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THE

GEOLOGICAL |

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MAGAZINE:

onthly Journal of Geology

OR,

WITH WHICH IS INCORPORATED
ntlHin GHOLmOGIS@®s

NOS. CCLXXI. TO CCLX XXII

EDITED BY

HENRY WOODWARD, LL.D., F.B.S., V.P.G.S., F.Z.S., F.R.M.S

Dey 4.
OF THE BRITISH MUSEUM OF NATURAL HISTORY;

VICE-PRESIDENT OF THE PAL/ONTOGRAPHICAL SOCIETY,
SOCIETY, PHILADELPHIA

MEMBER OF THE LYCEUM OF NATURAL HISTORY, NEW YORK; AND OF THE AMERICAN PHILOSOPHICAL
; 4 E
SOCIETY; OF THE GEOLOGISTS’ ASSOCIATION

HONORARY MEMBER OF THE YORKSHIRE PHILOSOPHICAL
» LONDON: OF THE GEOLOGICAL

SOCIETIES OF EDINBURGH, GLASGOW, HALIFAX, LIVERPOOL, AND NOR=
WICH; CORRESPONDING MEMBER OF THE GEOLOGICAL SOCIETY
OF BELGIUM; OF THE IMPERIAL SOCIETY OF NATURAL
HISTORY OF MOSCOW; OF THE NATURAL HISTORY

SOCIETY OF MONTREAL

AND OF THE
MALACOLOGICAL SOCIETY
OF BELGIUM.

ASSISTED BY

PObwnn REE RIDGE, ERS: i. & H., F.G.8., Ee

A 28, G5Cs,
OF THE BRITISH MUSEUM OF NATURAL HISTORY
WILFRID H. HUDDLESTON, M.A., F.R.S., Sec.G.S

GEORGE J. HINDE, Pz.D., F.G.8., &c

NEW SERIES. DECADE III. VOL. IV

JANUARY—DECEMBER, 1887

KSONIAN INST

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THE
GEOLOGICAL MAGAZINE
DECADE III. VOL. IV.
JANUARY—DECEMBEBR 1887.

LIST OF WOODCUTS.

Luphoberia ferox, Salter, sp. 5

Acantherpestes major, M.& W. .

Two Sections in the Culm of Devonshire

Four Illustrations of ‘‘ Cone-in-Cone” Structure.
Sections in the Cretaceous beds of Suffolk .
Progonoblaitina (Blatta) helvetica, Heer. .

Wing of Palzeozoic Cockroach (after Scudder) .

Ejioblattina Mazona, Scudder . .
Mylacris anthracophilum, Scudder

Section in Whitecliff Bay, Isle of Wight .

Restored outline of sternal apparatus of Dinosaur (Zgsanodon)

Lemiphyllum Siluriense, M‘Coy, sp. +

Tooth of Acrodus leiodus, Ag. .

Teeth of Acrodus levis, A. S. Woodw.
Map of the neighbourhood of Gelinden

Section in. Barkham Gravel-pit .
Luphoberia ferox, Salter . . .

Section in Carboniferous Limestone, Northampton .

Section of felspar in the Rill serpentine
“Section from West Hythe to Canterbury .

Cranial shield of Chondrosteus .
Head of Chondrosteus. .« «
Palatal apparatus of Chondrosteus .

Profile of head of Chondrosteus (restored)
Sections of rock of Tolcsva, and of perlitic lava of Wuenheim

Arius Egerton and Arius? Bartonensis «

Terebratula obesa, var. cuneata . .
Sketch-map of Carrock Pike. .
Cythere Hlarrisiana, Jones .- . .
Cythereis spinosissima, Jones . .
Crumpled and Contorted Gneisses .

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15, 17
18, 19, 20, 21

27
50

Vill List of Woodcuts.

Granite in Gabbro, Pen Voose - . .. -
iSehalacl (GinsyGses3 og 56 6 5 6 6 a Oo
Geological Map of Coast near Landewednack .
Diagram sketch of band of pseudo-agglomerate .
Diagram of Bursting Rock at Dent Head . .
Piloceras invaginatum ?, Salter. . +. + «© «
Sections of siphuncle of Piloceras, sp. » «+ -

PLATE
I. Carboniferous Myriapods .« + + »© + + «© « «@
II. British Paleeozoic Cockroaches.
III. Ophiurella nereidea, Wright 5
IV. Vertebrate Fauna of the Norfolk Forest Bed
V. New British Liassic Gasteropoda
VI. American Jurassic Mammals—Allodon
VII. Ay 55 5 Ctenacodon .-
VIII. 5 9 5p 6.0) ©
IX. 5A 39 a 6 6 .
X. Pholidophorus, Purbeck, Dorsetshire
XI. Ostracoda from the London Clay . . =. .-
XII. Carboniferous Cockroaches . « Re rics. 20) sh
XIII. Lurypterus scabrosus, H. Woodw. Gastonia Eskdale
XIV. je 1, Granite Veins in Diorite, Pen Voose, the Lizard
Fig. 2, Banded Gneissic series, Pen Voose, the Lizard. -
XV. Solaster Murchisoni, Willmson., Lias, Yorkshire

LIST OF PLATES.

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Geol. Mag. 1887. Decade I.VolIV.PLI.

G.M. Weodward del. et hth. West, Newman & Coump .
Carboniferous Myriapods.

THE

GEOLOGICAL MAGAZINE.

NEWOIESERIES, "DECADE Ill. VOLe. IV.

No. I—JANUARY, 1887.

@sEuss Gaia e Ata) eASeo a eC ae Se

——___—__

I.—On some Spinep Myriapops FRoM THE CARBONIFEROUS SERIES
oF ENGLAND.

By Henry Woopwarp, LL.D., F.R.S., F.G.S.
(PLATE 1.)

ALAM ONTOLOGISTS are largely indebted to Messrs. Meek and

Worthen for their very careful researches in the Coal-Measures

of Illinois, which have resulted in such large and valuable accessions

to the fauna and flora of the Carboniferous formation. Not the least

interesting of these has been the discovery of numerous organisms,

which were first recognized and correctly described by them in 1868?
as the remains of spined Myriapods.

The earliest record of the discovery of one of these curious terres-
trial Arthropods in England will be found in “A History of Fossil
Insects,” etc., by the Rev. P. B. Brodie, M.A., F.G.S., Svo. 1845,
in the “Introductory Observations ” to which Prof. J. O. Westwood
drew attention to a figure (pl. i. fig. 11) in that work, representing
a remarkable fossil preserved in a nodule of clay-ironstone from the
Coal-measures, Coalbrook-dale, which he believed to be probably the
remains “of some large Caterpillar furnished with rows of tubercles”
(pp. xvii, 105, and 115, op. cit.). The specimen is preserved in the
“Hope Collection,” in the University Museum, Oxford (Woodcut
Fig. 1).

The next specimen was figured and described by the late Mr.
J. W. Salter, F.G.S.,? eighteen years later, who named it Hurypterus
(Arthropleura) ferox, sp. nov., and referred to it as “one of the
most curious Crustacean fragments on record,” and as “part of the
abdomen of a Eurypterus” (op. cit. p. 87). It was obtained from
the clay-ironstone of the Staffordshire Coal-field at Tipton, from the
shale over the “ Thick-Coal” (Woodcut Fig. 2). Mr. Salter states
that “another specimen occurs in the Hope Collection at Oxford.”

So far back as 1859,? Prof. (now Sir) William Dawson, K.C.M.G.,
F.R.S., described a Chilognathous Myriapod from the Coal-measures
of Nova Scotia, under the name of Xylobius sigillarie.

1 Geol. Sury. Illinois, vol. iii. pp. 558—449.
2 Quart. Journ. Geol. Soc. 1863, vol. xix. p. 86, fig. 8.
3 Quart. Journ. Geol. Soc. vol. xvi. p. 268.

DECADE Ill.—VOL. IV.—NO. I. 1

2 Dr. H. Woodward—Myriapods of the Coal Period.

This form did not, however, appear to have been provided with
spines, like those from Illinois, discovered by MM. Meek and
Worthen.

Fic, 1. Huphoberia ferox, Salter, sp. Fie. 2. Euphoberia ferox, Salter, sp.
= Acantherpestes Brodiei, Scudder. (Salter’s original woodcut.) *

(Copy of Brodie’s original figure.)

[Having been kindly permitted by Prof. J. 0. Westwood to examine the original |
specimen in the “‘ Hope Cabinet,’ I am able to state that the supposed extra row of
tubercles are not the bases of spines broken off, but are depressions in the tergum
near the base of each of the great branched spines, and may be seen near the lateral
borders of each somite, in every specimen of #. ferox which I have examined. ]

Fie. 3. Acantherpestes major, M. and W., Coal-measures, Illinois.

Neither did the specimen which I described in 1866,? from the
Clay-ironstone of the Coal-measures, Kilmaurs, Ayrshire; which so
closely resemble Dawson’s specimen, that I referred it to even the
same genus and species.

1 Not an accurate representation of the fossil described by Salter.
* Trans, Glasgow Geol. Soc. vol. ii, pp. 234-238, pl. iii.

Dr. H. Woodward—Myriapods of the Coal Period. 5)

Mr. S. H. Scudder, however,! has changed the name to X. Wood-
wardii, on the ground that the marks which I interpreted as pro-
bably the openings of trachez, are in reality “the scars or bases of
spines, which appear as warts or tubercles in many of the Mazon
Creek Myriapods; or, when viewed from the interior surface, as
pits’ (op. cit. p. 149).

In 1868, Messrs. Meek and Worthen? described several well-
preserved remains of spined Myriapods from the Ironstone nodules
of Mazon Creek, Illinois (see Woodcut, Fig. 3), which are placed by
Scudder in five genera and twelve species (see infra).

In 1871, I figured another Myriapod from the Clay-ironstone of
the Coal-measures, Kilmaurs, Ayrshire, under the name of Huphoberia
Brownii.2 In that paper I compared H. Brownti, mihi, with HE. armi-
gera, M. and W., and stated, “There are indications of pores, and
also of the bases of tubercles or spines, along the dorsal line, but
the latter are less perfectly preserved.”

In 1882, Mr. S. H. Scudder‘ summarized our knowledge of the
Myriapoda of the Carboniferous formation, and added several new
species, in addition to proposing a classification for those already
described.

Later on (1884 *), Scudder described three species of a new genus
of Myriapods (Trichiulus), and gave a description of another
Myriapod which had first been noticed under the name of Palco-
campa anthrax by Messrs. Meek and Worthen in 1866, and for which
he proposed, in 1884, a new suborder, viz. PRorosyNGNATHA.

This form of Myriapod is remarkable on account of the dorsal
plates supporting several longitudinal rows of fascicles of needle-
like spines, giving it the appearance of a hairy Caterpillar of the
“Tiger-moth” (Arctia caja).°

The body-segments have a single dorsal and ventral plate, the
latter bearing a pair of widely-separated, stout, fleshy legs, one pair
to each segment behind the head. These stout fleshy legs of Paleo-
campa remind one of the legs of Peripatus, but that genus has no
hard tergal covering to its segments, as was the case in the fossil form.

All the other Palzeozoic Myriapods are included by Scudder in his
suborder ARCHIPOLYPODA.

These Myriapods have a more or less cylindrical body, the head is
slightly larger than the body-segments, being composed of probably
three or more coalesced segments, and bearing, as in other forms,
a single pair of antenns, a pair of compound eyes, mandibles,
maxille and having the first pair of post-cephalic appendages directed
forward, probably to assist in the process of feeding. The dorsal
portion (tergum) of each somite or segment of the body is composed

1 Mem. Boston Soc. Nat. Hist. 1882, vol. iii. no. v. p. 148. '

2 Amer. Journ, Sci. Arts, vol. xlvi. p. 25. _ See also Geol. Surv. Illinois, iii. 556.

3 See Grou. Mag. Vol. VIII. p. 102, Pl. III. Fig. 6a, 8, ¢.

4 Mem. Boston Soc. Nat. Hist. vol. iii. no. v. pp. 143-182, pl. x.-xil.

5 Mem. Boston Soc. Nat. Hist. vol. iii. no. ix. 1884, ‘‘On two new and diverse
types of Carboniferous Myriapods,” pp. 283-297, pl. xxvi. and xxvii.

6 Seudder’s Trichiulus villosus was also covered with fine hairs; but this sup-
posed Myriapod now proves to be the circinate vernation of a fern !

4 Dr. H. Woodward—Myriapods of the Coal Period.

of only asingle plate ; but the ventral portion (sternum) is seen to be
composed of two narrow parallel plates; and as each somite bears
two pairs of legs, and two pairs of spiracles, it seems certain (says
Claus) “that they may be regarded as double-segments,' formed by
the fusion of two somites.”

The raised anterior portion of the tergum of each segment is pro-
vided with a series of spines or tubercles, which, in some of the
Mazon Creek specimens, are doubly-forked.

The class Myrrapopa, at the present day, is divided as under,
viz. :—

I. Cuttopopa ( Centipedes). Antenne simple, body depressed, dorsal
and ventral plates horny, united by a membrane; the legs
inserted in single pairs at the sides of the segments, with the
exception of the first two pairs, which are converted into
mouth-organs.

II. Dietopopa = CurtoenaTHa (Millipedes). Antenne simple,
body convex, or even cylindrical, the dorsal plates bent round
so as to meet the narrow ventral plates nearly in the middle
line of the body; each segment after the 5th or 6th with two
pairs of legs.

III. Pavropopa. With branched antenne.

If we take the broadest possible lines for our guidance in the
classification of animals, it seems that Scudder’s ProtosyNGNATHA
will fall under the first of these divisions, viz. :—

Order I. Cutiopopa (Centipedes, recent).

Suborder ProtosynenatHa (Palgocampa, fossil),
and his ARCHIPOLYPODA will in the same manner find a place under

Order II. DreLopopa (Millipedes, recent).

Suborder ArcuipotyPopa (all Paleozoic forms), with the follow-
ing species :—

1. Family ArcuipEsmipm, Peach.

Genus Archidesmus, Peach.
a5 Macnicoli, Peach, Old Red Sandstone, Forfarshire.
i Remon is, Page.
2. a ’ For fariensis, Page, Old Red Sandstone, Forfar.

2. Family HupHoprripm, Scudder.

9 Acantherpestes, Meek and Worthen, 1868.

3 major, Meek and Worthen, Coal-measures, Illinois, U.S.
(Brodiei, Scudder, Coal-measures, Coalbrook-dale, 2
_Euphteri ia, Meek and Worthen, 1868.

56; ferox, Salter, Coal-measures, Staffordshire.

horrida, Scudder, Coal-measures, Illinois, U.S.

as armigera, Meek and Worthen, Coal-measures, Illinois, U.S.
36 Brownti, H. Woodward, Coal-measures, Ayrshire.

‘ granosa, Scudder, Coal-measures, Illinois, U.S.

10. ” Carri, »” ” ”

11. 99 flabellata, 4, 99 90

12. 9 anguilla, 2 ” ”

CO COMDN He CO

1 Not originated from a fusion of two primitively distinct segments, but from a
later imperfect division of each of the primitive segments into two, and the BODE
to each of the divisions of a primitive segment of a complete set of organs.’
(Balfour, Embryology, vol. i. p. 892.)

2 This is shown to be merely Z. ferow, Salter, sp. ; see ante p. 2, and infra p. 6.

Dr. H. Woodward—Wyriapods of the Coal Period. 3)

Genus Amynilyspes, Scudder, 1882.
138. Gs Wortheni, Scudder, Coal-measures, Illinois, U.S.
oe Eilecticus, Scudder, 1882.
14, 65 anthracinus, ,, 35 op

3. Family ArcuisuLipm, Scudder.

Genus Trichiulus, Scudder, 1884. Recently shown by Scudder to be
15. an villosus, Scudder, founded on the circinate vernation of
16. a nodulosus, Scudder, afern. (See Mem. Boston Soc. Nat.
1c x ammonitiformis, Scud. 5 Hist. vol. iii. No. xiii. p. 438, 1886.)

5 2 Archiulus, Scudder (Judus, Dohrn).
18. 5 Brassti, Dohrn, Rothliegendes, Lebach.
19. eS aylobioides, Scudder, Coal-measures, Nova Scotia.
20. a5 constans, Fri¢ a Bohemia.
21. ie costulatus, Frit a 45
228 wi pictus, Frié 3 3
sy Anthracerpes, Meek and Worthen.
23. a8 typus, Meek and Worthen, Coal-measures, Illinois, U.S.
55 Palegqjulus, Geinitz. Founded on the circinate
24. re dyadicus, Geinitz, Dyas, Saxony. } vernation of a fern.
99 Scolecopteris.
25. % elegans, Zenker, Coal-measures Germany.
5 Xylobius, Dawson, 1859.
26. Ae sigillarie, Dawson ws Nova Scotia.
27. OD Woodwardii, Scudder a Ayrshire.
28. % similis, Scudder 55 Nova Scotia.
29. 3 Sractus 50 06 6
30. be Dawsont ,, 35 a
31. es Chonionotus lithanthraca, Jordan, Coal-measures, Germany.

In a table prepared by Mr. Scudder for Prof. Dr. Zittel’s Hand-
buch der Palzontologie,' of the fossil Myriapods, he places all the
Paleozoic forms (save one) in his suborder ARCHIPOLYPODA, namely,
two Devonian species, thirty-one Carboniferous,’ and four Dyas (?).
The exceptional form belongs to his suborder ProtosynenaTHa.

He records one Diplopod from the Chalk-formation, seventeen
Curnopopa, and twenty-three Dretopopa, from the Oligocene: one
of the latter from the Miocene and forty-nine recent.

In the past year (1886) the British Museum (Natural History
Branch) acquired the well-known collection of the late Mr. Henry
Johnson, F.G.S., Mining Engineer, of Dudley, who had devoted the
best years of his life to the collection of the fossils from the Wenlock
Shale of his native place and those of the surrounding Coal-fields,
particularly the Clay-ironstone nodules of the Coal-measures of
Coseley, near Dudley, from the “‘ Binds” between the “ Brooch” and
«“Thick-Coal.” From these he obtained a rich collection of Crusta-
cean and Insect remains and also many spined Myriapods.

I exhibited the Insects and Myriapods at the British Association
Meeting, Birmingham, in Section C. (Geology) ; and I was favoured
with an opportunity to examine the rich collection of Silurian and
Carboniferous fossils in the Museum of Mr. C. Beale, of Lime ‘Tree
_ House, Rowley Regis, not far from Dudley. Mr. Beale kindly placed

1 Handbuch der Paleontologie yon Karl A. Zittel, Miinchen. I. Abtheilung, IT.
Band, V. Lieferung—Myriopoda, Arachnoidea, und Insecta. Bearbeitet von Samuel
H. Scudder (1885).

2 These numbers must now be reduced by four Carboniferous and one Dyas species.

6 Dr. H. Woodward—Myriapods of the Ooal Period.

eight specimens of spined Myriapods in my hands, all enclosed in
Clay-ironstone nodules similar to those in the Johnson collection.

Mr. Beale’s specimens were obtained from the shales or Clay-bands
at the top of the Brooch-coal, Sedgley, near Dudley.

These ironstone-nodules are considered to occupy a much higher
horizon in the Coal-measures than those described by Prof. Prest-
wich in his Geology of the Coalbrook-dale Coal-field (Trans. Geol.
Soc. Lond. 2nd ser. vol. v. pi. xli. 1840), but many of the organisms
are identical from both areas.

KUPHOBERIA FEROX, Salter, sp., 1863. (PI. I.)
‘¢ A Caterpillar? ’’ Westwood in Brodie’s Fossil Insects, 1845, p. xvii, 108, pl. 1. fig. 11.

Eurypterus ? (Arthropleura) ferox, Salter, Quart. Journ. Geol. Soc. 1863,

vol. xix. p. 86 (woodcut, fig. 8, reproduced on p. 2, ante).

Euphoberia ferox, Meek and Worthen, Geol. Surv. Illinois, vol. iii. (Paleontology)

(“A Myriapod !”’).
Euphoberia ferox, H. Woodward (‘‘ A Myriapod!’’), See Brit. Foss. Crustacea,
order Merostomata, Pal. Soc. Mon. 1872, p. 173.

Euphoberia ferox, Scudder, 1882, Mem. Boston Soc. Nat. Hist. vol. iii. no. v. p. 157.

Euphoberia ferox, H. Woodw., 1873, Guou. Mac. Vol. X. p.112 (and 2 woodcuts).

Acantherpestes Brodiei, Scudder, 1882, op. cit. p. 156.

I am disposed to refer the whole of the 20 specimens of spined
Myriapods, now under consideration, from the Staffordshire Coal-
field (most of which have both impression and counterpart pre-
served) to one species, namely, to Huphoberia ferox.

In my monograph on the Merostomata (Pal. Soc. 1872, p. 173)
I placed Salter’s “ Hurypterus ferox”’ with the Myriapopa,’ and in
the genus Huphoberia, as suggested by Messrs. Meek and Worthen.
In this conclusion Scudder agreed in 1882, but he eliminated the
specimen referred to in “Brodie’s Fossil Insects ” as a ‘‘Caterpillar,”
although Salter and I had both considered it as identical with
Euphoberia ferow, and he has placed it in the genus Acantherpestes,
making for it a new species, A. Brodiei. There are, however, no
grounds for either the generic or specific separation of this fossil
from Z. feroxz, save the obscurity of the specimen and the indistinct-
ness in character of the original figure, from which all the subsequent
ones have been merely copies.

From the excellent materials now collected together, in which
are included the Johnson and Beale Collections, also Brodie’s and
Salter’s original specimens, lent to me for examination by the
kindness of Prof. J. O. Westwood, M.A., from the Oxford Museum,
and Dr. A. Geikie, F.RS., from the Museum of Practical Geology,
Jermyn Street, I hope to be able to give some additional details which
may assist towards a complete knowledge of this remarkable spined
Myriapod from the English Coal-measures.

In four of the specimens the head is seen, and in two of these
the details can be clearly made out, but the remaining ones are
somewhat obscure and imperfect.

1 Scudder, however, in his Memoir (Joc. cit.), 1882, p. 157, cites me as still con-
sidering it to be a Eurypterus, whereas I most clearly state: ‘‘I am fully disposed
to agree with Meek and Worthen, and to refer it to the Myriapoda and to their genus

Euphoberia, feeling certain that it has no relation whatever to Eurypterus ’’ (Pal.
Soc. Mon. p. 173; Grou. Maa. Vol. X. p. 112).

Dr. H. Woodward—Myriapods of the Coal Period. 7

In one instance (Pl. I. Fig. 1) the head is associated with seven
consecutive well-preserved somites or body-segments ; in another
instance with five segments; the other two examples have portions
of segments only in association with the head, but of their identity
I feel no doubt on comparison with the others.

The head is somewhat rounded in outline, the sides being com-
pressed and the posterior border slightly incurved. The anterior
portion of the head, which is tumid, is without divisions, and is not
ornamented save for a minute granulation common to the general
surface. The posterior half has a clear straight groove down the
centre, and on either side is marked by two lateral curved grooves
which subdivide the back of the head into four tumid lobes ; the two
subcentral ones are the largest and are arched in front so that they
overlap the two outer lobes which lie within their lateral concavities.

At each antero-lateral angle of the two subcentral lobes there is
a small rounded prominence marked by a corresponding circular pit
on the inside of the head. These are no doubt the points of articu-
lation for a pair of simple antenna, and they are placed just in front of
the compound eyes. These occupy the two small elevated lobes at the
latero-posterior angles of the head, and are in almost similar relative
position as in the head of the modern Julus. There are about ten
rows of facets in each eye (Plate I. Fig. 3 0), and seven or eight facets
in each row; the smallest facets being those nearest the centre of the
head, and the largest towards the border. Behind the posterior
lobes of the head is a simple granulated margin, one millimetre
broad, running parallel with its posterior border. Breadth of head
14 mm., length 10 mm.

In addition to a very well-preserved detached head twisted half
round, seen in Plate I. Fig. 1 (closely agreeing with that drawn on
Plate I. Fig. 3), the same nodule retains the impression and counter-
part of seven body-segments united together exposing their dorsal
aspect. Hach segment consists of a broad, raised, median ridge,
bearing two subcentral bases of spines, the spines themselves having
been broken off. They are, however, occasionally to be seen in
sections of somites, as at the end of Figs. 4 s, and in 2 s.

This ridge extends to and unites with the lateral border, where it
gives origin to a large unequally branched spine, the longest ramus
of which measures 10mm. (in Pl. I. Fig. 1); at the antero-lateral
border of each somite there arises a simple pointed spine 4 to 5 mm.
long, directed forwards, and a very minute simple spine on the
postero-lateral border directed backwards. These larger spines were
at least 5 or 6 mm. long, if not more, and they are seen to be hollow.
They certainly varied slightly in character and in length in the same
individual, as did also the segments upon which they were borne,
according to their position in the animal’s body.

Occasionally, as in Pl. I. Fig. 7 s, the ordinary forked marginal
spine is seen to be trifid; but this I am persuaded is due to the single
simple spine, which is usually found at its base, occurring rather
higher up than usual, and is not a specific character.

The hindmost segment preserved in Fig. 1 measures 15 mm. in

8 Dr. H. Woodward—Myriapods of the Coal Period.

breadth and 6 mm. in length, and one of the anterior segments
12 mm. in breadth and 5 mm. in length.

Another specimen (not drawn) exposes seven body-somites in
juxtaposition ; the spines are wanting, save one perfect dorsal spine,
which is seen attached to the seventh somite, and measures 5 mm. in
height. The margin of the tergum of each somite is seen along ~
the right side, and is rather more rounded behind and slightly pointed
in front. (See Pl. I. Fig. 13, ep.) .

The left side is buried in the nodule for about one-third of the
surface of the terga. The seven somites together measure 50mm.
long, giving an average length of 7 mm. to each; but the somites are
rather more widely separated than usual, so that probably 6 mm. each
would be more correct.

Another (Plate I. Fig. 6), from Mr. Beale’s collection, exposes
five somites, one side displaying the large unequally branched spines,
and the small simple antero-lateral spines at their bases, with
a trace only of the small latero-posterior spine. On the other side
the spines are broken off, showing their hollow shafts, and displaying
the lateral border of the tergum of each segment, which is minutely
serrated posteriorly. From these specimens I infer that these large
spined Myriapods were less round in section than Scudder represents,
and that the epimeral portion of each somite projected slightly
outwards above its sternum. Length of five somites 35 mm.,
or averaging 7 mm. each; breadth 18 mm. (exclusive of spines,
which would project 9 or 10 mm. beyond this on each side).

This specimen represents a part of the largest example known in
England, being 2 mm. wider than Salter’s F. ferox in the Jermyn
Street Museum; but the length would be about the same. In Mr.
Beale’s specimen the somites are lying in one plane; in Salter’s
type they are highly curved, and the elevated ridge of each somite
has been slightly broken away along its posterior dorsal line. By
a misadventure, Figs. 6 and 7, Plate I. have both been drawn with
the anterior extremities downwards, the other specimens being all
drawn in the contrary direction, with the anterior end upwards.

Perhaps the most instructive specimen in the entire series is one
from the late Mr. Henry Johnson’s collection, from Coseley, dis-
playing seventeen segments of one individual in the same nodule.
The seven anterior somites exhibit their terga and also their branched
spines very well (save the first, which is broken), the next succeeding
seven somites exhibit a section of their terga, and expose the sterna
of five somites seen from within, and the bases of the legs of the
left side, and all the legs of seven somites on the right side.

In this specimen the legs, where fully exposed (Pl. I. Fig. 12), are
17 millimetres long; the first two or basal joints which unite with
the sternum measure together 3 mm.; the third joint is the longest
and widest (length 6 mm. and width 13 mm.) ; the fourth is 2 mm.
long, the fifth is 8mm., and the sixth is 3 millimetres.

At the base of each pair of legs, and lying in the median line of
the sternum, a pair of minute pores (Pl. I. Fig. 5 b) or puncta are
seen, which are described by Scudder as “a pair of supposed branchial

Dr. H. Woodward—WMyriapods of the Coal Period. 9

supports ;”’ but as each paired sternum is also perforated above the
point of articulation for the legs (Pl. I. Fig. 51) with two spiracles
in the form of oblong slits (four to each segment, Pl. I. Fig. 5 sp.),
agreeing with the two pairs of legs, I fail to see any reason for the
assumption that these minute pores, if pores they be, are the basis
of gills (see also Pl. I. Fig. 4).

Hven admitting that these forms may possibly have been some-
times either voluntarily (or involuntarily) aquatic in habit, yet such
a suggestion, unsupported by any evidence in its favour, would hardly
warrant one in establishing so anomalous a type as a Dipnoid order
of Myriapods breathing both by external gills and internal
tracheee.

This specimen seems rather to favour the notion of a slight dimi-
nution in the size of the body-segments towards both extremities of the
animal, although we are unable to state with certainty how many more
somites are wanting in order to complete the body at either extremity.

In addition to the two specimens showing heads, Mr. Beale’s col-
lection has also furnished a single terminal segment, or pygidium,
which is associated with a spined body-segment, showing it to belong
to the same genus, and probably to the same species. The tail-plate
is somewhat pentagonal in form, with two bifid curved spines, one on
each lateral border, and four smaller simple spines, two on each side
of the median line; the centre, which is transversely ridged, has two
obtuse tubercles placed like the body-spines subcentrally ; width of
tail 6 mm., length 5 mm., length of longest lateral spine 11 mm.,
length of submedian spines 5 mm.

It is not improbable that this pygidium may have been associated
with a form like that on Plate I. Fig. 7, or even Fig. 9; the details
of its ornamentation agree with all, and its size with Fig. 7.

So many important points attach to a full consideration of these
forms, that I reserve further figures, descriptions and comparisons for
my Monograph on the Arthropods of the Coal period, to appear in a
forthcoming Memoir of the Paleontographical Society, where I hope
to discuss fully the question of species. I may then, possibly,
separate Figs. 7 and 9 as distinct, but prefer at present to defer
doing so, more illustrations being needed for my task.

Meantime I have to return my best thanks to Mr. C. Beale for the
beautiful series of specimens with which he has so kindly entrusted
me, and to which I hope to do more ample justice anon.

Before quitting these Carboniferous Myriapods, I desire, however,
to draw special attention to a mere fragment of one from the Car-
boniferous Limestone of Grassington, Yorkshire, where it occurs in
association with numerous remains of Phillipsia Derbiensis and a
Fenestella. Only four somites are preserved, and these are evidently
spinigerous after the manner of Euphoberia; but the spines are longer
and more slender, and it does not seem quite certain that any of
them were branched (see Plate I. Fig. 10).

I only propose to call attention to the remarkable fact of this form
being found, not associated with Ferns and true winged insects, in
Clay-ironstone nodules of probable freshwater origin, but in a pure

10 W. A. E. Ussher—The Culm of Devonshire.

crystalline limestone full of marine organisms, a most improbable
gisement for a Myriapod! The specimen belongs to the Museum of
Practical Geology, Jermyn Street, 8.W.

EXPLANATION OF PLATE I.
Remains of Spined Myriapods from the Coal-measures.

Fie. 1. Huphoberia ferox, Salter, sp. Coal-measures, Sedgley. (Mr. C. Beale’s
Collection.) Head with seven body-segments. a. anterior margin of
head. . posterior attached border. o. one of the eyes. (Beale Coll.)

», 2. A detached head of another specimen showing the eyes and also segments
with the spines preserved, but much crushed. (Beale Coll.)

. Another detached head showing the eyes (0), the attachment for the simple

antenne (f), one of the antenne (a) close to the front of the head.

», 4. Aspecimen of Huphoberia with 17 somites united in one animal. ‘This

specimen shows the legs and the spiracles (sp). (Hy. Johnson Coll.)

(SS)

», 0. A portion of the sternum with articulations of 4 legs (7) and the openings
of 4 spiracles (sy) ; also the supposed ‘‘ basis of branchiz ”’ (0).
», 6. Another specimen showing 5 somites with lateral bifid spimes and small

marginal ones attached. (Beale Coll.)

», @. Another form, longer and narrower in proportion than Fig. 6, with 5 somites
bearing lateral bifid and one trifid spine (possibly a new species ?). (Hy.
Johnson's Coll.)

», 8. Terminal segment or ‘telson.’ (Mr. C. Beale’s Coll.)

,, 9. Another and smaller example of Huphoberia with 12 connected somites
(associated with leaves of Neuropteris), bearing one or more trifid spines
(possibly a new species) ?

», 10. Fragment consisting of 4 somites bearing slender curved spines. Carbon-
iferous Limestone, Grassington, Yorkshire. (Mus. Pract. Geol.)

», 11. Ideal section through Huphoberia ferox, showing position of simple and
bifid spines on tergum (¢) and the legs and spiracles (sy) on the sternum

8).

5, 12. Two of the legs drawn separately from Fig. 4.

», 13. Side view of three segments to show the profile of body-rings with their
ridges and the bases of their spines. The lateral margin (ep) is seen
to be slightly serrated along the posterior border.

Mr. Beale’s specimens are all from the Clay-ironstone of the Coal-measures of
Sedgley, near Dudley. Mr. Henry Johnson’s are all from Coseley, near Dudley.

IJ.—Tue Curm Measures or Drvonsurre.
By W. A. E. Ussusr, F.G.S.
(Printed with the permission of the Director-General of the Geological Survey.)

ROBABLY from the great preponderance of interest attaching
to the Devonian rocks of North and South Devon the Culm
Measure rocks, constituting the great central table land, have been
to a certain extent overlooked. The attempt to subdivide them by
ascertaining their different lithological characteristics, and observing
to what extent these characteristics are peculiar to definite horizons,
has seldom been made. We may, in fact, sum up the literature of the
subject with one notable exception—the late Prof. J. Phillips in his
“Figures and Descriptions of the Paleozoic Fossils of Cornwall,
Devon, and W. Somerset”’—as bearing upon the position of the series
as a whole, or calling attention to some special point of interest.
Phillips, in the work referred to, pointed out the relative position
in the series of the most characteristic or important members, such as
the limestones, and the cherty beds of the Coddon Hill type. He

W. A. E. Ussher—The Culm of Devonshire. ag

also showed that these typical rocks had their equivalents along the
southern margin of the great Culm Measure Synclinal.
Phillips gives the following grouping of the Culm Measures in the
south part of their range.
Upper or Grit Group of Central Devon.
Upper Shale Group—A mass chiefly of dark shales, carbonaceous grits and shales,
the lowest part being the Coddon Hill chert series.
Middle or Calcareous Group—Limestone, mostly black, irregularly bedded, asso-
ciated with shales, often resting on trap rock and fossiliferous.
Lower Shale Group—Black argillaceous plate, or very laminar shale, not subject
to slaty cleavage, and scarcely fossiliferous.

“ Following the line of the carbonaceous group of North Devon to
the east,” says Phillips, p. 194, “it is lost under the superimposed
red marls and sandstones; these range nearly north and south across
the general strike of the carbonaceous group and conceal it... On the
west the carbonaceous group occupies the coast from Fremington nearly
to Tintagel, and on the south it follows a line much bent by the
effect of the protruding granitic masses, especially of Dartmoor. In
the centre of this great district no limestone occurs, and there are no
other fossils than obscure marks of plants or mere carbonaceous
stains; but on the southern border the limestone bands reappear
almost exactly as on the northern side with similar mineral characters
and accompaniments, and: similar or identical organic remains; for
example, at Trescott near Launceston, Lew Trenchard, Bridestow,
and Okehampton.”

Beds of Anthracite occur in the Culm Measures of North Devon in
the neighbourhood of Chittlehampton, Tawstock, Abbotsham, and
Alverdiscot; they are alluded to by Polwhele,’ by Vancouver,’ by
Lysons,’? by Sedgwick and Murchison,‘ and De la Beche ;° the latter
says: “Anthracite or Culm occurs in a few beds of very variable
thickness between Greenacliff on the coast west from Bideford and
Hawkridge Wood near Chittlehampton.”

*¢ Sufficient Anthracite was at one time raised near Greenacliff, in
Barnstaple Bay, to burn with the limestone brought there from South
Wales.”

Mr. T. M. Hall (Trans. Dev. Assoc. for 1875), in a paper entitled
“Notes on the Anthracite Beds of North Devon,” says: “The widest
culmiferous band is nearly 18 feet in width, but several smaller
strings of the same material traverse the slates and shales.

“At Bideford, a few yards north of the Railway Station, may be
seen the black shales forming the outcrop of the veins which, until a
very recent period, were worked to a considerable extent. . . . About
a mile east of this spot the present works, consisting of a shaft and
level adit, are still carried on for the purpose of obtaining the softer
varieties of Anthracite, which when ground to powder are sold as a
pigment under the name of Bideford Black.”

1 History of Devonshire, p. 55 (1797).

2 General View of the Agriculture of the County of Devon, p. 266 (1808).
3 Magna Britannia Devon (1822), p. 266.

4 On the Physical Structure of Devonshire (1840).

5 Report on Geol. Corn. Devon, ete. (1839), p. 513.

12 W. A. E. Ussher—The Culm of Devonshire.

Mr. Hall gives the following list of fossil plants obtained from the
North Devon Culm Measures :—

Asterophyllites foliosa. Neuropteris heterophylla,
a galioides. 99 Loshi.
3 longifolia. Pecopteris lonchitica.
Bowmanites (fruit of Calamite). oF muricata.
Calamites arenaceus ? 99 Serlit.
a canneformis. Poacites cocoina.
a nodosus ? Sigillaria.
es Steinhauerti. Sphenopteris acuta.
FH undulatus. KS; latifolia.
Cyperites bicarinata. Spenophylium sp. (?).
Lepidodendron. Sternbergia.
Lepidophyllum intermedium. Stigmaria ficoides.
Neuropteris cordata. A single shell of the genus Anthra-
a gigantea. costa also found near Bideford.

Mr. H. B. Woodward informs me that Celacanthus has been found
at Instow.

In Lower Culm Measure Shales at Waddon Barton near Chudleigh,
? Mr. Reid obtained four species of Phillipsia, Goniatites sphericus,
Orthoceras striolatum, Posidonomya Becheri, Avicula lepida, Chonetes
deflexa, Spirifera Urit, ete.

In a survey of the Triassic rocks of Devon extending over several
years, I had ample opportunities of observing the Culm Measures on
their borders ; but it was not till the years 1876 and 1877 that I had
the opportunity of studying the Culm Measure area in a less desul-
tory manner, my researches being confined to the districts east of a
line between Hartland Point and Okehampton.

In this area I discovered that the Culm Measures were broadly
divisible into three groups, which, however, owing to the passage of
one group into another, and to local intercalations, and to a great
extent to the innumerable flexures of the beds, cannot be separated
by hard and fast lines. Whether such a separation could be effected
on a 6-inch scale map I cannot say, but it would entail an infinite
amount of labour. The following is the general succession :—

Upper —Eggesford Perot thick, even-bedded grey grits, slaty beds and
snales,

Middle—Morchard type.—Thick-bedded grey, greenish, and reddish sandy grits,
associated with marly splitting shales, irregular grits,
slates, and shales.

{ Dark grey shales, with grit beds, seldom thick, and gene-
| rally even, slaty, and splintery shales (type St. Davids

Moweree. esc used alee aa Xeneu)

| Even-bedded cherty shales and grits (of Coddon Hill type).
( Limestones and dark-grey shales.

In general facies these groups are quite distinct, thus the even
bedding and regular appearance of the fine-grained grey grits of
Eggesford is very distinct from the irregularly associated grits and
shales of the underlying beds, whilst the massive bedded sandstones
and marly shales which occur in them about Zeal Monachorum, and
other places on the north of the Crediton Valley, give the Middle
Series or Morchard Bishop type of beds a very different general

1 For a further list of the Waddon Barton Fossils, including the Trilobites, described
by me, see Grou, Mac. Decade III. Vol. I. 1884, p. 539.—H. W.

W. A. E. Ussher—The Culm of Devonshire. 13

aspect from the lower series, although splintery shales (of the St.
Davids Exeter type) appear to be interstratified with them in places.

Upon the one-inch map it is perfectly impossible to work out the
structure except in a broadly general way ; there is no room on a
small scale map to indicate the numerous folds, and it is quite impso-
sible to ascertain the effect and magnitude of the faults.

The great Culm Measure Synclinal is not a simple curve, the beds
troughed by it being crenulated, so to speak, into an infinity of small
folds, and in this crinkling process they have no doubt been forced
to accommodate themselves to an area so much smaller than that of
their pristine extent, that we may suppose overthrust faults very
likely to have occurred, and, coupled with natural impersistence of
lithological horizons, lenticular association of grit and shale masses
and structural peculiarities such as may frequently be found in the
Middle, and sometimes in the Lower Culm Measures; these con-
siderations tend not a little to obscure the relations of the beds.

Lower Culm Measures.—On their northern outcrop the beds forming
this series occupy a very much narrower tract than that to the south.
Their northern outcrop is about two to three miles in breadth; their
southern outcrop varies very considerably, its breadth from Dartmoor
northward through Okehampton being about five miles, whilst on the
east of Dartmoor it is about 15 miles, and about the same on the west
of Dartmoor through Lidford ; but it must be remembered that this
estimate in the southern part of the area is necessarily based on the
old geological Map, and that both in northern and southern districts
the Lower Culm Measures may occur far beyond the limits assigned
to them, through repetitions by faults or anticlinal axes in the areas
occupied by the Middle Culm Measures.

The Lower Culm Measures, owing to the occurrence of limestones
and of the remarkable buff and grey shales and cherty grits of the
Coddon Hill type in them, and to their connection with the Upper
Devonian beds, naturally excited more interest and attention than the
other members of the series, except the Anthracite beds of the Middle
Culm Measures of the north; but I do not think, at least in the
northern area, that they can be subdivided in anything like persistent
groups. If, for instance, we take the faulted and much-flexured lime-
stone patches of West Leigh,’ Hockworthy, Whipcoats, and Kitton
Barton, it is not difficult to determine their boundaries; but to esta-
blish their connection in a continuous series is by no means easy.
Furthermore, when we follow their horizon westward, although we
can have no hesitation in regarding the limestones of Bampton and
of Ven near Barnstaple, as the same series, the entire absence of con-
tinuity for such considerable distances forbids the hypothesis of a
persistent caleareous horizon, which could only be proved by systems
of faults of which we could not hope to obtain sufficient proof. From
their local development, and very partial occurrence, both in the
northern and southern areas, I regard the limestones as lenticular
masses in the shales and grits.

1 Vide Trans. Dev. Assoc. for 1878 and 1879, Fossils in Culm Measures Lime-
stone, etc., by Rev. W. Downes.

14 W. A. E. Ussher—The Culm of Devonshire.

Again, the peculiar baked appearance of the Coddon Hill beds is
more or less local, although appearing at such wide intervals as the
Northern and Southern Culm Measure areas, wherein their character-
istic appearance was severally noticed by Phillips; and the lime-
stones may be said to occur in them, the reddish even Goniatite
shales of the West Leigh area belonging to this group.

Referring to the Coddon Hill beds, pp. 189, 190, Phillips says :—
“The beds, which in this range overlie the shales and limestones of
Swimbridge and Venn, are a whitish or grey or black chert in thin
striped beds. . . . With these lie white arenaceous and argillaceous
layers, mostly very soft, and sometimes cleavable, other parts show
black and reddish shales. In these laminated beds lie Goniatites,
Orthoceratites, Terebratule, and Posidonizs. The debitumenized
condition of these white shales parallel to the black bituminous
shales of Swimbridge is remarkable; aud it is a fact repeated not
only on the Northern range near Bampton, but also on the southern
range near Launceston and Lew Trenchard. In a quarry on this
range near Tawstock, Major Harding found Zurbinolopsis pauct-
radialis” (Petraia celtica).

To take one or two examples from many furnished by my notes :
The Venn limestones are exposed in two adjacent quarries ; in the
smaller one they are very much disturbed, being probably affected by
two faults ; they appear to overlie beds of the Coddon Hill type. In
the larger quarry even-bedded dark grey limestones dip 385° W.; at
60°, they are interleaved in places by shaly parting. One of the beds
is covered on its surface with impressions of Posidonomya (Posidonia)
lateralis, and less frequently P. Becheri and P. tuberculata.

Near Hastcombe, west of Tawstock, thin beds of fine grit and thick
shale of whitish buff and dark grey colours, split up by numerous even
joints into small angular pieces, are quarried for “gravel.” The
joints, as is usual in beds of the Coddon Hill type, are local contrac-
tion-cracks of individual beds.

The flexures and contortions of this series are too numerous to
furnish any generalized observation as to the relations of the beds,
and space fails me to enter into local details.

