacial period.

E. T. Hardman—Fossiliferous Beds of Lough Neagh. 215

Although drift deposits are well exposed in the vicinity and along
the shores of the lake, no similar clays are to be seen amongst them.
And on the whole, without further investigation and more con-
vincing proofs, I am unwilling to admit that the deposit I described
can belong to the Glacial period, seeing that it resembles in every
respect the lacustrine clays, while totally differing from the drift
beds.

5. Age and Mode of Formation of Lough Neagh.—Kiven if we
should be obliged to reject the lacustrine origin of the Crumlin
deposit, I confess I -cannot follow the argument by which as a
sequitur Mr. Swanston endeavours to quash the theory formerly
proposed by me with respect to the age of the lake. This particular
deposit cannot affect that theory one way or the other. If there is
anything geologically certain, it is that Lough Neagh occupies a
depression primarily caused by large faults which occurred after
the latest sheets of basalt we are acquainted with had been poured
forth... This is sufficiently clear from the fact that the upper
basalt is brought down against the lower, as at Templepatrick and
Shane’s Hill. It is also capable of proof that the Lough Neagh clays
(the lacustrine origin of which has never been doubted) are later
than the basalt, and older than the drift, which covers them in
many places. Also that they are the delta of one or more rivers
flowing from the southwards after a considerable area of country
had been denuded of the basalt which formerly extended at least as
far as Slieve Croob and the Mourne Mountains. Mr. Swanston,
however, prefers to consider the lake as of intra-Miocene age; and
as a consequence of the supposed Glacial age of the Crumlin deposit
—but why, I am unable to conjecture—places the Lough Neagh.
pottery clays as contemporaneous with the lacustrine iron-ore
deposits of Antrim, ete. He forgets that first the Lough Neagh
deposits are proved to be 300 feet thick. 2nd. That the depression
of Lough Neagh is more than 1,700 feet, and that it would certainly
have been filled up by the next flow of basalt. 3rd. That the
faults around it, some of 500 feet, which must have altered the face
of the country considerably, are post-basaltic. And last, but not
least, that the Lough Neagh deposits are totally different in every
respect from the ferruginous deposits of Antrim.

The iron-ore beds of Antrim were formed in a series of shallow
depressions by the denudation of the basalt itself. By a well-known
series of chemical changes the basalt yielded soluble carbonate of
iron, which, being carried into these shallow “broads,” was oxidised
and deposited as hydrated oxide of iron, subsequently dehydrated.
According to the freedom or otherwise of the lake from silt or mud,
rich iron-ore, lithomarge or aluminous ore was produced. All these
deposits are rich in iron, and are not of great thickness.

With these the Lough Neagh clays have nothing in common.
They consist simply of clay, more or less sandy, usually very light

1 For full details on this and the following statements see ‘‘ On the Age and Mode

of Formation of Lough Neagh,” Brit. Assoc. Rep. 1874, and Journ. Roy. Geol.
Soc. of Ireland, vol. iv. pt. i. new series.

216 Dr. C. Callaway—On Plagioclinal Mountains.

grey or nearly white, occasionally dark grey or purple, from organic
matter or the material, probably Silurian slates, from which they
were derived. Although they contain a few nodules of siliceous clay
ironstone in some places—very sparingly—and not unlike those of
the Coal Measures, the small quantity of iron the clays contain will
be inferred when I mention that all qualities are largely used for the
manufacture of tiles and coarse pottery; for which, of course, ferru-
ginous clays would be utterly useless.1_ Yet of these clays Mr.
Swanston pens the following remarkable passage, on the assumption
that they are of the same age and origin as the Antrim iron-ores :—

“Should subsequent researches prove these to be the same, it may
safely be inferred that one reason why the Lough Neagh beds still
retain their clayey character is owing to the simple fact that the
later outflows of Miocene basalt did not reach them, and convert
them into iron-ores, etc., similar to those so largely developed to the
east and north of Antrim” (!). The simpler fact that they are non-
ferruginous clays is the easier mode of explanation. Hx nihilo nihil fit.

If the Lough Neagh clays were of intra-Miocene age, and formed
in the same way and time as the Antrim ore deposits, they would be
found resting only on basalt, or absent where basalt does not occur.
They however overlap the previously denuded basalt, and their
continuation is found in several places resting on Triassic rocks.

Mr. Swanston is doubtless unaware of these facts, which are, I need
not observe, completely antagonistic to his doctrine as to the age of the
clays. And but that I fear to trespass on the kindness of the Editor
of the GrotocicaL Magazine, whose space is valuable, it would be
easy to give numberless other facts as overwhelming proofs of the
post-Miocene age of the Lough Neagh clays, and of the lake itself.

Returning to the Crumlin shells. I must now, at the cost of
repetition, point out that even if they are hereafter proved to be
Glacial fossils, such a matter can hardly be evidence in favour of the
intra-Miocene age of the lake: yet this is apparently the conclusion
to which Mr. Swanston’s arguments would lead us.

With regard to the silicified wood, I can only say that it has never
been found in any of the numerous clay-pits to the south of the
lake. And in the only case where Barton records its existence
in sitd, it may have belonged to the drift. Excavations and borings
in the same locality in the true lacustrine clays revealed none of it;
and the origin of this wood is a matter still enveloped in great
obscurity.

VIII.—On Praciocrinat Movuntatrns.
By Cuarires Cattaway, M.A., D.Sc. (Lond.), F.G.S.

NHE object of this paper is to show that the received explanations
of the structure of mountain chains will not account for the
formation of certain Precambrian ranges, and to state facts in sup-
port of a new theory of the origin of some mountains. A brief
summary of the ordinary views of the subject will first be necessary.

1 The analysis of these clays, given by Sir Robert Kane, shows them to be
remarkably free from iron.

Dr. C. Callaway—On Plagioclinal Mountains. 217

Most mountain chains are produced by the puckering of the
earth’s crust into parallel flexures, and the greater systems consist of
a combination of these earth-waves. Hach wave usually rises higher,
and the crests approximate more closely, towards the axis of the
chain. The Alleghanies of North America well illustrate this
structure. Towards the east, the anticlinals are squeezed up to such
a height by lateral thrust that they sometimes fall over on one side,
like an ocean wave rolling in upon a shallow shore. But, towards
the Mississippi Valley, the waves gradually flatten out into low broad
undulations. Of course, denudation has acted powerfully upon the
flexures, by marine action during their emergence from the ocean, and
by sub-aerial forces since their elevation. No trace of the original
curved outline of the earth-waves appears in the shape of the
ground. ‘The tops of the anticlinals were planed off by the waves
of the sea, and rivers have since scored and fretted the surface into
a seemingly lawless irregularity.

But amidst this apparent disorder, one law is clearly seen. This
law is that primary mountain ridges run parallel with the geological
strike. A range sometimes consists of a denuded anticlinal; some-
times of a synclinal converted into a prominence by the erosion of
the anticlinals on each side ; sometimes of combinations of both, or
parts of either. But in all these cases, the strike of the mountain
chain corresponds with the strike of the beds of which it is com-
posed. Amongst examples of this law which will at once occur to.
geologists, are the Pennine chain, the Cotteswolds, the North and
South Downs, the Swiss Alps, and the Andes. The normal structure
of mountains may be called orthoclinal.

The reason of this correspondence between geographical and
geological strike is not far to seek. ‘Take the case of an anticlinal
mountain. Here the ridge is simply the upper half of a mutilated
earth-wave. During the emergence of the land, the anticlinals were
first exposed to the action of the sea. Notwithstanding the erosion
of the ocean-waves, the anticlinal axes succeeded in raising them-
selves, though in a very mutilated state, into dry land. Subsequent
sub-aerial action would score and carve the slopes of the saddle into
ravines and valleys, but it would not interfere with its strike.
Synclinal ridges are formed in a similar manner; but with one
difference. During emergence, the waves plane off the top of the
anticlinal, and expose softer strata which lie beneath. The anti-
clinals thus become lines of weakness, along which denudation
works with great rapidity till it reaches a lower level than the
synclinals, which stand up as ridges. ‘The alternative between
anticlinal and synclinal ridge is, then, mainly determined by the
relative hardness of the strata. In both cases, the strike of the
chain will be parallel to the original earth-waves, that is, to the
geological strike.

In reconstructing portions of the geology of Shropshire, the writer
has observed some remarkable exceptions to the above rule. The
southern half of the county is grooved by a series of parallel valleys
trending to the §.W. The intervening elevations, of course, strike in

218 Dr. C. Callaway—On Plagioclinal Mountains.

the same direction. These, taken in order from KH. to W., are the
Clee Hills, Wenlock Edge, the minor ridges of Chatwall and
Hoar Edge, the Wrekin and Caer Caradoc chain, the Longmynd, and
the Stiper Stones. Most of these elevations form parts of a great
broken §8.W. anticlinal, of which the Caer Caradoc and Wrekin
chain is the axis. The escarpments to the E. of the axis face, of
course, to the N.W.; the escarpments to the W. of the axis break
down to the S.E. All the ridges follow the ordinary rule, except
the Wrekin and Caer Caradoc chain, to which attention is specially
directed.

This chain is nearly 30 miles in length, and is broken by three
broad gaps of from 4 to 8 miles in breadth. The chief elevations,
taken from the N.E., are Lilleshall Hill, the Wrekin range, Caer
Caradoc range, and Wartle Knoll. The last, being of inconspicuous
elevation and of doubtful structure, may be neglected. The other
three agree in displaying the same peculiarity of structure. The
beds of which they are composed strike across the axis.

Tilleshall Hill is one mile in length by one-sixth of a mile in
breadth at the base. Its trend is $.S.W. The beds of volcanic ash
of which it is composed strike W.S.W. The difference between the
geographical and the geological strike is about 45°.

The Wrekin chain, consisting of four elevations, the LHrcal,
Lawrence Hill, the Wrekin, and Primrose Hill, is three miles in
- length by half a mile in its greatest breadth. It consists of alter-
nations of lavas and tuffs dipping to the N., the ridge trending to
the 8.W. In this case also the divergence of the two strikes is
about 45°. An inconspicuous elevation, lying two miles W. of the
Wrekin, named Charlton Hill, ranges due N. and 8. In this ridge
is a band of conglomerate striking EH. and W., the divergence of
strike amounting to a right angle.

The Caer Caradoc chain is about six miles long by about half a
mile in its greatest breadth. Its chief summits are the Lawley,
Caer Caradoc, and the Ragleth. Its strike is to the S.W. The
average strike of the grits, tuffs, and felstones which make up the
chief part of the range is HE. and W.; intrusions of greenstone
sometimes twisting round the strike 20° to 30°, and, on the 8.H.
side of the Ragleth, causing it to coincide with the trend of the
ridge. These disturbances are only local, the usual E. and W.
strike being resumed at a distance from the disruptive masses. A
great spur which springs from the §.E. side of the range, and juts
out for two miles to the E., is composed of beds of grit, breccia, and
felstone, which strike in the same direction as the spur.

It is clear that, with local exceptions, the bedded rocks of the
Wrekin and Caer Caradoc chain strike across the axis at angles
varying between 45° and 90°.

It would be evident, a priori, that such a mountain range could
not be formed on the normal plan. The geographical strike bears
no causal relation to the original earth-waves. It has been deter-
mined not by axes of upheaval, but by parallel faulting.

A great §.W. line of dislocation commences near Lilleshall Hill

Dr. C. Callaway—On Plagioclinal Mountains. Pa llis,

on the N.E.; passes through the Wrekin and Caer Caradoc chain ; is
continued to Stanner Rock and Hanter Hill, W. of Kington ; passes
under an anticlinal N.W. of Brecon; appears to sweep round to the
W., and to be connected with the Precambrian ridge of St. Davids.
In Shropshire it is a complex system of faults. There appear to be
in all about six primary dislocations parallel to each other and to
the mountain ridges. For our present purpose, we shall not require
more than a pair of these.

Commencing with Lilleshall Hill, we find that it is bounded by
faults on both sides. On the §.H., the Hollybush Sandstone (Caradoc
in the Survey) has been thrown down; on the N.W., the lower beds
of the Trias. The structure of the ground is the same in the
Wrekin range, save that faulted bands of quartzite are interposed
between the axial rocks and the Hollybush Sandstone and the Trias
on either side. The Caer Caradoc chain is in like manner bounded
by two nearly parallel faults. On the N.W., the lower slates of the
Longmynd series rest against the axis; on the 8.E., the Shineton
Shales, the Hollybush Sandstone, and the Caradoc Sandstone are
successively thrown down.

It is evident that in each case a wedge of the solid crust has been
separated from the main mass by two nearly parallel faults, and
thrust up through overlying Cambrian and Silurian strata. Or it is
probable, in the case of the Wrekin at least, that the wedge was
first pushed up in Pre-Cambrian times.

As the rocks of this chain consist, not of eruptive greenstones
(according to the late Sir R. Murchison and the Geological Survey),
_ but of bedded lavas, tuffs, grits, conglomerates, and other stratified
material; and as they are flanked on each side by strata, some of
which are at least as old as the Lower Cambrian; it is clear that
these mountain ridges are of Precambrian age.

The writer has been greatly interested to find that certain other
Precambrian elevations, described in recent times by Prof. Phillips,
Dr. Holl, and Dr. Hicks, display a similar abnormal structure.

The Malvern Hills trend N. and S., but the schists and granitoid
rocks of the chain strike across the axis in a 8.H. direction. A great
dislocation throws down Triassic sandstones against the eastern
flank, and the author is convinced from a personal examination that
the ridge is also bounded by a fault on the W.side. These rocks are
still more ancient than those of the Wrekin chain. The range has
evidently been formed in the same way. A solid slice seven miles
long, composed of strata striking to the S.E., has been isolated by
two parallel N. and S. faults, and pushed up as the original ridge
out of which the Malvern Hills have been sculptured by frost and
rain.

A third Precambrian ridge exhibiting a similar structure occurs
at St. Davids, and has been described by Dr. Hicks. It extends for
about two miles from the city to the S.W., and has an average
width of rather less than a mile. It consists of quartziferous and
granitoid rocks distinctly bedded, and striking across the axis to the
S.E., that is, at about a right angle with the strike of the ridge.

220 Dr. C. Callaway—On Plagioctinal Mountains.

This series has been named the Dimetian. It is flanked on both
sides by a younger Precambrian formation, the Pebidian. In
Dr. Hicks’ sections in the Quart. Journ. of the Geol. Soc. 1877 and
1878, the junction between the two groups is not represented by a
fault; but it is difficult to explain the vertical and sometimes
inverted position of the lower beds of the Pebidian without the aid
of such an hypothesis, and a recent inspection by the writer con-
firms this view. But this is only a minor point. In any case, the
Dimetian ridge is on the type of the Shropshire and Malvern chains.

The same peculiarity has been noticed in North Wales. Professor
T. M‘Kenny Hughes, in describing certain Precambrian rocks near
Bangor, observes that ‘the bedding is generally in an easterly
direction, sometimes a little S., sometimes a little N. of H., but
always oblique to or across the trend of the hills.” No information
is given on the influence of faults in determining the structure of
these ridges.

In summing up these facts, it has been shown that, in the three cases
examined by the writer, the trend of the elevations has been deter-
mined by parallel faulting; in the other example, the influence
of faults has not been ascertained; in all four, the strike of the
beds is transverse to the strike of the ridge.

On the hypothesis of parallel faulting, it is not difficult to suggest
a reason why these transverse strikes should be found only in
Precambrian mountains. In every observed case in Britain, there is
a great interval between the newest Precambrian and the oldest
Cambrian. The marked discordance of strike is one proof of this.
An equally emphatic evidence is seen in lithological characters.
The Precambrian rocks are everywhere intensely altered, and the
alteration in many instances took place before the Cambrian epoch.
But the overlying Cambrian strata are frequently as unaltered as
ordinary Tertiary beds. It is highly probable that the fragments of
Precambrian land which jut up here and there through newer for-
mations represent a succession of epochs perhaps as long as from the
Cambrian to the present day. Paleontological facts point in the
same direction. The gap between the simple Protozoan of the
Laurentian and the highly organized Trilobites of the Lower Cam-
brian is perhaps as wide as the hiatus which stretches between the
Trilobite and the Mammal.

It follows from this that Precambrian formations have been sliced
up by faults much more frequently than younger deposits. It is not
necessary to assume, though the assumption would not be rash, that
faults were more frequent in Precambrian times than they are at the
present day; but it is evident that the Precambrian crust was
traversed by Precambrian faults in addition to those from which it
has suffered in common with newer deposits.

In Precambrian times, the surface of the earth was ridged by
mountains as at present, and it is fair to assume that they were
formed on the normal plan. But during an immense succession of
epochs, they have been partially worn down, and the chief part of
the Precambrian surface has been buried beneath great accumula-

Notices of Memoirs—E. Stohr—Sulphur Deposits of Sicily. 221

tions ; which, in their turn, have been puckered into earth-waves
which bear no relation to the old strikes of the crust.

Faults, as might be expected, display a tendency to run parallel
with earth-waves. When the crust is being forced into sharp curves,
eracks will naturally occur at right angles to the lateral pressure.
Hence the faults which traverse Cambrian and Postcambrian strata,
being parallel to the newer flexures, will be transverse to the under-
lying Precambrian strikes.

It is now easy to see how a pair of parallel faults traversing at the
surface rocks of (say) Silurian age, and cutting down through Cam-
brian and Precambrian strata, will account for the origin of Pre-
cambrian ridges with transverse strikes. The upheaval of the
isolated wedge, and the denudation of the overlying Cambrian and
Silurian beds, require no explanation. The continued prominence
of the ancient ridge would be secured by the superior induration of
its metamorphic or altered volcanic constituents.

To distinguish mountains of this type from anticlinal and syn-
clinal ridges, the term plagioclinal’ is suggested.

This peculiarity of structure may prove to be of practical aid in
detecting Precambrian formations. A plagioclinal axis is not neces-
sarily Precambrian, but its transverse strike should suggest inquiry.

The facts here announced militate against an extreme school of
geologists, who deny that faults have had any perceptible share in
shaping the landscape. They have certainly very largely contri-
buted to determine the scenery of South Shropshire. That the
original surface produced by great dislocations has been modified by
subsequent denudation does not materially affect the question. It
would be equally just to argue that, because the Romance words in
the English language have been modified by time, the Norman
Conquest has not affected our modern tongue.

IN @ pian @ se) Ora eh iaka he @ aes Ss

— SS

I.—Tuer Turo anp TripoLt oF THE SULPHUR ZONE OF SICILY.”

WO years ago Sig. E. Stohr, when placing the sulphur deposits

in the Messinian II. of C. Mayer, and the ‘tufo” in the

Messinian J., remarked that perhaps this last should be removed

lower down, and in the December number of the Bolletino R. Com.

Geol. d'Italia he says, that the discovery of fossiliferous beds in a

sulphur mine, near Grotte, in the Province of Girgenti, has confirmed
this opinion.

Immediately below the sulphur beds is a bituminous schist, then
the tuff and tripoli, and in this “tufo,”’ which is described as an
almost plastic clay, are a great number of Foraminifera, the subject
of Sig. Stohr’s paper. Of the 115 species found, 28 are new, and
are mostly described and figured by Dr. Schwager in an appendix.

1 From mAd-yios, oblique, and KAlvw, to incline.

2 Sulla posizione geologica del tufo e del tripoli nella zona solfifera, per E, Stohr.
Boll. R. Comit. Geol. d'Italia, vol. ix. No. 11-12, 1878.

222 Notices of Memoirs—Prof. J. D. Dana—On Lithology.

Of the remainder, the absence of Milliolidea (of Spiroculina tenuis one
example was found), Amphistegina, Heterostegina, and Polystomella
is noticeable, while the quantity of Rhabdoidea (88 species), Cristel-
larotdea (14), Globigerinidea (17), not only in the number of species,
but also of individuals, is striking, and a deep sea is indicated, and
is confirmed by the Radiolarian fauna, though the Radiolaria are
only found scattered in the clay. Of the Foraminifera 63 are found
at Baden, near Vienna; 388 are known living; and 52 are supposed
to be extinct. The Molluscan fauna is also very similar to that of
the Baden beds.

The tripoli beds, which are below the ‘‘tufo,’ were evidently
deposited in a still deeper sea, as shown by the rich Radiolarian
fauna of 109 species, studied by Mr. Stohr. It most nearly resembles
the tripoli of Caltanisetta, from which Ehrenberg described 31
species; but the Grotte beds furnish 68 new species, which will
shortly be figured and described, and of the rest 29 are known
living, about half of these in the Mediterranean. Some families
and genera, hitherto unknown in the fossil state, are now described ;
for instance, the genus Huchitonia, which was previously only known
as recent, furnishes several species, some identical with those found in
the sea near Messina. The author says that this genus is sometimes
so abundantly represented at Grotte that we might almost call this
tripoli a mass of Euchitonia.

The conclusions arrived at are that both tripoli and “tufo” belong
to the Tortonian (Miocene), and were deposited in deep water ; after-
wards there was elevation of the land, and lacustrine conditions
supervened, when the deposits which now yield the sulphur were
formed, during the Messinian I. II. and probably III. (of Mayer),
after which sinking of the land and marine conditions followed.

A. W. W.

TI.—On Some Potnts 1n Lirnotoey. By Prof. J. D. Dana.

NDER the above title Prof. Dana has recently published! a
suggestive paper, which will be perused with much interest
by those engaged in the study of rocks, and may possibly call forth
a few remarks or further observations on some points discussed in
the paper”; the object of the author being to consider the value of
some of the distinctive characters which are generally accepted at
the present time in defining certain kinds of rocks. As some of our
readers interested in petrology may not have ready access to the
original communication, we have reproduced the summary, by
Prof. Dana, of the principal points with regard to rocks which
have been brought out in this paper, together with his proposed
classification of the crystalline rocks.

«1, The necessities of the science of Geology constitute the most
prominent motive for distinguishing finds of rocks; and they should
determine to a large extent upon what characters distinctions should
be based.

1 Amer. Journ. of Science and Arts, vol. xvi. Nov.-Dec. 1878.
2 See Article in the present Number, by Prof. Bonney, M.A., F.R.S., ante, p. 199.

Notices of Memoirs—Prof. J. D. Dana—On Lithology. 223

“2. In determining the rocks to be grouped as one in kind under
a common name, near identity in the chemical and mineral composi-
tion of the chief constituents is the main point to be considered ; not
near identity in their crystalline forms, for isomorphism presupposes
diversity of composition.

©3. Distinction of kind should be based on difference in chemical
and mineral constitution as regards the chief constituents. When
such difference exists, rocks are different in kind, and need, for the
purposes of geology, distinct names. If it does not exist, the dis-
tinction is only that of variety ; unless (asin the case of trachyte and
felsyte), the very wide extension of the rock under persistent
characters makes a distinction of name important to geology.

“4, It follows from the preceding, that differences in texture: as
coarse, or fine, or aphanitic ; porphyritic, or non-porphyritic ; stoney
throughout, or having unindividualized portions among the stoney
grains ; and differences in microscopic inclusions ; are no basis for
a distinction of kind among rocks, but only of variety; and that
porphyritic structure is of hardly more consequence than coarse or
fine granular.

“5. No marked change in the constituents of the earth’s erupted
material occurred after the close of the Cretaceous period, or just
before the commencement of the Tertiary era ; and, hence, no ground
exists for the distinction of ‘older’ and ‘ younger’ among eruptive
rocks. The ‘ younger’ eruptive rocks are essentially like the ‘older’
in chemical composition and their chief mineral constituents; and
they differ when at all only in texture and some other points of as
little importance—qualities that distinguish merely varieties, and
which have proceeded from greater prevalence in these later times
of subaerial eruptions.

“6. Since ‘plagioclase’ is not the name of a mineral species,—
several minerals, of widely different compositions, being embraced
under it—it is a confounding of differences and resemblances to
speak of it as a constituent of a rock. And since it now includes,
through the defining of the feldspar microcline, a large part of
potash feldspar, which had been supposed to be orthoclase, it has
become almost synonymous with the term feldspar. The ‘simplicity ’
its adoption has been supposed to give to lithological system would
be greater if ‘feldspar’ were substituted, and with its present range
of constitution, the evil would be hardly less.

“7. Rocks differing mineralogically, and not chemically, like re-
lated hornblendic and augitic rocks (the minerals hornblende and
augite being dimorphous), are rightly made distinct rocks, since the
difference has depended, to a large extent, on wide-reaching geolo-
gical operations or conditions, and is, therefore, of great geological
significance.

“8. Since quartz is the most widely distributed and therefore the
least distinctive of the minerals of rocks, it may rightly be regarded as
of subordinate importance in the distinguishing of rocks, and hence
not only such names as dioryte and quartz-dioryte, trachyte and quartz-
trachyte, etc., are acceptable, but also syenyte and quartz-syenyte.

224 Notices of Memoirs—Prof. J. D. Dana—On Lithology.

“9. Biotite being closely like muscovite in composition, and not
less common than it in granites, gneisses and mica schists, and
being, moreover, unlike the mineral hornblende in chemical con-
stitution and formula, the rocks in which biotite isa chief constituent
cannot rightly be put in the same group with hornblende rocks; or
those in which hornblende is a chief constituent in a group of mica-
bearing rocks. Consequently the name ‘mica-dioryte,’ for a rock
containing no hornblende, and the name ‘hornblende-granite’ for a
rock containing no mica but hornblende instead, imply alike false
relations.

“The discussion suggests the following additional remark :

“The incapabilities of the microscope and polariscope have favoured
the use of the term ‘plagioclase,’ and have led some investigators
to overlook or slight distinctions in chemical constitution. Lithology
is to receive hereafter its greatest advances through chemical
analyses; for chemistry alone can clear away the doubts the micro-
scope leaves, and so give that completeness to the Science of Rocks
which geology requires for right and comprehensive conclusions.

‘‘Moreover the researches made in the laboratory to be of real
geological value should be, if possible, supplemented by investiga-
tions in the field as to transitions among the rocks, and as to other
kinds of relations. This field-work has often been well done, but
not so by all lithological investigators.

“The principles presented lead to the following subdivisions in
an arrangement of crystalline rocks, exclusive of the Calcareous and
Quartzose kinds. Since leucite is a potash-alumina silicate, like
orthoclase and microcline (it affording twenty per cent. or more of
potash), it is here referred to the same group with the potash
feldspars; and nephelite, sodalite, and the saussurites being
eminently soda-bearing species, they are included with the soda-
lime feldspars (anorthite to albite). This reference for lithological
purposes of these minerals is sustained by their resemblance to the
feldspars in constituents, and also in the quantivalent ratios between
the alkalies, alumina and silica, this ratio being in leucite 1:3: 8,
as in andesite, and in sodalite and nephelite 1 : 3: 4, as in anorthite.
The term potash feldspar, as used in the headings below, is hence
to be understood as covering orthoclase, microcline and leucite ;. and
soda-lime feldspar, as including the triclinic feldspars from anorthite
to albite, and also nephelite, sodalite and the saussurites.

“The arrangement is as follows. In the first series, the rocks
graduate into kinds which are all feldspar, and into others that are
all mica; and yet the amount of potash present is approximately the
same.

I. Tar Mica anp Porasu FELpspar Sxries: including Granite, Granulyte,
Gneiss, Protogine, Mica schist, etc., Felsyte, Trachyte, etc., and the Leucite rock of
Wyoming.

Il. Tue Mica anp Sopa-Lime Fernpspar Series: including Kersantite,
Kinzigite; and the nephelitic kinds Miascyte, Ditroyte, Phonolite, etc. (These
nephelitic kinds belong almost as well in the preceding series.)

III. Tut HornsienpE AnD PorasH Fripspar Series: including Syenyte
(with Quartz-syenyte), Syenyte-gneiss, Hornblende schist, Amphibolyte, Unakyte

Reviews—C. Struckmann—The Upper Jura of Hanover. 225

(this last containing epidote in place of hornblende); and the nephelitic species
Zircon-Syenyte, Foyayte.

TV. Tue Hornsienpe anv Sopa-Limz Feipspar Series: including Dioryte
(with Propylyte), Andesyte, Labradioryte (or Labrador-dioryte), etc., and the
saussurite rock, Kuphotide.

V. Tue Pyroxene AND PorasH FELDsPAR Serres: including Amphigenyte.

VI. Tue Pyroxene anp Sopa-Lime Fextpspar Series: including Augite-
Andesyte, Noryte (Hypersthenyte and Gabbro in part), Hypersthenyte (containing
true hypersthene), Doleryte (comprising Basalt and Diabase), Nephelinyte, etc.

VIl. Pyroxrens, Garnet, EprpotreE anp CuHRyYSOLYTE Rocks, CONTAINING
LITTLE OR NO FrLpspar: including Pyroxenyte, Lherzolyte, Garnetyte (Garnet
rock), Eclogyte, Epidosyte, Chrysolyte or Dunyte (Chrysolite rock), etc.

VIII. Hyprous Macnesian anp ALuMINoUS Rocks, CONTAINING LITTLE OR
no Fretpspar: including Chlorite schist, Talcose schist, Serpentine, Ophiolyte,
Pyrophyllite schist, ete.”

IJJ.—A New Orper or Extinct REPriLEs.

ROF. O. C. MARSH has recently described! a genus of reptiles
from the Jurassic formation of the Rocky Mountains, which he
considers to represent a new extinct order—the Sauranodonta. ‘The
genus Sauranodon is closely related to Ichthyosaurus, and presents,
in most of its skeleton, the characteristics of that genus, but is
without teeth. 'The vertebre, ribs, and other portions of the skeleton
preserved cannot be distinguished from the corresponding parts of
Ichthyosaurus, and many features of the skull show a strong re-
semblance. The great development of the premaxillaries, the
reduced maxillaries, the huge orbit defended by a ring of bony
plates, are all present, but the jaws appear entirely edentulous, and
destitute even of a dentary groove. This genus Sauranodon, from
the absence of teeth, bears a similar relation to the Ichthyosaurs
that Pteranodon does to the true Pterodactyls, and it is interesting
to find the two highly specialized forms preserved in the same region.

J. M.

15% Jaq WF JE JH WwW So
———_——
I.—Derr OBERE JURA DER UMGEGEND VoN HANNOVER EINE PALmON-
TOLOGISCH-GEOGNOSTISCH-STATISCHE DARSTELLUNG, von C. StRUCK-
MANN. (Hans’sche Buchhandlung, Hannover, 1878.)

HILST the English Oolitic rocks are remarkable for the num-

ber of their beds and the organic richness of their contents

in the Lower and Upper Middle divisions of the series, the Oxford-

clay, Kimmeridge-clay, and Portland beds have not yet afforded

corresponding results to the paleontologist, and the student of

Jurassic Geology has therefore to turn his investigations into other

regions in order to obtain an insight into the condition of the shore
life of Oxfordian, Kimmeridgian, and Portlandian strata.

We therefore welcome the appearance of Herr. Struckmann’s
beautiful Monograph on the Upper Jura of Hanover, and recom-
mend its careful study to all students of Jurassic Geology. The
formations described in this work are the Oxford; Coralline Oolite,

1 American Journal of Science and Arts, vol. xvii. p. 85, January, 1879.
DECADE II.—VOL. VI.—NO. Y. 16

226 Reviews—F. V. Hayden's U. S. Geological Survey Reports.

Lower, Middle, and Upper Kimmeridge; the Under, and Upper
Portland ; and Purbeck beds.

The author gives first a short clear résumé of the Geological
relations of each of the formations of the Upper Jura, and the
paleontology of each of the groups into which he has subdivided
them. The Coralline Oolite and the Kimmeridge exhibit a rich-
ness in forms of life very different from anything these formations
present in our English rocks of the same age.

The catalogue of the fossils out of the Upper Jura beds is very
instructive. The author has arranged the remains, consisting of 404
species, in a well-constructed table, which shows at a glance the
name of the fossil, the literature of the species, its distribution in
the different beds, and the locality in which it has been found.
This section of the work has been most carefully executed, and
conveys a large amount of information in a small compass.

In the critical remarks upon the species enumerated in the
catalogue, the author appears to have exercised considerable dis-
crimination, and has pointed out his reasons for differing with many
of the determinations. He has added several new species, and
given beautiful figures of them in the eight plates which accompany
the work.

The concluding section is devoted to a review of the correlations
of the Upper Jura of Hanover, to beds of the same age in the
Swabian, Swiss, and French Jura, and the substance of the author’s
inquiry upon this branch of the subject is embodied in a number of
well-constructed tables, followed by a learned summary of the facts
they disclose. AN:

I1.—Pretiminary Report or tHe Firtp Work or THE UNITED
STATES GEOLOGICAL AND GoGRAPHICAL SURVEY OF THE
TERRITORIES FoR 1878. By F. V. Hayprn. (Washington,
1878.)

ie pamphlet contains a brief summary of the field work by the
Geological Survey of part of the Territories during the season of

1878, which, owing to the delay of the usual appropriation fund for

the work of the Survey, was of comparatively short duration, never- -

theless much additional material was obtained. Four parties were
organized. To the first division was confided the primary triangula-
tion of the area to be surveyed. ‘To the second was entrusted the
making of a detailed survey of the Yellowstone Park. This Park is,
in round numbers, 8,500 square miles. Its surface is in large part
level or rolling, with several groups and short ranges of mountains
diversifying it. In the eastern part, extending its whole length and
forming the water-shed between the Yellowstone and the Bighorn,
stand the rugged volcanic peaks of the Yellowstone Range. Nearly
all of the park is covered with a dense growth of magnificent pine
timber; indeed, west of the one hundredth meridian, there is no
area so densely timbered with the exception of Washington Territory.

The mean elevation of the park above sea-level is between 7,000 and

8,000 feet, which implies too cold a climate to admit of agriculture,

save in certain very limited localities. Except along the northern

Reviews—F. V. Hayden’s U. S. Geological Survey Reports. 227

border, grazing land exists only in small patches of a few acres each.
There are not, so far as is known, any mines or mineral deposits
within the park. The greater portion of the park was found to be
covered with somewhat uniform flows of the ordinary volcanic rocks.
Features of more than ordinary geologic interest occur, however,
along the northern border of the park district. Here a small belt,
not more than 15 by 30 miles in extent, contains a fair epitome of
the geology of the Rocky Mountain region. The whole series of
formations from the earliest to the most recent are almost typically
developed. The only marked irregularity in the succession of geo-
logic events occurred during the great mountain-building period of
the Middle Tertiary. After that followed a number of inferior
oscillations of the surface, during which an extensive series of
recent Tertiary and volcanic rocks were deposited. Connecting this
period with the present are the deposits of a number of great lakes,
which at the present time have their chief representatives in the
Yellowstone Lake.

The third party surveyed the Wind River Mountains, the
Wyoming and Gros Ventres ranges, and a large area of the Snake
River Valley.

Dr. Hayden accompanied the fourth or photographic division, and
the route pursued gave him an opportunity to secure a very accurate
general knowledge of the geological structure of a large area. The
Wind River Range proved one of remarkable interest. It has a
trend about north-west and south-east, with a length of about 100
miles. On the west side all the sedimentary belts have been swept
away, down to the Archean, older than the Wahsatch, and the latter
formation rests on the Archeean rocks all along the base of the range,
seldom inclining more than 5° to 10°. On the east side of the range
the seams of sedimentary formations usually known to occur in the
north-west are exposed from the Potsdam Sandstone, which rests
upon the Archean rocks, to the Cretaceous inclusive.

Along the north-western portion of the range the Wahsatch
Group only is seen for some distance, but as we proceed down the
Wind River Valley the formations appear one after the other, until at
the lower end the entire series is exposed. The Wind River Range
may be regarded as originally a vast anticlinal, of which one side
has been entirely denuded of its sedimentary series, except the Middle
Tertiary. On the same side of the range the morainal deposits and
glaciated rocks are shown on a scale such as we have not known
in any other portion of the West. Three genuine glaciers were
discovered on the east base of Wind River and Frémont Peaks, the
first known to exist east of the Pacific coast.

The morainal deposits are also found on a grand scale in the
Snake River Valley, on the east side of the Teton Range. The
numerous lakes have been the beds of glaciers, and the shores of the
lakes are walled with morainal ridges. North of the Teton Moun-
tains the prevailing rocks are of modern volcanic origin, and in the
Yellowstone Park the hot springs and geysers are the later manifes-
tations of the intense volcanic activity that once existed.

228 Reviews—F. Rutley’s Study of Rocks.

_ Already has Dr. Hayden conferred a great boon on geologists by
the results (published by the Department of the Interior) obtained
by his colleagues and himself during their explorations for some
years past of the Western Territories, one portion of which was
examined and described by Dr. Hayden eighteen years ago.

The publications of the Survey during the last year have been
both numerous and important, including the magnificent Atlas of
Colorado, in twenty sheets (noticed in Grox. Mac. Dee. II. Vol. V.
1878, p. 365).

The tenth annual report of 300 closely-printed pages, with 80
maps, plates and sections, will soon be followed by the eleventh, a
portion of which is already printed, and this again by the twelfth,
for which the materials are ample and of great interest, embodying
the full details of which the present pamphlet is only a preliminary
report.

Tt is to be hoped that no unforeseen circumstances will prevent the
progress of the survey of this remarkable country, which even at
present has been so graphically laid before us by Dr. Hayden, and
that the liberal aid of the United States Government will be con-
tinued towards the final completion of the work so ably begun and
so energetically carried out,—a work, the value of which, whilst it
is of such national importance, is also fully appreciated by Huropean
geologists. J. M.

JI].—Tue Srupy or Rocks. An Elementary Text Book of Petrology.
By Frank Rorttry, F.G.S. 8vo. pp. 319. (London: Long-
mans & Co., 1879.)

BR the publication of this handy little volume, the author has

supplied the want that has for some time been felt by all
geologists, whether learners or workers, of a text-book comprising
within a moderate compass the more essential information con-
cerning the minuter phenomena of structure and association of
minerals in rock masses, which it is now customary to distinguish
as petrology or lithology, and which the student has had up to the
present time to gather, often with considerable labour, from the volu-
minous pages of Zirkel, Rosenbusch, and other Continental writers.

Although the greater part of the work is devoted to the description of

microscopic structure in minerals, the practical details of preparation

of thin sections and other methods of manipulation, the larger
aspects of the subject are not neglected ; the first forty pages being
devoted to a brief but clear description of the phenomena observed
on the large scale in the field—including well-illustrated definitions
of the terms employed in geological surveying; the methods of
representing formations upon maps; the rules to be observed in
collecting specimens, and smaller details of outdoor work. The
art of making thin sections of rocks is very completely described,
several new points, the results of the author’s experience, being
given for the first time. The descriptions of individual minerals,
and the manner in which they group into rocks, are given in
sufficient detail for all the practical purposes required by the

Reviews—Macfarlane’s American Geological Railway Guide. 229

geologist. The forms assumed by skew sections of crystals, and
the relation of the cleavages to the faces in crystals of hornblende,
augite, and the allied species, being represented in large-sized
diagrams.

The manner in which the constituent minerals of rocks vary in
deviations from the normal type is indicated in tables, and by a
graphic method of considerable ingenuity. The weakest point of
the book is in its chemistry, which is somewhat unsystematic, though
such want of system may fairly represent the state of mind of many
mineralogists trained in the older systems of notation, and hesitating
between the many new ones. It would be well in this respect, for
the sake of uniformity, if geologists were to agree to adopt the same
standard system, preferably that of the new edition of Rammelsberg’s
Mineralchemie. An example of eccentric etymology, on p. 101,
millemeter, is calculated to add new horrors to the metrical system,
and we trust that ere long the author may have an opportunity of
correcting it in a second edition.

We had intended to go into more detail in our notice of this very
sterling work; but as the price is exceedingly low, we think it better
to recommend our readers to become possessed of it, and study it
carefully for themselves. Joly 1335

IV.—An American GeronocicaL RatLway GUIDE, GIVING THE
GeEoLocicaAL FormMaTION AT EVERY Ratuway STATION, WITH
Nores on tue Inrerestine Puaces on tue Rourss, etc. By
James Macrartang, Ph.D. (New York: D. Appleton & Co.,
1879.)

R. MACFARLANE is already known to the readers of this
Magazine, by his work “The Coal Regions of America” (see
Grou. Maa. 1874, Decade II. Vol. I. p. 37). Further anxious to render
_ himself useful, he has published the above Geologists’ Railway Guide,
which is both novel and instructive. The object of the author has
been to place in the hands of the traveller a series of geological time
tables indicating the formations which can be observed at the prin-
cipal stations on the railways at present constructed throughout the
States. Prefixed to each State is a list of the geological formations
occurring in it, and which subject is further expanded by about
fifty pages of prefatory matter, containing a general description of
the various geological formations of North America, with tables
showing their succession, and a geological sketch-map of the United
States. There are also foot-notes directing attention to interesting
geological places and objects on the routes of the railroads.
Independently of his own geological knowledge and travelled
experience, Dr. Macfarlane has been considerably assisted in the
work by those geologists conversant with the different districts or
states which he has not personally visited. This assistance has
materially enhanced the value of the guide; and, while it is specially
intended for the use of American travellers, yet the prefatory
matter above referred to will afford much useful information to the

230 Reports and Proceedings—The Geologists’ Association.

reader on this side of the Atlantic who wishes to become acquainted
with the general geological features of the different districts traversed
by railways in the United States and Canada, so clearly and concisely
put before him.

V.— PracticaL Grotocy. By W. Jerome Harrison, F.G.8., ete.
Small 8vo., pp. 157. (London, Stewart & Co., 1878.)

dea is a very clearly expressed and accurate guide to the main
features of British geology, written with the object of tempting

junior students to learn the science as much as possible out of doors.

Descriptions of geological apparatus, and accounts of all the principal

formations, are given, with which are interspersed many notes in

explanation of phenomena to be observed.

Ie e= Oissslis)) 7 AINpaD) ASO Capa Ds NK ers

—————<>_——
Tur Gronocists’ ASSOCIATION.

T a Meeting held at University College, on the Tth March last,

Mr. H. Goss, F.L.S., F.G.8., etc., communicated a paper on

“The Insect Fauna of the Primary or Paleozoic Period, and the

British and Foreign Strata of that Period in which Insect-remains
have been detected.”

After making some introductory observations, and alluding to the
rarity of fossil insects in the Paleozoic rocks of the United Kingdom,
the author stated that on the Continents of Europe and America
fossils of this class had been met with more frequently, especially in
the Coal-measures, and that a few had also been obtained from the
Permian rocks of Saxony, and from the Devonian rocks of New
Brunswick, North America.

The author then alluded to those geologists and zoologists who
had determined and described fossil insects from Palaeozoic recks,
calling special attention to the writings and investigations of
Dr. Henry Woodward, F.R.8., in England; of Prof. Goldenberg,
Prof. Germar, Dr. Giebel, Prof. Oswald Heer, Dr. Dohrn, Herr
Hugen Geinitz, Dr. Geinitz, Prof. Van Beneden, M. Preudhomme
de Borre, M. Ch. Brongniart, and M. Coemans, on the Continent of
Europe; and of Mr. 8. H. Scudder, Dr. Dawson, Prof. Dana,
Prof. Leo Lesquereux, Mr. C. F. Hartt, and others, in America.

The few fossil insects discovered in the British Coal-measures
were then enumerated; they included a beetle and a locust from
Coalbrook Dale, three Orthoptera, described by Mr. Kirkby, from
the neighbourhood of Sunderland, and one insect of that order
from the Scotch Coal-measures, which had been described and
named by Dr. Henry Woodward.

The Permian strata of Continental Europe, in which fossil insects
had been detected, were next noticed, and attention was called to a
remarkable fossil insect obtained from the neighbourhood of Birken-
feld, which belonged to an extinct order, and combined some of the
characteristics of the Newroptera and Hemiptera, and was supposed

Reports and Proceedings—The Geologists’ Association. 231

by Dr. Dohrn to have been descended from a common ancestor of
both those orders.

About 12 other species from the Permian of Saxony, including
2 Hemiptera, and 9 Orthoptera (Blattide), were then enumerated.

The Coal-measures at Wettin and Lobejiin, in Westphalia, and at
Saarbriick, near Tréves, were then referred to; from these Coal-
fields a considerable number of insects had been discovered, the
majority of which had been referred by Prof. Germar and Dr.
Goldenberg to the orders Orthoptera and Neuroptera, and a few to
an extinct order, which had been named by Dr. Goldenberg Palgo-
dictyoptera. A number of other insects from Loebjiin, Mannebach,
Erbignon, Valais (Switzerland), Saarbriick, and elsewhere, which
had been described by Prof. Heer, Dr. Goldenberg, Dr. Dohrn,
Herr HE. Geinitz and others, were then alluded to. One insect
(Blattina Helvetica), from Erbignon, was of especial interest as being,
according to Dr. Heer, the oldest Swiss fossil animal known.

Amongst the most interesting of the fossil insects obtained from
the Belgian Coal-fields was one described by Prof. Van Beneden
and M. Coemans, and which had recently been referred by Dr. Gol-
denberg to the extinct order (Paleodictyoptera) before mentioned.

Another specimen from the same Coal-fields had been referred by
Dr. Breyer and M. Preudhomme de Borre to the Lepidoptera. This
supposed butterfly had been recently examined by Mr. R. M‘Lachlan,
F.R.S., who had decided that the fossil was that of a Neuropterous
insect belonging to the Ephemerina, and a note of his opinion to
this effect had been read in August, 1877, by the Baron de Selys-
Longchamps, before the Entomological Society of Belgium.

The various localities in the Coal-fields of North America in
which insects had been found were then enumerated.

It appeared that all the insects discovered in the American Coal-
measures were either Orthoptera or Neuroptera, though some three
or four of the latter order had lately been referred by Dr. Golden-
berg to the extinct order before mentioned.

The six oldest fossil insects in the world had been obtained by
Mr. C. F. Hartt, in rocks of Devonian age, in the neighbourhood of
St. Johns, New Brunswick. They were all representatives of the
order Neuroptera; though most of them were synthetic, combining
characteristics of two or more families or groups.

The author stated that altogether about 113 species of fossil insects
obtained from Paleozoic rocks had been named and described, 5 of
which were from the United Kingdom, 80 from the Continent of
Europe, and 28 from America; and that they included 3 species
of Coleoptera, 3 Hemiptera, 66 Orthoptera, 27 Neuroptera, and 14 of
the extinct order Palcodictyoptera. These fossils were geologically
distributed as follows, viz. 138 from the Permian, 94 from the
Carboniferous, and 6 from the Devonian.

The author then proceeded to summarize the facts which he had ~
brought under notice in this and his two preceding papers on the
subject. After quoting Prof. Hickel, Dr. Fritz Miller, Sir John
Lubbock and others, as to the supposed origin of insects, and re-

232 Reports and Proceedings—

marking on the vast antiquity of many of the family types of this
class of the animal kingdom, and calling attention to the fact that
the fossil species, even from the very oldest rocks, had, with very
few exceptions, been referred to existing orders, the author observed
that it was evident that the geological record was not nearly old
enough or perfect enough to afford much direct evidence in support
of the theory of the evolution of the existing orders of insects from
inferior organisms. ‘The best evidence afforded by Paleontology in
support of this theory seemed to him to be, that some of the species
from the older rocks were synthetic, combining essential characters
of two or more orders, and that it was probable, therefore, that
if insects should be detected in still older rocks, they might be found
to depart still further from existing types.

Attention was then called to the antiquity of many of the existing
genera, and the very small amount of change, as compared with
that of some other classes of the animal kingdom, which had taken
place in many of them during the geological record.

Mr. Goss then referred to the dates of the apparition of the
various orders of insects on the geological horizon. It appeared
that the extinct order Palgodictyoptera and the Neuroptera were the
oldest orders; that they were followed by the Orthoptera, and that
those orders included, with three or four exceptions, all the Insecta
of the Palzeozoic period, towards the close of which the Coleoptera
and Hemiptera appeared. Harly in the Mesozoic period the two
last-named orders began to be abundant and widely distributed, and
somewhat later were followed by the Diptera and certain families of
the Hymenoptera, and that towards the close of this period other
families of the Hymenoptera, including the bees, appeared; and
about the same time, or early in the Tertiary age, succeeded the
Lepidoptera.

Attention was then called to the important deductions which might
be drawn from a study of fossil insects, as to the probable state of
the vegetation prevailing during the period of their existence. The
author also observed that a comparison of Huropean fossil species
with those now existing in Europe, furnished satisfactory evidence
of the fact that the temperature of the Continent had undergone
many changes, and that the size of the species, the distribution of
genera, and the numerical relations existing between various groups
indicated the former prevalence of warmer climates than those now
existing in the same latitudes.

Gerotocican Society or Lonpon.—I.—March 12, 1879.—Henry
Clifton Sorby, Esq., F.R.S., President, in the Chair.—The following
communications were read :—

1. «On Perlitic and Spherulitic Structures in the Lavas of the
Glyder Fawr, North Wales.” By Frank Rutley, Hsq., F.G.S.

The rock, to the eye and under the microscope, has all the appear-
ance of a felstone, but in the latter also exhibits perlitic structure
as clearly as one of the Saxony perlites. Some of the other felstones
of the Glyder Fawr show numerous spherulites. These felstones
have been determined by the Survey to be lavas of Bala age.

Geological Society of London. 233

_ 2. “The Gold-leads of Nova Scotia.” By Henry S. Poole, Esq.,
M.A., F.G.S., Government Inspector of Mines.

The author remarked upon the peculiarity that the gold-leads of
Nova Scotia are generally conformable with the beds in which they
occur, whence Dr. Sterry Hunt and others have come to the conclu-
sion that these auriferous quartz veins are interstratified with the
argillaceous rocks of the district. With this view he does not agree.
He classified the leads in these groups according to their relations to
the containing rocks, and detailed the results of mining-experience
in the district, as showing the leads to be true veins by the following
characters :—1. Irregularity of planes of contact between slate and
quartz; 2. The crushed state of the slate on some foot-walls ;
3. Irregularity of mineral contents; 4. The termination of the
leads; 5. The effects of contemporary dislocations ; 6. The influence
of strings and offshoots on the richness of leads. The author further
treated of the relative age of the leads and granite, and combated
the view that the granites are of metamorphic origin, which he
stated to be disproved by a study of the lines of contact. He also
noticed the effects of glaciation on the leads, and the occurrence of
gold in Carboniferous conglomerate.

3. “On Conodonts from the Chazy and Cincinnati groups of the
Cambro-Silurian, and from the Hamilton and Genesee-Shale divi-
sions of the Devonian, in Canada and the United States.” By
G. Jennings Hinde, Hsq., F.G.S.

After a sketch of the bibliography of the subject, the author
described the occurrence of Conodonts. In the Chazy beds they
are associated with numerous Leperditie, some Trilobites, and
Gasteropods ; in the Cincinnati group with various fossils; and in
the Devonian strata principally with fish-remains; but there is no
clue to their nature from these associated fossils. They possess the
same microscopic lamellar structure as the Russian Conodonts
described by Pander. The various affinities exhibited by the fossil
Conodonts were discussed; and the author is of opinion that though
they most resemble the teeth of Myxinoid fishes, their true zoological
relationship is very uncertain. The paper concluded with a classifi-
cation of the Conodonts from the above deposits.

4. “On Annelid Jaws from the Cambro-Silurian, Silurian, and
Devonian Formations in Canada, and from the Lower Carboniferous
in Scotland.” By G. Jennings Hinde, Esq., F.G.S.

After referring to the very few recorded instances of the discovery
of any portions of the organism of errant Annelids as distinct from
their trails and impressions in the rocks, the author noticed the
characters of the strata, principally shallow-water deposits, in which
the Annelid jaws described by him are imbedded. A description
was given of the principal varieties of form and of the structure of
the jaws. They were classified from their resemblances to existing
forms under seven genera, five of which are included in the family
Eunicea, one in the family Lycoridea, and one among the Glycerea.
The author enumerated fifty-five different forms, the greater pro-
portion of which are from the Cincinnati group.

234 Reports and Proceedings—Geological Society of London.

II.—March 26, 1879.—Henry Clifton Sorby, Esq., F.R.S., Presi-
dent, in the Chair. The following communications were read :—

1. “ Results of a Systematic Survey (in 1878) of the Directions
and Limits of Dispersion, Mode of Occurrence, and Relation to
Drift-deposits of the Erratic Blocks or Boulders of the West of
England and East of Wales, including a Revision of many years’
previous Observations.” By D. Mackintosh, Hsq., F.G.S.

The author’s researches lead him to the following conclusions :—
Boulders from the North-Criffell range and Lake-district can be
traced from the Solway Firth to near Bromsgrove (about 200 miles),
and over an area in greatest breadth (from near Macclesfield to
Beaumaris) of 90 miles, those from Criffell being particularly abun-
dant near Wolverhampton. Boulders from the Arenig occupy a
triangular area, limited by a line drawn northward from Chirk to
the Dee estuary, and to the south-east of that town are found as far
as Birmingham and Bromsgrove. The dispersion of the more
distant Criffell Boulders would require submergences of from 400 to
1400 feet ; of the Lake-district a little deeper ; while the distant dis-
persion of the Arenig Boulders took place at submergences between
800 and 2000 feet. The author describes several of the more local
drifts, and correlates the Lower Boulder-clay of the North-west with
the Chalky Boulder-clay of the Hast of England. He considers
floating-ice, not land-ice, to have been the agent of dispersion.

2. “On the Glaciation of the Shetland Isles.” By B. N. Peach,
Hsq., F.G.S., and John Horne, Esq., F.G.S.

After an account of previous opinion on the subject, the authors
proceeded to describe the different islands, reviewing in succession
the physical features, geological structure, the direction of glaciation,
and the various superficial deposits. From an examination of the
numerous striated surfaces, as well as from the distribution of
Boulder-clay and the dispersal of stones in that deposit, they inferred
that during the period of extreme cold Shetland must have been
glaciated by the Scandinavian Mer de Glace, crossing the islands
from the North Sea towards the Atlantic. In the island of Unst,
blocks of serpentine and gabbro are found in the Boulder-clay on
the western shores derived from the rock-masses occurring on the east
side of the watershed. Moreover, on the mainland between Scallo-
way and Fitful Head, blocks derived from the Old Red Sandstone
formation on the eastern sea-board are abundant in the Boulder-clay
on the west side of the watershed. The relative distribution of
these stones in the sections on the west coast is in direct proportion
to the relative areas occupied by the rocks on the east side of the
watershed. It was likewise pointed out that after the period of
general glaciation Shetland nourished a series of local glaciers, which
radiated from the high grounds, the direction of the striz being at
variance with the older system, while the morainic deposits also differ
in character from the Boulder-clay produced by the great Mer de
Glace. The authors described the order of succession in the Old Red
Sandstone formation in Shetland, and referred to the discovery of an
abundant series of plant-remains in rocks which have hitherto been

Correspondence—MUr. Horace B. Woodward. 288

regarded as forming part of the series of ancient crystalline rocks.
The plant-remains are identical with those found in the Old Red
Sandstone rocks in Caithness, Orkney, and Shetland, from which it
was inferred that the quartzites and shales in which the fossils are
imbedded must be classed with this formation. The authors also
described the great series of contemporaneous and intrusive igneous
rocks of Old Red Sandstone age, adducing evidence in proof of the
great denudation which has taken place in the members of this for-
mation in Shetland. ;

3. “On the Southerly Extension of the Hessle Boulder-clay in
Lincolnshire.” By A. J. Jukes-Browne, Esq., B.A., F.G.S.

The southern boundary of the Hessle Clay has not hitherto been
satisfactorily determined. The author traces this deposit along the
border of the flat fen land in South Lincolnshire, near Burgh,
Steeping, etc., and the east and west Fen. He concurs with Mr.
Searles Wood in believing the clay to be the product of shore-ice
along a coast-line, and that the materials were in great part derived
from the older “ Purple Clay.” He differs, however, from that
author as to the correlation of the Hessle series, thinking this more
probably older than the oldest river-gravels of the South-east of
England. In an appendix a deep well-section at Boston is discussed,
and reasons are given for assigning the greater part of the beds in
this to the Jurassic Clays, not to the Glacial.

CORRESPONDENCE.

THE MAMMOTH NOT PRE-GLACIAL IN BRITAIN.!

Srr,—Many will regret that Prof. Dawkins has lent the authority
of his name to the opinion that the Mammoth is pre-Glacial in Britain,
but perhaps few may take the trouble to point out how very
unsatisfactory is the evidence he brings forward (Quart. Journ.
Geol. Soc., Feb. 1879). His evidence that the Mammoth is pre-
Glacial in the South of England rests upon the assumption that the
gravel beneath the Boulder-clay at Bricket Wood, between Watford
and St. Albans, is pre-Glacial. There is no proof that it is older than
the Lower Boulder-clay or Cromer Till of the Norfolk coast; on the
contrary, it may be newer. And this being the case, the evidence is of
no value whatever in assigning a pre-Glacial age to the animal-
remains found in it.

Mr. Clement Reid pointed out in a recent number of “ Nature”
(vol. xix. p. 122) that there was no evidence to show that any single
specimen of the Elephas primigenius had been obtained in situ from
the pre-Glacial or Forest Bed series of the Cromer coast—a conclusion
which only bore out the repeated statements of Mr. Gunn and others.
As the subject is one of great interest, perhaps Prof. Dawkins will
kindly state where are to be seen those specimens upon which he
founds his opinion that the Mammoth has been found in the Forest
Beds. Horace B. Woopwarp.

AyisHam, Norwicu.

1 The publication of this letter has been unintentionally delayed.—Epir. Gzou. Mac.

236 Correspondence—Rev. H. H. Winwood.

GEOLOGY OF NORTH DEVON.

Str,—Mr. Kinahan has made a statement in his communication to
you, in February, which I cannot allow to remain any longer un-
noticed. At the end of his “Note in Press,” p. 74, whilst attributing
but little value to the fossil evidence as determining the position of
the North Devon beds, he writes, ‘The species have been collected
without that care and precision which can alone render them of use
in marking horizons. The localities assigned to the specimens, in
the collections chiefly relied upon, are such as Torquay, Chud-
leigh, etc.; where two, if not more, distinct groups of rocks are
developed.” Now, I must leave the South Devon geologists to
defend themselves, and the care with which their collections have
been made, and the localities properly assigned ; they have plenty of
hard work before them in their attempt to correlate these extremely
puzzling beds with the Northern beds. A recent visit to Torquay
strengthens my view of this; but so far as the fossil evidence affects
the question of the regular sequence of the beds, from the Foreland
Sandstones to the Pilton beds, I venture to think nothing can well
be clearer. As to the care and precision with which the collections
have been made, I boldly assert none can be greater. I need only
refer to those of Mr. Townshend Hall and Mr. Valpy; and to the
Catalogue of North Devon Fossils published by the former in Quart.
Journ. Geol. Soc. 1867, p. 376. Mr. Hall’s accuracy and know-
ledge of the North Devon strata will not be questioned by any one
who knows him. And to Mr. Valpy’s keen eye for fossils, his
care in assigning the proper localities to them, and his intimate
knowledge of the coast-line from the Foreland to Baggy Point, I,
who have spent many a long and pleasant day with him, can most
fully testify.

A word as to the stratigraphical position of the beds. If “ Jukes’s
fault” has not been sufficiently disposed of by Mr. Etheridge, I
invite my friend Mr. Kinahan to attend the approaching Meeting
of the Devonshire Association at Ilfracombe, where he, with his
fellow-countrymen, who have looked at the Devon geology across
the water from an Irish point of view, will have a hearty welcome;
and I ask him to prove then to the satisfaction of the Secretary,
Mr. Pengelly, the disproof of an “hypothetical” fault, which has
never yet been proved. Can he do it? ‘The coat has been trailed:
let him take up the challenge. H. H. Wriywoop.

Batu, March 21st, 1879.

KINAHAN’S GEOLOGY OF IRELAND.

Srr,—In Mr. Kinahan’s Manual of the Geology of Ireland (p. 315),
I find a reference to Mr. Jukes’ explanation of the formation of the
valleys in 8.W. Ireland, accompanied by the following footnote:
“Jukes at the time considered that the Cork rocks were once covered
by the Carboniferous Limestone of the central plain. Subsequently
he had to allow that this was incorrect, and his theory formed on the
supposed Limestone hills therefore falls to the ground, although it
is still quoted.”

Correspondence—Ir. Jukes-Browne—Mr. Kinahan. 287

In Mr. Kinahan’s former book, “‘ Valleys and their Relations to
Fissures, etc.,” the following passage occurs: ‘‘ The first of these pro-
positions [that limestone once existed over the whole of S.W. Ire-
land] Mr. Jukes subsequently gave up. ... This, however, does
not much affect the present subject [7.e. formation of river-valleys],
as some of the other rocks are nearly as easily denuded as limestone.”

I should feel obliged to Mr. Kinahan if he would explain the full
meaning of the extraordinary statement contained in the first of the
above quotations, and also how the latter passage is to be reconciled
with the former.

I entirely fail to see how Mr. Jukes’ theory depends on the
supposition that the Carboniferous Limestone once extended over the
South-west of Ireland, and if Mr. Kinahan will carefully re-read the
original paper in the Quart. Journ. Geol. Soc., vol. xviii., I think he
will see that he has been under a misapprehension regarding the
“supposed Limestone hills.” There is only one passage in which
such hills are supposed, and this forms part of a hypothesis men-
tioned only to be presently dismissed as leading to utter absurdity
and confusion. The dominant ridges really involved in Jukes’
explanation are the great anticlinals of so-called Old Red Sandstone
separating the synclinal valleys in Cork and Waterford ; he supposes
the streams to have commenced the erosion of their channels along
the surface of a plain of marine denudation which sloped southwards
from these dominant ridges.

I am aware that Mr. Kinahan has published his idea of the origin
of these and other valleys, and I have no desire to enter into a dis-
cussion regarding his peculiar views; but I must protest against so
summary a dismissal of Jukes’ well-considered theory. I need only
add that I am one of those who believe that it completely explains
the courses of many river-valleys both in England and Ireland.

Hieueats, March 10. A. J. JuKEs-Browne.

PROF. HULL AND G. H. KINAHAN.

Sir,—The statements of Prof. Hull in the Grotogrcat Macazine
for March, 1879, being mostly personal, I cannot think my
answering them would be any advantage to Science. My facts can-
not be disproved, and any one interested in the question can judge
which is right by examining the Irish rocks for themselves. As to
the supposed Permian, if Prof. Hull is mistaken, I am not bound
blindly to follow him; and my opinion as to the age of the
rocks is backed by the opinions of Griffith and others, also by the
fossils found in the rocks. G. Henry Kinanan.

GEOLOGICAL SURVEY oF IRELAND.

OCCURRENCE OF EURYNOTUS IN THE CARBONIFEROUS
LIMESTONE OF BELGIUM.

Str,—Prof. de Koninck has, in the recently published first part
of his new great work on the ‘“‘ Faune du calcaire Carbonifére de la
Belgique,” p. 25, plate iii., described, under the name of Platy-
somus (2) insignis, De Kon., a fish from the Carboniferous Limestone

238 Correspondence—Dr. Traquair—Mr. Dakyns.

of Viesville, a query being appended to the genus on account of
want of evidence as to dentition.

An inspection of the figures by which Prof. de Koninck’s descrip-
tion is illustrated at once convinced me that not only was the query
justifiable, but that the fish in question could not possibly belong to
the genus Platysomus, the scales being represented as strongly
denticulated on their hinder margins, besides being more obliquely
arranged and differing essentially both in sculpture, and in the
position of their articular spines, from those characteristic of the
above-named genus.

I accordingly wrote to Prof. de Koninck, expressing these convic-
tions, as well as my desire to see the specimens; whereupon my
distinguished friend, with great kindness and courtesy, at once
communicated my wish to the authorities of the Royal Museum of
Natural History in Brussels, to whom I am much indebted for the
opportunity of examining one of the specimens referred to.

As I had suspected, I find that it belongs to the genus Hurynotus,
and to a species closely allied to, if not identical with, the well-
known EHurynotus crenatus, of the Scottish Lower Carboniferous
rocks. This genus has hitherto been found only in Scotland
(Agassiz’s “ Hurynotus” tenuiceps, from the American Triassic rocks,
having turned out to be an Ischypterus), and the Viesville specimens
are therefore the first veritable examples of Hurynotus which have
been discovered elsewhere. In geological range, it remains, how-
ever, still confined to the Lower division of the Carboniferous
formation, not a scale of Hurynotus having been as yet found above
the horizon of the Millstone Grit. R. H. Traquair.

EpinspureGH, 14th April, 1879,

THE BRIDLINGTON AND SEWERBY GRAVELS.

Sir,—The gravels overlying the Purple Boulder-clay at Bridling-
ton Quay have been generally considered as decidedly Post-glacial,
if not quite recent.

I cannot now enter into a full discussion of the age of all these
gravels; but a careful examination of the cliff has convinced me of
the Glacial age of a portion of them. IJ made some sketches of the
coast section last November, which I hope some day to publish; and
these will, I think, convince any one of this; but at present I must
confine myself to saying this much. On the north side of the town
the Purple Boulder-clay is overlaid by gravels, which are shown to
be of Glacial age by their contorted bedding, and by the way in which
they are jammed into and against the Boulder-clay. These crushed
and crumpled gravels occur where the cliff is low, extending about
as far as Sands Lane. North of this point the cliff rises at Potter
Hill and continues to rise towards Sewerby ; and along this part of
the cliff the Boulder-clay is overlaid by gravels evenly bedded, which
I call the Sewerby gravels. I shall not now discuss the question of
the relation of these to the previously mentioned gravels. I will
merely say that these Sewerby gravels, though as a rule evenly
bedded, do exhibit in some places near their base contortions and

Oorrespondence—Mr. J. R. Dakyns. 299

erushings, such as bespeak ice-action, or inclose small masses of
Boulder-clay in their lower layers; so that I consider it established,
independently of further considerations, that these gravels at all
events date back to glacial times. I have other reasons for thinking
so, but content myself at present with the above. I would only add
that it by no means follows, because these gravels began to be
deposited before ice-action had ceased in this area, that their deposition
did not continue down to Post-glacial times. In other words, while
their lower part is of Glacial, their upper part may be of Post-
glacial age.

South of the town is a corresponding cliff, consisting of current
bedded sand and gravel, and finely laminated sandy clays (Phillips’
Warp Beds). These do not show any undoubted signs of ice-action ;
they would seem, however, to have once been continuous with the
Sewerby gravels, but to have had their continuity interrupted by the
denudation of the valley by which the Gypsey Race escapes to sea.

In none of the above-mentioned beds have any shells been found
as yet; this, though it proves nothing, is quite in keeping with the
idea of their being of Glacial age, and is possibly due to their having
been deposited in shallow seas freshened by the melting of the great
ice-sheet; the current bedding, dipping now in one direction and
now in the opposite, bespeaks tidal currents in shallow water, and
the warp-like character of the laminated clays is equally suggestive
of a tidal estuary.

I may mention that I have found fragments of marine shells in
sand-beds in the interior in localities where they have not been
noticed before—viz. in the remarkable series of sand-hills running
south from Harpham Moor and at Brigham. These, I suspect, will
turn out to belong to the set of beds described by Phillips at pages
61 and 62 of his work on the Yorkshire Coast.

It is right to add that the gravels at Bridlington mentioned above
are here and there overlaid or replaced by more recent fresh-water
deposits, gravels, and marls. This, of course, is well known.

BRIDLINGTON Quay. J. R. Daxyns.

GLACIAL TROUGHS BENEATH THE GLACIER DES BOSSONS.

Str,—Glacial grooves and furrows are always described in
geological works as running in the direction of the ice-flow which
formed them. That this should, perhaps generally, be the case, is
so obvious that it may seem superfluous to give proofs thereof; nor
are such far to seek; they are these: the direction of the grooves is
often found to coincide with that of glacial striz, with that of the
transport of erratics, and with the direction of motion indicated by
crag and tail, and by the forms of roches moutonnées. Yet it is not
always so. In many cases grooves and furrows, such at least as are
broad and shallow, must have been formed by ice moving not along
but across the direction of the grooves. This would be apt to be
the case especially on steep ground, and such I would call troughs.
I saw a very good instance of this in the year 1873, in the case of
the Glacier des Bossons. From a point in the hill-side beyond the

240 Correspondence—Mr. William Vicary.

pavilion of the Pierre Pointue, and on the right-hand side of the
Mont Blanc route, as you ascend, I got a capital view of the glacier’s
rocky floor, partly laid bare; and made a rough diagram of the form
of the ground, which it is not necessary to reproduce. The bed of
the glacier was seen to be scooped out transversely to the glacier’s
length. It was evident that the rocky floor beneath the ice consisted
of a wave-like series of ridges and hollows running along the hill-
side across the line of ice-flow. The reason of this, and the mode of
formation of the hollows or troughs, was obvious. ‘The rocks over
which the ice is moving consist of a series of crystalline schists, of
varying degrees of hardness, dipping into the hill at a high angle.
Accordingly, as the ice descends, it will wear away the softer
strata more than the harder, and thus scoop out a series of troughs
along the strike of the schists. In the case of the Mont Blanc
range this strike is across the glacier, and thus the latter’s rocky floor
gets furrowed across the direction of ice-flow.

In my sketch is represented in one spot a mass of moraine stuff
caught in a deep hollow in the rocks below the ice.

Another point interesting to geologists, which 1 may mention, is
that the lateral moraines of the Glacier des Bossons are rudely but
distinctly stratified. The layers, as might be expected, dip down
the valley, very much with the fall of the ice. J. R. Dakyns.

BRIDLINGTON QUAY.

MIOCENE OR EOCENE? AGE OF THE BOVEY LIGNITES.

Str,—If it be necessary to remove the Bovey beds from the
Miocene to the Eocene, why not carry them back at once to the
Cretaceous age ?

According to Professor Morris, the Floras of the Tertiary and
Cretaceous have been mistaken one for the other.! Dr. Duncan” says
the mean temperature required for the growth of the Corals now
found in the Haldon Greensand would be equal to 74° Fahrenheit,
which must have been a climate equally favourable to the plants of
the Bovey beds. In fact the Sequoia, a very characteristic fossil in
these beds, also occurs in the Coral bed on Haldon. There would
then be no need of going eighty miles for its nearest neighbour.

Tur Priory, Corurron Crescent, Exerer, Wizitam Vicary.
April 13, 1879.

IMEI SG Ast ao wes oy sO OS)

GxoLoGcicaL SuRvEY or THE TrRRITORIES.—The United States Congress has
sanctioned a scheme for the reorganisation of the American Surveys. It is understood
that the Geological Survey will be placed under the control of Mr. Clarence King,
who has so long had charge of the Geological Exploration of the 40th Parallel; but
no details have yet reached us.— Nature, April 17th.

CPSs PAstee pan
We regret to record the death of James Nicol, F.R.S.E., F.G.S., late Professor
of Natural History in the University of Aberdeen. He published a Guide to the
Geology of Scotland; a Geological Map of Scotland; and is the author of many
original contributions to its Geology.

1 Prof. Morris, on Cretaceous Flora, vol. xv. p. 47, of Popular Science Review.
2 Prof. Duncan, Journal Geol. Soc. Feb. 7, 1879, page 96.

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Caoradoe Corwen. N.Wales

Ramipora Hochstetteri var. carinata, Eth.

THE

GEOLOGICAL MAGAZINE.

NEW SERIES. DECADE II. VOL. VI.

No. VI—JUNE, 1879.

Oleg Geen ASE Astin aa a @ ae se Se

—>—_—_

T.—On toe OccurRENCE oF THE GENUS RaurIPORA (Touna) nN
THe Carapoc Breps or THE NEIGHBOURHOOD OF CoRWeEN.

By R. Erserince, Junior, F.G.S.;
of the British Museum.

(PLATE VI.)

O the recently published paper by my father, “ Paleontology of
the Coasts of the Arctic Lands visited by the late British
Expedition,” ete.,* I contributed some notes on the Polyzoa obtained
during the progress of the Expedition from the Paleozoic rocks of
the regions visited. Amongst other forms I referred at some length
to Dr. F. Toula’s genus Ramipora, and pointed out its affinities to
various genera of Paleozoic Polyzoa, and more particularly to
Synocladia, King, in the following words :—‘“ It appears to differ
from the first of these” (i.e. from Synocladia) ‘in the absence of
dichotomization of the stem and primary branches, so far as the
remains of it are known to us; secondly, in the bilateral symmetry
of the latter; thirdly, in the fact that the cells all open on the same
plane on each side the median keel, whereas in Synocladia the stems
and branches are divided longitudinally by several carinz, between
which the cell apertures occur. Again, in Ramipora both aspects of
the polyzoarium are carinate, but in Synocladia only one. Lastly,
in Synocladia the dissepiments all appear to be regularly celluli-
ferous, but in Ramipora this does not appear to hold good to the
same extent.”

Mr. G. J. Williams, of Tanygrisian, Festiniog, lately brought to
the British Museum some really beautiful impressions, in a grey
micaceous schist, of a Polyzoon found by himself in the neighbourhood
of Corwen, and which constitutes, I believe, an undescribed variety
of Toula’s Ramipora Hochstetteri. So far as I know, Ramipora has
hitherto been met with in the Permo-Carboniferous beds of the
Arctic regions only, and this extension backwards in time of a
Synocladia-like type is a point of much interest. I am also
acquainted only with one species, k. Hochstettert, which the Corwen
form very closely resembles, in many points of detail.

1 Quart. Journ. Geol. Soc. 1878, vol. xxxiy. pp. 668-639.

DECADE II.—VOL. VI.—NO. VI. 16

242 Rh. Etheridge, jun.—On Ramipora in the Caradoc.

A reference to the Plate will show that the habit of the polyzo-
arium is clearly that of Ramipora, as distinguished from Synocladia,
a central or chief stem from which are given off a series of straight
non-bifurcating branches, without any separation by longitudinal
ridges or keels, beyond that occupying the centre of each stem or
branch, and the cells all opening much on the same level; instead
of, as in the latter, a series of continually dichotomizing branches,
longitudinally divided by several carinze separating the cells.

The polyzoarium in this interesting Polyzoon was probably openly
infundibuliform, or basket-shaped, there being a series of the princi-
pal straight stems, all branching off at the base from a common
root, or stolon, but in no way bifurcating or springing from one
another. Four of these stems are shown in the larger specimen,
each giving off laterally, and at subalternate distances, the secondary
stems, which, as in the former case, in no way bifurcate or dichoto-
mize, but proceed direct, and intact in themselves, to the periphery
of the frond. Here and there however, between two of the secondary
stems, similar short (or abortive?) ones arise from the main stem,
which unite directly with the cross-bars or dissepiments. As in
most of these frondescent Polyzoa, the common root is devoid of
pores or cell-openings.

From the secondary stems are given off the interstices, or cross-
bars, by the union of which are formed the mesh-openings, or what
in a Fenestella would be called the fenestrules. These dissepiments
spring from opposite sides of each secondary branch at an acute
angle, and on a level with one another, and uniting more or less in
the middle line between every two contiguous secondary branches,
with those arising from the latter give rise to the broadly v-shaped
fenestrules. Asa rule, great regularity may be noticed in the form
of these openings, taking the whole surface of the frond, but here
and there an irregularly-formed one is to be met with. The section
of the main stems, secondary branches, and dissepiments was bi-
angular or diamond-shaped.

The angular or apical ridge of the various stems and branches of the
frond is devoid of any pores, or other features of interest; but on the
sides of the main stems, immediately under the apical ridge, are two
linear rows of contiguous pores or cells with round apertures, those
of the one row being a little subalternate with those of the other.
There may be a third row, but I have not been able to distinguish it,
and from the width of the lateral portions of these stems I hardly think
there is room for the expansion of the cell-mouths. The description
of the arrangement of the cells on the main stems will also suffice
for that on the secondary stems and the interstices—for I cannot
detect any difference in their distribution. The reverse face of the
frond is, as before said, angular, but non-celluliferous.

So little has been done in this country towards the elucidation of
Silurian Polyzoa, with the exception of the brief original descrip-
tions, mostly by Lonsdale, and scattered through the works of
Murchison,’ that there is always the chance of re-describing or re-

1 And those contained in Prof. M‘Coy’s Brit. Pal. Fossils.

R. Etheridge, gjun.—On Ramipora in the Caradoc. 243

naming some already known form, which may have been noticed
from a mere fragment, and that imperfectly—no matter how carefully
the literature of the subject is searched.

So far as my acquaintance with British Silurian Polyzoa goes, the
only one which could possibly be, in fragments, confounded with
that now under description is Glauconome disticha, Goldf. This
error has been committed in specimens in the British Museum, and
in the Museum of Practical Geology; but after Prof. M‘Coy’s clear
description of G. disticha, an easy separation may readily be
arrived at. Fragments of the latter may be at once distinguished
from those of Mr. Williams’ fossil, by the rounded contour of the
stems and branches on the reverse face, and their granular orna-
mentation, whereas in the specimens now under consideration it is
angular, and so far as known without granules or strie of any
kind. Again, as regards the cell-bearing face; in G. disticha the
pores are large, oblong, thick-edged, occupying the whole width of
the face on each side the central keel, and their ends in contact. In
Ramipora, on the contrary, the apertures are round, similarly
placed, without elevated edges of any kind, merely forming a series
of depressions on the interstitial surface, and separated from one
another by an appreciable distance.

It now only remains for us to consider how far this interesting
Caradoc fossil agrees with the single species of Ramipora hitherto
described, R. Hochstettert, Toula. The arrangement of the branches,
primary, secondary, and ternary, is identical in both; the cross
section of the latter appears to be the same. The chief points of
difference appear to lie in the greater development of the central keel
of the branches, and judging from Dr. Youla’s figure, a greater
regularity in the disposition of the pores. Finally, taking the whole
frond into consideration, the Caradoc form exhibits a tendency
towards a less robust habit. Pending a more complete description
of Rk. Hochstetteri, Toula, I fail to see the advisability of establishing
a new species for this interesting fossil, but shall at present content
myself with considering it as a variety only, under the name of
Ramipora Hochstetteri, Toula, var. carinata (mihi). For those
observers who prefer to look upon the points above brought forward
as of specific value, the designation carinata will, perhaps, be
acceptable in that sense.

The undoubted interest attached to this elegant fossil lies in the
fact of the extension backwards in time of a form only previously
known to exist towards the close of the Paleeozoic period.

Iam indebted to Mr. G. J. Williams for the loan of his really
beautiful specimens. I have also been permitted to borrow a series
contained in the Museum of Practical Geology. For the loan of
Lonsdale’s type specimen of Glauconome disticha, Goldf., contained in
the Murchison Collection, Iam indebted to the President and Council
of the Geological Society. This assemblage of examples, with a few
which unexpectedly came to light in the British Museum Collection,
has enabled me to study a fine series from the Welsh Caradoc rocks.

Localities and Horizon.—“ A little south of the town of Corwen,” in

244. G. J. Hinde—A New Favosite Coral.

beds of Caradoc age (G. J. Williams). Bwlch-y-Gasy, near Corwen,
and near Cynwyd, in a micaceous clay slate of similar age (British
Museum). South of Cefn Coch, near Llangollen, similar matrix and
horizon (Museum Practical Geology).

EXPLANATION OF PLATE VI.

Fic. 1. Ramipora Hochstettert, Toula; var. carinata, R. Eth., jun. Caradoc,
nr. Corwen (Cabinet of Mr. G. J. Williams, Tanygrisian).
la. General view, natural size.
14. Portion of a frond, enlarged about twice (drawn from a plaster cast).
Fic. 2. Ibid. ur. Llangollen (Mus. Pract. Geology, nat. in
Fie. 3. Zid. ur. Corwen (Brit. Mus., nat. size).

IJ.—On a New Genus or Favostre Cora From THE NIAGARA
Formation (U. Sizurian), Manrroutin Isnanp, Lake Huron.

By G. Jennies Hinpz, F.G.S.

ERTAIN zones of the massive grey dolomite belonging to the
Niagara Formation in North America are so largely composed
of fossil corals as to indicate similar conditions of formation to that
of the coral reefs of the present age. Perhaps no better examples
of these Paleozoic coral reefs could be found than those which are
exposed in many tracts of the surface of the Great Manitoulin Island,
which are literally covered with complete and fragmentary corals in
a silicified condition, which have been weathered out of the matrix
of hard dolomite in which they had been imbedded. The great
majority of these corals belong to the well-known genera Favosites,
Halysiies, Heliolites, Alveolites, Coenites, Syringopora, Strombodes,
Cyathophyllum, Zaphrentis and Omphyma, and many of the species
are also common to the Silurian rocks of Hurope. A recent search
in the débris of one of these ancient reefs has brought to light a
coral which appears to belong to a new genus, with the following
characters.
SYRINGOLITES, gen. nov.

Gen. char.—Corallum composite, growing in large flattened masses
with a basal epitheca. The corallites are polygonal, comparatively
thin-walled, closely in contact, vertical in their direction of growth,
and with one or more rows of mural pores on each of their prismatic
sides. In the centre of each corallite is a cylindrical tube, with non-
perforate walls, formed apparently by the invaginated extension of
a series of funnel-shaped tabule. This median tube appears to be

continuous as a rule, though rarely a thin horizontal plate may be

seen crossing it. The upper surface of the funnel-shaped tabule
carries numerous well-marked rows of short septal spines or tubercles,
which converge from the sides of the corallites to the central tube
into which they also extend. In certain examples the walls of the
calices are crenulated by vertical septal ridges.

Obs.—The only genus with which the above is at all closely allied
is that of Roemeria, Edwards & Haime (Polyp. Foss. des Terr. Pal.
p- 253). This genus was formed to include the single species of
Calamopora infundibulifera, Goldfuss (Petrefacten Germ. part i. p. 78,
plate xxxii. figs. 1 a, b), and is thus described: ‘‘ Polypier en masse

G. J. Hinde—A New Favosite Coral. 245

arrondie, polypiérites unis par leurs murailles; planchers infundibuli-
formes.” In the description of the only species of the genus the
authors further add, “Nous ne savons pas, sil existe réellement des
trous aux murailles.” The above generic description is of so wide
and general a character that it would certainly include my new
form, and at first disposed me to refer it to Remeria ; but having had
the opportunity (for which I am indebted to the obliging courtesy
of Professor Andrea, of Bonn) of making a close examination of the
original specimens, upon which Goldfuss and Edwards & Haime
based their descriptions, I find that the differences are too great to allow
the forms in question to be placed in the same genus. Thus in Remeria
(Calamopora) infundibulifera, the corallites have unusually thick
walls, and are not in contact at their summits, which are circular.
There is, further, the very important fact, that no mural pores can be
distinguished in the specimens, notwithstanding the statement of
Goldfuss that such existed; and the character of the corallite walls,
and their separation from each other at the surface of the
corallum, tends to negative the probability of their presence. Again,
there is no appearance in the type specimens of the open central
tube as shown in Goldfuss’ figure (plate xxxii. fig. 1 b), but there are,
instead, funnel-shaped tabule resembling those present in the genus
Syringopora, consisting of a series of elongated closed cones closely
fitting into each other. The specimens of R. infundibulifera may,
indeed, be compared to a Syringopora, in which the connecting pro-
cesses are absent, and the corallites are in contact with each other.
There are, besides, no indications in Reemeria of septal spines. It is
thus apparent that there is sufficient divergence in the characters of
Remeria, as shown in the only known examples of the genus, and
Syringolites, to justify the separation of these forms into distinct
genera.

Syrincotires Huronensis, Hinde.

A. Fragment of a colony of the natural size. 3B. A single calice of the same,
enlarged eight times, showing the central tube and radiating lines of septal tubercles.
©. Part of a corallite of the same, split open and enlarged six times, showing the
composition of the central tube out of invaginated tabule. D. Part of a corallite of
the same viewed from the exterior, and enlarged six times, showing the mural pores.

The only difference between Syringolites and Favosites (Lamarck)
(= Calamopora, Goldfuss) consists in the central tube and the rows
of septal spines on the tabular surfaces and in the tube of the coral-

246 William Davies—On Ovibos moschatus.

lites of the former genus; in all other respects, the resemblance
between the two genera is very close.

The absence of connecting processes, the mural pores, and the
open character of the central tube, sufficiently distinguish Syringo-
lites from Syringopora.

SYRINGOLITES HURONENSIS, Sp. nov.

Besides the above-mentioned generic characters, it may be added
that the upper surface of the corallum is nearly flat; the walls of
the corallites are well defined, and occasionally possess a wavy
outline. The calice formed by the uppermost tabula is moderately
deep, and gradually slopes from the sides to the central tube. The
corallites are of generally uniform size, about one line in diameter,
the central tube is about 2 line wide, and the tabule are about 4 line
apart. ‘There are on the upper surfaces of the tabule about twelve
complete rows of septal tubercles or spines extending from the sides
of the corallites to the central tube, and between these are incom-
plete rows, which only reach part of the distance. The central tube
is of nearly uniform diameter throughout. The mural pores occur
at irregular intervals, and appear to alternate with each other.

The specimens are all silicified and free from the dolomitic matrix,
so that their characters are very distinctly shown. Not infrequently
the central tube has been filled up with silica, and in this condition
it presents the appearance of a solid columella, for which it might be
mistaken.

Formation and Locality.—Not uncommon in the Niagara dolomite
(Wenlock), near Manitouwaning, Great Manitoulin Island, Lake
Huron.

I1J].—On some Recentiy Discoverep TreetH or OViB0s MOSCHATUS,
FROM CRAYFORD, Kent.

By Witt1am Davis, F.G.S.,
of the British Museum.

HE great geological interest which attaches to the fossil remains

of the Musk-ox or Sheep (Ovibos moschatus, Blainv.), found in

British Pleistocene deposits, and the few instances hitherto recorded

of their occurrence (together with a recent discovery brought to my

notice), have suggested to me the desirability of a brief enumeration
of them.

They consist respectively of a portion of a skull, from the
low-level Thames gravel, near Maidenhead, first described by
Prof. Owen;! a fragment of a skull from the gravels of Green
Street Green, near Bromley, Kent; both of which are preserved
in the British Museum; “fragments of the skulls of a male and
female, from the gravels of the Avon at Freshford, near Bath ;”
a “basal portion of a skull obtained from the gravel of Barnwood,
near Gloucester ;” and, ‘a nasal bone, a tibia, and an astragalus,
from the low-level gravels of Fisherton,” near Salisbury; and,
lastly, “the head of a fine bull, wanting the facial bones, dis-
covered and exhumed by Prof. Boyd Dawkins, from the lower

1 Bubalus moschatus, Owen ; Quart. Journ. Geol. Soc. vol. xii. (1856), p. 124.

William Davies—On Ovibos moschatus. 247

brick-earths of the Thames Valley, at Crayford, Kent.1 Of these
nine specimens, six are fortunately characteristic portions of the
skull, these being the most important factors in the verification
of the species, and its authentication as a British fossil. Neverthe-
less, its remains are so rare, that any new discovery of characteristic
fragments which add to the evidence are of sufficient scientific
value to be placed upon record; and such evidence is afforded by the
discovery of the molars of a mandibular ramus, which I detected
amongst a series of miscellaneous mammalian remains, recently
obtained from the brick-earth at Crayford, and which were
submitted to me for examination by my friend, Robert Cheadle,
Hsq., F.G.S.

The specimens consist of the three true molars and the fourth
premolar of the right side. They were found in situ in the jaw,
but unfortunately the bone was too decomposed and friable to be
preserved. The first molar is imperfect, the others are entire and
in good preservation, and they belonged to a large and fully
mature animal, the last lobe of the third molar having just come
into wear. They greatly resemble in their general form and
characters the teeth of Ovis and Capra, inasmuch as they have
no supplementary lobe in the external valleys of each molar, in
their simpler structure, and in being much more compressed
laterally, than are the teeth of Bos or Bubalus.

That they belonged to an individual of large size is inferred from
the measurements of the teeth as compared with the teeth in a lower
jaw of a recent Musk-ox, of about the same age, in the British Museum
(612 f), and with which, excepting size, they agree in all essential
characters. These measurements in inches and tenths, are as follows:
—Combined length of series of four last molars in situ—Fossil, 5:6 ;
Recent, 4:5. Measurements of teeth, separately :

Foss. RECENT.
M. M. M. P.M. M. M. M. P.M.
IIl. Il. I. M. III. Il. I. Ty.

Antero-posterior length | 1°85 | 1: 4] 1: 1] 0°86 || 1° 6 1:12 | 0°9| 0-8
Transverse diameter of

anterior lobe ......s.... 0-75 | 0°78 | 0:75 | 0: 5 || 0: 6 | 0: 6 | 0°59 | 0:45
Do. do. second lobe | 0°64 | 0°73} 0: 7 | 0:44 || 0- 5 | 0°58 | 0°57 | 0°41
Do. do. third lobe | 0°35 0°32

The recent jaw I assume to be the specimen from which Prof.
Boyd Dawkins obtained the measurements given in his Monograph
(op. cit. p. 138), as they exactly coincide with those given above,
taken by myself.

With regard to the position in the brick-earth, Mr. Cheadle
informs me that the teeth were found in the well-known chalk-pit

1 See an exhaustive memoir upon the osteology, geographical range, and geological
distribution of this interesting Arctic animal, by Professor Boyd Dawkins, F.R.S.,
“ Pleistocene Mammalia,’ Part V. (Ovibos moschatus) ; in the Monographs of the
Paleontographical Society for 1872.

248 Prof. CO. H. Hitchcock—Glacial Period in E. America.

through the tunnel, and in the clay near the zone of the “ Cyrena
bed.” This, although in the same deposit, would be at a higher
level than that of the skull already mentioned, and, therefore, cannot
be supposed to have belonged to it. The deposit is rich in remains
of Mammalia, both of extinct and still existing species; the teeth
and bones of Elephants, Oxen, Deer, and the Horse predominating ;
those of the Rhinoceros (three species), although frequent, are far
less common; whilst the remains of Carnivora are rare.

Whether these brick-earths are Pre-glacial, as Prof. Dawkins
supposes them to be, or, as more generally considered by geologists,
belong to a later period than the true Glacial epoch, they contain,
curiously commingled, the débris of animals which were respectively
inhabitants of temperate and of rigorous climes. The species, exclud-
ing the Invertebrata, whose remains are recorded as having been
found at Crayford, are the following :—

Ursus ferox, Linn. Cervus elaphus, Linn.

», arctos, Linn. Elephas antiquus, Fale.
Felis spelea, Goldf. » primigentus, Blum.
Hyena spelea, Goldf. Equus fossilis, Mey.
Canis lupus, Linn. Rhinoceros tichorhinus, Cuv.
Bison priscus, Ow. “4 leptorhinus, Ow.
Bos primigenius, Boj. 3 megarhinus, Christ.
Ovibos moschatus, Blainy. Arvicola amphibia, Desm.
Megaceros Hibernicus, Ow. Spermophilus erythrogenotdes, Fale.

The fossil remains of the Musk-ox are as equally rare in the
Upper Tertiaries of the European continent as in England. Prof.
Dawkins cites three localities in France, and four in Germany,
where its remains have been discovered. They have also been
found in three places in Siberia; and also in the frozen mud cliffs
of Eschscholtz Bay, on the coast of Arctic America, but nowhere
abundantly ; and only in one instance, and that a single tooth, “in
the gravel of the Oise,” near Chauny, France, have the teeth,
previously to those here described, been found. It is assumed, on
account of the paucity of its remains in Europe, that it was only an
occasional wanderer so far south of its usual habitats.

The distribution of the existing Musk-ox is at present limited to
the barren lands of Polar America, between the 60th and 88rd
parallels of latitude. During the late Arctic Hxpedition a fine bull
was shot near the coast of Grinnell Land, in latitude 82’ 27” ; the
stuffed skin of which is exhibited in the National Collection.

IV.—Tue Guactat Preriop in Hastern AMERICA.
By Prof. C, H. Hrrcucocx.

ECENT studies of the glacial phenomena as exhibited in the
State of New Hampshire and adjoining regions enable us to
maintain the following propositions.
1. The ice-sheet at the time of its maximum development passed
south-easterly over all New England, New Brunswick and Nova
Scotia. It came from the St. Lawrence Valley, where all the

Prof. C. H. Hitchcock—Gacial Period in E. America. 249

observed striation is at right angles to this south-east course, and
travelled directly over the highest ridges and summits towards the
sea. I find upon the summit of Mount Washington boulders weigh-
ing 90 Ibs. that have travelled certainly ten miles and ascended as
much as 4000 feet above their source. I also find strize and ‘till’
there. Heretofore the top of this mountain, 6291 feet above the sea,
has been regarded as a glacial island.

2. In the decline of the ice period local glaciers radiated from the
White and Green Mountains. Those passing southerly were the
most conspicuous. Their traces consist partly of striz, and, in their
absence, of transported material. Careful preliminary studies of the
position of the several formations has made such identification
possible.

3. The till consists of two parts, called lower and upper, and
believed to be the equivalents of the corresponding parts of the till of
the British Islands. The lower consists of bluish compact earth
containing small striated and far-travelled boulders, with occasional
lenticular gravel sheets. Its iron oxide is mostly ferrous, the same
as that of the rocks before transportation. The upper till is
universal; is a reddish-brown loose material with imbedded and
overlying rough blocks of large size which have usually travelled a
short distance. The iron oxide is hydrous ferric. The description
of the common varieties of the Scottish till, by James Geikie, in the
Great Ice Age, second edition, p. 116, seems to agree with this, All
these facts, especially the condition of the iron oxide, necessitates
the belief that our lower till is the proper ground moraine, while the
upper till consists of all the ice-borne materials (lateral, median and
much of the terminal moraines with imbedded detritus), which fell
upon the subjacent hard face when the ice melted. The upper till
would therefore cover the lower deposit uniformly and universally,
save where enormously accumulated in the terminal or frontal
moraines; and the original anhydrous ferrous oxides would absorb
water and oxygen by exposure to air and water during the melting
process. Careful analyses confirm our impression of this diverse
nature of the iron oxides.

4. No facts seen confirm the theory of the presence of a
universal interglacial warmer period. The few marine beds lying
between the two tills contain boreal fossils, or the remains of such
animals as now flourish in Greenland, and they are covered only by
our upper till. A true ground moraine never overlies the inter-
glacial beds. An excellent case may be seen at Portland, Maine, where
we find, first, enormous deposits of lower till; second, marine beds
(called Champlain) containing 121 species of fossils, reaching to 100
feet above the present sea-level, thus indicating a submergence of
that amount; third, deposits of upper till, 25 feet thick, covering
uniformly both the lower till and the marine beds. Recent excava-
tions made in grading the streets show these facts incontestably.
Hence it seems plain that for a brief period the glacier retreated a
short distance, allowing the marine beds to accumulate just as they
do now in Greenland ; then the ice re-advanced so as to cover the

200 Prof. C. H. Hitchcock—Glacial Period in EL. America.

fossiliferous deposit, bringing a load of coarse ferric material, but no
ground moraine. The ice soon melted, and thus the upper till was
precipitated upon the previously formed floor. In the Champlain
and St. Lawrence valleys no occurrence of till overlying the marine
beds has yet been observed ; so that the recurring glacial conditions
were too insignificant to cause a re-advance of the ice-sheet less
than 200 miles to the north of Portland.

5. All the facts of striation and drift dispersion from the Gulf of
St. Lawrence to the Rocky Mountains are best explained by the
existence of a central mer de glace in the Labrador peninsula, or
somewhat farther west. 'Torell and Dana have maintained that the
starting-point of the glacier was in Greenland; but we find (a) the
glacial movements from the Labrador peninsula have been towards
Greenland instead of away from it; (b) the Greenland ice must
have been twenty-two miles high to flow to the Saskatchewan
region; (c) the bridging of Davis Straits could be hardly possible.

6. The Labrador plateau is lower than the New England hills.
To overcome this difficulty Professor Dana supposed there had been
an elevation of the northern Laurentian watershed, sufficiently
gigantic to allow of a south-east sliding of the ice. There is no
evidence of such elevation of the land beyond the requirements of
the theory. It will be easier to accept Dr. Croll’s view that the ice-
sheet itself became miles in thickness, by the gradual retention of
frozen moisture, and moved then as readily as if a less amount
capped high mountains. It first moved south-westerly as far as
Manitoba, Dakota, and Missouri ; then when the St. Lawrence Valley
became filled to the brim, the surplusage moved towards the Atlantic
in a south-east direction. Hither of these theories is extreme ; but
there seems to be no escape from accepting one of the two horns of
the dilemma.

7. The south edge of the American ice-sheet is well marked by
the presence of enormous terminal moraines, coupled with extensive
sand and gravel plains washed from the glacial debris by the waters
derived from the melting ice. The eastern extremity is at Cape
Cod, Massachusetts, and Long Island, New York. ‘These long drift
hills, consisting largely of gravel and sand, are isolated from all present
appearance of connexion with any possible higher land from whence
the depositing waters could have flowed. By supposing that they
formed the front of the glacier just before its decadence, it is easy to
understand both how an immense supply of drift material was
furnished, and the origin of the freshwater streams which formed
plains and hummocks of stratified sand far above the present water-
level. A study of the writings of all the State geological reports
enables us to discover more than one continuous moraine line, from
Massachusetts to the Red River country west of Manitoba, save in a
portion of Pennsylvania, which needs further study.

W. A. E. Ussher—Pleistocene Geology of Cornwall. 251

V.—PLEIStoceNcE GEOLOGY oF CoRNWALL.!
By W. A. E. Ussuzr, F.G.S.
Part [VY.—SusmMerGeD Forests AND StReAM Tin GRAVELS.

HE evidence under this head is necessarily a compilation; the
very exceptional exposure of the old forest ground, and the
nature of stream tin sections, leaving no room for personal investi-
gation. The names of the observers are in most cases sufficient
vouchers for the accuracy of their statements. The submerged
forests are given first, as there is no evidence forthcoming to show
the priority of the stream tin gravels to the general growth of the
forests. The forest bed overlying the stream tin which Mr. Carne
rightly synchronizes with the forest beds on the coast may represent
a very brief portion of a long period of forestial growth.

Submerged Forests.—Proceeding round the coasts from Plymouth.

1. Looe. Mr. Box (26th Ann. Rep. Royal Inst. Corn. for 1844)
noticed trunks of oak, alder, ash, and elm, on Millendreath Beach,
in vegetable mould extending for 250 yards from east to west, and
sloping from below high-water mark to the southward for 150 feet,
where it was lost sight of under fine sand, which, though explored
for 50 feet farther out, yielded no further traces. The plants in the
mould resembled those found in a neighbouring marsh, 130 feet
above high water, of which the following section is given :—

Peat of flags and arundaceous plants.

Dark brown vegetable matter with holly and alder.

Layer of sand with vegetable matter, numerous hazel nuts, and the elytra
of Coleopterous insects, also black oak and ? holly, resting on firm light-
coleured clay.

Numerous angular slate fragments were met with, but no shells.

2. Near Mevagissey. Sir C. Lemon (T.R.G. 8. Corn. vol. vii. p.
29) gives the following section disclosed in cutting a drain at Heli-
gan (about a mile inland from Mevagissey Bay) near the foot of a
hill 20 feet above the stream in the valley bottom, and in another
place, higher up, at 40 feet above the stream :—Loam 1 foot 8 inches
from the surface, upon a mass of whitish, bluish, and yellowish clay
with broken slate, with the stump of an oak 4 feet long and nearly .
afoot in diameter, 7 feet 4 inches from the surface at its lower
extremity.

Submerged forests have been observed after severe gales—

3. At Fowey by Mr. Peach (T. R. G.8. Corn. vol. vii. p. 62), the
trees being rooted in stiff clay.

4, At Porthmellin, near Mevagissey (Ibid, vol. vi. pp. 23 and 51),
the roots resting on clay apparently 7n situ.

5. At Maen Porth, near Falmouth, by the Rev. J. Rogers (Ibid,
vol. iv. p. 481), the roots being in clay.

6. At Porthleven near the Loo Pool, by the Rev. J. Rogers (Ibid,
vol. i. p. 286), oak and willow roots apparently in situ. At Fowey
and Porthmellin, elytra of beetles were found.

7. Mr. H. M. Whitley (Journ. R. Inst. Corn. No. 18, p. 77) gives

1 Continued from the May Number, p. 211.

252 W. A. H. Ussher—Pleistocene Geology of Cornwall.

the following section at Market Strand, Falmouth, exposed during
excavations at the Landing Pier :—

Layer of sand on a thin bed of shale, thinning out seaward ... 2ft. Qin.
on—Forest Bed, compact peat, flags, ferns, trees of oak, hazel,
fir, beech ; fir and beech most abundant; no hazel nuts obtained 7ft. Oin.
The top of this bed occurred at about the level of ordinary
spring-tide low-water mark. Its base rested on a layer of
gravel Sree . 4ft. Oin.

Mr. Whitley was informed that the forest bed extended for a short
distance up the valley, and that another part of it had been met with
in an excavation at Bar Pools. The open space before the market is
called “the Moor.”

8 a. Mounts Bay. Leland thus alludes to the submerged forest
in Mounts Bay—‘“‘In the Bay betwyxt the Mont and Pensants be
found near the lowe water marke Roots of Trees yn dyvers places as
a token of the ground wasted.”

b. Dr. Borlase (Trans. Roy. Soc. for 1757, p. 80) noted the dis-
covery of roots, trunks, and branches of oak, hazel, and willow, on
the shores of Mounts Bay, in black marsh earth with leaves of
Juncus, under 10 feet of sand.

ec. Dr. Boase (T. R. G. 8. Corn. vol. ii. p. 181) mentioned the oc-
currence of vegetable mould with roots and trunks of indigenous
trees, under 2 to 3 feet of sand on the west of St. Michael’s Mount.

d. Mr. Carne (T. R. G. §. Corn. vol. vi. p. 230) noticed the occur-
rence of trees on peat, east of Penzance, the largest being an oak
trunk with bark on, 6 feet long and 14 feet in diameter.

e. He also mentioned the occurrence of a peat bed 38 to 8 feet
thick in the low tract between Marazion and Ludgvan (a reclaimed
marsh); it extends for 2 miles, from a little eastward of Chyandour
to the Marazion River. Near Longbridge, where it approaches the
surface, it is from 4 to 7 feet thick, and used for fuel; it rests on a
thick bed containing Cardium edule, and is generally concealed by
alluvium.

9. Mr. Henwood (40th Annual Rep. R. Inst. Corn. for 1858)
describes a submarine forest on Dunbar Sands in the Camel Hstuary.
Nothing save spongy masses of peaty sand were visible in 1875, when
I visited the spot, the roots, etc., having been probably washed away
in the interim.

10. De la Beche says that traces of submarine forests were noticed
at Perran Porth, Lower St. Columb Porth, and Mawgan Porth.
(Report, p. 419). No signs of them were visible on the occasion of
my visit. St. Columb Porth is a sand flat, at low water, between
cliffs not 10 feet in height, exhibiting no traces of old marine action.
Mawean Porth is a similar sand flat, but broader, and terminating in
low sand dunes, to the south of which narrow strips of alluvium
border the streams.

11. Bude. Mr. 8S. R. Pattison (T. R. G. 8. Corn. vol. vii. p. 35)
noticed roots of trees of large size, apparently in situ, in dark clay, at
-Maer Lake, near Bude Haven. -

12. Mr. Pattison also noticed large accumulations of bog timber
in the Fowey Valley on Bodmin Moor. At Bolventor the heads of
the trees pointed down the valley.

W. A. E. Ussher—FPleistocene Geology of Cornwall. 258

Stream Tin Sections.

1. De la Beche (Report, p. 405) says that in the interior the tin
ground is usually covered by river detritus, more open spaces fre-
quently having a bed of peat (in which oaks are common) interposed
between the tin ground and other detrital accumulations, as in
Tregoss Moor and the moors adjacent to Hensborough. ‘In some
whole ground (stream tinners’ term for stanniferous gravel) and
superincumbent beds not previously disturbed by the old men, upon
Bodmin Coast Moor, the peat beds with oak, alder, etc., covering
the tin ground very irregularly, were in some places several feet
thick, in others absent, though on the whole they seemed to keep a
somewhat common level above the tin ground. In some places thin
peat beds had been accumulated at still higher levels among the
gravels, sands, and clays. The shelf composed of semi-decomposed
granite was very irregular, holes 30 or 40 feet deep presenting
themselves, in the bottoms of which there was usually good stanni-
ferous gravel.”

2. Mr. Pattison (op. cit.) gives a section of the Fowey Valley Works,
in which the (hard and black) forest bed was met with at from
23 to 27 feet below the surface, resting on stream tin gravel, and
overlain by sand with a peat bed containing ferns and hazel.
The granite shelf, tin gravel, and forest bed presented a faulted
appearance.

3. Par. De la Beche (Report, p. 403). In cutting the Par Canal
at Pons Mill, near St. Blazey, granite blocks, as if arranged for a
bridge, were found beneath 20 feet of gravel, probably in part
resulting from stream tin washing. Section in low ground near the
Par Estuary—

1. River deposits... .. 1ft. 6in.
2 and 3. Mud, sand, clay, stones, “much disturbed by the
stream tinners in the upper part; with vegetable

matter in the lower part ... 1dft. Qin.
4. Fine sand with sea shells like cockles, ‘and rolled

pebbles in the upper part ... .. dod. Soc 4ft. in.
5. Mud, clay, sand, wood, nuts, ete. , mixed. s see sft. Qin.

6. Tin ground resting upon an uneven surface of slate ... Gin. to 6ft. Oin.
4. North of St. Austell. Mr. Henwood gives the following
sections. The letters prefixed denoting beds probably contempor-
aneous. (T.R.G.S. Corn. vol. iv. pp. 60 to 64.)
A. Merry Meeting, in parish of St. Roche.

a. Mud, with decayed vegetable matter ... ... ... .. ... 2ft. to 3ft.
1. Granitic gravel -, Ps 2ft.
2. Silt, with decayed vegetable matter and plates of mica ... 4ft. to dft.
b. Granitic stones, eravel and sand mixed with silt and nuts ... 4ft.
3. Vegetable matter Ce called nae moss, ae wood

(? charred) ... Se cus ttess 633) 099 an ons lit.
4. Silt (vegetable remains ?) Gai) (Gag eco.) aoe 1ft.
5. Vegetable remains (charred like No. Be io) God.) dod.) Spas aelilte THO bt,
6. Vegetable matter passing into silt ... . 8in. to 10in.
c. Tin ground, with enormous quartz blocks, some 165 ft. square ;

tin ore as sand, stones, and pebbles mixed with quartz,
granite, and schorl rock ; little rounded, and of the best
quality where the decomposed granite shelf is softest... ... 4ft. to 30ft.

254 W. A. E. Ussher—Pleistocene Geology of Cornwall.

B. In the centre of Pendelow Vale.

a. Granitic sand and oe ® ec MpS Sey leeel iiveslidees Lusaenmece wl othe. QaT,
il, (Sits Q@rag@ralalig mentee) 55 cap doa doo goo coo coo Hails Oh
2. Granitic sand... 4ft. in.
3. Vegetable matter (like ‘No. 5 in other sections, but with ‘sand) 2ft. Qin.
b. Silt, sand and gravel mixed... soo ong At Oita,
4, Vegetable matter (like No. 5 in other sections) (Fen) 4ft. in.
5. Tin ground, ore not abundant, most plentiful near the base ft, Oin.
C. Watergate.

a. Mud with granitic sand and gravel... «wee ee 5ft. in.
1. Fine granitic sand .. aso) coo 60a, Al WO antin. (Orin,
2. Silt (with decayed vegetable matter rf) . goo, G00 000 2ft. 6in.
3. Fine granitic sand .. ... SOA, cho” 1odb. cog) abil HO) ia,

4, Silt (resembling No. 2) ... ... 30 sft. Qin.
b. Silt, sand, gravel, and large stones , indiscriminately mixed éft. Qin.
5. Vegetable matter passing into silt in the lower part (like

Nos. 5 and 6 in the Merry Meeting section) ... ... dft. to 6ft.
c. Tin ground; the ore occurs as sand ‘and pebbles... ... . 2ft. to 20ft.

D. Broadwater, Luxillion. Tin ore much Teer towards the sea
than up the vale. A patch of slate some hundreds of feet in area

was found resting on tin ground, and apparently unconnected with
the shelf.

a. Granitic sand ... eeeeey Onb etOp/ them Outs
b. Mud, apparently of vegetable origin, ‘mixed with granitic

sand and gravel. ... .. w. 4ft. to dft. in.
ce. Tin ground; ore, small pebbles not much rounded... 7ft. Qin.

The tin bed is sometimes divided by a bed of granite (cap shelf)
as at Grove and Merry Meeting. Numerous blocks of quartz lie on
the shelf. Below the shelf (soft granite) tin ore is not abundant.

The following are from Journ. R. Inst. Corn. vol. iv. p. 214 :—

H. Levrean in St. Austell’s parish.

1. Granitic sand and gravel ... 1ft. Oin.
2. Peat (Fen), often mixed with, and sometimes divided
by, very thin layers of granitic sand eee 1ft. in.

3. Granitic matter, particles and granules of tin, ‘rarely

minute specks ‘of gold (Upper Tin Ground) ... ... 38ft.to 6ft. in.
4. Angular and subangular masses of granite in granitic

sand without any ‘tin ore (False Shelf) ... ... ... ft. to 1yft. Oin.
5. Tin ground; angular and subangular granite, felspar,

quartz, schorl, veinstone materials mixed with

granitic gravel and sand, grains and particles of tin

oxide, and less frequently flakes of schistose matter

with specks of gold. A few ancient shovels of

wood, bound on “the edges with iron, have been

found in this bed. The shelf is of granite of

unequal hardness... .- lOft. to 15ft. Oin.

F. Pit Moor in St. Austell’s Didhs
ils Weewmole maomllel on doo odd, fond 000 doo!) obo a08 1ft. Oin.
2 and 3. Granitic detritus in many ‘layers ASS .. oft. to 6ft. Oin.

4, Tin ground; angular, subangular, and rounded
masses of granite, quartz, schorl, veinstones, small
quantities of tin ore ; clay-slate lamine, occasional ;
on soft granite Shel G MESA cstil Sa est setbete MUSHE MtoMNOtE (Gin:

G. Upper Creamy (Wheal Prosper).

1. Peat . Oft. 6in.
2. Granitic clay, often mixed with lamin of yellowish slate Lift. to 3ft. in.
3. Tin ground; small angular and rounded granitic and

W. A. E. Ussher—Pleistocene Geology of Cornwall. 2565

veinstone material; tin stone as sand and gravel;
microscopic particles of gold. On shelf of bluish and
brownish clay. The roots of marsh ee Date
the tin ground... 4ft. to 5ft. Qin.

H. N.W. of the Tavis Bridge” over the high road between
Lanivet and the Indian Queens.

1. Vegetable mould... 6in. to 1ft.
2. Angular and subangular. stones of. quartz, slate, elvan,
schorl rock, slate veinstones, and occasionally granite din. to 4ft.

3. Tin ground ‘like the overburden, but with rounded
masses of tin ore, often ah small; on shelf of clay

slate ... GO 06) OGG. 060 con) 600, ode 1ft. to 2ft.
I. Gun-deep in St. Denis!
1. Vegetable mould... 6in. to 1ft.
2. Gravel, stones of slate, quartz, elvan, ‘schorl. rock, and
occasionally ¢ REMIND | 'ba6'! B86 ech", (Gbe! Seog? oda BO 4ft.
3. Peat . oor 1ft.

On 4. Tin ground; ‘poor.

J. On N. side of Tregoss Moor. Ancient works resumed at Golden
Stream about half a mile 8.E. of Castle-an-dinas in St. Columb Major.
1. Vegetable mould... Oft. 6in.
2. Angular and subangular n masses of slate, quartz, elvan,
schorl rock, veinstones, and occasionally granite ;
lumps of peat had been previously removed from this
bed A .. Oft. to 6ft. Oin.
3. Tin ground “resembling the overburden, ‘but with more
numerous fragments of elvan; the tin ore as gravel
or sand . . .» 2ft. to 3ft. Oin.

K. Dr. Boase (Tr. R. G. S. (Cor. sk Ft 2 248) mentioned the
occurrence of siliceous sand under diluvial debris in the Stream
Works near Hensborough, on the road to Roche. At Tregoss and
Roche the tin ground contained quartz and schorl pebbles, and the
shelf consists of decomposed slaty felspathic rock.

L. Henwood (J.R. Inst. Corn. vol. iv. p. 230). Section at Penny
Snap (Wheal eae in Alternun) H. of the Drains River—

IL, JEGENG G0 c60 : 7ft. Oin.
2. Angular and worn eranite, elvan, ‘schorl, and quartz stones

in 1 pale blue felspathic clay, averaging... dft. Oin.
3. Tin ground as above, with tin ore as waterworn sand 0 or

erayel; on granite shelf ... ... 006 3ft. Oin.

5 A. The section of the Happy Union “Works: iy Mr. Colenso
(1829) has been quoted by several writers, but by none more fully
than De la Beche, from whom I extract (Report, pp. 401, 402, 403),
giving the deposits in reverse order.

1. Rough river sand and gravel, here and there mixed with sea

sand and silt. A row of wooden piles with their tops 24

feet from the surface, apparently intended for a bridge,

were found on a level with spring-tide low-water ... ... 20ft. Oin.
2. Sand; trees all through it, chiefly oaks, lying in all directions;

animal remains, bones of red ee hog, human skulls (2),

bones of whales. ... .. 2 Ofie One
3. Silt or clay and layers of stones, ‘a conglomerate of ‘sand,

silt, bones and wood ... .. 2ft. in.
4, Sand with marine shells; water draining through this bed

is salt above, fresh below oes Oft. 4in.

5. Sludge, or silt, brownish to a lead colour in places, with

256 W.A. E. Ussher—Pleistocene Geology of Cornwall.

recent shells which, particularly the bivalves, are often in
layers, double and closed, with the siphonal end upward,
rendering it likely that they lived and died there; they
are of the same species as those existing in the neighbour-
ing sea; wood, hazel nuts, and occasionally bones and horns
of deer and oxen are found in this bed: a piece of oak,
shaped as if by man, with a barnacle attached, was found
at 2 feet from the top . eee Often O1ns
6. A layer of leaves, hazel nuts, “sticks, and moss (in a perfect
state, almost retaining its natural colour apparently where
it grew). It extends, with some interruptions, across the
valley, occurs at 30 feet below low-water mark, and about

48 feet below spring-tide high-water... .. .. Gin. to 12in.
- Dark silt, pee mixed with decomposed "vegetable
matter ... 1ft. Qin.

8. Roots of trees in their natural position ; oaks with fibres
traceable for 2 feet deep. ‘From the manner in which
they spread there can be no doubt but that the trees have
grown and fallen on the spot where their roots are found.’
Oyster-shells still remain fastened to some of the larger
stones and to the stumps of trees... .
9. Tin ground, with rounded pieces of granite, ‘and subangular
pieces of slate and greenstone. Most of the tin occurs in
the lower part, from the size of the finest sand to pebbles
10lbs. in weight; some rocks riehly impregnated with tin
weigh 200lbs. and ae Thickness Cae No.
8) from wu. ws ... oft. to 10ft.
B. De la Beche (Report, p: 408) says, “These works are now
abandoned,” others on 8. of London Apprentice Inn were carried on
in 1837: “from which it would appear that from the general rise
of its bottom, the sea had not entered this valley sufficiently high
to permit marine deposits to be there accumulated.” This probably
refers to Mr. Colenso’s section of Wheal Virgin Works (T.R.G.S.
Corn. vol. iv. p. 38), a mile from Happy Union, in which no sea
sand was found. The tin ground betraying signs of old men’s
workings lay beneath 382 feet of silt and river gravel, with oak,
willow, etc., in considerable quantity, with their roots in situ where
soil exists. ‘‘ How far,” says Mr. Colenso, ‘“ Pentuan Valley extended
seawards is conjectural, but at its present declivity of 45 feet to
a mile between St. Austell and Pentuan, it must have continued
a mile further than it does now.” Mr. Smith (Ibid, p. 400)
mentions the rapid descent of the valley from Hensborough (900 to
1000 feet in height), and the continuance of a bed of pebbles all
the way.
C. Section of Lower Pentewan work, quarter of a mile from the
beach given by Mr. Smith (op. cit.)—

1. Soil with growing trees, some very old; gravelly towards

the bottom Bod 3°3
2. Fine peat, roots of trees, ‘fallen trunks, ‘sticks, ivy, sea
layer, rushes, impregnated with salt ... 127152

3. Sea mud, with compressed leaves at the top, “cockles at

31 feet from the surface, bones, human skulls (one of a

child) deer horns. At the boron a bed of oy small

shells a foot in thickness... .., 20°35
. Sea mud, oysters, and cockles ... .. 4:39
- Compressed leaves, vegetable matter, : a few rotten shells 63°453
. Vegetable matter, rushes, fallen trees, leaves, roots, moss,

the wings of Coleopterous insects ... 12, 20 e+ eo ‘L465

DO

W. A. E. Ussher—Pleistocene Geology of Cornwall. 257

7. Moss, hazel nuts, sticks, on pebbles of killas, growan, ete. 3°
8. Rough tin ground, stones light and poor . 2:
9. Rough tin ground, rich stones with quartz pebbles and
yellow ferruginous clay. Killas at about low-water mark 37544
D. (op. cit.) Section of Upper Pentuan works, 1 mile N. from the
beach, where the valley is half a mile wide.

492
513

1. Soil with trees growing on it pele Say 8ft. 3in.
2. Mud with gravel seams resembling false bedding BBS Us es 21ft. lin.
3 and 4. Spar and killas upon growan, spar, and killas ... 12ft. Yin.
5. Gravel, with trees and branches of oak of great size at the

Bottom © Pee Se ne FN Eat waacnlacd ah 8ft. Oin.
6. Tin ground ... 000 8ft. din.

tc Clay, i in which were found the roots of a vast ‘oak, ‘and a
branch 4 feet long and 3 inches in diameter, projecting
from the wall of the work. A second mineral deposit
may occur below this.
HE. Mr. Smith also gives a section of Pentowan work (either a
place near Pentuan, or a misprint) in 1807.

SeimGly Obiy, SIEMES, BIEL 45g con ped ~ 608 G00 060. e066 9ft. Oin.
Peat with roots and leaves... fl cee, Peateith 188t Base Ti. Oin.
Sand with branches and trunks of trees ay a 8ft. Qin.
Finer sand, with shells, bones, horns, ver tebra of a “whale,

human skulls... Beet asthe TAR Ee cates pimereh ps Watts uROLTs
Coarse gravel ... Spoetaues 2ft. Oin.
Close sand with clay, ‘becoming peaty near the base... ... 12ft. Oin.

Loose stones and gravel, 1 foot thick, resting on tin ground.
Falmouth district.
F. Tregoney Stream Work in 1807, given by Mr. Smith op cit.).

1. Granitic gravel with layers of sand . 6 oben) dldings Gite
+2. Black mud with shells (a cow’s horn and horns of stags) 15ft. in.
3. Tin ground... ... averaging 2ft. in.

6. In Journ. Roy. Inst. Gon voll Iv. on 204, etce., Mr. Henwood
gives the following sections in two places, where the bed of Restr on-
guet Creek is some 12 feet below spring-tide high-water.

A. Section 1.—

1. Mud of the river, te soft... 6ft. Oin.
2. Mud and coarse sand-. Sft. Qin.
8. Mud (hardened) ... ... 6ft. Oin.
4. Mud (with numerous oyster shells) | 12ft. in.
5. Mud (hardened) . c09 900 3lft. in.
6. Tin ground, 6 inches to 6 feet thick... ... .. averaging 4ft. in.
Shelf of buif or blue clay slate.
B. Section 2.—

1. Soft river mud... ee (ft. to 9ft. Oin.
2. River sand and mud ... 300 abe 9ft. Oin.
3. Blue mud (shells of oyster, “cockle, ete. Nipeus 9ft. Qin.
4. Stiff blue mud without shells ... ... 6 36ft. Oin.
5. Tin ground; subangular masses of granite, slate, elvan,

quartz, etc., and tin ore in large masses intersper sed with

smaller erains, 6 inches to 6 feet thick; ... averaging 4ft. in.

Shelf of clay-slate.

De la Beche (Report, p. 403). Up the Carnon Valley in the direc-
tion of St. Day, the tin ground is partly covered by marine sediments,

partly by common river detritus.

Carnon. Mr. Carne mentioned (T.R.G.S. Corn. vol. iv. p
some beds of slate found reposing on the tin ground in the Ca

Valley, unconnected with the sides and bottom.
DECADE II.— VOL. VI.—NO. VI.

17

. 105)

258 W. A. E. Ussher—Pleistocene Geology of Cornwall.

C. Mr. Henwood (T.R.G.S. Corn. vol. iv.) gives the following
section of Carnon Stream Works, the letters denote beds probably
contemporaneous with those in the Watergate, Merry Meeting, and
Broadwater sections.

a. Sand and mud; 2 beds; river wash anal acca nate sft. Oin.
2. Silt and shells: 3 successive beds... Oft. 10in.
8. Sand and shells (a stream of fresh water percolates

throug hythisshed)) aimee laseey assis ent cll iee ieee 2ft. Oin.
4, Silt; 3 beds AUS ACE Ae EA eRe R laren Lie bd 12ft. in.
5. ‘Sand andighellsiy a ducts onl Sy ota aee ies ... oft. to 4ft. Oin.
6. Silt with numerous shells ... 20. 12. 12. sue one 12ft. in.
Cay silt wathystonesiim places) vee «cr sessed ene el OktetOy22 then mm Ont.
6. Wood, moss, leaves, nuts; dark coloured as if

charred; a few oyster shells; animal remains,
chiefly cervine; human skulls. Towards the sea
this bed gives place to silt (No. 7)... ... lit. Gin.
e, Tin eround, rounded tin ore, unmixed, and in a
quartz matrix and capel (quartz and schor 1); from
a few inches to 12 feet im thickness; ... averaging 4ft. Oin.
Rounded pieces of slate, granite, and quartz, mixed
with the tin stones.

Mr. Henwood observes that above Carnon Section, either the old
forest never flourished, or it has been destroyed in the accumulation
of alluvia, in which periods of peat growth and transport of vegetable
matter are indicated.

Mr. EH. Smith gives a section of Carnon Works in 1807 (Geol.
Trans. vol. iv. p. 404).

7. Sections given by Mr. Henwood (J. R. Inst. Corn. vol. iv. pp.
200, 201) which from similarity of names seem to refer to localities
lying between Falmouth and Helston.

A. 1. The Upper part of Carn Wartha.

1. Worn and unworn granitic detritus, mixed with lumps of
peat, and refuse of previous operations 500 12ft. in.
2. Tin ground—granitic sand and gravel, sprinkled here and
there with waterworn granules of tin ore; interspersed
at intervals with blocks of granite and schorl rock... 12ft. in.
Shelf of disintegrated granite. “
B. At Lezerea in Mean Vroaz.
1. Peat; with nuts and branches of hazel in deeper parts, in

places... 560 4ft. Oin.
2. Coarse granitic gravel Gritht foccasionl subangular ‘stones

of tin ore ... . 2ft. to 3ft. Oin.
3. Granitic sand, slightly ‘mixed at intervals with felspathic

clay... 2ft. Qin.

4, Tin ground, “angular ‘and " subangular masses of eranite
and schorl rock, largely mixed with tin ore of different
character from that at Carn Wartha ... ... 3ft. Qin.

“Tn other parts of the Moor sections of sneien works show beds
of detrital matter resting immediately on the outcrop of tin-bearing
veins in the granite.”

C. Near Tregedna in Mawnan (? at mouth of R. Helford) vegetable
mould and hardened silt, 20 or 80 feet thick, overlie a poor deposit
of tin ore resting on slate shelf.

(Ibid.). Waterworn granules of pure gold have been found in
detrital tin ore (which | is less rounded than in other parts of Corn-

wall) near Helston.

W. A, E. Ussher—Pleistocene Geology of Cornwall. 259

Mr. Henwood (T. R. G. S. Corn. vol. v. p. 129) said that the
valleys between Breague Church and Porthleven, and from Helston
to the Loo Pool, have been streamed for tin.

Penzance District.

8. A. Mr. Henwood (op. cit. p. 84) gives a section in the valley
between Huel Darlington and Marazion Mine near Newtown, at 20
to 30 feet above the sea. Sea sand with shells was found on
vegetable matter, with trunks and branches of oak, willow, hazel in
abundance, resting on poor tin ground on shelf at about the level of
the sea.

B. At Tregilsoe (Tregilliow), on the confines of Ludgvan and St.
Hilary, a section of the short shallow vale terminating in Marazion
Marsh is given by Mr. Henwood (Journ. R. Inst. Corn. vol. iv. p.
197). Peat about 6 feet in thickness rests on the tin ground,
divided through its entire width by a thin seam of clay, impervious
to water, and running obliquely both to the shelf and to the surface.
Above the clay seam, the gravel consists of angular and subangular
masses of slate, quartz, veinstones, granules of crystalline tin ore,
all imbedded in bluish clay. Below the clay seam, slate pebbles
still prevail; elvan nodules are not uncommon, but the quartz is
smaller and less frequent. Tin ore is diffused through the tough
reddish-brown clay matrix. Although within a mile of granite no
trace of granitic matter was found in these works.

Land’s End District.

9 A. (Henwood, op. cit. p. 195). Near Bejowans, in Sancreed,
section of a confluent with the little vale from Tregonebris to the
coast at Lamorna.

1. Granitic sand and gravel with small angular and sub-

angular stones... ee OLb a bon e2itaam Oine
9, Peat with nuts, branches, and roots of hazel sce ooo.) Att 180) FhaR,” Oban,
3. A few inches of granitic sand, gravel, and pebbles, with

occasional large granite boulders like the tin ground.
4. Tin ground, rounded masses of felspathic granite and

tin ore, fragments of vemstones and quartz crystals 2ft. to 9ft. Qin.

B. Mr. Henwood (op. cit. p. 193) mentions the sprinkling of tin
ore on §.E. of St. Just, in the southern and central parts of a ravine
trending from Kelynack north-westward to Pornanvon. He gives
a section at Bosworlas, in a narrow strip of virgin tin ground.

1. Vegetable mould, in some parts of the glen succeeded by 2ft. or 3ft.
2, Granitic gravel, sprinkled sometimes with tin ore... a few inches.
3. Tin ground of granitic matter, subangular and rounded

tin-bearing veinstones, pure tin stone, subangular or

PINS 366 coo ol 66 oso cdg, GHUMy 150) An, Bion

The surface of the Sin ‘ground angfistinfing a tolerably uniform sea-
ward slope throughout the 2 ravine.

C. (op. cit. p. 196). Between Towednack Church and Amellibrea,
in the lower part of Cold Harbour Moor.

Ils TEEN ac sa p00. |) Mati, Grid
2. Granite detritus; inixed with blue clay, ‘and “unproductive in

the upper part; buff and reddish brown, with a little tin ore
and tin-bearing veinstones in the lower part .. sessed leon SOLEMN OLGs

D. On Leswhidden and Bostrase Moors, ‘Mr. Carne GeRAGa Se

260 W. A. E. Ussher—Pleistocene Geology of Cornwall.

Corn. vol. iii. p. 882) mentioned the occurrence of alluvial soil 6 to
9 feet in thickness on the shelf, and at Numphra Moor not exceed-
ing 5 feet.

10. Mr. Henwood (J. R. Inst. Corn. vol. iv. p. 199) gives a
section of the bed of a rivulet at St. Hrth, near Hayle, as follows, the
thickness of the deposits not being given: Gravel, sand, and mud,
on peat, under which roots, trunks, and branches of trees, with
quantities of mud, were found resting on tin ground, poor and not
extensive.