Tn the south of the area, notwithstanding the local repetition of the
calcareous horizon, and of beds equivalent to the Coddon Hill series,
there is some difference in the general characters of the Lower Culm
Measures; thus slaty grey shales which, from their typical exposure
on St. David’s Hill, Exeter, I have called splintery shales of the St.
David’s type, are by no means uncommon in them, also beds of a
nodular or concretionary character ; the grits vary from thin and even,
to rather thick irregular beds.

Phillips thus describes the Lew Trenchard section: “ Argillaceous
and arenaceous laminar beds, white or coloured by oxide of manganese,
which correspond to those of Coddon Hill in North Devon, contain
Calamites, Asterophyllites, Neuropteris, and a Goniatite, . . . below are
quarries of black limestone” with “shaly partings rich in Posidonie”
in the upper part. No Goniatites found in the limestone. Phillips
points out the occasional presence of oolitic structure in the limestones
of this series.

W. A. E. Ussher—The Culm of Devonshire. 15

The junction between the Lower Culm Measures and Upper
Devonian slates of North Devon is very seldom visible, but there are
cases, as in the railway cutting near Dulverton Station, where we
pass from shales distinctly belonging to the Culm Measures to shales
lithologically indistinguishable from them in which Petraia celtica
was obtained.

Phillips says, p. 189, “The exact circumstances of the passage
from the upper part of the Pilton group to the lower part of the
Carbonaceous group . . . are scarcely anywhere completely seen in
North Devon. There is usually a longitudinal valley on the line of
junction which obscures the phenomena. Fremington Pill is per-
haps the best locality for observation of this passage.” As to the
junction between Culm Measures and Devonian in South Devon, it is
one of the questions of the future. Phillips points out appearances
of unconformity between the Petherwin beds (Upper Devonian) and
Lower Culm Measures at Landlake, south of Launceston, op. cit. p. 196,
and I do not think that the comparative absence of the Upper Devo-
nian strata has been accounted for in South Devon. On the broad
questions of correlation many plausible suggestions have been made;
but if the Pilton beds are unquestionably representative of the
Lower Carboniferous Slate of Ireland, what becomes of that repre-
sentation in South Devon? Is it possible that the Upper Devonian
Slate series is in South Devon represented by Lower Culm Measures,
through that Division attaining a much greater thickness in the
southern area?. It may be that the greater extension of Lower
Culm Measures in the southern area is due to low dips or more
constant repetition by faults and flexures, see F. Rutley “On the
Schistose Volcanic Rocks of Dartmoor,” Q.J.G.S. vol. xxxvi. p.
287, 1880, and Harvey B. Holl, Q. J. G.S., vol. xxiv. p. 407, 1868.

Middle Culm Measures.—These rocks occupy the coast from West-
ward Ho to Portledge Mouth. The breadth of their outcrop from
Northam to Wear Giffard in the longitude of Bideford is about four
miles ; their southern outcrop from the Triassic valley of Crediton
northward embracing Morchard Bishop, Iddesleigh, Meeth and
Petrockstow, is from 4 to 5 miles in breadth.

Fic. 1.

The Middle Culm Measures are a very variable series, their special
characteristics are rather coarse sandstones, which, near Zeal Mona-
chorum and other places in their southern outcrop, occur in beds
about five feet thick, and are associated with marly splitting shales

16 W. A. E. Ussher—The Culm of Devonshire.

or red finely micaceous mudstones. In the north part of the area
the marly shales are less frequent, and hard thick-bedded whitish
sandstones and siliceous grits occur. Through the very irregular
association of the slates, shales and grits which form the major
portion of this series, many structural peculiarities are presented,
especially in the very irregular manner in which the constituent beds
have yielded to the strains to which they have been more than once
subjected since their deposition. The accompanying diagram repre-
sents a case of contortion in the cliff near Westcot, the occurrence
is presented in a space of about seven square feet. Near it we have
a bed of greenish grey grit lying across the edges of a trough in the
subjacent shales (Fig 2).

The coast from Portledge Mouth towards Westward Ho shows
successively reddish-brown and lilac grits, grey grits, blackish shales
and grey grits, dark grey shales and slaty beds, hard grey grit form-
ing an anticlinal, shales with thin beds of grit, massive grey grits
and grey shales. It was from this part of the coast that the diagrams
were taken,—irregular concretionary grits on a thick bed of whitish
grit at about 85 chains from Portledge Mouth, upon thick beds of
grey sandy grit broken by irregular joints, upon massive beds of
grey quartz-veined grit associated with dark grey shales forming
a fine anticlinal, hard coarse grey grits and dark grey shales flaking
off in splintery fragments in places, under these beds dark shales
with thin even beds of grit, possibly Lower Culm Measures, come on,
they appear to be faulted against massive beds of grey grit, one bed
being eight feet in thickness. The above represents the coast section
for more than a mile and a half; in that space we have about 18
well-marked anticlinal and synclinal curves, not to mention numerous
lesser flexures, and two appearances of fault.

Space fails me to particularize the continuation of the coast-section
in the direction of Westward Ho. From Peppercombe to Clovelly
the coast is formed for the most part of beds of the Eggesford type,
Upper Culm Measures.

From Clovelly to Hartland Point the coast has not been observed,
but from its projection it would appear to consist of Middle Culm
Measures, of which the following is the downward succession at
Hartland Point: Light greenish grit; on dark grey slates and shales
with beds of greenish grit; thick bed of brown grit; reddish
schistose beds and shaly mudstones splitting in sub-cuboidal pieces
like marl, associated with thin beds of grit; thick beds of hard lilac
grit with shale; dark grey shale; even-bedded quartz-veined grey
grits; dark grey indurated shale; hard grits with dark grey shale
partings; bed of grey quartz-veined grit; dark grey shales and
schistose beds. The beds are contorted.

The Eggesford grits or Upper Culm Measures form a much more
regular and less variable series than the beds hitherto described ;
they form a band of six or seven miles in breadth. They are well
exposed in the railway cuttings near Eggesford, in the Torridge
Valley about Great Torrington and in the coast near Clovelly. It is
impossible on the one-inch scale to convey any idea of the many

W. S&S. Gresley—On “ Oone-in-Cone”? Structure. M7

flexures in them, every section almost, of a few yards in length,
affording an indication of disturbance.

Between Clovelly and Portledge Mouth the Upper Culm Measures
consist of grey, lilac-grey and reddish thick-bedded even grits, with
interstratification of dark grey shale. The even-bedded character of
this series renders the flexures in the cliffs very apparent, especially
when dark grey shale bands are affected by them, as at 31 chains

from Clovelly Pier where sharp
Fie. 3. inverted curves are shown, V
shaped flexures are visible about
14 chains from the Pier, and from
18 to 22 chains from the Pier the
beds are contorted and faulted.
At about 70 chains from Clovelly
beautiful examples of marine tun-
nelling are afforded by the Black
Church rock, in which two tunnels
have been excavated along the bedding, and by a neighbouring reef
in which the sea attacked the opposing strike surface, the tunnel
being roofed by a massive bed dipping landward.

To enter more fully into the many inverted and ordinary curves
exposed in this interesting coast would be beyond the purport of
this paper. I have not attempted to give a digest of the numerous
notes I have made of the Culm Measure area, nor do I think it
would be possible to do so; but I trust that I may have succeeded in
directing attention to a large district practically unknown to geolo-
gists, and in showing that, in spite of the confusing complexity of
detail, it is possible to obtain something like a definite sequence. To
make out the structure thoroughly would require years of patient
labour on the 6 inch scale, and is in no sense feasible in holiday
rambles; but there are curious structural phenomena which would
amply repay the labours of the casual visitor.

IIJ.—Norsrs on “ Conz-1n-Conge” STRUCTURE.
By W. 8. Grestey, F.G.S.

N Decade III. Vol. II. of the Grotocicatn Magazine, for 1885,
at page 283, an abstract of a paper on ‘‘ Cone-in-Cone” by Mr.
John Young, F.G.S., of Glasgow, was given. The author of this
interesting paper has kindly presented the writer with a copy of it,
to which, since it was read in Glasgow last year, has been added
some additional remarks, together with two very beautiful plates,
by ‘photogravure,’ in illustration of some of his typical Scottish
Specimens.

The result of Mr. Young’s labours in this connection have
warranted him in arriving at the following conclusion respecting
the origin and formation of cone-in-cone structure, which, briefly
stated, is this :—That the formation is due to the “upward and suc-
cessive escape of gases generated in the lower portion of the
stratum in which the structure is found, probably by the decay of

2

DECADE III.—VOL. IV.—NO. I.

18 Weak Gresley —On “© Cone-in-Cone”’ Structure.

organic matter in the deposit whilst still in the process of formation
and in a soft, sedimentary condition ; each ebullition of gas being
marked by a new or successive layer of sediment within each cone.”
“That the cones, large and small, have their apices invariably directed
towards the lower portion of the stratum.”

As, in the course of the last year or two (due chiefly to the occur-
rence of some interesting examples of cone-in-cone in the breccias
of the Permian? series in Leicestershire, see Q. J. G. S. vol.
xli. Proceedings, page 109, and the “ Midland Naturalist,” vol. ix.
No. 97 [new series]), the writer has given some attention to this
interesting rock-structure, his observations in the field and elsewhere
have brought to his knowledge several important facts, and such as
have reluctantly prevented him from accepting Mr. Young’s theory.

Although Mr. Young has gone very fully into the question, he
does not appear to have noticed one or two important points often
seen in cone-in-cone structure, which I will now endeavour to
describe.

$ nat. size. 4 times nat. size.

(a) In the case of large, strong, well-developed cones, often four
or five inches in length (see Fig. 1), and generally composed of com-
pact siliceo-ferruginous sandstone in the Coal-measures, which I will
call ‘ master cones’ because they seem to cut out the feebly developed
ones in their upward expanding growth; the walls, or substance of
the cones, or conical-shaped cups or portions of such (for whole
hollow cones are rarely met with), often as much as a quarter of an
inch in thickness between the usual concentric layers of corrugations
more or less filled with clayey material, are themselves composed of
cone-in-cone formation (also possessing their clay-filled serrations) ;
the bases of the cones abutting upwards upon the clay wrinkles
which separate each great cone or part of a cone. A reference to

W. S. Gresley —On “ Cone-in-Cone” Structure. 19

Fig. 2 will probably better explain what is intended to be noticed
above. It represents a portion of a vertical section of one of the
master cones enlarged about four times. The specimen is from a
bed of clay-ironstone occurring above the fire-clays of the Western
division of the Leicestershire Coal-field —a horizon which has
furnished the writer with more than one illustration of the way in
which cone-in-cone structure occurs.

But further, I would point out that the concentric serrations
between the cones, and shown as adhering to the exterior surface of
one of them at c, Fig. 2, are also composed of scaly or semi-cone-in-cone
structure. This, though of minute development, can readily be
detected with a pocket lens, especially upon partially weathered
samples. The bases of these tiny flakes seem to terminate against
the serrations of the master cones, and upon the sides of the cone-
structure forming their walls (see Fig. 2). In short, this specimen
(and doubtless it is a typical one) appears to be wholly built up of
‘cone-in-cone,’ of at least three separate and distinct developments,
a,b, ande. For this curious three-fold structure I fail to see how
the ebullition-of-gases theory can satisfactorily account.

With reference to the question of cone-in-cone found upon the
under as well as the upper surface of a stratum or a concretionary
mass, Mr. Young would have us believe that when this does occur
it has probably been due to the shrinkage of the mass, such contrac-
tion having actually carried the coned surface round to the underside.
I think the following instances of reversed or double cone-in-cone
at once upset his theory.

(b) In a stratum of blue shale or ‘bind’ at the village of Donis-
thorpe in the Leicestershire Coal-field, occur some large concre-
tionary masses—often several tons in weight—of hard and compact
fine-grained siliceo-ferruginous sandstone, locally called ‘ cank,’ whose
upper and lower surfaces are often largely covered with cone-in-cone
formation. That upon the under surface, however, is always the
most feebly developed. Now, as the coned surfaces are always most
strongly formed in the centre of the mass, or, in other words, as the

edges towards b b (see Fig. 3, which represents a transverse section)
are almost devoid of cone structure, it is at once apparent that the
cones upon the under side cannot have been brought into their pre-
sent position by any known process of shrinkage or curling up, or
downwards, of the nodules. Besides, in one instance, we have at a,

20 W. S. Gresley— On “ Cone-in- Cone” Structure.

a double cone-in-cone development on the surfaces of a large crack
or cavity in the side of the specimen; whilst at c, in the interior of
the same nodule, occurs a small and rather feeble development of
the same structure, in no way connected with the top and bottom
cone-in-cone layers. Again, as the band marked b 6, which is a layer
of three or four inches of argillaceous ironstone, is crowded with
well-preserved leaflets of Neuropteris gigantea, surely these organic
remains must have greatly suffered had contraction of the mass taken
place to any extent, which is not the case.

(c) Very good hand-samples of whole disc-shaped clay-ironstone
nodules, exhibiting on both flat surfaces well-formed cone-in-cone
structure, are preserved in the Geological Museum of Owens College,
Manchester, and here again we find that this structure is much more
strongly developed on one side than on the other, and that the coned
surfaces are confined to the central parts of the nodules, as shown
in Fig. 3, which is roughly half the size of the Manchester specimens.
As these nodules were not labelled, I cannot give their locality, ete.

(d) In the Museum of the Yorkshire College of Science, Leeds,
there is a small specimen of earthy limestone from the Wealden
beds, Brixton Bay, Isle of Wight, upon whose upper and lower
surfaces cone-in-cone formation is seeu—very minute upon the
underside—the upper one commencing in contact with a layer of
fossil bivalve shells whose uneven surface corresponds with that of
the apices of the cones.

(e) I have quite recently noticed in the shale “‘ baring” of the fire-
clay opencast workings in the Leicestershire Coal-field singular
nodular masses of hard flinty fine-grained stone (a worthless variety
of clay-ironstone), one of which is shown
in cross-section in Fig. 4. Upon the sur-
face of this specimen the cone-structure
has the appearance of having been sub-
jected to considerable shrinkage, as the
cones or rather wedge-shaped scales of
cone-in-cone- structure, occur in curious
wrinkles or ridges upon the general sur-
face of the stone. As these singular ex-
amples were not seen in situ, I cannot say
which sides were uppermost in the shale.

(f) Again, occurring in the same stratum are some large concre-
tionary somewhat tabular-shaped masses of the same kind of rock as
that last noticed, and having a kind of clay-ironstone band running
through their centres (see Fig. 5). These nodules are sometimes
several tons in weight. Now, forming the entire upper and lower
portions of these singular stones are cone-in-cone structures as shown
in the sketch ; and occupying zones lying between the cone-in-cone
portions and the rather sharp edges or peripheries of the masses, both
upon upper and lower surfaces, are formations of innumerable little
spheres or spherulitic concretionary masses, and, as it were, grown
together,—very perfect and distinct upon the surface, but rapidly
dying out towards the interior of the stone, and apparently grading

W. 8S. Gresley—On “ Cone-in- Cone” Structure. 21

into the cone-in-cone formation on the one hand and disappearing in
the opposite direction, namely :—towards the periphery of the nodule
(see Fig. 5).

;
7 BPS, yd 5, on}
BS ee '
Fee PSS aa
RO eb eee PRR

; oa pa
PM a Be
Se ee Bs
ES al
eh
20.

A peculiarity in the appearance or arrangement of this spherulitic
structure is that the surface of it often takes a beautiful wavy or
fantastic stalagmitic form, giving the idea that the substance of the
structure was in a semi-fluid condition during formation of the
botryoidal structure. The aspect is not altogether unlike a number
of flat bunches of very small grapes, disposed in more or less regular
rows or terraces one above another (see Fig. 6). The globules or
spheres forming the apices or lowest points of these little wavy ridges
are always the largest or most perfectly developed of the individual
groups or bunches. These tiny spheres contain a considerable per-
centage of lime, as do the cone-in-cone masses which are encircled
by them.

With respect to the mineral constituents of cone-in-cone rock,
Mr. Young seems to hold that calcareous matter was essential to its
existence. As many of my specimens are not affected by the acid
test, the lime, if originally present, has been since removed.

It may be interesting to remark here, that cone-in-cone structure
occurs in the Upper Cambrian rocks—the Skiddaw slates—near
Shap. Were it necessary, I could instance other interesting examples
of cone formation, but from what has been said it will be obvious that,
notwithstanding my admission of Mr. Young’s perseverance and care
in having worked out so much and given a very reasonable explana-
tion of cone-in-cone, which, had it not been for the discovery of the
double and the complicated instances, I should certainly have ac-
cepted as the probable correct one, Iam compelled to discard it as
not being sufficient to account for all the observed facts.

It is exceedingly improbable that this kind of cone-in-cone struc-
ture can have been formed in one way as regards the upper layers of
it; and in another way as to those found with their bases pointing
downwards. I myself have no explanation to advance. The struc-
tures observed are, however, very complex, they seem to deserve a
closer examination than they have yet been subjected to, not in the
field only, but in the laboratory and also microscopically.

Fie. 1, natural size. Vertical section of portion of three ‘master’ cones.

Fie. 2, x 4. Enlarged view of part of a ‘master’ cone. a. showing the cone
structure in its walls. 0. and ¢. thé semi-cone formation of the clay serrations on
the back of the ‘ master’ cone.

22 Prof. H. Carvili Lewis—Genesis of the Diamond.

Fic. 3, one-twentieth natural size. Transverse section of a large concretionary
mass of compact siliceous ironstone, exhibiting cone-in-cone structure upon both
upper and under surfaces, as well as in the interior of the mass, ata@ande. The
band 4, 4, is clay ironstone crowded with leaflets of Newropteris gigantea.

Fie. 4, one-tenth natural size. Transverse section of a nodule of compact
siliceous ironstone, entirely coated with cone-in-cone structure.

Fie. 5, one-tenth natural size. ‘Transverse section of a large concretionary mass
of close-grained ferruginous sandstone exhibiting cone-in-cone structure upon upper
and under surfaces, and also a peculiar double arrangement of a spherulitic formation
surrounding the cone-in-cone areas.

Fic. 6, one-twentieth natural size. Shows the appearance, on the surface of
nodule in Fig. 5, of the spherulitic structures occupying the areas surrounding the
cone-in-cone masses.

IV.—On a Diamantirerous Prriporite, AND THE GENESIS OF THE
Diamond.

By Prof. H. Carvitt Lewis, M.A., F.G.S.
(Abstract of a Paper read at the Birmingham Meeting of the British Association for
the Advancement of Science, September, 1886.)
HE discovery of diamonds at Kimberley, South Africa, has proved
to be a matter, not only of commercial, but of much geological
interest. The conditions under which diamonds here occur are unlike
those of any other known locality, and are worthy of special attention.

The first diamond found in South Africa was in 1867, when a large
diamond was picked out of a lot of rolled pebbles gathered in the
Orange river. This led to the ‘‘river diggings” on the Orange and
Vaal rivers, which continue to the present time.

In 1870, at which time some ten thousand persons had gathered
along the banks of the Vaal, the news came of the discovery of
diamonds at a point some fifteen miles away from the river, where the
town of Kimberley now stands. These were the so-called ‘dry
diggings,” at first thought to be alluvial deposits, but now proved to
be volcanic pipes of a highly interesting character. Four of these
pipes or necks, all rich in diamonds, and of similar geological structure,
were found close together. They have been proved to go down
vertically to an unknown depth, penetrating the surrounding strata.

The diamond-bearing material at first excavated was a crumbling
yellowish earth, which at a depth of about 50 feet became harder and
darker, finally acquiring a slaty blue or dark green colour and a greasy
feel, resembling certain varieties of serpentine. This is the well-
known ‘‘ blue ground”’ of the diamond miners.

It is exposed to the sun for a short time, when it readily disinte-
grates, and is then washed for its diamonds. This ‘“ blue ground ”’
has now been penetrated to a depth of 600 feet, and is found to become
harder and more rock-like as the depth increases.

Quite recently, both in the Kimberley and De Beers mines, the
remarkable rock has been reached, which forms the subject of the
present paper.

The geological structure of the district and the mode of occurrence
of the diamond has been well described by several observers. As
Griesbach, Stow, Shaw, Rupert Jones, and others have shown, the
diamond-bearing pipes penetrate carbonaceous strata of Triassic age,
which are known as the Karoo formation.

‘

Prof. H. Carvill Lewis—Genesis of the Diamond. 23

The Karoo beds contain numerous interstratified sheets of dolerite
and melaphyre, also of Triassic age, and the whole reposes upon ancient
mica-schists and granites. The careful investigations of Mr. KH. J.
Dunn demonstrate that the diamond-bearing pipes inclose fragments
of all these rocks, which fragments show signs of alteration by heat.
Where the pipes adjoin the Karoo shales, the latter are bent sharply
upwards, and the evidence is complete that the diamond-bearing rock
is of voleanic origin, and of Post-Triassic age.

The diamonds in each of the four pipes have distinctive characters of
their own, and are remarkable for the sharpness of their crystalline
form (octahedrons and dodecahedrons), and for the absence of any signs
of attrition. These facts, taken in connection with the ‘‘ blue ground,”
indicate, as Mr. Dunn has pointed out, that the latter is the original
matrix of the diamond.

Maskelyne and Flight have studied the microscopical and chemical
characters of the ‘‘blue ground,” and have shown that it is a ser-
pentinic substance containing bronzite, ilmenite, garnet, diallage, and
‘‘ vaalite”’ (an altered mica), and is probably an altered igneous rock,
the decomposed character of the material examined preventing exact
determination of its nature. They showed that the diamonds were
marked by etch figures, analogous to those which Prof. Gustav Rose
had produced by the incipient combustion of diamonds, and that the
‘‘blue ground” was essentially a silicate of magnesium impregnated
with carbonates.

The ‘‘blue ground” often contains such numerous fragments of
carbonaceous shale as to resemble a breccia. Recent excavations have
shown that large quantities of this shale surround the mines, and that
they are so highly carbonaceous as to be combustible, smouldering for
long periods when accidentally fired. Mr. Paterson states that it is
at the outer portions of the pipes where the “blue ground” is most
heavily charged with carbonaceous shale, that there is the richest yield
of diamonds.

Mr. Dunn regards the ‘blue ground” as a decomposed gabbro,
while Mr. Hudleston, Prof. Rupert Jones, and Mr. Davies regard it as
a sort of voleanic mud. Mr. Hudleston considers that the action was
hydrothermal rather than igneous, the diamonds being the result of
the contact of steam and magnesian mud under pressure upon the
carbonaceous shales, and compares the rock to a ‘boiled plum-
pudding.”

The earlier theories as to the origin of the diamond have, in the
light of new facts, quite given way to the theory that the diamonds
were formed in the matrix in which they lie, and that the matrix
is in some way of volcanic origin, either in the form of mud, ashes,
or lava.

The exact nature of this matrix becomes, therefore, a matter of great
interest. The rocks now to be described are from the deeper portions
of the De Beers mine, and were obtained through the courtesy of Mr.
Hedley. They are quite fresh, and less decomposed than any previously
examined. Two varieties occur, the one diamantiferous, the other
free from diamonds, and the lithological distinction between them is
suggestive. The diamantiferous variety is crowded with included

24 A. J. Jukes-Browne—Red Chalk in Suffolk.

fragments of carbonaceous shale, while the non-diamantiferous variety
is apparently free from all inclusions, and is a typical volcanic rock.

Both are dark, heavy, basic rocks, composed essentially of olivine,
and belong to the group of peridotites. Both are of similar structure
and composition, differing only in the presence of inclusions. The
rock consists mainly of olivine crystals lying porphyritically in a
serpentinic ground-mass.

The olivine is remarkably fresh, and occurs in crystals which are
generally rounded by subsequent corrosion. The principal accessory
minerals are biotite and enstatite. The biotite is in crystals, often more
or less rounded, and sometimes surrounded by a thin black rim, due to
corrosion. Similar black rims surround biotite in many basalts. The
biotite crystals are usually twinned according to the base. The
enstatite is clear and non-pleochroic. Garnet and ilmenite also occur,
the former sometimes surrounded by biotite, and the latter often partly
altered to leucoxene. All these minerals lie in the serpentinic base,
originally olivine. This rock appears to differ from any heretofore
known, and may be described as a saxouite porphyry in which the base
is not holocrystalline.

The diamond-bearing portions often contain so many inclusions of
shale as to resemble a breccia, and thus the lava passes by degrees into
tuff or volcanic ash, which is also rich in diamonds, and is more readily
decomposable than the denser lava.

It seems evident that the diamond-bearing pipes are true volcanic
necks, composed of a very basic lava associated with a volcanic breccia
and with tuff, and that the diamonds are secondary minerals produced
by the reaction of this lava, with heat and pressure, on the carbona-
ceous shales in contact with and enveloped by it.

The researches of Zirkel, Bonney, Judd, and others, have brought to
light many eruptive peridotites, and Daubree has produced artificially
one variety (lherzolite) by dry fusion, but this appears to be the first
clear case of a peridotite voleano with peridotite ash.

Perhaps an analogous case is in Elliott County, Kentucky, where
Mr. J. 8. Diller has recently described an eruptive peridotite which
contains the same accessory minerals as the peridotite of Kimberley,
and also penetrates and incloses fragments of carboniferous shale, thus
suggesting interesting possibilities.’

V.—Nore on a Bep or Rep CHALK IN THE LowER CHALK oF SUFFOLK.
(A paper read before the British Association, Birmingham.)
By A. J. Juxzs-Browng, B.A., F.G.8.

(]\HE section exposing this stratum was discovered during an excursion
made last June by Mr. W. Hill, F.G.S., and the author. It occurs
in a quarry near West Row Ferry, about two miles west of Mildenhall ;

1 Since this paper was read, additional evidence that diamonds originate by the
action of peridotites on carbonaceous rocks has been collected from many localities.
The most instructive examples are from New South Wales, where the diamond
gravels lie near the contact of basalts or serpentine with Carboniferous rocks, the
serpentine here being an altered olivine enstatite rock. At the Bingera diamond-field
amass of eruptive serpentine is almost surrounded by Carboniferous rocks containing
coal-seams. In Western America, also, the diamantiferous gravels are near higher
ground, where serpentines and carbonaceous rocks occur together. Possibly a clue
may be thus afforded for more systematic search.

A. J. Jukes-Browne—Red Chalk in Suffolk. 25

here a band of red marly chalk is seen near the entrance, dipping
westward at a low angle, but soon becoming horizontal and running
along the whole face of the quarry, till it is cut off by a fault, which
brings up lower beds on the southern side.
The complete section at the deepest part of the pit, not far from
the entrance, is as follows :— Feet.
Soil and rubble of yellowish chalk ... ..
Pink marly chalk, weathering into yellow rubble towards the out-
cro bo) £00, dos" Gaon GOB G00 |) cos doo) as
imdraodules orey Vohalimey eer | “2,” Nema 24
Grey shaly chalk... ... 2
Very hard grey nodular and gritty chalk, ‘containing large Ammo-

nites, Belemnitella plena, and Terebr atula semiglobosa... 1
Thin-bedded whitish chalk (0. vesicularis) BoD co cee een Ss
Hard greyish chalk ... SEA ooo ood cco,
Softer thin-bedded chalk (Holaster sudglobosus) bc so, 1G
Hard lumpy yellowish rock _.. Bon) 008 05

At the western end of the pit, where the red band is further from
the surface, the following is the section exposed :—

Feet
Chalky soil . ¢ BCcN COREE aa OEIREPP RM Sco lu aoc) ioe) al!
Rough yellowish oritty chalk ... 4
Red marly chalk, brick-red at the top, pink below, a and passing
down into grey ‘marly chalk with hard lumps... 5
Hard grey rocky and nodular chalk . ; 2
Soft grey shaly chalk, seen for ... 1
13

The red chalk breaks into small angular blocks, the edges of which
are pinkish white, and all the joint-planes are bordered by whitish
bands, about a third of an inch thick; facts which seem to indicate that
the percolation of water from the surface has effected a certain amount
of decoloration, and that the whole was originally of one uniform colour,
darkest at the top, and becoming lighter in tint towards the base.

With regard to the stratigraphical position of these beds, we ascer-
tained that the quarry lies between the outcrops of the Totternhoe Stone
and the Melbourn Rock, and is opened in a shallow synclinal trough,
so that there must be an anticlinal to the east of the pit and a
second outcrop of the red chalk with an easterly dip along a line
nearer to Mildenhall, but of this no indication was found. The
Totternhoe Stone is found at Isleham, and traces of it occur near
West Row, about three-quarters of a mile N.W. of the ‘‘red chalk
quarry’; the Melbourn Rock is seen between Worlington and Milden-
hall, and its outcrop appears to run round Mildenhall at a distance of
about a mile and a half from West Row Ferry. Holaster subglobosus
is found in the lower part of the section at West Row, and the occur-
rence of typical Belemnitella plena points to a high horizon in that
zone; the existence of this Belemnite here is indeed an interesting and
noteworthy fact, for the typical forms have never yet been found in
Suffolk or Cambridge, except at the very summit of the Lower Chalk,
From the red chalk itself we obtained no fossils. It is clear, therefore,
that the horizon of the red band is about the centre of the zone of

26 A. J. Jukes-Browne—Red Chalk in Suffolk.

Holaster subglobosus, and at least 100 feet above the base of the Chalk
Marl; and, further, that it has no connection whatever with the red
rock which forms the base of the Chalk at Hunstanton and in
Lincolnshire.

It is well known, however, that the Lower Chalk of Lincolnshire
contains two other bands of red chalk, and the author’s examination
of this district for the Geological Survey enables him to compare the
Suffolk and Lincolnshire sections in detail. The following account of
the Lincolnshire beds is given with the permission of the Director-
General, and in anticipation of the Explanation of the Survey Map
(Sheet 84), which is now in the press.

In Lincolnshire, as at Hunstanton, the red (Hunstanton) rock
forms the basement bed of the Chalk, and is overlain by four or
five feet of hard grey sandy chalk (Inoceramus beds). These are
succeeded by about 70 feet of grey chalk with many layers of
hard nodular rocky chalk, and including two bands of pink chalk,
one (the lower) being in some places of a decided red colour,
while the upper band is generally of a yellowish pink tint. The
lower band is of a loose and marly nature inclosing hard lumps, which
are generally of a lighter tint inside; it varies in thickness from 43
to 7 feet, and sometimes it is only the central part of the band which
is of a decided red colour, the upper and lower parts shading into pink
and grey; Holaster subglobosus occurs both in and below this band,
together with a few other fossils, but Belemnitella plena has not yet
been found in Lincolnshire. The upper band consists of much harder
and more evenly bedded chalk; it is generally about seven feet thick,
and varies in tint from light-pink to yellowish-white; it is overlain by
a course of hard white chalk surmounted by a band of soft mottled
marl, which is usually two feet thick, and exhibits tints of red, grey,
and buff. Above this are beds of hard yellowish-white chalk, which
seem to represent the Melbourn rock; these contain Jnoceramus
mytiloides and Rhynchonella Cuvierc.

From the above description it will be seen that the West Row bed
closely resembles the lower of the two red bands which are seen in the
quarries near Louth, and as this occurs very nearly on the same
horizon, I have little hesitation in correlating them with one another
as homotaxial beds, though they may not be identical, because they
do not appear to be continuous across the intervening space in Norfolk
and Lincolnshire.

Figs. 1 and 2 are comparative vertical sections, showing the position
of these bands of red chalk in Suffolk and Lincolnshire, both being
drawn to a scale of 16 feet to the inch; the exact distance of the West
Row chalk below the Melbourn rock can only be estimated approxi-
mately, but the Lincolnshire section is drawn from actual measure-
ments taken in quarries at Louth. The upper portions of the two sec-
tions are similar, but the lower parts are very different. The base of
the Chalk Marl is not seen in Suffolk, but the Marl is known to be
between 60 and 70 feet thick, whereas in Lincolnshire there is only
some 20 feet of grey and red chalk to represent the combined thickness
of the Totternhoe Stone, Chalk Marl and Gault.

With regard to the horizontal extension of the red chalk in Suffolk

A. J. Jukes-Browne—Red Chaik in Suffolk. QT

we obtained but little evidence. North of Mildenhall there is either
a cross fault or a decided sinking of the beds in the direction of the
strike, so that near Lakenheath the whole of the Lower Chalk lies
below the surface of the Fens. he valley of the Little Ouse or
Brandon River appears, however, to coincide with a line of fault, for
the Lower Chalk comes to the surface again on the north side of the
valley by Hockwold and Feltwell in Norfolk, and rises to a height of
at least 60 feet above the level of the fen.
Fig. 1. SurroLr. Fie. 2. LincoLNsHirReE.

—Mottled marl.
Winte chalk.

Pink chalk.

Grey shale and white
chalk.

Blocky greyish-white

chalk. Hard whitish chalk.

Hard grey nodular chalk.

Rough nodul -
ough nodular yellow { Red chalk.

ish-grey chalk.
Red band of West Row. :

Hard grey chalk, with
bands of softer chalk

Hard grey chalk with below.

some softer bands.

Hard grey chalk.
Hard grey gritty chalk.

->| Hard red rock with red
4 marl at the base.

Totternhoe Stone.

Chalk Marl (upper por-

tion). Brown sand (Carstone).

- Scale—32 feet to one inch.

At Feltwell we were fortunate enough to find a small exposure of
reddish chalk in the bank of a dry pond by the roadside, a quarter of a
mile N.E. of St. Mary’s Church; as it overlies a band of very hard
nodular rock, below which a softer greyish white chalk is visible, there
can be little doubt that it is the same band of red chalk, and that the
section here is similar to that at West Row.

Beyond this we did not meet with any indications of red chalk, but
it is quite possible for the band to extend some distance farther north
without being seen, for large areas are covered with glacial and post-
glacial deposits, and the pits near Stoke-Ferry are all either above or
below the horizon on which I have placed this particular band.

At the same time it should be mentioned that the red bands in the
Lincolnshire chalk only extend over an area of 12 or 15 miles in length,
and are not found at the southern extremity of the Wolds. Whether
they are really absent over the intervening space, or whether the beds
themselves continue, but gradually lose their distinctive colour, and so
become indistinguishable trom the rest of the grey chalk, is a difficult
point to decide, and one upon which I do not at present offer an opinion.

28 Prof. H. Carvill Lewis—Comparative Studies in Glaciation.

It only remains to add that nothing like the uppermost pink band of
Lincolnshire was seen either in Suffolk or Norfolk, all the quarries
exposing the horizon where it would occur exhibiting only whitish
chalk, passing down gradually into grey chalk.

VI.—Comparative StupIEs upon THE Guactation or Norra AMERICA,
Great, Brivarn, AND I[RELAND.
By Pror. H, Carvitt Lewis, M.A., F.G.S.
(Abstract of a paper read at the Birmingham Meeting of the British Association,
September, 1886.)

BSERVATIONS extending over several years upon glacial phe-
nomena on both sides of the Atlantic had convinced the author
of the essential identity of these phenomena; and the object of this
paper was to show that the glacial deposits of Great Britain and
Ireland, like those of America, may be interpreted most satisfactorily
by considering them with reference to a series of great terminal
moraines which both define confluent lobes of ice and also often

mark the line separating the glaciated from the non-glaciated areas.

The paper began with a sketch of recent investigations upon the
glaciation of North America, with special reference to the significance
of the terminal moraines discovered within the last few years. The
principal characters of these moraines were given, and a map was
exhibited showing the extent of the glaciated areas of North America,
the course of the interlobate and terminal moraines, and the direction
of striation and glacial movement. It was shown that apart from the
great ice-sheet of North-eastern America, an immense lobe of ice
descended from Alaska to Vancouver’s Island on the western side of
the Rocky Mountains, and that from various separate centres in the
Cascade, Sierra Nevada, and Rocky Mountains, there radiated smaller
local glaciers.

The mountains encircling the depression of Hudson Bay seemed to
be the principal source of the glaciers which became confluent to form
the great ice-sheet. In its advance this ice-sheet probably met and
amalgamated with a number of already existing local glacial systems,
and it was suggested that there was no necessity for assuming either
an extraordinary thickness of ice at the Pole, or great and unequal
elevations and depressions of land.

Detailed studies made by the author in Ireland in 1885 had shown
remarkably similar glacial phenomena.

The large ice-sheet which covered the greater part of Ireland was
composed of confluent glaciers, while distinct and local glacial systems
occurred in the non-glaciated area. The principal ice-sheet resembled
that of America in having for its centre a great inland depression sur-
rounded by a rim of mountains.

‘These appear to have given rise to the first glaciers, which after
uniting poured outwards in all directions. Great lobes from this
ice-sheet flowed westward out of the Shannon and out of Galway,
Clew, Sligo, and Donegal Bays, northwards out of Loughs Swilly
and Foyle, and south-eastward out of Dundalk and Dublin Bays;
while to the south the ice-sheet abutted against the Mullaghareik,
Galty, and Wicklow mountains, or died out in the plains.

Prof. H. Carvill Lewis—Comparative Studies in Glaciation. 29

Whether it stopped among the mountains or in the lowlands, its
edge was approximately ontlined by unusual accumulations of drift
and boulders, representing the terminal moraines. As in America,
this outer moraine was least distinct in the lowlands, and was often
bordered by an outer fringe of drift several miles in width.

South of an east and west line extending from Tralee to Dungarvan is
a non-glaciated zone free from drift. Several local systems of glaciers
occur in the south of Ireland, of which by far the most important is
that radiating from the Killarney mountains, covering an area of
2000 square miles, and entitled to be called a local ice-sheet. Great
glaciers from this Killarney ice-sheet flowed out of the fiord-like
parallel bays which indent the south-westernmost coast of Ireland.
At the same time the Dingle mountains, the Knockmealdown and
Comeragh mountains, and those of Wexford and Wicklow furnished
small separate glaciers, each sharply defined by its own moraine.

No evidence of any great marine submergence was discovered,
although the author had explored the greater part of Ireland, and
the eskers were held to be phenomena due to the melting of the
ice-sheet and the circulation of subglacial waters. The Ivish ice-
sheet seemed to have been joined at its north-eastern corner by ice
coming from Scotland across the North Channel. All the evidence
collected indicates that a mass of Scotch ice, reinforced by that of
Ireland and England, filled the Irish Sea, over-riding the Isle of
Man and Anglesey, and extending at least as far south as Bray
Head, south of Dublin. A map of the glaciation of Ireland was
exhibited, in which the observations of the Irish geologists and of
the author were combined, in which was shown the central sheet,
the five local glacial systems, all the known striz, and the probable
lines of movement as indicated by moraines, strie, and the trans-
port of erratics.

The glaciation of Wales was then considered. Wales was shown
to have supported three distinct and disconnected local systems of
glaciers, while at the same time its extreme northern border was
touched by the great ice-lobe of the Irish Sea. The most extensive
local glaciers were those radiating from the Snowdon and Arenig
region, while another set of glaciers radiated from the Plinlimmon
district and the mountains of Cardiganshire, and a third system
originated among the Brecknockshire Beacons. The glaciers from
each of these centres transported purely local boulders and formed
well-defined terminal moraines. The northern lobe, bearing granite
boulders from Scotland and shells and flints from the bed of the
Irish Sea, invaded the northern coast, but did not mingle with
the Welsh glaciers. It smothered Anglesey and part of Carnarvon-
shire on the one side and part of Flintshire on the other, and
heaped up a terminal moraine on the outer flanks of the north
Welsh mountains. This great moraine, filled with far travelled
northern erratics, is heaped up in hummocks and irregular ridges,
and is in many places as characteristically developed as anywhere
in America. It has none of the characters of a sea-beach, although
often containing broken shells brought from the Irish Sea. It may
be foilowed from the extreme end of the Lleyn Peninsula (where

30 Prof. H. Carvill Lewis—Comparative Studies in Glaciation.

it is full of Scotch granite erratics), in a north-easterly direction
through Carnarvonshire, past Moel Tryfaen, and along the foot of
the mountains east of Menai Strait to Bangor, where it goes out
to sea, re-appearing further east at Conway and Colwyn. It turns
south-eastward at Denbighshire, going past St. Asaph and Halkin
mountain. In Flintshire it turns southward and is magnificently
developed on the eastern side of the mountains, at an elevation of
over 1000 feet between Minera and Llangollen, south-west of which
place it enters England. There is evidence that where the ice-sheet
abutted against Wales, it was about 1350 feet in thickness. This
is analogous to the thickness of the ice-sheet in Pennsylvania, where
the author had previously shown that it was about 1000 feet in
thickness at its extreme edge and 2000 feet thick at points some
eight miles back from its edge. The transport of erraties coincides
with the direction of strie in Wales as elsewhere, and is at right
angles to the terminal moraines.

The complicated phenomena of the glaciation of England, the subject
of a voluminous literature and discordant views, had been of high in-
terest to the author, and had led him to redouble his efforts towards its
solution. He had found that it was possible to accurately map the
glaciated areas, to separate the deposits made by land-ice from those
due to icebergs or to torrential rivers, and to trace out a series
of terminal moraines both at the edge of the ice-sheet, and at the
edge of its confluent lobes. Perhaps the finest exhibition of a terminal
moraine in England is in the vicinity of Ellesmere in Shropshire.
A great mass of drift several miles in width, and full of erratics
from Scotland and from Wales, is here heaped into conical hills
which enclose ‘‘ kettleholes’’ and lakes, and have all the characters
of the ‘‘ kettle moraine’’ of Wisconsin. Like the latter, the Ellesmere
moraine here divides two great lobes of ice, one coming from Scotland,
the other from Wales. This moraine may be traced continuously from
Ellesmere eastward through Madeley, Macclesfield, to and along the
western flank of the Pennine chain, marking throughout the southern
edge of the ice-sheet of northern England. From Macclesfield the same
moraine was traced northward past Stockport and Staley Bridge to
Burnley, and thence to Skipton in Yorkshire. North-east of Burnley
it is banked against the Boulsworth Hills up to a height of 1300 feet
in the form of mounds and hummocks. South and east of this long
moraine no signs of glaciation were discovered, while north and west
of it there is every evidence of a continuous ice-sheet covering land
and sea alike. The strie and the transport of boulders agree in
proving a southerly and south-easterly direction of ice-movement in
Lancashire and Cheshire.

From Skipton northward the phenomena are more complicated. A
tongue of ice surmounted the watershed near Skipton, and protruded
down the valley of the Aire as far as Bingley, where its terminal
moraine is thrown across the valley like a great dam, reminding one of
similar moraine dams in several Pennsylvania valleys. A continuous
moraine was traced around this Aire glacier. Another greater glacier,
much larger than this, descended Wensleydale and reached the plain
of York. The most complex glacial movements in England occurred

Prof. H. Carvill Lewis— Comparative Studies in Glaciation. 31

in the mountain region about the Nine Standards, where local glaciers
met, and were overpowered by the greater ice-sheet coming down from
Cumberland. The ice-sheet itself was here divided, one portion going
southward, the other in company with local glaciers, and laden with
the well-known boulders of the ‘‘Shap granite,” being forced eastward
across Stainmoor Forest into Durham and Yorkshire, finally reaching
the North Sea at the mouth of the Tees. The terminal moraine runs
eastward through Kirkby Ravensworth towards Whitby, keeping
north of the Cleveland Hills, and all eastern England south of Whitby,
except Holderness, appears to be non-glaciated. On the other hand,
all England north of Stainmoor Forest and the River Tees, except the
very highest points, was smothered in a sea of ice.

There is abundant evidence to prove that the ice lobe fillimg the
Irish Sea was thicker towards its axis than at its edges, and at
the north at its southern terminus, and that it was reinforced by
smaller tributary ice-streams from both England and Ireland. It
may be compared with the glacier of the Hudson River valley in
New York, each having a maximum thickness of something more
than 8000 feet. The erosive power of the ice-sheet was found
to be extremely slight at its edge, but more powerful farther
north, where its action was continued for a longer period. Towards
its edge its function was to fill up inequalities rather than to
level them down. It was held that most glacial lakes are due to an
irregular dumping of drift, rather than to any scooping action, observa-
tions in England and in Switzerland coinciding with those in America
to confirm this conclusion. Numerous facts on both sides of the
Atlantic indicate that the upper portion of the ice-sheet may move in
a different direction from its lower portion. It was also shown that
a glacier in its advance had the power of raising stones from the
bottom to the top of the ice, a fact due to the retardation by friction of
its lower layers. The author had observed the gradual upward passage
of sand and stones in the Grindelwald glacier, and applied the same
explanation to the broken shells and flints raised from the bed of the
Irish Sea to the top of Moel Tryfaen, to Macclesfield and to the Dublin
mountains. The occurrence of stratified deposits in connection with
undoubted moraines was shown to be a common phenomenon, and
instances of stratified moraines in Switzerland, Italy, America, and
‘Wales were given. The stratification is due to waters derived from
the melting ice, and is not proof of submergence. It was held that,
notwithstanding a general opinion to the contrary, there is no evidence
in Great Britain of any marine submergence greater than about 450
feet. It was natural that an ice-sheet advancing across a sea should
deposit shell fragments in its moraine.

The broad principle was enunciated that wherever in Great Britain
marine shells occur in glacial deposits at high levels,’ it can be proved
both by strize and the transport of erratics that the ice advanced on to
the land trom out of the sea. The shells on Three Rock Mountain
near Dublin, and in North Wales and Macclesfield, all from the Irish
Sea; the shells in Cumberland transported from Solway Firth; those
on the coast of Northumberland brought out of the North Sea; those

1 7.¢. higher than about 440 feet.

32 R. D. Oidham—Facetted Pebbles from the Punjab.

at Airdrie in Scotland carried eastward from the bottom of the
Clyde; and those in Caithness from Moray Firth, were among
examples adduced in proof of this principle. The improbability of a
great submergence not leaving corresponding deposits in other parts of
England was dwelt upon.

It was also held that there was insufficient evidence of more than
one advance in the ice-sheet, although halts occurred in its retreat.
The idea of successive elevations and submergences with advances and
retreats of the ice was disputed, and the author held that much of the
supposed interglacial drift was due to subglacial water from the
melting ice.

The last portion of the paper discussed the distribution of boulders,
gravels, and clays south of the glacial area. Much the greater part of
England was believed to have been uncovered by land-ice. The drift
deposits in this area were shown to be the result in part of great
freshwater streams issuing from the melting ice-sheet, and in part of
marine currents bearing icebergs during a submergence of some 450
feet. The supposed glacial drift about Birmingham, and the concen-
tration of boulders at Wolverhampton, were regarded as due to the
former agent; while the deposits at Cromer and the distribution of
Lincolnshire chalk across southern England was due to the latter.
The supposed esker at Hunstanton was believed to be simply a sea-beach,
and the London drift deposits to be of aqueous origin. Thus the rival
theories of floating icebergs and of land glaciers were both true, the
one for middle and southern England, the other for Scotland, Wales,
and the north of England; and the line of demarcation was fixed by
great terminal moraines. The paper closed with an acknowledgment
of indebtedness to the many geologists of England and Ireland, who
had uniformly rendered generous assistance during the above investiga-
tion.

VII.—Norte on THe Facerrep Pessies FRoM THE OLIVE GROUP OF
THE Sart Rance, Ponsa, Inpia.
By R. D. OupHam, A.R.S.M.,
of the Geological Survey of India.
T the last meeting of the British Association certain facetted
pebbles derived from the Olive group of the Salt Range, and
presumably of glacial origin, were exhibited and commented on.’
Some doubt appears to have been expressed as to their being due to
glacial action. The following notes on these pebbles and the bed
they were derived from may prove of interest.
The boulder bed of the Olive group in the Salt Range consists of
a fine-grained, thin-bedded, shaly matrix, usually of that shade of
green from which the name of the group is derived; through this
are scattered blocks of hard crystalline and metamorphic rock, of
all sizes, from an inch or less to several feet in diameter. ‘They are
too abundant for their occurrence to be explained by the action of
drift wood, nor is there any sign of cabonaceous matter in the bed ;
there is no indication of volcanic action, and, as many of the frag-
ments must have travelled scores, if not hundreds of miles, we are

1 See Grou. Maa. 1886, Decade III. Vol. IIT. pp. 492, 494, 574.

R. D. Oldham—Facetted Pebbles from the Punjab. 33

compelled to allow that their occurrence in their present position
is primarily due to the action of floating-ice. So much has long been
allowed by all who know the bed.

Of these blocks of stone an appreciable proportion show a flattened
striated surface, exactly like that produced by glacial action; but a
peculiarity of this boulder bed is that a very large proportion of
those blocks which show this feature are not striated on a single face
only, but on several; and in some cases the original form of the
pebble is so completely obliterated, and the facets meet on so clean-
cut an edge, that the pebble assumes almost the appearance of a
erystal. Something similar to this is known in the Boulder-clay of
England ; instances were quoted at the British Association, and I
have myself seen a pebble from the Boulder-clay of the Midland
Counties so striated on three faces; but these surfaces did not meet
in a sharp edge, like those so commonly met with in the Salt Range
specimens.

Having shown that the occurrence of these pebbles in their
present position is due to the action of floating-ice, we have next to
consider whether their peculiar form is also due to the action of
ice, and if so whether as coast-ice or in the form of a glacier.

A suggestion was made at the British Association that the facetting
might be due to the action of wind-blown sand; this, however, I
cannot admit. Without egotism I may say that I have had oppor-
tunities of studying the erosive action of blown sand such as fall to
the lot of few geologists. I have seen numbers of stones facetted by
the sand blown ayainst their different faces as they were overturned
from time to time through one cause or another; but I have never
seen anything which, to a practised eye, resembled these Salt
Range pebbles any more than these latter do a crystal of felspar.

Where blown sand acts on a rock sufficiently hard or fine-grained,
a polished surface, marked with numerous fairly parallel scratches
in the direction of the prevailing wind, is produced. These scratches,
however, could not be confounded with glacial striz; for they are
such as would result from particles of grit getting into an artificial
polisher, and are very different from the clean and finely-cut scratches
produced by glacial action. Where the rock is softer, it is often cut
into grooves parallel with the direction of the prevailing wind ;
these, too, are not like the grooving produced by ice, but broad
shallow channels separated by sharp-crested ridges, giving the rock
an appearance as if it had been roughly dressed with a carpenter’s
gouge. In any case there is an entire absence of anything approach-
ing to a sharp edge except in the direction of the wind, all angles
oblique or transverse to that being rounded off. Now the facetted
pebbles and boulders of the Salt Range show by the direction of the
striz on them that in almost every case the facets are due to some
cause acting in a direction more or less transverse to the line along
which they meet ; consequently the facets cannot be due to the action
of blown sand, which would have rounded off any angle so situated
with reference to the direction in which the sand was drifted.

The number of stones showing one or more striated surfaces pre-

DECADE IIIl.—VOL. IY.—NO. I, 3

o4 R. D. Oldham—Facetted Pebbles from the Punjab.

vents us from ascribing their origin to a movement of the soil-cap,
while the steadiness of direction of the strie on each face shows
that the fragment must have been firmly held, and, in the case of
the smaller ones, it is difficult to see how they could have been so
held except by being imbedded in some material which, like ice,
would adapt itself completely to the shape of the pebble.

The striated faces bear no resemblance to slickensides, and as the
fragments seldom touch each other in the bed, but are separated by
a greater or less thickness of the fine-grained matrix, any attempt to
explain their origin by friction of the pebbles against each other
subsequent to deposition is inadmissible; moreover, there is no
exceptional disturbance of the beds, and the striated fragments are as
common where they lie nearly horizontal as where they are tilted.

The only other agency by which the facets could have been pro-
duced is that which is at first sight suggested by the appearance of
the pebbles, viz. ice, and it only remains to see whether this was in
the form of coast-ice or glaciers. Here we must leave the domain of
certainty, and enter on that of probability.

Prof. J. Milne has shown ! that, as far as the live rock is concerned,
many of the appearances usually considered characteristic of glacier
action may be produced by coast-ice ; but in the present case we are
not concerned with what happens to the rock in situ, but with the
effect produced on the loose pebbles and boulders caught up in the
ice and ground on the solid rock. At first sight the number of
striated faces on many of these pebbles would seem to point to the
action of coast-ice, for, after every melting of the ice, the pebble
would probably be fixed each winter in a fresh position, and offer a
different face for abrasion ; but it is doubtful whether the facets do
not indicate a greater pressure and a greater constancy of direction
of motion than could be given by coast-ice, and it is still more doubt-
ful whether they could be produced during a single winter, which on
this supposition is all that can be allowed for each facet.

A much stronger objection is the entire absence of any sign of the
action of water on some of the pebbles. Had the facets been due to
the action of coast-ice forming in winter and melting again in
summer, the pebbles would every year have been exposed for a longer
or shorter time to the action of waves, and the sharp, clean-cut
junction of the facets which we find would have been more or less
abraded ; so that, if the shape of these pebbles is due to the action of
coast-ice, it must have been perennial. I need but point out that
coast-ice lasting through winter and summer implies a much severer
climate than is needed to account for glaciers descending to the sea ;
a priori then the latter is the more probable hypothesis as requiring
the least climatic change, besides being more in consonance with the
evidence derived from the appearance and mode of occurrence of the
boulders and pebbles showing signs of glacial action.

I have now shown that these boulder beds owe their origin
primarily to the action of floating-ice, that the shape of the facetted
fragments must be due to glacial action, that some at least of them

1 Gzort, Mag. Dec. II. Vol. IV. p. 298 (1877).

J. HE. Marr—Lower Paleozoic Rocks of Settle. 30

can never have been exposed to the action of waves on a sea-beach,
and that consequently they must have been shaped either by perennial
coast-ice rising and falling with the tides, or by a glacier which
descended to the sea and there gave off icebergs. In either case they
imply a change of climate which, if we bear in mind that the frag-
ments have all come from the southwards, and in many cases from
long distances, is of a degree and kind difficult if not impossible to
explain in accordance with accepted theories.

VIII.—Tuer Lowrr Patmozorc Rocks NEAR SETTLE.
By J. HE. Marr, M.A., F.G.S.

HE rocks of this area have been previously described by Professor
Hughes (Grot. Mae. Vol. LV.), and some notes upon the same
were subsequently submitted by myself to the British Association at
York in 1881, and published in the Proceedings of the Yorkshire
Geological and Polytechnic Society (Proc. Y. G. & P. 8. n-s. vol. vii.).

Further work was carried on this year, in company with a party of
Cambridge geologists, under the guidance of Prof. Hughes, and I have
to thank him and them for much information, and for the opportunity
of examining many specimens.

Firstly, I would correct one or two errors in my previous paper.

In the section in Austwick Beck, a considerable thickness of black
shales is indicated between the conglomerate and the calcareous band
with Phacops elegans. These black shales are really below the con-
glomerate, which latter appears in each limb of the anticlinal repre-
sented in the section, though much attenuated, and the black shales
have yielded Bala fossils, including Orthis testudinaria, Dalm.

The only deposit between the conglomerate and the bed with
Phacops elegans consists of two or three inches of lead any shales,
in which no fossils have been yet found.

The beds marked 5 in the section already referred to, ‘and described
as pale green shales, are really a portion of the same series as 6, and
contain identical fossils with it, and the difference of colour is simply
due to weathering.

We must therefore strike the beds 3 and 5 out of the list of those
which I correlated with the Stockdale shales (Valentian), and admit
that these are represented at Austwick only by the conglomerate, the
leaden-grey shales, and the zone of Phacops elegans. That these thin
beds represent the whole of the Valentian of other areas is doubtful,
and it is possible that the representatives of the Coniston mudstones
are here absent, and that the pale slates only are represented. That
this may be the case is further indicated by the fact that Phacops
elegans does occur in the higher Valentian beds, as in the Tarannon
shales of Onny River, for I have recognized this species in the Jermyn
Street Museum from that locality.

I may now proceed to a more detailed description of the different
deposits in ascending order, as seen in the small valley near Austwick,
through which Crummack Beck runs, and in the main Ribble Valley
to the north of Settle.

As I do not wish to introduce new names, I shall speak of the beds

36 J. E. Marr—Lower Paleozoic Rocks of Settle.

by the names given to similar beds in the Lake District, with which

they have already been correlated, or ought, in our opinion, to be so.
A. Coniston Limestone series.—These beds are largely developed in

the neighbourhood of Austwick. The probable succession is as follows:—

. Calcareous blue shales, weathering olive-brown.

. Ashes.

. Blue, shivery shales.

. Blue, flaggy, Brachiopod shales.

mo bd

Conglomerate of succeeding series.

The calcareous blue shales (1) are well seen at the angle of the road
below Norber Brow, where they are very fossiliferous. We have
obtained from this locality the following fossils :—

Diplograptus (like pristis, His.). Cybele Loveni, Linnrs.
Dicellograptus anceps, Nich. Lichas laxatus, M‘Coy,
Stenopora sp. Turrilepas,

Tentaculites anglicus, Salt. Phacops (Pterygometopus) sp.
A teleocystites sp. Leptena transversalis, Wahl.
Trinucleus seticornis, His. un sericea, Sow.
Dindymene ornata, Linnrs, ?4 Orthisina sp.

The same beds appear to be represented in a stream south of Wharfe.
From this locality fossils have been collected by the Rev. A. Pagan,
amongst which are—

Ateleocystites sp.
Phacops (Pterygometopus) sp.
similar to those of Norber Brow.

The ashes (2) have as yet not furnished us with any fossils.

The blue shales (8) occur at Wharfe Mill Dam, and near a barn on
the other side of the lane. In them we have found :—

Trinucleus seticornis, His.
Iilenus Davisii, Salt.

Calymene Blumenbachii, Brongn.
Leptena transversalis, Wahl.

The blue shales (4) which oceur immediately below the conglomerate
of Valentian age have yielded, as already stated, Orthis testudinaria,
Dalm., along with a species of Strophomena.

B. Stockdale Shale Series—I have nothing to add to the remarks
made upon these beds, except to give a fuller list of fossils, which
includes—

Petraia, sp.

Phacops elegans, Boeck & Sars.
Cheirurus bimucronatus, Murch.
Encrinurus punctatus, Briinn.
Leptena quinquecostata, M‘Coy.

All these occur in the thin bed of hard calcareous mudstone, which
has been described as the zone of Phacops elegans, and which is almost
entirely made up of fragments of Trilobites.

C. Lower Coniston Flags.—These beds immediately succeed the
Phacops elegans zone of the preceding series, and are well developed in

1 A fine specimen of Dindymene was discovered by Mrs. T. McK. Hughes, which
is unfortunately somewhat distorted by cleavage. Until other specimens are found we
refer it provisionally to D. ornata, Linurs., though it will probably have to be separated
eventually. Only eight body-rings occur.

J. E. Marr—Lower Paleozoic Rocks of Settle. 37

the Crummack Valley. They consist of laminated blue, slightly
gritty flags, with

Monograptus priodon, Bronn. -

M., personatus, Tullbg. ?

M. cultellus, Tornq.

Retiolites Geinitzianus, Barr.

Orthoceras.

D. Grits.—These beds, the Grits A c 2 of Prof. Hughes’ section, are
largely developed in both valleys. They have as yet furnished no
fossils.’

E. Upper Coniston Flags.—Seen at Studrigg, on the east side of the
Crummack Valley, and in Dryrigg, Arco Wood, and Combs Quarries in
Ribblesdale. They resemble, in lithological characters, the Lower
Coniston Flags, but the fossils are different.

At Studrigg Monograptus Roemeri, Barr., was found by one of Prof.
Hughes’ party, and the Ribblesdale quarries have yielded : —

Monograptus colonus, Barr.
45 bohemicus, Barr.
Favosites fibrosus, Goldf.

Be alveolaris, Goldf.
Actinocrinus pulcher, Salt.
Pentamerus ?

Orthoceras primevum, Forbes.
Trochoceras giganteum, Sow.

F. Grits. — Mentioned by Prof. Hughes as occurring above the
Flags (E) at Studfold Low Pasture, on the east side of Ribblesdale.
These are the highest Lower Paleozoic beds seen in this area.

Comparison with other Areas.—The general resemblance between the
beds of this district and those of the Lake District, whether we take
into account lithological or palzontological characters, is so striking,
that there is little or no difficulty in correlating the beds of the two
areas. The following table shows the probable equivalents :—

Serrte Disrricr. Lake Disrricr.
Coniston Limestone Series. Coniston Limestone.”
Absent 2 Ashgill shales.

Absent ? Coniston Mudstones.
Conglomerate ? Pale slates.

Phacops elegans zone ?

Lower Coniston Flags. Brathay Flags.

Grits. Lower

Moughton Whetstones ? Middle Olslehras) Wea
Upper Coniston Flags. Upper Coldwell beds.
Grits (Studfold). Coniston Grits.

The most interesting feature of the rocks of the Settle District is the
approach to the characters of the Scandinavian beds.
The Coniston Limestone series is much more shaly than the typical

1 It is possible that the remarkable whetstones near the head of the valley, which
have not been detected in situ, are interstratified with the grits. Amongst the fossils
contained therein are :—

Monograptus dubius, Suess.
M. Nilssoni, Barr.

M. uncinatus, Tullb. ?
Orthoceras primevum, Forbes.

2 The beds with Dicellograptus anceps have not been detected in the Lake District
proper, but similar beds occur at Melmerby Scar, on the west slope of the Pennines.

3 Unless the beds with Orthis testudinaria, immediately below the conglomerate,
are the equivalents of the Ashgill shales.

38 Notices of Memoirs—Dr. Le Neve Foster—Manganese Mining.

Coniston Limestone, and indeed is intermediate in lithological character
between that Limestone and the Trinucleus Shales of Sweden. Palzeon-
tologically it is connected with the latter by the occurrence within it of
Diplograptus like pristis, Dicellograptus anceps, Trinucleus seticornis,
Dindymene ornata ?, Cybele Lovent, and Turrilepas.

The Lower Coniston Flags have the fauna of the Cyrtograptus
Shales, though Cyrtograptus has not yet been found in them. Our
fossils are derived from near the base of this series, and that they occur
in beds about. the horizon of the lower part of the Cyrtograptus Shales
is possibly indicated by the occurrence of JJonograptus cultellus, of
which, however, only one specimen has hitherto been found in the
Settle District. A further examination of these Lower Coniston Flags,
at points more remote from the base, will probably be rewarded by the
discovery of other species of Graptolites.

That the Moughton Whetstones are really intermediate in position
between these Lower Coniston Flags and the flags in the quarries of
Arco Wood, Dryrigg, ete., seems proved by the occurrence in them of
Monograptus dubius, M. uneinatus? and M. Nilssoni, all of which are
found at the base of the Cardiola beds of Sweden, whilst the higher
parts of the Cardiola beds contain fossils identical with those of Arco
Wood, ete., including Monograptus colonus, and M. bohemicus. The
zone with J. dubius, etc., has, so far as I am aware, been hitherto unre-
corded in Britain, and the probable corresponding beds in the Lake
District are not of a nature suitable for the preservation of Graptolites.

The Swedish affinities of these Settle rocks will probably be further
proved, when more work has been carried on in the district, and from
the simplicity of the sections, the area can confidently be recommended
to the notice of any geologist who wishes, by patient work, to assist in
establishing the zones of the Lower Paleozoic rocks of our country.

Dj @ sea SS Oa” AV Ese VE @zayS-
eg
PAPERS READ BEFORE SEcTION C. (GEoLocy) British Association MEETING,
BirnMINGHAM, 1886.
I.—Maneaness Mining in Merionerusuire. By C. Lz Neuve
Foster, D.Sc., F.G.S.

ANGANESE ore is now being worked in the Cambrian rocks at
several places near Barmouth and Harlech. It occurs in the
form of a bed varying from a few inches to three feet in thickness; the
average thickness is one foot to one foot and a half. The undecomposed
ore contains the manganese in the form of carbonate, with a small pro-
portion of silicate; but at the outcrop it is changed into a hydrated
black oxide. Some of the outcrops of the manganese bed are erroneously
marked on the Geological Survey Maps as mineral veins, though Sir
Andrew Ramsay was of opinion that the deposits were not true lodes.
Recent workings show plainly that the deposits are truly stratified
beds, or possibly various outcrops of one and the same bed, extending

over a considerable area.

The ore contains from 20 to 35 per cent. of metallic manganese, and
is despatched to Flintshire and Lancashire for the manufacture of ferro-
manganese. The new Merionethshire mines are the first instance of
workings for carbonate of manganese in the British Isles.

Notices of Memoirs—E. W. Bucke—Geysers of New Zealand. 39

I1.—Ow tHe SrraricRaparcaL Postrion or THE Satt MrAsuREsS OF
Sourh Durnam. By G. A. Lzepour, M.A., F.G.S., Professor of
Geology in the Durham College of Science, Newcastle-upon-Tyne.

HE beds above the main mass of the Magnesian Limestone in Durham
are seldom exposed at the surface, as the south of the country is
covered by a thick spread of drift. The presence of salt deposits
having, however, been proved some years ago in the adjoining part of
Yorkshire near Middlesbrough, several borings for working them in
the form of brine were soon put down in the flat country between the
Tees and the coast south of Seaton Carew. There are now altogether
some fifteen or sixteen such borings, most of which have reached beds
of salt at depths varying from 600 feet to over 1200 feet. These have
thrown much light upon the rocks, hitherto scarcely known in this part
of England, which lie between the Rhetic and the great Permian
Magnesian Limestone of Durham. The author exhibited sections of
these beds, and gave reasons for suggesting that much of the Salt
Measures of this district is probably the representative of the Upper
Permian or Rauchwacke of Germany.
The following table summarizes fairly the classification tentatively
suggested by the author :—

Avicula contorta beds (proved in Eston shaft and boring) ... Rheetic.
7. Red and green marls, with g gypsum pron only south of

Tees) Bo) |-H8G), Poder God 4) tec tas SECM ERE Upper Trias.
6. Red sandstone. 6, Boo.) woba, a Hoot, LSaOU INGDOMReReCEMs CaS

Unconformity (?)
Hephedssandstones and marls) cen). 3. wee nee cee (2 ower) Priag:
Unconformity (°)

Upper Permian.

4. Red marly sandstones, marls, with lenticular beds of

anhydrite, gypsum, and salt, and foetid limestone a

variable bands towards the base s06.| ane (arene)
3. Main Magnesian Limestone ... ... ... ..- --- . :
2. Marl slate with fish-bed 0), Doo -Bdbpy “eaBw Loo Aeuvelly eat
Heme Velo sandst "5.00 vs. saa Utne) gee =< os» one) os ¢ eOWerpbermian.

Unconformity.
CARBONIFEROUS Rocks.

I11.—Gurysers or tHe Rororva Disrrict, Norra Istanp oF NEw
ZEALAND. By E. W. Bucks.

HE author of this paper has recently returned from the Lake

_ district of New Zealand, where he spent eighteen months, and
had exceptional opportunities for making observations upon the
volcanic phenomena of the district. The largest geyser in New
Zealand, that of the White Terrace of Rotomahana, is now destroyed ;
the three next in size are those of Pehutu, Waikiti, and Wairoa, all of
which are situated close together at the back of the native village
named Whakarewarewa, about three miles to the south of the Rotorua
township, and these are particularly described in the present com-
munication. The author was able to determine by soundings the depth
of the tubes of several geysers of this district, and in the case of an
extinct one, that of Te Waro, he was Iet down the tube. He found
that this tube, at a depth of 18 feet from the surface, opened into
a chamber 15 feet long, 8 feet broad, and 9 feet high, and that from
one end of this chamber another tube led downwards to an undeter-
mined depth.

40 Reviews—Prof. Hébert—Older Rocks of N.W. France.

Living entirely among the natives for many months, and speaking
their language, the author was able to test the power claimed by the
natives of being able to predict the outbursts of the geysers. He is
convinced that by constant observations on the direction of the wind
and the condition of the atmosphere, the natives have learnt to prog-
nosticate the movements in all these hot springs with wonderful
accuracy. He was also able to prove that during the whole time
of his residence in the district certain of the geysers were only in
eruption when the wind blew from a particular quarter.

TV.—On an Accurate anp Raprp Meruop or Estimating THE SILICA
In AN Iengous Rock. By J. H. Prayer, F.G.S8., F.C.S.

HIS paper describes a method of estimating the silica in igneous
rocks by

1. Fusing the finely ground rock with a flux prepared by mixing
carbonates of potash and soda and nitrate of potash.

2. Disintegrating the glass so obtained by the action of strong nitric
acid.

3. Driving off nitric acid at a temperature just below 250°, thus
rendering all silica insoluble.

4, Treating with hydrochloric acid, to leave the silica with some
impurity, for weighing after calcination.

5. Separating the impurity by means of ammonium fluoride and
weighing it.

RAV Taw Ss.
elise
OBSERVATIONS SUR LES GROUPES SHDIMENTAIRES LES PLUS ANCIENS DU
NORD-OUEST DE LA France. Par M. Héperr. (Extrait des Comptes
rendus des Séances de ]’Académie des Sciences, tom. cili., Seance
du 26 Juillet, 1886.)
N this memoir, Professor Hébert submits to the Academy a view of
the Geology of North-Western France which differs in some points
from previous interpretations. Brittany and Western Normandy present
difficulties such as have perplexed British geologists in many of the
tracts occupied by the older rocks. French writers are agreed that in
North-Western France there are (omitting the true crystalline schists)
(1) a granite, (2) a great formation of phyllite, and (38) a series of
purple conglomerates and (?) shales (schistes). The last-named group
is overlain by the Grés Armoricain, and over this sandstone come shales
and slates, with Acidaspis Buchu, and more than one species of Placo-
paria. These Placoparia beds, with the same Acidaspis, occur in our
Salopian area, not far ahove the grits of the Stiper Stones; so that the
Gres Armoricain may be safely regarded as Arenig. But below this
horizon, the interpreters of Brittany geology find the materials for
widely diverging opinions. The theory of M. Hébert may be thus
~ summarized.

The oldest of the three rock-masses is the granite. It furnishes
numerous rolled blocks to a conglomerate in the phyllite series, and it
never penetrates the adjoining strata in veins. At its junction with the
phyllite, the granite is in the state of sand, and the phyllite also is

Reports and Proceedings—Geological Society of London. 41

decomposed. The stratified rocks of the district are indeed penetrated
by veins; but these consist of ‘‘granulite’”’ (not granite), and they
ramify through both granite and sedimentaries alike; in the former
they are called pegmatite, in the latter granulite proper. They
behave like true eruptive rocks, and are welded to the walls of the
adjacent phyllite, which they harden and modify at the contact.

The phyllite is next in age, but is older than the purple series. M.
Hébert submits twofold evidence for this contention. (1) The purple
series includes beds of rounded fragments of a quartz which is iden-
tical with certain quartz-veins inthe phyllite. One of these varieties,
a black quartz, is at Coutances quarried in the phyllite, and is found
not far off in the conglomerate of the purple group. (2) While the
phyllite usually dips at high angles, or is tilted to the vertical, the
purple series lies at much lower dips, and these relations are some-
times seen where the two groups are in contact. M. Hébert concludes
that the phyllites are Archean; but he would confine the term to this
formation, which he regards as the oldest sedimentary group, ‘le
premier terrain.”’ The granite and the crystalline schists are thus left
unclassified. The phyllite is regarded by M. Hébert as the equiva-
lent of the less crystalline of the Pre-Cambrian rocks of Anglesey, and
of the beds which, according to Prof. Green, underlie the Cambrian
conglomerates of Llanberis.

The purple conglomerates and (?) shales, separated by a marked
discordance from the phyllite series, are placed in the Cambrian.

It would be rash for a stranger to the district to express an opinion
on a question of such evident difficulty as the one before us. M. Ch.
Barrois, writing only last year (1885), is at variance with M. Hébert
on the main points discussed, and he will doubtless take up the
cudgels which he can wield so well. The issue, whatever it be,
should have an important bearing on the geology of the Channel
Islands, recently brought to our notice by the Rev. Edwin Hill, and it
may tend to smoothe, or the reverse, the troubled waters of the
Archean controversy.

It would aid our future studies in this direction if a precise meaning
were attached to certain terms used in M. Hébert’s paper, especially
to the words ‘‘ phyllites” (les phyllades), ‘‘ schist,” and ‘‘ grauwacke.”’

Cu. CaLLaway.

REPORTS AND PROCHHDIN GS.
——_@——_
I.—November 17, 1886.—Prof. J. W. Judd, F.R.S., President,
in the Chair.—The following communications were read :—
1. A letter from the Lieutenant-Governor of the Falkland Islands,
communicated by H.M. Secretary of State for the Colonies :—

‘** Government House, Stanley, Falkland Islands,
3rd June, 1886.

‘My Lorp,—I regret to have to report that a slip of the peat-
bog at the back of the town of Stanley, similar to that which
occurred in November, 1878,! but about two hundred yards to the

' See Quart. Journ. Geol. Soc. vol. xxxv. Proce. p. 96.

42 _ Reports and Proceedings—

westward of the scene of that accident, took place last night. A
stream of half-liquid peat, over a hundred yards in width, and 4 or
D feet deep, flowed suddenly through the town into the harbour,
blocking up the streets, wrecking one or two houses in its path, and
surrounding others so as completely to imprison the inhabitants.
Fortunately, as the night was wet and stormy, almost every one was
within doors, and the few who were in the wrecked houses escaped
in time. One child was, unfortunately, smothered in the peat, whose
body has been recovered, but no other casualties are known to have
occurred. An old man is, however, reported to be missing this
morning, and it is feared he may also have perished, as part of
his house is almost filled with peat..... The slip was caused,
apparently, by the unusually heavy rains which have fallen during
the last few days, and which the drains constructed by Mr. Bailey,
the Surveyor, in 1878, proved insufficient to carry off. Deeper and
wider cuttings will now be made, and I trust that the recurrence of
any similar catastrophe may thus be prevented. ‘The town of
Stanley is, however, from its situation and the mass of peat-bog on
the high ground behind it, always to some extent exposed to danger
of this nature in times of unusually heavy rainfall.—I have, etc.
« (Signed) ArtTHurR Bark Ly.

“The Right Hon. Harl Granville, K.G.. &e., &c., &e.”

2. “On the Drifts of the Vale of Clwyd, and their relation to the
Caves and Cave-deposits.” By Prof. T. M‘Kenny Hughes, M.A.,
F.G.S.

The author divided his subject as follows:—I. Introductory
Remarks; II. The Drifts, viz. (i.) The Arenig Drift, (ii.) The St.-
Asaph Drift, (iii.) The Surface-Drifts ; III. The Caves, viz. (i.) The
Caves themselves, (ii.) The Cave-Deposits; IV. Conclusion.

He exhibited a table showing the tentative classification he pro-
posed. II. (i.) The Arenig Drift, he said, might be called the
Western Drift, as all the material of which it was composed came
from the mountains of Wales; or the Great Ice-Drifi, as it was the
only Drift in the vale which contained evidence of direct ice-action.
He traced its course from the Arenig and Snowdon ranges, by striz
on the solid rock and by the included fragments, a large proportion
of which were glaciated. There are no shells in this drift.

II. (ii.) The St.-Asaph Drift might, he said, be called the Northern
Drifi, as it was the deposit in which fragments of north-country
rocks first appeared; or the Marine Drift, as it was, excepting the
recent deposits at the mouth of the estuary, the only drift in the
vale which showed by its character and contents that it was a sea-
deposit. It contained north-country granites, flints, and sea-shells,
of which he gave lists. Most of them are common on the adjoining
coast at the present day, a few are more northern forms. None of
the rocks are striated, except those derived from the Arenig Drift (i.).

II. (ii.) The Surface-Drifts included the older and newer alluvia
of the rivers, the Morfa Rhuddlau Beds or estuarine silt, the recent
shore-deposits or Rhyl Beds, and all the various kinds of deposits
known as talus, trail, rain-wash, head, run-of-the-hill, etc., of which,

Geological Society of London. 43

in so long a time, very thick masses have accumulated in many
places. He explained some methods of distinguishing gravels
according to their origin.

Turning to the subject of Caves, he thought they should be care-
ful not to confound (III. i.) the question of the age and origin of the
caves themselves with (III. ii.) that of the deposits in the caves.
He then described some of the more important caves of the district,
explaining the evidence upon which he founded the opinion that
the deposits in Pontnewydd Cave were postglacial paleeolithic. He
arrived at the same conclusion with regard to the deposits in the
Ffynnon Beuno Caves. Combating the objections to this view which
had recently been urged, he pointed out that the drifts associated
with the deposits in those caves cannot have ben formed before the
submergence described under II. (ii), because they contained north-
country fragments and flints, and that, even if they were of the age
of the submergence, they would not be preglacial; that they cannot
have been formed during the submergence, as the sea would have
washed away the bones, etc., from the mouth of the cave, and its
contents must have shown some evidence of having been sorted by
the sea. He considered that the greater part of the material that
blocked the upper entrance of the upper cave belonged to the
surface-drifts described under II. (iii.), and were, as they stood,
almost all subaerial.

He further pointed out that, so far as paleontologists had been
able to lay before them any chronological divisions founded on the
mammalia, the fauna of the Ffynnon Bueno Caves agreed with the
later rather than with the earlier Pleistocene groups.

II.—December 1, 1886.—Prof. J. W. Judd, F.R.S., President, in
the Chair.—The following communications were read :—

1. “On a new Genus of Madreporaria — Glyphastrea, with re-
marks on the Glyphastrea Forbesi, Edw. & H., sp., from the Tertiaries
of Maryland, U.S.’ By Prof. P. Martin Duncan, M.B., F.R.S.,
F.G.S8., etc.

The specimens of Septastrea Forbesi, Edw. & H., were examined
many years ago, and the author had always a doubt about their generic
position. Lately a very well-preserved specimen has been received,
which when compared with those in the National Collection and care-
fully studied, is found to have a columella and a remarkable dome of
endotheca at the top of the base of the calicular fossa, resembling the
well-known structure in Clistophyllum.

Two opposite primary septa become very narrow, extend inwards,
form, with another structure, a narrow linear columella, and thus
produce the appearance of a continuous lamella. The other primaries
and some of the secondary septa reach this long structure, and the
endotheca stretches between the ends of the septa, their sides, and the
columella, and closes up the interseptal loculi. The epithecal dis-
sepiments are dome-shaped at the base of the calice, and are ornamented
with sparsely distributed granules: superficially a corresponding
granulation occurs on the narrow and also on the wide marginal parts
of the septa.

44 Reports and Proceedings—

There is a groove between the calices, and it corresponds with the
imperfect junction of the corallite walls. Fissiparity occurs and also
gemmation.

Natural sections show a narrow ribbon-shaped columella.

The examination of the perfect specimens proves that whilst they
cannot be understood without sections, sections alone would never
enable the paleontologist to realize the elaborate superficial structures.
It was pointed out that weathering utterly destroyed the generic and
specific characters, and the author ventured to caution the students of
the Madreporaria against describing weathered and worn specimens of
any types, and not to depend entirely upon sections.

The new genus Glyphastrea includes Astreide of the Goniastreeoid
alliance with fissiparity, gemmation and a ribbon-shaped columella.
Septastrea Forbesi becomes Glyphastrea Forbesi, Kdw. & H., sp.

2. ‘*On the Metamorphie Rocks of the Malvern Hills.” Part I.
By Frank Rutley, Esq., F.G.S., Lecturer on Mineralogy in the Royal
School of Mines.

Part I. is the result of conclusions arrived at in the field. Part II.
will be devoted to a microscopic description of the rocks.

The author referred especially to the paper by the late Dr. Holl,
whose work he, in the main, confirmed. Dr. Holl’s object was to
demonstrate that the rocks which had hitherto been treated as syenite,
and supposed to form the axis of the hills, were in reality of metamorphic
origin, and belonged to the Pre-Cambrian. Mr. Rutley restricted his
observations to the old ridge of gneissic syenite, granite, etc., which
constitutes the main portion of the range, and reversing the order of his
predecessor, commenced at the north end of the chain.

He considers that the beds of crystalline rock, mostly of a gneissic
character, in the old ridge have been disposed in a synclinal flexure,
which stretched from the north end of the chain to the middle of
Swinyard’s Hill, where they receive an anticlinal flexure, and are
faulted out of sight. The length of this synclinal fold would be over
53 miles. The lithological evidence is in favour of the rocks forming:
the north part of Swinyard’s Hill being a repetition of those on the
Worcestershire Beacon. We might expect to find the older beds
having the coarsest granulation, and being even devoid of foliation, and
this is what occurs on the Malverns, where the northern hills are made
up of the coarsest rocks, with finer schistose beds towards the south ;
the exception is at Swinyard’s Hill; hence there are two groups of
coarsely crystalline rocks at either extremity of the presumed synclinal.
The contrast between these and the fine-grained rocks of the other
portions of the range has already attracted attention. The most
northern of the coarse-grained masses is cut off towards the south by a
fault near the Wych, while the other lies between a fault on the north
side of the Herefordshire Beacon and the before-mentioned fault on
Swinyard’s Hill.

The metamorphic rocks of the Malverns seem, therefore, to be
divisible into three series extending from the North Hill to Key’s End.
A Lower, of coarsely crystalline gneissic rocks, granite, syenite, etc., a
Middle, of gneissic, granitic and syenitic rocks of medium and fine
texture, and an Upper, of mica-schist, finely crystalline gneiss, ete. A
diagrammatic section shows the distribution of these ; the northern

Geological Society of London. 45

block, extending as far as the Wych, consists of the Lower and the
lower part of the Middle; the central block, from the Wych to the
fault in Swinyard’s Hill, consists chiefly of the Lower and upper
Middle, but with a portion of the Lower at the south end. The
southern block, south of the fault on Swinyard’s Hill, consists wholly
of the Upper series.

How far the foliation of these rocks and their main divisional planes
represent original stratification must, the author thought, remain an
open question. It has been held that the strike of foliation les parallel
to the axes of elevation ; but this is far from being the case in the
Malverns. Still, a once uniform strike may have been dislocated by
repeated faulting.

The author further discussed the general question of how far
foliation may or may not coincide with planes of sedimentation. He
admitted that the absolute conversion of one rock into another by a
process of shearing has been shown to occur, but doubted its appli-
cation in this case. Although he is inclined to believe that the
divisional planes, with which the foliation appears to be parallel, may
be planes of original stratification, yet, as a matter of fact, they are
nothing more than structural planes of some sort, between which the
rocks exhibit divers lithological characters.

3. “On Fossil Chilostomatous Bryozoa from New Zealand.” By
Arthur W. Waters, Esq., F.G.S.

The fossil Bryozoa described in the present paper are from the
localities of Petane, Waipukurau, Wanganui, and some simply desig-
nated as from the neighbourhood of Napier. The first three represent
deposits of a well-known position, which was considered Miocene by
Tenison- Woods, but which Professor Hutton (Quart. Journ. Geol. Soc.
vol. xli.) has more recently called Pliocene. Some others, sent over
as from ‘‘ Whakati,” are thought to be from Waikato.

The genus Membranipora, which is largely represented from near
Napier, is not one of the most useful paleontologically, because the
shape of the opesial opening only, and not the oral, is preserved, and
also the appearance of the zocecia is often remarkably modified by the
ovicells, which, however, are frequently wanting, and in many well-
known species have never been found.

The author pointed out that in the commoner and best-known species
of Bryozoa the amount of variation is recognized as being very great,
and considered that in the face of this there is too great a tendency to
make new species on slight differences which may be local variations,
and that even in some cases, instead of the description referring to a
species, it may be that only a specimen has been described.

A list of New-Zealand Bryozoa has been drawn up by Professor
Hutton, and our knowledge of the New-Zealand and Australian
Bryozoa is being constantly increased by MacGillivray, Hincks, and
others ; nevertheless, enough is not yet known to fix the exact age by
means of the Bryozoa alone, but the large number of species entirely
identical with those living in the neighbouring seas, and the general
character of the others, show that the deposits must certainly be con-
sidered as of comparatively recent date.

Out of the 78 species or varieties, 61 are known living, 29 of these

46 Correspondence—Mr. H. Woods.

from New-Zealand seas, 48 from either New-Zealand or Australian
waters, and 28 have been found fossil in Australia. Judging from
these alone, it would seem that some authors have assigned too remote
an age to the deposits. The new forms described were :—

Membranipora occultata Porina grandipora.
Monoporella capensis, var. dentata. Lepralia semiluna, var. simplex.
waipukurensis. bistata
Micropora variperforata. Schizoporella cinctipora, var. personata.
Mucronclla tricuspis, var. waipukurensis. tuberosa, var. angustata.
> var. minima. Cellepora decepta.
—— _——— _jirmata. » Sp.

CORRES PON DEHINCEH
——— — ———
ON THE OCCURRENCE OF PHOSPHATIC NODULES IN THE LOWER
GREENSAND, EAST OF SANDOWN.

Srr,—When working near Sandown, in company with Mr. H.
Keeping, we observed several beds of phosphatic nodules in the Lower
Greensand ; these do not appear to have been previously noticed, no
mention being made of them in the Survey or other memoirs on the
district. Mr. Bristow describes some ‘‘ concretionary masses or bodies”’
which occur in Fitton’s bed No. xvi. at Rocken End, near Black
Gang: these may represent some of the nodule beds at Sandown.

The phosphates are of a light brown colour, and occur at four horizons.
The three lowermost are very distinct, and come between 160 and 200
feet from the top of the Lower Greensand, whilst the fourth is some
distance higher up. The second band from the bottom is about seven
inches in thickness, and from it the following fossils were obtained :—
Ammonites biplex, Sow. A. cordatus, Sow. Plewrotomaria sp. COardium
striatulum? Lucina sp. Myacites sp. Cytherea rugosa? Arca con-
tracta, Phill. They are all much rounded, and difficult to determine.
In this bed there are also fragments of various rocks, such as quartzite,
lydian stone, etc., the first of which greatly resembles those in the
Budleigh Salterton pebble bed. The nodules in the upper band are
much smaller, and are associated with a great many quartz pebbles.

The phosphates and fossils of the lower beds are very similar to
those of Brickhill and Potton in Bedfordshire, Wicken in Cambridge-
shire, and Tealby in Lincolnshire. The second bed noticed above is
sufficiently thick to be worked for commercial purposes, but the strata
dip at such a high angle, that but little of the phosphates could be
profitably obtained.

The Geological Survey is now engaged in the district, and the exact
horizons at which the nodules occur will no doubt be given in their
sections. H. Woops.

Woopwarpian Musrum, CAMBRIDGE.

THE PEA GRIT OF LECKHAMPTON HILL.

Srr,—The letter of my friend, Mr. HE. Wethered, in the last num-
ber of the Magazine, requires some notice from me. Mr. Wethered
takes exception to a remark in my paper on the basement-beds of
the Inferior Oolite, that the beds between the Pea Grit proper and the

Correspondence—Ur. Edwin Witchell. 47

Cephalopoda-bed have been included by the late Dr. Wright and
others in their published works in the term “Pea Grit,” and he
refers me to the paper by Dr. Wright on the so-called sands of the
Inferior Oolite” as showing that I am in error. I have referred to
the paper cited, and find that in the section (Fig. 1) only one bed is
shown as including the Pea Grit and the underlying beds, although
in the explanation at foot it is called “Pea Grit and ferruginous
oolite,” and marked A B C; but the description in the following
page is headed ‘ Pea Grit (Inferior Oolite),” and under this heading
the beds A B and C are described: the description of A and B
appears, however, to be substantially the same.

In Dr. Wright’s latest work “ Monograph on the Lias Ammonites”
the section of Leckhampton Hill is repeated (fig. 11, page 151); and
on reference to the description (p. 152), I find the heading is
«Pea Grit (Zone of Harpoceras Murchisonie, Inferior Oolite),” the
subdivision being the same as before, and the description being
wholly under this heading.

I think the meaning is clear, namely, that it was intended that the
term “Pea Grit” should apply to all the beds, although, for the
purpose of giving a more accurate description, a subdivision of them
was convenient.

Mr. Wethered refers me to Dr. Wright’s section of Cleeve Hill,
but the extract is incorrectly given, doubtless an error in printing.

For—
Rea Grity 2. ee MMe osetia: cane, elites OIDs
Coarse ferruginous oolite SRA Ee AA re Ma PR hepa HLT ft) TA,
Read—
Tests Gath, IN@3 PW") gus cee, GkE) Seen Caen ee: mcllrans) » Oa,
Coarse ferruginous oolite ... ... Sool tedo ti, | @ ting

The correct reading confirms my statement, except as regards the
lower 5ft.

The section of Cleeve Hill is also repeated in the monograph on
the Lias Ammonites (fig. 12, p. 155), and in the description (p. 161)
the beds are called ‘Pea Grit,” and the three subdivisions are
described in much the same language as is used in the description
of the beds at Leckhampton. Epwin WItTcHELL.

CORRECTION OF MIOCENE INSECTIVORA.

Sir, —With your permission I will avail myself of the GronogtcaL
MaGazine to correct an error into which I have been led by the
writings of others in part i. of the “Catalogue of Fossil Mammalia
in the British Museum” (1875).