Mr. Carne (T. R. G. 8S. Corn. vol. iv. pp. 105-111) gives the
following general notes on Diluvial tin. Cap shelves are tabular
masses of rock projecting from sides or bottom of the tin ground, so
as to allow of the occurrence of tin ore under them. Copper, not
found in tin gravels, probably because rarely so near the surface
as tin, and in the form of sulphuret so liable to decomposition. ‘The
traces of gold met with were probably derived from undiscovered
veins on the east. All the productive streams occupy valleys
opening on the 8. coast, whilst most of the richest tin veins are
near the N. coast. The direction of the tin streams seems to have
been from N.N.W. to §.8.H. In narrow vaileys little tin ore is ob-
tainable. In steep valleys all the ore is upon the shelf. In very
gently sloping valleys tin ore is met with to within two or three
feet of the surface, as at Chyanhall. In gently sloping valleys the
tin ground is thick but poor, owing to admixture with alluvial
sediments.

General Notes.

As the stream tin gravels were deposited during the last stages in
the elaboration of the present drainage system, their watershed
boundary can scarcely have differed much from the present; it is,
therefore, only natural that, whilst the richest tin veins are near the
north coast, the most productive streams occupy valleys opening on
the south coast.

The position of the tin ground with reference to the sea-level in
the estuarine sections is, unfortunately, seldom given. In Mr. Hen-
wood’s section on Marazion Green (8 A), mention of overlying alluvia
seems to have been omitted; as Mr. Carne, in a section at Huel
Darlington, near Marazion River, gives twelve feet of peat and gravel
above the sea sand, and the surface is given in Mr. Henwood’s
section at twenty to thirty feet above the sea-level, the top of the
marine bed would appear to be a few feet above high water (Carne,
T. R. G. S. Corn. vol. vi. p. 230).

Again, in Mr. Smith’s section (5 C) of Lower Pentuan, the shelf is
said to be at low-water level, which would place the top of the
upper marine bed at about forty feet above low water, which, con-
sidering the absence of marine deposits at Wheal Virgin Works (5 B)
and Upper Pentuan (5 J), is out of the question ; so that either the
thicknesses are not given in feet and inches, or the level of the shelf
is erroneous.

Mr. Carne (T. R. G. 8. Corn. vol. iv. p. 47) describes the tin
ground of Drift Moor Works, near Newlyn, as resting on the sides

W. A. E. Ussher—Pleistocene Geology of Cornwall. 261

(which come to within a few feet of the surface) and bottom (forty
feet from the surface) of a clay-lined basin. This is a most excep-
tional phenomenon, and seems to show the great erosive power of
the stream tin floods rushing into and deepening a depression, very
much in the manner in which giants’ kettles are produced by the
pestle-like friction of fragments swirled round hollows by subglacial
streams. A somewhat analogous phenomenon is mentioned by Dr.
Boase, which, although not relating to stream tin, I give here
(T. R. G.S. Corn. vol. iii. p. 131): “A person surveying the Channel
took his station on Wolf Rock, where he observed a cavity resembling
a brewer’s copper, and containing rubbish at the bottom; it was
covered by the sea nine hours out of twelve.”

The occurrence of an oblique clay seam in the tin ground at
Tregilsoe (8 B), separating accumulations of slightly different
characters, suggests the existence of bedding, true or false. The
exceptional occurrence of clay shelf (4 G and perhaps 5 D) is worthy
of note.

The changeable character of the deposits in stream tin sections
precludes the absolute correlation of individual beds. Inland streams
cannot be expected to furnish such sections as their estuaries, yet it
is scarcely safe to identify tin ground, when not overlain by sedi-
ments (as 9 C); when composed of fine material under a thin cover-
ing of sediment with no indication of a land surface (as in 4 G, H,
J, J, and 9B); or where it rests on outcropping tin veins (as 7 B),
with the stanniferous gravels of Par (3), Pentuan (5 A, B, C, D),
Carnon, etc. (6 A, B, C); whilst in some sections stanniferous deposits
oceur at different horizons, as 4 E (probably 5 D), 7 B.

To synchronize the forest remains in the various sections is unsafe,
because in many valleys deposition seems to have gone on con-
tinuously, or to have been interrupted by such very brief periods of
peat accumulation or undergrowth, that their relics became entirely
mixed up and incorporated with the succeeding deposits, as in 4 B,
C, D, E, and 5 F; also4 Jand 7 A.

The deposition of stream tin gravels evidently extended over a
much longer period than is represented by the tin ground ; for the
very irregular wear of the sides and bottoms of their channels, and
the existence of false shelf (4 D, H) here and there, and of masses
of the surrounding rock, the apparent debris of fallen cap or false
shelves (4 A, 5 A, 6 C), can only be accounted for by powerful
streams carrying their detritus to lower levels, and occupying the
enercies of their upper and more torrential reaches in eroding their
banks and beds into such irregular shapes as the unequal durability
of the rocks permitted.

In like manner, the duration of the forest growth is not to be
measured by the forest beds overlying stream tin in Marazion Marsh,
Pentuan (5 A, C), etc., which can only be regarded as synchronous
with a comparatively short part of the period; whilst the recurrence
of peat beds with arboreal remains at different horizons in the stream
tin sections (4 A, B, 5 EH, 7 B, 9 A, 10) shows that even after the
forests fringing the coasts were submerged and buried with the

262 W. A. E. Ussher—Pleistocene Geology of Cornwall.

peat, which had accumulated around them during the last stages of
their existence, it was some time before forestial growth in inland
districts succumbed to unfavourable climatal conditions, and still
longer before the succeeding undergrowth gave place to the bare and
shrubless character presented by so large a part of western and
central Cornwall now.

Although it seems only reasonable to regard the deposition of
metallic detritus, as now going on, wherever the stream channels are
traversed by tin veins, this process is so insignificant that as a whole
the stanniferous gravels must be referred to a period considerably
posterior to the raised beach formation, and, either long after the
culmination of the elevation during which Head was accumulated,
or in part synchronous with its accumulation, when, through greater
elevation and increased rainfall, the force and volume of the streams
was greater. The commencement of the forest growth is also in-
definite, but subsequent to the accumulation of the Head, during the
prevalence of a subsidence which produced conditions unfavourable
to the existence of the tin floods as they became more suitable for
its extension. So that the forest growth may have begun before the
stream tin floods dwindled away, and the latter may have been
partly contemporaneous with the Head. Whilst marine sediments on
the forest bed or tin ground in estuarine sections (3, 5 A, C, H, 6 A,
B, C, 8 A) prove the last great movement to have been one of sub-
sidence, the more orderly arrangement of the deposits; the general
absence of heavier far-borne detritus; the entire desertion of parts of
their old channels by some of the present streams, indicate the
gradual prevalence of conditions more akin to those now prevailing
than to those in operation during the deposition of the stanniferous
gravels.

The growth of trees, some very old, on the surface (5 C, D), shows
that the latest of these changes must have been some time in opera-
tion, whilst the presence of human remains at great depths beneath
the surface, at Carnon and Pentuan, and the tradition respecting St.
Michael’s Mount, would seem to justify the belief that the period in
which the forests were finally submerged, although geologically very
recent, is yet prehistoric.

As the subsiding movement gradually enabled the sea to cireum-
scribe the forest tracts on its old fore-shore, the beach materials
pushed forward would finally tend to bar the drainage of the valleys
opening on the coast, and to convert the low lands into peat mosses,
forming round the surviving trees till the further advance or disper-
sion of the beach dams permitted the sea to regain its old coast-line,
entombing the forest fringes and their peaty surroundings beneath
its sands. Hliminate from this all changes of level by internal
movements, and explain the entombment of the forests by the
lowering of level consequent on removal of gravel bars releasing
the pent-up drainage, and the low district theory is presented.
Without changes of level, however, it is perfectly untenable as
applied to Cornwall, where the stream tin gravels indicate a greater
elevation of the land (5 B), as at Carnon and Restronguet Oreek (6 A,

Count de Saporta—On the Ancient Plant- World. 263

B, C), for instance, where the tin ground is more than sixty feet
below the sea-level, whilst the estuarine deposits overlying the forest
bed prove that the subsidence was progressive. Also, if the forests
were submerged according to the low district hypothesis, they must
have flourished under geographical conditions identical with the
present, and yet these conditions have proved unfavourable to their
growth on the present low lands. On the other hand, it cannot be
argued that the submerged forests are mere rafts of drift wood,
stranded with vegetable matter borne down by rivers, and finally
buried beneath the sea sands. The traces of submerged forests are
too numerous and too extensive (1, 7, 8) to be thus accounted for; in
several cases, moreover, the roots are said to occur in siti (8, 5, 11,
?6), and the elytra of beetles have been found (1, 6). Mr.
Godwin-Austen (Q.J.G.S. vol. vi. p. 93, etc.) says: “It is diminished
area and elevation which at present unfit the West of England to
produce that growth of oak and gigantic fir which. .... seems to
have clothed every portion of the region of Dartmoor, and which
would still more be unfitted for it when at its lower Pleistocene
level. On such low districts, however, and in a climate modified by
a surrounding sea, some portion of a previous flora might have
been enabled to live on.” By substituting the words “at a few feet
below its present” for “at its lower Pleistocene,” the passage reads
in accordance with my ideas.

(To be concluded in our next Number.)

IN @ aan @ ees) OzLe Ge N/iaenVE@ tees Se

Toe Pruant-WoRLD BEFORE THE APPEARANCE OF MAN.

LE COMTE DE SAPORTA has recently pointed out? that
» life was aquatic before it became amphibious, and amphibious
before it became aerial, and that terrestrial life is but the latest ex-
pression of the sequence that took its initial point of departure in
the ocean. The seas that deposited the Laurentian and Huronian
rocks, 50,000 feet in thickness, contain only the Rhizopod Hozoon.
The Cambrians of Britain and Sweden give but 50 species of primi-
tive types, marine vegetables, a few Sponges, Corals, and Hchino-
derms, Brachiopods alone representing the Mollusca, which gradu-
ally spread from their first birthplace in the Polar Ocean to other
basins, no cause formerly operating to limit their extension. In
Silurian times Crustacea were alone represented by Trilobites, which
occurred in profusion, disappearing suddenly in the Coal-measures,
and the order is now only represented by Limulus. Similarly, at
the close of the Secondary epoch, the Ammonites as suddenly cease
to exist.
The most ancient terrestrial Vertebrates show traces of affinities
with the Fishes on one side, and the Batrachians on the other, and
the Reptilian affinities of Archzopteryx are commented on; the

1 Le Monde des Plantes avant apparition de homme. Paris. J. Masson. 1879.

264 Notices of Memoirs—Count de Saporta—

mandibles with teeth found in the American Chalk showing a bird
less Reptilian than Archaopteryz.

The Labyrinthodonts of the Coal-measures were less highly organ-
ized than those of the Trias, the ossification of the vertebrae being
imperfect, and the disposition of the teeth resembling that of fishes.

The Fern, Hopteris Moriérei, Saporta, discovered by Prof. Moricre
of Caen, is the oldest terrestrial plant known, being derived from
the Ardoises of Angers. In the Cincinnati group of America, Les-
quereux has recorded several vascular Cryptogams and Gymnosperms,
a Sigillaria (Protostigma sigillarioides, Lesq.), Calamites (Annularia
Reemingeri, Lesq., and Sphenophyllum primevum, Lesq.).

Insects are present in the Devonian, and no less than 30 species
occur in the Carboniferous according to Heer. A Myriapod,
Anthraceps, recently discovered in Illinois, has similar breathing
apparatus to that of the order at the present day.

The Scorpion of Bohemia differs but little from the venomous
species of the tropics.

From the Infra-Lias of one locality (Argovie) M. Heer records
no less than 148 species of insects. Beetles and leaf-eating forms
abound ; but Butterflies, Bees, Ants, and Flies are still absent.

In the second chapter the author gives a careful analysis of the
theory of Evolution, especially as to the facts adduced by Mr. Darwin.

In Chap. III., on ancient climate, it is pointed out that :—

At the foot of the Himalaya, tropical vegetation is maintained up
to 1000 métres ; at 2000 Palms and Bananas have disappeared, and
are replaced by Oaks and Pines; at 5000 snow falls in winter; at
3500 occurs a zone of Cedars; at 5000 corn is still cultivated, at an
elevation about that of the top of Mont Blanc; at 5500 all life
disappears.

Since the “Golden Age” of the poets there has always been present
a legend of successive changes undergone by the world.

In the Quaternary age M. de Saporta considers the climate was
much more humid, and the rivers consequently larger, both in
Europe, Asia, and Northern Africa.

He refers to the extension of the glaciers of the Alps not only to
the Jura, but from the observations of M. A. Falsan almost to Lyons.
He comments on the colossal proportions of the glaciers of Argeles in
the Pyrenees worked out by MM. Martins et Collumb, and the
former extension of the glaciers of Scandinavia and Spitzbergen,
during which the shells of the Arctic Ocean lived in the British Seas,
and the plants and mammals of the Far North occupied the plains of
Hurope. He points out that the species found in the low grounds—
to which the excessive size of the glaciers might be supposed to
drive both animals and plants—are associated with species indicating
warm conditions; thus the mammals of the alluvia of the Seine and
Somme, worked out by M. E. Lartet and by M. A. Gaudry, are associ-
ated with Elephas antiquus near to that of India, and shells of Cyrena
fluminalis, while the Mosses tell the same story as regards the plants;
Vines and Laurels occurring in great abundance, not only in the

middle of France, but at Moret, near Paris, and he considers that

On the Ancient Plant- World. 265

the polar forms did not travel far from the glaciers themselves, and
that the valleys enjoyed a more humid and temperate climate, and
evidences the observations of Haast as to the descent of glaciers in a
humid climate in New Zealand.

The mean annual heat of Lyons is now 11° Centigrade; in
Quaternary times it was 14° to 15°; in Pliocene times it was 17° to
18°; the flora of the Canaries flourishing on the banks of the Sadne.

The author lays great stress on the discoveries of Nordenskjold,
in Southern Spitzbergen, of plants of Carboniferous, Jurassic, Cre-
taceous, and Tertiary times, and states the labours of Professor Heer
show the position of the earth’s axis was the same in Tertiary times
as at present. To Greenland he assigns a mean temperature of 9°7°
Cent. in Miocene times, rising to 22° in Switzerland, the northern
limit of Palms traversing the Rhine provinces and Belgium about
the 50th parallel, while at the present time (excepting the Chamerops
humilis at Nice) their limit is the 30th to the 35th parallel.

The Hocene era was marked by the multiplication and extension of
Palms, Pandanas, Bananas, and other tropical plants in Hngland
and Germany, indicating a mean temperature of 25° Cent.

The Cretaceous flora of Bohemia (Cenomanian) is characterized by
the first appearance of Dicotyledonous plants, including the genus
Credneria, Magnolias, and Laurels; at Toulon, seven degrees further
south, these are rare, and Conifers are the dominant forms, especially
a fine Araucaria, and the author concludes that Dicotyledonous plants
travelled from north to south, and that climate in this period first be-
came differentiated. In Jurassic times the same vegetation spread
from India, Siberia, and Spitzbergen to Hurope.

The author considers in early times the earth was covered with
thick fogs, the atmosphere being charged with a diffused light.
With Buffon, he believes that life originated at the Poles, and
travelled equatorially, and he comments on the fact that the chief
Coal deposits occur at the polar sides of the equatorial zone, and
that the still older Hozoon of the United States and Bohemia are
similarly limited in area, and he regards the 50th parallel as the
equator of the origin of life. An equal distribution of heat, probably
not exceeding 25° or 30° Cent., prevailed throughout the world in
the early periods, the contrasts of day and night, summer and winter,
being but slightly marked; that light, though diffused, was certainly
present, is proved by the existence of the reticulated eye of the
Trilobite.

He considers the former tropical heat of the earth to be in no way
connected with its central heat, nor does he ascribe the gradual
secular cooling of the crust to have influenced the cessation of warm
conditions on the surface—no signs of gradual decrease being
apparent, as would have been the case, and especially no signs of
intense heat, in the indication given by the earliest vegetation ;
and agrees with M. Burmeister that the earth’s crust had so far
solidified as to be a considerable thickness before life appeared on
its surface, and points out the low conducting power of the rocks
forming this crust.

266 Notices of Memoirs—Count de Saporta—

In the second part, the author reviews in succession the Vegetable
Periods, which he divides as follows :—

Geological Stages. Phytological Phytological
Formations. Epochs. Periods,
Primorpiat ( Laurentian. Primordial
or Cambrian. or Primordial,
Prortozorc. ( Silurian. Kophytic.
( Devonian.
Devonian. Carbonterous | Paleeanthracitic.
Pat#mozoic. < Carboniferous, 4 Carboniferous.
Permian. Paso | Supracarboniferous.
( Permian.
Bunter. ) { Triassic.
Triassic. Mushelkalk. rs
a sees Ss E Infraliassic.
ESOZOIC . ias a eS,
or SEBEL, { Oolite. ; 3 4 Oolitic.
SECONDARY. Neocomian. | a ‘st | Wealden.
Chloritic Chalk. ( Urgonian.
Cretaceous. Rouen Chalk. ; { Cenomanian.
L Upper Chalk. 3 | Supracretaceous.
| F> SB | Paleeocene.
So >
‘5 Sl ¢ Eocene.
Nerozoic Eocene. s 8 Oligocene.
or Miocene. 4 | Miocene.
TERTIARY. Pliocene. J | Pliocene.

In the first chapter of the second part the author reviews the
vegetable contents of the various formations. The earliest traces
are marine, the Bilobites (Cruziana) rugosa, D’Orb., being a true
Algze from the Silurian; Harlania Hallii, Goepp., Chondrites fructi-
culosus, Goepp., Murchisonites (Oldhamia) Forbesi, Goepp., from the
Trish Silurian, and Spirophyton, Hall, of America, belonging to the
same category. He comments on the plants of the Lower Silurian
being purely marine, and figures the oldest terrestrial plant, Hopteris
Moriérei, Sap., discovered by Prof. Moriére in the slates of Angers,
in the zone of Calymene Tristani {base of Middle Silurian), a Fern
near to Cyclopteris of the Coal-measures. In America M. Les-
quereux, and in Canada Principal Dawson, have recognized Spheno-
phyllum from the Upper Silurian, the species being S. primcevum,
Liqx. Lesquereux has also described Protostigma sigillarioides, Lqx.,
and a Lycopodiaceous plant, Psilophyton, has been recognized by
Dawson, with affinities leaning towards the Ferns through Hymeno- .
phyllum, with the Rhizocarps through Pilularia, with the Lycopods
through Psilotum. Psilophyton also occurs in the Devonian of Canada,
with Asterophyllites, Annularia, Calomendendron, Lepidodendron, and
ferns.

Before describing the Coal-measure flora, the author notices the
formation of modern peat-mosses, and points out the conditions
necessary for their production, the most important being an equable
temperature, constant humidity, a flat country allowing free access
to water supported by an impermeable soil, and a moderate amount
of heat, peat-mosses not growing south of the 40th parallel.

On the Ancient Plant- World. 267

‘The Carboniferous period marks an epoch during which a large
continental area was from time to time slightly submerged beneath
the water, forming vast shallow lakes, whose shores were tenanted
by dense masses of vascular Cryptogams and Phanerogamous Gymno-
sperms, under a thick atmosphere charged with vapours precipitating
rain, with a violence now unknown, producing an equable damp and
warm climate. The labours are summarized of Grand’ Hury, Renault,
Brongniart, of Corda, Gceppert, Geinitz, Goldenberg, Stur in Ger-
many and Austria; Schimper of Strasbourg; Lesquereux, Dawson,
Dana, in America; and Williamson and Binney in England.

The Permian flora exhibits transitional and ambiguous characters,
the characteristic elements of the Carboniferous being absent—
Cycads, Conifers, and some Ferns have the preponderance (Walchia
piniformis, Ginkgophyllum Grasseti).

In the succeeding Mesophytic, or Secondary epoch, the Triassic flora
marks a period of decadence of old types barely replaced by new
forms—species and individuals being alike rare. The Conifers are
represented by Voltzia heterophylla, Schimp.,and Albertia Braunii,
Schimp.; the Ferns by Daneopsis Marantacea, Hr., and Teniopteris
superba, Sap.

In the Jurassic epoch, though the Carboniferous types of plants
are gone, the Angiosperms, which form nine-tenths of the existing
flora, have not yet appeared, except some rare Monocotyledons.
Cryptogams are represented by Ferns; Gymnosperms by Conifers
and Cycads, ranging from the Arctic regions to Hindustan and
Europe, from Greenland to Irkutsk. Cycads now live in the
Tropics, Florida and Japan marking their northern limit. The
Infra-Lias Ferns, Clathropteris platyphylla, Goepp., Thinfeldia
rotundata, Nath., and Cycads, Podozamites distans, Presl., Ptero-
phyllum Jegeri, Brogn., and Pterozamites comptus, Schimp., in-
dicate a damp and humid locality. Ferns also occur in the
Corallian, Bathonian, and Kimmeridgian stages. Amongst the
Conifers are some resembling the modern Araucaria, others the
Cypress.

Hurope, at the commencement of the Jurassic period, formed an
archipelago of large islands; the central plain, at the end of the
Lias, was still separated from the Vendée to the west, and from
the Vosges and Alps to the north-east. These islands gradually
coalescing formed one Continental mass, atethe close of the Oolitic
period, when lacustrine and fluviatile conditions set in, over a large
part of England and North Germany, expressed by the Wealden,
and Urgonian strata of Wernsdorf, in the Carpathians, which latter
has much in common with the Greenland Cretaceous flora. Amongst
the latter is the Cycad, Pterophyllum concinnum, Hr., and Sequoia
ambigua, Hr.

The author comments on the circumstance that led to the
appearance and rapid multiplication of Dicotyledons, at the com-
mencement of the Cenomanian epoch. He describes the Dakota
beds of America as ranging through Kansas, Arkansas, Nebraska,
Minnesota, and the region of Missouri, up to the Rocky Mountains,

268 Notices of Memoirs—Count de Saporta—

and resting on the Trias. Of similar age are the freshwater bands,
with plants, of the Quadersandstein of Bohemia; they occur also in
Moravia, the Hartz, and some localities in Saxony, Westphalia,
Scania, and the neighbourhood of Aix-la-Chapelle and Toulon, and
in Disco and Noursoak in West Greenland.

The most southern locality is that of Beausset, near Toulon,
including Magnolia telonensis, Sap., Lomatopteris superstes, Sap.,
Araucaria Poucasi, Sap.; but other Dicotyledonous genera are rare,
and are numerically stronger in the German localities, between 49°
and 51° N. lat., which present a mixture of tropical and boreal
forms, the genus Credneria being an example of the first, Hymenea of
the second (one of the latter group, Ceratonia siliqua, still lives on
at Mentone). In the Dakota group, the Crednerias are represented
by Protophyllum multinerve, Lqx., and Aspidiophyllum. M. Lesquereux
has also recognized Oaks, Ivy, Beech, Planes, and Chestnuts. The
flora of the Middle Chalk (Cenomanian) marks the commencement
of the fourth and last vegetable era the author recognizes, specialized
by the appearance of Dicotyledons.

This group increases in importance in the succeeding Tertiary
epoch. The Monocotyledons, which had gradually been decreasing
in number and importance, also become somewhat more salient again,
as conditions more favourable to vegetable life come in. Hurope
had still no winter, and though already to a certain extent con-
tinental, the Alps and Pyrennes were only represented by insignifi-
cant islets; lakes were scattered over much of the surface, and plants
were imbedded in volcanic ashes.

In the Palaeocene (Saporta, Suessonien d’Orbigny) the flora is little
changed. It extends from the N.H. of Paris into Hainault and Liége;
in the latter province it has yielded a rich flora at Gelinden, con-
taining Laurels, Cinnamons, Oaks, Vines, and a species of Thutes, near
to those of Japan, the flora of which resembles the facies to a cer-
tain’ extent. The European Paleocene flora has some affinities with
the American lignitic flora, and also with the Greenland Tertiaries,
especially that of Atanekerdluk.

The Eocene period was characterized by the existence of the Num-
mulitic sea, a larger Mediterranean extending from Asia Minor and
Arabia to Western Europe, and from Africa to a Gulf including the
London, Paris, and Belgian basins; it is present in Persia, India,
and China, and forms the summit of the Alps, forming one of the
vastest inland seas of geological history, tenanted by similar bio-
logical forms.

Washed up on the shores of the Brito-Belgian gulf were seeds of
a Nipa, of an Indian type, near to that now flourishing on the banks
of the Ganges. Near Paris, on the site of the 1867 Exhibition,
at the Trocadéro, occurred Palms, Pines, Thujas, and. a Dryandra
(Michelotti), a type now characteristic of the Australian flora. A
similar flora occurs in the collection formed by MM. Aymard and
Vinay, at Puy, in Velay, including the now African genus Pheenia
(P. Aymardi) allied to the modern Date. To this age belong the
sandstones of Beauchamp, the limestones of St. Ouen, the gypsum

On the Ancient Plant- World. 269

of Montmartre, the plant beds of Sarthe (M. Crie), and the neigh-
bourhood of Angers, the Isle of Wight, and the lignite of Skopau in
Saxony.

The flora of Aix is somewhat newer; it occurs in an old lacustrine
deposit, 20 kilométres in length, by 15 in width; it exhibits a rich
flora, made up partly of European elements, and partly of plants
now become purely exotic—Palms, Flabellaria Lamanonis, near to
those of China, Dracene near to the Dragon Trees of the Canaries,
Bananas near to those of Abyssinia and Africa, with plants of
Australian and Madagascan flora affinities. Acacias abounded, whose
modern representative affords the favourite food of the Giraffe.

Amongst the flora is a Magnolia leaf, the corolla of a Catalpa near
to a Chinese species. Magnificent corollas of Bombax, and a Fig,
Ficus venusta, near to F. pseudocarica, Mig., of Upper Egypt.
Associated with the tropical types are the temperate forms, Oaks,
Beeches, Elms, Poplars, and other temperate forms; these, however,
are of rare occurrence, and it is suggested that they lived well above
the level of the ancient lake, and experienced a different climate to
that prevailing in the lower valleys. The facies of this apparently
more temperate flora is rather that now existing in Central Asia
than in Northern Europe as regards the Birch and Elm, while the
Oaks resemble those of Louisiana, the Poplars those of the Euphrates
and River Jordan; and on the whole the flora appears to have resembled
that of Central Africa, with some elements in that of Southern Asia
and China—conditions which lasted on to the end of the Oligocene,
which is, however, characterized by the gradual introduction of
Miocene species. Amongst the new types that appeared in Hurope
were species of Conifers, Chamecyparis, many Sequoias, Taxodium.
Amongst the Palms the Sabal Heringiana, S. major, and Flabellaria
latifolia; amongst the Myricas, Comptonia dryandrefolia, Brogn., most
of them plants of an American type requiring either the presence of
water or of a humid atmosphere. These plants traversed Northern
America, Europe and Asia, and are associated with Oaks, Elms, etc.,
replacing the plants with African affinities, whose modern repre-
sentatives require a large precipitation of rain.

The author refers to the presence of tropical types, as Cycads, Ferns,
and Gleichenia, in the Jurassic and Cretaceous deposits of the Arctic
lands, and especially to the number of species and profusion of the
genus Sequoia, the presence of Glyptostrobus thuja; and he
comments on the absence of the more purely southern forms, as the
Palms, Pandanas, and Dragon Trees. In the succeeding epoch, the
Miocene, of the Arctic region, the larger number of species appear for
the first time on a horizon about parallel with that of the. Huropean
Oligocene, which received from the Arctic Ocean the Limes, Chest-
nuts, Willows, Cedars, Birches, just alluded to, which migrated over
the whole of Europe, and occupied the whole of the temperate area.
Elevation of Central Europe took place, and the sediment called
Flysch, or “shales with Fucoids,” was thrown down in saturated salt
lakes resembling the Caspian and Sea of Aral. These Algze become
extinct in this deposit, though ranging up from the Paleeozoic, and

270 Notices of Memoirs—Count de Saporta—

it is suggested that they were preserved unmodified in an inland
salt sea. The Alps during this epoch probably formed a plateau,
here and there covered by salt lakes; after a time the sea again
gained on Europe; this Tongrien sea traversed a different direction to
the older Nummulitic sea. It occupied anew the Paris basin, united
the Isle of Wight, traversed Belgium, Westphalia, penetrated the
Gulf of Cassel, fringed the Adriatic, and bordered the Vosges and the
Black Forest. From the various localities including them in Alsace
and Austria M. Schimper records no less than 800 to 900 species
of plants. The general aspect of the vegetation resembles that now
living in Australia. Palms (Sabal major) as large as the Parasol
Palm of the Antilles. Sequoias, near to those of California. In the
lake a profusion of Nymphacea and Nenuphars existed, now only
found in Senegambia, Nubia, and Hgypt. At Armissan, near
Narbonne, the flora is specially rich, and exhibits characters tran-
sitional to the more modern Lower Miocene or Aquitanian.

The Oligocene period terminated with the retreat of the Tongrien
Sea, which deposited the Fontainbleau grits, and at the commencement
of the Miocene period the Paris basin emerged above the water, and
the “ Falun Sea” to the west was separated from the ‘‘Molasse Sea”’
of §.E. France by a central dry arm; the Faluns, of the Aquitanian
period, mark deposits tranquilly deposited in lakes, gradually dimin-
ishing in depth; beds of the same age occur in the Baltic Amber
region (54° lat.), at Bovey Tracey, Thorens in Savoy, Coumi in
Greece (88° lat.), and Radoboj in Croatia, ranging through 16 degrees
of latitude, though the included flora points to an almost absolute
identity of climate. The Ferns point to a damp soil and climate.
An Osmunda (O. lignitum) flourished near to the O. presliana of
Southern Asia, Ceylon, Java, and Southern China. The genus
Lygodium also now finds its most northern limit, with one species in
Florida, and another in Japan, the Aquitanian forms most resembling
the American species. The Palms (Flabellaria and Sabal, etc.) had
not yet diminished in Europe. Sequoias still abound, but the Pines
are becoming rarer, while the Oaks, Alders, Beeches, and Poplars
commenced to exhibit their modern morphological characteristics.
In the Baltic amber region Camphor Trees abound, but Palms are
absent, but a number of the genus Smilax occur there. The limit
of Palms passed probably a little north of Bovey Tracey to along the
52nd parallel. The Sabal major apparently did not pass north of
Bonn, 50° 45’ W. lat., the lignites of which contain many other
tropical plants, sensitive Mimosas, many Acacias, Azaleas, ete.

In the Coumi deposits temperate forms are few in species and
individuals, and they are characterized by a profusion of tropical
species. Palms are, however, rare ; but the last Cycad that lingered
in Europe occurs in it, the magnificent Encephalartos Gorceixianus,
Sap., discovered by M. Gorceix.

Succeeding the Aquitanian lacustrine deposits come the Upper
Miocene ‘ Molasse Sea,” the last that invaded our Continent, and
turned Central Europe into a scattered archipelago. To the west the
sea of the Faluns occupied the Garonne, but did not communicate

On the Ancient Plant- World. Die

with ‘‘ the Molasse,” which extended from Marseilles north-eastward
by Lyons, the Jura, north of the Swiss Alps, to Bavaria, and
occupied the whole of the valley of the Danube, the western shores
of the Adriatic, Illyria, Thrace, and the 8.W. of Greece, to which
Prof. Heer has given the name Pennino-carnienne. The marine
deposits at Carry, near Marseilles, being somewhat older than the
inland Molasse beds, serve to show the gradual invasion of the
Aquitanian land by the ‘“‘ Molasse Sea” took place from south to
north. During this period the steps by which the temperate zone
was becoming colder, though continuous, were softened by the heavy
yains of summer and the mildness of winter, which still allowed
a rich and varied vegetation. At no later period of the world’s
history did it contain so many species of Poplar, all sections of
the group being represented in France, including many types driven
southward by the cold, and only now found in North Africa and
Southern Asia, as the variable-leaved Poplar, Populus Euphratica,
which is the modern representative of P. mutabilis of Ciuingen ;
the former the author considers to be the plant referred to in the
Psalm of Jeremiah, commencing, “By the rivers of Babylon,”
translated Willows, the Weeping Willows introduced from China
being unknown in Hebrew times.

Remarking on the fact that for representatives of the Miocene
flora we have often to turn to America, a successive immigration
from the Pole southwards in all directions is suggested as the expla-
nation of these ancient geographical connections. Amongst the
Ferns (Adiantum and Pteris), we have several ancestors of existing
Ferns. A Salisburia near to S. adiantifolia of Japan, Sequoia,
Taxodium, and Glyptostrobus, occur among the Conifers. Comptonias
in rich and elegant variety, now only represented by one form in the
sandy marshes of Pennsylvania. The Green Oaks of Giningen re-
produce the aspect of Mexico and Louisiana. Through the long
summers of equal heat and mild winters, the genera Zaurus, Persea,
Benzoni, Oreodaphne, Cinnamomum, and Camphora, still lived in the
centre of Hurope, but in this epoch reached their final limit in this
area. Again new types commenced to appear from the north, such
as the Limes. An Aralia (Panaxz circularis, Hr.) still lived at
(ningen, a Magnolia (M. Ludwigi, Htt.) at Salzhausen.

The author draws a striking picture of the number and variety of
the vegetable forms, and the richness and elegance of the forests of
the Molasse epoch, the locality of iningen, near Schaffhausen, alone,
having yielded to M. Heer no less than 475 species of plants, besides
numerous Pachyderms, Birds, Reptiles, Fish, Mollusca, Crustacea, and
Spiders, and 800 species of Insects. He considers that the climate
must have resembled that of Madeira, Malaga, the South of Sicily
and Japan, and Georgia, or indicates a mean temperature of 18° to
19° Cent. Broken branches and crushed leaves and flowers testify to
violent storms and heavy rains; but the character of the vegetation
shows that flowers and fruits persisted throughout the whole year.
In these primeval forests lived the great Salamander (Andrias

Scheuchzert, Holl.), of which the living type is found in Japan (Z.

272 Notices of Memoirs—Count de Saporta—

japonicas, Tem.). Amongst other fossiliferous localities are the
lignites of Wétéravic (Salzhausen, Roekenberg), Gunzbourg in
Bavaria, Bilin in Bohemia, Menat in Auvergne, Mt. Charray in
Ardéche, Parschlug and Gleichenberg in Styria, Tokay in Hungary,
and the neighbourhood of Vienna.

Reviewing the Tertiary floras, the Count de Saporta points out
the vigorous and complete flora of the Paleocene was succeeded by
the poorer but more varied flora of the Eocene, containing an
assemblage of plants with African and Southern affinities, which per-
sisted on in the rich flora of the Miocene, in which, at the commence-
ment of the Oligocene, an influx of Northern types is observable,
which gradually increased in importance, as the influence of winter
first appeared in Central Europe; the vegetable zenith was reached
in this epoch, and with the succeeding Pliocene a gradual exodus of
exotic forms took place, with the definite climatic change which is
too marked to have been due simply to alteration of geographical
configuration; though the elevation of the Molasse sea-bed into land
and the appearance of the Alps probably snow-covered would not
be without effect in assisting the general chilling of the atmosphere.
But the change was a cosmical phenomena, commencing with the
Oligocene, and embracing the earth in its effects. At the commence-
ment of this era the ice at the pole would be sporadic and occasional,
gradually becoming permanent, and to give off masses of floating ice
to chill the more southern districts, themselves now covered with
glaciers inthe more mountainous parts. These changes were pro-
bably gradual. Resting on the marine Molasse, with Ostrea cras-
sissima of Provence, are lacustrine deposits, in which tropical plants
still linger. An exotic Fig, Ficus Colloti, Sap., and a Bamboo. At
Cucuron, at the foot of Mont Léberon, M. Gaudry has discovered a
large number of Mammals, and he observes the end of the Miocene
is characterized by a great development of Herbivores; this is the
case not only in Provence, but at Pikermi, in Greece, and Eppelsheim
on the banks of the Rhine. Stags also began to appear. Oxen were
still absent.

Mio-pliocene.—Arms of the sea still occupied the valleys of the
Rhone, Danube, and the Po, and extended over parts of Belgium,
north of the valley of the Thames, in Sicily and Algeria.

In the Vienna basin, resting on the Molasse, is the Sarmatic stage,
with Cerithium, which contains a rich flora, near to that of CGiningen.
Cinnamons, Camphor Trees, Acacias, and Sequoias, and a Callitris, in
the succeeding deposits, ‘‘the zone of Congeria,’—all these have
disappeared for ever, except the genus Sequoia, and the Cinnamons,
which still lingered in the floras of Stradella, near Pavia, and of
Senigaglia, in the Marches; and in the Hast a true bamboo, Phrag-
mites, still existed. The Sassafras of North America, the Glypto-
strobus of China and Japan, the Planera, Platanus, Liquidambars of
Southern Asia, are also still represented at Senigaglia; associated
with Limes and Oaks, clearly the ancestors of our own Huropean
trees, and in beds of similar age (marine molasse of St. Fons, Isére),
in the Rhone Valley occurs a Beech with entire curved leaves like

On the Ancient Plant- World. 273

that of our forests—Fagus sylvatica pliocenica, affording a valuable
index of the existing climatal conditions, requiring, as it does, rain
throughout the year.

In the somewhat newer fluviatile beds of Vaquiéres, explored by
Prof. Marion, grew an Alnus, between a Syrian and a Japanese
species; a Glyptostrobus, near to that of Canton; a reed, near to the
green reed of the Nile (Arundo Aigyptia antiqua, Sap.), covered the
sand banks of this ancient river. The calcareous deposits of Mexi-
mimiex, discovered by M. Falsan, disclose rich forests, resembling in
the character of their vegetation those of the Canaries, joined with
Asian, North American, and European facies; but tenanted yet, only
by Stags, Mastodons and Tapirs.

To this age belong the lacustrine deposits associated with basaltic
overflows of Auvergne; in that overlying the older lava M. B. Rames
has found in Cantal the remains of Dinotheriwm, Mastodon, Hip-
parion, and Machairodus, which places these beds on the horizon of
the Upper Miocene of Mont Léberon and Pikermi. Over these
come porphyritic basalt, and trachytic conglomerate. The country
‘was broken into ridges and escarpments, the northern and southern
aspects of which were covered by a somewhat different vegetation,
which also now varied with elevation,—profound forests occupying
the hollows of great magnificence, and tenanted by a numerous
fauna. New eruptions, first of trachyte, then basalt, then phonolites,
then of more modern lavas. These are associated with volcanic tuff
and ash beds, containing a numerous Pliocene flora, especially at
Puy, in the “Grey marne with tripoli,” at Ceyssae (Haute-Loire),
examined by MM. Aymard and Haydes, and the Cantal beds ex-
amined by Rames, which he correlates with those of Lyons. At
Pas de la Mongudo, on the south of the volcanic district, and Saint-
Vincent, on the north, occurs a Japanese species of Acer (A. poly-
morphum), which has recently been reintroduced into France by the
horticulturist. In these flora modern genera and species, Oaks, Elms,
Alders, Poplars, etc., multiply in numbers, and preponderate over the
few remaining exotic types. The same temperate facies is observable
in the littoral deposits of the Val d’Arno, and in the travertines
of Lipari, where the Palm, Chamerops humilis, still lingered on.

“At the commencement of the Pliocene period, favoured by the
dampness of the climate and the increasing cold, glaciers gradually
descended the flanks of the high mountains to the valleys beneath,
and great aqueous precipitation took place. The Norfolk Forest Bed
is correlated with the horizon of St. Martial in Herault and the more
recent parts of the Val d’Arno series. Mastodons had quitted Kurope;
Monkeys had emigrated to Africa; but Rhinoceri and Hippopotami
had never been more numerous; Stags abounded; but the age was
specially characterized by Hlephas meridionalis, found associated in
the sandy marls of Durfort, with the leaves—on which it fed chiefly —
of an Oak, of a species still living in Southern Italy. A Laurel lived
on in the Rhone Valley, and Abies montana, and other northern species,
in the Forest Bed; climatal difference of vegetation in the North
and South of Europe being first strongly accentuated in this period.
DECADE Il.—VOL. VI.—NO. VI. 18

274 Reviews— Waagen’s Paleogeography of India.

The author closes his work by summing up the seven elements
into which the past and present French flora may be divided. The
indigenous plants being those, like the Vine, that have never quitted
France. Others, though fully developed in the Tertiaries, are now _
only tropical ; others are cosmopolitan; some now live in foreign
warm temperate regions, though extinct in France; others inhabit
Madagascar and Africa; a small number have American affinities
(Sabal Palms, etc.); whilst the Greenland and Arctic flora is well
represented by Sequoias and Glyptostrobus of the French Tertiary.

C. E. De Rance.

d5e) JEONG 2G dah 6 Se
Le ae

T.—“ Dr. W. Waacen On GeroGrapuicaL Distrispution oF Fossit

ORGANISMS IN Inpra.” (Read at the Imperial Academy of

Science, Vienna, December, 1877. ‘Translated in Records Geol.

Surv. India, vol. xi. p. 267.)

HIS paper, from the scope of its subject and the largeness of the

conclusions put forward, may be called both important and ambi-
tious. Important because, independently of the author’s speculations,
it contains a well-condensed summary of the geology of India as now
known; and ambitious, in that it seeks to present somewhat of the
changing scene of the ancient physical geography of this great
portion of the earth’s surface since early Paleozoic times. It speaks
well for the progress of geological knowledge regarding India, that
data of so tangible a nature exist to aid the impulse towards specula-
tive inquiry.

No ‘‘fear to fall” would seem to prevent our author from climbing,
and if we cannot quite go with him to heights within the region of
pure conjecture, it must be admitted that his “bold” theoretical
sketch wears an aspect of consistency so far as he adduces evidence,
and, despite one’s doubts of large assumptions, leaves the impression
of being, at least to some extent, founded on fact.

The former existence of a continent of which India formed a part
ever since Paleozoic times, is not by any means a new idea; this
has been suggested or mentioned by many writers; + but the definition
of its form at various geological periods, as indicated by the distribu-
tion of marine fossils, is the special object of the paper under notice;
the author dissenting strongly from the supposition of Mr. H. EF.
Blanford, that this continent was connected with Africa or Australia.

After noticing all the formations of Peninsular-India, the Himalaya,
Burmah, the Garrow hills, on the east, and the Suliman ranges to the
west, and referring to his neat geological sketch-map, Dr. Waagen
concludes from the distribution of “slaty” and sandstone Palzo-
zoic rocks (the word ‘slaty’ being evidently used as synonymous
with ‘marine’) that there was in Paleozoic times an Indian con-
tinent whose northern limits coincided with the foot of the Himalayan
chain, and which included the whole of British India to the south.

! Heckel, Hist. Creation. H. F. Blanford, Physical Geography of India, 1873.
W. T. Blanford, J. A. Soc. Bengal, 1876. GEOL. Mac. Decade II. Vol. III. etc.

Reviews—Waagen’s Paleogeography of India. 275

During the most of the Mesozoic period the great outer crystalline
zone of the Himalayas was a coast-range of this continent, and in
Triassic times its northern boundary lay almost parallel to the Palzeo-
zoic coast-line, but between the outer and inner great crystalline
zones, supposed to form the fundamental skeleton of those mountains.

In the Jurassic and Lower Cretaceous periods the continent had
nearly the same outline to the north, though somewhat enlarged, its
western limits coincided with the Suliman mountains, but the sea
sent a great gulf up the Narbada (Nerbadda) valley for half its
length, and also encroached upon the Madras coast from the mouth
of the Godavery southwards to beyond Pondichery.

Upper Cretaceous times brought another change: the old central
Himalayan coast-line in the longitude of Simla was moved somewhat
further north, its eastward extension being uncertain. On the west
the Suliman mountain regions were submerged, with the north-
western part of the Punjab, the whole of Sind, Kach, and part of
Kattywar. On the east a small area near Madras, the Sunderbans,
Cachar, the south flanks of the Garrow hills, and the whole of
Burmah, were under water, but the great peninsular area was mainly
dry land.

In the Eocene period the sea spread over western India, and
extended as far as the river Jumna. On the east its traces occur at
the mouth of the Godavery, it reached up to the Garrow hills, and
covered western Burmah.

Upper Tertiary marine deposits of Siwalik age are only known in

southern Sind, and perhaps in Kach, hence the whole region was, it
is presumed, at this time chiefly continental.
_ Except the Tertiary, all these changes in the outline of the land
are shown by lines of different character on Dr. Waagen’s map.
And through all these eons the vast series of peninsular India’s
aqueous strata is declared to have been of inland fresh-water origin
—a point already noticed, we may remark, by the late Dr. Oldham
and Mr. W. T. Blanford '—but whether formed in basins or by rivers
our author does not decide.

It is evident his reasoning upon this distribution of land and ocean
throughout geological time is based upon known exposures of marine
fossil-bearmg rocks, but further discovery of marine beds of any
age would modify the whole value of the conclusions, as would also
any circumstance favouring the marine origin of strata as yet not
known to contain fossils, and there are large deposits of this class
in India.

Inspection of Dr. Waagen’s map shows that nearly all his lines of
limit of marine deposit converge at the N.W. corner of the empire ;
this being also the only region in which he was employed even for a
short season in the field, beyond a mere trip or so on one side or other
of the Ganges valley, it may be fair to suppose that here the sound-
ness of his conclusions can be tested. Let us glance at the evidence
on which his reasoning is based in this country—one not altogether

1 Pal. Ind. Series 4.1. Records Geol. Sury. Ind. vol. iii.

276 Reviews— Waagen’'s Paleogeography of India.

-undescribed,! though the most extensive memoir on the local geology
by the Indian Survey (that on the Salt Range) has been for years
awaiting publication, and has lain printed but unissued since the
summer of 1877.

Dr. Waagen’s Paleozoic continental shore-line edges the Salt
Range escarpment, in which there occurs a group of beds said to
have been prematurely referred to the Silurian age,” as well as a
later development of generally-admitted (though the author uses the
term ‘so-called’) Carboniferous strata. These marine groups are cut
off by the escarpment on the south side of the range; the upper one
reappears strongly on the Indus to the west, and it is evident the
beds once extended further to the southward, hence there is absolutely
no reason why they might not have reached as far as Delhi, or be
even now buried beneath the great Sind-Punjab deserts. Here, at
least, the author’s conclusion as to continental limits must be founded
on loose conjecture rather than on fact.

But in still earlier Palzeozoic times an adjacent southern continent
is better indicated amongst the older Salt Range strata, by the occur-
rence of derived crystalline boulders in an earthy matrix, of kinds
unknown in the crystalline series to the north. The deposits are
unfossiliferous, and their partly shore-like aspect or association with
enormous layers of salt and gypsum are but slight reasons for
asserting their marine, estuarine, or terrestrial origin. Consequently
the presumed continental boundary in this direction at that early age
becomes hazy if not totally obscure.

The supposed Palzeozoic Attock slates, which occur further to the
north, and comprise many sandstones and limestones as well, may
be of course marine, though, in the absence of fossils, both this
point and their exact age are quite incapable of proof; they are,
“nevertheless, included in Dr. Waagen’s Paleeozoic “slaty facies.”

Nor can we find more satisfactory reason why the author supposes
the outer Crystalline zone of the Himalayas to have formed the
coast-range of a continent for most of the Mesozoic period; the only
one he advances seems to be merely the absence of as yet recorded
marine beds of this age along the south flanks of these mountains.
The Himalayan crystalline rocks, however, are not the same as those
of peninsular India, and he admits the possibility of their represent-
ing Paleozoic beds in a metamorphosed state. It is plain that a
series of rocks, thus altered beyond recognition, might be of any age
anterior to the Tertiary elevation of the range, and equally plain
how slender and transparent is the assumption upon which the
imaginary coast-line of a great ancient continent has been drawn.

Again, the author points out that his Triassic continental boundary
line is visible in the Salt Range, but omits to say that the formation

1 See papers by Fleming, Asiat. Soc. Bengal. Also Quart. Journ. Geol. Soe.
London, 1874-78. Records Geol. Sury. Ind. vols. iii. vi. vii. viii. Memoirs Geol.
Sury. Ind. vol. xi. and xiv. (‘‘to be issued shortly.”’)

2 Dr. Waagen himself, when in India, favoured this view, and never suggested its
being doubtful, though the evidence was in his hands, in the shape of shells of an
Obolus, determined as Silurian by the late Dr. Stoliczka.

bo

Reviews—Ramsay’s Physical Geology. 204

with salt pseudo-morphs, seen in the eastern part of this range, and
which he describes as replaced by marine beds to the west, is an
entirely unfossiliferous group, whose Triassic age has no better
foundation than a choice of guesses.

This being a special illustration of our author’s system of coast-
lines, we are bound to conclude that his most confident assumptions
may be but visionary suggestions, the value of which depends
largely upon unknown possibilities. And when some of these
assumptions deal with a mass of formations so vast that the British
Isles might be excavated vertically from within them twice over, or
many larger countries made out of their materials, the whole being,
on the negative evidence of absence of marine fossils, referred
entirely to inland freshwater deposition, we may well pause before
accepting in full the conclusions which the paper would establish.

Indulgence in such speculative flights as these has a dangerous
tendency to encourage the charlatanism of a would-be “higher
culture” in geology, when put forward with the arrogance of know-
ledge; and so far as the case before us is concerned, examination
has but confirmed the doubts felt at first, as to whether we were
really reading history or romance. W.

I].—Tue Puysicat GroLocy anp GeocrarHy oF GREAT BriTArn:
A Manvat or British Geotocy. By A. C. Ramsay, LL.D.,
F.R.S., etc., Director-General of the Geological Survey of the
United Kingdom. With a Geological Map, printed in colours,
and numerous Woodcuts. 5th edition. S8vo. pp. 639. (Stanford,
London, 1878.)

OT much more than ten years ago this excellent work first
appeared as collected notes from the Professor’s lectures on

the Geological Structure of the British Isles, elucidating the opera-
tions of water, ice, and other natural agents in producing and
modifying the surface of the earth in general, and of the British
area in particular. By gradual increase of explanatory and illustra-
tive matter the fourth edition had become twice as thick as the first,
and proportionately valuable to the student desirous of recognizing
and understanding all the characteristic features of mountain, moor-
land, and valley, sea, lake, and river, which interest, or ought to
interest us both at home and abroad. The fifth edition, lately
issued, has attained double the bulk of the last, by the introduction
of thirteen chapters on the historical, successional, or stratigraphical
geolog y of Britain. This portion has necessarily considerable value,

possessing the interest which the teachings of so accomplished a

geologist as the author must carry with them; but the paleontology

is not equally well handled as the older portion of the work, in
which the physics of geology are so well and plainly discussed, so
perfectly illustrated, and so enthusiastically worked out with the
results of the author’s own researches and reasonings.

Those portions of the new chapters which treat of the physical
geography and hydrography of each successive geological epoch will
be useful to many readers, since they extend the results of what

278 Reviews—Geikie’s Old Red Sandstone.

Elie de Beaumont, Godwin-Austen, and others, well began, in ap-
plying definite geological observation to the discovery of the old
shoals, shore-lines, and margins of the several great formations of
strata. This is a subject of considerable interest in both practical
and hypothetical aspects; and we trust that the life-long studies of
Mr. Godwin-Austen will yet result in the atlas of paleogeography,
towards the completion of which he had already done so much in
1862, when the Geological Society awarded him their Gold Medal
in recognition of his sound and useful labours, particularly in work-
ing out the history of the geologic changes of land and sea in
Western Europe.

This new edition of the Physical Geography and Geology of
Britain is enriched with many new woodcuts, both of characteristic
scenery, and of fossils belonging to the several formations. Furnished
with these latter, and the description of the successive groups of
strata, the new edition is now entitled “A Manual of British
Geology,” and will be found useful to many general readers as well
as to schools and classes. T.R.J.

JI.—On tHe Oxtp Rep SanpstonE or Western Europe. By
ARCHIBALD Gutnin, LL.D., F.R.S., ete. (Part I.)

[From the Transactions of the Royal Society of Edinburgh, vol. xxviii. 1878.]

HE recent papers in the Grotocican MaGazine on the Devonian
question, and on the relations of the Old Red Sandstone to the
Silurian and Carboniferous rocks, especially those by Mr. Kinahan,
Professor Hull, and Mr. Champernowne, have suggested new inter-
pretations of these great rock-masses and some important revisions
in their classification.

There is a tendency to split up and almost annihilate the Old Red
Sandstone. Thus Mr. Kinahan has grouped the Irish representative
as Carboniferous, placing the Dingle or Glengariff grits as Silurian ;
while both Professor Hull and Mr. Champernowne are inclined to
regard portions of the Devonian rocks also as Silurian.

Professor Geikie’s memoir on the Old Red Sandstone of Western
Europe will therefore be read with particular interest by those who
have paid any attention to the varieties of opinion on its equivalent
deposits, and all geologists will hail its appearance as giving not
merely a summary of what is known on the subject, but a large
amount of original observation.

Commencing with an historical introduction, Professor Geikie
tells of the first application of the term Old Red Sandstone, and how
it came to be regarded as the lacustrine equivalent of the marine
Devonian rocks, although, as he observes, “the alleged contempo-
raneity of these two groups of strata. had, in England at least, been
assumed rather than proved.” Into this question, however, he does not
enter, his object being to examine into the distribution and history of
the deposits which admittedly belong to the Old Red Sandstone.

Discussing the value of the threefold division of Murchison, Pro-
fessor Geikie says, “‘My own work in the centre and south of Scot-

Reports and Proceedings—Geological Society of London. 279

land had proved the Old Red Sandstone to consist of two great
divisions —a lower passing down conformably into the Upper
Silurian shales, and an upper graduating upward into the Lower
Carboniferous sandstones, with a complete discordance between the
two series. Mr. Jukes and Mr. Du Noyer had made out a similar
arrangement in the South-west of Ireland.” And he adds, “‘ The
lithological argument seems to favour the classification adopted by
Mr. Jukes, for a great part of his Dingle beds would answer well for
much of the lower Old Red Sandstone.” ;

Until we are able to study the succeeding parts of Professor
Geikie’s memoir, we must be content with quoting the above
passage, which is significant when taken in conjunction with Mr.
Kinahan’s researches.

After a brief consideration of the condition of Western Europe
previous to Old Red Sandstone times, Prof. Geikie passes on to the
consideration of the Lower Old Red Sandstone, and its basins of
deposit in the British area. These basins he limits to five, termed
respectively, Lake Orcadie (including the whole of the Orkney
Islands), Lake Caledonia, or the Mid-Scottish Basin, Lake Cheviot,
the Welsh Lake, and Lake of Lorne (Argyllshire, etc.).

He observes, that in no part of its European distribution does the
Old Red Sandstone attain the thickness and variety which it presents
in Scotland. The present part of his memoir contains the account otf
the rocks in the area described as Lake Orcadie. It contains a table,
showing the vertical range of the known fossils of the Old Red
Sandstone of Caithness, compiled chiefly from data furnished by
Mr. ©. W. Peach; and a list of the fossil fishes of the Lower Old
Red Sandstone of the North of Scotland. A folding-plate gives
coloured sections of the strata of Shetland, Orkney, Caithness, Tarbat
Ness, Culloden Moor, Gamrie, ete. H. B. W.

REPORTS AND PROCHHDINGS.-

——@——_

GeronocicaL Socirry or Lonpoy.—I.—April 9, 1879.—Henry
Clifton Sorby, Esq., F.R.S., President, in the Chair.—The following
communications were read :—

1. “On the Geological Age of the Rocks of the Southern High-
lands of Ireland, generally known as ‘the Dingle Beds’ and
‘Glengariff Grits.’ By Prof. E. Hull, M.A., F.B.S., F.G.S.

After reviewing the opinions of previous writers with reference
to the age of these beds, including those of Hamilton, Griffith,
Murchison, Kelly, Jukes, and the Officers of the Survey, which
showed that great uncertainty has hitherto prevailed, the author
quoted a passage of the late Prof. Jukes, in which he confessedly
left the determination of the age of these beds open for future
examination ; and he therefore determined to reinvestigate the
question, bringing to bear upon it the knowledge which had since
been acquired of other districts. For this purpose (and accom-
panied by Messrs. O’Kelly and M‘Henry) he examined a series of

280 Reports and Proceedings—

sections, from the coast of Dingle southwards to Bantry Bay; and
having also carefully examined the field-maps of the Survey of
those districts, had arrived at the following results :—

First, that “the Dingle Beds” are perfectly conformable to, and
continuous with, the Upper Silurian Beds of the Dingle promontory.

Secondly, that they are the representatives of ‘the Mweelrea
Beds and Salrock Slates,” of West Galway and Mayo, the age of
which, as shown by the fossils, is Upper Silurian, and that “the
Dingle Beds” may therefore be regarded as of the age of the
Ludlow Rocks, but unusually developed. This view was adopted
as far back as 1859 by Sir Richard Griffith.

Thirdly, that throughout the south of Ireland “the Dingle and
Glengariff Beds” are disconnected from the succeeding conformable
series, consisting of (¢) Lower Carboniferous Slate; (b) The Upper
Old Red Sandstone with Anodonta Jukesii; (a) The Lower Old
Red Sandstones and Conglomerate ; as these three conformable
formations are found resting upon, and against, the Glengariff beds
successively in a direction either from south to north, or from south-
west to north-east, owing to a conformable overlap against the flanks
of an old shelving shore formed of the Glengariff beds.

Fourthly, that at the close of the Upper Silurian period, and after
the deposition of “the Dingle and Glengariff Beds,” these strata
were disturbed, upraised, and denuded, and were not again sub-
merged till the commencement of the Old Red Sandstone (a), when
they were successively overlain by the beds of that formation with
the succeeding ones of the Lower Carboniferous period, probably
including the Carboniferous Limestone in some places.

Lastly, that it was during this period of upheaval that, as the
author believes, the marine Devonian Beds (Ilfracombe and Morte
series) were deposited, which accounts for their absence in the
Irish area, which was either a land surface or only partially sub-
merged. To this part of the subject the author hoped to call the
attention of the Society on a future occasion.

2. “On some Three-toed Footprints from the Triassic Conglo-
merate of South Wales.” By W. J. Sollas, Hsq., M.A., F.G.S.

The author described the discovery by Mr. T. H. Thomas of
some three-toed footprints in the Triassic Conglomerate at Newton
Nottage, South Wales. They were stated to resemble in their most
important characters the footprints of some Ratite birds, such as
the Emeu : and this facet, taken in connexion with the occurrence of
Dinosaurian remains in the Magnesian Conglomerate of Bristol, led
the author to attribute to them a Dinosaurian origin.

3. “On the Silurian District of Rhymney and Pen-y-lan, Cardiff.”
By W. J. Sollas, Esq., M.A., F.G:S.

The paper commences with a history of the previous observations
on the district; a description of the geographical distribution, geo-
logical structure, and vertical succession of the Silurian rocks is next
given. They comprise beds belonging to the Wenlock and Ludlow
groups, and pass conformably upwards into the Old Red Sandstone.
The district affords a good base for a measurement of the thickness

Geological Society of London. 281

of the Old Red Sandstone on the south of the South- Wales Coal-field.
This was found to be a little over 4000 feet. The thinning out of
the Old Red Sandstone and Silurian strata, together with the marked
change which takes place correspondingly in the lithological cha-
racters of the latter formation on passing from the north to the
south side of the coal-field were taken to indicate an approach to a
shore-line. This shore-line belonged to land which, as shown by
the great thickness of the Devonian beds, could not have extended
far south. It corresponded to Mr. Htheridge’s barrier between the
Old Red Sandstone and Devonian seas. The sandstones with Old-Red
characters, such as the Hangman Grit and the Pickwell-Down
Sandstones, occurring in the Devonian formation, were deposited at
intervals when this barrier was submerged to a greater depth than
usual. The Cornstones were stated to thin out to the south along
with the other sedimentary beds of the Old Red Sandstone, and
were regarded as derived from the denudation of previously up-
heaved limestones, such as the Bala and Hirnant. The paper con-
cluded with a description of the characters of the more interesting
rocks and fossils.

II.— April 30, 1879.—Henry Clifton Sorby, Hsq., F.R.S., President,
in the Chair.—The following communications were read :—

1. “A Contribution to the History of Mineral Veins.” By John
Arthur Phillips, Esq., F.G.S.

In this paper the author described the phenomena of the deposition
of minerals from the water and steam of hot springs, as illustrated
-In the Californian region, referring especially to a great ‘sulphur
bank”? in Lake County, to the steamboat springs in the State of
Nevada, and to the great Comstock lode. He noticed the formation
of deposits of silica, both amorphous and crystalline, inclosing other
minerals, especially cinnabar and gold, and in some cases forming
true mineral veins. The crystalline silica formed contains liquid-
cavities, and exhibits the usual characteristics of ordinary quartz. In
the great Comstock lode, which is worked for gold and silver, the
mines have now reached a considerable depth, some as much as 2660
feet. The water in these mines was always at a rather high tem-
perature, but now in the deepest mines it issues at a temperature of
157° Fahr. It is estimated that at least 4,200,000 tons of water are
now annually pumped from the workings; and the author discussed
the probable source of this heat, which he was inclined to regard as
a last trace of volcanic activity.

2. “ Vectisaurus valdensis, a New Wealden Dinosaur.” By J. W.
Hulke, Esq., F.R.S., F.G.S.

The author described some fossil remains, obtained by him in
Brixton Bay, Isle of Wight, in 1871, consisting of an ilium, several
pre-sacral, and one post-sacral vertebra. He established the Dino-
saurian nature of the animal represented by them, and offered proof
of its distinctness from already-known forms. He proposes for it
the name Vectisaurus valdensis, a name descriptive of the locality and
formation in which the remains were found by him. The characters

282 Leports and Proceedings—Geological Society of London.

presented by the genus Vectisuurus were stated to be as follows :—
Ilium with a long compressed ant-acetabular process, having its
greatest transverse extent in a vertical plane, and strengthened by a
strong ridge produced from the sacral crest. Vertebre in anterior
dorsal region having opisthoccelous centres, their lateral surfaces
longitudinally concave, transversely gently convex, meeting below
in a blunt keel.

3. “On the Cudgegong Diamond-field, New South Wales.” By
Norman Taylor, Esq., of the late Geological Survey of Victoria ;
communicated by R. Etheridge, Hsq., Jun., F.G.S.

The author described in detail the various spots at which diamonds
have been found in this locality. They occur in river-drift, associated
with gold and other gems. The drifts in the district are at least six
in number. The oldest is considered by the author to be Upper
Miocene or Lower Pliocene ; the next Middle Pliocene; others Upper
Pliocene, Pleistocene, and Recent. Between the Middle and Upper
Pliocene flows of basalt lava took place, which have sealed up much
of the older drifts. Diamonds are found in the oldest drift and, pro-
bably by derivation from it, in the newer. Gold, metallic iron, wood,
tin, brookite (?), iron-sand, quartz, tourmaline, garnet, pleonast,
zircon, topaz, sapphire, ruby, and corundum are also found. The
author then considers the question of whether the diamonds are
derived from some of the igneous or sedimentary formations (from
Upper Silurian to Mesozoic) which have contributed to the drift ;
and concludes, from a variety of reasons, that the diamonds have
been formed ¢n situ in the older drift.

4. “On the Occurrence of the Genus Dithyrocaris in the Lower .
- Carboniferous, or Calciferous Sandstone Series of Scotland; and on
that of a second species of Anthrapalemon in these beds.” By R.
Etheridge, Esq., Jun., F.G.S.

The author, in the first place, referred to the extension of the
range in time of the genus Dithyrocaris, by the discovery of nume-
rous fragmentary remains of D. testudineus, Scouler, in the Calcife-
rous Sandstone or Lower Carboniferous Series of the south of
Scotland, about the horizon of the Wardie Shales near Edinburgh,
and in the Cement-stone group of Roxburghshire.

A further and more complete description of <Anthrapalemon
Woodwardi, Eth., jun., was then given, in which the characters of
some of the appendages were more particularly alluded to, such as
the eyes, inner and outer antenne, and first pair of ciliate appen-
dages, thus placing the stability of the species beyond a doubt.

The paper concluded with the description of a second species of
Anthrapalemon, from the Lower Carboniferous rocks of Roxburgh-
shire, for which the author proposed the name of A. Macconochii,
after the discoverer of the specimen. This remarkable species, of
which the carapace is at present the only portion known, differs
essentially in the characters of this part of the body from all the
other described species of the genus.

Correspondence—Mr. W. Upham. 283

COR russ Ss] SiN 2 sea INiS sa -

THE TILL IN NEW ENGLAND.

Sir,—Recent explorations of Professor C. H. Hitchcock and the
writer in the Geological Survey of New Hampshire show that the
unmodified drift in that State consists commonly of two deposits,
quite distinct from each other. These appear to correspond to the
lower till and upper till of Scotland and Sweden, described in the
second edition of Geikie’s Great Ice Age.

The lower till of New Hampshire and other parts of New England
is composed of boulders, gravel, sand, and clay, indiscriminately
mingled together, without any traces of stratification such as is pro-
duced by currents of water. Most of its pebbles and boulders have
their sides planed to flat surfaces, which often retain striz. ‘The
detritus in which these are imbedded is usually clayey and dark or
bluish in colour, its iron being in an imperfectly oxidized state.
This deposit is also distinguished by its being very hard and com-
pact, so asto require it to be loosened by a pick before it can be
shovelled, which has gained for it among the common people the
name of “hard pan.” It is the lowest in our series of glacial
deposits, and appears by all these features to be the ground-moraine
of an ice-sheet. Its accumulation seems to have been by the gradual
addition or lodgment of material upon its surface, as is shown by a
kind of lamination, which is almost always noticeable in sections
that have been for a short time exposed to the weather. The detritus,
though filled with rock-fragments, is obscurely divided into flakes
one-eighth to one-fourth of an inch thick, which lie in planes parallel
to the surface.

The upper till is a confused mixture of boulders, gravel, and
sand, but seldom contains any considerable proportion of clay. It
usually shows no stratification of any kind. Its rock-fragments are
mainly rough and sharply angular, showing no marks of attrition,
and they are generally larger than those in the lower till. Blocks
occur in both up to ten feet in diameter, and in the upper till have
sometimes from twice to four times that size. The colour of the
upper till is yellowish, its iron having been fully oxidized. This
deposit is loose, and may be easily excavated. It seems probable
from these characteristics that this was material contained in the ice-
sheet, gathered into it in its passage over hills and mountains, and
that at its final melting the upper till was dropped loosely upon the
lower till, or ground-moraine, on which it lies, being separated at a
definite line.

.The lower till occurs in flattened or undulating sheets generally
throughout New England. It also forms in some districts very
remarkable oval hills, which are from a few hundred feet to a mile
in length, with two-thirds as great width, while their height corre-
spondingly varies from 25 to 200 feet. But whatever may be their
size, they are singularly alike in form, having steep sides crowned
by a gracefully rounded top, presenting a very smooth and regular

284 Correspondence—The Geological Congress.

contour. From their resemblance in shape to an elliptical con-
vex lens, Professor Hitchcock has called them lenticular hills. The
trend of their longer axis is always approximately parallel with the
striz marked upon the bed-rocks of the same region. These accu-
mulations are scattered without any apparent order quite abundantly
upon areas five to ten miles wide, and ten to twenty-five miles long.
One of these areas includes Boston and its harbour, and extends five
to fifteen miles on all sides of that city ; while North-eastern Massa-
chusetts and Southern New Hampshire have three belts of territory
upon which these lenticular hills abound. ‘These areas are separated
by others of equal extent, which are entirely destitute of such
accumulations of till, or show only occasionally one, quite typical
and prominent, but isolated from all others of its kind.

These hills, like the valleys and the whole of New England, are
overspread by the nearly universal mantle of the upper till, which is
commonly between one and five feet in depth, but sometimes reaches
to ten or twenty feet.

As this Macazrnu has formerly presented instructive comparisons
of the superficial deposits in Great Britain and in America, I would
like to inquire through its pages whether British geologists have
noted accumulations of till like our lenticular hills.

Nasuva, New Hampsuire, April 14, 1879. Warren UPHAM.

THE GEOLOGICAL CONGRESS AT PARIS.

Srr,—I am requested by an eminent foreign geologist to make the
following additions and corrections with regard to the article on the
International Geological Congress signed “ A. L.,” which appeared in
the GrotocicaL Macazine for this month.

The Committee on Nomenclature included Professor Dewalque of
Liége as Secretary, Professor Hébert being its President. Since
then, Professor Ferdinand Romer, of Breslau, has occupied the office
of German representative.

Professor Hughes, of Cambridge, is entered as member of both
Committees; this double appointment has been made since the
Congress, and is contrary (as 1 am informed by the eminent geologist
aforesaid) to the principles of the Congress. The complete absence
of non-colonial Englishmen at the Congress was much discussed at
the time, and the fact that a country like England should be unable
to provide two geologists to join in the Universal Congress augurs
but poorly for the success of the meeting at Bologna. HG. 8:

April 28th, 1879.

BEEKITE FROM THE PUNJAB, INDIA.

Srr,—In a paper read before the Geological Section of the British
Association held at Cheltenham, in 1856, Mr. W. Pengelly brought to
notice a very remarkable and somewhat unique form of chalcedony,
found plentifully in Torbay among the Triassic conglomerates, to
which the name of Beekite has been given from Dr. Beeke, a former
Dean of Bristol, by whom they were first publicly noticed. ‘These
Beekites consist of calcareous nuclei in a more or less advanced

Correspondence— Capt. H. W. Jamieson. 285

stage of decomposition incrusted with a thin surface of chalcedony
arranged in tubercles, varying in size from a pin’s head to a pea.
These tubercles are surrounded by several rings, and frequentiy the
same ring invests two or more tubercles. Occasionally the inclosed
organism, which is either a Zoophyte or Mollusc, is found entirely
decomposed and resolved into a few pinches of dust, and all that
remains is the peculiarly mottled shell of chalcedony. In this case
the Beekite will float as easily as a blown egg. There is a very fine
specimen of a floating Beekite to be seen in the Silica Group of the
Horse Shoe Mineral Case in the Geological Museum in Jermyn
Street. Mr. Pengelly is of opinion that this peculiar siliceous
deposit is due to the decomposition of calcareous pebbles in Triassic
conglomerate surrounded by water holding chalcedony in solution,
which has been caught up and deposited on the organic nucleus, the
more readily from its being in a state of decomposition. The tuber-
cular appearance may easily be accounted for from the appearance
presented by a mass of fermenting and bubbling yeast. Thus the
Beekite presents us with a most interesting stereotyped record of the
evanescent, visible, and mechanical process of fermentation. Up to
the present, I believe the range of this peculiar deposit is supposed
to be restricted to the shores of Torbay, Australia, and the banks of
the Nerbudda River in India. Mr. Pengelly, in the paper above
referred to, gave it as his opinion that Beekites were only to be
expected in conglomeratic rock containing decomposing calcareous
pebbles, and through which water charged with chalcedony passes.

I have in my possession a very perfect specimen of Beekite which
I found some years ago while travelling in an out-of-the-way part of
India. It was on the slopes of Mount Sakesur, a high isolated peak
forming the western extremity of the Salt Range in the Sind Sagar
Doab of the Punjab; a locality fraught with the utmost interest to a
naturalist, and especially so to a geologist, exhibiting, as it does, at
a glance, almost a vast panoramic view of nearly all the typical
paleontological forms familiar to Huropean geologists, ranging
from gigantic specimens of Brachiopodous shells, such as Spirifer,
Strophomena and Productus, steadily up through Jurassic and Oolitic
forms to those of the Eocene and Nummulitic Limestone. It was in
the face of a precipitous cliff midway up the slopes of Mount Sakesur
that I found my specimen deeply imbedded in a block of massive
sandstone which had fallen from the overhanging cliff, which in itself
consisted of a compact arenaceous formation of a dark grey colour
literally teeming with Paleeozoic fossils, such as the Productus,
Spirifer, Rhynchonella, Lithostrotion basaltiforme, Crinoids, ete.

The specimen consists of a fragment of Productus shell, very
probably Productus horridus—the formation itself being possibly
Permian Magnesian Limestone. It is coated over with a crust of
Chalcedony possessing identically the same tubercular structure
met with on the specimens from Devonshire. As far as is as yet
known, the geographical range of Beekites is in a limited area. The
discovery, therefore, of my specimen in the Punjab Salt Range may
possibly possess some interest to the question of distribution, coupled

286 Correspondence—Ur. W. Carruthers—Mr. A. Strahan.

also with the fact that it was discovered in compact sandstone, instead
of conglomerate. J shall be most happy to forward the specimen for
the inspection of any one interested in the matter.

H. W. Jamieson, Capt., F.R.G.S.,

Junior Army anp Navy Crus. _ Bengal Staff Corps.

NOTE ON MR. LEE’S SPECIMENS OF FOSSIL WOOD FROM
GRIQUA LAND.

Srr,—The Lignite from Kimberly Mine, Claim 196, consists of
stems, or branches converted into a brittle lignite, which still pre-
serves the original size and form of the stems, and exhibits the
internal structure peculiar to the Coniferee. The wood cells have a
single series of discs, as in the wood of the recent Pines.

The specimens from Kimberly Mine, Claim 165, are more altered,
and approach the condition of our Paleeozoic coal. The small por-
tions which show structure (mother-coal) consist of fragments of
Coniferous wood, exhibiting the disciferous wood tissue with the
discs in single rows.

The slides from the coal of Heilbron, Vaal River, Free State,
consist of wood cells, with discs in single or double and opposite
rows, as in the recent Pines. W. CarRuUrtHERS.

BoranicAL DEPARTMENT, British Museum.

GEOLOGY OF THE ISLE OF MAN.

Srr,—I examined in April, 1878, with Dr. Stolterfoth, of Chester,
the Conglomerate of Langness in the Isle of Man, and can add my
testimony to that of Mr. Morton (Guon. Mac., May, 1879), that Mr.
Cumming was not mistaken in assigning them a position below the
Carboniferous Limestone. Not only are they seen in the beach to
dip under the Limestone, but the lower beds of the latter are them-
selves conglomeratic and interstratified with beds of red conglomerate,
resembling those which occupy a large part of the promontory.
Like Mr. Morton, I failed to find any limestone pebbles in the
Conglomerates. A. STRAHAN.

Hotywet, May 12, 1879.

[The following is a copy of a letter addyessed to the Hditor of the
Times; published May 19th, 1879. Its contents are so important
that we gladly take leave to reprint it in the GroLocicaL MaGazine.

- —Hpit. Grou. Mac. |

“‘PosITION OF THE SILURIAN Rocxs In Herts.
«Sir,—In June, 1877, you did me the favour to insert in the Times
the announcement and recognition by myself of the Devonian rocks
in the deep boring at Messrs. Meux’s Brewery, 'Tottenham-court-road,
which there occurred below an abnormal condition of the Lower

Greensand at the depth of 1,140ft. This announcement was at first

received with doubt; nevertheless, the problem as to what was the

nature of the Paleozoic rocks below London was there and then
solved. Since then borings of greater diameter still have been put
down in other parts of the London Basin for the same purpose.

Mr. R. Etheridge, F.R.S.—Silurian Rocks in Herts. — 287

“Two of the trials have been some time in progress by the New
River Company—one at Turnford, near Cheshunt, and the other at
Ware, near Hertford. Both these important borings and extensions
were undertaken by the New River Company for the purpose of
obtaining a larger supply of pure water from the Chalk, and for
settling the question of the existence or non-existence of the Lower
Greensand in Hertfordshire. To a considerable extent the desire and
anticipation of the Company have been realized through large sup-
plies from their deep penetrations into the Chalk, this being especially
the case at the Turnford deep well, near Cheshunt. _

«The presence, however, of the Lower Greensand below the Gault
in Hertfordshire has long been problematical; but, knowing that
usually it is a source of extremely pure water and in considerable
quantities, the New River Company undertook, with great public
spirit, the completion of the two deep borings named, through the
Chalk and Gault. They were quite aware of the probability or
possibility of finding some Palzeozoic rock under their trials in Hert-
fordshire, and, unfortunately for the deeper supply of water, such has
proved to be the case, owing to the absence of the Lower Greensand
at Ware (one of their stations), and the occurrence of the partly
anticipated more ancient rocks, upon which they now find the Gault
immediately rests, without the intervention of the Lower Greensand.

“Tt is well known how much interest is attached to the question
of the extension of the older formations under the overlying or
newer rocks of the south-east of England; this interest is now
intensified through the Ware boring by the discovery of one of the
oldest formations in the British Islands immediately beneath the
Gault and at the depth of 800ft. At this depth I have to announce
the presence of the Upper Silurian rocks (the Wenlock Shale), richly
fossiliferous, dipping at an angle of 40 deg., but to which point of
the compass is not at present known. I believe this delicate matter
will be ascertained by the engineers of the New River Company—a
question of the utmost importance in determining the strike or
bearing of the older strata at any depth. Fresh interest is now
attached to the Turnford boring, the diamond crown being now low
down in the Gault at 980ft.

“So spirited and costly an undertaking to seek for pure water
for the supply of the metropolis is, indeed, highly judicious and
important on the part of the New River Company. We must not
too hastily complain of the want of public spirit, when every effort
is made to obtain, even at great cost, an element so important to the
sanitary condition of the people. In this the New River Company
have not failed in intuition or purpose, and to their enterprise is
due the solution of another geological problem.

“ May 16. Rogpert ETHERIDGE.”

Nore —Since the above letter was written to the Times, we have
received from Mr. Etheridge the names of the fossils found in the
cores of Wenlock rock at the bottom of the bore-hole at Ware. We
hope to receive from him, for our next Number, a more detailed
notice of the probable Physical Geography and extension of these

288 Ir. R. Etheridge, F.R.S.—Silurian Rocks in Herts.

old rocks underlying the Tertiary and Cretaceous strata of the
London Basin. It is to be hoped that the direction of the “strike”
may be determined in the course of a few weeks, a matter of
paramount interest and importance to a true understanding of the
distribution of the Paleozoic and other rocks, either here or under-
lying any other area where it has been determined they exist.

This is at present a problem of the first consideration in deep-
boring, and upon its successful solution must depend in great
measure the practical value of our knowledge that strata of high
economic importance probably lie within an accessible depth beneath
our feet. Until we know approximately the ‘strike’ of these Paleeo-
zoic rocks, it will be of little avail to suggest where next to seek, or in
what direction we should test them by further experimental borings.

The following fossils have been determined by Mr. Etheridge
from the few feet of cores examined :—

I. Protozoa. 14. Pentamerus linguifer, Sby.
1. Ischadites Koenigti, Murch. 15. Strophomena euglypha, Dalm.
Il. EcurnopERMATA. 16. depressa, Dalm.
2. Taxocrinus, sp. 17. ——— rhomboidalis, Wilckens.
III. ANNELIDA. 18. antiquata, Sby.
3. Tentaculites ornatus, Sby. 19. Chonetes, sp.
IV. Crustacea. 20. Leptena sericea, Sby.
4, Phacops caudatus, Brinn. 21. transversalis, Dalm.
VY. Motziusca-BracuiopoDA. 22. Streptorhynchus, sp.
5. Orthis canaliculata, Lindst. CoNCHIFERA.
6. Meristella tumida, Dalm. 23. Pterinea, sp.
7. Cyrtia exporrecta, Dal. 24. Mytilus mytilimeris, Conr.
8. Spirifera plicatelia, Linn. 25. Orthonota rigida, Sby.
9. Athyris, sp. GASTEROPODA.
10. Crania implicata, Sby. 26. Huomphalus rugosus, Sby.
11. Rhynchonella cuneata, Dalm. ? CEPHALOPODA.
or deflexa, Sby. 27. Orthoceras attenuatum, Sby.
12. Atrypa reticularis, Linn. 28. — sp.

13. Pentamerus galeatus, Dalm.

@i=S aeRO RPASEC Ys

TrenHAM ReeExs, Died 5th May, 1879.

With much regret we record the death of Mr. Trenham Reeks, the
esteemed Registrar of the Royal School of Mines, Jermyn Street.
By his death one of the oldest associations of the Geological Survey
and School of Mines is severed. When only about sixteen years of
age, he became connected with the infant Museum established by the
energy of his friend, Sir Henry de la Beche, in Craig’s Court; and on
the enlargement of that establishment, and the creation of the School
of Mines, he was appointed to the office he has held until now; so
that, although but 56 years of age, he had seen nearly 40 years
of public service. Having worked at Chemistry and Mineralogy
under Richard Phillips, F.R.S., he devoted himself to the enrichment
of the Mineralogical collection under his charge in Jermyn Street.
He also possessed great knowledge of pottery, and his illustrated
handbook of the Ceramic collection is still a valued work of reference.
Personally he was singularly courteous and obliging, and he so
thoroughly: identified himself with the interests of the School of Mines,
that his loss to that Institution will long be felt.—(‘‘ Nature,” May 8.)

feat
Ap wai

GEOL, MAG, 1879. NEw SERIES.

Dec. II. Vou. VI. Pl. VII.

Tis
wl
~ ZN!

ine i

id

q]
\

D

Cladochonus and JMonilopora,

from the Carboniferous Limestone.

my as

THE

GEOLOGICAL MAGAZINE.

NEW SERIES. DECADE SH VORAeMI:

No. VIL—JULY, 1879.

ORIGINAL ARTICLES.

—__$_@__

T.—On tHe Microscoric Structure oF THREE SPECIES OF THE
Genus Cz4abocuonus, M‘Coy.

By Prof. H. A. Ntcuotson, M.D., D.Sc., F.R.S.E., ete. ;
and R. Erueripes, Jun., F.G.S8.

(PLATE VIL.)

1. History.—The genus Cladochonus was founded by Prof. M‘Coy
in 1847 (Annals Nat. Hist. vol. xx. p. 227) for certain Australian
Paleozoic corals, with “some relation to Aulopora,” but differing
“in their curious erect habit, regular, angular mode of branching,
slender, equal stem-like tubes, and abruptly dilated terminal cups
bent in nearly opposite directions.” Prof. M:Coy also lays stress
upon the thickness of the walls in Cladochonus, and the propor-
tionately small calices, and states (loc. cit., and Ibid. 1849, vol. iii.
p- 184) that the curious little corals formerly referred by him to
Lamouroux’s Jania will fall into this genus, viz. Jania crassa, and
Jania bacillaria (Synop. Carb. Limestone Foss. Ireland, 1844, p. 197).
The Australian species Cladochonus tenuicollis is distinguished by
the slenderness of the stolons connecting the calices. In 1851
Messrs. Milne-Edwards and Haime described a genus under the
name of Pyrgia (Polyp. Foss. Terr. Pal. p. 310), which has been
placed by subsequent writers as a synonym of Cladochonus, and we
think with good reason. To their genus they assign the following
characters—the corallum is free, pedicellate, with a strong epitheca,
very deep calices, and without traces of septal strize, and they
consider that it differs from Aulopora in its simple and free habit.
Two species were described, Pyrgia Michelin, Wd. and H., and P.
Labechei, Hd. and H. The Janie of M‘Coy they reserve their opinion
on, but C. tenuicollis of the same author is referred by them to the
young of the genus Syringopora (loc. cit. p. 296). Similar views
were expressed by them in their subsequent “Monograph of the
British Fossil Corals” (pt. 3, Corals from the Perm. Form. and
Mountain Limest. p. 164), and they further describe their Pyrgia
Labechei (loc. cit. p. 166). In 1849 Prof. M‘Coy added to the
species of Cladochonus by the description of a form from the
Carboniferous Limestone of Derbyshire as C. brevicollis (Annals
Nat. Hist. 1849, vol. iii. p. 128), which possesses a peculiar zigzag

1 See also Hist. Nat. Corall. 1860, vol. ii. pp. 298 and 322.
. 19

DECADE II.—VOL. VI.—NO. VII.

290 Prof. Nicholson and Rk. Etheridge, jun.—

corallum. This species was afterwards figured in the British Paleeo-
zoic Fossils (1851, fase. i. p. 85, t. 3 B. f. 10), and two of the former
Species were redescribed, C. bacillarius and C. crassus. In the
generic diagnosis preceding the descriptions of these species, M‘Coy
states that the “‘cup-shaped terminal chambers are marked within by
more than twelve longitudinal striz.” With regard to C. crassus we
are told that ‘the mode of attachment of the young is most usually
by the early branches growing in a circle round a crinoidal stem.”

So far as we are aware, Prof. John Morris, F.G.S., was the first
palzontologist to unite the genera Cladochonus, M‘Coy, and Pyrgia,
Ed. and H., in 1854, in the secon! edition of his excellent Catalogue

p. 49).

In 1866 Herr Ludwig sroponda the genus Liodendrocyathus
(Paleontugraphica, vol. xiv. p. 213) for the reception of the well-
known coral Syringopora serpens and a new species L. tubeformis ;
the latter is considered by Prof. de Koninck to be a Cladochonus
(Nouvelles Recherches, 1872, p. 152), a supposition in which he is
in all probability correct. We unite our protest with that of Prof.
de Koninck against the unnecessary introduction of genera by Herr
Ludwig for various Paleozoic corals, the generic affinities of which
are quite well known. One of the most important discoveries yet
made in the structure of Cladochonus was that by our friend Dr. H.
Woodward, F.R.S., who, in 1869, drew the attention of the late
Mr. John Rofe, F.G.S., to the microscopic structure of the calices
(Gron. Mac. 1869, Vol. VI. pp. 3852-538, Fig. 4 and 4a), which
appear to have their walls minutely reticulate, not tabulate as Mr.
Rofe supposed. The latter also entered at length into the peculiar
habit, possessed by at least one species of Cladochonus, of attaching
itself to the surface of Crinoidal stems, a fact first pointed out by
Prof. M‘Coy, but which was much more attentively studied by Mr.
Rofe. We shall return to these points further on.

In 1872 Prof. L. G. de Koninck published a fresh description of
C. Michelin, Hid. and H., and brought together a large mass of
information concerning the genus generally. He defines the
corallum as multiplying by lateral gemmation, furnished with a
pedicle of attachment, very deep circular calices with feeble septa,
and no tabule (Nouv. Recherches, 1872, p. 150).

The foregoing is, so far as we are acquainted with Cladochonus, a
tolerably full outline of its history.

The following are the described species :—

Cladochonus bacillarius, M‘Coy.
oh crassus mF
“S brevicollis
Michelini, Ed. and H. (CLG)
® Labechet i
tubeformis, Ludwig.
hians, Eichwald. 2
A tenutcollis, M‘Coy

1 We think it exceedingly probable that Prof. Morris and de Koninck are correct
in referring this genus to Cladochonus with doubt (Cat. Brit. Foss., 2nd ed. p. 49,
and Nouv. Rech., 1872, p. 152), and we also agree with the latter in omitting Sania
antiqua, M‘Coy, from the genus. 2 Lethea Rossica, t. 28, £1.

oh)

On the Genus Cladochonus. 291

In our remarks which follow we first give some notes on the
relation of Cladochonus to Aulopora, and we next describe the
microscopic structure of one or two species, more particularly of
Cladochonus crassus.

2. Relations of Cladochonus to Aulopora.—The general resem-
blance subsisting between Cladochonus and Aulopora is so close as to
strike the most superficial observer, and this is particularly the case

between the aberrant C. crassus, M‘Coy, and the larger forms of the

latter, the habit of the coral being in both cases the same. It would
lead us too far, upon the present occasion, to enter at any length into
the general structure and relations of Aulopora, nor are our investiga-
tions on this head as yet completed ; but there are one or two points
in this connexion to which we may with advantage draw attention.
Aulopora has generally been believed to possess corallites with
entirely open visceral chambers, no tabule being present; and in
this has been placed the principal distinction between this genus and
young colonies of Syringopora. We have, however, made microscopic
sections of two forms of Aulopora, one, a large species from the
Devonian deposits of Canada (Fig. 1, d—/), and the other the well-
known A. repens of the Hifel Limestone (Fig. 1, g, h); and in both
we find that the cavities of the tubes are crossed by strongly arched
transverse partitions or tabule. The invagination of the tabule is
not so conspicuous as in Syringopora, but cross-sections of the tubes
present a very similar appearance to that seen in the latter genus ;
and it seems clear that the internal structure of Aulopora is essen-
tially the same as that of young colonies of Syringopora. We are
not, however, prepared to assert that tabule are present in all the
species of Aulopora, nor can we enter here into the question of the
relations between this genus and Syringopora.

Coming next to the relations between Cladochonus and Aulopora,
we have figured (Fig. 1 ¢) a longitudinal section of what we believe
to be a corallite of Cladochonus Michelini, Edw. and H., from the
Carboniferous rocks of Scotland. It must be borne in mind, how-
ever, that though one may identify a given specimen as belonging
to such a small Cladochonus as C. Michelini, it is really impossible to
be certain that one has not in fact to deal with a detached corallite of
Aulopora ; and there must therefore always attach a certain doubt to
such sections as Fig. 1 c. That this section is really one of Cladochonus
Michelini, H. and H., we believe, because the specimen from which
it was taken had all the external features of this species. and it also
occurred with others also having the characters of this form (Fig. 1,
a and b), and again because we know of no Aulopora in the Carboni-
ferous rocks of Scotland, from the breaking up of which fragments
of this nature could have been derived. Further than this, however,
we cannot go. All, therefore, that can be said is, that we find, in this
and in similar longitudinal sections, that the visceral chamber of the
corallite is sometimes, though apparently not invariably, crossed by
delicate curved tabule (Fig. 1 ce). Sometimes we have failed to
detect these partitions, and in any case they are always remote, and
very delicate in structure ; so that they may be chiefly recognizable

292 Prof. Nicholson and R. Etheridge, jun. —

by the fact that the surrounding matrix has penetrated into the
visceral chamber to a certain depth, and that its lower limit is
marked by a clean and regular curved line. So far, then, as the
evidence at present before us goes, it would appear that the
internal structure of Cladochonus Michelini is essentially the same as
that of those species of Aulopora which we have submitted to micro-
scopic examination. It seems to be “tabulate,” and it does not,
therefore, conform to the definition of the Zoantharia tubulosa given
by Milne-Hdwards and Haime.

On the other hand, Cladochonus crassus, M‘Coy, exhibits an
entirely different structure, unlike that of both C. Michelini, H. and
H., and the species of Aulopora which we have here figured. We
shall deal with the internal structure of this remarkable species at
greater length hereafter (see Fig. 2); and we need only say now that
the visceral chambers of its corallites appear to be entirely open and
free from transverse partitions of any kind, while the wall is greatly
thickened, and exhibits in parts a very exceptional and abnormal
differentiation of its tissues, which entitles it to take rank as a distinct
generic type.

Cladochonus Michelini, Edwards and Haime.

Pyrgia Michelini, Kd. and H., Polyp. Foss. Terr. Pal. 1851, p. 310, t. 17, £.8, a& 5.
5) e Quenstedt, Handb. d. Petref. 1852, p. 638, t. 56, f. 18.
on a Milne Edwards, Hist. Nat. des Corall. 1860, vol. i. p. 322.
Fromental, Introd. & P étude des Polyp. Foss. 1861, p. 318.
Cladochonus "Michelini, de Koninek, Nouv. Rech. sur les Anim. Foss. etc. 1872, p.
158, t. 15, f. 6, and 6 a. ©

Observations.—It is unnecessary for us to redescribe this species
after the full and detailed notice of Prof. de Koninck, our object now
being to make a few remarks on the microscopic structure of the
corallum.

As before noted, there must remain some doubt as to the reference
of any given specimen to this species, rather than to the detached
corallite of an Aulopora. ‘The specimens, however, which we have
selected for sectioning appear to us, for the reasons before given, to
be really referable to C. Michelini, EH. and H., and they appear to
correspond in their general structure with Aulopora repens. ‘That
is to say, they generally exhibit a tubular visceral chamber (Fig.
1, ce) crossed by a few irregular curved tabule, but otherwise un-
interrupted. In other specimens we can detect no traces, however,
of transverse partitions. The walls of the corallites are solid
throughout, and we have failed to find any evidence of the peculiar
reticulate structure of the wall which characterises C. crassus,
M ‘Coy.

Loc. and Horizon.—Catcraig Quarry, near Dunbar, in shale above
the Skaleraw Limestone; Skaleraw Quarry, near Dunbar, similar
horizon—Lower Carboniferous Limestone Series—Coll. Geological
Survey of Scotland.

Collector.— Mr. James Bennie.

On the Genus Oladochonus. 293

Cladochonus bacillarius, M‘Coy ?

Jania bacillaria, M‘Coy, Synop. Carb. Limestone Foss. Ireland, 1844, p. 197,
t. 26, f. 11.
» bacularia, MCoy, "Annals Nat. Hist. 1847, vol. xx. p. 227.
Cladochonus baculari ius, M‘Coy, Annals Nat. Hist. 1849, vol. i. p. 134.
a bacillarius, M‘Coy, Brit. Pal. Foss. 1851, fase. i. p. 84.
Jeunes Syringopores, Edwards and Haime, Polyp. Foss. Terr. Pal. 1851, p. 296.
Young Syringopore, Edwards and Haime, Mon. Brit. Foss. Corals, 1852, pt. 3,
p. 164.
Cladochonus bacillaris, Morris, Cat. Brit. Foss. 1854, 2nd ed. p. 49.
Jeunes Syringopores, Milne Edwards, Hist. Nat. Corall. 1860, vol. ii. p. 298.

Observations.—The forms we refer to this species from the Scotch
Carboniferous Series we have only seen in fragments, and would
therefore simply make the reference provisionally. The chief points
of specific importance appear to be slender, straight, cylindrical
branches, with the short conical cups at the summits, if these points
can be accepted as a means of separation when no differences can
be detected in their internal structure. We fail to see how the two
so-called species, the present and C. Michelini, can be kept apart, as
they appear to be clearly different stages of growth, or varieties of
a single species. They do not differ in their microscopic structure,
and nothing but perfectly trivial external differences exist.

Loc. and Horizon.—Charleston, Fife—Lower Carboniferous Lime-
stone Series—OColl. Geological Survey of Scotland.

Collector.—Mr. James Bennie.

Genus Monilopora, Nich. and Hth., jun., (gen. nov.)
Monilopora (Cladochonus) crassa, M‘Coy, sp.

Jania crassa, M‘Coy, Synop. Carb. Limestone Foss. Ireland, 1844, p. 197.

Ps », MCoy, Annals Nat. Hist. 1847, vol. xx. p. 227.
Cladochonus crassus, M‘Coy, 9 1849, vol. iil. p. 134.

ss Brit. Pal. Foss. 1851, fase. 1. p. 85.
Jeunes ‘Syringopor es 2? Edwards and Haime, Polyp. Foss. Terr. Pal. 1851, p. 296.
Young Syringopore ? Edwards and Haime, Mon. Brit. Foss. Corals, 1852, pt. 3,
p. 164.

Cladochonus crassus, Morris, Cat. Brit. Foss. 1854, 2nd ed. p. 49.
Jeunes Syringopores, Milne Edwards, Hist. Nat. Corall. 1860, vol. iii. p. 298.
Cladochonus crassus, Rofe, Gzou. Maa. 1869, Vol. VI. p. 352, Figs. 2, 3, 4 and 4a.

Observations. — Monilopora crassa, M‘Coy, sp., may be dis-
tinguished from the other corals with which it has been usually
associated by its large size, and by its thick, conical, short branches.
Prof. M‘Coy states that “‘the mode of attachment of the young is
most usually by the early branches growing in a circle round a
erinoidal stem,” and a figure of this was given in his early work.
There is, however, more than mere attachment when young, because
the coral goes on growing and growing, until at last what with the
increase of the parasite, and the deposition of matter by the crinoid
about that portion of its stem infested by the coral, an excrescence of
no small size is formed. The habit thus possessed by M. crassa has
been referred to more in detail by the late Mr. Rofe, who has pub-
lished figures illustrating the manner in which the coral attached

294 Prof. Nicholson and R. Etheridge, jun.—

itself permanently to the columns of crinoids. The subject has also
been entered on at some length by one of the present writers, in a
paper lately read before the Natural History Society of Glasgow.
The Geological Collection of the British Museum contains a number
of specimens of Carboniferous Crinoid stems singularly contorted
and gnarled by the growth of Monilopora (Cladochonus) crassa and
the subsequent efforts of the Crinoid to envelope its parasite. These
are contained in the collections of the late Messrs. Gilbertson and
Rofe. In almost every case the corallum is more or less entirely en-
closed in the substance of the crinoid stem, and those with the coral-
lites projecting for any distance from its periphery are exceedingly un-
common. ‘This has been explained by Mr. Rofe on the supposition,
that those not enveloped escaped simply because of the death of the
crinoid before complete enlargement of the column had taken place.
The usual external appearance presented by the combined crinoid
stem and its encircling parasite is that of a swollen, or contorted stem,
with a ring of circular apertures, sometimes with projecting lips, at
other times on a level with the surface of the stem, or even with the
substance of the latter closing over them. This last is much the most
common condition, but occasionally we meet with two or more rings
one under the other, and instances are before us in which successive
growths have taken place so rapidly as almost to obliterate all
trace of the original crinoid stem. Of specimens with the calices
partially free, Mr. Rofe has figured a good example; of those with
the mouths only showing in a single circle round the crinoid stem
we give an example, and another where two circlets are preserved,
and a third illustrating the confused condition produced by con-
tinued growth. In only one specimen have we been enabled to
detect any trace of septa—and then only in the form of indistinct
flutings in the interior of one of the calices. It should, however,
be remarked that the specimens which have come under our obser-
vation have not been in the best state of preservation for the reten-
tion of delicate septal markings.

As regards the mode of growth of Monilopora crassa, the usual
method adopted by the coral consists in the encircling of a crinoid
stem by a single ring of corallites, the connecting stolons being
applied directly to the surface of the crinoid stem, and the corallites
thrown off from this at intervals and projecting outwards at a more
or less oblique angle to the stem to which they are attached; while
occasionally they project nearly at right angles. On this simple
structure successive growths take place until a more or less confused
aggregation of corallites results.

The very curious microscopic structure of the corallum in M.
crassa was, so far as we know, first pointed out by Mr. Rofe (Grou.
Mag. 1869, Vol. VI. p. 352, Figs. 4, 4a), though we are of opinion,
as previously stated, that his conclusion as to its real significance
was founded upon a misapprehension. He pointed out that there
existed in the corallum of this form a singular reticulated structure,
which he regarded as showing that the coral was “tabulate,” and
he figured this structure in the paper just referred to. Our own

On the Genus Cladochonus. 295

microscopical sections of M. crassa have entirely confirmed Mr.
Rofe’s discovery of this reticulated tissue, but have failed to
demonstrate its existence elsewhere than in the substance of the
walls of the corallites. So far as our observations go, we find the
visceral chamber of the corallites of M. crassa to be entirely open
and free from tabule, being usually filled with matrix from end to
end (Fig. 2e). This being the case, M. crassa clearly conforms to
the definition of the Zoantharia tubulosa laid down by Milne-
Edwards and Haime, and cannot be regarded as a member of the
old group of the “ Tabulata.” In this respect, also, it differs from
C. Michelini, as well as from those examples of Auloporu, which we
have been able to examine by means of thin sections. Moreover,
its structure is quite peculiar, and so far as we Agnow, such as does
not occur in any known coral except the présent. The wall (Fig.
2e) is extremely thick, and for the most part exhibits a distinctly
fibrillated structure, as if composed of successive concentric layers,
this structure being equally conspicuous in longitudinal and trans-
verse sections. In parts of the corallum, however, the concentric
lamellee of the wall become separated from one another so as to
include a series of distinct interspaces or cavities, which are ap-
proximately parallel to the axis of the visceral chamber, and which
are crossed at right angles by numerous delicate cross-bars or
trabeculee of sclerenchyma (Fig. 2, e and f). This singular
reticulate or cellular tissue seems to be sometimes partially developed
in the basal portions of the corallum (see Fig. 2, d), but is essenti-
ally and principally, if not altogether, present in that portion of
the wall which forms the actual cup of each corallite. As before
said, we have entirely failed to discover any traces of this cellular
tissue as encroaching upon the true visceral chamber; and there
thus arises a discrepancy between our observations and those made
by Mr. Rofe (loc. cit.). This, however, may admit of explanation
if we suppose that the longitudinal section figured by Mr. Rofe has
really been excentric, and that instead of passing along the axis of
the visceral chamber, it has really traversed the thickness of the
wall. We are at present unable to parallel the peculiar structure
of C. crassus, as above described, with that of any other coral known
to us, nor can we offer any opinion as to the precise functions or
homologies of the cellular tissue of the calicine walls.

_ Loe. and Horizon.—Carboniferous Limestone of Derbyshire and

Lancashire; Gilbertson and Rofe Collections, British Museum.

So far, therefore, as our preliminary examination of certain species
of Oladochonus has gone, it would appear that the genus as originally
constituted contained corals of very different structure, judging by
the conformation of C. Michelini, and C. crassus. The latter has a
special structure of its own, quite distinct from C. Michelini, as
well as from Auwlopora, and for it we have ventured to propose the
generic name Monilopora.

In conclusion, we have to express our thanks to Professor Geikie,
F.R.S., for the use of specimens contained in the Collection of the
Geological Survey of Scotland.

- 296 W. O. Crosby—On the Appearance of a Fault.

EXPLANATION OF PLATE VII.

Fig 1.—a. Two examples of Cladochonus (Aulopora 2?) Michelini, H. and H., of the
natural size, Lower Carboniferous, Dunbar.

6. A small example of the same enlarged five times.

ce. A longitudinal section supposed to be of the same species, enlarged five times.

d. Portion of a colony of Awlopora sp., from the Devonian of Ontario, of the
natural size.

e. Longitudinal section of part of the same, enlarged five times.

Ff. Cross-section of a corallite of the same, similarly enlarged, showing the tabule.

g. Portion of a colony of Avlopora repens, E and H., from the Eifel, of the nat. size.

h. Section of the same, enlarged seven times, showing curved tabule.

Fie. 2.—a. A full-grown colony of Monilopora crassa, M‘Coy, growing upon the
stem of a crinoid, of the natural size.

5. A younger colony of the same, encircling a crinoidal column, and viewed from
above, of the natural size.

e. A detached fragment of the corallum of the same, of the natural size.

d. Transverse section of a young colony of the same growing upon a crinoidal
column, magnified 23 diameters (the visceral cavities of the corallites are more
or less largely filled with matrix, and the peculiar reticulated structure of the
skeleton is here and there visible in the wall, while the whole has been finally
enveloped by the growth of the stem of the crinoid).

e. Longitudinal section of a single corallite of the same, enlarged five diameters,
showing the open visceral chamber, the fibrous wall, and the reticulated structure
of the wall of the calice.

Jf. A portion of the reticulated tissue still further enlarged.

All the specimens are from the Carboniferous Limestone of Lancashire. (British
Museum.)

IJ.—How tHe Apprarance or A Favitt May BE PRODUCED
WITHOUT FRACTURE.
By W. O. Crossy, 8.B.

HE general structure and mode of growth of coral reefs and
islands is well understood ; but there is one attendant circum-
stance of considerable geological interest, to which, so far as I am
aware, attention has never been called. This is the peculiar strati-
graphic relation of the different strata in the reef to their chrono-
logical equivalents in the deposits of the surrounding ocean; a
relation due to the comparatively rapid growth of the reef as a whole.
Deposits of some sort, it may be safely said, are forming in all
parts of the sea, of coarse materials and with comparative rapidity
in shallow portions adjacent to the land, and of finer sediments and
with extreme slowness in the oceanic abysses remote from the conti-
nental borders. Calcareous sediments usually accumulate much more
slowly than those of mechanical origin, but to this statement the
limestones of coral reefs probably constitute an important exception ;
while the growth of the reef under favourable circumstances is in-
comparably more rapid than the vertical increase of the impalpably
fine, and mainly organic, ooze and mud covering the greater part of
the ocean floor. This is proved by the fact that the coral reef and
island are usually able to keep pace during countless ages with the
progressive subsidence of the sea-bottom, so that their living
growing crests are always within reach of the sunlight and air,
while the dead and consolidated mass below stands like a wall
towering thousands of feet above the slowly increasing and yet strictly
synchronous deposits of the surrounding ocean, which appear to main-

tain their fineness and uniformity up to the very base of the reef.

W. O. Crosby—On the Appearance of a Fault. 297

The numerous soundings made in the vicinity of reefs have shown
that their outer slopes are usually very steep and abrupt, often nearly
vertical, and in some cases probably overhanging. Although un-
doubtedly extremely ragged and cavernous, at all depths below one
hundred, or at the most two hundred, feet, these slopes are beyond
the influence of the waves; and in consequence are not subject to
decay, except as the calcareous matter may be slowly attacked by the
carbon dioxide so abundant in sea-water at great depths.

Of course when the formation of a reef first begins, it is on the
same level with the differently and more slowly formed but synchro-
nous sediments of the adjacent portions of the ocean-bed; as its
growth continues, however, it rises wall-like above these, and
synchronous layers in the two sorts of deposits, always differing in
thickness, are no longer stratigraphically continuous, those in the
reef lying at higher levels than those outside. And with the lapse
of time the vertical separation of beds of the same age must become
greater and greater; so that if we may assume that the reef grows
three feet (a low estimate) while the surrounding deposit is rising
one foot, then when the former has attained a height of three
thousand feet, the latter will be only one thousand feet thick, and
the last-formed beds on either side will be separated vertically by
two thousand feet. Supposing now that the subsidence, and, as a
necessary consequence, the growth of the reef cease, then the gradual
silting up of the outside ocean will continue as before, and in the
course of time we will have, theoretically at least, lying on the same
level with the upper part of the reef formations of a much later age,
as shown in the diagram, where the horizontal bands within and
without the reef are to be synchronized according to the numbers.

C.R.=Coral-Reef.

The reef is elevated to form dry land, and subsequent erosion
developes the surface a 6. Thus there is produced the general
appearance of a fault, but without a fracture; and it is easy to con-
ceive how a geologist might be deceived and led to conclude that the
old coralline limestone of the reef had reached its present strati-
graphic position through the agency of a fault.

In this pseudo-fault, it will be observed, the vertical displacement
gradually diminishes downwards, becoming zero at the bottom of the
reef; and many true faults, geologists are agreed, must die out below
the surface in a manner equally gradual. Of course observation of

298 K. Pettersen—The Rise and Fall of Continents.

the actual contact would probably undeceive the careful student, as
the merely seeming fault would bear little resemblance, on close
examination, to a bona fide fracture ; but it is necessary to remember
that our knowledge of the existence of faults usually rests upon more
or less probable inference rather than direct observation.

Many coralline limestone formations are regarded by geologists as
ancient reefs, and other limestones more compact may very well
have had this origin, for it is well known that on modern reefs much
of the rock formed only yesterday, as it were, is exceedingly compact
and almost destitute of recognizable organic remains. My knowledge
of the stratigraphy of our old reef limestones is too imperfect to
enable me to determine whether their relation to the bordering
formations is often such as I have sketched above, but it seems very
improbable that this relation should not exist in some cases.

TIJ.—Tue Stow Secunar Rise or Fatt or Continentat Masszs.
By Karu Petrrersen, Tromso.

OINING a foreign geologist, who was staying here a while last
summer on his journey to the North, I followed the old shore-
line or sea-level of Bredviken, cut in the solid rock, and extending
along the north part of the island of Tromso, near the sound bearing
the same name. When, at the end of that line, about Oerendalen, we
threw a glance at the low ground beneath, named Skatoeren, this
appeared furrowed with a series of natural ditches, stretched hori-
zontally and parallel to the present coast. Seen from above, they
were marked very sharply and distinctly. This attracted my attention,
the more so as I had often been there, and as frequently traversed the
plain, without having discovered the fact. We accordingly went
down on the low ground to examine the matter more closely, but
it did not appear there so distinctly, as might be supposed when
seen from above. But after a more searching examination, we
succeeded in detecting a series of more or less distinct and parallel
furrows. Our time being limited, however, we could make no closer
inquiry for the moment; but as I considered the matter worth more
minute studying, I returned to the place a few days afterwards.

I did not see furrows this time from above as distinctly as last,
owing to a less favourable light, and on the plain itself I now found
it very difficult to trace every single furrow. The only way to do
so was to fix your eye from above upon a single furrow, then walk
down to it, and follow its course across the plain.

The flat low ground at Skatoeren is, it seems, composed altogether
of remains of shells, mixed with sand. It ascends gradually from
the present shore for nearly 120 métres up to a height of about
10 métres, thus forming the base of a row of hills that rise
from its upper side. The plain has, it is evident, extended a great
deal farther north. In course of time great washings and slips
have taken place in that direction, and thus the plain in our day
ends in a steep bank, consisting completely of shell-sand. The
subsoil of the lowland, which consists of shells and sand, is over-

K. Pettersen—The Rise and Fall of Continents. 299

grown on the surface with moss, which mossy cover is intersected
crosswise with furrows, caused by the water purling down from
above. At the first glance the surface appears as an infinite
number of molehills, cut separately, and spread irregularly all
over the plain. By this constant digging out, the original furrows,
notwithstanding their distinct and regular course, when seen from
above, have been effaced to the view so much, that you have some
difficulty in discerning most of them when you walk across the plain.

From the sea upwards you will meet, at first, four successive fur-
rows, at a distance from one another of about 3 métres. From the
fourth one there is an interval of 18 métres to the next, that has
been traced. This furrow is very distinct, and may be pursued
longitudinally for 70 métres. Above this one J have found still
eight more furrows at different intervals, the highest of which lies
about 8 metres above the surface of the sea. It is very probable,
however, that there are many furrows besides the above mentioned
that have not yet been traced, or have perhaps been effaced.

When seen from above at least, the furrows appeared, however,
close to each other, and seemed to follow each other at more regular
distances.

There can be no doubt, it seems, that these furrows have been
formed by the surf. Where our shores are made of fine sand or
crushed shells, you will frequently find one or even several succes-
sive ridges, like walls, running parallel to the beach, caused by
the lashing of the waves, that heap the sand in long drifts, lying in
one level.

The uppermost of those lines on our present coast generally indi-
cates the highest spring tide.

When seen from above, there is a striking likeness between the
before-mentioned furrows and the ridges on the present beach.

With regard to our Arctic regions, it has already been proved some
time ago, that the rise of the land, for the last 10 to 12 métres at
least, must have been effected slowly and evenly. Those proofs may
be found in the frequently appearing banks of shell, that rise, in
some places without interruption, from the present shore up to a
height of about 10 métres.

What we have said about the furrows at Skatoeren seems to prove,
still more decidedly, that the rise has gone on by degrees and
uniformly. Such perfect preservation of a series of successive
shore-lines or margins admits of no supposition of a violent or
sudden change of level.

As to the question of the secular rise or fall of the continent,
relatively to the level of the sea, it has been considered long ago a
scientific fact amongst most geologists, that during this change the
surface of the sea has been, on the whole, unchangeable. John
Playfair was, it is well known, the first who held this in his “ I/lus-
trations of the Hutionian Theory,” published 1802. In that work he
even mentions the slow rise of Sweden. Quite independent of that
book, Leopold v. Buch comes to the same result. In his publication
of 1810, “ Journey through Norway and Lapland,” he accentuates the

300 K. Pettersen—The Rise and Fall of Continents.

fact—while mentioning the rise of land around the Gulf of Bothnia
—in the following words: “ Gewiss ist es, dass der Meeresspiegel
nicht sinken kann; das erlaubt das Gleichgewicht der Meere schech-
terdings nicht.” Supposing the centre of gravity of the earth to
occupy always its original place, and that the quantity of the water
spread over the globe remains, on the whole, unaltered, the
doctrine of Buch is indisputable. Meanwhile, none of these sup-
positions can be considered quite certain. To answer the question
with perfect surety, there is as yet too great deficiency in the
materials of research. It has been tried, therefore, very often indeed,
to shake the supposition of an absolute stability in the level of the
sea. There has been no intention hereby of course to refer any
alteration in the surface of the sea that bears no distinct local
character, to the variability of the average level. It is evident, too,
that a long series of risings or sinkings—throughout the different
geological periods—must be regarded as an uprising or subsiding
movement of the solid rock. Amongst other writers, James Croll
has narrowly discussed the question in his book, “ Climate and Time
in their Geological Relations,’ 1877. He supposes the change in the
level of the sea to arise partly from a displacement of the centre of
gravity of the earth, caused by the spreading of an enormous ice-sheet
over one of the polar basins, and partly by the solidification of so
comparatively great a mass of water, as a consequence thereof. In
fact, the continental masses of the Northern hemisphere seem, on
the whole, to have risen throughout the Quaternary period, while in
the Southern hemisphere they have sunk. The Antarctic basin
being at present covered with ice on a large scale, this seems to coin-
cide very well with Mr. Croll’s supposition. Suppose the ice-sheet
constantly increasing here, the tracts of land all over the Northern
hemisphere must be rising continually in proportion, which is no
doubt the case with large tracts. If this rise of the land had ap-
peared quite regular, there would have been weighty reasons indeed
to lean to the said theory. But, according to what has hitherto been
observed relative to the rising and sinking of the ground at different
places within the Northern and Southern hemispheres, not a few
deviations have presented themselves, which do not coincide with
Mr. Croll’s doctrine. As to the east part of North America for
instance, Prof. Dana has proved, that the observations made there
do not tend to support that opinion. Furthermore, it has been con-
sidered a fact that a great part of the west of Greenland is at present
sinking. Hven some parts of England, Normandy, and the coasts
of the North Sea, etc., are believed to be, or to have been, sinking ;
while, supposing that theory to be right, and that the changes in
the level of the water are to refer altogether to it—all those regions
ought, on the contrary, to have been rising constantly, and in the
same proportion as Scandinavia.

Similar irregularities are to be found, it is said, even in the

1 “Tt is certain that the level of the sea cannot fall, the equilibrium of the ocean

renders this impossible.’”’—See Leopold yon Buch’s Gesammelte Schriften, Bd. i1.,
1870, p. 504.

K. Pettersen—The Rise and Fall of Continents. 301

Southern hemisphere. New Zealand, for instance, is believed to be
rising, while in this case subsidence might be expected, which is in

fact pre-eminently the case over the Southern part of the globe.
Added to this, the many observations relating to the rise of Scandinavia
must—supposing those observations to be right—absolutely prove
that rise to depend on an upheaval of the mountains.

The very frequent and distinct sea-levels or ancient sea-margins,
which run parallel to the present coast of the North of Norway,
should—it seems—be so many more proofs hereof.

Bravais was the first who studied those lines about the Altenfjord.
According to his observations, which were afterwards—partly at
least—confirmed by Mr. R. Chambers in his ‘‘ Ancient Sea Margins,”
two sea-levels are said to extend along the recent coast-line at
different elevations above the sea. These lines may be traced, it is
said, although interrupted by shorter or longer interstices, from the
bottom of Altenfjord towards Hammerfest for a length of about 60
English miles. According to Bravais these two lines are not parallel,
either to the present line of coast, or to each other. He found the
furrows bending slowly down after their course from the fjord to the
outward coast, while at the same time they converge in their relation
to each other.

However, the inquiries that have been made into this matter of
late years do not tend to confirm the correctness of those observa-
tions. The recent researches have not been, it is true, so extensive
as necessary to be able to come to any absolute conclusion. Still,
there has been noted so much already tending to prove that the
opinions of Mr. Bravais are founded on erroneous suppositions, and
that his conclusions must be kept, at least for the present, apart from
the range of positive facts.

But with it falls one of the weightiest arguments for the doctrine
of an unchangeable state of the level of the ocean, which has been
until now acknowledged, and which theory relies mostly, as we have
said, on circumstances along the North of Norway, pointed out by
Bravais.

We shall try to give, in the following lines, an account of the
result of the researches of late years in this matter.

Mr. H. Mohn, in a treatise published 1877,' has collected rich
materials towards the explanation of the appearance of ancient sea-
levels along the coast of Norway, from Bergen northwards to the -
Varangerfjord. According to his measurements there is a remark-
able recurrence in the levels of those lines within large tracts of the
North of Norway (in West Finmark and in the district of Tromsoe).
But even about Bergen two of the lower lines correspond in their
respective elevations with two similar lines about Tromsoe. It
seems quite evident, therefore, that the rise of the whole coast from
the very North of Norway to Bergen must have been quite uniform,
at least throughout long periods of the Quaternary age.

* Bidrag til Kundskab om Gamle Strandlinier i Norge. Nyt Mag. for Naturv,

1877. (Contribution to the Knowledge of Ancient Sea Margins i in N orway. New
Mag. of Science, 1877.) -

302 K. Pettersen—The Rise and Fall of Continents.

In a discussion in 1878, ‘‘ On the Sea Levels Engraved in Rocks,”
the author has treated of some of these lines in the neighbourhood
of Tromsoe. He proves that upon their course from the outward
coast into the fjords—which has been pursued step by step for many —
miles—they maintain at all points an unaltered height above the sea.
If these lines had been bending upwards like those in Alten, as
said by Bravais, and at the same measure as those, such a rise could
hardly have remained unnoticed.

As the elevation of the shore-lines about Alten, according to what
has been stated, have been found to coincide with those about
Tromsoe, there will be, even beforehand, no weighty argument in
favour of the supposition, that any difference should exist between
the Tromsoe and Alten lines, as held by Mr. Bravais. On the other
hand, there is some reason to believe that this writer has joined
fragments of different sea-levels and terraces together as parts of
one line.

Thus the treatise of Mr. Bravais cannot be considered as part of a
scientific deduction, or as a proof of an unchangeable state of the
sea, while, on the other hand, the rise of the ground all over the
Scandinavian peninsula seems to find its best explanation by
supposing a changeable state of the level of the ocean.

We have remarked already, that the rise of the land over wide
adherent tracts of Scandinavia throughout the Quaternary age has,
at least through long periods of it, taken place at a slow and
exceedingly uniform pace. ‘There is no proof whatever that this
rise has been at any part of that age effected suddenly, or by
shocks. The rise of Scandinavia, therefore, cannot be simply
regarded as synonymous with that of the west coast of South
America.

The forces that may have caused the successive secular changes
in the sea-level of Scandinavia are purely hypothetical. In fact, as
yet no attempt has been made to account for their real nature. It is
quite natural that local sinkings or risings should take place, as these
may be accounted for by well-known forces. But the rise of all
Scandinavia is quite another case. As before mentioned, these
changes must have gone on quite uniformly in the tracts from
Varanger to Bergen. This is a matter concerning a coast of nearly
2,000 English miles; and, moreover, the whole Scandinavian penin-
sula is believed to be rising, and there seem to be beforehand
weighty reasons to believe that the scale of this rise has been very
uniform all over the peninsula, with the only modification, that the
coefficient of elevation has declined a trifle, though regularly from
north to south.

The Hast of Finmark and Varanger (that is, the North-east part
of Norway) are connected, as to their system of mountains, rather
nearer to the tracts of land about the Gulf of Bothnia, than to the
West of Norway; consequently, it may be supposed that the
changes in the level of the sea about Varanger correspond with
those about the Baltic. The observations hitherto made into this
respect seem to support such a conjecture. But even if we. look

K. Pettersen—The Rise and Fall of Continents. 303

only at the coast regions from Varanger to Bergen, these by
themselves already form such extensive groups of land, that it will
be difficult to imagine the nature of the force that should be
able, not only to raise the land, but even to make it so slow and
uniform as we have seen—not unlike the rise of the piston in a
steam-cylinder. Those powers that have raised such mountains
as the Alps, the Himalayas, or the Andes, have worked, it is evident,
with a violence quite different. Deep and extensive old strata have
thereby been broken, upset, or folded up. The rise of the Norwegian
coast through the Quaternary period exhibits little or nothing of this
kind. Layers of shells with alternately intersected strips of coarser
or finer material lie there, quite unaltered, in their original position,
although they had been lifted up from 10 to 12 métres above the
present waters. Shore-lines, at different heights—rising to hun-
dreds of feet above the sea—extend through thousands of miles in
an entirely horizontal course. All this seems to indicate that the
forces which are pushing Scandinavia upwards are of an entirely
different nature from those that have in their time lifted, for instance,
the Alps.

Were there any possibility of accepting the theory of a change in the
level of the sea, the many different circumstances that appear relative to
the rise of Scandinavia would find a plain and natural explanation.
By any other supposition, that may be held by science at present,
the matter will remain unaccountable and obscure.

The question as to the probability of a change in the axis of our
planet during the geological periods, which has been much discussed
of late years, seems to have met with a decided negation, as well by
natural philosophers as by geologists. If, notwithstanding, the
centre of gravity of the earth should have been subject to a change,
that displacement must have taken place along its axis, in such a
manner, that the latter always retained an unchangeable position.

Whether the cause hereof ought to be explained by the theory of
Adhemar and Croll, or is due to other circumstances, it will be neces-
sary, before such a theory can be held, to remove the contradictions
that seem to exist in the above-mentioned unequal changes in the
sea-level within the same hemisphere.

Tn this respect it must be remembered at first, that the material
hitherto collected concerning the question of changes in the level of
the sea through the Quaternary period and the modern age is
by far too insufficient to draw, from a broad point of view, any
certain scientific deductions. As to the Scandinavian peninsula, it
has been held a fact long ago, as is well known, that the north part
of it was rising while the south has sunk. But, if I recollect right,
it seems to result, according to the researches of late years, that the
southern part of Sweden, instead of sinking, is on the contrary
about to rise, although, perhaps, not in the same degree as the northern
part. Thus there might be at least some possibility that the sup-
position of a sinking of the West coast of Greenland should prove, by
some more careful researches, just as untenable. But even supposing
this not to be the case, the question would not be settled yet. Hven

3804 EH. T. Newton—On Emys lutaria from the Norfolk Coast.

admitting a changeable level of sea, not every irregularity can be
referred to it. On the contrary, it is, as said above, a scientific fact,
that sinkings and upheavals of the land throughout all the great
geological periods have been effected in a way that seems to prove,
without a doubt, that they must have been the results of subterranean
forces. Consequently, a sinking of the land may, it is evident, go
on within a hemisphere, where at the same time the level of the sea
is becoming lower. In order, therefore, to clear up the question in
every particular, it will be necessary to examine whether the
changes in the elevation of the mountain region are real or only
apparent. Only after sufficiently exhaustive researches have been
gathered and carefully studied, will it be possible to draw any
conclusions, entitled to the name of scientific facts, touching the
above question.

TV.—Note on some Fosstn Remains or Huys LUrARIA FROM THE
Norrotk Coast.
By E. T. Newton, F.G.S.,
of the Geological Survey.

HE remains of a Tortoise from that peculiar fluviatile deposit on

the Norfolk coast, known as the “‘Mundesley River Bed,” have

lately been placed in my hands for determination by Mr. C. W. Ewing,

of Eaton, near Norwich, and, although the European freshwater tortoise

has already been recorded as occurring in a fossil condition in Norfolk

(Prof. A. Newton, Ann. and Mag. Nat. Hist., 1862, ser. 3, vol. x.

p- 224), yet it seemed desirable that some notice should be taken of

this most interesting discovery. The specimen was obtained by Mr.

Ewing from the peaty bed in the cliff section at Mundesley, so long

ago as 1863; but it was only quite recently that it was for the first

time exhibited, at one of the meetings of the Norwich Science Gossip
Club.

This specimen includes the greater part of the left half of the
carapace and plastron, and one costal plate of the right side. None
of the neural plates were found, and the first costal of the left side is
likewise wanting. Portions of each of the left costals from the
second to the seventh are sufficiently well preserved to allow of
their being fitted together with the nine marginal plates which are
also preserved, so that the general contour of the carapace may be
very fairly made out. The nine marginal plates form a consecutive
series, the hinder eight of which correspond to the eight costal
plates, and each has a pit at its upper and inner margin for the
reception of the end of arib. The marginal plates corresponding
to the second, third, fourth, and fifth costal plates, are produced
downwards and form an elongated, roughened surface for the attach-
ment of the plastron; but from the nature of this surface it is
evident that there was no osseous connexion between the carapace
and plastron, but that cartilage or ligament intervened, as in the
recent Emys. The portions of the plastron which have been pre-
served are the left xiphiplastron, and pieces of the left hyoplastron
and hypoplastron.. The last-mentioned bone retaining the ascending

E.. T. Newton—On Emys lutaria from the Norfolk Ooast. 305

process which attaches it to the carapace, while the similar process
of the hyoplastron is broken away.

Prof. A. Newton, in the paper cited above, made known to us for
the first time, the fact of the occurrence of the European freshwater
tortoise, in a fossil condition, in this country. It appears that the
specimens were obtained in the year 1836, from below a consider-
able accumulation of peat (seven feet), at Hast Wretham, but the
true nature of these remains was not recognized until they were seen
by the author of that most interesting paper.

The Mundesley specimen does not quite agree with the figures
given by Prof. Newton, for when due allowance has been made for
their difference of size, it will still be seen, by the grooving of the
surface, that the large plates of tortoiseshell overlapped the
marginal ossicles to a greater extent in the latter than in the former.
By the kindness of Dr. Gtinther, I had the opportunity of examin-
ing the recent specimens of Hmys Jutaria in the British Museum
osteological collection, and there I found, as Dr. Giinther had already
assured me was the case, a very noticeable variation in the extent of
this overlap. There is yet another point which deserves a passing
notice. In all the specimens of EH. lutaria, both in the British
Museum and in the Royal College of Surgeons, there is a thickening
of the outer edge of some of the more anterior of the marginal
plates, producing a kind of rounded ridge; the prominence of this
ridge varies, being much more obvious in some specimens than in
others. This character is not seen in the Mundesley specimen.
However, the close agreement between the recent Hmys lutaria and
the fossil from the ‘‘Mundesley River Bed,” not only in their
general form and in the arrangement of their plates, but also as
regards the ligamentous connexion of the carapace and plastron,
leaves little room for questioning their specific identity."

Prof. Newton tells us in his paper (loc. cit.)* that the fossil
remains of Hmys lutaria have been found in Denmark and Sweden
under conditions similar to those in which the Norfolk specimens
occurred, and with regard to the present distribution of the species,
we are further told that it is not now known in either Holland,
Belgium, N. France, or N.W. Germany. Such being the case, it is
not a little interesting to be able to add Belgium to the list of
countries from which the Emys lutaria has been obtained in a fossil
condition. My friend Mr. W. Davies directed my attention to a
specimen which is preserved in the Geological Department of the
British Museum ; it is an almost perfect carapace of this species of
tortoise, and formed a part of the rich collection of the late Prof. van
Breda, of Haarlem, who obtained it from a freshwater peat-deposit
at Ghent, Belgium. This specimen agrees very closely with that
fivured by Prof. Newton. Here then we have another link in the
chain of evidence of the former distribution of Emys lutaria.

1 The Mundesley specimen has recently been secured for the Norfolk and Norwich
Museum, where it 1s now preserved.

* See also his paper on the Zoology of Ancient Europe, read before the Cambridge
Phil. Soc., March, 1862.

DECADE II.—VOL. VI.—NO. VII. 20

306 E. T. Newton—On Emys lutaria from the Norfolk Coast.

It may be interesting to note that Lyell (Antiquity of Man, 4th
edit., p. 268) records the following remains from the black peaty
deposit of Mundesley :—‘ Shells of Anodon, Valvata, Cyclas, Sucecinea,
Limnea, Paludina, etce., seeds of Ceratophyllum demersum, Nuphar
lutea, scales and bones of pike, perch, salmon, etc., elytra of Donacia,
Copris, Harpalus, and other beetles.” He also includes Paludina
(Hydrobia) marginata, but this has very recently been identified by
Mr. H. Norton with the Bythinella gibba figured by Moquin-Tandon.!
I may also add that a detailed account of the Mundesley bed, with
some additions to its list of organic remains, will be given in the
Geol. Survey Memoir on the Cromer District, by Mr. Clement Reid.

The following notice of opinions on the subject of the age of the
bed has been kindly furnished to me by my friend and colleague Mr.
H. B. Woodward :—

Age of the Mundesley River-bed.

[The Mundesley River-bed occupies a hollow eroded in the Lower
Glacial Beds (Cromer Till or Lower Boulder-clay, and Contorted
Drift). At one time it was held both by Lyell and Joshua Trimmer
to be intercalated in this Drift ;? but Mr. Gunn and Prof. Prestwich
subsequently showed that the Freshwater deposit really overlaid the
Lower Boulder-clay, a view in which Lyell himself coincided.? By
them it has since been spoken of as a Post-Glacial deposit. It is,
moreover, interesting to note that Mr. Prestwich pointed out some
resemblances between the Mundesley bed ‘and that at Hoxne, which
is so well known as the locality for many paleeolithic implements ;
and he went so far as to suggest a search in the Mundesley bed for
these flint weapons. The Post-Glacial age of the Hoxne bed has,
however, been recently called in question by more than one authority ;*
while the stratigraphical evidence at Mundesley merely shows that
the river-bed is newer than the Lower Glacial Beds. There is
nothing to prove it might not be older than the Chalky Boulder-clay;
or, in other words, to determine whether it be Inter-Glacial or Post-
Glacial. The occurrence, therefore, of the remains of the Emys lutaria,
taken in conjunction with the position of the remains of this species
elsewhere, tend to prove that the Mundesley River-bed is Post-
Glacial.—H. B. W.]

EXPLANATION OF PLATE VIII.

Fic. 1.—Emys lutaria, left side of carapace, seen from above.

ditto with plastron, side view.

portion of left side of plastron, seen from below. Hyo. Hyo-
plastron; Hypo. Hypoplastron ; Xip. Xiphiplastron.

be) 2. ” bP)
oy) 3. 2 9?

1 Trans. Norfolk and Norwich Nat. Soc., vol. il. p, 357.

2 Lyell, Phil. Mag. 1840, vol. xvi. p. 853; Trimmer, Quart. Journ. Geol. Soc.,
vol. vil. p. 20.

3 Prestwich, Geologist, vol. iv. p. 68; Lyell, Antiquity of Man, 4th ed. p. 267.

4 J. Geikie, Great Ice Age, 2nd edition, p. 525; Belt, Quart. Journ. Science,
July, 1876.

5 The appearance of this Plate is unavoidably delayed till the August Number.—
Epiv. Geou. Mae.

W. A. E. Ussher—Pleistocene Geology of Cornwall. 307

V.—PLEISTOCENE GEOLOGY oF CoRNWALL.!
By W. A. E. Ussuer, F.G.S.
Part V.—Biown Sanps ano Recent Marine.

Notes on Blown Sands and Gravel Burs.

Proceeding round the coast from Plymouth.

1. Par. A low range of sand dunes separates the alluvial tracts
from the Par sands.

2. Pentuan. A bank of coarse granitic sand, with bedding and
false bedding indicated by black bands of schorlaceous material,
dams off the sea from the low land at the mouth of Pentuan stream ;
on the landward margin of the low tract a low range of sand dunes
has accumulated, apparently from the wind drift off the sand bank ;
the surface of the alluvium between them is strewn with similar
granitic sand.

3a. Falmouth. At the curve in the shore at Gyllyngvaes (Clay-
pole, Proc. Brist. Nat. Soc. Ser. 2, vol. v. p. 35) the top of the gravel
beach or bar coincides with the highest spring-tides.

b. Swan Pool is dammed by a bar of small quartz pebbles, 80
yards broad, and in the highest part 5 feet above high-water.

ce. Mr. Godwin-Austen noticed (Rep. Brit. Assoc. for 1850, Trans.
of Sects. p. 71) a platform of bare rock near Falmouth, occupying
an intermediate position between high-water mark and the base of
the adjacent raised beach, which varies from 8 to 10 feet above it.

d. Between Pennance Point and Maenporth, rock platforms occur
at about the level of spring-tide high-water, the traces of raised
beach in the vicinity being about 4 feet higher.

e. South of Maenporth, rock reefs and platforms were noticed at
about 6 feet above ordinary high-water, the base of the adjacent
raised beach being 10 to 15 feet above that level.

4. A strip of blown sand flanks the stream at Poljew; at Gun-
walloe a considerable accumulation of blown sand covers high land
between Castle Mount and Towan. On N.W. of Castle Mount,
owing to the exposed situation, no blown sand occurs.

Dd. The Loo Pool is dammed by a bar of small quartz pehble
gravel and coarse sand, with occasional flint and slate materials:
coarse brown blown sand caps the low cliffs to the south of it.

6 a. Penzance.

Dr. Boase (T.R.G.S. Corn. vol. iii. p. 131) gives a section of the
West Green sand bank, between Penzance and Newlyn, as follows :—

1. Granitic sand, of quartz, mica, hornblende slates with a little tin

ore ; quartz predominating ... cca coo LU) rier.
2. Gravel, of hornblende slate pebbles ‘from 1 to 3 inches in 1 diameter,

16 feet thick, resting on a submerged forest.

He points out the difference between the present sea sand and
that forming the Green sand banks, between Marazion and Penzance
and Newlyn; the former being finer, and composed of pulverized
clay-slate and elvan, whilst the latter appears to have been derived

1 Concluded from the June Number, p. 263.

308 W. A. EH. Ussher—Pleistocene Geology of Cornwall.

from the destruction of a continuous band of granite between
Mousehole and Cudden Point.

The original length of the Green (op. cit. vol. ii. p. 136) “was
about three miles on the east and one mile on the west of Penzance ;
and is already much shortened. The ancient breadth is unknown.”
The West Green contained but two or three acres, and in no place
exceeded 130 feet in width, when Dr. Boase wrote (op. cit. vol. iii.
p- 151, ete.); whilst in Charles the Second’s time it is mentioned in
a letter to Mrs. Ley, of Penzance, as affording 36 acres of pasturage.

b. Mr. Edmonds (Edin. New. Phil. Journ. vol. xlv. p. 118, for
1848) mentions the following facts. Seventy years ago a meadow
lay outside the present sea-wall at the entrance to Newlyn; several
houses and gardens stood on the seaward side of the cottages at
Sandy Bank in Penzance; these extremities of the old Western ©
Green are no longer visible.

In 1848 a sea-wall was built by the Corporation of Penzance to
protect the remainder of the sand bank. Off the eastern bank
numerous rocks between high- and low-water mark, below both sand
banks, near Newlyn, Chyandower, and Marazion, buried beneath
4 to 5 feet of sand 40 years previous to 1848, were uncovered.

c. In the sand bank between Penzance and Marazion, near
Marazion Bridge, Mr. Edmonds discovered a great number of land
shells (Helix virgata and Bulimus acutus), in perfect preservation,
throughout a depth of about 10 feet from the surface. In one
instance, in the same locality, he observed a layer of small rounded -
pebbles, an inch or two in thickness, 3 feet below the surface of
the sand, and more than 15 feet above the level of high-water. In
the subjacent sand, for 4 or 5 feet in depth, he found numerous
perfect land shells.

7 a. Whitesand Bay, to the North of Sennen Cove, is bounded by
sand dunes, capping the low cliffs, and extending for a little distance
inland, surrounded by higher ground.

b. On the north side of Cape Cornwall rock platforms are visible
at about high-water mark, the traces of raised beach adjacent are
about 6 feet above that level.

8. Lelant, Phillack, and Gwythian 'Towans.

“The Cornish word ‘Towyn,’ says Mr. Edwards (T.R.G.S. Corn.
vol. vi. pp. 800-304), means ‘a turfy down,’ the word ‘down’ being
perhaps a mere corruption of ‘towyn’ by the very common change
of the letter ¢ into d; and it is remarkable that the name ‘Les
Landes,’ ‘barren heaths,’ given to the sandy districts on the 8.W.
coast of France, is almost precisely the same with ‘Lelant,’ the
parish in the Towans where an ancient market town is said to have
been buried by the sand. Hence Towans, Downs, Lelant, and Les
Landes may all be regarded as synonymous.”

In the same paper he characterizes the blown sands of St. Ives
Bay as accumulations of comminuted shell sand nourishing a scanty
growth of Arundo arenaria.

a. North of Hayle and west of Phillack an excavation of about
30 feet, at the termination of a tramway, afforded me a good section

'

W. A. E. Ussher—Pleistocene Geology of Cornwall. 309

of the blown sands, here consisting of rather fine buff sand, made
up of a mixture of quartz grains with comminuted shells, intersected
by numerous dark bands near the top, apparently dipping northward
at 10°, as though caused by the successive entombment of rank
grass surfaces under gradually accumulating sand. Below the dark
bands the sand still presents an appearance of bedding, such as
might be occasioned by successive slips from an eminence, wherever
the slopes became too sharp for the accumulating sand to rest.
From this bedded appearance, and from the frequent linear distribu-
tion of perfectly preserved land shells, (b.) Mr. Edmonds (op. cit.)
considered that the sand in its gradual accumulation had buried the
latter ‘‘ without ever completely covering the growing turf whereon
the animals were feeding or hybernating.”

c. Mr. Boase (T.R.G.S. Corn. vol. ii. p. 142) says, “In some
places where the sand has been bored to a great depth, distinct
strata separated by a vegetable crust are visible; which seem to
indicate a succession of inundations at distant periods; but it is
possible . . . . that this may be owing to a local shifting of the
sands, because in other places the like series of strata is not found.”

d. In a deep cutting in the sand, about a mile from the sea, Mr.
Edmonds discovered a nest of small land shells, 50 feet from the
surface, of the following species :—Helix virgata, Zonites radiatulus,
Bulimus acutus, H. pulchella, Zua lubrica, Vertigo edentula, Pupa
marginata, P. umbilicata, P. anglica, Bithinia ventricosa.

He gives the following list (T.R.G.S. Corn. vol. vii. p. 71) of shells
found under the surface of Phillack Towans (those marked with an
asterisk are now living within 10 miles of Penzance).

Bulimus acutus. Helix fulva.* Vertigo edentula.

obscurus. Susca. palustris.*
Carychium minimum. hortensis. pygmea.*

Clausilia biplicata. nemoralis. Vitrina pellucida.

Conovulus bidentatus. pulchella. Zonites alliarius.
denticulatus. virgata. cellarius.

Helix aspersa. | Pupa anglica. — nitidulus.
caperata. marginata.* —— pygmeus.

rotundatus.

umbiheata.

ericetorum.

Mr. Edmonds mentions the occurrences of numerous shells of
Helix pulchella, at depths varying from 1 to 30 feet, in various parts
of the sands, and says that living specimens have been observed,
and that their exuvie have been found in Whitesand Bay sandhills
as well as those near Gunwalloe and Mullion, Mounts Bay, and
Gorran (on the South Coast of Hast Cornwall).

Mr. Crouch, who identified the species given above, observes that
Helix pulchella is uncommon in the locality, that it has been found
by him near Falmouth, at Pendennis; and near Penzance, at Tre-
reife; also near the Land’s End.

From the quantity of shells found in so small a space in the
Towans, Mr. Crouch considers that they were once abundant in Corn-
wall, but are now gradually becoming extinct.

Pupa marginata and Bithinia ventricosa he alludes to as rare, a few
dead shells having been obtained by him at Whitesand Bay (Land’s

310 W. A. E. Ussher—Pleistocene Geology of Cornwall.

End) and near Hayle, but that no live specimens have been found
in Cornwall.

e. Near Godrevy Island, rock platforms are visible at about the
level of spring-tide high-water; the base of the adjacent raised beach
is from 4 to 5 feet above ordinary high-water.

9. Mr. N. Whitley (25th Ann. Rep. Roy. Inst. Corn. for 1843)
mentions ‘‘ the succession of sand hills, principally composed of com-
minuted shells, covering about 1,500 acres, on the north-east of
Perran Porth. The inland portion,” he says, ‘“‘ being level and well
sheltered, might easily and profitably be reclaimed by an admixture
of clay with the sandy wastes, as in Norfolk, where by this means a
free sandy loam, forming a most productive soil, has been obtained.
Owing to the extent of the Perran Sands, being more heated by the
sun’s rays than the surrounding districts, in calm weather by the
radiation of heat from the sand hills, it is often oppressively warm
at the Porth during the early part of the night.”

10. The patch of blown sands bordering Hollywell Bay may be
regarded as a continuation of the Perran Sands, it is partly bounded
by a stream.

11. The flattish tract between New Quay and Fistral Bay is
covered by blown sand.

12. Sand dunes occur at Porth Barn, Mawgan Porth, and Porth-
cothan, Tregarnon, and Permizen bays; they are very insignificant.

13. Between Constantine and Perleze Bays a low tract is covered
by blown sand; as exposed near Constantine Island (vide Raised
Beaches, 19 e), itd is 44 feet in thickness, and contains layers of Patelle
and broken Mytili, and occasional angular slate fragments at the base.

14. The low tract in which St. Enodock’s Church is situated is
composed of blown sand.

15. In Perleze Bay, and near Port Isaac, rock platforms were
noticed at about ordinary high-water mark.

General Notes.

Wherever the area covered by the blown sands is extensive, we
note that the lands generally lie low with reference to the sea or
relatively to the surrounding country : That the accumulation spreads
from west to east, and only occurs in considerable quantity in locali-
ties at or near the coast-line facing westwards.

Thus, in bays where the cliffs aye very low and unbroken by
gorges or stream channels, facing westwards and receiving the full
force of winds and waves of the Atlantic, the most favourable con-
ditions occur for zeolian transport on the Cornish coast.

Naturally, the inland extension of the sand depends upon the
extent of low-lying country ; but, besides this check on its extension
exercised by barrier hills, running water and the growth of certain
plants may arrest its progress ; the former intercepts the fugitive
grains which seldom rise more than a few inches above the ground
and are suspended for a short time (De la Beche, Report, etc., p.
446). As to the latter, Major T. Austin (Proce. Brist. Nat. Soc., Tall
ii. No. 11, for Dec. 1867) gives the following plants as best suited

W. A. E. Ussher—Pleistocene Geology of Cornwall. 311

to arrest the inroads of blowing sand, in some cases by collecting
hillocks kept together by their matted roots—Ammophila arenaria
(sea reed); Triticum junceum (sea wheat grass) ; Hippophe rham-
noides (sand thorn); Cakile maritima (sea rocket); Salsola kali (salt
wort); and Sonchus (sand thistle).

Mr. Henwood (40th Ann. Rep. Roy. Inst. Corn. for 1858) alludes
to the progress of the sand drift covering the low lands of St. Minver,
on the east of Padstow, being checked by the growth of Arundo
arenaria.

The appearances of bedding in the blown sands are worthy of
note, as they betray the incipient characters which in the old blown
sands of Fistral Bay and Greenway have developed on consolidation
into marked laminz or thin flaggy sandstones, and near Godrevy
and New Quay into thick beds. Although the constant shifting and
accumulation of the sands (8 6) upon a growing surface must be true,
yet the final entombment and successive growth of grass, or Arundo
arenaria, is more likely to have been occasioned by heavy gales
drifting large quantities of sand upon the dunes (8¢); for, constant
shifting of particles would be less likely to produce definite layers ;
the cohesion of the particles of successive surfaces of comminuted
shell sand lending itself readily to the formation of definite beds, and
when counter wind drifts prevailed, to false beds, in the process of
consolidation through the downward passage of rain waters. But as
far as I am aware no traces of old vegetable surfaces have been
found in the old consolidated blown sands. The false-bedded
appearance is well shown in the old blown sands of Barnstaple Bay.
The thin layers of schorlaceous and quartzose grains in the sand
bank at the mouth of the Pentuan Valley seem to be due to marine
action, sorting the materials.

The absence of sand or gravel bars on parts of the Cornish coast
directly exposed to the waves of the Atlantic, and their limitation
on the southern coast to sites where promontories and headlands
shelter them from the direct influence of the prevalent winds, and
where the rapid transport of shingle is lessened by projections of the
coast on the further side, is worthy of note. Thus, the West Green
bank sheltered by the Land’s End district occurs in the centre of
Mounts Bay; the Loo Bar, somewhat similarly sheltered, has been
piled up where the southerly trend of the Lizard coast-line becomes
pronounced ; the Swan Pool Bar and the extensive beaches of Fal-
mouth, lying between the flow of the Fal and Helford nearly at
right angles, are sheltered in a measure by the Lizard district, and
the further transport of shingle is checked by the projection of
Pendennis Point.

The set of the coast-line has been aided by the inability of the
stream waters to keep a seaward passage clear, as in the case of the
Loo Pool, which represents the ponded drainage of the Cober and its
tributaries. The ceremony of cutting the Bar annually to allow the
waters to escape more rapidly than by filtration through it, and thus
prevent floods, shows how effectually the seaward outlet of the
stream has been overcome. The finer accretions to some of the

812 W. A. EH. Ussher—Pleistocene Geology of Cornwall.

banks, as in the West Green, have been shifted higher by winds; a
tongue of sand occurs on the east of the Loo Pool similarly drifted.

The surfaces of the planed Killas reefs, of which I have only
given a few examples, occupy in most cases a position intermediate
between the base of the several raised beaches in their vicinity and
high-water mark (8c, d,e; 7b; 8e; 15). Mr. Godwin-Austen
attributed (Rep. Brit. Assoc. for 1850, Trans. of Sects. p. 71) their
positions to a recent elevation (preceded by a subsidence) of not more
than 10 feet. In further proof of this he cites the mud beds of the
Hxe and Sussex Ouse, containing estuarine shells at slight elevations
above the present sea-level. The occurrence of many of the rock
platforms are explainable without invoking changes of level. The
comparatively recent subsidence by which the forest lands were sub-
merged would have brought again within the influence of the waves
such portions of the old platforms, upon which the raised beach
rested, as had survived the intervening subaerial waste, and, whilst
robbing them of whatever superimposed deposits might have existed,
would plane anew those more durable portions which came within
the influence of the waves, leaving others shorn of their deposits,
marking by the heights of their surfaces the seaward slope of the
old plane of marine denudation. Bearing in mind the very unequal
heights of old beaches of the same age, and the irregular levels of
their platforms in places at the base of the same cliff (in places,
as in Fistral Bay, the base of the raised beach occupies an almost
uniformly persistent level), except where great discrepancies in their
levels with reference to adjacent raised beaches occurred, the plat-
forms might be explained as above. Other phenomena, however,
whilst in no way interfering with the above explanation, would
appear to favour the idea that a pause in the downward movement,
after the submergence of the forests, was succeeded by a slight con-
trary movement. Such an oscillation might serve to explain the
river sediments gaining on the marine, in estuarine stream tin sec-
tions, and to enable them to continue pari passu with a resumption
of the subsiding movement. If, from the sections in Marazion Marsh
given by Messrs. Henwood (T.R. G.S. Corn. vol. v. p. 34) and Carne
(Ibid. vol. vi. p. 230, etc.), we may place the top of the marine bed
at 2 or 3 feet above high-water, an oscillation would alone account
for its position. The formation of the Warren Sand Bank and
Northam Pebble Ridge might also be explained by a slight elevation,
whilst the rapid diminution of both would seem to indicate a return
to the previous contrary movement. The formation and diminution
of the West Green Sand Bank might be similarly explained.

Mr. Edmonds (Edin. New Phil. Journ. for 1848), commenting on
the diminution of the bank, says, that 300 years ago, in Leland’s
time, the causeway leading to St. Michael’s Mount was uncovered
six hours out of twelve, and continued so for 220 years. The passage
to the Mount in 1848 was open four hours out of twelve, and often
during strong S.W. winds covered at neap tides for days together.
He ascribed these rapid changes (6 6) within 80 years to the removal
of sand, which supported the western side of the ridge, for ballast

J. W. Davis—Erratic Boulders of the Calder Valley. 318

and agricultural purposes. ‘Some idea,” he says (T. R. G. S. Corn.
vol. vii. p. 31), “of the vast quantity of sand thus abstracted (for
manure) may be formed by the fact that a very usual clause in farm-
ing leases in this neighbourhood is, ‘That ten butt loads of sea sand
shall be spread on every acre whenever it is broken for tillage.’ ”
This explanation is a very plausible one, and, coupled with the
hypothesis before mentioned, would be a powerful adjunct in ac-
counting for more rapid recent waste. Great quantities of commi-
nuted shell sand are also carted from Bude by the farmers of North-
west Devon.

In conclusion, I have to express my sincere thanks to Mr. W.
Whitaker, Dr. C. Le Neve Foster, and to Mr. E. Parfitt, of Exeter,
for kindly furnishing me with all the information in their power
concerning the literature of the subject; to Mr. Robert Hunt, F.R.S.,
Keeper of the Mining Records, for placing at my disposal some beauti-
fully executed sections of the St. Agnes deposits by Mr. A. C. Davies,
some of which I have submitted to the Geological Society in a reduced
form; also to Mr. Horace B. Woodward for the kind interest he took
in this paper in its original form, and the information he obtained for
me as to the best means of insuring its publication.

VI.—On tue Sovrcr oF THE Erratic BouLpDERS IN THE VALLEY
oF River CaLpEr, YORKSHIRE.

By James W. Davis, F.S.A., F.G.S., ete.

HE reference, in my paper on the Calder Valley, to the extensive
deposits of boulders and sand which fill up the lower part of
the valley, and form a series of long level surfaces, is necessarily very
brief. It may assist a proper understanding of the subject, and the
point raised in Mr. Dakyns’ letter, if I recapitulate, as briefly as
possible, the main facts of the case. The river has its source in two
or three small streams which rise in the hills on the Lancashire side
of the Pennine Anticlinal. These are joined into one stream, and
pass along a narrow but deep valley cut at right angles to the range
of elevated gritstone hills which form the boundary between Lanca-
shire and Yorkshire. For five or six miles the valley is rarely more
than about 200 yards in breadth, and on each side the slopes of the
hills are extremely steep, composed of shales, surmounted by a pre-
cipitous gritstone escarpment. At Hebden Bridge the Calder
is joined by the Hebden, and in its course south-eastwards the
valley gradually assumes larger dimensions, and south of Halifax
spreads out into extensive level plains, along which the Calder has
carved its channel with many devious turnings. On reaching the
district from Mirfield to Wakefield these characteristics are still more
apparent, its path being amongst the softer beds of the Coal-measures.
Below Wakefield to the confluence of the Calder with the Aire at
Castleford, the country generally is of a comparatively flat and un-
interesting nature.
The lower reaches of the valley are filled with great quantities of

314. J. W. Davis—Erratic Boulders of the Calder Valley.

gravels, sand, and boulders. At Wakefield wells have been dug to
a depth of twenty-eight and thirty feet, and at Thornhill and Dews-
bury excavations have proved the deposits to be between forty and
fifty feet in depth. Still further up the valley, from Elland to
Sowerby Bridge, the gravels and boulders occur in some force, and
are at least twelve to sixteen feet deep. The valley nearer its source
than the latter locality is almost devoid of graveis; and where they
do occur, as at Mytholmroyd, the travelled boulders are rare, or
altogether absent. From Sowerby Bridge southwards the drift or
gravel is composed of rounded pebbles and sand; these, near the
surface, are almost entirely derived from the local sandstones
and Calliards; in the lower strata boulders of granite, trap, and
syenite become gradually more frequent, until in the lowest parts they
attain a great preponderance, and rocks of local origin are almost as
rarely found as crystalline ones were in the upper part of the series.
In tlie sections low down the valley, the boulders are frequently of
considerable size, and at Dewsbury masses of granite and limestone
were found near the base of. the section exceeding a foot in diameter ;
they were in all cases well rounded and quite devoid of scratches.
The following section of a well sunk at Dewsbury may be taken as
an average example :—
Hee Harchvandysandyisubsoilessiee eases eeenetesetiy camer cme OL
2. Boulders, consisting in the upper part of sandstone with
a slight intermixture of granite, etc., gradually

TANTRA WA oo bog a0 666) | cao. G00 24ft. Oin.
3. Boulders, almost entirely of crystalline rocks not

occurring in the district 2m situ ... ... ... ... Gft. Oi.
4. Clay with sand and boulders... ... .-. ... .-. ... | Oit. | Oin:

Carboniferous sandstone

A remarkable circumstance is the occurrence in the lower beds of
rounded masses of flint, along with granite, syenite, and trap
rocks, the latter having been identified with their parent rocks in
Westmoreland and Cumberland, and even in some few instances with
rocks of Scotch derivation, whilst the flints are similar to those
occurring in the Chalk in the eastern parts of the Yorkshire Wolds.
There is an entire absence of shells of Mollusca, but near Thornhill
the trunks of several trees have been found at a few feet below the
surface of the gravel beds, presenting an appearance indicating that
they grew at no great distance from the position they occupied when
found. A more detailed description may be found in the Proceedings
of the Yorkshire Geological and Polytechnic Society for the year
1875, page 93.!

In addition to the boulders already enumerated, Shap Fell granite
has been found in the district south-east of Wakefield. ‘Though
comparatively rare, they are found sufficiently often to form a
characteristic boulder ; the large masses of pink felspar being a very
important constituent, which renders their identification unmistakable.
The occurrence of this granite, as will be shown hereafter, throws a
most important light on the origin of the gravels.

1 See also a paper by J. Travis Clay, Esq., of Rastrick, Proc. Geol. and Polyt.
Soc. of the West Riding of Yorkshire, vol. i. p. 201 (1841).

J. W. Davis—Erratie Boulders of the Calder Valley. 315

The question at issue is, ‘“‘ How were the erratic boulders trans-
ported into the Valley of the Calder?” There are two sources from
which the boulders may have been derived, the one on the western
side of the Pennine range of hills dividing Lancashire and Yorkshire,
and the other occupying a part of the great plain of the Ouse in the
central part of Yorkshire. In all probability the glacial clays,
originally containing the boulders, may have had a common origin
in the mountainous ranges of Westmoreland, or possibly amongst the
mountains of the south of Scotland. Whether one or both these
localities served as the source of the glacier, it appears to have
passed along the valley of the Eden, grinding against the Crossfell
escarpment until it reached the somewhat lower ground of Stainmoor
Forest. At this point a part of the glacier was deflected eastwards
over hills rising to a beight of 1,500 to 1,600 feet above the sea-
level into the valleys of the Tees and its tributaries, and also into
Arkendale and Swaledale, which are branches from the valley of the
Ouse. The glaciers penetrated far down the valleys, and the
immense quantities of boulders and till left on their recession
testify to their great size and importance. The second portion of the
Eden Valley glacier, which did not pass over Stainmoor, continued its
course in a southerly direction, and one part of it, filling the valley
between Mallerstang and Wild Boar Fell, passed along the district
known as Lunds and entered Wensleydale. Mr. J. G. Goodchild *
has demonstrated that this glacier must have been 1,600 feet in
thickness, and points to numerous evidences of its extent and action
in this, and the tributary dales of Snaizeholme Widdale and other
streams. The remaining portion passed along the western escarp-
ment of the Pennine Chain, and deposited great thicknesses of
Boulder-clays in the valleys of Lancashire. Mr. Dakyns is of
opinion that the latter is the source whence the “ erratics may very
well have been washed down out of these glacial beds into the
Calder Valley by ordinary rain and river action,” and I believe that
this opinion is also shared to a great extent by other officers of the
Geological Survey.” It has already been observed that the sources
of the Calder are extended to the Lancashire side of the Pennine
Anticlinal, but an inspection of the country drained by it shows that
it is surrounded by high hills, with the exception of the two valleys
along which the railway lines run north-westwards to Burnley and
southwards to Littleborough. The watershed between Burnley
and Littleborough is formed by a series of hills rising about 1,400
feet above the sea-level, extending from Shieveley Pike and Heald
Moor southwards to Tooter Hill and along Trough Hdge to the
summit near Walsden. Throughout the whole of this district on the
Yorkshire side of the watershed, with the exception of a small
patch of gravel in Walsden, near the Waggon and Horses public-
house, there is no trace of gravel or drift. The beds of the several

1 Quart. Journ. Geol. Soc. vol. xxxi. p. 78.

2 See also “ Notes on the Lancashire and Cheshire Drift,” by E. W. Binney, read
in 1842, and printed in the Transactions of the Manc. Geol. Soc. vol. vill. part 1.
page 30 (1869).

316 J. W. Davis—Erratic Boulders of the Calder Valley.

streams in Dulesgate, Howroyd Clough or Ramsden Clough, though
deeply cut, exhibit no sections in which drift can be found. On the
western or Lancashire slopes of the hills Boulder-clays and drift
occur, often reaching a thickness of 150 to 200 feet. In excavating
Hollingworth Reservoir, which is four or five miles west of the
summit, and 568 feet above sea-level, extensive beds of gravels
were found, which contained marine shells of the genera Fusus,
Cardium, Purpura, Neritella, etc. Marine shells in the Drift are not
uncommon in other parts of the district.

The Yorkshire and the Lancashire Calders rise near together at
Calder Head. The latter is fed by many small tributaries which
have their source on the slopes of the hills eastwards. These tribu-
taries have formed deep valleys or cloughs, and exposed great thick-
nesses of gravel and Boulder-clay. Good examples may be seen in
Cant Clough and Hurstwood Brook near Worsthorn, and in the
Catlow and Thursden Brooks. The boulders have been derived
from the Boulder-clay, which still in many instances is found at the
base of the Drift. The latter is composed mainly of Carboniferous
limestones and sandstones, with an intermixture of Silurian grits,
traps, quartzites, and granites. The Carboniferous Limestone occurs
in such abundance that it was formerly very extensively used for
burning to obtain lime. The remains of lime-kilns may be seen
studding the hill-sides throughout the locality. In the valley with
Burnley for its centre the remains of glacial origin occur frequently.
The gravels in the valley of the Yorkshire Calder may have been
derived originally from the Boulder-beds in these districts, but a
glance at the physical features of the district renders this view of
the case somewhat problematical. The distance from Todmorden to
Burnley is 94 miles. The two Calders rise at Calder Head four
miles from Todmorden. The valley of the Yorkshire Calder,
running south-eastwards, is narrow, rugged, and falls rapidly from a
height of more than 700 feet above the sea-level at the summit, to
about 880 feet at Todmorden. On either side the valley the ground
rises rapidly and is surmounted by precipitous escarpments of sand-
stone. The Pennine Fault runs in a line with the valley, and has
displaced the rocks, so that those on the Lancashire side are com-
posed of the Third Grit, the opposite one being thick beds of the
Kinderscout Grit. Surmounting the latter, the picturesque groups
of weathered rocks, the Bridestones and Hawkstones, ornament the
sky-line. Near the source of the stream the Lower Coal-measures set
in, and the sides of the valley being, in consequence, of a much looser
and more friable nature, landslips have resulted, producing a great
number of rounded hillocks. The Lancashire Calder rises and runs
in a similar narrow valley falling with equal or still greater rapidity
in the opposite direction, the bed of the stream at Burnley being 350
feet below that of its source. Beds of gravel are occasionally
exposed in the sides of the stream, as at Walk Mill, two miles from
its source and 200 feet less in elevation, where, beneath a bed of
peat, principally composed of the remains of hazel trees, there is a
rough sandy gravel; the contained stones are for the most part semi-

J. W. Davis—Erratice Boulders of the Calder Valley. 317

angular, and have all been derived from the neighbouring hills.
Granites, limestones, or other travelled boulders, do not appear to
be present. Some distance lower down the valley, as Burnley is
approached, however, the travelled boulders become common.

If the erratics in the bed of the Yorkshire Calder were derived
from the Boulder-clays east and north-east of Burnley, it is quite
evident that they could not have been transported by river action.
The great rise to the summit of drainage disposes of that theory.
The only agent equal to the task appears to be drifting icebergs.
It is possible that large masses of ice may have been in existence in
the Burnley Valley, and these, becoming loose and floating away,
would carry with them any stones or boulders with which they
happened to be in contact. In order that these icebergs should be
able to float over into the valley of the Yorkshire Calder, it would be
necessary that the land should be lowered to the extent of between
750 and 800 feet, so that the sea might overflow the summit to a suf-
ficient depth to afford a passage for the ice-floes and their contents.
There are also other objections to this method of their entrance into
the valley ; amongst others, that the valley is entirely devoid of
erratic blocks or boulders for many miles from its source, and it is
only when the lower parts are reached, that they occur, and the
nearer the mouth of the valley, the more numerous are the boulders.
It might also be expected that some of the boulders would lie strewn
on the sides of the hills, bounding the valley; but hitherto both the
hill-sides and their tops have proved entirely devoid of such evidence.
For eight or ten miles the deep valley does not present any sections
exposing erratic boulders. At some distance below Hebden Bridge,
Dr. Alexander! quotes Mr. Gibson as having found a few fragments
of granite or trap whilst the railway line was in process of con-
struction, and a few well-rounded boulders are occasionally found at
Mytholmroyd, two miles further down the valley, but they do not
occur in any considerable quantity until North Dean is reached.

Turning next to the second source whence the Boulders may have
been derived, it is well known that the Valley of the River Ouse con-
tains immense quantities of Boulder-clay, Brick-earths, sands, and
gravels, derived from the glaciers which it has been shown descended
Swaledale and Wensleydale. The Boulder-clay may be con-
sidered as the foundation on which the others are deposited, and
where it has not been subjected to the action of water, still extends
across the whole breadth of the valley from the elevated Permian
Limestone plateau on the west to the Liassic and Oolitic wolds on
the east. Sections exposing the relative position of the series in the
valley are not frequently exposed. The Boulder-clay occurs exten-
sively east of Knaresborough, and southwards; and on the opposite
side of the valley it is 60 or 80 feet thick near Hasingwold. At
York the Boulder-clay is 70 feet thick, and the new railway station
works are all built on this material. South of the River Wharfe the
clay has a thickness of 60 feet. It contains immense quantities of
scratched stones, boulders of Mountain Limestone are numerous ; pink

1 Proc. Geol. and Polyt. Soc. of the W. Riding of Yorkshire, vol. i. p. 148.

318 J. W. Davis—Erratie Boulders of the Calder Valley.

granite, trap, syenite, and others, derived from the mountainous dis-
tricts, are common, and mixed with these there are also boulders of
sandstone, chert, and chalk. The centre of the valley is covered with
deposits of a more recent origin; sands and gravel occur plentifully,
and appear to have been derived from the glacial clays beneath by
the disintegrating action of water. The stones are generally more
rounded, and the striz or ice-scratches have been removed by attri-
tion. In a few cases, the boulders still retain scratches. ‘These
sands frequently exhibit very irregular stratification, and occasion-
ally the beds are much contorted, as if from lateral pressure, such as
might be produced by icebergs grounding in shallow water.” *

There is little trace of glacial deposits on the Permian Limestone,
but on the western side, in the valley of the Aire, there is abundant
evidence of glacial action. The hollow in which Bradford is situated
is covered with a thick deposit of Boulder-clay, and at Guiseley and
Apperley Bridge, patches of similar drift occur. North of Leeds
great masses of drift are found, consisting principally of stiff blue
clay, containing rounded and anguiar stones of local origin, as sand-
stones and grit, and also many others of foreign origin, granite and
trap being the most common. At Whinmoor, at a height of 380 feet
above the sea-level, a boring went through 114 feet of Boulder-clay.
These deposits are probably the remains of an old glacier, which
descended the Valley of the Aire from the neighbourhood of Skipton.
It is within the range of possibility that this glacier may have ex-
tended as far south as the neighbourhood of Barnsley, for Prof. A. H.
Green has described a bed of glacial clay? filling a basin-shaped
hollow about two miles north of that town. The exposure is three-
quarters of a mile in length; the Boulder-clay is divided into Upper
and Lower, and contains, besides stones of local origin, boulders of
highly metamorphosed breccia, granite, and others, from the Lake
District. There are other patches of glacial clay scattered over the
district, and also quantities of drift. From a consideration of all the
facts, Prof. Green arrives at the conclusion that the whole district
was probably covered by a layer of Till or Boulder-clay, resulting
from the presence of an ice-sheet which probably had its termination
in this district, and being thin could not exert a very great influence
in grinding up the rocks over which it passed. The greater part of
the Boulder-clay so deposited has since been removed by denudation.

The glacier, whose existence is thus indicated, descended from the
northwards, and consequently must have crossed the lower part of
the valley of the Calder in the neighbourhood of the place where
Wakefield now stands, and several miles west of its confluence with
the Aire at Castleford. The facts already stated, though very briefly,
go to prove that on the recession of the glaciers which once
enveloped the country north of the hills separating the Calder from
the Aire, immense quantities of stiff glacial clay, filled with sub-
angular, scratched boulders of both local and distant origin, were left
filling up the valleys. The land appears at this period to have been

1 Memoir of the Geological Survey illustrating Sheet 93 N.W. p. 14.
2 Proc. York Geol. and Polyt. Soc. 1876, new series, pt. iil. p. 122.

J. W. Davis—Erratie Boulders of the Calder Valley. 319

submerged to the extent of some four or five hundred feet, and
the glacial clays subject to the denuding and abrading action of
water. The boulders released from the clay, and rolled hither and
thither by the waves, were gradually reduced to a more rounded
form, and by the same process the scratches were obliterated. There
can be little doubt that to this action is due much of the sand and
gravel existing in the Valley of the Ouse, and also in the Aire Valley
in the neighbourhood of Leeds. The climate appears to have been
still cold, and icebergs, broken off from the receding ice-sheet, or
masses of ground-ice bearing the boulders frozen from the bottom
into their mass, drifted in every direction, and, melting, dropped their
burden of boulders in new localities.

Under such circumstances as these the Valley of the Calder would
be an estuary from the sea, of considerable width at its mouth, and
gradually closing inland to a comparatively narrow channel. The
united action of the floating icebergs and the tides would be amply
sufficient to account for the presence of the boulders which have
already been described. They are most abundant in the lower and
wider parts of the valley, and the boulders of distant origin pre-
ponderate in number, in every section, in the lowest beds, those
higher in the series being for the most part, and near the surface
entirely, composed of sand and boulders of local origin. The ice-
bergs would in the first place supply the erratics in the lower beds,
and as the ice-sheet still receded, and a warmer climate prevailed, the
rolling action of the tides reduced the boulders higher in the series
from the rocks of Carboniferous age which surrounded the valley and
were constantly being broken away by the action of the water wear-
ing away the shales supporting them.

The fact that in all the sections which have been noted in the
lower part of the valley, the erratic boulders are always most
numerous, and that they are much larger in size, frequently a foot
or more in diameter, at the base of the section, diminishing in size
_ and frequency higher up until they are lost completely, and layers
with only stones of local derivation occur. In the higher parts of
the valley, as at Elland and North Dean, where the beds are half
the thickness of those at Wakefield or Dewsbury, no large boulders
have been found, and they are rarely seen to exceed two or three
inches in diameter. There is also a great decrease in the pro-
portionate number of foreign and local stones even in the lowest
beds. This arrangement of the heavier boulders at the base of
the sections, and especially their localization in the lower parts of the
valley, points most clearly to their eastward origin and the sorting
action of the sea. Had they come westward by river action, the
largest boulders would have been left in that part of the valley
nearest its source, or, if carried to their present positions, would have
been disposed indiscriminately with smaller ones throughout the
whole section.

That the latter theory is probably the correct one, receives ad-
ditional support from the occurrence of erratic boulders in the
valleys which branch from that of the Calder, as, for example, the

320 J. W. Davis—Erratice Boulders of the Calder Valley.

Colne. It is quite impossible that these could have come from the
west; the river rises on the high moorlands of Millstone Edge and
Holme Moss, nearly 2000 feet above the sea-level, and falls rapidly
to its confluence with the Calder at about 200 feet above the sea-level.

Some other peculiar circumstances may possibly be accounted for
if we suppose the land to have been submerged to about 400 feet
lower than its present level, and at the same time these facts act re-
ciprocally in affording evidence that such was really the case. There
are numerous beds of gravel and well-rounded boulders, composed
entirely of rocks of local origin, millstone grit, flagrocks, pieces of
coal, and the harder shales, and, where the peculiar siliceous sand-
stone called Calliard occurs in the vicinity, it is found in the gravel
or drift. These beds occur on the hill-sides bounding the valleys,
and generally at a height of 350 feet, a little more or less, above the
present level of the sea. Examples may be seen at Kirklees Park,
near Mirfield, at Exley, in the Elland Cemetery, at Mytholm, in a
branch valley west of Halifax, and in other places as far westwards
as Hebden Bridge. These gravels are quite distinct from those in
the bottom of the valley, and are usually found occupying a plateau
formed by a gritstone, from which the softer superincumbent shales
have been denuded. In each of the situations cited above they are
at least a hundred feet higher than the present level of the valley.
Where exposed in section, they are current bedded, with thin layers
of sand intermixed, and present every appearance of having been
subjected to tidal action. The presence of these beds has been
accounted for in a variety of ways; but the one I now suggest—
that they were the shores of the old sea—perhaps appears the most
reasonable, when considered in connexion with the drift deposits
filling up the base of the valley. If they are the remains of the
shores of an old lake, as some authors have described them to be,
there remains the difficulty of damming up the waters to so great
a depth, which does not appear probable, and of which there is
no evidence at present existing.

In conclusion, the evidence that the erratic boulders in the valley
of the Yorkshire Calder were derived from the sources so plentifully
supplied in the great valley occupying the whole of the centre of the
county, rather than from the district westwards of the summit of
drainage, appears conclusive. In the one case we have the source
of the Calder bounded by a series of hills rising to a height of 1,500
feet or more, and the only openings being at Calder Head on the
northern and at Hollingworth on the southern part of the Chain.
In either of these the land rises rapidly from the Lancashire side to
the height of 610 feet and 700 feet respectively, and in each case
they form the summit of drainage. All evidence proves that the
general form and direction of the valleys remains unchanged since
pre-glacial times, and this being so, the ordinary action of rivers
being the agent which has carried the boulders from the Lancashire
districts over the summits of drainage may be dismissed as out of
the question, and, along with it, the theory of some of the early
geologists, of a great wave of translation which was supposed to

Notices of Memoirs—Prof. J. Prestwich. — 321

have swept across the Atlantic to our shores, and was made answer-
able for every unaccountable phenomenon in surface geology pre-
sented to their notice. A more probable theory is, that they were
carried over by icebergs, but this necessitates that the land be
submerged to the depth of 700 or 750 feet, and if that be granted,
there can be no reason why the ice-floes should not have been
occasionally stranded on some of the higher lands below the level of
the water, and there have left evidence of their presence in heaps of
travelled boulders, as well as in the lower parts of the valley ; but
such evidence is entirely wanting.

On the other hand, the glacial clays are extended across the mouth
of the Calder, and the boulders derived from them may have been
washed into the valley, during a slight submergence, by the action of
the tides and waves and also borne up the valley by ice-floes. The
statement of Prof. Green that a glacier at one time extended as far
south as Barnsley, and left its detritus spread over the country
northwards, furnishes a source for the boulders actually within the
valley of the Calder as far west as Wakefield, and during the denu-
dation of this district by marine action, the boulders would be
naturally washed into the sheltered bay which the valley under
those circumstances would form. It is not necessary that the land
should be submerged more than 250 or 500 feet; but if it was
lowered to the extent of about 350 feet, there is evidence of its
former presence in the beds of sand and gravel which are found in
many places on the hill-sides at a nearly uniform height above the
sea-level.

D@ ree @ ze SS 7 Oran aViskVE@ sees =

Royvat Socrery or Lonpon, May Isr, 1879.

On THE OrIGIN oF THE ParaLLEL Roaps oF LocHaBER, AND
THEIR BEARING ON OTHER PHENOMENA OF THE GLACIAL PeERIop.
By Josrrpa Prestwicn, M.A., F.R.S., F.G.S., etc., Professor of
Geology in the University of Oxford.

A PAPER bearing the above title was read before the Royal Society

on May Ist, in which the author gave a fresh interpretation
to these well-known terraces. He commenced by stating that
of the various hypotheses that have been brought forward since
the time of Macculloch and Dick-Lauder to account for the origin
of the Parallel Roads of Glen Roy, the one so ably propounded
by Mr. Jamieson, in 1863, has been most generally received and
adopted. It is a modification of the views originally expressed by

Agassiz, to the effect that the barriers of the lakes—to the shore

action of which both the above-named geologists attributed the

“roads,” but were at a loss to account both for the formation and

removal of barriers—had been formed during the Glacial period. by

glaciers issuing from Glen Treig and Glen Arkaig, supplemented by
others from Ben Nevis. The subsequent determination, by the

Scotch geologists, of an intermediate milder period succeeded by a

second cold period, led Mr. Jamieson, with whom the preglacial and

DECADE II.—VOL, VI.—NO. VII. 21

322 Notices of Memoirs—Prof. J. Prestwich—

glacial deposits of Scotland had been a subject of especial investiga-
tion, to conclude that the extension of these two glaciers took place
during the second cold period, which he thinks was of little less
intensity than the first, and that, while the glacier from Glen Arkaig
blocked up Glen Gluoy, the glacier from Glen Treig formed a barrier
to Glen Roy. He observes, “‘Grant, then, these two ice-streams,
one in the Great Caledonian Valley and the other at Glen Treig, and
the problem of the Parallel Roads can be solved, provided we allow
that glaciers have the power to dam such deep bodies of water as
must have occupied Glen Gluoy and Glen Roy.”

Mr. Jamieson, in support of this view, adduces the extensive
glaciation apparent at the entrance both of Glen Arkaig and of Glen
Treig, and shows that near the entrance of Glen Gluoy there are ice
striz, pointing W. 5° N., or in the direction that a glacier coming
from Glen Arkaig would take, and that, in the Spean Valley, opposite
Glen Treig, the ice striz are transverse to the valley, or in the direc-
tion of the axis of Loch Treig, while on either side they point
respectively up and down Glen Spean. He infers, consequently,
that the central portion of the glacier ascended the opposite hill to
the Col of Glen Glaster, while one branch passed down the valley
blocking Glen Roy, and another branch travelled up the valley east-
ward to the Pass of Makoul, and thence into the valley of the Spey.

The “roads”’ were, he considers, formed by long-continued shore
action at each successive level of the lake, that level being determined
by the height of the cols over which the lake waters escaped. In
proof of the long duration of the lakes, Mr. Jamieson refers to the
great extent of the “roads,” and the large size of the mounds
at the junction of Glen Turret and Glen Roy, and of that at the
entrance of the Gulban in Glen Spean, which mounds he considers to
be deltas formed by the respective streams flowing into the old lakes.

The author passed in review the opinions of Mr. Milne-Home,
Prof. Nicol, Sir John Lubbock, Macculloch, Chambers, and other
geologists, and whilst objecting to the hypothesis advanced by Mr.
Jamieson, he considers that that theory affords the most satisfactory
solution of the problem, only that he would suggest a different
interpretation in explanation of the phenomena.

Dismissing the hypothesis of local glaciers of the second period of _
glaciation, the author falls back upon the original idea of Agassiz
with the development acquired by more recent research, and assigns
the Lochaber lakes to the close of the first period of great glaciation.
He considers the phenomena are due to the peculiar physiographical
conditions of the district, and shows that, owing to the configuration
of the country, the drainage of the Ben Nevis range, instead of flowing
off from the centre to two or more sides, is diverted to the north side
only, because the two streams which receive the southern drainage,
not only of Ben Nevis, but also part of that of the range of hills to
the south of Ben Nevis, after flowing respectively east and west,
turn nothward and debouche —one through Glen Treig and the
other through Glen Nevis, into the lower part of the Spean Valley
and the Great Glen near Fort William. These conditions, which

Origin of the Parallel Roads of Lochaber. 328

now give this area an excess of water drainage, must in the like
manner, during the Glacial period, have there led to an exceptional
accumulation of ice.

With the incoming of this Glacial period, local glaciers must have
descended from every mountain range, and so long as the glacier of
one steep glen became confluent with another of the same chain flow-
ing in the same general direction, so long would their course be
uninterrupted, and the propelling and abrading force maintained, as
in the Alps at the present day ; but when, emerging from these glens
into valleys of small gradients dividing the several mountain chains,
they met with glaciers descending from these other ranges, their pro-
gress was not only subject to be checked, and their forces neutralized,
but their course diverted, for if the lines of natural drainage
were barred, the ice took those of least resistance, although such
might be up-hill and against the lines of drainage. This, however,
could not be effected without excessive pressure and heaping up of
the ice at the points of junction.

These interferences must have been especially frequent in the valley
of the Spean. On the one side, the glaciers descending the steep
ravines of Larig Leachach, the Cour and others, adjacent on the
northern flank of the Ben Nevis range, would issue into Glen Spean
and project across it to the Glen Roy hills opposite. Below to the
west, the great Nevis Glen glacier emerged into the valley of the
Lochy, while above to the east the great glacier, issuing from Glen
Treig, would flow down Glen Spean; but, meeting with the aforesaid
group of glaciers from Ben Nevis, was partly diverted over the flanks
of Craig Dhu, and upon the entrance to Glen Roy.

While the glaciers from this system of mountains were becoming
confluent in and fillmg Glen Spean, those from the opposite range
of hills were descending Glen Roy, Glen Feitheil, the Rough Burn,
and the other ravines of that chain, and coming into collision with
those of the Ben Nevis range. In the same way, the valley of Loch
Hil, Glen Nevis, Glen Mhuilinn, Glen Loy, and others were focussing
their glaciers upon the end of the Great Glen north of Ben Nevis,
barring in that direction the passage of the ice down Glen Spean,
and diverting it northward towards Loch Lochy and Loch Oich.

Therefore, the great mass of ice descending Glen Spean, in con-
sequence of meeting with these obstructions, was driven to accumulate
in mass in the lower part of that valley opposite Glen Roy, until,
overcoming further resistance and confluent with the Ben Nevis mass,
it wheeled round into the Great Glen at Loch Lochy, where the united
stream found not only a more contracted passage, but, meeting also at
right angles the glacier issuing from Glen Arkaig, was forced against
and up the entrance to Glen Gluoy opposite.

The author then points out the many mounds and terraces in the
Spean Valley formed of moraine detritus, though since levelled and
often masked by a covering of gravel due to subsequent water action.
To this cause also he attributes the large accumulation of débris at
the entrance to Glen Roy, between Bohuntine and Glen Glaster,
where he shows it to be in places 200 or 300 feet deep and to

O24 Notices of Memoirs—Prof. J. Prestwich—

consist of a light grey argillaceous unstratified matrix with angular
fragments of the local rocks capped by stratified gravel. The mass
rises nearly to the level of the lower parallel road.

The author next discussed the height of the land in relation
to the sea at the period of the great glaciation, and he sees reason
to conclude that the land then stood at not less than from 1000
to 1500 feet higher than at present, so that the Irish Channel was
then above the sea-level, and land extended a considerable distance
westward from the present coast of Scotland.

This was followed by a submergence of not less than 1200 to
1500 feet in central and northern England, Wales, and Ireland, and
of 600 feet in the southern part of Scotland, as proved by the
occurrence of marine shells at those heights.

The influence of difference in level upon climate was next dis-
cussed, and its effect was stated to be, probably, not less than from
12° to 15° F., which is about equivalent to the difference of climate
between Paris and St. Petersburg.

It is well known that the Parallel Roads are terraces composed of
perfectly angular fragments of the local rocks with a few rounded
pebbles, both local and foreign to the district. The former show an
entire absence of any prolonged beach wear. 'The wear of the latter
is due to other causes. There is also an entire absence of any notch
or cliff line such as would be due to the wearing back of a shore
line, and of any projecting ledge such as would result from the
throwing forward of the shore débris. The slope of the hills above
and below the “roads” varies from 25° to 40°, and the inclination
with the horizon of the “roads” themselves, which are from 50 to
70 feet wide, varies within the limits of from 5° to 30°.

Although therefore the ‘‘roads” indicate a line of water-level,
there is nothing in their form or structure to show that they have
been formed by the long-continued action of lake waters on a shore
line. To what then are they to be ascribed ?

The first or highest “roads” is confined to Glen Gluoy, the second
and third to Glen Roy, and the fourth or lowest to Glen Roy and
Glen Spean. What the conditions were immediately antecedent to the
formation of the first, second, and fourth road, is not shown; but in the
case of the third road, the conditions preceding its formation are to
be traced uninterruptedly from the conclusion of No. 2 “Road.”
When the lake stood at the level of “‘ Road ” No. 2, its waters escaped
by the col leading to Glen Spey, while when they stood at the level
of No. 3 “ Road,” they escaped by the Glen Glaster Col. Now as
there is a difference of 76 feet between the height of the two cols, it
is evident that a barrier must have existed on the latter col during
the time the lake stood at the higher level. Whether the barrier was
detrital or ice-formed is immaterial for the argument. In both cases,
either by gradual weathering or melting, the time would come when
the barrier would be lowered in some place to the level of the lake.

Now, it is well known to engineers that a breach once established
in a detrital barrier becomes so rapidly enlarged that, if not at once
stopped, nothing can stay the rapid destruction of the barrier, as in

Origin of the Parallel Roads of Lochaber. 320

the case of the Holmfirth, Crinan, and other floods. Nor is evidence
wanting of similar catastrophes in connexion with glacier lakes. In
the notable case of the Gietroz Glacier barring the valley of the
Drance, a lake was formed which attained a length of nearly two
miles, and a depth at the barred end of 200 feet. So rapid was the
discharge when the barrier yielded, that the lake was drained in
twenty minutes. The still greater flood recorded by Vigne, which
descended a branch of the Indus in one day for a distance of 125 miles,
has since been shown by Mr. Drew to have been caused by the
bursting of a detrital barrier formed by a landslip. In consequence
of this a lake had been formed, which he estimates to have been 36
miles long by one mile broad and 300 feet deep at its lower end.
The whole was drained in a day.

In the same way, it is to be assumed that the Glen Glaster barrier,
which was probably formed by a remnant of the glaciers descending
from the mountain ranges (2,994 feet) at the head of the glen, at last
gave way with great suddenness, and caused the rapid fall of the
waters from the level of the higher “road” in Glen Roy to that of
that Glen’s second “road,” at the height of the Glen Glaster Col, when
the escape of the waters was stopped. '

Now, it must be borne in mind that, at this time, the great mantle
of snow and ice which had so long covered the country, was passing
away, leaving the surface of the hills in Glen Roy covered with
a thick coating of angular local débris mixed with sand and clay, the
result of the intense cold and of the decomposition of the underlying
schistose and granitic rocks. This and the glacial débris must have
long remained bare and unprotected by vegetation ; at all events,
that below the water-line wasso. Now, the angle of repose of purely
angular and subangular débris varies within the limits of from 35° to
48°, but that of clayey sands, which when dry is from 21° to BO
becomes, when saturated with water, as low as 14° to 22°. The
angle of repose of the hill-side débris would, therefore, depend on
the relative proportion of the angular materials and their matrix, and
on the extent of saturation. The slopes of the hills*being on the
whole greater than that of the angle of repose of the saturated
under-water rubble, this latter, easily set in motion owing to the
settlement of its constituent parts as the water drained from it would,
as the level of the lake water fell, tend to slip or slide down with
the falling water, and this slip would continue until the disturbing
cause ceased, and the momentum of the mass was checked by the
inertia of the water gradually coming to rest on reaching the level of
the col of escape. The effect of the arrested slip, combined with
the state of maximum saturation of the mass, would be to project it
more horizontally forward, and form a ledge. This ledge, modified
slightly by subsequent subaérial action and weathering, and by the
dressing of its slope on the occasion of the next fall of the lake,
constitutes the “road.”

Although in the case of the other “roads” there is not the same
evidence of a minor col-barrier, as the results are alike in all, the
causes which led to them must have been the same; and it is shown

326 Reviews—F.. G. H. Price’s Gault.

that there is nothing incompatible in the features of the ground with
the existence of such barriers, or rather that there is some evidence
in each glen, however slight, of water lines at levels higher than the
‘‘roads.” There are difficulties in the way of the lower “road,”
No. 4, which extends through Glen Roy and Glen Spean, that need
discussion, but they are not considered more serious than these which
attend the other hypothesis.

This is followed by a discussion on the Till; on the parallelism of
the Roads; and the general conclusions drawn by the author from
the phenomena in Lochaber and the surrounding district.

25% Jam WW SE Ja WAY [SS

T.—Tuer GaAvLtT, BEING THE SUBSTANCE OF A LecturE DeELiverepD
IN THE WoopWwARDIAN Museum, CAMBRIDGE, 1878, AND BEFORE
THE GkoLoctsts’ AssocraTion, 1879. By F. G. Hinton Pricer,
E.G.S. (London, Taylor and Francis, 1879.)

EW formations have received a larger share of attention of late

years than the Gault, and this may be partly due to the exten-
sive exploitation of the Cambridgeshire Phosphate-bed, whose
organic remains have been so largely derived from its denudation.

As the Upper Cretaceous geology of England has been much
studied by French geologists, and especially by Dr. Barrois, the
Gault and its equivalents have naturally come in for close scrutiny,
and the French classification differs somewhat from that usually
adopted in this country. Much of this misunderstanding arises
from our using the lithological term “Gault,” originally a Cambridge-
shire provincialism, for all the blue and grey marly clays at the base
of the Chalk, whilst the similarly situated glauconitic sands and
other beds have been called Upper Greensands, Red Chalks, etc. ©

For purposes of mapping, and for economic geology, this is by far
the best plan, and indeed the only one that could well be adopted,
as the tracing of a merely paleontological line over a large extent
of country where there is only an occasional exposure is practically
impossible. The surveyor must therefore be guided in the main by
the composition of the beds he is mapping; where all is clay, he
may easily class two very different faunas under one denomination,
whilst, on the other hand, as the composition changes, he will be apt
to give beds more or less contemporaneous very different titles.

This is exactly what has happened in the case of the Gault in
England. Nothing can be clearer, when, by the help of Mr. Price,
we have studied the Folkestone section, which for many reasons
must be deemed the typical one, that under the general term “Gault ”
are included two extremely different formations.

The one known as the Lower Gault consists of black clays, much
subdivided by nodule-beds, and is remarkable for the abundance of
its Gasteropoda, and grooved Ammonites, of which A. interruptus
may be taken as the type. It is the equivalent of the Albien in
part, and would seem to be more extensively developed in France
than throughout England generally. Not a single Brachiopod is

Reviews—F. G. H. Price’s Gault. 327

quoted from it in Mr. Price’s Table. The minor subdivisions noted
at Folkestone may be made out at Wissant, but it is not clear that
such is the case as regards English localities generally. Westwards
the clays of Black Venn probably belong to this zone, and it may
be traced northwards for some distance beyond Cambridge, though
hardly as far as Hunstanton. There is no paleeontological evidence,
according to Mr. Price’s Table, for its existence further north.

This Albien, or Lower Gault, underwent in places an extensive
denudation, of which at Folkestone Mr. Price’s Junction or Nodule-
bed is in part the evidence. Upon its remains was deposited the
overlapping Upper Gault, which, under various lithological aspects
—a grey marl with over 25 per cent. of carbonate of lime at Folke-
stone—a glauconitic and cherty sandstone in the West of England,
a “red chalk” at Hunstanton and Speeton—forms the base of the
Chalk throughout England, itself resting upon a variety of beds
where the Lower Cretaceous rocks are absent. Keeled Ammonites
are characteristic of this formation, and A. inflatus, as the most
abundant and typical, gives its name to the group, which corresponds
to the greater part of the Cenomanien. At Folkestone, Brachiopoda
are tolerably plentiful, and wherever Kingena lima, Terebratula
biplicata, and Avicula grypheoides are congregated in abundance, we
may feel sure that we are on this horizon, even if the characteristic
Ammonite fail us for a time.

The student of Cretaceous Geology will find Mr. Price’s publica-
tion most useful. The bibliography is brought up to date, and shows
how much has been published within the last twelve years—a por-
tentous accumulation, if the literature is to go on increasing in the
same ratio. This is succeeded by a sketch of the hydrography of
the period in North-west Europe, with an indication of the probable
limits of the Anglo-Parisian basin at that time. A detailed descrip-
tion of the Gault of Folkestone follows, being the substance of the
author’s paper in the Q.J.G.S. for 1874, with the addition of new
matter, and then a brief account of the Gault along its outcrop in
the several counties from Kent to Yorkshire. A sketch of the Gault
of France, with paleontological correlations, concludes about 40
pages of the text.

But it is the Table, occupying nearly 40 additional pages, which
constitutes the chief value of Mr. Price’s book. This enumerates
about 800 species, exclusive of foraminifera, and is arranged in 20
principal columns as follows :—1. Junction (basement bed) LowEr
Gaur; 2. Folkestone, in vi. subdivisions; 8. Cambridge; 4. Wis-
sant; 5 and 6. Zone of Am. interruptus in the Aube and Yonne.
Juncrion 7. Folkestone; 8. Nodules a Epiaster Ricordianus of the
Ardennes and Meuse. Uprsr Gaur 9. Folkestone in iil. sub-
divisions; 10. Cambridge, derived; 11. Speeton Red Chalk; 12.
Hunstanton Red Chalk; 13. Blackdown Greensand; 14. Wissant ;
15. Ardennes, Meuse (fossiles en phosphate de chaux); 16. Ardennes,
Meuse (fossiles en gaize); 17,18, 19. Other localities in France ;
20. Puttenham, Bucks. We HE

328 Reports and Proceedings—

IJ.—Meénmorre sur LE Terrain Oritack prs ARDENNES ET DES
REGIONS VOISINES. Par le Dr. CHartEes Barrots.

[Extrait des Annales de la Soc. Géol. du Nord, tome v. pp. 227-487, Lille, 1878.]

HERE exists no more indefatigable a labourer in the cause of
geological science than Dr. Barrois, for not only has he carried
his observations into many formations and over an extended area,
but his works are always characterized by a scrupulous care to do
credit to every previous observer in the branch of inquiry which he
takes up. The present work contains a description of the Cretaceous
rocks forming part of the Paris Basin, in a department situated
to the north-east of France. It embraces accounts of the Aptian,
Albian, Cenomanian, Turonian, and Senonian strata, known more
familiarly to us as Lower Greensand, Gault, Upper Greensand,
Lower and Upper Chalk, respectively.

Full descriptions, and lists of fossils from the several formations
are given, and comparisons are made with beds developed in other
districts.

The following is a summary of the divisions described :—

{ Bedwith ( Chalk of Epernay with Belemnitella mucronata.
| Belemnitella. \ Chalk of Reims with Belemnitella quadrata.

SHANNA. Bed pay Magnesian Chalk with Marsupites.
Nes ame Magnesian Chalk with Inoceramus involutus
L coranguinum. 5 y
f Bed elas Chalk of Vervins with Zpiaster brevis.
| MMicraster le aan Fe ]

T < breviporus. alk rock wit olaster planus.

URONIAN. : : te
| Marl with Terebratulina gracilis.
iS Bed with Inoceramus labiatus. t
¢ White Marl of Argonne and glauconitic marl of
Upper. Thiérache with Belemnites plrenus.
CENOMA- Z Marl with Ammonites laticlavius.
Se | leower Sa ee ct Zone of Pecten asper.

| . .
L Zone of Ammonites inflatus.
( Zone of Epiaster Ricordeanus. Phosphates of Talmats.

ALBIAN. Bed with Ammonites interruptus.
{ Bed with Ammonites mammillaris.

Clay and Sands with Ammonites milletianus, Ostrea arduennensis.
APTIAN. y ?

—_—

Tronstone of Bois-des-Loges.

H. B. W.

Isis Ousyanss VND) 1S1syO\CnsasaI DAN ierS-

—————<——__—_

Grotogicarn Soctpry or Lonpon.—-I.—May 14, 1879.—Prof. P. M.
Dunean, M.B., F.R.S., Vice-President, in the Chair.—The following
communications were read :—

1. “Further Observations on the Pre-Cambrian Rocks of Caer-
narvon.” By Prof. T. M‘Kenny Hughes, M.A., F.G.S.

The author divides these into (1) the volcanic series, (2) the felsitic
series, (3) the granitoid series. He traces the former of these, con-
sisting of coarser and finer varieties, from Caernarvon to near Port
Dinorwig. Beyond these come the felsite series, which is overlapped
by grits and conglomerates as far as the Bangor road, N.E. of Brithdir.

Geological Society of London. 329

Above the latter comes the ‘‘ volcanic series,” well developed in the
neighbourhood of Bangor. The author is of opinion that the Cam-
brian conglomerate, with associated grits, may be traced in the edge
of the older massif from Twt Hill, Caernarvon, to Garth Point,
Bangor, and that the beds in each of these places and near Brithdir,
recently described as separate, are identical ; also that the bed with
purple fragments near Tairffynnon and the Bangor Poorhouse are
only Cambrian conglomerate faulted down. Further, he considers
that the strata of the above three series are fairly parallel through-
out, and that they only form three subdivisions of one great series.

2. “Notes on the Structure of the Palzozoic Districts of West
Somerset.” By A. Champernowne, Hsq., F.G.S., and W. A. HE.
Ussher, Esq., F.G.S.

The authors confirmed the general accuracy of Mr. Etheridge’s
views as to the structure of North Devon and West Somerset, but
differed from him in ascribing the limestone of Cannington Park to
the Carboniferous, both on account of lithological character, the
fossils in Taunton Museum, said to be obtained from it, and the
latitude of its position with reference to the Carboniferous Lime-
stone of the Mendip, South Wales, and the steep and flat Holmes.
They described four traverses made by them in West Somerset.
1st. From Dulverton to Dunster, in which, proceeding northwards,
the following beds were encountered :—Culm-measures faulted
against Pilton Beds (Upper Devonian), Pilton Beds faulted against
Pickwell Down Sandstone (base of Upper Devonian), Pickwell
Down Sandstones becoming slaty in passing into Morte slates
(Middle Devonian) and troughed in them by faulted synclines,
Morte slates passing into Ilfracombe slates (overlying Hangman
grits) near Cutcombe, Hangman Grits, evidently faulted against
Foreland grits, as no representative of the Lynton beds is present
between Oaktrow and Timberscombe.

In traverse 2, the fault between the Hangman and Foreland grits
is proved by the presence of the Lynton beds in the valley west of
Luccot Hill and their conformable infraposition to the Hangman
series, and abrupt termination by fault against the Foreland grits of
Porlock and Oare Hills. At Oare a patch of schist of the Lynton .
zone was noticed resting on the Foreland grits on the north side of
the fault.

The 3rd traverse in the Tone valley gave the following succession
of beds :—Culm-measures on Pilton beds ; Pilton beds with grits,
much flexured, on Olive slates with Lingula and grits with Cucullaa,
conformably overlying Pickwell Down grits, which make a con-
formable junction (following the feature) with the underlying
quartziferous slates of the Morte series (Middle Devonian); the latter
were observed between Huish Champflower and Clatworthy ; but,
as the Middle Devonian slates appear to extend considerably north-
ward in the Brendons, they were not traversed beyond Clatworthy.

The 4th traverse from West Quantockshead to Cannington Park
proved the composition of the Quantocks along that line to be grits,
in places associated with schistose shales, apparently belonging to
the Hangman series (Middle Devonian); whilst the Paleozoic

330 Reports and Proceedings—

inliers, in the Triassic area of Bridgewater, are unlike the Quantock
rocks in character. The limestones of Asholt and Hollwell, asso-
ciated with slates of the Ilfracombe series, are very similar to varie-
ties of the South Devon limestone, and are quite unlike the lime-
stone of Cannington Park.

3. “The Whin Sill of Teesdale as an Assimilator of the surround-
ing Beds.” By C. T. Clough, Esq., F.G.S.

Owing to the general absence of mechanical disturbance, the
author is of opinion that “the Whin consists in part of altered sedi-
mentary beds, that it partly represents beds which were once in the
position it now occupies, that it did not make room for itself simply
by thrusting aside these beds, but also by incorporating them into
itself.” He proceeds to describe sections at Caldron Snout, Cronkley
Fell, Noon Hill, etc., which seem to him inexplicable on any other
theory. The author discusses objections on chemical grounds, hold-
ing that the general uniformity in chemical composition of the Whin
may be explained by supposing the absorbed beds to have permeated
a large mass of the Whin, as an alloy does melted metal. He thinks
the explanation may be extended to other intrusive masses.

4, “On the Silurian Rocks of the Valley of the Clwyd.” By
Prof. T. M‘Kenny Hughes, M.A., F.G.8.

The author gives a preliminary sketch of the Silurian rocks of the
southern and western part of the Clwyd valley. He describes first
some beds below the horizon of the Denbigh Grits at Ffriddfawr
which agree very well in their characters with the base of the
Coniston Grit, and others near agreeing with the passage-beds
between these Grits and Flags. He next describes sandstones in
the Clywedog valley, the equivalents of the lower Grits ; and lastly,
at Bod Renail, flags, etc., the Pale Slates, which contain Graptolites,
and are thus to be identified with the Graptolitic mudstones of the
Lake-district. Thus he is of opinion there is a basement-series here
for the Silurian, corresponding in all its details with that in the
Lake-district.

II.—May 28, 1879.—Henry Clifton Sorby, Esq., F.R.S., President,
in the Chair.—The following communications were read :—

1. “On the Endothiodont Reptilia, with evidence of the species
Endothiodon uniseries, Owen.” By Prof. R. Owen, C.B., F.R.S.

The author referred to the characters assigned by him to his
Endothiodon bathystoma, which had the alveolar borders of both
jaws toothless, perhaps covered with horn during life, as in the
Chelonians; whilst within this border there were three series of
teeth both in the palate and the mandible. He next described a new
species, under the name of Endothiodon wniseries, founded upon the
fore half of a skull, having only a single row of teeth in the palate,
a character which may prove to be of generic importance. The
author finally discussed the relationships of this genus, which he
regarded as belonging to the order Anomodontia, and as showing,
like Oudenodon, traces of derivation from Dicynodon in the presence
of caniniform processes in the upper jaw. The development of teeth
interior to the alveolar margins in both jaws was to be regarded as a

Geological Society of London. 381

character of family value, and the author remarked upon the interest
of the continuance of a common Ichthyic and Batrachial dental
character in exceptional cases among the Reptilia up to the establish-
ment of the Crocodilian type, above which, in the vertebrate series,
calcified palatal teeth no longer appear.

2. “Note (3rd) on Hucamerotus, Hulke, Ornithopsis, Seeley, =
Bothriospondylus magnus, Owen, = Chondrosteosaurus magnus, Owen.”
By J. W. Hulke, Esq., F.R.S., F.G.S.

In this paper the author gave a description of an unusually perfect
dorsal vertebral centrum of Ornithopsis, and some additional informa-
tion respecting the cervical and anterior dorsal vertebra. He further
compared the prosacral vertebre with those of several recently dis-
covered Dinosaurians of the Colorado region, showing several agree-
ments, but also such differences as to prove the generic distinctness
of Ornithopsis. He discussed the question of the nomenclature of the
species indicated in the title of his paper, and maintained that the
name Ornithopsis ought to be adopted for the single genus to which
he referred them.

3. ‘ Description of the species of the Ostracodous genus Bairdia,
M‘Coy, from the Carboniferous Strata of Great Britain.” By Prof.
T. Rupert Jones, F.R.S., F.G.S., and James W. Kirkby, Esq.

The long persistence of the genus Bairdia, from the Silurian
period to the present day, and its essentially marine character, were
first noticed ; also the relatively rare occurrence of any species of
Leperditia, Beyrichia, and Kirkbya (associates of Bairdia in Carboni-
ferous strata) in freshwater or estuarine beds. Carbonia, on the
other hand, was confined to the fresh or brackish waters in which the
Coal-measures were formed. The difficulty of defining the species
of Bairdia from carapace-valves alone, without limbs and soft parts,
and the possibility of several genera being grouped under this head,
were mentioned. The species of Bairdia described and figured in
this paper were, it is believed, all that have been found in the British
Carboniferous rocks, with the exception of M‘Coy’s B. gracilis. Two
of Count Miinster’s Bavarian Bairdie, from Hof, have not yet occurred
with us; neither have four of Dr. D’Eichwald’s Russian Carboni-
ferous species, nor the Australian B. affinis, Morris. Including these,
there are twenty-three known Carboniferous species of Bairdia.
Seven of these are recurrent in the overlying Permian limestones,
which have yielded twelve species of this genus. With six Silurian
forms, there are altogether thirty-four recorded Paleeozoic species of
Bairdia.

4, ‘Report on a Collection of Fossils from the Bowen River.
Coal-field and the Limestone of the Fanning River, North Queens-
land.” by R. Etheridge, Hsq., jun., F.G.S.

The collection on which the present paper was founded had been
received from Mr. R. L. Jack, F.G.S.. and the information furnished
by it was supplementary to that obtained from Daintree’s collection.
The fossils are from three distinct horizons. The author first briefly
described the geology of the formations from which the fossils were
derived, and stated that the results of his investigations led him to
refer those from the Fanning River Limestone to the Devonian, those

3832 Reports and Proceedings—Ceological Society of London.

of the Bowen River Coal-field to the Upper Carboniferous or Permo-
Carboniferous, and those from the Tait River to the Cretaceous.
Twenty-six species of animal remains, chiefly Mollusca, are described
in all, twenty of which are from the Bowen River Coal-field; the
latter include a fine series of Strophalosig. 'The new species are
Protoretepora Koninckii from the Permo-Carboniferous of Bowen
River, and Crioceras Jackii from the Cretaceous; also Strophalosia
Jukesii from the Carboniferous of New South Wales. The paper
included a list of the localities in which the specimens were
collected, and a full bibliography of Queensland paleontology.

5. “Ona Fossil Squilla from the London Clay of Highgate, part
of the Wetherell Collection in the British Museum.” By H. Wood-
ward, Hsq., LL.D., F.R.S., F.G.S.

The specimen described is preserved, as usual, in a phosphatic
nodule, and exhibits five well-preserved abdominal segments (xIv.—
XvitI.), a portion of the carapace, traces of the thoracic appendages,
and the appendages of the twentieth segment preceding the telson.
The abdominal segments increase in breadth posteriorly as in
modern Squille. The species is most nearly allied to a recent
Australian Squilla (unnamed) related to S. Desmarestii. The author
proposed the name of Squilla Wetherelli for the London-clay fossil.

6. “On Necroscilla Wilsoni, a supposed Stomatopod Crustacean
from the Middle Coal-measures, Cossall, near Ilkeston, Derbyshire.”
By H. Woodward, Hsq., LL.D., F.R.S., F.G.S.

The specimen described was found by Mr. HE. Wilson, of Notting-
ham, in a nodule of Clay-ironstone. It consists of the four posterior
abdominal somites and the telson. The author discussed its zoolo-
gical characters, which led him to regard it as approaching the
Stomatopoda rather than the Isopoda. He thought it probable that
Dr. Dawson’s Diplostylus is allied to this newly-discovered form, for
which he proposed the name of Necroscilla Wilsoni.

7. “On the Discovery of a Fossil Squilla in the Cretaceous Depo-
sits of Hakel, in the Lebanon.” By H. Woodward, Esq., LL.D.

This fossil Squilla occurs im a collection, chiefly consisting of
fossil fish, but also including several Crustacea and some beautifully
preserved Cephalopods, obtained in the Lebanon by Prof. E. R.
Lewis, of Beirit. The specimens are in a compact cream-coloured
limestone, most of the slabs of which contain examples of Clupea
brevissima and C. Botte, fragments of Eurypholis Boissieri, and other
fishes. Like the London-clay form, the species seems to be most
nearly allied to the Australian species collected by Prof. Jukes,
the segments are not ornamented with spines and ridges. The
author proposed for it the name of Squilla Lewisii.

8. “On the Occurrence of a Fossil King-Crab (Limulus) in the
Cretaceous Formation of the Lebanon.” By H. Woodward, Esq.

This was another of Prof. Lewis’s discoveries, and was of much
interest as helping to bridge over the interval between the Jurassic
Limuli of Solenhofen and those now living. The author described
the characters presented by the single specimen, for which he pro-
posed the name of Limulus syriacus.

Correspondence—Mr. G. H. Kinahan. 3393

CORRESPONDENCE.

JUKES ON RIVER VALLEYS, 8S. W. CORK.

Sir,—In reply to Mr. A. J. Jukes-Browne’s letter in the Grot.
Mae. for May, 1879, I would point out that the apparent discrepancy
between the statements in “ Valleys and their Relations, etc.,” and
in the “Geology of Ireland,” is easily explained. In the first, the
statement refers to the formation of valleys in any country and in
any kind of rocks; while in the second, the statement refers solely
to the valleys of 8. W. Cork. Such a general statement as the first
would not refer to a peculiar country like 8. W. Cork, where the
Carboniferous slate rocks are as hard and are as capable of resisting
denudation as the Old Red Sandstone, while if Coal-measures once
existed in the synclinal troughs, they probably were also indurated
and similar to the rocks that form the hills immediately north of the
Black Water Valley and hills elsewhere in South Ireland.

Jukes distinctly states that the Carboniferous slate was once
covered by limestones, while subsequently he relies on the soft
nature of the limestone to expedite the formation of his valleys.

I cannot exactly see why this theory has a claim to be called “ well
considered.” When put forward, it was founded on suppositions
that were then questioned, and which have since been shown to have
been too hastily arrived at. It also ignores all faults and dislocations
of strata in the different areas mentioned, while originally it totally
ignored ice-action. It was only an afterthought, to bridge over the
last, that the statement ‘‘a glacier is only a frozen river’ was intro-
duced; but this does not meet the objection, as the actions of moving
frozen and unfrozen waters are very different.

I do not for a moment presume to say that in no place could rains
and rivers produce the effects described ; but as the theory was
founded in a country and on suppositions which were afterwards
found to be erroneous, I think I am justified in saying the general
theory “falls to the ground.” G. H. Krnanan.

Ferns, May 13, 1879.

DEVON GEOLOGY.

Sir,—From the Rev. H. H. Winwood’s letter, Gnor. Mac. May,
1879, it would appear that my statement casts a slur on the Devon-
shire Amateur Geologists; for this I am extremely sorry, as such
was never my intention, the remarks being intended solely to refer
to a paper which I believe has been given much more importance
to than it merits. I can assure Amateurs that I look on them with
great respect, and I sincerely wish there were more of them in
Ireland, as they are the only safeguard against the overwhelming
vagaries and egotism of the ‘Trained Geologists”; and I would
have much more respect for them if sometimes they were more
independent, as they often allow their well-worked-out results to be
snuffed out by individuals whose only claim to be heard is that they
are Officials.

I regret I cannot accept my friend’s hospitable challenge for

334 Oorrespondence—Mr. J. A. Birds—Mr. A. Strahan.

various reasons; because I have given up “coat strealing,” and
principally that I cannot devote sufficient time to be such a master
of the Devonian sections as would give me a claim “to beard the
lion in its den.” I must, however, say that if the Devon geologists
are satisfied with the evidence brought forward to refute the exist-
ence of Jukes’s, or rather De la Beche’s fault, they are very easily
satisfied.

Various Irish geologists have gone to Devon, Cornwali, and
Wales, to compare the Irish and the English rocks; yet how many
of them have written on the English rocks? I do not know of any
English geologists except De la Beche (who we may nearly claim
as an Irish geologist) who have examined the Irish rocks, further
than taking a hurry scurry on a car through the country, yet we
are coolly asked to squash the work of years to suit these ideas.
Who therefore,—English or Irish,—take the cross channel view of
the rocks ? G. H. Kinanan.

Ferns, May 13, 1879.

BEEKITE IN THE CHANNEL ISLANDS.

Sir,—Will you allow me to add to Capt. Jamieson’s interesting
account of his discovery of Beekite in the Punjab, contained in the
last Number of the Grontocican MaGazine, that this mineral also
occurs in a Triassic conglomerate in Bouley Bay, Jersey, described
in Ansted and Latham’s “‘ Channel Islands,” p. 274.

A year or two ago I picked up several specimens on the beach
there in pebbles containing corals and shells. Thus the range of
Beekite in Europe is slightly extended beyond the shores of Torbay.

It would be interesting to know if the same conglomerate with
Beekite also occurs in Normandy, among the rocks believed by Mr.
Ussher to be a south-easterly extension of the Triassic beds of
Devonshire (see “On the Triassic Rocks of Normandy, etc.,” by W.
A. E. Ussher, Esq., F.G.S., Quart. Journ. Geol. Soc., vol. xxxv.
p. 245). J. A. Brrps.

82, GLoucEsTER TERRACE, HypE Park,

June 4, 1879.

P.S.—There is a specimen of Beekite in the British Museum, from

Vallecas, near Madrid.

BEEKITE IN FLINTSHIRE.

Srr,—Capt. Jamieson, in his letter on Beekite from the Punjab, in
the GronocicaL Magazine of last month, mentions Torbay as the only
known locality in Great Britain for this mineral. It occurs also in
the Carboniferous Limestone of Flintshire, and in every specimen
that I have hitherto met with as a crust replacing the shell of a Pro-
ductus. The siliceous gangue of many of the veins and the silicifi-
cation of the Encrinites and other fossils in the Limestone in and
near such veins is a further indication of the passage of water
containing silica in solution. A, STRAHAN.

HonyweEtu, 18th June, 1879.

Correspondence—Prof. Edward Hull.— Obituary. O89

THE DISCOVERY OF UPPER SILURIAN ROCKS UNDER THE CHALK
OF HERTFORDSHIRE.

Srr,—Allow me to call attention to the fact that the dis-
covery of the Upper Silurian Rocks in Hertfordshire under the
Upper Cretaceous—an account of which has been given by Mr.
Etheridge, F.R.S., in The Times'—corroborates the views I stated
as far back as 1861, in the second edition of ‘ The Coal-fields of Great
Britain,’ and again in the third edition of 1873. The little ideal
section, by which J intended to show the structure of the central and
eastern counties, represents (p. 475) the “Silurian and Cambrian ”
rocks as underlying the Cretaceous in the part of the country corre-
sponding to Hertfordshire. This ought to convince sceptics that
geologists can see deeper than other men into a millstone.

GxEoLocicaL SurRvEY oF IRELAND, Epwarp Hvt1.
Hume Street, Dus.

@ Peo ANE ye

JOSE BE WHE SO NE OWI RY HESREGHS-
Born Octoser 7, 1808. Diep June 15, 1879.

Deatn has just erased another well-known name from the roll of
workers on the Geological Survey of Great Britain—that of J. W.
Lowry, the eminent engraver, whose maps, sections and plates of
fossils form so interesting a part of the records of this important
branch of the scientific public service.

Joseph Wilson Lowry was the only son of Wilson Lowry, F.R.S.,
and Rebecca Lowry, well known as a mineralogist some seventy
years ago. His father was the leading architectural and mechanical
engraver of his time, and he trained up his son to follow his own
pursuits. From his early youth his father’s house was the resort of
men of high intellectual culture, and his mother’s pursuits leading
her also to associate with the scientific men of the day, what wonder
that young Lowry early imbibed his parents’ tastes, and became an
ardent lover of all Natural History studies and pursuits, an accom-
plished draughtsman, and a well-informed scientific man.

His first practical effort was directed to the construction of a
model in plaster of the Isle of Wight, geologically clooured, and
divided transversely so as to give a section (also geologically
coloured) through the centre of the island.

His pursuit of Natural Science led him early in life to become
acquainted with John Phillips, at that time Keeper of the Yorkshire
Philosophical Society’s Museum in York, and later on, when
Assistant-General-Secretary of the British Association for the
Advancement of Science, and when associated with De la Beche on
the Geological Survey, or when Professor of Geology in Oxford
until his death, Prof. Phillips remained the attached friend of J. W.
Lowry.

1 See also Grou. Mac. 1879, for June, pp. 286—289, with a complete list of the
fossils determined.

336 Appointment of Mr. F. W. Rudler, F.G.S.

Lowry’s first important work, as an engraver, was the execution
of the plates for the Encyclopedia Metropolitana. He also executed
for Sir John Rennie a series of plates of London Bridge. For many
years Mr. Lowry prepared all the engravings for Scott Russell illus-
trative of wave-lines and the contours of Vessels. He also
designed and executed numerous maps and charts for the Society for
the Promotion of Christian Knowledge; the Atlas of Maps pub-
lished by the Dispatch newspaper—the first really cheap and good
atlas ever produced.

The plates illustrating Phillips’s Geology of Yorkshire, Weale’s
Scientific Manuals, and many other educational and scientific works,
were engraved by Mr. Lowry. We are indebted to Mr. Lowry for
the excellent series of Natural History Charts of British Fossils
Stratigraphically arranged; British Tertiary Fossils; Recent and
Fossil Crustacea, by J. W. Salter and Dr. H. Woodward, ete., ete.

Hundreds of plates of fossils exquisitely engraved, and maps and
sections too numerous to recount, published for the Geological Survey
of Great Britain, amply testify to Mr. Lowry’s rare ability as a
scientific engraver. Even the familiar card-maps of each town
visited year after year by the British Association were invented
and produced by Mr. Lowry’s skill and ingenuity.

But the days of engraving seem drawing to a close (at least so
far as printing from engraved plates is concerned), but the beautiful
plates prepared by Mr. Lowry cannot well be surpassed by modern
lithography save in cheapness. His Geological and Natural History
Charts, produced at great personal expense and labour, are still the
best of their kind extant, and continue greatly in demand.

Much as Mr. Lowry’s work was valued by scientific men, his
amiability of disposition and his modesty won for him even higher
esteem among his friends. Many who knew him personally will
recall his readiness on all occasions, even at great personal sacrifices,
to help those who needed his assistance. His freshness of heart and
kindness to the young were marked features in his character, and
endeared him to all.

MISC HiOAINHOUS.

THE AppoInTMENT oF RecisTRAR To THE Royan ScHooL oF
Mines.—Mr. F. W. Ruptuer, F.G.S., who, from 1861 to 1876, held
the office of Assistant Curator, under Mr. Trenham Reeks, to the
Museum of Practical Geology, in Jermyn Street, and subsequently
* was appointed to the University College of Wales at Aberystwyth,
has been duly appointed to succeed Mr. Trenham Reeks as Registrar
of the Royal School of Mines and Curator to the Museum of Practical
Geology. This appointment will afford great satisfaction to a large
circle of scientific friends, by whom Mr. Rudler has long been known
and highly esteemed. _

Le Drag ra bare,

Emys lutaria Merr Mundesley,Norfolk.
(See p.806 7

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(See p.806.)

THE

GEOLOGICAL MAGAZINE.

NEW SERIESS) DECADE He VOLE Vir

‘

No. VIII—AUGUST, 1879.

Ors de AEIN (AE, | /ISYARIE Oa S i

J.—A Cruisz among THE VoLcANos oF THE KuriLe Isnanps.
By Professor Joun Mitne, F.G.S.,
Imperial College of Engineering, Yedo, Japan.
(PLATE IX.)
/J\HE following notes upon the Kuriles were collected during an
excursion which I made to these islands in the summer of 1878.

Owing to a continuance of foggy weather, which I do not think
would find its equal even in Newfoundland, the want of harbours,
and the strong currents, although I was almost a month steaming
amongst these islands, it was seldom that we could effect a landing.
In consequence of this the bulk of the material embodied in the
following notes was written from what I saw from the deck of our
vessel. However, as I had good opportunities for seeing nearly
every island in the group, and many of these from several points of
view, the following notes may not be altogether without value.
One advantage which was gained by viewing these islands from a
distance was, that I was thereby better able to judge of the number,
and the general form of the mountains they contained, and _ to
roughly make comparisons of their relative heights, than I could
have done had I been actually on the islands themselves.

In a few cases I endeavoured to estimate the heights by means of
sextant observations. I also made many measurements of the slopes
of the mountains which I saw; but as these were made with a small
hand clinometer from the deck of a rolling ship, these measurements
must only be regarded as rough approximations.

I have spoken of several of these volcanos as conical, but it must
be understood that this, in many cases, only indicates a general form,
the true form of the slopes being approximately logarithmic.

In the majority of cases the mountains and different portions of
these islands are without names, and I have therefore had to describe
them by their positions.

We finished our journey northwards at the southern extremity of
Kamschatka, which is terminated with high black snow-capped
peaks, looking as cold, cheerless, and uninviting as the most dreary
part of Iceland.

Commencing from the north we first have Shumushi or Pervi
Island. This is the most northern of the Kuriles, and it is separated
from Kamschatka by the Kurile Straits, which are about eight miles
wide. Towards the south it is separated from Paramushir by the

DECADE II.—VOL. VI.—NO. VIII. 22

338 Prof. John Miine—A Cruise among the Kurile Islands.

Little Kurile Strait, about two miles wide. As compared with the
other islands in this group, Shumushi is extremely flat. Looking at
it as we approached the northern entrance of the Little Kurile Strait,
it presented an undulating surface. Where the convexity of these
undulations came down to the shore, they terminated in low perpen-
dicular cliffs. In other places which marked the low sweeping
valleys, the land rose gently upwards and backwards as it receded
inland. It was opposite to the entrance of one of these valleys at a
place called Myrup where we anchored. Here there were three
wooden houses which had been built by the Russians, and quite
a number (perhaps a score) of half-underground dwellings. On
landing we found that all these were deserted, and in many cases
even difficult to find, owing to the growth of wormwood and wild
grasses.

The inhabitants of the island, who call themselves Kurilsky, are
twenty-three in number. They chiefly live at a place called Seleno
about four miles distant. In addition to their own language, they
speak Russian very fluently, and also know something of the Aino
language. For the last three or four years they have lived on fish,
a few blay-berries and the various animals they could shoot. I
mention these people as they appear to be the only inhabitants in the
Kuriles north of Iterup. By going up the bed of a small stream which
flows down the Myrup valley, and by traveling along the shore, I
saw several exposures which showed beds of breccia overlying beds
of volcanic rock. At a distance this breccia is generally of a whitish
grey colour. Looking along the shore from Myrup northwards, you
apparently see beds of grey breccia overlying beds of a_ black
volcanic rock. On close inspection, however, the black rock is seen
to be also a breccia, coarse in its lower portion, where it contains
fragments of rocks, gradually becoming finer higher up, and finally
merging into a grey tuff. The difference in colour seems to be
greatly due to a difference in weathering and the action of the sea.
Here and there standing up through this breccia are bands and
masses of volcanic rock. One of the former of these, which has had
the breccia worn away from its sides, stands up at right angles to the
shore-line like a huge wall.

Its continuance towards Paramushir is marked by outliers which,
by the action of the sea-waves, have gradually been cut off from it.
At right angles to its length—+that is, in a direction running from side
to side—it is seen to have a columnar structure, which, whilst adding
to its peculiar appearance, gives you some idea of the way in which
it cooled.

Up the valleys masses of a similar rock are also to be found.
Upon the sloping sides of these valleys the breccia (which was
friable) is thick, but it is thinner near the tops of the hills.

As we entered the straits, to see headland facing headland was
very noticeable. If we imagined the curves of the volcanic ridges
from Paramushir to be continued eastwards across the straits, it was
clearly evident that in many cases they would make an unbroken line.

When on Shumushi, by looking across the Straits at Paramushir,

Prof. John Milne—A Cruise among the Kurile Islands. 339

it was observable that in many cases the undulations, and more
especially the bluffs, of the land on one side correspond with those
upon the other. These observations suggested the idea that in times
not far remote these two islands have been continuous. At the time
when the high volcanos of Paramushir were in full activity, they
probably gave forth the materials which form the breccia. At first
these materials were large and coarse, but as the intensity of the
eruptions gradually decreased, the ejectamenta became finer and
finer, as is indicated in the deposit of tuff overlying the coarser
stones. From the absence of any appearance of stratification, I
should be inclined to think that this action was a continuous one; at
first violent and fierce, and finally, after the beds in Shumushi had
accumulated to a thickness of a hundred feet or more, weak and
feeble, puffing out fine dust and ashes, which fell and formed the tuff.

This continuous action, of which we have here evidence, I may
remark, is very different to the action which has been carried on by
the volcanos further south in Yezo and Niphon, where we have
stratified beds of varying thickness, showing that sometimes we had
a violent eruption, and next a feeble one. Sometimes these rapidly
succeeded each other, but at other times, as is indicated by an inter-
mediate layer of soil, there were periods of repose. The outbursts
of the Japanese volcanos have been spasmodic; whilst the outbreaks
which covered Shumushi, which apparently came from the high
volcanos of Paramushir, have probably been more regular in their
action. When speaking of these volcanos under the headings of the
several islands in which they oceur, I will give other reasons for my
belief that the building up of many of the Kurile mountains has
been by a continuous action rather than by a series of spasmodic
eiforts.

Immediately after these eruptions we must imagine the Kurile
Strait to have been bridged across by the lower part of a continuous
voleanic curve. Subsequently, because the materials which formed
this bridge were soft, the sea has gradually eaten itself a channel
through it. This channel is not lke the channels between the other
islands, almost unfathomable, but shallow. The greatest depth being
about thirteen fathoms. Whilst this was going on, subaerial actions
have worn out the ridges on the volcanos and the slight hollows on
Shimshis, which now form the valleys, shallowing the sea by the
material derived from the land near their entrance.

At the southern entrance to the Little Kurile Straits are a number
of small islands called Torishima (Bird Islands). These I did not see.

Alaid Island.—This is a small] island lying almost eleven miles off
the north-west coast of Paramushir. Its general appearance is that
of a solitary cone. From a rough observation made at a distance of
almost six miles this appears to be over 3,000 feet in height. When
I first saw it, we were steering N.N.E. between it and Paramushir.
At this place we sounded with forty-five fathoms of line without
finding bottom. At that time the base of Alaid was covered with
clouds, but above these the top showed itself like a huge wedge-
shaped cap. The edge of the wedge, which apparently was the

3840 Prof. John Milne—A Cruise among the Kurile Islands.

ruined rim of an old crater, formed the top ridge of the mountain.
This ridge is on the W.S.W. side. As we continued on our course,
the N.E. end of this ridge rose in a point, and was seen to be the
highest portion of the island. Subsequently, when I again saw
this mountain, I had an uninterrupted view from its summit to the
base. On the §.W. side the slope near the top was 25°. Lower
down this gradually decreased to 12°. From the E.S.E. this side of
the mountain was seen to have a slope of 30°, and an almost perfectly
symmetrical appearance. The measurement of 25° had been taken
along the edge of some degraded ridge which at the time of obser-
vation formed a profile of the mountain. On the N.H. side the slope
at the top was almost 23°, and lower down 23°, and near the base
3°. From all points of view the mountain exhibited a distinct and
beautiful curve. Looking at the surface, this was exhibited as a
sweeping hollow. And if we except a few deep furrows which had
been cut by rain and weather, its contour was perfectly regular.

Round the base of the mountain there was a growth of scrub.

In many places the shore-line was seen to be bounded by low
cliffs. At the S.W. end these terminate in a small abrupt peak.
These cliffs have in places a stratified appearance, a few thin earthy
beds being intercalated with beds of ashes. From the way in which
any one of these beds is seen to be continued along the shore-line,
and also upwards along the scarp of the furrows, it would seem that
the structure of the outer portions of this mountain must be that of a
series of skins, or superimpose more or less conically formed envelopes.
Although I looked carefully over the 8.E.,S., and 8.W. slopes of this
mountain, nowhere did I see anything which looked like or indicated
the presence of a stream of lava.

From the structure exhibited by this mountain, the apparent
absence of lava streams, and its beautiful form, the slopes of which,
so far as the eye could judge, were of logarithmic curvature, this
mountain, like many others in the Kuriles, of which I have yet to
speak, was in all probability built up by a more or less continuous
action, and consequently exhibited that elegant form which is natural
to any heap of loose materials. Since the last eruption materials
have been washed down from higher to lower levels, the top being
made a little steeper, and the base more horizontal. [Alterations
near the summit, tending to increase the steepness, have probably
taken place more rapidly than at lower levels, from the fact that
degrading agencies like rain would, for many reasons, be more active
at high levels than at low ones. It is also possible that horizontality,
and even a quaquaversal internal dip, may have been provoked, as Mr.
Mallet has suggested, by the weight of the cone pressing down at
the centre and raising up the rim]. During these processes furrows
were cut which hold perennial snows, and plants which fringe the
base grew up from drifted seed.

Paramushir Island.—This island may be classed among some of
the largest islands in the group. It is about 60 miles in length, as
measured from N.E. to 8.W.; its breadth is about 14 miles. From
what I saw of it on the N.E., N., and N.W. shores, it appears to be

Prof. John Milne—A Cruise among the Kurile Islands. 341

altogether a mass of mountains. The S.E. point, however, is said to
be long and low. On the N. and N.H. shore facing the Little
Kurile Straits, here and there, there are a few low cliffs; but for the
most part the land slopes upwards from the sea to the summit of a
line of irregularly-peaked mountains.

An irregular mountain, forming the northern end of this group,
is giving off steam. It is covered with reddish scarps and patches
of snow. As this mountain, which is remarkable as being one of
the flickering embers of those internal fiery forces which raised the
Kuriles, appears to be without name, either on the charts or amongst
the inhabitants, I have ventured to name it Mount Ebeko. Three
other high mountains may be picked out of the irregular collection
which is presented at the northern end of Paramushir. These are
chiefly noticeable for their conical truncated forms and curvatures.
From near the entrance to the Straits they respectively bear 8.8.W.,
S.W. by W., and W. by 8S.W. The N.W. side of Paramushir shows
a mass of irregular mountains. With the exception of a few red and
yellow patches or scarps, apparently marking the effects of fire,
everything looks black.

Rising above these there are four remarkable mountains, which can
be distinctly seen. Commencing from the north there is Mount
Ebeko, which on this side presents the same irregular surface as it
does when viewed from the Kurile Straits. It is easily to be
recognized by the steam issuing from its summit.

Farther from the south we have:

No. 1. A sharp peak... ... ... 50° 25’ N. Latitude.
No. 2. A well-defined cone ... 50° 20’
INGs Ds JEMSS FUEAIZ | ypeo. ange dod) HO Alls rf

No. 1. From the views which I had of this mountain, it showed
nothing more than a sharp peak which rose above the neighbouring
mountains.

No. 2 and No. 8. These two mountains are from their regular
form to be ranked with Alaid, as being among some of the more
remarkable peaks which build up the Kuriles. They appear to be
the highest mountains in the island, and at the same time the most
beautiful in shape. Approaching them in a south-westerly direction,
they look like two slightly truncated cones.

No. 2, which from all points of view appears to be the highest,
on its N.E. side looks as if it were joined on to some rugged
hills, but from other points of view this appearance is seen to be
illusory, and the mountain to be almost isolated. On the side which
faced us it showed a brownish red patch ; with this exception, all the
rest of its surface was black. On the N.E. side its inclination near
the summit was 30°. On the opposite side it was 22°. On this side
it sweeps down towards the plain with a decreasing inclination.
Before it becomes quite horizontal it rises to form the slope of No. 3
(Mount Fuss). The curving profiles of these two mountains have
the appearance of a cycloid, but although I had not the means of
determining their form, I conclude that, like all other volcanic slopes
which I have measured, they must be approximately logarithmic.

73

342 Prof. John Milne—A Cruise among the Kurile Islands.

Whilst here I compared the slopes of these two mountains by
bringing their profiles into contact by means of a sextant held
horizontally, and so far as I was enabled to judge by the eye, they
were in all respects similar. The two sides of Mount Fuss appear
to be balanced in form, each side having a slope of 28°. As we came
closer, the profiles of these mountains, which had appeared to he
perfectly regular, now showed a slightly ragged outline, no doubt
due to the same cause which produced the furrows which could now
be seen scoring their sides. Looking south, across the curve which
joined these mountains, in among the mountains behind No. 2, a wall
of rock was visible not unlike that of some ruined crater. From this
point of view, the crater of Mount Fuss, which was slightly breached,
was seen to be filled with snow.

As we sailed southwards, and looked back towards the N.N.H.,
No. 2 was seen first to the left of Mount Fuss, then towering above
it, next immediately behind it, and finally to the right. From this
point of view Fuss was seen to be very much truncated, and to have
a very ragged and ruined crater-lip. Its sides, which were green,
were suddenly terminated by reddish scarp-like cliffs, looking as if
from time to time large masses from the face of the mountain had
slipped seawards.

In addition to the mountains which I have mentioned, in the
Admiralty Chart three large peaks are indicated on the 8.9. coast.

On the whole, in Paramushir, if we except the isolated peaks,
the mountains in the N.E. half are higher than those in the 8.W.
Apparently it is for this reason that there is so much more snow on
the mountains at the northern end of the island than upon those in
the southern half.

Shirinki Island.—This is a small island which has apparently a
flat top, lying about nine miles from the 8.W. point of Paramushir.

Makanrushi Island.—This island lies about 15 miles N.N.W.
from Onekotan. When looked at from the east, it shows itself as a
fine cone. On the N.W. side it has a dip of about 30°, and on the
opposite side 28°. On the top three small points can he seen.

Onekotan Island. —This island, which is about 24 miles long, and
from 5 to 10 in breadth, lies about 20 miles 8.W. from Paramushir.
On the south it is separated from Kharim Kotan by the Shistoi
Strait, which is about eight miles broad. On the Chart it is shown
as having six principal peaks, two of which are said to be dome-
shaped. Looked at from near the north end, in a 8.S.H. direction,
three larger mountains can be distinctly seen, raising themselves
above the rest.

No. 1, on the left, has a rounded top. At the base of this on the
right there is a small volcanic cone.

No. 2, which is apparently the highest, terminates in a point.

No. 3 is a well-formed truncated cone. (Further to the right in
a §.S.W. direction the truncated cone on Kharim Kotan and Makan-
rushi can be seen.)

One of these mountains had slopes of 380° and 29°.

Onekotan, as seen from a distance of about 13 miles, exhibits on

Prof. John Milne—A Cruise among the Kurile Islands. 3438

the east side four large mountains, the two middle ones of which
are well-formed volcanic cones.

Kharim Kotan.—This lies 8 miles to the 8.W. of Onekotan.
Tt is an island about seven miles in diameter. When looked at from
the south, it exhibits a truncated cone.

Shiash Kotan.—This lies about 20 miles farther to the S.E.
It is about 12 miles long and 3 broad. Near the south end
there is a well-formed truncated cone, and near the centre a similarly
formed cone, which is still higher, and is yet active. Round the
shores there are many low cliffs.

Ekarma Island.—This island lies about 5 miles distant from
Shiash Kotan: On its N.W. side it stands up as a high irregular
cone.

Chirim Kotan.—This island is about 24 miles distant from
Shiash Kotan, on the same side as Ekarma. It shows two tall
hills, which from their shape are probably of volcanic origin.

Musir Island shows three small points or peaks. It consists of
four small islets lying about ten miles from Shiash Kotan.

Matua Island.—This island, which is about 7 miles long, lies
about 50 miles S.W. from Shiash Kotan. Near its S.W. side there
is a lofty peak terminating in a sharp point. From the side of this
peak steam can be seen issuing.

Raikoki Island.—This island lies about 5 miles N.N.E. from
Matua. It has a flattish top, with one small peak.

Rashua Island lies about 19 miles S.W. from Matua. This
island, when looked at from a distance of about 12 miles, is seen
to be made up of several hills, but none of them exhibited a form
which could be identified with a modern volcanic cone.

Ushishir Island lies about 10 miles 8.W. from Rashua. It is said
to be made up of two islands, each about 14 miles long, connected
by areef two cables long. When viewed from the north, one of its
ends is seen to be terminated by a high peak.

Ketoy Island lies almost 30 miles to the 8.W. from Rashua. It is
mountainous, and its contour exhibits several rough peaks.

Shimushir Island.—This is separated from Ketoy by the Diane
Straits, which are about 18 miles wide. It is 27 miles long and about
5 miles broad. On the Chart it is drawn as exhibiting three peaks
at its N.E. end. One large peak, known as Prevost’s Peak, and four
smaller ones, are to be seen near the centre, and another mountain
at its S.W. end. The three peaks at the northern end are all con-
spicuous, and from their form they are evidently of volcanic origin.
The central one is estimated as having an elevation of 2,100 feet.
‘ When approached from the north, this peak is seen to overlook
Broughton Harbour. This harbour, from its plan and description,
would appear to be an old crater, which has been breached by the sea.
Its length is about 3 miles and its breadth 1 mile. Round the sides
it has an average depth of 20 fathoms, and near the centre of 50
fathoms.

It is surrounded by steep hills. The entrance is by a channel
about =2;ths of a mile wide and with only a depth of from 1} to 2

344 Prof. John Miine—A Cruise among the Rurile Islands.

fathoms. In consequence of this, it can only be entered by small
boats.

The north-eastern coast of Shimushir, immediately outside the
harbour, is bounded by steep hills which terminate in perpendicular
cliffs.

The central mountain, known as Prevost’s Peak, is very high, and
in form is a well-shaped truncated cone.

On the north-west side of the peak, which rises at the southern
end of the island, there is said to be a crater.

Broughton Island or Makanruru.—This island is situated about 25
miles from the N.H. end of Urup. As seen from the S.H. it looks
like a huge mound. At its N.E. end there are perpendicular cliffs,
and at its §.W. end it slopes towards the sea.

Rebutsiribot or Chirnoi Island.—These two islands lie about 20
miles from the N.E. end of Urup. They each show a well-formed
cone. When I saw them, the more northern was apparently giving
off a little steam.

Urup Island.—This is separated from Shimushir by the Boussole
Channel, 56 miles broad, and towards the south from Iturup by
Vries Strait, which is about 138 miles wide. The island is about 58
miles long and 15 miles broad. On the Chart it is drawn as showing
along its length 11 mountains. Looked at from the N.W. it shows
a mass of mountains, many of which terminate along the coast in
formidable cliffs. Amongst them there appear to be three which
might be reckoned as volcanic cones. From one of these, which was
bare and red, steam was issuing. Towards the south the land,
although steep, is much lower; but at the southern extremity it
runs up to form a terminal mass of irregular hills.

Along the §.E. coast from the middle of the island four volcanic
cones could be counted. The central one of these, known as Atatsu-
Nobori, is remarkable for its steepness, on one side having a slope of
50° and on the other of 49°. This is the steepest volcanic cone I
have yet seen. The probability is that it is either solid or else it is
formed of very fine materials. On this eastern side of the island
there is a small harbour. To the south of this there are two peaks
known respectively as Pai-wa-nobori and Kaira-nobori.

Tttrup or Staten Island.—This is separated from Kunashiri by the
Pico or Catherine Channel, which is about 15 miles wide. This
island, which is the jargest in the Kurile group, is 185 miles long
and about 25 miles broad. It contains several large blocks of moun-
tains separated by intervening spaces of lower ground.

Commencing at the N.H. and going towards the $.W. I saw the
following mountains, which I think might be classed as volcanic
peaks.

1. Atseya-nobori and Moshisi-nayma, together with others, form
a rough black group at the N.H. end of the island. From this latter
mountain, which, when looked at from the south, shows a conical
form, much steam is being given off.

2 and 3. These mountains form two sharp peaks which le in
juxtaposition.

Prof. John Miine—A Cruise among the Kurile Islands. 345

4, 5, and 6 form the next irregular group of mountains. No. 4
is a truncated cone, No. 5 an irregular-shaped mountain (Rebunshiri-
no-bori), from which steam is being given off, No. 6 is a rough-
looking stony mountain with a dome-shaped top.

No. 7 is an irregular dome-shaped mountain slightly truncated
(Atsusa-no-bori). When looked at in a westerly direction, it is seen
to be a solitary double cone.

No. 8 is a truncated cone (Moshiri-no-bori). On the §.E. coast of
Iturup there are many bold cliffs surmounted by wooded slopes.
On Iturup there is one small harbour on the §.H. coast. And on the
N.W. several small settlements. Near Cape Ikabanots there are
also two peaks, the most northern of which is called Chiritsubo-
no-bori.

Kunashiri Island.—This island is separated from Yezo by a
channel about 8 miles wide; it is about 65 miles long and 12 miles
broad. Near its northern end a conspicuous mountain rises up, which
is known as Chacha-no-bori. This mountain shows two distinct cones,
the upper one of these is sharp and pointed, and rises above the trun-
cated summit of the lower one, which sweeps in a beautiful curve
down to the plain beneath. This mountain is easily recognized by its
superior height standing up black and sharp above all that surrounds
it. The crater, forming the summit of the lower cone out of which
the upper cone springs, is said to be filled with water, forming a
crater lake, from which the upper cone rises like an island. For
this reason the summit of the mountain is said to be inaccessible.
Near the base of this mountain, which yet gives off a little steam,
and contains deposits of sulphur, there are many hot springs.

Further south there are Suisaikenobori and Stara-na-bori, Louso-
yama, and Shimanobori. Of these Lousoyama, which, when viewed
in an H.S.H. direction, shows a truncated cone, yields sulphur, and
still gives off steam.

At the extreme 8.W. is Tatshinouse-nabori, which, when looked at
in a N.E. direction, shows on its left side the volcanic curve. This
end of the island is bounded by low greyish white cliffs.

Skotan Island or Spauberg.—This island lies about 40 miles from
the S.E. coast of Kunashiri. It is nearly circular in form, having
a diameter of about 5 miles. At a distance, when looking in a
southerly direction, it appears to be rugged, and not to have any
distinct peak, although the “China Pilot” says that from the centre
there is a mountain which is even and uniform to its summit.

Itashibai Rock, Paraku Island, Shibrton Island, Mushirika Island,
Hamkaru Kotan Island, Akiro Island, Sisio Island, Moyurure Island.
—These are flat rock-bound islets lying to the 8.W. of Skotan, and
between it and Yezo. Looked at from a distance, they appear like a
broad black line drawn upon the horizon. From the outliers which
they throw off towards each other, and also towards the adjacent
mainland, which in all respects resembles them (being flat, and with
a slope of 20 or 30 feet down to the shore), it is probable that not
only were these islands at one time continuous amongst themselves,
but were also at the same time united to the N.E. end of Yezo.

346 Prof. John Milne—A Cruise among the Kurile Islands.

Conclusion.—In looking at the Kurile Islands, we see that they
form portions of the long chain of volcanic mountains which bound
the western shores of the Pacific. If we compare them with the
group of volcanic mountains which we find to the north of them in
Kamtschatka, or with the group we find in Japan to the south, we
shall see that they are probably of more recent date. In Japan
many of the volcanos have become extinct, and since the first
outbursts of voleanic rock I think that it can be very clearly shown
that many stratified rocks have been deposited on their flanks.
Besides these old volcanos, there are in Japan many which are
comparatively recent. Looking at the more recent stratified and
volcanic rocks of Kamtschatka, it is probable that there has been a
sequence in events not unlike that which seems to be indicated in
Japan. As to what this sequence has been, I hope to explain in
another paper.

In the Kuriles, on the other hand, the volcanos are altogether
recent, and, from what I saw, sedimentary rocks are as yet without
existence.

In Japan many of the volcanos have suffered so much by denudation
that their original forms have in many cases been destroyed. In the
Kuriles, on the contrary, the greater number of the more important
mountains show a well-defined form. Their sides are covered with
ashes, and they show those slopes which indicate that they have
suffered but little since they were first built up.

Without going into a detailed description of the differences which
exist between the mountains of Japan and those of the Kuriles, it
seems evident that these latter must be regarded as being much the
younger. As a whole, they are probably contemporaneous with the
younger volcanos of Kamtschatka and Japan. They are so to speak
amongst the last of the links which together build up the volcanic
chain which bounds the shores of the West Pacific.

Altogether in the Kuriles I counted about fifty-two well-defined
peaks, and of these nine are certainly active. No doubt there are
many more—those which I have enumerated being only the moun-
tains which I saw. All these mountains, from their shape alone, I
should say are volcanos; and farther, from their shape we see that
they must be of quite recent origin.

Besides these there were many mountains of irregular forms,
which might also be classed as volcanos; and in addition to all these
there must have been many mountains, both regular and irregular,
which I had not the opportunity of observing. Altogether, in
the Kurile Islands, the area of which is reckoned at 14,865 square
kilometers, there is a collection of active and recently extinct volcanos,
as compared with the area on which they stand, equal to the groups
we find in any other volcanic district. When we look at these
mountains, we must remember that they represent so many orifices,
by which material has escaped from beneath the superficial crust of
the earth.

The work which has here been done in building up new land is,
on the face of it, exceedingly great. If, however, we compare the

Prof. John Miine—A Cruise among the Kurile Islands. 347

volcanos of the Kurile chain with those of Kamtschatka lying to the
north, or those of Japan to the south, we shall find that these
voleanos of the older countries, Kamtschatka and Japan, as land
formers, have done greater work, and raised up higher mounds above
the level of the sea than anything we find in the Kuriles.

At first sight this would seem to indicate that the forces which are
driving up material through these vents were waning in their
powers, and that when mountains lke Klutchewsk (16,500 feet) in
Kamtschatka, or Fujiyama in Japan (12,565 feet), were raised, the
volcanic energy of the West Pacific was greater than when the
smaller mountains of the Kuriles, whose elevation perhaps does not
exceed 6,000 feet, were uplifted. YVirst it must be observed that I
have here compared the mountains of the Kuriles with mountains
whose formation was probably contemporaneous; and secondly
that these latter mountains were commenced to be built up from
a land surface, whilst those of the Kuriles probably were built up
from the bottom of an ocean which is perhaps the deepest in the
world.?

Looked at in this way, although the Kuriles may not have done
so much as the more recent mountains of the groups lying to the
north and south of them in adding to the land surface of the globe,
they may represent vents from which as much material has been
ejected, and this by forces just as powerful as any of more ancient
date.

From the few specimens I collected, the rocks which have been
erupted appear to be augitic andesites. These rocks are similar to
those in Kamtschatka, Japan, Java, New Zealand, those described
by Prof. Zirkel as characteristic of a large area in the 40th parallel,
many in Hungary, and, in fact, they have a character in common
with many volcanic rocks of recent origin, which have been collected
in many parts of the world.

That we should find the same character of rock breaking out at
so many points, and these in many cases along the same volcanic
line, is extremely interesting.

In reading the description of the several islands, it must be
observed that mention of streams of lava has been omitted. The
absence of lava streams, as compared with the number you find in
a country like Iceland, is very striking, and at the same time
suggestive of the way in which these islands have been built up.

From the small number of mountains which are still giving off
steam, as compared with those which are apparently quite extinct,
it would seem that the activity of the Kurile chain is fast becoming
spent. Why a volcano should become extinct is an interesting
speculation. Probably it is that by giving off vapours its energy is
becoming exhausted. Another suggestion would be that, by building
up cones of such a height, it has gradually destroyed itself by its
own increasing hydrostatic pressure. If this were the cause, we
_ should expect to find that when the forces were no longer strong

1 The soundings made by the Challenger gave for one of the depths to the east of
the Kuriles 27,930 feet—the deepest sounding in the Pacific.

348 G. H. Kinahan—Dingle and Glengariff Grits.

enough to force up the column of lava which fills the tube they
have built by piling up ashes, they would find a point of weakness
in its sides, and parasitic cones would be formed. When we see
such parasitic cones it is not at all unlikely that they may indicate
an extinction of visible volcanic energy by means of hydrostatic
pressure.

Nature, however, when working geological changes of this de-
scription, works under variable conditions, and if it were possible
for’ us to determine with certainty the reason why the various
volcanos have become extinct, we should find that a complication of
causes had been in operation, and in no two cases ought we to
expect to find agencies which had been anything more than ap-
proximately the same.

I1.—Dine.e and GLENGARIFF Grits.
By G. H. Kinanan, M.R.1.A.,
President Royal Geological Society, Ireland.
(Read before the Royal Geol. Soc. Ireland, April 21st, 1879.)

ROM the comments on my discussion of the relations existing

between the Dingle beds and the Glengariff grits, with the
accompanying diagrammatic section (Geol. of Ireland, chap. iv. p.
52), it would appear that it isnot as clearas it might be. I therefore
propose now to explain myself more fully on this subject.

But first I would refer to the recently published memoir on “ The
Old Red Sandstone of Western Europe,” by Dr. A. Geikie (Trans.
Roy. Soc. Hdinb., vol. xxviii. p. 345), as his statements in reference
to the Old Red Sandstone of Scotland are more or less connected
with the present question. At page 3847 the author states :—
1. “My own work in the centre and South of Scotland had proved
the Old Red Sandstone to consist of two great divisions—a Lower
passing down conformably into the Upper Silurian Shales, and an
Upper graduating upwards into the Lower Carboniferous Sand-
stone, with a complete discordance between the two series.” At
page 853, when contrasting the regular uniformity of the rocks
of Silurian age with those of the Old Red Sandstone, he states
respecting the latter: 2. ‘‘ No such general uniformity of stratifica-
tion presents itself. On the contrary, with the accumulation of the
deposits in limited basins come local and often peculiar features,
whereby even contiguous tracts are distinguished from each other.
It is still possible roughly to make out with more or less clearness
the limits of these basins, etc.” These remarks, as I have shown in
a former paper, are very applicable to the Irish rocks;! as every-
where, except in South-west Ireland, the rocks similar to those called
by Dr. Geikie “Upper and Lower Old Red Sandstone” are
discordant; while everywhere the “Upper” graduates into the
Carboniferous rocks, and in different localities the Lower passes
down conformably into the Silurians. We also find great lithological

1 Geikie still retains the name Old Red Sandstone; but as he has proved a complete

discordance between the Upper and Lower, he has come to the same conclusion as
myself, and the names by which the two groups are called does not materially signify.

G. H. Kinahan—Dingle and Glengariff Grits. 349

differences in the rocks of both the Upper and the Lower Old Red
Sandstone in the various areas or basins.

Let us now return to the Dingle and Glengariff rocks. Geikie,
at page 354, divides up the rocks he classes as the Lower Old
Red Sandstone of Britain, into five great “Basins of Deposit.”
No. 4 he calls the deposit of “the Welsh Lake” Basin, and on
looking at a geological map of Great Britain and Ireland, it is
evident that the rocks the subject of this paper are some of those
accumulated in the north-west portion of this basin.

Although Griffith classed the Dingle and Glengariff rocks with the
Silurians, while Jukes classed them as Lower Old Red Sandstone, yet
both would seem to have agreed that the Dingle beds were equiva-
lents of the older portion of the Glengariff grits ;! or—as stated by
Griffith before the Society—the visible Glengariff grits, as a mass,
are higher up doubtless than the visible Dingle beds as a mass.

These observers also agreed that while the Dingle beds are capped
unconformably by the “Old Red Sandstone,’”’? the Glengariff grits
extend upwards conformably into the ‘‘Old Red Sandstone,” and
from thence up to the Coal-measures. The Dingle beds to the
westward of the promontory, near Dingle, as indicated in the
accompanying diagrammatic section, are at least 10.000 feet thick, but
eastward higher beds occur; and it is even possible, although I
believe it improbable, that nearly the whole thickness of the rocks
may be under the “Old Red Sandstone” of Sleve Mish near
Castlemaine. On the other hand, south of Dingle Bay the Glengariff
grits, as far as seen, have been estimated to be of about a similar
thickness; this being due to the upper beds occurring in that area,
while the lower 3,000 or 4,000 feet, which in the Dingle Promontory
rest on the Marine Silurians, here, although probably present, are
not exposed to view.

It is evident that a nearly east and west fault, having a downthrow
to the northward, extends along the valley of Dingle Bay, the throw
near Killorglin being about 5000 feet, as here the Coal-measures are
brought down nearly, if not quite, into juxtaposition with the Glen-
gariff grits.° The situation, in about which this Dingle Bay fault
occurs, 1s indicated in the diagrammatic section. In this section,
other faults, minor breaks and undulations, known to occur in the
country to the south, cannot be represented; the horizontal distances
however are nearly correct; that is, the distances from the centre of
Dingle Bay to those of Kenmare River and Bantry Bay. The dis-
tance from the south boundary of the “Old Red Sandstone” south
of Dingle Bay to the north boundary of the ‘“‘Old Red Sandstone”
north of the Kenmare River is about sixteen miles. In the diagram-

1 In Memoirs Geol. Survey of Ireland, Expl. Sheet 182, fm. page 10, Jukes says,
‘can interpretation ” (that of Griffith) “ which is theoretically the better of the two.”

2 Here and hereafter in this paper the Upper or Carboniferous Old Red Sandstone
will be spoken of as ‘‘ Old Red Sandstone,” while the Lower will be called ‘“‘ Glen-
gariff grits” or “ Dingle beds.”

3 Tf we consider the difference in the heights of the ground occupied by the ‘ Old
Red Sandstone” and that in which we find the Coal-measures, the latter, in depth
at the fault, ought to be lying against Glengariff grits.

300 G. H. Kinahan—Dingle and Glengariff Grits.

matic section it is shown that near Dingle there is a thickness
represented by the strata A, B, Cand D; these rocks or the major
portion of them are also found in the country to the south, but in
addition to these are found the rocks H; and upon the latter the
‘‘Old Red Sandstone ” rests conformably.

We have now to account for the fact that while the strata H were ac-
cumulating in the country south of Dingle Bay, no contemporaneous
beds were laid down in the western portion of the Dingle promontory.
From the records of the rocks it appears that for a time after the
Marine Silurians were deposited, there were successive accumulations
of matter, represented by the strata A, B, Cand D, on the whole of
the area; but after the strata D were deposited a great disturbance
took place north of the line of the valley of Dingle Bay, and the
rocks to the north of the bay, but especially to the westward, were
squeezed up, upturned, and brought under the influence of a
denudant. But at the same time, while this was taking place in
the northern portion of the area, in the country to the south, rocks
were still being successively deposited, and the strata, represented by
EH in the diagrammatic section, accumulated. How this could take
place has been fully described by Le Conte! and others, who have
made the sinking and upheaval of land their special study; it is
therefore unnecessary for me to enter into it.

But after the strata H in the south country were deposited, a
change took place in the north country, and the result of this change
was; that instead of the rocks being denuded,—on them the “Old
Red Sandstone” was deposited; as well as on the rocks in the south
country ; while over it, in the whole area, were successive accumula-
tions up to the Coal-measures. In support of this hypothesis, the
sections published by Jukes show that the ‘‘ Old Red Sandstone ” in
the country to the southward is thicker than to the northward ; also
that on the Dingle beds and the accompanying Marine Silurian it is
of unequal thicknesses, while still farther northward it gradually
becomes thinner.

At the commencement of the paper attention was directed to
Geikie’s observations as to the Scotch rocks having marked litho-
logical differences. This can be also observed in Cork and Kerry ;?
but at the same time in this area the rocks of one type nearly
invariably can be traced into the rocks of other types, while certain
peculiarities are more or less common to all; and one of the more
marked peculiarities is the presence of metalliferous strata in the
upper portion of the ‘Old Red Sandstone.”

These metalliferous strata are best developed south of Bantry Bay,
but they can be traced eastward into Waterford and Kilkenny; and
to the north they are found south and north of Kenmare river, while
further north traces are found in the Tralee and Kerry Head districts,
and to the N.E. in the counties of Limerick, Tipperary, and Clare. In

1 American Journal of Science and Art, ser. i. vol. iv. pp. 345 e¢ seg.

2 To the northward, near the margin of the area of deposition, the rocks necessarily
are of a more littoral character than to the southward, for the reasons explained by
Prof. Geikie.

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G. H. Kinahan—Dingle and Glengar

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302 G. H. Kinahan—Dingle and Glengariff Grits.

the Kerry Head and Tralee districts the “Old Red Sandstone” is
more or less conglomeratic; this is also the case near Douglas Head
in the west portion of the strip south of Dingle Bay, while eastward
thereof it gradually loses this character, and near Killarney it presents
more of the usual Cork type. The Cork type, however, changes as
the rocks are followed eastward, and in Waterford,’ Tipperary, and
Kilkenny, conglomerates are again found.

In 8.W. Kerry and W. Cork the sequence of the rocks, as laid
down by Griffith and Jukes, is as follows :—

Carboniferous Slate (6)

Vellow Sandetencion (5) greenish, grey, and yellow grits, with shale parting

Caps Ol Bea | Ceca UR eastncciar
(3) purplish and green grits, and slates, many of the
Old Red Sandstone green rocks being cupreous.
(2) red and purplish grits, gritty slates, and slates.
Glengariff grits (1)

As strata representing the groups 2, 38, 4, and 5, occur everywhere
in this area under the Carboniferous Slate, it is perfectly impossible
that in any place there can be an unconformity between the
Glengariff Grits and the Carboniferous Slates. These facts in
reference to the Kerry and Cork rocks have already been mentioned
elsewhere; it is however necessary to draw attention to them again,
on account of some misapprehension on the subject still existing.

Subsequent to the end of the Carboniferous Period, a great rupture
(besides others) took place along the line of the valley of Dingle
Bay, and further eastward in the Flesk and Blackwater valley,
which evidently was a downthrow to the northward. However, it is
readily conceivable that here, as elsewhere along great lines of dis-
turbance, a newer displacement along the same line of weakness need
not by any means have necessarily the same horizontal extent, any
more than it should have the same amount of vertical throw. This
Post-Carboniferous fault, which may have been on the same line as
an older one, has a northward downthrow, in some places of greater
magnitude than in others. Near Millstreet it seems to bring down
the Coal-measures against the Glengariff grits, but eastward of this
the throw is much less, while westward for some distance it also
decreases ; but after a time it again increases, as we proceed toward
Killorglin, where it possibly may again bring down the Coal-
measures against the Glengariff grits; but farther west it decreases.

I would refer to the fossils found in the Dingle beds and Glen-
gariff erits; as statements made in reference to them are calculated
to mislead. No officer of the Geological Survey of Ireland who
has examined the rocks in which the fossils are found has suggested
that the rocks are Coomhoola grits or Carboniferous slate. There
is no doubt as to the localities in which the fossils were found.
Some of them are far from being obscure.

In the Dingle beds, north of Dingle Bay, there are more or less
obscure markings in various places that may be due to either land

1 T suspect that some of the Waterford rocks, at present supposed to be “ Old Red
Sandstone,” will eventually have to be included among the Dingle beds.

W. J. McGee—Geology of the Mississippi Valley. 309

plants or fucoid remains. South of the Bay, at Valencia Lighthouse,
are tracks, suggested by Mr. W. Hellier Baily to be those of a Crusta-
cean. They may, however, be a track made by a fish, as I have
seen somewhat similar tracks made by the grey gurnets on the sand
floor of their tank at the Crystal Palace, Sydenham. ‘The plants at
Glanroe, west of Coomasahara, are well preserved and are perfectly
distinct, and Mr. Baily’s diagrams show that some of them are
indistinguishable from those called Sagenaria Veltheimiana, found in
the “Old Red Sandstone” at Tallow Bridge, co. Waterford, and at
Kiltorcan, co. Kilkenny.

Nore in Press.—Since this paper was read Mr. Baily has found
similar “ Kiltorcan type” plants in other localities in the “Glen-
gariff grits.”

III].—Nores on THE SurFACE GEOLOGY oF A Part oF THE
Mississtper VALLEY.

By W. J. McGze, etc., etc.,
of Farley, lowa.

SOMEWHAT detailed description of the parece deposits of
North-eastern Iowa, with references to observations of a
similar nature in other localities. and some general conclusions, was
read by the author before the American Association at its St. Louis
meeting, and is printed in the Proceedings for 1878.1 Since the
preparation of that paper additional observations have been made in
the same region; and some other localities, mainly in the State of
Illinois, have been visited. A general section has been made across
the northern portion of this State, from the Mississippi on the west
to Lake Michigan on the east, at about 42° N. lat. A like section
has been made the greater part of the length of the State from north
to south, at about long. 89° W. from Greenwich. The data employed
in the construction of these sections were chiefly derived from
personal observations on the surface, in channels of erosion, and in
artificial excavations; but use has also been made of the observa-
tions of other persons, collected by means of extensive inquiries
from, and correspondence with, local geologists and others. In Iowa,
a formation, believed to be distinct from any previously described,
has been discovered, and a rather anomalous distribution of the
member considered to be the equivalent of the loess has been brought
to light. Several dsar, which seem to be homologous with those of
Scandinavia, have also been traced over some distance.