On page 19 of that volume I followed Dr. O. Fraas’ in identifying
the Auvergne Plesiosorex soricinoides (Hrikaceus soricinoides, of
Blainville) with Parasoreax socialis, Meyer, of Stemheim. Having
recently, however, had cause to consider further the affinities of the
Miocene Insectivora, I have been led from an examination of the
figures given by Fraas and De Blainville to the conclusion that
the identifications made by the former writer are totally erroneous.
The Steinheim Parasorex socialis is, as Fraas states, closely allied to

1 « Fauna von Steinheim,” p. 4 (1870).

48 Correspondence—Messrs. Lydekker, Keeping, and Dalton.

Tupara, while Plesiosorex soricinoides is a totally different form,
whose affinities, as stated by Pomel, are rather with Myogale. I am
further led to conciude that Fraas’ identification of Hrikaceus
arvernensis of De Blainville, with Plesiosorex soricinoides is likewise
erroneous, and that the fauna is probably identical with E. arvernensis
of Gervais."

The specimen entered in the Museum Catalogue under the name
Plesiosorex must therefore be named Parasorex, and the former genus
referred to the Talpide. This error will be noticed in the supple-
ment to be published in part v. of the Museum Catalogue; but as the
publication of that part will be several months hence, I have thought
it advisable to correet the error as soon as possible.

HaRrPENDEN, Dec. 10, 1886. R. LyDEKKER.

ON THE OSBORNE BEDS.

Srr,—I wish to correct a mis-statement of my views respecting the
position of the Osborne Beds, which appears in the Report of the
International Geological Congress for 1885, and also I find is repro-
duced in Mr. Jukes-Browne’s new Handbook of Historical Geology.
My opinion has always been that the Osborne Beds should have
been a part of the Bembridge Series, and not a separate member.

Woodwardian Museum, H. Keerpine.

Cambridge.
THE COLLINGHAM OR SCARLE BORING.

Str,—In the recently issued Report of the British Association for
1885, pp. 3888, 389, the original inaccurate account of this boring
is reproduced, and I am credited with the alternative figures given
in a second column.

Permit me to state that I have published no account of the boring,
and that the figures alleged to be mine do not coincide with the
section preserved among my papers, viz. :—

Gravel cca een een, a's. « Sache Gide! tues Bleek 21 feet.
Lias BSG) fab6) 2606. |) G66 le mene amr amiss 2 29
TRIES Oso oag cost, » cba LRaRELMA ER Rae eel ay 15
Keuper Marleen) s.5 coc fact Ee Ace OSS
‘KeuperjSandstonemegrers...- son -:e, ae eros
Bunter ‘‘Pebbie Beds” ... 2... 1... 0. 2. 819
Lower Bunter PEN deces yssicl) Geek ages) Mec EES
wanes Miarls Ssh eemieciirccey cscs beaks Nec Ut TEE Ey saat:
ate Tei stone) Lek. upeen tee) Ces s.). slab te. Dieta diene 433
3802 Marks, 325: ys teeeeauiie-s. eve’, teat ee gelesen ROO)

2) NAG HESTON: Meteaenecwmmceryy <a’: (ick stpuaee aoa Muses 68%
Lower ( Sandetone SEMEL MIRAI cies isi! ecto! wee Laer 20
Permian <MarlSlatesijesssaeeanceeniis. «sce areec) Siece me cen ammmLOLtS

139 VN Breccia eae eeu... Lk Ae a 1
Coal MeasureyShalesmamecme.- .cns0 seceareee aes 12
2032
The site is not in the parish of Scarle/Lincolnshire, but in Colling-
ham, Notts. W. H. Datron, F.G.S.,

Late H.M. Geological Survey.
1 See ‘Cat. Foss. Mamm. Brit. Mus,”’ pt. i. pp. 17, 18. .

Geol. Mag. 1887. Decade III Vol. IV. PLII.
a

tl

West, Newman & CSamp.

G.M.Weodward del. et hth.
British® Palaeozoic Cockroaches.

x

THE

GEOLOGICAL MAGAZINE.

NEVE SERIES!) "DECADE IN: WOE? IV;
No. I.—FEBRUARY, 1887.

ORIGINAL ARTICIES.

—= >

I.—Some New Baitisa Carsonirerous CockroacHEs.
By Henry Woopwarp, LL.D., F.R.S., F.G.S.

(PLATE IL.)

aes early appearance in geological time of terrestrial Arthropods

has always been to mea subject of deep interest, and I have
been fortunate in noticing several of these in the pages of this
Macaztne and elsewhere.?

The oldest insect at present recorded is the impression of an
Orthopterous wing referred to the family Buarripm, obtained
from the Silurian sandstone of Jurques, Calvados, France, about
the horizon of the May Hill Sandstone (Middle Silurian). M.
Charles Brongniart, its discoverer, observes that what is especially
remarkable about this fossil, and which distinguishes it from all
other Cockroach-wings, living or fossil, is the length of the anal
vein, and the narrowness of the axillary area.

This primitive insect has been named by him Palgoblattina
Douvillei?

The occurrence of Cockroaches in the Coal-measures of Germany
(Wettin) was announced by Germar as early as in 1842.°

The only example heretofore met with in England was obtained
by Mr. James W. Kirkby (and described by him in the Gror. Maa.
1867, Vol. IV. Pl. XVII. Figs. 6-8, pp. 888-390), from the Coal-
measures, opposite Claxheugh, near Sunderland ; but little attention
seems to have been given to its discovery.‘

By far the most important Memoir on Paleozoic Cockroaches
which has yet appeared is that by Mr. Samuel H. Scudder, of

1 See on Hophrynus (Cur culioides) Prestvict, Buckl. sp., Geou. Mac. 1871, Vol.
VIII. Pl. XI. pp. 385-388.

On Architarbus subovalis, H. Woodw. op. cit. 1872, Vol. IX. Pl. IX. p. 384.

On Brachypyge carbonis, H. Woodw. op. cit. 1878, Dec. II. Vol. V. Pl. XI. p. 434.
[I described this form as a Crustacean ; but it has since been suggested to me by itr Ss.
H. Scudder that it was more probably the abdomen of an Arachnide nearly related
to Lophrynus.—H. W.]

On Lithomantis carbonarius, H. Woodw. Quart. Journ. Geol. Soc. Lond. 1876,
vol. xxxii. pl. ix. pp. 60-64.

On Eoscorpus carbonarius, H. Woodw., op. cit. 1876, ue Vill. pp. 57-59.

On “ Spined Myriapods,”’ Guot. Mac. 188%@ No. I. p. 1. Plo 1:

2 “Comptes Rendus,”’ Acad. des Sciences, Paris, No. 29, Decr. 26, 1884.

3 See Munster’s Beitriige zur Petrefactenkunde, Stuttgart,

4 Mr. S. H. Scudder has since named it Etoblactina “mantidioides, Mem. Boston
Soc. Nat. Hist. 1879, vol. iii. pt. i. No. 3, pp. 72-73 (woodcut).

DECADE III.—VOL. IV.—NO. II. 4

50 Dr. H. Woodward—British Carboniferous Cockroaches.

Boston, who has not only described all the species that have come to
his hands from the Coal-measures of N. America, but many European
ones also, and has given us “a complete revision of the species of
both worlds” (see Mem. Boston Soc. Nat. Hist. Boston, 1879, 4to.
vol. iii. pp. 23-184, and plates 2-6).

According to a still later summary on ‘‘The Cockroach of the Past”
(published as an appendix to “‘The Structure and Life-History of the
Cockroach (Periplaneta orientalis),” by Prof. L. C. Miall and Alfred
Denny, London, 1886, 8vo.), Mr. Scudder gives the number of
Carboniferous Palgoblattaria at 70 species.

Fies, 1 and 2.—Progonoblattina (Blatta) helvetica, Heer (Swiss Cockroach), from
the Coal-measures of Erbignon.
1. Wing, of the natural size. 2. The animal restored.
Reproduced from Prof. O. Heer’s Primeval World of Switzerland, London,
1876 (translated by W. 8. Dallas, F.L.S.), 2 vols. 8vo. p. 20, fig. 16¢.

It must, however, be borne in mind that our knowledge of this
ancient type of Orthopterous Insect is derived almost entirely from
its wings ; and upon the well-marked variations which the principal
veins present in their arrangement (see Fig. 3),

Scudder, who adopts the terminology proposed by Prof. Oswald
Heer, of Zurich, writes :—‘‘ These principal veins are six, counting
the marginal vein, which here merely thickens the anterior border,
as one; and starting from the anterior margin, they are the marginal,
mediastinal, scapular, externo-median, interno-median, and anal. ‘The
general disposition of these veins is as follows :—The ‘ mediastinal’
and ‘scapular’ veins, with their branches, which are superior (7.é.
part from the main vein on the upper or anterior side), terminate

Dr. H. Woodward—British Carboniferous Cockroaches. 51

upon the anterior margin. The ‘interno-median’ and ‘anal’ take
the opposite course, and their branches are inferior, or, at least,
directed towards the inner margin; while the ‘externo-median,’
which is interposed between these two sets, terminates at the tip of
the wing, and branches indifferently on either side.”

Anterior Posterior
or or
superior inferior
margin. margin.

pa40 7oUNsnipayyy

Fie. 3.—Schematic view of left wing of Paleeozoic Cockroach, showing the veins”
and areas (after Scudder).

“‘ Now these veins are all present in both front and hind wings of
Paleozoic Cockroaches, and also in the hind wings of existing species ;
but in the front wings or tegmina of the latter, the number is never
complete, the externo-median vein being always amalgamated either
with the scapular, or with the interno-median, and the mediastinal
frequently blended with the scapular vein” (Scudder).

The following is a list of the genera and species of Buartipa from
the Carboniferous formation hitherto described, arranged under the
families and genera suggested by Scudder.

PALHOBLATTARIZA.
Mylacride—

Mylacris bretonense, Scudder, Coal-measures, Sydney, Cape Breton.
i Heerii, Scudder, 3

39 ?

a pennsylvanicum, Scudder ,, Cannelton, Penn. U.S.
a5 Mansfieldi, Scudder op 39 »

‘3 anthracophilum, Scudder ,, Colchester, Illinois, U.S.
3 antiquum, Scudder ba Port Griffith, Pittston,

55 lucifugum, Scudder 7% 55 50

5 carbonum, Scudder A Cannelton, Penn. U.S,
p ovale, Scudder 35 39 3

os priscovolans, Scudder ap ” ”

52 Dr. H. Woodward—British Carboniferous Cockroaches.

Promylacris ovale, Scudder, Coal-measures, Mazon Creek, Illinois, U.S.
30 rotundum, Scudder an

or) 9?

Paromylacris rotundum, Seudder ,, 25 ”
Lithomylacris pauperatum, Scud. ,, Pittston, Penn. U.S.

an pittstonianum, Scudder ,, » »

”
29

angustum, Scudder
simplex, Scudder

Necymylacris heros, Scudder

2?

lacoanum, Scudder

BLATTINARIA.
Htoblattina mantidioides, Gold.

be)
99

didyma, Rost
manebachensis, Gold.
primeva, Scudder
labachensis, Scudder
insignis, Gold.
euglyptica, Germ.

Danville, Tilinois.
Cannelton, Penn. U.S.
Pittston, Luzerne Co. Penn..

Durham, England.
Manebach.

Auerswald, Saarbruck.
Lebach 55

Weittin, Saxony. if

An affinis, Gold. a Lobejin.

» flabellata, Germ. 5 Wettin, Saxony.

35) anthracophila, Germ. 9 45 nn

ap Dohrnii, Scudder Ae ne ie

se anaglyptica, Germ. its % A

si carbonaria, Germ. 9% is x

iy russoma, Gold., a Lobejuin.

5 leptophlebica, Gold. a 3

» parvula, Gold. 9 90

aA spectabilis, Gold. A, an

9 lanceolata, Sterzel af Lugau.

50 venusta, Lesq. se Arkansas.

a5 Mazona, Scudder os Mazon Creek, Illinois.

Lesquereuxvi, Scudder __,, Appalachian.

Archimylaeri is par allelum, Scudder ,, Pennsylvania.

#3 acadicum, Scudder ie Picton, Nova Scotia.

30 paucinerve
Anthracoblattina wintertana, Gold. ,, Saarbriick.

a Remigii, Dohrn. 5 Cusel, Rhenish Bavaria.

5 spectabilis, Gold. a Wettin, Saxony.

dresdensis, Gein. a Klein-Opitz, near Dresden.

Ger ablattina Goldenber ‘git, Mahr. ,, Manebach.

ap clathrata, Heer 3 ss

56 Mahri, Gold. 99 59

he. weissiana, Gold. i Briicken, Rhenish Bavaria.

$5 intermedia, Gold. ay Wemmetsweiler.

99 Geinitzi, Gold. an Lobejiin.

a Miinsteri, Gold. es Wettin, Saxony.

a producta, Gold. 99 a 3

Bo Germari, Guth. 96 33 .

ae scaberata, Gold. as Attenwald.

aA latinervis He Saxe- Weimar, Ilmenau.

ss Jfascigera, Scudder An Pittston, Pennsylvania.

balteata, Scudder W. Virginia and Ohio.
Hermatoblattina wemmetsweilert iensis, Gold. Coal-measures, Saarbriick.

BG Tischbeini, Gold. A
Progonoblattina Fritschii, Heer * Manebach.

s Helvetica, Heer ” Valais, Swiss.
Oryctoblattina reticulata, Germar Y Wettin.

$5 occidua, Scudder a Mazon Creek, Illinois.
Petrablattina sepulta, Scudder i Sydney, Cape Breton.

He bretonense, Scudder ts # op

Anthracoblattina Scudderi, Gold. As Saarbruck,

Three of the specimens about to be described (namely, Pl. -Il..
Figs. 1, 2, 3), are in nodules from the Clay-ironstone band, between,

Dr. H. Woodward—British Carboniferous Cockroaches. 58

the “Brooch” and the “Thick-coal” at Coseley, near Dudley, and
form a part of the valuable collection made by the late Mr. Henry
Johnson, F.G.S., Mining Engineer, of Dudley, now preserved in the
British Museum of Natural History, Cromwell Road, London.

The remaining specimen (Plate II. Fig. 4a, b) was placed in my
hands some years since, by the kindness of Mr. James W. Kirkby,
who obtained it from the Upper Coal-measures, near Meithil, on the
Fifeshire coast.

Fig. 4.—Eioblattina Mazona, Scudder (14 times nat. size), Carboniferous, Illinois
(after Scudder).

Erosiartina Jounsont, sp. nov. (Pl. II. Figs. 1a, 10.)

With the exception of Blattina insignis of Goldenberg from the Coal
of Saarbriick. and Hioblattina Mazona, Scudder, from the Carboniferous
of Ilinois (Woodcut Fig. 4), this is one of the most perfect Cockroaches
yet discovered in the Coal. The specimen is exposed in a small
oval clay-ironstone nodule, so fortunately split open, as to show an
equally well-preserved impression and counterpart of the fossil. The
pronotum or prothorax is rounded in front, being 13 millimetres
broad and 8 mm. long, and is divided into two parts by a straight
line, clearly visible both on the impression and counterpart; the
central part of the shield has a slightly raised pyriform area, pointed
in front and broadly truncated behind; the surface is transversely
wrinkled and bears a pair of minute spots near the anterior point.
The hinder border of the shield is rounded and somewhat deeply
emarginated on the median line.

The mesothorax is 8mm. broad, but its length cannot be seen,
being covered by the wings.

The paired wings measure 25 mm. in breadth and 28mm. in
‘length (they were probably about 3mm. longer, but their edges are

04 Dr. H. Woodward—British Carboniferous Cockroaches.

lost on the border of the nodule). The metathorax and abdomen
are not visible, being covered by the closely-folded wings.

It has been a matter of no small difficulty to the artist accurately
to trace out the venation of the wings in this specimen. When a
single wing is preserved on the surface of a piece of shale, its veins
can usually be traced distinctly ; but when two pairs of superposed
wings have to be studied, they present, after compression, a some-
what complex problem to unravel. I believe, however, that the outline
(Pl. Il. Fig. 1, and 1a, nat. size) gives a fairly accurate representation
of the veins. The wing is oblong-ovate in form; the ‘mediastinal ”
vein commences at the proximal end of the wing, about 38 mm. within
the border, and runs almost parallel with the superior marginal vein,
but gradually bends towards, and unites with it, at 20 mm. from
its commencement. It gives off, at first, several single branches,
followed by five equidistant bifurcating ones; the ‘scapular’ vein
takes its origin at the proximal end, close to the ‘mediastinal’ vein,
and after pursuing a course nearly parallel to it, it terminates on the
anterior distal margin of the wing, 25 mm. from its commencement,
giving off five simple branch-veins from its superior border. The
‘externo-median’ vein takes its rise from the inferior side of the
‘scapular’ vein, about half-way in its course, and extending to the
extremity of the wing, it gives off one single superior and one bifur-
cated inferior branch.

The ‘ interno-median’ follows the course of the conjoined ‘externo-
median’ and ‘ scapular’ veins, arching towards the inferior or interno-
median margin of the wing, giving origin in its course to six inferior
branch-veins about equidistant from each other, the first (proximally)
being bifid, the second simple, the third, fourth and fifth bifurcated,
and the sixth simple. The anal area of the wing is strongly marked
by the arched anal vein which is branched, and is followed by about
five simple similarly arched veinlets, whose origin appears to be
along the inner proximal border of the wing.

The whole surface of the wings exhibits a very delicate tracery
produced by the slighly-elevated microscopic net-work of cross-veins,
which need the aid of a magnifying glass to reveal, and are not
attempted to be represented in our Plate.?

Several of the species of Hioblattina, figured by Scudder, present
a general resemblance in form and in the distribution of the veins to
our specimen; but they differ materially in the area which the
branches of each principal vein occupies. There is not one in which
the ‘scapular’ and ‘externo-median’ veins rise half-way down the
wing from a common main trunk. This is a character which has
been frequently observed in the veins of the front wings, or tegmina,
of existing species (Scudder). It would require, however, a far
larger series of specimens than we possess, and at least several
examples of each species (a consummation devoutly to be wished
for, but not the least likely to be fulfilled), before one could venture
to speak with any degree of confidence of species founded on such
fragmentary evidence as we at present possess.

1 Mr. Scudder’s artist has successfully reproduced this wonderful and complex lace-
structure in Ltoblattina venusta, Lesquereux (Scudder, op. cit. pl. 6, fig. 12, p. 70).

Dr. H. Woodward—British Carboniferous Cockroaches. 58

I have much pleasure in dedicating this species to the memory of
its discoverer, the late Mr. Henry Johnson, F.G.S., Mining Engineer
of Dudley, than whom I have never known a more earnest and
enthusiastic worker, a more assiduous collector, or one who more
willingly lent his specimens for scientific purposes to those who
requested their lean.

The specimen was obtained from an ironstone nodule from Coseley
near Dudley, and is now preserved as a part of the “ Johnson
Collection” in the British Museum (Natural History).

Posterior Anterior
or or
inferior superior
margin. margin.

Fie. 5.—Right wing of Mylacris anthracophilum, Scudder, x 2 nat, size,
Carboniferous, Illinois (after Scudder),

Litnomytacris Kirxeyi, sp. nov. Plate II. Fig. 4a, 6.

This specimen consists of a single detached left wing preserved on
the surface of a piece of thin purple shale from “Bed No. 83” in
the Upper Coal-measures near Meithil, on the coast of Fifeshire.
This shale-bed, which overlies the lower coal and thin limestone, con-
tains, with rootlets, rare specimens of species of Newropteris, Peco-
pteris, and Cyclopteris, along with an Anthracomya.}

Although the border of the wing is somewhat imperfect, sufficient
is preserved to show its general form, and the venation of the wing
stands out in distinct relief on its surface.

Outline of wing pointed-ovate, slightly flattened on its superior
border; length of wing 15 mm., breadth 8mm. The ‘mediastinal ’
vein occupies rather more than a fourth of the entire area of the
wing; it extends to about two-thirds of the length, where it unites
with the superior margin of the wing; it branches six times, one of
these branches has three forks. The ‘scapular’ vein extends nearly
to the extremity of the wing; it remains single for over one-fourth of
its length, and then branches into three veins, the middle one of

1For a full account of this area see a paper “ On the Upper Beds of the Fifeshire

Coal-measures,” by Edward W. Binney, F.R.S., and James W. Kirkby, Esq.
(Quart. Journ. Geol. Soc. Lond. 1832, vol. xxxviii. pp. 245-246, pl. vi.)

56 Dr. H. Woodward—British Carboniferous Cockroaches.

which is again forked. The ‘externo-median’ vein continues parallel
to the scapular vein, for a slightly longer distance before it
branches at the extremity of the wing into three inferior veins, two
of which are again forked. The interno-median vein occupies about
one-fourth the entire area of the wing; it gives off three almost
equidistant inferior branches, none of which appear to be forked.
The anal vein is nearly straight, and has three other almost parallel
oblique simple veins occupying the anal area.

The wings of the Mylacride have the veins spreading in a fan-
shape and appearing to arise in a single point, or near a single point,
close to the base of the wing. (See Woodcut Fig. 5, ante p. 55.)

On comparing our Hnglish specimen with Scudder’s figures on

plate v. of his memoir, already referred to, one is struck with the
general likeness they present; but the wings of Mylacris seem to be
all more complex in the forking of the secondary or branch-veins
than in our specimen, which agrees best with Scudder’s genus
Lithomylacris, and with such species as L. Pittstonianum (pl. v. figs.
4 and 10 op. cit.) or L. simplex (fig. 5, op. cit.); but our form is cer-
tainly distinct from any species figured by Scudder. I have great
pleasure in dedicating this the second English form of Blatta met with
‘by him, to its discoverer, Mr. James W. Kirkby, of Ashgrove, Leven,
Fife, N.B., who has contributed so largely by his researches to
increase the fauna and flora of the Carboniferous series of Great
Britain. ;

LEPTOBLATTINA EXILIS, gen. et sp. nov. PI. Il. Figs. 2 and 3,

The species about to be described is represented by two examples,
each of which is in a nearly perfect state as regards the greater
part of the insect, but neither specimen exhibits the legs (save
only a fragment of one). In both specimens there is a portion of
the head preserved (more being exposed in Fig. 3 than in Fig. 2).

The prothorax (or pronotal shield) is preserved entire in both, and
the meso- and metathorax, followed by ten abdominal segments more
or less distinctly to be made out, and having a pair of appendages
(cerci) attached to the 10th segment in both (but only drawn by the
artist in Fig. 3).

Two pairs of wings are seen in both specimens, springing from
the lateral borders of the meso- and metathorax, with their outlines
fairly exposed (especially: so in Fig. 2). The total length of the
original of Fig. 2 (which, like Fig. 3, is drawn twice natural size)
is 00 mm.

_ Head.—The head is very small and somewhat bluntly pyramidal
in form, and measures 2 mm. in breadth at its base, where it dis-
appears beneath the pronotum, and is 2 mm. in length. There is a
suture visible down the centre (in Fig. 3h), which divides the two
epicranial plates, at the sides of which the eyes would be seen; in
front of the epicranium a small projection no doubt represents the
clypeus with the labrum at its extremity. (This is only indistinctly
shown in Plate II., which was drawn and printed off, before the final
touches of the needle developed these additional points of interest.)

Dr. I. Woodward—British Carboniferous Cockroaches. d7

Thorax.—The prothorax, or pronotum, is circular in outline in
front, the sides being slightly compressed and the posterior border
rather incurved near the centre (in Fig. 3) ; but this incurving of the
posterior border is not seen in Fig. 2, so that it may be due to a
slight lateral compression of the pronotal shield in the former
specimen. In confirmation of this suggestion it may also be stated
that the one specimen (Fig. 2) displays - no median suture (or ridge)
on the shield, whilst the other (Fig. 3), which is incurved on its
posterior border, is also distinctly marked by a sharp ridge down its
centre. Both specimens display the same indentation around a
central pyriform slightly raised, area (similar to that observable on
the pronotum in Plate II. Fig. 1).

Length of the pronotum, wee mm.; breadth, 9 mm. The meso-
thorax is about 1 mm. broader hem the metathorax ; they are nearly
of equal length and closely resemble each other in form, being
broader in (Roan than behind, and indented upon the lateral margins,
to give attachment to the wings. Breadth of thesothenazs 6 mm.;
Jensth 34 mm.; breadth of retoras 5 mm.; length 35 mm.

The denen consists of ten somites; the ai is narrower than the
rest, and the second is the longest; the whole measure 16 mm. in
length, and about 3 mm. or a little more in breadth. There is
evidence in Fig. 2 (uncovered with the needle-point, since figuring)
of epimeral pieces to the 7th, 8th, and 9th segments on one side,
which, repeated on the other side, would add 2 mm. to the breadth
of the abdomen, making the total breadth 5 mm. The cerci are
3 mm. in length, the articuli cannot be seen; they are broader in
the centre, curved and pointed at the extremities.

Wings.—The wings are remarkably short in proportion to the
total length of the body, and the anterior ones are strongly arched
along the superior margin. The upper wings measure 11 mm. in
length, es the lower or under wings 10 mm. Breadth of upper
wings 5 mm., and of lower wings 4 mm.

Owing to some slight difference in the lithological character of the
clay-ironstone composing these nodules, rendering them slightly
coarser in texture than that which enclosed Fig. 1,—or else, as is
more probable, the wings themselves were actually composed of
thicker chitine in which the more minute veins were less delicately
delineated ;—whatever the cause, it is certainly much more difficult
to decipher the venation of the wings in these specimens than in the
other examples figured above.

We see in the upper wings, or tegmina, of both Figures 2 and 3,
one very prominent vein, traversing the whole length of the wing,
almost parallel with the superior “margin ; this is evidently the
mediastinal vein. Only the very faintest traces of branches along
the superior border of this vein can be detected in Fig. 2, on the
right-hand wing. The anal vein can be made out pretty clearly in the
wings of both specimens (see Pl. II) Figs. 2 and 3), it extends down
to about one-third the length of the inferior border of the wing. The
separation of the intermediate area into interno-median, externo-
median and scapular, is most difficult to follow. The interno-median

08 — Dr. H. Woodward—British Carboniferous Cockroaches.

appears to occupy the largest area, and gives off very numerous.
branches which fork near the margin of the wing. The venation is.
most distinct upon the under wings, but these, although the most
interesting, cannot be seen so fully as the upper ones, being partly
covered by the latter.

Detached limb.—Near the extremity of the abdomen of Fig. 3
lie the detached tibia and tarsus of one of the limbs. It can be just
made out with its numerous distal segments.

There can, I think, be no doubt that these two specimens from the.
Dudley Coal-field, which, in the narrow elongated form of the
abdominal somites, present so remarkable a divergence from the
living Cockroaches, are very closely related to (though probably not
specifically identical with) Dr. F. Goldenberg’s Blattina insignis,
figured and described by him in his work, entitled ‘‘ Fauna Sarepon-
tana Fossilis”’ (4to. 1873, I. Heft, taf. ii. fig. 14, p. 17), from the
Coal-measures of the Skalley Shaft, Saarbriick.

Dr. Goldenberg’s Blattina insignis has the same general form of
the pronotum and wings, and is characterized by the same slender
abdominal somites, but it is very much smaller in size than our
English specimens ; and if reliance may be placed upon the sketch
of the venation of one of its wings (sent by Goldenberg to Seudder,
and reproduced by the latter author in his Memoir, 1879, op. cit.
pl. iv. fig. 9), the details of the wings do not agree; but this, like
the outline given of the wing itself, may very well be subject to
revision.

Mr. 8. H. Scudder has arranged all his American Blattine and
also all the old-world forms under new genera, and has placed Golden-
berg’s Blattina insignis with a note of interrogation under Htoblatiina.
This seems waste of energy merely to remove a species from one
genus to place it doubéfully in another. Now that its characters are
more fully revealed to us, it is apparent that its place is not in
Kioblattina, but in a distinct genus which might be appropriately
designated Leptoblattina, for the reason sufficiently apparent in the
foregoing remarks.

Leptoblattina exilis, like Etoblattina Johnsoni, was obtained by the.
late Mr. Henry Johnson, F.G.S., from the clay-ironstone of Coseley,
near Dudley, and the specimens are now, with the rest of the treasures
of the Johnson Collection, preserved in the British Museum of
Natural History, Cromwell Road, London, 8.W.

EXPLANATION OF PLATE II.

Fie. la. Etoblattina Johnsoni, H. Woodw., sp. nov. (nat. size). Clay-ironstone,

Coal-measures, Coseley, near Dudley (Johnson Coll.).

», 10d. The same, enlarged twice nat. size, to show venation of wings.

Bes \ Leptoblattina exilis, H. Woodw., gen. et sp. nov. (twice nat. size). Same.

Re tO: locality as Fig. 1 (Johnson Coll.). h, head; ¢, pronotum; ab. abdomen.

» 4a. Lithomylacris Kirkbyi, H. Wood., sp. nov. Bed 33, Upper Coal-measures,
Meithil, Fifeshire, from the collection of J. W. Kirkby, Esq.

», 4b, The same wing enlarged twice nat. size.

Rev. LE. Hill—Geoloyical Visit to Brittany. 59

Il.—In Brirrany with THE GroLoGcican Society oF FRANCE.

By the Rev. E. Hitz, M.A., F.G.S.,
Tutor of St. John’s College, Cambridge.

HE French Geological Society last year made Finistére the
object of their annual excursion, and by their kindness I had
the great pleasure of joining the party. As Brittany is so interest-
ing a region, already very accessible by railways, and soon to become
even more so, it has occurred to me that a brief account of the
excursion may be acceptable to our English geologists, and at any
rate afford them an index to some localities which will well repay
a visit.
It will be convenient to preface with a table of the strata,
according to the nomenclature and classification of Dr. Barrois.' He
arranges the beds of this region as follows:

CARBONIFEROUS.

Coal-measure Schists and Conglomerates.
Schists and Sandstones of Chateaulin.
Porphyrite Tufts.
Porphyry Conglomerates and Tufts.
DEVONIAN.
Nodular Schists of Porseuen.
Schists and Limestones of Néhou.
White Grit of Landevennec.
Schists and Quartzites of Plougastel.
Limestone of Rozan (with Strophomena Lootensis).

SILURIAN.
Nodular Schists (with Cardiola interrupta).
Ampelite Schists (with Graptolites).
White Sandstones.
Slaty Schists of Angers.
Armorican Grits (Grés a scolithes).
Red Conglomerates and Schists of La Chevre.

CAMBRIAN.

Schists and Conglomerates of Gourin.
Phyllades of Douarnenez (or of St. Lo).

PRIMITIVE.
Schists of Groix.
Mica-Schists of Audierne.
Granitic Gneisses of Pont-Scorff.

Dr. Barrois regards the Cambrian Schists of Gourin as correspond-
ing to Barrande’s Etage C; any identification of the beds below
must at present be conjectural.

Among the eruptive rocks the granite of Pontaven is Cambrian or
Pre-Cambrian ; the porphyroid granites of Rostrenen and Huelgoat
are of Carboniferous age; the granites with two species of mica
(granulites) of Quimper, Le Faouet, and Morlaix, are also Carbon-

1 See ‘‘ Apercu sur le constitution géologique de Finistére’’ in the June number of

“Te Guide Scientifique” (Paris, J. Michelet, 25, Quai des Grands Augustins ;
London, J. A. Berly, 3, Deronda Road, Herne Hill, 8.K.).

60 Rev. HL. Hill—Geological Visit to Brittany.

iferous and posterior to the last. The kersantons cut the (Carbon-
iferous) Chateaulin schists and are the latest of the eruptive rocks.

Quimper was our rendezvous. On the afternoon of Aug. 19, after
the first meeting, a stroll was taken along the promenade on the
left bank of the stream to look at outcrops of ‘ Petrosilex ’ seen there.
This is much crushed and a confident opinion on it is not easy to
form. Then walking out of the town to the west, we saw, first in
the town a conglomerate of Carboniferous age, then successively
along the high road a coarse white gneiss, a mica-schist well exposed
in a road cutting, finally a granite. These rocks are said to occur
in this alternate fashion over a vast tract of country. Returning, we
deviated a little to examine a diorite dyke.

Proceeding by rail to Chateaulin, we commenced the next day by
examining the schists of Chateaulin here worked for slates. They
closely resemble the slates (also of Carboniferous age) of Vernayaz
and Salvan (Switzerland). No fossils occur here; the position of
the rocks is established by a few impressions found in some limestone
beds towards the base of the series. At Port-Launay below Cha-
teaulin a steamer was waiting, placed at our disposal by the Port
Admiral of Brest, and embarking, we commenced our descent of the
river. After some hours of pleasant transport and pretty scenery, a
landing was made on the right bank near Terenez, where the quart-
zites of Plougastel are exposed, and where the grits of Landevennee
can be seen to succeed them conformably. We walked along the
strand for a mile or two, and found our boats waiting to re-embark
the party nearly opposite Landevennec.

The boats again transferred us from the steamer to the shore in
the Riviere de lHopital, at the spot on the right bank marked as
Moulin de Mer. ‘There is a tide mill here, whence the name, with
large and good machinery; a breakfast spread in a spacious loft
was very welcome. Hast of the mill and behind it is a fine quarry
of kersanton and porphyry. ‘The schists of Néhou are here cut by
a mass consisting of kersanton between two bands of porphyry, but
the relative age of these two igneous rocks can be determined better
by a section described below. From Moulin de Mer, walking west
through Logonna and seeing at an estuary the schists of Porsguen,
we collected the rare rock quartz-kersanton in a rocky beach at
Goulet-quer, and were again put on board the steamer. Kersanton,
so frequent in this district, was named after a shallow quarry in this
neighbourhood, now, however, disused and overgrown.

We were landed for the last time this day, about three miles to
the N.N.W., at a promontory near Porsguen, to see a most beautiful
section. It is in the sea-cliff on the east side of the promontory, and
shows the schists of Porsguen, porphyry (micro-granulite) overlying
them, and a dyke of kersanton breaking through both. The black
sedimentary rocks are little altered, but tremendously crushed by this
double intrusion, and show a rude cleavage set up across the old fissile
bedding. Time not allowing a purposed visit to the Isle Longue,
our steamer took us through the vast landlocked gulf that is called
Brest Roads (Rade de Brest) direct to the quay at Brest itself.

Rev. E. Hill—Geological Visit to Brittany. 61

On the following day the same steamer, again devoted to our
service, carried the party south across the Roads to a little pier at
Le Fret. Vehicles were ready, but as soon as they had taken us
across the embankment to the 8.E., we left them and walked along
the strand eastwards, to see the outcrops of the schists of Porsguen
and to collect Devonian fossils at a spot about 300 yards from the
road. Returning, we were driven through Crozon across the isthmus
to a very lovely bay, combining the broad beach of Sandown with
the tall cliffs of Ilfracombe, and possessing every qualification for
a watering place except accessibility. A good hotel is named from
the neighbouring village of Morgat; and this name is the one used
by geologists in referring to the cliff-section, the most complete
which we saw in the excursion. We commenced by walking to the
south, to see in succession the Schists with Graptolites (fossiliferous) ;
the slates of Angers; the Gres Armoricain or Gres a Scolithes
fossiliferous about 100 yards above the pier of the little fishing port ;
and (if time had permitted) the Red schists of Cap de la Chevre
which form the base of the Silurians here. The succession is clearer
on this side than on the north side of the bay. Returning and
passing along the upper edge of the cliffs, we traversed repetitions.
by several folds of the complete Silurian system with part of the
Devonian, as high as the quartzites of Plougastel, which here form
some of the most striking cliffs. After walking three or four miles,
and crossing by an embankment the estuary called Aber to Rosan,
we were shown at the neck of the peninsula that forms the Isle
d’Aber, a singular series of stratified diabase tuffs. They are placed
by Dr. Barrois between the uppermost Silurian and lowest Devonian
beds (Schistes a Nodules and Calcaire de Rozan). Proceeding along
the cliffs past Kerglintin and further east some two miles or more,
where the path passes along a cliff slope, we saw the Gres a Scolithes
succeeded by the Red schists, and these passing down into a
singular quartz conglomerate so veined with quartz that I was slow
in being convinced of its true nature. Then descending into the
little bay, we saw rocks of an entirely different aspect: the Phyllades
of Douarnenez belonging to the Cambrians; and the few active
geologists, who, after so long and rapid a walk on a broiling day, were
‘in at the death,’ threw themselves down on the sand and commenced
a lively discussion on the evidences of the succession, which my
knowledge of French was insufficient to follow. The carriages were
waiting for us as Tal-ar-groes, about three miles to the N.W., and
took us to our steamer, which brought us back to Brest.
We arrived at so late an hour that, had the rules of entry into a
fortified town been strictly carried out, we should have had to
dispense with supper and bed.

After a morning of rest, an afternoon of.railway back through
Chateaulin and Quimper took us to Quimperlé. Next day we
started early for a very interesting excursion. Crossing at first
gneiss with an intrusion of ‘granulite,, we drove west as far as
Pontaven. Here about one kilometre to the south, on the left bank
of the river, we examined in shallow quarries the granite of Pon-

62 Rev. L. Hill—Geological Visit to Brittany.

taven, supposed to be of Pre-Cambrian age. The granite is not
perfectly homogeneous, but has some faint appearance of structure
or incipient foliation, and I noticed a seam that to me resembled a
line of crush. Scattered masses tend to weather into oval boulders,
North of the village, a short distance on the right bank, we saw
granite closely followed by a much contorted rock ; a gneiss or mica-
schist in contact with the granite. This gneiss is regarded as rather
later than that of Quimperlé.

Returning as far as Riec, and then diverging south-east, we passed
rocks of varying nature, named as sometimes granitic gneiss, and
sometimes gneissic granite, till where a new road has been made
for a mile or two skirting the estuary of the Belon, a series of fine
sections are furnished. Any geologist interested in the question of
mica-schist and gneiss originating out of igneous rocks should especi-
ally study the sections in a cutting which succeeds an embankment
made for the road.

Thence we drove through Moelan and Clohars to the mouth of
the river Ellé, from Quimperlé, and descended to the sandy beach
at Port Clohars (gay with bathers, country people, the tourist is
unknown). Here the cliffs to the east afford fine exposure of a
succession of stratified rocks regarded as Pre-Cambrian in age.
Some are hornblende schists, fairly compact; some are extremely
coarse-grained rock, that seemed to me an arkose of a coarse gneiss,
and are by no means highly indurated: there are also some quart-
zite beds, and some chlorite schists, besides an intrusion or two.
These beds recur in similar order, so that there are probably repeti-
tions by faults; unfortunately I had not time to study this most
interesting section, and had to be satisfied with viewing it ina simple
traverse. We rejoined the carriages at St. Julien, and returned to
Quimperlé, obtaining good specimens of the Quimperlé gneiss
(gneiss of Pontscorff), after passing under the railway, at the entrance
to the town.

On Tuesday morning our procession of vehicles defiled from the
town to the north-east along the road to Le Faouet. Granite was
examined at Le Combout, but nothing remarkable was seen till
when, within two miles of Le Faouet, we left the carriages and passed
the very interesting church of St. Fiacre. Making our way east-
wards by footpaths we came out on another high road, near the mill
of Rochepierou, to view the (Cambrian) Phyllades of St. Lo, at or
near their junction with a granite (granulite) : the only sections are
small roadside outcrops. ‘Thence we walked to Le Faouet, which
was made a lively scene by the occurrence of a fair that day. Be-
tween this place and Gourin ‘ granulite’ is passed at Pont du due,
and a rather fine-grained granite at Le Saint. Gourin is said to be
the critical point for deciding on the conformability or otherwise
between the conglomerates of Gourin and the phyllades of St. Lo;
but the evidence is I believe only circumstantial. Grey schists are
well seen near a rivulet just before entering Gourin, and the con-
glomerates in a quarry about 14 miles east of the town on the road
leading to Plouaray. We again saw the red conglomerate north-

Rev. E. Hill—Geological Visit to Brittany. 63

east of the town, and then a section of the Schistes dAngers. The’
road gave some good scenery in its traverse of the low ridge called
the Montagnes Noires, but whatever else of interest there may be
between these and Carhaix was lost in the shades of evening and
night.

Two days were spent at Carhaix, occupied by two long excursions
eastwards to Rostrenen and Goarec respectively, to study the pheno-
mena of metamorphism on each side of the great intrusion of the
Rostrenen granite. Deviating from the direct road to pass through
Paule, we were there shown the first signs of alteration in (Carboni-
ferous) Chateaulin schists. Near Glomel the change had gone
further, and small but perfect crystals of andalusite had been formed.
We walked about two miles west of Glomel on a road, and then
turning north down a lane about half a mile collected in a quarry
near Bressillion andalusite in altered (Devonian) schists of Plou-
gastel, thence returning south-west and south, saw near Kervennan
the same mineral developed in the (Silurian) schists of Angers,
while at Rostrenen itself, just outside the village, we collected the
beautiful porphyritic granite that is the agent of all this change.
The porphyritic crystals of felspar reach a large size, and in decom-
posed rock they lie as pebbles in a sand. To the south of the village,
in a large rock on the side of the road, near Kerbescont, the schists
of Plougastel reappear altered into leptinolite.

Beyond Rostrenen (this was on the second day), about the kilo-
metre stone marked 17, a fragment of schist is seen actually included
in granite; further on, sandstones belonging to the Chateaulin
schists occur little altered, and about one mile before reaching
Plouguernével, a small excavation on the road-side shows an actual
contact ; a mass reposing in a trough of the granite, with an isolated
piece completely surrounded. Further on, they are seen again ina
pit with a pond, less altered as being further from the granite.

At Goarec, at the east end of the village, on the north side of the
road, is a quarry in a rock unlike anything we saw elsewhere, and
said to resemble the Porphyroides of the Ardennes. It is supposed
to pass into the schists, but its relations are not seen here. South-
east from Goarec along the high road the Schistes d’Angers are seen
in fine crags. Quitting the route at Bon Repos, and denying ourselves
more than a distant glance at the picturesque abbey, we crossed the
canal and entered on an extensive wood. After following the canal
bank a mile or more, we turned south to reach the abandoned Forges
des Salles, just beyond which in the wood is a quarry in some highly
cleft ‘schistes a chloritoid.” On the roadside three or four miles
further (east side, just before the group of houses called St. Brigitte),
is a shallow quarry in a kind of slate, which while showing only
traces of cleavage, and containing fairly abundant and quite recog-
nizable fossil impressions (Trilobites, Orthis, etc.), is also full of fine
erystals of andalusite, which lie in the closest proximity to the
fossils.

Quitting Carhaix on the 27th August, and driving to the N.W.,
cuttings made for the road show sections of Chateaulin shales with

64 Rev. BH. Hill— Geological Visit to Brittany.

some indistinct remains of plants. Beyond Poullaouen are some
fine dykes of kersanton, and further on a small one of micro-
granulite; thus intrusions of both these rocks must have been going
on as late as in Carboniferous times. For the kersanton, there is
some evidence that it did not occur earlier; no pebbles of it are
found in conglomerates which include all the other igneous rocks;
as for instance at about four kilometres before reaching Huelgoat, in
a conglomerate belonging to the base of the Carboniferous series.
In a quarry about a mile from the road, at Bruguec north of Kerrion,
a microgranulite tuff again proves that the eruptions of this rock
towards the end of the Devonian age continued into the Carboniferous.

The mine of Huelgoat has hada long and interesting history, but now
is abandoned. In the walls near it are a few fragments of the Roche
Verte, a green breccia, which has been the subject of much discussion,
but is now considered to be a bed below the Chateaulin schists, and
above those of Porsguen (Porphyrite tuffs of the Table). From
beyond the mine a path leads for some miles through a beautiful
wood by the bank of a water channel at a high level on the hill-side
to the quaint little town of Huelgoat.

The porphyroid granite of Huelgoat resembles that of Rostrenen,
and belongs to the same (Carboniferous) age. The great rocking
stone called the Roche roulante, distant about half a mile, is worth
a visit, and just below it is a quarry in the granite which there con-
tains abundantly pinite. Thence we regained the Carhaix road, and
returned along it some two kilometres to the east to see the contact of
the granite with Porsguen schists. A dyke of microgranulite cuts the
granite a little before reaching the junction. The schists are indu-
rated into a rock which has been called Cornien, and the alteration
is certainly considerable. We turned north along the main road’
towards Morlaix to reach, after 3 or 4 kilometres, a long shallow
quarry in quartzites of Plougastel, here altered by the granite, and
went about a quarter of a mile up a footpath (not marked on the
map) to Le Vern for schists of Angers rendered crystalliferous. At
An Avallennon on the high road, the Grés a Scolithes is seen little
altered. We returned a few hundred yards and took a lane to the
south-west, which soon led us over the granite. After some three
kilometres it brought us out at Ty le Brennou, where Plougastel
schists are seen at their contact with the granite, and where a quarry
in a field west of the high road gives a beautiful section of the
junction. This completed for the Huelgoat granite what had been
done on the previous days for the Rostrenen granite, an examination
of the effects produced on all the beds broken through. The parallel —
bands of strata which cross the country from east to west are in each
case interrupted by the great intrusion, and the resulting alteration
in each case surrounds the igneous mass as a sort of aureole or halo,
intensest at the boundary and dying away at a mile or so from it.

Our last day was devoted to the neighbourhood of Morlaix. In
the morning we drove southwards along the road which leads at first
south-west from the centre of the town (past the post-office). About
a mile from the town, and a quarter of a mile east of the road (at’

Prof. T. G. Bonney—On the Rauenthal Serpentine. 68

Buvette a Pont Neuf), a moorland hill affords a few Devonian fossils
in a grit belonging to the schists of Morlaix. Further along the
road occur schists of Plougastel altered by granite (of Pompol).
A quarry on the west side ‘of the road, about two miles from the
town, shows garnets and chloritoid in the altered schists. About
a mile further, in another quarry about 100 yards west of the road,
behind some houses (Le Fume ?), the schists have become leptinolite.
The road-sections, a little beyond, of granite tongues running into
schists, are as fine as I ever saw.

An afternoon excursion from Morlaix took us a circuit north of
the town. We passed on the right bank of the river singular bedded
rocks (Schists of Morlaix), with a granite dyke cutting them, and
made deviations to see the quarry of Kerscou and its wonderful
junction of granite and schist (a strip of black shale, 30 feet long
by 18 inches broad, is included as if torn off), and at a hamlet
called Ploujean a unique porphyry dyke. Thence regaining the
main N.N.E. road we passed in a valley a diabase dyke badly seen in
road-sections, followed by some conglomerates, and arrived at the
head of the estuary of the Dourdu, where, by walking half a mile
along the northern strand, we were to have seen a limestone conglo-
merate; but a tide of phenomenal height obstinately continued to
rise and entirely barred our progress. Quartz conglomerates were
again seen in the road along the slopes above, and about the 5 kil.
stone from Morlaix, in shallow quarries for road metal, the Grés a
Scolithes. Thence returning through St. Antoine, and driving east
for several miles, we Pevorsed dae whole basin of the Morlaix
schists, until we again encountered the Grés rising from under
them. Ina shallow quarry in the midst of fields, and almost buried
from sight, we were shown the locality where a few rare fossils
have proved its Cambrian age. This ended the excursion.

The guiding idea in its arrangement was to show first the com-
plete series of unaltered beds, “and afterwards the modifications
which these rocks present around the invading masses of granite.
I cannot attempt to reproduce in any way the interesting discussions
on these phenomena which occurred between the distinguished
geologists of the party. From my own observations I come back
with the strengthened conviction that it was no causes of this kind
which gave origin to the crystalline schists.

I desire to take this opportunity of expressing my gratitude to the
members of the party, and especially to its residene Dr. Barrois,
both for the opportunity of joining the excursion, and for the parti-
cular kindness and attention bestowed on me at every possible
occasion.

IIT.—Note on Specimens oF THE RAUENTHAL SERPENTINE.

By Professor T. G. Bonney, D.Sc., LL.D., F.R.S.

N the very valuable work on “ British Petrography” by my

friend Mr. J. J. H. Teall, now in process of publication, there

is a rather full notice of an interesting serpentine vine occurs in
DECADE IIIl.—VOL. IV.—NO. II. = )

66 Prof. T. G. Bonney—On the Rauenthal Serpentine.

the Rauenthal (Vosges), and has been investigated by Herr Weigand.'
According to the latter author, as summarized by Mr. Teall,’ this
serpentine “has been formed by the alteration of a hornblende rock,
and the change has been accompanied by the removal of lime and
the development of a chlorite, in which the original alumina of the
hornblende is retained.”

Such an origin for a serpentine would of course be perfectly
possible, supposing that a certain amount of silica was also removed ;
for the formation of the mineral serpentine from malacolite and other
non-aluminous varieties of pyroxene is familiar; but inasmuch as
masses either of pure hornblende or pure pyroxene? are certainly
very rare, we should expect such’a serpentine to be extremely local
in its occurrence, and (like the pyroxene-serpentine) rather abnormal
in aspect. Hence it will be well for the student of “British Petro-
graphy” to remember that, if Herr Weigand be correct, the origin
assigned to the Rauenthal serpentine is not likely to interfere with
the general rule that normal serpentines result from the alteration
of peridotites. But is Herr Weigand quite correct, and does not his
statement require a little limitation? I confess that his paper has
awakened some suspicions in my mind which are confirmed by the
examination of specimens, procured by Mr. Teall from Stirtz of
Bonn, and by him kindly placed at my disposal.

First, as regards the results of Herr Weigand’s studies of the rock.
In his paper, which is a most conscientious piece of work, he gives
us, in addition to an analysis of the white mica-like constituent—a
chlorite—an analysis (A) of the soluble portion of the rock (@.e.
practically all but the chloritic constituent, not generally abundant),
a bulk analysis (B) of the whole rock, and an analysis (C) of the
amphibolite into which the serpentine is said to pass. These are as

follows :—
A. B C

Sip © sesso STROGMAN Tastes of MOGrO4d ie (eee 46-407
SIRO oe geome O20 | 13352) eee 6-727
TD Ogi vce AOS |... 6868. oe 4-649
ReOM 2. He a ae 3-056) ee 2°107
COM armen IGG Ph Bs 1°303)| (pee 10-642
IME Oj) Poche BG sO02I ae fh. 4: 362022 Weaee 26252
1310) ahs 13°386 (diff.) ...... 18-089) eee 3:584

100-000 99-625 100:368

Now a glance at A and B shows that either the one or the
other would be a very fairly normal analysis for an ordinary
serpentine.* As usual the silica and magnesia are nearly equal in
amount; there is about the ordinary proportion of iron oxides and
water. ‘The percentage of lime, though not large, would lead us to
suppose that augite or hornblende rather than enstatite had been

1 Tschermack, Min. Mitt. 1875, p. 175. 2 British Petrog. p. 112.

3 I find that the diallage rock at Lendalfoot, described by me, Q.J.G.S. vol. xxxiv.
p. 778, is not quite free from olivine. This too is a comparatively small mass.

4 That is to say, a rock which has resulted from the alteration of a rock consisting
of olivine with a certain amount of a magnesian bisilicate. A serpentine formed
from a perfectly typical dunite should have MgO in excess of Si0..

Prof. T. G. Bonney—On the Rauenthal Serpentine. 67

associated with the dominant olivine of the original rock, that is,
that it had been one of the varieties of peridotite, which approach
nearest to picrite, and by some would even be included under that
name.! If we can take the amphibolite as in any way representing
the parent rock of B, we see that not only must we remove a con-
siderable amount of lime (almost enough, so far as figures go, to
make up the difference in water), but we must get rid of a consider-
able proportion of alumina, and a large amount of silica.’

If these substances have been removed, it is a little strange that
we do not find traces of them in the form of veins and similar
deposits in the rock itself. But Herr Weigand does not mention
any, and I find none in the specimens before me. It may, however,
be objected to this mode of reasoning, that the amphibolite does not
fairly represent the rock from which the serpentine (B) was formed,
but only a rock which was closely related to it; and, having
regard to the “ badly mixed” condition of many of the basic igneous
rocks—such as the peridotites and picrites—the objection is not un-
reasonable. Let us then see whether the difficulty would disappear
if we were dealing with some other variety of hornblende rock.
Clearly we must select as its constituent mineral a hornblende poor
in alumina, rich in magnesia. In all the analyses quoted by Dana
in his Mineralogy, the percentage of silica (as we should expect in a
bisilicate) is greatly in excess of magnesia. Hven antholite, which, by
its richness in iron and poorness of lime, would be the most suitable
constituent of the mother-rock of the Rauenthal serpentine, has at
most SiO, : MeO = 584 : 314.3 Thus a consideration of Herr
Weigand’s analyses alone suggests that either the specimens analyzed
or the specimens examined microscopically were abnormal, or there
had been some slight error in the one or the other investigation.

I proceed now to the result of my own examination of Mr. Teall’s
two specimens. Slides have been cut from each, two from one (that
which he kindly gave me), one from the other. After careful study
of these, while lagree with Herr Weigand that the original rock has
contained a variety of hornblende, and that some of this has been
altered into a serpentinous mineral, I can come to no other con-
clusion than that the dominant constituent in each is a serpentine
formed from olivine.

On examining one of the slides cut from my specimen,* we see
that it is chiefly composed of two constituents rather irregularly dis-

1 For myself I think it better to apply the term pierite to the rather indefinite
group which is intermediate between the true peridotites (or felsparless rocks where
olivine dominates) and the olivine-dolerites. Olivine + augite and olivine + horn-
blende need names.

* Suppose, for purposes of comparison, we assume that no magnesia has been
removed. In (B) AhO;: MgO = 14: 360; in (C) AlO3: MgO = 67: 263.
These proportions expressed in decimals are 038 and :254. Again in (A) SiO, : MgO
= 369 : 360—almost equal; in (C) SiOz: MgO = 464 : 262—about 17 : 10.

3 Anthophyllite would also be a very suitable mineral, but it is evident that we are
not dealing here with a rhombic mineral, but one which much resembles tremolite.

* These happen to be slightly thicker than Mr, Teall’s slide, so that the distinction
of the constituents is rather more conspicuous.

68 Prof. T. G. Bonney—On the Rauenthal Serpentine.

tributed. The one—almost colourless—clearly is or has been a horn-
blende, as described by Herr Weigand. It shows, even when con-
verted into serpentine, the characteristic cleavages parallel to oo P in
cross-sections and the parallel lines formed by these in longitu-
dinal sections. Occasionally portions of the mineral still remain
unaltered. The other constituent is a pale sap green in colour; it
consists of a rather irregular network of a doubly refracting mineral,
with interspaces chiefly occupied by an isotropic mineral. This
meshwork can be readily seen by transmitted light, but is rendered
more distinct by using crossed Nicols, when the ‘strings’ appear
either white or pale golden yellow. This structure, and this mineral
or association of minerals are perfectly familiar to me as the result of
the alteration of olivine; there are various minute structural dif-
ferences between the isotropic parts of this and the most highly
altered portions of the other mineral, which it is almost impossible
to describe without entering into details which would be tedious, but
which become readily apparent to a practised eye after a little study,
so that while I will not undertake to say that J can distinguish every
grain of the two constituents, I have no hesitation as to distinguish-
ing them in at least five-sixths of the rock. Hence I cannot admit
the general accuracy of my friend’s statement, founded upon Herr
Weigand’s paper: ‘Microscopic examination shows that the rock
differs markedly from normal olivine serpentine. It consists of a
transparent green or colourless substance,’ in which the irregular
‘maschenstructur ’ due to the separation of the iron oxide along the
original cracks of olivine is absent.” But the ‘“‘ maschenstructur ”
of a serpentine derived from olivine is not due “to the separation of
the iron oxide,” but “to the original cracks” (i.e. the imperfect.
cleavage planes) of the mineral itself. It is, indeed, very commonly
exhibited in great perfection by the deposition of iron oxide, which
plays the part of an injection in an organic structure ; but it is quite
a mistake to suppose that the iron oxide is always separated and
deposited in this way.” The ‘ mesh structure’ in the Rauenthal rock is.
not seldom divided down the middle by a line (indicating the original
cleavage plane); this is sometimes made more distinct by a slight
deposit of iron oxide, and the minuter structures of these strings.
agree perfectly with those in a normal serpentine. Thus the above-
quoted sentence would be more correctly worded as follows :—*“ It
consists of a transparent green and a colourless substance,” and the
remainder of the sentence would then apply to the latter of these,
viz. the altered hornblende. As to the relative amounts of the two-
minerals, it is difficult to speak exactly, as they are rather irregularly
mixed; but in no case, I think, does the hornblendic constituent
dominate in the field of view under a one-inch objective, and on the

1 T observe that very commonly there is a slight green band between the cracks
(cleavages) of this mineral, as though a liquid had been injected from without. I
have noted the same thing in the case of the pyroxenic minerals present in other ser-
pentines. The mineral may be derived from the olivine and “‘ injected”’ during the
hydration of the olivine, which process must set up considerable strains and pressures.

2 See, for instance, Wadsworth’s Lithological Studies, pl. iv. fig. 4. The decided.
green colour is probably due to imperfect separation of the iron.

Prof. T. G. Bonney—On the Rauenthal Serpentine. 69

whole I have no doubt that in my slides the peridotic constituent is
distinctly in excess. Hence either our specimens are exceptional,
or Herr Weigand has examined slides cut from an exceptional
specimen, or he has failed to distinguish the two minerals. So far
as I can form an opinion from the woodcut given in his paper, I
confess that I incline to the last solution, for I think that even there
I can see indications of a difference in the constituents. In any case
it is, I think, clear, that the Rauenthal serpentine is only a variety of
the group of serpentines derived from the alteration of olivine-horn-
blende rocks, of which we have excellent examples at Mullion,
Pradanack, and other localities at the Lizard.1. To some of these
indeed the Rauenthal rock has, both macroscopically and microscopi-
cally, a considerable resemblance. All that we can assert is that
occasionally (possibly) the white hornblende is rather exceptionally
abundant, and that (as sometimes occurs elsewhere) a peculiar variety
of chlorite is locally developed.

I may take this opportunity of calling attention to another state-
ment on p. 119 of Mr. Teall’s work, which I believe to be not quite
accurate. Speaking of the occurrence of felspar in the Lizard ser-
pentines, Mr. Teall says, ‘It is present also in slides of a variety of
serpentine from the Rill Head, near Kynance, lent to the author by
Mr. Waller,” to which he appends the note, “The author has recently
visited the district and ascertained that serpentine containing felspar
forms a large portion of the Rill Head. The original rock, therefore,
was of the nature of a picrite.” It would not, of course, be sur-
prising if a little felspar occurred in a mass of serpentine, and I had
already noticed at Gue Graze (on the same coast further to the north)
a decomposed mineral which I thought might be felspar, as is men-
tioned by Mr. Teall in the passage from which I have quoted, though
it would be more correct to say, “Professor Bonney records it
(felspar) as [probably | occurring at Gue Graze,” as will be seen on
reference to my description of the Gue Graze rock (Quart. Journ.
Geol. Soc. 1877, p. 918). But in regard to the Rill rock I do not con-
sider the mineral mentioned by Mr. Teall to be felspar. No doubt
it occasionally closely resembles a plagioclastic felspar, both in its
earthy decomposition and its lamellar twinning; but after carefully
examining my own slides (including one cut from a specimen kindly
given me by Mr. Teall, and one which Mr. Waller freely placed at
my disposal, I am distinctly of opinion that the mineral is not felspar.
This earthy decomposition (which weighed much with me in ex-
amining the Gue Graze rock) is, I now find, not unfrequent in
colourless minerals belonging to the pyroxene group, and the mode
in which the transparent parts of the crystal are attacked appears to
me to be different from that in which kaolinization proceeds in a
felspar. There are also some minute structural peculiarities in the
mineral, which to my eye recall a member of the above-named group
and notafelspar. The twinning, which however is not very common,
is no doubt curiously like that of a plagioclastic felspar; but similar
twinning does occur, though rarely in augite or diallage (Fouqué and

1 As mentioned in my paper, Q.J.G.S. vol. xxxix. p. 28.

70 HH. Keeping—The Zone of Nummutina elegans.

Lévy, Roches Eruptives, p. 358). Hence I feel convinced, after
repeated examination, that the presence of felspar in this Rill rock
cannot be asserted on the evidence before us, and that it consists:
chiefly of olivine (more or less altered into serpentine) and augite
(diallage). Further north the pyroxenic constituent appears to be
commonly a colourless hornblende. It is possible that this mineral
is also present in the Rill rock, and I think I have detected a grain
or two of rhombic pyroxene.

IV.—On tHe Discovery or tHe Nuwuurinwa ELEGANS ZONE AT
Wauitrctirr Bay, Istz or WiGcHT.

By H. Kzrprne,
of the Woodwardian Museum, Cambridge.

HEN visiting Whitecliff Bay, Isle of Wight, last September, I
was so fortunate as to find exposed on the shore at low-water,
the whole of the various strata from the Brook Bed of the Brackle-
sham, to the Bembridge Limestone inclusive. I have visited this
locality many times, but have never before seen the Barton Series
exposed. On my return to Cambridge, I mentioned the subject to
Prof. Hughes, and he suggested that I should make another visit in
order to obtain a larger collection of fossils; but on this second oc-
casion, I was surprised to find that the whole of the strata, which I
had seen on the shore in September were now covered with sand to
the depth of twenty inches. Therefore, seeing that nothing could
be done on the shore, I set to work at the cliff, and succeeded in
finding the same beds there.
For the sake of reference I have copied a part of Professor Prest-

North. South

LS eee =z L Sh Ig See A ee moo

1 2 3 4
1. L. Headon. 2. Upper Bagshot. 8. Barton Series. 4. Bracklesham Series.
Brockenhurst
Bed.

SEcTION IN WuiTEcLIFF Bay, IstzE or WiGuHT.
Scale 1 inch =150 feet.

wich’s ’ section, which I consider so good that it would be difficult
to improve upon it, except by adding details of zones since dis-
covered : these are shown by the dotted lines. In ascending order

1 On the Tertiary “Formations of the Isle of Wight, Quart. Journ. Geol. Soc.
vol. ii. p. 223, plate ix. 1846.

H. Keeping—The Zone of Nummutlina elegans. 71

the beds seen, commencing with the Brook Bed of Bracklesham,

are as follows :—
(a) Brook Bed.

(b) Grey sandstone or Tellina bed of Selsea.

(c) Nummulina variolaria zone, measuring about 20 feet, being
quite full of these small Foraminifera.

(d) Dark green sandy clays, with glauconite grains. This part of

the series I consider to be the equivalent of the beds just above
the Nummulina variolaria zone of Stubbington and Hunting
Bridge in the New Forest, which has been described by the
Rev. O. Fisher.!. I could find no fossils sufficiently well pre-
served for identification in this part of the series. Thickness
about seventy feet.

(e) A thin band of dark earthy-coloured sand, rather coarse: this
I did not find on the shore at low-water, where, however, I have
no doubt it occurs. Ostrea flabellula is fairly abundant in it.
The thickness is seven inches.

This brings us to the bottom of the Nummulina elegans® zone,
which therefore is now shown to be of such wide extent and constant
occurrence that it seems more convenient to adopt the Rev. O.
Fisher’s® classification, and take this horizon as the basement of the

Barton Series.

(f) Nummulina elegans zone, consisting of rather dark green

and blue glauconitic sandy clays, much crowded in places
with Nummulina elegans. I was much interested in find-
ing this rich bed for the first time in this locality, as the
Bracklesham and Barton Series have not been found before in
juxtaposition with sufficient fossil evidence. There cannot now,
however, be any doubt of the existence of the Barton as well as
the previously known Bracklesham at Whitecliff Bay, as at that
locality the fossils give abundant evidence of the existence of
each. The following are the fossils from the Nummulina elegans
zone, which has a thickness of thirteen inches :—

Typhis pungens, Brand.
Fusus bulbus, Brand
Cominella Solandri, Edw.
Pleurotoma exorta, Brand.
Voluta luctatrix, Brand.
digitalina, Lam.
Mitra parva, Sow.

Calyptrea trochiformis, Lam.

Dentalium striatum, Sow.
Bulla, sp.

Corbula pisum, Sow.
Crassatella sulcata, Brand.
Cardium semigranulatum, Sow.
Leda minima, Sow.

Ostrea flabellula, Lam.
Nummutlina elegans, Sow.

The specimens of Nummulina elegans at Whitecliff Bay are,
I think, somewhat finer than those at either Alum Bay or Highcliff.

(g) Pale blue and yellow sandy clays, with very few and badly
preserved fossils. Thickness, 54 feet.

(h) A stiff laminated clay, with occasionally dark patches. Few
or no fossils. Thickness, 18 feet.

1 Quart. Journ, Geol. Soc. vol. xviii. 1862, p. 65.
® Formerly called NW. Prestwichiana, but the recent researches of Prof. Rupert

Jones prove it to be WV. elegans.
December 15th, 1886.

See his paper read before the Gcological Society,

3 Op. cit.

72 A. J. Jukes-Browne & W. Hill —Gault and Chalk Marl.

(i) Grey and pale blue clays, with light fawn-coloured bands
near base. Thickness, 36 feet.

(j) Imperfect ironstone band not well seen. Thickness, 3 feet.

(k) Blue sandy clays, with mottled brown patches of soft earthy
ironstone near the base. Thickness, 50 feet, the upper fifteen
feet of which consists of a bluish sandy clay, and contains the
following fossils :—

Terebellum sopitum, Brand. Nucula bisulcata, Sow.
Voluta humerosa, Edw. Chama squamosa, Brand.
Pyrulanexlis, Lam. Cardium porulosum, Brand.
Natica, sp. Lucina gibbosula, Lam.
Calyptrea trochiformis, Lam. Crassatella tenuisulcata, Edw.
Ostrea flabellula, Lam. Cypricardia sp.
Fecten carinatus, Sow. Cardita oblonga, Sow.

sp. Cytherea tenuistriata, Sow.
Lima, sp. Tellina ambigua? Sow.
Avicula media, Sow. Corbula ficus ? Brand.
Arca, sp. Panopea intermedia, Sow.
Pectunculus deletus, Brand. Shizaster D’ Urbani, Forbes.
Limopsis scalaris, Sow. Ditrupa plana, Sow.

For the convenience of collectors, I give the following measure-
ments taken along the cliff at high-water, commencing with the
Bracklesham Sandstone, which can always be seen, so that the strata
under consideration can be found at any time :—

Bracklesham Sandstone to the N. elegans Zone ..........00.e00e- 126 feet
Nivelegans Zone TOMbop Ol Barbone... .p-eecees so a- eee eeeneeeeeeeseeee 161 ,,
Top of Barton to top of Upper Bagshot.................ssseeeseee 186 ,,
Tower Head ones weenie once a vlesctav deieaiatdtiiedte eater meee 19

The Whitecliff Bay section is almost complete from the Chalk to
the top of the Bembridge Series, as it not only shows a good exposure
of Barton Clays, but also the Brockenhurst and Roydon zones (Middle
Headon). It is therefore by far the most perfect section of the
Tertiary formation in England.

I am indebted to Prof. Rupert Jones for examining the specimens
of Nummulina, both from the Bracklesham and Barton Series; he
considers N. elegans to be the only species found in the Barton,
the so-called N. variolaria, found some forty feet above the true
N. elegans zone, being only a thickened form of N. elegans.
There seems, therefore, to be only one species in the Barton
and two in the Bracklesham Series.

It will be seen that a few of my measurements differ slightly from
those given by Professor Prestwich: this is due to the latter having
been made along the cliffs, while mine were taken on the shore at
low-water.

The specimens referred to in the above paper are preserved in the
Woodwardian Museum, Cambridge.

V.—Nore on rae Gaunt ann Cnank Mar or West NorFor.
By A. J. Juxes-Browne, B.A., F.G.S., and W. Hitt, F.G.S8.
NTIL the appearance of the article by Messrs. C. Reid and G.

Sharman in the GrotocicaL Macazine for February, 1886,
p. 55, no one had ever thrown a doubt on the existence of true Gault

A. J. Jukes-Browne §& W. Hill—Gault and Chalk Marl. 73

in Norfolk. The grounds on which these gentlemen venture to
doubt its existence are these :—

(1) No clear line of separation between the Gault and Chalk
Marl, and no phosphatic bed marking the base of the latter,
could he found by the Geological Surveyors.

(2) They give a list of unphosphatized fossils from the marly clay
of West Dereham, which they regard as a Chalk Marl fauna.

(8) The phosphatic casts of Gault species they regard as derived
fossils.

From these premises, and without any attempt to determine the
horizon of the ‘Totternhoe Stone, which would fix the upper limit of
the Chalk Marl, they come to the conclusion that the whole of the
so-called Gault in Norfolk is Chalk Marl, and not really Gault.

We have recently endeavoured to follow the subdivisions of the
Chalk through the western parts of Suffolk and Norfolk, and having
visited the localities mentioned by Messrs. Reid and Sharman, we
wish to record our entire dissent from their conclusions, and to give
our reasons for maintaining the existence of Gault in West Norfolk.

(1) In the first place we found that the upper part of the Chalk
Marl changes its character as it is traced northwards, and becomes
a hard greyish chalk, passing, in fact, into the “hard chalk,” which
Messrs. Reid and Sharman speak of as resting upon “the Chalk
Marl.” At Stoke Ferry, twenty-two feet of this hard “Chalk Marl”
is exposed below the representative of the Totternhoe Stone; its
full thickness is probably about thirty feet, and between it and the
level of the springs on the border of the [Gault] clay plain, there
may be ten or fifteen feet of soft Chalk Marl. Now the width of the
clay plain near West Dereham is about two miles, and an easterly
dip of only 1° would give a thickness of fifty-nine feet. That this
calculation is within the mark is proved by a boring at Wretton,
west of Stoke Ferry, the particulars of which were obtained by Mr.
Whitaker, and which gives a thickness of sixty feet of clay at a spot
which is certainly below the summit of the clay. If, therefore, the
whole of this clay is to be referred to the Chalk Marl, we must add
it to the thickness of the overlying beds above mentioned in order
to get the total thickness of this stage; doing this we obtain a
minimum of 100 feet, and a possible thickness of 120 feet for the
Chalk Marl of Norfolk. Near Cambridge its thickness is about sixty
feet, and we are therefore asked to believe that it has expanded
to double its thickness in a direction in which all the beds are
evidently and admittedly thinning out.

(2) In the next place we cannot allow that the assemblage of
unphosphatized fossils obtained from the clay is such as to merit the
name of a “Chalk Marl fauna.” Nearly all of them are species
which range from the Gault to the top of the Lower Chalk, and
are therefore of no use in deciding the exact age of the bed containing
them. The only species on which any argument can be founded are
Beiemnites attenuatus, B. minimus, and Ostrea acutirosiris.

The Belemnites are decidedly Gault forms, and do not, so far as
we know, occur in true Chalk Marl, where Belemnites are not

74 Col. McMahon—On the Lizard Glabbro.

common, though B. ultimus occurs sometimes; it is true that all
three are often regarded as varieties of one species, but that makes.
no difference to the fact of the two varieties being specially character-
istic of the Gault.

Ostrea acutirostris has not, I believe, previously been found below
the Chalk Marl, but it is not a common shell anywhere, and is
believed to occur in Upper as well as in Lower Chalk, so that it is
evidently a species which has a long range.

The statement that Ostrea vesicularis has not been discovered
below the Chalk is quite erroneous, for it is a common shell in the
Upper Gault of Folkestone and elsewhere.

(3) Lastly, the clay above the “coprolite bed” at West Dereham
has the lithological characters and general appearance of Gault. It
is by no means unusual for the lower part of the Gault to contain
fossils in the form of phosphate casts, more or less rolled and worn ;.
such phosphatized fossils are particularly abundant within twenty
feet of the base of the Gault in Buckinghamshire, and in the same
county the passage-beds between the Gault and Lower Greensand
often contain large lumps of sandy phosphate, which resemble those-
of the junction-bed at West Dereham. ‘There is nothing therefore
in the character or contents of the West Dereham clay that is incom-
patible with its being true Gault. For the reasons above stated we
must maintain that all the previous authors were right in accepting
the sections near West Dereham as proving the existence of Gault in
that part of West Norfolk. How much farther north the Gault ex-
tends is another question which we are endeavouring to ascertain,
and such evidence as we can obtain will be embodied in a paper
which we intend to bring before the Geological Society. We shall
also endeavour to account for the apparent passage between the Gault
and the Chalk Marl; but we may remark that at Shouldham we
found what appears to be the true glauconitic base of the latter,
above the clay which Mr. Reid describes as containing Belemmnites:
and Plicatula.

[ Postscript.—Since the above was written we have had a boring
made in the quarries at Stoke Ferry to a depth of fifty-five feet, and
have proved the existence of a bed of Chloritic Marl at the base of
the Chalk Marl, and resting on blue clay; the total thickness of the.
Chalk Marl there is seventy-three feet, and it must be remembered
that below this there is at least sixty feet of Gault. |

VI.—Note on tHE Foutation oF THE Lizarp GABBRO.
By Colonel C. A. McManon, F.G.S.

4) ee appearance of Professor Bonney’s letter in the December
Number of the Gronogicat Macazinn, in which he suggests that
Mr. J. J. Harris Teall’s proposed explanation of the cause of the
foliation of the Lizard gabbro “ ought to be regarded as an hypothesis.
on its probation, and should not be quoted as an undoubted fact,”
emboldens me to offer some remarks on the subject.

Mr. Teall suggests that the ‘foliation in the Lizard gabbro is the

Col. McMahon—On the Lizard Gabbro. (45)

result of pressure” acting “after the consolidation of the rock ;” or,
as he puts it shortly in another place, the foliation is “‘a secondary
structure due to earth-movements acting upon the solid rock.” [The
italics are mine. |

Mr. Teall does not expressly state, in his interesting and valuable
paper, how the pressure acts so as to produce the results described ;
but we are told that at Pen Voose “‘ massive gabbro passes over into
gabbro schist at a fault plane,” and “the foliation in the gabbro is
such as would be produced by a shearing motion parallel with the
fault plane.”

Are we to understand that foliation has been produced by mere
mechanical crushing, and consists of the rearrangement of minerals
already formed sliding over each other’s backs—a sort of mineralogi-
cal leap-frog—in consequence of a ‘shearing motion parallel with
the fault plane ;” or are we to understand that the ‘shearing motion”
was transmuted into heat, and the heat so produced resulted in the
fusion and subsequent recrystallization of the component minerals ?

On either supposition I shall be glad to know how the foliation
of the “veins and dykes of gabbro” to the north of Coverack, and
the “small dykes of gabbro in the serpentine near Karakclews,” is
to be accounted for? Do all these veins and dykes concur with fault
planes, or do they ramify in all directions in the usual manner of
intrusive veins? If they coincide with fault veins, how is it that
they are not always foliated? Mr. Teall states that the Coverack
veins, and the small dykes near Karakclews, are “often foliated ”
(which implies that sometimes this is not the case); and further,
that ‘‘not seldom one may see the transition from massive gabbro to
gabbro schist taking place in the space of a few inches.” If the
veins and dykes in question coincide with fault planes, this occa-
sional failure of ‘shearing motion” to produce foliation seems to
need explanation. On the other hand, if some of the foliated veins.
and dykes do not coincide with fault planes, I fail to see how the
“shearing ” hypothesis can account for the foliation.

Again, if the foliation is accounted for on the supposition that
the shearing motion developed heat, and recrystallization took place
on the subsequent cooling of a rock in which molecular motion had
been set up by the heat so developed, I do not at present understand
how masses of gabbro “more than a hundred yards in width”
(p. 487) have become, “with a few local exceptions, foliated
throughout” their “entire mass.” If the heat produced was suffi-
cient to fuse the rock, why was its structure, on reconsolidation, not
granitic, as it presumably was on its first consolidation, and as the
dykes, sheets, and veins of ordinary eruptive rocks are?

Most geologists with field experience will doubtless be able to
point to numerous instances of such eruptive dykes, and sheets, that
have consolidated under enormous pressure, but which, notwith-
standing, do not show a trace of foliation.

The above, I think, are difficulties which need clear explanation
before the hypothesis can be accepted that pressure acting on a solid
rock is sufficient to account for the foliation of the Lizard gabbro.

76 Ool. McMahon—On the Lizard Gabbro.

In the mean while, I venture to offer another explanation for con-
sideration.

After having studied what used to be called the granitoid-gneiss
of the Himalayas for some time, I came to the conclusion, from the
stratigraphical, petrological, and microscopic facts observed, that
what is now called the gneissose-granite of the Himalayas was
erupted through lines of fracture in a partially consolidated condition.

1 do not wish to apply that explanation to all cases, but I suggest
a modification of it to account for the foliation of the Lizard gabbro ;
namely, that the latter was produced by “shearing motion ” on the
rock after its consolidation had advanced considerably but was still
incomplete. This, it seems to me, would account for the observed
facts better than any hypothesis yet proposed for acceptance ; it would
account for the foliation being generally marked at the contact of the
gabbro with other rocks along joint planes; it would account for any
signs of crushing in the gabbro that the microscope may reveal;
and indeed for all the observed facts so far as I am acquainted with
them. The great depth to which the foliation sometimes extends
might, on this hypothesis, be accounted for either by supposing that
the “shearing motion” continued for a long time; or, better still,
that it was repeated frequently at intervals of sufficient duration to
allow the marginal portions of the gabbro to cool and consolidate.
Very slight movements parallel with the fault-plane would be suffi-
cient, on the latter supposition, to produce foliation to a great depth.

If the foliated veins and small dykes, alluded to by Mr. Teall, do
not run with fault planes, the foliation might be explained on the
supposition that they were, like the gneissose-granite of the Himalayas,
intruded in a viscid. or semi-plastic condition, when the shearing of
the main mass of the gabbro along the fault planes was going on.
Traction action on an imperfectly consolidated mass would in this
case account for the foliation observed.

The fact that in some of the dykes a rapid passage from a foliated
to a granitic structure is observed, is of course a difficulty in the way
of any hypothesis; but I suggest that on my hypothesis it is capable
of explanation. In the first place, I think it might reasonably be
supposed that the cooling, and consequent consolidation, of the rock
proceeded more rapidly in some parts of the dyke than in others.
Rocks are rarely perfectly homogeneous; we often find variations in
density, and hardness, within short distances even in some rocks
of apparently homogeneous composition—a difference not due to
weathering, but which weathering, and the agents of erosion, speedily
find out. Then the power of conducting heat must have varied much
in the bounding rocks. From these two causes the solidification of
parts of a dyke might have been in advance of neighbouring portions,
and have resisted the shearing motion more than the latter. The
portions in which solidification was most advanced might thus have
retained their granitic structure, whilst the less solid parts might have
yielded to the shear and have become foliated.

In the second place, I think it possible that shearing motion might
result in the development, or what would come to the same thing,

Col. McMahon—On the Lizard Gabbro. (a

. the retention of heat (owing to variations in the conducting power
of the surrounding rocks), more in some spots than in others ; and
thus some parts of the dyke might become more fused than other
portions, and might lose the foliated structure previously imparted
by the shearing motion. The heat thus generated, or retained, would
account for the assumption of a granitic structure in portions of
a dyke, but not for the foliation of the other portions.

Mr. Teall considers “that the most convincing proof that the
foliated structure is the result of movement after the consolidation
of the rock is furnished by its relation to fault planes. A rock must
necessarily be solid before it can be faulted.” But we learn from
Mr. Teall’s paper that there must have been a lengthened series of
earth-movements at the Lizard; thus he speaks of the ‘“super-
position of the effects of distinct movements” ; the fractures there-
fore, to which he alludes, may have taken place after the consolida-
tion of the rock; and after the foliation had been produced. Do all
the faults in the gabbro present foliated margins? I gather from Mr.
Teall’s article (read with Professor Bonney’s paper in Q.J.G.S. vol.
xXxxill.) that this phenomenon is principally to be observed at the
junction of the gabbro with other rocks. But even if some of the
faults in the gabbro do present this phenomenon, I do not see why,
in those exceptional cases, the faulting should not have taken place
before the complete consolidation of the gabbro. If the fault ran
through the rocks above and below the gabbro, the gabbro would
surely have divided in the line of the fault as readily as a layer of
jam between slices of sponge cake does when the cake is broken. If
the gabbro was not completely rigid where thus divided, the shear
might have produced a foliated structure in the portions exposed to
the tearing effects of the rupture.

In conclusion, I would invite the attention of the readers of the
GrotocicaL Magazine to the sketches of two foliated gabbro veins
in the Lizard serpentine drawn by Professor Bonney (figs. 2 and 4),
which will be found at pp. 893, 897, of his paper in vol. xxxiii.
(1877), Q.J.G.S. Professor Bonney, in his letter published in the
December Number of your MaGazinzg, tells us that the serpentine is
“free from all indications of mechanical disturbance.” This being
80, it seems physically impossible that the foliation of the gabbro in
the veins depicted in his paper can be due to ‘“‘ shearing movements”
acting on a ‘solid rock.” Furthermore, it will be observed that the
foliation in one of the veins (fig. 2) not only runs with the two sides
of the vein, but also with the boundary of the terminal end (vide the
illustration). Professor Bonney tells us that the foliation runs
“roughly parallel to the longer sides of the vein, except towards the
top, where it tends to become parallel to the upper surface.” This
is what I should expect to see if gabbro in an imperfectly con-
solidated, or semi-plastic condition were forced into, or through,
an opening in the serpentine rock; but it is, to me, totally in-
comprehensible on the hypothesis of “ shearing motion parallel with
a fault plane.”

78 Notices of Memoirs—Prof. Lapworth on the Ordovician.

IN @Pe eras) @iat Aves VEO reise

—————~@___

J.—Pretiminary Notre on tHE Orpovictan Rocks or SHROPSHIRE.
By Professor C. Larwortn, LL.D., F.G.S.

[A Paper read before the British Association, Birmingham, Section (C) Geology,
September, 1886.]

N this note the author gave a brief review of the history of
discovery and opinion respecting the Lower Paleozoic rocks
of Wales and the West of England, and pointed out that the results
developed of late years by “British and foreign geologists made
it evident that Murchison’s Silurian System, as einel in the later
editions of “Siluria,’ was in reality composed of three distinct
geological systems, and that of these three the only one which
belonged to him by right of discovery and correct description was
the so-called Upper Silurian, which was therefore the only true
Silurian System. The lowest known fossiliferous system (the
Primordial Silurian of Barrande) was not discovered by Murchison,
but by Sedgwick, who regarded it as the lower half of his own
Cambrian System, and it ought, as a matter of justice and convenience,
to retain that name only. The intermediate system (claimed as
Lower Silurian by Murchison, and as Upper Cambrian by Sedgwick)
belonged to neither, for its life-types are wholly distinct from those
of the true Cambrian below and of the true Silurian above. This
distinction must be recognized by a distinct title. The Silurian was
named by Murchison after the ancient British tribe of the Silures,
who inhabited South Wales, where its rocks attain their fullest
development. The rocks of the disputed intermetliate system,
however, are most fully developed in North Wales—the land of the
equally ancient tribe of the Ordovices. The author had proposed in
1879 that the middle system should be entitled the Ordovician System,
after this old tribe, and this name is gradually coming into use
among geologists.

During the last few years the sequence and fossils of the Ordo-
vician strata of Shropshire have been studied in detail by the author,
and their igneous rocks, both interbedded and intrusive, have been
worked out by Mr. W. Watts. In this note a general summary of
his own conclusions was communicated by the author, and illustrated
by maps, sections and lists of characteristic fossils.

Ordovician strata occur in two distinct sub-areas in Shropshire,
viz. in the district of Shelve and Corndon to the west of the
Longmynd, and in the Caradoc district to the east of that range.
In both districts these strata are overlain unconformably by the
basement beds of the Silurian, which rest transgressively upon every
zone of the Ordovician in turn.

In the Shelve and Corndon district the Ordovician rocks repose at
once upon the highest known strata of the local Cambrian, and are
arranged in the following ascending order :—

Notices of Memoirs—Prof. Lapworth on the Ordovician. 79

SwHetve Series.

(a) Stiper Group, consisting of the well-known Stiper Quartzites
and their associated strata.

(6) Ladywell Group, composed of the dark shales and flagstones
of Mytton, Ladywell and Hyssington, with Dichograptide
and Ogygia Selwynii, ete.

(c) Stapeley Volcanic Group, andesitic lavas, ashes and inter-
bedded shales.

Mrapowtown SERIES.

(a) Weston Group of Grits, flagstones and dark shales.

(6) Middleton Group, composed of dark shales, with Didy. Murchi-
sont, and calcareous flagstones, with Ogygia Bucchi and
Asaphus tyrannus.

(c) Rorrington Group, of intensely black shales, with Conograptus
gracilis and Leptograptus.

CurIrBury SERIES.

(a) Aldress Group, composed of the Spy Wood calcareous grit, and
the Aldress Graptolitic shale.

(6) Marrington Group, including the Hagley volcanic ashes and
shales, and the Whittery ashes and overlying shales.

The only Ordovician rocks occurring east of the Longmynd are
those forming the local Caradoc Series of the author (the Caradoc
formation of geologists). The basement beds of this series rest
unconformably upon all the older rocks of the district—upon the so-
called Uriconian, Longmyndian, Wrekin Quartzite, and Shineton
Shales, and its component zones are each covered up unconformably
in turn by the basement beds of the Silurian. This isolated
Ordovician Series is composed of the following members :—

CARADOC SERIES.

(a) Hoar Edge Conglomerate, grits and limestone; (b) Harnage
Shales; (c) Chatwall Sandstone; (d) Longville Flags; and
(e) Onny, or Trinucleus Shales.

The Shelve series answers generally to the strata commonly
designated Arenig ; the Meadowtown series includes the typical
members of Murchison’s Zlandeilo; and the Chirbury and Caradoc
series correspond broadly to Sedgwick’s Bala formation of North
Wales.

Some of the most characteristic fossils of each of the Ordovician
sub-formations and zones were given, and it was shown how
naturally the physical and paleontological sequence agrees with that
of the corresponding Ordovician rocks of Britain and Hurope. The
peculiar physical conditions of the Shropshire area in Ordovician
times, as indicated by the very different lithological characters of the
strata upon the opposite sides of the Longmynd, was pointed out ;
and the evidences for the geological horizons and relationships
of the volcanic rocks indicated in outline. In conclusion, it was
pointed out that the clearness and simplicity of the sequence, and

80 Reviews—Dollo’s Dinosauria of Bernissart.

the highly fossiliferous nature of its strata, render it tolerably certain.
that this Shropshire succession will form the general standard
to which all other British Ordovician strata must ultimately be
referred.

IJ.—TRANSACTIONS OF THE CUMBERLAND AND WESTMORLAND Asso-
cration. No. XI. . 1885-86.

PW\HIS part contains notes on “The Mineral Springs near Keswick,”

by J. Postlethwaite (pp. 142-145.) They comprise saline waters
at Brandley Mine and Saltwell Park, and a chalybeate spring at Wood-
end Mine, near Threlkeld. Mr. T. V. Holmes contributes some
remarks on “‘ Purple-grey Carboniferous Rocks and the Whitehaven
Sandstone” (pp. 146-148). He points out that purple-grey rocks,
similar to the Whitehaven Sandstone, occur on almost every horizon
throughout the Carboniferous series in Cumberland.

IE% Je Wh dE Jah WY Se

MPEGS
I.—M. Dotno’s Notes on THE DinosauriaAn Fauna or BERNISSART.

W\HE remarkable preservation of a Fauna of Wealden reptiles at

Bernissart has been utilized with admirable skill, so that the
skeletons, though necessarily extracted in fragments, have been
again reunited in the anatomical relations of the bones, in the
Brussels Museum, under the able direction of M. de Pauw.

The animals thus displayed in a perfection which no other reptile
fauna in Europe can surpass have been the subject of a series of
valuable preliminary memoirs by M. Dollo, published during the
last few years in the Bulletin du Musée Royal d’Histoire Naturelle
de Belgique. The object in issuing these notes, in anticipation of
the full description which is to follow, is professedly to gain from
the criticism of scientific men suggestions which may aid in the
perfection of the final monographs. I gladly avail myself of this
opportunity for drawing attention to the excellent work which
M. Dollo has thus far performed ; and at the same time offer a few -
suggestions upon points where a difference of opinion seems to me
legitimate.

“The great interest of this work centres in the Dinosaurians, which
were examined by M. Boulanger, and referred to the Iguanodon
Mantelli, and a new species navine by him Iyuanodon Bernissartensis,
in days before M. Dollo commenced his labours.

The author begins by contrasting the differences between these
two forms. Separating the vhemadiens of the animals, we are able to
define the two types thus: Iguanodon Mantelli is a relatively small
and slender animal, with a skeleton nearly twenty feet long. Its
skull, 50cm. long, is relatively elongated, being moderately deep,
and three times as long as wide. ‘The anterior nares are long
narrow vacuities, half as long as the lower jaw, and descending:
anteriorly for some distance over it. ‘The orbit for the eye is rather
longer than deep. The temporal vacuities, seen from above, are

‘Reviews—Dollo’s Dinosauria of Bernissart. 81

long narrow slits, which diverge anteriorly. The scapula is
relatively slender and elongated, being eight times as long as wide.
The coracoid is pierced by a foramen placed near to the scapular suture.
The posterior border of the coracoid is rounded—the sternal elements
are relatively small. The fore limb is half the length of the hind
limb. The humerus is relatively short. The manus is nearly one-
fourth of the length of the limb. The ungual phalange of the first
digit, which forms a sort of spur, is one-third the length of the
longest digit. The metacarpal bones are compressed together
laterally, indicating a relatively narrow extremity. There are five
sacral vertebra. The pre-acetabular process of the ilium is nearly
one-half the length of that bone. The pre-pubis is short, thin, and
expanded; its length, depth and thickness being expressed, in
millimetres, by the numbers 400, 200, 10. The large lateral
trochanter of the femur is in the middle of the length of the bone.
The tibia is relatively long.