Advantage has been taken of the wide circulation of the Grono-
GICAL MaGazInE among workers in this department of geology, to
lay before them a brief réswmé of these observations, in advance of
any more comprehensive publication. The division of the superficial
deposits into separate formations or members, adopted in the paper
just mentioned, will be adhered to, but the description of each will
be so modified as to apply to the wider area since examined ; and

1 The full title of the paper is, ‘‘ On the Complete Series of Superficial Forma-
tions in North-eastern Iowa, by W. J. McGee.”

DECADE II.—VOL. VI.—NO. VIII, 23

304 W. J. McGee—Geology of the Mississippi Valley.

in other respects, only new matter will be presented, collated since
the meeting of the Association.

General features—The complete series of surface formations in
this region consists of six distinct members, though it is unusual to
find all in the same section. Any one or more may be absent, and
the sixth, or lowest, is but seldom seen. Some of these members
may be subdivided into two or more seemingly distinct portions in
particular sections where a considerable thickness is exposed; but
none of these subdivisions are found to remain constant over large
areas. The individuality of each of the six principal members,
however, is preserved over a large territory. They may be recog-
nized, indeed, in descriptions of drift phenomena in any glaciated
region. It is believed, hence, that only confusion would result from
any further subdivision of the drift deposits of this part of the
Mississippi Valley ; and it is also believed that the grouping together
of any two or more of these members will only tend to confuse the
mind in regard to the agencies to which they probably owe their
origin.

For reasons which cannot be fully set forth in a descriptive paper,
the writer is inclined to provisionally hold that these six members
were formed during three distinct epochs, probably separated by
considerable intervals. It is believed, also, that all are due either
directly or indirectly to glacial action, and, hence, that they afford
evidence of three separate glaciers. These epochs, and their corre-
sponding formations, are represented in the accompanying table, in
their natural order. (See opposite page.)

There can be no doubt that the advantages to be derived from a
systematic classification of the surface deposits are relatively as
great as those resulting from the like division of the older rocks;
though it must be admitted that the arbitrary divisions are not
always as readily recognizable. That classification suggested by
the deposits of the Mississippi Valley, and which is here offered,
may not, however, be generally applicable without considerable
modification—though the principal divisions have already been
recognized by geologists over most of the glaciated portions of the
northern hemisphere.

The recent fluviatile deposits are disregarded in this classification.
It will, perhaps, be unnecessary to remind the reader that this is by
no means a prominent class of formations on the Western prairies,
and that their relations cannot be well studied.

Member number one-—This member is usually confined to the
vicinity of the larger water-courses, and their tributaries for a few
miles from their mouths. It very frequently attains a thickness of
20 or 30 feet, and sometimes much more, along the Mississippi and
its larger tributaries; but it diminishes in thickness as the river is
receded from. If the valley does not reach the sedimentary strata,
but is wholly eroded in the drift materials, there is usually a constant
diminution in the thickness of the member until the general upland
level is reached, when it disappears. On the contrary, if the valley
has a single broad flood plain, bounded by high hills, extending up

W. J. McGee—Geology of the Mississippi Valley. 3090

CLASSIFICATION OF THE GuAcIAL Dzpostrs or THE MississrpPr VALLEY.

Epocus. MEMBERS.

A whitish-yellow, loess-like clay, unstrati-

pines Nos Ts fied, free from gravel, sand, and boulders.

9. Very pebbly and gravelly clay, with sand,

Memser No. and small rounded and water-worn boulders.

EPOCH III.

Coarse yellowish clay, with sand, gravel,
pebbles, and large angular, subangular, and
Member No. 3. | rounded boulders, sometimes striated. It is
sometimes imperfectly stratified, and contains
lumps of blue clay.

A blue clay, often fine and clean, but some-
times with sand, gravel, and boulders, many
striated. It frequently contains wood and
other organic substances.

Member No. 4.

EPOCH II.

Dirty-yellow or brownish clay or sand,
Memser No. 5. | with much gravel, pebbles, and boulders both
rounded and flattened, and often striated.

Deep-brown gravel or clay, with yellow
EPOCH I. | Memper No. 6, | streaks; cemented into a ferruginous con-
glomerate where sandy and pebbly.

to the general level, as is sometimes the case, this member may be
found only on the brows of the hills, having been removed from
their bases by erosion, and evidently never deposited on their
summits.

Stratification has never been observed in this member, except
where it has been re-arranged by fluviatile agencies, and mixed with
sand and gravel, as it frequently is in ‘‘ bottoms.” It has the “vertical
internal structure”’ described by Pumpelly, which characterizes the
loess of China, and vertical cracks and fissures form in it during
seasons of drought. In consequence it washes easily, especially in
a vertical direction, and surfaces covered by it are characterized by
great numbers of steep-sided and narrow, irregularly ramifying
ravines. In this respect, as in many others, it strikingly resembles
the loess of the Missouri Valley,—the “bluff-deposit” of several
American geologists. Indeed, it has been traced by the writer, with
no important breaks, from the Missouri, where characteristically
developed, into the most north-easterly portions of Iowa; and at
no place could any essential or well-defined distinction be drawn
between successive sections. True, the materials are not so finely

306 W. J. McGee—Geology of the Mississippi Valley.

comminuted in the latter region, and there is a greater admixture of,
foreign substances; and in consequence of this and of its greater
tenuity, it is much less compact than the true loess. Still, banks
25 feet high and sloping not more than 10° from the vertical, have
stood for years with but little change along the Wapsipinnecon
river, in Jones county, Iowa; and steps cut in banks nearly as steep
may be used for several consecutive seasons, just as they have been
seen to be by the writer in Western Iowa and in Dakota and Nebraska
—the loess region of America, par excellence. The greater the thick-
ness, too, the more striking is the resemblance to the typical loess.
The calcareous concretions characteristic of the loess have not been
seen in Northern Iowa and Illinois, however. nor are the tubular
rootlet-like pores, lined with carbonate of lime, on which Baron von
Richthofen lays so much stress, very clearly defined. It would seem,
though, that this member, wherever found, is a somewhat modified
but probably equivalent representative of the loess proper.

As previously intimated, however, its distribution sometimes
seems altogether anomalous. In passing from north to south over
the western half of Dubuque county, five or six “divides” are
crossed. ‘These seem to be quite independent of the general
drainage system, as they all extend in very nearly the same direction
(about S. 75° H.), and are in many places cut by the nearly trans-
verse water-ways and valleys of erosion. Their width is very
irregular, but seldom exceeds a mile or two; and they are generally
much broken and cut up by ravines. Their surfaces consist of the
member number one of this paper. Its depth is not great, very
rarely exceeding 20 or 30 feet; and it thins out and finally dis-
appears on approaching the lower level of the imtervening areas,
just as it usually does in approaching the high levels bounding
valleys covered by it. These broad intervening valleys may have
a width of 4 or 5 miles, and their surfaces are composed of un-
modified glacial drift, with exposed boulders. There is no evidence
that these areas were ever overspread by the loess-like deposit, and
that this was subsequently removed by erosion—indeed, in many
instances, the lines of drainage are such as to show conclusively that
this could not have been the case.

The same member is often found, also, covering the summits of
kames, which, like the divides, overlook the country for miles
around. ‘This has been observed not only in Jowa, but in Illinois,
near Clarendon Hills, 20 miles west of Chicago, on nearly the
highest land in the State, and in Macon, Christian, Shelby, and
Fayette counties, near the southern point of the State, where the
surface of the kames graduates directly into the true loess. This
will be recurred to later.

The anomalous fact is that the loess-like member forms the upper
surface of hills and ridges rismg 40 or 50, or even more, feet above
the general level, over which the same materials were never deposited.

Member number two.—The materials composing this member are |
largely coarse sand, gravel, and well-rounded and water-worn
pebbles, with more or less of clay. The pebbles are both local

W. J. McGee—Geology of the Mississippi Valley. 357

and erratic, and very rarely, if ever, striated. The materials are
frequently stratified and assorted, when the member is thick. Some-
times the overlying formation graduates into it, but usually there is
a clear line of demarcation. More frequently, indeed generally,
it graduates into the subjacent member. Hence its thickness is
difficult to determine; but from one to five feet may be taken as
the most common variations.

Though found to almost invariably accompany member number
one in North-eastern Iowa, where there are large quantities of chert,
which forms a prominent material in the pebbly member, it has
been found absent in many localities. It can, therefore, scarcely
be considered a constant feature in the superficial deposits; but its
occurrence is much too general to allow of its being disregarded.
It does not always present a common aspect. For instance, in Jersey
county, Illinois, it consists of nearly pure sand, often accumulated
in long strips or bars. Here the true loess of the Missouri covers it.

Kames and asar are composed in a large part of this member,
considerably thickened. Like member number one, it frequently
exists at a higher level than any of the surrounding deposits of un-
modified drift. If these two could be mingled, the mixture would
contain about as much gravel and sand as, though fewer boulders
than, the ordinary glacial drift. They are supposed to have had a
common origin ; and from their anomalous distribution the conclusion
seems inevitable that they were, at least in some places, deposited
before the complete disappearance of the ice of the last glacier.

Member number three.—TVhis forms the natural surface over most
of the region described. It is simply unmodified or slightly modified
glacial drift, and is distinguished by the same features here as else-
where. Its colour is yellowish to light brown, usually a dirty
yellow. Its materials are sometimes imperfectly assorted and strati-
fied, with intercalated layers and lenticular patches of gravel and
sand, but are commonly wholly devoid of arrangement. Boulders
of the Archzan rocks from far to the northward (few have travelled
less than 200 miles, and many much more) are abundant and
quite large, frequently reaching a diameter of 8, 10, or even
12 feet; and a few are striated. In the visually boundless, and
almost perfectly level prairies of Central Illinois, the boulders are
but rarely found on the surface, though quite as frequently en-
countered in excavating wells as in Iowa. Over these vast cham-
paigns there seems to have been a greater assortment and vertical
distribution of materials, in the order of their fineness, than is
usually observed. Granite is the predominating material of the
boulders, but quartzites and other classes of rocks are repre-
sented. Hornblendic rocks are rare in this member in North-
eastern Iowa, but are frequently observed in some other localities.
Lumps and bands of blue clay, easily identified with the subjacent
member, are a common feature. The pebbles and gravel are made
up both of northern and local rocks. In the parts of Iowa and
Illinois in which the Niagara Limestone (the Mississippi Valley
equivalent of the Wenlock group) crops out, there are great quan-

308 W. J. McGec—Geology of the Mississippi Valley.

tities of chert, or hornstone, both in perfect nodules and in
splintered fragments, mingled with the drift.

The average thickness of this member may be roughly stated at
20 or 25 feet, though it is very variable. Its base is far from being
horizontal, but is to a remarkable degree conformable with its
surface; and the same may be said of the subjacent member.
Before the deposit of either, the surface of the sedimentary rocks
had been eroded into valleys and ravines, and a like process took
place subsequent to the deposit of each; and the recent contours
correspond closely with their pre-glacial prototypes.

Member number three is by far the most continuous and constant
over wide areas of any of the superficial deposits. It is only inter-
rupted by occasional ridges and roches moutonnées where the older
rocks are exposed, and in a few valleys where removed by erosion.
It does not, extend as far southward as the subjacent member,
however. On the meridian of 89° W. it was only traced to about
lat. 59° 30’, while the blue clay extends nearly or quite a degree
further. Along its southerly margin it gives place to a deposit
usually spoken of as littoral or lacustral (but which is probably
only a considerably modified glacial drift); and only the underlying
formation is usually considered to be of northern origin. Further
to the northward, where number three is well developed, it is
universally recognized as glacial drift, but is seldom distinguished
from the next member. The writer has traced this so-called
lacustral deposit of the southern drift regions northward into the
region of member number three, and found the one to graduate
into the other; the relative position of the next member mean-
while remaining constant.

Member number four.—The colour of this member varies from
bluish white to black; the prevailing colour, where not mentioned,
being deep blue. This colour is due to the presence of black
oxide of iron. In North-eastern Iowa it rarely contains boulders or
pebbles, though in other localities they have been found quite
abundant. Such as are found in that region are usually of the
hornblendic rocks, syenite, diorite, hornblende schist, etc. Granite,
which characterizes the superincumbent member, is rarely seen in it.
This distinction has not been observed in other localities, and is
probably only local. A much larger proportion of the boulders is
striated than in member number three. ‘The pebbles are both local
and erratic, and there are sometimes intermingled fragments of
ferruginous conglomerate and lumps of dark brown granular clay,
easily identified with member number six. ‘The materials are some-
times imperfectly stratified, having intercalated beds and bands of
sand, gravel, or differently coloured clay, often lenticular in form.
Frequently the clay is very fine and clean, affording an excellent pipe
or potter’s clay, and exhibiting a columnar and jointed structure
when dry. Parts of it are sometimes so indurated and laminated as
to resemble shale in structure and consistency; and fragments of
this shale are occasionally so highly bituminous as to be imperfectly
combustible. This is most frequently the case where quantities of

W. J. McGee—Geology of the Mississippi Valley. 309

vegetable matter are found associated. It is not very uncommon
indeed for the vegetation itself to be converted into lignite. Though
there is generally a thin stratum only of this member so highly
bituminous, it is not very rare to find the whole mass so rich in
carbon, nitrogen, etc., as to act as an excellent fertilizer.

It is very common to find wood in this member, which may be
either in the shape of small fragments, or of trunks and branches of
trees. These may be sound, and so slightly mineralized as to burn
readily, or they may be almost wholly decomposed. The species
represented are usually identical with those now found on the
surface in the same region; but there is a much larger proportion of
coniferous trees in the drift than growing upon the present surface.
Endogenous plants of undetermined relations have also been
observed, as well as cones, leaves, etc., though these are so indiffer-
ently preserved. and in so fragile a matrix, that they cannot be
successfully studied. It is impossible to get good specimens into the
hands of paleeo-botanists. These remains are very abundant near
Otterville, Jersey county, Illinois, where the structure containing
them (and which is largely made up of vegetable humus, with many
logs and fragments of wood and bark) rests upon the Keokuk Lime-
stone (the third formation above the base of the Sub-Carboniferous,
noted for its geodes), and is overlaid by (1) 20 feet of blue clay,
‘with a few boulders, and (2) 20 feet of brown clay, with a little
gravel and a few boulders near its base. Coniferous trees are not
now found in the vicinity. Peat is also found occasionally, but is
usually quite metamorphosed. Sometimes, however, its mass is well
preserved, as in the case of a stratum a foot in thickness just 100
feet below the surface in Mendota, Illinois, passed through in boring a
well. Many specimens of well-preserved Sphagnum were obtained, and
several, mounted on slides, have been placed in the hands of the writer.

Bones, and rarely shells, are reported from this member. None of
the latter to which any value could be attached have been examined.
A cranium of Bison latifrons, and an abnormally developed molar
belonging to some member of the Ox family, which cannot
be identified, have been found in place in this formation. Two
molars of Equus complicatus, Leidy (perhaps E. major, De Kay), are
believed to be from this member, but both were found where the
total thickness of the drift was limited, and the divisions not well
marked. Charred wood has been observed in several instances.

With some reservation it may be said that these organic remains
occur indiscriminately in all parts of the member. When it is
wholly unstratified, however, they are most commonly found only
at or near its surface, and occasionally extending slightly into the
superimposed deposit. This is quite general beyond the southerly
limit of member number three. Thus in Ohio, the ‘forest bed ”
(as it was designated by Dr. Newberry) occurs above the blue clay,
and seems to be distinct from it. The colouration of the clay of this
member is suspected to be due to the action of the carbonic acid set
free in the decomposition of the vegetation of the ancient surface, in
liberating the iron from the rocks and earths, and permitting it to

360 W. J. McGee—Geology of the Mississippi Valley.

combine with the oxygen of the air. Even to-day the clay is some-
times so fully charged with the gases of organic decomposition that
foul smells are emitted for years into wells penetrating it; and in not
a few instances the water has been rendered wholly unfit for potable
or culinary uses. In several cases, indeed, it has been suspected
that sickness was due to the use of water collected from this member.

Ferruginous concretions are common in this member, and thin
layers of bog-ore are occasionally found. Cylindrical concretions of
clay, stained and partially cemented by sesquioxide of iron, frequently
occur. ‘They exhibit a concentric structure when viewed in cross-
section, and are gnarled and knotted like twigs and rootlets. They
may be hollow, or may yet contain the remains of the woody
substances around which they were originally formed.

Member number four is believed to be the equivalent of the
Lower Till of the British geologists, and probably of the Canadian
Evie clay of Sir William Logan. It is observed to the best advan-
tage near its southern limits. Further to the northward the later
glacier has sometimes removed it entirely, and often mingled its
materials in inextricable confusion. Still, its distinctness from the
later drift is nearly always very strongly marked. In one instance
only have their positions been observed to be reversed, and this in a
valley (of the Illinois River, at Aurora, Illinois), and very probably
by post-glacial agencies. Where found, its thickness usually
averages about half that of the whole series of surface deposits; but
it is absent on rocky divides, and sometimes in valleys of erosion.
In view of their extensive commingling, and sometimes reversal of
position, it is scarcely deemed expedient to distinguish it from the
forest bed recognized by Dr. Newberry in Ohio, and by both British
_ and Continental geologists on the other (European) side of the
Atlantic.

Member number five-—This formation is usually thin, generally
ranging from one to five or six feet, but occasionally expanding to
a much greater magnitude. Its principal constituents are coarse
sand, gravel, pebbles and small boulders, and coarse clay ; and either
may predominate. The character of the pebbles is the same as in
the overlying member, except that there is a larger proportion of
local materials. Ground and striated pebbles are more frequently
found in this than in any other member.

This member almost invariably accompanies the last, and usually
rests on the older rocks. It is of considerable economic importance,
as, within the frequently stratified and laminated sand and gravel
composing it, an abundance of good water is usually found. It
sometimes graduates into the overlying member. No well-marked
distinction between the two can be observed, except that of colour—
the lower having generally a dirty yellow or yellowish brown
colour. If the colouration of the upper member is due to the
agencies suggested, it is a little difficult to see why the process
should have stopped on reaching the more pebbly and stratified clays.

Member number six.—This basal member is very unfavourably
situated for observation, and is so often absent that its occur-

W. J. McGee—Geology of the Mississippi Valley. 361

rence is the exception rather than the rule. It seldom exceeds
three or four feet in thickness, and often only fills the crevices in
the rocks. It is rarely stratified, but often exhibits false bedding
and lamination in lines conformable with its irregular base. It
usually consists of a deep brown clay, quite hard when wet, and
resisting erosion very perfectly, but crumbling into minute angular
fragments when dried. When a freshly exposed lump of it is
broken, the surfaces are found to have a granular or crystalline
appearance, like that of granite. This structure renders the lumps
of it found in the blue clay easily recognizable. Though the colour
of the greater part of it is due to the presence of the hydrous
sesquioxide of iron, it is sometimes interspersed with specks and
streaks of a light yellow colour.

It is sometimes sandy, pebbly, and gravelly, and its pebbles are
both local and northern, rarely striated. When sandy or gravelly,
the materials have been generally cemented into a puddingstone by
means of the infiltration of ferriferous solutions and the deposit of
limonite. Fragments of this conglomerate are found scattered
through all the upper members. The pebbles in the conglomerate,
as well as those in the clay, where not cemented, are usually stained
externally, and for a little distance beneath the surface, by ferric
oxides. Good exposures of this member are very rare. Consider-
able quantities of the conglomerate (these of very fine materials)
are seen at Rockville, Iowa.- With a little experience and some
care this member is readily distinguishable from the superimposed
deposit; and the one never graduates into the other.

Disintegrated Materials—None of these formations should be
confounded with a fundamentally distinct one, due to the secular
disintegration and chemical decomposition of the sedimentary or
crystalline rocks by atmospheric agencies. The importance of these
processes are strongly insisted upon by Prof. Raphael Pumpelly ;*
and the occurrence of such a formation over a great part of the
Level Region of Wisconsin has been pointed out by Prof. J. D.
Whitney.” Accumulations of this character, often 20 or 30 feet
thick, are well known to the writer as occurring over the Niagara
Limestone along the western border of the Wisconsin “ driftless
region.” They are distinguished by great numbers of nodules of
chert, often fractured by internal expansion, in the positions in
which they were formed in the rock, by the presence of siliceous
fossils, mainly corals and crinoid stems, with a few bivalves, and by
the absence of erratics. Two miles north of. Farley, Iowa, such a
bed reaches a thickness of 25 feet, and is overlain by true glacial
drift. It bears no evidence of having been disturbed since the
decomposition of the rock.®

1 In a paper read before the National Academy of Science, April 10th, 1878.
See also Am. Journ. Sci., iii., vol. xvii., Feb. 1879, p. 138, e¢ seq.

2 “ Geology of Wisconsin,” 1853, vol. i. p. 121.

3 This is important as bearing on the question whether a Continental glacier
removes all of the lighter materials, and lays bare the rocks over which it passes.

(Zo be concluded in our next Number.)

362 Prof. T. G. Bonney—Ligurian and Tuscan Serpentines.

IV.—Nores on some Ligurian anp Tuscan SERPENTINES.
By Professor T. G. Bonney, M.A., F.R.S., etc.

OTWITHSTANDING the distinct assertion by more than one
geologist’ of the intrusive character of the serpentines of these
districts, some uncertainty seems to exist on this point and still
more as to the original character of the rock. Hence the result of
my examination of a few localities, and of my subsequent studies of
the rocks then obtained, may be of sufficient interest to justify
publication.

I commence with the serpentine on the sea-shore to the west of
Genoa. Quitting that town by the road to Pegli, serpentine first
occurs a little west of Conegliano, where a small boss forms a head-
land by the sea. The rock is of a dull greenish colour, and is so
greatly decomposed as to be worthless for microscopic examination.
Still, the general aspect, form, jointing, etc., are quite those of the
Lizard serpentine. I have little doubt that the mass is intrusive,
though buildings, etc., prevented me from finding an actual junction
with the neighbouring sedimentary rock. This can be seen within
a yard of the serpentine. It is an indurated shale of schistose
aspect, much shattered, and traversed by calcareous veins, looking
in short as if it had been affected by the intrusion of an igneous
rock. Beyond Pegli, serpentine is again found on the sea-shore.
Here (just after passing some houses) is a considerable exposure of
serpentinous breccia, which can be studied in the cliff and in some
small skerries. This at first sight closely resembles an agglomerate,
being composed of fragments of serpentine, with some of gabbro,
and a few of a dark slaty rock in an ashy-looking paste, reminding
me by its aspect of one of the “necks” so common on the Fifeshire
coast. As I have long been anxious to ascertain whether serpentine
ever occurs as a truly eruptive rock,—z.e. as an altered lava flow,
tuff or agglomerate,—I examined this section with great care, but
was unable in the field to come to a positive conclusion. The gabbro
1s probably the latest rock, being intrusive in the breccia, and, as I
think, in the serpentine also, though the latter point was not quite
so clear to me as the former.

The next two headlands to the west mainly consist of gabbro.
This rock varies from a fine-grained variety of a dark greenish to
bluish colour—at a short distance hard to distinguish from the
serpentine—to a coarse variety composed of a white saussuritic
mineral and a dark green or almost black diallage or augite. The
latter rock much resembles some of the gabbros on the Cornish coast,
except that the pyroxenic mineral is less metallic and the “‘saussurite”
less abundant. It includes one or two fragments of a slaty rock
of rather serpentinous aspect. I have examined a slide of the
more compact gabbro. At a glance it is seen to have been highly
altered. ‘The ground-mass consists of a rather confused mixture of
a clear and sometimes granular mineral, and a pale, rather fibrous

1 D’Achiardi, vol. ii. p. 180. Stoppani, Corso di Geologia, iii. § 701. Jervis,
Quart. Journ. Geol. Soc. vol. xvi, p. 480,

Prof. T. G. Bonney—Ligurian and Tuscan Serpentines. 363

mineral, which is probably a variety of hornblende. In these are
several rather large grains of decomposed ilmenite, some grains
resembling a decomposed diallage, and a considerable quantity of a
hornblendic mineral, showing here and there distinctly the cleavage
of hornblende; in other parts in rather fibrous or filmy patches,
many of which show a peculiar deep blue colour. On testing the
last for dichroism, we observe them change from this colour to
a pale yellowish olive, and find that with ordinary transmitted light
the latter tint is seen in sections cut approximately parallel to a
basal plane, while the blue colour appears to belong to most sections
cut at right angles to it. This mineral appears, from its association
and mode of occurrence, to be of secondary formation, as the horn- _
blendic constituent usually is in agabbro. There can be little doubt
it is glaucophane.! A grain or two of epidote, and various minute
decomposition products, are present. Though no felspar is now to
be distinguished, I think the general habit and structure of the rock
justifies us in assuming that this mineral was formerly present, and
we may accordingly call it a glaucophane-gabbro.

As regards the brecciated rock mentioned above, the impossibility
of obtaining a thin slice makes it difficult to arrive at a conclusion.
The grains are not markedly angular or scoriaceous in aspect. Ilmenite,
glaucophane, and a pyroxenic mineral can be recognized, with pos-
sibly bits of serpentine and of a hornblendic or chloritic rock. There
is nothing about it specially suggestive of a volcanic origin; and if it
be an agglomerate, I feel certain it is connected with the focus of the
gabbro, not of the serpentine.

The included slaty rock gives indications of fragmental origin, but
has been much altered, recalling a little some of the ashy rocks of
the North Wales Lower Silurian. At present, however, it is chiefly
composed of fibrous hornblendic minerals, among which is glauco-
phane, and granular earthy minerals, ferrite, ete. A grain of decom-
posed diallage (?), associated with glaucophane, is present.

Beyond this place we find on the shore of the Bay, near Pra, a bold
eminence (crowned by an old fort) rising above the sands, and now
isolated by a railway cutting. It is composed of a brecciated serpen-
tine; the fragments, angular and varying from less than an inch
to a foot in diameter, are cemented by a whitish mineral, which
appears to be sometimes steatite, sometimes calcite or aragonite ; the
whole mass is in a very decomposed condition, but it appeared to me
certain that it had been brecciated in situ.

To the west of this spot the shore becomes for a while flat and sandy.
The serpentine obviously extends inland for a considerable distance,
but as all that was visible appeared to be much decomposed, and
there were no signs of quarries, I did not quit the coast. Even

1 An aluminous variety of hornblende; it has been found at Zermatt (see Dana,
Text-Book of Mineralogy, p. 277), and at Syra (Zeitsch. deutsch. geol. Ges. Bd.
xxviii. heft 2, p. 248). For the above determination, and the opportunity of com-
paring specimens, I have to thank Mr. T. Davies, F.G.S., of the British Museum,
to whom, as not seldom before, I had recourse when in perplexity as to the name of
the mineral.

364 Prof. T. G. Bonney—Ligurian and Tuscan Serpentines.

here I was not able to obtain any good specimens from rocks in situ.
The shore, however, especially about Pegli, is strewn with small
boulders and pebbles of dark green serpentine, which have probably
been brought from inland by the Varenna torrent.

I observed two varieties: one a very dark green, nearly black,
rock, with numerous crystals of bronzite, very like the black
serpentine of Cadgwith ; the other rather harder and almost free from
included crystals. The latter did not seem likely to offer anything
of interest for the microscope, and I already possessed a slide cut
from a rock closely corresponding with the other; so that, as these
specimens are not in situ, I have not investigated them microscopically ;
indeed, I feel justified, from their general identity in appearance
with the serpentines of Cadgwith! and Colmonell,? in claiming for
them a similar origin, without further examination.

The railway from Genoa to Spezzia traverses a large mass of
serpentine, which forms the coast-line for several miles. It is first
seen at Framura, and extends as far as Bonasola, being much decom-
posed, and exhibiting in places a curious subspheroidal structure. In
colour it is sometimes a dull rusty red, sometimes greenish. Just
south of the latter place occurs a considerable mass of coarse gabbro,
composed evidently of “saussurite” and a greenish pyroxenic con-
stituent. Serpentine is exposed along the coast, and obviously extends
far inland up to Levanto and on to Monterosso. Just north of that
village it comes to an end; and on emerging from a tunnel we find
at the station a dark coloured rock, which is now rather schistose
looking, and greatly crumpled and crushed, but appears to have
been originally a shale with irregular stony bands or concretions.

After crossing this section in the train I returned to Levanto
(where I had observed quarries), in order to examine the serpentine
more Closely. From this place the serpentine extends a considerable
distance inland. Just north of the village are numerous small pits,
and excellent specimens of the rock may be obtained. There are
two varieties : one, the commoner, a purplish or brownish black rock,
veined occasionally with dull green, and with crystalline folia of
glittering bronzite—very similar to the rock already described ; the
other, of a more granular texture and rougher fracture, also dis-
tinctly “ tougher” under the hammer, rather greener in colour, with
a less metallic lustre on the included mineral. South of the village
is also serpentine. The first rock which is exposed on the shore is a
breccia (the fragments resembling the former of the above serpen-
tines and just beyond it is a great dyke (not less than seven yards
wide) of very coarse gabbro. The gabbro is rather decomposed and
consists of ‘‘saussurite”’ and diallage—the former decidedly pre-
dominating, and the crystals of the latter often 1 inch and sometimes
2 inches in diameter. Beyond this is more serpentine.

Magnificent quarried blocks of beautiful brecciated serpentine
were lying near the railway awaiting shipment. On inquiry, I
found the quarries were some four or five miles distant among the

1 Quart. Journ. Geol. Soc. vol. xxxiii. p. 890.
2 Quart. Journ. Geol. Soc. vol. xxxiv. p. 770.

Prof. T. G. Bonney—Ligurian and Tuscan Serpentines. 365

mountains; so I procured a guide, and set off to visit them. The
road passed above the quarries already mentioned, and wound round
the upper part of the headland north of Levanto, till it turned up
the ravine which descends on Bonasola. The country is for the
most part wild and uncultivated—a waste of serpentine crags and
boulders, thinly overgrown by brushwood, myrtles, and scattered
pines. The serpentine is often very rotten, but masses also occur where
the rock is well preserved. In general character it resembles the
Lizard serpentine ; joints are frequent and irregular, but sharp, often
coated with white steatite; the outer surface turns brown in weather-
ing, and often becomes rough. In one place the weathered rock
exhibited a fairly perfect spheroidal structure, which, so far as my
experience goes, is not common in serpentine. About a mile below
the first quarry I noted a mass of altered sedimentary rock, six or
seven yards long, apparently included in the serpentine. It is of a
claret-red colour, is rather harder than calcite, and is evidently
an indurated argillaceous rock. A coarse gabbro of the usual
character occurs some distance further on. Apparently it is intru-
sive in the serpentine, but both are so rotten that it is not easy to
ascertain their relations.

The first quarry is high up in the mountains, probably not less
than 800 feet above the sea, and the surrounding summits rise some
hundreds of feet higher, all being serpentine. This quarry affords
a good opportunity of examining the breccia, as it is some forty
yards long and perhaps twelve deep. The beautiful structure and
colour is easily brought out by dashing a little water on the surface.
There is another quarry about ten minutes’ walk higher up, in
which a similar rock occurs, and there are two or three more in the
vicinity, so that there must be a considerable tract of this breccia.
The result of my examinations, both in the quarry and of the great
blocks at Levanto (which were hardly less instructive), may be thus
summed up). The serpentine is of the ordinary type, but a red
variety is as common, or perhaps commoner than the dark green.
The cementing material is crystalline calcite. The rock is evidently
not an agglomerate, but has been brecciated in situ. For example,
one block might be quarried which would be a mass of serpentine,
only traversed by a few cracks which had been filled up by infil-
trated calcite. Another would show fragments smaller, and some-
times displaced a little, the calcite being more abundant, and the
spaces occupied by it larger. Another would give no clue to its
origin, but would be simply a breccia of fragments of serpentine
cemented by calcite, which would now and then seem to form
almost half the rock. Parts exhibit an intimate mixture of pulverized
serpentine and calcite, and here and there are filmy patches of
a serpentinous mineral. Yet every gradation, from the almost un-
broken rock to this complete “smash,” may be traced. One face of
rock in the lower quarry exhibited it perfectly in a space of about
four yards.

I have examined microscopically slides cut respectively from a
specimen greatly brecciated and from one merely veined with calcite.

366 Prof. T. G. Bonney—Ligurian and Tuscan Serpentines.

They fully confirm the opinions expressed above, and from the
appearance I should conjecture the brecciation took place when the
rock had become a serpentine. In one there is part of a vein (?)
containing a pale feebly dichroic variety of hornblende and an
associated mineral more like an altered enstatite; probably they are
of secondary origin. With the calcite a little dolomite, I believe, is
intercrystallized.

We have then here a mass of ordinary serpentine which has been
crushed into a breccia in sitw and consolidated again by infiltration of
calcite. Any one who has examined serpentine much in the field
will remember that its sharp irregular jointing and brittle nature
would cause it to crush more readily perhaps than most other rocks.
The whole of the hilly district bordering the Riveria di Levante has
been greatly disturbed, and its rocks are often much contorted.
During one of these disturbances no doubt the crushing took place.
At that time limestones, which still predominate among the sedi-
mentary rocks around this serpentine massif, doubtless extended
above it, and the water which percolated downwards from them
while they were undergoing denudation deposited the CaCO, with
which it was charged in the fissures of the subjacent rock. ‘This has
now been exposed to view, all trace of the once overlying rock
having disappeared."

Besides the above breccia, I have examined microscopically the two
varieties of serpentine, described above, from Levanto. The slide
from the more granular rock (with crossing Nicols) is seen to consist
chiefly of very characteristic olivine grains, separated by threads (of
variable thickness) of serpentine, about equal quantities of the two
minerals being present. There are the usual clots of opacite. In short,
the appearance of the ground-mass of the slide is so similar to what
I have already described in a Cornish serpentine,” that repetition is
needless. Enstatite and augite are both present, as I have proved
by optical tests, etc., and perhaps also a little diallage. I think
the first mineral rather predominates, but there are difficulties in
determining the crystalline system of some of the grains. Endo-
morphs of opacite are rather commoner than is usual in the enstatite.
There is a little picotite. The other and compact variety exhibits a
more complete conversion into serpentine. No olivine remains to show
chromatic polarization, though here and there a grain is still doubly
refracting. In this also there is (as might be expected) more
opacite. It often forms continuous strings, is more or less present
in the grains (formerly olivine), being either disseminated through-
out them, or in bands towards the exterior. Diallage and enstatite

are both present, the latter being surrounded by a border of a serpen-
' tinous mineral, into which the planes of principal cleavage are con-
tinued, and are often picked out by thin lines of opacite. The cleavages

1 T should perhaps state that there is nothing to favour the idea of this crushing
having been sudden, or associated with any exceptional amount of heat. It may have
been the result of long-eontinued pressure and yielding now here now there —
possibly, indeed, the process of crushing and cementation may have been repeated

more than once. ee
* Quart. Journ. Geol. Soc, vol. x. sec, xxxill. p. 916.

Prof. T. G. Bonney—Ligurian and Tuscan Serpentines. 367

parallel to oo P are indicated by thin lines of serpentine. The same
change is common in other serpentine rocks which I have examined.
This second mineral can be seen with a hand-lens, forming a talc-
like border to the unaltered crystal; probably it is nearly allied to
that mineral. One small grain of picotite is present, and some of
the most minute opacite is dichroic, and is probably manganese.
Through the kindness of Prof. Liveing a specimen of this second
rock has been examined for me at the Cambridge University Labora-
tory by Mr. C. T. Heycock, of King’s College, to whom I return my
best thanks. Together with his analysis I reprint for comparison
those of serpentines very similar in appearance from Ayrshire and
Cornwall.

LEVANTO. BaLHaAmte.! CaDGWwITH.?2
8. G. 2°705. 8. G. 2°587
AEDS Oe oe ny eee a Vitra net PL eB WSO © secs ao 12°35
Hersey ee mer Mies HAC. aa, coe 0-41
SiON ae Gia we tee ae Soom mae tht 38:50
AOS pean eee CCE Symes ete! OOo dues 1:02
Fe.03 onan 7-61 { ono nee Doone vee ee 4°66
AO eae W Weis Lesa Sie URen ane Hin | al ie AS (4a ee agree SPBIL
CaOW eee res: OsSae ames ar OgoyaMendeaee 1:97
Mic: a 34-5 Oe SoRO Onn eet eee 36°40
NiO) ee Ona ey ERA C CHAM aA whet ee ten dra ae
INGO pes yee Oza Oye ace OsvoR a eeanete 0:59
FRVESTCLU CMe teem Rs ates ie UES Wie my dee ers kl aigl id 137
100-11 99:16 100°58

All dried at 100° Cent. In the Levanto specimen there was the slightest trace of
CO,. Hydrochloric acid dissolved 95:54 per cent. of the mass, leaving 4:46 residue
as a slightly green amorphous powder. The per-centage of alumina here, as in the
Ayrshire specimen, is larger than I should have anticipated, as I cannot see a
trace of felspar. Part of it, however, may be due to the pyroxenic constituents,
and the rest to picotite. The constant presence of nickel is interesting.

My next visit was to the quarries from which is obtained the
celebrated Verdi di Prato, for centuries one of the most important
decorative stones in the valley of the Lower Arno. These are at
Figline, a little village between two and three miles from Prato, a
town between Florence and Pistoia. Here also the serpentine, as
may be seen from the railway, occupies a considerable tract of hilly
country, and rises from beneath the calcareous strata which are so
common in this part of the Apennines. Figline lies on the last
slopes of the hills, and on approaching it from Prato the serpentine
(which has the usual dusty purplish-brown or greenish-brown colour
and characteristic weathering) is seen forming the right bank of
the valley ; while on the left bank is exposed an indurated argil-
laceous rock, disturbed and sharply jointed, its aspect suggesting, as
does the contour of the serpentine mass itself, that the latter rock
is intrusive. The quarries, which are rather numerous, are situated
on the hill-side behind Figline. Almost directly on quitting the
village at the lower end, we come upon coarse gabbro, of the usual
character, but very rotten, and after ascending perhaps a hundred

1 Quart. Journ. Geol. Soc. vol. xxxiv. p. 771.
2 Quart. Journ. Geol. Soc. vol. xxxiil. p. 928.

3868 Prof. T. G. Bonney—Ligurian and Tuscan Serpentines.

feet, reach quarries in this rock, some of considerable size. The
gabbro is coarsely crystalline, consisting of plagioclase felspar (re-
sembling labradorite), partly of a dull bluish colour, partly changed
into white ‘“‘saussurite” and greenish diallage, with a rather silvery
lustre, the crystals commonly varying from 4” to 2” diameter, and
some dull green spots possibly denoting altered olivine. The slide,
however, which I have had prepared, does not show any of the last,
but consists of plagioclase felspar more or less altered, diallage,
ordinary augite, and a little secondary hornblende.' The rock is
locally known as pietra di macchina, and is quarried for mill-stones.
It varies a little in the relative amount of diallage and felspar and
evenness of crystallization, but is, on the whole, very uniform in
character. J had not time to trace out its limits, but the size of
the mass must be considerable.

Bearing away to the right and slightly ascending, we approached
the serpentine, which forms hereabouts the upper part of the hill.
The actual junction of the two rocks is obscured by vegetation,
soil, and detritus, but in a water-course I obtained a fair section,
which satisfied me that the gabbro was intrusive in the serpentine.
Quarries in the latter rock are still more numerous than in the
former, so that, though all the natural surfaces are much decomposed,
there is no difficulty in obtaining a good supply of specimens.

The general character of the serpentine appeared to be very
uniform—a ground-mass of a dull purple with a tinge of green
irreguarly mottled by the latter colour; in this are scattered rather
small crystals of a greenish mineral resembling enstatite. Thin
veins of green steatite are not unfrequent. After long exposure the
rock becomes of a pale grey green. It is sharply but irregularly
jointed, the joints often coated with a film of white steatite, and
sometimes becoming brown by exposure. In general character the
rock is identical with those already described and with that of the
Lizard, so that, from examination in the field alone, one might fairly
claim for them a similar origin. A microscopic slide shows no
unchanged olivine, but in parts, as in the last described, a structure is
visible indicating that this serpentine also is an altered olivine rock.
I do not find any unaltered enstatite or augite, but several grains
resembling the talcose mineral described above. In another slide,
cut some years since from a specimen purchased in Florence, the
enstatite still shows faint tints and a little of the serpentine in the
‘strings’ exhibits slight chromatic polarization.

On ‘returning from the quarries I descended into the glen above -
Figline, and a ‘short distance from the latter found stratified rock by
the road-side. This at first was an argillaceous rock, with concre-
tions, looking as if it had been much crushed. A little nearer occurs
a harder, bedded rock, bands of which have a flinty texture and
fracture of a dull reddish colour.’ The peculiar sharp jointing, baked

1 An analysis of the diallage is given by D’Achiardi, vol. i. P- 84, and of the
felspar (labradorite), 7d. p. 104. The rock is commonly called ‘ granitone”’ by
Italian geologists.

2 I believe this is the gabbro rosso’ of some authors.

Prof. T. G. Bonney—Ligurian and Tuscan Serpentines. 369

aspect, and wavy outline of the surface of the strata, which dip at
some 15° away from the serpentine, are almost enough to prove the
latter intrusive. But by ascending the bed of a streamlet, and
climbing up a little to the right, more conclusive evidence may be
obtained. Here we have the section roughly sketched in the
annexed diagram. A talus, D, it is true, masks the actual junction
of the serpentine and the stratified rock; but the state of the rock
in the little cliff is almost enough to prove intrusion. However, on
looking carefully about, I found a complete proof. At 4, about four
yards from B, the last exposure of the serpentine, and six yards
from the base of the cliff (measured on the slope), and on a lower
level by a few feet, was a small slab of the stratified rock yet
adhering to the serpentine. This collocation places the intrusive
character of the latter beyond all doubt.

RELATIONS OF SERPENTINE AND SEDIMENTARY Rocks, NEAR FIGLINE.

A Altered stratified rock. B Serpentine.
C Stratified rock 7 site. D Talus.

Microscopic examination of a specimen from the upper part of
D has produced interesting results. It consists of a very fine muddy
or silty ground-mass, in most parts stained of a deep red, crowded
with minute organisms, some resembling Sponge spicules, often
triradiate ; others resembling Polycystine or Foraminifera, such as
Orbulina or Lagena. They appear to be siliceous, and the internal
parts exhibit the black cross of aggregate polarization. Two or three
are pretty certainly minute Gasteropods. ‘To determine the position
of the rest is not easy. One eminent student of Microzoa, to whom I
submitted the slide, claims the majority for Polyzoa, another for
Polycystinee and Sponge spicules. If I may presume, without
having made such organisms a special study, to express an opinion,
it would be that while some certainly much resemble Polyzoa, others
are singularly like Polycystine. That all appear to be siliceous is
not conclusive, because under the circumstances replacement may
have taken place. Thus we are unable from these remains to fix
the precise geologic age of the rock, but still may fairly class it
with the strata of the immediate vicinity, which are, I believe,
Upper Cretaceous.

DECADE II.—VOL. VI.—NO. VIII. 24

370 Prof. T. G. Bonney—Ligurian and Tuscan Serpentines.

In the Mineralogical Museum at Florence, Professor Grattarolo (to
whom I am much indebted for information on localities, etc.),
showed me a collection of serpentine and gabbro from Impruneta, ~
a few miles from the city. These had the same general character
as the above; but both rocks were much decomposed, so that, on
hearing there were no excavations, I did not think it worth while
visiting the locality, as I probably should not have been able to
learn more than I could from the specimens.

These serpentines, then, and no doubt several other isolated
patches in the Ligurian Apennines, which I had not the opportunity
of visiting, must be added to the rapidly increasing group of altered
olivine rocks, primarily of igneous origin. To these also belong, as
I have already pointed out, the serpentines of Elba, and in our own
country those of the Lizard, Ayrshire, Portsoy, with other parts of
Scotland ; and—as I shall show on a future occasion—of North
Wales. To these also must be added some of the Alpine serpentines.
Here, however, careful discrimination will be needed, for though no
doubt true serpentine is present in the Alps, some of the rocks com-
monly mapped under that name have received it improperly, being
only serpentinous, i.e. rocks into whose composition other minerals
enter very largely, and in many cases simply serpentinous schists.

Further, it is impossible to avoid being struck with the frequent
association of serpentine and gabbro; at these four localities in
Italy, the two extremes being a good hundred and twenty miles
apart (and I believe in several others), at the Lizard in Cornwall,
and on the coast of -Ayrshire—to speak only of those which I have
myself visited, we have gabbro intrusive in serpentine. This can
hardly be a mere coincidence. These gabbros also are remarkably
like one another in aspect. Some observers, indeed, have asserted
that the serpentine is the result of transmutation of a gabbro. Now
that the microscope is used in petrology, I do not think we
shall hear much more of that statement, which in many cases was
founded only on very hasty examination in the field, and has seldom
a better base than the fact that serpentine is one of those minerals
which, like some people, can make a great show with but little means.
It is often instructive to see how “serpentinous” a rock will appear
to the eye, which, on careful examination, proves to be mainly com-
posed of other minerals. Reflection, too, should have suggested to
petrologists that felspar is not an easy mineral to remove froma rock.
The case of greissen, tourmaline-rock, etc., may, I am aware, be
quoted; but these are always comparatively local, while in the case
of serpentine we should have to pseudomorphose masses of gabbro
containing billions and billions of cubic yards so perfectly that no
trace of the felspar remained, and by so strange an agent that its
action is found to have stopped abruptly. The representatives, then,
of altered olivine-gabbros, will be found in the troktolite group;
and where gabbro and pure serpentine (i.e. a rock the ground-mass
of which consists almost entirely of hydrous silicate of magnesia
with some oxides of iron) are associated, the two rocks are of inde-
pendent origin. It will be well for travellers to observe carefully

Notices of Memoirs—A New Jurassic Mammal. 371

the relations of these two rocks, noting especially whether, as in the
above instances, the gabbro is the newer rock.

Another point of interest in connexion with these serpentines and
gabbros is that they are, beyond doubt, of late Cretaceous or early
Tertiary age, and yet are practically identical with serpentines and
gabbros which are almost as certainly of Paleozoic age.

INFOSESTCRHS) (Oust AMAR easy S\-

I.—A New Jurasstc Maman. By Professor O. C. Mars.
(From the American Journal of Science and Arts, vol. xviii. July, 1879.)

URING a recent visit to the Rocky Mountains the writer spent
some time in examining the deposits known as the Atlantosaurus
beds, and was rewarded by the discovery of several interesting fossils,
among them the lower jaw of a small mammal. This specimen indi-
cates a diminutive marsupial, quite distinct from the one previously
described by the writer from the same horizon (Dryolestes priscus),*
which has hitherto been the only mammal known from the Jurassic of
this country.

The present specimen, which is from the left side, has the larger
part of the ramus preserved, with a number of perfect teeth in position. -
Most of the symphysial portion is lost, and the posterior part is
missing, or only faintly indicated. The jaw was remarkably long and
slender. The horizontal portion is of nearly equal depth throughout,
and the lower margin nearly straight. The form of the coronoid
process, condyle, and angle of the jaw cannot be determined from this
specimen. The remarkable feature in this jaw is the series of premolar
and molar teeth. These were very numerous, apparently as many as
twelve in all, and possibly more. The premolars had their crowns
more or less compressed, and recurved, and some of them were
supported by two fangs. These had a small posterior tubercle at
the base of the crown, but none in front. The molar teeth were all
single-fanged, with elevated conical crowns. Those preserved have a
distinct cingulum. ‘he molars increase in size from the first to the
fifth. All the teeth preserved have the crowns raised considerably
above the upper margin of the jaw, and thus appear to be loosely
inserted. A large pointed tooth lying near the jaw appears to be a
canine. ‘The principal dimensions of this specimen are as follows:

Length of portion of jaw preserved ... ... soe sss see see «. 115 mm.
Extent of five molar teeth 60d POL ee
Extent of entire molar series coo 608 dob 800 00a 5
Height of fifth true molar above jaw. ocd aden. BAO 2°
Depth of jaw below fifth molar .. ... ... moa coat og) RI
Depth of jaw below last premolar ... 1... gon. 00a 60d 15
Depth of jaw below first premolar ... ... con asa. be!

In comparing this interesting fossil with the forms already known,
it is at once evident that it differs widely from any living type. Its

i Jervis, Quart. Journ. Geol. Soc. vol. xvi. p. 480, states that the ‘‘diallagic ser-
pentine ” pierces the Upper Cretaceous but not the Tertiary rocks. Stoppani, Corso
di Geologia, vol. ii. § 704, places it, if I rightly understand, at about the same
period. ‘Both speak of a compact serpentine ‘“‘ without diallage,” of Miocene age.
This I have not seen. See also D’Achiardi, vol. ii. p. 181.

® Silliman’s Journal, vol. xv. p. 459, June, 1878.

372 Notices of Memoirs—Fossil and Recent Sequoic.

nearest affinities are clearly with the genus Stylodon of Owen, from the
Purbeck beds of England,! and in many respects the correspondence is
close. This specimen clearly indicates a new genus, which may be called
Stylacodon, and the species represented, Stylacodon gracilis. With the
genus Stylodon, this form evidently constitutes a distinct family, which
may appropriately be termed the Stylodontide. The present specimen
indicates an animal somewhat smaller than a weasel, and probably
insectivorous in habit.

Il.—On tHE Fossin anp Recent Sequorm. By Prof. Oswaip
Herr. (Proceed. Inper. Geol. Instit. Vienna, March 4, 1879.)
WO species of Sequoia have survived to the present time, namely,

1. Sequoia sempervirens, Endl. (Zaxodium sempervirens, Lamb.),
still frequent, with distichous, divaricated leaves, small globular fruit,
and similar in habit to Taxus baccata: 2. Sequoia gigantea, Endl.

(Wellingtonia gigantea, Lindley), only in isolated groups, with narrow

leaves, adpressed to the branches, with much larger oviform fruit, and

showing the habit of Cupressus. ach of these species represents a

distinct type.

The Tertiary species are very numerous. Sequoia brevifolia, Heer, is
analogous to S. sempervirens, as S. (Araucarites) Sternbergi, Goepp.,
is to S. gigantea. The Miocene species—S. Langsdorfii (Brongn.),
S. brevifolia, H., 8. disticha, H., S. Nordenskieldi, H., 8. longifolia,
Lesq., S. angustifolia, Lesq., and S. acuminata, Lesq., are closely re-
lated to each other. The interval between the two extreme forms,
S. Langsdorfii and 8. Sternbergi, is filled up by six species—S. Couttsia,
H., S. affin’s, Lesq., S. imbricata, H., S. Sibirica, H., S. Heert, Lesq.,
and S. beformis, Lesq.

Of the ten Cretaceous species, three are of the Upper, two of the
Middle, and five of the Lower Cretaceous series. These last have
representatives in the two living forms: S. Smittecana, H., in S.
sempervirens, and S. Reichenbachi (Gein.), (Geinitzia cretacea) in S.
gigantea. The intermediate species are S. subulata, H., S. rigida, H.,
S. gracilis, H., S. fastigiata, and 8. Gardneriana, Carr.; the last three
have adpressed leaves.

The Jurassic strata, rich as they are in Coniferous plants, offer no
traces of Sequoia, which appears first in the Urgonian beds,—and then
in the two extreme forms which have alone survived beyond the
Tertiary Period.

Prof. O. Heer also remarks, with regard to the Arctic Tertiary flora,
that Mr. J. Starkie Gardner’s statement—that two fossil flore very
similar one to the other, but situated under widely distant latitudes,
should not be considered to be coéval—is not consistent with the
facts—that living plants (especially trees) are met with from the
Italian frontier up to 70° N. Lat.,—that the existing flora of Grinell
Land numbers among its 59 phanerogams 45 European and 6 Italian
species,—and that of the 559 phanerogamous species of the Island of
Saghalin, no less than 188 are found among the flora of Switzerland.
The Tertiary flora of the Arctic zone cannot be Eocene, as supposed
by Mr. Gardner, for in Northern Bohemia the Cretaceous strata are

1 Grou. Mae Vol. III. p. 199, 1866, and Pal. Soc, vol. xxiv. p. 46, 1871.

Reviews—Milne’s Crystallography. 370

succeeded by the Brown-coal series, the oldest horizon of which is
decidedly Middle Oligocene; and the Kocenes, strictly so called, are
wanting there. The whole discussion, adds Prof. Heer, proves the
necessity of ascertaining with more precision the age and geological
position of the Tertiary flore in each locality, At all events, the
present exact knowledge of the North-Polar Tertiary flore, he says,
has been highly profitable to Geology in proving the needlessness of the
hypothesis of a formerly existing ‘‘ Atlantis.” eRe a

IS) D2 Wh JE Ia WWF Se

SS
I.—NorEes oN CRYSTALLOGRAPHY AND CORrysTALLo-puysics. By
Joun Mine, F.G.S. (Professor of Geology and Mineralogy in
the Imperial College of Engineering, Yedo, Japan.) 8vo. pp. 80;
25 Woodcuts. (London: Triibner & Co., 1879.)

HE study of Geology is a wide one, implying a foreknowledge
of Biology, Chemistry, Physics, and Mineralogy, and to be well
acquainted with all these is rarely the lot of one man; therefore,
when a geologist writes a book on Crystallography and Crystallo-
physics, it is apparent that there must be a considerable want felt
by geologists for a work of this kind, viz. one which, while deserting
the awkward system of Naumann still taught in preference to any
other by several of our teachers of mineralogy, and using the elegant
system of Neumann and Miller, yet attempts (to use Mr. Milne’s
own words) “to give the general principles which crystallographical
calculations involve for the use of those students who wish to know

them, rather than for those who wish actually to employ them”’

It is to be regretted (for the sake of the author) that the publication
of Mr. Milne’s Crystallography was delayed, owing to his absence
from England, as, when the lithographed notes of these lectures
delivered in Japan were sent to England for publication “in the
GroLocicaL Magazine, or elsewhere,” Mr. Gurney’s little book on
Crystallography had not yet appeared. Had they been printed in this
country earlier, they would have taken precedence in publication of Mr.
Gurney’s pamphlet, as they undoubtedly do in date of issue in Japan.

The author expresses himself indebted for information to Prof.
Miller’s Treatise on Crystallography, and Prof. Maskelyne’s Lecture-
notes on the Morphology of Crystals; he might also have cited Prof.
Miller’s Tract on Crystallography, which, though shorter, is pre-
ferable to his Treatise, at least from a mathematician’s point of
view.

Important as the study of Lithology has now become to geologists,
we hope to see Mineralogy studied by them in a truly scientific
manner, and this work we take as an indication that this has
begun. Whilst taking exception to the way in which Mr. Milne
has tried to avoid some of the difficulties of the subject—as on page
16, where the proof given applies only to those crystals belonging to
four out of the six existing systems, and the results of which are
used on page 25 in dealing with a crystal belonging to one of
the two excluded systems—we cannot but admire his courage in

ord Reviews—T. M. Hali’s Geology of Devonshire.

publishing what has evidently been a labour of love, though beset
with difficulties.

In the chapter devoted to the physical properties of crystals, a
part needs careful revision by the author before its republication ;
no doubt, had Mr. Milne been in England, and able to consult
authorities, this would have been more carefully treated. Of course
Mr. Milne’s notes are printed verbatim, the Editor not altering the
author’s work at all, save in a few trivial instances.

The woodcut figures are clear, and exceedingly well chosen.

As to the rest we consider that Mr. Milne has displayed con-
siderable ingenuity in putting before his students in the way he
has done a confessedly difficult subject, but into which those not
versed in higher mathematics may yet hope to gain a fair insight.

The work has been seen through the press by Mr. Thomas
Davies, F.G.8., who for twenty-one years has been attached to the
Mineralogical Department of the British Museum, and is so well
known to all petrologists and mineralogists on account of his
intimate knowledge of these sciences.

TI. —Syuiiasus or a Course or Lectures on Gzonoey. (Cambridge
University Extension.) 1873 to 1877. By W. J. Sounas, M.A.,
F.G.S. 8vo. (London, 1878.)

HESE Heads of Lectures will be very useful to students and
teachers, as they are full and suggestive, and contain references

to the principal works on each subject. The lectures embrace some
matters more or less distinct from Geology proper, as those on the

Atmosphere, Rain, and Snow; but it is not difficult to see their

bearings on Geology, as also those of Astronomy, when we come to

discuss the Evolution of the Earth. In this respect the series of
lectures takes in a general scientific course, such as would be
included in Physiography. A prominent feature is the attention
given to the physical geography of past periods. The Permian beds,

‘we may mention, are grouped with the Mesozoic rocks; and the

Cambrian rocks are arranged according to the classification of

Sedgwick. H. B. W.

IJJ.—A Sxketcu or tHe GroLtocy or DevonsHire. By TownsHEND
M. Haut, F.G.S. [Reprinted from White’s History, Gazetteer,
and Directory of the County.] Svo. (Sheffield, 1878.)

N the closely-printed seventeen pages of this sketch, Mr. Hall
has given a very clear and condensed account of the Geology

of Devon. The Devonian and Carboniferous rocks, which together
occupy nearly two-thirds of the superficial area of the county,
naturally receive a considerable share of attention, and the lists of

fossils most commonly met with in their main divisions form a

particularly valuable feature of this work.

The Triassic rocks, with their fossiliferous Budleigh pebbles,
receive due attention; so also do the Cretaceous, Miocene, and Post-

Tertiary deposits, including with the latter the Cave remains, the

Reports and Proceedings—Geological Society of London. 375

Raised Beaches, and Submerged Forests. The Lias and Rhetic beds
are dismissed with very little notice, although so well known at
Axmouth and Axminster. The economic applications of the Igneous
and Metamorphic rocks, as well as those of the stratified rocks,
are pointed out; and a general account of the literature of Devon-
shire geology is given. In reference to this we may remind the
author that it was J. J. Conybeare (not his more distinguished
brother the. Rev. W. D. Conybeare) who wrote on the geology of
Okehampton and Clovelly. ERB We

ISS OwReysS) VAAND) IEIiC\OnalaI Dian Ke 7S).

ieee

Guotocicat Socrery or Lonpon.—I.—June 11, 1879.—Prof. Joseph
Prestwich, M.A., F.R.S., Vice-President, in the Chair.—The following
communications were read :—

1. ‘On a Mammialiferous Deposit at Barrington, near Cambridge.”
By the Rev. O. Fisher, M.A., F.G.S.

The gravel in which these remains were found is about 20 feet
above the alluvial flat by the River Rhee, and is evidently Post-glacial.
The gravel contains some of the ordinary land and freshwater shells,
but not Cyrena or Unio. Remains of the following Mammalia have
been found :— Ursus speleus, Meles taxus, Hyena spelea, Felis spelea,
Cervus megaceros, C. elaphus, and another, Bos primigenius, Bison priscus,
Hippopotamus major, Rhinoceros leptorhinus, Elephas antiquus and pri-
migenius, with a worked flint, almost certainly from the same deposit.
The author considers the abundance and admixture of these remains
due to the locality having been a sort of eddy or pool in the old river.
The remains are described, and the rest of the paper is occupied with a
correlation of the gravel with others in the adjoining district, and a
consideration of the physical conditions under which it was deposited.

2. ‘‘ Further Discoveries in the Cresswell Caves.”” By Prof. Boyd
Dawkins, M.A., F.R.S., F.G.S., and the Rev. J. M. Mello, M.A.,
F.G.S., with Notes on the Mammalia by the former.

This paper contained the account of digging-operations carried on
in one of the smaller caves of the Cresswell Crags, known as’ Mother
Grundy’s Parlour. The authors described the occurrence in the red
clay and ferruginous sand of this cave of bones of Hippopotamus and
the Leptorhine Rhinoceros, proving the existence of these animals in
the wooded valleys of the basin of the Upper Trent at the time of the
accumulation of these deposits; while at the same time, so far as the
evidence goes, there was an absence of Paleolithic man, of the Reindeer,
and of Horses, while Hyzenas were abundant. In a subsequent period,
represented in all the caves by the Red Sand, the Mammoth, Woolly
Rhinoceros, Horse and Reindeer inhabited the vicinity, and were sub-
ject to the attacks both of Hyznas and human hunters, whose quartzite
implements prove them to belong to the same people whose traces are
found in the river-deposits. In the breccia and upper cave-earth of
the larger caves the existence of the Paleeolithic hunter is evidenced
by flint implements, resembling those of Solutré, accompanied by im-
plements of bone and antler. Associated with these was the incised

376 Reports and Proceedings—

figure of a horse described in a former paper. The authors finally
dwelt briefly upon the characteristics of the caves in. prehistoric and
historic times, and indicated some of the anthropological points of
interest connected therewith.

3. ‘On the Pre-Cambrian Rocks of Shropshire.” Part I. By C.
Callaway, Esq., D.Se. Lond., F.G.S.

The author commenced by describing the physical geography of the
ridges intervening between the vicinity of Wellington and the Long-
mynds, viz. Lilleshall Hill, the Wrekin, and the chain of the Caradoc
Hills. He passed on to describe the stratigraphy. At Lilleshall are
slaty beds dipping about N.N.W., and a rhyolitic agglomerate. At
the N. end of the Wrekin a granitoid soil, probably of clastic origin,
with a mass of decomposed intrusive rhyolite. The Wrekin consists
of rhyolitic agglomerates, with (probably) lava-flows and a few basalt
dykes, the general dip of the bedded rocks being to the north. At the
southern end (Primrose Hill) granitoid gneisses (some closely resem-
bling the hornblendic gneiss of Malvern) occur. In the Caradoc range
intrusive greenstones are more largely developed; but here also are
bedded Pre-Cambrian rocks. Other smaller exposnres in this vicinity
were also described. The prevalent strike is over the whole district
about E.N.E.-W.S.W. The evidence of their age is often very clear,
as they are overlain (with marked unconformity) by quartzites (some-
times containing rhyolitic fragments) which are clearly much older
than the Hollybush Sandstones.

4. ‘On the Occurrence of a Remarkable and apparently New
Mineral in the Rocks of Inverness-shire.” By William Jolly, Esq.,
F.R.S.E., etc., and J. Macdonald-Cameron, F.C.8., etc.

In this paper the authors refer to a blue mineral of a somewhat
remarkable character, which was specially noticed at an excursion
of the Inverness Field Club in September, 1877. This excursion was
made to Englishton Moor and neighbourhood, distant westwards, from
Inverness, about five miles, where the mineral occurs in scattered
blocks. It has since been noticed at Moniack Burn, Reelig Glen, and
South Clunes Farm, all in the same direction, but distant from Inver-
ness about ten miles; also near Dochfour House, at the north end of
Loch Ness, close by Dochgarroch Lock on the Caledonian Canal. In
colour and general appearance this mineral resembles crocidolite, but
analyses point to its being more nearly related to egirite, a member of
the amphibole group, which has the general formula $i3($Ry+-R’).

The mean of several analyses shows it to have the composition
6Si0,, Fe,0;, 2Mg0.

IJ.—June 25, 1879.—Prof. P. Martin Duncan, M.B., F.R.S., Vice-
President, in the Chair.—The following communications were read :—

1. ‘‘On the Evidence that certain Species of Ichthyosaurus were
Viviparous.” By Prof. H. G. Seeley, F.K.S., F.G.S.

In this paper the author described certain specimens of Ichthyosaurs
in which the remains of one or more small individuals have been
preserved within the body-cavity of larger ones. One of these was
described and figured in 1822 by Jager; a notice of another was
published in 1846 by Dr. Chaning-Pearce, who suggested that it
furnished evidence in favour of the viviparity of the Ichthyosaurs.

Geological Society of London. 377

Other examples are preserved in museums in Germany, and one in
Madrid, and most of them have been examined by the author, who
adduces the state of preservation of the small individuals, in contrast
with that of the traces of fish and Cephalopoda, the remains of food,
which are found in the stomachal region of the larger individuals, in
advance of the position occupied by the smaller ones, as a proof that
we have not here to do with a case of cannibalism. The position of
the smaller skeletons, with the head generally turned towards the
pelvic region of the larger ones, is also regarded as indicative of their
standing in the relation of parent and offspring. As some of the
young specimens possess limbs, it would seem that the supposition that
Ichthyosaurus passed through a sort of tadpole stage is erroneous.

2. “On Rhamphocephalus Prestwich, Seeley, an Ornithosaurian
from the Stonesfield Slate of Kineton.”” By Prof. H.G. Seeley, F.R.S.

In this paper the author described the characters presented by the
impression of the skull of an Ornithosaur in a slab of Stonesfield slate
from Kineton, near Stow-on-the-Wold, the peculiarities of which are
such as to induce him to found for it a new genus, to which he thinks
it probable that most, if not all, the known Stonesfield-slate Ptero-
dactyles may belong. It is distinguished especially by the great length
of the roof of the skull posterior to the orbits, by the presence of a
very deep constriction of the frontal region between the orbits, by the
strongly marked sutures between the bones, and by the curiously
Crocodilian character of the plan of structure of the roof of the skull,
which suggests the existence of a lower grade of Ornithosaurian
animals than has hitherto been suspected. The genus appears to be
allied to some forms of Rhamphorhynchus. The author names the
species, which is in the Oxford Museum, Rhamphocephalus Prestwich,
and considers that the other bones of Ornithosauria discovered in
the Stonesfield slate support the generic separation of the group.

3. “A Contribution to South-American Geology.” By George
Attwood, Esq., F.G.S.

The paper describes a line of country in Spanish Guayana, Vene-
zuela, S.A., commencing from a small town called ‘the Port of Las
Tablas,” on the Orinoco River, extending about 150 miles, and con-
sisting of a series of crystalline and altered rocks. Syenite is the first
rock met with; and then are found granite, quartz-diorite, haematite,
and magnetic iron-ores, gneiss, slaty rocks, gabbro, and diabase.
In the diabase the quartz-veins are found to contain large quantities
of gold mixed with the vein-matter; the alluvial soil in the neigh-
bourhood of the quartz-veins also contains gold nuggets and small
grains of gold. Although quartz-veins are found in great numbers
from the river to the interior, none of them have so far been found to
contain gold in any appreciable quantity until the diabase is met with.
All the rocks analyzed show a higher per-centage of silica than is
generally found in other localities. Three analyses made from one
piece of diabase showing two distinct lines of alteration by weathering
(on the original rock), prove that silica is readily dissolved under
atmospheric influences; whilst alumina is not. Iron oxides contain
more oxygen near the surface than below it. Lime and magnesia are
both readily soluble; but lime much more so than magnesia. Soda

078 Reports and Proceedings—

is more sensitive to weathering than potash. The rocks contain more
combined as well as uncombined water on their surface than when
sheltered from atmospheric influences.

The paper was accompanied by an appendix on the microscopical
structure of some of the varieties of rocks by Prof. Bonney.

4. ‘‘On the so-called Midford Sands.”” By James Buckman, Esq.

The author quotes from the works of Professor Phillips and other
authors certain passages, in which the sands below the Oolitic Lime-
stones of the Cotteswold Hills and Dorsetshire are correlated with one
another, and the name of ‘‘Midford Sands” is applied to the formation
represented by these strata.

In opposition to these authors’ views Prof. Buckman maintains that
two distinct Ammonite bands have been by them confounded with one
another; that the sandy beds in the Cotteswolds really belong to a
much lower horizon than do the similar strata in Dorsetshire and
Somersetshire; and that while the former lie quite at the base of the
Inferior Oolite series, the latter represent a great part of that forma-
tion. In support of this view Prof. Buckman points to the fact that
a representative of the true Cephalopoda-bed lies at the base of the
so-called Midford Sands of Somersetshire; he illustrates the rapid
transitions which take place between sandy and caleareous strata in
this part of the series; and in conclusion he shows, by the study of
the somewhat fragmentary fossils found in the sands of Dorsetshire
and Somersetshire, that they are the true equivalents of several different
divisions of the Oolites of the Cotteswold Hills. He admits, however,
that some Liassic forms range upwards into these beds.

5. ‘*On the Physical Geography of the North-east of England in
Permian and Triassic Times.” By E. Wilson, Esq., F.G.S.

In this paper the author seeks to utilize the information he has
acquired from the study of the Permian and Triassic rocks of the
above district, towards solving some of the difficult and much-debated
questions as to their origin. With this end in view he traces the
various members of the Magnesian Limestone formation between
Notts and Northumberland, noticing in particular the amplification of
that group of rocks in northerly and easterly directions. Incidentally
attention is called to the increased importance of the Marl Slates as a
distinct and characteristic series. One of the main objects of the
paper is to establish the pre-Permian origin of the Pennine Chain.
The nature and relative values of the stratigraphical breaks which, in
the district in question, occur between the Carboniferous and Permian,
the Permian and Bunter, and the Bunter and Keuper formations, are
severally dealt with. The author concludes by speculating as to the
general conditions under which the Permians may have been formed,
and the physical fluctuations that may possibly have brought about the
succession in one geological epoch of rocks so distinct in mineral
constitution and in fossil contents as the Marl Slates, Magnesian
Limestone, and Permian Marls.

6. ‘‘ The Formation of Rock-basins.” By J. D. Kendall, Esq., C.E.

The author discusses the mechanical difficulties involved in the
glacier-excavation theory of lake-basins, and suggests that they are
due to the action of falling water engulfed in the crevasses of the

Geological Society of London. 379

ancient glaciers, being thus of the nature of ‘giants’ kettles,” though
on an enlarged scale.

7. ‘*Diorites of the Warwickshire Coal-field.” By S. Allport, Esq.

The diorites are intrusive in the lower and unproductive measures
of the above field and the underlying Millstone-grit below Atherstone
and Marston Jabet (two miles south of Nuneaton). The author
describes their microscopic characters. One variety is very finely
crystalline and contains brown hornblende. Another contains plagio-
clase felspar with a little orthoclase, small crystals of brown hornblende,
many crystals of clear yellowish augite, and several pseudomorphs
after olivine, with apatite, magnetite, ete. A mineral also occurs
belonging to the hexagonal system, which the author suspects to be
nepheline. Other varieties are described, one of which contains
augite with hornblende. These rocks differ considerably from the
syenites of Leicestershire.

8. On Lepidodiscus Lebourt, a New Species of Agelacrinites, from
the Carboniferous Series of Northumberland.” By W. P. Sladen, Ksq.

The genus Agelacrinites was unknown in the Carboniferous rocks
of Europe before the discovery of the fossil described in this paper ;
and even in the Silurian and Devonian rocks species referred to this
group were exceedingly rare. The specimen now illustrated by the
author, which belongs to the subgenus ZLepidodiscus, was found by
Prof. Lebour, and its study has thrown some new light on the structure
and affinities of the genus. One of the most striking facts concerning
it, now made out by the author, is that, like some recent forms of
Echinoidea, the species would seem to have been so constructed as to
permit of its plates overlapping, and thus to have been collapsible.

9. ‘On the Ancient River-deposit of the Amazon.” By C. Barring-
ton Brown, Esq., A.R.S.M., F.G.S.

The author described a series of alluvial deposits, varying in thick-
ness from 10 to 160 feet, which have been cut through by the river,
and form a series of cliffs, giving rise to striking and characteristic
scenery. The succession of beds exposed in these cliffs was illustrated
by a number of sections, and it was shown that the strata in question
must have been deposited by river-action. It was then pointed out
that the river is performing two classes of work, namely, cutting away
the older sheets of alluvial matter, and depositing the materials derived
from them at a much lower level. ‘he interesting phenomena of the
cutting of curves by the river, and the abandonment by the river of
parts of these curves, giving rise to the formation of lakes, was fully ex-
plained ; and in conclusion the author showed by a map what vast areas
in South America have thus been covered by these alluvial deposits.

10. “lhe Glacial Deposits of Cromer.” By Clement Reid, Esq.

In this paper the author described the beds shown in the cliffs be-
tween Weybourn and Happisburgh. The classification adopted was :—

Sands and Gravels (Middle Glacial ?).

Bedded sand and marl. Genrectndubaitt
Sedimentary Boulder-clay. fi
Fine Sands.

2nd Till (unstratified Boulder-clay).
Intermediate Beds (laminated marl, etc.).

1st Till (unstratified Boulder-clay).

Arctic Freshwater Bed.

380 Reports and Proceedings—

The beds below the 1st Till were not described: the Ist and 2nd
Tills were considered to have been formed by land-ice coming from the
W. or W.N.W.; while the Intermediate Beds appear to be stratified
glacier-mud deposited on the retreat of the ice. The Sands are probably
marine, and so also appear to be the Contorted Drift and Middle Glacial.
Glacial Beds later than the Chalky Boulder-clay appear to be represented
near Cromer by valley-deposits which were not treated of in this paper.
In dealing with the question of the age and mode of formation of
the contortions, the author pointed out that all, with the doubtful
exception of a few of the smaller ones, affected not only the Contorted
Drift, but also the Middle Glacial; while, at the same time, contortions
affecting the overlying beds were often much more complicated at the
base, and rested on an even, undisturbed surface of the Preglacial beds.
This he accounted for by considering the contortions to be formed by
an advancing ice-sheet, which pushed before it a mound of the older
glacial beds, while the beds below the level of the base of the ice were
undisturbed ; thus the junction of the contorted and uncontorted beds
is a horizontal fault-line. The ice-sheet he referred to the period of
the Chalky Boulder-clay. The author drew attention to the fact that
the hollows in which the Middle Glacial gravels rest are in every
instance due to contortion and not to erosion. The large masses of
Chalk in Boulder-clay were considered to have been torn off by the
same force that produced the contortions.

11. ‘‘On a Disturbance of the Chalk at Trowse, near Norwich.” By
Horace B. Woodward, Esq., F.G.S.

Attention was drawn to a section at Trowse, where the Chalk with
bands of flint was uplifted at an angle of about 37°. Abutting against
the Chalk was a mass of the same rock rearranged, containing broken
flints, and pebbles of flint, quartz, and quartzite. This rearranged
Chalk was traced underneath the uplifted beds; and the author gave
reasons for believing that the disturbance was produced by the agent
(land-ice) which formed the Chalky Boulder-clay. Allusion was made
to many cases of glaciated Chalk in Norfolk, and to the cervine and
other organic remains occasionally met with in it. Comparing the
Trowse section with that at Litcham, described by Mr. 8. V. Wood,
Jun., the author came to the conclusion that this was a similar and
striking instance of the incipient formation of a huge Chalk boulder,
serving to throw light on the origin of the large transported masses seen
in the Cromer Cliffs.

12. ‘‘The Submerged Forest of Barnstaple Bay.’”’ By Townshend
M. Hall, Esq., F.G.S.

Traces of an old forest-bed exist in many places beneath the Braunton
Burrows, on the shore of Barnstaple Bay. Some good sections were
exposed near Westward Ho after the winter of 1863-4 owing to an
inroad of the sea, trees being found in the position of growth. They
were mostly oak, and a few pine or fir, with an undergrowth of hazel,
with probably Betula nana, and with moss and leaves of an Jris.
The author gives details of the sections of kitchen-midden deposits
with flint-flakes and cores, pointed stakes, split bones, ete. Bones of
the red deer, roebuck, goat, hog, wolf, and Bos longifrons have been
found associated with the peat.

Geological Society of London. 381

13. ‘On a Section of Boulder-clay and Gravels at Ballygalley
Head, and an inquiry as to the proper classification of the Irish Drift.”
By T. Mellard Reade, Esq., C.E., F.G.S.

The section described is in a gravel-pit about 30 feet deep, situated
between Larne and Cushendall, in the north of Ireland. It shows
a considerable thickness of false-bedded gravel and sand, containing
shells, covered by Boulder-clay. The shells collected from the sand
and gravel of this section do not, however, agree with those found in
the so-called ‘‘ Interglacial beds’? of Lancashire; and the author
regards the section as confirming his views that the tripartite division
of the drift-deposits is not, as maintained by Hull and other geologists,
equally applicable to the Irish and Lancashire deposits.

14. ‘On the Augitic Rocks of the Canary Islands.’ By Professor
Salvador Calderon. Communicated by the President.

As the result of a long investigation of the eruptive rocks of the
Canaries, and especially of Las Palmas, the author has come to the
conclusion that there are two groups of such rocks in those islands,
an older one, characterized by the presence of hornblende, and a
newer, containing augite. In the latter he finds the essential minerals
to be plagioclase, augite, magnetite, olivine, sanidine, and nepheline ;
and he distinguishes among them the following kinds of rocks, all of
which have their characteristic minerals imbedded in a paste of augite
and plagioclase: —1. Augite-andesite, with a small quantity of sani-
dine; 2. Zephrine, with no sanidine, but abundance of nepheline;
3. Basanite, with some peridote; 4. Mepheline-basalt, with abundance
of peridote; 5. Dolerite, crystalline, characterized by the disappear-
ance of nepheline, the abundance of peridote and porphyritically im-
bedded plagioclase, and with porphyritically imbedded individuals of
augite and olivine; 6. Felspathic basalt (like 5), but semicrystalline ;
and 7. Essentially olivinic modern lavas.

15. ‘‘On the Cambrian (Sedgw.) and Silurian beds of the Dee

Valley, as compared with those of the Lake-district.”” By J. E. Marr,
Esq., B.A., F.G.S.
- The principal differences in these districts appear to be due,
(1) to the non-correspondence of the epoch of volcanic activity,
(2) to the upheaval and consequent denudation of a part of North
Wales after the end of the Cambrian period. The author correlates
the deposits in the two areas, the Dee valley having deposits parallel
to the various members in the Lake-district, from the Skiddaw Slates
to the Upper Coldwell beds inclusive. The Lower Bala series contains
ash-beds which appear to be andesitic. In the Middle Bala of Wales
are some fossils which, in the Lake-district, occur in the Ashgill
Shales above the Coniston Limestone. He finds the equivalents of the
Graptolitic Mudstone of the Lake-district, near Carrig-y-druidion,
corresponding in stratigraphical position, lithological character, and
fossils. One Graptolite, G. colonus, however, occurs at a higher
horizon in the Lake-district. In the lowest division of the Denbigh
Grits Acroculia haliotis is found, which, in the Lake-district, occurs in
the Upper Coldwell beds; and in the uppermost series there are other
fossils which occur in the Bannisdale Slates and Kirkby-Moor Flags,
thus giving further indications of a northward migration.

382 Correspondence—Mr. J. R. Dakyns.

16. ‘On some Superficial Deposits in the Neighbourhood of
Evesham.” By the Rev. A. H. Winnington Ingram, M.A., F.G.S.

The lower series of gravels on Green Hill contains unworn flints
about 10lbs. in weight. They are about 120 feet above the level of
the Avon, and were probably brought by floating-ice. A clay at
Bengeworth, beneath a sand with Unio ovalis (60 feet above the Avon),
has yielded entire heads and horns of Bos primigenius, Bison priscus,
an antler of Cervus tarandus, and a tooth of Hippopotamus, with other
mammalian bones. A similar clay on the opposite side of the river at
Evesham has furnished Cervus tarandus and river-shells, etc.

17. ‘‘ Descriptions of Paleozoic Corals from Northern Queensland,
with Observations on the Genus Stenopora.”’ By Prof. H. A. Nicholson,
M.D., D.Sc., ¥F.G.S., and R. Etheridge, Esq., Jun., F.G.S.

The Corals described in this paper were in part collected by the late
Mr. Daintree, chiefly from the limestone of the Broken River, regarded
as of Devonian age, and in part by Mr. R. L. Jack from various sources,
namely, the Bowen-river Coalfield, in beds probably of Permo-Carbon-
iferous age, the Fanning-river Limestone (Devonian), and the Arthur’s-
ereek Limestone (Permo-Carboniferous). Mr. Daintree’s collection ~
also contained corals in the chloritic rock of the Gympsie Goldfield.
From the Coral Creek, Bowen-river Coalfield, the authors record
Stenopora ovata, Lonsd., and S. Jackii, sp. n.; from the Fanning-river
Limestone, Heliolites porosus, Goldf., and Pachypora meridionalis, sp. D.;
from the Gympsie chloritic rock Stenopora ? sp. ind.; from the Broken-
river Limestone, Favosites gothlandicus, vars. Lam., Heliolites porosus,
Goldf., H. plasmoporoides, sp. u., H. Daintreei, sp. u., Heliolites sp.
ind., and Areopora australis, sp.n.; from the Arthur’s-creek Lime-
stone, Burdekin Down, Alveolites (Pachypora ?), sp., near A. robustus,
Rom., Alveolites sp. (lobate form), Aulopora repens, M.-Edw. & H.,
Heliolites porosus, Goldf., and vars., Lithostrotion sp. ind., Pachypora
meridionalis, Trachypora sp. ind., and species of Cannopora and Stro-
matopora. The genus Argopora is proposed as a new group; the genus
Stenopora is made the subject of a long discussion; and the geological
characters of the deposits from which the fossils are derived are in-
dicated and discussed.

The Society then adjourned to November 5th.

CORRS] @N a a INS ae

ee ee

LENTICULAR HILLS OF GLACIAL DRIFT.

Srr,—In the June Number of the Gronocican Magazine Mr.
Warren Upham asks whether British geologists have noted accumu-
lations of Till like the “lenticular hills” of Prof. Hitchcock. The
description given of these hills answers precisely to that given by
Messrs. Kinahan and Close, in their paper on the “ General Glacia-
tion of Yar-Connaught,” of the “drum-lines” of unsiratified
Boulder-clay. 5

Mr. James Geikie, also, in his “Great Ice Age,” says that “in
lowland tracts the till is frequently arranged in long round-backed

Correspondence—Dr. J. EH. Taylor—Rev. J. WM. Mello. 383

ridges, which. are parallel to one another and to the direction of the
principal valley of the district.”

Similar mounds are equally common in many parts of the York-
shire dales: they occur, for instance, in Bishopsdale, Wensleydale,
and Ribblesdale, and on the Haws between the latter dale and
Wharfdale. In Westmorland, too, such mounds are common at the
foot of the mountains, and they form a striking feature in the
landscape of the low ground near Kendal. J. R. Daxyns.

BRIDLINGTON QUAY.

FAULTS IN THE LONDON CLAY, NEAR HARWICH.

Srr,—The extensive excavations now going on at Ray Island, near
Harwich, where the new docks are being constructed for the Great
Eastern Railway Company, have exposed some splendid banded sections
of the London Clay. One of these is plainly visible to the railway
traveller, on the left-hand side, about a mile before he reaches Dover-
court Station. As nearly the whole of the humpy mass of land now
called Ray Island is intended to be carried into the neighbouring
estuary of the Stour for the erection of embankments, a notice of the
dislocations now visible in the sections is of geological value.

In many places the London Clay is seen to be thrown into a series of
very gentle folds. At no fewer than me places in the section, small
faults are as plainly visible as in a geological diagram, owing to the
banded character of the strata. With one exception all the faults have
an angle of about fifty degrees, the exceptional fault (seen in the
railway cutting) being nearly vertical. The latter shows a dislocation
of about two feet. The largest fault is visible in that end of the rail-
way cutting nearest to Dovercourt, and measures upwards of twelve
feet. A fault of more than eight feet is seen in a section near the
estuary, and some of the minor dislocations occur at intervals of from
fifty to one hundred yards. The line of fault is in most instances as
sharply defined as if the strata had been diagonally cut through with a
knife. J. KE. Taytor.

PYRITIFEROUS SAND FROM LAKE WINNIPEG.

Srr,—I have had a sample of somewhat curious sand put in’ my
hands by a man who has recently returned from America, and venture
to think it may elicit some further information about it could you find
space for my note. I send a sample of the sand; you will see that it
consists of a very fine grained siliceous sand, grey in colour, the grey-
ness being due to an innumerable quantity of almost microscopic
_ concretions of pyrites. Under the microscope these are pretty objects,
mostly globular, and when broken show very distinctly their concentric
structure; they appear very similar on a minute scale to the concretions
so commonly met with in the Cretaceous deposits, ete. Possibly they
have formed round a foraminiferous or other organic nucleus, but I
have not succeeded in detecting it as yet in any of the broken globules.

The locality from which the sand was brought is said to be on the

O84 Correspondence—UMr. W. Gunn.

North shore of Lake Winnipeg, the section exposed being a natural
one, and is as follows :—

1. Loam, 3ft.

2. Hard rock (Limestone ?) 10ft.

3. Pyritiferous sand, silvery to the eye when fresh, 4ft. (exposed).

The pyrites forms so large a portion of the sand that it might be
worth while to work the deposit; mere washing would probably
separate the ore readily from its matrix. The composition of the
pyrites is said to be Fe 46-4 S 53°6.

With regard to the origin of the pyrites, can it have been formed in
situ in the sand, or is it as well as the sand the product of the disin-
tegration of an older rock? I can find no account of any similar
deposit elsewhere; the nearest approach to such a bed in character
seems to be met with in beds containing diminutive spherical nodules
of iron ore in Manitoba, but these are not pyrites; they are chalybite
and much larger; and it is said in the report of the Survey of the 49th
Parallel, that a thin film of pyrites in the Lignite deposits near Porcu-
pine Creek was the first appearance of that mineral in connexion with
those deposits. J. Maguns Mento.

Tur Rectory, Brampton, 8. Tuomas,
CHESTERFIELD, June 28, 1879.

GLACIATION OF THE WEST YORKSHIRE DALES.

Sir,— Will Mr. J. W. Davis kindly tell us what evidence he has
to show that either the Scotch or Lake Country ice, after traversing
the valley of the Eden, passed down Wensleydale, Arkendale, and
Swaledale, as stated by him in your last Number, p. 315? I think
the statement must be new to most of your readers, unless they have
seen a somewhat similar one in Davis and Lee’s West Yorkshire.
Surely if the ice took this course, these dales should abound in
erratics. Yet so far as I know there are no foreign boulders in
Wensleydale—only local ones. There are no erratics in Arkendale
and none in Swaledale, except in the lowest part of the dale near
Richmond, where it can be shown clearly that they came over the
watershed from the north, out of Teesdale. Mr. Davis must have
entirely misunderstood Mr. Goodchild’s paper on this matter. It
may look at first sight to an outsider as if the ice ought to have
behaved differently, especially when it did not pass from the Eden
Valley over the low watershed into Wensleydale. ‘‘ But facts are
chiels that winna ding.” Perhaps it is not generally known that
the Lake Country ice in passing over Stainmoor did not take the
direction of the lowest pass, 1878 feet above the sea, and so cross
where the Stainmoor railway goes over into the valley of the Greta,
but it passed over higher ground further north into Deepdale, Balder-
dale, and Lunedale, and erratics have been found by Mr. Goodchild
and myself at various heights up to 1800 feet on the watershed
between the Eden and the Tees. W. Gunn,

Brrwick-on-T ween, Grou. Suny. or Ene. anp WALES.
July 12, 1879.

—

GEOL.MAG.1879. DECADE II.VOL.VI.PLATE X.

CL Griesbach del.ct lith.. West, Newman & Co.ump «

Sumatran -Fossil Shells, &c.

THE

GEOLOGICAL MAGAZINE.

NEVY SSERIES.) DECADE (Ile VOI sir

No. IX—SEPTEMBER, 1879.

ORIGINAL ARTICLIES.

J.—Notrs on A Coniection or Fosstn SHELis, Etc., FRom
Sumatra (opTaiIneD BY M. VerBrEK, Director or THE
GrotocicaL SuRvEY oF THE West Coast, Sumatra). Parr I.

By Henry Woopwarp, LL.D., F.R.S., F.G.S., etc. ;
of the British Museum.

(PLATE X.)

OUR years ago M. R. D. M. Verbeek, Director of the Geological
Survey of the West Coast, Sumatra, placed in the hands of my
friend Prof. T. Rupert Jones, F.R.S., for description, a collection of
fossil remains obtained by him in the prosecution of his geological
researches in Central Sumatra, accompanied by some notes and
sections of the geology of this little-known region of the globe.

These notes have already appeared,’ and a portion of the fossil
remains has also been published in this Journal.’ It is now proposed,
as far as practicable, to complete the description of the Invertebrate
remains forwarded by M. Verbeek, to illustrate which six excellent
plates have already been drawn by Mr. C. L. Griesbach, F.G.S.?

Paleozoic Rocks.—The oldest rocks of Central Sumatra appear to
consist of granites, granite-syenites, and syenites in several modifica-
tions. Next in order follow sedimentary rocks, which are probably
of either Carboniferous or Permian age, as they contain Fusuline,
only met with in rocks belonging to the Carboniferous and Permian
periods (Verbeek, op. cit. p. 478).

The species of Fusulina from the Carboniferous Limestone, Padang
Highlands, West Coast of Sumatra, has been referred by Mr. H. B.
Brady to Fusulina princeps, Khrenberg, sp. (see Grou. Mac. 1875,
p. 587, Plate XIII. Figs. 6 a, b, c). The only other Paleozoic fossils
which remain to be noticed are represented on our Plate X. Figs. 1,
2, and 3, Brachiopoda belonging to the genera Spirifera and Productus.

1 See Grou. Mac., 1875, Decade II. Vol. II. pp. 477-486, and op. cit. 1877,
Dec. II. Vol. IV. pp. 448-444 (Plate XIV.).

* The Fossil Foraminifera, by Henry B. Brady, F.R.S., Grou. Mac., 1875, Dec.
IT. Vol. II. pp. 532-539 (Plates XIII. and XIV.). The Fossil Fishes, by Dr. A.
Giinther, V.P.R.S., Grou. Mac., 1876, pp. 483-440 (Plates XV.—XIX.).

3 This memoir and its illustrations are, like the former communications, published
with the authority and assistance of the Dutch-Indian Government.

DECADE II.—VOL. VI.—NO. IX. 25

386 Dr. H. Woodward—On Fossil Shells from Sumatra.

1. Spirifera glabra, Martin, sp., 1809. Pl. X. Fig. 1.

This very variable and widely distributed species is amply illus-
trated in Mr. Davidson’s great work on “ British Fossil Brachiopoda,”
vol. ii. Permian and Carboniferous species (1858-63), pp. 59-62,
pl. xi. and xii. The following description of the species is given by
Mr. Davidson in his Paleontographical Monograph above cited :—
“'Transversely oval, rarely as long as or longer than wide. Valves
almost equally convex, with a mesial elevation or fold in the dorsal,
and a sinus in the ventral valve. Hinge-line much shorter than the
greatest width of the shell; cardinal angles rounded ; beaks rather
approximate, that of the larger or ventral valve prominent, incurved,
and of moderate dimensions. A hinge area in the dorsal valve, that
of the ventral one triangular or of moderate dimensions, with its
lateral margins more or less sharply defined ; fissure partially covered
by a pseudo-deltidium. The mesial fold in the dorsal valve is either
slightly and evenly convex rising gradually from the lateral portions
of the valve, or abruptly elevated, with a longitudinal depression
along its middle, which is also at times reproduced in the sinus of
the ventral one. The spiral appendages are large, and occupy the
greater portion of the interior of the shell. Surface of valves in
general smooth, but sometimes a few obscure rounded ribs may be
observed on their lateral portions.”

The largest of our Sumatran specimens (that figured in Pl. X.
Fig. 1) accords most nearly with Mr. Davidson’s fig. 8, pl. xi.,
but is broader in proportion to its length ; being 19 lines in length
and 24 lines in width. The surface of the shell is smooth. One
specimen sent exposes the interior of the ventral valve and exhibits
evidence of the spiral appendages.

Distribution: —Spirifera glabra has an extremely wide distribution,
being recorded from Britain, Ireland, Belgium, France, Russia,
America, Australia, and Sumatra.

[For the identification of this and the following Carboniferous
forms, I am indebted to my colleague Mr. R. Etheridge, jun., F.G.S.,
who has paid special attention to the fauna of the Carboniferous
epoch. |

2. Productus undatus, Defrance, 1826. PI. X. Fig. 2.

Davidson, Brit. Carb. Brach. (Pal. Soc. Mon.), 1861, Pt. V. p.
161, pl. xxxiv. figs. 7-13.

The following specific characters are given by Mr. Davidson :—
‘Shell somewhat sub-orbicular or slightly transverse, hinge-line
rather less than the width of the shell. Ventral valve regularly
vaulted, very convex, without sinus; beak small, rounded, incurved,
not extending much beyond the hinge-line; auriculate expansions
small. Surface covered with numerous irregular or interrupted sub-
parallel, undulating, concentric folds or wrinkles, which become
wider and more produced with age and having their narrow, almost
perpendicular, side directed towards the beak ; the valve is, moreover,
ornamented by numerous minute, rounded, thread-like striz,
separated by narrow sulci, and of which from five to six may be

Dr. H. Woodward—On Fossil Shells from Sumatra. 387

_counted in the thickness of a line, and swelling out at intervals they
give rise to a slender spine. Dorsal valve concave, following the
curves of the opposite one, and similarly ornamented. Interior
unknown.”

Distribution :—Britain, Ireland, Belgium, Russia, Tasmania, New
South Wales. and Sumatra.

3. Productus semireticulatus, Martin, sp. Pl. X. Fig. 3.
Davidson, Brit. Carb. Brach. (Pal. Soc. Mon.), 1861, Pt. V. p. 149,
pl. xliii. figs. 1-11, and pl. xliv. figs. 1-4.

The subjoined specific description is taken from Mr. Davidson’s
monograph :—“ Very variable in shape, transversely oval, sub-cylin-
drical or elongated; hinge-line as long as, or somewhat shorter than the
width of the shell; ventral valve gibbous and variably vaulted, with
a shallow longitudinal median sinus or depression ; auriculate ex-
pansions moderately developed ; beak wide, incurved, usually covered
with irregular, concentric, undulating wrinkles, larger and deeper
upon the ears, while the entire surface of the shell is ornamented by
many radiating, longitudinal, rounded strize, which become more
numerous towards the margin from bifurcation and interstriation
and from which project, at variable intervals, tubular spines of
sometimes considerable length. Dorsal valve moderately concave,
following the curves of the opposite one, and similarly sculptured.
Dimensions variable, some examples having attained three inches in
length, by four in breadth.”

Distribution :—Great Britain and Ireland, Belgium, Germany,
Russia, Spitzbergen, Punjaub, Australia, North and South America,
and Sumatra.

4. Productus costatus, J. de C. Sby., 1827. (Not figured.)
Davidson, Brit. Carb. Brach. (Pal. Soc. Mon.), 1861, Part V. p.
152, pl. xxxii. figs. 2-9.

Although unintentionally omitted from our Plate, we must not
fail to record this species from the Carboniferous rocks of Sumatra.

We subjoin the specific description of this form given by Mr.
Davidson :—‘“ Shell very variable in shape, transversely semi-
cylindrical, wider than long; hinge-line about as long as the width
of the shell. Ventral valve gibbous, very much vaulted, abruptly
arched, or obscurely geniculated ; beak incurved, but not overlying
the hinge-line, except at its attenuated extremity, a median longi-
tudinal sinus or depression dividing the valve to a greater or less
extent into two lobes; ears more or less developed, sloping abruptly
from the visceral portion, with a strong, rugged, semicircular ridge
on either side, obliquely placed to the hinge-line, and from which
project several long, cylindrical hollow spines, similar to those
situated close to the cardinal edge. Surface covered with a variable
number of strong, longitudinal, rounded ribs of unequal width, and
which become more numerous towards the margin from occasional
bifurcation or intercalation, while the whole visceral portion is
crossed by numerous regular concentric wrinkles, producing reticu-
late tuberculations. The spines are long, but variable in number,

388 Dr. H. Woodward—On Fossil Shells from Sumatra.

projecting here and there from the ribs. Dorsal valve somewhat
geniculated, following the curves of the opposite valve, a slight
median elevation corresponding to the sinus of the ventral valve ;
the visceral portion is usually somewhat flattened, while the anterior
portion of the valve becomes more or less abruptly bent upwards;
the sculpture being similar to that of the opposite valve.”

Distribution :—This species is recorded as occurring in Great
Britain and Ireland, in Belgium, Russia, North America, the Punjaub,
and in Sumatra.

This concludes our notes on the Paleozoic fossils of Sumatra, and
we pass on to consider those of later date.

5. Pecten, sp. Pl. X. Fig. 12.

This species is represented by a single minute example, having
both valves united. The ribs upon one side have every second or
third more prominent with one or more intermediate smaller ribs.
On the opposite valve they are rather more uniform in size.

We do not propose to name this species.

Formation and Locality :—Tertiary Limestone, Sumatra.

6. Pecien, sp. Pl. X. Fig. 13.

As only a portion of one valve is preserved, this specimen is too
imperfect to afford justification for specific description. The valve
exhibits about 24 rounded ribs broader than the interspaces, which
contain traces of fine linear strize.

Locality and Formation—Tertiary Marl-clay, Island of Nias.

7. Arca Verbeekii, H. Woodw. Pl. X. Fig. 9.

Shell subquadrate—inequilateral, beaks prominent and anterior,
hinge-area moderately wide, between 20 and 24 strongly imbricated
ribs of about the same width as the interspaces—posteriorly oblique.
This form approaches most nearly to A. diluvii, Lamk.

It affords me much pleasure to dedicate this elegant form to
Mynheer R. D. M. Verbeek, by whom it was collected.

Locality and Formation:—From the clay-marls of (probably)
Miocene age. Island of Nias, Government of the West Coast of
Sumatra.

8. Hemicardium, sp. Pl. X. Fig. 11.

A somewhat gibbose triangular shell having 12-14 rounded coste,
posteriorly subcarinated and depressed as in the ordinary forms
referred to this section of Cardium.

Locality and Formation :—From the Miocene Clay-marls, Island of
Nias, Government of the West Coast of Sumatra.

9. Lunulocardium limaforme, H. Woodw. Pl. X. Fig. 16.

This is a gibbose elongate shell with prominent umbones, slightly
recurved, having numerous rounded ribs, traces of which are, how-
ever, only faintly shown in the casts. Impressions corresponding
with the central and lateral teeth, and of the adductor muscles, are
also to be observed in the casts.

I am unable to refer this shell to any already-described form, and
have ventured, therefore, to treat it as a new species. There are
several specimens, that figured in our Pl. X. Fig. 16, being one of

Dr. H. Woodward—On Fossil Shells from Sumatra. 389

the smallest. Size of largest valve: Long. 55 mm.; Lat. 40 mm.
Size of smallest valve: Long. 30 mm.; Lat. 22 mm.

Locality and Formation:—From the Miocene Clay-marls, Island of
Nias, Government of the West Coast of Sumatra.

10. Lucina, sp. (cast). Pl. X. Fig. 7.

This is evidently a cast of Zucina, but the state of preservation
precludes the possibility of offering an opinion as to the species to
which it should probably be referred.

Locality and Formation:—This cast was obtained from Government
of the West Coast of Sumatra, “Stage 5”’ of M. Verbeek, Coral-
limestone “including internal casts of Gasteropods and Conchifers,
together with Hchinide comparable with the Hocene forms Prenaster
Alpinus, Desor, and Periaster sub-globosus, Desor.” (Verbeek, Guot.
Mae. 1877, p. 444.)

Gen. Isocardia, Lamarck, 1799.

Shell cordate, ventricose; umbones distant, sub-spiral; ligament
external; hinge-teeth 2:2; laterals. 1-1 in each valve, the anterior
sometimes obsolete. Of this genus five species are recorded from
Britain, Mediterranean, China, and Japan, and 70 fossil species
from the Trias and higher formations.

H. and A. Adams, in their Genera of Recent Mollusca, 1858, vol. ii.
p- 461, have proposed, for certain forms of Isocardia, a subgenus.

Sub-genus Metocardia, H. and A. Adams, 1858.

‘Shell with the surface of the valves concentrically grooved, not
covered with an epidermis.” (Valves strongly carinated at the posterior
end, forming a prominent acute diagonal ridge. Posterior slope con-
cave.) To this subgenus has been referred :—M. Lamarckii, Sby.; M.
Moltkiana, Chem.; M. Cumingii, A. Ad.; M. tetragona, Adams and
Reeve: M. vulgaris, Reeve; all recent forms: also M. Guerangeri,!
d’Orb. (Cénomanien), Chloritic marl of Le Mans; and M. (Isocardia)
pyrenaica, d’Orb., from the Cretaceous of Corbiéres, Aude, France.
This latter form, however, we should be more inclined to refer to
the genus Opis.

11. Meiocardia sub-Cumingii. Pl. X. Fig. 10.

Of the various species of Meiocardia, it is very interesting to
observe that the recent M. Cumingii from China seems almost
identical with our fossil; the only perceptible variation being that
in the recent form the raised concentric ridges are about 24 in
number, whereas in the fossil there are upwards of 30. In the
fossil form the diagonal ridge is even more prominent and acute
than in the recent species, and the posterior slope more concave.
These are the only points deserving of special attention—save that
one of the fossils (casts) is much larger than the recent form ;
probably half as large again as the specimens of M. Cumingit from
China in the British Museum.

1 Not mentioned in the text of d’Orbigny; but marked on his plate 257bis. as
“* Tsocardia Guerangeri, @ Orb.” In his Prodrome de Paléontologie Stratigraphique
Universelle, vol. ii. 20 Etage Cénomanien, No. 290, p. 160, however, he enters it
as “ Opis Guerangert, d’ Orb, 1848.”

390 =Dr. H. Woodward—On Fossil Shells from Sumatra.

I have to express my obligation to my colleague, Dr. A. Giinther,
F.R.S., Keeper of the Zoological Department, for permission to
compare and examine the recent species of Meiocardia in the Collec-
tion.

Measurements of Meiocardia sub-Cumingii:—Length of valve of
smaller specimen 21 mm., width 22 mm. Length of valve of largest:
specimen 30 mm., width 25 mm. Length of valve of Meiocardia
Cumingii 20 mm., width 20 mm.

12. Cardita Sumatrensis, H. Woodw. Pl. X. Fig. 5.

This species presents some affinity to Cardita Schwabenauii,
Hornes, and also to a form from the St.-Cassian Beds.

Shell quadrate, anterior slightly rounded, posterior straight, ribs
15 to 17 in number, carinated and imbricated, the intermediate
spaces being much wider than the ribs.

Width of valve 20 mm., length 16 mm.

This is a most abundant shell occurring closely packed upon the
surface of yellow argillaceous slabs, feeling like “‘steatite” to the touch.

Locality and Formation :—Tertiary, Sumatra. Probably from the
clay-band associated with Sandstones and Coals (56) described by
M. Verbeek (Grot. Mae. 1875, p. 479).

13. Cardita, sp. (cast). Pl. X. Fig. 6.

This specimen appears to have been somewhat more coarsely
ribbed than the preceding, and the umbones of the valves rather
more produced ; but the specimen is too much abraded to determine
satisfactorily.

Width of valve 21 mm., length 19 mm. Cast in limestone (No. 5),
Verbeek, Grou. Mac. 1877, p. 444. Hocene? Tertiary, Sumatra.

14. Cytherea, sp. (cast). Pl. X. Fig. 15.

Only a single valve preserved as a cast, which is referable to the
genus Cytherea.

Locality and Formation :—From the Miocene Clay-marls, Island of
Nias, Government of the West Coast of Sumatra.

15. Callista, sp. (cast). Pl. X. Fig. 14.

A cast of a compressed sub-quadrate shell, with the umbones pro-
minent and very anterior, lunule deep (no muscular impressions
visible, hinge-line long) ; below which the shell is slightly grooved.

Locality and Formation:—From the Miocene Clay-marls, Island
of Nias, Government of the West Coast of Sumatra.

16. Dosinia cretacea, Reeve (cast). Pl. X. Fig. 8.

Reeve (1880), Conch. Icon., sp. 35 (Artemis), pl. vi. fig. 35.
Sowerby, Thesaurus Conch., 1855, vol. ii. p. 667, No. 46, t. 142,
fig. 51.

My colleague, Mr. Edgar A. Smith, who has most obligingly com-
pared this and other fossil specimens with the recent shells in the
Zoological Gallery for me, remarks :—“ These casts agree remarkably
well with the recent Dosinia cretacea, Reeve. The form, the depth
and size of the lunule, and the shape of the muscular impressions as
far as traceable, are identical.”

Dr. H. Woodward—On Fossil Shells, etc., from Sumatra. 391

The following is the description of this species translated from
Dr. Eduard Romer’s Monograph on the Molluscan genus Dosvnia,
Scopoli (Artemis, Poli), 1862, 4to. p. 34.

Shell suborbicular, somewhat tumid, thick, very inequilateral,
rather flexuous posteriorly, finely and regularly striated concen-
trically ; strie at the sides, especially posteriorly, more elevated ;
chalky white, sometimes straw-coloured towards the umbones;
umbones rather tumid, occupying one-fourth the length; ventral
margin semicircular at both extremities, very steep; anterior
dorsal margin very short; posterior sloping moderately behind and
curved ; lunule cordiform, impressed, striated, sharply circumscribed ;
area somewhat large, slightly excavated; ligament conspicuous ;
nymphe slender; pallial sinus large, narrow, triangular, apex
rather acute, terminating nearly horizontally at the upper edge;
cardinal lamina narrow; lateral teeth large, papilliform; cardinal
tooth perpendicular, slender, greatly thickened; last tooth in right
valve very remote, slender, superficially bisulcated, median pit very
large.

This species is found living at Manilla, at the Island of Luzon,
Philippines. Our fossil specimens are derived from the so-called
Miocene Marl-clays of the Island of Nias, Government of the West
Coast of Sumatra.

17. Ecuinopermata. Spine of Cidaris? Pl. X. Fig. 17.

There are several of these spines from the locality mentioned
below. They appear to be referable to a species of Cidaris, but as
they are much worn, and as no plates of the test are associated with
them, it would be difficult to correctly assign them to any specific
form. :

Locality and Formation :—From bed 5, Coral-limestone, with casts
of Gasteropods and Conchifers, together with Hchinide (see GEOL.
Mac. 1877, p. 444), Padang Highlands, Government of the West
Coast of Sumatra.

Puantx.—Sparganilithes, gen. nov.

18. Sparganilithes gemmatus, H. Woodw. PI. X. Fig. 4.

This anomalous fossil remain was obtained from the division
marked No. 3 by M. Verbeek, who thus describes it (see GrOoL.
Mae. 1877, p. 444): “ Sandstones with Coal-seams, without organic
remains, nearly 1,000 feet thick, resting unconformably on the
Marl-shales. The only fossils in them are undeterminable stalks
and leaves of plants, small Melanie, and traces of fish.”

The Melanie are so abundant as to form almost the entire substance
of some of the shale-bands with their compressed shells. The
species closely resembles Aelania crebricostata in size and ornamenta-
tion; but is rather more strongly corrugated. The lime of the
shells has been entirely dissolved away and removed, only the
impressions remaining in the shale.

At first sight it appeared difficult, if not impossible, to refer the
fossil figured in our Plate (Fig. 4) to any known group or organism
with certainty. The specimens are three in number, being found in

392 Dr. H. Woodward—On a Fossil Plant from Sumatra.

dark, fine-grained, thinly-laminated, and bituminous coal-shale, appa-
rently detached from any other organism. The organism consists of
a disc-like polygonal body, surrounded, in one instance, by six, in
another by seven similar plates, and these again encircled by from
thirteen to fourteen similar but somewhat adpressed plates or scales
forming the outer circle. The surface of each separate plate or scale
is covered with a thin crust of pure coal, which is seen also to pass
down and penetrate between each separate polygonal body.

In one specimen the central plate is absent, but six closely pressed
plates meet and fill up the interior of the disc, whilst the border is
composed of fourteen slightly elongated adpressed plates.

Whilst engaged in the examination of this fossil, and instituting
comparisons with various other organisms, my friend Professor
Morris made the happy suggestion that I should compare it with the
fructification of Sparganium ramosum.

Having been kindly permitted by my colleague Mr. W. Car-
ruthers, F.R.S., to consult the Herbarium under his charge, I was
delighted to find that the fruit upon dried specimens of Sparganium
ramosum was, after lateral compression, almost identical in appearance
with our fossil, as well seen in the enlarged figure on our Pl. X.
Fig. 4. Even the slight ridges, represented on the outer circle of
seeds in our figure, are seen in the dried and compressed prismati-
cally arranged drupe of Sparganium. Of course the fossil does not
represent an entire fruit.

The following is the description of Sparganium ramosum, Hudson,
given in Sowerby’s ‘English Botany,’ 1869, vol. xi. p. 5: “ Radical
leaves broadly linear, stiff, not floating, sharply keeled and triquetrous
at the base, with the lateral faces channeled ; stem-leaves with their
‘sheaths not inflated. Flowering-stem erect, stiff, branched at the
apex. Flower-heads in a panicle. Female flower-heads sessile on
the lateral branches of the panicle, one to three on each branch.
Male flower-heads very numerous, sessile towards the extremities of
the lateral branches and termination of the rachis of the panicle.
Stigma lanceolate-linear. FRurr sessile, prismatic turbinate, with a
short beak. Leaves green, broadly linear, not pellucid.”

The Typhacee (“Cats-tails”) are true bog or marsh-dwelling
rush-like plants, and this genus is met with in almost every part of
the world, including the British Islands.

From the fact that the only other vegetable remains observed in
these coal-shales are linear leaves which answer to the description of,
and might very well have belonged to Sparganium (a truly aquatic
genus of plants); and further, that the only animal organisms
observed in these shales are hosts of freshwater snails (J/elaniz) and
a few scattered fish-teeth,, we may venture to conclude, both on
direct and collateral evidence, that the reference of our fossil to the
fruit of this genus is probably correct.

1 The teeth are referred by Dr. Gitinther to a Cyprinoid fish of the genus
Hexapsephus. The dorsal and pectoral spines are referred by him to a Stluroid
(aiso a freshwater form), and named Pseudeutropius Verbeeki (see Grou. Maa. 1876,
p- 440). :

G. W. Lamplugh—The Boulder-clay at Bridlington. 398

EXPLANATION OF PLATE X.
(Figs. 1-8, Carboniferous, Highlands, Sumatra.)

1. Spirifera glabra, Martin, sp. (ventral valve).

2. Productus undatus, Detrance (ventral valve).

3. ———— semireticulatus, Martin (ventral valve).

4. Sparganilithes gemmatus, H. Woodw., fruit of a Rush-like plant,
Tertiary Coal-shales, Sumatra.

5. Oardita Sumatrensis, H. Woodw., Tertiary, Sumatra.

6. Cardita, sp. (cast of) 6

7. Lucina, sp. (cast of)

», 8. Dosinia cretacea, Reeve, Miocene Tertiar y? Island of Nias.
9. Arca Verbeekii, H. Woodw., ,,
10. Metocardia sub-Cumingii a .

», Ll. Hemicardium, Island of Nias.

», 12. Pecten, sp. op

” 13. » SD. ”

», 14. Callista, sp. (cast) 51

», 15. Cytherea (cast)

5, 16. Lunulicardium limafor ry H. Woodw., Island of Nias.

» L7. Spine of Cidaris ; Padang Highlands, West Coast of Sumatra.

(Lo be continued in our next Number.)

TIl.—On tHe OccurrEeNCcE oF I'RESHWATER REMAINS IN THE
BovuLpER-CcLAY AT BRIDLINGTON.

By G. W. Lampivueu, Esq.

N this part of the Yorkshire coast, the storms of last winter have
often bared parts of the beach, for a time, of their usual covering
of sand and shingle, and have thus exposed to observation many
interesting features in connexion with the Drift series. Of these,
the most instructive point which has come under my notice is the
one which forms the immediate subject of the present communication.
In an exposure, on the beach, to the north of Bridlington, I saw
freshwater remains, intermingled with and covered by a Boulder-
clay. But before proceeding to details, it will perhaps be better to
give a brief account of the chief divisions of the glacial beds in the
neighbourhood, without a knowledge of which, the reader might
find much difficulty in understanding the continual references made,
in the sequel, to these divisions.

The base of the series is generally believed to be formed by the
“Basement” clay, which Mr. 8. V. Wood has shown! to be the
same as the “Great Chalky Boulder-clay ” of the country further
south. I pointed out in a former paper,” that this clay extended as far
north as Bridlington, and there contained the bed of sand with Arctic
shells long known as the “ Bridlington Crag.” Still more recently
I have seen the same clay in a very interesting exposure in Filey
Bay (north of Flambro’ Head). opposite the village of Reighton,
and here also it contained streaks of a clean blue clay, with many
crushed shells, identical in all respects with similar streaks in the
same clay at Bridlington, which are considered as forming part of
the “ Bridlington Crag.”

! Quart. Journ. Geol. Soc. vol. xxiv. p. 146.
2 Gro. Maa. 1878, p. 509; see also Note, p. 573.

304 G. W. Lamplugh—The Boulder-clay at Bridlington.

Above the “ Basement” clay, there sometimes lies a snuff-coloured
clay, which is generally beautifully laminated. This clay is abso-
lutely destitute of pebbles, and contains no shells, nor, in fact, any
foreign admixture. Its thickness is very variable, but it does not
often exceed four or five feet.

In the exposure at Reighton just referred to, I saw patches of this
clay occupying the same position with regard to the Boulder-clays
as at Bridlington.

One feature of great interest, which I have lately seen in connexion
with this clay, is that, in some places, it shows a very well-marked
unconformity between its upper and lower parts.

The lower division, which is the thicker, consists of very fine, pure
clay, clearly laminated, but twisted and contorted in all directions.
Over it lies the upper division, which is more sandy in nature, and
is also finely laminated, but lies perfectly even and undisturbed
over the edges of the contorted laminz below. This upper part
also occasionally shows clear steep ripple-marks, running H.N.E.
by W.S.W., and having their steep sides facing 8.S.H., which
shows the probable course of the current by which they were
formed, to have been from the N.N.W.

In one or two places a seam of sand comes between this Laminated
clay and the overlying Boulder-clay (see Section, F.).

Resting generally on the Middle Laminated clay just described,
but where that bed is absent, directly on the ‘‘ Basement,” is another
Boulder-clay, known as the “ Purple” clay. It contains a few well-
worn and rounded shell-fragments. It has, also, numerous inter-
calated beds of sand and gravel, which contain no shells, and which
do not generally continue for any distance. To this, however, there
is an exception in the case of the bed D of the section, which may
be traced continuously northward for over half a mile, when it is
lost to sight amid the slips which there obscure the cliff.

A slight difference is observable between the clay above and below
this sand bed. Both the sand, D, and the upper bed of Boulder-clay,
C, swell out to a much greater thickness a little further to the north
of the section, the sand attaining a thickness of 12 feet, and the clay
of nearly 10 feet. It is a matter of conjecture whether this upper
band of clay may not be a continuation of the peculiar clay, presently
to be referred to as covering the freshwater remains, a point which
can hardly be satisfactorily settled, as the sand and gravel bed, D,
dies out 70 yards north of the position of the freshwater remains on
the beach, and these latter also are only seen in a horizontal exposure,
and not in section. But if the band of clay, C, is really separate
from the remainder of the Purple clay, it may of course be continued
after the sand and gravel bed has thinned out, and resting then
directly on the Purple clay; in which case, as the difference between
them is only slight, it would be difficult to mark the line of division.
There is certainly a difference between the upper and lower portions
of the mass of clay, which forms the base of the cliff just under
Sands Cottage, the upper part being more stony, and showing irre-
gular streaks of various tints, generally greenish.

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3896 G. W. Lamplugh—The Boulder-clay at Bridlington.

It is in the “ Purple” clay that the blocks of Shap granite generally
occur. Though they are not often seen on the coast south of Flambro’,
and have been supposed to be absent,’ I noticed one lately, about a
mile to the south of Bridlington. It was resting on an exposure of
the lower part of the “ Purple” clay. Its dimensions were 14 by 1
by 1 feet.

Above the top Boulder-clay, in the South Cliff, lie thick beds of
laminated warp and sand, mingled with, and passing into, gravel.
To the north of the town, these are represented by the gravels, B,
of the section. These warps and gravels Mr. Dakyns has recently
shown to be glacial.2 They form the top of the glacial series
observable in the cliff sections near Bridlington.

On the beach near Sands Cottage, a small house which stands
close to the cliff edge about a mile north of Bridlington Harbour,
the sand and shingle have, during the late stormy season, been
frequently swept off. On examining one of these exposures, which
laid bare a peculiar Boulder-clay, which I supposed at the time to
be part of the “Purple” clay, I came across the remnants of the
freshwater deposit, consisting of patches of dark silty sand, peaty
vegetable matter, streaks of marly clay, passing into clayey sand,
often stained black, and containing in places shells, sometimes
sparsely, and sometimes in profusion. These shells were all of one
species—a variety of Limneea peregra.

These silty sands and clays were closely associated with patches
of gravel, generally of chalk, and sometimes ferruginous; a few of
these gravel patches, however, contained scarcely any chalk, and
appeared to be derived from the washings of a Boulder-clay. The
way in which these gravels and the undoubted freshwater remains
were intermixed and connected, made it evident that the gravels,
also, were of freshwater origin. I noticed in the gravels one or
two large foreign blocks.

These patches of gravels, sands and silts were seen to be con-
fusedly mingled with, and, in places, covered by a Boulder-clay, or
probably, more correctly, a till, of unusual aspect, the whole together
representing the top of the “Purple” clay of Mr. 8. V. Wood,*
which has here, as elsewhere, evidently suffered considerable
denudation.

This clay however differed in appearance from the general character
of the Purple clay in several respects. It was not of nearly so
compact a nature, and where washed by the waves, became very soft
and unctuous, almost resembling in this the Middle Laminated clay.
It was also not nearly so homogeneous, being full of curious
patches of boulders and detritus ;—here, the space of a couple of
square feet was covered with a mass of small angular fragments of
black shale ;—there, by a similar patch of well-rounded gravel,
entirely free from chalk; whilst other patches of gravel consisted
almost altogether of chalk. Streaks of variously tinted clays, as if
from the grinding of some particular rock alone, were plentifully

1 Quart. Journ. Geol. Soc. 1870, vol. xxvi. p.90. *% Gzox. Mae. May, 1879, p. 238.
3 Quart. Journ. Geol. Soc. 1868, vol. xxiv. p. 149.

G. W. Lamplugh—The Boulder-clay at Bridlington. 397

dispersed in the clay, with here and there a patch of fine soft clay,
entirely free from stones.

The abundance of boulders, of a size much above the average,
was another striking feature. I noticed this fact, and the difference
in the appearance of the clay, long before I even suspected the
presence of freshwater remains. The blocks, a great number of
which were from 14 to 2 ft. long, by about one foot in height
and breadth, were chiefly Carboniferous, and were therefore far-
travelled. The proportion of blocks from rocks in the district, was
surprisingly low; in fact, they were well-nigh absent. Carbon-
iferous Limestone was recognizable by its fossils, also Millstone-
grit, Gannister, Basalt, and Carboniferous Sandstone,—the latter
being particularly abundant. In one place on the beach, so thickly
were these blocks scattered, that, over an extent of nearly sixty
square yards, one might step from one to another.

Many of the blocks had their angles wonderfully preserved; and
such of them as were of flattened shape, were frequently tilted at
high angles or even set on edge in the clay. From the character of
the majority of the boulders, but few had retained scratches. I
noticed, however, a few examples. One mass of hard chalk 11 in. by
8 in., which showed well-preserved markings, was scored by two
distinct sets of scratches; the older ones, running east and west,
being crossed at right angles by others, running north and south.
This cross-scratching was also observable in many of the instances
in which markings were preserved. I could not find that the longer
axes of the stones preserved any definite direction, though, in one or
two instances, it agreed with the direction of the chief set of
scratches; notably, in the case of one large boulder of Mountain
Limestone, which was partially buried in the foot of the cliff, and
which had a length of 3 feet, by about 2 feet in breadth and height.
In this case, the scratchings and longer axis both ran N.W. and 8.E.

I have seen the clay showing these peculiarities, exposed on the
beach over an extent 160 yards in length, by about 30 in width
(see section). To the north, it is bounded by the Middle Laminated
clay, as shown in the section, which here rises above the level of
high tide, and to the south by the ‘‘ Basement” clay, on which it in
great part rests, the Laminated bed being absent for some distance
south of Sands Cottage. The ‘‘ Basement” clay, therefore, directly
underlies, in many places, the clay just described, and cuts it off
from the beach when it rises to the cliff-line opposite the Alexandra
Hotel.

The Boulder-clay which contained the freshwater remains, con-
tained also a few very small fragments of marine shells of the usual
Boulder-clay species ; an interesting point, as it is clear that Limnea
and Tellina could not live in the same place, at the same time. Yet
here they occurred on the same horizon of the same bed. There
was this difference, however, between their positions; that whereas
the freshwater shells were mostly perfect, and were still surrounded
by their own proper matrix, the marine shells were in minute
fragments, and were scattered through Boulder-clay. The latter
have therefore probably been the travellers.

398 G. W. Lamplugh—The Boulder-clay at Bridlington.

As I was unable to find any trace of the freshwater beds in the
cliff-section, it is difficult to make out their true relation to the beds
beneath, which were sometimes the lowest part of the Purple (which
has been almost altogether denuded away here), and sometimes the
‘Basement’ Clay. It is somewhat curious that just over the extent
covered by these remnants, the Middle Laminated clay should be
absent ; but as it is also absent at other places, this may be merely a
coincidence. .

The way in which the freshwater beds were tilted and cut up
into shreds, separated from each other by thick walls of Boulder-
clay, was remarkable. One long strip, containing shells, was five
yards long, by only three inches in width, and had gravel on each side.
In another case, a small patch of peat, one foot square, was bounded
on all sides by Boulder-clay, and was, to all intents and purposes,
a boulder itself. These ‘shreds and patches’ were spread here and
there over the whole extent of the peculiar clay just described.

To all appearances, we have here the silt of an old pond, of limited
extent, and interglacial in age, through which the ice, on its return,
has ploughed, partially destroying it.

As to the exact place of this interglacial period in the series, as
seen in the cliff, there is some doubt. It was, at any rate, later
than the pause which took place between the formation of the
“ Basement” and “ Purple” clays; and of which the Middle Laminated
band is a record. But whether it was formed during a local pause
in the Purple clay period itself, or was altogether later, it is a more
difficult matter to determine.

It is probable, from the many included sand and gravel beds in
the ‘ Purple” clay, that changes of some sort did take place during
its formation, but, as far as is known, these sand beds contain no
signs of life, either freshwater or marine.

If we allow that it was of later age than the Purple clay, we
must also grant that the peculiar clay already described, with which
it is mingled, and by which it is in part covered, is not merely
the upper part of the Purple clay, but is altogether newer. But
the only clay which is known to be newer than the “Purple,”
is the Hessle clay of Messrs. Wood and Rome,’ and between
it, and the bed under consideration, there are no points of resem-
blance. The number and size of its sharp-angled blocks; the
rarity of chalk fragments; and the distance which most of the
boulders must have been carried, make it impossible that this could
have been the product of the coast-ice of a limited submergence,
which derived its blocks from a pre-existing clay. It is difficult to
conceive how anything short of a general Ice-covering could bring
distant Carboniferous blocks of such size, and in such abundance.
It more nearly resembles the description which Mr. 8. V. Wood gives
of the upper part of the Purple clay* north of Flambro’, to which
he has given the name of “Purple clay without chalk,” and in
which he believes the Shap blocks to occur,—bespeaking a wide
expanse of ice.

1 Quart. Journ. Geol. Soc. 1868, vol. xxiv. p. 146. 2 Q.J.G.8. vol. xxvi. p. 90.

Norman Taylor—The Cudgegong Diamond Field. 399

As may be partly seen from the section (which shows its northern
side only), the freshwater remains occupy the site of an old hollow,
which is not even yet quite filled up. This hollow existed even in the
«Basement ”’ clay; is continued in the “ Purple” clay, and also in the
glacial gravels which overlie the Boulder-clay, and which are so
strangely, apparently, thrust into it (B. of section); and finally it
has been, in recent times, the bed of a pond, which has thrown
down the thick bed of marl (A.), partially obliterating the hollow.

This recent marl offers a strongly marked contrast to the ancient
bed in the variety of its shells, which are of many species, of Cyclas,
Planorbis, Limnea, Bithynia, etc.; whilst the old bed, though so rich
in individuals, can count but one species; as though, by some
chance, this one shell had, by virtue of its habits, gained a footing,
and had increased, undisturbed by any competitors, which at a
later period found the same position so favourable to them. I have
not seen Limnea peregra in the recent marl.

Tn conclusion, I may mention the similarity between these fresh-
water fragments and the so-called “ Bridlington Crag,” with regard
to their relations to the respective Boulder-clays which accompany
them. In an exposure of the “Basement” clay, on the beach
opposite the terraces which protect the town, which was bared in
March last, I saw several separate streaks of a fine, clean, blue clay,
and also of a sandy clay, twisted and distorted amidst the Boulder-
clay. These streaks contained marine shells of the well-known
Bridlington species — Astarte borealis, Tellina balthica, Cardita
borealis, Natica clausa, etc. Some of these shells were perfect, but
more were crushed as they lay, and the fragments more or less
separated, as if by the shearing under pressure of their yielding
clayey matrix. In a precisely similar manner were the freshwater
clays drawn out in their Boulder-clay, with the shells similarly
scattered, though not generally so broken.

Thus the movement of the ice at one time over a soft sea-bottom,
and, at another, over the silty bed of a pond, has produced precisely
similar effects. And the same ice, which cut up the freshwater
deposits in this manner, has passed over the sand and laminated
clay not 100 yards to the north, and has left scarcely a sign of its
passage.

>

IIJ.—On THE Cupcecone Driamonp Fretp, New Sovran Wats.
By Norman Tavtor, Esq., of the late Geological Survey of Victoria.

Communicated by R. Erueriper, jun., F.G.S.; of the British Museum.

INCE the publication, in the Quarterly Journal of Science for
July, 1876, of an article on the Indian Diamond Fields, in
which the writer, Captain Burton, does not appear to be aware of
what has been done in these Colonies towards adding to our know-
ledge of the geological history of the diamond, I have been induced
to re-write a paper, jointly prepared by the late Professor Alex. M.
Thomson, of the Sydney University, and myself, and read before

400 Norman Taylor—The Cudgegong Diamond Field.

the Royal Society of New South Wales on the 7th December, 1870 ;*
and to incorporate with it a series of my own papers (of which the
above was merely a summary), which appeared in the “Sydney
Morning Herald” previously to that date. I shall confine my
remarks to the mode of occurrence of the diamond in New South
Wales, as the late Rev. W. B. Clarke has, in his valuable and
interesting Presidential Addresses to the Royal Society of New South
Wales in 1870 and 1872, almost exhaustively treated the subject,
as far as regards our present knowledge of the occurrence of the
diamond all over the world.

Professor Liversidge, successor to the late Professor Thomson,
of the Sydney University, also read a paper before the Royal Society
of N.S. Wales on Ist October, 1873 (reprinted in Mines and Mineral
Statistics of N. S. Wales, 1875, p. 104), giving a short description
of the Bingera Diamond Field, in the New England District of
N. 8. Wales, which was discovered some years after its predecessor
“the Cudgegong,” to which I shall allude further on; as also to my
late colleague Mr. C. J. Wilkinson’s (now Government Geologist of
N.S. Wales) Reports on the discovery of diamonds in the Tin deposits
of Borah Creek, a tributary of the Gwydir River, and elsewhere.’

Diamonds were accidentally discovered on the Cudgegong river at
Warburton or “'T'wo-mile-flat,’ 19 miles north-west of Mudgee,
N.S. Wales, during the gold rush to that locality in 1867. They
were scarcely noticed at first, but, at last, several stones were sent
to Melbourne jewellers for their opinion, which, ultimately, led
to a company being formed to systematically work the deposits.
Operations were commenced in July, 1869,—numerous private parties
of miners taking up the search at the same time. A large number
of diamonds were obtained, although, in most instances, unfortu-
nately, the expense of sinking through considerable thicknesses of
solid basalt, the small average size of the stones obtained, cartage to
water, and effectual washing, were drawbacks which rendered the
search generally unprofitable, and stood in the way of successful
investment.

During several months’ residence in the district as manager of one
of the companies (after the abolition of the Geological Survey of
Victoria in 1868), and afterwards as a working miner myself, I
made a thorough geological examination of the country, and the
results then obtained are embodied in the following description. The
plan and sections I had made were unfortunately lost after my
departure from the district.

Before describing the nature and contents of the diamond drifts
(for they have never been found in these Colonies in any matrix of
greater age than our Tertiary drifts), it will be well to give a brief
sketch of the geology of the Cudgegong River Basin, and the neigh-
bourhood more immediately surrounding the diamond district. This
will assist in any inferences regarding the original sources of the

1 See Trans. Roy. Soc. N. S. Wales for 1870, pp. 94-106.—R. E., jun.

2 See Mines and Mineral Statistics of N. S. Wales for 1875, pp. 77-80.—
R. E., jun.

Norman Taylor—The Cudgegong Diamond Field. 401

various materials which compose the ancient river gravels, as well
as of those of more modern origin.

The Cudgegong River rises in the acute ‘angle, open to the west
and north-west, which the Great Dividing Range forms in latitude
33° south, and the first part of its course is westerly about 30 miles
to Cudgegong village, and north-westerly 37 miles to the junction
of the Wialdra or “‘ Reedy Creek.” In this part it is bounded on
its eastern side by the Dividing Range, which presents a summit
of horizontally-bedded Carboniferous rocks, with Coal-seams and
Glossopteris shales, and from which, farther eastward, rise the heads
of the Hunter River, the basin in which most of the celebrated Coal-
seams of N. 8. Wales occur. The range, in its continuation south-
wards, completely encircles the heads of the Cudgegong River, and
presents a similar formation of Carboniferous rocks, which occur in
great force on the upper sources of the river, the Hawkesbury
sandstones overlying them. The Carboniferous rocks only reach,
along the course of the river, on its north side, westerly to Rylstone.
Several outliers and cappings of basalt also occur on summits and
spurs of the Dividing Range, as at Mount Bocoble, and elsewhere.
The main area of the basin, and the ridges which confine it on the
south and west, consist of tilted slate and quartzite, with a few
interstratified, and lenticular, bands of fossiliferous limestone. These
beds are either of Upper Silurian or Devonian age, but most
probably the latter, as the late Professor Thomson discovered the
distinctive Devonian genus Calceola in the limestone of Mount
Frome near Mudgee. Both formations may, however, be repre-
sented. These rocks are penetrated in places by small areas of
granite, greenstone, quartz-porphyry, and felstone. At the Wialdra
Reedy Creek junction, near which the diamond drift first sets in,
the river suddenly bends to the south-west and south, and follows
that direction to its junction with the Macquarie River, about 28
miles distant. These distances are as the crow flies. This part of
its course presents a structure similar to that of the older portions
of its upper basin, with the exception that limestone bands are
wanting, and no members of the Carboniferous series, except some
doubtful outhers to the north-west of the ‘Two-mile-flat,” occur.
The whole course of the river is through a rugged mountainous
country—the only large flats being situated on and above the
diamond field.

Outhers of Carboniferous rocks, consisting of sandstones, con-
glomerates, and shales containing Glossopteris and other plants,
form links, at trifling intervals, along the eastern watershed; con-
necting the Carboniferous formation of the Dividing Range with the
Coal-measures of the Talbragar district to the north. A few miles
north of the junction of the Reedy Creek with the Cudgegong River,
the Carboniferous beds form horizontal cappings on hills of slate
and granite, with quartz reefs and limestone bands, as at Tallawang ;
whilst at Guntawang, to the south, and higher up the river, some
doubtful members are met with in the river valley; and near the
junction they occur at a similar low level, and have been covered

DECADE II.—VOL, VI.—NO. IX, 26

402 Norman Taylor—The Cudgegong Diamond Field.

up by the basalt without the intervention of any drifts. The great
differences in level, which these latter beds occupy, deserve con-
sideration. For my own part, I believe, with Professor M‘Coy of the
Melbourne University, to whom the fossil flora were submitted by
me, that the Guntawang and Reedy Creek beds, at the lower levels,
are Mesozoic. They have only been exposed in comparatively recent
times, by the deepening of the river channel, and no remains of
them are found in the older drifts. There is no trace of anything
like Glossopteris in them. For our present purpose it wiil be
enough to show that vast masses of Carboniferous strata have
suffered denudation, as, along the main stream, we find relics of
these rocks, not only in the present bed, but also in the older
drifts, but not in the oldest.

A short distance up the Reedy Creek from its junction with the
Cudgegong River, granite appears in the bed, very coarse-grained,
with large felspar crystals. Higher up the creek, this is overlaid
by basalt, which, a little below the junction of Hapdash Creek, is
cut through by the creek, and forms a causeway. At the Hapdash
Creek junction the basalt gives place to horizontal ferruginous grits
of doubtful age, but probably some portion of the Mesozoic beds
occurs lower down.

The deep auriferous “leads” of Gulgong (N.E. of Guntawang),
from 80 to 150 feet in depth, are composed of a mixture of angular
and partly rounded quartz, in no way resembling the diamond
drifts, although both are covered by apparently the same basaltic
lava flow. The bottom of these leads is higher than the Diamond
leads, and no trace of gems has been discovered in them. Fossil
bones have been found in a more recent lead, near the Pipeclay
diggings, south of Gulgong, and numerous fossil fruits and plant
remains in leads under the basalt at Gulgong, thus indicating their
fluviatile origin; whilst neither fauna nor flora (except as im-
bedded in drifted pebbles, or as particles of ferruginous wood in
the conglomerates) have been found in the diamond leads, and I
think the latter are undoubtedly of marine or fluvio-marine origin,
the circumstances and nature of the drifts having perhaps been
unfavourable to the preservation of fossil remains.

The localities on the Cudgegong, which produced the diamond, lie
on either bank of the river, extending from the Wialdra or Reedy
Creek (18 miles north 30° west from Mudgee) to a point further
down, seven miles south-west, known as Hassall’s Hill. Along
this line the distribution of the diamond is by no means general, but
is confined, chiefly, to a few small outliers of an old river drift,
which occur at various distances from the present river channel, and
at elevations varying from below the river level at the Reedy Creek,
to 40 feet more above it further down. This old drift is capped by
hard, compact, and, generally, columnar basalt. These outlying
hills of diamond-bearing drifts, with their basaltic coverings, though
once forming part of a continuous and widespread deposit, have

* See C. 8. Wilkinson, Annual Report of the Department of Mines, N. S. Wales, for
the Year 1876, p. 172; also Baron von Mueller, iid, pp. 178-180.—R. E., jun.

Norinan Taylor—The Cudgegong Diamond Field. 403

been isolated by extensive denudatign. No point of eruption, to my
knowledge, exists in the district, but the source of the basalt flow
must be to the eastward on the summit of the Great Dividing Range,
where it may possibly have been erupted along a line of fault. Its
remnants can be followed for, at least, 17 miles down the river,
sometimes showing a thickness of over 70 feet, proving the igneous
outburst to have been of considerable magnitude, sufticiently so to
materially alter the physical aspect of the river valley; we may
also infer, conversely, the enormous extent of the subsequent denu-
dation. There is the clearest local evidence that the course of the
river has been much altered since the older drift formed a portion of
its channel.

Enumerating, in descending order, the outliers of the older drift
which affords the diamond, the first area occurs near the junction of
the Reedy Creek with the Cudgegong River, and a short distance up
the former. At this point were situated the works of the Australian
Diamond Mines Company, and the village of Reedy Creek. Through
the Company’s lease a small fringe of basalt runs about north-east
and south-west, and under this, near the edge of the flat, and below
the present river-level, the most productive diamond drift was
discovered. On the hill to the north of the Company’s ground is a
lead, trending, from the north, southerly, and possibly the bed of
the old Reedy Creek, here uniting with the old river-bed. At
the south-west end of the basalt fringe, and at the foot of the rise,
numerous shafts have been sunk. They were originally worked on
a false bottom, at a depth of 29 feet, where the best gold was
obtained; but were afterwards worked by the Company on the
true bottom at a depth of 35 feet. The basalt was only from 4 to 8
feet thick, and the remainder a similar drift to that at Hassall’s
Hill (described hereafter), but without the usual fine sand. A short
distance to the north-east, near the extremity of this basalt fringe,
the sinking was through 80 feet of basalt, and the ground was very
wet. The Reedy Creek lead, from 20 to 25 feet in depth, on a dry
slate bottom, appears to be higher than the red drift in the above
wet ground, the first being the oldest.

The whole of the lead in the Company’s ground, though heavily
timbered below, settled down, owing to continued wet weather.
On the main bottom, in the Company’s lease, there occur high hard
bars of slate and quartzite, all running in the usual strike of the
country. No gold was obtained in the drift between the bars, and
the drift itself was semi-angular, and similar to that in the present
Reedy Creek bed. At first the ground yielded at the rate of 4 to 5
diamonds and 4 dwts. of gold to the load, but afterwards fell off
to one diamond in two loads; and there is no doubt but that
numbers of diamonds were thrown out of the machines (Hunt’s
patent), by careless manipulation, into the tailings, over 1000 tons
of which were swept away by the disastrous floods of the 22nd
and 23rd April, 1870. While at the works myself, I burned and
crushed five bags of cement (which occurs as a bed running in the
same direction as the basalt, and in places from 6 to 8 feet thick),

404 Norman Taylor — The Cudgegong Diamond Field.

and, passing the stuff through a small Hunt’s machine, obtained two
diamonds and # dwt. of gold. The diamonds seemed to have
suffered by the burning, as they were quite destitute of lustre. The
Reedy Creek deposits contain much larger masses of fossil wood and
agate than elsewhere, although the accompanying gems are of the
usual size. The total number of diamonds obtained by the Company,
while operations lasted, was 1765.

To the east of the village is a long ridge, capped by basalt under-
laid by drift, and running nearly due north from the junction back.
It is nearly connected, at its north end, by another outlying mass
of basalt running easterly. These are merely outliers of the main
flow, which is more extensively developed to the east. The basalt
of these outliers is higher than that in the Company’s lease, and
between these two outliers is shallow ground, the top of a sandstone
hill, which has split the old river channel. The higher ground is
covered by a rounded pebble wash, but on the fall to the back
of the diggings, slates and quartz-reefs crop out, evidently a
continuation of the rocks on the south side of the river. This
basalt hill was worked on its south and east faces, and a pretty rich
gold lead was discovered; some diamonds are said to have been
found, but were never properly looked for. The sinking varies
from 66 to nearly 90 feet. In sinking through the above-mentioned
easterly outlier, three-quarters of a mile north of the village, the
basalt was found to rest upon fine fissile white and grey shaly beds,
full of indistinct plant-remains, and with no intervening drift—in
fact, the drift further back appears to rest upon, and not beneath,
the basalt, but it 1s most likely a more recent wash. Some speci-
mens of the above-mentioned plants were forwarded to Professor
M‘Coy, and pronounced by him to be identical with those of the
Cape Patterson Mesozoic Coal-rocks in Victoria. J was unable, at
the time, to determine the relations of this bed to the Carboniferous
beds of Tallawang, or of either to the green and purple conglomerates
west of the Cudgebeyong Creek (described hereafter).

About half a mile above the Reedy Creek junction, and up the
river, is a small outcrop of horizontally-bedded alternating grey
shales and coarse grits, capped by a conglomerate bed. The shales
contain leaf impressions, and the grit traces. The beds form a
slight arch, dipping from the centre towards north-west and south-
east, but it is probably only a local undulation. They immediately
underlie the basalt, which here comes to the river, and forms a bold
escarpment, at first on the west side, but afterwards on both sides
to within a short distance below Guntawang. Several shafts were
sunk on Mr. Rouse’s property to the west of the river, and bottomed
on horizontal conglomerates; these are again seen at Biraganbil,
where they consist of friable grits, with indistinct plant-remains,
and hard thick-bedded conglomerates. These beds seem to occupy
all the lower country, at the foot of the ranges to the west of the
river; the east side is covered up with Tertiary drifts and basalt,
and the old river-bed must have been at some distance to the east
of its present course. The basalt has flowed from the north-east

Norman Taylor—The Cudgegong Diamond Field. 405

and north to the river at Guntawang, and then down it; and it is
most probable that the drift, in which the diamond occurs, has come
from the same direction, although I do not altogether hold with the
view that the diamonds have been drifted. All the valleys and
lower country (probably synclinal troughs) to the north and west
of Mudgee, and elsewhere, appear to be occupied by pebble drifts
and beds which may be the equivalents of the above-mentioned
Mesozoic rocks.?

At the Reedy Creek junction, and south of the river, were situated
the works of the Mudgee Gold and Diamond Mining Company.
This Company had all their endeavours frustrated by the continuous
floods, which destroyed their dams, races, ete., and at last their
machinery. Following down the river south-westerly, we pass out-
crops of slates, with several large untried quartz-reefs, and near an
out-station of Mr. Rouse’s, a small fringe of basalt on the rising
ground bounding the flat on the south side of the river. Another
small basalt rise is met with on the north side of the river, which
has here extensive alluvial flats on both sides. A shaft on this hill
passed through 25 feet of basalt, and 15 feet of sand, drift and
boulders. <A little gold and two small diamonds were obtained, but
the influx of water stopped further operations. Rounding a rocky
- point at a mile and a half, the flats go to the north side of
the river, while slates and sandstones abut on its south side. The
higher ranges to the north contain numerous untried quartz-reefs.
Thence the river turns north-west for half a mile, with a large flat
on the south side, the surface strewn with angular quartz from the
neighbouring hills, concealing the older river drift beneath it, which
has been exposed in a few holes sunk. Passing Cunningham’s Farm,
and going south-west over country composed of shales and brown
fissile arenaceous sandstones, a mile brings us to the Puggoon Creek,
coming in from the north. Jordan’s Flat now lies on the south side
of the river, which is here crossed by some “bars” of a very cal-
careous grit. In the centre of the flat, and resting partly against
the flank of the range to the east, is a hill (Jordan’s Hill) of the
older diamond drift, capped by basalt. This hill is in the form of a
triangle ; two sides bearing nearly north-east and north-west, and
the third nearly east and west facing the river. From the north-
west angle a spur runs south at a lower level, also facing the river.
The principal sinking has been along the west side of this spur, for
a short distance from the basalt, and between it and a high slate bar,
outside which are the more recent river drifts. Some shafts have
been sunk through the basalt; here about 25 feet thick, and beau-

1 In the Annual Report of the Department of Mines, New South Wales, 1876,
page 173, Mr. Wilkinson, the Government Geologist, states, ‘‘ The Coal-measures are
seen again at the junction of Reedy Creek with the Cudgegong River; they extend
into the Guntawang Paddocks, and then in a narrow belt as far as Beau Desert,
where, in a well sunk near Mr. George Rouse’s residence, the shales show markings
of coal.’ As a much older geologist than Mr. Wilkinson, and having had a longer
acquaintance with the district referred to, I cannot help stating that Mr. Wilkinson,
must be in error in placing these rocks on the same horizon as the true Coal-measures,
for the reasons given above.

406 Norman Taylor —The Cudgegong Diamond Field.

tifully columnar in six-sided vertical prisms. 'The columns decom-
pose and break up into concretionary spheroidal masses. Where
this spur joins the more elevated mass of basalt, there is a shaft
through 12 feet of rubbly and decomposed basalt, full of veins of
kaolin, resting on brown and red sandstones with no intervening
drift ; and it is doubtful whether the lower and higher basalts are
connected at all. A shaft was sunk at the north-west angle of the
hill through 16 feet of loose rubbly basalt, 42 feet of dense hard
basalt, and 18 feet of drift, mostly sandy and similar to the Hassall’s
Hill drift spoken of further on. A drive was put in on the bottom
60 feet south, where a high bar was met with, and beyond this
again was another channel or gutter. The “wash” was very heavy,
containing large blocks of “floating reef” and coarse gold. The
top of the shaft is about 95 feet above the river, while the top of the
hill is 108 feet. From the western angle of the hill, round to the
north-east, is a flat fringe of basalt, between the edge of which and -
the escarpment of the higher main mass, some sinking has been
done, but, curiously enough, without going through basalt. This can
only be explained by a slip having taken place, which has projected
the basalt over and beyond the drift. No drift appears to be present
under any part of the hill except the north-west angle, where the
‘lead must run from a little north of east to south of west. The ~
basalt is slightly vesicular, the cavities being occasionally filled
with aragonite, and an agatiform carbonate of lime and iron
(spheerosiderite), and the joint cracks are much coated with
hyalite or volcanic glass. The underlying drift is a good deal
cemented, and contains much silicified wood. This hill, by repeated
barometrical observations, appeared to be from 80 to 40 feet higher
than any of the other outliers, and from this fact, and the presence
of hyalite, I at first imagined it might be a point of eruption, the
absence of the usual scoriz and ashes being accounted for by the
immense denudation which had taken place, and which had swept
away all the lighter material, and left nothing but the denser basalt
below. At the spot where the drift from this hill, in the old gold-
working times, was washed at the river, the manager of one of the
companies obtained, with a Hunt’s diamond-saving machine, twenty-
one diamonds; and a Mrs. Alexander, with her children, had
previously obtained about the same number. A large waterhole,
running in the strike of the rocks and half a mile long, bounds the
west side of Jordan’s Flat, and, at its south end, the flagstones abut
on the river at Stony Creek. Here there has been a small lead
traced, but the sinking was very wet, as the bottom was below the
present river-level ; a little gold was obtained, but no diamonds. A
striking object is the large quantity of flat boulders of brown and
greenish grey grits and sandstones with pebbles of quartz, felstone,
porphyry, and greenstone, the latter evidently derived from that at
Gulgong, and containing large crystals of hornblende. This deposit
seems to be the remains of a former old drift, which has been
denuded down, and mixed with the recent river wash, and may
probably have occupied the same spot, or nearly so, that it does now.

Norman Taylor—The Cudgegong Diamond Field. 407

It may be the surface outcrop of the Gulgong deep leads. The
river now trends to the south, through large alluvial flats (unworked)
intersected by numerous backwaters or old channels. Turning
westerly we pass a red rocky bank composed of grey calcareous
grits containing minute Crinoid stems (Upper Silurian ?). Some of
the grits are much indurated, and the red colour of the rise is
due to the contained lime. ‘The river-bed has rocky bars crossing it,
where the main range has been cut through, composed of fine-
grained grey grits, flinty shales, and thin-bedded red sandstone—all
vertical. To the left is the northern extremity of the “scrub lead,”
which has here run to surface. At the head of a gully are two
parallel quartz-reefs in finely micaceous: red sandstone. On the
right of the river is a low bank showing occasional outcrops of
vertical coarse yellow sandstones and grits, covered by an old
shallow river wash. A large open alluvial valley joins the river
from the north, having at its head, three-quarters of a mile up, a
small deposit of river drift, in which a few shafts have been sunk,
some having bottomed on greenstone, which crops out at the foot of
the ranges. The river-bed is much contracted by the proximity of
the ranges, which touch it on the north side. Some workings have
been carried on in the ordinary river drift along the south bank.

We now leave the river, and, following the road southerly, pass
the ‘‘scrub lead” on the left, and Miller’s Claim on the right. This
claim is 25 feet above the river-level, and has yielded a good many
diamonds. It differs altogether from the other leads, with the ex-
ception perhaps of part of Buckley’s (see on), and is evidently
newer than the drift underlying the basalt, from the fact of its
lower level, and its containing pebbles of basalt derived from the
waste of the protective basaltic covering of the older drift. The
peculiarity. in this claim, of the bed which contains the gem-stones,
may possibly arise from the decomposition of boulders of greenstone
and basalt, the former being the bottom rock, which has produced
a pure white clay, apparently a hydrous silicate of alumina, etc. It
adheres strongly to the tongue, and contains small quartz pebbles,
rounded pieces of basalt, blue sapphire, ruby, black pleonast in great
profusion, and some wood tin. It is also veined throughout with
some bluish opaline mineral (probably phosphate of iron). This
bed varies from one to four feet in thickness; and between it and
the bottom there are two feet of red sandy drift. A newer river
wash, containing pebbles of Carboniferous conglomerates, and mixed
with the former, rests on this bed. This, with the alluvial covering,
is about 12 feet thick. The diamonds in this drift may have been
washed out of an older once-existing deposit, as the unusual ac-
cumulation of greensand, at this spot, renders probable. The “scrub
lead” is apparently a mixture of recent river wash with the older
denuded leads.

We next come to Buckley’s hill and lead. Shafts were sunk
here in the newer drift at depths varying from forty-three to
sixty-five feet. The wash dirt was exactly similar to that at
Miller’s, but gem-stones were not so plentiful. A few diamonds

408 Norman Taylor—The Cudgegong Diamond Field.

were obtained, but not sufficient to pay. Like Miller’s, this
part of the lead rests upon, or near to, a greenstone dyke, and the
drift contains large boulders of that rock. The lead passes along
the east and south sides of a basalt hill, but the older lead, from
which this is a wash, must underlie the columnar basalt, and has
not been tried. The south-west side of the small basalt hill is
shallow ground. Scattered shafts on the east side of the large flat,
forming the “Two-mile-flat,” and flanking the western foot of a
high sandstone range, running in the strike of the rocks (N. 25° W.),
indicate the position of the “Deep Lead.” The basalt is here very
little above the level of the flat, and is mostly obscured by a wash
of clay from the ranges. At Fitzpatrick’s Claim, 80 feet of basalt
rests on 30 feet of drift, which was worked for gold alone, and gave
good results. The bottom isa soft decomposed argillaceous rock, with
no visible dip or strike. The gold was contained in a brown loosely
cemented brecciated conglomerate of quartz pebbles, sand, and
“floating reef” (yellow concretionary sandstone). The adjoining
claim (Toby’s) yielded a few diamonds, all of good size, nine weighing
23 carat grains. On no other portion of this lead were they looked
for. The lead runs round the head of the flat, about 24 miles south
of the village of Warburton, crosses it, and then turns northerly
again to the river, which it joins a mile north of the village. The
“'Two-mile-flat”’—19 miles from Mudgee—is about one mile wide,
by three and a half miles long, and is bounded on the west by a
low range running in a nortb-west direction from the Big Hill, on
the Mudgee road, about 500 feet above the flat; from thence the
range rises towards the north-west, on the east side of the flat, to
an altitude of over 700 feet above it. The general direction of the
ranges is determined by the strike of the rocks (N. 25° W.). The
dip of the beds is generally vertical, or very rarely at a high east
or west angle. The rocks themselves consist of red and yellow,
coarse and fine-grained, indurated sandstone; thin white laminated
argillaceous shales; finely micaceous red shales and sandstones ;
pink and brown fine-grained sandstone, banded with purple stripes
in concretionary rings and layers; and hard metamorphic schists.
All these rocks, with the one exception named, are singularly devoid
of mica. Quartz-reefs occur, but are apparently non-auriferous.

The late Professor Thomson shared my opinion that the age of
these rocks is Upper Silurian, the only fossils discovered in them
im situ being the Crinoidal stems before mentioned. A rounded piece
of sandstone, containing distinctive Upper Silurian forms, was found
in the drift of Buckley’s lead, but has probably come from a con-
siderable distance; similar pebbles, inclosing Crinoidal stems, Orthis,
etc., were found in the brown sandstone (“floating reef”) of the
newer drifts on the flat—and also the cast of a Spirifer and sections
of Crinoidal stems in pebbles of hard quartzite.

On the inside flanks of the ranges on both sides of the “ flat,”
there are five small outliers of basalt, overlying the older gold drifts.
It was in these drifts, formerly worked for gold, that the diamonds
were found. The centre of the “flat” is occupied by a mass of

Norman Taylor—The Cudgegong Diamond Field. 409

greenstone (diorite), which originally acted as a barrier to the old
river, and diverted its course, in an elliptical curve, round “the
flat.” Subsequently to the formation or deposition of the drift, a
lava stream flowed down the river valley, completely filling its bed,
and covering the drift; a new river had then to cut its way, during
which process the denudation must have been very great, as nearly
all the basaltic lava, and the underlying drift, had been swept away,
and partially re-deposited, forming the next older drift. This drift
is at a much lower level than the older drift, but still above the
present river. The total length of the leads round the flat is
about four miles. The older lead is only in situ under the basalt
outliers; and, between and outside these, the lead is newer. The
drift only underlies the basalt on the eastern side of the basalt hills
on the west side of the flat, and on the western side of those on
the eastern side of the flat.

The drift underlying these outliers was only worked for gold on
the bottom, and the diamond vein may still remain overhead, as
diamonds were found in the tailings, and also in the “ spoil heaps”
at the mouths of the shafts. On the west side of the flat, the
newer drift is divided, ata depth of about 43 feet, by a high slate bar,
the depth on the west side of which is 58 feet, and on the east from
66 to 75 feet; further south it is 40 feet on the bar, from 28 to 54
feet on the west side, and from 70 to 80 feet on the east side. This
bar consists of white and grey arenaceous shales, and white mud-
stones, and runs in the usual strike. The newer drifts are
characterized by a flesh-coloured or reddish quartz gravel, which
appears to be derived from the Carboniferous conglomerates; and
also by “floating reef,” consisting of grey, brown or yellow, coarse
and fine siliceous and felspathic grits, in flat oval-shaped boulders,
occasionally containing Upper Silurian fossils, olive shales, and
fine, flaky, soft white sand rock. The “deep lead” seems to be
peculiar to the “flat,” and is a series of rather sharp undulations,
with occasional flat and sometimes pot-holed spaces. The lead has
been very imperfectly traced, for the miners have sunk their shafts
in straight lines from one basalt hill to the next, in a way it would
be extremely unlikely a river would flow. The bottom of the older
lead is from 80 to 40 feet above the present river-bed level ; and, at
a short distance from the river at both ends, the lead has been com-
pletely washed away by the river in cutting down to its present
level. The contents of these “leads,” as would naturally be ex-
pected, are very different; the older being destitute of local rocks,
whilst the newer contains remains of the latter, and of the basalt
which caps the older. The basalt is very dense, hard, and black in
its upper part, and sometimes incloses grains of olivine; below, it is
mostly decomposed, and of a light slate colour, with veins of a
white aluminous silicate. It decomposes very rapidly in concretions
when exposed to the air. The upper part affords numerous good
examples of columnar structure, occurring in long vertical hexagonal
prisms from a foot to eighteen inches in diameter. In the joints
between the columns, and other horizontal joints, a peculiar green

410 Norman Taylor—The Cudgegong Diamond Field.

mineral occurs, probably a clay coloured by silicate of iron. The
basalt is magnetic, with strong polarity in places, and the water
channels draining off it contain a fine black magnetic iron sand.
The columnar structure above noticed renders shaft sinking in these
basalt hills tolerably easy. From the peculiar position, with regard
to one another, of these basaltic outliers, and the apparent impos-
sibility of drifts of such varying thickness being part of the same
river-bed (I now allude to the older drift), I at first supposed that
“the flat” had once been a lake, subsequently drained by the river
cutting through the greenstone dyke; but, on taking a series of
barometrical levels across the flats, in and across the strike of the
rocks, with accurate measurements of shafts sunk, etc., this suppo-
sition proved erroneous; for the drift-bottom is higher at Buckley’s,
on the east, than at Driscoll’s, on the west side of “the flat” or fall
of the river, although Buckley’s has suffered more from denudation,
and is consequently lower than the other hills. During the forma- -
tion of the newer drift it may, however, have been temporarily a
lake. The “Deep lead” is a curious feature, for, at Fitzpatrick’s
Claim, the older drift-botiom is nearly 20 feet below what it should
be in the average fall of the river, and is nearly on a level with the
newer drift, and a very little above the present river-level. It is
evidently older drift, inasmuch as it underlies the basalt,—and the
only way to account for it is, that it must have been a large and
deep waterhole.

The centre of the north end of the flat is occupied by a mass of
greenstone, apparently intrusive. According to the late Professor
Thomson, some of the greenstone of the Wellington district is con-
temporaneous, and interbedded with the Upper Silurian rocks; but,
in one place here, we have it cropping out on both sides of a sand-
stone hill, but not appearing at the top; and, in another place, the
greenstone is capped by a mass of altered shales, similar to what
occurs at Lancefield in Victoria, where a high greenstone range is
capped, in patches, with undenuded outliers of altered flinty shales.
Its occurrence in parallel bands, having the same strike as the adja-
cent vertical and highly-metamorphosed shales, seems to favour the
view of its being interbedded, as also does the presence of what
may possibly be trappean ash-beds (described further on). I think,
however, that, were there any good sections across the strike ex-
posing these rocks, it would be found that the Upper Silurian rocks
are here underlaid by a large mass of greenstone, which throws up
veins through the joints of the slates and sandstones. The green-
stone (diorite) consists of a mixture of hornblende and felspar, and
varies from a fine-grained extremely hard and tough compact rock
to a coarsely crystalline one. Its colour is a dark green, and in
weathering it forms a rich red soil. It exhibits a concretionary
structure at the surface, but is very dense below. In places it is
largely intersected by epidotic veins of a light chrome green colour,
containing, occasionally, rhombic prisms of epidote; it is also cha-
racterized by the presence of quartz, sometimes containing confusedly
radiating olive-green prisms of actinolite. The felspar crystals have

Norman Taylor—The Cudgegong Diamond Field. 411

a pale green colour, and a rough parallelism in rings round the con-
cretions. It generally weathers brown, though the more felspathic
varieties have the external appearance of granite. It effervesces in
joints and minute fissures with hydiochloric acid, and contains traces
of a dark brown mica (?). The decomposition of the protoxide of
iron in the hornblende, and the partial removal of the lime and
magnesia, confer great fertility on the soil derived from the green-
stone; and the highest ranges in the neighbourhood which consist
of this rock are always clothed with open timber and fine grass, in
contradistinction to the Silurian ranges, which are rocky, scrubby,
and thickly timbered. To the decomposition of the greenstone is
also due the large quantity of magnesite which occurs—in fact,
erows—round the waste heaps at the mouths of the shafts. The
white clay turned up soon becomes covered with small spherical
nodules, which aggregate in time into a solid botryoidal mass of
mixed carbonates of lime and magnesia. This only happens super-
ficially, and where the clay has had access to the atmosphere.
There seem to be two varieties of this mineral (one of which may
be derived from decompdsing basalt) as well as a mineral resembling
common opal, also showing externally that it is an aggregate of
spherical nodules. An analysis of the last, made by the late Pro-
fessor Thomson, proved it to be a pure hydrated carbonate of
magnesia, with specific gravity 2-94, and containing—

IMiaenesiay: Ficus. Ane A a gels acetates he Silacpcetene 46°99

Garb onteiacidte tn cee ee Me ne Re oe cee 49:78

Wa be Tasch eee ene cere erect ieee si cra ieee Airis eet am 4:08
100°85

The greenstone possesses two systems of joints,—one striking
north and dipping west,—the other striking EH. 30° N. and dipping
N. 30° W. It was for some time mistaken by the diggers for basalt,
and sunk in to some depth. A quartz-vein intersects it, south-west
of Buckley’s, containing galena, but it had not been opened up.

Along the foot of the range, on the west side of “the flat,” isa
series of beds, about ten chains wide, having the same strike as the
slate rocks. It consists of flinty shales and a thick hard brecciated
conglomerate, full of nodules, like amygdaloids, of crystalline lime-
stone, which decompose out on exposed surfaces, and give the rock
a vesicular appearance. This breccia also contains fragments of
flint, red felspar, etc., in a greenish siliceous base. It shows no
bedding planes and passes to the west, by insensible gradations, into
a rock of a granitic character, full of felspar crystals, with specks of
iron pyrites and galena, and much resembies a felstone porphyry.
There seems to be a great similarity between these beds and those
in Ireland, described by Jukes as ash-beds. The flinty shales have
a peculiar system of joints or false-bedding, at right angles to the
strike or real bedding, which latter is seldom distinctly seen. These
highly altered shales are characteristic of greenstone intrusions, for
they, in every instance, occur as the contact rock, both in New
South Wales and Victoria.

The river, at the north end of the “ Two-mile-flat,” runs westerly
across the strike till it.reaches the above-mentioned beds, when its

412 W. J. McGee—Geology of the Mississippi Valley.

course is diverted, and it follows the strike of the rocks for some
distance.

Along the top of the range west of the “ flat,” and crossing the
Wellington Road, another greenstone dyke or outcrop occurs, about
ten chains wide, and also following the strike in general direction.
These dykes, which are all, more or less, of the same character
as that already described, run towards the head of “the flat” and
beyond it,—the ranges being confusedly intersected with ‘“ blows”
and outcrops of greenstone, containing quartz-reefs. These reefs
may, at some time, prove to be auriferous, like those at Merinda
and Gulgong.

A very peculiar isolated conglomerate-capped hill occurs to the
north-west of the “T'wo-mile-flat.”” The conglomerate, which is
about 70 feet thick, and 100 feet above the river, consists of loosely
cemented green, yellow, and purple grits with veins of calcite,
purple shales, mottled and banded grits, decomposed greenstone,
and small and large grained metamorphic breccias from the imme-
diate neighbourhood,—the whole imbedded in a hard, brittle, ferru-
ginous clay, and the large flat boulders and pebbles being all coated
with a glistening purple polish. This conglomerate rests uncon-
formably (horizontally) on the tilted Silurian rocks, and is probably
of Carboniferous age,—or younger. It bears a considerable resem-
blance to the rock from Mount Timbertop, in Gippsland (Case x.
No. 41, Victorian National Museum Catalogue), and others from the
Stony or Moitun Creek, Dargo Road, Gippsland (Case x. No. 17).

The lead, after leaving the Two-mile-flat, crosses the river to its
north side, and is there only represented by a thin deposit of newer
drift, the basalt and older drift having been entirely denuded away.
The gold obtained was not in payable quantity, and the lead was not
properly traced.

To the eastward is a schist range, on both sides of which the
greenstone dyke, before mentioned, crops out. This dyke appa-
rently splits, or rather underlies and crops out on both sides of, a
schist hill near Miller’s Claim,—the range, with its accompanying
parallel outcrops of greenstone, runs in the strike of the rocks
(N. 25° W.) up the east side of the valley of the Sandy or Cudge-
beyong Creek.

(To be concluded in our next Number.)

IV.—NoreEs on THE SurFACE Guotocy oF A Part OF THE
Misstsstppr VaLuny.?
By W. J. McGuz, Esq., etc., etc.,
of Farley, Iowa.

Kames, sar, and minor topographical features—Kames and asar
are usually found associated. Indeed, the one class of elevations
shades into the other so gradually that it is sometimes impossible to
draw the line between them. Though the kames may occur singly,
they are often in ranges of several, perhaps extending for miles.
Each is usually elliptical in outline, and its longer axis corresponds

' Concluded from page 361.

W. J. McGee—Geology of the Mississippi Valley. 413

in direction with the range. The Asar are frequently intercepted by
channels of erosion, by which they are divided into ranges of oblong
hills, the direction of which is very nearly the same as that of the
kames proper. In Dubuque county, Iowa, where these features
have been most thoroughly studied, this direction is about 8. 75° E.
Within 40 miles south-west from there the direction changes to
about S. 45° E., and in the next 50 miles the direction becomes
a trifle west of south; and this is the general direction over the
greater part of the region examined.

Though generally independent of the present minor lines of
drainage, kames, when they occur singly, often bear a distinct re-
lation to neighbouring topographical peculiarities. Thus in Dubuque
county, a single kame is often found at the head of a “draw” ex-
tending N. 75° W., and communicating with a deeper transverse
valley or streamlet. If several such ‘‘draws” are parallel, and of
about the same length, a series of kames may extend in a direction
corresponding with that of the larger valley; but their longer axes
correspond with that of the “draw.” Again, when a stream
flowing to the north or south bends abruptly to the east for a mile
or two, and then resumes its course, a prominent kame, which may
be of considerable length, may often be found on the upland east of
the bend. A fine instance of this character may be seen at Rock-
ville, on the line between Dubuque and Delaware counties, where a
kame nearly a mile long lies opposite such a bend in the Maquoketa
river. Its altitude exceeds that of all other hills in the vicinity.
There is a very small but strikingly characteristic kame near by,
directly opposite a steep, rocky ravine on the west side of the river,
extending about 8. 63° H. The kame is fully 60 feet high, and its
base is not more than 200 by 375 feet. Its longer axis extends
8. 60° KE.

The ridges already spoken of as extending across a part of
Dubuque county from west to east, are believed to be true asar.
One, which passes just south of Farley, has been traced over 10 or
12 miles, though there are two or three breaks in this distance.
The same ridge, probably, extends many miles further westward ;
but it is so broken by the two branches of the Maquoketa river and
their tributaries that it is difficult to positively establish any con-
nexion between the portions supposed to be related. This difficulty
is enhanced by the sandy and friable nature of much of the soil west
of the easterly branch of the Maquoketa. Similar elevations have
but seldom been observed in other localities; though some forma-
tions, believed to be analogous, were recently noticed in the vicinity
of Aurora, Illinois. Circumstances prevented their thorough ex-
amination.

Both kames and asar are chiefly composed of members one and
two in their proper relative positions, number two being much
thickened, and generally stratified, assorted, and laminated.
Geikie’s description of the kames of Scotland’ will often apply
word for word to those of this region, except that here they are

1 “Great Ice Age,” chapters xvi. and xvu.

414 W. J. McGee—Geology of the Mississippi Valley.

capped, in the large majority of cases, by the léss-like member.
The rather hurried examination given to those of the level plains
of Illinois failed to reveal any order or system in their distribution. °
They begin to appear at intervals about 40 or 50 miles north
of the southern limit of the unmodified upper drift (number three),
and dot the surface to the southward, increasing gradually in extent
and number, but finally diminishing in altitude, and at last becoming
merged in the léss there forming the uppermost deposit. These
elevations have in some cases been found to be wholly independent
of the subjacent members; and it is suspected that, where they are
not coordinated with the configuration of the basalt rocks, they are
always so.

Terraces are rare, and never prominent. There are none which,
in the judgment of the writer, owe their origin to continental oscilla-
tions in level, or even to a gradual elevation of the land. The two
principal surface deposits, too, are spread over the older rocks
uniformly, on hills and in valleys alike, independently of altitude.

Roches moutonnées occur in many localities, but their materials are
usually too friable, and their surfaces too greatly weathered, to
exhibit striz. Ground and polished rock-surfaces, which are so
often seen in broken and hilly countries, are almost unknown here ;
but it must be remembered that extensive surfaces are very seldom
exposed, being ordinarily deeply covered with drift. Neither have
the “‘ striated pavements” of Hugh Miller been observed.

SECTIONS.

To the working geologist a few actual sections will be of as great
value as the more general description. The following are taken
almost at random from the writer’s notes."

The relations of some of the members could only be clearly
exhibited by means of sketch sections: and hence no effort has
been made to select those containing such members. All were
observed in wells.

1. A well at Woolam’s Station, Stephenson county, Illinois.

Soil... PU eee ett A A eon eRe ae en prevents Si esll EeSep 2 feet

Coarse yellow clay, with boulders and chert wu. wu... Bo

Blue clay, clean and unstratified... coc. cee sees sass seees PNB)

Gravel and sand, stratified, on rock ow. 0k ce cee tees Oe
Ao) ilpeeeu mete: Rac er SIE AS Se MMR DOR ALE aed A OOM:

2. Mendota, Illinois.”

Yellow relay swithsbouldersiiy Ol.227 ha) an, Pik Oe 12 feet

Blueiclay,isometimes|sandiyj ies (ee) ce eel eee eae 55 4,

Gravel ef AUS tes aaa aes ear hay sale ead 3 inches

Blue clay, laminatedvandisandiytees sec) fectauteee (ee oes Cs

Water-bearing gravel reached. =
HUGH A ad ec eee ee ge (4.

A sample of the blue clay from 60 feet below the surface contains

1 In the paper read before the American Association is a table of eighty-three
sections in North-eastern Iowa.

2 Communicated, with the following, and with samples from different depths, by
Dr. J. D. Moody.

W. J. McGee—Geology of the Mississippi Valley. 415

many small fragments of wood, probably Red Cedar (Juniperus
virginiana). Boulders were not reported in the yellow clay, but
were seen in it in the immediate vicinity by the writer.

3. Artesian well at Mendota, Illinois.

Surtace'soilaas tity (ee We tt. Ee oes ahi) Mena 2 feet

Woalllony Glenys wat INOWIGETS acs ce oe! gee ne em che 12

Gravel Gas pi swe ess ces eae sea ta 2 or 3 inches

TEU ON "seco cece cotes. erie) eruam Ree Mince oe roegpmrenriee a SOE ols

Imdunatedrandishaly blierclaysa rence seni ene 2s

Coarse reddish and yellow clay .... os. cess seeee seeee tte GS) 5,
Mo tallieteige metre acai tal Heaton hse Cadets neg ye i 160 ,,

In a third well, at the same place, the layer of ancient peat
already mentioned was encountered.

4, Near Cascade, Iowa.

Clean light-yellow clay wu. sus om ea hey ee eke 6 feet.
Reb bly ditboraey uct ays eptecteeyrireceser yucctes) Mplestse shmsetay | easy pratt Liss
iellow clayaawathiboulldensies ays yeu nies rr. ir 1B a
Blackusandy oars. Vessel sasseyll arian Wersta senap iliac ee. irs

Cleanybluevclays ay ec Wig tsa hibeed | cetol Waa faedan goles 26
Yellow sand, with boulders and pebbles _.....

woh oli Ag) |

Wood was found in fragments on the surface, and in the upper
portion of the blue clay, in the black loam, and a little in the base
of the superincumbent yellow clay. Except for absence of member
number six, this is a typical section, and, besides, has the “forest
bed” in situ.

5. Near Epworth, Iowa.

Surfacersoile ee jor was a eels ntay) lary sien) atesesn UM sne te 1 feet.
Sandy yellow clay, with boulders. wa
Clear blue clay, with small pebbles
Clear, fine, white sand, lamimated = on, ok cess ceene sees 1
Coarse gravel, entirely free from clay

otal eee eae eos arte Rees Py pen eu eae Dafa

A sound log of Juniperus virginiana, 8 inches thick, extended
across the well at 20 feet from the surface, and was cut off at both
sides.

6. In Dakota, Humboldt co., Iowa.

Black SOn yyy ka: veces eeesapa lvsseng tease qrvesseeas Femseihaa Mee irarenyy ake 6 feet.
Yellow sandy clay, with boulders and limestone DERN: a 20s
Cleanpblireye iy halt) petra elated Cubes aierse a eatccu Veet accunld Chant 16 ,,
Coarse gravel and sand, Pritt waters ew whie oho s os
HO ballets ees chosen a nO INC, § ore scast= Mele tee 43 3

A stick (probably cedar) 2 feet long and 4 inches thick was found
30 feet beneath the surface. On reaching the water-bearing gravel,
the water rose 20 feet, and has ever since remained at the same level.
In a neighbouring well an upright trunk and branches of a tree
(probably Willow—Salix, sp. und.) were found below the yellow
clay.

416 W. J. McGee—Geology of the Mississippi Valley.

7. At Aurora, Illinois.

Yellow clay, with boulders... ce seen
Cleantblueselay yncohte) Srp ee We eats
Clean sand and gravel, stratified... 0...

fees eevee eee

8. Ten miles N.W. of Dubuque, Iowa.

Surfaceisoil Ac hes ete deaes een oats on eho
C@leantalight=yellowaclavaes ee) ieee oneal ae
Sand and gravel, stratified, with small, much-worn boulders
Loam, not distinguishable from surface ..... _ .....
Jointed blue clay, clean _..... ee) BR she, ha bee eee
Sand and gravel, with water . cee

9. Twelve miles S. of Storm Lake, Iowa.

Yellowiclay,with pebbles 225 3 Gs 2 Ee one

Clean, unstratified, blue clay, very hard when dry, but
Dlastichwhenewet esr mee

Sandy red clay, with rounded pebbles

eeeee aeeee eee ee eee

10. Near Ida, Ida county, Towa.

SCBA ePOSIb ocr aseed | Resch Label” tester se tated Meetreet | PERLE LEN
Nearly pure yellow sand ... .... ....
Clean blue clay, with roots and branches

11. Wyoming, Jones county, Towa.

Coarse yellow clay, with boulders, pebbles and gravel,
Sligshithy,stmatitled Weise lier cui eae eee Serhan
Blue clay, with occasional intercalated layers of fine
pravelmand(sand jj vasc..chas cers lisesi ee) ny ae

Sandy yellow clay, with pebbles.....

16 feet.
4 99

”

10 feet.

iy place
35,
15 feet.
10)
D 55
a
Wa §
4

52 ,,

20 feet.

64 ,,

This section seems anomalous, but it is probable that only
members three, four, and five, are represented. Four and five may
constitute a buried kame. This well was excavated in the highest

hill in the neighbourhood.

!

W. J. McGee—Geology of the Mississippi Valley. 417

INTERPRETATION OF THE RECORD.

Without the least disposition to discuss mooted points, especially
as regards the relative efficiency of land-ice and floating bergs in
laying down finely comminuted and coarser materials without
arrangement, the writer may briefly summarize the conclusions
to which he has been led by the study of the surface deposits of
the regions described.

Member number six is believed to be the product of a continental
glacier because (1) it contains pebbles of the Archeean rocks, which
must have been brought from a distance of from 200 to 400 miles,
mixed with a larger proportion of local ones; and because (2) it
occurs at various levels, and is unstratified. It is believed to be
distinct from, and much older than the incumbent members, because
its materials have undergone much more secular modification; and
by far the greater part of this took place before the advent of the
succeeding glacier. he cementing of a part of its materials into
pudding-stone occurred previous to any subsequent cataclysm, as is
attested by the finding of this pudding-stone in all of the more
recent formations. Even its erratic lumps of clay are easily dis-
tinguishable from their surrounding materials, and their true
relations readily traced.

Members number four and five also contain northern rocks, often
striated, and occur at all levels; and their materials are often con-
fusedly intermingled. Lumps of the blue clay occur also in member
number three; and in North-eastern Iowa the boulders of these
members are of a different character from those of the next. They
are therefore considered to be of glacial origin also, and to be
distinct from and much older than the overlying deposits. In
addition to the evidence above detailed, we have every reason to
believe that the accumulation of a great mass of vegetation, and the
development of a characteristic fauna,’ took place subsequently to
the laying down of these members and previous to the coming of
the latest glacier. Only during an immense period could this have
been accomplished.

For reasons which every geologist will recognize in reading its
description (even if he does not admit their adequacy), member
number three is believed to be of glacial origin. It is so considered,
indeed, by most of the various State and other geologists who have
examined and described it. The reasons for considering it to be
distinct from and much newer than the lower till, need not be
rehearsed.

Partly in consequence of a high estimation of the opinions of
many eminent men, member number one is provisionally assumed
to be due to sedimentation in local basins formed at or about the
close of the last glacial epoch; and member number two is thought
to be the coarser materials left when the lighter portion was carried
away to form the léss-like clay. As previously intimated, there is
reason for believing that a part, at least, of this assortment took

' Some references are given in the paper already mentioned, which bear upon
this point.

DECADE II.—VoOL. VI.—NO. IX. 27

418 W. J. McGee—Geology of the Mississippi Valley.

place before the final retreat of the ice. It may be mentioned in
passing that some carefui observations recently made in a neigh-
bouring State point to a yet more sweeping conclusion. During
last season, Prof. N. H. Winchell, the State Geologist of Minnesota,
found that the unmodified glacial drift of that State graduates
bodily into the loss of the Missouri Valley.’

As intimated at the outset, the general conclusion reached by the
writer is that three different glacial epochs have succeeded each
other at long intervals; and from analogy with the present, as well
as from direct evidence, that a characteristic fauna and flora spread
over the land during each of these intervals, whose counterparts are
to be sought for in the more recent marine formations. Though
purely hypothetical, and warranted only by the known uniformity
of the natural processes, and the apparent inadequacy of catastrophic
agencies,” it may also be suggested that earlier glacial eras have
probably occurred at long intervals, as argued by Dr. Croll, and
that these cataclysms may have inaugurated the disturbances
separating the successive geological eons.

It would seem, however, to be palpably unjust to the talented
author of “Climate and Time,” and to the able geologists who have
fallen in with his conclusions, to reject the hypothesis of inter-glacial
periods, in the sense in which the term is used by the Scottish
geologists, without offering any reason therefor. Hence, if the
introduction of arguments not strictly geological may be permitted,
the chief reasons for not adopting that view may be briefly outlined.

Premising that it may be laid down as an axiom that inter-glacial
eras of mild climate could only exist when the whole of the ice of
the preceding epoch had been removed from the Polar regions, the
-leading objections to the assumption of such eras may be summed
up in two propositions. First, it would probably require all, or
nearly all, of such an era to melt the ice accumulated around the
pole; and second, it would probably require a much longer period
to effect the fertilization of the morainic debris, and the introduction
and acclimatization of a luxuriant flora, such as that represented in
the North American forest bed.

Jn discussing the first proposition, the leading principles of the
ingenious theory explaining secular variations in climate, which was
first developed and elaborated by Dr. Croll, will be adopted.

For our present purpose it may be assumed that the melting of
ice and the elevation of the earth’s temperature is due to solar heat
alone; and both stellar and proper terrestrial heat may be disre-
garded. The amount of solar heat reaching the earth’s surface is
known; and the proportion cut off by the earth’s atmosphere has -
been determined by Pouillet and others. The amount reaching the
outer surface of the terrestrial atmosphere is thus known also. It is
sufficient, as we are told by Dr. Tyndall,’ to melt a layer of ice 100

1 « Ann. Rep. Nat. Hist. Surv. of Minn.,” 1878. See also Ann. Journ. Sci., Feb.
1879, p. 168.

2 Vide “‘Cataclysmic Theories of Geological Climate,” Croll—in Grou. Mac.

for Sept. 1878.
3 *¢ Heat as a Mode of Motion,” Amer. ed., par. 684.

W. J. McGee—Geology of the Mississippi Valley. 419

feet thick over the whole surface of the earth, provided it were
all employed in that direction and were uniformly distributed.
But the heat received by the frigid zones annually, per square foot,
is less than the mean received by the whole earth in the ratio of
5-45 to 9-83, according to Meech.’ Therefore only 55:44 feet would
be melted from the frigid zones in a year, if all the solar heat
reaching them were utilized for that purpose. But Prof. Tyndall
tells us in the same paragraph that four-tenths of the solar heat is
absorbed by the terrestrial atmosphere, on an average. Now it is
universally conceded that the atmospheric absorption is greater in
polar than tropical regions; but to be sure of erring on the safe
side, if at all, the mean mentioned by Tyndall may be taken as
representing the atmospheric absorption of the frigid zones.
Radiation and direct reflection from snow-covered regions may also
be disregarded, though important factors. Diminishing, therefore,
the solar power in arctic regions by four-tenths, we find that only
33°26 feet of ice could be melted annually from the frigid zones, if
all the heat were so employed.

But normally all the solar heat is expended in raising the
temperature of the earth’s surface to a certain point, which is too
low to remove all of the ice from polar regions. To keep the
temperature as at present, and at the same time remove 33°26 feet
of ice from the frigid zones, the solar action would have to be
doubled; and, similarly, to remove any less quantity of ice, the
heat would have to be proportionally increased. The same effect
could be produced, however, by lengthening the summer and
shortening the winter. The whole amount of heat reaching the
earth, or any part of it, may be conveniently represented as 365
days. Hach hemisphere may receive 365 days of heat; but, owing
to telluric changes, the amount received by one may be augmented,
and that received by the other diminished. This is argued by Dr.
Croll, who, while admitting that a lengthening of summer is exactly
counterbalanced by the greater relative distance from the sun,
insists that a chain of physical agencies is brought into operation,
by which the heat actually rendered effective is made to about
equal, proportionally, the lengthening of the summer. Jt would be
absurd to consider it more; and in truth it is probably less; but it
may be assumed that it is proportional. During the last period of
great excentricity in the terrestrial orbit, which occurred about
210,000 years ago, there was a time, according to Croll, when the
northern summer was nearly 27 days longer than its winter; and
it may be admitted that the whole northern hemisphere received
27 days more heat than the southern, or 15-5 days more than the
normal. ‘This is the maximum for a period of about 12,000 years,
and the two minima are each zero, when the distribution of heat
over the two hemispheres is equal, as it is when the apsides coincide
with the equinoxes. The mean excess for the period of say 12,000
years would thus be only 6°75 days, or $3% of the total accession
annually.

1 “Relative Intensity of the Sun’s Light and Heat,’ Smithsonian Contributions to
Knowledge, 1855, p. 36.

420 W. J. McGee— Geology of the Mississeppi Valley.

The temperature being supposed to remain the same as at present,
during each year $34 of 33:26 feet of ice, or 615 foot, would be
melted annually. At the same rate there would be melted in
12,000 years, 7.580 feet, or 1-4 miles. Though we do not know
how much ice was actually melted from the frigid zone at the close
of the glacial period, or within any inter-glacial era, it may be
mentioned that, in calculating the continental submergence supposed
to have been brought about by the last glacier, Dr. Croll estimates
that at least two miles of ice were removed from the southern
hemisphere. The inadequacy of the inter-glacial periods to ac-
complish this is obvious in view of the above calculation.

Regarding the second proposition but little need be said, though
the subject is a broad one, and worthy of the study of a Hooker or
a Darwin. We know that crude soils, such as fresh glacial clays
from some yards beneath the surface, are not adapted to the support
of a luxuriant vegetation. Thistles, yuccas, cacti, and other hardy
plants may spread over barren clays, sterile sands, and tufaceous
wastes, and are sometimes planted with the object of reclaiming
such areas: but even when other germs are not lacking, it is only
after considerable periods that a richer flora supersedes these plant-
pioneers.” After the retreat of a glacier, however, there would be
a dearth of seeds and germs; and their spread over the glaciated
wastes would be slow. This is substantiated by the observations
of Professor Alphonse de Candolle in the Alps, and of Professor
Blytt, of Christiana, in Scandinavia, who find that “of the valleys
laid bare at the glacial period, those whose glaciers retreated first
present a richer and more varied vegetation than those which re-
mained a long time covered with ice.”* Dr. Hayden also observed
an analogous phenomenon during the season of 1877. The western
slope of the Wind River Mountains exhibits abundant traces of
glaciation evidently quite recent, geologically speaking, though it
may well be doubted whether the glaciers have existed within many
centuries; yet ‘“‘scarcely any vegetation has sprung up on the light
glacial soil.’’*

While freely admitting that any conclusions, drawn from so
imperfect a record as that afforded by our surface deposits, and from
ulterior speculations, must be only provisional and of little weight,
the writer feels justified, in view of the foregoing considerations, in
rejecting the hypothesis of inter-glacial vegetation. He may be
permitted, however, to express the high estimation in which he is
inclined to hold the general principles of Dr. Croll’s most ingenious
and plausible theory.

1 «Climate and Time,” Am. ed., pp. 377 and 388. For difference in amount of
heat received by the two hemispheres, see ¢d7d., table iv. p. 320.

2 The well-known fact that the productiveness of soils and the richness and
variety of the flora they support, is directly proportional (other things being equal)
to the amount of humus in the soil, is strongly emphasized by the analyses given in

the annual report of the Wisconsin Geological Survey for 1878, which has just been
received.

3“ Report on the Transactions of the Geneva Society of Physics and Natural
History,’ by Dr. J. Miller, translated for ‘‘ Smithsonian Report,” 1877, p. 221.

4 Résumé for 1877 in Smith. Rep. 1877, p. 58.

Reviews—A. Daubrée’s Experimental Geology. 421

Tey SE V5 2 EE VV Se

L—Ertuprs SyNTHETIQUES DE GHOLOGIE EXPHRIMENTALE. PREMIDRE
partig. Application de la méthode expérimentale & l’étude de
divers phénoménes géologiques. Par A. DauBriiz. 8vo. (Paris,
1879.)

T has been objected to geology as a science that its conclusions

were frequently based upon insufficient premises, and that it was
lacking in actual demonstration. Indeed a writer of eminence once
described geologists as a set of persons who amused themselves by
constructing worlds and then pulling them to pieces again; and it
must be confessed that the reckless guesses of an imagination not
always scientific, which have at times obtained a temporary notoriety,

did in some cases justify the charge. Still it should be remembered,

as Mons. Daubrée points out, that the study of the Harth, after having

been for a long time hypothetical, did really, towards the end of the
last century, enter “‘une voie positive,” where it has taken for its
guide the observation of facts.

Exactly a century has elapsed since the first appearance of de
Saussure’s works on the Alps. Werner and Hutton followed
shortly, and the endless dissertations of their respective disciples
may perhaps have had something to do with the strictures pre-
viously mentioned, especially as they took root in those soils where
discussion on subjects more or less transcendental seems to be an
indigenous plant. Yet, even in the earliest years of the present
century, the importance to the geologist of the synthesis of minerals
was recognized, although it was at one time considered that the
divergence between certain minerals and the most analogous com-
pounds which the laboratory could furnish was such as to render
their actual reproduction impossible. The difference between crys-
talline quartz and the amorphous silica of the chemist was almost
as great as that between the diamond and the soot of our chimneys.
To effect such marvels, lapse of time and certain occult actions were
deemed necessary, or, as Leibnitz put it in the Protogea, “il faut du
temps, du repos, et de l’espace.”’

In 1805 Hall experimented with a view to control some of
Hutton’s views, and succeeded in making chalk semi-crystalline
under the influence of heat and pressure, whilst Haussmann, a tew
years after, turned to account in the interpretation of geological
phenomena the examination of the silicates of the metallurgical
furnaces.

The year 1823 marks a discovery of the utmost importance. Mit-
scherlich recognized that péridot, pyroxene, and other mineral species
crystallized in slags, and Berthier, by melting silica with different
bases in definite proportions, actually obtained crystalline combina-
tions identical with those of Nature, especially pyroxene. It was the
first step made in the direct synthesis of minerals.

The next step was to overcome the difficulty presented by in-
soluble combinations in the wet way, and Haidinger, being desirous
of controlling Von Buch’s hypothesis, inaugurated the employment

422 Reviews—A. Daubrée’s Experimental Geology.

of water under pressure in the formation of dolomite, whilst the
numerous minerals accumulated in metalliferous lodes, which ob-
servation had shown could not have been conveyed either in a state
of volatilization or of fusion, attracted attention with a view to their
reproduction in the wet way—uno easy task, when it was seen that
silica itself in separating from water assumes the condition of opal
rather than of quartz. This void in synthetic mineralogy Sémarmont
filled by the employment of appropriate substances, such as are
most widely distributed in existing thermal springs, operating at
temperatures above 100° C., and under pressure. In this way he
succeeded in the formation of quartz crystals, small, it is true, but
possessed of the physical and optical as well as the chemical pro-
perties of natural quartz. Since then another triumph of synthesis
has been scored by Hautefeuille in the artificial production of orthose
and albite.

Such is a brief outline of the very useful historical sketch which
Mons. Daubrée gives as a prelude to the results of his own researches,
which, after being continued for 40 years, and scattered through —
many publications, are now comprised in one volume. This will
enable the reader more fully to estimate the value of his labours,
and at the same time will materially assist the geologist who has
not carried on similar work. The bearings of experimental geology
may assist in explaining many of the chemical, physical, and mechan-
ical phenomena which he meets with in the field, and the causes of
which are difficult to understand, considering the complex subsequent
modifications which have too frequently masked their primal origin.

The first section of the volume deals with chemical and physical
phenomena in three chapters; wherein the author shows the applica-
tion of the experimental method, 1st, to the history of metalliferous
deposits, 2nd, to the study of metamorphic and eruptive rocks, 8rd,
to the history of volcanic phenomena. A portion of the second
section, where the author describes the chemical decomposition of
silicates, such as felspar, by mechanical causes, in part belongs to
the subjects discussed in the first section.

The history of metalliferous deposits is divided into (1) stanni-
ferous masses, (2) “ gites sulfurés,”’ commonly called plumbiferous,
(8) ‘ gites de platine.”

In dealing with the Stanniferous group M. Daubrée can point out
how accurately he described in the ‘“ Annales des Mines,” nearly
forty years ago, the origin and constitution of tin deposits. The
peculiarities of this group—so different from the other, in which
the electro negative is mainly sulphur—are noted; the mineral
occurs as an oxide, and the gangues are not the same. The metalli-
ferous fissures, too, are not like ordinary lodes in the proper sense of
the term, but seem to be more like a number of small shrinkage
cracks, and the neighbouring rock is charged for some distance with
the mineral (cassiterite). This network of small veins contains an
enormous proportion of quartz, and the oxide of tin is further
escorted by certain minerals unusual in ordinary lodes,—such as
topaz, pycnite, tourmaline (schorl), axinite, and also apatite,—so

Reviews—A. Daubrée’s Experimental Geology. 423

that the accompanying elements, besides silicon, are boron and
fluorine, and frequently phosphorus and arsenic, forming combina-
tions which cannot be explained by the mere chemical analogies
of these different elements, as is the natural association of iron with
manganese, or cobalt with nickel. These observations have been
supplemented in a recent contribution to the Quart. Journ. Geol.
Soc. by Dr. Le Neve Foster, who gives some very interesting details,
especially as to the fact of lodes, containing from one to three per
cent. of cassiterite, themselves consisting of schorl rock, which he
describes as a matted mass of fine needles of schorl in a ground mass
of quartz, with granules of cassiterite scattered through it, or ar-
ranged in little strings and veins. From these considerations it may
be gathered that fluorine was the agent which performed at once
the part of carrier and of mineralizer, thus discharging the task
allotted to sulphur in the plumbiferous (sulphuretted) group.

Fluoride of tin is a compound stable at high temperatures, and in
all probability the tin came up as fluoride from the general reservoir
of the heavy metals. Boron too has a tendency to combine with
fluorine, and fluoride of boron being volatile would also ascend.
In the artificial preparation of cassiterite, effected by M. Daubrée
as long ago as 1841, not having conveniences for the employment of
fluorides, he brought together in a porcelain tube the vapour of
bichloride of tin and steam at a temperature below 300°C. Small
but well-formed crystals resulted, having a density of 6°72, and
adhering closely to the sides of the tube. Similarly, by employing
perchloride of titanium, he obtained small crystalline grains of
titanic acid. The artificial production of apatite was effected by the
action of perchloride of phosphorus, first on caustic lime and after-
wards on chalk, the result being a true chlor-apatite. In these
operations some chloride of silicon was formed at the expense of
the porcelain. Thus he argues, that if the vapours of stannic
chloride and fluoride, which appear to have formed the stanniferous
deposits, were accompanied by perchloride of phosphorus, this latter,
when encountering lime in the enveloping rocks, must have formed
apatite accompanied by fluor spar.

Still referring to this subject, M. Daubrée, whilst apologizing for
introducing his own work as that of a geologist rather than of a
chemist, mentions that, seventeen years after these experiments
(viz. in 1850), Deville produced corundum by means of volatile
metallic fluorides re-acting on oxidized compounds, and that by
means of fluoride of titanium Hautefeuille reproduced the three
forms of titanic acid.

The sulphuretted group, being the one in which the majority of
metals occur, is not dealt with generally, but M. Daubrée points out
the existence of analogous products of recent formation in warm
springs, such as those of Bourbonne-les-Bains. An abstract of the
author’s paper in the “Comptes Rendus” for 1875 has already
appeared in this Magazine. Bourbonne-les-Bains is not the only
place where Roman coins have yielded metallic sulphides, but there
the circumstances seem to have been peculiarly favourable, and

424 Reviews—A. Daubrée’s Experimental Geology.

M. Daubrée illustrates these by a series of cuts with much exacti-
tude. Some 20 kilogrammes of bronze coins were found at the
bottom of a Roman well (puisard), associated with black organic
mud, where they had been bathed for sixteen centuries by mineral
waters at present containing 8 grammes of solid matter to the litre,
and having a temperature of 68° C. at the principal point of dis-
charge. In a permeable bed towards the bottom were evidences of
bronze coins, etc., which had undergone decomposition, more or
less complete. Four species of cupric sulphide result. The tin
appears as a white earthy crust, consisting chiefly of oxide. The
lead pipes in places were coated with phosgenite (carbonate of
lead and chloride of lead), which, by the reducing action of organic
matter in the presence of gypsum, has yielded small but definite
crystals of galena.

Such an automatic laboratory, containing within itself a sort of
electro-chemical apparatus, was a valuable legacy of the Romanized
Gaul to his descendants, not to be appraised so mnch for its metallic
worth, as for its utility in supplementing those essays in synthesis
which the shortness of human life too often forbids to be accom-
plished within the limits assigned to one generation. We also learn
in this case how Nature is gradually reversing the operations
of man; remarrying, as it were. those elements which had been
divorced by the laborious operations of the miner and the smelter.

It is just possible that discoveries such as the preceding, confirm-
ing our knowledge of what can be done in the wet way in warm
springs and mine-waters within periods short in a geological sense,
may tend to exaggerate the importance of the part played by water
as a solvent at a time when the great sulphuretted lodes received the
bulk of their metallic charge. These phenomena merely represent
the final stages of processes infinitely more energetic. M. Daubrée
asks, What should we see if it were possible to descend the fractures
serving as channels for the ascent of the thermal waters? We
should probably find additional proof of the important modifications
produced by water at increasing temperatures. but this would not
lessen the probability that the metals associated with lead have
been volatilized from depths where no water is in combination with
sulphur, selenium, tellurium, or arsenic, just as he has shown how
tin has been volatilized in combination with fluorine.

The second portion of the chemical and physical subdivision of
the subject treats of the metamorphic and eruptive rocks and of the
application of the experimental method to their study. The author
interprets the word ‘metamorphism’ in its widest and most conven-
tional sense, 1st, as simple molecular re-arrangement, 2nd, as crys-
talline re-arrangement based on matter already on the spot, érd, as
erystalline re-arrangement with importation of new or elimination of
old matter.

Metamorphism of juxtaposition is the term he prefers for those
modifications which are effected by invading rocks within moderate
distances, though such modifications may reach as far as 8000 metres
in the case of granitic invasions. In dealing with regional metamor-

Reviews—A. Daubrée’s Experimental Geology. 425

phism he expressly excludes the old gneisses and mica-schists which
underlie the stratified fossiliferous terranes, and confines his obser-
vations to the schistose masses whose metamorphie origin is, he says,
clearly demonstrated.

This is certainly begging a question which many persons would
be by no means willing to concede. The above quoted remarks
were originally published by M. Daubrée in 1859, and have not
been altered in the present work, so that no reference is made to the
numerous memoirs which have appeared since that date. It is clear
that M. Daubrée still continues a strong believer in the doctrine of
Epigenesis—that Hibernian form of metamorphism which is accom-
panied by considerable change of substance. It somewhat detracts,
therefore, from the interest of this part of his work, that he has not
thought fit to notice the numerous papers contributed to this subject
of late years. We find him, for instance, stating that this modifica-
tion (regional metamorphism) is easily recognized in such countries
as Wales, the Taunus, and the Ardennes. Certainly the alleged
metamorphism of portions of the former country has been disputed
on good grounds by very competent observers, who, although they
probably differ in details, have adduced most excellent evidence that
certain beds of obscure origin are by no means the metamorphosed
equivalents of beds elsewhere recognized as forming part of sedi-
mentary formations of known age. We leave the Taunus and the
Ardennes to the consideration of foreign critics.

In the Alps there seems to be better evidence of metamorphism
as understood by M. Daubrée, but the strongest case is the well-
known one in the Vosges, where, as observed by M. Delesse, the
organic remains so well preserved at Rothau deserve to be con-
sidered as the classical monuments of metamorphism. Here syen-
itic granite has penetrated Devonian beds, which for several
hundred métres from the point of contact are entirely modified.
At certain points the altered rock consists of a compound of lamellar
pyroxene, epidote, and compact garnet, associated with abundance of
fossil corals. The cavities bristle with elongated crystals of amphi-
bole, ete. Such a case as this should in fairness be quoted under
the head of metamorphism of juxtaposition ; but anyhow it is a hard
nut for those who disbelieve in the extensive alteration of sedimen-
tary beds to crack.

The causes of metamorphism are next considered, and here it is
again evident that change of substance as well as of form is the kind
of metamorphism most frequently present in the mind of the author.
Heat (which is from two sources), even when aided by certain
vapours, is not sufficient; we must, then, look te water as having
performed an important part “dans les phénoménes métamor-
phiques aussi bien que dans les éruptions des voleans.” This
requires to be further supplemented by pressure.

Tt became necessary, therefore, in the application of the experi-
mental method, to ascertain how far heat, water, and pressure could
be made to reproduce the principal phenomena of metamorphism.
The means to effect this are shown in a series of illustrations, the

426 Reviews—A. Daubrée’s Experimental Geology.

general principle being to operate upon a glass tube placed inside
one of iron. The tubes were exposed to a temperature of about
400° C. during several weeks. It was found that pure water
suitably superheated will transform an anhydrous silicate, such as
glass, into a hydrated silicate of zeolitic character. A glass, for in-
stance, containing silica 68°4, lime 12:0, magnesia 0:5, soda 14:7,
alumina 4:9, was found to lose silica, alkali, and alumina, whilst the
relative amount of lime seems to have increased, and the new silicate
had fixed a quantity of water.t

The results varied according to the different nature of the glass,
and of the substance added to the water. Crystals of quartz were
frequently formed. A figure is given at page 168 of a slice sub-
jected to polarized light, showing a number of colourless microliths,
and a few greenish crystals of pyroxene. The weight of the water
which effected all these alterations was only one-third of that of the
glass transformed. Obsidians and perlites were also tried with
partial success: some crystals of felspar and pyroxene associated
with these underwent no alteration, but were “sugared”? over with
little crystals of quartz. M. Daubrée enlarges on the wonderful
results which have thus been obtained in the wet way, even to the
production of an anhydrous silicate, such as pyroxene, at tempera-
tures far below the fusing-point of the mineral. The application of
these results to the phenomena of metamorphism is obvious, and
explains, amongst other things, by the ready liberation of silica
from compound silicates, the formation of quartz on a large scale.

The Roman masonry at Plombiéres and elsewhere, so long in
contact with warm mineral springs, affords an admirable instance of
“contemporaneous metamorphism.” The reaction of the alkaline
waters upon the mortar and bricks has resulted in the deposit of
chalcedony and of many zeolitic minerals. Microscopic sections of
bricks with geodes lined with chabasite, etc.. afford very effective
pictures, and many interesting chemical details are added. The
curious white concretionary substance called Plombiérite—gelatinous
when moist, and transported and deposited by the water like silica
itself—appears, according to Fouqué’s analysis, to be a compound or
mixture of carbonate and silicate of lime with water. All these
results have been effected at moderate temperatures and without
pressure. A valuable digest of these facts appeared in the Quart.
Journ. Geol. Soc. for 1878 (vol. xxxiv.), where M. Daubrée observes
that zeolitic minerals may be considered as a kind of “extract” of
the rocks that have been subjected to a continued lixiviation.

Water, he therefore insists, has played an important part in the
crystallization both of eruptive and of metamorphic rocks, especially
as it permits the crystallization of silicates at temperatures far below
their fusing-points ; we must thus look to the hydrothermal rather
than to the dry way for the explanation of the origin of silicates in
a large part of the rocks.

Under these circumstances, and adopting the very comprehensive

1 Some of the figures in the tables at page 161 appear to have got transposed, as
the calculations hardly agree.

Reviews—A. Daubrée’s Experimental Geology. 427

word ‘metamorphism’ in the sense used by M. Daubrée, it will
become more difficult than ever to distinguish between altered and
erupted masses when viewed merely under their petrological aspects.

Not the least interesting of M. Daubrée’s experiments was made
with a view to determine how far the capillary infiltration of water
could supply the immense quantities used in volcanic eruptions. A
suitable apparatus, figured p. 238, enabled the author to demonstrate
that liquid water will force its way through a slab of close sand-
stone against a very considerable pressure of steam. He therefore
infers, that in spite of the powerful upward pressure of aqueous
vapour, the cooler waters of the Earth’s surface do find their way
through the rocks themselves, and that what is known as quarry
water is nothing but this feeder surprised at the commencement of
its downward journey.

The second section of the work, being devoted to mechanical
phenomena, is worthy of a separate notice, but there are some
subjects discussed which have a chemical bearing. Important ex-
periments were carried on with a view to ascertain how far the
decomposition of silicates is effected by mechanical causes. There
is probably no question in the whole work which has a more im-
portant geological bearing than this, because it enables us to form
some idea how the débris of crystalline rocks is chemically altered
during the process of degradation. Dr. Sterry Hunt has always
emphasized this point, and those who question the wholesale intro-
duction of fresh matter into rocks which the ultra-metamorphic
school have taught, attach much weight to their chemical composi-
tion as controlling the possibilities of alteration.

Orthose in fragments was rotated in a cylinder along with dis-
tilled water. When the experiment was performed in an iron
cylinder, 3 kilogrammes of felspar, after a journey equal to 460
kilométres, yielded to 5 litres of water 124 grammes of potash,
with very small quantities of silica and alumina. To effect such a
decomposition mechanical division and the solvent action of water
must be exercised simultaneously. Curiously enough the presence
of chloride of sodium arrests the decomposition. The presence of
carbonic acid facilitates the solution, and much silica, as well as
potash, is dissolved. Obsidian and leucite are but slightly attacked.
In these operations the mud obtained is in such a fine state of divi-
sion as to render the liquid opaline, and it takes some days to settle:
the quantity of potash retained is still very considerable. Such a
substance would form the “ phyllades” or argillaceous schists which
occur in the stratified terranes at different geological stages: these
often contain from 6 to 7 per cent. of potash.

Finally, M. Daubrée once more returns to the subject of metamor-
phism, and having observed that dry clay triturated against itself,
had its temperature raised in three-quarters of an hour from 18° C.
to 40°C., speculates on the possibility of the transformation of
mechanical force into heat in regions such as the Alps, during the
period when those forces acted with the greatest intensity. W.H.H.

428 Reviews—Moyjsisovics’ Dolomite Reefs of South Tyrol.

IJ.—Tue Dotomire Reers or rae Sourn Tyron anp VENETTA.
Contributions to the History of the Formation of the Alps. (Die
Dolomit - Riffe von Siid-Tyrol und Venetia. Beitrige zur
Bildungsgeschichte der Alpen. Von Epmonp Mogsstsovics von
Mojsvar.) With a Map, in 6 Sheets, of the Tyrolese Venetian
Alps, 80 Photographs, and 110 Woodeuts; pp. 552.

Why ce the title of this work might lead one to suppose that

it merely treated of the geological history of the remarkable
mountains of dolomite which are so wonderfully displayed in this
portion of the Tyrolese Alps, an inspection of the book itself shows
that the author by no means confines himself to a single portion of
the geology, but traces out with great minuteness of detail the
complete history of the different series of rocks, from the Archaic to
the Tertiary, as well as the various glacial deposits and the physio-
graphy of the district.

As stated in the preface, the portion of the Southern Alps described
in this book lies between the Pusterthal on the north, the Htsch on
the west, the Piave to the east, and the neighbourhood of Belluno
and the Sugana Valley on the south, and contains the well-known
Alpine districts of Amperro, Landro, Sexten, Cadore, Zoldo, Agordo,
Primiero, Fassa, Groden, Enneberg, and Brags; the ancient
volcanic tracts of Fleims and Fassa, the eastern portion of the great
porphyry plateau of Botzen, the granitic island-mountain of the
Cima d’Asta, as well as the fruitful valley lands of Sugana and the
rich Tertiary basin of Belluno.

The first part of the book consists of a general introduction to the
geological history of the Alps, in which are sketched the various
formations, the localities in which they occur, their petrological
constituents, and their principal fossils. ‘The probable extension of
the land and water areas at the different periods, and the relationship
of these rocks to those of corresponding age in other parts of Hurope,
are also given. It is shown that whilst rocks of Archaic, Paleozoic,
Mesozoic, and Tertiary age are represented in this region, the
principal mountain masses belong to rocks of Permian and Triassic age.

In the second part, which embraces the fifth to the fifteenth
chapters, detailed descriptions are given of the sections exposed in
the most noted localities of the region, and numerous woodcuts
facilitate the explanations of the more complex sections. Dr. Doelter
has investigated and described the volcanic districts of Fassa and
Fleims, the quartz-porphyry districts and the granites of the Cima
d’ Asta.

The 16th chapter is devoted to a consideration of the age, struc-
ture, and extension of the vast masses of dolomite, of which this
Alpine region is largely formed. The author endeavours to prove
that these vast ranges of Triassic dolomite were formed as reefs
round the crystalline middle-zone of the Alps during a period of
depression, and that they may be compared to the great wall-reefs
which now border the Australian continent. On the land bordering
these reefs volcanos burst out, and to the eruptions from these and
submarine volcanos are largely due the beds of tuff and breccia

Correspondence—Ur. A. B. Wynne. 429

which have been deposited in the areas surrounding the reefs. These
dolomitic reefs are mostly poor in fossils, but the author attributes
their deficiency in this respect to the same causes which have
brought about the obliteration of organic remains in recent coral
reefs. The numerous sections figured and described, in which
mechanical deposits of tuff and other materials rest on, and occasion-
ally dove-tail into, the steep slope of the reef-like walls of pure
dolomite, are strong evidence of what the author puts forward as
the main object of this work to prove—the contemporary formation of
these deposits of such different characters in the period of the Trias.
The concluding chapter treats of the periods at which the different
dynamical forces have operated to produce the present mountain
ranges, and the principal direction of the various dykes and faults.
The maps accompanying the book are drawn to the scale of
sstoo, and no fewer than 47 different geological divisions are in-
dicated on them in different tints. The photographs are produced
by the Albertotype process, and give an excellent idea of the
physical characters of this Alpine region. This work merits the
study not only of those who purpose themselves to visit the region
described, but of every student of geology. EE

@ Ores Se @ aN) as S see

RECENT PUBLICATIONS OF THE GEOLOGICAL SURVEY OF INDIA.
Manual of the Geology of India, Introduction, chapters xx. and xxi., by

W. T. Blanford, Esq., F.R.S., ete.
Palzontologia Indica, Series XIII., Salt Range Fossils, by Dr. W. Waagen.

Sir,—Being the person to whom the geological examination of
the Upper Punjab, as well as the Salt Range, has been entrusted, I
would point out that in the publications above mentioned many of
my statements, as recorded in my Salt Range Memoir (Geol. Surv. Ind.
Mem. vol. xiv.) and other papers, have not been accurately reproduced.

In the Manual, although chapters xx. and xxi. are said in a foot-
note (p. 480) to be “chiefly compiled from data furnished by Mr.
Wynne’s papers, except where the contrary is stated,” there are very
numerous instances, unaffected by the last clause of this passage, in
which the published statements of my memoir are replaced by others
with which I cannot coincide.

So far as mere speculations are concerned, opinions may of course
differ widely, but as to statements of fact I adhere to the views pre-
sented in my various papers regarding the geology of the Upper
Punjab, including the structure of the Salt Range; with which no
other officer of the Survey is more fully acquainted than Iam myself,
while the writer in the Manual has not even seen the ground.

Throughout the introduction to the lately issued part of the Palee-
ontologia Indica, Dr. Waagen repeatedly attacks my classification of
the Salt Range Series, giving an even less definite one of his own,
and while condemning that which I adopted, never makes the least
allusion to the facts; that mine was based upon the general determi-
nations of our Survey paleontologists (and others), of whom he was

430 —. Oorrespondence—=Mr. A. B. Wynne.

then one ; also that this classification was made in his own presence,
in consultation with himself, without his offering a single objection
to it at the time, when specially deputed to assist in the interpreta-
tion of the ground. He implies that I treat these local divisions as
“real formations equal in importance to ‘Silurian, Devonian,’ ete.
(p. 2),” and says (p. 6) that I appear to have considered the older
division of the series ‘‘as equivalent to the whole Paleozoic series
as it has been defined in Europe and elsewhere.”

So far from these statements being correct, I referred the recog-
nizable divisions of the series, on the best paleeontological evidence
available, to their general ages as “rock groups”! merely—and not
as ‘‘ formations” with the definite sense Dr. Waagen would attribute
to my words, — leaving the ages of the unfossiliferous zones un-
certain, distinctly stating, at p. 281, there was no reason to assert
the presence of a Devonian group, and pointing out at p. 118 that
considerable intervals were left unrepresented.

Dr. Waagen now classes the Obolus beds, or Silurian zone of my
series, with the Productus limestone of his list in one division;
entirely omitting to mention that this Silurian zone was originally
founded upon Stoliczka’s determination of the fossils I obtained
from it, confirmed by himself.

His statement (foot-note to p. 3) that Dr. Fleming and I con-
sidered Terebratula (Waldheimia) Flemingi (belonging to the upper
part of the series) to be Carboniferous, is simply without founda-
tion, so far as ] am concerned (see my Memoir, p. 104, where it is
mentioned as coming from a higher stage; and section, p. 190,
No. 11, where a Terebratula supposed to be the same is noticed on
the evidence of Dr. Waagen’s own notes). I was quite aware of
Mr. Davidson’s remarks regarding this fossil, but left the settlement
of such a point as a matter of course to the Survey paleontologists.

Dr. Waagen further accuses me of wrongly grouping his sections,
which in all cases I copied from his own dictation in Hnglish; but
in one to which he refers at p. 30, owing to his own omission of the
groups, I had to supply these from comparison with others. If
there are errors in these sections, the fault is his own, and the
grouping into which they were thrown at the time is proof of Dr.
Waagen’s assent to the classification then adopted without reser-
vation or condition on his part.’

With regard to this classification generally, now altered by Dr.
Waagen, it will be observed he gives no reason at present for
questioning the accuracy of Stoliczka’s (and his own) determination
of the Obolus or Siphonotreta, on which the Silurian age of one
division was based, preferring to attribute error to myself alone.

And further, in referring to the peculiar fish teeth from Chel Hill

! See chap. il. of my Memoir referred to.

2 See his subsequently written paper, Mem. Geol. Surv. Ind. vol. ix. p. 351,
where, notwithstanding some uncertainty stated in the text, he uses the words
“ Carboniferous deposits of the Salt Range” in the title, and indicates elsewhere the
Carboniferous affinities of certain fossils of the Range. This shows that the Lower

Salt Range limestone was then referred to the Carboniferous period by others on the
Indian Survey, as well as by myself.

Correspondence—Ur. A. J. Jukes Browne. 431

(of which I certainly forwarded several specimens), my full account
of their discovery (Memoir, p. 145) and locality has not been given,
and my suggestion that they came from the horizon of this same
Obolus zone, rather than that of the Magnesian sandstone, has been
omitted.

My statement as to the absence of unconformity in the Salt Range
is indorsed at p. 2 (wherein he differs from the views presented in
the Manual), but he seeks to establish breaks in the perfectly con-
secutive and stratigraphically united series, both on paleontological
and other grounds; overlooking the point that the perfectly united
fossil-bearing groups distinguished as Carboniferous and Triassic,
Jurassic and Cretaceous, in my list (Memoir, pp. 66, 96, and 277)—
from one to another of which some genera at least pass upwards—
must be considered more definitely related to one another than any
of them are to the equally physically united but unfossiliferous
groups beneath.

One of these unfossiliferous groups at a higher stage in my list,
No.8, the red Trias (?),is entirely omitted from Dr. Waagen’s transcript
of my classification at p. 8 of his paper. Though dealing with other
Azoic groups, he seems to have been unable to find a place for this one,
leaving it suspended in the anomalous position of Mahomet’s coffin.

As a matter of fact, there is little choice as to which of the Salt
Range groups are most closely associated or most distinctly divided
by stratigraphic features ; difference of colour and texture, more or
less sudden change, or apparent local transition, being characters
observable with varying intensity along most of the boundaries ;
still I had little difficulty, except in one or two cases, in identifying
each group of the series as on a distinct horizon.

Should Dr. Waagen’s paleontological labours improve the classifi-
cation I adopted atter consultation with him (as above stated), it will
be a welcome result. I regret, however, that his indiscriminate im-
putations of error compel me to state the actual share taken by him

in what had been done previously.
A. B. Wynne,

Geological Survey of India.

JUKES’S THEORY OF RIVER VALLEYS.

Sir,—Mr. Kinahan’s reply to my letter on this subject is so extra-
ordinary that I must crave space for a few further remarks.

In his book on Valleys, Fissures, etc., he devotes several pages to
the discussion of Jukes’s explanation of the river valleys in South
Ireland, and from one of these pages I quoted a statement referring
to the limestone of that district; yet he now “explains” that the
extract “refers to the formation of valleys in any country and in
any kind of rocks.”

I maintain that the passage cited has no sense unless it refers to
the South of Ireland and to Jukes’s theory.

Admitting that Professor Jukes in 1862 did believe that the
Carboniferous Limestone was originally deposited over the whole
of §.W. Ireland, yet the theory then enunciated by him in no way

432 Correspondence—Mr. A. J. Jukes Browne.

depends upon the truth of this supposition. Jukes never supposed
the limestone to have had this extension at the period when the
erosion of the valleys was commenced; on the contrary, his theory is
expressly based on the supposition that the surface over which
the rivers originally ran was a plain of marine denudation, cutting
across the folds and contortions of the rocks.

Mr. Kinahan now affirms that the Carboniferous Limestone thins
out southward, and that its original thickness in the valleys of the
Lee, Bride and Blackwater was not so great as Jukes had supposed ;
but, assuming this to be true, the argument which Mr. Kinahan
founds upon this premiss is equally defective in logic and in gram-
mar ;—he thinks that ‘‘as the theory was founded in a county and on
suppositions which were afterwards found to be erroneous,” he is
justified in saying that it falls to the ground. I can only express
my astonishment that Mr. Kinahan should consider any part of his
own country to be erroneous,—the imputation is so utterly incon-
sistent with his patriotism that in a Dogberry sense it seems to be
“flat burglary.” As regards the erroneous supposition (for there is
only one), my answer is simply that Jukes’s theory was not founded
upon it; Mr. Kinahan himself admits this in the passage I quoted
from his earlier work, distinctly saying that it did not much affect
the subject, ‘as some of the other rocks are nearly as easily denuded
as limestone.”

It will be obvious to others, however, that, if the thickness of the
limestone was never sufficient to fill up the troughs to the level of
the original plain, their centre would be occupied by a strip of Coal-
measures; and that Jukes’s reasoning would still remain the same,
for his theory does not depend on the universal presence of lime-
stone, but on the fact of the rocks in the synclinals being more
easily denuded than those of the anticlinals.

Having entered the lists in defence of my late uncle’s views on
this subject, I am glad of the opportunity of noticing a difficulty
raised by Prof. Hull in .his “Physical Geology of Ireland.” Prof.
Hull accepts the theory in general, but dissents from its application
to the Blackwater, because the point where the present river is
deflected southward does not coincide with the influx of any stream
from the north. But Jukes’s main object was to explain the forma-
tion of the transverse ravines, and he looked back to a time when the
longitudinal part of the Blackwater Valley did not exist, and when
the two brooks from the north “may have united their waters some-
where about the northern end of the Dromana Ravine.” I am
quoting Jukes’s own words, and feel sure that were he now alive he
would make a similar answer. and would add that the present actual
point of deflection has been fixed by the subsequent changes in the
river-course since the establishment of the Dromana Ravine. I trust
that Prof. Hull will reconsider this point before bringing out a
second edition of his work, and may see his way to accept the theory
without excepting the Valley of the Blackwater.

Gro. Surv. oF ENGLAND, A. J. JUKES Browne.
ALFORD, Aug. 8, 1879.

THE

GEOLOGICAL MAGAZINE.

NEW SERIESS (DECADE Is VOER Vil:

No. X—OCTOBER, 1879.

QIK ALIN Ae) JAS ORE ES,

—=
I.—On tHE CLASSIFICATION OF THE British Pre-Camprian Rooks.!
By Henry Hicks, M.D., F.G.S.

HE results obtained of late years, through the numerous in-
vestigations which have been carried on amongst the Pre-
Cambrian rocks in Great Britain, combined with the important
discoveries of many additional areas to those previously known,
seem to require that some general attempt should now be made to
correlate the principal groups where they have been observed ;
and to classify them according to the prevailing types of rocks
recognized therein, and peculiarities observable.

It will be seen that the ordinary methods of investigation, used in
determining the order of succession in more recent strata, are equally
applicable to these; provided, we grant, that they were deposited
more or less in a similar manner, and that the crystalline or semi-
crystalline state in which they are now found has been subsequently
induced.

This being allowed, we arrive at the probable conclusion that the
sediments which hold the lowest, and hence the earliest position,
are those which have undergone most change; and that this will be
less marked as we ascend in the succession.

I believe that the facts obtained go to prove almost conclusively
that this is the case: and, moreover, that the majority of the rocks
now recognized as Pre-Cambrian were originally sedimentary strata,
which have undergone, during subsequent changes, a certain amount
of alteration, or metamorphism, but which still retain sufficient
evidence of their origin to warrant their being classified by the same
methods as those applicable to more recent deposits. That they can
in fact be distinguished by special characters due to the prevalence
of certain physical conditions at the time of deposition, by a well-
defined order in succession, and usually by a discordance in the
strike of the larger groups.

In the physical history of our globe, nothing, perhaps, becomes
more evident than the well-recognized fact that its crust has been

1 Read at the Meeting of the British Association at Sheffield, 1879.

DECADE II.—VOL,. VI.—NO. X. 28

434 Dr. H. Hicks—British Pre-Cambrian Rocks.

undergoing periodical contractions along certain defined lines. That
these lines have also periodically varied in their direction is well
known. If we require therefore to trace out the history of these
movements, we must seek for it in those strata which we know
must have been elevated at the time; and whose beds must have
generally assumed a strike parallel with the upward movements.
Sir R. Murchison years ago pointed out the fact that the majority
of the crystalline rocks in the Hebrides and North-western High-
lands of Scotland had a strike from N.W. to S.H.; and hence
in a direction not usual in the Cambrian and Silurian rocks.

This fact has been more or less qualified by all subsequent
observations, and it is one which cannot be lost sight of in any
inquiry made as to the early physical history of our islands. My
own observations tend to show that the oldest known upward
movements were in a direction almost due east and west, that 1s,
that the contractions took place from north to south; subsequent
elevations and depressions in a direction from N.W. to 8.H.; more
recent ones from N. to §., and those which immediately preceded
the Cambrian period from N.H. to 8.W. Each of these produced
new physical conditions, with breaks in the succession along well-
defined, and usually extensive, lines. Another important fact made
out in these inquiries is that it may be possible sometimes to
determine the age of the faults by the direction which they have
taken, especially if of great extent. For example, a tolerably rigid
crust under the influence of a lateral thrust acting from H. to W.
would most probably fracture in a direction from N. to 8. Now if
we take for granted that the last sediments deposited previous to
this lateral pressure being exerted were in a condition to yield
readily to the contractions, as they probably would be; but that
the underlying rocks would be in a hardened or metamorphosed
state; it is clear that these last only would be fractured. If these
movements also did take place in the direction of those which had
previously acted upon these rocks, then generally the fractures
would be across the beds, and in the direction of the curvatures of
the overlying sediments. That is to say, the faults affecting A
would be in the direction of the strike in B.

At present it is difficult to separate always those which may be
called the primary faults from those produced subsequently during
fresh contractions; still they may be recognized frequently, and when
they are they aid greatly any attempt made to unravel the early
physical changes. ‘The oldest faults which can be traced with cer-
tainty are in a direction from N. to 8. and were produced at the close
of the Arvonian. They cut across the beds of the Lewisian, and
Dimetian, and exposed these rocks as ridges in the Pebidian sea, and
Pebidian beds are now seen resting along the sides and unconform-
ably across the edges of these rocks. These faults therefore prove,
along with other evidence, that the former rocks were crystalline
ere the latter were deposited, and that they yielded by fracturing to
the lateral pressure exerted from H. to W. which gave the direction
of strike to the Arvonian group.

Dr. H. Hicks—British Pre-Cambrian Rocks. 435

In former communications I have attempted to classify these rocks
as exhibited in special districts, and I have usually found, when
examining new areas, that the order which I had previously made
out, as far as that evidence went, was almost invariably recognizable
there also. It is this fact that has mainly tempted me to bring for-
ward this paper to endeavour to show that a classification generally
applicable to the British Islands is even now possible.

Four well-defined groups are made out, and to each of these names
have already been given.

They occur in the following ascending order :—1l. Lewisian;
2. Dimetian; 3. Arvonian; and 4. Pebidian.

1. The Lewisian, so named by Sir R. Murchison to indicate the
crystalline rocks of the Hebrides and North-western Highlands of
Scotland, is here retained for the oldest group at present recognized
in Britain, and largely developed in the Hebrides. It is found also
in parts of the Malvern chain, and the North-west of Ireland; and
possibly also in Anglesey. The prevailing rocks in this group are
massive gneisses, in which hornblende and a reddish felspar are the
chief ingredients, and quartz, chlorite, and mica, but sparingly
present. They are usually of a dusky red, grey, or dark colour.
Sometimes almost a pure hornblende rock is found. The strike in
these beds is usually H. and W. or some point between that and
N.W. and 8.E.

2. The Dimetian.—This group is largely developed in Wales, as
at St. Davids, Carnarvon, Rhos Hirwain and Anglesey. It has been
found by Dr. Callaway in Shropshire, and I have recently seen it in
the Malvern chain, especially in the Worcester Beacon. I noticed it
also last year in large development at Ben Fyn, Loch Maree, and
near Gaerloch in Ross-shire, as well as at several other points in the
North-western Highlands of Scotland. The prevailing rocks in this
group are granitoid and quartzose gneisses, with pinkish, flesh-
coloured, or white felspar; and with limestones, micaceous, and
occasionally chloritic and hornblendic bands. Brecciated beds also
occur in which bits of the older Lewisian gneiss are sometimes
found. The strike is generally N.W. and S.E. or from this to N.
and 8. It evidently overlies the Lewisian unconformably in the
areas where both have hitherto been found associated ; and its highly
quartzose character and lighter colour generally is in marked
contrast to most of the members of that group.

3. The Arvonian.—At the last meeting of the British Association
I mentioned, for the first time, the discovery, or rather the separa-
tion of this group. It is largely developed in Pembrokeshire and
Carnarvonshire. It occurs also in Anglesey and Shropshire, and I
have recently found it at the base of the Harlech Group in the heart
of the Harlech Mountains. J have seen masses of it also from the
Orkneys, and it probably occurs both in the Western Islands, and
in the Grampians of Scotland. It is the great hilleflinta group of |
the Swedish geologists, and the petrosilex group (Hunt) found so
largely developed in North America. It is chiefly made up of

436 Dr. H. Hicks—British Pre-Cambrian Rocks.

quartzo-felspathic rocks, sometimes porphyritic, frequently brec-
ciated: and of compact quartzose rocks or hiilleflintas, which on
microscopical examination have the appearance of incipient gneiss.
The strike is usually about N. and 8.

4. The Pebidian.—This being the newest group in the Pre-
Cambrian rocks is the least altered in character, and most nearly
approaches in strike to the overlying unaltered or Cambrian rocks.
It resembles that group in many of its rocks, and on that account
was for a time supposed to be identical with it, only that it had
undergone local alteration. Now we know that it underlies the
latter unconformably, and that the apparent similarity in character
is to be attributed to the fact that most of the Cambrian rocks were
derived from the denudation of this group. That it was also ina
high state of alteration before the Cambrian rocks were deposited
upon it is evident from the fact that an abundance of pebbles and
masses of it occur in the conglomerates at the base of the Cambrian.
It consists for the most part of chloritic, talcose, felspathic, and
micaceous schistose rocks; alternating with massive and slaty green-
stone bands, dolomitic limestone, serpentine, lava-flows, porcellanites,
breccias and conglomerates. It is traversed also frequently by dykes
of granite, dolerite, ete. It is a group of enormous thickness, and is
largely distributed over Great Britain. It occurs in many parts of
Wales, in Shropshire, and in Charnwood Forest. I found it also
last year in the North-west of Scotland, and I have seen specimens
of it collected by Mr. James Thomson and others from Islay, and
other of the Western Islands. Dr. Hunt recognized it also along
the Crinan canal, and in the vicinity of Loch Foyle, in Ireland. It
is probably represented in America by the Huronian Group. The
prevailing strike is N.N.H. to $.8.W., or from this to N.E. and S.W.

The conglomerates at its base are largely made up of masses
derived from the Arvonian; and it is undoubtedly, at most of the
points examined, unconformable to that group.

These four divisions comprise at present all that we know of the
Pre-Cambrian rocks in Great Britain; but it is probable that as
fresh discoveries are being made others will still be found. In any
case the field is a wide one, and it has at present only been barely
touched, though the results have been very considerable. Many,
indeed the majority of the rocks found in these four divisions were
until recently supposed to be either intrusive masses, or altered sedi-
ments belonging to tolerably recent times. The success obtained of
late in their separation and recognition has been largely due to
microscopical examination, for the first application of which to that
purpose we are mainly indebted to Mr. Sorby. In addition to this,
it is becoming more and more an acknowledged fact that the meta-
morphism of great groups of rocks does not take place as readily as
was formerly supposed, but that some special conditions, such as do
not appear to have prevailed over this area since Pre-Cambrian
times, were necessary to produce so great a result.

Walter Keeping—On Oolumnar Sandstone. 437

II.—On some Cotumnar SANDSTONE IN Saxon SWITZERLAND.
By Water Kuzpine, B.A., F.G.S.
(Late Professor of Geology in the University College of Wales.)

NE of the most beautifulexamples of prismatic jointing that we
know of in a sedimentary rock has lately come under my
notice whilst travelling in N.H. Germany.

In a series of lithological specimens exhibited in the Dresden
Museum to illustrate the Cretaceous Period is a tray of small sand-
stone columns remarkable for their great regularity of size and
sharpness of outline. By the favour of Herr Deichmiller (to whom
I am indebted for many other acts of courtesy and kindness) I
was directed to the exact spot in the Meissener Hochland, or ‘Saxon
Switzerland’ as it is more commonly called, where they were found.

On many accounts the Saxon Switzerland is interesting to the
student of joint structure. It is a beautiful country, made up for
the most part of the well-known Quader Sandstein, of Upper Cre-
taceous age—well exposed along the steep natural cliffs of the Elbe
River and in the numerous quarries along its banks. The rock is a
rather thick-bedded pale yellow sandstone, usually with casts of
fossils, readily worked with the hammer and chisel. It is well cut
up naturally by two sets of joints running at right angles to one
another, which are so regular as to divide it conspicuously into large
cubical blocks—on this account the name ‘Quader’ was given to the
formation. According to A. von Gutbier! the joints are very persis-
tent in direction throughout the whole district of the Quader Sand-
stone hills, running from N.W. to S.E., and N.E. to 8.W. respec-
tively. Further up the Elbthal and in its tributary valleys this
cubical jointing is even more striking. Looking, for example, across
the Amselgrunde to the opposite cliff, we have presented to us the
appearance of a colossal wall of regular, gross’ masonry about 500
feet high; and, again, all those extraordinary and characteristic
features of this remarkable country—the deep narrow chasms and
ravines, perpendicular cliffs, sets of pinnacles and outstanding
columns—have for their ewistenzgrund this same regular, cubical
jointing.

But leaving these more varied and picturesque parts, and turning
southwards up the country from Schandau, we come to the hill
known as Gorischstein, where occurs that particular prismatic sand-
stone which it isthe purpose of this paper to describe. It is curious
how little known this section is. I have only been able to find a
single account of it in German or English literature, namely, that by
von Gutbier already referred to above.*

The quarry is on the east side of the hill called Gorischstein, at
a height of 1150 ft. above the level of the sea. It is but a small
opening, no longer worked, which may be detected by the basalt

1 Geognostische Skizzen aus der Sachsische Schweiz und ihrer Umgebung, 1858,
pp. 30—381.

2 T am indebted to Herr Deichmiiller for an account of this description by A. von
Gutbier.

438 Walter Keeping—On Columnar Sandstone.

“metal” on the road of approach. On entering it, evidences of
former volcanic activity are seen in some rubbly basalt-ash on one
side. A closer search is necessary, in the present condition of the
quarry, to find the mass of the basalt in the floor of the quarry.
This proves to be a very hard, close-grained olivine basalt, excellent
for road metal, and, as recorded by Gutbier, columnar in structure.

————
PAL Movs
WWD IS | 7

5

Fic. 1. Columnar Sandstone as seen in a quarry at Gorischstein,
West of Schandau, ‘‘Saxon Switzerland.” (A walking
stick is placed against the bank as a scale of height.)

We may pause for a moment to consider what are
the petrological aspects of this mass of basalt: whether
it was a dyke, sheet, or “neck.” There can be little
doubt that it was an old neck; for, judging from the
contour of the quarry, the horizontal section was
circular, and the basalt is a pipe-like mass. At the
sides of the quarry ashy materials are still to be seen.
A small cinder-cone probably once capped the ground
above.

On one side of the pit some loose sandstone prisms,
small and regular like those in the Dresden Museum,

ae. D. are scattered over the slope, but these are only part

A Single Columnof of the débris fallen from the pit sides higher up. In
the Natural Size. the undisturbed quarry-face above they are seen in
astonishing perfection, as indicated in the annexed

woodcut (Fig. 1), which represents a drawing of part of this exposure.

Here, facing the spectator, is a series of tiers of colonnades made up

of regular prisms. Those nearest the front lie nearly horizontal,

whilst as we recede into the sandstone they approach more and more
towards the vertical, till, at last, about two or three feet from the
outer series, the columns stand perpendicular; so forming altogether
the regular curve seen in the woodcut. Now this curving is not
produced to any important degree, by a binding of the prisms them-
selves, but is due to the gradual and regular variations in the

ec ee i RL Ae EI IE pF
> ee
Gee = ~ = <=
ra —e = = Pe > Se <= Sen fe =
ANY

Walter Keeping—On Columnar Sandstone. 439

directions of the columns in the several tiers of prisms. The
wondrous. regularity of the columns and their small size are
particularly striking in this exposure, viz. they are nearly all from
three inches to five inches long, and little more than half an inch
thick (see Fig. 2, natural size). They are by no means constantly
hexagonal, but vary from three- to seven-sided. In all, however,
the faces are clean and well defined, and the angles sharp. The
rock material of which they are composed is a brittle sandstone, so
hard that the columns clink when struck against one another, but
loose and porous in appearance when examined on a broken surface.
On such fractures it is seen to be made up of small irregular
quartzose grains, which look as though fused together at their edges,
but with vacant spaces as great as themselves left abundantly
amongst them. Towards their exterior the columns are more
compact, and upon the joint surfaces themselves the quartz grains
are more or less fused together; indeed, we may often see here a
continuous layer of vitreous quartz over a small area, where the
outlines of the component grains are only indicated, if at all, by
such a granular appearance as is seen in a compact quartzite. It
is as though each prism had been half fused in a hot mould, so
that the clean surfaces and sharp angles were most altered by the
heat, and the interior was less so.

There is no such special structure on the joint surfaces of the
ordinary Quader Sandstein. Comparing the fractured surface of one
of these columns with rock specimens from the ordinary Quader
Sandstein, I cannot detect any very striking differences between
them. The columnar rock is even of looser build, internally, than
usual; but the whole column is harder and less easily crumbled
than the unaltered rock, this being especially the case with the
surface layer.

A microscopic examination and comparison of prepared thin ~
sections of the two kinds of rock, the altered prismatic and the
ordinary sandstone, does not yield us any special characteristics of
distinction. Professor Bonney, who has kindly examined the slides,
writes concerning the columns, that they “consist of angular to rather
rounded quartz grains, with one or two which may be decomposed
felspar, cemented by a rather abundant dark substance (quere if
this be not in part discolouration from powder used in preparing the
slide, as the texture is rather open). In the quartz many minute
inclosures, almost always less than -001’, appearing when highly
magnified of a pale purplish colour, and in form rather like irregular
tubes. In one or two there was an appearance which might indicate
a very minute bubble, but in most cases there was no sign of this.
Very little difference between the two slides, except that the
cementing substance in that from the column is paler, and the quartz
grains look a little cracked.”

We may next notice the well-marked layers in which the prisms
are arranged. This is in no way connected with stratification lines
of deposition, but is a superinduced joint-structure such as occurs
not unfrequently in prismatic basalt masses, e.g. in the great basalt

440 Walter Keeping—On Columnar Sandstone.

quarry above Forst, near Durkheim.’ It is the “Tabular” structure
of Professor Bonney. In these altered prismatic Saxon sandstones
this structure is unusually regular, dividing the rock into zones
about 4 inches in thickness.

According to A. von Gutbier, an irregular line of clay ironstone 4
to 5 inches thick, and next a zone of “reddish green steinmark,”
intervened between the sandstone columns and the basalt.

Next, to inquire into the mode of origin of these prisms and their
associated structures. The production of columnar structure by
contraction during cooling or drying is now very well understood ;
being well illustrated by the structure of dry starch on the one hand,
and in the artificial formation of columns in the sandstones of
furnaces on the other. The evidence of the former presence of heat
in close proximity with the Gorischstein prisms is obvious enough,
for the outermost sandstone columns were almost in contact with
the liquid lava mass. But whether the heat was also the immediate
cause of the prism of the quartz grains, as above described, on the
surfaces of the columns, is not quite so clear; though the fact of its
special association with the prismatic structure must not be over-
looked. There is no evident reason why the deposition of silica in
the wet way should go on over the prismatic joints differently from
that over the ordinary rock joints, except during that special period
of cooling when the columnar joints were in course of formation. I
am therefore disposed to refer this alteration of the superficial layer
of the prisms to the later stages of the volcanic period, when such
joints would have served for the passage of heated water or of steam
to the surface.

Note by the Rev. Professor Bonney on the origin of the curved
arrangement of the prisms.

The rock in order to break requires (1) that its temperature
should be considerably elevated; (2) that this should be again
gradually lowered.

A surface of uniform temperature is a surface of
uniform tension. 1B

Now if A BC be a heated mass, losing heat prin-
cipally from A B, a rock at surface, the surface of C
uniform tension lies parallel to A B.

Again, if DHF be a mass in contact with an igneous rock K at
some depth, the main loss of heat will be laterally,
and so the surface of uniform tenison be vertical and D
the columns horizontal. ba

At the top, then, the loss of heat will be mainly K F-—>
_ from the top; deep down mainly laterally. Thus |=
the surfaces of equal tension will descend in the , x
mass radially, the lateral loss producing no effect i
at first and vice versa. So that I take it just at
first the columns should lie pretty nearly parallel with the basalt,

1 Quite a distinct thing from the bedding of successive lava flows. See Prof. T.
G. Bonney, Quart. Journ. Geol. Soc. vol. xxxii. p. 146.

GEOL.MAG.1879. DECADE II.VOL.V1I.PLATE XI. :

C.L.Griesbach oel.et ith. West, New moar Co. imp.

Sumatran Tertiary Shells & Corals.

Dr. H. Woodward—On Fossil Shells, etc., from Sumatra. 441

and at last become perpendicular ; of course the top layers will be
formed long before the bottom.—T.G.B.

In a paper on “Columnar, Fissile, and Spheroidal Structure,”
read before the Geological Society (Q. J. G. S. vol. xxxii. p. 141),
the Rev. Prof. Bonney has given a list of examples of columnar
structure in non-igneous rocks. Amongst these the altered clay bed
in Tideswell Dale! most nearly resembles our Gorischstein prismatic
sandstones. But the Yorkshire clay prisms are from 1 to 6 inches
thick and 8 to 9 feet long (Mello), and the columns themselves are
curved, as is common in basalts, etc.

In addition to the examples mentioned in the paper above referred
to, Prof. Bonney now tells me of a columnar sandstone underlying
basalt from Johnsdorf, near Zittau, Saxony; ironstone, columnar
from burning, exhibiting bent, wavy and radiating columns, about
;/’ diameter, from South Wales; and columnar sandstone from
furnaces in Wales, Staffordshire, and Russia—all of which may be
seen in the Museum of University College, London.

Another good example of this structure was observed by my
friend Mr. A. F. Griffith, of Christ’s College, last year, near Clermont,
Auvergne. It occurs in a pale marl under the old lava flow of
Graveneine near its extremity, about three-quarters of a mile from
Clermont on the Issoire road. Here a quarry has been opened so as
to expose some 12 feet of the lava; beneath this is a zone of
porcellanized material, irregularly jointed, and about two inches
thick; and next below comes a layer of diminutive hardened
columns 5 or 6 inches in thickness. The better prisms are about
4 inches long, and 4 inch across; but others are not more than
14 inches long. Beyond the limits of the lava, the prismoidal clay
is seen to pass into a pale freshwater marl. Mr. Scrope? has
described a similar case near St. Saturnin beneath the lava current
of the Puy de la Vache.

IlJ.—Furrurr Norges on A Courection oF Fosstn SHELLS, ETC.,
From Sumatra (opTarneD BY M. VeRBEEK, DIRECTOR OF THE
GxotocicaL Survey or THe West Coast, Sumatra). Parr II.

By Henry Woopwarp, LL.D., F.R.S., etc. ;
of the British Museum.

(PLATE XI.)

MONG the Conchifera transmitted by M. Verbeek, is a specimen
of Cyrena. ‘The shell is certainly from a very modern forma-
tion, as it retains its translucency and traces of a pale buff colour
externally.
19. Cyrena sinuosa, Deshayes. Pl. XI. Fig. 1.
Mr. Edgar Smith, after comparing this specimen with recent
Cyrene in the collection, observes, “The outline of this valve is
1 Described by the Rev. J. M. Mello, Quart. Journ. Geol. Soc. vol. xxvi. p. 701,
and Gzou. Mae. Vol. VII. p. 520.

2 Volcanos of Central France, p. 92.
3 Continued from the September Number, p. 393.

442 Dr. H. Woodward—On Fossil Shells, etc., from Sumatra.

precisely like that of Cyrena sinuosa, and the fait shallow groove
down the posterior side is likewise traceable. The hinge-teeth both
in form and number also agree.”

The following is Deshayes’ description of this species from the
Proc. Zool. Soc. 1854, p. 18 :—

“Shell ovato-rotundate, tumid, cordiform, solid, very inequilateral ;
epidermis dark russet-colour, covered by slender transverse ridges ;
anterior end short, rounded, subtruncated posteriorly; deeply grooved
on the upper posterior side, grooves sinuous, decurrent ; umbones
tumid and short, generally eroded; ligament narrow, partially con-
cealed; valves white within, hinge thick; tridentate on either
side; teeth oblique, median and posterior tooth in right valve bifid ;
lateral teeth short; anterior tooth thick, conical ; apex acute.”

The recent specimens in the British Museum were obtained from
the river Paningbang. Java, and are much thicker than the fossil
valve from Sumatra, and have their umbones more eroded.

The thick rough dark olive-brown epidermis and prominent
ligament, seen in the recent examples, are of course wanting in the
fossil specimen.

Measurement of right valve of fossil, 60 millimétres broad, height
55 mm.

Locality :—Sumatra. (Subfossil ?).

20. Pectunculus, sp. (cast of). Pl. XI. Fig. 2.

The casts of this species of Pectunculus exhibit a portion only of
the interior shelly layer, and indicate a somewhat compressed and
internally-ribbed shell, showing also the characteristic dentition of
this genus.

Dimensions :— Breadth 35 mm., height 37 mm.

Formation :—Tertiary Clay-marls.

Locality :—Island of Nias, Government of the West Coast of
Sumatra.

21. Venus? non-scripta, Sowerby. Pl. XI. Fig. 3.

Trans. Geol. Soc., 1840, 2nd ser. vol. v. pl. xxv. fig. 8.
D’Archiac and Haime, Descrip. Anim. Foss. du Groupe Num.
de l’Inde, 1854, p. 246, pl. xvii. fig. 7, Ta.

The specimens of this shell obtained by M. Verbeek appear to be
identical with the above species described by Jas. de Carle Sowerby
from Soomrow, Kutch, India, and also noticed by D’Archiac and
Haime as being very common in the yellow sandy limestone of the
Hala range in Scinde.

The following is the description of this species, as given by Mr.
Sowerby :—

“Transversely oval, convex, smooth, concentrically undulated,
‘lunette elongated, pointed, concave, breaks nearer the anterior
extremity, [and strongly recurved]. A smooth and thin shell, with
little of the aspect of a Venus.”

We agree with Mr. Sowerby in assigning this specimen to Venus
with considerable doubt.

Measurements :—Length 53 mm., depth 50 mm.

Formation and Locality :—The same as the preceding.

Dr. H. Woodward—On Fossil Shells, ete., from Sumatra. 448

22. Perna, sp. Pl. XI. Fig. 4.

Two fragments showing the characteristic hinge-line and nacreous
interior.

Formation and Locality :—The same as the preceding.

28. Pecten asper, Sowerby (non Lamarck). PI. XI. Figs. 5 and 6.

1847, Thesaurus Conch., vol. i. p. 50.

Shell inequivalve, equilateral, ears equal, minutely serrately
striated ; left valve flat, a little raised towards the umbones, rayed
with eighteen rather flatly two-angled ribs; ribs and interstices con-
centrically striated, dotted everywhere with pale red; right valve
convex, rayed with nineteen rather smooth ribs ; ribs white, sparingly
lineated with red; interstices red towards the margin.

Dimensions of flat valve :—Breadth 33 mm., height 32 mm.

Locality and formation :—The same as the foregoing species.

24, AsprRGitium sp., Lamarck. Pl. XI. Fig. 7.

Shell with two equal minute ovate valves, mostly angled posteriorly,
soldered into the lower wall of a long sheath; sheath at the upper
part open, sometimes attenuated, with the edge simple, sometimes
nearly straight, with the edge rather largely two to eight times fur-
belowed, at the lower part club-shaped, closed by a perforated,
generally tubularly, fringed disc.

This shell is probably referable to the recent A. Javanum, sp.
Brug., or A. sparsum, Sowerby, from Java.

Formation and Locality ;—The same as the preceding.

25. ZOANTHARIA.— Acanthocyathus, sp. Pl. XI. Fig. 8.

Corallum turbinate, compressed towards the base, and broadly
attached ; calyx elliptical ; costee slightly prominent, extending to the
base and minutely granulated: columella elongated and irregular ;
principal septa 22-24 in number, their surfaces covered by minute
styliform processes or synapticulee.

This coral agrees closely with the specimens of the living Acan-
thocyathus Grayt, in the British Museum, from the seas of Australia
and Japan, but the fossil examples have not the prominent lateral
shoots seen in that species.

Formation :—From grey sandy-clay rich in Gasteropoda, Tertiary.

Locality :—Island of Nias, Government of the West Coast of Sumatra.

26. Montlivaltia, sp. Pl. XI. Figs. 9 and 10.

Corallum subturbinate, slightly attached, epitheca moderately
thick ; calyx subelliptical, fossa moderately deep, with about 50
septa, the majority of which reach the centre ; upper surface of septa
imbricated.

Fig. 9 a, b, appears to be only a more conical variety of the same
species and its fractured state exposes the dissepiments connecting
the septa (see Fig. 9 b).

Formation :—Vertiary Clay-marls.

Locality :—Island of Nias, Government of the West Coast of Sumatra.

27. Fungia, sp. Pl. XI. Fig. 11 (under-side).

A nearly flat discoidal form with minute projecting point of
attachment, as seen in young examples of the common recent Fungia.
Coste minute, numerous, extending from centre to circumference.

444 Norman Taylor—The Cudgegong Diamond Field.

Septa excessively numerous, the longer ones alternating with the
shorter ; septa or pali, furnished with numerous synapticule.
Formation and Locality :—The same as the last-named species.

EXPLANATION OF PLATE XI.

Fic. 1. Cyrena sinuosa, Deshayes, subfossil, Sumatra.
», 2. Pectunculus (cast of), Tertiary Clay-marl, Island of Nias, W. Coast of
Sumatra.

» 98. Venus 2 non-seripta, Sby., Island of Nias, W. Coast of Sumatra.

» 4. Perna, sp. (fragment of hinge) 55 3

» 9. Pecten asper, Sby. (flat valve) a a

» 6. ————., Sby. (convex valve) 5 Pe

» t. Aspergillum (Javanum ?) 5 4

» 8. Acanthocyathus, sp., Tertiary, Grey Sandy Clay, Island of Nias,

West Coast of Sumatra.
» 9. Montlivaitia, sp., (a) side-view; (4) view of top.
0 , (a) side-view; (4) view of the interior of the calyx.
Tertiary Clay Marl, Island of Nias, West Coast of Sumatra.
», Ll. Fungia, sp. (view of under-side), loc. ibid.

(Lo be continued in our next Number.)

IV.—On tHe Cupcecone Diamonp Fretp, New Sovurn Watss.!
By Norman Taytor, Hsq., of the late Geological Survey of Victoria.

Communicated by R. Eruertpex, jun., F.G.S.; of the British Museum.

The next appearance of the older lead is at the ‘“ Rocky-ridge,”
where the river, after running northerly for three-quarters of a mile,
along the strike of the metamorphic beds, turns abruptly to the
west. This ridge is a basalt-capped hill on the north side of the
river, running in a north-west direction; it is about a mile long,
with a bold rocky escarpment on its west side, facing the Sandy or
Cudgebeyong Creek. Some tunnels have been driven in, and shafts
sunk on this hill, and tolerably rich deposits of gold were found, but
never followed out. Only in the southern half of the hill have
diamonds been found (all more or less spotted). The drift is remark-
able for the number and size of the agates it contains. The northern
half of “the ridge” is underlaid by another outlier of the before-
mentioned doubtful purple conglomerate, into which some tunnels
have been driven in the western escarpment. The basalt is merely
a fringe here, resting against the flank of the conglomerate hill to
the east. A few inches of drift rest upon this conglomerate, in which
a small quantity of nuggetty gold was obtained; and from one
to two inches thickness of lignite, or carbonaceous clay, is seen
between it and the bottom of the basalt. The basalt is intersected
by numerous veins of a mineral allied to kaolin. The purple con-

_glomerate is similar in character to that near ‘the flat,” and contains,
on some of the joint faces, small spherical crystalline aggregations of
chalybite (carbonate of iron). At the extreme north end of “the
ridge” are great quantities of ironstone and conglomerate, but,
from their mode of occurrence, I should imagine them to be part of
the Carboniferous series, which is largely developed further north.
The first diamonds which found their way to Melbourne were obtained

1 Concluded from page 412.

Norman Taylor—The Cudgegong Diamond Field. 445

from ‘the Rocky,” at Hill’s, or the diamond Claim, in the bend to the
south-west in the centre of the hill. A short distance to the east of
this claim is Ryan’s, from which as much as two ounces of gold to
the load were obtained, as well as a few diamonds. Crossing the
Cudgebeyong Creek, in the bed of which is a horizontally bedded
mass of conglomerate (some part of the Carboniferous series, or
possibly Mesozoic), we arrive at another basalt outlier. The hill
itself is composed of slates, capped with purple conglomerate. A
ring-like fringe of basalt surrounds it, leaving the top uncovered ;
while between it and the basalt, Tertiary ferruginous cement and
drift crop out on the flanks of the hill. The decomposed basalt,
from shafts on the north side of the hill, is very full of kaolin. The
metamorphic beds crop out again a short distance to the west of this
hill. It is difficult to imagine the course taken by the old river from
this point ; it could not have gone westerly, as the country consists
of high schist ranges, intersected by numerous greenstone dykes,
running as usual in the strike of the slate rocks. On the south-west
flanks of the “‘ Rocky-ridge”’ the surface is covered with a wash of
drift, which is continuous across the river (here running westward)
to the “Horseshoe bend.” The late Professor Thomson suggested
that the basalt, on arriving at the Cudgebeyong Creek, may have
flowed or been backed up by this tributary for some distance. The
old junction of this creek with the river was probably near the
centre of the “ Rocky-ridge.”

The ‘‘ Horseshoe bend,” on the south side of the river, is a semi-
circular basalt-capped hill, having its concave side facing the river,
and its convex one resting against the side of the purple con-
glomerate hill, first mentioned as occurring to the north-west of the
“'Two-mile-flat.” The basalt of this hill, like the others, is under-
laid on its north or river side by older drift; the lead dips into the
hill on its western side, but it was not rich either in gold or
diamonds. A few diamonds were obtained in the shallow ground
of the northern concavity, and the associated gems were larger there
than anywhere on the whole course of the lead. A fine example of
columnar basalt occurs in a shaft at the south-west horn of the hill.
Between this hill and Hassall’s fence, on the river, the greenstone
dyke, west of the “'Two-mile-flat,” which disappeared under the
purple conglomerate-capped schist hill, again crops out, and crosses
the river. Its course is now somewhat altered, both it, and the
accompanying band of metamorphic rocks, being thrown a few
chains to the west, probably by a fault. From the “Horseshoe
bend,” in about half a mile south-westerly, we reach Hassall’s Hill,
adjoining Mr. Hassall’s property. These hills are separated by a
low schist range.

“‘ Hassall’s Hill,” like the ‘‘ Horseshoe bend,” is nearly semi-
circular, with the horns flattened inwards so as to form two parallel
shoulders, and with its convexity towards the river,—it consists of
basalt overlying older drift. ‘The south-west portion of this hill is
lower than the north-eastern, the denudation having only left a
thickness of about thirty feet of basalt, whilst at the highest part

446 Norman Taylor—The Cudgegong Diamond Field.

of the hill there is from 80 to 90 feet. The drift underlies it in
two distinct leads, from north to south, in the centre and west of
the hill, but not on the east. The leads form a sort of elongated
ellipse. The concavity of the hill faces south-west and the horns
are nearly connected by the lower or more denuded portion of the
flow. In the innermost portion of the concavity, which rises gradu-
ally to the table-topped main mass, a shallow hole exhibits a fine
friable thin-bedded greyish white sandstone, inclosing perfect, but
minute, double hexagonal pyramids of quartz. This is evidently
the top of a hill or island, round which the old river, and subsequent
-lava-streams, have flowed. The denudation not having been so
extensive here as on the upper portions of the lead, a greater
width of basalt and increased thickness of the underlying drift is
the result. In the easterly lead, where it curves round to the
south horn, as much as one ounce of gold to the load was obtained ;
but, from the length of time occupied in sinking the shafts (over
five months), it was unprofitable. Some very long drives were put
in, and a few diamonds were obtained, but the area was never
specially worked for diamonds. The rock on the top of the hill
consists of from thirty to forty feet of loose concretionary basalt,
getting denser below, and resting on vertical columnar basalt. The
whole of the upper stratum has been denuded away from the lower
ground. On the south face of the central sandstone hill is a small
shallow lead, which must be the edge of the older drift, resting
against the sandstone island, and now exposed by denudation. A
similar instance occurs again near the apex of the southern horn;
where the basalt of the northern horn nearly joins that of the
southern one, the ground is quite shallow (about 12 feet deep), but
deepens westerly to 30 feet, and contains very large semi-angular
blocks of quartz, and much ‘‘cement.” ‘The south side of the
southern horn was worked, and yielded a few diamonds, but
not much gold. The drift is full of large semi-angular blocks of
quartz, and is a side wash, as the ground dips to the north. The
quartz, from its character, is, in a great measure, derived from veins
in, or in the neighbourhood of, greenstone. In the deepest parts of
the leads the quartz boulders are all perfectly rounded. The richest
diamond claim discovered was situated at about the centre of an
imaginary line joining the two horns; it was owned by a working
party of miners—Messrs. Cooney, Hennessy, Ward, and others.
Their shaft. sunk to the depth of 51 feet, shows 27 feet of basalt,
resting on brownish-yellow sand, and that again on alternating
sandy, gravelly, and pebbly beds, mostly loose and friable, with
- occasional thin layers of ferruginous “cement.” The whole of the
drift below the basalt had to be very securely slabbed, as the fine
sand runs like water. In their southern drive there are three
distinct veins of very loose granitic quartz detritus, separating, and
alternating with, the gem-bearing veins. These gradually cut out,
going north, and the gem-wash becomes more solid. There is also
a bed consisting entirely of loose and open quartz pebbles, super-
ficially covered with a brownish-black greasy-looking coating of

Norman Taylor—The Cudgegong Diamond Field. 447

oxide of manganese. In one of the drives they cut through what
appears to have been a portion of a large tree, lying horizontally in
the cement on the “bottom,’—the wood itself had entirely dis-
appeared, and nothing but a hollow casing or shell of oxide of iron
remained,—this was internally longitudinally striated, and was
composed of several coats. On the inside were some peculiar
metallic efflorescences presenting the appearance of small round
black velvet buttons, composed of confusedly foliated plates of a
substance, which, when rubbed, assumed the metallic appearance of
graphite, and soiled the fingers. Fragments of drift wood had been
found on the bottom; not silicified like that derived from the
Carboniferous rocks. The gem-stones can be traced most thickly
in slightly cemented (by silica) flesh-coloured veins. The total thick-
ness of the drift is 24 feet, and the bottom dips westerly. On
driving northwards the bottom rose and fell again, and the diamonds

became scarce.

Adjoining the above claim was another, belonging to Messrs. Scott
and Allen, which was 54 feet deep. The ferruginous “cement” in
this claim inclosed abundance of pleonaste, zircon, sapphire, and
topaz, with small fragments of brown ferruginous wood, like that
occurring in most of the Tertiary cements in Victoria. The ‘‘cement”
forms but a very small proportion of the drifts, and occurs in irre-
gular thin veins, sometimes fine- and at others coarse-grained. |
Other shafts were sunk west and east of these rich claims. but un-
successfully, as they did not appear to possess the few bottom feet
which contained the diamonds. To the north of this, and on the
river-side of the northern horn, another shaft yielded a very heavy
drift, giving an average of one diamond and five pennyweights of
gold to the load. The basalt increases in thickness to the west at
Hassall’s fence, whilst the drift diminishes; a shaft there passing
through 32 feet of basalt, and 15 feet of drift. Messrs. Cooney and
party had, up to April, 1870, obtained over 1000 diamonds, and
Scott’s party about 700. The lease of the former party had then
been proved for a distance of 300 feet along their main drive (N. 35°
W.) with a breadth of over 100 feet. A washing of 53 loads yielded
306 diamonds, weighing 744 carats (largest 1$ carats). They have
washed from 1 to 15 diamonds to the load, but the average was
about 5, with 38 dwts. of gold. A washing of from 12 to 15 loads
of Scott’s gave at the rate of 8 diamonds and 3 dwts. of gold to the
load. The small quantity of gold obtained is due to the fact of the
diamonds not being on the bottom, while the gold is, and conse-
quently, a thickness of as much as d and 6 feet of wash dirt had to
be taken out, thus reducing the gold per-centage. The southern face
of the northern horn is very shallow ground.

The basalt runs westerly through Mr. Hassall’s fence and into his
paddock, where it is concealed by alluvial soil, and nowhere crops
out again. The diamond ground was supposed to run in that direc-
tion, but, being private property, it had not then been prospected.

Between this and the river,—which, after running a mile westerly
from the ‘“‘ Rocky-ridge,” turns abruptly to the south, and keeps this

448 Norman Taylor—The Cudgegong Diamond Field.

course for two miles,—we cross another greenstone dyke running in
the same direction as those before mentioned, and crossing the river
about midway in the bend to the south. There are some extensive
alluvial flats between Mr. Hassall’s house and the ford, where the
Wellington Road crosses, in which some good gold leads may pro-
bably exist.

Above this crossing place a rocky bar spans the river, consisting
of a dark grey breccia, having a gneissose appearance and associated
with flinty beds. About a mile along the road to the north of this,
on Mr. Lowe’s property, and about 15 miles due west from Hassall’s
Hill, is another small basaltic outlier, resting on drift; there are
also several drift or “‘made” hills uncapped by the basalt. These
had been formerly worked for gold. Below this there is no trace of
basalt for seven or eight miles down the river, till a little below
Laby’s Farm, at Uumby, where there is a very small outlier on the
river bank, but whether the older drift underlies it or not, had not
been proved. “Made” hills of drift, apparently the newer drift,
skirt the river-banks on both sides to its junction with the Macquarie
River, but there is no further trace of basalt on the Cudgegong River;
although there are outlying remains down the valley of the Mac-
quarie River of a former sheet of basalt, which had perhaps flowed
down the valley of that river, and covered up the Tertiary drifts,
which have been worked for gold, at a considerable elevation above
the present river. The rocks down the river are similar in character
to those above, but are less metamorphosed and more shaly, with
interbedded brecciated conglomerates. Syenitic granite crops out
occasionally, and quartz-reefs are very numerous.