On every one of these points of structure the animal named
Iguanodon Bernissartensis differs, so that the animal may be defined
in comparison with I. Mantelli as being more massive in all its
proportions; and it is about thirty-three feet long. The skull is
relatively broad, the width being half its length, which measures
65cm. ‘The anterior nares do not descend so low upon the lower
jaw, while the length of the anterior narine is contained three times
in the length of the lower jaw. The orbital vacuity is elongated
vertically. The temporal fossa are each wide and four-sided in
form. The scapula is relatively stouter and shorter, being six times
as long as wide. ‘The coracoid is pierced by a foramen, which takes
the form of a notch, opening posteriorly towards the humerus.
The sides of the bones are excavated, and their posterior borders
diverge, as if to receive sternal elements. The large sternal bones
are relatively strong. The fore-limb is two-thirds as long as the
hind limb, so that the proportions of the extremities are more
nearly equalized. The humerus is relatively longer, and the manus
shorter, being scarcely one-fifth the length of the limb. The first
digit has its spur-like, inwardly directed, terminal phalange, half
as long as the longest digit. The metacarpal bones are sub-quadrate
in transverse section. There are six vertebre in the sacrum. In
the pelvis, the pre-acetabular part of the ilium is only one-third of
its total length. The pre-pubis is long, massive, and straight. Its
length, depth and thickness being expressed in millimetres by the
numbers 700, 170, 40. The large lateral trochanter on the femur
is situate in the lower third of the bone. The tibia is relatively
shorter.

The author then goes on to discuss the taxonomic value of these
differences, considering three hypotheses. First, whether the two
varieties are to be attributed to age ; secondly, whether the differences

-may be individual or sexual; and, thirdly, whether they afford
evidence of two species, or indicate two genera. M. Dollo con-
cludes that the differences enumerated constitute a species. This
conclusion is based on a consideration of the characters by means of

DECADE III.—vVOL. IV.—NO. II, 6

82 Reviews—Dollo’s Dinosauria of Bernissart.

which various authors have defined the genera which are allied
to Iguanodon; and on an estimate of the characters by which the
three known species, at present referred to Iguanodon, have been
characterized. Those species cannot, however, be completely com-
pared. The Iqguanodon Mantelli has five sacral vertebra, and the
pre-acetabular part of its ilium is half the length of the bone.
Iguanodon Prestwichi has four sacral vertebra. Iguanodon Seelyt
has the ilium three times as long as its pre-acetabular portion ; but
its sacrum is not at present known.

The author then goes on to show that the differences of propor-
tion between the principal bones of the fore and hind limbs in the
type specimen of Iguanodon Mantelli, and the smaller Iguanodon in
Brussels, amount to only a small percentage; and compares the
type slab from the Lower Greensand of Maidstone with the Brussels
animal, with the following results :—

Ilium. Femur. Tibia. Scapula. Humerus. Radius.

Maidstone spm.... 0°75 0-81 0:75 0-72 0°47 0:45
Brussels spm. ... 0°71 0-71 0°67 0°62 0°43 0°37
showing that the Brussels animal is somewhat smaller, and that
the proportions of the fore and hind limb are not quite the same.
He then discusses the nomenclature of the larger type, and recog-
nizes its extremely close correspondence with the Iguanodon Seelyi
of Hulke, with which he would have had apparently no hesitation in
identifying it, but for the following remarkable passage, in which
Mr. Hulke states “I had long possessed evidence that Iguanodon
had a scuted hide; but until the acquisition of these remains, such
evidence was very fragmentary. In cutting away the rock from the
larger bones of the hind limb, I found beneath it a layer of bony
tissue, separated from the endoskeleton by a deeper layer of rock,
enclosing much black carbonaceous matter. From its position with
reference to the endoskeleton, it was obvious that the outer layer of
bony tissue was exoskeletal—was in short a dermal mail.” Mr.
Hulke further describes these bones as irregularly polygonal, with
a surface slightly pitted, some of them 2cm. thick and Tem. in
diameter. M. Dollo finds evidence of the integument, but no trace
of bony armour, which he thinks should separate the species, but
maintains that if the large Brussels form is identical with the
Iguanodon Seely, priority must be claimed for Boulanger’s name,
Iguanodon Bernissartensis.

The author follows Marsh in placing Iguanodon in the Ornitho-
poda, but makes a criticism, which was valuable at the time, in
opposition to the view that clavicles formed a characteristic of the
group, urging that the bones which were thus identified by Marsh
are elements in the sternum. The note concludes with a definition
of the order Ornithopoda, and its families, a definition of Iguanodon,
and definitions of the three species.

There is no doubt that M. Dollo is substantially in harmony with
Mr. Hulke in his views concerning the classification of these
Dinosaurs. But I ventured, when the description of the Iguanodon
Presiwichi was read before the Geological Society in 1880 to
express an opinion that the characters of the sacrum, of the

Reviews—Dollo’s Dinosauria of Bernissart. 83

astragalus, and os calcis, the relation of the fibula to the tibia and
other osseous characters, could only be regarded as generic
characteristics. More mature consideration has only deepened my
conviction that the Iguanodon Prestwichi is not an Iguanodon in the
sense in which the term Iguanodon should be used as a generic
distinction. There would be an end of zoological method if organic
differences of the magnitude which divide this animal from the
Iguanodon Mantelli could be classed as specific characters. The
earlier writers made species in this way; but it was by the institu-
tion of a method altogether distinct from that used in the modern study
of existing life. I believe it to be imperative that no such difference
of method should prevail in the study of existing and extinct
animals, and therefore contend that, since the structures which I
have named differentiate the Kimmeridge Clay animal so that
it would have been referred to a new genus had it been an existing
animal, we have no choice but to class it as a genus, though no name
has as yet been proposed to designate its characteristics. Similarly,
when the Memoir on Iguanodon Seelyi was read before the
Geological Society, two years later, I suggested that it would have
been safe to have constituted it also as a new Dinosaurian genus.
I therefore find myself differing from M. Dollo, not so much upon
the results of his own work, as upon matters in which he depends
upon and has the support of one of our most accomplished and most
cautious comparative anatomists. But when the value of the character-
istics of these two Iguanodon types, which M. Dollo has so well
contrasted, is estimated, I am tempted to ask, is there any living
reptilian genus which in the skeletons of its species comprises so
wide and varied an assemblage of differential characters? If the
differences were limited to one series of characteristics, or to one
region of the body, we might accept them as specific; but when
they range through all parts of the skeleton, so as to imply many
differences in the soft parts of the body, I cannot but reiterate that
the close correspondence between Iguanodon Bernissartensis and
I. Seelyi sustains my earlier belief that the larger Belgian type
constitutes a new genus. The form of the head, of the nares, of the
orbit, of the temporal vacuities, of the pre-dentary bone, in Iguanodon
Mantelli, all seem to me generic characters; and the elevation of the
nasal bones into a sharp crest may be of similar importance, seeing
its relation to the nasal crest or horn in Ceratosaurus. These
characters are sustained by the proportions of the several parts of
the ilium, the form of the prepubic bone, the shape of the femur and
position of its third trochanter, no less than by the characters of the
scapular arch and the metacarpal bones. The taxonomic value of
these characters should be beyond question.

If I am right in my exposition that two of the three species
which have hitherto been referred to Iguanodon belong to new
genera, then it necessarily follows that I am unable to accept either
the data with which M. Dollo works, or the conclusions at which he
arrives in consequence, in so far as this concerns the classification.
It is unnecessary to define my view by suggesting names for these

84 ‘Reviews—Dollo’s Dinosauria of Bernissart.

genera now. Some bones of the Iguanodon Seelyi type may have
‘been referred to Pelorosaurus in Mantell’s collection, but the genus
Pelorosaurus has no existence, and should be erased from catalogues
as having been founded upon a humerus of Cetiosaurus.

In his second note M. Dollo limits himself to a discussion of the
sternum. He describes the pair of large triangular bones with
elongated processes which were found in association with the
scapular arch, bones of the fore limb, and sternal ribs, and believes
himself justified in concluding that they are in their natural undis-
turbed position in contact with the coracoids, and therefore combats.
the conclusion of Professor Marsh that they are the clavicles. In
the remainder of the paper the author goes on to cite the descriptions.
of the sternal bones in other Dinosaurs, which have been given
by other writers.

I give in outline the sternal apparatus as restored by M. Dollo.

Scap.—scapula. Cor.—coracoid. St.—sternal bones.

But I am unable to accept his arrangement of the bones. Fully
admitting that the bones which he terms sternal are in natural
contact with each other in his slab (pl. xii. fig. 2), Iam unable to-
admit that they are in natural contact with the coracoids. Mr.
Hulke has been more fortunate in obtaining a better preserved
example of the sternal apparatus of Iguanodon Mantelli (figured im
the Quart. Journ. Geol. Soc. August, 1885), and he regards the bones.
cited by Dollo as a pair of sternal ossifications, comparable to the
immature sternum of a Struthious bird, as being clavicles—a conclu-
sion previously arrived at by Mr. William Davies, and adopted by
Professor Marsh. I first studied the specimen described by Mr..

Reviews—Dollo’s Dinosauria of Bernissart. 85

Hulke in 1870, and failed to form any decisive opinion on its inter-~
pretation, till I saw it again after Mr. Hulke’s paper had been read.
Mr. Hulke regarded the fossil, which he described, as consisting of the
clavicle and interclavicle of Iguanodon. And, in a restoration, the
elavicles are shown divided from each other by the interclavicle, which
has its chief extension posterior to them. The clavicles are represented
as also articulating with the scapula; while the coracoids, repre-
sented as passing behind the clavicles and anterior part of the
interclavicles, articulate for a short distance with the sides of
the interclavicles, and afterwards with a hypothetical sternum,
which is supposed to pass behind the interclavicle. I regret to find
myself unable to adopt any one of these determinations. First, what
Mr. Hulke regards as sutures defining the specimen into clavicles
and interclavicles, I regard as fractures in the specimen. The
bones, which for the moment I will distinguish as the sternal
elements of Dollo, I regard as being in close median contact, as in
the Belgian specimen already cited. I am unable to admit that
these bones articulated with the scapula, because I have never seen
a facet on any Iguanodon scapula, which could have received such a
bone. While the surfaces on Mr. Hulke’s fossil sternum, which
are supposed to have articulated laterally with the coracoids, seem
to me to have given attachment to sternal ribs. It is manifest from
evidence in the British Museum that the specimen found by Mr.
Beckles, and figured by Mr. Hulke, and represented in the British
Museum by an excellent cast, includes another ossification, extending
beyond the sternal bones of Dollo. Professor Cope has some
interesting observations on this subject in the American Naturalist
for February, 1886. First he suggests that the bones in dispute are
neither clavicles nor sternum in the ordinary sense of the term, but
the pleurosteal elements in the sternum, which were developed so
that the long process extended backward and outward, as in the
sternum of a fowl. It happens that Diclonius mirabilis has these
elements perfectly preserved, and closely resembling in form and
arrangement the same bones in Iguanodon Mantelli. Professor
Cope, however, identifies his sternum with the sternum of Mono-
clonius crassus, so that he would place the coracoid bones in direct
articulation with these sternal bones, almost in the position in which
Dollo placed them originally. Professor Cope was unaware of the
true structure of the sternal apparatus, described by Mr. Hulke, or
he would not have proposed to bring the coracoids into connection
with osseous surfaces, which in that fossil are manifestly separated
by a broad, thin, ossified mass, from any other bone. Nevertheless,
I entirely agree with Professor Cope that the bones in dispute are
not clavicles, and further, that the specimen to be understood must
be turned upside down, in the way which he suggests. I am also
prepared to accept these sternal elements as approaching more nearly
to the pleurosteal elements in the sternum of a bird than to any
other ossification, in so far as they are posterior to the articulations
for the sternal ribs; but in position they are essentially the xiphoid
bones, which have preserved as marked and as distinctive an

86 Reviews—Dollo’s Dinosauria of Bernissart.

individuality in the sternum of Dinosaurs, as in the plastron in
Chelonians. The sternal ossification, anterior to these xiphoid
elements, which is seen in the fossil figured by Mr. Hulke, is thin,
and is not commonly preserved. The anterior extremity of this
Dinosaurian structure is at present unknown. ‘The posterior xiphoid
ossification may have been connected with the prepubic bones,
in much the same way as the abdominal ribs of Crocodiles extend
down to the pubic bones.

In the third paper M. Dollo discusses the attitude of the Iguano-
don. First, there is the view originated by E. D. Cope that they
progressed chiefly upon their posterior limbs, in the manner of the
Ratite, of which they were supposed to be the parent stock.
Secondly, I have accepted the bipedal progression, but denied that
these Dinosaurs are the ancestors of Birds. And, thirdly, Sir R.
Owen regards them as having been exclusively aquatic, with the
body carried in a horizontal position. In support of the upright
position, it is urged that there is a remarkable correspondence
between the pelvis of Iguanodon and that of Ratite Birds; while the’
difference in structure between the fore and hind limbs of Iguanodon ;
the relative dimensions of the head and thorax as compared with
quadruped reptiles; the nature of the vertebral column; and the
Wealden footprints described by Beckles and other writers furnish
conclusive evidence. Hach of these points is considered in detail.

The author begins by discussing the pelvis, and endeavours to
combat the views of Sir R. Owen, and to prove that the ilinm
of Iqguanodon agrees in the most striking manner with the homo-
logous element in Birds. I am not concerned to do more than urge
that the author rather undervalues the resemblances to the ilium
of a Crocodile. If we begin with the geological history of the
Dinosaurian ilium, and trace it in development through successive
generic types of evolution, I do not see how the conclusion can be
resisted that the Dinosaurian ilium is a modification of the Croco-
dilian ilium, which only resembles the ilium of a bird in such ways»
as indicate a modification of the Crocodilian plan. This plan of the’
Dinosaurian ilium, as seen in such types as Zanclodon and Theco-
dontosaurus, is remarkable for the mass of the bone lying behind the
acetabulum, as in Crocodiles. ‘The form of the post-acetabular part
is wonderfully alike in both groups. And the difference begins.
with the Dinosaurian elongation of the pedicle for the pubis, which
throws the bone upward, and the concurrent elongation of the
preacetabular process, which at first is so short as not to extend in
advance of the acetabulum. Hven when the latter process is
elongated, as in Iguanodon Mantelli, or I. Bernissartensis, it
never loses trace of its origin, or approximates to the ilium of a bird
in form, any more than in osteological connections; though the
ilium of Stegosaurus makes perhaps as near an approximation to
the Ratite contour as is seen in a Dinosaur. The ischium and pubis.
of Iguanodon are treated by M. Dollo in the same spirit, with the
conclusion that the ischium in Dinosaurs, and especially in Iguano-
don, shows a strong avian resemblance, while in the pubis there is.

Reviews—G. H. Williams’s Gabbros of Baltimore. 87

perfect agreement. This conclusion is open to exactly the same
criticism as we offered concerning the ilium. If the only Dinosaurs
known were such types as Morosaurus, Atlantosaurus, Brontosaurus,
and the allied types described by Professor Marsh, no doubt could
exist that the Dinosaurian pelvis was not avian. Nor would its
avian resemblances have been sustained by the discovery of such
types of animal as have been named Ceratosaurus, Allosaurus, and
Celurus. Yet it is perfectly true that if Iqguanodon, Camptonotus,
and Laosaurus, were the only known Dinosaurs, an avian re-
semblance might be recognized in the ischiac and pubic bones.
But the very fact that these bones vary their forms and change
their resemblances within the same order, so as to be avian in some
genera, and not avian in others, robs the resemblance of all taxo-
nomic importance, and demonstrates that the character of an order
or sub-class cannot at the same time be both avian and not avian.
The resemblances accordingly sink to the value of sub-ordinal
characters, by which some Dinosaurs may be differentiated from
others, and are thus proved, I think, to owe their remarkable avian
forms to conditions of existence. Exception is taken by M. Dollo to
certain details in Mr. Hulke’s restoration of the pelvis of Iguanodon,
stating that in Iguanodon Mantelli the pubis is not inclined ventrally
inward and forward, but, on the contrary, ventrally forward and
outward, like the rudiment which exists in birds. There is no
symphysis pubis. The post-pubis is not continued to the extremity
of the ischium, and is therefore not applied against it in the distal
region. M. Dollo also takes exception that the Brussels specimens
show by the way in which processes from the ischium extend in
front of the pubis, two foramina, instead of the one shown in Mr.
Hulke’s restoration. M. Dollo is certainly correct with regard to the
structure in the genus represented by I. Bernissartensis; but he has
presented no evidence that Mr. Hulke was incorrect in his restoration
of the pelvis of Iguanodon. He objects to the identification of the
pre-pubis of Iguanodon with the small process which is similarly
placed in birds, by showing that the supposed pre-pubic structure
is developed from the ilium in the common fowl, and cannot there-
fore be homologous with the pre-pubis of Iguanodon and other
Dinosaurs. The author enters into many details to contest the
views which have been advanced by Sir Richard Owen concerning
the interpretation of the pelvis of Dinosaurs, and does good service
in bringing under the notice of continental writers the more modern
interpretations which, we may say, without any disparagement to
M. Dollo’s originality, have long been current in this country.
H. G. SEEey.
(To be continued.)

I].—Unirep Srates Grorocican Survey: Buxtierin No. 28. Tux
GABBROS AND ASssocraTED HornBLENDE Rocks OCCURRING IN
THE NriGHspourHoop or Batrimore, Mp. By G. H. Wrouiams.
Pp. 59 and iv. Plates. (Washington, 1886.)

HIS is a valuable contribution to American petrology, and many
of the conclusions established must have a special interest for

88 Reviews—G. H. Williams’s Gabbros of Baltimore.

British geologists also. The author has minutely studied, in the
field and by microscopical and chemical analysis, the conversion of
a pyroxenic to a hornblendic rock. The rocks occur (Chapter I.) in
an oval district 50 square miles in area, breaking through the
gneissic rocks to the west and north-west of Baltimore. The
pyroxenic type (Hypersthene-gabbro, Ch. II.) is a massive rock con-
sisting essentially of bytownite, diallage, hypersthene, and some
brown hornblende. The typical hornblendic rock (Ch. III.), which
the author names Gabbro-diorite, is either massive or schistose. It
contains green hornblende, often true uralite but in part compact,
and bytownite showing incipient saussuritization and also breaking
up into epidote near the contact of the felspar with adjacent
hornblende.

Chapter IV. deals with the genetic relations of these two very
different rocks. In the field they are found to be inextricably
involved, and to graduate imperceptibly into one another. The
average analyses of the two agree closely, though considerable
variations of composition occur under each type. Microscopical
examination of the transition-zone reveals the nature of the changes
that have taken place. Both the diallage and the hypersthene of
the gabbro are seen to pass gradually into green hornblende, but in
different ways. The conversion of the diallage is apparently a true
paramorphosis, this mineral and the resulting hornblende giving
closely similar analyses. The hypersthene, on the other hand, for its
amphibolization, must take up alumina and lime from the felspar,
and in the earlier stages of the change the mineral is bordered at its
contact with the felspar by a double rim, the inner zone of fine
colourless fibres, the outer dark green and comparatively compact.
This is analogous to what has been observed when olivine passes
into amphibole.

The evidence of the metamorphism of gabbro into diorite in this
district is complete at all points. The author regards augite and
hornblende as dimorphous, the former representing the stable form
of the molecules at high, the latter at low temperatures. Augite
being unstable at low temperatures will tend to revert to hornblende
under any influence which facilitates molecular motion. Pressure,
though a potent condition in many instances, is not regarded as
necessary. The concluding chapter is devoted to the description of
certain associated olivine-bearing rocks and serpentines. ‘The chief
type of olivine rock is described as a felspathic peridotite: besides
olivine, bronzite and diallage, it contains up to five per cent. of
bytownite, partly zeolitized. The olivine and pyroxenic constituents
exhibit the usual secondary actions, and the double rim of amphibole
is also found at the contact of the olivine and felspar. The structure
is remarkable, the olivine being the latest-formed mineral, in which
the pyroxenes occur porphyritically. The most abundant type of
serpentine in the district is one containing tremolite, probably
secondary after pyroxene. In some cases a further change of
amphibole into tale is observed. AS.

Reviews—Delgado’s Paleozoic Rocks of Portugal. 89

Ii].—Trrrains Patéozorques pu Porrucan. Erupr suR LES
BILopiTes ET AUTRES FossILES DES QUARTZITES DE LA BASE
pu Systeme Srtnurieue pu Portucau. Par J. F. N. Deweano,
Chef de la section des travaux Géologiques. 4to. pp. 1138, with
43 phototype plates. (Lisbonne, 1886.)

is central and northern Portugal the problematical bodies known
as Bilobites or Cruziana are the most ancient fossils known;
they occur in great abundance in beds of grit and quartzite, at
an horizon probably corresponding to the Arenig grits of this
country, and to the “‘ grés armoricain ” of Normandy and Bretagne.
M. Delgado, in this elaborate memoir, discusses in detail their
characters and probable origin, and gives full descriptions of the
varieties of form which they present. A striking feature of the work
is the magnificent series of plates, in which the fossils have been
phototyped, for the most part natural size, and they represent very
clearly and faithfully their peculiar features.

M. Delgado maintains the same views respecting these bodies
as MM. de Saporta and Marion, and upholds, with much skill, the
opinion that they are the impressions of alge. It cannot be said,
however, that these Portuguese examples afford any fresh evidence,
sufficiently decisive to decide the question as to their origin, and
whilst giving due weight to the arguments so skilfully brought
forward by the author, we do not think they are sufficient to counter-
balance those which! Dr. Nathorst has lately re-stated, viz. that the
impressions have been produced by the infilled tracks and burrowings
of marine animals. (Cardinals

REPORTS AND PROCHEHDINGS.

—<——_—_-

I.—December 15, 1886.—Prof. J. W. Judd, F.R.S., President,
in the Chair.—The following communications were read :—

1. “Notes on Vummutlites elegans, Sow., and other English Num-
mulites.”” By Prof. T. Rupert Jones, F.R.S., F.G.S.

The author finds in the ‘Sowerby Collection,” now in the British
Museum, the original specimens on which Sowerby founded his
Nummularia elegans (1826, Min. Conch. vol. vi. p. 76). These are
partly specimens from that part of the bed “No. 29” of Prof.
Prestwich’s section of Alum Bay? (Quart. Journ. Geol. Soc. vol. u.
(1846) p. 257, pl. ix. fig. 1), which is known to be the lowest of the
Barton series ; and partly some in a stone said to be from Emsworth,
in Hampshire. The former are the same as those named Nummu-
lites planulata, var. Prestwichiana, by Rupert Jones in 1852; and
the latter are WV. planulata, Lamarck (1804), and probably foreign.
Thus JV. elegans has priority over Prestwichiana ; and as this last was
determined by De la Harpe to be a variety of N. wemmelensis, Van
den Broeck and De la Harpe, this variety should be var. elegans.
The author thinks that, on broad zoological principles, N. planulata
might still be regarded as the species; but, in view of the careful
differentiation worked out by De la Harpe, he accepts the “specific”

1 Grou. Mac. 1886, p. 409. 2 See Mr. H. Keeping’s Article, ante, p. 70.

90. Reports and Proceedings—

standing of ‘‘wemmelensis” as useful among Nummulites; but “‘ Prest-
wichiana”’ has to give way to “ elegans” for the peculiar “ Barton ”
variety. A bibliographical history of the long-misunderstood N.
elegans, Sowerby, description of this form and of N. variolaria (Lam.),
notes on N. levigata (Brug.), and an account of their range in
England, complete the paper.

2. “On the Dentition and Affinities of the Selachian Genus
Piychodus, Agassiz.” By A. Smith Woodward, Hsq., F.G.S.

The genus Piychodus, owing to the detached condition in which
the teeth are usually found, has hitherto been imperfectly under-
stood. Agassiz referred it to the Cestraciontide on account of a
supposed resemblance in the arrangement of the teeth, and Owen’s
researches on their microscopic structure served to confirm this view.
On the other hand, several writers have pointed out characters
tending to show affinity between Piychodus and Rhynchobatus.

More recently, however, Prof. Cope and the author had shown
that the supposed affinities between Ptychodus and the Cestraciontide.
were only apparent, and in the present paper additional evidence
was brought forward.

The author proceeded to describe several specimens of P. decur-
rens in the British Museum, and in the collection of Mr. H. Willett,
of Brighton, one of the latter, especially, containing, what had been
previously entirely unknown, the dentition in part of both jaws.
These specimens showed that each jaw contained six or seven longi-
tudinal rows of teeth on each side of the median row, and that the
genus must be referred to the true Rays, and not to the Cestraciont
Sharks, though the precise family to which Ptychodus belongs was
more difficult to determine. On the whole, the writer was disposed
to assign it a place either amongst the Myliobatidz or in their
neighbourhood. The microscopic structure of the teeth was shown
to be insufficient, by itself, to show their affinities.

3. “On a Molar of a Pliocene type of Equus from Nubia.” By R.
Lydekker, Hsq., B.A., F.G-S.

A small collection of Mammalian remains from near Wadi Halfa
had recently been placed in the author’s hands; some of the bones
were mineralized similarly to those of the Upper Pliocence of the
Val d’Arno, or the Lower Pleistocene of the Narbadda valley.
Amongst others the most interesting is a right upper cheek-tooth
of Hquus but little worn. It evidently does not belong to any of
the late Pleistocene or Recent species of the genus, but to the more
generalized group comprising EF. sivalensis, etc.: though, bearing
in mind the impossibility of distinguishing many of the existing
species of the genus by their teeth alone, its absolute specific identity
is not asserted. We may infer, then, that the ossiferous beds of
Wadi Halfa are not improbably of Pliocene age, since this group.
of Horses, both in Europe, Algeria, and India, had totally dis-
appeared after the period of the Forest-bed. Moreover, it is of
interest, in view of previously expressed opinion, to find in the Ter-
tiary of Nubia a species of this primitive group of Aquus which is
apparently more nearly allied to the Siwalik than to the Huropean
species.

Geological Society of London. 91
II.—Jan. 12, 1887.—Prof. Judd, F.R.S., President, in the Chair.

The PresrpEntT announced the sad loss which the Society
had sustained since the last Meeting, by the death on 4th
January of Mr. John Arthur Phillips, F.R.S., who had been
for several years a valuable member of the Council, and one of
the Vice-Presidents of the Society.

1. “The Ardtun Leaf-beds.” By J. Starkie Gardner, Hsq., F.G.S.,
F.L.S.; with Notes by Grenville A. J. Cole, Esq., F.G.S.

The description of these beds by the Duke of Argyll thirty-five
years ago indicated that enormous tracts of Trap in the Inner
Hebrides were of Tertiary age. Prof. Edward Forbes, who described
the leaves, inclined to the idea that they might be Miocene; but in
estimating the value of this conjecture, we must remember that at
the time the existence of Dicotyledonous leaves of similar aspect, but
of undoubtedly Cretaceous age, was quite unsuspected, and that no
typical Eocene flora had then been properly investigated or described.
Prof. Heer, however, adopted the opinion that the age of this for-
mation was Miocene, and unfortunately extended its application to
formations containing similar floras in Greenland and elsewhere.
One object of the present communication is to show that, instead of
belonging to the Miocene, these floras are of Eocene age, and in fact
older than the Thanet beds. The other object is to redescribe the
plant-beds, and to show that they are part of a rather extensive
series of sedimentary rocks intercalated among the Traps.

The rapid accumulation of knowledge as to the distinguishing
characteristics of Cretaceous, Hocene, and Miocene floras has rendered
the attainment of the former object at least possible, and it is of the
greater importance, since the error in determining the age of the |
fossil floras of Ardtun and Antrim, and of a part of the Arctic flora,
is a great impediment to further progress. Instead of all these
immense thicknesses of beds belonging to the Miocene, they have
their base somewhere in the so-called Cretaceous series; 400 feet
higher up we are about the horizon of the Thanet Beds; while at
1000 feet up the flows were contemporaneous with the Bracklesham
and Barton deposits. The first acid eruptions were Miocene, as
shown by the floras preserved in Iceland.

The author described the various exposures from his own
observations and Mr. Cole’s notes. At Ardtun the Traps are
surmised to be parts of once continuous flows, still represented
at Staffa and Burgh, but broken through by an intrusive sheet. The
leaf-beds are varied in composition, the richest being very friable,
while the best matrix is a limestone as fine as lithographic stone, in
which plant-remains are few, but exquisitely preserved. They are
overlain by thick deposits of river-gravel, chiefly composed of flint
or silicified chalk, but in which Mr. Cole has detected fragments of
sanidine like that of Ischia or the Rhine, and of trachyte. At Carsaig
the gravels are coarser and less evenly bedded, and the sandy matrix
apparently is entirely made up of flint. The coarse gravels are
flanked by sands and indicate a rapid flow of water, occupying a

92 Reports and Proceedings—

valley not less than a mile across. The Ardtun gravels indicate

a less rapid but more extensive river. The section at Burgh is very .
like that at Ardtun, with the addition of an extensive ash-bed at the

base, with sand instead of gravel, and with many hundred feet of

Trap above. In the Wilderness there is a small outcrop of Chalk-

rubble, less than 300 square feet in extent, and evidently redeposited.

Some distance under this is Greensand in situ, then Lower Lias, and

lastly Poikilitic sands. This descriptive part of the paper concluded

with some remarks on the estuarine formation between the Chalk
and Upper Greensand at Beinn Jadain in Morven, which the author

investigated in the hope of finding plant-remains belonging to that

interesting age. He doubts that the Chalk is in situ, and considers

the evidence of age to be not quite conclusive.

The second part of the paper deals with the paleontological
evidence. The evidence, if confined to the plants of Ardtun, was
said to be scarcely worth serious discussion, and the analysis was
extended to the far richer plant-bed at Atanekerdluk. The identi-
fications of these with Miocene plants of Europe were discussed
seriatim, and shown to be groundless, or only applied to such pre-
vailing types of leaves as are common to widely distinct genera, and
occur in floras recent as well as fossil, and which cannot be super-
ficially distinguished in even a living state. The strong resemblance
and even identity of the best-characterized forms with the older
Eocene plants has been, on the other hand, hitherto ignored. The
most strongly marked types of Greenland, and which recur in
Antrim, are met with in the Heersian of Gelinden and at no other
horizon, and amply suffice to fix the date of the Antrim floras. ‘The
Mull flora, as its aspect indicates, is still older, and consequently
earlier than the Thanet Bedsof England. Independently of positive
evidence, the absence of any late Tertiary types, even of the Legu-
minosee, which abound as low down as the Reading Beds, sufficiently
indicates their extreme antiquity.

2. “On the Hchinoidea of the Cretaceous Strata of the Lower
Narbadaé Region.” By Prof. P. Martin Duncan, M.B., F.R.S., F.G.S.

A collection of fossils from the Limestone near Bag, in Western
India, made by Colonel Keatinge, was described by the author in
the Quarterly Journal of the Society for 1865, and shown to be of
Upper Greensand or Cenomanian age. The country was subse-
quently examined, and a sketch-map made by Messrs. Blanford and
Wynne, who found near Bag the following beds in descending order
beneath the Deccan and Malwa traps :—Coralline limestone, Argilla-
ceous limestone, Nodular limestone, Sandstone. All were conform-
able, the whole thickness of limestone did not exceed 50 feet, and
the fossils obtained by Colonel Keatinge were shown to have been
exclusively derived from the Argillaceous limestone. All the beds
were referred to the same Cretaceous sub-division.

Good topographical maps having been prepared, the area was
remapped by Mr. Bose, who obtained several additional fossils from
the Coralline and Nodular limestones, and a few from the upper beds
of the Sandstone. He accepted the Cenomanian age for the Argil-
laceous limestone, but referred the overlying Coralline limestone toa

Geological Society of London. 93

Senonian age, and the underlying Nodular bed to the Gault, whilst
he regarded the Sandstone at the base as probably Neocomian.

Mr. Medlicott, Director of the Geological Survey of India, in com-
‘pliance with the author’s request, had sent to him the Echinoidea
collected by all the geologists named, and, on examination, the
collection was found to comprise the following eight species :—
Cidaris, sp. nov., Salenia Fraasi, Cyphosoma cenomanensis, Orthopsis,
sp. nov., Hchinobrissus Goybeti, Nucleolites similis, var., Hemiaster
cenomanensis, and H. similis. All the known forms were found in
beds of Upper Greensand age in the Lebanon, Europe, etc., except
the Nucleolites, which was a Chloritic-marl species. Of the eight
species all were found in the Argillaceous limestone, five in the
Coralline, and two in the Nodular limestone, the last two, Hemiaster
cenomanensis and H. similis, occurring throughout. Under these
circumstances there appeared no reason for assigning the beds of
limestone to different stages of the Cretaceous system.

3. “On some Dinosaurian Vertebre from the Cretaceous of India
and the Isle of Wight.” By R. Lydekker, Hsq., B.A., F.G.S.

The author, in 1877, described some Dinosaurian caudal vertebree
and a femur from the Lameta beds of India (Middle or Upper
Cretaceous), and as he was unable to find any described forms that
resembled them, he proposed for them a new genus, which he called
Titanosaurus. Two species were represented. After noticing the
principal characters of the Indian specimens, he showed that some
caudal vertebre in the British Museum, collected by the late Mr.
Fox from the Wealden of Brook, in the Isle of Wight, agreed in
form with those found in India, and were, in fact, intermediate in
some respects between the two Indian species. An inquiry into the
associated remains at Brook indicated that the caudal vertebra in
question probably belonged to Ornithopsis, and this probability was
supported by the structure of certain American fossil genera placed
by Marsh in the same suborder, Sauropoda, of the Dinosauria. In
any case there is great probability that at least one of the Indian
and the Isle of Wight vertebree should be referred to the same genus.

Some other instances of fossil vertebrates appearing in Indian beds
of a rather later geological age than in Europe were noticed.

4. “* Further Notes on the Results of some Deep Borings in Kent.”
By W. Whitaker, Esq., B.A., F.G.S.

This paper contained some details on the borings at Chattenden
Barracks and at the Dover Convict Prison, in addition to those
already published in the Quarterly Journal of the Society for 1886.
Sections of the new borings, one at Strood, the other at Lydd, were
also given.—The Chattenden boring has been successful in reaching
the Lower Greensand, and a supply of water had been obtained.
This result showed that on the section accompanying the previous
paper the beds of the Lower Greensand should have been carried
rather further to the northward.—The Dover boring was abandoned
at 931 feet from the surface. The examination of the specimens
showed that the thickness formerly assigned to the Lower Greensand
Should be reduced to 31 feet, the upper five feet referred to that
stage belonging to the base of the Gault, whilst the bottom, 18 feet,

94 Correspondence—Ur. E. T. Newton—Mr. A. B. Wynne.

together with an additional 69 feet, mostly of clay, subsequently
_ cut through, were, for reasons given, assigned to the Wealden series

and probably to the Hastings beds. The results of these additional
details went to show (1) that, though the Lower Greensand itself was
rather thicker at Chatham than at Dover, comprising two divisions,
the Folkestone and the Sandgate beds at the former place, and only
the Sandgate at the latter, the Lower Cretaceous beds, as a whole,
were much thinner at Chatham, owing to the disappearance of the
Wealden series ; and (2) that in passing to the eastward the Weald
clay thinned out before the Hastings beds, instead of the reverse,
which was previously suggested.—The Strood and Lydd sections were
merely of importance as furnishing details. The paper concluded
with some remarks on the best site for additional borings at Dover,
in order to prove the deeper-lying rocks.

CORRESPONDENCE
ae eee
THE FFYNON BEUNO CAVE.

Str,—So much interest has been shown in the Ffynon Beuno
Cave, and especially in the determination of the age of the bed from
which Dr. Hicks and Mr. Luxmoore obtained the flint implement,
that I trust you will allow me space in the Grotocican MaGazinE
for a few remarks on the mammalian remains which have been
found, and concerning which, as it seems to me, Dr. Hicks is under
a misapprehension. In a note to Dr. Hicks’s paper, published in the
December Number of this Macazine (p. 567), he alludes to a
remark made by Prof. Hughes on the same subject (November,
p- 492), and says: “Prof. Hughes’s paleontological argument is
found on examination to be almost equally inapplicable, as a very
large proportion of the animals occur in the Norfolk Forest Bed,
which is acknowledged by all to be of Pre-Glacial age. The fact
that some others have not been found in the caverns probably indicates
that they did not migrate into the area.”

The evidence to be derived from the list of mammals given by
Dr. Hicks on p. 571 would certainly lead one to the conclusion that
the deposits, from which they were obtained, were of Pleistocene
age. It is quite true that most of these species have been found in
the Pre-Glacial Forest Bed of Norfolk, and it is probable that others
of them will yet be found; although at present the Lion, Reindeer,
and Woolly Rhinoceros are conspicuously absent from the Forest
Bed fauna. On the other hand, the whole of these Ffynon Beuno
cave mammals are met with in acknowledged Pleistocene deposits.
And further, it must be remembered, that the forms which are common
to the Ffynon Beuno cave and the Forest Bed are those which link
on the Forest Bed to the Pleistocene times; and not those which are
characteristic of the Pre-Glacial fauna. This brings us to another,
and perhaps the most important point, and that is the entire absence
of characteristic Pre-Glacial forms from the Ffynon Beuno cave.

Some of the most characteristic species of the Pre-Glacial Forest
Bed are Rhinoceros Etruscus, Trogontherium Cuviert, Myogale moschata,
Elephas meridionalis, and several large Deer such as Cervus Sedgwickit,

Obituary— Henry Michael Jenkins, F.GS. 95

€. verticornis, C. poligniacus, C. Savinii, etc., and the finding of any one
of these forms in the Ffynon Beuno deposit would be strong evidence
in favour of its Pre-Glacial age; but not one of them has been found.
With regard to the stratigraphical evidence of the age of this
deposit, I have nothing to say: but the mammalian fauna would
certainly lead one to assign to it a Pleistocene and not a Pre-Glacial
origin. EK. T. Newron.

PHOSPHATIC NODULES OF THE SALT RANGE, INDIA.

Srr,—Dr. H. Warth, of the Indian Civil Service, writes from
Dehra Dun, under date 17th Nov. 1886, referring to certain nodules of
Phosphate of Lime, which he found in overlying shales associated
with the Salt Range Coal at the localities of Pid, Dandét, ete. He
speaks of these phosphatic nodules as being “nearly equal in purity”
to the “bed” of phosphate of lime at Mussoorie Hill-station, which,
so far as I am aware, he was the first to notice in this connexion ;
having sent me some samples from the locality nearly a year ago.

From this locality, it would seem some inferior specimens had
been sent home for examination, by order of Government, the
London results giving only one-ninth of the quantity of phosphoric
acid found by Dr. Warth’s own analysis of better specimens. As to
the Salt Range nodules which he has also analyzed, I extract from
his letter, viz. :—

“‘ Analysis of phosphatic nodules with hemispherical pores all over the surface

from the Pid, Dandése Colliery, etc., in the Eastern Salt Range; scattered in the
shales which overlie the Eocene Coal Seam, and sometimes replacing shells.

Insoluble silica, etc. 4 per cent.
(P20;) Phosphorus pentoxide 30)" 35
SOO) ee Carbone oxitley Ae eae isco scdetseddaceovsvesenes Anan:
(SO3) Sulphur trioxide ............. 74 op
(Cl) OUMOTING isa geassee-se cot tenchte sce sddcessdasectecae trace
PAO) aluminium Oxader ie teescccsaseivecsscseccs.cesee trace
CeO) Me Herrous: Omiderssssetesososccccecseescesetnocsercnces a9
(MIG) eS MiaoniestumlOxide) sos. 20k: scat cssccdeccsccnceecosse Qe

Balance, Calcium Oxide, water, organic

MAbversAn del OSsuree mesa eMaceecccackh os siecs si0 56 Cs,
100.””

The importance of the occurrence of the valuable mineral phos-
phate of lime in India leads to the hope that Government will take
steps to have the Himalayan limestone zones specially explored with
regard to such deposits and to their worth. A. B. Wynne.

@iSseeOe Ae;
gen
HENRY MICHAEL JENKINS, F.G.S.
Born 30 June, 1841; Diep 24 Dercemper, 1886.

We have to record with deep regret the loss of a valued friend
and sometime colleague in the Hditorship of this Macazrnz (1865),
who has passed away at the close of the old year whilst still in the
prime of life, with the hope of at least many more years of work
before him.

Henry Michael Jenkins was born at Fairwater Mills, Ely, near
Llandaff. His father, Mr. John Jenkins, an energetic and clear-

96 Obituary—Henry Michael Jenkins, F.GLS.

headed corn and flour merchant, died whilst his son was yet an
infant, and his mother having been married to Mr. Box, corn
merchant, young Jenkins was in due time sent to Mr. Browning’s
school near Bath. He showed great aptitude for business affairs,
first in his step-father’s office, then as barter-clerk on a voyage to
the west coast of Africa, undertaken for his health (for he early
developed symptoms of asthma, from attacks of which he was always
liable in unfavourable conditions of the weather), afterwards in the
shipowner’s office in Bristol. H. M. Jenkins came to London in
March, 1859, having been appointed Assistant to Prof. Rupert Jones,
in the Geological Society, Somerset House.

Here he won the good opinion of the officers and Council by his.
intelligence and aptitude for his duties, and on the removal of Prof.
T. Rupert Jones, F.R.S., from the Geological Society to the Royal
Military College, Sandhurst, Mr. Jenkins was appointed to succeed
him in 1862 as Assistant Secretary. He was elected a Fellow of
the Geological Society in 1863, and edited the Quarterly Journal
with marked success from 1862 to 1868; at the end of the latter
year he was chosen Secretary to the Royal Agricultural Society of
England, a post which he has held for eighteen years with marked
success, not only as Editor of the Society’s Journal, but also as
Secretary and Manager of its Annual Shows.

Mr. Jenkins’s career, extending over twenty-seven years, has been
one of steady upward progress, due to his indomitable energy and
great capacity for mastering rapidly the details of all matters,
whether scientific or commercial, which it was needful for him to
understand and decide about judicially. His business shrewdness
enabled him to save the Royal Agricultural Society hundreds of
pounds annually, and his scientific ability as Editor has brought
their Journal up to a standard of excellence which few Societies can
equal and probably none surpass.

Mr. Jenkins was, in the early days of his career, for some time
assistant editor to Mr. Samuelson, in conducting the Quarterly
Journal of Science, to the pages of which he contributed many
Reviews and Notices, also to the Grotogican Magazine and the
Quarterly Journal. We give the titles as under :—

‘< On the Tertiary Mollusca from Mount Séla, in the Island of Java.’’ Quart. Journ,
Geol. Soc. 1864, vol. xx. pp. 46-73, pl. vi.—vii.

<< On the Occurrence of a Recent Species of Zrigonia in Tertiary Deposits in Australia.”
Grou. Mac. 1866, Vol. IIT. p. 201, Pl. X.

“‘ Hypothetical Continents.’ Intellectual Observer, 1866, vol. x. pp. 88-97.

‘Brackish Water Fossils in Crete.’? Quart. Journ. Science, 1864, vol. i. pp. 413—
421 (Plate No. 3).

“ Strata Identified by Organic Remains.” Quart. Journ. Sci. 1865, vol. 1. pp. 622—
630 (Plate No. 8).

‘© Amber; its Origin and History.” Quart. Journ. Sci. 1868, vol. v. pp. 167-185
(with a Map and Plate).

“On Paleocoryne’?’ (Joint paper with Prof. Duncan, F.R.S.), Phil. Trans. Roy. Soc.
1869.

The nnmerous writings of his later years have been directed to
Agriculture in all its branches, and in the future his name will
be best remembered by these; but his memory will be cherished by
all who knew him, whether Geologists or Agriculturists.

E

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' Ophiurella nereidea, Wright.

Calcareous Grit, near Weymouth.

\ “er

THE

GEOLOGICAL MAGAZINE.

NEW SERIES. 1 DECADE: Ill. VOLwIV.

No. III—MARCH, 1887.