About a mile to the north of the northern end of the “ Rocky
ridge” there has been a small “rush” (Cunningham’s) to a gully
and “made” ridge under the schist ranges forming the eastern
watershed to the Sandy or Cudgebeyong Creek. A nugget weighing
86 ounces was found there, but no diamonds. The sinking varies
from 12 to 20 feet, very little quartz occurs in the wash dirt, and
what there is is angular ; but magnesite occurs in considerable quanti-
ties, both massive in large lumps, and as peculiar curved cylindrical
concretions. The ranges at the creek head are everywhere inter-
sected by small quartz veins.

This, then, being the history, at the time of my residence there, of
the diamond-bearing localities, I will next enumerate the various
drifts and the materials of which they are composed.

There are, on the Cudgegong, at least six drifts of different ages,
the oldest of which the late Rev. W. B. Clarke took to be as young
as Pleistocene. I differed from his view, and placed them temporarily
with Older Pliocene, following my Victorian experiences, and later,
in working out the discovery, at the ‘“‘ Welcome rush” near Stawell,
Victoria, of a bed of marine littoral fossils overlying a gold drift, I
came to the conclusion (see Progress Report of the Geological Survey
of Victoria, No. 8, p. 264) that these fossils were probably of Upper
Miocene or Lower Pliocene age, and the gold drift under them much
older. I am now of opinion, after reading the report of my friend

Norman Taylor—The Cudgegong Diamond Field. 449

and late colleague, Mr. C.S8. Wilkinson (Mines and Mineral Statistics

of New South Wales, 1875, p. 77, et seq.), on the Tin-mines of New

South Wales, that the older diamond drifts must be of the same

age as the older Tin “leads” of Borah Creek, which also contain

diamonds.?

In ascending order, commencing with the oldest, they would pro-
bably occur as follows :—

1. Urprr Miocene, oe Older Drift, possibly fluvio-marine, underlying basalt,

Lower Puiocenz. § and containing gold, tin, and gems ~--no fossils to prove
age. This drift may again be sub-divided into two—one containing
semi-angular quartz (a reef wash), and the other rounded boulders.”

Lapse of time, during which were formed—

2. Minpite Priocene.—The Gulgong deep leads with plant-remains, the latter
described by Baron von Mueller. These leads perhaps drain into an
old lake-basin at the head of Reedy Creek.

. Basaltic overflow, filling lake and flowing down the Cudgegong Valley.

. Wash of conglomerate pebbles, etc., over the surface of the basalt.

Urrrer Puriocene.—Newer Drift, fluviatile, and derived from all the above
during the cutting out of a new river channel. To this or the next
division may belong the “leads,” higher up the river, containing fossil
bones at the Pipeclay Diggings, and cinnabar near the village of
Cudgegong.?

6. Puerstocenr.—The older river channels, now silted up, and below the level of

the present river-bed.

7. Recent.—The present river-bed.

With regard to these older drifts, it must be borne in mind that
they vary much in position; they are below the river-bed at the
Reedy Creek, and much above it at the Two-mile-flat, the present
river falling at a greater rate than the old river.

The older diamond-bearing drift, underlying the basalt, is a coarse
and heavy deposit,—some boulders in it weighing several hundred
weights,—for the most part loose, but portions of it united into a
compact conglomerate. It varies greatly in thickness, from a few
inches to 80 feet, according to the irregularities, in some cases, of
its own upper surface, which is not uniformly level; and in other
cases, due to the old river-bed. Huge blocks of hard slate, sand-
stone, quartz, greenstone, and felspathic rock, the two latter often
decomposed into masses of clay, still retaining the original shape of
the boulders, lie at the base of the drift in many parts.

The following are the contents of this drift, which is, however,
very variable in different localities: large and small boulders and
pebbles of quartz, generally coloured a reddish-yellow or brown
externally by oxide of iron; sand of various degrees of fineness ;
pebbles and sand cemented by oxides of iron and manganese, or by
both together, the iron coating the quartz in concentric rings, and

Ori co

1 These are considered by Mr. Wilkinson to be of Miocene age.—R. E., jun.

2 At the time of the formation of the older drift, the Carboniferous rocks to the
east and south-east may have been above the reach of marine action, and so escaped
the denudation; thus accounting for the absence of any traces of them in the drift.
The denudation of the Carboniferous rocks may have commenced after the basaltic
outbursts, and during the cutting out of the new river valley.

3 At the Cudgegong cinnabar mine, boulders of coal and sandstone occur in the
drifts, with large sapphires and zircons, but no diamonds or topazes, nor did I find
ruby, though it is stated to occur there.

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Norman Taylor—The Cudgegong Diamond Field. 451

the manganese in dendritic markings, or as if smoked, and soiling
the fingers when rubbed; a white siliceous cement, sometimes
coloured apple-green by silicate of iron (probably derived from the
veins of green clay, mentioned before as occurring in the joints of
the basalt) ;! quartzite; white, grey, and black flints and slates, the
latter showing oblique lamination, and reticulated with veins of
white quartz, and passing into a breccia; a greenish silico-felspathic
rock or felstone, weathering yellowish-white to a depth of an inch
or more, and ringing, when struck, with a metallic sound, and
generally sculptured into curious forms ; hard altered siliceous sand-
stone; schorl rock (a quartzite with nests of schorl); a peculiar hard
white stratified rock, with flattened annular concretions, having
depressed centres, very numerous on the bedding planes; black or
smoky quartz, sometimes inclosing felspar ; orthoclase in waterworn
erystals; double hexagonal pyramids of quartz, occasionally rounded ;
bluish opaline quartz in pieces about the size of a pea, showing,
when wetted, a yellow ray; amethystine quartz; silicified wood and
wood opal ; jasper (occurring also in the form of beans, since called
by the Bingera miners “morlops”), which the miners suppose to
be an unerring indication of the presence of the diamond, for what
reason they could not themselves explain; agates, generally of inferior
quality and colour; carnelian; chalcedony; tourmaline in rounded
crystals; common corundum or adamantine spar, in flattish pieces
showing distinct cleavage planes; black corundum; blue, yellow, and
green sapphire, occasionally double-coloured, in flat plates and
rounded crystals; olivine (?) ; white and brown zircons in rounded
crystals and as a fine sparkling heavy sand; large quantities of brown
and greenish-black rounded pieces of pleonaste; thin lenticular
plates of pink and violet ruby; white, yellow, and pale - blue
crystallized and rounded topaz, generally of a larger size than any
of the other gems, and showing distinct cleavage planes ; beryl (2) ;
a new variety of corundum in rounded opaque grey six-sided prisms,
tapering towards one end; brookite in flat plates ; titanic iron, and
probably chromite; magnetic iron, sometimes in quantity; and
lastly a jet-black glistening vesicular variety of pleonaste, in flattish
conchoidal grains, exceedingly hard, and cutting glass nearly as well
as the diamond, the vesicles being filled with a magnesian clay.
Wood tin occurs also rarely, and fragments of brown ferruginous
wood have been detected in the cement.

The newer drift, derived from the above, is composed of the same
contents as the older drift, with the addition of boulders of green-
stone and basalt. Semi-angular blocks of the metamorphic rocks
occur, as also the white kaolinic clay from which the magnesite
already mentioned is produced. Osmiridium has been found in
minute silvery scales after amalgamating the gold. A noticeable
feature in this drift is the quantity of small pebbles of flesh-coloured
quartz, derived, I believe, from the Carboniferous conglomerates.

1 The pebbles from these cements have sometimes a very peculiar resinous glaze

on their surfaces, which is certainly not due to friction, as the cavities are equally
glazed as the exposed surfaces. It is probably siliceous.

452 Norman Taylor—The Cudgegong Diamond Field.

In the drift also may occasionally, though rarely, be found some
Carboniferous conglomerate pebbles. Rounded pebbles of coral
(Favosites Gothlandica) are not uncommon; shales with Glossopteris,
and various Upper Silurian, or Devonian fossils (Orthis, Spirifer,
and Crinoidal stems), as before mentioned, together with silicified
wood, have been observed in this drift in the so-called “ floating
reef.” ‘The newest drifts (upper and lower), comprising the present
river-bed, and the older and deeper channels, contain pebbles,
boulders, and shingle of the neighbouring sandstones, slates, cal-
careous grits, red flinty porphyries, felstone, Carboniferous con-
glomerates, quartz of all kinds, greenstone, and silicified wood. A
very noticeable feature in these drifts is the prevalence of blackish
quartz pebbles and grains, inclosing crystalline felspar, which are
evidently derived from the granite of Aaron’s Pass, on the Mudgee
Road, south of the village of Cudgegong. The basalt, which might
have been expected to be present, must, from its easy decomposition,
have been entirely washed away, and is nowhere seen except in the
immediate neighbourhood of basalt escarpments: Garnets, in minute
brown rhombic dodecahedrons, with angular replacements, occur,
and also cubes of oxide of iron (pseudomorphs after iron pyrites),
locally termed ‘“ Devil’s dice.” Many diamonds were obtained from
the river-bed; but in every case, only where the older drift has
been discharged into the river by the miners during gold-washing
operations.

The following are descriptions of the gems and other minerals,
found in the diamond drifts, with the analyses of some of them by
the late Professor Thomson.

Diamond.—The diamond itself is distributed through the older ~
drift very sparingly and irregularly, and does. not appear to be
confined to any particular level in the drift deposit, though the
lower five or six feet are generally taken out by the miners, in
consequence of the certainty of finding gold in that portion. The
fact of the very frequent occurrence of diamonds on the waste heaps
round the mouths of the old shafts sunk for gold, is enough to
suggest that the diamond may occur in the higher portions of the
deposit, since the bottom layers only have been carted to the river
for gold-washing. One diamond, in situ, occurred three feet from
the bottom, imbedded in a mass of loosely cemented quartz pebbles
the size of peas. As regards the weight of the diamonds, the follow-
ing parcels afford a fair average :—

106 diamonds weighed 742 carats, the largest 12 carats.

81 oy) 19 19 bP) 29 iG 9
110 9 » 263 »

16 ” bP) 6 29
700 99 bP} 1515 9

giving an average of 0-23 carats each, or nearly one carat grain.
The largest gem discovered was a colourless perfect octahedron,
weighing 53 carats; it was found in the river, between the “Two-
mile-flat”? and the “ Rocky ridge,” at a spot where the older drift
had been discharged in gold-washing. Another large stone, weigh-
ing 34 carats, was found, by a boy, lying on the sandy bed of a dry

Norman Taylor—The Cudgegong Diamond Field. 453

creek, running down the centre of the “‘ Two-mile-flat.” During the
first five months of systematic washing, over 2,500 diamonds were
discovered, and several thousands more were afterwards obtained ;
but, as the collectors were generally rather reticent as to their finds,
the exact numbers could not be ascertained. The gems were mostly
pellucid and colourless; many have a straw-yellow tint, and tints
of brown, light or dark bottle-green and black are more rarely met
with. One or two opaque black ones have been found, and another
of a dark green colour, with the external appearance of having been
polished with black lead. Black specks within the crystals were
not uncommon. The specific gravity, deduced from a number of
crystals, is 3:44. They all show a well-defined crystalline form,
though irregularities of development are frequent. It is very rare
to meet with fractured stones, and these only on cleavage planes;
water-worn stones I never saw from any direct treatment of the
undisturbed older drift. Some shapeless diamonds occur, but, if
water-worn, the process has not impaired their lustre. They are
never found coated superficially with any foreign matter. When dull
or lustreless, an examination proved it to be caused, not by any
water-wearing or incrustation, but by multitudes of minute angles
and edges of structural planes, which gave a frosted appearance to
the crystal. The forms met with were the octahedron, twin-octa-
hedron, dodecahedron, tris-octahedron, and hexakis-octahedron ; the
two latter are often hemihedral, with curved faces, and are some-
times developed into flat triangular twins. One specimen of the
deltoid dodecahedron or hemihedral triakis-octahedron was found.

The above-named curious triangular twin crystals are, according
to the late Professor Thomson, derivable from the tris-octahedron.
If we regard the latter as an octahedron with a low triangular
pyramid on each of its faces, and out of the eight pyramids we
imagine that only two, corresponding to opposite and parallel octa-
hedral faces, are developed, on applying these two pyramids
together, they would not form a closed figure, but, by twisting one
180° round, we form the triangular twin crystal; or, more simply,
if we inspect a twin-octahedron, there are but two of the original
triangular faces entire; these are opposite and parallel, and, by
replacing these two faces by the corresponding planes of the tris-
octahedron, the rest of the faces of the twin-octahedron may be
obliterated, and the triangular crystal will result. The structural
lamin are very distinct in some crystals, and many of the octa-
hedrons show these successive layers of growth in a very marked
and beautiful manner. A few show indented angles, and sunk
triangular depressions on their faces, having the apices of the
triangles pointing to the centres of the sides of the triangles in the
main crystal.

Gold.—Occurs fine, scaly, and occasionally inclosed in quartz,
The quantity is variable, the average being about three pennyweights |
to the load of “ wash dirt.”

Osmiridium.—In minute silvery scales after amalgamation and
retorting—only from the newer drift.

454 Norman Taylor—The Cudgegong Diamond Field.

Metallic iron. — Hackly fragments of slightly rusted metal,
evidently derived from the tools used. Analysis failed to detect any
trace of nickel.

Wood tin.—Rare, and in small pieces.

Titanic acid.—Probably brookite, in flat red transparent or red-
dish-white translucent plates, with striated surfaces, but too worn to
distinguish the crystalline form. The plates vary in thickness up to
one-twelfth of an inch, and are often one-fourth of an inch across ;
hardness, 6; specific gravity, 4:13; composition found by analysis
to be pure titanic acid, with only a minute trace of iron.

Black magnetic tron sand.—Common.

Black titaniferous iron sand.—Common.

Tourmaline-schorl.—Rolled black prisms half an inch long are
common ; small nests of schorl in quartz pebbles rare.

Garnet.—In minute brown icositetrahedrons, rare and only occur-
ring in the recent river drifts.

Black vesicular pleonaste-— Occurs in small grains from one-
twentieth to one-fourth of an inch in diameter, and is very abundant.
Tt has a dull black surface, but shows a brilliant fracture. Some
pieces are coated bluish grey or rusty brown; but the interior is the
same in all, the external differences seeming to be the result of
decomposition. It never occurs in crystals, nor shows any traces of
faces, and has no cleavage; its fracture is conchoidal and jet black,
with a strong vitreous lustre; hardness 8; streak grey ; composition
found by analysis :—

Silica (and undecomposed)... ... 1... 2. 2.75
dA aMITIAA A gays. eves) Aem Euecortebead bolt sesey-seemeO 4920
Chromictoxideyiug. bye asus ts tie scl -ueeriin--oe Oo
I ENaneS ey. Wuahen ego Bose tyadee das imneada meee Woody Aes
IBGTEROUS OAK.) “4o5", bag. a0’ 000) G00 loca cog | APD)

98°10

Oxygen ratio 3:2: 1; Specific gravity 3-77.

The mineral is amorphous and vesicular. The latter character is
remarkable, and the grains do not all show it in the same degree.
One variety (the least abundant) with a lustrous surface shows it
best, the grains resembling a perfect cinder when seen through a
lens. Several pounds weight of this mineral were obtained from each
load of gravel washed, more especially from the newer drift.

Topaz.—ln waterworn fragments, and sometimes in imperfect
crystals, with terminal planes; transparent and usually white, rarely
yellow or light blue. This is the largest of the associated
minerals, varying in size up to half an inch in diameter.

Zircon.—In small rolled pieces, and as a fine heavy sparkling sand
in abundance ; transparent, brown, very pale red, or colourless. They
rarely exceed one-fourth of an inch, and are mostly smaller; but are
found higher up the river, and above the diamond fields, in pieces
of much larger size and richer in colour.

Corundum.—

Var. (a). Sapphire.—Transparent, blue, green, yellowish, and particoloured ;
too small and of bad colour to be of value.
(2). Adamantine spar.—Hair-brown and black with chatoyant lustre.

Norman Taylor—The Cudgegong Diamond Field. 455

(c). Barklyite.—An opaque magenta-coloured variety first discovered in Victoria
and named after Sir Henry Barkly.

All the above occur in small fragments (larger higher up the river) in great
abundance.

(2). A variety, locally termed ‘‘mouse dung,” which it much resembles, is
characteristic of the locality. It occurs in six-sided prisms, slightly
barrel-shaped or tapering, with flat end faces; one-fourth of an inch
long, and one-twentieth of an inch in diameter; bluish white, with a few
dark blue spots, opaque; hardness 9; specific gravity 3-59; composition
found by analysis :—

sAUMIN AY eM Mlecenhreton,. loca Piaee Necet bees! vues 1 OOSOT
INGA Oa) ce Gog /ac6 ceo sce Migs) Gon ce RL
IDI og eda 885 oad 0G co) 35a) 355) Sse “45

101-27
(e). Ruby.—A transparent pink variety, found sparingly in flat grains one-tenth
of an inch in diameter; its shade often passes into violet and blue;
hardness 9; specific gravity 3-96 ; composition found by analysis :—

Alumina SON MRCP BR IeEA) | COG BL. GeaARt gat eeS LA ee OO
HELriCROXICE Ande MC Etis: 5, [ecugiicccy se oseh ap lsou,
INIGYBINESE. sos s00 G06 800 | ae 000-000 008 63
GTMCNT ee eerste esees sited Wy Se, eaten pees: 52

100°44

(f). A few large rolled oval pebbles of corundum have also been noticed,
exceeding half an inch, of a mottled dirty white and pink colour, per-
fectly opaque. From their low and variable specific gravity (3°21 to
3°44 and upwards) they appear to be impure massive forms of the
mineral, and possess the requisite hardness. They look like jasper
pebbles, and are probably what are termed ‘‘ morlops” by the Bingera
miners. Their specific gravity accounts for their association with the
diamonds in washing off.

Quartz.—Opaque double hexagonal pyramids, one-eighth to one-fifth of an inch
in diameter, are very common. Quartz pebbles occur of all sizes. The
varieties comprise agate of poor quality, carnelian, jasper, rock crystal,
smoky quartz, amethystine quartz (rare), and a bluish opaline variety.
Fragments of grey quartz, imbedding felspar, derived from the granite
of Aaron’s Pass, 40 miles up the river, are common. A geode of
chalcedony, haying the cavity filled with quartz crystallized in rhombs,
was also found.

Having thus fully described the geology of this diamond field,
and seeing that the diamond occurs in an old river drift, we are
led to inquire whether the diamond has been drifted, like the other
minerals with which it is associated, and, if so, which of the forma-
tions—Ieneous (granite, greenstone, basalt, etc.) or Sedimentary
(Upper Silurian, Devonian, Carboniferous or Mesozoic)—has afforded
it? or, has the diamond grown in the older drift in which it is now
found ?

Diamonds were first reported by the late Rev. W. B. Clarke
(Southern Gold-fields of New South Wales, page 272) from the
Macquarie River in 1860. On this river, at Suttor’s Bar, they were
worked contemporaneously with the Cudgegong, but, owing to
heavy floods, little could be done. The Bingera field was reported
on by Professor Liversidge in 1873 (Mines and Mineral Statistics of
New South Wales, 1875, p. 104).!. The Borah Creek (a tributary of

1 See also, Liversidge, Quart. Journ. Geol. Soc. 1875, vol. xxxi. pp. 489-492.—
R. E., jun.

456 Norman Taylor—The Cudgegong Diamond Field. ‘

the Gwydir River, New England District, New South Wales) tin and
diamond mines were reported on by my late colleague, Mr. C. S.
Wilkinson (Mines, etc., New South Wales, 1875, p. 79); and at Bald
Hill, near Hill End, Lambaroora, diamonds were also reported on
by Prof. Liversidge (Mines, etc., New South Wales, 1875, p. 115),
where some tolerably large ones were found—one slightly over
three carats (9°6 graims Troy), and another one and a half carats
(4:5 grains Troy). The late Professor Thomson was shown some
diamonds which were said to have been obtained in the sands at
the mouth of the Clarence River; and the writer was shown one
from a drift underlying basalt near Trunkey Creek, Tuena, Aber-
crombie River. In all these instances, with the exception of Borah
Creek, the surrounding country is entirely Paleeozoic, intersected,
however, by dykes and masses of various igneous rocks.

The fact of the diamonds exhibiting structural or growth planes
is, I think, sufficient to enable us to disregard the igneous rocks for
their origin, unless some of these rocks (the granites and green-
stones) are metamorphic. Wohler asserted that the diamond could
not have been formed at a high temperature, least of all by fusion.
Brewster thought that the old conjecture, that diamonds were of
vegetable origin, was confirmed by their optical properties, and
analogy to amber.

The occurrence of tin with the diamond at Borah Creek, New South
Wales, and at Beechworth, Victoria, both in granitic areas, indicates
granite as their possible source; but tin always occurs with diamond,
in small quantity, in the other districts mentioned, which are more
numerous, and all in older sedimentary rock areas.

In Mines and Mineral Statistics of New South Wales, 1875, p. 79,
Mr. Wilkinson states that the Borah Creek tin and diamonds occur
in a newer drift, a wash from the older Miocene drift underlying
the basalt, and that the entire watershed of the country is granitic.
He also notices the occurrence of small black pebbles of jasper,
which seem to him to indicate that the rock producing the diamond
may have been entirely denuded away. On this field the diamonds
average in weight about one carat grain each (the largest 5:5 carat
grains), and their facets and edges are never waterworn or abraded.
On page 88, speaking of diamonds and tin, Mr. Wilkinson states,
“There seems but little doubt that they have been derived from the
older Tertiary gravels; and this is an agreement with the observa-
tions of the late Professor Thomson and Mr. Norman Taylor on the
Cudgegong diamond field.” Mr. Wilkinson seems partly to have
subscribed to the writer’s view that the older drift is the matrix of
the diamond.

In Captain Burton’s “ Highlands of Brazil,” vol. ii. page 187, he
says, ‘“‘For reasons that will presently appear, it (the diamond) is
evidently younger at times than the formation of gold, and it is
probably still forming, and with capacity for growth.” The writer
failed, however, to notice the reasons that were to appear.

Professor Liversidge remarks that the Bingera diamond field is
surrounded by rocks of Devonian or Carboniferous age, but that he

Norman Taylor—The Cudgegong Diamond Field. 457

had no fossil evidence. The diamond drift rests on argillaceous
shales with interbedded conglomerates. The miners regard these
conglomerates as being diamond bearing, but without any proof.
He states also that he had not detected any fractured diamonds.'

If the diamond is derived from the Carboniferous rocks, why is it
not found in the present river-bed (except where tailings have been
washed into it) which abounds in Carboniferous detritus; more
than one-half of the pebbles and boulders consisting of Carboniferous
conglomerates? Why also is it totally absent, although carefully
looked for, in close proximity to the Carboniferous rocks, as at
Cudgegong, and immediately under their escarpments at Tallawang,
and in all the streams of the upper sources of the river? It is rare
to find a trace of the Carboniferous rocks in the older drift, and
only occasionally in the newer, whilst they are common in the most
recent river drifts. The sand in the newer drifts is probably the
remains of the Hawkesbury sandstones, which overlie the Carbon-
iferous rocks, and must at one time have had a far wider extension.
The late Rev. W. B. Clarke observed that the occurrence of grains
of graphite in the Hawkesbury rocks looks like an approach towards
the diamond; and, in a letter to the writer, he says that the evidence
of fossil wood must be rejected, as it is found in various formations
of all ages.

If the gem-stones in the older drift (underlying basalt) were derived
from basalt, this basalt must have been older than that now covering
the drift, and there is no trace of such older basalt, if we except that
capping Mount Bocoble, west of Cudgegong, which is of a totally
different character to the Cudgegong flow, and at nearly 1000 feet
higher elevation. We are then driven to the greenstones and
granites for the origin of the gems, and here we are completely at
fault.

The Broombee and Cudgegong limestones (Devonian) may have
supplied the rubies, as they do not occur above the latter place, nor
are topaz or diamond found there.

The gems associated with diamonds are very common in most of the
river drifts of Victoria and New South Wales, but in one instance only
in the former colony, at Beechworth, have diamonds been found.
And, if these gems are derived from igneous or metamorphic rocks,
and their presence is an indication of the diamond, how is it they
are associated in one place and not in another, the surrounding cir-
cumstances being apparently the same ?

Why is the corundum family—all the members of which, or nearly
all, are as hard as the diamond, and harder than all other rocks which
would be at all likely to grind down their angles—rounded and
fractured, and not the diamond, which, although the hardest mineral
known, is brittle and easily fractured on its cleavage planes ?

1 The cinnabar erroneously quoted by Professor Liversidge (from the article by
the late Professor and the writer) as occurring at the Mudgee diamond field, does
not do so. It is found in an old river drift near the village of Cudgegong, over
40 miles higher up the river, and has no connexion whatever with the diamond
drifts.

458 Norman Taylor—The Cudgegong Diamond- Field.

Why are diamonds, if drifted, so variable in size, being often
larger down the river than nearer their supposed source ?

Why are diamonds, nearly always, more or less contorted from the
true octahedron, forming oblique octahedrons ?

Why are the diamonds, when they occur in the largest quantity,
both larger and purer than when in small quantity ?

Why are diamonds locally variable in aspect, one spot turning out
straw-yellow coloured gems, another with internal black spots, and
another perfectly pure ?

Any answer to the above queries must of necessity lead to the
conclusion that the diamonds have been formed in situ in the older
drift. The writer, for his own part, believes that the so-called asso-
ciation of other gems with the diamond is purely accidental, that
these gems occur at the bottom of the older drift, with the gold; the
diamonds occurring at irregular depths above it, and their associa-
tion being merely due to the miners taking out some six feet or more
of the drift, and thereby bringing them together in the process of
washing.

All the extracts brought forward by the late Rev. W. B. Clarke, in
his Presidential Address to the Royal Society of New South Wales, in
May, 1870,! only prove that a large amount of unreliable and un-
reconcilable data have been collected, which add little or nothing to
our knowledge of the true matrix of the diamond; and, as to how
the diamond has been formed, taking this gem as an illustration of
the purest form of the element carbon, as little is known or likely to
be, as there is of any of the other-elementary substances. Until
chemistry throws some light upon the possible modes of formation
of the diamond in nature, and demonstrates the necessity of its
occurrence in metamorphic rocks, it is perhaps as easy to suppose
that the gem may originate in a late Tertiary drift deposit, as in the
most ancient strata of a somewhat similar origin. Quartzites and
quartzose conglomerates occur in Australian Tertiary deposits having
as highly metamorphosed an aspect as those in the Silurian rocks.
If the diamonds have been formed in the older drift, it will account
for their absence in the present river-bed ; on the other hand, if the
diamond has been drifted from its original matrix, either it might be
expected to occur in the river, where it has never yet been detected,
or, its matrix has been entirely denuded away in older Pliocene or
earlier times. Large areas of Carboniferous and older strata, as well
as extensive tracts of Tertiary basalt, have disappeared from the river
basin; and some persons have therefore proposed to assign the
original position of the diamond to local and limited deposits in the
demolished Palzeozoic rocks.

1 See Trans. R. Soc. N. 8. Wales for 1870, pp. 1—48, ‘‘ On the Discovery of the
Diamond in N. S. Wales ;” and Ibid. for 1872, pp. 1—66, “‘ On the Natural History
of the Diamond.” —R. E., jun.

J. P. Lesley— Origin of Pipe Ore. 459

V.—Oricin or Pipr Ore.
By J. P. Lestxy, of Philadelphia.

HE following account of the discovery of an underground lake
in Algeria went the rounds of the newspapers in July, 1879.

The Tlemcen Courier (Algeria) describes a wonderful discovery recently made at
the picturesque cascades of that place. Some miners had blasted an enormous rock
near the cascades, and, on removal of the débris, found it had covered a large
opening into a cave, the floor of which was covered with water. Constructing a
rude raft, and providing themselves with candles, the workmen sailed along this
underground river, which, at a distance of 60 métres, was found to emerge into a
large lake of limpid water. The roof of the cavern was very high, and covered with
stalactites, the brilliant colours of which sparkled under the light of the candles.
Continuing their course, the workmen had, at certain places, to navigate their craft
between the stalactites, which, meeting stalagmites from the bed of the lake, formed
enormous columns, which looked as if they had been made expressly to sustain the
enormous arches. They thus reached the extremity of the lake, where they noticed
a large channel extending toward the south, into which water quietly made its way.
This is supposed to be a wide fissure which has baffled exploration hitherto at
Sebdon, and which connects the cascades with that locality, and thus with the
mysterious sources of the Tafna. It is possible that here they have found an
immense natural basin, supplied by powerful sources, and sending a part of its
waters towards the lake, while the rest goes to Sebdon. The workmen estimated
the distance underground traversed by them at three kilométres, and the breadth of
the lake at two. They brought out with them a quantity of fish, which swarmed
round the raft, and which were found to be blind.

Whatever exaggerations may have been indulged in by the
reporter of the discovery described above, I think that it is worthy
of the thoughtful attention of geologists, for several reasons :—

1. It offers a rational solution of the problem how the roofs of
wide caverns in limestone regions have been, and still are, supported.

2. It supports the views which I have repeatedly published re-
specting the prime agent for determining the topography of the
earth’s surface, viz. the dissolution of the limestone formations, the
letting down of the over-rocks, and the gradual withdrawal of the
outcrops from each other on opposite sides of anticlinals; and in
steps determined by the limestone formations.

3. It clears up the chief obstacle to a rational theory of the genesis
of our pipe-ore deposits; and this is why I invite to it the attention
of my fellow-geologists in Great Britain, hoping to get from them
expressions of assent or dissent.

In the larger limonite mines of Pennsylvania, botryoidal ore
masses occur, the origin of which has never been explained. The
older mines are now open quarries, hundreds of yards long and
wide, and from 50 to 150 feet deep; of irregular shapes; surrounded
by walls of massive limestone; and floored with mud and standing
water. They are vast pots in the Lower Silurian or Siluro-
Cambrian Magnesian Limestone formation, No. II. of our old survey,
the Calciferous and Chazy formations of the New York and Canada
reports. Many of them have been excavated to their beds; all the
iron ore removed, and the mine abandoned. Others still hold
unknown quantities of limonite beneath the mud floor, as shown by
trial bore-holes.

The clay which filled (and partly still fills) such a mine is

460 Notices of Memoirs—-Dr. E. von Mojsisovics—

in some cases nothing but the decomposed limestone rock in
place, or rather the intercalated impure limestone layers reduced
to clay. In other cases the clay has been brought from the
neighbourhood into the pot with, or without, lignite. In all cases
it is rudely stratified; some of the layers being full of shot ore and
ball ore; others being nearly pure white, yellow, or black clay.
Usually the quantity of ore increases with the depth; solid floors of
ore occur; or the bottom of the pot is filled with solid ore.

Up through this ore-bearing clay-mass rise steeples of pipe ore,
the tops of which are struck by the miners at various distances
beneath the sod. Some of them projected from the forest-covered
soil, as humps of pipe-ore, and led to the discovery of the mine;
others were not encountered until the quarry floor had been sunk
10, 20, or 50 feet. But in all cases the pipe-ore mass is a steeple,
enlarging downwards with ever-broadening base, and standing
finally on the limestone foundation at the bottom of the clay. Often-
times several steeples unite their bases, like a clump of trees. Some
of them have been 100 feet high, and proportionately wide at the
base.

The common idea has been that they are concretionary masses,
derived from the moist iron-bearing clays.

I have long held that all these limonite deposits have been made
in caverns. I now suggest that the broader caverns had their roofs
supported (for a time) by masses of stalactite (now removed by
erosion) and stalagmite; and that the stalagmite piers have been
metasomatized into pipe ore, and remain standing in the surrounding
clay.

1008, CLINTON-sTREET, PHILADELPHIA,

July 29, 1878.

IN@ eke SS) Ora 7 Vier @ ieee =

EAD at
AMMONITES OF THE MEDITERRANEAN AND JuvAviIAN Trias. By
Dr. Ep. von Mogsisovics.

[ Proceed. Imper. Geol. Instit. Vienna, April 1, 1879. ]
(Communicated by Count Marscuatt, F.C.G.8., etc., etc.)
GENERAL CONSIDERATIONS.

YHE forms united in one genus must agree in their least variable
characters (disposition and form of the lobes, form and structure
of the shell, length of the body-chamber, and form of the margin of
the aperture). In continuous genetic series, the limits between the
primary genus and those descending (?) from it must necessarily be
traced somewhat arbitrarily. Forms or groups of forms, of sporadic
occurrence, not possessing indubitable characters of known genera,
are generally best considered as constituting independent genera.
Isolated forms. notably aberrant in one direction from the generic
type, are provisionally ranked among the primary genera.

ARCESTID A. J
The genera Cladiscites, Joannites, and Sphingites being eliminated,

Ammonites of the Mediterranean and Juvavian Trias. 461

the genus Arcestes, Suess, comprises the groups of Hatra-labiat?,
Sub-labiati, Bi-carinati, Coloni, Intus-labiati, Galeati, and Sub-
umbilicati; all of them characterized by more or less modified
body-chambers of the full-grown individuals and by a contraction
of the umbilicus, frequently occluded by a callosity.

Sphingites, Mojs.—This genus coraprises the group of Co-angustati,
characterized by a widely open umbilicus, prominent ridges, and
strictures in the shell of the whorls, including the inhabited chamber,
and coarse wrinkled striations. Cladiscites, Mojs.—The Tornati and
Multilobati bear a number of characters different from those of the
typical Arcestes. The constantly closed whorls, of nearly quadran-
gular transverse section, show neither internal nor external ridges
and keep their form even in the last whorl of full-grown individuals.
Their lobes offer a peculiar structure. The projection of the pre-
ceding whorl coincides with the first auxiliary lobe, not, as in all
other Arcestide, with the second lateral lobe. This is an approxi-
mation to the distribution of the lobes of the Pinacoceratideg, and
becomes still more conspicuous in Cladiscites sub-tornatus by the
deepening of the second lateral lobe. Prof. Quenstedt was the first
who noticed the peculiar structure of the anti-siphonal lobe with its
two many-jointed branches.

Joannites, Mojs.—Like the Tornati, the Cymbiformes are to be generi-
cally separated, as they agree in every respect with Arcestes except
in the form of their lobes, which is the same as in the genus Cladiscites.
They are characterized by their arcuate lobe-line.

Didymites, Mojs.

Lobites, Mojs.= Clydonites, Laube,= Coroceras, Hyatt.

AMALTHEIDH.
Piychites, Mojs.
Amaltheus, Montf.—Triassic forms, standing next to the group of
Fissi-lobati. The Amalthei comprise a number of evidently distinct
groups, which may be generically separated.

PINACOCERATID#.

Pinacoceras, Mojs.

Megaphyllites, Mojs.—The group of Megaphylli, Beyr. (Type:
Ammonites Tarbas), differ from Pinacoceras in the form of their
lobes.

Sageceras, Mojs.

Carnites, Moys.—Comprises Carnites floridus, Wulf., Carn. rari-
striatus, Hauer, and a nondescript species from the Muschelkalk. Very
probably this genus is to be connected with Ceratites Hedenstremi,
Keys., or with a form nearly allied to it. The form of the lobes
distinguishes Carnites from Pinacoceras.

Norites, Mojs.—The Triassic species are—Norites Caprilensis,
Mojs., and Nor. Gondola, Mojs. Shell similar to Sageceras. Rugose
stratum linear. One adventitious saddle of less height than the first
primary saddle. Saddles narrow, high, rounded above. Lobes with
few indentures, first chief lobe divided by a large indenture. More
ancient forms from the sandstones of Artinsk, described by de

462 Notices of Memoirs—Dr. E. von Mojsisovics—

Verneuil and Karpinsky, such as Goniatites cyclobus, Gon. post-carbon-
narius, and Gon. pre-permicus, may be very closely related to Norites.

LyTocERATIDS.

Monophyllites.—Lytoceras spherophyllum and Lyt. Morloti are to
constitute a genus distinct from Lytoceras on account of the peculiar
form of their lobes.

Phylloceras, Suess.

AEGOCERATIDE.

Aegoceras, Waag.—This generic denomination may provisionally
be reserved for a number of forms from the Mediterranean Muschel-
kalk, and further researches must decide how far it is to be super-
seded by that of Psiloceras, Hyatt.

TROPITIDE.

This family is nearly related to the Arcestide, and distinguished
by a well-developed system of sculpture, and by the length of its
inhabited chamber, extending over a whole whorl. The rugose
stratum has only been observed in the genus Halorites.

Tropites, Moys.—This genus includes the manifold forms allied to
Trop. sub-bullatus, Hauer; Trop. Jokelyi, Hauer; and Trop. costatus.
Some of these forms show spiral undulated lines similar to those of
some Goniatites, whose external form reminds us of Tropites.

Entomoceras, Hyatt.—The American type of this genus, Entom.
Laubei, Meek, stands extremely near to the group of Ammonites
Sandlingensis, Hauer (Entomoc. Theron, Dittm., ete.), which group is
nearly allied to Tropites. It is characterized by a flat compressed
shape, a high cultriform carina, aberrant lobes, and, in some cases, by
the presence of a number of spines, reminding us of Trachyceras.
Length of the inhabited chamber still unknown.

Halorites, Mojs.—Includes the group of Halorites Ramsauert,
Quenst., characterized by a body-chamber and mode of growth
similar to those of Arcestes, sculpture like strings of pearls on the
inner whorls, and high saddles with many lateral branches. Lateral
lobes reduced. Whorl of the inhabited chamber different in shape
and sculpture from the inner whorls. Margin of the mouth with a
slight stricture. Aberrant forms: Hal. semi-plicatus, Hauer; Hal.
decrescens, Hau. ; Hal. semi-globosus, Hau.; and Ammonites Medley-
anus, Stol.

Juvavites, Mojs.—Comprises the groups of Juv. Ehrlichi, Hau. ;
and Juv. alterni-plicatus, Hau. Near to Halorites; different from
this genus by the similitude of the whorl of the inhabited chamber
with the inner whorls, and by the lobes being less slitted. Periodical
constrictions of the shell are frequent.

Distichites, Mojs.—Convex portion with a channel-like depression
in the middle, frequently with smooth carine along the margins.
Inner whorls, save the double carina, similar in sculpture to those of
Tropites Jokelyi. Outer whorls gradually flattening; the outer range
of spines advancing to the middle of the sides, where also the ribs
increase in number by bifurcation and intercalation. Inhabited
chamber extending beyond a whorl. Lobes similar to those of

Ammonites of the Mediterranean and Juvavian Trias. 463

Sagenites. Generic type, Dist. Celticus, Mojs. Only a few species,
such as Dist. pseudo-aries, Hau., and Dist. Harpalus, Dtm., are as yet
described.

CERATITIDS.

This family appears first in the Permians, and reaches, under
manifold modifications of form, upwards into the Lower Carnian
deposits. The Indian and Armenian forms, described by MM.
Koninck, Waagen, and Abich, stand in evident contrast with those
typical of our ‘‘ Werfen” beds, and of our Muschelkalk. The Tirolites
from the Werfen beds represent a far lower stage of development
than those of India and Armenia, so that, were the age of the
deposits in which they appear not sufficiently ascertained, they
might be regarded as having belonged to a far remoter period. The
types of the Asiatic Permian forms reach far upwards into the Trias,
as proved by Hungarites scaphitiformis, Hau., a sporadic “colonist” in
the Norian Hallstatt Limestones, nearly resembling Ceratites tropitus,
Abich, in its outward form, as in the details of its lobe-line. MM.
Griinewaldt and Karpinsky have described two species from the
Artinsk Sandstones: Goniatites Artiensis and Sageceras Sakmare,
whose lobes are still unknown, but whose form and sculpture strongly
remind us of the typical forms of Trachyceras from the Norian and
Carnian horizons.

Tirolites—The typical forms are: Tir. Idrianus, Hauer, Tir.
Dalmatinus, Hau., and Tir. Muchianus, Hau. The genus is character-
ized by a simple lobe-line, with entire margin, as that of Nautilus.
The non-dentated, large, lateral lobe is followed by a broad and flat
saddle, sinking gradually with a slightly undulated bend towards
the suture. Another lateral lobe is but slightly marked. The pro-
jection of the preceding coincides with the large lateral saddle. In
the group of Tir. Cassianus, these forms are associated with some
others having an incipient denticulation of the lobes and distinct
second lateral lobe. The convex portion is smooth, or somewhat
flattened ; the sides are smooth, or covered with straight radially dis-
posed folds, frequently ending in strong hollow spines on the margin
of the convex portion. Tirolites is chiefly developed in the Alpine
‘“Werfen” strata. After along interval of time, the genus re-appears,
again isolatedly, in the genuine “St.-Cassian”’ strata (Tirolites spurius,
Mstr.= Clydonites Friesei, Laube, non Mstr.), and another, as yet un-
named form, belonging to the series of Ammonites Cassianus.

Ceratites, de Haan (Haaniceras, Bayle (?), Gymnotoceras, Hyatt).
—Besides Ceratites Liccanus, Hauer (very nearly allied to the
Siberian species Cerat. Middendorfi, Keys.), another species, standing
next to the group of Tirolites Cassianus, is met with in the
“Werfen” strata. The same affinity appears in Cerat. Smiriagini,
Auerbach, and in Ceratites Bogdoanus, Buch, both from the Bogdo
Hills in the Steppe of Astrachan. In some of these transitional forms
(Cerat. Liccanus, Cerat. Smiriagini) the second lateral saddle is
wanting, so that the projection of the precedent whorls falls on the
umbilical side of the large lateral saddle. A Siberian form, differing
from Cerat. Hichwaldi, Keys., by its rounded and smooth convex

464 Notices of Memoirs—Dr. E. von Mojsisovies—

portion, may be considered as a connecting form between Ceratites
and Tirolites. The genus Ceratites, as adopted here, nearly coincides
with the group Nodosi, Beyrich. The convex portion is constantly
without sculptures, smooth, convex or flattened (in one series of forms
with an indistinct medial carina). The sides are covered with
moderately curved ribs or folds, multiplied by bifurcations or inter-
calations, and frequently adorned by umbilical, medial, and marginal
spines or teeth. The number of knotted spirals varies between
Oand 8. The anti-siphonal lobe is double-pointed. The Ceratites
of the German Muschelkalk are strikingly discrepant from the
Mediterranean types by the shallowness of their lobes, possibly in
consequence of anomalous proportions of the salt held in solution
by the old German Sea, in which the Muschelkalk was deposited.

In Cerat. Khanikofi, Opp., an Indian species, the notch of the
lobe-line extends over the tops of the saddles.

Balatonites, Mojs.—This genus comprises the series of forms of
Balat. Balatonicus, Moys., Balat. euryomphalus, Ben., and Balat. Pra-.
gensis, together with the Central-European form Palat. Ottonis, Buch.
Lobes like those of Ceratites; anti-siphonal lobe unknown. Convex
portion with a range of knobs running over its centre, in some cases
taking the form of a carina by confluence of the knobs. «Ribs
numerous, constantly with umbilical and marginal spines, frequently
with one or more intermediate ranges of knobs. One form from the
Muschelkalk has on each side seven ranges of knobs, besides the
row on the convex portion.

Acrochordites, Hyatt.—Only one very rare Mediterranean form
from the Upper Muschelkalk is connected with Acroch. Hyatti, Meek,
the American type of this genus, characterized by ribs, passing over
the convex portion, and alternatingly confluent by three and three
into a large knob on the umbilical margin, and other ribs, simply
terminating at the same marginal lobes as those of Ceratites. Certain
Mediterranean forms with continuous sculptures over the whole con-
vex portion, without any knobs, or with a number of small spirals of
knobs, may be conveniently ranked among this genus, which seems
to be very closely allied to Balatonites. Possibly Ammonites
spinescens, Hauer, may find its place in it. :

Hungarites, Moys.—Narrow, fold-like ribs, high median carina ;
lobes like those of Ceratites. Possibly Ammonites scaphitiformis,
Hauer, so similar to Cerat. tropitus, a Permian form from the Araxes
defile, may rank in this genus. If there be a real connexion between
the Alpine Triassic forms and the Permian species from Armenia, it
would be a proof of genetic difference between the preceding and
the coeval Huropean forms.

Arpadites, Moys.—A limited, well-characterized group, represented
in the Mediterranean province by Arp. Arpadis, Mojs., Arp. Szabei,
Boeckh, Arp. Manzonii, Ben., Arp. Achelous, Mstr., Arp. brevi-costa-
tus, Klpst., Arp. sulcifer, Mstr., Arp. Rueppeli, Klpst., Arp. Sesostris,
Laube, Arp. Hirschi, Laube, and several new forms ;—in the Juvavian
province by the groups of Arp. Hernesi, Hauer, and Arp. Lauber,
Mojs. (Arp. Rueppeli, Hauer). The genus is characterized by a deep

Ammonites of the Mediterranean and Juvavian Trias. 465

furrow in the centre of the convex portion, and a long one-pointed
antisiphonal lobe. This furrow is frequently limited by smooth or
knobly carine. In some forms the ribs end in a thickening near
the furrow. A number of dichotomous or simple ribs, all of them
beginning at umbilical knobs, cover the sides, on which there are
also rows of knobs. The forms of higher geological age have high
saddles, with entire margins; in others of less age, from the “St.-
Cassian ” strata, the notch extends over the heads of the saddles.

In Arp. modestus, an aberrant form, standing next to Arp. Lauber,
the ribs unite over the convex portion.

Trachyceras, Laube.—-The sculpture extends without interruption
as far as on the convex portion, in the centre of which it is always
interrupted by a narrow interval, close to which the Mediterranean
forms show constantly one or more ranges of spines. In the
Juvavian forms, minute notches at the ends of the ribs (see Trachyc.
bi-crenatum, Hauer) or notched carinz are of more frequent oc-
currence. Spirals of spines, of variable number in the different
series of forms, appear on the inflected, bifurcated, or imtercalated
ribs. These spirals are more numerous on the series of less remote
geological age. In some cases, all spines, except those of the
characteristic ranges on the convex portion, are wanting. The lobes
in forms of more remote geological age are quite concordant with
those of Ceratites; in those geologically less ancient, Professors
Quenstedt and Laube have first noticed the digitiform notches ex-
tending over the saddles, and the denticulation of the lobes in-
creasing in depth.

Heraclites, Mojs.—A limited series of forms in the Norian strata
of the Juvavian Province, with intermediate forms, connecting
Her. Poeschli, Hauer, with Her. robustus, Hauer. Body-chamber
very short, about half of a whorl. Strong, in some cases inflated,
ribs on the sides. Convex portion flattened, traversed by two
delicate, filiform, spiral lines, sometimes with nodules at the points
where they run across the ribs. Her. robustus loses every trace of
sculpture on the convex portion as it advances in age. Sculpture
is likewise wanting in some forms of less remote geological age, as
Her. foliaceus, Dtm. The lobes are characterized by a few irregular
deep sections, hanging far downwards—here Her. quadrangulus,
Hauer.

Sagenites, Mojs.—The known forms, belonging to this genus, are—
Sag. reticulatus, Hauer, Sag. Giebeli, Hauer, and Sag. inermis, Hauer.
In the typical forms the sculpture passes without interruption over
the vaulted convex portion, which sinks gradually into the lateral
portion; in some aberrant forms there is an interruption in the
centre of the convex portion (as in Ceratites) and the narrow,
canaliform, unsculptured band is accompanied by nodular incrassa-
tions. The numerous, delicate, pliciform, transversal ribs are crossed
by a system of more or less undulated spiral lines, lying very close
to each other. Umbilicus narrow. Occasionally the shell is orna-
mented here and there with broad obtuse knobs. Body-chamber half
to three-quarters of the whorl in length. Type of the lobes aberrant

DECADE Il.— VOL. VI.—NO. X. 30

466 Notices of Memoirs—Ammonites of the Trias.

TapuLAR CoNSPECTUS OF THE VERTICAL DISTRIBUTION OF THE TRIASSIC

AMMONITES.
eae JuVAVIAN Province.
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from other Ceratitide. Broad high saddle-trunks, from which depart
divided leaf-like branches. Similar branches rise from the bases of
the lobes. Auxiliary lobes uncommonly small.

CLYDONITIDAR.
Clydonites, Hauer.—Generic type: Clyd. decoratus, Hauer. Evolute
whorls beset with thronged, irregularly granulated, small ribs, uniting
over the convex portion. Lobe-line with entire margin, undulated.

Reviews—Clarence King—Survey of Fortieth Parallel. 467

The high external saddle followed by a lower lateral one. Clyd.
modicus, Dtm., possibly belongs to this genus.

Choristoceras, Hauer.—Generic type: Chor. Marshi, Hauer, with
two-pointed first lateral lobe. Next to it stand several forms with
entire-margined, rounded, first lateral lobe. HEvolute whorls, free in
adult individuals of certain forms, with simple straight ribs, inter-
rupted on the convex portion, except in old individuals of certain
forms. whose convex portion becomes somewhat flattened or de-
pressed. Knobs, disposed in spirals, on the depressed or un-
sculptured part of the convex portion. In the whole six lobes,
the deeply descending one-pointed anti-siphonal lobe particularly
remarkable. Chor. Marshi, Hauer, Chor. Haueri, Moys., Chor.
rectangulare, Hauer, and Chor. Buchi (Klipsteinianwm, Laube) rank
among this genus.

Helictites, Mojs.—Whorls evolute, with strong straight ribs,
running without interruption over the convex portion. Lobe-line
simply undulated, with minute notches, scarcely perceptible by the
unaided eye. Species: Hel. geniculatus, Hauer, Hel. Henseli, Opp.,
Hel. nasturtium, Dtm.

Badiotites.—The §t.-Cassian forms— Ammon. Eryx, Mstr., and
Ammon. glaucus, Mstr., characterized by a narrow or keel-like pointed
convex portion, and by falciform ribs, are morphologically so dis-
crepant from Choristoceras that they must constitute an independent
genus. Lobes entire-margined, undulated ; anti-siphonal lobe long,
one-pointed.

Rhabdoceras, Hauer.

Cochloceras, Hauer.

d5Y Jen Wr aE 2s WY Se

J.— Untrep States Grorocican ExpnLoration oF THE FortTIETH
Paratiet. By Crarence Kine, U. S. Geologist. Illustrated
by 28 Plates and 12 Analytical Geological Maps. (Washington,
1878.)

HIS fine work forms the first volume (although the last pub-
lished) of the Report of the Geological Exploration of the

Fortieth Parallel, under the direction of Clarence King, its subject

being the ‘Systematic Geology ” of that region. The Exploration

has covered a belt of country about 100 miles wide from N. to §.,
and 800 miles long, extending from the eastern foot of the Rocky

Mountains to the Sierra Nevada of California, or almost across the

Cordilleras where they are the broadest. Assisted by an ardent and

untiring corps (including A. Hague, S. F. Emmons, and others)

Mr. King has endeavoured to work out the continuous geology of

this almost unexplored gap connecting it, as far as possible, with the

territory surveyed by Whitney on the one hand, and with Hayden’s
field on the other.

The purpose of this volume is to present a brief systematic account
of the data collected, and the inductions deducible therefrom, so that
the arrangement is chronological, beginning with the deposits of

-468 Reviews—Clarence King—Survey of Fortieth Parallel.

Archean time and proceeding without break through the entire series
to the Quaternary. The first chapter contains the leading geographic
features of the area, which, however, are more fully treated of in the
second volume. The second to the sixth chapters contain a detailed
account of the Archean, Paleozoic, Mesozoic, and Cainozoic rocks,
the seventh chapter comprising the history of the Tertiary volcanic
rocks.

The characters of the Archean rocks are treated of under the
different localities where they are exposed; these rocks are con-
sidered to attain a maximum thickness of 50,000 feet, and comprise
the Laurentian—consisting of red orthoclase granite, mica gneisses
and schists, with deposits:of ilmenite and graphite, and the
Huronian—composed of plagioclase-hornblende granites, diorite-
gneisses, argillites, limestones and quartzites. Between the rocks
referred to Laurentian and Huronian ages, there is a characteristic
difference in the intensity of the metamorphism which has taken
place and also in the obliteration of original structure and in the
increase in thickness, when considered in relation to depth. The
lowest Laurentian aplitic granitoid bodies of the Laramie Hills are
the heaviest beds and the most changed from their original sedi-
mentary condition; the higher MHuronian group of gneisses,
quartzites, conglomerates, dolomites and argillites are at once the
most thinly-bedded and the least metamorphosed.

The granites are divided into four groups:—1. With muscovite ;
2. With little or no plagioclase and biotite; or 8. With biotite and
hornblende; and a 4th type more complex than the others, con-
taining a high per-centage of biotite, with an equal proportion of
hornblende, the plagioclase often equal, or sometimes exceeding in
quantity the orthoclase and titanite; the muscovite type being the
oldest, and the dioritoid variety being the youngest. These granites
and the crystalline schists are pre-Cambrian.

The section (p. 112) on the genesis of granite and crystalline
schists contains some points which of late years have occupied the
attention of geologists, and embodies the author’s views as to their
comparative origin.

In alluding to Dr. Sterry Hunt’s theory, that early magnesian
silicates are chemical precipitates from the acid ocean of their period,
Mr. King sees no reason to seek for a different origin for the
magnesian silicates from that of the commoner aluminous minerals,
and so far as the gneisses and crystalline schists are concerned, he
is led to give in a complete adhesion to the hypothesis of diagenesis
for the anhydrous silicates, and of subsequent pseudomorphism for
the hydrous magnesian rocks.

“Jn the crystalline schists and gneisses are found identically the
same minerals which characterize the granites. The characteristic
features of the schists are, the parallel-bedded arrangement, the
strict retention of chemical materials in their original zones, and the
intercalation of beds made of simple materials, like quartzites and
limestones. The sole difference seems to be that granite is often
demonstrably a plastic intrusion, and possesses ‘no parallel arrange-

Reviews— Clarence King—Survey of Fortieth Parallel. 469

ment of minerals, its various components lying more or less evenly
distributed throughout the mass.” With regard to the genesis of
granite, the author supposes, were the chief factor to be tangential —
or, as he terms it, orographical pressure, there must of necessity be
all the transitions from a uniform homogeneous granite down to
those rocks in which radial or gravitation has produced the ordinary
bedded schists.

The Paleeozoic rocks, which are everywhere unconformable to the
underlying Archean, are strictly conformable from the lowest
Cambrian beds to the top of the Upper Coal-measure Limestone.
Slightly developed in the Rocky Mountain system, not over 1,000
feet in thickness, they thicken out westward, as in the Wahsatch, to
more than 30,000 feet, and about 40,000 feet at the extreme western
Paleozoic limit. In the whole Paleozoic section there are 18,000
feet of siliceous sediment, 15,000 feet of limestone, and about 1.400
feet of slates and shales.

“The general absence throughout the Coal-measure horizons of
beds of coal, and the conspicuous absence of shallow-water deposits
(with the exception of some conglomerates), indicate that the whole
great Paleeozoic series was from the first received on the bed of a
deep ocean.” Within the Palzeozoic series of this region there are no
considerable passages of metamorphism.

Directly overlying the Paleozoic limestones are the well-known
Rocky Mountain red-beds, which have been generally assigned to the
Triassic age. The Trias beds are succeeded conformably by the
Jurassic and Cretaceous groups, the exposures of which within the
Fortieth Parallel are clearly shown in Map III. (p. 356). Owing to
the widespread but unequal mechanical disturbance at the close of
the Paleeozoic period, the physical features of the old land area were
considerably modified, so that the Trias-Jura series were formed in
two separated seas, an eastern and western, differing in depth and in
the nature of their sediments (p. 537).

Between the Cretaceous and Jurassic there is absolute conformity.
The former represented a period of comparative calm, so far as
orographic disturbances go, although it was characterized by subsi-
dences, but so general and gradual as to leave no traces of their
mode of operation, except the succession of conglomerates and tiers
of coal-beds.

The Cretaceous group in descending order consists of—1l. The
Laramie or the Lignite group of Hayden, 1,500 to 5,000 feet. 2.
Fox Hill group, 3,000 to 4,000 feet. 38. Colorado group, equal to
Fort Benton, Niobrara and Fort Pierre groups of Meek and Hayden,
800 to 2,000 feet. 4. Dakota group, 300 feet.

With regard to the position of the upper member of this series
(the Laramie), considerable difference of opinion now exists, so that,
‘aside from the Taconic system, no single geological feature in all
America has ever given rise to a more extended controversy than the
true assignment of the age of this group.”

Mr. Clarence King discusses the position of the Laramie group,
the geological horizon of which has been referred by Dr. Hayden and

470 Revriews—Clarence King—Survey of Fortieth Parallel.

others (based on the plant-remains) to the Tertiary, or considered as
a transition member between the Cretaceous and Tertiary. Although
containing the facies of a Tertiary flora, this is associated with
Dinosaurian reptiles characteristic of Mesozoic age, which, together
with a period of immense disturbance at the close of the Laramie
beds and complete nonconformity of the overlying series of purely
freshwater shale, should constitute a division between the Mesozoic
and Tertiary. “It will be seen,” says the author, “ that the strati-
graphical break, with its unmistakable Eocene facies at the base of
the one group, and the Dinosaurian reptiles at the close of the other,
marks the period of nonconformity as distinctly at the close of the
Cretaceous.”

The fauna up to the base of the Laramie is strictly marine. The
Laramie itself carries the remains of an estuarine or brackish water
life, associated with strictly Mesozoic saurians.

With the close of the Cretaceous the conformable series of marine
and estuarine deposits came to an end, and was immediately followed
by one of the most important orographical movements of the whole
Cordilleran history. The most important result of this post-Cre-
taceous movement was the elevation of the whole interior of the
continent and the complete extinction of the inter-American Medi-
terranean Ocean.

From the date of this movement no marine waters have ever
invaded the middle Cordilleras, and the subsequent strata are all of
lacustrine origin. The Hocene of the Fortieth Parallel region was a
period of four lakes, whose deposits—unconformable among them-
selves—amount to 10,000 feet, and are characterized by an abundant
series of vertebrate life. At the close of the Hocene an important
orographical movement took place by which the province of the
northern Great Plains, and a long narrow tract lying on the eastern
base of the Sierra Nevada and the present Cascade Range became
depressed and received the drainage of the surrounding countries,
forming two extended Miocene lakes. The deposits of the western-
most lake are chiefly the tuffs and re-arranged ejecta of volcanic
eruption ; the deposits of the plains are the simple detritus from the
surrounding lands.

Another orographical movement followed the close of the Miocene,
affecting differently the areas of the western and eastern lakes, so
that the Pliocene opened with two enormous lakes, one covering the
basin country of Utah, Nevada, Idaho, and eastern Oregon, the other
occupying the province of the plains. Both of these Pliocene lakes,
as do the Miocene, contain the remains of rich faune. The extent
of the Tertiary exposures are seen in Map IV., and the sequence of
the Tertiary lakes at p. 458. The close of the Pliocene period was
signalized by another considerable movement, which affected
differently the area occupied by its sediments, and was followed by
the varied series of deposits of the Quaternary age, described in
Section V. (pp. 459—529), which is full of interesting matter, not
only as relating to glacial phenomena and the lake deposits of the
period, but also as to the structure and origin of the remarkable
gorges or caiions, which are wholly within this period.

Reviews—Olarence King—Survey of Fortieth Parallel. 471

“During the Quaternary period most modern mountain topo-
graphy received its present form. Most, if not all, of the sharp
canons were carved, and the mechanical results of that erosion are
seen in the great accumulations of subaerial gravel in regions of
interior drainage like the Great Basin, and in deposits of unknown
thickness classed as Lower Quaternary, which gathered on the beds
of the Quaternary lakes.”

It has therefore been the object of Mr. King in Chapters II. to V.
to give a general account of such facts as seemed to be necessary to
a comprehension of the sequences and subdivisions of sedimentary
geology. In the 120,000 feet of these accumulations, the grander
divisions of the Archean or Azoic, Palaeozoic, Mesozoic, are distinctly
outlined by divisional periods of marked unconformity. From the
first of the Cambrian age to the present day every important interval
of time is recorded in the abundant gathering of sediments, which
are with singular fullness characterized by appropriate and typical
life forms. Of the 77,000 feet of beds from the Lower Cambrian to
the close of the Tertiary, nearly 20,000 feet are limestone, the rest
is purely detrital, the limestones, however, throughout the entire
Cretaceous and Tertiary are all fragmentary, and are simply the
pulverized sediments which were washed down from the neighbouring
limestone formations.

Chapter VII. comprises the more important facts accumulated
during the Exploration relative to the Tertiary volcanic rocks as to
sequence, geological dates, modes of occurrence, reciprocal relations,
and petrographic distinctions. The latter subject has also been fully
treated in the admirable and instructive memoir by Prof. Zirkel,
forming vol. vi. of the series. The material is classed under three
groups: Ist. The detailed occurrence of species; 2nd. The relations
of each rock to the orographical actions which brought it to the sur-
face, and the succession of each species; 3rd. The origin of igneous
fusion and the genesis and petrological classification of volcanic
rocks.

The close of the Jurassic age was characterized in Nevada and
Utah by scattered eruptions of middle-age eruptive rocks, including
diorite, diabase, and porphyries; with a doubtful exception, all the
other volcanic series are referable directly to the Tertiary. The
natural sequence of the volcanic rocks observed in the Fortieth
Parallel corroborates the previous researches of Richthofen, which is
as follows: 1. Propylites; 2. Andesites ; 3. Trachytes; 4. Rhyolites ;
5. Basalts. The acidic products are enormously in excess of the
basic products (as shown in Map VII.), and almost equally in excess
of rocks of mean constitution, as the hornblende propylites, andesites
and trachytes. Taken as a whole, Rhyolite is the predominating
voleanic rock of this field, and considerably exceeds the Basalts,
which rank next in territorial area. These two families, at once the
most acidic and most basic, cover together ten times as many square
miles as all the rest of the volcanic series combined.

The section on the fusion and genesis of volcanic rocks (pp. 696-
725), and their classification, is well worthy of the attention of those

472 Reviews—Prof. L. G. de Koninck—

interested in this branch of geology, especially as regards the author’s
view of volcanic fusion.

After alluding to the various hypotheses on this subject, the
author says :—‘‘ Suppose above the temperature of fusion is a column
of thirty miles of rock, and suppose three miles are rapidly removed
by erosion. The position of the couche of temperature of fusion
will constantly tend to retire towards the centre of the earth. If it
retires at the same rate as erosion, the effect of pressure on the
couche of the temperature of fusion will remain the same; but if
the rate of erosion and consequent removal of pressure is greater
than that of the recession of the couche of temperature, plus that of
general secular recession, the effect, it would seem, must be to create
a local fusion.”

The orography of the region forms the subject of the eighth
chapter, and is further explained by five coloured maps, showing
the exposures of successive orographic disturbances ; of these—‘“ the
post-Carboniferous, post-Jurassic, post-Cretaceous—taken together—
were the main building-times of the modern American continent,
and each of these orographical disturbances were most violent at
the western edge of the region involved” (p. 759).

The limited space at our disposal prevents us from entering
into more details of the contents of this suggestive work, which the
reader must consult for himself in order to fully appreciate its
nature as a piece of connected history, bearing in mind, however,
“that it is not a geological survey, but a rapid exploration of a very
great area, in which literally nothing but a few isolated details was
before known. It is an attempt to read the geology of the Middle
Cordilleras, and to present the leading outlines of one of the most
impressive sections of the earth’s surface film.”

For our own part we fully recognize, after perusing this work, not
only the arduous labours of Clarence King and his colleagues during
their ten years’ exploration in the field, but, also, the instructive and
systematic manner in which some of the most striking geological
and physical features of the region are recorded, as further illustrated
in the twenty-eight beautiful plates and the twelve analytical geolo-
gical maps, interspersed throughout the 800 pages of letterpress.

J. M.

I].—Fatne pu Catcarre CarBonrrireE DE LA Beterque. Par L.
G. pE Kontnex. Folio, pp. 182. Atlas 31 Planches. (F.
Hayez: Bruxelles, 1878.)

F ANY apology were needed for the appearance of this valuable
addition to paleontological literature, that offered by the dis-

tinguished author as the raison détre of this initial volume of a

series to be devoted to the fauna of the Carboniferous Limestone of

Belgium is surely a most valid one. In 1842 Professor de Koninck,

in a somewhat similar work, raised the number of known species

from two hundred to nearly five hundred described forms. At the
present time, however, more than double that number, or from one
thousand to twelve hundred species, from that horizon, are contained

Fauna of the Belgian Carboniferous Limestone. 473

in the rich collections of the Royal Museum of Natural History,
whence the chief part of the material for this, and the contemplated
volumes of “ Extraits des Annales du Musée Royale de la Belgique,”
have been, or will be, derived.

Prefacing his first volume with a brief but clear outline of the
limits and nature of the lowest division of the Carboniferous forma-
tion, in Belgium, the Carboniferous or ‘ Mountain” Limestone,—M.
de Koninck proceeds to a further subdivision into three main groups,
each of which is characterized by a distinct biological fauna. Here,
as usual in Paleozoic deposits, the Brachiopoda are to the fore as
classificatory indices. The position of the Visé Limestone, overlying
the Devonian, is definitely settled. It comprises the uppermost or
most modern beds. This reverses Murchison’s grouping, originally
followed by the author and other Belgian geologists, but now shown
to have been erroneous. The Upper or Visé Limestone is charac-
terized by Productus giganteus, the middle series by Spirifer striatus,
and the Lower or Tournai Limestone by Spirifer mosquensis. The
entire series, about 800 métres in thickness, is again subdivided into
six beds according to the arrangement of M. E. Dupont. |

As no reptilian or amphibian remains have as yet been furnished
by the Belgian Carboniferous rocks, this volume is occupied by
figures and descriptions of the forty-three species of fishes occurring
in the Upper and Lower divisions. The middle beds are entirely
barren of piscine remains, and the conditions were evidently un-
favourable to their preservation during the deposition of the whole
series. For the number represented is less than half that of the
described British species from the same epoch. Some of the Belgian
forms are, however, very remarkable. Forty belong to the Selachii
and the remaining three to the Ganoidei. The interesting Dipnoid
discovered by the author and M. van Beneden, Paledaphas insignis,
does not find a place in this volume, as the horizon originally given
as Carboniferous is now known to be of Devonian age. The classifi-
cation adopted throughout is Dr. Traquair’s Miillerian modification of
Professor Huxley’s system. But M. de Koninck gives only necessary
classificatory details, leaving the systematization of the Carboniferous
fishes to those possessed of more ample material. Of the fifty-two
species of Nautili figured and described, twenty-two are new to
science. Several forms are restricted to certain horizons; none make
their appearance prior to that epoch, and not one survives it. The
genus is abundantly represented in Belgium, but occurs but rarely in
Australian deposits of similar age.

The specific descriptions, clear though not diffusive, are accompanied
by careful comparisons with Huropean, American, and Australian
forms, and liberal recognition is awarded to the labours of pre-
decessors and contemporaries in the same field of inquiry. The atlas
comprises thirty-one folio plates of fishes and cephalopods, beauti-
fully executed by G. Severeyns. The work gives promise of a
mine of information for comparative purposes to all interested in
the history of the fossils of this rich formation, and cannot but
add to the acknowledged repute of the author as a distinguished

A474 Reviews—M. J. Barrande’s Bohemian Brachiopoda.

paleontologist. In a word, the ‘‘Faune Caleaire Carbonifére de
la Belgique,” with the Silurian System of M. Barrande, and the
“ Jura Normand” of M. Eugene Deslongchamps, may be taken as
excellent illustrations of the method adopted by foreign authors as
historians, not of one especial group of organisms, but of the physical
characters and complete fauna of an entire geological formation. By
this means local variations in general physical conditions are duly
recognized, and uniformity of geological grouping and zoological
classification is secured. No English works of a similar nature can
rival those above cited in excellence of paleontological illustration,
save the decades of the Survey, or the volumes of our Palzon-
tographical Society. NEC:

IiI.—Bracuropopes Hruprs Locares. Par Joacnuim BaRRanbE.
Svo. pp. 3835, and 7 Planches. (Prague, 1879.)
Ay Ei have here another of those excellent memoirs in which M.
Barrande reviews his former labours in the same field; an
epitome, in fact, of those lengthened researches, the results of which
are embodied in his classical volumes on the Silurian system of
Bohemia. To the student these most instructive résumés are in-
valuable as an author’s summary of his own investigations, affording
information on important points, with references to the exact locale
of further details. They furnish the author at the same time with
an opportunity for revision and addition, rendered necessary by in-
creased discoveries, and for drawing those inferences and conclusions
which he is necessarily best qualified to supply.

Although only two species of Brachiopods were known in
Bohemia prior to 1840, M. Barrande now transmits about six
hundred and forty named Silurian species to his successors. A
number which illustrates the exceptional richness of the Bohemian
deposits, and the thorough investigations to which they have been
subjected through the energy and laborious industry of the author.
It considerably exceeds Mr. Davidson’s provisional estimate of 210
species from the British Silurian rocks, and almost amounts to half
that given by Dr. Bigsby (1422) in his “Thesaurus Siluricus” as
the approximate total of known species from the Silurian deposits
of the world. Only two of the Bohemian forms are primordial,
124 occur in the second zone, and 521 in the third. Thirty-nine are
common to France, and forty-two to the “‘Septentrional” zone of
Europe and America. Three new genera, Clorinda, Mimulus, and
Paterula, all Secondary, or local types, are added.

In this memoir M. Barrande gives some very interesting and
novel facts concerning the variations observed in Bohemian forms,
treats of their vertical distribution, and specific relations with those
of other Paleozoic areas. Thus, it would appear from these
researches that neither longevity of type nor the fecundity of a
species can be considered as the primary cause of variability. For the
long-lived forms often exhibit but few variations, while a species
but sparsely represented may be accompanied by numerous ex-

Reviews—Skertchly’s Gun-Flints. 475

amples. Furthermore, that the numerical abundance of a species,
on the same horizon, and with a limited area, has apparently no
influence upon, or connexion with, the origin of varieties. Some
appear simultaneously with the type, others during its existence,
while the mutatory forms do not come into being until after its
disappearance or extinction. The average vertical distribution is
extremely limited. These facts, M. Barrande concludes, are opposed
to the conception of the adaptability of the Brachiopods to the
environment, and afford no support to the theories of descent by
modification. At the same time, it is en evidence (Table, p. 162)
that generic forms enjoying the longest vertical range, such as
Atrypa, Discina, Orthis, and Rhynchonella, are invariably represented
by the greatest number of species.

These local studies in Brachiopoda may not perhaps be of such
general interest as the preceding volume on the Cephalopods, but
to the student and specialist they afford valuable and novel data
with reference to a group of organisms daily becoming more useful
as indices of paleontological time. Nor can those who are not
prepared to accept M. Barrande’s views with regard to the separate
origin of every individual species, or variety, fail to admire the
marvellous energy and vast labours of one of the most distinguished
and indefatigable of pioneers in paleeontological science. Js Or

TV.—On toe MAnuracrure or GuN-FLINTS, THE Metuops or Ex-
CAVATING FOR Furnt, THE AGE OF PaLmoLitHic MAN, AND THE
ConNNEXION BETWEEN NEOLITHIC ART AND THE GUN-FLINT TRADE.
By Sypney B. J. Sxerrcuty. [Memoirs of the Geological
Survey. 8vo. pp. 80. (London, 1879.) Price 17s. 6d. ]

HE title of this Geological Survey Memoir gives its contents at a
elance, and introduces to our notice subjects that possess a far
wider interest than do most of the Survey publications. The neigh-
bourhood of Brandon, so well known, through the labours of Messrs.
Prestwich, Evans, and Flower, for its paleeolithic and neolithic im-
plements, has recently been invested with much additional import-
ance from the researches made by Mr. Skertchly into the geological
position of the earlier works of art, and which he has determined
to belong to deposits of Interglacial age.

In his present work, the author first places before his readers a
very careful and detailed account of the modern manufacture of
gun-flints, a trade now steadily dying out, though this decline is not
owing, as he tells us, to a falling off in the demand, but to a lack of
hands, the boys preferring agricultural and other labours to the con-
finement of a knapper’s shop.

Under such circumstances, the record of the trade, while illustrat-
ing the economic applications of geology, possesses an archological
value which time will no doubt enhance.

The particular layers of flint with their local names are described
and illustrated in a section of the Chalk at Lingheath, where the
flint now manufactured at Brandon is obtained. Other localities,

476 Reports and Proceedings—

formerly worked, are likewise described, including the gun-flint
manufacture once carried on at Beer Head in Devonshire. The
various tools employed are explained and figured, and the methods
of digging the flint, and of drying, quartering, flaking, and knapping
it are similarly illustrated. And in this part of ‘the subject the
author acknowledges his indebtedness to Mr. W. J. Southwell, a
practical knapper, in whose workshop he learnt the trade, and wrote
many of his notes. Hach form of gun-flint, from that of the musket
to the pocket pistol, is engraved, and full descriptions are given of a
set of specimens deposited in the Museum at Jermyn Street.

The author observes that from Paleolithic times to the present
day the vicinity of Brandon has been one of the great emporia for
flint, and he briefly sums up his conclusions that the early paleo-
lithic implements found in the “ Brandon Beds” are older than the
Chalky Boulder Clay. The present flint-knappers at Brandon he
regards as the direct descendants of the old workers in stone who
dug the ancient flint-pits at Grime’s Graves, which have been so
well described by Canon Greenwell.

V.—JouRNAL OF THE Soh MicroscoptcaL Socrety. Edited by
Frank Crisp, LL.B., B.A., F.L.S., ete. Vol. Il. No. 2, April;
No. 3, Extra Number, May, 1879. 8vo. (Willams & Norgate,
London.)

HERE are so many points in the natural history of plants and
animals, and in the nature of rocks, that the microscope assists

the geologist in determining, and so many microscopists work ardently
at the elucidation of these matters, that we cannot take up any part
or volume of the Proceedings of the several Microscopical Societies now
flourishing at home or abroad without meeting with some, and often
with important, additions to our knowledge. This is the case with the

Journal before us. The industrious accumulation of notes and memo-

randa from British and foreign works adds much to the value of this

work ; and, with the Bibliography, these are now arranged on a classi-
fied plan, referring (1) to the histology and embryology of the Verte-
brata; (2) structure and natural history of the Invertebrata, according
to classes and orders; (3) general histology and embryology of the
Phanerogamia; (4) the Cryptogamia in order; (5) Microscopy and
Miscellanea.

IRIDI-SOsiRayS) YNaypapy 1-43 OQC12 psoas GS

———_>——_
British AssocraTIoN FOR THE ADVANCEMENT OF SCIENCE,
Forry-ninta Mererinc, SHerrietp, Aucust 20TH, 1879.
J.—Tittes or Papers Reap tn Section C. (GEOLOGY).
President—Professor P. Martin Duncan, M.B. (Lond.), F.R.S., V.P.G.S.

The President’s Address.

Rev. H. W. Crosskey, F.G.S.—Seventh Revel of the Committee
appointed for the purpose of recording the position, height above
the sea, lithological characters, size, “and origin of the Erratic
Blocks of England, Wales, and Ireland; reporting other matters

Forty-ninth Meeting of the British Association. AT7

of interest connected with the same, and taking measures for their
preservation.

J. H. Lee, F.G.S.—Notice of the occurrence of a Fish allied to
Coccosteus in a bed of Devonian Limestone, near Chudleigh.

J. E. Lee, F.G.S.—Notice of Fossils found in a bed of Devonian
rocks at Saltern Cove, in Torbay, and in a quarry of the Old Red
Sandstone, near Caerleon, in Monmouthshire.

P. H. Carpenter, M.A.—On the Nomenclature of the Crinoidal Calyx.

V. Ball, M.A., F.G.S.—On the Coal Fields and Coal production of
India.

J. F. Blake, M.A., F.G.S.—On Geological Episodes.

F. M. Burton, F.G.S.—On the Keuper Beds between Retford and
Gainsborough.

F. M. Burton, F.G.S.—On the Northerly extension of the Rhetic
Beds at Gainsborough.

W. Pengelly, F.R.S.—Fifteenth Report on the Exploration of Kent’s
Cavern, Devonshire.

J. Evans, LL.D., F.R.S.—Report on the Bone Caves of Borneo.

Professor W. Boyd Dawkins, M.A., F.R.S.—On the Bone Caves of
Derbyshire.

fi. J. Ussher and Professor A. L. Adams, M.A., F.R.S.—Discovery
of a Bone Cave near Cappagh, County Waterford.

C. Ricketts, M.D., F.G.S.—On some remarkable Pebbles in the
Boulder-clay of Cheshire and Lancashire.

The Abbé A. Renard and T. Murray.—On the Volcanic Products of
the Deep Sea of the Central Pacific, with reference to the
“ Challenger’? Expedition.

C. Moore, F.G.S.—On Ammonites and Aptychi.

E. W. Claypole-—Notes on a Fossil Tree from the Upper Silurian of
Ohio.

J. W. Davis, F.G.S.—On Ostracocanthus dilatatus (gen. et sp. nov.),
a Fossil Fish from the Coal-measures, S.E. of Halifax, Yorkshire.

E. Wilson, F.G.S.—On the Age of the Pennine Chain.

M. Blair—On the Foundations of the Town Hall, Paisley, with
Notes on the Rocks of Renfrewshire.

Dr. J. Phené, F.S.A.—On the Deposit of Carbonate of Lime at
Hierapolis, in Anatolia, and on the Efflorescences of the Lime-
stone at Les Baux, in Provence.

Prof. A. S. Herschel, M.A., F.R.A.S., and Prof. G. A. Lebour, M.A.,
F.G.S.—Sixth Report on the Conductivities of certain Rocks.
(Read also before Section A.)

Prof. J. D. Everett, F.R.S.—On some broad features of Underground
Temperature.

Prof. W. C. Williamson, #.R.S.—On the Botanical Affinities of
Sigillaria and Stigmaria.

S. B. J. Skertchly, F.G.S.— Evidence of the Existence of Paleolithic
Man during the Glacial Period in Hast Anglia. (Read also
before Section D.)

J. H. Collins, F.G.S.—On the Geological Age of the Rocks of
West Cornwall.

J. Perry.—On the Surface Rocks of Syria.

478 Reports and Proceedings—British Association.

Rev. G. Blencowe.—On certain Geological Facts observed in Natal
and the Border Countries during nineteen years’ residence.

C. E. De Rance, #.G.S.—¥ifth Report on the Underground Waters
in the Permian, New Red Sandstone and Jurassic Formations.

W. Whitaker, B.A., F.G.S.—Report on the Progress of the “ Geo-
logical Record.”

W. J. Sollas, M.A., F.G.S.—On the Replacement of Siliceous
Skeletons by Carbonate of Lime.

G. R. Vine—On Carboniferous Polyzoa and Paleeocoryne.

H. Hicks, M.D., F.G.S.—On the Classification of the British Pre-
Cambrian Rocks. (See p. 483.)

R. A. C. Godwin-Austen, F.R.S.—On some further evidence relating
to the range of the Paleozoic Rocks beneath the South-east
of England.

Prof. G. A. Lebour, M.A., F.G.S.—On “Culm” and “ Kulm.”

I].—Tities or Papers, Brartne upon Gronogy, READ IN OTHER
SECTIONS.
Section B.—Cuemicat Scrence.

W. Ivison Macadam.—On the Chemical Composition of a nodule of
Ozokerite found at Kinghorn-ness.

Thos. Andrews.—On some curious Concretion Balls derived from a
Colliery Mineral Water.

W. Thomson, F.R.S.H.—Notes on a sample of Fuller’s Earth found
in an old Fullonica recently excavated at Pompeii.

Suction D.—Brotoey.

Report of the Committee on preparing plates illustrating a Mono-
graph on the Mammoth.

S. B. J. Skerichly, F.G.S.—On a new Estimate of the Neolithic Age.

E. B. Tylor, D.C.L., F.R.S.—Address to the Department of Anthro-

ology.

Tones Knowles.—On Flint Implements from the Valley of the Bann.

V. Ball, M.A., F.G.S.—On the Forms and Geographical Distribution
of Ancient Stone Implements in India.

J. W. Davis, F.S.A., F.G.S.—On the Discovery of Chipped Flints
beneath Peat on the Yorkshire Moors.

Professor W. Boyd Dawkins, M.A., F.R.S.—On the Geological
Evidence as to the Antiquity of Man.

S. B. J. Skertchly, F.G.S.—On the Survival of the Neolithic Period
at Brandon, Suffolk.

John Milne, F.G.S.—On the Stone Age in Japan.

Section EH.— GroGraPny.

C. Rk. Markham, C.B., F.R.S.— Opening Address.—The Valley of
the Don.

B. Tower.—The Physical Aspects of Zululand and Natal.

Trelawny Saunders.—On the Orography of the north-west frontier
of India.

Section G.—Mecnanican Scrence.
Baldwin Latham.—On the Temperature of Town Water Supplies.
Joseph Lucas.— On the Quantitative Hlements in Hydrogeology.

————

Correspondence—Prof. T, Rupert Jones. 479

CORRESPONDENCE.

—

A NEW LAKE IN THE PISTOJESE MOUNTAINS.

Srr,—An interesting example of lake-formation has recently been
noticed in one of the valleys of the Apennines by my friend Captain
Cecil Norton, 5th Lancers. The road from Florence by Pistoja to
Modena crosses the mountain-range at Boscolungo, where the lime-
stone rocks form a semicircular arc, facing the south; and from the
northern side of this ridge a spur juts out towards the north-east,
and forms a V-shaped valley, giving rise to a small tributary of the
river on which Modena is situated. On the neighbouring heights
the snow occasionally lies until late in the year. During the last
summer, as late as August 25th, snow was lying near Abetone, the
mountain -top of Boscolungo, and about 4,500 feet high ; also
away eastward, on the hill-tops on the southern side of the gorge
beyond Monte Cimone, which is the crest, 6,700 feet high, at the
head of the valley above mentioned. As in the Alps and elsewhere,
these Italian snows are subject to sudden meltings, though it is said
to be fifty years since so rapid a thaw, or such a flood of snow-
water, has been recorded as that of this year. The mountains here,
it will be remembered, are composed of limestone and sandy macigno,
and therefore so highly susceptible of frost-action that the
accumulation of débris on and at the foot of the slopes is
often considerable. Some time in June last so sudden and rapid a
melting of the snow occurred as to sweep down a large mass of
débris, sufficient indeed to completely block the bed of the rivulet
above mentioned, forming one of the head-waters of the Modena
river. The result was the formation of a lake, some 300 or 400
yards long, by 150 or 200 yards wide, at the time when it was seen
(from the pass) on the 24th August.

It will be interesting to notice hereafter what effect the retention
of the water will have on the dam of this little lake. Will the dam
be violently cut through, or totally swept away, by gradually ac-
cumulated water ? Will it be strong enough to withstand the
pressure ? Will it be quietly worn down by the overflow, so as to
allow of the gradual lowering of the lake? Will it be undermined
by the destruction of its lower part? In any case the débris left
will be moraine-like in character; and might, but for the want of
the regular série, be mistaken for the results of an old glacier.

Thus, it may be instructive to place on record this formation of
a moraine-like heap, which, without careful examination as well of
detail as of general appearance and situation, might at some future
time be attributed to the action of a force very different from that
which brought it to its place. T. Rupert Jonzs.

Starr CoLLEGE, CAMBERLEY,
Sept. 16th, 1879.

480 Correspondence—Dr. James Croll— Rev. W. Downes.

INTERGLACIAL PERIODS.

Str,—In the last Number of this Macazrnr Mr. McGee does me
the honour to refer to the theory which I have advanced to account for
those warm interglacial periods, of which the records are preserved
in most highly glaciated regions which have been examined with
adequate attention. As Mr. McGee appears to have misunderstood
what I have written, and to have fallen into a misapprehension in
regard to the melting of polar ice, perhaps you will kindly allow
me, for the sake of those not familiar with the subject, to point out
where he has gone wrong. I have not, as he supposes, assumed
that the comparative disappearance of ice on the warm hemisphere,
during the period of high excentricity, is due to any additional heat
derived from the sun in consequence of the greater length of the
summer, for there is no such increment. <A shortening of the winter,
or snow-falling season, would no doubt considerably diminish the
quantity of the ice; but the mere lengthening of the summer would
have little effect. The real and effective cause of the disappearance
of the ice was the enormous transference of equatorial heat to
temperate and polar regions by means of ocean currents. My
theory holds that the polar ice was melted mainly by heat carried
from equatorial regions, rather than by the direct rays of the sun.

Mr. McGee calculates that only -615 of a foot of polar ice would
be melted annually ; but there is no reason why there may not have
been more than twenty times that quantity. JAMES CROLL.

PALMOLITHIC IMPLEMENT FOUND IN DEVONSHIRE.

Srr,—About a month ago I had the good fortune to find a paleo-
lithic implement in the parish of Kentisbeare. It is, I believe, the
first which has been found in the valley of the Culm. Some time
ago Mr. H. B. Woodward suggested to me the probability that
paleolithic implements might be found here. When, therefore, his
forecast was verified, I wrote to him informing him of the fact, and
I am now writing to you at his suggestion. I found it on a heap of
stones collected from a field and piled up in the corner of the field
for removal as road metal. It is of bluish chert, weathered white.
The field is one only lately brought into cultivation, has a thin
peaty soil, and is situated near the centre of Ordnance Sheet XXI.,
where the words “ Kentisbere Moor” occur; and its exact position
would be about the middle of the word “Moor.” It must have
lain at no great distance beneath the surface, and have either been
brought up by the plough, or by ditching and draining work. I have
shown it to Mr. D’Urban, Curator of the Albert Memorial Museum
at Exeter, and to Mr. P. O. Hutchinson, of Sidmouth, the latter
of whom has kindly taken the inclosed rubbing. As, however,
the rubbing does not quite correctly represent the shape (for the
surface when spread out will of course slightly exceed the actual
breadth) I have traced its outline, and shown the extreme length
and breadth.’ W. Downes.

KENTISBEARE, CotLuMPToN, Dzyon, Sept. 12, 1879.

1 The implement agrees closely with that drawn in Dr. John Evans’s invaluable
work on Ancient Stone Implements, plate 1. fig. 17. —Hpir. Grou. Mac.

THE

GEOLOGICAL MAGAZINE.

NEW SERIES.) DECADE Tlk VOLES Mir

No. XI—NOVEMBER, 1879.

Ores Gas east Aes ole ele @ aie

—Ss—=—==

I.—On tHe Rocks or Brazit Woop, CHarnwoop Forest.
By 8S. Atiport, F.G.S.

N interesting discovery having just been made in consequence
wa of the examination of a single thin slice of rock, the following
communication is recommended to the attention of those geologists
who, to say the least, still fail to recognize the value of the micro-
scope in geological investigations.

A short time since, a friend in Leicester kindly sent me a speci-
men of the so-called gneiss from Brazil Wood; having prepared a
thin section and placed it under the microscope, I immediately re-
cognized an old acquaintance. It so closely resembled some of the
altered clay-slates which surround the Land’s End mass of granite,!
that I could not but regard it as another illustration of contact
metamorphism, and the following day was devoted to an examina-
tion of the locality in which it occurs.

Under the guidance of Mr. W. J. Harrison, of Leicester, who kindly
accompanied me, a small quarry in the wood was soon found, and in
a few minutes we were gratified by the discovery of a mass of granite
in contact with the “gneiss.” It is at present the only known
junction of the granite with the old sedimentary rocks, and proves
conclusively that, like the syenites of the district, the granite is also
an intrusive rock. Subsequently to our visit, Mr. Harrison has
discovered a bed of indurated banded slate overlying the gneiss; it
has a distinct cleavage, and contains numerous small garnets. This
slaty rock is interbedded with another which is rather more com-
pact, and has a less perfect cleavage; it also contains garnets.
The discovery of these slaty rocks is another point of interest, as
none have been previously observed to the east of the Swithland
slates. There can be no doubt that they belong to the Charnwood
series, and it will be seen that their altered condition may be fully
explained by their close proximity to the intrusive granite. As
the locality in which these discoveries have been made has been
frequently visited and described, it may afford satisfaction to previous
observers to learn that the granite just found has been exposed to
view by very recent quarrying of the rock.

The microscopic structure of the Mount Sorrel granite, and of

1 Described by me in Quart. Journ. Geol. Soc. 1876, vol. xxxii. p. 407.
DECADE I.—VOL. VI.—NO. XI. 31

482 §. Allport—Rocks of Brazil Wood, Charnwood Forest.

many other Charnwood rocks, has quite recently been admirably
described by Messrs. Hill and Bonney in a most valuable paper read
before the Geological Society ;! it will therefore suffice to give a
short account of two masses of granite and the altered sedimentary
rock.

In Brazil Wood a small conical hill of granite rises about 70
or 80 feet above the surface, and is separated from the knoll of
“‘oneiss”’ by an interval of 385 yards; this depression is occupied
by soil and vegetation, so that the junction of the two rocks cannot
be observed. On the occasion of our visit we found that recent
excavations had been made in the north-west corner of the quarry,
and had exposed to view a mass of granite which clearly forms
part of an intrusive vein. In one place there is a piece of the
gneiss completely inclosed in it, and it has thrown off smaller veins
which penetrate the gneiss in various directions. It will be seen,
then, that the beds of “gneiss” and slate are within 35 yards
(measured along the surface) of a considerable mass of granite, and
that they are also penetrated by granite veins; they have heen
subjected, therefore, to influences of the same kind which, in
Cornwall and elsewhere, have converted ordinary clay-slates into
crystalline micaceous schists.

Hornblendic Granite, Brazil Wood.—The rock forming the conical
hill is a rather fine-grained granite of dark colour; its constituents
are orthoclase, plagioclase, quartz, hornblende, biotite, magnetite,
and a few long slender prisms of a light brown colour not determined.
Although orthoclase predominates, the triclinic felspar is very abun-
dant, and occurs here and there in rather large crystals beautifully
striated. Both felspars are in a remarkably fresh state of preserva-
tion. Hornblende of a brownish-green colour is abundant, and is
frequently quite unaltered ; other crystals are however either partially
or completely altered to a green fibrous variety which closely
resembles uralitic pseudomorphs after augite. ‘The Biotite is occa-
sionally quite unchanged, and exhibits its usual optical characters ;
much of it has, however, been altered to a pale green substance,
which is less strongly dichroic. The rock is a good one for the
study of this mineral, as it may be seen in every stage of alteration.

Quartz is plentiful and contains many minute fluid cavities.

Granite intrusive in schist.—This rock is also rather fine-grained,
but contains many crystals of white felspar, which give it a some-
what porphyritic character. The constituents are orthoclase, plagio-
clase, quartz, biotite. Both felspars are well preserved; the orthoclase
exhibits many Carlsbad twins ; the plagioclase is comparatively clear,
and shows a very characteristic twin striation. The mica agrees in
every way with that described in the last-named rock.

The Quariz is clear, but contains numerous very minute cavities
disposed in parallel lines; it is worthy of remark that the direction
of these lines is the same in several adjacent grains of quartz. There
are a few small garnets near the junction with the schist, but none
have been observed at a greater distance than an inch. It is

1 Quart. Journ. Geol. Soc. 1877-78, vols. xxxili. and xxxiv.

S. Allport—Rocks of Brazil Wood, Charnwood Forest. 483

remarkable that hornblende should be absent, as it occurs in all the
other granites of the district.

The junction with the schist is interesting, as it presents two
varieties. In one specimen the junction is as sharp and distinct a
line, as in any of the Cornish examples described in the paper
already quoted; in others, it is not so well defined; the two rocks
have, in fact, been so completely blended together, that there is a
narrow band of such indefinite character, that one can hardly say
to a quarter of an inch where one begins and the other ends. A
thin slice shows under the microscope a narrow belt between normal
granite and normal schist, which consists almost exclusively of
imperfectly developed felspar crystals and mica. This felspathic
band is also marked by the presence of numerous minute black
grains of magnetite, which are here and there loosely aggregated in
clusters. The slice contains small garnets in both the granite and
schist.

Micaceous Schist—The rock into which the granite has been
intruded has been called a peculiar or unique gneiss; it is, in fact,
so peculiar that the term is inappropriate, as the rock has neither
the mineral composition nor the structure of gneiss; it contains no
recognizable felspar, and there is no true foliation. It is tough and
difficult to break, though rather more fissile in one direction than in
others; it is purplish grey in colour, and glitters with numerous
bright flakes of mica. The description of its microscopic structure
given by Professor Bonney in the paper already cited agrees in the
main with my own observations; in my slices there is, however,
so little of the “fine granular base,” that I should prefer to describe
it as a rock consisting almost entirely of two micas, with a few
grains of quartz, and numerous minute black grains (doubtless
magnetite) irregularly scattered through the mass; and, in addition,
there are occasional small patches of the fine granular substance
showing aggregate polarization; it occupies spaces between the
flakes of mica, but exhibits no crystalline forms. There are also
small flakes and streaks of clear red ferric oxide. The brown and
greenish-brown mica has all the characters of altered biotite. The
white mica is more abundant, and occurs here and there in rather
large flakes; in its brilliant chromatic polarization, and other
optical characters, it agrees perfectly with a white mica in the
altered clay-slate in contact with the granite of St. Michael’s Mount,
Cornwall. As it is not quite like muscovite, it may probably be
paragonite as suggested to me by Prof. Bonney; and this would
agree well with the analysis given by him at p. 224, as that mineral
contains from 386 to 40 per cent. of alumina. As regards structure,
there is no approach to foliation in any of my slices; the con-
stituents lie in all possible directions without any definite arrange-
ment. There is, however, a banded appearance in some specimens
caused by the crystallization of the two micas in rather larger plates
along roughly parallel lines. Near the junction with the granite
the schist contains many small garnets, which are interesting micro-
scopic objects.

484 8. Allport—Recks of Brazil Wood, Charnwood Forest.

It will be seen, then, that this schist is neither a gneiss nor a true
mica-schist; it belongs, in fact, to a group of rocks which have
not yet received distinctive names, although they are far from
uncommon. They occur round the skirts of granitic masses,
especially when the latter have broken through clay-slates. When
the prevailing constituent is mica, and they are more or less fissile
in one direction, they may for the present be called micaceous
schists, in order to distinguish them from normal mica-schists. This
Charnwood rock is singularly like some of the Devonian slates near
their junction with the Land’s End granite, it is not more highly
altered, and the present crystalline condition of both may clearly be
explained by the same cause, namely, their contact with large masses
of intrusive granite.

It may possibly be objected to this explanation that no such
amount of alteration has been produced in the sedimentary rocks of
the district by the intrusion of the syenite. It must not be under-
stood, however, that the syenite has produced no effect whatever.
But the two cases are not strictly analogous, and the following con-
siderations may probably suffice to remove the apparent difficulty. If
we regard the large masses of granite which occur among our
Paleozoic strata as crystalline products formed at the roots of old
volcanos, and subsequently exposed by denudation, it is evident that
the surrounding rocks must have been exposed to great heat and
intense metamorphic action during the entire period of volcanic
activity ; whereas rocks lying at a distance would receive no more
heat than that given out by any gradually cooling masses which
might be intruded among them. In the first case, the heat would
be far more intense and continuous; in fact, its duration might
probably be measured by an entire geological period; while in
the second, the heat would be far less at the commencement,
would be a gradually diminishing quantity, and the duration
of its efficient action might be reckoned by years. Sheets
of molten matter intruded among rocks at a distance of a very
few miles would everywhere meet with cold surfaces, and would
necessarily be cooled down at a comparatively rapid rate. It
has frequently been observed that granite has produced greater
alteration in contiguous strata than other intrusive rocks; but it is
also true that the amount of change is very unequal, sometimes being
comparatively slight. Such facts are quite in accordance with the
theory here advocated. Leaving out of consideration any inequality
due to differences of composition in the rocks attacked, it is probable
that prolonged volcanic action would vary greatly in intensity at
different times and in various directions. It might then easily occur
that the molten material of granite forcing its way through strata
towards the close of a volcanic period would produce far less effect
than in the earlier stages of activity; or the occasional transfer of
the volcanic source from point to point during periods of varying
length would also account for very considerable variations in the
amount of alteration produced.

The slaty rock overlying the micaceous schist is very fine grained,

Dr, O. Feistmantel—The Flora of E. Australia. 485

and may fairly be described as an indurated banded slate. Although
highly altered, the mass is less perfectly crystallized than in the
schist, and has more the character of a spotted slate; minute red
granules and flakes of brown mica being grouped in clusters and
straggling lines. A very thin slice examined with a quarter-inch
objective shows that the mass is in a crystalline state, and crowded
with minute flakes of white mica. This difference in the condition
of the two adjacent beds is common in the Cornish rocks, and is
doubtless due to original differences of composition or texture in the
sedimentary deposits. ~

II.—Notrs on THE Fosstn Frora or Eastern AUSTRALIA AND
TASMANIA.

By Dr. OrrokKar FEISTMANTEL,
of the Geological Survey of India, Calcutta.

HROUGH the kindness of the late Rev. W. B. Clarke, of Sydney,

I had the opportunity of examining two collections of fossil

plants from Australia, which that gentleman had kindly placed at my

disposal, together with explanatory notes, which he communicated
to me in private letters.

My own remarks upon the plants contained in the first collection
(which I obtained three years ago) were published in the 4th edition
of Mr. Clarke’s “Remarks on the Sedimentary Rocks of New
South Wales,” 1878, but they require a few corrections now. The
descriptions of the plants and figures were published by me in the
“ Paleontographica,” 1878-79.

The second collection sent by Mr. Clarke contained also numerous
new forms; besides this, Mr. C. 8. Wilkinson, another Australian
geologist, has recently contributed some specimens from the Hawkes-
bury beds (see further on), and as in the mean time Mr. Clarke’s
above-mentioned work was published, and also Mr. R. Htheridge’s
“Catalogue of Australian Fossils,” I was enabled to write a supple-
mental memoir (with several plates), on the fossil Flora in Australia.

Before it can, however, be published, I may be permitted to give
a short account of the present state of our knowledge of this Flora;
but the Paleeozoic and Mesozoic forms only are here taken into
consideration.

I shall first indicate the stratigraphical classification of the beds
containing the plants, based upon the observations of the most
trustworthy authors, and shall then proceed to a short systematic
discussion of the Flora (with addition of the few fish remains).

I. QUEENSLAND.

The best account of the Geology is found in Daintree: Geology
of Queensland, Quart. Journ. Geol. Soc. 1872, vol. xxvii. The
plants are described by Mr. W. Carruthers, F'.R.S.

The following classification is given :

1. Carbonaceous (Mesozoic strata) (see l.c. pp. 273, 283). Teeniop-
teris Coal-measures (.c. p. 288 and p. 325). Localities: Brisbane,
Tivoli Mines, near Ipswich, etc.

486 Dr. O. Feistmantel—The Flora of E. Australia.

Fossil plants, described by Mr. Carruthers (from Tivoli Mines) :
Pecopteris (Thinnfeldia) odontopteroides, Morr. (Fstm.); Toeniopteris
Daintreei, Carr.,’ Cyclopteris cuneata, Carr., Sphenopteris elongata,
Carr., Cardiocarpum australe, Carr.

In Mr. Clarke’s second collection there were several specimens
from near Talgai, and I determined the following: Teniopteris
Daintreei, M ‘Coy (the original form), Sagenopteris rhoifolia, Presl,
and an Otozamites* (comp. Mandelslohi, Kurr.). These beds are
equivalent with the Upper Mesozoic beds in New South Wales,
Victoria and Tasmania (see Daintree, l.c. p. 288).

2. Carboniferous (Paleozoic). — The northern Coal-fields in
Queensland (Daintree, l.c. pp. 273, 285, etc.).

Plants, generically only mentioned: Glossopteris, Schizopteris,
Pecopteris, etc.

Apparently on the horizon of the ‘‘ Lower Coal-measures” in
New South Wales.

3. Devonian (Daintree, l.c. pp. 273, 288-9), ete.

Localities : Mount Wyatt, Canoona and Broken River, etc.

Fossil Plants: Lepidodendron nothum, Ung. (Carr), Cyclostigma, sp.

Equivalent: The Devonian beds (Goonoo-Goonoo), with the same
plants in New South Wales.

II. New Soura WaAtEs.

For stratigraphical descriptions, see Strzelecki,* Dana,‘ Clarke,°
and Wilkinson. Plants were described by Morris (in Strzelecki,
l.c.), Dana (l.e.), M‘Coy (l.c.), and lately by myself.’ Some fishes
were described by Dana (l.c.), and Sir P. Egerton.®

1. Mesozoic (see Wilkinson, l.c. p. 127). Certain beds on the
Clarence River—with Teniopteris Daintreei, M‘Coy (the real form),
and Alethopteris australis, Morr.

These beds are to be classed with Mr. Daintree’s Teniopteris-beds
in Queensland. Other equivalents: Upper Mesozoic beds in
Victoria and Tasmania.

2. Wianamatta and Hawkesbury beds (see Clarke, l.c. pp. 70 and
72), classed under the heading “‘ Mesozoic, or Secondary formations”
(Clarke, lc. p. 68 e¢ seg.), and in another place as ‘“ Supra-
Carboniferous” (Clarke, l.c. p. 155).

Localities: Clark’s Hill, Paramatta, etc., Wianamatta beds;—
Cockatoo Island, Mt. Victoria, etc., Hawkesbury beds.

Fossils: Fishes and Plants.

Fishes partly heterocercal. Of plants I mention now Pecopteris
odontopteroides, Morr.,? only ; this species is not known lower than the

1 This seems to differ from M‘Coy’s original form from Victoria.

2 These two are new for Australia.

3 Physic. Descr. of N.S. Wales and Van Diemans Land, 1845.

4 United States Exploring Expedition, Geology, 1849.

> Ann. and Mag. Nat. Hist. vol. xx. ser. 2, 1847.

6 In Mines and Miner. Statistics of N.S. Wales, 1875.

7 Paleontographica, 1878-79.

8 On some Ichthyolites from New 8. Wales Q. J. G.S. vol. xx. 1864, p. 1.
9 Tclass it with Thinnfeldia.

Dr. O. Feistmantel—The Flora of FE. Australia. 487

Hawkesbury beds.” (I explain further on that the quotation of it in
the ‘‘ Newcastle beds ” is a mistake.)

3. Upper Paleozoic (Clarke, l.c. p. 27). Mr. Clarke distinguishes
several subdivisions (see l.c. p. 66).

a. Upper Coal-measures, or otherwise called Newcastle beds.

Localities: Black-man’s-swamp, Bowenfels, Guntawang, Mudgee,
Illawara, Mulubimba, Newcastle, Wollongong, ete.

Fossils: Urosthenes australis, Dan. (heterocercal).

Plants very frequent—mostly: Phyllotheca australis, Brong.,
Vertebraria (australis, M‘Coy), several species of Sphenopteris,
several species of Glossopteris (very numerous), one Gangamopteris,
Cycadeaceous leaves (Néggerathiopsis and Zeugophyllites), etc.

These Coal-beds were considered by Prof. M‘Coy as “ Oolitic,” and
Mr. R. Etheridge (l.c.) also classes them as “Mesozoic,” while
Mr. W. B. Clarke includes them under his heading ‘“ Paleozoic.”
I myself classed them under the heading “Strata above the
marine Fauna,” and my belief is, that they are younger than the
Lower Coal-measures (below the marine Fauna). -

b. Upper Marine Beds.

ce. Lower Coal-measures. Localities: Anvil Creek, Greta, Harper’s
Hill, Rix’s Creek, Stony Creek, etc., with Phyllotheca, several
species of Glossopteris,t and Néggerathiopsis. Also an Annularia.

Localities: Arowa, Port Stephens and Smith’s Creek, with “ Lower
Carboniferous plants,” as Calamites radiatus, Brong., Sphenophyllum
sp., Rhacopteris comp. inequilatera, Gopp., and several other
species; Archgopteris, Cyclostigma australe, Fstm., Lepidodendron
Volkmannianum, Sternb., Lep. Veltheimianum, Sternb., etc. Also
a Glossopteris.?

d. Lower Marine Beds.

4, Middle Paleozoic.—Devonian strata, of Goonoo-Goonoo, on the
Peel River and Back Creek diggings, on the Barrington River, with
Lepidodendron nothum, Ung. (Carr.), and Cyclostigma, sp.

Equivalents: The Devonian beds of Queensland, with the same
fossil plants.

III. Vicrorta.

For the stratigraphy and fossil Flora of the plant-bearing beds in
Victoria, we have to consult :— .

M‘Coy, Prodromus of a Paleontology of Victoria, Decades I.—-V.
(1874-77).

Brough Smyth, Reports of Progress of the Geol. Survey of
Victoria, 1876 et seq.

1. Upper Mesozoic (Bellarine beds).—Localities : Barrabool Hills,
Bellarine, Cape Paterson, Coleraine (Wannon River).

Fossils (plants): Phyllotheca australis, Brong., Alethopteris
australis, Morr., Teniopteris Daintree’, M‘Coy, and three species of
Zamites (partly Podozamites).

1 Several species described by myself.

2 This is on the authority of Prof. M‘Coy, who quotes from Arowa a Glossopteris
linearis, M-Coy, together with an Otopteris ovata, M‘Coy, which, however, is
a Rhacopteris, comp. ineguilatera, Gopp.

488 Dr. O. Feistmantel—The Flora of E. Australia.

Equivalents: Mesozoic beds in Queensland, in New South Wales
(and in Tasmania).

2. Lower Mesozoic beds (Bacchus Marsh sandstones), of Bacchus
Marsh (W.N.W. of Melbourne) ; also termed the Gangamopteris beds,
having yielded, as far as known at present, one genus of fossil plants
only, namely, Gangamopteris, M‘Coy, with four species: Gang.
angustifolia, longifolia, spatulata, and obliqua.

Gangamopteris is a genus allied to Glossopteris, having the same
netted venation—but no midrib. This circumstance, as well as the
occurrence of Gang. angustifolia, M‘Coy, in the Upper Coal-measures
(Newcastle beds) in New South Wales, brings these beds in a
certain relation to the Bacchus Marsh sandstones, which, however,
very likely are a little younger—but at all events not older than the
Neweastle beds. This is of great importance, as I believe that the
Bacchus Marsh sandstones, with their abundance of Gangamopteris,
represent, to a certain extent at least, the basal beds (the Talchir
beds) of the Indian Gondwana system, in which Gangamopteris is
also very numerous, in which case it would then be impossible to
correlate the Indian Coal-strata (Damuda Series) with the Lower
(Paleozoic) Coal-measures in Australia.

3. Carboniferous (Avon River sandstones), on the Avon River, in
Gippsland, with Lepidedendron australe, M‘Coy.

4. Devonian (Iguana Creek sandstones), on the Iguana Creek,
Gippsland, with Sphenopteris Iquanensis, M‘Coy, Aneimites Iguan-
ensis, M‘Coy, Archgopteris Howitti, M‘Coy, Cordaites australis,
M‘Coy.

IV. Tasmanta.

1. Mesozoic. — Count Strzelecki described certain beds on the
Spring Hills, Jerusalem’s Basin, containing Pecopteris (Alethopteris)
australis, Morr., Pecopteris odontopteroides, Morr., and Zeugophyllites
elongatus, Morr., as doubtfully dipping below other beds, with
Pachydomus globosus, from which it was, of course, afterwards
inferred that these plant-beds were Paleozoic. But Prof. M‘Coy*
clearly stated that Mr. Selwyn, the Director of the Victorian Geol.
Survey, who made an official Survey of the Tasmanian Coal-fields,
found the Pachydomus-beds in their natural position, under the
Coal-beds.

Moreover, Mr. Crepin, in his note? on Pecopieris odontopteroides
from the Jerusalem’s Basin in Tasmania, states, that on the same
specimens of shale together with this species occurred still another
fossil plant, Sphenopteris elongata, Carr., just as it was observed on
specimens from the Mesozoic beds in Queensland, which certainly
leaves little doubt as to the homotaxis of these beds in Tasmania,
when compared with those in Queensland, and consequently also in
New South Wales and in Victoria.

I shall now enumerate and shortly discuss the fossils
(including the few fishes), as we know them at present from the
Australian plant-bearing (coal-bearing) strata.

1 In Trans. R. Soc. of Victoria, vol. v. 1860, p. 104.
2 Bull. de l’Acad. Royale de Belgique, 1875, vol. xxxix. pp. 258-263.

Dr. O. Feistmantel—The Flora of £, Australia. 489

A. Anmmaura.— PISCEHS :—Urosthenes Australis, Dan., a hetero-
cercal fish, from the “Upper Coal-measure” (Newcastle beds) in
New South Wales.

Paleoniscus antipodeus, Egert., Wianamatta beds, N. 8S. W.;
heterocercal.

Cleithrolepis granulatus, Eg., Wianamatta and Hawkesbury beds,
N.S. W. (not apparently heterocercal).

Myriolepis Clarkei, Eg., Hawkesbury beds, N. S. W. (tail not
known).

B. Puanta.—1.—HQUISETACEA :—Genus Phyllotheca. This
genus appears in Australia in the ‘“ Lower Coal-measures” (below
the first marine Fauna), is most numerous in the Upper Coal-
measures (Newcastle beds), and is still found in the Upper
Mesozoic beds.

Otherwise the genus is known in Europe from Jurassic beds only
(Italy), in Siberia also from the Jura, and in India from the upper
portion of the Coal-beds.

Phyllotheca australis, Brong., Victoria (Upp. Mesoz.) and New South
Wales (Upp. Coal-m.). Jam not aware whether the form in the
Lower Coal-measures belongs to this species also, or to another’ one.

Genus Vertebraria, Royle —a plant of doubtful systemaiical
position—but most probably rhizome and rootlets of an Equisetaceous
plant—very likely of Pyllotheca. Known from the Upper Coal-
measures (Newcastle beds) in N. 8. W., and from the Indian Coal-
beds. The species is Vertebraria australis, M‘Coy.

Calamites radiatus, Brong. From the Lower Carboniferous beds,
Smith’s Creek, near Stroud, N. 8. Wales. (Figured by me for the
first time.)

Amnularia australis, Fstm. From the Lower Coal-measures at
Greta, N. 8. Wales. The only form of this genus in Australia.

Sphenophyllum sp. Fragmentary specimens from the Lower Car-
boniferous at Port Stephens, N. 8. Wales.

2.—FILICES :—Genus Sphenopteris—six species from the Upper
Coal-measures (Newcastle beds) in N. S. Wales (by Morris and
M‘Coy) ; one species from the Devonian in Victoria (Iguana Creek).

Sphenopteris elongata, Carr. (together with Pecopt. odontopteroides),
from the Mesozoic coal-strata in Queensland (Tivoli Mines), and
Tasmania (Jerusalem’s Basin).

Aneimites Iqguanensis, M‘Coy, Devonian, Iguana Creek, Victoria.

Archeopteris Howitti, M‘Coy, Devonian, Iguana Creek, Victoria.

Arch. Wilkinsoni, Fstm. Archeopteris sp., Lower Carboniferous,
Smith’s Creek (near Stroud), N. 8. Wales.

Genus Rhacopteris was rather numerous in the Lower Carboni-
ferous beds.

Rhacopteris, comp. inequilatera, Gopp., Smith’s Creek (Stroud),
N.S. Wales. Mr. W. B. Clarke sent also two specimens of M‘Coy’s
Otopteris ovata from Arowa; but after careful comparison, I arrived
at the conclusion that this species is identical with those forms
which I refer to the above species, so that the locality Arowa is also
to be included amongst the Lower Carboniferous localities.

490 Dr, O. Feistmantel—The Flora of E. Australia.

Rhacopteris intermedia, Fstm., Port Stephens; Rh. comp. Rémeri,
Fstm., Smith’s Creek (Stroud) ; Bh. septentrionalis, Fstm. ibidem.

Thinnfeldia (Pecopteris) odontopteroides, Morr. Prof. Morris
described in Strzelecki’s work certain ferns from the Jerusalem’s
Basin in Tasmania as Pecopteris odontopteroides; it was found in
those beds, which I mentioned before, as doubtfully dipping below
the Pachydomus beds. Prof. M‘Coy referred it to Gleichenites. Mr.
Carruthers described and figured it again as Pecopteris odontopteroides
from Queensland.’ Recently, Mr. Crepin (l.c.) discussed and figured
several specimens of this species, also from Tasmania; they agree
very well with those from Queensland. Relying apparently upon
Count Strzelecki’s description, he considered the Jerusalem’s Basin as
Carboniferous, and took the plant to be an Odontopteris, comparing
it with Prof. Geinitz’s Odontopteris alpina. But, at the same time,
he made the important statement, which I mentioned before, about
the association of this plant with Sphenopteris elongata in Tasmania.
In my papers on the Australian Flora, I gave figures of specimens
from Queensland, Tasmania, and from the Wianamatta and Hawkes-
bury beds in N. S. Wales. A careful examination of these specimens
from the different localities showed them to belong to one and the
same form, and I think that, from reasons which I have given
elsewhere, it belongs to Thinnfeldia.

It is known from the Upper Mesozoic beds in Queensland and
Tasmania, and from the Wianamatta-Hawkesbury beds in New
South Wales—but not from the “ Upper Coal-measures ” (Newcastle
beds) in N. 8. Wales. The quotation of this species from the New-
castle beds in my paper was a mistake, caused by my considering
the locality ‘“Clark’s Hill,” in New South Wales, as belonging to
the Upper Coal-measures, while it belongs to the Wianamatta beds.

Odontopteris microphylla, M‘Coy, Wianamatta beds (and not New-
castle beds).

Cyclopteris cuneata, Carr., Upper Mesozoic, Queensland.

Alethopteris (Pecopteris) australis, Morr. At present known from
the Upper Mesozoic beds only (Clarence River, New South Wales ;
Victoria; Tasmania); but not from the Newcastle beds in N. 8S.
Wales.

Pecopteris? tenuifolia, M‘Coy, and Gleichenia dubia, Fstm., from
the Wianamatta beds, N. 8S. Wales.

Teniopteris (Angiopteridium) Daintreei, M‘Coy, Upper Mesozoic
beds in Queensland (Talgai) ; New 8. Wales (Clarence River), and
Victoria.

Macroteniopteris Wianamatte, Fstm., Wianamatta beds.

Genus Glossopteris, Brong. This genus, as far as is known at
present, begins, in Australia, in the Lower Carboniferous beds, and is
most frequent in the “ Upper Coal-measures” of New South Wales.
In India it is found in the Coal-measures (Talchir and Damuda
Series), in the Panchet group, and in the Jabalpur group (Jura).
In Africa in the Karoo beds.

‘ His specimens differ, however, somewhat from Morris's original type—but later

quite similar forms were also found in the Jerusalem’s Basin, Tasmania; Morris’s
specimens were altogether badly preserved.

Dr. O. Feistmantel—The Frora of E. Australia. . 491

Prof. Trautschold described one species from the Russian Jura.

Glossopt. Browniana, Brong., Gl. elegans, Fstm., Gl. primeva, F'stm.,
Gl. Clarkei, Fstm., Gl. linearis, M‘Coy, from the Lower Coal-
measures (Greta, Stony Creek), New South Wales, and the Lower
Carboniferous (Arowa), N.S. W.

Glossopt. Browniana, Brong., Gl. ampla, Dan., Gl. reticulum, Dan.,
Gl. elongata, Dan., Gl. cordata, Dan., Gl. Teeniopteroides, Fstm., Gl.
Wilkinsoni, Fstm., Gl. parallela, Fstm., from the Newcastle beds
(Upper Coal-measures), New South Wales.

Gangamopteris obliqua, Gang. spatulata, and G. angustifolia,
M‘Coy, from the Bacchus Marsh sandstones (Lower Mesozoic),
Victoria. The importance of these forms, was pointed out before,
when the Bacchus Marsh sandstones were mentioned.

_ Gangamopteris angustifolia, M‘Coy, from the Newcastle beds (Upper
Coal-measures).

Sagenopteris rhoifolia, Presl, from the Talgai diggings, Queensland.

Sagenopt. Tasmanica, Fstm., from the Mesozoic beds in Tasmania.

3.—LYCOPODIACE :—Lepidodendron nothum, Ung. (Carr.),
Devonian, Queensland (Mt. Wyatt, Broken River, etc.) ; New South
Wales (Goonoo-Goonoo on the Peel River, Back Creek diggings
on the Barrington River).

Lepidodendron Veltheimianum, Sternb., and Volkmannianum, Sternb.,
Lower Carboniferous, Smith’s Creek (near Stroud), New South Wales.
The Rev. W. B. Clarke’s specimen of Lepid. rimosum, Sternb., of which
he sent a photograph, seems to belong to Lep. Veltheimianum, Sternb.

Lepidodendron dichotomum (?), Sternb., Lower Carboniferous,
Smith’s Creek (Stroud), New South Wales.

Cyclostigma australe, Fstm., from the Lower Carboniferous, Smith’s
Creek (near Stroud), New South Wales. This plant, together with
the others from the same locality, appeared to me to indicate Prof.
Heer’s “ Ursastufe.”

4.—CYCADEACE :— Otozamites (comp. Mandels/ohi,’ Kurr.).—
The first Otozamites from Australia, Talgai diggings, Queensland
(Upper Mesozoic Coal-beds).

Genus Néggerathiopsis, Fstm.—I established this generic name
(1878) for those leaves which, in India and Australia, were described
as Néggerathia. When examining, last year, the Indian leaves, I
found that they differed from Néggerathia, and named them Noggera-
thiopsis; finding afterwards that the Australian leaves also belong
to this genus, the same name is now used for them.

Similar leaves were described from the Altai by Prof. Goppert,
also with the generic name Noéggerathia, and the formation was
described as Permian. Prof. Schmalhausen (Kiev) has, however,
recently stated that this Flora from the Altai, and another Flora on
the Upper Tunguska (which at first was also considered Carbon-
iferous), are, in fact, of a Jurassic age; the said Néggerathia was
placed by him in a new genus, Rhiptozamites; it appears that
Noggerathiopsis and Rhiptozamites are closely allied genera, probably
identical.

1 This is probably a misprint for Mendelsohnii—Epiv. Grou. Mac.

492 Dr. H. Woodward—On Fossil Shells, ete., from Sumatra.

Noggerathiopsis prisca, Fstm., Lower Coal-measures, Greta, New
South Wales.

Négg. spatulata, Dan., and N. media, Dan., Upper Coal-measures
(Newcastle beds), New South Wales.

Zeugophyllites elongatus, Morr.—At first described by Prof. Morris,
from Tasmania, from the doubtful beds, which, however, from the
evidence of Thinnfeldia (Pecopteris) odontopteroides, Morr., sp.
(F'stm.), and Sphenopteris elongata, Carr., appear to be Mesozoic.

Later, also found in New South Wales (in the Upper Coal-
measures, Newcastle beds).

Cordaites australis, M‘Coy, Devonian, Iguana Creek, Victoria.

Zamites (Podoz.) ellipticus, M‘Coy, Zam. (Podoz.) Barklyi, M‘Coy.

Zam. longifolius, M‘Coy, Upper Mesozoic beds in Victoria.

CONIFER! :—Brachyphyllum australe, Fstm. Upper Coal-
measures (Newcastle beds), N. S. Wales.

Cardiocarpum australe, Carr., Upper Mesozoic, Queensland (Tivoli
Mines).

The most important deductions are:

1. The doubtful strata in Tasmania (Jerusalem’s Basin) are, from
a palzontological point of view, equivalent with the Upper (Meso-
zoic) Coal-strata in Queensland, consequently also in N.S. Wales
and Victoria.

2. Phyllotheca, which in Europe and Siberia is Jurassic, appears
in Australia already in Paleozoic beds, and is found still in the
Upper Mesozoic beds in Victoria.

3. Glossopteris appears in Australia in Paleozoic beds (for the
first time with Lower Carboniferous plants), is most frequent in
the Upper Coal-measures (Newcastle beds), continues in India and
Russia into Jurassic beds.

4. Néggerathiopsis begins in Australia in Paleeozoic beds, and has
a closely allied representative (Rhiptozamites) in the Jurassic beds
in Siberia.

5. The Lower Carboniferous Flora of Port Stephens and Smith’s
Creek (Stroud), New South Wales, is of great importance for the
knowledge of the geographical distribution of the Lower Carbon-
iferous Flora.

II].—Furtuer Nores on a Courection oF Fosstn SHELLS, ETC.,
FROM SUMATRA (OBTAINED BY M. VerBeuk, DirEcTOR OF THE
GroLoGicaL Survey or THE West Coast, Sumatra). Parr III.

By Henry Woopwarp, LL.D., F.R.S., etc. ;
of the British Museum.

(PLATES XII. ann XIII.)

28. Conus, sp. (cast). Pl. XII. Fig. 1.

This cast indicates a subfusiform shell with a somewhat elongated
conical spire, but the apex is imperfect: volutions contiguous and
convex ; the body-whorl gradually tapering to a somewhat acute

base.
1 Continued from the October Number, p. 444.

Dr. H. Woodward—On Fossil Shells, etc., from Sumatra. 493

Dimensions :—Length about 3 inches; width of broadest part
nearly 12 inch. Number of whorls 6-8.

This cone in its general form is evidently near to the Conus Noe
of Brocchi (Conchiologia Fossile Subapennina, 1814, tom. ii. p. 2938,
tab. ili. fig. 3); but as it is only preserved to us in the form of a cast,
it is impossible to do more than point out approximately its specific
relations. .

Formation :—Obtained by M. Verbeek from the bed marked (5),
consisting of Tertiary Coral limestone, including internal casts of
Gasteropods and Conchifers, etc. (Verbeek, Grou. Mac. 1877, p. 444).

Locality :—Government of the West Coast of Sumatra.

29. Conus substriatellus (cast), H. Woodw. PI. XII. Fig. 2.

This cast—which approaches most nearly to Conus striatellus of
H. M. Jenkins (Quart. Journ. Geol. Soc. 1863, vol. xx. p. 54, pl. vii.
figs. 3a, 3b) from Java, and particularly with the figures of a cone
referred to that species by Dr. K. Martin, in his work “ Die Tertiar-
schichten auf Java” (Univalves), Leyden, 1879, p. 9, tab. i. figs.
2 and 2a—represents a conical ventricose shell; the axis being short
in proportion to its breadth; the whorls narrow, volutions 7-8 in
number, apex depressed, aperture narrow, slightly dilated at the base.

Dimensions :—Height of shell 40 mm.; breadth of shell at widest
part 28 mm.

The figure given by Mr. Jenkins is evidently that of a young
individual, whereas our cast is that of an adult shell; Dr. Martin’s
figures represent three stages of growth, and his Fig. 2 most nearly
corresponds with M. Verbeek’s specimen.

It must, however, be borne in mind that the Javan fossils are
represented by specimens having the shell preserved, whereas the
Sumatran fossil is only a cast. I have therefore preferred to name it
C. substriatellus.

Formation and Locality:—From the bed marked (5), found with
the preceding species.

30. Cyprea subelongata, H. Woodw. Pl. XII. Fig. 3.

This species is represented by four examples, two of which have
the shell partially preserved, which was tolerably thick ; in general
form it is somewhat amygdaloidal or ovato-elongate; the spire is
slightly visible, but depressed; the aperture is narrow at the upper
part, and somewhat dilated from the middle towards the base; there
are well-marked indications of crenulations on the inner lip.

Dimensions: — Length of figured specimen 33 wmillimétres;
breadth of shell 214 mm. The three other specimens referred to
this species are somewhat smaller.

This shell closely resembles, in general form, the so-called Ovula
elongata of D’Archiac (Descrip. des Animaux Fossiles de l’Inde,
1854, p. 331, pl. xxxili. fig. 9 and 9a) from the Hala Chain; but
as the Sumatran fossil affords distinct evidence of crenulations on
the body-whorl, as above stated (although, unfortunately, our artist
has omitted to indicate them in Fig. 3), we have not ventured to
refer it to that species. Possibly—as the Indian shell is so like a
Cyprea in general form—the artist of M. D’Archiac’s plate may

494 Dr. H, Woodward—On Fossil Shelis, etc., from Sumatra.

have in a similar manner overlooked the indications of crenulations
on the body-whorl.

We have, however, considered it safer to refer this Cyprea to a
new species, and have named it C. subelongata.

Formation and Locality :—Obtained with the preceding species.

31. Cerithium, sp. (casts of). Pl. XII. Fig. 4.

Our figure represents a cast of four somewhat convex volutions,
very gradually increasing in size, and exhibiting traces of longi-
tudinal ribs. Two other casts, probably belonging to the same
species, indicate a considerably larger form. From their general
character they no doubt indicate a species of Cerithium; but from
their state of preservation, it is difficult to assign them to any
particular species. They resemble somewhat the casts figured by
D’Archiac (plate xxvii. fig. 18 and 14, p. 308, op. cit.) from the
Nummulitic formation of India. These casts of Cerithium do not,
however, exhibit any external indications of ribs. They might have
represented the interior of Cerithium Montis-Sele, K. Martin, plate
xi. fig. 1 (Die Tertiirschichten auf Java, Leiden, 1879).

Formation and Locality :—Found with the preceding species.

02. Turbo (Borneensis? Bottger). Pl. XII. Fig. 5.

This is represented by the cast of a turbinated shell showing
about four rapidly increasing very convex volutions, separated by
a deep suture; portions of the shell remaining apparently indicate a
thick and smooth test. Base umbilicated.

Dimensions :—Height of shell 36 mm.; breadth 86 mm. Thick-
ness of body-whorl 19 mm. It seems probable that our specimen is
closely allied to, if not actually identical with, the Turbo Borneensis
of Dr. O. Béttger (Paleontographica: Beitrage zur Naturgeschichte
der Vorwelt, Supplement III. Lief. I. 1875, 4to. p. 11, table i.
fig. 3, a, b, c, and 4), obtained from the Nummulitic Limestone of
Pengaron, Borneo, and also from the Tertiary formation of Sumatra.

This cast may also be compared with the Turbo Pendjabensis,
D’Archiac and Haime (pl. xxvii. fig. 2, op. cit.), from the Tertiary
Calcareous Marl, Punjaub, India.

Formation and Locality :—Found with the preceding species in
bed marked (5), by M. Verbeek.

08. Turbo, sp. (not figured).

There are two other casts of a much larger form, probably
belonging to the same genus, indicating a more discoidal shell, the
body-whorl being much expanded, and the spire more depressed,
the shell having also fewer whorls and a larger umbilical cavity.

Dimensions :—Height 14 inch; breadth 24 inches.

Formation and Locality :—Found with the preceding.

34, Phusianella Oweni, D’Archiac, 1854. Pl. XII. Fig. 6.

An oval elongated shell composed of 6-7 somewhat convex
volutions, that increase very regularly and are separated by a well-
marked suture. The aperture is subovate and the shell is not
umbilicated; body-whorl equalling in length the height of the spire.

Dimensions :—Actual height of shell 833 mm. (Height of shell with
the spire restored, about 41 mm.) Breadth of body-whorl 25 mm.

Dr. H. Woodward—On Fossil Shells, etc.. from Sumatra, 495

This species is represented by two casts which agree closely with
the Phasianella Oweni, D’Arch. (pl. xxvii. fig. 3, 3a., D’Archiac
and Haime, Animaux Fossiles de l’Inde, p. 298), from the Nummu-
litic Limestone of the Hala Chain, and the compact Chalk-marl of
the Salt-range, Punjaub.