QiRiiGHliny Awl, JNIs/ihagesnsyS\-

See Se

I, -On a New Oparvretta From THE Catctrerovus Grit, NEAR
SanpsFoot CastLteE, Weymourn, Dorset.!

By the late Dr. Toomas Wricut, F.R.S., F.G.S.
(PLATE III.)
Genus OpHruRELLA, Agassiz, 1836.

ISK small, membranous, often indistinct, a character which
separates this genus from Ophiura. Rays very long, slender,
depressed, formed of circles of plates, four in each circle; the
lateral plates are the largest, most prominent, and provided with
long spines; the basal plates are small and spiniferous, and the
dorsal smooth and without clothing. Mouth plates small and
triangular. All the species known have been found in the Jurassic
rocks.

Ophiurella nereidea, Wright, 1880. (Pl. III.)

Description.—Disk small, irregularly penta-lobed, each lobe con-

sisting of a shield-like elevation formed by the radial plates, which
are covered by a tegumentary membrane closely studded over with
small granules; the interlobular integument is entirely absent,
having apparently, if it ever existed, been destroyed in the process
of fossilization.
_ The arms, or rays (five in number), are long, four times the length
of the disk’s diameter. They do not taper much between the
radial plates and their termination, and consist of innumerable
highly movable rings composed of:—1st a centro-dorsal plate,
which, with its fellows, form a long, smooth, convex, continuous
chain, flattened at the summit, and laid along the middle of the rays ;
2nd, two rows of lateral plates which bend downwards, closely clasp-
ing the sides of the ray ; each plate supporting a small tubercle, on
which a stout thorn-like spine is articulated by a kind of ball and
socket joint; 3rd, the basal or ventral plates which close the ray
below are small and much concealed, they likewise carry short,
stout spines. One of the spiniferous arms of the Ophiurella, as
it lies on the slab of calcareous grit before me, resembles a marine
worm, the Nereis nuntia, and hence the origin of the specific name
I have ventured to give to this Brittle-star. The arms are very
much bent and curled, so that this species may be said to have had
highly moveable arms.

1 Extracted from the Dorset Natural History and Antiquarian Field Club, vol. iv.
p. 56, printed at the ‘‘ Journal’’ Offices, South Street, Sherborne,

DECADE III.—VOL. IV.—NO. III. 7

98 R. F. Tomes—Patleozoic Madreporaria.

Dimensions.—Diameter of the disk six-tenths of an inch; length
of arm, two inches and six-tenths. This is less than in the living
state, as none of the arms are preserved up to their termimations.

Affinities and Differences.—The fragmentary condition of the disk
prevents any definite conclusions as to the true generic position
of this form, but it agrees with Ophiurella closer than with any
other. It has the small disk with the upper and under surfaces
flattened, the lateral and ventral plates supporting spines, which
are specially jointed to the lateral plates. In all these essential
generic characters it agrees with Ophiurella. I know of no figured
species from the Corallian rocks that resembles this Brittle-star.
The only form that occurs to my mind is Ophiurella bispinosa, d’Orb.,
which has only been named, but was neither described nor figured
by the author. Our species is so widely different from all the
others, that there can be no confusion with them.

This Brittle-star was obtained by Professor Buckman, F.G.S.,
from the Calciferous Grit at Sandsfoot Castle, near Weymouth.

I].—On Two Sprcies or Patmozoric MaprEePoRARIA HITHERTO
NOT RECOGNIZED AS BRITISH.

By Rozert F. Tomss, Ese.

las present communication is the result of the examination of
a considerable number of small Silurian Corals, from Wenlock
and Colwall, made as long ago as 1883, and it was written with the
intention of its being communicated to the Geological Society. I
very much regret, however, that circumstances have arisen which
render it extremely difficult, perhaps impossible, for me to place
myself again in communication with that body. The paper appears
therefore in the pages of the GronocicaL Macazine, a medium for
publication which I hope from time to time to have recourse to.

Of the two species of Corals, an account of which I now lay before
the readers of the GuotocicAL MaGazin#, one represents an entirely
new genus, which I designate Hemiphyllum, and the other is a species
of Cyathaxonia.

HeEMIPHYLLUM, nov. gen.

Cyathaxonia, M‘Coy ?

The corallum is simple, small, conical, and curved. It has a
porous structure, and is surrounded by a thin epitheca, which is more
or less rudimentary at the calicular extremity. There is a large and
spongy columella, but no septal fossette. The calice is circular
and bounded outwardly by a ring of spongy tissue, formed by
spongy septa united by porous endotheca, constituting a thick and
spurious wall. At the inner margin of this ring each pair of septa
coalesce to form a septum, which passes across the intervening space
and unites with the columella. All the septa are irregularly per-
forate, the punctures appearing to be due rather to their porous
nature than to any regularly arranged perforations. The loculi
appear to be open from the bottom to the top of the corallum.

R. F. Tomes—Paleozoie Madreporaria. 99

I place this peculiar form in the vicinity of Cyathaxonia, though
only on account of the open loculi, and am somewhat doubtful as to
its real affinities. There is no true wall, and when the epitheca
is worn off, the edges of the porous septa are exposed. But the
absence of a wall is compensated for by the ring of endotheca which
takes its place and binds the septa together outwardly.

As it is quite possible that the species on which I here propose to
form a new genus is no other than the one described by M‘Coy
under the name of Cyathaxonia Siluriensis,' I adopt for it the specific
name given by him.

HemriPHytium Sriturtensis, M‘Ooy, sp. ?
Cyathaxonia Siluriensis, M‘Coy ?

The corallum is small and cornute, the curvature being sometimes
confined to the small extremity, but is more frequently uniform
throughout its whole length.

The epitheca is thin, somewhat annulated, and it does not ever
extend to the margin of the calice. When well developed, it has a
well-defined upper margin, above which the calice projects; but
when it is less complete, the upper margin is ill defined, and it does
not always extend more than half-way up the corallum.

Iii Y4

Hemiphyllum Siluriensis, M‘Coy,sp.?
Magnified 27 times.

The calice is circular, shallow, and saucer-shaped, and when un-
worn the columella is nearly hidden by the septa which run into it.
The outer ends of the septa project upwards, in the position usually
occupied by the wall, and, with the abundant endotheca, form the
margin of the calice. They are twenty-six in number, irregular in
development, nearly equal in size throughout, and there is no
distinction between the cycles. All of them pass inwards to the
columella, the irregular papille of which blend with those of the
septa, and the exact union of the columella and septa is obscured.
The whole of the septa are perforate, but the perforations have no
definite arrangement, and each septum divides into two near the

1 Ann. and Mag. Nat. Hist. 2nd series, vol. vi. p. 281, 1850.

100 R. F. Tomes—Paleozoic Madreporaria.

outside of the corallum. Their denticulations bear but little re-
semblance to those of the Astreide and Fungide, and more nearly
resemble undulations of the septal margin than actual denticulations,
and they may be due to the want of continuous development
incident on an open-work septum, rather than to the termination of
vertical columns or ridges, as in so many of the Astraide.

When worn down, this coral assumes a different aspect. The
calice is then distinctly tri-areal. There is the outer ring of spongy
endotheca, an inner circle across which the septa pass, and a large
central columellary space of spongy tissue.

The largest specimen I have seen has a height of one inch, and
a calice of half that diameter.

It occurs in the Upper Silurian formation at Woolhope and Wen-
lock, but I have only met with a limited number of specimens from
those localities.

By an error in transcribing M‘Coy’s description of Cyathaxonia
Siluriensis, MM. Milne Edwards and Haime give it sixty or seventy
septa instead of sixteen or seventeen,’ and the error has been re-
peated in their general work on Corals.?

CyatHaxonta Datmani, MM. Edwards & Haime, Mon. Polyp. Foss.
des Terr. Paleeon. p. 322, pl. i. fig. 6.

In a Silurian quarry at the west foot of the hill at the back of the
mansion at Old Colwall, Herefordshire, the residence of Mrs. Holland,
I found, on the occasion of a visit there, a considerable number of
small corals which could not be referred to any known English
species, but which, on examination, proved to be identical with the
Cyathazonia Dalmani of MM. Milne Edwards and Haime.

The strata at the place mentioned are nearly vertical, and I was
unable to ascertain the position of the corals in them, though, from
the manner in which they were clustered in some of the nodular
lumps of stone lying in the bottom of the quarry, I did not doubt
that they were confined to one bed or zone. ‘The quarry, so far as
I can ascertain by reference to the map of the Geological Survey, is
either in the Aymestry limestone, or the Ludlow bed.

One specimen only of another coral, in a very bad state and as
yet undetermined, was found associated with the present species.

The figured specimen of Cyathaxonia Dalmani was obtained from
the Upper Silurian of Gothland, and was preserved in the collection
of M. Verneuil; and I have in my own collection examples from
Gothland with which I have compared the Herefordshire specimens,
and found them to be identical.

The figures accompanying this communication represent Hemi-
phyllum Siluriensis, magnified 21 times. Figure 2 shows a horizon-
tal section a little below the calice.

1 Brit. Fos. Cor. pl. 5, p. 279. 2 Hist. Nat. Coral. t. ii, p. 382.
Pp Pp P

A. Smith Woodward—Acrodus Post-Liassic. 101

III.—Norzs on Some Post-Liasstc Species oF AvRODUS.
By A. Smrra Woopwarp, F.G.S., F.Z.S.,
of the British Museum (Natural History),

O little is known of the extension through later Mesozoic deposits
of Selachian teeth belonging to the familiar type of Acrodus,
as represented in the Lias, that any additional evidence upon the
subject is invested with considerable interest. It is impossible, of
course, from these isolated relics, to determine whether the original
Sharks were as closely allied as the resemblances in their dentition
might at first lead one to suspect; in one case,} indeed, it has been
proved that the complete fish differs much from the Liassic species ;
but the persistence of the dental type is at any rate of some signifi-
cance, and it may therefore be acceptable to offer a few notes upon
the undescribed Jurassic and Cretaceous Acrodonts preserved in the
British Museum. These specimens furnish evidence of at least two
new specific modifications, and they are also suggestive of novel
points in regard to some of those already known.

Acropus Letopus, Agassiz, MS.

1844. A. leiodus, L. Agassiz, “ Rech. Poiss. Foss.’’ vol. i. p. xxxiii (name only).
1871. -Aerodus, J. Phillips, ‘‘ Geol. of Oxford,” p. 177, fig. 10.

In the recently acquired collections of Sir Philip Egerton and the
Earl of Enniskillen, there are several teeth from Stonesfield bearing
the name of Acrodus leiodus in Agassiz’ own handwriting; and
these may consequently be regarded as the types of the species
intended to be so described in one of the projected supplements of
the “Poissons Fossiles.” The form, however, appears to have
remained hitherto undefined, and the only allusion to it that I have
succeeded in discovering occurs in Prof. Phillips’ work quoted above.

The Egerton specimens (No. P. 2134) are very unsatisfactory—two
being much broken, and the third somewhat waterworn—but two of
those in the Enniskillen Collection (No. P. 2753) and others in the
Museum are in a comparatively good state of preservation. The
species is but a small one, as indicated by the annexed woodcut
(Fig. 1), which is twice natural size, and the teeth vary considerably
in shape, according to their original situation
in the jaw; some are much elongated and
relatively narrow, being referable to a posterior
position, while others, evidently pertaining to
Fig. 1. Tooth of Acrodus the symphysial area, are notably short and

ieiodus, Ag. Twice broad. It is interesting to remark, also, that

natural size. Great even the latter are destitute of any prominent

Oolite, Minchinhamp- yising of the coronal surface, and there are

ton. [Byne Coll., Brit. ; :

Mus. | but slight traces of lateral points or cusps.

All the less abraded examples show a very
characteristic surface-ornament, consisting of large and rounded
ridges, closely approximated, and disposed in the ordinary manner ;

1 A, Wagner, ‘‘ Monographie der fossilen Fische aus den lithographischen Schiefern
Bayerns,’’ Abh. k, bayer. Akad. d. Wiss. cl. ii. ; vol. ix. pp. 300-304, pl. v. fig. 1.

102 A. Smith Woodward—Acrodus Post-Liassic.

and these seem to be most nearly paralleled in the smaller species,
A. minimus, which occurs so abundantly in the Rheetic formation.

From those of A. leiopleurus, the present teeth are readily dis-
tinguished by the flatness of the grinding surface, and the rounded
character of the ornamental ruge. And there can be no doubt of
their distinctness from A. falcifer of the Solenhofen Lithographic
Stone, for Wagner’s specimen of the last-named species has every
appearance of being adult, and yet has teeth of much smaller size;
while there is good evidence, also, that in the present Bathonian form
the symphysial teeth were rounded and not acuminate.

Formation and Locality.—Great Oolite—Stonesfield, Minchin-
hampton; Forest Marble—Atford near Bath.

A. LEIOPLEURUS, Agassiz (‘‘ Rech. Poiss. Foss.” vol. i. p. 149,
pl. 22, fig. 5).

This species is founded upon asingle tooth in the Bristol Museum,
supposed to have been derived from the Great Oolite; and its chief
characteristics are the height of the crown and the angularity of the
ornamental wrinkles upon its surface. A beautifully perfect tooth
from the Great Oolite of Minchinhampton, preserved in the Byne
Collection, appears to be referable to the same form, only differing
in the extension of the ornament over the lateral prominences; and
it seems not improbable that this slight divergence depends merely
upon the abraded character of the original type specimen.

A. ELEGANS, Sauvage (Mém. Acad. Boulogne-sur-Mer, vol. ii.
1867, p. 54, pl. iii. fig. 9).

From the Great Oolite of Caen, Normandy ; appears to be wrongly
placed in the genus under consideration. The few specimens avail-
able for study leave little doubt that they belong to a species of
Strophodus. It ought, however, to be added, that satisfactory evidence
of the complete dentition of the latter genus has only been obtained
since Dr. Sauvage’s original description.

A. utrupo, Agassiz (‘‘ Rech. Poiss. Foss.” vol. iii. p. 148, pl. 22,
fig. 27).

The type specimen of this form is said to be preserved in Dr.
Mantell’s collection, but was not received among the fossils sent to
the British Museum. A very characteristic tooth, however, from the
Wealden of Telham Hill, near Battle, has recently been presented by
John Edward Lee, Esq., F.G.S., and this (No. P. 4994) seems worthy
of a passing note. The summit has been considerably abraded, so
that the longitudinal wrinkle of the enamelled surface is represented
rather as a faint groove; but numerous very fine corrugations are
directed transversely outwards on either side, exactly as remarked in
Agassiz’ original description. The coronal surface has a remarkably
unusual contour, being distinctly concave in the median portion, and
rising into a slightly tumid prominence at either extremity.

A. LEVIS, Sp. nov.
None of the Cretaceous teeth hitherto described under the name

A. Smith Woodward—Acrodus Post-Liassic. 103

of Acrodus exhibit any very close resemblance to the typical forms
from the Trias and Lias; and it is therefore of considerable interest
to be able to record some most characteristic examples of this dental
type from the Gault of Folkestone. The British Museum possesses
about nine well-preserved specimens, obtained from the Gardner
Collection, and it requires but a brief examination to recognize their
distinctness from all previously described species. The teeth are of
comparatively small size, and vary considerably in form according
to their original situation in the jaw; examples that are evidently
referable to the symphysial area are short, with much-raised crowns,
aud indications of lateral cusps (Fig. 2) ; while those from posterior
positions (Fig. 3) are more elongated and have the coronal surface

Fie. 2. Fic. 3.
Figs. 2, 3. Anterior and posterior teeth of Acrodus levis, A. S. Woodw. Twice
natural size. Gault, Folkestone. [Gardner Coll., Brit. Mus. ]

gently rounded and showing but little elevation. The superficial
ornament consists of sharp wrinkles disposed in the ordinary manner,
but relatively far apart, and never approaching a reticulate arrange-
ment; and in most cases the ruge do not extend far down upon the
sides of the crown, so that there is a noticeable smoothness of the
enamel, which suggests the appropriate specific name of levis.

Formation and Locality.—-Gault—Folkestone.

A. TRANSvERSUS, Agassiz (‘‘ Rech. Poiss. Foss.” vol. iii. p. 148, pl. 22,
figs. 28, 29).
A. potypyorios, Reuss (“‘ Verstein. bohm. Kreideform.” pt. il. p. 97,
pl. xxi. figs. 1-8).
A. oretaceus, Dixon (Geol. and Foss. Sussex,” Ist edit. p. 364,
Die exe. told).

There can be no doubt that the species described under the above
names are founded upon teeth of Drepanephorus. Agassiz himself
admitted (l.c. p. 149) that the first of the three forms exhibited note-
worthy deviations from the typical early Mesozoic species of Acrodus,
and might be generically distinct; and later discoveries have now
established this original surmise as a fact. All the teeth have the
characteristic median ridge of those occupying the more posterior
positions in Drepanephorus, and there is the same well-marked
ornamentation —nuimerous fine ruge descending on either side from
the ridge and passing more or less abruptly into a complex and
delicate network. To the first-named species, which was founded
upon teeth from the Maestricht Beds, may probably be referred a
well-preserved specimen obtained from the Chalk of Lewes by the
late Dr. Mantell, and also one other small fragment from the same
locality. The root is not displayed, so that it is impossible to deter-
mine whether there is the curious perforation noted by Egerton in

104 A. Smith Woodward—Acrodus Post-Liassie.

the teeth of D. canaliculatus; nor is it possible, upon such fragmentary
materials, to formulate any very definite specific diagnosis. The A.
polydyctios of Reuss is evidently rather smaller, and may be distinct;
but the figure of the tooth made known by Dixon as A. eretaceus
does not suffice to distinguish it from Hgerton’s fossil already men-
tioned and I have not seen the type.

A. Ituineworrut, Dixon (“ Geol. and Foss. Sussex,” 1st ed. p. 364,
pl. xxx. figs. 11, 12, and pl. xxxii. fig. 9.)

From an examination of the detached teeth of this species, it is
impossible to determine whether it is to be referred to the generic
type under consideration, or ought rather to be placed with those
Cretaceous teeth hitherto regarded as pertaining to Hybodus. The
National Collection comprises a small group of about twelve naturally
associated examples, but this does not afford any information as to
the character of the complete dentition ; and the discovery of further
Specimens must be awaited before it is possible to arrive at any
definite conclusions. In form, the English fossils are remarkably
similar to some minute teeth described by Reuss from the Chalk of
Bohemia, under the name of Hybodus polyptychus.}

As already mentioned, comparatively satisfactory remains of at
least one post-Liassic Selachian, with teeth of the Acrodus-type, have
been described by Wagner (loc. cit.) from the Lithographic Stone (or
Lower Kimmeridgian) of Solenhofen, under the name of A. falcifer.
This species, however, differs so much from the typical forms of
Liassic age, that it seems not unlikely that future discoveries may
lead to its generic separation; the dentition, for example, is less
uniform, the symphysial teeth being conical and pointed ; the dorsal
spines and shagreen are quite different, and there are no dermal
“ Sphenonchi” in the cephalic region; and there is considerable reason
for suspecting that the vertebral column attains a much higher stage
of development.

It seems also very probable that some of the species described
above, upon mere dental evidence, may eventually prove to be equally
distinct. As regards the Jurassic and Wealden forms, of course, it is
quite possible that they were Sharks of the ordinary type as repre-
sented in the Lias; for both ribbed dorsal spines and dermal hooklets
(Sphenonchi) are not unfrequently met with in the same deposits.
But since none of these appendages can he distinguished from those
of the true Hybodus, and since also there are numerous Hybodont
teeth upon the same horizons, it is equally probable that they all
pertain to the latter.

In Cretaceous formations, however, dorsal spines with a ribbed
ornamentation are almost entirely wanting; Owen’s Hybodus com-
planatus,’ in fact, appears to be the only example hitherto described,

1 A. E. Reuss, ‘‘ Verstein. bohm. Kreideform.”’ pt. ii. p. 97, pl. xxi. figs. 9, 10.

2 R. Owen, ‘ Notes on Two Ichthyodorulites hitherto undescribed,’ Grox. Mac.
Vol. VI. 1869, p. 482. The small fragments in Dr. Mantell’s Collection, said to
have been obtained from the Chalk of Lewes, and described by Agassiz (op. eit. vol.
ill. p. 44, pl. 100, figs. 15, 16) as Hybodus sulcatus, are undoubtedly Wealden
fossils: see S. J. Mackie, ‘‘ The Geologist,’’ vol. vi. p. 242.

Dr. Hicks—Fauna of Ffynnon Beuno Cave, ete. 105

and this is not of later date than the Neocomian ; and, so far as is
known, there are no traces of the curious hooked Sphenonchi. But
a small smooth spine, originally described by Agassiz under the
name of Spinax major,’ is quite commonly discovered both in the
Gault, Greensand, and Chalk; and its remarkable resemblance
to the homologous appendage of the Solenhofen Acrodont is very
suggestive of its true correlation, in part, with the new species of
Acrodus recorded in the foregoing notes. This spine, of course, has
already been proved to characterize the Drepanephorus of Egerton ;”
but it is not in the least unusual for the dorsal fins of distinct genera
to be armed with dermal weapons of an essentially similar type.
And it is interesting to add, in this connection, that Acrodus levis and
Drepanephorus canaliculatus are almost certainly members of the
same family of Cestraciontide, the last-named form having been
originally referred in error to the Spinacide, as is shown by the
asterospondylic structure of its vertebral centra.®

IV.—Tue Faunas or tHe Frynnon Beuno Caves, AND OF THE
Norrotk Forest Bep.

By Henry Hicks, M.D., F.R.S., F.G.S.

ROM Mr. Newton’s letter in the February Number of the Gro-
LocicaL Magazine, I am inclined to think that he has some-

what misunderstood my meaning where I referred to the fauna of
the Norfolk Forest Bed in my paper in the December Number.
Prof. Hughes had stated in his paper that the bones from the caverns
“belong to the newer group of animals found elsewhere in un-
doubtedly Post-Glacial river deposits.” As Mr. Newton admits
“that most of these species have been found in the Pre-Glacial
Forest Bed of Norfolk, and it is probable that others of them will
yet be found,” it is clear that I was correct in my contention that
‘a very large proportion of the animals occur in the Norfolk Forest
Bed.” My remarks, however, were not intended to claim the Forest
Bed fauna as necessarily of the same age as the remains obtained
from the caverns (though on careful analysis they are found to be much
more closely allied than is usually supposed), but rather to point out
that some highly important questions connected with the compulsory
migration of animals in consequence of climatic changes are not
taken sufficiently into consideration in these discussions, and also to
show the fallacy of any such idea as that species suddenly jumped
into existence to mark special stages in Geological history. Surely
the species of Northern origin lived where the conditions were
suitable for them long before this country was much affected by the
gradually advancing glacial conditions, and only arrived here as the
increasing severity of the climate compelled them to migrate further

1 L. Agassiz, ‘‘ Rech. Poiss. Foss.”’ vol. ii. p. 62, pl. 104, figs. 8-14.

2 Sir Philip Egerton, ‘Figures and Descriptions of British Organic Remains,
Dee. xiil.”? (Mem. Geol. Surv. 1872), pl. ix.

3 C. Hasse, “ Palaontologische Streifziige im British Museum,’’ Neues Jahrb.
1883, pt. ii. p. 66.

106 Dr. Hicks—Fauna of Efynnon Beuno Care, ete.

south. We may, therefore, legitimately assume that ancestors of the
Pleistocene animals of Northern origin (probably also Man) must
have been in existence somewhere during the time the Pliocene
deposits were accumulating in the south-east, for it is generally
admitted that the cold crept slowly over this country from the north,
and that there was much land with high mountain ranges in the
north and north-west during Pliocene times. It is important to
remember also that wherever Reindeer remains have been found,
there also we find traces of Man.

Although Man probably reached this country from the east, it
seems to me equally clear that he must also have arrived here with
the Reindeer from some northern source during the advance of glacial
conditions. A fauna therefore which would be Interglacial in the
north would be Pre-Glacial for some of the areas further south. The
Forest Bed Fauna is specially interesting in showing the southward
extension of some northern mammalia such as the Glutton, Mammoth,
and (according to Prof. Boyd Dawkins), the Musk Sheep, before
glacial conditions had actually affected that area, and the absence
from it of the Reindeer and Woolly Rhinoceros is only what might
be expected, as most of the herbivorous animals would naturally
keep near to the edge of the advancing ice and in the mountain valleys,
until driven to the southern areas by the increased cold towards the
climax of the Ice age. The apparent absence of the Lion is easily
accounted for, since its remains, like those of the Hyena, are chiefly
found in caverns which were their dens, and where they died! It
must not be forgotten also that the Forest Bed contains the fauna
of an eastern, not of a western, area, as the river on the banks of
which the animals roamed flowed from the south-east. Moreover, the
conditions in the north and north-west were such during Pliocene
time as would not tempt the more southern forms to migrate there.
If Pliocene deposits occurred in the north and north-west, it is
strange that no traces of them are now anywhere to be seen, or that
some of the remains should not be found re-deposited in the Drift.
The Pliocene fauna throughout shows that the climate was during
that period becoming gradually colder, and the Forest Bed fauna is
a further indication of an important stage in the onward advance of
the ice. Some lists recently published by Mr. Jukes-Browne? demon-
strate this very forcibly. They show that of the Mammalia of the
Pliocene, seventeen only are found in the Forest Bed, and of these
no less than seven, namely, Zippopotamus major, Rhinoceros mega-
rhinus, Klephas antiquus, Cervus elaphus, Equus caballus, Machairodus
latidens, and Castor europeus, pass up into the Pleistocene. Of those
which appeared for the first time in the Forest Bed, twenty-one
ranged to newer beds, seven species of Deer and Caprovis Savinii
being the only forms not known as yet in the Pleistocene. All the
Mollusca of the Forest Bed pass up into the newer beds. If the

1 Mr. W. Davies mentions (Catalogue of Sir Antonio Brady’s Collection, p. xxxiii)
that ‘‘as we might expect from the known habits of the Fede, their remains are
comparatively rare in all aqueous deposits, being more generally found in caves and
rock fissures.”’ * Historical Geology, pp. 499 and 500.

J. Starkie Gardner & GF. Harris—The Gelinden Flora. 107

Forest Bed is proved to be of Pre-Glacial age, because it is covered
by Glacial deposits, then certainly we can claim the remains found
in the Ffynnon Beuno Caves to be of Pre-Glacial age, since they
also were completely covered over by undoubted glacial deposits, and
the fact that the mammalian fauna of the Caverns would ‘lead one
to assign to it a Pleistocene” age is certainly no proof against such
a conclusion.

V.—-On tHE Brps ConTatninG THE GELINDEN FLORA.
By J. Srarkie Garpner, F.L.S., F.G.S.

HE Gelinden Flora, described by Saporta and Marion (Mém. de
lAcad. de Belge, t. 837; and Révision de la Flore Heersienne
de Gélinden, ibid., t. 41), has assumed an immense importance owing
to the fact that it alone, among Tertiary fossil floras whose age is
definitely ascertained on stratigraphical and paleontological grounds,
contains certain remarkable types of leaves which are common to it;
to the inter-basaltic beds of Glenarm in Antrim, and to Atanekerdluk
in Greenland. Two of these are long lanceolate leaves, with three or
more parallel mid-ribs. The larger, called Daphnogene, is confined
in Greenland to the so-called Miocene at Atanekerdluk and to the
horizon from which the collections of McClintock, Whymper, Robert
Brown, and Colomb were obtained; but the smaller, McClintockia,
has been met with in the so-called Cretaceous as well. There is
some variety in the latter, the number of mid-ribs varying, and the
margin being either toothed or smooth. The McClintockia is also the
more common in Antrim, being equally found at Ballintoy and
Ballypalady. The venation is very peculiar, and appears to represent
an early type still preserved in phyllodes, bracts, and sepals, but
almost lost in true leaves, though a not dissimilar plan is to be found
in a few herbaceous plants such as the Plantain, Peony, ete. The
splendid specimens which I had the good fortune to find, after drain-
ing the disused mine at Glenarm, prove beyond doubt that they were
true deciduous leaves, with long and distinctly articulated foot-stalks.
The McClintockia was originally placed in the Proteaceze by Heer,
but subsequently removed to the Urticeee, where both types un-
doubtedly belong. The Daphnogene in fact seems to almost still
exist in the Debugesia of the Himalayas. The presence of these
types in the Heersien alone, of all the innumerable stages of the
Tertiary in Europe which have yielded fossil plants, shows so far
that they are characteristic of one definite horizon only, and in the
absence of any evidence to the contrary, it is to this horizon and no
other that the floras of Antrim and Greenland containing these
plants must be referred. If paleontological evidence of such nature
is not to be accepted, when there is absolutely nothing to urge
against it, the basis of geology would be sapped and common-sense
rules ignored.
The Gelinden plants are preserved in a fine white chalky lime-
stone. My friend, Mons. Th. Lefévre, of Brussels, was instrumental
in procuring me a fine series, now in the British Museum; but as 1

108 J. Starkie Gardner & G. F. Harris—The Gelinden Beds.

am personally unacquainted with the district, I have induced my
friend Mr. G. F. Harris, F.G.S., to send the following notes upon it.
The importance of a true appreciation of the evidence upon which the
age of the plants is based is apparent, when it is considered that
at the present moment the relative ages of the whole of the immense
Tertiary formations of Ireland, Scotland, and Greenland rest almost
solely upon it. This fact is brought into strong relief in my paper
on the beds of Ardtun Head, Mull, read before the Geological Society
on the 12th January, and further insistance upon it here is therefore
unnecessary.
On THE GELINDEN Bens, ETC.

By Gzo. F. Harris, F.G.S.

Gelinden is a village about a mile and a half N.W. of Heers in
Limbourg. The formation in which the flora occurs is called by
the Belgian geologists Heersien supérieur; and the pit whence the
great majority of the plants came from is very close to Overbroeck,
about three-quarters of a mile due south of Gelinden.

On the opposite page is a geological map of the district, scale
zoo00 (about 384 inches to the mile).

It will be observed that the section near Overbroeck is just off an
outlier. The main mass, however, is close by, and the section in
the “ Heersien” is in fact in the valley of the Molen Beck, which
cuts the outlier from the main mass. The Zandenien beds thus thin
out on the outlier, and their greatest thickness on it is probably not
more than 3m. 40. I am nearly certain that no fossils have been
found in the Lower Landenien beds on this outlier, but on the main
mass, just a little N.W. of Gelinden, fossils occur in them, and the
beds are thus easily identified. The base of the Landenien beds here
is a more or less hard greenish sand.

The Heersien beds in the pit at Overbroeck are a pure whitish
grey ‘“marne,” 10m.’ thick, fossiliferous (especially towards the
base). The base presents rather larger “‘ bancs” than the other parts,
but it is very much cracked up. The “bancs” towards the top are
hard. The following fossils * have been found in the marne :—

Cycloides incisus. Lamna elegans, sp ?
Osmeroides belgicus. Callorhynchus, sp. ?
Smerdis Heersensis. Natica Deshayesiana?

1 The following analysis is by M. Laminne, of Tongres. Analyse de la marne
de Gelinden, 100 parties de marne de Gelinden renferment :—

Carb. de chaux mélangé d’un peu de carb. de magnésie ............ 71-290
Phosphate de chaux ......... Lynde Gianna ees e'vicaterlbmonte tne blak aeeec nee 0-141
Sulfate de soude ; sulfate de chaux; chlorure de sodium ............ 0°155
iliCeysolib lem ..contebe rie pecker asc oree eer eine cmsiseie oe Aas ene eee 0:170
Sable;varsule etoxyderdepleng §-.....ecsescreis.ee. osialeoss ae one eee eeeee 26°612
Matiene XOreani (ties. cyte taeeet a>. epacttene ce. ant ccnacts ccceeee eee 1°380
AANATNOTL AGE! et. 8 eR ER EEE Ro vhclan culleteistion delae set eceten notes eee Re eae traces

(Extracted from ‘“ Explication de la feuille de Heers,’’ by Rutot and Van den Broeck
(1884), p. 125.) Marne of exactly similar appearance is found in many Belgian
Kocene beds, even up to the Bruxellien. It usually occursin bands more or less divided
by sands (often false-bedded).

* Rutot and Van den Broeck, op. cit. p. 21.

~
uw
3
o
ort
uw
13)
io%)
3
DP.
SS
a
fa
=
n
2
i=]
Fs

J. Starkie Gardner & G. F. Harris—The Gelinden Beds.

Chenopus (Aporrhais) dispar.

Teredo, sp.?

Panopea triplicata.

Pholadomya cuneata.

Cytherea orbicularis.

Cytherea, sp.?

Cyprina Morrisii.

— transversa.

— acuminata,

Astarte inequilatera (A. tenera, syn.).

,

-NFERIEUR
(Marin).
TONGRIEN.

LANDENIEN I

109

Nucula Ryckholtiana.

lanceata

quadrangula.

Cucullea crassatina (0. decussata, syn.).
Modiola Heersensis.

subcarinata.

Mytilus gelindenensis.

Ostrea inaspecta.

Spongiaire, sp.?

110 =~J. Starkie Gardner & G. F. Harris—The Gelinden Beds.

Besides the above, 59 species of fossil plants have been found on
the same horizon in this pit, described by de Saporta and Marion.

There is not the slightest doubt, therefore, that the flora is entombed
in marine strata.

Everywhere, in the district under consideration, the Heersien beds
rest unconformably on Maestrichtien.

Now, with regard to the position of the flora with reference to
English beds.

The fauna of the Heersien Supérieur of Belgium is a very poor
one, there being but few species, and they are all very badly pre-
served, with the exception of the fish teeth. There are only 23
species of Molluscs in them, unless others have been discovered
within the last year. Of these at least eight are found in our Thanet
beds. These are:—Cyprina planata, Cucullea decussata, Modiola
elegans, Oyprina Morrisii, Astarte tenera, Cytherea orbicularis, Nucula
Bowerbankii, and Pholadomya cuneata. All these, with* the exception
of N. Bowerbankii, are very common in the Heersien (as far as that
term ‘‘common” can apply), whilst it is a curious fact that the
remaining species are exceedingly rare. In other words, Thanet fossils
are the characteristic ones. If the Heersien Supérieur beds contained
as many species as our Thanet, we should then be ina better position
to get out a percentage; but as we have only, comparatively speaking,
negative evidence to go upon, I think that the general facies should
rule the day, and in this case this is decidedly a Thanet facies. I
have no hesitation in making the beds which entomb the Gelinden
flora, then, homotaxial with the lower part of our Thanet beds, and
cannot see the slightest particle of evidence—as far as the fauna
shows—for making them any older.

The Landenien beds overlie the Heersien. They are divided into
two parts, an upper and a lower. The lower part—Landénien
Inférieur—is marine; and contains in Belgium at least 105 species of
fossils, many of which have not yet been described. The Landénien
Inférieur are generally admitted to be the Belgian equivalents of our
Thanet beds; but whilst thinking they in part represent them,
I am inclined to believe that they in part also represent newer beds.
There are only 12 species of Molluscs common to our Thanet beds.
These are :—Ficula Smithit (2), Scalaria Bowerbanki, Ostrea bellova-
cina, Modiola elegans, Cucullea crassatina, Nucula Bowerbanki,
Astarte inequilatera (tenera), Cytherea orbicularis, Cyprina planata,
Sanguinolaria Hdvardsii, Corbula regulbiensis, Pholadomya Koninektt ;
five of these are rare. There are 10 London Clay species in all :—

Beloptera Levesquet. Modiola elegans.

Aturia zic-2ae. Nucula Bowerbankii.

Ficula Smithi (2). Cyprina planata.

Ostrea bellovacina. Corbula regulbiensis.

Pinna affints. Panopea intermedia.
and nine are met with in the Oldhaven Sands :—

Scalaria Bowerbankii. Cytherea obicularis.

Ostrea beliovacina. Sanguinolaria Edvardsit.

Modiola elegans. Corbula regulbiensis.

Astarte tenera. Panopea intermedia.

Cytherea bellovacina.

Rev. A. Irving—Outlier of Upper Bagshot Sands. 111

Not so much reliance, however, can be placed on the actual species
as on the general facies in this case. The Landénien Inférieur beds
contain 12 species of Pleurotoma, 1 Voluta, 6 Natica, 5 Cerithium, 2
Turritella, 2 Solarium, 2 Arca, 2 Crassatella, 1 Nautilus, 1 Neera, etc.,
a fauna quite unlike that of the Thanet beds.

Wherever the Landénien Inférieur comes in contact with the
underlying Heersien beds in the many sections I have seen, I have
not noticed a true unconformability, though there is occasionally an
overlap. ‘The sand is sometimes coarse, otherwise the passage, from
a stratigraphical point of view, is quite conformable. When the
Landénien beds rest on the Calcaire Grossier de Mons, or on the
Cretaceous beds, there is in the former case generally a pebble bed
at the base, and in the latter green-coated flints, the same as we
see in the London Basin. This bed of green-coated flints is present
wherever the Tertiary beds, Heersien and Landénien, touch the
Cretaceous. It is seen also in many parts of France occupying the
same position.

With respect to the Landénien Supérieur beds of Belgium, they
are generally regarded as the equivalents of our Woolwich and
Reading beds. The only places in Belgium where molluses from the
Landénien Supérieur beds have been met with are in the artesian
wells at Ostend and Ghent. There are only nine species of fossils
in all. These are Melania inquinata, Melanopsis buccinoides, Ceri-
thium funatum, Ostrea bellovucina, O. tenera, Cyrena cuneiformis, C.
antiqua, Mytilus, sp., and Cliona erodens. The Landénien Supérieur
beds are so deeply seated when fossiliferous, that it is with great
difficulty that they can be identified when they crop out at the
surface. The only fossils I have met with from them in an outcrop
is a piece of silicified wood and tubes of Annelides. I may mention
that the general character of much of the Landénien Supérieur beds
in Belgium is such as to cause some geologists there to think it not
only fluvio-marine or freshwater, but marine.

I regard the greater part of the Landénien Supérieur beds as
being part of the Landénien Inférieur, for reasons I will not enter
upon now.

VI.—An Ovruirer or Urrer Bacsnot Sanps on Lonpon Cray.
By the Rey. A. Irvine, B.Sc., B.A., F.G.S.

\HE chief object of this paper is to describe an unmapped outlier
of Bagshot Sand, in which the pebble-bed, frequently met with

at this level,’ exhibits an extraordinary thickness and compactness.
It is situated at Bearwood, on the estate of John Walter, Esq., who
has kindly given me every facility for investigating it. The extent
of the outlier may be said to coincide approximately with the space
enclosed within the 250 foot contour-line of the Six-Inch Ordnance
Survey Map. On the south side it extends a little way to the
south of that line, in the form of several spurs forming low ridges,
the principal of which is crossed, and partly cut through, by the main

1 See Proceedings of Geol. Assoc., vol. viii. pp. 149—151; Q.J.G.S., vol. xli.
(Aug. 1885), p. 508; Proc. Geol. Assoc. vol, ix. pp. 219, 223, 224.

112 Rev. A. Irving—Outher of Upper Bagshot Sands.

road from Arborfield Cross to Wokingham. The highest point on
this outlier is on Birtle Heath, where it is capped with Quaternary
Drift, containing an intermixture of rounded flint pebbles and sub-
angular discoloured flints, and partaking therefore of the general
character of the plateau gravels of this district. Close by Barkham
Lodge (at the south-east corner of Bearwood Park) the altitude is
marked on the Survey Map 280 above O.D. The well at Barkham
Lodge is 40 feet deep; and as this well in all probability reaches
the water-bearing line at the top of the London Clay, we may take
this as representing very nearly the greatest thickness of the sands
of this outlier, together with the capping of later Drift. Bearwood
House is situated at an altitude of 240 feet, a little way off the mass
of Bagshot Sands, and stands on a drift-gravel, consisting of pebbles
and subangular fragments of flint embedded in a matrix of sand,
of the same character as that which forms the mass of the outlier.
I had a good opportunity during the summer of examining a section
of this in a wide open trench across the yard of the house. The two
feet of made earth at the top was well marked off from the gravelly
sand below, which was seen resting at depths of from 4 to 6 feet
upon an eroded surface of London Clay,’ which could be identified
with certainty, although it had lost its character as “ blue-clay ” by
oxidation toa bright brown red. The large lake in Bearwood Park,
about 50 feet lower than the house, lies in a hollow of the London
Clay.
Tue Presie-Bep.

The best exposure of this in situ is in a “ gravel-pit,” about a
quarter of a mile to the south-west of Barkham Lodge, just behind
a small group of cottages, which stand in the angle of the roads.
At the present time some hundreds of tons of flint pebbles, and
nothing but flint pebbles, may be seen lying in heaps in this pit, the
pebbles being of various sizes from that of a hazel-nut up to large
pebbles measuring 6 xX 4 xX 2 inches. Nothing can exceed the
smoothness and regularity of their contour. In the face of the quarry
the pebble-bed is exposed in a horizontal band from 2 to 5 feet in
thickness. The pebbles are closely huddled together, as closely as
the Bunter pebbles are in the well-known quarries in Sutton Park,
near Birmingham, which during the last meeting of the British
Association I had the pleasure of examining in company with
Mr. Harrison. They are enclosed in a greenish sandy matrix, pre-
cisely like that in which the pebbles are embedded at some points
in the cutting north of Wellington College Station, about four miles
distant from this section. The boundary-line between the pebble-
bed and the bed of Bagshot Sand which comes immediately above it
is as sharp and well defined as anything can possibly be. The latter
bed is a strong loamy sand, very ferruginous and rather coarse in
grain; so loamy that on weathering it flakes off on the face of the
section, and its outline becomes somewhat rounded. The beds

1 Proved depth 256 feet. See Mem. Geol. Survey, vol. iv. p. 428. Compare
my paper in Grot. Mac. for September, 1886,

Rev. A. Irving—Outlier of Upper Bagshot Sands. 113

exposed in the pit pass northward under the hill-slope, which is
occupied by a ploughed field. On the southern side of the quarry a
bed beneath the pebble-bed is exposed; and the lithological resem-
blance between this and the bed exposed beneath the pebble-bed * in
the railway-cutting at Wellington College Station is very striking.
I subjoin a diagram of the section as it is exposed in the gravel-pit,
of which a description has just been given. The full thickness of
the pebble-bed and the nature of the subjacent bed on the north side
were proved by an excavation which Mr. Walter was good enough
to have made for me.

Iam aware that several very competent geologists, whose oppor-
tunities for detailed observation of the stratigraphy of the Bagshot
Series have been but limited, are very sceptical as to the existence of
veritable Bagshot pebble-beds, since in many instances, these beds
have been examined at the present surface, where, in arresting
further denudation, they have often got somewhat reconstructed and
mixed up with a few discoloured subangular fragments of flint
(which belong to the later Quaternary Drift. and are easily recogniz-
able) ; but I am quite sure that such scepticism would be removed by
an inspection of this Barkham pit. The pit was re-opened only last
winter, after having been disused for years, and getting quite over-
grown with weeds and brambles. The pebble-bed crops out in great
force in the gardens of the adjoining cottages, and in the lane which
runs along the south side of them.

The bed of pebbles exposed in the gravel-pit just described runs
through beneath the road which leads up the west side of the field
in which it is situated towards the southern boundary of Bearwood
Park, and is seen again in the wood which covers the slope of
Coomb Hill behind Barkham Vicarage, where it forms a rude
terrace, numerous flint pebbles appearing in the sides of the ditch,
and even here and there among the forest-litter. In this direction
it has been proved recently by a trial shaft sunk in the nose of the
hill at a spot about 260 feet above O.D. In this hole some 6 feet
of bufi-yellow loamy sand is at present exposed in a fresh section,
which no uuprejudiced observer who knows the stratigraphy of the
Bagshots of this district could, I think, hesitate to refer to the Upper
Bagshot. On following the 250 foot contour-line through the wood,
the frequency of the occurrence of pebbles shows the extension of
the deposit in that direction. There is no exposure that I have been
able to find in Bearwood Park, as the same contour-line is followed
towards Bearwood Lake; and as the line is followed towards the
house, everything is covered up with ornamental shrubberies and
gardens. ‘I'he model gravel-walks through these are, however, little
else than artificially reconstructed “ pebble-beds.”