It presents also some slight resemblance to the figures given by
Dr. O. Béottger of his Buccinum Pengaronense (Paleeontographica :
Beitriige zur Natur. der Vorwelt. Suppt. III. Lief. I. 1875, taf. ii.
fig. lla., b. p. 16), from the Nummulitic Limestone of Pengaron,
Borneo, and the Eocene formation of Sumatra; but the form of the
aperture differs.

It might also be compared with Dr. K. Martin’s Natica Bandon-
gensis, K. Martin, p. 82, tab. xii. fig. 15 (but not fig. 16), Die
Tertiirschichten auf Java, 4to. 1879, from the Tertiary beds of
Java.

Formation and Locality:—The same as that of the preceding
species.

35. Trochus, sp. (casts of). Pl. XII. Fig. 7.

This species is represented by three casts. Shell trochiform, with
six flattened volutions gradually increasing in size with a distinct
suture, and ornamented with from 6 to 7 longitudinal ribs, broader
than the spaces which separate them: base expanded, umbilicus
deep and conical.

This shell presents some points of resemblance to the Trochus
radiatus, Gmel. (see Dr. K. Martin, Die Tertiirschichten auf Java,
1879, Lief. I. p. 72, tab. xi. fig. 16); but the outer surface not
being preserved in our specimens, it cannot be compared satisfac-
torily with this or allied forms.

Formation and Locality :—The same as the preceding species.

36. Prenaster, sp. Pl. XII. Fig. 8a, 8b.

The diagram of an Echinoderm on our Plate (Figs. 8a, b.) was
transmitted with the collection to Prof. T. Rupert Jones, F.R.S., and
submitted by him to Dr. Wright, F.R.S. His note has since been
mislaid; the diagram-figure on the Plate only serves therefore to
record its occurrence in the Sumatran Tertiaries.

In a letter lately received from Dr. Wright, he observes :—“ In the
absence of the specimen, I cannot venture to give a definite opinion
about M. Verbeek’s Echinoderm. If my memory serves me, when I
first saw the diagram, I concluded that it was a Miocene Urchin differing
from any that had been figured as coming from Java, and it reminded
me of a form I had described from Malta belonging to the genus
Prenaster,! which comprehends ovoid Urchins with inflated tests,
having the ambulacral summit very excentric; the petaloid ambu-
lacra slightly depressed, nearly level with the surface, and very
divergent; often almost perpendicular; the anteal sulcus is

1 This observation is extremely interesting, as M. Verbeek had already noticed in
Grou. Maa. 1877, p. 444, under head of bed 5, the occurrence of ‘“ casts of Gastero-
pods and Conchifers, together with Hchinide, comparable with the Eocene forms
Prenaster alpinus, Desor, and Pertaster sub-globosus, Desor,’ which Dr. Wright's
observation tends to confirm.

496 Dr. H. Woodward—On Fossil Shells, etc., from Sumatra.

nearly obsolete. The form I figured as Prenaster excentricus re-
sembles the diagram-sketch on your Plate more than any other
species that occurs to me now, so that your Sumatran Hchinoderm
may be an allied form belonging to the genus Prenaster. More than
this I cannot say.”

37. Conus Niasensis, H. Woodw. PI. XIII. Fig. 1.

Shell conical-elongate, concentrically-striated, strie wider apart
towards the base of shell and rather more strongly accentuated ;
spire conical, apex obtuse, showing about seven volutions, concen-
trically striated and crenulated, the outer margins ornamented with
a series of flattened tubercles ; aperture narrow.

Dimensions :—Height 15 millimétres; breadth at widest part of
shell 65 mm.

The ornamentation of the upper portion of the whorls around the
apex presents a close agreement with Conus acutangulus, Chemn., as
figured by K. Martin from Java (Die Tertiirschichten auf Java, p. 11,
tab. i. fig. 2) ; but the apex of this species is more regularly conical
and the shell itself is more robust. |

Dr. Bottger also figures a cone under the name of Conus gracili-
spira, Bottg., from Pengaron, Borneo (p. 18, taf. ii. fig. 18, 14 a,
and b, Paleontographica, 1875) ; but the apex is too truncated, and
the specimen, being a cast, cannot be compared certainly with our
fossil.

Formation :—Tertiary Grey Marl.

Locality :—Hiligara, Island of Nias, Government of the West Coast
of Sumatra.

38. Oliva mustelina? Lamarck. PI. XIII. Fig. 2 a, 6.

The specimen figured consists only of the body-whorl, the apex
being wanting; the shell is much eroded, and it would be difficult
of identification, but it presents a great similarity to the Oliva
mustelina, Lamarck, which is commonly met with on the coast of
Japan, the Philippines, and Singapore.

The following is the description of Oliva mustelina (from
Sowerby’s Thesaurus Conchyliorum (1871), part xxx. p. 22).

“Shell oblong-cylindrical, subtruncated at both ends, thick; colour
greyish yellow, marked with obliquely-longitudinal undulating
lines; spire short, broad, suture acute, punctated ; columella plicated
throughout, terminating posteriorly in a thick elevated callus,
having a few very strongly-oblique plice in front; aperture violet
within ; lip thick, elevated behind, interior and exterior smooth.”

Formation :—(Sub-fossil ?)

Locality :—Government of the West Coast of Sumatra.

39. Oliva pseudoaustralis, H. Woodw. Pl. XIII. Fig. 3.

This is a smooth ovate shell with a conical spire, and having a
strongly ribbed columella which is thickened towards the base.
It appears to be allied to the Oliva australis of Duclos, but it is
rather shorter, and has a more conical spire.

This species may also be compared with the Oliva Javana, K.
Martin, (op. cit.) tab. iti, fig. 8 and 8a, but the spire of this latter
Species is more acute.

GE OL.MAG.1879.

mpsad

aasnere:
gan eeseseees
\ at?

wp. 43%
SASS RAEI

ti thetexe

C.L .Griesbach delet lith,

Dit, CADn, Me ViOI Wal. Pi, Ae Xa

ae

West,New mae b Co.tmp.

Sumatran Tertiary Fossils.

GEOL.MAG.1879. DECADE II.VOL.Vi.PLATE Xm.

C.L Griesbach del.et lith.. West, Newman b& Co. imp.

Sumatran Tertiary Shells &c.

te

Dr. H. Woodward—On Fossil Shells, etc., from Sumatra. 497

Dimensions :—Length 20 mm. ; greatest breadth 10 mm.

Formation :—From Grey Tertiary Marl-clay.

Locality :—Island of Nias, Government of the West Coast of
Sumatra.

40. Oliva pupeformis, H. Woodw. PI. XIII. Fig. 4.

This is a more attenuated and cylindrical shell than the preceding,
with a produced and pointed spire, the columella having only two
folds upon it. The aperture of the shell is narrow. Although
resembling several small living species, yet upon close comparison
it appears to be distinct.

Dimensions :—Height 18 mm.; breadth 7 mm.

In general proportions it agrees very nearly with Sowerby’s
Oliva pupa, from Soomrow, Cutch (Trans. Geol. Soc. 1840, vol. v.
2nd series, pl. xxvi. fig. 32).

Formation :—From Grey Tertiary Marl-clay.

Locality :—Island of Nias, Government of the West Coast of
Sumatra.

41. Ancillaria, sp. Pl. XIII. Fig. 5.

This is a narrow cylindrical shell, with moderately wide aperture ;
columella with eight folds; marked by a broad and smooth band at
the base ; apex subacute.

Dimensions :—Height 14 mm.; breadth 6 mm.

Formation and Locality :—The same as preceding species.

42. Terebellum, sp. (cast). Pl. XIII. Fig. 6.

This narrow cylindrical form is destitute of any test, but from its
general characters may very well be compared with the Terebellum
subulatum, Chemnitz, a species distributed in the Indian Ocean, the
Philippines, and the neighbouring seas of China, ete. The spire of
the Sumatran fossil, however, is shorter, the sutures are less oblique,
and the body-whorl near the spire is rather more tumid than in the
recent form. (See Sowerby’s Thesaurus Conchyliorum, vol. iii. 1866,
pl. 218.)

Dimensions :—Height 20 mm.; breadth 5 mm.

Formation :—In light-coloured Tertiary Clay-marl.

Locality :—Island of Nias, Government of West Coast of Sumatra.

43 Cyprea, sp. (cast). Pl. XIII. Fig. 8a, b.

This is a smooth and polished cast of a short and very ovate and
tumid Cypreea, which was probably not unlike the Cyprea Reevit,
from Swan River. The spire seems to have been exserted ; outer lip
broad and marked by small but numerous teeth; the inner lip was
also denticulated, especially towards the anterior end ; the aperture is
narrow near the centre, but expands somewhat towards each extremity.

Dimensions :—Length of shell 31 mm.; breadth 21 mm.

Formation :—In light-coloured Tertiary Clay-marl.

Locality :—Government of West Coast of Sumatra.

44. Cyprea nucleus, Linn. Pl. XIII. Figs. 7a and 6.

Shell (in living state) white, or reddish-yellow ; ovate; produced
at the extremities, elevated dorsally, irregularly tuberculate, with
faint traces of ribs between the tubercles; base rounded, denticula-
tions numerous, the intermediate ones diverging at margin of aperture,

DECADE II.—VOL. VI.—NO. XI. 32

498 Dr. H. Woodward—On Fossil Shells, etc., from Sumatra.

terminal ones distinct, divaricating; aperture narrow, dorsal cicatrix
rather broad.

My colleague, Mr. Edgar Smith, having compared this fossil shell
with the recent examples in the Collection, remarks : “‘ Undoubtedly
this is the Cyprea nucleus, Linn., whose geographical range extends
from the Mauritius to the Philippines, Borneo, and the islands of the
Pacific.”

Dimensions :—Length of shell 15 mm.; breadth 94 mm.; height
7 mm.

Formation :—In bluish Clay-marl (Miocene ?), Tertiary.

Locality :—Island of Nias, Government of West Coast of Sumatra.

45. Cyprea erosa, Linn. Pl. XIII. Fig. 10 a, 6.

Shell ovate-oblong, solid, somewhat depressed, colour (in living
specimens) golden-yellow on the back, scattered over very commonly
with minute white spots, more obscurely marked with a few chestnut
spots ; sides somewhat expanded and thickened, white at the
extremities, marked by reflexed chestnut bands, and close-set crenu-
lations; painted with a large dark-brown quadrate spot in the centre;
base somewhat flattened, white, sometimes marked by puncta and
converging lines of reddish chestnut. Aperture somewhat broad,
expanded in front, bluish within; dentations 14 to 19 in number,
short on the columella, prolonged on the lip; lip at the marginal
terminations crenulated.

There is no doubt about this species, although subject to great
variations. It occurs widely distributed, being recorded living from
the Mauritius, Mozambique, Ceylon, Seychelles, Andaman Islands,
North Australia, New Guinea, and several islands in the Pacific.

Dimensions of Fossil :—-Length of shell 31 mm.; breadth 20 mm.;
height 15 mm.

Formation :—In light-coloured Clay-marl (Tertiary).

Locality :—Government of West Coast of Sumatra.

46. Bulla (Hydatina) crebristriata (cast), H. Woodw. Pl. XIII.
Fig. 9 a, b.

The cast of this shell shows it to have been roundly oval, umbili-
cated, the spire retuse; the surface closely and finely striated both
longitudinally and transversely. Aperture wide near the umbilicus,
and decreasing to one-half the width near the spire.

Dimensions :—Height of shell 24 mm.; greatest breadth 23 mm.

The nearest analogue to our fossil is to be found in the Bulla
physis of Linnzus from the Mauritius (see Sowerby’s Thesaur.
Conch. 1855, vol. ii. p. 565, pl. cxx. fig. 9), but the aperture is
wider in the recent shell. 2. physis is also similarly striated. —

It may also be compared with the Bulla vexillum, Chemnitz
(Sowerby, Thesaur. Conch. loc. cit. pl. exx. figs. 12-14), from Ceylon.

Being a cast, however, it is difficult to relegate it to any existing
species.

Formation :—In light-coloured Tertiary Clay-marl.

Locality :—Government of the West Coast of Sumatra.

47. Pyrazus palustris, Linn. Pl. XIII. Fig. 11.

Shell large, pyramidal (colour brown in living examples), whorls

Dr. H. Woodward—On Fossil Shells, ete., from Sumatra. 499

straight, longitudinally plaited, and spirally distantly sulcated,
interstices flat, aperture (broken in fossil) subquadrate, canal short,
outer lip produced in front of the canal below. (The outer lip of
the fossil shell is, however, broken.) Operculum not preserved—but
in living shell spiral, with the whorls fluted.

Habitat:— This specimen is identical with the recent Pyrazus
palustris, of Linnzus (see Reeve’s Conchologia Iconica, vol. xv. genus
Pyrazus, May, 1865). A very common species found in salt-marshes
at the mouths of rivers, in the Eastern Archipelago, in Ceylon, in
North Australia, and other localities.

Dimensions of fossil: —Height 4 inches; greatest breadth 1} inches.

Formation :—(Subfossil ?)

Locality :—Government of the West Coast of Sumatra.

48. Terebra subacuminata, H. Woodw. PI. XII. Fig. 12.

Shell elongated, turriculated, very tapering, solid, with simple
closely-united and numerous whorls, only a little rounded, and with
but slightly indented sutures. Hach whorl, at a distance of one-
third of its breadth below the suture, is circumscribed by a single
indented line, or fold,’ parallel to the suture, and equally as clearly
marked, which follows the course of the whorls of the shell from
the apex to the aperture.

The shell is ornamented with numerous fine obliquely-curving
parallel raised lines, the curvature of which is reversed above the
indented line or fold. Aperture (broken) very small in proportion
to the shell, elongated and deeply emarginated at the base.
Columella simple, curved, with a single fold near the base. Nine
whorls of our Sumatran fossil only are preserved, giving a length
of 24 inches. If the spire were restored, the length would have
been about 4 inches.

This specimen approaches very closely to many recent forms of
Terebra, but it differs from each in some minor points of form, orna-
mentation, or growth. It presents considerable affinity to Terebra
duplicata, a species common to China and Singapore, but the costz
are much more strongly marked than in the fossil. Terebra
Lamarckii, from Zanzibar, may also be compared with it, but the
ornamentation in the living shell is too coarse. In Terebra sene-
galensis and in T. pertusa the parallel strize agree better with our
fossil, but in the former, the rate of increase of the shell is greater ;
whilst in the latter the ornamentation follows a different curve.

Its nearest fossil analogue appears to be found in the Terebra
acuminata, Borson (Saggio di Oritt. Piem. Mem. della Accad. di
Torino. t. xxv. p. 224, t. 1, fig. 17; and Hornes, Die Fossilen Mollus-
ken des Tertiaer-Beckens von Wien, 1856, Bd. i. p. 180, taf. 11,
figs. 22, 23, 24, a, 6), but the cincture or fold is less distinct and
nearer to the suture than in M. Verbeek’s specimen. The ornamental
lines or strize agree very nearly with 7. acuminata.

1 This indentation, or fold, reminds one of the similarly situated line or fold
marking the position of the filled up slit, or notch, near the suture in the lip of
Pleurotoma ; there is no slit in the lip of Zerebra, but in the recent Terebra
duplicata the lip is slightly indented.

500 E. Wilson—Age of the Pennine Chain.

I have ventured, however, to consider this fossil as distinct, and
have named it Terebra subacuminata.

Formation :—From Tertiary Grey Marl-clay.

Locality :—Government of the West Coast of Sumatra.

49. Celosmilia? Pl. XIII. Fig. 13.

An imperfectly preserved Coral with the habit of growth of a
Coelosmilia.

EXPLANATION OF PLATES XII. AND XIII.

Prats XII.
Fic. 1. Conus, sp. (cast), Tertiary Coral Limestone, Government of the West
Coast of Sumatra.

» 2. Conus substriatellus, H. Woodw., Gov. of the West Coast of Sumatra.
» 8. Cyprea subelongata, H. Woodw. i ws
» 4. Cerithium, sp. (cast) is Je
» 95. Turbo (Borneensis ? Bottger) 3 i
» 6. Phasianella Oweni, D’ Archiac on SS
», 7. Trochus, sp. (cast) 3 i
8

. Prenaster, sp. a

a upper, 4 under side (Drawn from a Diagram.)
Prats XIII.
Fic. 1. Conus Niasensis, H. Woodw., Tertiary Grey Marl, Hiligara, Island of Nias, ~
Government of the West Coast of Sumatra.

2a,b. Oliva mustelina ? Lamarck (subfossil?), Government of West Coast of
Sumatra.

. Oliva pseudoaustralis, H. Woodw., Tertiary Grey Marl, Government of

West Coast of Sumatra.

. Oliva pupaformis, H. Woodw., Government of West Coast of Sumatra.

. Ancillaria, sp. on ie

. Terebellum, sp. (cast). In light-coloured Tertiary Clay-marl, Ditto.

. Cyprea nucleus, Linn. Miocene Clay-marl, Island of Nias. -

fae sw Sp. (cast) ” i 9
55 . Bulla crebristriata, H. Woodw., Ditto, Government of W. Coast of Sumatra.
Me . Cyprea erosa, Linn. . Ss
Pe . Pyrazus palustris, Linn. (subfossil ?) ss

3

4

i)

6

7

be Sb
9

10

11 99
12. Terebra subacuminata, H. Woodw., Grey Tertiary Marl. #

», 18. Celosmilia ? sp. 59
(To be continued in our neat Number.)

TV.—Tue Ace or THE “ PENNINE CHAIN.”
By E. Wison, F.G.S.

HE “Pennine Chain” is the name (restored about fifty years
ago by Conybeare and Phillips from the ‘Alpes Penini” of
the Romans) for that hilly tract of country that stretches from the
borders of Scotland on the North to the centre of Derbyshire on the
South. This important range possesses the structure of a great,
though complex, anticlinal, the result of a meridional movement of
upheaval that took place at a remote period in the physical history
of our island. This axis of elevation, which ranges a little west of
North through North Derbyshire and West Yorkshire, throws off the
Coal-measures of Yorkshire and Derbyshire on the one side, and
those of Lancashire and North Staffordshire on the other, with a
steeper dip on the West, and a gentler inclination on the Hast. The
maximum of this upheaval is attained in North Derbyshire, where
a dome-shaped mass of Mountain Limestone has been exposed at
the surface at an altitude of 1500 feet above the sea.

E. Wilson—Age of the Pennine Chain. 501

In many ways this prominent feature in the physical structure
of our island is worthy of notice. It has had a great deal to do
with the distribution of the mineral wealth of the North of England,
and if, as one result of that elevation, a vast amount of valuable
Coal-measures have been swept away, still many mineral substances
of great economic value have been brought within our reach, that
would otherwise have been hopelessly buried in the bowels of the
earth; while we are at the same time indebted to this ancient
earth-movement for that bold and beautiful scenery, moorland and
mountain, scar and dale, that characterizes the Pennine Chain in its
range through the counties of Derby and York. It is not, however,
from an economical or an esthetic, but from a physical point of
view, that I propose to consider this ancient mountain chain. In
particular I seek to arrive at its age.

The age of the Pennine Chain has long been a matter of doubt and
debate among physical geologists. While all are agreed that the
upraising of this great anticlinal took place before the Triassic epoch,
the question still remains whether it was or was not also Pre-Per-
mian. In 1861, Prof. Hull stated his belief that the Pennine Chain
was elevated into land during the deposition of the earlier Permian
strata.1 In 1868, however, the learned Professor had come to the
conclusion that this earliest upheaval took place between the close
of the Permian period and the commencement of the Trias, “that it
belonged to that period of general stratigraphical disturbance which
marked the close of the Paleozoic age.’* As a rule, geologists
appear to have been content to follow in the wake of so high an
authority.? Several years ago my local rock studies in the adjoining
county of Nottingham led me to believe that the Pennine Chain
was older and not younger than the Magnesian Limestone, and sub-
sequent observations have tended to fortify me in that opinion. Let
us first, however, examine what is to be said in favour of the
opposite view.

The chief, if not the only item cited by Prof. Hull in support of
a Post-Permian upheaval, is the supposed identity in origin (in
Lancashire, Cheshire, and Staffordshire) of two important lines of
fracture respectively known as the Anticlinal Fault and the
Red Rock Fault.* The Anticlinal Fault and the Red Rock
Fault run meridionally (approximately) parallel with each other
and with the Pennine Chain. Professor Hull, therefore, concludes
that all three were the results of a common movement: The Anti-
clinal Fault near Leck passes under Bunter (conglomerate) with-
out faulting that rock, therefore this common movement was
Pre-Triassic ; the Red Rock Fault near Stockport faults Permians,
consequently this common movement was Post-Permian. But,

1 Quart. Journ. Geol. Soc. vol. xvi. p. 63.

2 Quart. Journ. Geol. Soc. vol. xxiv. p. 323. Triassic and Permian Rocks, p.
111. Coal-fields of Great Britain, 1873, p. 468.

3 Grou. Mac. 1872, p. 889; 1879, p. 110; West Yorkshire, p. 9; President’s
Address to Geological Section, British Association Meeting, 1879.

* Quart. Journ. Geol. Soc. vol. xxiv. p. 323.

502 E. Wilson—Age of the Pennine Chain.

the same Red Rock Fault elsewhere, viz. near Macclesfield and
Congleton, displaces Upper Keuper rocks. To get over this dif-
ficulty, then, Professor Hull assumes that the Red Rock Fault
is the result of two independent displacements, the first Pre-
Permian, the second Post-Triassic. To this style of reasoning I
object: in the first place, that it is unphilosophical to base an argu-
ment on assumptions; in the next place, that on the hypothesis of
two movements for the Red Rock Fault, the failure of participation
in the second of such movements by the Anticlinal Fault shows that
faults may run parallel to one another and to great anticlinals with-
out being contemporaneous; and lastly, that on the assumption that
the Red Rock Fault, the Anticlinal Fault and the Pennine Chain
were coéval, and that the Red Rock Fault has undergone a second
displacement, there is yet no evidence to show that it was not the
second of such movements that for the first time faulted the Permians
near Stockport and that the earlier displacement of the Red Rock Fault
was, with the Anticlinal Fault and the Pennine Chain, Pre-Permian.
Having now disposed of the theory of a Post-Permian origin of the
Pennine Chain, I proceed to the consideration of the evidence I
have been able to gather together in favour of a Pre-Permian
upheaval. .

I. The great Yorkshire Coal-basin was evidently formed before
the commencement of the Permian period, for all along the eastern
borders of the exposed portion of the Coal-field, wherever the Coal-
measure strata are seen to pass under the Magnesian Limestone, the
easterly dip of the Coal-measures is more or less evidently greater
than that of the Permians. Now, as the North and South axis of
the Coal-field runs parallel with the Pennine axis, we may safely
assume that these had a common origin. Consequently the Pennine
Chain is also Pre-Permian. In some magnificent sections, recently
opened out by railway extension at Kimberley, near Nottingham,
the Middle Coal-measures may be seen dipping north-east at angles
varying from 5° to 10° or 15° beneath Permians (Marl-slate, and
Lower Magnesian Limestone) that dip east at about 1°. In con-
sequence of this greater inclination of the Coal-measures, any par-
ticular seam of Coal is found at constantly increasing depths going
east. The “Top Hard” or Barnsley seam, for instance, which, at
Kimberley, is only 284 feet below the Permians, is 630 feet beneath
the same at Cinderhill, two miles to the east. Again, this Coal at
Clowne is €90 feet deep, but at Steetley, which lies about three
miles further east, it is 1590 feet down to it. “All along the edge
of the escarpment of the Magnesian Limestone,” says Prof. Hull,
‘‘and for a short distance beyond, in Notts and Derbyshire, as far
North as Rotherham, the Coal-seams are found to dip eastward at
a greater angle than the Limestone itself, which (with the Lower
Red Sandstone) rests unconformably on the Coal-measures.” !

IJ. The Marl-slates, slowly but surely, alternate in a westerly
direction as if approaching a margin. In some recent unsuccessful

1 Coal-fields of Great Britain, 8rd edition, 1873, p. 245.

E. Wilson—Age of the Pennine Chain. 508

explorations for Coal at South Scarle, Lincolnshire, the Permian
rocks proved to be much more developed than in West Notts. At
Searle the Lower Magnesian Limestone and Marl-slates together
amount to a thickness of 219 feet, at Bestwood to 95 feet, and at
Kimberley to from 538 to 33 feet only, while west of the Erewash no
Permians are found, and Triassic rocks repose directly on various
members of the Carboniferous formation.

III. Coincidently with this attenuation the Magnesian Limestone
becomes intermingled with sedimentary materials on the west. The
Lower Magnesian Limestone, though no thicker on the east than
on the west, is a very different rock. Under Lincolnshire, it is a pure
cream-coloured compact limestone; while in West Notts it is instead
a coarse granular dolomite, interleaved with seams of marl and
micaceous sand, and may become gritty, and even conglomeratic.
These phenomena would seem to indicate the shallowing of the
waters, and the vicinity of land on the west in Zechstein times.

IV. Mountain Limestone pebbles are said to have been found in
Permian rocks on the east, and certainly occur in Permian breccias
west of the Pennine Chain. The basement Permian breccia of
Notts is largely composed of the debris of Coal-measure rocks.
Such fragmental materials could only have been derived from the
denudation of a central tract of land composed of Carboniferous
rocks in Permian times, and clearly indicate not only that the
Pennine Chain had come into existence in Pre-Permian times, but
also that denudation had supervened to such an extent, that rocks so
low down as the Mountain Limestone were then laid bare in that
range.

V. Though the Bunter Sandstone of West Notts and East Derby-
shire contains numerous fragments of Carboniferous rocks,—Lime-
stone, chert, and Millstone Grit,—no fragments of Permian rocks are
to be found in that or any other member of the Trias. This fact,
though negative, and therefore inconclusive, would seem to show
that the Permians were formed subsequently to the elevation of the
Pennine Chain, and consequently were not uplifted so as to be
exposed to denudation on the flanks of that range in Triassic times.

VI. The absence of Permian outliers, at any distance west of the
Magnesian Limestone escarpment, taken in conjunction with the
absence of fragments of Permian rocks in the Triassic rocks of the
neighbourhood, indicates that the original margin of the Magnesian
Limestone waters did not lie very far west of the present escarpment.

VII. There is no similarity either in character, thickness, or
succession of the Permians on the opposite sides of the Pennine
Chain. In Lancashire and Cheshire the Lower Permians are re-
presented, according to the Government Surveyors, by a mass of
unfossiliferous red sandstone, estimated to attain a maximum of
1500 feet (near Stockport), while the Upper Permians of South
Lancashire consist of from 100 to 250 feet of red calcareous marls
with thin bands of earthy limestone and gypsum.’

1 See Geological Survey Memoirs of the district.

504. F. T. 8S. Houghton—Olivine Gabbro from Oornwall.

Omitting from consideration the “Lower Permian Sandstone,” the
true horizon of which seems doubtful, we still find a very dissimilar
grouping of the Permians on the two sides of the Pennine Chain.
In Lancashire and Cheshire we look in vain for any deposit answer-
ing to the highly characteristic Marl-slates of the North-east of
England, nor do we find any considerable masses of dolomite com-
parable with those of Yorkshire and Durham. From Notts to
Northumberland the Marl-slates, Magnesian Limestone, and Upper
Marls are severally distributed, but on passing across England from
Notts to Lancashire—a much less horizontal distance—we find that
we cannot positively recognize one of these members of the Zechstein.
This marked dissimilarity is in part at least to be accounted for by
the presence of an intervening land-barrier—the Pennine Chain.

We may then, I think, without hesitation, conclude that the
elevation of the Pennine Chain took place before the commencement
of the Permian epoch, or at any rate prior to the deposition of the
Permian rocks of the North of England.

I have already called attention to some of the results of the
elevation of this important range. Its influence on the distribution
of the rock masses of the neighbourhood, which began in early
Permian times, persisted into the Keuper epoch. Having in Pre-
Permian times acquired the elevation and stability of an arch, this
great and complex anticlinal still maintains that relative superiority
to the surrounding country that has justly earned for it the epithet
of the “ Backbone of England.” Though marine denudation has
planed away its top, while subaérial decay has cut deeply into its
framework, the great hardness and extreme durability of its more
axial rocks has enabled this ancient anticlinal to resist these agents
of destruction so successfully that it still forms a broad elevated
tract of country, while rearing its loftier peaks from two to three
thousand feet above the sea.

V.—Nor# on An Oxivine Gappro (FoRELLENSTEIN) FRoM CoRNWALL.

By F. T. 8. Hoveuron, B.A.,
Scholar of St. John’s College, Cambridge.

N Quart. Journ. Geol. Soc. 1877, pp. 906, e¢ seg., Prof. Bonney
describes a Gabbro from Coverack, on the eastern coast of the
Lizard peninsula, which he remarks bears, macroscopically and
microscopically, a close resemblance to the Forellenstein of Volpers-
dorf. In order to investigate further the nature of the rock, I made,
at his suggestion, an analysis of it. The piece selected had proved
on microscopic examination to be almost free from pyroxenic con-
stituents. No. I. was decomposed by fusion with alkalies. No. II.
by hydrochloric acid. The residue in this case was white, and
probably consisted of undecomposed felspar, showing that at any
rate it was not all anorthite. No. III. is an analysis of the Volpers-
dorf rock quoted by Zirkel (Lehrb. der Petrog. ii. 139).

F. T. 8. Houyhton— Olivine Gabbro from Cornwall. 508

I. Il. JO.
i Winter vascteeess) tees oe 4580" Weea siees BG 65g G00 8°30
Silica este oes aves AOR Oug te eye eg EAs occas coe meme S,
Alumina Sno ede ee) weclhynices PINAY Bae coc 13°56
Ferric Oxide Homes UST y eit asoember 0286) Sets 2°19
Herrous) Oxidem seceweerorOl cee eee Sian veel a ees 6°19

ITE) Ae og cod EPA 5 cn SPUD) eco cor 6-72
WERIGSE). wees) “back TUS Co geae Gao MUIR eaS” cae 9 PE
Potash Boa Mec EIOLO4 es Moset vase OB dd. onc 0°83*
SOO 55 ecg deo PRE og coe 2S) cog cae 0:96
Residue soc cod ws SPY eco =

INOOOB. cog ane! MOIST = oh Soo UMBRO)

* This proportion of Potash and Soda hardly agrees with that given in the
analysis of the felspar (2).

From a comparison of these analyses, the two rocks would appear,
at first sight, to be of very different natures; but on examining the
results, it is seen that, whereas the Cornish rock contains only 38 per
cent. of olivine, the Volpersdorf has 45 per cent.; a difference in
proportion quite observable under the microscope.

There being this great difference in the proportion of the minerals,
it remained to determine the composition of the felspar. A sufficient
quantity, freed as much as possible from olivine, was submitted to
analysis with the result detailed in No. I. No. II. is an analysis of the
felspar of the Volpersdorf rock quoted by Zirkel (loc. cit.).

I. II.
Wiateticens sercieec meu Or) Uae-reumiacoh ee lcO,
SHUEIEE, G60 cba. (coo FED an con © ID
ANION, 455 ap BEB sca
Iron Oxides soo OB) co 00 1 56
TFG p00 coo coo PNG dc NO
WIEST, G55 con WED oa can 0-09

TROIS vacg Gao. ono OES bade “ced 0:78
Soda Ges ar SEU SOW ese oes 2-10

99-51 100°42
Oxygen ratios 1:3:5°7 1:2°7:4°5
This gives a composition for the felspar of the Cornish rock of
11 {A1,0,. CaO. (Si0z)2} + 3 {Al0,. Naz. (Si0,)5}
Anorthite Albite

which is an excess of two molecules of anorthite over that necessary
to form labradorite. The felspar thus proves to be—like that of
the Volpersdorf rock—not a true anorthite, but possibly a decom-
posed labradorite, which has lost some of its alkalies ; this being
suggested by a slight excess of silicate of alumina over and above
that required by the formula above given. Vom Rath suggests a
similar origin for the felspar of the German Forellenstein. We
may, therefore, without hesitation, place the Cornish rock among the
Forellensteins—adding another locality to the few already known
for this rock.

506 Prof. John Milne—On the Form of Volcanos.

ViI.—Furruer Notes upon toe Form or Voucanos.!

By Joun Mitne, F.G.S.,
Professor of Geology and Mineralogy, Imperial College of Engineering, Yedo, Japan.

URING the last summer I made a OLED from Yedo as far
north as the southern end of Kamschatka.? As when upon this

trip I saw and visited many volcanos in Yezo and the Kuriles, I
venture to offer a few remarks in addition to those which I have
already expressed upon the form of this interesting class of mountains.

In the Grotogican Magazine, August, 1878, I endeavoured to
show that the sides of all regularly- formed volcanos are not straight
slopes, but have a curvature which in form is logarithmic. This form,
it was pointed out, was that which would be assumed by any heap of
loose materials such as those out of which we may suppose a volcano
to be built. From this it was inferred that these regular volcanos
were natural forms, and not forms which had been produced by the
wearing away of one part and the bolstering up of another, as we
find spoken of in treatises on volcanos and physical geology. It was
also pointed out that from the external form of a mountain it might
be possible to calculate the dimension of any internal core.

To illustrate these views, I used several profiles traced from a
series of photographs of two volcanos.

From the volcanos which I have subsequently seen in Yezo, the
Kuriles and South Kamschatka, I see that my views were very
poorly illustrated, and had I the means when there of obtaining other
profiles, I feel that the case stated in the above- mentioned paper
might be more satisfactorily demonstrated. In looking at the illus-
trations which I have given, it will be observed that some of my
curves, although generally logarithmic in character, are by no means
absolutely so. By comparing the curves of each profile it will be
seen that the discrepancy in the fourth column is greatly due to not
having had any true method of fixing an axis, and it would have
been better to have taken the mean of each pair of ordinates and
treated the two sides of a profile as a single curve.

Another point to be observed is, that if the logarithmic curve drawn
for purposes of comparison had been placed on profile No. 4 rather
than upon profile No. 2, it would have been seen to have a nearer
coincidence with the curvature of the mountain.

Notwithstanding these misleading illustrations, the logarithmic
character of the curvature is clearly to be recognized.

Similarity in curvature.— When in the Kuriles, I saw many beauti-
fully formed volcanos, and these, almost one and all, showed a slope
which, so far as I could judge, was similar to that upon the mountains
which have been shown to have a logarithmic curvature. Unfortu-
nately I was unable to take an outline of these mountains which,
for purposes of geometrical measurement, would be of any value.
All that I can say is that these contours appeared to have a general

1 For my previous paper, ‘‘On the Form of Volcanos,’ see Guox. Mac, 1878,

Decade II. Vol. V. pp. 337—345, Plate IX.
2 See Grou. Mac. 1879, Decade II. Vol. VI. p. 337, Pl. IX.

Prof. John Mitne—On the Form of Volcanos. 507

character, and that this character was similar to what I have
already described.

One confirmation of this identity I find by reference to my sketches.
Another confirmation was obtained whilst taking the angular distance
between several of these mountains by means of a sextant held
horizontally. By this I was enabled to carry the reflected image of
one mountain and place it in juxtaposition with the image of its
neighbour, the latter being seen directly. Whenever this was done
the similarity in the curvature of the two mountains was very
striking. Experiments of this sort were made at several places.
The first were made along the north-west shore of Paramushir,
where there are a number of extremely well-formed mountains.
The only one of these which bears a name is Mount Fuss. Another
well-formed mountain is the Island of Alaid.

Curvature of hills, piles of debris, ete.—Curvatures which appear
to be similar to those we see upon the sides of volcanos are to be
seen upon the slopes of many hills. These are especially noticeable
upon the surface of debris lying beneath steep scarps. These curves
are, however, seldom to be observed. The reason is that it is only
rarely we can obtain their profile view. In looking at a range
of hills, we usually see them curving downwards towards the low
ground, and if we ascend them we usually remark that the climb-
ing becomes more difficult the higher we go up. When the slope
of hills like these can be looked at from the end of the range
instead of from the front, a peculiar curvature will be observed, and
this is not unlike the logarithmic curvature of volcanos. Profile
views of curvatures are strikingly exhibited upon the sides of
Hakodate Head. This is a solitary mountain at the south end of
Yezo, upon which the town of Hakodate is built. Its position and
its shape make it very like Gibraltar. It consists of a mass of
trachytie rock covered with alluvium. Near the top of the mountain,
which is more than 1,100 feet in height, the alluvium is thin, but
near the base it is many feet in thickness.

From its nature it is to a large extent evidently the result of the
degradation of the rocks on which it rests. Materials from high
levels have been constantly rolling to low levels, larger stones
rolling farther than smaller ones, and the consequence has been that
from the base to near the summit long curvatures have been
formed. As the mountain is a solitary one, these curvatures can be
seen in profile, and their form is remarkably like that exhibited
by volcanos.

Experiments upon the form of heaps.—In order to determine the
form which a heap of loose material assumes, I made several ex-
periments by allowing a stream of sand and gravel to fall through
a funnel upon a level floor. The heaps which were produced were
as follows :—

1. Fine sand.—This fell from a height of about 3 feet until it formed a heap
27 inches high. The sides appeared to be straight, and they had a slope of 31° 30’.

2. Fine gravel.—This fell until it formed a heap 21 inches high. ‘The sides of
this were also straight, and the slope was 31° 30’.

508 Prof. John Milne—On the Form of Volcanos.

3. Fine gravel mixed with sand.—This fell to form a heap 26 inches high.
Round the base a slight curvature was observed.

4. A mass of sannal mixed with sand was formed by throwing it against a board,
on which a sheet of paper had been stretched. Here also a slight curvature was
obtained, which was marked off upon the paper.

Taking these experiments as a whole, it will be observed that I
did not obtain much evidence in favour of my views. In experi-
ments number 8 and 4, where slight curvatures were obtained, it
must be noticed that I was using a material the particles of which
were of different sizes. Had the experiments been upon a larger
scale, ] think the results might have been more satisfactory. Also,
if the sand and gravel, instead of falling in a column, had fallen as
a rain upon the heap, and the heap had subsequently been left some
months to settle, the curvatures would in all probability have been
more decided.

By allowing water to fall for some time as a light shower over
the heaps, I endeavoured to imitate the effects of denudation. Although
many of the showers were infinitely greater in proportion to the size
of my heaps than the showers of rain which fall upon a mountain are
to the mountain and its materials, the dragging of materials to the
base was not sufficient to produce any observable curvature. This
would seem to show that it is not denudation of a kind like this
to which we must turn in order to find an explanation for the
curvatures of volcanos.

In looking at any large heap of materials, the component parts of
which are of different sizes, a curvature will, I think, be always
observed.

A short time ago I observed this upon a number of heaps of gravel,
which, for purposes of measurement, had been piled in large rect-
angular cases. These cases had subsequently been removed, and
the heaps left to themselves. First, the sides had fallen downwards
and outwards, the larger stones rolling the farthest, and a curvature
had been produced. Since the first general form had been assumed,
a similar action had been slowly going on under the combined
influence of gravity, and, to a slight extent, the weather.

These heaps were about 3 feet high. Their curvature was best
observed by standing at a distance, and then stooping until you
brought your eye on a level with the heap.

As the result of these experiments and observations, IT would
classify the principal causes which tend to affect the form of a
volcano under the following three heads :—

Ist. Causes tending to give a volcano its characteristic curvature.

a. The tendency of a aire naeeene heap under the influence of its own weight
to spread outwards at the base. This would tend to give a logarithmic curvature.

b. The tendency during the building up of a mountain of “ihe larger particles to
roll farther than the smaller ones. This will also depend on the specific gravity, the
porosity, etc., of the particles thrown out during an eruption. We may regard this
action as extremely rapid denudation carried on by gravity.

e. Denudation by weather and gravity. This tends to efface a mountain by
digging away materials from the top and making its steepness less and less. At the
bottom of the mountain, where denudation is also going on but at a slower rate than
it takes place near the top, these materials are deposited and spread out.

Prof. John Milne—On the Form of Volcanos. 509

It must here be noticed that on a volcano, and especially near its
summit, material is seldom to be found lying at an angle which is
less than its angle of repose. Of this fact I have convinced myself
that it is the case upon the slopes of many volcanos; 1st, by ob-
serving that the materials on any particular slope were uniform in
size; and, 2nd, that if upon such a slope I dropped a piece of
material larger than those of which the slope was made, it com-
menced to roll towards a lower level.

If this be granted, then the levelling action of denudation cannot
have played a very important part in giving the form to a volcano;
otherwise we should expect to find materials lying at angles less
than that which a heap of them would naturally exhibit. However,
denudation must have had some effect, and as this effect will pro-
bably have been nearly the same on all sides of the mountain, it
will not materially affect its regularity.

2nd. Causes principally affecting the regularity of a mountain.

About these I have written before. Briefly they are as follows :—

1. Position of the crater. If this is central, we should expect the
mountain to be regular.

2. Lateral and parasitic craters will tend to destroy the regularity.

3. Direction of the wind during an eruption.

4. Nature of the eruptions. If these have been paroxysmal, and
have blown away portions of a crater,—if lava has flowed on one
side more than on another, etc., we have causes tending to destroy
regularity.

3rd. Causes partially affecting the form of a volcano, but prin-
cipally its height.

The movement of the strata upon which a volcano is built.

As has been pointed out by Mr. Mallet, the weight of a volcano
may tend to crush the strata on which it rests so as to form a saucer-
shaped depression. Round the bottom of the mountain the ground
may be caused to rise.

Evisceration or honeycombing beneath a mountain may also cause
a depression to take place.

I would also suggest that because it is probable that during the
period of activity, which is a length of time to be measured by
many years, the rocks beneath the protective covering which has
been built above them must become extremely hot, and the mountain
will have an augmented height due to the expansion of the beds
upon which it rests. When the activity becomes less intense, con-
traction sets in, and a sinking may take place.

To form any accurate idea of the effect which may be produced
by any action of this description is very difficult. If we think of
the small amount of heat which passes through the bricks of a fur-
nace, we might suppose that the conduction of heat from the heated
nucleus of a volcano into the surrounding rocks would be too small
to produce any appreciable effect, whilst if we think of the rapidity
with which heat travels through a glass into which we pour hot
water, we might arrive at opposite conclusions. The rate at which

510 Prof. John Milne—-On the Form of Volcanos.

heat flows through rocks is a subject of which we have little or no
personal experience, and about which we cannot therefore form any
prima facie opinion.

To give some idea of what actually must take place, the case of
an infinite mass of rock heated from a plane surface of constant
temperature has been taken as the simplest case for which calcula-
tions can be made. The temperature of the plane is taken at 2000°
Fahr.; and the time during which conduction has taken place at
2000 years, the object being to find the temperature at various
distances from the hot plane in the surrounding rock. We might
consider the hot surface to be spherical or a vertical cylinder, but
the simple case of a plane surface kept constantly at a high tempera-
ture is easier to calculate, and at the same time sufficiently illustrates
my idea.

If the isothermal surfaces are parallel planes, and x is measured
at right angles to these planes, then an element of rock of unit area
and thickness dx, if it is at a temperature v at the time ¢, receives
heat when increasing in temperature dv ;—

C.D. dv. dx in the time di, where C.D. is the capacity for heat of
the rock.

But through one face it receives heat by conduction in the time
dt, and through the other face it loses by conduction, and the dif-
ference is—

K being the conductivity, and hence—

dv dv
dv K. dv

di GOD. dz?
The initial conditions are that where x=0, the temperature v is

constant ; when =0, then v=0 everywhere except where s=0, and
the above equation leads under these circumstances to the result—

d ==
— ee — g € 4 kt
dat VTkt.
This equation cannot be integrated in finite terms, but the follow-
d
ing table of values for — = has been calculated; ¢ being 2000

years, K as equal to 400 in Foot, Year, Fahrenheit units,1 and V,

the temperature of the melted rocks which fill the plane fissure,
being at least 2000° Fahr.

1 For this value I am indebted to the experiments of Professors Perry and Ayrton,
‘On the Conductivity of Stone,’ Phil. Mag. 1878.

Prof. John Milne—On the Form of Volcanos. 511

x wx

in feet. dz
OPPS OE RT aay 1:2500
SOON WF Fee eeat Ree 1°1560
TUN Sy ie Tae vetoes ey ee 1:0690
THOX OX) tii sy a ea 0:9140
ZO OO tere een rcs, res kaos 0°3580
SOOORM PE Hires eT bE Oat 0:0751
SOOO a Wy rte sash Cscoreets 0:0005

A curve was drawn with these numbers as co-ordinates, and it is
evident that the area of this curve up to any value of aw is the
difference between the temperature at that point and 2000° Fahr.
In this way the following table showing the temperature at various
distances from the hot surface was obtained.

Rise of Temperature Produced in

Distance from Hot Surface in feet. 2000 Years.

0 2000° Fahr.
GOON MEY ey Ln Rt 7b We
SOOM MM Ante enn ie, ieee tl pic's 10622
ONO RT ae eee a 862).
MOO. ee thts vevtten cfeccou: Litsteal cease 667° ,,
LOO when hince OEE SA Wt RAP
OO OMIM RR Ntsc in ee Gin’ AGES
US OOP abr ibn crore eto sed By.
AOU 7 RN NSE a SMS MALO
22 OOM pee een yore iS
QAO ORM ehh hic Aen en Came Sh ime: 12, Oza
PATO Aa Ses Mice rank LANL cs: Q2P ti me
DSO On| wiceae cae cheb tatty le 642)
SOO Opera! aun us mesg eel ce AP,

On looking at these results, it will be observed that they are far
greater than might have been anticipated. Perhaps it may be
objected that the conditions which have been taken as compared
with those which occur in nature have been overrated. I think quite
differently.

First, 2000 years is hardly an overestimate of the length of time
during which a volcano may remain in activity. Vesuvius is recorded
as having erupted in the year a.p. 79, and it still continues in activity.
Before that time it was a recognized volcano, but how many
thousands of years it may have been in existence we do not know.
In Ischia and neighbouring places there were eruptions 400 years
previously. All that we can say is that, as evidenced by the large
amount of ejected matter which was in existence before the eruption
of 79, it was even then a mountain of some antiquity.

Secondly, a temperature of 2000° Fahr. for molten matter, such as
that about which we speak, is an estimate which is extremely low.

Sir William Thomson, in his calculations relative to the age of
the earth, takes the temperature of molten rocks from 7000° to 10,000°
Fahr., but these temperatures are purposely taken as large as possible.
Bischof, in his “ Geologie,” p. 98, takes as the melting point of lava
2250 °Fahr.

When speaking of this temperature, it must be remembered that it
is not supposed to exist in molten rocks near the surface, but in

012 Prof. John Miine—On the Form of Volcanos.

rocks beneath the base of a volcano, which at their central parts are
buried beneath a mass of material equal to the height of the volcano,
which will usually be many thousands of feet. And just as the
water at the bottom of an Icelandic geyser is hotter than that near
the surface, so we may expect the rocks of which we speak to have
an augmented temperature.

Another condition is that of the heated plane. From what is
known of the internal structure of a volcano, a central column termi-
nating in a crater above, and provided with many branches ramifying
through the mass of the volcano, would be a truer representation of
the actual conditions than those which have been taken. These
ramifications would probably be continuous into the ground beneath,
and deep down it is not at all unlikely that they converge towards a
highly heated nucleus from which all the molten matter emanates.
If these are anything like the conditions beneath a volcano, and I
see no reasons why they should not be, then the plate of heated
matter is but a very feeble representative of the heating surfaces
which actually exist.

The only point about which I think any doubt can be expressed
will be relative to the length of time during which such a heating
surface may be imagined to retain a constant temperature. Whilst
a volcano is in actual activity, the temperature deep down beneath
the crater probably remains constant far above 2000° Fahr., and —
during the intervals which fall between the eruptions, whilst the
volcano is only perhaps giving out wreaths of vapour, it does
not seem at all improbable that, if it were possible to take the
temperature some thousands of feet below the crater from which
the steam is issuing, we should also find a temperature far above
2000° Fahr.

It must be also remembered that the heating effect which takes
place is over and above any original temperature which the rocks
may be supposed to have had before any volcanic eruption took place.

On the whole, therefore, I think the conditions of the given case
have by no means been overestimated, but rather, were we able to
take the conditions which actually exist, we should find temperatures
far above 2000° Fahr., acting over periods longer than 2000 years, and,
what is more important, instead of heat being given off from a single
plane, it would be found to be given off from a multitude of sur-
faces, and the effect dependent on these temperatures enormously
exaggerated.

Confining one’s self to the example which has been taken, it now
only remains for us to consider what these effects might be.

In vol. ii. p. 288, Lyell, in his “ Principles of Geology,” says,
“Tt was ascertained that fine-grained granite expanded with 1° Fahr.
at the rate of -000004825 ; white crystalline marble -000005668 ;
and red sandstone ‘000009532, or about twice as much as granite.
Now, according to this law of expansion, a mass of sandstone a mile
in thickness, which should have its temperature raised 200° Fah.,
would lift a superimposed layer of rock to the height of ten feet
above its former level. But suppose a part of the earth’s crust fifty

Prof. John Milne—On the Form of Volcanos. 513

miles in thickness, and equally expansible, to have its temperature
raised 600° or 800°, this might produce an elevation of between
1,000 and 1,500 feet. The cooling of the same mass might after-
wards cause the overlying rocks to sink down again and resume
their original position.”

In the case we have been considering, we see that temperatures
are produced far greater than those spoken of by Lyell, and conse-
quently the effect will be correspondingly augmented.

But the effect produced by simple expansion is not all. The rocks
distant from the heating surface will offer resistance to the expanding
mass which lies between them, and cause it to elevate itself towards
the centre, the action being not unlike that which is exhibited by
the iron arch of a bridge when expanding on a hot day. In the
bridge the rise is only perhaps one or two inches. To us this is
almost imperceptible. But if the same fact could be communicated to
a creature no larger than a fly which lived upon the bridge, it would
seem to be immense. Similarly if we could only learn the height to
which a volcano is elevated by the heat developed during its period
of activity, we might be equally astonished ; for, when reckoned in
feet, it is probably very great.

So far we have only considered the heat beneath a volcano as an
agent producing expansion, and consequently elevation. If we
imagine the heat to be much greater than that which I have taken,
it is possible that in certain tracts it might produce fusion or at least
plasticity, the result of which might be that the pressing downwards
of the superincumbent weight would produce depression. However,
if such conditions have any existence, I fancy that their extent is
limited; and anyhow, outside the plastic area there will be expansion
and consequent elevation. ;

Results of elevation or depression.—As elevation or depression
beneath a volcano, such as those of which I have been speaking, will,
in all probability, take place so slowly, the effect cannot be expected
to materially alter the form of a volcano, degrading influence tending
to produce a natural form compensating sufficiently rapidly to out-
weigh the influence of these motions. ‘The effect which will be pro-
duced is rather a change in height.

We have here perhaps in part the means of explaining why the
measurements of the heights of certain voleanos when made at long
intervals apart should have given different results.

We may carry these ideas from a single volcano to a volcanic
district. During periods of activity we should expect to find the
heat gradients steeper than during periods of repose, and therefore
during such periods of maximum temperature, elevation might be
expected. Also the rate at which the steepness of a heat gradient
in a district varies might indicate the approach or recession of
volcanic agency, and perhaps may even yet give us a measure of
the time by which such actions are removed.

1 J think that these discrepancies have been noticed and written upon in the
“ Geographical Magazine,” October, 1877, but I have not the means of making
reference.

DECADE II.—vVOL. VI.—NO. XI. 33

514 Notices of Memoirs—Mr. G. W. Stow—

Conclusion.—In this, and a preceding paper already referred to, I
have endeavoured to point out, firstly, what are the actual forms of
certain volcanos, and secondly, the principal causes which produce
and subsequently modify these forms.

Taken as a whole, these causes are very varied in their character.
If we examine them singly, we can but barely form an idea as to the
nature of their actions, and when we remember that, not only are
they irregular in themselves, but that they act irregularly in their
relations to each other, we see that the task of unravelling their
complications becomes quite hopeless. In cases like this mathe-
matical investigation helps us to obtain a clearer idea of an action,
but it is seldom that it can be made to measure it. All that we can
do is to fall back upon opinions, observations, and common-sense,
the ordinary weapons which build up or destroy geological hypo-
theses.

INCOME eAwS) Ol IMn IM Orunieys.

— a —
J.—Coat anp Iron 1n Soutu Arrica.!
(From the “ Friend of the Free State,”’ etc., Bloemfontein, August, 7, 1879.)

HE following extracts from Mr. G. W. Stow’s Geological Report

on the Orange-River Free State show what immense supplies

of coal and iron-ore await the arrival of the miner in that region :—
Taking the road to Rietvlei, before reaching the homestead of
Fieldcornet Stoffel Bosman, the old partially metamorphosed sand-
stones* are again met with, cropping up above the surface. Here
they are pinkish-white, fine-grained, and dip to the W.S.W. at an
angle of 54° to 55°. The most important feature connected with
their appearance at this spot is the great beds of iron-ore associated
with them. These become distinctly visible immediately in the rear
of Mr. Bosman’s house. I was first struck in finding fragments of
these ferruginous rocks employed in building portions of the fences
round the land and kraals. Once upon their trail they are easily
traced for miles. At one spot, about a couple of miles from the
homestead, three beds are most clearly exposed. They are as
follows :—On the top of a high bank the first bed is exposed on the
surface for a breadth of about sixty feet, with a westerly dip of
about 60°; about 450 feet from this a second bed makes its ap-
pearance, with a surface exposure of 45 feet, continuing towards a
lower bank on the right about 750 feet distant; a third, but smaller,
bed next crops out, with a surface exposure of about 25 feet. The
dip of these last is similar to the first. These beds, therefore, run
parallel one to another, and are regularly interstratified with the
sandstones. The true thickness of the respective beds is: first
bed, 50 feet; second bed, 40 feet; third bed, 20 feet; making a
total thickness of 110 feet. A considerable quantity of magnetite,
or magnetic iron-ore, is found in them, which quickly makes itself

1 Kindly communicated by Prof. T. Rupert Jones, F.R.S.
2 See Quart. Journ. Geol. Soc. vol. xxx. p. 624, etc.

Coal and Iron in South Africa. 515

known by its influence on the compass. In a mile’s length, the two
largest of the iron-ore beds must contain in a breadth of 300 feet
on the surface of the plain amass of ore equal to 5,280,000 tons;
in a breadth of 600 feet, a mass of ore equal to 10,560,000 tons ; in
a breadth of 1,000 feet, a mass of ore equal to 17,555,000 tons or
52,800,000 tons at 600 feet in a length of five miles.

Outcrops of these beds show themselves at intervals as far as the
farm Klipdrift, on the banks of the Lower Rhenoster River, a
distance of more than fifteen miles. There is, therefore, every
reason to believe that they are continuous for that distance.

The value of iron-ore, delivered at the smelting furnace, is
about £1 per ton; but, however large the quantity of iron-ore may
be, it is valueless unless fuel can be obtained for smelting within a
convenient distance. ‘Thus, the excellent iron-ore in Griqualand-
West is unavailable at present for this reason. That of the Free
State is found under more favourable circumstances. The outcrop of
these metalliferous rocks on the high ground, near Klipdrift, is
within a few miles of a sixteen-inch seam of coal cropping out near
that river-valley at two separate places, both above and below where
the iron-ore is found. While the greater outcrop at Rietvlei is
within 20 or 30 miles of the great coal-bed, and so situated that
any train or railway which may hereafter be constructed for the
conveyance of the coal to such great centres of consumption as the
Diamond Fields, must of necessity pass within a very few miles of
the place where the largest quantity of iron-ore is exposed, and will
thus bring the fuel and the ore almost into juxtaposition. This is
an advantage which cannot be over-estimated; but I must leave
others to decide the important bearing a discovery of this kind must
have upon the posperity of the State, when these buried treasures are
properly utilized, and the inhabitants avail themselves of such
resources.

Mr. Stow, F.G.S., reports that the following useful materials
occur in the Free State :—

1. Nodular limestone, such as used in other countries as cement-
stone, scattered over various parts of the State.

2. Great beds of old crystalline limestones (siliceo-calcareous
rocks).

3. An immense area of country filled with porphyritic rocks,
which would vie with granite for durability and beauty.

4, An abundant supply of magnetic and other rich iron-ores,
within a convenient distance of the necessary fuel for smelting.

5. A great coal-bed.

In a former report he stated that, judging from the excavations
made in the Sand River district, the coal underlying that portion of
the country would, at a low estimate, amount to some 145,800,000
tons. We can now safely state that in the new coal-field, since dis-
covered in the Vaal River valley, the minimum quantity would be
some 350,000,000 tons; making a total, in the two coal-beds, of
495,800,000 tons, which, at five shillings a ton, would represent a
money-value of more than £128,900,000. If, however, instead of

516 Notices of Memoirs—M. D. Ghlert—On New Crinoids.

taking a minimum quantity, we take an average, we should find,
even leaving the Sand River coal out of the calculation, that in the
Vaal River coal-bed alone there must be some 1,225,120,000 tons
awaiting the miner—a quantity of coal which, at the same low rate
as that before mentioned (5s. per ton), would represent a value of
£300,000,000.

From calculations based on those used in England, Mr. Stow
finds that the Free State coal-supply would be sufficient to allow of
a yearly consumption of more than 6,000,000 tons for a period of
1,200 years!

It is not improbable that, as great outcrops of coal in this portion
of South Africa show themselves in the Free State, along the Vaal
Valley, and also in the Transvaal, west of the Drakensberg, asso-
ciated with the rocks dipping eastward, and as they again appear in
the Utrecht Division of the same province, as well as at Biggarsberg
(Newcastle) in Natal, to the east of the same great range, these are
all parts of the same great coal-field; the Drakensberg mountains
occupying their synelinal trough. If, after proper investigation,
such should prove to be the case, the supply of South-African coal
will be enormous, throwing the figures above quoted, vast as they
appear, completely in the shade.

The Free-State coal has not yet been analyzed; but, as a rule, the
amount of “ash” in this Sonth-African coal is much greater than
that imported from Hurope. Some of the duller kinds leave
“clinkers ”’ when burnt; but all those I have tried, says Mr. Stow,
give out an intense heat. Mr. North, the Colonial Engineer, in his
excellent Report upon the subject, considers that with specially
constructed furnaces and movable fire-bars, the objections raised
against Cape coal may be overcome; while Mr. A. N. Ella, who
consumes large quantities of fuel for steam-purposes, considers that ~
a ton (of 2000 Ibs.) of Indwe coal at 40s., would be cheaper than
two loads of firewood at the same price, besides the labour saved in
chopping up the latter.

In the present Report Mr. Stow has not touched upon the addi-
tional scientific knowledge gained during this geological survey ;
but the facts collected fully bear out, he believes, the deduction to
which he was led by a study of similar rocks in Griqualand- West.

Although much work has been done, a reference to the map of
the Report will show that much of the Free-State has yet to be
examined; and it is to be hoped that the completion of this im-
portant Survey will be fully carried out.

IJ. — DEscrIPTION DE DEUX NOUVEAUX GENRES DE CRINOIDES DU
TERRAIN Di&VoONIEN DE LA Mayenne, par M. D. Giutertr. (Bull.
Soc. Géol. de France, 3° série, t. vii® pp. 6-10.)

eee with the beds of shelly Devonian Limestone at

La Baconniére, Saint-Germain and Saint-Jean (in the Depart-
ment of Mayenne), are some layers of black schist. These schists
contain but few fossils, the following, excepting the subjects of this

paper, being the only species yet found :—Spirifer Rousseau, S.

Reviews— Hitchcock's Geology of New Hampshire. 517

levicosta, Terebratula sub- Wilsoni, Chonetes sarcinulata, Tentaculites
Velaini, and a few Polyzoa.

The Crinoidal remains that M. Gihlert has been so fortunate as
to discover in these beds are, he thinks, sufficiently complete to
establish the existence of two new genera, each represented by a
single species.

For these our author proposes the respective names of Thylaco-
erinus Vannioti and Clonocrinus Bigsbyt.

The genus Thylacocrinus comes nearest in its formule to Rodo-
erinus, Miller, and Eucrinus, Angelin; whilst Clonocrinus, we are
told, greatly resembles Angelin’s figure of Melocrinus spectabilis.

This last-named species M. Gihlert is inclined to consider has
been erroneously referred by Angelin to the genus Melocrinus as
founded by Goldfuss, and he ventures to suggest that it might,
perhaps, be more properly classed as another species of this new
genus, Clonocrinus. (The Plates are not given.) B. B. W.

REVIEWS.

——

I. —Tue Grotocgy or New Hampsuire. By C. H. Hirencocr,
State Geologist, and Assistants, Vol. II., Part 2, Stratigraphical
_ Geology ; Vol. III., Part 3, Surface Geology ; Part 4, Mineralogy
and Lithology ; Part 5, Economic Geology. Accompanied by a
Folio Atlas of Maps and Jllustrations. (Concord, 1877-78.)
HESE two volumes, published in 1877-78, conclude the report
on the Geology of New Hampshire, and give the results of the
exploration of that State, under the direction of Mr. C. H. Hitchcock.
Filling more than 1,200 pages, they contain a detailed account of the
geology of the different districts of the State, preceded by a brief
notice of the relations of the geology of New Hampshire to that of
the adjacent territory. ‘The second volume, on the Stratigraphical
Geology, is mostly due to the labours of Mr. Hitchcock, chapters i1.
and v. and parts 3 and 4 being supplied by his assistant, Mr. Hunt-
ington. There are no formations in the State of later date than the
Lower Helderberg, save the surface deposits. The stratified groups
comprise in descending order—l. The Cenozoic,—include the glacial
and modified drifts, about 450 feet. 2. Paleeozoic,—Lower Helder-
berg, Coos group and Cambrian Slates, 15,800 feet. 3. Strata doubt-
fully referred to the Paleozoic, 11,600 feet. 4. Hozoic, comprising,
Upper Huronian, 12,129 feet, Labrador system, Montalban, 11,370
feet, Laurentian, 34,900 feet.

The Labrador system is in very limited amount, and recent investi-
gations make it difficult to say that the Labrador rocks are not of
eruptive character, and whether (as at Waterville) they really
represent the Labrador system of Canada. With regard to the
Montalban rocks, Mr. Hitchcock differs from Dr. Sterry Hunt as to
their position, and from the observations of the former we are led to
the view that they underlie and not overlie the Huronian, though the
precise relationship is not beyond controversy (p. 669). The eruptive

518 Reviews—Hitcheock’s Geology of New Hampshire.

masses consist of various kinds of granitic, felspathic, and augitic
rocks.

The third volume will probably be found of more interest than
the second, as under the head of “Surface Geology” there are two
important chapters on the Glacial period, and associated phenomena
of New Hampshire, which are perhaps as well shown there as in any
part of the earth. The first, by Mr. W. Upham, treats fully of
the observations made by him in the different districts, and includes
the “ Lower Till” deposited during the Glacial period, and found
throughout the State. This is succeeded by the Upper Till, and the
Champlain period, which embraced the time occupied by the final
melting of the great ice-sheet, during which the abraded materials
contained in the ice-mass were washed away and deposited as
kames, kame-like plains, and valley or modified drift; these were
followed by the recent or terrace period, during which deep and
wide channels were excavated in the Champlain deposits; a table
is given showing the formations which have been described in the
chapter, arranged in the order of their deposition (p. 176).

The general characters of the glacial drift are also further de-
scribed by Mr. C. H. Hitchcock, who treats, amongst other points,
of the causes of the glacial cold, of interglacial deposits, and the
length of the Glacial period, concluding with his most recent
opinions on the order of events occurring in New Hampshire, in the
Glacial, Champlain, and subsequent periods.

The Glacial period of the northern hemisphere has been a subject
of considerable attention among geologists and physicists, and various
theories have been suggested to account for the cause of the glacial
cold, but none have been universally accepted. Every additional
information tending to enlarge our knowledge of the origin, extent,
and movement of the ice-sheet, as fully indicated for New Hampshire
by Mr. Hitchcock, will be usefully consulted by those interested in
the subject.

Part 4 contains a description by Mr. G. W. Hawes of the minerals
and rocks of the State, illustrated by eleven plates showing their
microscopic structure. Part 5 gives an account by Mr. Hitchcock of
the localities, modes of occurrence, and quantity of materials valu-
able for economic purposes, as metals and their ores, building
materials, and natural fertilizers.

The vast amount of information systematically arranged in these
volumes, on the physical features, agricultural character, geological
structure, and economical products, will be of great advantage
to those persons more directly interested in the natural resources
of the State. But the value of the descriptive portion is further
enhanced by the fine folio atlas which accompanies the work, con-
taining two topographical maps of the State, in the years 1784 and
1816; a large map showing the geological features and position of
the mines in the Ammonoosuk mining district, the details of which
are given in vol. il. p.272; a series of panoramic views and camera
profiles, illustrating the contours of many picturesque parts of the
country; five maps showing the position of the modified drift and

Reviews—Dr. T. Sterry Hunt’s Pennsylvanian Report. 519

direction of the glacial strize so fully described in vol. iii. (chapters
1 and 2); besides a geological map in six sheets, clearly illustrating
the description of the stratified and other rocks given in the second
volume. This map, while indicating the results of the labours of
the State Geologist and his colleagues during their explorations,
will, besides its local interest, facilitate the comparison of the geo-

logical features of New Hampshire with those of the surrounding
territories. J.M

II.—Sprrecitan Report on THE TRap-pyKes AND Azorc Rocks OF
SourH-nasterN Pennsytyania. By T. Srerry Hun. Part I.
Historical Introduction. (Harrisburg, 1878.)

| ees work forms the first portion of a special report by Dr. Hunt
on the Azoic Rocks, Trap-dykes, and Iron Ores of Pennsylvania.

It contains an Introduction to the Geology of South-eastern Pennsyl-

vania, an account of the Cambrian Rocks of Europe and America,

and three chapters (II. III. V.) on American Pre-Silurian Geology,
which comprise an historical and critical review of the progress of
our knowledge bearing on the older rocks of North America, during
the last sixty years,—from the publication of Maclure’s map in
1817, until the present time. It would be impossible to condense
satisfactorily, in this brief notice, the opinions and descriptions of
the various writers cited throughout the work, which Dr. Hunt has
himself so concisely and clearly treated, as well as interspersed
many suggestive remarks, on the characters, origin, and sequence of
the Azoic rocks, considered to be of Pre-Paleozoic age, and which
are also fully noticed in his Chemical and Geological Essays. As,
however, the recent researches of Dr. Hicks and others in this
country (see Guot. Maa. ante, p. 483) have shown certain crystal-
line rocks to be of Pre-Cambrian age, it may be useful to give the
results of the recent studies of Dr. Sterry Hunt on the older rocks
of Eastern North America, including the Lake Superior region.

These terranes are, in descending order, as follows :—

8. StnuRo-Camprran.—The Upper Cambrian of Sedgwick, part of the Lower
Silurian of Murchison, and of the Matinal of Rogers. : :

7. Camprian.—The Lower and Middle Cambrian of Sedgwick, the Lower and
Upper Cambrian of Hicks; the Upper Taconic of Emmons, and the Quebec group
of Logan; the Primordial, and part of the Lower Silurian of Murchison. :

6. KrEwEENntan.—The Copper-bearing series of Lake Superior, found in the
same geological interval as the aconian, but not identified with it. :

5. Tacontan.—The Lower Taconic of Emmons, including a part of the Primal,
Auroral, and Matinal divisions of Rogers, and constituting, with the Montalban,
what was once called Terranovan by the writer.

4, Monratpan.—The White Mountain or Mica-schist series.

3. Hurontan.—The Green Mountain series, or altered Quebec group of Logan.

2. Nortan.—The Labradorian, or Upper Laurentian of Logan. Litre

1. Lavrentran.—A lower division, the Ottawa Gneiss, and an upper division,

the Grenville series, between which is a supposed unconformity. These two con-
stitute the Lower Laurentian of Logan.

With regard to the five lower terranes, they have, notwithstanding
their differences, certain lithological resemblances with each other.
“All of them include quartzites, and crystalline limestones, in

520 Reviews—Jukes-Browne—Post-Tertiary Cambridgeshire.

which certain mineral silicates, such as serpentines, hornblende, and
micas, are occasionally met with. It is in those aluminiferous rocks
which are without lime and magnesia, that are found the essential
and characteristic differences, and these depend upon a progressive
diminution in the proportion of the alkalies to the alumina, as we
pass from the older to the newer geognostical groups” (p. 210).

The above classification is different from the opinions held by the
author previous to 1871, as he maintained that the crystalline rocks
of the Green Mountain and White Mountain series were altered
Paleozoic sediments, but which he now considers to be of Pre-
Cambrian age.

Some of Dr. Hunt’s views given in the report are.not in ac-
cordance with those of Pennsylvania geologists of the first or second
surveys, and although the State Geologist (J. P. Lesley) feels “it is
somewhat premature to dogmatise about the Taconic system; as it
is impossible yet for any competent judge to express a positive
opinion respecting such terms as Montalban, Norian, etc., in Penn-
sylvania,” yet he fairly acknowledges “that a debt of gratitude is
due to Dr. Hunt for this historical monograph, which will supply a
deeply felt deficiency in the literature of our science.’ J. M.

I1J.—Tue Post-Tertrary Deposits or CampripGEesHire. By A. J.
JuKES-Browne. 8vo. pp. 85. (Cambridge, Deighton, Bell &
Co., 1878.) Price 2s. 6d.

ia 1876 the Sedgwick Prize was awarded to Mr. Jukes-Browne for
fi an essay on “The Post-Tertiary Deposits of Cambridgeshire
and their relations to deposits of the same period in the rest of Hast
Anglia.” This with some few additions is here reproduced. and is
so neat in form and moderate in price that our Geological Survey
authorities might well take a lesson from it.

Commencing with some historical notices on the study of drifts in
general, the author proceeds to review the various works dealing
with the tract he describes—from the time of the Rev. Professor
Hailstone in 1816 to the date of his own publication. After a brief
account of the physical features of Cambridgeshire, he turns at once
to the description of the Glacial Beds. These include the Chalky
Boulder-clay, usually classed as Upper Glacial, and certain gravels.
Mr. Jukes-Browne considers that the Boulder-clay was accumulated
during the period of most intense glacial cold, and he would not
exclude other beds from the glacial series simply because they
happen to lie above this particular clay.

No deposits of Lower or Middle Glacial age are recognized by
him in the area, for although here and there certain sands and loams
are interposed between beds of Boulder-clay, he regards this feature
as probably the result of contemporaneous current action. Brief
mention is made of the great boulder of Gault and Chalk seen in the
celebrated pit at Roslyn Hole, and which has been described in
detail in Prof. Bonney’s “Cambridgeshire Geology,” and in Mr.
Skertchly’s ‘Geology of the Fenland.”

Reviews—Dr. A. Fritsch’s Permian Amphibia of Bohemia. 521

The “ Hill Gravels” are next described ; these overlie the Boulder-
clay, where it occurs, and contain many fragments derived from it.
Much of the gravel is described as coarse and unstratified. Succeed-
ing these in point of time are the “Valley Gravels of the Harly
River System.” These are similar in composition to the Hill
Gravels, but are entirely separated from the Glacial deposits.
While they appear to have a distinct relation to the valley systems
in which they lie, yet in their lower prolongations in the Cam Valley
they stretch away almost at right angles to its present course. Still
their fluviatile origin remains conspicuous. The March gravels
which form little islands in the Fenland are described with these
valley gravels, although they contain marine shells. Their con-
nexion is not discussed. Prof. Bonney and Mr. 8. V. Wood, jun.,
hold them to be coeval with the older (Cyrena fluminalis) gravel of
Barnwell.

The ‘Valley Gravels of the Present River System” are then
described ; the first determination of the waters towards which is
marked, according to Mr. Jukes-Browne, by the series to which the
Barnwell gravels belong.

A short chapter is devoted to the correlation of the Cambridge-
shire drifts with those of the Hastern Counties. Mr. Jukes-Browne
is not satisfied with the evidence brought forward by Messrs. Wood
and Harmer to make an unconformity between the Lower and
Middle Glacial deposits of Hast Anglia; indeed he suggests that the
Cromer Till, Contorted Drift, and Middle Drift might be bracketed
together as Lower Glacial; and the Chalky Boulder-clay and over-
lying Plateaux or “‘Cannon-shot” gravel, as Upper Glacial. This
view, which considerably simplifies the geology of the Hastern
Counties, is one in which we cordially agree.

From the title of the work it might have been expected that
descriptions of the Alluvial strata of the Fenland would have been
included ; this, however, was considered to be beyond the scope of
the subject proposed.

JV.—AMPHIBIANS FROM THE PrRMIAN Rocks oF BoHeEmta.’

R. ANTON FRITSCH, whose important works on the fossils of
the Cretaceous formation in Bohemia are well known, has com-
menced to publish, with the assistance of the Imperial Academy of
Vienna, a Fauna of the Coal and Limestone of the Bohemian rocks
of Permian age, of which the first part is just issued. This mono-
graph, which, when completed, will extend over three volumes, will
rank as one of the most important modern contributions to Palzeonto-
logy, on account of the large number of new and singular types of
life which it describes and makes known by splendid illustrations.
It is essentially a descriptive work, and the author treats his subject
rather from the zoological point of view than that of the comparative

anatomist.
1 Fauna der Gaskohle und der Kalksteine der Permformation Béhmens, von Dr.

Ant. Fritsch, A O. Professor der Zoologie an der Universitat in Prag. Band 1.
Heft I. (Prag. 1879.)

522 Reviews—Dr. A. Fritsch’s Permian Amphibia of Bohemia.

This Fauna has been discovered during the last ten years,
and in the preface a detailed account is given of the gradual
augmentation of material, which comprises in all some forty-three
species of Amphibians, thirty-three Fishes, and eleven Arthropode,
besides a single shell of the genus Anthracosia. This first part con-
sists of ninety-two pages of text, with many woodcut illustrations
and twelve quarto plates. The work opens with an interesting
geological description of the deposits which have yielded the
remains. It describes with the help of excellent sections the
structure of the Pilsen basin, giving some useful lists of the plant
remains and other fossils, and then at less length describes the Schlan-
Rakowitz basin: so that the horizons of the specimens are all accu-
rately determined. To this memoir succeeds a systematic list of the
Species, giving an enumeration of the materials available for descrip-
tion. The next section of the work is called a history of the
classification of Labyrinthodonts, in which the views of Owen, as
stated in his Paleontology, and of Dawson, are briefly referred to ;
but the bulk of the article is a verbatim translation of Prof. Miall’s
two reports to the British Association upon the Carboniferous
Labyrinthodontia; and in conclusion, the work of Prof. Cope on
the American Amphibians, and of Prof. Gaudry on Protriton, is
briefly noticed. This preliminary matter occupies the first sixty-
seven pages. The remains described in the succeeding pages are all
referred to Cope’s order Stegocephali, which is co-extensive with the
Labyrinthodontia, Ganocephaia, and Microsauria, and defined by the
supra-occipital and epiotic bones forming well-developed ossifica-
tions, by the temporal fossa being covered by the supra-temporal
and post-orbital bones, by the presence of a parietal foramen, and by
the lower pelvic elements being well developed. The genera now
described are named Branchiosaurus, Sparodus, Hylonomus, and
Dawsonia.

Branchiosaurus resembles the Harth-salamanders, and especially
the young forms, in possessing gills, and the author remarks that the
broad anteriorly rounded head, the short thick body, and the well-
developed extremities terminating in digits, together with the rudder-
like tail, strongly suggest the larval forms of the living Urodela.
Branchiosaurus salamandroides is known from ten complete speci-
mens, and fragments which may have belonged to fifty or sixty
other individuals. The skeleton ossifies at an early period in life,
and all the bones of the skull, vertebral column, and extremities are
already defined in examples sixteen millimétres long. And in a
somewhat larger individual even the sclerotic plates, ribs, and pha-
langes are distinctly seen.

The largest specimen of this species is 64 millimétres long. If
Dr. Fritsch is right in referring all these remains to one species,
they present the remarkable condition of the growth of the limbs
remaining stationary while the body increases in size and length.
Both the humerus and fore-arm are absolutely longer in the animal,
measuring 44 millimétres, than in that which has a length of 64
millimetres, while in the hind-limb the bones are of equal length in
both specimens.

523

Reviews—Dr. A. Fritsch’s Permian Amphibia of Bohemia.

The skin was dense, and its impression is preserved in most
specimens, as may be seen in the subjoined and following figures.

SEY

S Fist
WS ee
A SSH SS a:
SINS OY \
SAe> WS)!
SS
y, aN MM SJ)
WS x Y, SS
¥ ‘a 5 eS SSG
) SF AN, OC INS Ws
pe 7 NSS
RN ONY \ ASS
ii NAS Is S

q
S WY xy
REA
S S WN
ASG
NARA

SSS

x

=
=

Fic. 1.—The largest example of Branchiosaurus salamandroides, Fritsch.

Dorsal view.

Enlarged three times.

524 Reviews—Dr. A. Fritsch’s Permian Amphibia of Bohemia.

When highly magnified, slight ridges are seen upon it; these
are the first indications of scales, which become more developed on

Fic. 2.—Branchiosaurus salamandroides, Fritsch.
Enlarged to twice the natural size.

Fie. 3.—Upper side. Restoration of the skull of Branchiosaurus salamandroides,
Fritsch. Enlarged six times.

the under-side of the body. The scales are ovate, truncated in front,
and somewhat irregular behind.
In the median part of the abdomen the scales are long, and assume

Reviews—Dr. A. Fritsch’s Permian Amphibia of Bohemia. 525

a V pattern. The impressions of small rounded bodies seen in this
region upon the scales are considered to be eggs.
The form of the skull and general relations of the bones will best
be gathered from Figs. 8 and 4. The osteological details are given by
the author at great length. The premaxillaries (im) are ornamented
with delicate long pits, and carry from 6 to 10 short pointed teeth,
which are larger than those in the maxillary bones and lower jaw ;

they are smooth and have a round pulp-cavity.

Fie. 4.—Under side of the skull of Branchiosaurus salamandroides, Fritsch.
Six times natural size.

The maxillary (MS.), which is similarly pitted, and extends back
to the quadrato-jugal (QJ.), carries from 10 to 18 teeth. There are
probably two or three irregular rows of teeth behind these. The
nasal bones (N.) are notched in front to form with the premaxillary
bones the small nasal apertures, which they border on the inner side
with an elevated ridge. The lachrymal bone is absent. The
frontal bone (F.) is excluded from the circle of the orbit by the
triangular prefrontal bone (P.) in front, and the sickle-shaped post-
frontal bone (Pt. f.) behind. Its upper surface is covered with deli-
cate long pits; and the post-frontal bone is strongly sculptured.
The triangular post-orbital bone (Pt. 0.) forms the outer and hinder
border of the orbit. The jugal (Ju.) is a long bone which extends
back from the nasal and parallel to the maxillary, so as to form part
of the border of the orbit, and partly divide the quadrato-jugal (QJ.)
from the supratemporal (8.T.). Between the parietal bones (Pa.)
in the middle of the suture is the ovate or round foramen parietale,

526 Reviews—Dr. A. Fritsch’s Permian Amphibia of Bohemia.

measuring a fifth or a sixth of the length of the suture. The Epiotic
(Ep.) terminates backward and outward in a strong free process; it
bounds the ear. In the outer edge of the supra-temporal bone (S8.T)
is often a notch, which may indicate the outer opening of the ear. The
quadrate bone (Q.) is very small. The supra-occipital (S.O.) is well
developed; but the exoccipitals cannot be determined with certainty,
though they may form the occipital condyles. The under-side of the
skull, Fig. 4, is remarkable for the large size of the palatal apertures,
which are defined by the parasphenoid bone (Ps.) in the middle, by
the pterygoids (Pt.) at the outer sides, and by the palatine bones (p)
in front. As in some living Urodela, there is a small aperture in
the sutural line between the vomers (V.). There are traces of small
groups of teeth on the hinder and outer edges of the vomerine bones.

The lower jaw always becomes attenuated anteriorly. It consists
of three bones, articular, angular, and dentary. The latter element
carries a row of about 20 large smooth teeth.

The sclerotic circle is made up of about 14 oblong plates, which
are marked with concentric lines.

On each side of the hinder part of the skull are two branchial
arches which carry two rows of strong spheroidal bones, each bear-
ing a little curved spine.

The vertebral column is divided into back and tail. From the
head to the pelvis there are about 20 vertebra, and all except the
first bear ribs. The second to the thirteenth are all about the same
size. All are compressed to the thinness of paper, so that the details
of their structure are obscure. Lower down the back the vertebre
slightly decrease in size. There is apparently only one sacral
vertebra, which is always covered by the pelvic bones. There are
about 21 vertebrae in the tail, gradually diminishing in size to a
fourth of their original width.

The dorsal ribs from 2nd to 13th have a length equal to three-
quarters of the width of a vertebra; posterior to this they become
shortened. Ribs exist in the tail, and are about half as long as the
vertebrae are wide.

The shoulder girdle includes seven bones, scapulz, coracoids,
clavicles and thoracic scute ; and the pelvic girdle is formed by the
iliac and ischiopubic bones. The hind-foot has the digits much
longer than in the fore-foot, but the longest digit is the second,
while in the fore-limb the third digit is longest. In the fore-limb the
number of the phalanges is 2, 2, 3, 8, 2, and in the hind-limb it is
3, 4, 3, 2, 2.

The other species of Branchiosaurus which are described and
figured are B. umbrosus, Frit., B. Moravicus, Frit., previously described
as Archegosaurus austriacus of Makovsky, B.? venosus, Frit., and
B.? robustus, Frit.

The next genus, Sparodus, Fritsch, is represented by two species :
S. validus, Fr., and S. crassidens, Fr. It is nearly related to the
American genus Hylerpeton and to Brachiderpeton. The large broad
vomer carries numerous uneven large conical teeth. And the pala-
tine bone has a single row of teeth, which increase in size posteriorly.

Reviews—Dr. A. Fritsch’s Permian Amphibia of Bohemia. 527

In Sparodus validus there are 17 teeth in the lower jaw ; and there
are 27 on each vomer, the largest rows being towards the palatine
bone. The palatine bone carries 11 teeth. The skull is more wedge-
shaped than in Branchiosaurus.

Of Hylonomus two species are recognized, but these are only
known from small portions of jaws. Hylonomus acuminatus has
the teeth marked with distant parallel ribs.

The last genus in the present part of the work is named Dawsonia.
It is very nearly allied to Hylonomus, but the author is unable to
see his way to uniting the genera, because Dr. Dawson figures
elements of the skeleton which differ from the Bohemian specimens.
The vomer (v) has a small group of minute teeth on its outer edge,

ABAAA A

Fic. 5.—Restoration of the under-side of the skull of Daewsonia polydens, Fritsch.
Twice the natural size. |
and both the parasphenoid (Pf.) and pterygoid (Pt.) carry numerous
small teeth. The palatine bone (p) has a single row of teeth which
become larger posteriorly. The hindermost and largest tooth is
grooved at the base. The external surface of the skull-bones is strongly
sculptured. The thoracic scute has a long rhomboidal form, and is
furrowed like the skull-bones. The teeth in the jaws are smooth
and of uniform size. The premaxillary is broad, with about eight
large teeth of equal size. The anterior process of the parasphenoid
widens in front, and is slightly forked. This skull has never yet
been found entire, but has been reconstructed from several frag-
ments, and is believed to have been rather broader than long. The
vomer (vy) is forked behind, as though for the posterior nares. The

528 Correspondence—Messrs. Dakyns, Hicks, McGee.
¢

pterygoid shows two kinds of dentition; on its outer edge is a
single row of twenty-six large teeth of equal size, which are some-
what smaller than those of the maxillary bone. Internal to these
on the anterior part of the pterygoid are from three to six irregular
rows of short pointed teeth similar to those on the parasphenoid.
In the under-jaw there are thirty teeth.

This instalment of Dr. Fritsch’s work leads us to look forward to
its subsequent progress with great interest. It is a monument
of conscientious labour and admirable skill in deciphering remains
in which the characters presented more than ordinary difficulty.

H. G. SErxey.

(Gln st 1S44 SON PID sstINi@ ssh

THE PURPLE BOULDER-CLAY AT HOLDERNESS.

Srr,—In the excellent account of English glacial deposits, given
in the second edition of “The Great Ice Age,” it is stated that “in
Holderness the purple clay is quite unstratified.” It is true, that in
many places the “Purple Boulder-clay”’ is unstratified ; but in many
others it is distinctly stratified. The stratified and unstratified por-
tions are, however, so mixed up together, and run so into one another,
as to be quite inseparable. The deposit has also been much shoved
about, the thrust having in some well-marked cases come from

the N.N.E. J. R. Daxkyns.
DRirFiELD, Oct. 9th, 1879.

ON THE CLASSIFICATION OF THE BRITISH PRE-CAMBRIAN ROCKS.
Srr,—Will you kindly call attention to the fact that by some
mistake the word not has been left out after the word did in my
paper, p. 484, line 19 from bottom of page. The sentence should
read, “If these movements also did not take place, etc.” As the
absence of this one little word does away with the proper meaning,
I shall feel obliged if you will kindly notice it in the next Number
of the Grou. Mag. Hy. Hicks.
Henpon, N.W., Oct. 3, 1879.

SURFACE GEOLOGY OF THE MISSISSIPPI VALLEY.

Mr. W. J. Mc Gee writes from Farley, Iowa, September 18, 1879,
in reference to his communication, which appeared in the (Gxot.
Magazine for August, pp. 853-362, and September, pp. 412-421 :—
«Thanks for your care in revising proofs of my paper in the Gxot,
Maa. A very few errors have crept in, however, which I will note.

W. J. Mc Grn.”
Page 358 (August No.), Zine 30, for ‘‘ mentioned ” read ‘“‘ weathered.”

55) COW) 3, Si Ones ecmassiy by OP TENORS”
» 9361 $5 Fy 835) oye evel 22 Paieecliead sd
» 414 (Sept. No.), ,, 11, ,, “basalt” eeuibasallae
» 418 » imfootnote, ,, “p.168” oy Sido WOR.”

COLUMNAR SANDSTONE IN SAXON SWITZERLAND.

We are requested by Mr. Walter Keeping to make the following corrections in his
article which escaped notice—namely, at p. 438, line 2 from foot, for ‘ binding’ read
‘bending.’ and on p. 441, line 8 from top, for ‘ Yorkshire,’ read ‘ Derbyshire.’—
Epir. Gon. Mac.

THE i

GEOLOGICAL MAGAZINE.

NEWrSERIES@) DECADE. Il; VOL, VI.

No. XII—DECEMBER, 1879.

(@ysvil GEN AUIby | YS Lae a na=satSs

——\_@—__
I.—Tur Parauutet Roaps or Guen Roy.

By J. R. Daxyns, M.A. ;
of H.M. Geological Survey of England,

AST summer I paid a visit to the Parallel Roads of Glen Roy,
and saw certain features which must, I think, have hitherto
escaped notice. It has been asserted that the roads consist of, or
are cut out of, mere superficial detritus; and that they never appear
where the solid rock appears; and much discussion has arisen as to
the mode of formation of the roads on this supposition, viz. that they
consist of detritus merely.

In order to get a section of the roads, J examined several water-
courses descending the side of Leana Mhor, west of the River Roy.
These water-courses were cut to the depth of about ten feet in the
ordinary superficial detritus of the mountain side; and where they
crossed the roads, the material exposed on their sides was precisely
the same as that along the rest of their course. This did not surprise.
me, as I had recently read in the Gronocican Magazine for July
(p. 321), ina notice of a paper by Professor Prestwich, ‘‘On the Origin
of the Parallel Roads of Lochaber,” that “the Parallel Roads are
terraces composed of perfectly angular fragments of the local rocks.”
However, as these water-courses nowhere reached the solid rock,
I was not satisfied. I accordingly went next day to the east side
of the River Roy, where the roads are very well marked indeed, and
are crossed by two or three comparatively large gills. These gills
descend along the west face of east Leana Mhor; for there are two
hills of this name given on the One-inch Ordnance Map, one on
the west, and the other on the east side of the River Roy.

I walked along the topmost road northward; and the first gill
I came to showed me at once that the road was cut out of the solid
rock. Both above and below the road the solid rock came practically
to the surface, being covered with a mere film, about a foot thick, of
its own detritus: the surface along the road itself was, however,
hidden by a small fan of detritus shot on to the road from the gill
above. ‘The section of the second or middle road was obscure along
this gill. I walked on along the highest road till I came to a big
gill cut deeply into the native rock, and bifurcating a little below
the 1250 contour line. The highest road crosses this pair of gills
above the point of bifurcation, and was so utterly destroyed as to be
quite obscure; but the second road ran right up to the edge of the

DECADE II.—VOL. VI.—NO. XII. 34

530 J. R. Dakyns—The Parallel Roads of Glen Roy.

deep gill, which it meets just below the junction of the two branch
gills, and started at once again on the opposite side; no talus con-
cealed the road; it is cut out of the solid rock. A subordinate road
which occurs a little further north between the two ordinary top
roads was also seen to coincide with and, in fact, to be a rock feature.

I was satisfied: I went no further: I had had two clear sections
of the two best-marked roads, one of each: the roads are, at all
events in some cases, cut out of the solid rock. It is reasonable
to conclude that where they appear to be confined to superficial
detritus, it is because the rock shelf is hidden by said detritus, which
has, in fact, accumulated along the road just because it is a shelf.
It is noteworthy that whereas the roads on the east side of Roy,
where being free of detritus they are seen to form rock shelves, are
wide enough to allow two carts to pass each other. On the west
side where encumbered with debris they are no broader than a good
sized foot-path.

The roads, though sensibly parallel and horizontal, are not abso-
lutely so; for, according to the measurements of the Ordnance Sur-
veyors, the first road in Glen Roy varies in elevation from 1144 to
1155 feet above the sea, the second from 1062 to 1077, and the third
from 850 to 862. Such variation in height would necessarily be
caused by the unequal accumulation of debris on the original shelves.

It is right to say that there is an error in the mapping of the
roads on the One-inch Ordnance Map, Sheet 63: on the map the top-
most road is represented as crossing the big two-grained gill just
below the bifurcation ; it really is considerably higher up, while it
is the second or middle road which crosses the gill at the fork.

Diagram showing the profile of the mountain side with the three roads, the two
highest, Nos. 1 and 2, well marked, and the lowest, No. 3, not so well marked,
as seen by an observer looking up Glen Roy.

I have not seen the places where, as Mr. Darwin! observes, the
shelves entirely disappear on crossing the part of the mountains in
which the base-rock is exposed; but I would ask whether the rock

' Quoted by Sir John Lubbock, Quart. Journ. Geol. Soc. vol. xxiv. p. 84.

J. W. Davis—On a New Fossil Fish Spine. 531

may not be more than usually tough in these places. Generally
the rock seemed to me to be of a character easily disintegrated.

How then were the roads formed? Obviously by the planing
action of waves acting on the rock and cutting the shore-line back.
Subsequently, on the lowering of the water-line, the detritus of the
mountain side falling, and being washed down hill by rain, etc.,
lodged on the platform of the shelves, and there accumulating
gradually formed a pile of loose material sloping towards the
valley, and slowly obliterating the true roads.

I add a sketch of the profile of the mountain side, as seen from
the big gill looking up the valley. It will be seen that my profile
is quite similar to the diagram given from Macculloch by Sir John
Lubbock in the Q.J.G.S. for 1868, vol. xxiv., with this remarkable
difference: in my sketch the two highest roads are represented as
comparatively near to one another, while the lowest is much lower
down; this is the case in nature; the average heights of the roads
above sea-level being, according to the Ordnance Surveyors, 1148,
1067, and 855 feet; but in Sir John Lubbock’s diagram, after
Macculloch, the two lowest roads are represented as close together,
and the third much higher up: the diagram has evidently been
drawn or printed upside down; for turn the book topsyturvy and
the diagram is right.

As to the nine points then, on which, according to Sir John Lub-
bock, we have a substantial agreement, the whole question of the
true nature of the roads turns upon the second and third: these I
would controvert thus: the horizontal roads are shelves cut out of
the solid rock; and these shelves only appear when the solid rock
itself appears, being in other cases entirely hidden by the debris of
the mountain side, which has fallen and accumulated upon the shelves.

It is further to be noted that the disintegration of the rock forming
the shelves would in course of time disguise the fact that the roads
consisted of rock shelves, and cause them to appear as mere heaps
of detritus.

IJ.—Description or A New Species oF Fosst Fisn Spring,
CTENACANTHUS MINOR, FROM THE LOWER COAL-MEASURES OF
YORKSHIRE.

By James W. Davis, F.L.S., F.G.S., ete. ;
Hon. Secretary of the Yorkshire Geological and Polytechnic Society.

A SHORT time ago, whilst examining and appending the names

to a number of specimens of fossil fish in the collection of
the Bradford Philosophical Society, which are being arranged and
exhibited in the new Corporate Museum in that town, I came across
the spine which is the subject of this notice. It is from the Black-
bed Coal at Dudley Hill, near Bradford. It was associated with a
number of fish remains. amongst others :—

Ctenacanthus hybodoides, Kgerton. Petalodus Hastingsie, Agass.
Gyracanthus formosus, Agass. Acanthodes, sp. ?
Pleuracanthus levissimus, Agass, Megalichthys Hibberti, Agass.
Diplodus gibbosus, Agass. Celacanthus lepturus, Agass.

Ctenoptychius, sp. Rhizodus Hibberti, Agass.

532 EF. Wilson and J. Shipman—The Keuper Basement Beds.

Several specimens of Labyrinthodonts, in excellent preservation,
have been found along with the remains of the fishes. One of them,
a new genus of large size, was described and named by Professor
Huxley Pholiderpeton scutigerum.

The Black-bed Coal is in the Lower Coal-measures about 120 feet
higher in the series than Elland Flag-rock. Immediately above the
Coal there is a bed of shale containing a considerable quantity of
Clay-ironstone in nodules, which is worked by the Low Moor Iron
Company along with the Coal. The fossil fish and Labyrinthodonts
are from this shale immediately above the Coal.

Ctenacanthus minor, Davis, sp. nov. (Natural size.)

Ctenacanthus minor, mihi. Spine: length, 1-4 inches; greatest
breadth, -3 of an inch. The base is imperfect, and the tip of the
spine is also wanting. It is slightly curved, is very strong, and has
been very deeply implanted in the flesh ; the basal portion constitutes
more than half the entire length, and if the specimen had been perfect
would have taken up quite two-thirds ; probably a larger proportion
than exists in any other species of Ctenacanthus. The lateral faces
are compressed anteriorly ; posteriorly they expand and give to a
section of the spine a triangular form. Along the back of the spine
there is a deep groove, no posterior denticles can be seen. ‘The line
dividing the exposed part of the spine from the base forms an angle
to the length of the spine of about 45°. The anterior portion is pro-
duced so as to form a median keel, whilst on each side there are six
or seven well-defined ridges or coste separated by deep intercostal
spaces. The ridges run parallel to the posterior margin for the most
part, whilst those near the anterior portion run out towards the
point without impinging on the median keel.

This spine does not appear to be in close relationship with any of
Ctenacanths hitherto described. Its short wedge-shaped form in the
part exposed, and the extremely large and strong base, serve to dis-
tinguish it from all other species of the genus. I suggest the
specific name minor as signifying its relatively small size.

TJ].—On THE Occurrence or THE Kerurrr Basement Beps 1Nn
THE NriGHBouRHOOoD oF NorTiINGcHAM.
By E. Witson, F.G.S., and J. SHrpMan.

ITHERTO, exposures of the junction of the Bunter formation
with the Keuper, in the Nottingham district, have shown the
brown sandstones and red marls of the “ Waterstones,” with a band
of dolomitic conglomerate at the base, resting directly on an eroded
surface of the Bunter Pebble Beds.! Recently, however, between

1 J. Shipman, “Conglomerate at the Base of the Lower Keuper,’ Grou. Mac.
1877, p. 497.

E. Wilson and J. Shipman—The Keuper Basement Beds. 533

these formations there have been observed to intervene certain de-
posits that agree both in mineral composition and in physical cha-
racters with the white sandstones and conglomerates, known as the
“Basement Beds,”! that form so important a feature in the Keuper
of the West Midlands.

The Hunger Hills—These “ Basement Beds” were exposed to
view during the progress of some excavations on the Hunger Hill
Road, Nottingham, and a good section showing their junction with
the Bunter Pebble Beds was supplied by a cutting for a culvert in
Beverley Street. These rocks here consist of soft coarse and
“sharp ” grained white micaceous sandstone. Owing to inequalities
in the surface of the Bunter, they vary rapidly in thickness from a
few inches only to as much as six feet. Throughout the sand-
stone are scattered quartzite pebbles like those of the ‘“ Pebble
Beds,” but it was in the cavities in the old surface of the Bunter
that the pebbles were mostly met with. Two deep furrows in
the Bunter surface trended from west to east, shallowing out on
the west. About two hundred feet further east, the white sand-
stones were again found resting on a ridged and undulating surface
of the “Pebble Beds.” The “Basement Beds” were not at this
spot proved over a greater space than about 250’ x 3800’, being
cut off and overlapped by the Keuper dolomitic conglomerate on
all sides, except the north-east, where they were lost to view
beneath the Lower Keuper Sandstone of the Hunger Hills. They
appear to occupy a shallow cavity eroded out of a plane of Bunter
sloping to the east at about one in fifty. The upper surface of the
white sandstone itself showed distinct signs of erosion, being worn
into irregular hummocks and cavities, filled in with the rusty-coloured
sand and pebbles of the Keuper conglomerate.

Colwick.—The “Basement Beds” were also exposed in the tunnel
for the Leen Valley Outfall Sewer, at Rough Hill Wood, near
Nottingham.? These Beds consist of at least twenty feet of massive
light-grey micaceous and felspathic sandstone, grit and conglomerate,
with lenticular seams of red marl. False-bedding is prevalent in the
sandstones, the planes sloping east at from 5° to 25°. The pebbles
are nearly all quartzites or quartz, and agree with those of the
Bunter Pebble Beds, except that many of them have chipped
corners or angular faces as if fractured during transport or the pro-
cess of deposition. In the tunnel heading near the top of the series
is a bed of marl, that for a space of about a hundred feet maintains a
thickness of from two to four feet, and then becomes split up into
wedges that dovetail in a peculiar manner with the beds of sandstone
and conglomerate that it locally displaces. These beds show signs

1 Aull, “ Triassic and Permian Rocks of the Midlands,” pp. 66, e¢ seq.

2 We are indebted to C. F. Gripper, Esq., contractor for the works, and to M. O.
Tarbotton, Esq., F.G.S., Engineer to the Nottingham Corporation, for the lower
portion of the third section, which was arrived at by means of a shaft sunk for the
purpose at Rough Hill Wood; but owing to the water-level of the Trent valley
being reached, the sinking had to be abandoned without proving the Bunter.

In consequence of the great length of two of the sections referred to, their pub-
lication with the present paper has been abandoned by its authors.

5984 FE. Wilson and J. Shipman—The Keuper Basement Beds.

of contemporaneous erosion, the sands having been apparently cut
through by channels and replaced by other sands or by marls, while
the marls have been broken up and their débris, in the shape of
flakes, and lumps, scattered plentifully through the surrounding
sediments. Notwithstanding their intimate association with the
coarser deposits, the marls keep remarkably fine and pure. These
rocks are succeeded by the regularly bedded sandstones and marls
of the Lower Keuper. The line of junction, which is sharply defined,
is pretty level, but the “ Basement Beds” appear to have been trun-
cated by denudation prior to the deposition of the Waterstones.
Other Localities.—The “Basement Beds” of the Lower Keuper
are very variable in thickness, and, except in their areas of typical
development, very irregular in distribution. Prof. Hull long since
showed that the sediments which compose the Keuper rocks of
England probably came from the west or north-west; for he
demonstrated that the Triassic rocks, along with other Secondary
formations, attenuate in a south-easterly direction.! It was there-
fore to be expected that this lowest member of the Keuper
would be found to thin away going east, and such is actually the
case. On the west, in Delamere Forest, and the Peckforton Hills,
Cheshire, the Basement Beds proper are from 50 to 150 feet thick,
but, with the overlying red and white freestones, attain a thickness
of 250 feet or more.?, At Alton, midway to Nottingham, these rocks
are not more than sixty feet, while still further east, at Nottingham,
they probably do not exceed twenty feet in thickness. Hast of the
valley of the Dove, these rocks rapidly attenuate, and are soon lost
beneath newer members of the Keuper, which then repose directly
on the Bunter Pebble Beds. Nor do they appear to be present
between the Derwent and the Hrewash. Crossing that stream, how-
ever, we again meet with them—at Bramecote, Notts—as a few feet
of calcareous sandstone cropping out from beneath the “ Waterstones.”
They are found at Highfields, two miles nearer Nottingham, resting
on an eroded surface of Bunter Pebble Beds. Here they consist of
about seven feet of thick-bedded cemented quartzose grit, with
bands of compact conglomerate. They are also exposed in a small
boss of rock, at their outcrop near Rough Hill Wood—the most
easterly point at which they are to be seen in this country. We
have not attempted to trace these rocks further south than Burton-
on-Trent, near to which they are to be seen at Bladon Hill, in the
Trent escarpment, as white quartzose false-bedded grits, with thin
grey micaceous sandstones. Red grit and pebbly sandstone, ap-
parently belonging to this series, are exposed near Ticknall, South
Derbyshire, between Heath Wood and Seven-Spouts. These beds are,
however, absent further east at Melbourne and at Castle Donington.
Conclusions.—To arrive at satisfactory conclusions as to the
physical conditions under which the Basement Beds of the Lower
Keuper were formed, is no easy matter. That these rocks are all of

1 Hull, “ On the South-easterly Attenuation of the Secondary Rocks of England,”
Quart. Journ. Geol. Soc. vol. xvi. p. 66.
? Hull, ‘‘ Triassic and Permian Rocks of the Midland Counties.”

Dr. H. Woodward—On Fossil Shells from Sumatra. 535

the same age, and have all had a common origin, their remarkable
uniformity in mineral character and in physical structure, in dis-
tricts so widely separated as Cheshire and Nottingham, satisfactorily
demonstrates. The easterly attenuation of these beds indicates that
their source lay in an opposite direction, whilst the nature of their
materials—the angular grains of quartz, the abundance of mica, and
the abundance and often undecomposed state of the felspar in the
sandstones, point to their derivation from the breaking up of crystal-
line rocks such as granite and highly altered schists. ‘These
sediments appear to have been drifted by westerly currents along
a strait or series of shallow channels, that in early Keuper times
stretched across the Midlands, and which, owing to preponderating
subsidence in that direction, covered a large area in the west, but
became narrower towards the east. This channel was shut in by
the southern flanks of the Pennine Hills on the north, and by the
Carboniferous rocks that flank the Leicestershire Coal-field and
Charnwood Forest on the south. For, north of a line drawn through
Alton, Derby, and Nottingham, the Basement Beds rapidly thin out,
while east of Burton-on-Trent they likewise speedily attenuate, and
eventually disappear; nor have we any reason for supposing that
they were ever deposited any distance north or south of where we
now find them.

TV.—Furturr Nores on a Couuection oF Fossin SHELLS, ETC.,
FROM SUMATRA (OBTAINED BY M. VeRBEEK, DireCTOR OF THE
GEOLOGICAL SURVEY OF THE West Coast, Sumatra). Parr IV.!

By Henry Woopwarp, LL.D., F.R.S., etc. ;
of the British Museum.
(PLATES XIV. anp XV.)

50. Triton, sp. (cast of). Pl. XIV. Fig. 1.

This cast indicates a fusiform turrited shell adorned by discon-
tinuous varices ; the spire is wanting; it also shows that the shell
was transversely ribbed and corrugated; the outer lip was strongly
plicato-dentate internally ; the aperture rather small; canal mode-
rately long.

From the general aspect of this cast, I think it probably may be
referred to the Triton corrugatum, Lamk., so widely distributed in
our European Miocene deposits; and found living in Vigo Bay
(S. P. Woodward) and in the Mediterranean.

Formation :—In light-coloured (Miocene) Tertiary clay-marl.

Locality :—Government of the West Coast of Sumatra.

51. Pleurotoma terebra, Basterot, 1825. Pl. XIV. Fig. 2a, b.

Pleurotoma terebra, Basterot, 1825, Mém. géologique sur les Env. de Bordeaux.

Paris, 1825, pl. 3. fig. 20.

multinoda, Des Moulins, 1843, Revision des Pleurotomes ; Actes Soc.
Linn. de Bordeaux, tome xii. p. 167.

Dufourti, Des Moulins, op. cit. p. 180.

(Clavatula) sinensis, Hinds, 1843, Proc. Zool. Soe. p. 38, pl. v. fig. 10,
and 1844, Zool. Voyage of H.M.S. Sulphur, vol. ii. p. 17, pl. v.
imieers TL

1 Continued from the November Number, p. 500.

536 Dr. H. Woodward—On Fossil Shells from Sumatra.

Shell fusiform, costellated, transversely striated, whorls 8-9 in
number, somewhat angular, tabulated above, smooth ; cost thick,
prominent at the angles, truncated above; suture marginated ; aper-
ture scarcely equal to half the length; canal straight; columella
smooth ; lip thickened, expanded, striated within, sinus deep, rounded.

After instituting a careful comparison between this Sumatran
fossil and a series of very similar forms from the Miocene faluns of
Touraine, Dax, and Bordeaux, obtained by M. Deshayes for the British
Museum, and figured and described by MM. Basterot, and Des
Moulins, I have arrived at the conclusion that this Pleurotoma, Pl.
XIV. Fig. 2a, 6, is identical with the Pleurotoma terebra, Bast.,
and that Pl. multinoda, Des Moulins, and Pl. Dufourit, Des Moul.,
must also be considered as synonymous with it, and with the
Sumatran species; the variations which they present being only
individual, and too trivial to be treated as of specific value.

I have further compared this Sumatran fossil with the Pl. (Clava-
tula) sinensis of Hinds,—a recent shell found living at New Guinea,
the Straits of Macassar, Celebes, in the China Seas, and at Malacca ;—
and in doing this I have had the benefit of the opinion of my colleague
Mr. Edgar A. Smith, of the Zoological Department. The chief differ-
ences appear to be in the form and proportion of the last whorl to
the entire length of the shell, the last whorl being smaller and
shorter in the recent shell, than in the fossil. In the Sumatran fossil
it is less contracted and attenuated towards the base, and occupies
nearly half the entire length, but in Pl. sinensis it is much shorter
in proportion. In the latter, the upper part of the volutions is more
concave beneath the wavy keel, or ridge, which borders their margin,
and the costee or plice: are more prominent and slightly more angular.
The spiral or transverse sculpture offers but little difference in the
two species.

In all the larger specimens of this form from Bordeaux (especially
in Pl. terebra, and Pl. multinoda) the aperture is always consider-
ably less than half the entire length of the shell; but in the smaller
French specimens the proportions are nearly the same as that of
the smaller Sumatran one. The spire of the smaller specimens is
also more acute.

The following are the relative dimensions of the species of Pleuro-
tome referred to :—

Large Specimen. Small Specimen.

Cs |e. ea 3s |S.) as
Species of Plewrotoma proposed to be s £ oa Sa SS ao gs
placed together. 2s bei we ay bp BEA

s = @ AAS oe So Ax

=| A< | S

Pleurotoma terebra, Bast. Sumatra ...| 12 30 10 8 16 6
=== », Bordeaux...| 10 26 8 7 19 i

multinoda, Lamk. Sau-

lominges, IDE, 65 con) il 30 10 9 17 a

Dufouri, Des Moul. Dax.) — = = 7 17 6

sinensis, Hinds (recent) ...| 9 22 7 7 17 6

GEOL. MAG. 1879. . TSAR CuO Ae IE WOR. Wal, ISI AatIe Saye

C.L.Griesbach del. et lith West, Newman & 0° imp.

: pumatran Tertiary Shells.

XV.

DECADE II. VOL. VL PLATE

GEOL. MAG.1879.

imp.

°

West,Newman & C

C.L. Griesbach del. et lith.

Sumatran Tertiary Shells.

Dr. H. Woodward—On Fossil Shells from Sumatra. 537

Although the divergence pointed out between our Sumatran
shell and the recent Pleurotoma sinensis of Hinds may be deemed
sufficient in the eyes of recent students of Malacology to separate the
two specifically, yet we venture to think it probable that we have in
Pl. sinensis, Hinds, only the modern representative of the Sumatran
fossil, and also of the Pl. terebra, Bast., with its associated forms
from the Miocene of France.

Should this view find favour, then four species, hitherto separated,
will in the future be enrolled under one name, as I. terebra, Bast.,
or be treated as varieties only, a method particularly convenient
in dealing with genera of Mollusca, which are extremely rich in
species and varieties, like Pleurotoma.

Formation :—In bluish-grey Tertiary Marl-clay.

Locality :—Government of the West Coast of Sumatra.

52. Pleurotoma concinna, Dunker, 1856. Pl. XIV. Fig. 3a, 6.
Proc. Zool. Soc. Lond. 1856, p. 356.

The following is a translation of Prof. Wm. Dunker’s description
of Pleurotoma concinna :—

Shell acutely-turrited, subfusiform, solid; colour light-reddish
brown; mouth and canal roseate, encircled with elevated lines and
ridges; whorls about 10, slightly convex; suture indistinctly divided;
last whorl scarcely equal to the height of the spire; canal sub-
oblique ; fissure in outer lip deep.

Dimensions of recent shell: length 27 mm.; greatest breadth 9 mm. ;
length of aperture 12 mm.

There can be no doubt of the identity of our fossil, Pl. XIV.
Fig. 3, with the living Plewrotoma concinna, of Dunker, specimens
of which are preserved in the British Museum, said to have been
obtained from Sibonga in the Philippine Islands, and from New
Treland. It differs from that species, at first sight, in being shorter
and of Jess slender build, with a shorter basal canal. (The length
of the canal, however, should in all probability have been greater
than the artist has represented in our Figure, as the extremity of the
canal is certainly abraded.)

The whorls in the fossil are more deeply excavated than in the
recent specimens, both above and below the central carina, the
nodules of which are more clearly defined in the fossil. The other
spiral liras and oblique sculpture also offer certain differences. The
suture is less deep in the fossil than in the recent shell from New
Ireland, but equals that of the type specimen. In the fossil form
the surface reticulations are more strongly marked than in the
recent species, approaching in this respect more nearly to the
Pl. cataphracta of Brocchi from Dax. It agrees also with Pl.
Hantoniensis, Hdw., in having the line of tubercles upon the central
carina divided into two; but the strie in Pl. Hantoniensis are some-
what coarser and less markedly reticulated. This shell might also
be compared with Plewrotoma turbida, Solander, and Pl. granata,
Edw. Near the apex the four earliest whorls of the young shell in
the fossil are seen to be roundly inflated and simply ribbed longi-

538 Dr. H. Woodward—On Fossil Shells from Sumatra.

tudinally. The apex in Pl. cataphracta, and less markedly so in
the recent Pl. concinna, exhibits the same embryonal character.

Dimensions of fossil:—Length of smaller shell 18 mm.; of larger
Specimen (anterior canal partly broken off) estimated at 21 mm. ;
breadth smaller shell 74 mm. ; larger specimen 84 mm.

Formation :—In bluish-grey Tertiary Marl-clay.

Locality :—Government of the West Coast of Sumatra.

53. Phos Borneensis, Sowerby, 1866. Pl. XIV. Fig. 4a, 0.

Shell subfusiform, turrited, encircled with distant spiral lire and
prominent nodular rounded ribs, finely striated between the ribs;
costze narrow, somewhat distant (the regularity of the ornamenta-
tion is occasionally broken by a few discontinuous varices, more
prominent than the equidistant coste); thickened on the varix
behind the aperture; aperture narrow below; canal subrostrate; hp
corrugated within; whorls 7-8 in number.

Dimensions :—Height of shell 21 mm.; breadth of shell 10mm.

This shell appears not to be separable specifically from the living
Bornean form. The whorls are perhaps a trifle less shouldered at
the upper part, the spiral lire are more numerous, and the minute
or subordinate sculpture is also of a finer character.

The thread-like lirations within the aperture are more numerous,
and the oblique simple keel which winds round the extremity of the
body-whorl is more distinct. These are but trifling differences, and
hardly sufficient to entitle the Sumatran fossil to separate specific
rank. The general facies of this fossil and normal examples of the
living shell is remarkably similar, the proportion of the whorls being
identical.

Formation: —In bluish-grey Tertiary Marl-clay.

Locality :—Government of the West Coast of Sumatra.

54. Phos subplicatus, H. Woodw. (not figured).

Shell solid, turrited, liree seabrose, cost nodular, spirally cinctured ;
spire short, 5-6 whorls, whorls somewhat rounded; coste rounded,
tolerably close, more numerous near the aperture.

Dimensions :—Height of shell 12 mm.; greatest breadth 7 mm.

The shell of this species is much saantier in the spire, and
increases in size more rapidly than that of the preceding one. It
closely resembles the Phos plicatus, A. Adams (Proc. Zool. Soc. 1859).

It differs from the recent Phos plicatus in the less angularity of
the whorls and the more rounded character of the ribs; they are
also less close-set than in the recent form.

We have ventured to consider this as distinct.

Formation and Locality :—Found with the preceding species.

55. Turbinella subcostata, H. Woodw. Pl. XIV. Fig. 5, a, b.

Shell fusiform, subturrited, thick; spire with the sutures some-
what squamose, whorls about 7 in number, with prominent rounded
coste transversely plicated ; plicee about three in number (more
numerous upon the body-whorl); plications acute; aperture small,
ovate, and canaliculate, posteriorly notched, sulcated within; columella
thickened and subtransversely triplicated; canal moderately long.

Dr. H. Woodward—On Fossil Shells from Sumatra. 539

Dimensions :—Height of shell 174 millimétres; greatest breadth
8 mm.; length of aperture 8 mm.

This shell approaches nearly to the Turbinella subcraticulata of
D’Orbigny, figured by Dr. Hoérnes (in Die Fossilen Mollusken des
Tertiaer-Beckens von Wien, fol. 1856, Band I. p. 302, taf. 58,
figs. 10 a, 6),—a species also found at St. Paul, near Dax. The
Sumatran shell has, however, a less acute spire than that from the
Vienna Basin ; the canal is straighter, the aperture smaller, and the
body-whorl less in-proportion. ‘The spiral lirations are also fewer.

Formation and Locality :—The same as the preceding species.

56. Pisania subdiscolor, H. Woodw. PI. XIV. Fig. 6.

Shell elongated, fusiform, apex sub-acute, whorls six in number,
spire delicately cancellated, body-whorl finely striated; aperture
somewhat elliptical, one-half the entire length of shell, inner border
of outer lip canaliculate; denticulated near the posterior extremity,
anterior canal slightly produced, and notched; columella smooth,
slightly thickened, with a smali denticulation near the posterior
extremity of the aperture.

Dimensions :—Height 10 mm.; breadth 5 mm.

Most of the species belonging to this genus are represented by
small shells which have very generally been confounded with
Buccinum, Murex, Ricinula, and Nassa.

These shells have numerous indistinct varices, or are nearly
smooth and spirally striated; the canal short, inner lip wrinkled,
outer lip crenated.

Our Sumatran shell might easily be mistaken for a dwarfed form
of Pisania (Buccinwm) discolor (Quoy and Gaimard, Voyage de
l’Astrolabe, 1832, Zoologie, tome ii. p. 422, pl. 80, figs. 23-25),
specimens of which in the British Museum are labelled as from the
“China Seas.” On close inspection, however, the whorls are seen
to be more numerous, the apical ones being smaller and less mam-
millated in character. The last whorl is a trifle more constricted just
below the middle, and_ the basal canal is a little longer. The style of
sculpture and proportions of the whorls, however, are very similar.

It may also be compared with the Pisania (Nassa) Andrei, Bast.
(1825), pl. iv. fig. 7, from the Miocene of Bordeaux.

Formation :—Grey Tertiary Marl-clay.

Locality :—Government of the West Coast of Sumatra.

57. Ranella ? tritonoides, H. Woodw. PI. XIV. Fig. 7.

Shell subturrited, ventricose (lateral varices scarcely so continuous
as in most of the species referred to this genus, and for that reason
doubtfully placed under it); transversely lirate, liree numerous,
three being more prominent than the rest, and becoming more dis-
tinctly marked as they pass over the coste; longitudinally costated,
coste prominent, body-whorl somewhat ventricose, aperture ovate,
dilated anteriorly, obliquely canaliculate, columella obscurely
biplicate.

Neither of the two specimens of this shell have the mouth perfect.

Formation and Locality :—With the preceding.

540 Dr. H. Woodward—On Fossil Shells from Sumatra.

58. Borsonia granifera, H. Woodw. Pl. XIV. Fig. 8.

Shell fusiform or biconical ; spire conical, acute, sutures scarcely
marked, body-whorl equal in length to the spire, aperture narrow,
outer lip ridged, columella with one prominent fold, surface
ornamented with numerous transverse ridges distinctly granulated,
the two ridges near the suture being more prominent than the rest.

Dimensions :—Height 15 mm. ; breadth 8 mm.

This shell may be compared with species of the genus Conorbis
of Swainson, and particularly with C. dormitor, Solander, from the
M. Eocene, of Barton, Hants, etc. (Edwards, Eocene Moll. part iii.
1856, p. 200, tab. xxiv. fig. 11 a, b, c, Pal. Soc. Mon.), from which
it differs, however, in being more tumid and in the granulated
nature of its ornamentation. ‘The prominent fold on the columella
is also wanting in that species.

Formation and Locality :—Found with the preceding species.

59. Cerithium Verbeekii, H. Woodw. PI. XIV. Fig. 9 a, 6.

Shelli turrited, volutions nine to ten in number, flattened ; suture
distinct, each volution with about four rows of prominent transverse
tubercles separated by distinct striz; granulated on the body-whorl,
tubercles arranged in regular rows; aperture sub-rotund, outer lip
thickened, the inner margin very prominently crenated, inner lip
slightly arcuate, posterior canal well marked, anterior short and
oblique.

Dimensions :—Height 20 mm.; breadth 10 mm.

This shell may be compared with the Cerithium Duboisii of
Hornes, 1856 (Fossilen Mollusken des Wiener Beckens, p. 399, taf.
42, figs, 4and 5). It differs, however, from this Austrian species,
in being more robust in its spire, in the larger size of its body-
whorl, in the aperture not being inflated, and lastly in possessing a
thickened and prominently crenated outer lip.

I dedicate this species to Mynheer Verbeek, the Director of the
Geological Survey of the Government of the West Coast of Sumatra,
whose careful researches have resulted in so large an addition being
made to our geological and paleontological knowledge of this
distant region of the earth.

Formation and Locality :—Found with the preceding species.

60. Pleurotoma (Glyphostoma, Gabb) Jonesiana, H. Woodward.
Pl. XIV. Fig. 10a, 6.

Shell subfusiform, spire elongate; volutions somewhat convex,
longitudinally costated, costes prominent, nearly straight and orna-
mented or crossed by from three to five transverse ridges or lire;
suture distinct and depressed, ornamented or marked with curved
ridges, more numerous than the coste; aperture narrow, elongate,
outer lip thickened, and strongly denticulate, inner lip distinctly and
closely plicated; canal slightly produced and recurved; ornamentation
on body-whorl somewhat moniliform in consequence of the greater
prominence of the transverse striz as compared with the coste.

Dimensions :—Height 22 mm.; breadth 10 mm.

This form presents a general resemblance to the Pleurotoma strom-

Dr. H. Woodward—On Fossil Shells from Sumatra. 541

billus of Dujardin (Mém. sur les Couches du Sol en Touraine, 1835,
Mém. Soc. Géol. France, p. 290, pl. xx. fig. 15), but in that species
the volutions are more tabulate, and the aperture is wider and shorter,
and less distinctly denticulated.

It may also be compared with the illustrations of the same species
given by Hornes, p. 79, t. 40, figs. 1 and 2 (1856, Fossilen Mollusken
des Wiener Beckens) from the Vienna Basin.

I dedicate this species to my esteemed friend Prof. T. Rupert
Jones, F'.R.S., F.G.S., to whose kindness I am indebted for the oppor-
tunity of examining and describing this very interesting collection of
Sumatran fossils.

Formation :—In bluish Tertiary Clay-marl.

Locality :—Government of the West Coast of Sumatra.

61. Ranella? sp. (cast). Pl. XTV. Fis. 11.

Judging from the presence of continuous varices on this cast, we
should attribute it to a species of Ranella. It represents an elongated
turrited shell, with convex, rapidly-increasing, transversely-costated
volutions ; outer lip strongly denticulated within ; varices continuous.

Dimensions :—Height 28 mm. ; breadth 14 mm.

Formation :—In white Tertiary Clay-marl.

Locality :—-Government of the West Coast of Sumatra.

62. Turbo Smith, H. Woodw. Pl. XIV. Fig. 12.

Shell somewhat pyramidal, imperforate, volutions convex, whorls
about five in number, banded with numerous parallel spiral lire,
the larger ones prominently tuberculated or moniliform, the inter-
vening ones, especially on the body-whorl, being less distinctly
marked, the ornamentation becoming more squamose on the body-
whorl ; aperture plain, ovate.

Dimensions :—Height 17 mm.; breadth 15 mm.

I venture to name this species after my colleague Mr. Edgar A.
Smith, F.Z.S., whose kind assistance has been at all times most
willingly afforded me in my researches.

Formation :—In white Tertiary Clay-marl.

Locality :—Government of the West Coast of Sumatra.

63. Turbo Sumatrensis, H. Woodw. Pl. XIV. Fig. 13.

Shell moderately thick, turbinate, spire rather elevated, whorls
tumid, slightly angular above, with numerous minute ridges crossed
by very oblique longitudinal strie, giving the shell a faintly reticu-
late appearance ; aperture circular ; ugg lip somewhat callous.

Dimensions :— Height of shell 8 mm.; breadth 8 mm.

This shell may. be compared with the Turbo squamulosus, Lamk.,
(see Deshayes, 1837, Descrip. des Coquilles Foss. des Envy. de Pari
Atlas, pl. 32) figs. 4 and 5), but the French specimen is more strongly
squamose and much larger in size.

Formation :—From Tertiary deposit ? (no matrix visible).

Locality :—Government of West Coast of Sumatra.

64. Monodonta submamilla, H. Woodw. PI. XIV. Fig. 14, a, b.

Shell subturbinate, smooth, rather thick, volutions five in number,
rounded; aperture subovate, oblique, produced, inner lip toothed,

542 Dr. H. Woodward—On Fossil Shelis from Sumatra.

callous, nonumbilicate, very faintly striated; columella solid, base
of shell somewhat flattened.

Dimensions :—Height T mm.; breadth 7 mm.

This shell presents some resemblance to the Monodonta mamilla of
Andrzejowski (figured by Hornes in Fossilen Mollusken des Tertiar
Beckens von Wien, p. 498, t. 44, fig. 8), but the whorls are not quite
so inflated in appearance as in our Sumatran form.

Formation and Locality :—With the preceding species.

65. Solarium Javanum? Martin. Pl. XIV. Fig. 15.

Shell orbicular, depressed ; umbilicus wide and deep; the upper
surface of each whorl encircled by about four sets of spiral moniliform
lire, margin of umbilicus strongly corrugated. So far as the very
imperfect state of this specimen permits us to form a comparison,
we have little doubt in referring it to the Solarium Javanum of
Martin (Die Tertiiirschichten auf Java, p. 74, tab. xiii. figs. 2, 2a),
but the Sumatran shell is much smaller.

Formation :—In bluish Tertiary Clay-marl.

Locality :—Government of the West Coast of Sumatra.

66. Turbo Martinianus, H. Woodw. PI. XIV. Fig. 16a, 0.

Shell orbicular, depressed; whorls 4 to 5 in number, convex, trans-
versely finely sulcated, sulci regular, very faintly and obliquely
striated between the sulcations; base of last whorl somewhat flat-
tened, umbilicus closed in the adult; in specimens in which the
callous has been removed by decortication, the shell is seen to be
deeply and widely umbilicated, the sides of the umbilicus being
striated within ; aperture of shell rounded.

This shell agrees closely in form and general ornamentation with
the Turbo planorbularis of Deshayes, from the Caleaire Grossier
Houdan (see Descrip. des Coq. Foss. des Env. de Paris, 1824, tome ii.
p- 258, pl. 33, figs. 19-22), but the French specimen is much smaller
and the umbilicus is not closed.

The French specimen is only 3 mm. in height and six in diameter.
The Sumatran shell is 11 mm. in height, and 15 mm. in diameter.

I have named this specimen after Dr. K. Martin, whose fine folio
memoir, with its excellent plates, Die Tertiarschichten auf Java
(1879), now in course of publication, promises, when completed,‘ to
be of great value to paleontologists.

Formation :—In whitish Tertiary Clay-marl.

Locality :—Government of the West Coast of Sumatra.

67. Turritella, sp. Pl. XIV. Fig. 17.

All that is preserved to us of this specimen is the upper part of
the spire of a Turritella, very near to the group of Turritella imbri-
cataria, in which the suture is very indistinctly marked (much less so
than the artist has represented in the Plate), and the volutions are
ornamented with a series of transverse ridges alternately larger and
smaller, the latter being more numerous than the former.

Formation :—In bluish-grey Tertiary Clay-marl.

Locality :—Government of the West Coast of Sumatra.

1 Part I. containing the Unzvalves, with fourteen plates, has already appeared
(Leiden, E, J. Brill, 1879, pp: 94, folio).

Dr. H. Woodward—On Fossil Shells from Sumatra. 548

68. Cerithium, sp. Pl. XIV. Fig. 18.

This is a portion of the spire only of a very much waterworn shell,
belonging to the group of Cerithium mutabile, showing the suture
bordered on each side by a line of tubercles both above and below,
with one or more intermediate striz. It may be compared with
the Cerithium Hellii of D’Arch. (Foss. Numm. de l’Inde, t. 29, fig. 1).

Formation and Locality :—Found with the above.

69. Strombus Sumatranus, H. Woodw. (cast). Pl. XIV. Fig. 19.

This specimen is near to, but is not to be identified with the
Strombus Javanus (also a cast), figured and described by Dr. K.
Martin (1879, in Die Tertiirschichten auf Java, p. 47, tab. ix. fig.
2), from Java. It is the cast of a rather ventricose shell, with a
slightly produced and costated spire ; aperture long, outer lip broadly
expanded, ear-shaped, corrugated within, and produced posteriorly
into a rounded lobe rising above and separate from the penultimate
whorl, notched at the anterior extremity ; inner lip striated.

In the S. Javanus the outer lip is semicircular and shorter pos-
teriorly, and the spire, which is more produced, numbering about 6
whorls, is smooth.

Dimensions :—Height 25 mm. ; breadth 19 mm.

Formation :—In light-coloured Tertiary Clay-marl.

Locality :—Government of the West Coast of Sumatra.

70. Delphinula fossilis ? K. Martin. Pl. XV. Fig. 1a, 0.

Shell orbicular, depressed; whorls few, angulated distantly and
obliquely undulated or costated above, bordered by about 10 spines
on the angle of the body-whorl; lirated and transversely striated
beneath ; peristome continuous, umbilicus open, aperture round,
internally nacreous.

Dimensions :—Height 25 millimetres ; breadth 85 mm.

The nearest recent form to this species appears to be the Delphi-
nula sphera, of Kiener. It agrees with this shell in general outline
and in the swollen undulations on the upper flattened surface of the
whorls; but may be distinguished from it by the difference of
character in the spines along the superior angle of the volutions,
which in D. sphera are very greatly produced, becoming quite
branch-like, whilst in the Sumatran fossil they are quite short and
much .compressed, resembling in this respect, to some extent, D.
aculeata, Reeve, an inhabitant of the seas around the Philippine
Islands.

Our Sumatran shell also closely resembles, in general appearance,
the D. fossilis of Martin from Java (Die Tertiirschichten auf Java,
1879, tab. xiii. fig. 4); but the transverse ridges on the last whorl
are rather more prominent on our shell than on the Javan fossil,
which is, unfortunately, only represented by a broken specimen, so
that we cannot fully compare it with this species. In our specimen
the longitudinal coste on the upper surface of the whorls are also
somewhat more prominent than in D. fossilis.

Formation :—In white Tertiary Clay-marl.

Locality :—Government of the West Coast of Sumatra.

544 Dr. H. Woodward—On Fossil Shells from Sumatra.

71. Xenophora agglutinans? Lamk. Pl. XV. Fig. 2.

The want of all trace of the exterior surface of this shell
precludes our determining it with precision. Jt may, however,
be compared with the Xenophora agglutinans, Lamarck, figured
by Dr. K. Martin in his work on Javan Fossils (tab. xii. fig. 6),
and with Vicomte D’Archiac’s figure of the Trochus cumulans, Brong.
(Foss. Numm. de l’Inde t. xxvi. fig. 16). The portion preserved
shows 5 to 6 whorls, on which numerous foreign bodies had been
agglutinated during the growth of the shell.

Dimensions :—Height 35 mm. ; breadth 45 mm.

Formation and Locality :—Found with the preceding species.

72. Natica, sp. (cast). Pl. XV. Fig. 3.

This is an imperfect cast of the last whorl of a large and very
tumid species of Natica; but the want of the spire and any external
shell-layer necessarily prevent any accurate description of this fossil.

formation and Locality :—Found with the preceding species.

73. Turbo (Senectus) setosus? Gmelin, Operculum of. Pl. XV. Fig. 4.

This is almost identical with the operculum of Turbo setosus,
Gmelin, a species at the present time found living in the Pacific.
The differences are so slight that they may be treated more as indi-
vidual peculiarities than as of specific value. The short granular
ridges, for instance, on the exterior, near the inner side just above a
groove parallel with the extreme margin, are coarser, and the sur-
face, from the centre to the opposite or outer margin, is less raised,
and more coarsely granulated than in the normal form of this oper-
culum. Both have an orange-red stripe bordering the outer edge.

Dimensions :—Greatest diameter 27 mm.; shortest diameter 25 mm.;
thickness 13 mm. _

Formation and Locality :—Found with the preceding species.

74. Cassis, sp. (cast). Pl. XV. Fig. 5.

At first sight this cast appears to be that of a Natica, with a some-
what produced spire ; but on examining the specimen closely, we at
once detect the impressions of denticulations’ on the interior of the
outer lip so characteristic in the genus Cassis.

Cast of shell ventricose, spire slightly produced, aperture long,
auriculate, outer lip denticulated.

This fossil may be compared with the Cassis Herklotzii of Dr.
Martin (Die Tertiirschichten auf Java, tab. viii. fig. 7), and also
with the figure of Cassis sublevigaster, D’ Arch. (D’Archiac and Haime,
Foss. Numm. de V’Inde, Pl. 31, fig. 4).

Formation and Locality :—Found with the preceding species.

75. Neritina subfossilis, H. Woodw. Pl. XV. Fig. 6, a, b.
Shell somewhat globose and auriculate, with a depressed and
nearly obsolete spire; surface smooth and shining,* body-whorl

1 Tn figuring this fossil Pl. XV. Fig. 5, the mouth-view only is given, so that one
cannot see from the drawing the crenulations or denticulations on the cast, marking
what was the character of the interior of the outer lip.

2 This coloration in the figure (see Pl. XV. Fig. 6, 6) unfortunately conveys to
the eye rather the appearance of corrugations or cross-ridges, but the surface is
really quite smooth.

Dr. H. Woodward—On Fossil Shells from Sumatra. 545

retaining its colour and ornamentation, which consists of concen-
trically arranged, somewhat elongated white spots upon an olive-
brown ground.

The painting of this shell calls to mind that of N. punctulata,
Lamarck, a living West-Indian species, but the form and columellar
region are different. This shell might also be compared with the Nerita
Rumphit of Martin (see Die Tertiarschichten auf Java, t. xiii. fig. 19).

Dimensions :—Height 7 mm.; breadth 14 mm.

Formation :—(Subfossil ?') Tertiary.

Locality :—Government of the West Coast of Sumatra.

76. Neritopsis Morrisianus, H. Woodw. Pl. XV. Fig. 7, a, b.

Shell subglobose, neritoid, thick, spire very short and small, sur-
face ornamented with numerous linear tuberculated lire of nearly
equal size, 15 to 16 in number, the tubercles being united to those in
the rows above and below them by delicate oblique striz ; aperture
subovate, inner margin of outer lip distinctly denticulate ; columellar
margin deeply notched.

Dimensions :—Height 11 mm. ; breadth 11 mm.

M. Grateloup, in 1832, established the genus Neritopsis, for a
fossil shell from the Miocene of Dax, Landes; which he named
N. moniliformis (Actes de la Société Linnéenne de Bordeaux (tome
v. no. 27, p. 125, pl. 38, fig. 1, 2). This species is four times as
large as our Sumatran shell, and agrees better with the living N.
radula, Linn., found in the seas around the Sandwich Islands.*
From both of these it may, however, be distinguished by its shorter
spire, the smaller number of the granular ridges and the coarser liree
within the labrum. The abrupt notch in the columella is of pre-
cisely the same form as in the recent species.

The operculum of the latter is a comparatively recent discovery.
It is of a thick shelly substance, and has a prominence upon the inner
side, which fits into the notch in the columella. It is described by
M. Souverbie (Journ. de Conchyliologie, 1874, vol. xxii. p. 199),
and in the succeeding volume of the same work by M. Crosse. The
curious fossil organisms from the Upper Lias of Normandy (Soane-
et-Loire and Calvados), from Wiirttemberg, and from the Coral-Rag
of England, upon which MM. Eudes and Eugéne Deslongchamps
founded their genus Peléarion in 1859, are only the opercula of a
species of Neritopsis.2 The operculum of Neritopsis has also been
named Scaphanidia by J. Miiller. Mr. Ralph Tate observes * of the
genus Peltarion, that it is “Founded on the mandibular armature of
Tetrabranchiate Cephalopods.”

1 The fresh condition and coloration of this shell render it difficult, in the absence
of more exact knowledge of these beds, to refer it to any but a very modern deposit.

2 Twenty fossil species of Neritopsis are described from the Trias?, Lias, and
Oolites. Dr. Hérnes has also figured a Neritopsis (which he refers to the recent
NV. radula) from the Vienna Basin. I find that Hornes considers Grateloup’s JV.
monilifera to be only a synonym of N. radula (Foss. Moll, des Wiener Beckens,

. 528, pl. 47, fic. 8).
H 3 See apie ee (Bull. Soe. Géol. France, 2e série, t. xxvi. 1869, p. 182).

4 Manual of Mollusca, by Dr. S. P. Woodward, Appendix by Ralph Tate, 1879,
pp- *12 and *13, fig. 11.

DECADE II.—VOL. VI.—NO. XII. 30

046 Dr. H. Woodward—On Fossil Shells from Sumatra.

I beg leave to dedicate this interesting Tertiary representative
of a Mesozoic genus, now almost extinct, to my valued friend and
colleague Prof. John Morris, M.A., F.G.S., whose stores of palzon-
tological knowledge are always so freely accessible to all his scientific
friends, and who has rendered me much valuable assistance in
preparing the present memoir.

Formation :—Tertiary Clay-Marl.

Locality :—Government of the West Coast of Sumatra.

77. Melania subfossilis, H. Woodw. Pl. XV. Fig. 8, a, b.

Shell fusiform, surface smooth, with fine longitudinal striae;
whorls 7 in number, spotted around the suture with brown spots ;
body-whorl with occasional brown streaks ; earliest volutions of spire
distinctly costated ; suture strongly marked; lower part of body-whorl
distinctly lirated ; aperture entire, oval, pointed behind, outer lip thin.

This shell, like the Neritina already noticed, has all the appearance
of having been living at a very recent date.

It is probably near to the Melania (Aulacostoma) levissima.

Dimensions :—Height 12 mm.; breadth 7 mm.

Formation :—(Subfossil ?) Tertiary.

Locality :—Government of the West Coast of Sumatra.

78. Melania rivularis? Philippi. Pl. XV. Fig. 9, a, 6.

The following is Philippi’s description of this species :—Shell
turrited, greenish ; apex decollated, whorls 7, convex, suture strongly
marked; transversely striated, the upper whorls marked with red
lines, the middle series with transverse spots below the suture;
aperture ovate-oblong, acute above, base expanded; lip near the
base somewhat produced (length 20 mm.; breadth, 6 mm.), (Abbil-
dungen und Beschreibungen Conchylien von Dr. R. A. Philippi,
band. ii. lief. 6, Cassel, 1847, 4to.)

The shell here figured agrees very well indeed with Philippi’s
description of Melania rivularis. but differs somewhat from his
fizure, which represents the whorls a trifle less convex and the
aperture a little more elongated and produced at the base. M. rivu-
laris is a Javanese form. M. fontinalis, of Philippi, is another
closely-related species, and in fact (as suggested by the author him-
self) may probably only be a local variety of the preceding species.
It is found in the aqueducts in the Island of Pulo Pinang.

Dimensions :—Height 16 mm.; breadth 5 mm.

Formation :—(Subfossil ?) Tertiary.

Locality :—Government of the West Coast of Sumatra.

79. Melania ? (cast). Pl. XV. Fig. 10.

This specimen makes us acquainted with an elongated cast show-
ing six convex volutions carinated near the suture; none of the
shell is preserved save the inner layer.

This cast might be compared with that of the Turritella Su-
bathooensis, D’Arch. (D’Arch. and Haime, Numm. Foss. de l’Inde,
t. 28, fig. 1), with which it agrees in general form.

If this be the internal cast of a Melania, of which there seems
little doubt, it affords some grounds for assuming that the very

Dr. H. Woodward—On Fossil Shells from Sumatra. 547

recent-looking Melania shells (Figs. 8, 9, 11, 12, and 13) may, after
all, prove to be exceedingly well- -preserved fossils from the same
series of clays of Tertiary age.

Dimensions of cast:—Height 60 mm.; breadth 25 mm.

Formation :—From white Tertiary Clay-marl.

Locality :—Government of the West Coast of Sumatra.

80. Melania pyramis (Benson), Reeve. Pl. XV. Fig. 11 a, b.

Shell elongated, fusiform, whorls 9-10 in number, slightly con-
vex, finely striated spirally, maculated, smooth, suture very distinct ;
body-whor! nearly equalling the height of the spire ; aperture entire,
oval, pointed above, outer lip sharp, columella smooth.

Dimensions :—Height 20 mm.: breadth 7 mm.

My colleague, Mr. Edgar Smith, has kindly assisted me in the
examination of this shell, which agrees very well in most of its cha-
racters with the Melania pyramis (Benson, Reeve, Conchologia Iconica,
xii. sp. 51), a Bornean species, the type of which is preserved in the
British Museum. The spiral sculpture is much the same in character,
but is only obsolete on a part of the last whorl, and not altogether
absent, as described by Reeve. In this statement he is scarcely
justified, for on carefully examining the figured specimen, a few
spiral striz can be distinctly traced; two other recent examples are
sculptured to the same extent on the last three or four whorls, as in
the Sumatran specimen; both the Bornean and Sumatran shells
agree in having a deeply canaliculated suture.

~ Formation -— (Subfossil ?) Tertiary.

Locality :—Government of the West Coast of Sumatra.

81. Melania sublactea, H. Woodw. Pl. XV. Fig. 12.

Shell elongated, fusiform, whorls nine in number, somewhat
convex; body-whorl equalling the height of the spire; without
colour-bands or ornamentation, save fine longitudinal striz ; suture
distinct, aperture somewhat small, entire, oval, pointed posteriorly ;
outer lip sharp, columella smooth.

Dimensions :—Height 17 mm.; breadth 7 mm.

This shell resembles the Melania lactea in form, but the whorls
are less in number (7), and are not quite so convex; the columellar
border of the recent shell is thickened, which is not the case with
the fossil one.

Formation :—(Subfossil ?) Tertiary.

Locality :—Government of the West Coast of Sumatra.

82. Melania costata, Quoy and Gaimard, 1884.

Melania costata, var. glabra, H. Woodw. Pl. XV. Fig. 18.

Shell subulate, elongated; spire acute; whorls 9, smooth, slightly
striped beneath the suture; upper volutions ornamented with fine
spiral strize, body-whorl nearly equal in height to the spire.

Dimensions :—Height 56 millimetres ; breadth 15 mm.

The shell here figured appears inseparable from the Melania costata
of Quoy and Gaimard, 1834 (Voyage de l’Astrolabe, Zoologie, tome
ili. p. 105, pl. 56, figs. 34-37), one of the most variable species in
form and sculpture of the whole genus. Certain specimens in the

048 Dr. H. Woodward—On Fossil Shells from Sumatra.

British Museum from the Philippine Islands are just of the same
smooth unplicated or uncostated character, with similar fine spiral
strie on the upper volutions, and painted with the same short reddish
stripes just beneath the suture, as in the Sumatran shell. The lip of
the latter is considerably broken away, and consequently displays a
less patulate aperture, and a different curve at the columella.

Formation :—(Sub-fossil ?) Tertiary.

Locality :— Government of the West Coast of Sumatra.

83. Dentalium, sp. Pl. XV. Fig. 14.

This is a fragment only of a smooth form of Dentalium, but the
Specimen is too fragmentary for description.

Formation :—In light-coloured Tertiary Clay-marl.

Locality :—Government of the West Coast of Sumatra.

In concluding this description of M. Verbeek’s Fossils, I must beg
leave to tender my best thanks to my colleague, Mr. Hdgar A.
Smith, of the Zoological Department, for his many notes and sugges-
tions with regard to recent species; also to my friend Prof. Morris,
M.A., for his kindly and valuable assistance in preparing this paper
for publication.

At the suggestion of Professor T. Rupert Jones, F.R.S., F.G.S.,
the whole of the specimens sent from Sumatra by M. R. D. M. Verbeek
have, with the sanction of the Dutch-Netherland Government, been
presented to the British Museum, where they are preserved for
reference.

EXPLANATION OF PLATES XIV. AND XY.
Puate XIV.

Fie. 1. Triton (cast of). In Grey Tertiary Clay-marl, Govt. West Coast Sumatra.
», 2. Plewrotoma terebra, Bast. In Bluish Tertiary Clay-marl ; loc. cit.
ahonito. concinna, Dunker. 13 0
et 4, eiaek "Borneensts, Sby. ‘a Bi
a 5. Turbinella subcostata, H. Woodw. a es
- 6. Pisania subdiscolor, H. Woodw. 5 ‘

99 7. Ranella ? tritonoides, H. Woodw. 0 39
5 8. Borsonia granifera, H. Woodw. “ iy
th 9. Cerithium Verbeekti, H. Woodw. % A
» 10. Pleurotoma Jonesiana, H. Woodw.
» ll. Ranella ? sp. (cast). In white Tertiary Clay-marl, 30
» 12. Lurbo Smithii, H. Woodw. os
» 13. 4, Swmatrensis, H. Woodw. Tertiary, dp
» 14. Monodonta submamilla, H. Woodw. _,, -
» 15. Solarium Javanum ? Martin. In bluish Tertiary Clay-mazl, ,,
» 16. Turbo Martinianus, H. Woodw. In white . op
» 17. Lurritella, sp. In bluish Tertiary Clay-marl, .
» 18. Cerithium, sp. oy
» 19. Strombus Sumatranus, H. Woodw. In white $0 7
Puate XV.

Fic. 1. Delphinula fossilis ? K. Martin. White Tertiary Clay-marl, Government
West Coast Sumatra.

ss 2. Xenophora agglutinans 2? Lamk. us loc. cit.
» 3. WNatica, sp. (cast). a: 3)
» 4. Lurbo setosus ? (operculum of). mS i
99 5. Cassis, sp. (cast). . >”
6. Neritina subfossilis, H. Woodw. Wariory: op

Notices of Memoirs—Limestone an Index of Time. 549

Fie. 7. Neritopsis Morrisianus, H. Woodw. Clay-mavrl, Tertiary, Zoe. cit.
5) 8. Melania subfossilis, H. Woodw. Tertiary,
@)

rivularis 2 Philippi. is

9 ” ” ’
» 10. 4, ?(castof). White Tertiary Clay-marl, ai
op, lle » pyramis, Benson. Tertiary, PA
an LDS » sublactea, H. Woodw. ,, 5
cm ge Se 1, _ costata, var. glabra, H. Woodw. Tertiary, ay
» 14. Dentalium, sp. Tertiary Clay-marl, Me

NOTICES OF MEMOIRS.

I.—“ Limestone aS AN INDEX or GerotocicaL True.” By T.
Metiarp Reaves, C.H., F.G.S. [From the Proceedings of the
Royal Society, No. 192, 1879. ]

HE geological history of the globe is written only in its sedi-
mentary strata, but if we trace its history backwards, unless we
assume absolute uniformity, we arrive at a time when the first sedi-
ments resulted from the degradation of the original crust of the globe.
There is no known rock to which a geologist could point and say
“that is the material from which all sedimentary rocks have been
derived,” but analogy leads us to suppose that if the earth had an
igneous origin, the original materials upon which the elements first
began to work were of the nature of granite or basalt.

From a variety of considerations drawn from borings, mines,
faults, natural gorges and proved thicknesses of the strata of certain
mountain chains, the author arrives at the conclusion that the sedi-
mentary crust of the earth is at least of an average actual thickness
of one mile, and infers from the proportionate amount of carbonates
and sulphates of lime to materials in suspension in various river
waters flowing from a variety of formations, that one-tenth of the
thickness of this crust is calcareous.

Limestone rocks have been in process of formation from the
earliest known ages, but the extensive series of analyses of water
made by Dr. Frankland for the Rivers Pollution Commission, shows
that the later strata in Great Britain are much more calcareous than
the earlier. The same holds true of the continent of Europe, and the
balance of evidence seems in favour of the supposition that there has
been on the whole a gradual progressive increase or evolution of
lime. The “Challenger ” soundings show that carbonate of lime in
the form of tests of organisms is a general deposit characterizing the
greater part of the ocean bottoms, while the materials in suspension
are, excepting in the case of transport by ice, deposited within a
distance of 200 miles of land.

This wider distribution in space of lime, the author thinks, must
also profoundly influence its distribution in time, and he shows this
by example and illustration. It can also be proved to demonstration
that the greater part of the ocean bottom must at one time or another
have been land, else the rocks of the continents would have become
gradually less, instead of more, calcareous.

Thus the arguments drawn from the geographical distribution of
animals are reinforced by physical considerations.

500 Notices of Memoirs—Limestone an Index of Time.

The author goes on to show that the area of granitic and volcanic
rocks in Europe and the part of Asia between the Caspian and the
Black Sea, as shown in Murchison’s Map of Europe, is two-twenty-
fifths (325) of the whole; much of this is probably remelted sedi-
ments, and some of the granites the product of metamorphism.

From considerations stated at length, it is estimated that the area
of exposures of igneous to sedimentary rocks would be for all geo-
logical time liberally averaged at one-tenth (35) of the whole.

These igneous rocks are either the original materials of the globe
protruded upwards, or they are melted sediments or a mixture of the
two.

The only igneous rocks we know of are of the nature of granites
and traps. If these rocks do not constitute the substratum of the
earth, and all known rocks, igneous as well as sedimentary, are
derivative, either geological time is infinite, or the rock from which
they are derived is, so far as we know, annihilated geologically
speaking, and we have no records of it left.

If we assume the latter as true, the past is immeasurable, but in
order to arrive at a minimum age of the earth, the author starts from
the hypothesis that the fundamental rocks were granitic and
trappean.

From eighteen analyses by Dr. Frankland, it is shown that the
water flowing from granitic and igneous rock districts in Great
Britain contains on an average 3°73 parts per 100,000 of sulphates
and carbonates of lime.

The amount of water that runs off the ground is given for several
of the great continental river basins in Europe, Asia, Africa, and
America. The annual depth of rain running off the granitic and
igneous rock areas, taking into consideration the greater height at
which they usually lie and the possibility of greater rainfall in
earlier ages, is averaged at 28 inches, and the annual contribution of
lime in solution in the forms of carbonates and sulphates at 70 tons
per square mile.

With these elements, and giving due weight to certain physical
considerations that have been urged in limitation of the earth’s age,
the author proceeds to his calculations, arriving at this result, that
the elimination of the calcareous matter contained in the sedimentary
crust of the earth must have occupied at least 600 millions of years.
The actual time occupied in the formation of the groups of strata as
divided into relative ages by Prof. Ramsay, is inferred as follows :—

MILLIONS oF YEARS.

Laurentian, Cambrian, and Silurian ..... ...... Bee Eee i teae 200
Old Red, Carboniferous, Permian, and New Red ............... 200
Jurassic, Wealden, Cretaceous, Eocene, Miocene, Pliocene,
and uPostlvocene meceeeeeeteeeereadececoecseestocenecece sees 200
—— 600

The concluding part of the paper consists of answers to objections.
The author contends that the facts adduced prove geological time to
be enormously in excess of the limits urged by some physicists, and
ample to allow on the hypothesis of evolution for all the changes
which have taken place in the organic world.

Notices of Memoirs—Fossil Forests of Yellowstone Park. 551

II.—Fossiz Forests oF THE YELLOWSTONE Park.

kh. W. H. HOLMES has given a brief but interesting account of
the voleanic Tertiary beds of the Yellowstone region (Bull. U.S.
Geol. and Geog. Survey of the Territories, vol. v. p: 125), which are
stated to cover or to have covered an area of not less than 10,000 square
miles. The chief materials consist of volcanic fragments apparently
distributed by water, and now form breccias, conglomerates, and sand-
stones, and contain an abundance of silicified wood. Where typically
developed, as in the valley of the Hast Fork, they have a thickness
of 5,000 feet, and rest upon eroded surfaces of granitic and Paleozoic
rocks. The lowest observed occurrence of these beds is in the
valley of the main Yellowstone, between the first and second cajions,
at an elevation of about 5,000 feet above the level of the sea. They
appear to be destitute of animal remains, but the greater part of this
immense group of strata is filled with the silicified remains of a
multitude of forests. The roots and stems are found in situ, and
prostrate trunks are of frequent occurrence, besides branches, leaves,
and fruits. These old forests are well exposed at successive levels
in the 2,000 feet of strata exposed on the north face of Amethyst
Mountain, and from the character of the vegetation, Prof. Leo
Lesquereux considers the strata to belong to the Lower Pliocene or
Upper Miocene. In many cases the wood is completely opalized or
agatized, and the cavities are filled with beautiful crystals of calcite,
quartz, and amethyst. J.

I1I.—Rerort on THE SrormBERG Coan-FIeELD. By Mr. HE. J. Duny.
4to. pp. 86. (Solomon & Co., Cape Town, 1878.)

N R. DUNN describes the constituent strata of the Stormbergen

as—at top—l. Volcanic: lavas, tuff, agglomerate, ash-beds,
and amygdaloids, with volcanic bombs in sandstone, about 400 feet.
2. Cave-sandstone: buff-coloured, pinkish, greenish, white and
grey, fine-grained, thick-bedded sandstone; about 150 feet; with
fragments of Sauroid bones. 3. Red beds: friable, red and purple,
arenaceous shale, and similar sandstone, mottled green, alternating
with grey felspathic sandstones, also conglomerate (p. 8) ; about 600
feet ; with Sauroid bones; and fossil wood in the lower beds, scarce.
4, Coal-measures: grey and light-coloured sandstones, generally
felspathic, alternating with shales, in which coal-seams occur, and
conglomerates ; about 1,000 feet; carbonized plant-remains abundant
in the sandstones, ferns in the shales; fossil wood abundant ; fossil
bones very rare. Doleritic dykes penetrate the whole series. The
“ Stormberg ”’ strata, he says, continue throughout the Drackensberg
range, and the series is as strongly marked near Harrismith as in
the Stormbergen. They lie conformably on red, greenish, and grey
shales, with grey sandstones, rich with Dicynodont and _ other
reptilian remains. Mr. Dunn separates the latter series, as “ Upper
Karoo Beds,” from the former (as “Stormberg Beds”) ; but why
the whole should not remain, as heretofore, as parts of the great
‘‘ Karoo Formation ” of A. G. Bain, is not at all clear.

The Coal-bearing beds of the Stormberg as seen on the north

502 Notices of Memoirs—Report on the Stormberg Coal-field.

side (Albert), and the conditions of working, are described at pages 5
and 6 and 16-383. The seams of coal are not numerous nor thick;
the aggregate being not more than 6 feet 6 inches, at Bushman’s
Hoek and the Indwe River, with 4 feet more represented by “ one
or two thin seams of inferior coal, occupying a higher position in the
series,” a few miles to the south. Ferns from the coal-shales are
identified (p. 19) with Pecopteris odontopteroides (p. 11), Cyclopteris
cuneata, and Teeniopteris Daintreet of Queensland.

The “‘ Red Beds” are described at pages 7-9. The ‘Cave Sand-
stone,” described at pages 9 and 10, forms conspicuous precipices,
being at some places a solid freestone more than 150 feet thick,
almost withont any lines of bedding. Water, running over its edge,
or oozing out from beneath, forms the numerous caves to which it
owes its name. One of these is 330 feet wide at the entrance, 144
feet deep, 60 feet high at mouth, lessening to nothing at the back of
the cave. The kloofs (gorges), krantzes (precipices), kops (little
hills), blocks, caves, and fantastical masses (pulpit-rocks, ete.), of
this sandstone give rise to picturesque and sometimes grand scenery.
The felspathic material in this sandstone, acted on by infiltrating
rain-water, gives the calcareous stalagmite (drip-cale) seen in some
of the caves and krantzes. In this sandstone, as in the “ Coal-
measures” and ‘“‘ Red-beds,”’ ripple-marks and mud-cracks are present,
also “‘ tracks of crustaceans.”

The ‘“ Voleanic rocks” are described in detail at pp. 10-16. “Two
of the cores still preserve a crater-like form ;” these are of very
great interest, and are “Glat Kopjes” and “Telemachus Kop.”
Pipes, throats, flues, plugs, ete., of old voleanos are also met with
among the ‘“‘Stormberg beds” in the Nieuwveldt and Karreebergen
(near Caernarvon). ‘The numerous dykes of igneous rock all over
the region are referred to; also the agate-gravel of many rivers of
South Africa is noticed as having been derived from the amygda-
loids ; and the origin of “ pipe-agate,” as due to the uprise of steam
in hot vesicular and siliciferous lava from the damp ground over
which it flowed, is concisely stated among other interesting facts
connected with this division of South-African Geology.

We may mention that in the “Cape Monthly Magazine,” new
series, vol. ii. 1873, p. 60, is Mr. Dunn’s earlier report on the Storm-
berg Coal; and that Mr. Evans, of Queenstown, has given some
useful notes on the Stormberg Coal as known in 1870 (see the
“ Mining Journal,’ January 14, 1871); also that Mr. G. W. Stow,
F.G.S., has described and illustrated the Geology of Dordrecht and
other places north and south of the Stormberg, in the Quart. Journ.
Geol. Soc. vol. xxvii. 1871, pp. 523, ete.

In conclusion, Mr. Dunn states (p. 32) :—‘'The tract of country
over which coal-outcrops may be expected to occur on the South
slopes of the Stormberg, lying between Bushman’s Hoek and the
Indwe, has not been examined. From the position the coal-measures
occupy, it is clear that coal-outcrops will be found right round the
base of the Drackensberg, and equally clear that the seams are
thicker and the quality better the further they occur to N.E. from the

Notices of Memoirs—Report on Camdeboo, ete., Coal-beds. 558

Stormberg. In Natal, at Biggar’s Berg, is a seam of coal, eight feet
thick, of better quality than the Stormberg coal. In the Transvaal
equally thick seams of superior coal are known in the High Veldt.
A few outcrops are known in the Free State. Properly directed
explorations would result in tracing the outcrops through Kaffirland,
Natal, the Transvaal, and Free State. In the higher parts of Basuto-
land, and, in fact, along the higher portions of the Drackensberg chain
and its spurs, no coal will be found; the seams do not occur at such
altitudes.” Shee Ie

IV.—ReEport oN THE CamMpEBOO AND NiguwetptT Coat, Care or
Goop Horr. By HE. J. Dunn, Esq. 4to. pp. 24, with several
Sections and Plans. (Solomon & Co., Cape Town, 1879.)

HE occurrence of two sets of Coal-bearing beds on the N.H.

margin of the Stormberg (near Bushman’s Hoek), north of

Queenstown,—one of probably old ‘‘Carboniferous” age, and the other

belonging to the upper part (‘‘Stormberg”’) of the great Karoo Series,

—was indicated in the Quart. Journ. Geol. Soc. 1871, vol. xxvii. p. 52;

and, though the Report above noticed does not support that view,

something like it is now proved to be the case at about 150 miles

W. by 8. from Queenstown. Mr. Dunn has found an exposure

(inlier) of some underlying coal-bearing (anthracitic) strata, distinct

from the surrounding and unconformable Karoo Beds, at Buffel’s

Kloof, on a spur of the Camdeboo Mountains, between Graaf-Reinet

and Beaufort West; and again at Brandewyn’s Gat, by the Leeuwe

River, on a spur of the Nieuwveldt, 386 miles N.W. of Beaufort West,

and 100 miles W. of Buffel’s Kloof. By making careful sections of

the strata between Beaufort and Graaf-Reinet, and by examining the
sections opened out by the new railway running §.W. from Beaufort,
across the Dwyka, Bloed, and Buffel’s Rivers and the Wittenberg
range, Mr. Dunn has fully explained the relation of the horizontal

Karoo series as unconformable to the underlying tilted, folded, and

broken “ Ecca Beds,” with their inclosed and conformable “‘ Dwyka

Conglomerate” (Dunn). This remarkable rock, once thought to be

of igneous origin (‘‘T'rap-breccia,” etc.), is now known to be com-

posed of dense sandy mudstone and blocks, and to be probably of
elacial origin. Having thus successfully traced these Ecca Beds,
from the (Devonian or Carboniferous) sandstones of the Witteberg,
with which they are conformable, to the Camdeboo district, Mr.

Dunn shows good reason why the inlier of highly inclined coaly

rocks under the horizontal Karoo beds there are part of the Ecca

group; and the more so because anthracite and a highly carbonaceous
limestone occur in one part of that group of strata near Buttel’s

River on the Beaufort and Cape-Town line of railway.

The author, however, is not correct in stating that the Karoo Beds
have always been supposed to be conformable to the Heca Beds.
In 1857 and 1858 (‘Eastern Province Monthly Magazine,’ No. 17,
December, 1857, p. 187, and Quart. Journ. Geol. Soc. vol. xv. pp.
197, 198) the late Dr. Rubidge argued that in the Eastern Province
of Cape-Colony the “ plant-beds of Hcca” (the lower portion, at

054 Reviews—Dr. T. Sterry Hunt’s Ohemico-Geological Essays.

least) were of Devonian age, that they did not belong to the Karoo
series, and that the latter abutted against them unconformably ; and
these conditions are expressed in Mr. Pinchin’s sections in the Quart.
Journ. Geol. Soc., vol. xxxi. 1874, p. 106, pl. 4.

At Buffel’s Kloof the diggings and shaft clearly show that one or
more rather thick seams of coal (anthracite) in the underlying
inclined beds have been broken and crushed by a fault, and even
forced up into the higher fissures contained in the overlying
horizontal Karoo beds, which do not hereabouts contain coal.
The shales in which the coal is bedded contain “Glossopteris
and Calamites.” The value of these fossils in proving the exact
age of the bed depends on many circumstances; and, although not
quite so good as the Lepidodendron and Sigillaria from the northern
margin of the Stormberg, yet Calamites, at least, evidently belong
to beds below the Karoo Series, and Glossopteris may be old “Carbo-
niferous,” as in Australia.

Hcca shales with plant-remains in the Eastern Province, and fossil
wood on the Pataties and anthracite on Buffel’s River, in the West,
indicate this to be a carbonaceous formation. Mr. Dunn suggests

_that there may be plenty of good coal in the covered-up “ Ecca Beds”
of the Camdeboo and neighbouring hills, to be found by judicious
boring ; and, although the exposures now known show only crushed
anthracite, not only the crushing, but the metamorphic change from
coal (hydrocarbon) to anthracite (carbon) may there be due, as else-
where, to local pressure and disturbance.

The descriptions and sections in this Report elucidate the nature
and relative positions of the Eeca Beds (pages 6-10), and of the
lower portion of the Karoo series (pages 10-24) omitting the Stormberg
portion, well described in the foregoing Report, very satisfactorily, and
thus add very much to our knowledge of South-African Geology.

4 cee

REVIEWS.
Se

I.—Cuemicat anp Grotocican Essays. By Tuomas Srerry Hunv,
LL.D. Second edition. (London, Tribner & Co., 1879).
daa recent issue of a second edition of Dr. Sterry Hunt’s Chemical

and Geological Essays, which first appeared as a separate

volume in 1875, affords a fitting opportunity for noticing some of
the questions with which the author is so well qualified to deal. The
work consists of a series of papers published in various scientific
journals during the last twenty years, which are now reproduced
more or less verbatim, with short introductory notes occasionally
prefixed by way of explanation. There are twenty essays in all,
dealing with a variety of subjects, most of which may be grouped
under the following heads :—

1. Chemical and dynamical speculations on the early condition of
the planet, and on subsequent volcanic phenomena.

2. History of the crystalline rocks.

3. Essays in chemical geology not directly related to either of the
above subjects.

Reviews—Dr. T. Sterry Hunts Chemico-Geological Essays. 555

4, Purely chemical and mineralogical essays.

Some of these essays have appeared in the columns of this
Magazine, and we may, therefore, suppose that many of our readers
are familiar with them; but as the first and second group of essays
deal with subjects which have been provocative of constant and
progressive discussion, a brief notice of some of the points on which
they touch may not be without interest.

Chemical and dynamical speculations, etc.—A vision of chemical
cosmogony is presented to us about the period in the general
history of Kosmos, when the partially cooled globe—our planet—
began to settle down to what must always be a subject of interest
to a geologist, viz. the formation of the nearest approach to rocks
we can conceive. ‘Two principal hypotheses have been maintained
with respect to this consolidation. 1. That of a solid crust resting
on an uncongealed nucleus. This is perhaps the view which has
been most generally believed. 2. That solidification commenced at
the centre, and advanced towards the circumference, but that at the
close of this process a condition of imperfect liquidity supervened,
resulting in the formation of a superficial crust which retained a
liquid zone between itself and the solid centre. This portion of
uncongealed matter would be the seat of volcanic action, the evident
facts of a flexible crust requiring something of this sort.

In the lecture which he delivered at the Royal Institution in May,
1867, “‘ On the Chemistry of the Primeval Earth,” Dr. Sterry Hunt
adopted the theory of a solid crust, partly on the grounds that “numer-
ous and careful experiments show that the products of solidification
(always excepting water) are much denser than the liquid mass.”
To this view the late lamented David Forbes took exception, as
indeed he did to almost every point in our author’s lecture. The
consequence of this was a somewhat embittered controversy carried
on between these eminent geological chemists, for the most part in
the pages of this Magazine. That was a time when few persons
in this country availed themselves of chemistry and the allied sciences
in the study and grouping of the rock-masses; a time when almost
any rock that was green might be put down as a “greenstone,” and
when the numerous analyses which had been made on the Continent
and in America were almost unknown to our geologists. The return
of David Forbes from a long sojourn in foreign countries was marked
by a not unsuccessful effort on his part to assert the importance of
chemical geology. He thus acquired great and well-merited influence
in fashioning and controlling opinion in this country on all points
relative to the chemistry of rocks.

Although doubtless Dr. Sterry Hunt laid himself open to
criticism in some respects, as, for instance, when he states that “ quartz
can only be generated by aqueous agencies and at comparatively low
temperatures,” it may be questioned whether Forbes was particularly
happy in his criticisms or in the reasons by which he sought to
enforce them. Let us take, for instance, his appeals to the results
seen on a small scale in the cooling of melted metals; where, as
observed by Hunt, the conditions of a liquid congealing in an atmo-

i]

596 Reviews—Dr. T. Sterry Hunt's Chemico- Geological Essays.

sphere greatly below its own temperature, and having a crust growing
out from and supported by the sides of the vessel, are widely different
from those of a liquid globe slowly cooling beneath a very dense and
intensely-heated atmosphere.

The composition of the Harth’s crust and atmosphere are the next
subjects discussed. The original crust, says Sterry Hunt, is now
everywhere buried beneath its own ruins, and he considers that it
must have resembled certain furnace slags or volcanic glasses, whilst
the primeval atmosphere would contain all the carbon, chlorine, and
sulphur in the form of acid gases with nitrogen, watery vapour, and
a probable excess of oxygen. Forbes took strong objection to these
speculations, especially as regards the primitive atmosphere. No
excess of oxygen, he said, could exist with so much sulphurous
acid; moreover, hydrochloric and sulphurous acids at high tempera-
tures decompose each other with the formation of water, chlorine and
sulphur. From the affinity of sulphur for the metals, and from the
fact that sulphurous acid is decomposed by metals with the formation
of sulphides and oxides, he infers that this element (sulphur) in
reality united itself to the metals, and thus formed dense sulphides
which at once sank through the lighter fluid layer. So far as he
confined himself to criticisms, especially on the action of sulphur,
Forbes was pretty safe; but in his reply he unfortunately ventured
on the production of a rival atmosphere in zones, where, as eagerly
pointed out by his opponent, he forgot the specific gravities of some
of his gases, and altogether ignored the law of their diffusion. Those
who care to pursue this subject further will find the several papers
in the GEeotocicaL Macazine. (See 1867, Vol. IV., pp. 357, 483,
and 477, and 1868, Vol. V., pp. 49, 92, 93, 106, and 866.)

The subject of the earlier condition of the atmosphere is again
discussed by Dr. Hunt in the preface to the second edition, and he
alludes especially to the probabilities that even a very moderate
extra amount of carbonic acid in the atmosphere would diminish loss
of heat from radiation. He recalls to the minds of his readers the
enormous amount of carbonic acid now locked up in the earth’s
limestones, equal in weight to 200 of the present atmospheres. The
progressive diminution in the height of the atmospheric column has
been due to its elements having been condensed in the form of
liquid water, or fixed as hydrates, oxides, or carbonates; hence a
gradual refrigeration of the earth’s climate. The application of these
views is, he observes, contrary to the hypothesis of an alternation of
warm and glacial climates in past ages, but is more in accordance
with the facts of the geological story, where everything tends to show
that a warm climate prevailed everywhere at the sea-level. (Read in
conjunction with the highly suggestive and ingenious hypothesis
propounded by Mr. Ball at the Royal Geographical Society in June
last, which ‘really took Sir J. Hooker’s breath away,” we may
believe that we have now obtained some clue to the history of the
earth’s climate in time, which has been so long obscured by ice on
the brain.) The amount of carbonic acid which the life of the
successive ages could endure presents however the chief difficulty,
and is a physiological question which must doubtless be answered.

Reviews—Dr. T. Sterry Hunt’s Chemico- Geological Essays. 557

In discussing “The probable seat of Volcanic Action,” Dr. Hunt
alludes to a modification of the theory of the liquid zone between the
solid core and the crust, which he is inclined to adopt, whilst accepting
in the main the theory of Hopkins. This theory of Sterry Hunt is
Neptunean in the highest possible degree, but there is one point on
which he has always been staunch—viz. that the originating heat is
derived from the central mass. Indeed, he thinks it probable that
any chemical processes which may be set up in the buried sediments
for their conversion into igneous rocks and voleanic products would
absorb rather than generate heat. As some people, perhaps from an
instinctive dread of telluric heat, have exercised much ingenuity of
speculation on the causes of the heat of vulcanicity, it is satisfactory
to find that Hunt, though a Neptunist, has no difficulty on this point.
But he considers that, although in early times a yet unsolidified sheet
of molten matter may have existed between the solid core and the
superficial crust, such is not now the case. He believes that the
cushion on which the flexible crust undulates is in fact the base of
that crust impregnated with water and in a state of aquo-igneous
fusion. When there is an excess of pressure, this may tend to pro-
duce fluidity —the very reverse of Scrope’s idea that relief of
pressure effected this. Hence also the belief of Hunt that the
phenomena of volcanic eruptions are the most likely to occur under
the more recent formations, where he appears to conceive that there
is the greatest amount of pressure, and he endeavours to show,
though perhaps not very successfully, that the present distribution
of volcanic areas favours this view. Certainly the ancient volcanos
in Auvergne and the Hifel, piercing as they did rocks of high
antiquity, do not substantiate his case; and this is the more important,
as Dr. Hunt seems to predicate for the old crystalline areas an
immunity from volcanic disturbance in future.

The composition of the semifluid cushion is of course all impor-
tant. The existing crust being the water-deposited débris of the
primeval slag mixed with such precipitates as have from time to time
been abstracted from the liquids which condensed upon it, contains
all the substances and may yield all the phenomena of volcanic
eruptions. Hence it may be deemed self-containing, and requires no
reinforcement from below, the central solid core acting merely as a
stove to supply heat. There is no necessity therefore for the acidic
and basic magmas of Durocher and others, and the admitted division
of the rocks, both volcanic and crystalline, into what corresponds on
the whole to trachytic and doleritic, is capable of another explanation,
which also will better accord with the complex nature of the rocks
themselves. Such a separation has in fact been going on from the
very earliest times, owing to the effects of atmospheric waters, which
remove from the rocks soda, lime, and magnesia, leaving behind
silica, alumina and potash—the elements of granitic and trachytic
rocks. This action is more or less complete, according to the perme-
ability of the rocks, and thus arises a tendency to a division into two
classes of silico-argillaceous rocks constituting the bulk of the earth’s
crust,—doubtless an ingenious suggestion, though hardly meeting
cases such as that of the abundance of alumina in anorthic felspars.

558 Reviews—Dr. T. Sterry Hunt's Chemico- Geological Essays.

In 1878 we find Dr. Sterry Hunt complaining that, in his endeavours
to reconstruct dynamical geology on a new basis since 1858, his views
have been appropriated without acknowledgment by Le Conte,
Mallet, and others. Le Conte, we are told, says that the whole theory
of igneous agencies must be reconstructed on the basis of a solid earth,
a view adopted, and ably defended, but not originally propounded,
by Hunt, who takes the opportunity of pointing out that his theory
of the plastic zone of sediments affords the necessary cushion be-
tween the outer crust and the rigid central mass. There are, it must
be admitted, instances when people appropriate the doctrines of
others, after having opposed something like them for years, and this
may occur both in the political and scientific world. But we must
also bear in mind that great ideas are epidemic, and that discoveries
have at times been announced almost simultaneously from different
quarters. ‘The question of priority is often rather delicate, though
in one instance at least, as Professor Dana has admitted with
characteristic candour, Dr. Sterry Hunt’s claims to priority were
incorrectly denied.

History of the crystalline rocks.—This subject is so bound up on
the one hand with the questions already discussed, and on the other
with the geognosy of extensive areas both in the Old and New
World, that it may be regarded as a sort of connecting link between
the previous speculations and pure geology. Most of the former
questions are likely to remain open for some generations to come;
but in the history of the crystalline rocks we have more accessible
ground for discussion, and the subject is one in which geologists can
take an especial interest. Our author’s general declaration of faith
has appeared so recently in this Magazine (Gron. Mac. for 1878,
p- 466), that a very brief epitome will meet the case, viz. that the
various “ crystalline stratified rocks are not plutonic, but neptunean
in origin, and, except so far as they are mechanical sediments coming
from the chemical or mechanical disintegration of more ancient rock-
masses, were originally deposited as, for the most part, chemically
formed sediments or precipitates, in which the subsequent changes
have been simply molecular, or at most confined to reactions, in
certain cases, between the mingled elements of the sediments.” He
claims that some of the most enlightened students now favour the
neptunean origin of rocks; one of the most notable examples being
that of Delesse, at one time a pillar of the metamorphic school, who
has recently criticized the views of Yon Lasaulx and Knop with
regard to wholesale metasomatic changes, which Delesse designates
as métamorphisme a Voutranee. Hunt further quotes Delesse as
objecting to the idea of orthoclase being connected on the one hand
with the volcanic mineral leucite—from which the transmutationists
would derive it—and on the other hand with potash-mica supposed
to be formed from the orthoclase. He challenges his reader to com-
pare the above citations from Delesse with his own language on the
doctrines of pseudomorphism by alteration as applied by some who
would maintain the possibility of converting almost any silicate into
any other (vide also p. 824 et seq.). Finally, at the close of the preface

Reviews—Dr. T. Sterry Hunt’s Chemico- Geological Essays. 559

to the second edition of his Essays, he expresses his belief that J. D.
Dana has abandoned his former opinions on metamorphism, though
not to the extent that might be desired.

The essay on Granite and Granitic Veinstones (1871-1872) is a
very useful contribution. Dr. Hunt’s experiences are chiefly derived
from the Green and White Mountain Series, and from the Laurentians
in Canada and New York State. The distinction between granite
and gneiss must be made chiefly on geognostical grounds. As regards
granitic veins, the notion that all are the result of some process of injec-
tion is a general one, though the author has pointed out that some are
concretionary and of aqueous origin. He would call these rather
endogenous, to distinguish them from intrusive or exotic rocks (such
as granitic dykes) and from sedimentary or indigenous rocks. They
are in fact, according to this view, exfiltration veins, and vary from a
few inches (sometimes an isolated nodular mass almost like a geode)
to 60ft. or more. Such veins, to judge from numerous descriptions
given by him, often exhibit a banded structure with alternations of
minerals, as quartz and felspars (chiefly orthoclase), and frequently
contain fine crystals of different minerals, chiefly silicates. It is no
great strain upon our faith to believe in exfiltration as the origin of
hydrated silicates, as zeolites; but to attribute to such quantities of
anhydrous silicates a concretionary origin is a bolder conception.
Yet it is evident to any one who has studied a veined gneiss in section
that there do occur geodic cavities and strings filled with bands of
quartz and felspar in large masses, which seem to be cut off and
isolated. The difficulty in these cases has always been to understand
how the apple got into the dumpling. At the same time Sterry Hunt
considers that, although there is a distinction between open veins and
geodes formed in cavities, the contents, whether in granitic rocks or
fossiliferous limestones, are not sensibly affected thereby. Such vein-
stones must consequently be looked upon as a kind of extract of the
rocks, due to hydrothermal action, the many varieties resulting from the
changing composition of the waters which circulate in the fissures, or
are diffused through the rock itself.

It should be observed that in the Laurentians, the metalliferous
veins carrying galena, blende, pyrites, and chalcopyrite are more
recent than the veinstones just noticed, as the former cut the Pots-
dam sandstone, etc., whilst the latter group of veins are old enough
for the Potsdam sandstone to rest upon their eroded outcrops. This
fact may have an important bearing upon the origin of metalliferous
deposits; a subject discussed, in the next essay, before a general
audience at New York, where he declared that, what the alchemists
sought for in vain—viz. the universal menstruum, is neither
more nor less than water aided by heat, pressure, and the presence
of certain substances. The metals, he had previously stated,
seem to have been originally brought to the surface in watery
solutions, were afterwards separated and reduced as sulphides,
and mingled with contemporaneous sediments, and were during
subsequent metamorphism redeposited in fissures in the metal-
liferous strata, or ascending to higher beds gave rise to metalli-

560 Reriews—Dr. T. Sterry Hunt's Chemico-Geological Essays.

ferous veins in other strata. He rejects the notion of intense heat,
sublimation, and similar hypotheses. This theory may be a good
one, but some of the arguments adduced in support of it will hardly
bear examination. Speaking of the solubility (p. 281) of the salts
and oxides of copper, lead, and silver, he asks why they do not
accumulate in the sea-water like the salts of sodium. Most chemists
would have thought that the sparing solubility of the chlorides of
the two latter metals, especially of silver, was quite sufficient to
account for the phenomenon; but when a chemist has at command
the universal alkahest, he cares but little for a table of solubilities.

The most important paper in the collection is “'The Geognosy of
the Appalachians and the Origin of Crystalline Rocks” (xiii. p. 239),
an address delivered on retiring from the office of President of the
American Association for the Advancement of Science in 1871.
Without following the author into the intricacies of Transatlantic
geognosy, we must now consider Dr. Hunt in his capacity of geologist,
merely remarking by the way that the references in this paper
are necessarily of great value to those interested in American geology.
At this time he viewed the Taconic system, as defined by Emmons,
to constitute the true base of the Paleeozoic column ; but in the preface
to the second edition he seems to draw an important distinction
between the Upper Taconic and Taconian (see also Gzou. Mac. 1879,
p- 519). It is of some importance to ascertain where he would
draw this base-line, as immediately below come his four great
groups of crystalline rocks, and it appears that we are threatened
with other groups, “since it is by no means certain that the
whole of the crystalline stratified rocks of New England are
included in the above”’ (p. 281).

It would be unfair perhaps to dwell too much on the remarkable
change of front exhibited by Dr. Sterry Hunt in his interpretation
of the crystalline series above the Laurentians. We know that im
1861 he wrote that ‘the Green Mountain Gneissic formation, instead
of being beneath the Silurian series, is really a portion of the Quebec
eroup more or less metamorphosed, so that we recognize nothing in
New England, or South-east Canada, lower than the Silurian system ”
(Can. Nat. vi. 93). In the two succeeding volumes he enlarges on
this topic—the Montalban (now placed by Hitchcock below the Huro-
nian) at that time figuring as metamorphosed strata of Upper Silurian
and Devonian age. It is probable that Hunt at this period, with his
usual impetuosity, was reflecting the views of others rather than re-
cording his matured convictions, and it is singular, to say the least,
that one holding the views on chemical geology which he seems then
to have held could ever have given his adhesion to such a piece of
epigenic metamorphism. And yet, as may be gathered from what
he says with respect to the origin of granitic veinstones, and still
more of metalliferous deposits, he is prepared to admit an amount of
circulation, both greater and lesser, throughout the rocks, which,
with the aid of the alkahest or universal menstruum, must be capable
of producing not only molecular but metasomatic changes which
shall meet all the requirements of the most advanced transmuta-

Reviews—Nicholson’s Tabulate Corals. 561

tionist. Dr. Hunt has written much and well, and his ample ex-
periences as a geologist and a chemist entitle his opinions to respectful
consideration. He may be a trifle hasty, and perhaps in the
exigencies of the moment he is not always too particular. Thus he
has been at issue with many writers and speakers, himself amongst
the number; but we are bound to admit that in the interpretation
of the crystalline series above the Laurentian his recantation is com-
plete (p. 276), and he does not waste the time or abuse the patience
of his audience by vain endeavours to maintain a reputation for
infallibility.

The dates of Dr. Hunt’s views are always of importance, and we
find him stating in 1871 his conviction that the crystalline schists of
Germany, Anglesey and the Scotch Highlands will be found anterior
to the deposition of the Cambrian sediments. As is well known, he
professes to be able to correlate by their lithological characters the
schists of the British Isles with those on the other side of the
Atlantic. The andalusite-schists in Donegal may be, as he states, of
the type of the White Mountain series; but when he hints rather
than affirms that the chiastolite schists of Skiddaw are to be referred
to this group—placed by Hitchcock, be it remembered, below the
Huronian—admiration gives place to incredulity; since the next step
would be to claim the Skiddaw granite as Laurentian gneiss !

W. H. H.

IJ.—On tHe Srrucrure anp AFFINITIES oF THE ‘TABULATE
Corats” oF THE Patmozorc PERiop. With Critical Descrip-
tions of Illustrative Species. By H. Aunuyne Nicuorson, M.D.,
D.Sc., ete., Professor of Natural History in the University of St.
Andrews. Illustrated with Engravings on Wood and fifteen
Lithograph Plates. Super Royal 8vo. pp. 342. (London and
Edinburgh, William Blackwood & Sons.)

T might have been thought that the various memoirs on Fossil
Corals which have been written by Edwards and Haime, Lind-
strom, and other paleontologists, including Dr. Nicholson himself,
would have pretty well exhausted all that could be said on the sub-
ject, and rendered a fresh work almost unnecessary ; but a glance at
the contents of this elaborate book at once shows that it is no mere
recapitulation of what has already appeared in previous publications,
but that it contains a great amount of additional knowledge respect-
ing this division of Fossil Corals. This is not owing so much to the
description of new forms, but rather to the results obtained by the
examination of microscopic sections of forms already known. Whilst
it is true that this method of investigation involves, in the preparation
of thin transparent sections, a vast amount of preliminary work
which only those who have undertaken a similar task are capable of
estimating, there can be no doubt that it is only by this means that
reliable evidence can be obtained and satisfactory conclusions drawn
as to the true characters and affinities of these fossil organisms. Dr.
Nicholson may be said to be the first to apply to any extent the

DECADE II.—VOL. VI.—NO. XII. 36
2

562 Reviews—Nicholson’s Tabulate Corals.

microscopic method of investigation to elucidate the intimate struc-
ture of fossil corals; and the results which he has obtained serve to
show in a striking manner the importance and necessity of micro-
scopic examination in determining the intimate structure of corals.
The great amount of material which the author has been collecting
for many years past from those localities in Britain, the Continent of
Europe and America, which have yielded most of the known fossil
Tabulate Corals, has enabled him to carry out the task of a critical
description of these forms with the great advantage of being able at
will to compare and collate the specimens in his own cabinet.

Though this book treats of the Palwozoic Tabulate Corals, the
author fully recognizes the necessity of abandoning this division as
a natural group, and distributing the various families and genera
included therein by Edwards and Haime amongst the other divisions
of the Actinozoa. The presence of Tabulee or horizontal diaphragms,
which constituted the basis of the ‘‘ Tabulata,” has been shown by
the researches of Louis Agassiz on the animal of Millepora, of Verrill
on Pocillopora, and Moseley on Millepora and Heliopora, to be of very
limited value as a main ground of classification, this structure
appearing alike in organisms which undoubtedly belong to the
Hydrozoa, Actinozoa, and Polyzoa. This fact of the existence of
tabule in organisms so widely separated in the zoological scale has
given rise to great differences of opinion as to the true affinities of
the animals which constructed the numerous and varied tabulate
corals of the Paleozoic rocks. Agassiz, basing his conclusions on the
Hydrozoal nature of Millepora, would have relegated all the
Tabulata to the Hydrozoa; but Verrill showed from the true Zoan-
tharian character of the T'abulate Pocillopora that there was no
ground for such a sweeping conclusion, and this opinion has been
further justified by Moseley’s discovery that the Tabulate Heliopora
belongs also to the Actinozoa. The absence of a satisfactory basis
for a determination of the true position of these fossils is sufficiently
manifested, however, by the very varied positions to which different
genera are assigned by the most eminent writers on this subject.
One has only to consult the memoirs on Fossil Corals by Professor
Martin Duncan, Dr. Lindstrom, M. Dollfus, Dr. Nicholson, Dr.
Rominger, Professor Zittel, and others, to be convinced of the diffi-
culty and uncertainty attending this subject. No small amount of
this division of opinion probably arises from an incomplete know-
ledge of these fossils, and therefore the new facts respecting their
minute structure which are recorded in the present treatise ought to
have a great influence in reconciling opposite views.

Dr. Nicholson regards the old division of “ Zoantharia Tabulata ”
of Edwards and Haime as comprising twelve distinct groups of
animals, viz. Milleporide, Pocilloporide, Favositidee, Columnariade,
Syringoporide, Auloporide, Halysitide, Tetradiide, Thecide, Helio-
poridee, Cheetetide, and Labechide. Of these, all, except the first
two families, are represented in the Paleozoic period.

The Milleporide and Pocilloporide being of comparatively recent
origin, do not enter into the scope of this work ; but the author fully

Reviews—Nicholson’s Tabulate Corals. 563

accepts the Hydrozoal position of the first, and places the second in
the Zoantharia Aporosa, associating therewith in the same family the
recent genus Seriatopora.

The family of the Favositide, by far the largest and most impor-
tant group of the “ Tabulata,” is referred to the order of the Zoan-
tharia Perforata, and placed near the Poritide. No fewer than 22
genera are enumerated in this family, of which 20 are Paleozoic;
one, Koninckia, is Cretaceous; and only one, Favositipora, Sav.
Kent, of recent age. The great development of this family occurs
in the Silurian and Devonian rocks, but few surviving into the
Carboniferous, and perhaps but one. Stenopora, passing into the Per-
mian. So important a part of the fauna of the Paleozoic age is
constituted by the genera of this family, that it will be of interest to
give a list of them :—

Favosites, Lam, Columnopora, Nich.
Alveolites, Lam. Koninckia, KE. and H.
Vermipora, Hall. Favositipora, Say. Kent.
Michelinia, De Kon. Areopora, Nich. and Eth. jun.
Pleurodictyum, Goldf. Remeria, K. and H.
Chonostegites, KH. and H. (= Haimeophyl- Syringolites, Hinde.
Zum, Bill.) Nyctopora, Nich.
Pachypora, Linds. Rémingeria, Nich.
Striatopora, Hall. Stenopora, Lonsdale.
Trachypora, E.and H. (with Dendropora, Billingsia, De Kon.
Mich., and Rhabdopora, M‘Coy.) Laceripora, Eichw.
Cenites, Kichw. Nodulipora, Lindstrém.

It would occupy too much space to follow the author in his
exhaustive description of this and the other families, whose history,
characters and relations are treated; all we can do is to refer briefly
to a few salient points.

Dr. Nicholson includes in the genus Favosites the genera Calamo-
pora, Goldf.; Hmmonsia, EK. and H.; and Astrocerium, Hall, all of
which have been based on characters too variable to allow of generic
distinction.

In the comparatively new genus Pachypora, Lind., 1873, of which
the more distinguishing feature is the great thickening of the walls
of the corallites by a deposition of sclerenchyma, is included a
number of corals from the Silurian and Devonian of Europe and
America, which had previously been referred to Favosites, Alveolites,
and Cladopora, but have now been proved by microscopical exami-
nation to possess the peculiar characteristics of this genus. Micro-
scopical sections have also determined the Favositoid character of the
genera Striatopora and Trachypora; in this latter genus the secon-
dary deposit of sclerenchyma in the corallites exists to such an
extent that it had previously been believed to be provided with a
dense ccenenchymal structure surrounding the somewhat widely
separated apertures of the corallites. The genus Cenites, with its
peculiarly elongated calices, is also allied to Pachypora, and possesses
a similar thickening of the corallite walls.

As respects the confusing genus Alveolites, the author concludes
that the presence of septal teeth as a generic distinction will have to

564 Reviews—Nicholson’s Tabulate Corals.

be abandoned, and that the only difference between this genus and
Favosites is in the possession, in Alveolites, of oblique calices, and the
compressed or triangular forms of the corallites.

_ The genus Pleurodictyum, Goldf., formed for the peculiar fossil P.
problematicum, Goldf., so long a puzzle to paleontologists, is still
retained as distinct from Michelinia. In a form belonging to the
same genus from the Devonian of North America, Dr. Nicholson has
detected the presence of the peculiar vermiform tube which appears
to be constantly associated with P. problematicum, but he is unable to
throw any fresh light on its probable character.

The genus Stenopora, Lonsdale, is shown to belong to the Favosi-
tide, and to possess very distinctly marked characters, in the coral-
lites being annulated by periodical ring-shaped thickenings. 'The
position of the genus Remeria, EH. and H., is regarded as uncertain,
as it has not been proved to possess mural pores; Syringolites,
Hinde, appears to form a connecting link between the Favositidee
and the Syringoporide, and Nyctopora, Nicholson, seems to be inter-
mediate between the Favositide and the Columnariade, as it possesses
all the characteristics of this latter family except in having mural
pores. |

We pass now to the next family of the Columnariadz, which has
been constituted by the author to include a small group, principally
of American Silurian corals, distinguished by the non-perforate walls
of the corallites, well-marked tabule, and well-developed septa. The
family seems to be closely allied to the Rugosa, whilst it has also
resemblances to the Astreeide of the Zoantharia Aporosa. With
the genus Columnaria, Goldf. (= Favistella, Hall), is also associated,
to form this family, the genus Lyopora, Nich. and Hth. jun.

The family Syringoporidee is looked upon as an aberrant group of
the Zoantharia Perforata, having genuine but distinct relations with
the Favositide. The author regards the hollow processes connecting
the corallites, which distinguish this family, as homologues of the
mural pores of Favosites, corresponding with the hollow transverse
floors connecting the corallites in Chonostegites Clappi, Kdw. and
H.; whilst in the central tube of another Favosite genus, Syringolites,
Hinde, there is a close similarity to the infundibular tabule of
Syringopora.

Our present knowledge of the family Auloporide is insufficient to
determine its true relationship, though the author conjectures that it
may be a peculiar group of Alcyonaria. It includes the genera
Aulopora, Goldf., Cladochonus, M‘Coy (= Pyrgia, Edw. and H.), and
Monilopora, Nich. and Eth. jun.

The family of the Halysitidee is formed for the single well-known
genus Halysites, Fischer, and regarded as a distinct and ancient
group of the Alcyonaria. Halysites catenularia, Linn., is shown to
possess intermediate smaller tubes, indicating the existence of two
classes of zooids, as in Heliopora; but in the otherwise closely re-
sembling H. Escharoides, Lam., there are only uniform corallites,
in which, however, spiniform septa are constantly present and
disposed in cycles of twelve. If these septa bear any relation to

Reviews—Nicholson’s Tabulate Corals. 565

the number of mesenteries in the living animal, it is difficult to see
how Halysites can be regarded as an Alcyonarian, this group having
only eight mesenteries.

The family of the Thecide comprises merely the single genus
Thecia, Edw. and H., with very peculiar characters, now, for the first
time, made known from microscopic sections. There are two kinds
of corallites; the larger, though well defined, have no distinctive
bounding walls, and the interspaces between these are occupied by
very small tubular corallites, doubtfully tabulate, but with well-
defined walls. There are also horizontal canals connecting the
larger corallites. The family is regarded as a special group of the
Aleyonaria.

The important family of the Helioporide mostly comprises the
Paleozoic genera Heliolites, Dana, Plusmopora, Edw. and H., Propora,
Edw. and H., Pinacopora, Nich. and Eth. jun., and Lyellia, Edw.
and H.; the Cretaceous genus Polytremacis, D’Orb., and the recent
Heliopora, De Blain. ‘These various genera are included in this
family from the supposed correspondence of their fossil structures
with the corallum of the existing Heliopora, the animal of which has
been proved by the researches of Mr. Moseley to be a true Aleyonarian
Zoophyte, furnished with eight mesenteries, and eight pinnately-
fringed tentacles. It appears to us, however, that there are con-
siderable differences between the corallum of Heliolites and its
allied Paleozoic forms, and the recent Heliopora cerulea, sufficient
to throw considerable doubt as to the propriety of associating them
in a single family of Alcyonaria. We regret that Dr. Nicholson has
not subjected the modern corallum of Heliopora to the same critical
examination which he has bestowed on the Paleozoic Heliolites,
before accepting the classification of Mr. Moseley, and we will
venture to point out what appear to us some of the points of
difference. In the first place, the larger corallites or calicles of
Heliopora coerulea do not appear, from Mr. Moseley’s account, to
possess any distinctive proper wall. He says:! ‘‘ New calicles are
formed by the junction of a number of tubes around a central tube
or tubes arrested in growth, which form a base. The outer walls
only of the surrounding tubes continue to grow, and form the
lateral wall of the calicle. The newly-formed calicle thus has
tabular prolongations at its base, and the so-called septa are, in the
main, due to the circumstance that the wall is composed of a series of
curved outer walls of tubes.” Our own observations of H. cerulea
fully confirm the correctness of the above description. Now, so far
as we are acquainted with Heliolites and its allied Palaeozoic genera
which have been placed with Heliopora, there is not a single species
in which the tubes of the larger corallites are formed in a similar
manner to those of Heliopora, but in all there is a distinct proper wall
to the larger corallites. Again, with regard to the septa of Heliopora,
these, according to Moseley, are in the main due to the curved outer

1 We quote from the Report given in the Ann. and Mag. of Nat. History, Feb.

1876, p. 147, et. seg., “On the Structure and Relation of certain Corals, etc.,” by H.
N. Moseley, M.A., F.R.S.

566 Reviews—Nicholson’s Tabulate Oorals.

walls of the tubes bounding the calicles, and therefore cannot be
compared with the regular normal septa which are met with in
Heliolites, and which in some instances extend nearly to the centre
of the corallite. The pseudo-nature of the septa of Heliopora
sufficiently explains the absence of all correspondence between their
variable numbers and the number of the mesenteries; but it is
highly probable that the septa of Heliolites indicate a similar
number of mesenteries in the living animal; and as there are pretty
constantly twelve septa, it follows that the animal could not have
been Alcyonarian. There is no doubt that Heliolites and some of
its allied forms possessed two kinds of zooids, the same as Heliopora ;
but a corallum of larger and smaller tubes indicating this, is also
found in the Monticuliporide, Halysitide, and not improbably in
some of the Favositide, whilst it is very doubtful whether the genus
Lyellia, Edw. and H., here placed with Heliopora and Heliolites,
actually possessed smaller incomplete zooids ; for the intermediate
structure between the larger corallites, instead of being tubular, is
distinctly vesicular—the larger corallites themselves closely re-
semble those of a typical Heliolites. We therefore think that the
evidence is insufficient to conclude that Heliolites and the allied
Paleeozoic genera above named are truly Alcyonarian the same as
Heliopora.

Two chapters, the twelfth and thirteenth, are devoted to a con-
sideration of the families of the Cheetetidee and Monticuliporide, and
the author believes that he has discovered satisfactory grounds of
division between these very confusing groups. To the Cheetetide
are referred corals with uniform corallites, having the walls com-
pletely amalgamated, and but few and remote tabule, whilst the
Monticuliporide: are distinguished by corallites of different sizes in-
dicating the existence of two kinds of zooids; their walls are not
fused with each other, and the tabule are well developed. The
author rejects the idea which has been proposed to place these
families with the Polyzoa, though it is very probable that many of
the inerusting forms probably belong to this higher group of animals,
and is disposed to regard them as a special group of Aleyonaria.

In the final chapter the family Labechide is treated, and the
characters of the very aberrant genus Labechia are described. The
absence of all apertures on the surface of the corallum of this form
and the peculiar projecting solid calcareous rods render it so different
from all other groups of corals, that its relations must for the present
remain a matter of conjecture.

In concluding our notice of this work we desire to express our
admiration, not only at the unwearied industry of the author in
bringing together such an amount of research into the characters
and relations of these ancient corals, but also at the very excellent
manner in which the treatise is published. In addition to the wood-
cuts in the text, there are fifteen beautifully executed lithographed
plates, mostly illustrating microscopic sections, and the drawings
for these have been made by Dr. Nicholson himself. Whatever
future discoveries may disclose as to the affinities of these corals,

Reviews—Nicholson’s Manual of Paleontology. 567

this work will always retain a permanent value for its minute and
faithful description of these organic remains, and all students of
Paleontology will be indebted to Dr. Nicholson for thus bringing
together in a single volume the history of this important division.
We can only express the hope that what the author has here accom-
plished for the old order of the Tabulata, he may be induced to
undertake for the other orders of the Palzeozoic corals.

IIJ.—A Manvat or PanmonroLoGy FoR THE USE oF STUDENTS, WITH
A GENERAL INTRODUCTION ON THE PRINCIPLES OF PALMONTOLOGY.
By Henry Atteyne Nicuotson, M.D., D.Sc., Ph.D., F.R.S.E.,
F.G.S.; Professor of Natural History in the University of St.
Andrews. 2nd Edition. Revised and greatly enlarged. In two
vols. Royal 8vo. pp. 1070, with 722 Woodcut Illustrations.
(Edinburgh and London: William Blackwood & Sons, 1879.)
HOSE who, like the writer, can carry back their intimate acquaint-

ance with geological events for more than a quarter of a century,
cannot fail to be astonished at the change which has arisen in
the literature connected with their special branch of study, and
particularly that which relates to text-books and works for the
use of students. In 1855, “ Lyell’s Elements” had already attained
its 5th edition; it was the book, and almost the only book, for
the learner. Previously Mantell’s works, Buckland’s Bridgewater

Treatise, and Conybeare and Phillips, were the only really good

sound books to consult; now there are more than a dozen authors

ready to impart to us out of their stores of geological and paleonto-
logical knowledge, things old and things new.

Happy is that student who obtains the aid of a really sound
geological Mentor, one who is able to guide his steps in safety
amidst Glacial epochs, Volcanic eruptions, Pluvial periods, Hozoonal
Limestones, Evolutionary ancestral forms, and Quaternary deposits,
into the haven of Truth.

Not only have our teachers vastly multiplied, but our subject of
study has divided itself, so that, like a complex system of railway
lines, one may travel on the Physiographical branch, or the Geo-
graphical one, on the Stratigraphical, the Petrological or the Palzon-
tological—and may be, and we trust are, all moving forward, but
on quite different roads, so extensive has our subject become in
the last twenty-five years.

Formerly a geologist was also a mineralogist, and a paleontologist;
now a man may be a geologist without knowing either of these
subjects; or he may be a crystallographer, a petrologist, a mathe-
matician, or a chemist, and yet not a mineralogist; or, a paleon-
tologist, or zoologist, and yet not a geologist !

Certainly the more one studies the relics of bygone ages in the
light of forms of life still existing on our planet, the more we are
able rightly to understand “The Ancient Life History of the Earth.”

Prof. H. Alleyne Nicholson, the writer of the Manual of Palzon-
tology now before us, is peculiarly fitted for the task he has set him-
self to perform. He is not only a sound practical geologist, but he

“568 Reviews—Nicholson’s Manual of Paleontology.

is also an excellent zoologist and paleontologist; added to which,
he has had more than ten years’ experience as a teacher of students,
and has thus been brought face to face with the needs of his class.
Neither is Prof. Nicholson a mere “ prentice-hand” at the writing
of Text-books. Already he stands credited with :—

. “A Manual of Zoology.”

. “A Text-Book of Zoology.”

‘An Introductory Text-Book of Zoology.”

. “Outlines of Natural History for Begmners.”

“ Examinations in Natural History.”

“Introduction to the Study of Biology.”

“The Ancient Life-History of the Earth;” and

8. “ A Manual of Paleontology ” (already in its 2nd edition).

The first edition of Nicholson’s Manual of Paleontology, which
appeared in 1872, was contained in a single volume of moderate
Svo. size, numbering 600 pages, with 400 woodcuts. The present
edition occupies two handsome 8vo. volumes, consisting of 1070 pp.,
with 722 woodcuts, and is so largely re-written and augmented, that
it forms to a great extent a new work.

The First Part (embracing 6 chapters and 94 pp.) is devoted to a
General Introduction to Paleontology in connexion with Strati-
graphical Geology.

From this we are led on in Part II. (Paleontology) to consider
group by group the several divisions of the great Invertebrate sub-
kingdom from the Protozoa to the Lamellibranchiata, their general
characters and their distribution in time, and the literature of each
division. This occupies 17 chapters and 417 pp., and lands us at the
end of vol. i.

The Invertebrata extend through the first 100 pp. of vol. ii.
including the Gasteropoda and Cephalopoda, and with chapter xxix.
commences the Vertebrata—treated much in the same fashion, giving
to each order its distribution in time as well as its general characters.
This portion of the work occupies 20 chapters and pp. 326.

Part III. is divided into four chapters on Paleobotany, and fills
50 pages, treated very briefly, but in a similar manner to the
previous divisions.

The volume ends with a Glossary and Index.

One important feature of the work is its illustrations, more than
700 in number, which are very excellent; a few (as invariably
happens in so large a work) had better, however, have been omitted
—as, for example, fig. 212, labelled Illenus Barriensis, and the
singularly crafty-looking, but decidedly stuffed, I/yrmecobius fasciatus

fig. 600).

: Hundreds of the figures are of the highest merit as wood en-
gravings, and many appear for the first time, being engraved ex-
pressly for this work by Mr. Charles Berjeau.

Each Order has its diagnostic characters printed in italics at the
commencement of its own chapter; and at the end of each will be
found a copious list of references to works and authorities who have
specially treated upon the group just summarized.

I OTR go bo

Reports and Proceedings—Chester Society of Natural Science. 569

In passing rapidly over the pages, we notice that Hozoon Canadense
still holds its place among Foraminifera; the researches of Dr.
Mobius not having reached the author in time to become available for
incorporation. Sufficient, however, is said concerning MM. Carter’s,
and King’s, and Rowney’s investigations, to render its organic nature
at least doubtful.

Under Mollusca (vol. il. p. 14) a curious error is retained from the
first edition—viz. that “the small cowries, of which Cyprea Europea
is the type, are not known as occurring in the fossil condition.”

There are thirteen species of Cyprea given in Morris’s catalogue,
including Cyprea Europea from the Suffolk Crag.

The Coniferous trunk (vol. il. p. 448, fig. 701), from the Lower
Devonian, Gaspé, Canada, named by Dawson Prototaxites Logant,
and referred by him to the Tawine@; was shown by Mr. Carruthers
(in 1872) to be only a Cellular Cryptogam, and was renamed by him
as Nematophycus Logani, Carr. (Monthly Microscopical Journ.,
vol. viii. Oct. 1872, pp. 160-172, pl. 31 and 32; see also GEOL.
Mae. 1873, Vol. X. p. 462). :

Like every large text-book, however, it is easy enough to take
exception to special points in the work, and whilst regretting the
year’s delay which has occurred in its issue (see Preface), which
makes it seem, in parts, perhaps, a little in need of more rigid
posting up, it is certainly the best book of its kind for the use of
students, and for the general reader, which we possess. In saying
this, it is well to recall the fact that ‘‘Owen’s Paleontology ”
(A. & C. Black) appeared as early as 1860, and the 2nd edition in
1861; and although now rather out of date, we are indebted to
Professor Owen, and to the late Dr. 8. P. Woodward (author of the
Invertebrate portion of the work), for the first issue of a Manual
specially devoted to Paleontology in this country ; a work which
may (to use Prof. Owen’s own term) perhaps have served as the
“« Archetype” to the author of the present work.

We trust that Nicholson’s Manual of Paleontology will have the
success it merits, and shall look forward with confidence to succeed-
ing editions still more complete than even the present volumes.

IRI SOAS) VND) ASqsyO.Ous SINE ys

—~.—__

J.—Curster Soctery or Narurat Scrence.—Annual Conversa-
zione.—The Annual gathering of this flourishing provincial Society
took place on Thursday, 2nd October, 1879, under the presidency of
Prof. T. McKenny Hughes, M.A., F.G.8. On this occasion the
«Kineaspey Memorian Mupat,” established in memory of the
Society’s first President, Canon Kingsley, was awarded to Sir
Puinre pz Maras Grey-Heerron, Bart.,. M.P., F.R.S., ete., for
“having contributed materially to the promotion and advancement
of natural science.” In presenting the Medal, Prof. Hughes referred
to the splendid work which Sir Philip Grey-Egerton had achieved in
his researches on Fossil Fishes, in which branch of study he was now
universally recognized as the foremost man among all his contem-

570 Reports and Proceedings—

poraries. The President also alluded to his valuable services in
Parliament for well-nigh fifty years—but most of all as the repre-
sentative man of science; and in this his highest capacity he asked
Sir Philip Egerton to accept the Kingsley Memorial Medal.

Sir Philip Grey-Egerton in reply thanked the President and
Committee of the Society for having awarded that medal (founded
to perpetuate the memory of the late Canon Kingsley) to him. He
wished he could be inspired with the fervid eloquence which flowed
from the lips of him whose likeness was so faithfully portrayed
on that medal, and whose burning words found their way into the
hearts of all his audience, not only in Chester, but throughout the
United Kingdom. He should look back to this presentation as one
of the happiest events in his life, as connecting his name with that
of his late friend, Canon Kingsley; and he thanked his friends in
Chester who had wished thus to associate him with the founder of
their Society. He trusted the flame which Canon Kingsley had
kindled would never be darkened, but extend its genial light further
and further, illuminating with its brilliancy all who might be for-
tunate to come within reach of its radiance.

II.—Geronocicat Socrery or Lonpon.—November 5, 1879.—Henry
Clifton Sorby, Esq., F.R.S., President, in the Chair.

The following communications were read :—

1. “On the probable Temperature of the Primordial Ocean of our
Globe.” By Robert Mallet, Esq., F.R.S., F.G.S.

According to the latest hypotheses as to the quantity of water on
the globe, its pressure, if evenly distributed, would be equal to a
barometric pressure of 204:74 atmospheres. Accordingly water,
when first it began to condense on the surface of the globe, would
condense at a much higher temperature than the present boiling-
point, under ordinary circumstances. The first drops of water
formed on the cooling surface of the globe may not impossibly have
been at the temperature of molten iron. As the water was pre-
cipitated, condensation of the remaining vapour took place at a
lower temperature. The primordial atmosphere would be more
oblate and less penetrable by solar heat than the present, and the
difference of temperature between polar and equatorial regions
would be greater; so that, in the later geologic times, ice may have
formed in the one, while the other was too hot for animal or vege-
table life. Thus, formerly the ocean would be a more powerful dis-
integrant and solvent of rocks, mineral changes would be more rapid,
and meteoric agencies would produce greater effects in a given time.

Replying to remarks from the President, Mr. John Evans, Prof.
Prestwich, Dr. Hicks, Prof. Bonney, and Capt. Galton, Mr. Mallet
said he did not suppose any part of the original crust of the globe
remained at present visible at the surface. Such geological deductions
as were made in his paper were only illustrative, and might be open
to question. The epoch at which the phenomena occurred to which
his paper referred was long anterior to the existence of either animal
or vegetable life upon our globe. Hence the paleontological ob-

Geological Society of London. 571

servations that had been made did not seem to him to apply. What
he does affirm as certain is that the method he has indicated, requiring
for its data a more extended experimental knowledge of the relations
between temperature and pressure in aqueous vapour, and a more
exact knowledge of the total volume of water now upon our terraque-
ous globe, affords the means of determining the temperature of our
oceanic water at every period, from that of the primordial ocean to
our own day. :

2. “On the Fish-remains found in the Cannel Coal in the Middle
Coal-measures of the West Riding of Yorkshire, with the description
of some new Species.” By James W. Davis, Hsq., F.G.S., ete.

The remains described by the author were from a bed of Cannel
Coal about 400 feet above the base of the Middle Coal-measures, and
were chiefly obtained from this bed at the Tingley Colliery. The
author described the general geological structure of the district. At
Tingley the fish-remains were stated to occur in greatest abundance
between the Cannel Coal and the ‘“‘hubb”’; but they are also found
in both those portions of the deposit. Of known species the author
has identified :—Celacanthus lepturus, Ctenodus elegans, Megalichthys
Hibberti, Rhizodopsis, sp., Palgoniscus, sp., Gyracanthus formosus, Cte-
nacanthus horridus, Diplodus gibbosus, Cienoptychius pectinatus, Helodus
simplex, teeth of Cladodus and Petalodus, scales of Rhizodus, ribs and
bones of Ctenodus, Pleuracanthus levissimus, and six other species,
and the following which are described as new forms :—(1) Compsa-
canthus triangularis, (2) C. major, and (8) Ostracocanthus dilatatus,
the type of anew genus resembling Byssacanthus, Agass. The teeth
of Celacanthus were said to be small and sharply pointed ; they have
not been found attached to the jaw, but in certain specimens of the
latter the alveolar spaces are well shown, extending in a single row
along the rami. The air-bladder of this genus is also said to be pre-
served, and to present some resemblance to the bony air-bladders of
Siluroid fish inhabiting the fresh waters of Northern India; and in
general the author dwelt at considerable length upon the possible re-
lationships existing between the fishes whose remains he described
and the Teleostean Siluroids and Ostraczon.

3. “On the Skull of Aryillornis longipennis, Owen.” By Prof. R.
Owen, C.B., F.R.S., F.G.S., etc.

In this paper the author described a fragmentary cranium from the
London Clay of Sheppey, from which it was procured by W. H.
Shrubsole, Esq., who also furnished him with the humerus described
in a former paper under the name of Argillornis Jongipennis.' In
the present specimen the lower jaw and the fore part of the upper
jaw are deficient. The author described the characters presented by
the specimen in detail, and stated that, like those of the humerus pre-
viously described, they seemed to approximate the fossil most nearly
to the Albatross among existing birds, although, like Odontopteryx, it
differed from Diomedea and also from the Cormorant and the Totipal-
mates generally, in the absence of the basirostral external nares and
of the supraorbital gland-pits. The present fossil differs from Odon-

1 Quart. Journ. Geol. Soc. vol. xxxiv. p. 124.

072 Reports and Proceedings—Cambridge Philosophical Society.

topteryx in having the fore part of the frontal broader and the upper
tract of the bill less defined, as also in some other characters; but
no comparison of the palatal structure can be made upon the existing
specimens. In point of size, taking the Albatross as a term of com-
parison, this skull may well have belonged to a bird with wings of
the extent indicated by the humerus already described ; and the
resemblance of the skull to that of the Albatross would also seem to
be confirmatory of the specific collocation of the two specimens. The
presence of four small pits or perforations on the only part of the
alveolar border which appears to be uninjured, leads the author to
conjecture that the bird may have been dentigerous.

TI.—Campripee Puinosoprican Socrrty.—Monday, Nov. 10.—
Prof. Newton, M.A., F.R.S., President, in the chair.

The President alluded to the great loss sustained by Science in
general, and by the Society in particular, by the death of Professor
Clerk Maxwell, who had so recently occupied the position of President.
He considered it a great privilege to be able to give expression to
the deep and sincere sorrow that every member of the University felt
in the death of so distinguished a member as Professor Maxwell.

The following communication was made to the Society :—

“On implement-bearing loams in Suffolk,” by Mr. O. Fisher. The
author gave an account of two visits paid to the district in which Mr.
Skertchly of the Geological Survey has lately discovered flints worked
by man, in loams described by him as interglacial. The first of these
visits was made in 1876, and the country examined lay chiefly to the
north-east of Brandon. The author was not convinced by anything
which he then saw of the correctness of Mr. Skertchly’s views. But
since he saw only a portion of the district which that gentleman had
examined, the data were necessarily incomplete. The second visit
was made by him at the end of September last, and he then saw sec-
tions inthe neighbourhood of Mildenhall and Bury St. EHdmund’s,
which convinced him of the truth of Mr. Skertchly’s announcement
of the occurrence of the loams in question with their implements be-
neath massive Boulder Clay in situ. At the brickyard at Culford, near
Bury, in particular, the section is unmistakeably clear. Fifteen feet
of the ordinary Chalky Boulder Clay, a spur of the great mass which
spreads over a large part of the county, is seen covering the stratified
loam, and from the loam at this place Mr. Skertchly extracted with
his own hands a worked flint which he exhibited to the Society at the
reading of the paper. The author did not himself see the Boulder
Clay lying beneath these loams at the places where they had yielded
implements. He was, however, assured by Mr. Skertchly that when
some of the sections were better exposed, this was evidently the case.
The loam in question has the appearance of being a fluviatile deposit,
and at one place freshwater shells occur in it; it evidently occurs
over a considerable district.

A discussion took place, in which Mr. Skertchly, Professor Hughes,
Dr. Campion, and Mr. EH, Hill, took part.

Correspondence—Prof. Edward Hull. 573

CORRESPONDENCE.

SS

THE AGE OF THE PENNINE CHAIN.

Str,—The Number of the Grotogican Macazine for November
contains a very thoughtful paper by Mr. Wilson, F.G.S., on the age
of the upheaval of the Pennine Chain or “ Backbone of England,”
in which he controverts my views regarding the precise epoch of
primary upheaval, and comes to the conclusion that it was Pre-
Permian, instead of Post-Permian and Pre-Triassic; the conclusion
I had previously arrived at. He has very fairly stated my argu-
ments and his objections to them. With the time at my disposal. it
would be impossible for me to recall all the facts and inferences
which were vividly impressed on my mind at the time I wrote the
paper on this subject to which Mr. Wilson refers.!

The arguments are there, and every one must judge for himself
whether they are conclusive or not. I admit the force of Mr. Wil-
son’s inference, that there must have been some westerly uptilting
of the beds of the Yorkshire Coal-field before the Permian period,
from the well-known fact that the Coal-measures dip at a slightly
greater inclination towards the east than does the Magnesian Lime-
stone which overlies them. This dip is, however, but slight, because
it only amounts to the difference between the inclination of the two
formations ; and I suppose it to be due to a sort of sympathetic move-
ment which took place during the progress of the more powerful
east and west flexuring at the close of the Carboniferous period.

The principal objection to Mr. Wilson’s reasoning seems to lie in
his statement that the Permian beds on either side of the Pennine
axis were originally disconnected, and on this he bases one of
his arguments for supposing the existence of the disconnecting
Carboniferous ridge during the Permian period. To this view I
entirely dissent, on grounds which I have stated at some length
in a paper which Mr. Wilson seems to have overlooked, and
perhaps with some reason, considering its title.* In that paper, I
eall attention to the remarkable resemblance between the Permian
formation as it occurs in Lancashire, and the same formation as it
occurs in Yorkshire and Durham, which strongly impressed me with
the conviction that there could have been no intervening barrier
between the two areas. Mr. Binney, and, still later, Mr. Kirkby,
have shown that the fossils of both districts are truly representative
of each other, and deposited in the same general basin, although under
somewhat different conditions—the Upper Permian beds of Lan-
cashire having been formed in shallower waters and in a sea some-
what clouded by muddy sediment. Though quoted by Mr. Wilson
as one of the authorities for the statement that ‘there is no similarity

1 Quart Journ. Geol. Soc. vol. xxiv. p. 323 (1868).
2 “On the Evidences of a Ridge of Lower Carboniferous Rocks under the Plain of
Cheshire, etc.,’ Quart. Journ. Geol. Soc. vol. xxv. p. 171.

574 Correspondence—Prof. Edward Hull.

either in character, thickness, or succession of the Permians on the
opposite side of the Pennine Chain,” I quite dissent from his way
of putting my views, except in the matter of “thickness,” which is
of very little importance in an inquiry of this kind. On the con-
trary—both in Yorkshire and Lancashire—we have Upper Permian
beds represented by Magnesian Limestones with identical fossils,
and Lower Permian beds, consisting of soft sandstone of very great
thickness at Stockport and elsewhere, close to the edge of the Pen-
nine Chain.

I cannot consent “to omit from consideration” the ‘ Lower Per-
mian Sandstone” as Mr. Wilson wishes us to, on the ground that
“its true horizon seems doubtful.” There is really no such doubt,
as, both at Manchester and Stockport, these sandstones have been
proved to rest unconformably on the Coal-measures on the one hand,
and be overlain by marls with limestone containing Permian fossils
on the other. Then, again, both of these formations are unconform-
ably overlain by the New Red Sandstone, as was clearly proved by
the borings at Heaton Mersey, below Stockport, and other places. I
must repeat, therefore, that there can be no question that the Lower
Red Sandstone of Stockport is the representative of the Lower Red
Sandstone of Durham and North Yorkshire ; for they agree both in
position, character, and their relations to the adjoining formations—
both above and below.

If this be so, I would ask Mr. Wilson how can he account for the
fact that this Lower Permian Sandstone is remarkably free from
fragments of Carboniferous rocks, or, indeed, of rocks of any kind, if
it was deposited at the base of a Carboniferous ridge ?

As I have already shown, in the paper just quoted, the differences
in the characters of the Permian rocks in the N.W. and N.E. of
England are those of degree rather than of kind, and may be ac-
counted for on the law, or principle, which will be found to charac-
terize many natural groups or formations; namely, the development,
in opposite directions, of calcareous and sedimentary strata. The
real Carboniferous barrier of this period lay below the Cheshire
Plain, reaching the Carboniferous tract along the valley of the Dane,
near Bosley. To the north and south of this ridge the Permian
beds were connected more or less across the country.

In conclusion, I cannot admit that the absence of such a thin and
local formation as the Marl-slate of the North-east of England in
Lancashire or Cumberland is of much importance in this inquiry.
I can point, on the other hand, to real Magnesian Limestones at Skil-
law Clough, and two or three other spots, as evidences of connexion
between the east and west. I do not therefore see sufficient reason
for altering the conclusion to which I have already arrived, while I
admit that both points of view—that held by Mr. Wilson, and by
myself—have their difficulties. Epwarp Hutt.

1 Ibid, p. 176,

Correspondence—H, B. Woodward—A. G. Cameron. 575

FOSSILS ON CLEAVAGE PLANES.

Srr,—The Rev. W. Downes, who has done good service among the
Limestones of Westleigh and Holcombe Rogus, in Devonshire, has
in a second paper on this subject ['Trans. Devon Assoc. 1879] brought
forward the question, “Is it absolutely a universal rule that fossils
do never occur otherwise than on a plane of bedding ?”’ He notices
his discovery of organic remains, referred by Prof. T. R. Jones to
Posidonomya, on a surface of rock which is unquestionably a cleavage
plane. Among his specimens from Westleigh is a Spirifer manifestly
imbedded in a vertical position, while upon the same piece of rock a
Chonetes and a Posidonomya are lying upon the plane of bedding. He
suggests, that the planes of separation will be determined by the
lines of least cohesion, and that the presence of a flattish fossil,
approximately parallel to the lines on which the cleavage force was
acting, would be apt to create a plane of weak cohesion on which
the external pressure would most readily take effect. We should
have been disposed to think that the position in which the fossil was
imbedded accidentally coincided with the cleavage plane, and it was
therefore saved from distortion. Mr. Downes however remarks that
the cleavage is of an irregular kind ; seeming often to result from the
folds of the hard limestone rocks crushing the intervening shaly beds.
The subject is one well worthy of attention. H. B. Woopwarp.

RIPON SWALLOW-HOLES.

Sir,—The Rev. J. S. Tute of Markington, near Ripon, has a notice
of these “natural pits” in Vol. V. Grou. Mac. page 178. That the
denuding agencies employed in producing them are no more dormant
now, than formerly, is certain. The latest subsidence occurred in ’77,
in the West Field, near Hutton Conyers. This field is pitted over
with holes of more ancient date, and there also, cylindrical-shaped
holes, locally known as “man-holes,’ appear at intervals. When
first found, they are seen to contain water, which soon disappears.
To prevent animals falling in, they are filled up as quickly as pos-
sible. A ‘‘man-hole” that has been closed, after a time, becomes
again an open shaft, when the material with which it had been filled
is found to have been “swallowed.” The subsidence of ’77 is a
hole of very considerable dimensions, in shape an inverted cone, the
walls being thick-bedded red sandstone. It is fenced round. About
one hundred yards from it, and abutting on the footpath leading
from the village to Ripon, there is a shallow basin-shaped depression
in the surface of the soil. This place has been watched for a number
of years by a gentleman residing in the village,” who finds it sinks
four or five inches in a year.

The “man-holes”’ are said to occur, mostly, during very wet
seasons, and some of the farmers think after sheep have cleared the

land of turnips. A. G. CamMrEron,
NortTHaLLERTON, Nov. 1879. H.M, Geol. Survey.

1 Also a full account in a paper read at Ripon, before York. Geol. Society, in 1869.
2 Mr. Thomas Wells, of Hutton Conyers,

576 Obituary—MUr. John King.

ON THE STRUCTURE AND AFFINITIES OF THE PLATYSOMIDA.

Str,—I am very sorry to find that my esteemed friend, Professor
H. Alleyne Nicholson, has in the new edition of his “ Manual of
Paleontology ” (vol. ii. p. 188, footnote) committed the mistake of
quoting me as his authority for elevating the Platysomid fishes
to the “rank of a distinct division of Ganoids.” No such propo-
sition occurs in the unpublished paper to which he refers, which
was wiitten to follow up the views indicated in my account of
the structure of the Paleeoniscide (Pal. Soc. Mon. 1877) regarding
the abolition of the suborder ‘“ Lepidopleuride,” necessitated by the
demonstration of the fact that the Platysomide, as a family, are not
really allied to the Pycnodontide, but are on the other hand so closely
linked to the Palzoniscide, by ties of structure, that wherever we
place the latter family, thither the Platysomide must follow.

My paper on the “Structure and Affinities of the Platysomide ”
was read before the Royal Society of Edinburgh on May 5, of this
year, and will in a few weeks appear in the forthcoming fasciculus of
that Society’s Transactions. Prof. Nicholson’s mistake has obviously
arisen from his having had only a very hurried glance over my proot-
sheets, and that only on a single occasion. R. H. Traquarr.

8, Dean Park CRESCENT, EDINBURGH,
12th Nov. 1879.

IM DI pS\ Ops baby NaNyssHS) 1S)

We are glad to notice that Mr. G. A. Lebour, F.G.S., Lecturer in
Geological Surveying in the University of Durham College of
Physical Science, Newcastle-on-Tyne, has in preparation a Nomen-
elator Stratigraphicus, gr Handbook of the Nomenclature of the
Sedimentary Rocks. This work, which has been in hand for several
years, consists of a list—as complete as may be—of the subdivisions
of the Geological Scale now, or at any time, in use in this country
or abroad. The names are arranged in alphabetical order as the
easiest for reference. In every possible case the author responsible
for each name is mentioned. The date of publication, the meaning
when it seems necessary, and the equivalence, are also given.
The volume will be of at least 250 pp., and will be published as
soon as the number of subscribers has reached two hundred. Price
to subscribers 7s. 6d. Subscribers’ names and subscriptions may be
sent to Mr. G. A. Lebour, 2, Woodhouse Terrace, Gateshead-on-Tyne.

OPS a PAw Eas

We regret to learn the death of Mr. John King of Thorpe Hamlet,
Norwich, whose extensive collection of fossils from the Upper Chalk
of the country around Norwich was at all times open to students. So
long ago as 1833 Mr. King’s collection was noticed as a large one,
containing many rare specimens (8S. Woodward, Geology of Norfolk,
p- 32). These ultimately included a fine series of Echinoderms,
Mollusks, Sponges, etc.; and numerous flints cut and polished to
show organic and inorganic structure. Mr. King was the surviving
partner of the well-known firm J. & J. King, Stained Glass Painters,
etc., of Norwich. He died on October 19, aged 72 years.—H. B. W.

IN DEX.

——_>—_—_

AFR

FRICA (South), Fossils from Dia-
mond Fields, 192; Iron and Coal
in, 514.

(Western), Geological Notes
on, 172.

Allier, France, Orthopterous Insect from
Upper Coal-measures of Commentry,
97.

Allport, S., Rocks of Brazil Wood,
Charnwood Forest, 481.

Alpine Geology, 182.

America (Eastern), Glacial Period in, 248.

American Geological Railway Guide, 229.

— Quarterly Microscopical Jour-
nal, 85.

Ammonites of Mediterranean and Juva-
vian Trias, 460.

Amphibians from Permian Rocks of
Bohemia, 521.

Annelide, New Fossil, Terebella Lewes-
zensis. 146.

Arctic Regions, Miocene Flora in, 95.

Ardennes, Cretaceous formation of, 328.

Australia (Eastern), and Tasmania, Fossil
Flora of, 485.

Ayrshire, Silurian Fossils of Girvan, 135

Azoic Rocks and Trap-dykes of S. E.
Pennsylvania, 619.

AGSHOT, Upper and Middle Beds
of London Basin, Correlation of
Bournemouth Marine Series with, 148.

Balkan (West), Geology of, 36.

Ball, V., m.a., F.c.s., Volcanos of Bay
of Bengal, 16.

Barrande, M. J., Studies of Bohemian
Brachiopoda, 474.

Barrois, Dr. C., Cretaceous formation of
Ardennes, 328.

Basalt near the Shore of Lough Neagh,
Fossiliferous Pliocene Clays overlying,
62, 214.

Bay of Bengal, Volcanos of, 16.

Beekite in Channel Islands, 334.

in Flintshire, 334.

DECADE If.—VOL. VI.—NO. XII.

BRI

Beekite from Punjab, India, 234.

Belgium, Eurynotus in Carboniferous
Limestone of, 237.

— Fauna of Carboniferous Lime-
stone of, 472.

Benecke and Cohen’s Geological Map of
Heidelberg, 41.

Bengal, Volcanos of Bay of, 16.

Birds, J. A., Beekite in Channel Islands,
304,

Birds, Extinct Wingless, of New Zea-
land, 81.

Bivalves in Gilbertson Collection, British
Museum, and figured in Phillips's
“‘ Geology of Yorkshire,” 161.

Bohemia, Amphibians from Permian
Rocks of, 521.

Bohemian Brachiopoda, Studies of, 474.

Bonney, Prof. T. G., Ligurian and
Tuscan Serpentines, 362; Prof. Dana’s
Classification of Rocks, 199.

Boulder-clay at Bridlington, Freshwater
Remains in, 393.

———— — Purple, at Holderness, 528.

Boulders, Erratic, in Valley of River
Calder, Yorkshire, Source of, 313.

Bournemouth Marine Series, Correlation
of, with Bracklesham Beds, Upper and
Middle Bagshot Beds of London Basin,
and Bovey Tracey Beds, 148.

Bovey Lignites, Age of, Miocene or
Eocene? 240.

Bovey Tracey Beds, Correlation of
Bournemouth Marine Series with, 148.

Brachiopoda, Studies of Bohemian, 474.

Bracklesham Beds,Correlation of Bourne-
mouth Marine Series with, 148.

Brazil Wood, Charnwood Forest, Rocks
of, 481.

Bridlington and Sewerby Gravels, 238.

: Freshwater Remains in
Boulder-clay at, 393.

Britain, Mammoth not Pre-Glacial in, 235.

British Association, 476.

British Pre-Cambrian Rocks, 433.

37

578
BRO

Brongniart, C., New Orthopterous In-
sect of Family Phasmide, trom Upper
Coal-measures of Commentry, De-
partment Allier, France, 97.

Browne, A. J. Jukes, Chloritic Marl and
Upper Greensand, 47, 148; Kinahan’s
Geology of Ireland, 286; Jukes’s
Theory of River Valleys, 431; Post-
peay Deposits of Cambridgeshire,

20.

aa Quaternary Deposits near,

176.

Co Valley, 46, 191.

Yorkshire, Source of
Erratic Boulders in, 318.

Callaway, C., Division of Silurian and
Cambrian Formations, 142; Plagio-
clinal Mountains, 216.

Cambrian and Silurian Formations,
Division of, 142.

Cambridge Philosophical Society, 572.

Cambridgeshire, Post-Tertiary Deposits
of, 520.

Caradoc Beds of Corwen, Ramipora in,
241,

Carboniferous Limestone of Belgium,
Hurynotus in, 237.

Carruthers, W., Fossil Wood from
Griqua Land, 286.

Chalk, Fish Exuyie from, referred to
Dercetis elongatus, and New Fossil
Annelide, Terebella Lewesiensis, 145.

above Upper Silurian of Herts,

330.

Champernowne, A., Devonian Question,
126,

Channel Islands, Beekite in, 334.

Charnwood Forest, Rocks of Brazil
Wood, 481.

Chemical and Geological Essays, T.
Sterry Hunt, 554.

Chester Society of Natural Science, The,
569.

Chloritic Marl and Upper Greensand,
47, 143.

Cladochonus, M‘Coy, Microscopic Struc-
ture of, 289.

Classification of the Lower Palzozoic
Rocks, 1.

Clays, Fossiliferous Pliocene, overlying
Basalt near the Shore of Lough
Neagh, 62, 214.

Climate, Former, of Polar Regions, 91,
144,

Coal, History of, 137.

Coal and Iron in South Africa, 514.

Coalfields of the Stormberg, 551.

of Camdeboo and Nieuweldt,
Cape of Good Hope, 553.

Coal-measures, Upper, of Commentry, De-

partment Allier, France, Insectfrom,97.

Index.

DAK

Cohen and Benecke’s Geological Map of
Heidelberg, 41.

Columnar Sandstone in Saxon Switzer-
land, 437.

Commentry, Department Allier, France,
Orthopterous Insect from Upper Coal-
measures of, 97.

Continental Masses, Rise and Fall of, 298.

Coral, New Favosite from Niagara
Formation, Manitoulin Island, Lake
Huron, 244.

Corals (The Tabulate), their Structure
and Affinities, 561.

Cornwall, Historical Geology of, 27, 74,
102, 166, 203, 251, 307.

Olivine Gabbro from, 504.
Post-Tertiary Geology of, 102.

Correspondence, Birds, J. A., 334; Cal-
laway, C., 142; Cameron, A. G., 575;
Carruthers, W., 286; Croll, Dr. J.,
480; Dakyns, J. R., 46, 96, 238, 239,
382,528; Davis, J. W., 191; Downes,
Rev. W., 480; Etheridge, R., 286 ;
Fisher, Mr. O., 144; Gunn, W., 95,
384; Hall, T. M., 94; Haughton, Prof.
S., 91; Hicks, Dr. H., 528; Hull,
Prof. E., 45, 192, 385, 573; Jamieson,
Capt. H. W., 284; Jones, Prof. T.R ,
479; Jukes-Browne, A. J., 47, 143,
236,431; Keeping, W., 528; Kinahan,
G. H., 144, 237, 333; Mc Gee, W. J.,
528; Mello, Rev. J. M., 383; Meyer,
C. J. A., 148; Strahan, A., 286, 334;
Taylor, Dr. J. K., 383; Traquair, Dr.,
237, 576; Upham, W., 283; Ussher,
W.A.E., 98; Vicary, W., 240; Win-
wood, Rev. H. H., 286; Woodward,
H. B., 235, 575; Wynne, A. B., 429.

Corwen, Ramipora in Caradoc Beds of,
241.

Crayford, Kent, Teeth of Ovibos moscha-
tus from, 246.

Cretaceous formation of Ardennes, 328.

Crinoids, Devonian, Two Genera of, 516.

Crisp, F., Journal of Royal Microscopical
Society, 188, 476.

Croll, Dr. J., Interglacial Periods, 480.
Crosby, W. O., Appearance of Fault may
be Produced without Fracture, 296.

Crustacea, Paleozoic, 196.

Crystallography and Crystallo-physics,
373.

Ctenacanthus minor, a New Fossil Fish-
spine, 531.

Cudgegong Diamond Field, New South
Wales, 399, 444.

AKYNS, J. R., Bridlington and
Sewerby Gravels, 238; Calder
Valley, 46; Glacier Troughs beneath _
Glacier des Bossons, 239; Hitching
Stone, 96; Lenticular Hills of Glacial

Index.

DAK

Drift, 382; Purple Boulder-clay at
Holderness, 528; The Parallel Roads
of Glen Roy, 529.

Dana, Prof. J. D., Some Points of Litho-
logy, 222.

Dana’s Classification of Rocks, 199.

Daubrée, Prof. A., Synthetic Studies in
Experimental Geology, 421.

Davies, W., Fish Exuvie from Chalk,
generally referred to Dercetis elon-
gatus ; and new species of fossil An-
nelide, Terebella Lewesiensis, 146;
Teeth of Ovibos moschatus from Cray-
ford, Kent, 246.

Davis, J. W., Calder Valley, 191; Source
of Erratic Boulders in Calder Valley,
Yorkshire, 313; New Fossil Fish-
spine, 5381.

Delesse and De Lapparent’s Review of
Geology for 1876 and 1877, 84.

Dercetis elongatus, refered to, Fish Exu-
vie from Chalk, and a new Fossil
Annelide, Terebella Lewesiensis, 146.

Des Bossons, Glacier Troughs beneath
Glacier, 239.

Devon Geology, 333.

Devon, North, Section, 45, 94, 236.

Devonian Crinoids, two Genera of, 516.

————— Question, 125, 127, 192.

Devonshire, Geology of, 374.

Paleolithic Implement found

in, 480.
Diamond Field, New South Wales, 399,
444,

—— §. Africa, Fossils from,
192.

Dingle and Glengariff Grits, 348.

Dolomite Reefs of South Tyrol and
Venetia, 428.

Downes, Rev. W., Paleolithic Imple-
ment found in Devonshire, 480.

Dunn, E. J., The Stormberg Coal-field,
Report on, 551; The Camdeboo and
Nieuweldt Coal, Cape of Good Hope,
Report on, 553.

GERTON, Sir P. M. Grey-, Award
of the Kingsley Medal to, 669.
Eimys lutaria from Norfolk Coast, Fossil
Remains of, 304.

English Lake District and Notes on
Skiddaw Slates, 50, 110.

Eocene or Miocene? Age of Bovey
Lignites, 240.

Erratic Boulders in Calder Valley, York-
shire, Source of, 313.

Eruptive Rocks of Saar and Moselle, 84.

Etheridge, R., Silurian Rocks in Herts,
286.

Etheridge, R., Jun., Bivalves in Gilbert-
son Collection, British Museum, figured
in Phillips’s ‘* Geology of Yorkshire,”

579
FRA

161; Ramipora in Caradoc Beds of
Corwen, 241; Silurian Fossils of
Girvan, Ayrshire, 135.

Europe, Western, Old Red Sandstone of,
278.

Eurynotus in Carboniferous Limestone
of Belgium, 237.

Eurypterus Scouleri, Hibbert, 196.

Extinct Reptiles, New Order of, 225.

Extinct Wingless Birds of New Zealand,
81.

Exuvie of Fish from Chalk, referred to
Dercetis elongatus, and New Fossil
Annelide, Zerebella Lewesiensis, 145.

1 ae pee Appearance of, may be Pro-
duced without Fracture, 296.

Faults in London Clay, near Harwich,
383.

Fauna of Carboniferous Limestone of
Belgium, 472.

Favosite Coral, New, from Niagara For-
mation, Manitoulin Island, Lake
Huron, 244.

Feistmantel, Dr. O., Fossil Flora of
Eastern Australia and Tasmania, 485.

Fish Exuvie from Chalk, referred to
Dercetis elongatus, and New Fossil
Annelide, Zerebella Lewesiensis, 145.

Fish-spine, New Fossil, 531.

Fisher, O., Former Climate of Polar
Regions, 144.

Flintshire, Beekite in, 334.

Flora, Fossil, of Eastern Australia and
Tasmania, 485.

Flora, Miocene, in Arctic Regions, 95.

Fossil Forests of the Yellowstone
Park, 551.

Fossil, New, Annelide, Teredella Lewes-
densis, 146.

Flora of Eastern Australia and

Tasmania, 485.

Organisms in India, Geological

Distribution of, 274.

and Recent Sequoie, 372.

Remains of Hmys lutaria from

Norfolk Coast, 304.

Shells from Sumatra, 385, 441,

492, 536.

Wood from Griqua Land, 286.

Fossils from Diamond Fields, South
Africa, 192.

of Girvan, Ayrshire, 135.

Fossiliferous Band of Shotover Sands,
193.

—— Pliocene Clays overlying
Basalt near the Shore of Lough Neagh,
62, 214.

France, Orthopterous Insect from Up-
per Coal-measures of Commentry,
Department Allier, 97.

580
FRE

Freshwater Remains in Boulder-clay at
Bridlington, 393.

Fritsch, Dr. A., Amphibians from Per-
mian Rocks of Bohemia, 521.

ARDNER, J. S., Correlation of
Bournemouth Marine Series with
Bracklesham Beds, Upper and Middle
Bagshot Beds of London Basin and
Bovey Tracey Beds, 148, :
Gault, 326.
Geikie, Prof. A., Old Red Sandstone of
Western Europe, 278.
Geological Age of Lough Neagh, 214.
— _ Congress, Paris, International,
186, 284.
Distribution of Fossil Organ-
isms in India, 274.
Essays by T. Sterry Hunt, 554.
— Exploration of Fortieth Paral-
lel, 467.
Lectures, 374.
———— Map of Heidelberg, 41.
— Railway Guide, American, 229.
— Survey of England and Wales,

178.

— Survey of India, Publications
of, 429.
— Survey of U.S., Report of
Field Work, 226, 240.
— Society of London, 42, 85, 138,
189, 232, 279, 328, 375, 570.
Time, Limestones as an Index
of, 549.
Geologists’ Association, 230.
Geology of Alps, 182.
of Western Africa.
of West Balkan, 36.
of Cornwall, 27, 74, 102, 166,
208, 251, 307. :
- of Devon, 236, 3383.
— of Devonshire, 374.
of N.W. of Essex and N.E. of
Herts, with parts of Cambridgeshire
and Suffolk, 178.
and Geography of Great Britain,

277.

of New Hampshire, 517.

of Ireland, 37, 236.

of Isle of Man, 211, 286.
Practical, 230.

Review of, for 1876 and 1877,

Surface, of Part of Mississippi

Valley, 353, 412, 528.

Synthetic Studies in Experi-
mental, 421.

Gilbertson Collection of Bivalyes in
British Museum, figured in Phillips’s
“Geology of Yorkshire,” 161.

Girvan, Ayrshire, Silurian Fossils of,
136.

Index.

HOL

Glacial Drift, Lenticular Hills of, 382.

Period in Eastern America, 248.

Troughs beneath Glacier des
Bossons, 239.

Glaciation of West Yorkshire Dales, 384.

Glengariff and Dingle Grits, 348.

Glen Roy, Parallel Roads of, 529.

Gravels, Bridlington and Sewerby, 288.

Greensand, Upper, and Chloritic Marl,
47, 143.

Grey-Egerton, Award of the Kingsley
Medal to, 569.

Griffith, Sir R., and Old Red Sandstone,
144,

Griqua Land, Fossil Wood from, 286.

Giimbel, Prof. Dr. C. W., Introduction
to Alpine Geology, 182.

Gun-flints, Manufacture of, 475.

Gunn, J., Miocene Flora in Arctic
Regions, 95.

Gunn, W., Glaciation of West Yorkshire
Dales, 384.

HA T. M., Geology of Devonshire,
94, 374.

Hanover, Upper Jura of, 225.

Hardman, E. T., Fossiliferous Clay Beds
overlying Basalt, Lough Neagh, and
Geological Age of that Lake, 214.

Harrison, W. J., Practical Geology, 230.

Harwich, Faults in London Clay, 383.

Haughton, Rev. Prof. §., Former
Climate of Polar Regions, 91.

Hayden, F. V., Preliminary Report of
Field Work of U.S. Geological and
Geographical Survey of Territories for
1878, 226.

Heer, Prof. O., Fossil and Recent
Sequoie, 372.

Heidelberg, Geological Map of, 41.

Heim, Prof. A., Mechanism of Moun-
tains, 131.

Herts, Silurian Rocks in, 286.

Hicks, Dr. H., Classification of British
Pre-Cambrian Rocks, 433, 528.

Hinde, G. J., New Favosite Coral from
Niagara Formation, Manitoulin Island,
Lake Huron, 244.

Historical Geology of Cornwall, 27,
74, 102, 166, 203, 251, 307.

History of Coal, 137.

of the English Lake District,
with Notes on Subdivision of Skid-
daw Slates, 50, 110.

Hitchcock, Prof. C. H., Geology of New
Hampshire, 517; Glacial Period in
Eastern America, 248.

Hitching Stone, 96.

Holderness, Purple Boulder-clay at, 528.

Holmes, W. H., Fossil Forests of the
Yellowstone Park, 551.

Index.

HOU

Houghton, F. T. §., Olivine Gabbro
from Cornwall, 504.

Hull, Prot. E., Additional Notes on the
N. Devon Section, 45, 192; Devonian
Question, Reply to Mr. Kinahan’s
Note, 127; Upper Silurian under
Chalk of Herts, 335; Age of Pennine
Chain, 573.

Hull and Kinahan, 237.

Hunt, T. Sterry, Trap-dykes and Azoic
Rocks of Pennsylvania, 519; Chemical
and Geological Essays by, 554.

Huron, Lake, New Favosite Coral from
Niagara Formation, Manitoulin Is-
land, 244.

ieee in Kimmeridge Clay,
Oxford, 193.

Implement, Paleolithic, found in Devon-
shire, 480.

Index of Geological Time, Limestone as
an, 549.

India, Beekite from Punjab, 284.

— Distribution of Fossil Organisms
in, 274.

—— Publications of Geological Survey
of, 429.

Insects, Orthopterous, from Upper Coal-
measures of Commentry, Department
Allier, France, 97.

Interglacial Periods, 480.

Intrusive and Metamorphic Rocks of
Tyrone, 154.

Ireland, Kinahan’s Geology of, 236.

Manual of Geology of, 37.

Silurian Rocks of, and their
Relation to Old Red Sandstone, 65.

Iron and Coal in S. Africa, 514.

Isle of Man, Geology of, 211, 286.

AMIESON, Capt. H. W., Beekite
from Punjab, India, 284.

Jones, Prof. T. R., New Lake in the
Pistojese Mountains, 479: G. W.
Stow’s Report on Coal and Iron in
S. Africa, 514.

Jukes on River Valleys, 8S. W. Cork, 333.

Jukes’s Vheory of River Valleys, 431.

Jura, Upper, of Hanover, 226.

Jurassic Mammal, 371.

EEPING, W., Columnar Sandstone
in Saxon Switzerland, 437.
Keuper Basement Beds, near Notting-
ham, 532.
Kimmeridge Clay, Oxford, Iguanodon
in, 193.
Kinahan, G. H., Devon Geology, 333.
— Dingle and Glengariff

Grits, 348.
— Sir R. Griffith and Old
Red Sandstune, 144,

581
MAP

Kinahan, G. H., Jukes on River Valleys,
S. W. Cork, 333.
Manual of Geology of

Treland, 37.

Silurian Rocks of Ire-
land, and their Relation to Old Red
Sandstone, 65.

Kinahan’s Geology of Ireland, 236.

Kinahan and Hull, 237.

King, C., U. 8. Geological Exploration
of Fortieth Parallel, 467.

King, John, Obituary of, 576.

Koninck, Prof. L. G. de, Fauna of Car-
boniferous Limestone of Belgium, 472.

Kurile Islands, Volcanos of, 337.

AKE District of England, with Notes
on Subdivision of Skiddaw Slates,
50, 110.

Lake, New, in Pistojese Mountains, 479.
Lamplugh, G. W., Freshwater Remains
in Boulder-clay at Bridlington, 393.
Lapworth, C., Tripartite Classification

of Lower Paleozoic Rocks, 1.

Lasaulx, Prof. Dr. A. von, Eruptive
Rocks of Saar and Moselle, 84.

Lenticular Hills of Glacial Drift, 382.

Lenz, Dr. O., Geological Notes on
Western Africa, 172.

Lesley, J. P., Origin of Pipe Ore, 459.

Lignites, Age of Bovey, Miocene or
Hocene P 240.

Ligurian and Tuscan Serpentines, 362.
Limestone, Carboniferous, of Belgium,
Fauna of, 472; Hurynotus in, 237.
Limestones as an Index of Geological

Time, 549.

Lithology, Some Points of, 222.

Lochaber, Origin of Parallel Roads of,
d21,

London Basin, Upper and Middle Bag-
shot Beds of, Correlation of Bourne-
mouth Marine Series with, 148.

London Clay, Harwich, Faults in, 383.

Lough Neagh, Fossiliferous Clays over-
lying Basalt, 62, 214.

Lowry, J. W., Obituary of, 335.

Lycett, Dr., Trigonia Elise, 195.

ACFARLANE, J., American Geo-
logical Railway Guide, giving
Geological Formation at every Rail-
way Station, 229.
McGee, W. J., Surface Geology of Part
of Mississippi Valley, 353, 421, 528.
Mammal, New Jurassic, 371.
Mammoth not Pre-Glaciai in Britain,
236.
Man, Plant-World before Appearance
of, 263.
Manual of Geology of Ireland, 37.
Map of Heidelberg, Geological, 41.

082
MAR

Marine Series, Bournemouth, Correla-
tion of, with Bracklesham Beds, 148.
Marl, Chloritic, and Upper Greensand,

47, 143.

Marsh, Prof. O. C., New Jurassic Mam-
mal, 371.

Mediterranean and Juvavian Trias, Am-
monites of, 460.

Mello, Rev. J. M., Pyritiferous Sand
from Lake Winnipeg, 383.

Metamorphic and Intrusive Rocks of
Tyrone, 154.

Meyer, C. J. A., Chloritic Marl and
Upper Greensand, 148.

Microscopic Structure of Three Species
of Genus Cladochonus, M‘Coy, 289.
Microscopical Journal, American Quar-

terly, 85.

—— Society, Journal of Royal,
138, 476.

Milne, Prof. J., Cruise among Volcanos
of Kurile Islands, 337; Crystallogra-
phy and Crystallo-physics, 373; Form
of Volcanos, 506.

Miocene or Kocene? Age of Bovey
Lignites, 240.

— Flora in Arctic Regions, 95.

Mississippi Valley, Surface Geology of
Part of, 353, 412, 528.

Mojsisovics, Dr. E. von, Ammonites of
Mediterranean and Juvavian ‘Trias,
460; Dolomite Reefs in South Tyrol
and Venetia, 428,

Morton, G. H.,Geology of Isle of Man, 211.

Moselle and Saar, Eruptive Rocks of, 84.

Mountains, Mechanism of Formation of,
131.

Mountains, Plagioclinal, 216.

Nee Lough, Fossiliferous Clays
overlying Basalt, 62, 214.

Nehring, Dr. A., Quaternary Deposits
near Brunswick, in Illustration of
Subaerial Origin of Loess, 176.

New England, Till in, 283.

—— Hampshire, Geology of, 517.

—— South Wales, Cudgegong Diamond
Field, 399, 444.

Zealand, Extinct Wingless Birds
of, 81.

Newton, E. T., Fossil Remains of Emys
lutaria from Norfolk Coast, 304.

Niagara Formation, Manitoulin Island,
Lake Huron, New Favosite Coral
from, 244.

Nicholson, Prof. H. A., Microscopic
Structure of Three Species of Genus
Cladochonus, M‘Coy, 289; Structure
and Affinities of the Tabulate Corals,
561; Manual of Paleontology, 567.

—— and Etheridge, Silurian

Fossils of Girvan, Ayrshire, 135.

Index.

“PLA

Nicol, Prof. J., Obituary of, 240.

Nolan, J., Metamorphic and Intrusive
Rocks of Tyrone, 154.

Norfolk Coast, Fossil Remains of Hmys
lutaria from, 304.

Notes on N. Devon Section, 45.

Nottingham, Keuper Basement Beds,
near, 632.

BITUARIES of King, John, 576;

Lowry, J. W., 335; Nicol, Prof.
J., 240; Reeks, Trenham, 288 ; Sop-
with, T., 96.

(Chlert, M. D., Two Genera of Devonian
Crinoids, 516.

Olivine Gabbro from Cornwall, 504.

Organisms, Fossil, in India, Geological
Distribution of, 274.

Orthopterous Insects of Family Phas-
mide from Upper Coal-measures of
Commentry, Dept. Allier, France, 97.

Ovibos moschatus, Teeth of, from Cray-
ford, Kent, 246.

Owen, Prof. R., Extinct Wingless Birds
of New Zealand, 81.

Oxford, Iguanodon in Kimmeridge Clay,
193.

i aa ee Implement found in
Devonshire, 480.
Paleeontographical Society’s
graphs, 180.
Paleontology, Handbook of, 183.
Manual of, Nicholson’s,

Mono-

567.

Paleozoic Crustacea, 196.

—— Lower, Rocks, Tripartite Clas-
sification of, 1.

Parallel Roads of Lochaber, Origin of,
o21,

- of Glen Roy, 529.

Paris, Geological Congress in, 284.

‘*‘ Pennine Chain,’”’ Age of, 500.

Pennsylvania, 8.-H., Trap-dykes and
Azoic Rocks of, 519.

Permian Rocks of Bohemia, Amphibians
from, 521.

Petrology, Elementary Text- book of, 228.

Pettersen, K., Slow Secular Rise and
Fall of Continental Masses, 298.

Physical Geology and Geography of
Great Britain, 277.

Physical History of the English Lake
District, with Notes on Possible Sub-
division of Skiddaw Slates, 50, 110.

Physical System of the Universe, 82.

Physiography, Outline of, 82.

Pipe Ore, Origin of, 459.

Pistojese Mountains, New Lake in, 479.

Plagioclinal Mountains, 216.

Plant-World before Appearance of Man,
263.

Index.

PLI

Pliocene Clays overlying Basalt near the
Shore of Lough Neagh, 62, 214.

Polar Regions, Former Climate of, 91,
144,

Post-Tertiary Deposits of Cambridge-
shire, 520.

Geology of Cornwall, 102.

Pre-Cambrian Rocks, British, 433, 528.

Pre-Glacial in Britain, Mammoth not,
235.

Prestwich, Prof. J., Iguanodon in Kim-
meridge Clay, Oxford, and very Fos-
siliferous Band of Shotover Sands,
193; Origin of Parallel Roads of
Lochaber, 321.

Price, F. G. Hilton, Gault, 326.

Punjab, India, Beekite from, 284.

Pyritiferous Sand from Lake Winnipeg,
383. :

UATERNARY Deposits near Bruns-
wick, 176.

AMIPORA in Caradoc Beds of
_ Corwen, 241.

Ramsay, Prof. A. C., Physical Geology
and Geography of Great Britain, 277.

Reade, T. Mellard, Limestones as an
Index of Geological Time, 549.

Reefs, Dolomite, in South Tyrol and
Venetia, 428.

Reeks, Trenham, Obituary of, 288.

Renevier, Prof. E., Notice of Prof. A.
Heim’s Work on Mechanism of Forma-
tion of Mountains, 131.

Reptiles, New Order of Extinct, 225.

Review of Geology for 1876 and 1877,
84.

Rise and Fall of Continental Masses, 298.

River Valleys, 8. W. Cork, 333.

Jukes’s Theory of, 431.

Rocks, British Pre-Cambrian, 433.

of Brazil Wood, Charnwood
Forest, 481.

——— Prof. Dana’s Classification of,
199.

——— Eruptive, of Saar and Moselle,
84.

——w— Metamorphic and Intrusive, of
Tyrone, 154.

——— Silurian, in Herts, 286.

of Ireland, and their
Relation to Old Red Sandstone, 65.

——— Study of, 228.

Rutley, F., Study of Rocks, Elementary
Text-book of Petrology, 228.

Nee and Moselle, Eruptive Rocks of,
84.

Sandstone, Columnar, in Saxon Switzer-
land, 437.

583
SWA

Sandstone Old Red, and Sir R. Griffith,
144,

————— of Western Europe,
278.

Silurian Rocks of
Treland, and their Relation to, 65.

Saporta, Count de, Plant-World before
Appearance of Man, 263.

Saxon Switzerland, Columnar Sandstone
in, 437.

Schimper, Prof. W. P., Handbook of
Paleontology, 183.

Sequoie, Fossil and Recent, 372.

Serpentines, Ligurian and ‘Tuscan,
362.
Sewerby and Bridlington Gravels,
238.

Shells from Sumatra, Fossil, 385, 441,
492, 535.

Shipman, J., and Wilson, E., Basement
Beds of Keuper, Nottingham, 532.
Shotover Sands, very Fossiliferous Band

of, 193.
Sicily, Tufo and Tripoli of Sulphur
Zone of, 221.
Silurian and Cambrian Formations, Divi-
sion of, 142.
Fossils of Girvan, Ayrshire, 135.
Rocks in Herts, 286.
Rocks of Ireland and their Re-
lation to Old Red Sandstone, 65.
Upper, under Chalk of Herts,

330.

Skertchly, S. B. J., Manufacture of
Gun-flints, 475; Physical System of
the Universe, an Outline of Physio-
graphy, 82.

Skiddaw Slates and English Lake Dis-
trict, 50, 110.

Sollas, W. J., Lectures on Geology, 374.

Sopwith, T., Obituary of, 96.

Stohr, E., Tufo and Tripoli of Sulphur
Zone of Sicily, 221.

Stone, Hitching, 96.

Stow, G. W., Iron and Coal in South
Africa, 514.

Strahan, A., Beekite in Flintshire, 334.

Geology of Isle of Man,

286.
Struckmann, C., Upper Jura of Hanover,
225.
Structure, Microscopic, of Three Species
of Genus Cladochonus, M‘Coy, 289.
Subaerial Origin of Loess, Quaternary
Deposits near Brunswick, 176.

Sulphur Zone of Sicily, Tufo and Tri-
poli of, 221.

Sumatra, Fossil Shells from, 385, 441,
492, 539.

Swanston, W., F.G.s., Supposed Fossili-
ferous Pliocene Clays overlying Basalt
near Lough Neagh, 62.

584
TAB

ABULATE Corals, The Structure of,
561.

Tasmania and Eastern Australia, Fossil
Flora of, 485.

Taylor, Dr. J. E., Faults in London
Clay, Harwich, 383.

Taylor, N., Cudgegong Diamond Field,
New South Wales, 399, 444.

Teeth of Ovibos moschatus from Cray-
ford, Kent, 246.

Terebella Lewesiensis, New Fossil Anne-
lide, 145.

Till, in New England, 283.

Time, Index of, 549.

Toula, F., Geology of West Balkan, 36.

Trap-dykes and Azoic Rocks of S.E.
Pennsylvania, 519.

Traquair, Dr. R. H., Hurynotus in Car-
boniferous Limestone of Belgium, 237,
576.

Trias, Ammonites of Mediterranean and
Juvavian, 460.

Trigonia Elise, Cornet and Briart, 195.

Tripartite Classification of the Lower
Paleozoic Rocks, 1.

Tripoli and ‘lufo of Sulphur Zone of
Sicily, 221.

Troughs beneath Glacier des Bossons,
239,

Tufo and Tripoli of Sulphur Zone of
Sicily, 221.

Tuscan and Ligurian Serpentines, 362.

Tyrol and Venetia, Dolomite Reefs in,
428,

Tyrone, Metamorphic and Intrusive
Rocks of, 154.

ae States, Geological Explora-
tion of Fortieth Parallel, 467.

Universe, Physical System of, 82.

Upham, W., Till, in New England, 283.

Ussher, W. A. E., Facta Non Verba, 93;
Historical Geology of Cornwall, 27,
74, 102, 166, 203, 251, 307.

ALLEY of the Calder, 46, 191.
Valleys, River, Jukes’s Theory of,
431.

Index.

ZIT

Venetia and South Tyrol, Dolomite
Reefs in, 428.

Verbeek’s Collection of Fossil Shells
from Sumatra, 385, 441, 492, 535.
Vicary, W., Miocene or Eocene? Age of

Bovey Lignites, 240.
Volcanos of Bay of Bengal, 16.
Form of, 506.
———— of Kurile Islands, 337.

AAGEN, Dr. W., Geological Dis-
tribution of Fossil Organisms in -
India, 274.

Ward, Rev. J. Clifton, Physical History
of the English Lake District, with
Notes on the Possible Subdivision of
the Skiddaw Slates, 50, 110.

Wilson, E., Age of “ Pennine Chain,”
500.

————— and Shipman, J., Keuper
Basement Beds, Nottingham, 532.

Wiltshire, Rev. T., History of Coal, 137.

Wingless Birds of New Zealand, Extinct,
81.

Winnipeg, Pyritiferous Sand from Lake,
388.

Winwood, Rev. H. H., Geology of
North Devon, 236.

Wood, Fossil, from Griqua Land, 286.

Woodward, Dr. H., Description of Fossil
Shells from Sumatra (obtained by
M. Verbeek), 385, 441, 492, 535.

Notes on Paleozoic
Crustacea, Eurypterus Scouleri, Hib-
bert, 196.

Woodward, H. B., Mammoth not Pre-
Glacial in Britain, 235; Fossils on
Cleavage Planes, 575.

Wynne, A. B., Recent: Publications of
Geological Survey of India, 429.

ELLOWSTONE Park, Fossil Forests
of the. 551.
Yorkshire, W., Dales, Glaciation of, 384.

ITTEL, Prof. K. A., Handbook of
Paleontology, 183.

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