At rather less than half a mile to the south-east of the house, an
excavation for a reservoir was made a few years ago. I saw it when
just dug, in company with my former pupil, Mr. Norman Walter,
and was fairly puzzled at the time, from the extraordinary resem-
blance of the sands exposed to those in our railway-cutting at

1 Bed No. 4 of my section, Q.J.G.S. April, 1885.
DECADE III.—VOL. IV.—NO. III. 8

114 Rev. A. Irving—Outiier of Upper Bagshot Sands.

Wellington College Station. The depth of the pit is 9 feet, and all
round the sloping sides the pebble-bed comes out in a most unmis-
takable manner below a surface capping of Drift about 2 feet thick.
The pebble-bed itself is from 1 to 2 feet in thickness; its altitude
is, within a few feet, that of the bed in Barkham Pit; the pebbles
are embedded in sand, and not so compactly aggregated as they are
in the Barkham gravel-pit ; but there is no mistaking the character
of the bed.

If we return to the Barkham Pit, and follow the 250 feet contour-
line eastwards and northwards, we can trace the outcrop by the
exposure of the pebbles at the surface. Where the hill-slope
is rather steep, they have been carried down the slope a few feet
by the wash of heavy rains and the action of melting winter-
snows. I traced a broad band of them across a turnip-field in
the spring of 1886, on a rather steep slope near Sandy Bottom.
Many of the pebbles were of large size (3 and 4 inches in length),
and so thickly strewn were they across the field that it was
impossible to step between them. As the contour-line is followed
northwards (on the east side of the Bagshot Outlier), we come
across the pebbles again in ditches and in the spinny to the north-
west of the Scotch Farm; and they appear to crop out ayain at the
northern extremity of the outlier, outside the churchyard, which is
just on the 250 feet contour-line.

There are not many sections of the sands above the pebble-bed,
but a small one occurs in the wood on the northern side of Birtle
Heath, where I made a clearance of the steep slope in several places
with a spade, and satisfied myself as to the Upper Bagshot character
of the sands. A more extensive section is exposed in the sand-pit,
to the east of Sandy Bottom, some 20 feet or so above the pebble-bed.
On one side of this pit there is a very fresh exposure of sands evenly
stratified ; but as these are followed round the pit, the stratification
disappears suddenly, as if it terminated against an ancient sand-dune.
The character of the higher bed in this pit bears a striking resem-
blance to one on the Wellington College Estate, in the Upper Bagshot,
not many feet below the 300 feet contour-line.t Crossing over to
the west side of Sandy Bottom (in reality a small valley of erosion
with much sand-wash from the adjoining hills at the bottom), the
Upper Sands are again seen in the road-cutting, above the level of
the pebble-bed, and they can be seen along the same road as it skirts
the south side of Bearwood Park. On descending the hill into the
valley of the Loddon, we come again rather suddenly upon the
London Clay of the usual dull bluish-grey colour, as I saw it last
summer exposed in a fresh road-side excavation, with pebbles of
flint dispersed through it. Lithologically, I am unable to recognize
in the loamy bed which occurs in this outlier above the pebble-bed
anything but the equivalent of the loamy (sometimes even clayey)
bed with which I am very familiar, as it occurs at about the same
altitude and above the pebble-bed, in the country about Wellington
College, and in other parts of the interior of the main mass of the

1 T am not sure that they are not in reality, in both cases, parts of a later drift.

Rev. A. Irving—Outlier of Upper Bagshot Sands. 11d

Bagshot Sands, where the strongest possible evidence (that of proved
superposition) leaves no room for doubt as to its occupying a low
horizon in the Upper Bagshot.

The longest of the three spurs mentioned above as projecting to the
south of the mass of the outlier terminates in a hill about 240 feet
above O.D., just to the east of Manor Farm, and rather more than a
quarter of a mile to the north of Barkham Church. This hill is of
London Clay uncovered by drift on its slopes, and capped by a mass
of pebbles and sand of the same nature as that in the Barkham pit.
The pebbles were dug here in quantity for some time for road
material. The pit is now ploughed over, but the enormous number
of well-rounded pebbles seen in the ploughed surface at the top of
the hill bears testimony to the nature of this hill-cap, though, not
having seen the pit open, I am unable to say whether the cap con-
tained the pebble-bed in situ, or consisted of a mass of re-constructed
materials.

There are some very ancient gravel-pits about half a mile nearly
south-west of the Scotch Farm, where the nature of the drift which
caps the outlier can be studied ; and in the open field close by there
is an open gravel-pit on the crest of the hill, remarkable for the
number of Sarsen-stones which occur in the sandy gravel, and for
the huge size of some of them; but of the Sarsens I hope to have
something to say ina future communication, in addition to what I
have already written.!

One or two remarks are suggested by this Bagshot outlier at Bear-
wood.

1. The pebble-bed occurring here so remarkably well developed
(as has been shown above) in such a way as to leave no possible
room for doubt of its Bagshot age, at the same altitude as the pebble-
bed at the base of the Upper Bagshot in the more central parts of
the Bagshot area, we can hardly avoid assigning it to the same
horizon. Though there is no fossil-evidence to bring forward in
support of this view, it must be borne in mind that it is only
from a few sections in the Upper Bagshot that fossils have been
recorded, and such as have been found are nothing more than mere
ferruginous casts. There is no dip to the south or east in this
pebble-bed.

2. If, on the strength of the pretty strong physical evidence cited
above, we are led to assign the outlier at Bearwood to the horizon to
which it is assigned in this paper (and I see no valid argument
against so doing), then we have here a clear case of Upper Bagshot
Sands resting directly upon the London Clay; a phenomenon which
ean only be explained by the former overlap of the Upper members
of the series.”

1 See Proc. Geol. Assoc. vol. viii. pp. 153-160.

2 A very similar case of a massive pebble-bed at the base of the Bracklesham Series,
and resting upon London Clay, has been récently mentioned in a letter to the author
by Mr Whitaker, as occurring in the Hampshire Basin. No authenticated instance
of a bed of pebbles in undoubted Lower Bagshot Sands has yet been recorded in this
western part of the London Basin. while those in Essex may for very good reasons
be assigned to a higher horizon. (See Whitaker, Geol. of London, p. 42.)

116 Dr. H. Woodward—Note on Euphoberia ferox.

3. There is a remarkable coincidence in the altitudes of the
Bagshot Pebble-bed at Bearwood and of the Pebble-bed at Hasthamp-
stead Church and at Bracknell with a similar relation of the pebbles
to the sands; ' and I regard the beds of all these three localities as
occupying the same horizon and consisting of detritus from older
strata accumulated along the northern London Clay shore of the tidal
estuary, which covered over the earlier delta-deposits of the Middle
and Lower Bagshot, in which the old sand-dunes were for the most
part levelled down, while the Upper Bagshot Sands accumulated
as we now find them.

Section (East anp West) IN BARKHAM GRAVEL-PIT, BEARWoOD, BERKS.

[Massive bed of flint pebbles underlying Bagshot Sands. ]

feet.
3. Reconstructed material of bed 2 with a few pebbles and flints as in the
ordinary angulaniDritt | 2.016 och )eee * ses) Uses) ie ele ne
2. Strong ferruginous loamy sand without very pronounced bedding (Bag-
shot Sand) et Meee lt bois hl a EU acle a") RST UOC, HS a a ee
1. Bed of well-rolled flints, completely rounded, densely packed in a grey-
green sand in the upper portion, in a brown loamy sand below.
Thickness proved in the excavation 5
12. Light-grey clay, slightly laminated ... ... ... ... 1
71. Puce-coloured clay extremely tenacious and plastic ... doh al
—10

The clay 72 appears to be a decolorized portion of 71, somewhat reconstructed. It
is difficult to say if this is original London clay. Both these clays can be matched
exactly by well-defined clay-beds in the Wick Hill Section (Finchampstead), only
three miles distant, which are high up in the Middle Bagshot; also by a clay (at
Woodhay) of the Middle Division (Bristow, Mem. Geol. Survey, vol. iv. p. 330), for
specimens of which I am indebted to F. J. Bennett, Esq., F.G.S.

VIL.—Svrriementary Nore on Hupvoperia FEROX, SALTER.

By Henry Woopwarp, LL.D., F.R.S., F.G.S.
British Museum (Natural History).

HEN I noticed this species in the January Number of the

GroLocicaL Magazine (pp. 1-10, Plate I.), I had not pre-

pared a figure of the original specimen from the Hope Collection at

Oxford, which had been kindly lent me by Prof. J. O. Westwood for
that purpose.

1 See Q. J. G. S. August, 1885, and Proc. Geol. Assoc. vol. ix. p. 223. Since
the statements here referred to have been published, they have been called in question
by the authors of a paper in the Quarterly Journal. The authors of that paper, from
insufficiency of observation, have misunderstood the Easthampstead section, and have
mistaken a mass of Quaternary drift at the surface for the pebble-bed which I
described as occurring at a horizon some 20 feet lower !

Notices of Memoirs—Classification of the Carboniferous Series. 117

Having since obtained a careful drawing, I think it may be
desirable to place the earlier figure of this specimen beside the later
figure, in order to show how Mr. Scudder was misled by the former,
and that in fact (as may be seen by comparing the woodcut Fig. 2
below, with the drawings of other examples given on Plate I.) there

i
ely

CUTE
coon : iy
AA
qos

Nai

Ig g

Fig, 2.
Euphoberia ferox, Salter, Coal-measures, Coalbrook-dale (‘‘ Hope Collection”).

Fre. 1.—Rough copy of original figure in “ Brodie’s Fossil Insects”’ (1844, pl. i.
fig. 11).

Fre. 2.—The same specimen re-drawn to show that there are only two pairs of
spines to each segment.

can be no reason for separating this specimen from its congeners,
with which it agrees in every particular.

The lateral spines are bifid, there are two submedian spines, broken
off as usual: the supposed third pair of spines on each somite, one
on either side above the pair of lateral branched spines, are (as
already pointed out on p. 2 op. cit.) only depressions in the tergum
near the base of these lateral spines. his led to the error of attri-
buting the Oxford specimen to the genus Acantherpestes, to which
it certainly does not belong.

IN@ aesk Gin S een Mee @ ae SS

L.—On tHe CLASSIFICATION OF THE CaRonIFEROUS LIMESTONE
Series; Norraumsrian Typx. By Hues Miucer, F.R.S.E., F.G.S.1

T is now twenty years since the late George Tate, of Alnwick,
published a completed classification for the Carboniferous
Limestone Series of North Northumberland. For more than half
that period it has been set aside as of merely local value. It will
be the endeavour of this paper to restore it to its true place.

1 Read before British Association, Birmingham, in Section C (Geology).

118 Notices of Memoirs—Hugh Miller—Carboniferous Series.

Tate’s classification may be summarized as in the following
table :—

CARBONIFEROUS LIMESTONE SERIES OF NortH NORTHUMBERLAND: TATE’S
CLASSIFICATION, 1856-1868.

[References :—G. Tate, History of Berwickshire, Naturalists’ Club, 1856, p. 219 ;
Ibid. vol. v. 1866-7, pp. 288, 857 ; Hist. of Alnwick, 1866, p. 444; Tyneside Transac-
tions, vol. 11. 1868, p. 6.]

Upper or Calcareous group:—From the base of the Millstone Grit to the Dun
Limestone —“‘ the lowest limestone of any value.” Good workable limestones,
interstratified among alternations of sandstone, shale, and coal; large numbers
of marine organisms connected with the calcareous strata. Thickness,
about 1700 feet.

Lower or Carbonaceous group:—From the base of the Dun Limestone to the top of
the Tuedian group. Marked by the number, thickness, and quality of its coal-=
seams; limestones thin and generally impure; marine organisms in fewer
numbers. Thickness, 900 feet.

Tuedian Groups :—Beds intermediate between the Productal and Encrinital limestones
and the Upper Old Red Sandstone. Distinguished by coloured shales, by
thin, argillaceous and cherty or magnesian limestone, and by the rarity of
of Knerinitesand Brachiopoda ; some Stigmarian layers, but no beds of coal.
Thickness, about 1000 feet. In one of his papers Tate distinguishes an
upper group of ‘‘ Tuedian grits.”

[Upper Old Red Sandstone. liocal conglomerates, “‘ more connected with the
Carboniferous than with the Devonian.” No Stigmaria.]

The southern part of Northumberland Tate seems to have visited
only very occasionally; but from his small map of the county,
in which he uses three colours for his three divisions throughout
(Tyneside Transactions, vol. ii.), and from his treatise upon the
geology of the Roman Wall (Bruce’s Roman Wall, 4th edition),
it is evident that his careful eye detected nothing to conflict with
his classification. Mr. Tate died in 1873.

In 1875, Tate’s classification of the upper divisions of the series
was set aside by Professor Lebour in favour of an arrangement
more “natural and convenient.” Professor Lebour abolished the
distinction between the Calcareous and Carbonaceous groups, and
threw them together—along with some of the Tuedian grits—into
a single large series, to which he applied the term Bernician.
It is based on the assumption that Tate’s two divisions either do not
exist in nature or do not persist throughout the county.

CARBONIFEROUS LIMESTONE SERIES IN NORTHUMBERLAND: LEBOUR’S

CLASSIFICATION, 1875-1886.

[References :—G. A. Lebour, ‘‘ On the Larger Divisions of the Carboniferous Rocks
in Northumberland,” Trans. N. of England Min. Inst. 1876; ‘On the terms
Bernician and Tuedian,”’ Grou. Mac. 1877, p. 19; “Outlines of the Geology of
Northumberland,” Neweastle, 1878; “Sketch of the Geology of Northumberland,”
Geologists’ Association, 1886. ]

Bernician . . . . . A large group—which ‘cannot be divided in any natural
manner ’”’—of limestones, grits and sandstones, shales,
and coals; lower limit, ‘‘a variable one,” not keeping to
any one horizon; thickness, in North Northumberland,
2600 feet (after Tate); in Mid Northumberland, a
maximum of ‘tat least 8000 feet”; in South North-
umberland, 2500 feet (after Westgarth Foster).

Tuedian . .. . . As in Tate’s classification, but without definition at its
upper limit.

Basement Conglomerates Local.

It has never been contended, the author believes, that Tate’s prior
classification is not applicable to North Northumberland. It is now,
as the result of the labours of the Geological Survey shows, found to

Notices of Memoirs—Hugh Miller—Carboniferous Series. 119

be equally applicable to South Northumberland, and to the whole of
what deserves to be distinguished as the Northumbrian Type of the
Carboniferous Limestone series, in contrast with the Yorkshire type
and Scottish type. It is amplified in some not very important
details, as set forth in the following table :—

CARBONIFEROUS LiMESTONE SERIES—NoORTHUMBRIAN TyPE (Northumberland,
East Cumberland, and Liddisdale).

[Reference :—H. Miller, Article ‘‘ Northumberland,” Encyclopedia Britannica,
9th edition. |

( Felltop or Upper Calcareous Division :—From the Millstone Feet
Grit to the zone of the Great Limestone. Sandstones
Upper and shales; one or more beds of marine limestone, in-

Limestone < cluding the Felltop Limestone; some coals . . - 9850—1200
Series. Calcareous Division:—From the Great Limestone to “the
bottom of the Dun or Redesdale Limestone. Many beds

IL of good marine limestone; sandstones and shales; coals 1800— 2500

( Carbonaceous Division (Scremerston Beds of North North-
umberland) :—From the Dun or Redesdale Limestone to
Tate’s ** Tuedian Grits.” Strata prevalently carbon-
aceous; limestones chiefly thin, many of them con-
taining vegetable matter; coals . . 800—2500
Tuedian Division or Fweed Beds: — Upper Tuedian or Fell
Sandstone Group, the ‘‘ Tuedian Grits” of Tate:—From

Thowek the Carbonaceous Group to the Cement-Limestones.
RE oe J Great belt of massive grits (Tweedmouth, Chillingham,
Sates } the Simonside and Harbottle Hills, the Peel and

Beweastle Fells). Shales greenish and reddish as well

as carbonaceous-grey ; coals rare, thin, orabsent . . 500—1600
Lower Tuedian or Cement-Limestone Group :—From the base
of the Grits downwards. Cement-stone bands passing
(Rothbury, Bewcastle) into limestones; coals very
rare; generally some coloration of the shales and

sandstones . . . 580—1500

( Basement Co nglomerates ( Upper Old Red Sandstone) ; local . 0— 500

The relation borne to the lines of this extended classification by
Prof. Lebour’s Bernician limit, so far as he has hesitatingly defined
it by horizons,’ is shown in the following diagram :—

CARBONIFEROUS LIMESTONE SERIES»
NORTHUMBERLAND.

NORTH SOUTH-

CALCAREOUS DIVISION.

ESS tt
Dun Limestone ~2p, Redesdale Limestone
CARBONACEOUS DiviStonss e
‘Ne 7 = SSS ee
Rs $+" Plashetts Dun Limest®
a ——
5 “S- Harbott Bey
*~S Grits a
TUEDIAN Fell 3S LeRn\O” we” Sandstenes
OIVISLON.

BASEMENT CONGLOMERATES

¥ “To the north of Berwick, the lowest accepted Bernician limestone is the Dun
limestone, well known throughout the northern part of Northumberland, but only
with great reserve to be correlated with a bed of the same name in the Upper North
Tyne district (the Plashetts Dun Limestone of the diagram). ‘This is the limestone

120 Notices of Memoirs— Carboniferous Limestone of N. Flintshire.

Tate’s admirable classification presents us with well-defined types,
generally recognizable almost at a glance by the practised eye, anid
bounded by lines as good probably as from the complications of the
structure (faults, obscurities, etc.) could be expected. His names, if
not high-sounding, are at least sufficiently expressive.

IJ.—Tue Carsontrerous Limestone or Norra Fritsuree. ByG. H.
Morton, F.G.S.

(Abstract of Paper read before the British Association, Birmingham, September, 1886.)

N the year 1870 I described before the Association the subdivisions
into which the Carboniferous Limestone of North Wales is
naturally divided by clear lithological characters, and in 1877 more
fully described the subdivisions of the formation as they occur in the
Eglwyseg ridge, near Llangollen. Since then the whole of Flintshire
has been examined, and the original classification found to extend to
the sea-coast at the north of the county. Although the subdivisions
are not piled up, one over the other, in a precipitous outcrop, the
succession is as clearly shown between Prestatyn and Meliden as at
Llanymynech and Llangollen, and the uniform character of each sub-
division along the intervening 44 miles of country is remarkable.

The following four subdivisions of the Carboniferous Limestone are
all well exposed in a fine mural section 34 miles in length, from Castell
Prestatyn on the north to the end of Moel Hiraddug on the south, and
occur in the following descending order :—

Upper Black Limestone—a black, fine-grained, thin-bedded lime-
stone, containing very few fossils, but including Poscdonomya Bechert
and the remains of many plants. Thickness, 200 feet.

Upper Grey Limestone—a dark grey, thin-bedded limestone, with
thin seams of interstratified shale, containing numerous fossils, including
Productus giganteus and Corals. Thickness, 500 feet.

Middle White Limestone—a white or light grey, thick-bedded lime-
stone, containing very few fossils. Thickness, 600 feet.

Lower Brown Limestone—a brown or dark grey, irregularly-bedded
limestone, containing few fossils, but with interstratified shales at the
base of the subdivision, which contain the remains of Plants. Thickness,
400 feet.

The total thickness of these four subdivisions, forming the Carboni-
ferous Limestone of the North of Flintshire, is 1700 feet, which is much
greater than anywhere else in North Wales.

Although the line of the section is nearly N. and §., the average dip
of the strata is about 14° to the E.N.E. at Coed-yr-Hsgob, N.W. at
which crops out for some miles along the coast at Lamberton . . . But in the Upper
Coquet district (Mid-Northumberland), where the Tuedians are extremely well
developed, no such limestone can (could) be traced, and the Harbottle Grits are so
thoroughly Bernician in facies, and so well divided stratigraphically from the
Tuedians, that there the base of this great sandstone series forms quite the most
convenient boundary-line. Now there is little doubt that the horizon of the
Lamberton or Dun Limestone is above the Harbottle Grits, so that the merely
expedient and artificial character of the boundaries thus arrived at is shown at once.
The truth is that no line should be drawn at all except as the merest matter of
convenience,”—Lebour, Outlines of the Geology of Northumberland, p, 44. In the

diagram it is of course a matter of convenience that this confessedly artificial limit
should be represented by a dotted line.

Notices of Memoirs—Spurrell’s West Kent Denudation. 121

Bryniau, and N.E.N. at Moel Hiraddug, so that it is greater than it
appears to be in the section. The highest subdivision, the Upper Black
Limestone, occurs at the north end, and the Upper Grey Limestone
crops out from under it, and extends to Nant-yr-ogof, where there is
a considerable fault, which brings up the top of the Lower Brown and
the base of the Middle White Limestone. From the fault the Middle
White extends three-quarters of a mile, when the Lower Brown Lime-
stone crops out, continues some distance, and forms the conspicuous hill,
Moel Hiraddug, on the top of which the lower beds of the Middle White
Limestone are again exposed.

Along the west and parallel with the section there are two great
faults, known as the Prestatyn fault and the Vale of Clwyd fault, and
on the western side of the former a bare limestone hill, Graig-fawr, rises
to an elevation of 500 feet, and presents a grand exposure of the Middle
White Limestone, which is 600 feet in thickness. Numerous fossils
occur at the north end of Graig-fawr, and a greater number has been
obtained there than from the Middle White Limestone anywhere else.

On the west of the Carboniferous Limestone shown along the line of
section several faults, including the two already referred to, have
thrown down the limestone beneath the level of the sea, and the Lower
Coal-measures have been proved to occur at Meliden and Dyserth,
beneath a deep covering of drift. In one of the recent ‘‘ Memoirs of
the Geological Survey,” by Mr. A. Strahan, M.A., F.G.S., a full
description of the Geology—LZxplanation of Quarter-sheet 79 N.W.—
will be found, with all the details of the drift and underlying strata.

II.—A Sxercn or tue History oF tHe Rivers anp DenupATION
or West Kent, ere. By F.C. J. Spurren, F.G.S. 8vo.
Greenwich, 1886. [Reprinted from the Report of the West
Kent Natural History Society, 1886. |

HE author commences with some remarks on the “ plane of marine

denudation ” which was produced over the Wealden area before
the present features were carved out by subaérial forces. He
observes that nowhere over the Wealden rocks is there to be found
any deposit belonging to that old marine age; but it is quite
possible that the Pliocene deposits of Lenham, etc., may be relics
of the period. He then refers to the denudation by rain and rivers,
and the breaching of the Chalk Downs, and states that ‘‘ On the
crest of the Downs there may be found in some places relics of the
rocks from the Weald, Gault Clay, Chert, Greensand, Sand and
Limestone, etc., lying on the Chalk, not in the condition of river
gravel, but of patches of the old beach.” The gravel of Shooter’s
Hill is, in his opinion, largely composed of the wreck of Bagshot
Beds, and there are many similar outliers of pebbly gravel. These
beds occur, as a rule, at a higher level than the Thames Valley
gravels, and they may be distinguished from them by the absence of
the erratic pebbles and fossils of northern origin (derived from
Glacial Drifts), that occur in the newer deposits. These Thames
Valley gravels, in Mr. Spurrell’s opinion, lie below the 200 feet
contour-line, the highest elevation being at Wimbledon, 190 feet.

122 Reviews—Prof. Rosenbusch’s Microphysiography.

Referring to the Flint Implements found at different levels over
the whole district, he observes that he is unable to draw a sharp
line of demarcation between Paleolithic and Neolithic forms.

Turning his attention to the subject of superficial deposits, he
devotes the second part of his paper to the Warp and Trail, described
by Joshua Trimmer, and the Rev. O. Fisher (see Gror. Mac. 1867,
p- 193); and this subject is illustrated with a number of sections
showing the superficial disturbances affecting the Trail. To the
folds he applies the name “ Underplight,” reserving the name Trail
for the material filling the troughs and hollows. He believes that
the folds or Underplight ‘“‘ may have resulted from the heavy
pressure of a superincumbent mass of snow on a soil in a condition
capable of yielding, and frequently repeated.” No doubt many
instances of Trail may in this way have been disturbed, for the
Trail after all is generally but the relic of a more extensive gravelly
accumulation which has been for the most part denuded. Surface
disturbances of similar character are produced in strata over which the
Chalky Boulder Clay has been accumulated, and are referable
to the agent (probably land-ice) which formed it. Mr. J. G.
Goodchild also has drawn attention to many instances of surface
disturbance in Kent (to whose paper, by-the-bye, no allusion is
made by Mr. Spurrell), and he has suggested that they were pro-
bably produced in Glacial times (Proc. Geol. Assoe. vol. ix. p. 151).

J5o Je OV, 26 JET We tS)

I.—MrKroskopiscHE PHYSIOGRAPHIE DER MASSIGEN GESTEINE.
Von H. Rosensuscu. 1 Abtheilung. Zweite ginzlich umgear-
beitete Auflage. (Stuttgart, 1886.) [Pp. 416.]

Microscoric PuysioGRAPHY OF THE Massive Rocns. By H.
Rosrensuscu. Part I. Second edition, completely revised.

A ec appearance of a second edition of Professor Rosenbusch’s
well-known treatise on the microscopical study of the igneous
rocks will be hailed with satisfaction by all workers in petrology.
The present instalment is the first part only : the remaining portion,
with the plates for the whole work, is to be expected next Haster.
On the publication of a new edition of a standard work, the reader
naturally wishes to note what alterations and additions have been
made to the former text; but the present edition is so completely
re-written as to be practically a new work, and important differences
of principle, as well as method, render fatile any detailed comparison
with the original. The chief features of the author’s new treatment
of the subject are the prominence given to structure and geological
mode of occurrence, the subordination to them of purely mineralo-
gical characters as a criterion of classification, and the abandonment,
to a great extent, of geological age, or assumed age, as an essential
character of igneous rocks. It is true that the division into older
(Pre-Tertiary) and newer (Post-Cretaceous) groups is retained among
the volcanic rocks: but the only reasons assigned for this artificial

Reviews—Prof. Rosenbusch’s Microphysiography. 123

classification are those depending on the history of the science, and
the practical difficulty of referring the older rocks definitely to a
volcanic origin, owing to the ‘‘ ephemeral”’ nature of volcanic forma-
tions and the easy removal of the tuffs by denuding agencies (pp. 6
and 346). ‘These reasons will perhaps not appear conclusive to most
English geologists.

At the outset the author divides igneous rocks, according to their
mode of occurrence, into plutonic (Tiefengesteine), volcanic (Hrguss-
gesteine), and a group of intermediate nature occurring character-
istically in the form of dykes (Ganggesteine). ‘The volcanic class
includes the tuffs as well as the lavas.

The structure of igneous rocks is dealt with on the lines indicated
in the author’s valuable paper in the Neues Jahrbuch (1882, vol. ii.
p- 1), in which he divides the rock-forming minerals into four groups,
and lays down the important law that in granular igneous rocks of
the normal type the minerals have consolidated in a definite order,
that of “decreasing basicity.” The term granular is restricted to
those holocrystalline rocks in which each constituent mineral is
entirely of one generation, thus indicating a steady change of
chemical and physical conditions throughout the process of consoli-
dation. This is opposed to the porphyritic structure, where some of
the minerals recur in a second generation, giving evidence of two
distinct periods in the formation of the rock. The form of an indi-
vidual mineral in a rock may either be due to its own mode of
crystallization (idiomorphic), or dependent on causes other than the
molecular forces proper to the mineral (allotriomorphic). The normal
plutonic rocks are characterized by a structure in which idiomorphic
constituents occur only in small proportion (hypidiomorphic) : this is
contrasted with the panidiomorphic structure of a certain type of
dyke-rocks, in which nearly all the component minerals exhibit
more or less crystalline forms.

The plutonic rocks are divided by the author, according to their
mineralogical constitution, into eight families. Here the chief new
features noticeable are the division of the felspars into alkali-felspars,
and lime-soda-felspars, superseding to some extent the old distinction
of orthoclase and plagioclase, and the introduction of a family of
plagioclase-nepheline-rocks (styled Zheralites) to balance the eleo-
lite-syenites. The diabases are placed in the plutonic class, though
with an admission of their intermediate nature (p. 173). The head-
line “The Tuffs of the Diabase-rocks” under the class ‘“ Tiefenge-
steie”’ certainly has an anomalous appearance.

As in the old edition, each family is fully treated under several
heads—mineralogical composition, classification, structure, and the
phenomena of metamorphism produced or suffered by the rocks.
There is much new matter, especially with reference to the local
variations (/aciesbildungen) of rock-masses, the effects of contact and
mechanical metamorphism, and the secondary alterations of rock-
forming minerals. The bibliographical lists are much enlarged, and
the matter throughout is brought well up to date.

The author next treats of the dyke-rocks, among which are found

124 Reviews—Dollo’s Dinosauria of Bernissart.

mineralogical representatives of four of the above eight families—
the granites, syenites, elxolite-syenites, and diorites. They exbibit
three types of structure: the granitic, met with only in the most
acidic rocks (Aplite, which is thus removed from the granites) ; the
granite-porphyritic, divided mineralogically into granite-porphyry,
syenite-porphyry, elzolite-syenite-porphyry, and diorite-porphyrite ;
and the lamprophyric, including syenitic and dioritic families only.
The lamprophyres, as that name is used by the author, are either
panidiomorphic-granular or holocrystalline-porphyritic in structure.
The syenitic lamprophyres comprise Minette and Vosgesite, the latter
name being given to those members which contain hornblende or
augite in place of biotite; similarly the dioritic family divides into
Kersantite and Camptonite.

The characteristic structure of the volcanic rocks is the porphyritic,
which is classified under various types according to the nature of the
ground-mass. The paleo-volcanic rocks are ranged under five
families: quartz-porphyries, quartzless - porphyries, porphyrites,
augite-porphyrites and melaphyres, and _ picrite-porphyrites; of
which only the first is treated in the part of the work already
issued. The discussion of the essential nature of the ground-mass
in the quartz-porphyries and the section devoted to the classification
and structure of these rocks have been rendered fuller, but little is
said on the subject of secondary devitrification. The artificiality
of the separation of paleo- and neo-volcanic rocks is sometimes
apparent, as for instance in the description of the Arran pitchstones
on p. 407.

Professor Rosenbusch’s treatise seems to be a real step towards
a true natural classification of rocks, and perhaps we may even be
Sanguine enough to hope that it will afford a basis for a uniform
system of nomenclature in petrological writings. A. Hi.

IJ.—M. Douto’s Notzs on tHE DrnosauRIAN Fauna oF BERNISSART.
(Continued from p. 87.)

The hind limbs next claim attention. Having insisted on the
avian form of the femur, and its divergence from birds in being
relatively longer as compared with the tibia, M. Dollo goes on to
argue that, whereas the femur is horizontal in birds, its length
implies a more inclined or mammalian position in these Dinosaurs.
We are unable to appreciate the force of the argument, which might
have some weight if the animal were an ordinary quadruped. But,
in the first place, the Kangaroo, an animal not entirely beyond com-
parison in its proportions, carries the femur at rest in a nearly
horizontal position ; and, secondly, by giving the femur this highly
inclined position, M. Dollo raises the extremity of the ischium and
the chevron bones of the caudal vertebra off the ground to a level
with the distal extremity of the tibia. Now, when the skeleton of
such an animal as Iguanodon Bernissartensis is examined, the tail,
unlike the tail of a Kangaroo, is seen to have consisted of dense
muscular substance like the tail of a Crocodile, of enormous weight,
extending from the extremities of the chevron bones to the

_ Reviews—Dollo’s Dinosauria of Bernissart. 125

extremities of the neural spines. Just as the lifting of this weight
from the ground would be a purposeless expenditure of strength
when the animal was at rest, so I think the analogy of the Crocodile,
which is not quite incomparable in caudal structure, may be appealed
to in evidence that the tail was carried in a lower position than
M. Dollo gives it. To bring this result about we must flex the
limb more at the knee, so as to make the femur more nearly hori-
zontal, and incline the tibia further forward, which would give a
more easy, and I think more natural position, than the expectant
attitude into which the animals are at present hoisted. The bones
of the posterior extremity are well described. Evidence is given
that the outer distal condyle of the femur articulates with the
cnemial crest of the tibia, and that the fibula, which is shorter than
the tibia, has its distal extremity brought in front of the tibia, in the
way indicated by Marsh in the Archeopteryx, so as to articulate with
a proximal facet of the caleaneum, a portion of which is applied to
the tibia. The author does not clearly distinguish in his description
between the two types referred to Iguanodon; but since he states that
the two bones of the proximal series of the tarsus articulate with each
other, the description may well refer to I. Bernissartensis, in which
we know, from other evidence, that this condition obtains. The
distal tarsal row, not hitherto described in Iguanodon, is said to
consist of three bones. A thin bone articulates proximally with the
astragalus, and distally with the first and second metatarsals; a
second bone, rather stouter, lies between the astragalus and the
third metatarsal; and the third, of intermediate size, rests on
the fourth metatarsal, and articulates with the calcaneum. This
distal row is noticed as being quite as avian in general character as
the proximal row. The author describes the metatarsus, which has
long been well known in Iguanodon Mantelli. He points out that
the second to fourth metatarsals are the three usually developed in
birds, and that the bones are placed with regard to each other as in
birds, so that the middle metatarsal is slightly displaced forward
distally, and backward proximally. The number of phalanges
corresponds with the number in lacertilians and birds, being 3-4-5.
Finally, M. Dollo adopts the dictum of Huxley that if the
structures between the ilium and the digits of a young fowl are
supposed to augment to the bulk of a Dinosaur, and then to be
ossified and fossilized, there would be no characters to separate the
corresponding parts from those of these gigantic reptiles. There
is no doubt much truth in this generalization, which we should be
disposed to accept in principle so far as Iguanodon is concerned. If it
were worth while for M. Dollo to pursue his line of argument concern-
ing the avian characteristics of the Dinosaurian pelvis and hind limb,
practically to the exclusion of all other resemblances, the comparisons
must derive their importance from being steps in a chain of proof,
either that Dinosaurs have acquired: their avian characteristics in
consequence of the muscular development and functions of the
posterior extremities being avian, in types like Iguanodon, or else that
these genera, in which avian characters culminate, are ancestors of

126 Reviews—Dollo’s Dinosauria of Bernissart.

birds. M. Dollo has already elected to dismiss for the present both
of these questions, but the subject is one which must eventually be
faced, and I venture to urge that the functional development of avian
characters is the safest basis of interpretation; first, because func-
tional conditions are the primary directing cause of structural
variations ; and, secondly, because the modifications of structure in
any Dinosaur which would be necessary to convert it into a bird, are
not less considerable than would be required to convert a Crocodile
into a Dinosaur. If Dinosaurs and Birds are supposed to descend
from an ancient common stock, then the functional evolution of some
avian characters in certain families of Dinosaurs becomes more
intelligible. M. Dollo’s chief inference, however, from the avian
resemblances is, that the Iquanodon also must consequently be
inferred to have been a biped. He quotes Sir Richard Owen to
show that the mere difference in size between the fore and hind
limbs would not establish this conclusion, since the difference, as
marked in the Crocodile and in Iguana, is relatively almost the same
as in Iguanodon Mantelli. The proof of the biped condition is made
to rest upon the greatly reduced size of the anterior extremities, the
difference in number of digits on the anterior and posterior limbs
(both of which characters are common to the Crocodile) ; and,
thirdly, divergences of structure which show a different physiological
use for these members. Here a good deal is assumed. The presence
in Iguanodon of a powerful offensive spine on the inner anterior digit,
which has no parallel in the hind limb, is surely a doubtful argument
that the animal was a biped. The argument would have been much
stronger if the author had been content to show that the weight of the
tail would necessitate the trunk being thrown into a forward position,
so that the body could only have been carried when balanced on the
pelvic axis. The author goes on to contest Sir Richard Owen’s argu-
ments against the upright position, in the course of which he states that
the neck is relatively long, containing ten or twelve vertebree, while
in the dorso-lumbar region there are sixteen or eighteen. The
opisthoccelous articulation of the centrum, and the nature of the
zygapophyses give great mobility to the neck; and, although
the number of vertebrae in the sacrum is smaller than that in birds,
yet this number may be apparently reduced, since the number of
sacral vertebree in Archeopteryx is probably fewer than in Iguanodon
Bernissartensis. M. Dollo remarks that the position of the occipital
condyle is interesting as having an intermediate position between
the horizontal arrangement of quadruped reptiles and the condition
in birds, in which the head is carried at right angles to the neck.
The foot-prints which have been attributed to Iquanodon Mantella
are discussed, with the result that the author finds evidence of no
other known Wealden Dinosaur which could have produced these
tridactyle impressions, while the bones of the three digits are super-
imposed successfully on the natural cast; and hence it follows that
the animal walked as a biped, without leaving any impression of its
tail upon the shore. The author agrees with Sir Richard Owen that
the resemblance of the tail to that of a Crocodile, and the develop-

Reviews—Dollo’s Dinosauria of Bernissart. 127

ment of the lateral trochanter to the femur, may be taken as
evidence of aquatic habits for these Dinosaurs, which are supposed
to have frequented marshes, and to have been, like Crocodiles, more
frequently in water than on land. And on this view the bipedal
position is regarded as a protective adaptive modification, by which
the animal was enabled to discover carnivorous enemies and
encounter them with advantage.

At this point M. Dollo diverges into an interesting note on the
presence of the third trochanter in birds, and on its function.
Describing the femur of the Crocodile and bird, it is stated that the
femur of Iguanodon is constructed upon the avian plan, and this view
is supported by a dissection of the Wild Duck, in which, as in the
Bernicle Goose, and Swan, a faint indication of the lateral Dinosaurian
trochanter is found. The author shows that the distal portion of
this ridge in birds gives attachment to a small caudo-femoral muscle
(which, however, was large in some Dinosaurs, such as Orthomerus
Dolloi), and to a large proximal ischio-femoral muscle. Accordingly,
the trochanter which occupies the middle of the inner side of the
shaft in a Dinosaur is attributed to these muscles. It is probable
that this explanation may be substantially correct; only the tail of a
Dinosaur is so essentially the tail of a Crocodilian, that we must
suppose its muscular structure to have resembled that of the
Crocodile’s tail, in which the transverse division of the caudal
muscular masses is as well marked as in other cold-blooded
Vertebrata. I would especially urge that, even if this homology of
the lateral trochanter is beyond question, it does not in itself quite
establish the view that the Iguanodon femur is built on the bird
type, or used under conditions like those of a bird’s femur.

In common with many other naturalists, M. Dollo prefers to
name the lateral trochanter the fourth trochanter, reserving the
name third trochanter for the process usually so named in mammals.

The fourth note is devoted to the skull and axial skeleton.
Commencing with the mandible, it is shown that the coronoid
process occupies an unusually backward position, and that the teeth
extend behind it, as far as the middle of the temporal fosse. In
addition to the dentary, coronoid, and articular bones, which are
seen on both sides of the jaw, the angular, surangular, and splenial
bones are visible only on the inner side. Anteriorly, in front of
the dentary bone, forming a horse-shoe-shaped extremity to the jaw, is a
bone which the author names pre-symphysial, and which Mr. Hulke
has named pre-dentary. It is convex externally, concave internally,
and its upper border, relatively thin, rises into bony processes like
denticles. This ossification appears to characterize the group of
Dinosaurs allied to Iguanodon, and probably gave a cutting surface
to the front of the jaw, comparable to that seen in Chelonians.
The author would compare it to a representative of the two pieces
which unite the rami of the mandible of anourous Batrachians, which
Professor Albrecht terms inferior intermaxillaries; and as these
elements carry teeth in Amphignathodon Guentheri, the author believes
that a like toothed condition is developed in Hypsilophodon. Detailed

128 Reviews—Dollo’s Dinosauria of Bernissart.

descriptions follow of the other elements of the jaw, from which it
appears that the coronoid process is formed by the dentary, coronoid,
and articular bones. As a whole, the lower jaw perhaps has most
correspondence with Hatteria.

The skull in Iguanodon Bernissartensis is 65 centimetres long, 25
centimetres wide, and including the mandible, 35 centimetres high.
The head is described as having a transversely compressed lacertilian
aspect, with the external narines divided, sub-terminal and lateral ;
with the orbits lateral, of moderate size, without sclerotic ossifications;
the temporal fossa are limited by superior and inferior arcades. The
cerebral cavity is completely ossified. Teeth are limited to the
maxillary bone. The description treats of the roof of the skull,
and its cavities. I cannot give here all the details conveyed in the
description and figures; but there are two pre-maxillaries, extending
between the nares and forming their anterior and inferior borders.
The alveolar margin is edentulous, and no doubt had a horny cover-
ing opposed to that of the predentary bone below. It closely
resembles the premaxilliary of Hypsilophodon, except that the bones
in Hypsilophodon carry teeth. The maxillary bone is large, uniting
anteriorly with the premaxillary, superiorly with the nasal, with a
bone termed supra-orbital, as well as with the lachrymal and pre-
frontal, while posteriorly it unites with the jugal. On the palate it
connects with the external pterygoid, and apparently with the palatine.
It carries 25 teeth in use. Its resemblances are with the maxillary of
Hatteria and Iguana. It contains towards the lachrymal, a pre-
Jachrymal vacuity. The nasal bones are long and well developed,
forming the roof of the skull between the orbits and nares. The
frontal bones have a great transverse expansion, and are large and
flat. They margin the orbit above, and on their lateral border are
two bones termed supra-orbital. There is no trace of a median
suture to the frontals such as characterizes Iguanodon Prestwichi.
The prefrontals each carry a supra-orbital, so that they are hidden
laterally. The lachrymal is connected with the prefrontal, maxillary,
and jugal. The jugal is attached to a special process of the maxillary,
which is given off some distance in advance of the termination of
the alveolar border. This bone unites with the lachrymal, post-
frontal, qudrato-jugal, and maxillary. It is stated that there is a
quadrato-jugal, which unites with the quadrate, but in the figure
(plate ix. fig. 1) there is no suture to separate the parts of the bone
which are lettered respectively jugal and quadrato-jugal. Up to the
spring of 1879 I supposed that the quadrato-jugal had no separate
existence in Dinosaurs, and so wrote of it; but I learned better in
the autumn of 1879, when, by the courtesy of M. de Pauw, 1 was
enabled to draw the details of the parts of the Bernissart skeletons
which were then developed. ‘The post-frontal bone has the usual
connections with the parietal, frontal, squamosal, and jugal. It
divides the orbit from the lateral temporal fosse, and borders the
anterior margin of the supra-temporal fosse. The squamosal bone
is connected with the post-frontal, the parietal, supra-occipital,
parotic, and quadrate bone. These bones, like the parietals, find

Reviews—Dollo’s Dinosauria of Bernissart. 129

considerable resemblance in the living Hatieria. They are un-
divided, and have a somewhat prominent median crest. The form
of the brain case appears to correspond with that already described
by Mr. Hulke. The quadrate bone is remarkably long and strong,
covered proximally by the squamosal bone, like a hat; it sends a
process inward to articulate with the pterygoid. Many of the bones
of the palate, notably the vomer and palatine, are extremely thin
long bones. The pterygoids are thrown back towards the occiput.
They are in contact with the ectopterygoids, below the temporal
fossa, and closely resemble the pterygoids of Hatteria. Regarding
the Hatteria as a Lizard, the author agrees with Huxley and Hulke
that the palate was lacertilian rather than crocodilian. But Hatteria
is I submit no more a Lizard than aCrocodile. The vertebral column
in Iguanodon Bernissartensis comprises 85 vertebra, of which 10 are
cervical, 18 dorso-lumbar, 6 sacral, and 51 caudal. In the neck the
vertebree are opisthoccelous, in the back and loins flat at both ends,
in the sacrum anchylosed, and in the tail slightly amphiccelous.
In the neck all the vertebrae except the atlas carry ribs; one
vertebra in succession to the dorsal series is counted as lumbar,
having no ribs.

The fifth note states that in Iguanodon Mantelli 65 vertebre are at
present known. They comprise 10 cervical, 16 dorsal, 2 lumbar,
© sacral, while in the tail only 32 vertebree are preserved. All the
cervical vertebre except the atlas carry ribs. The atlas has the
usual reptilian condition. The author then enters into a discussion
of the bones named by Marsh post-occipital,’ identifying them with
the pro-atlas of Albrecht.

The author then goes on to show that the form of the skull
depends upon the development of the muscles which work the lower
jaw. And states that in Sawropsida the temporal and masseter
muscles are often united. When the temporal is predominant, there
is a strong sagittal crest, the coronoid process of the mandible is well
developed, the supra-temporal fossee are large openings; while the
pterygoids are thin, parallel to the plane of the skull, and the quad-
rate process of the pterygoid is not ossified. When the internal
pterygoid muscies have a predominant development, there is neither
sagittal crest to the skull nor coronoid process to the mandible; the
supra-temporal fossa are closed, the pterygoid bones are thick plates,
perpendicular to the median plane of the skull; while there is a
mandibular fontanelle. The former type is Lacertilian, the latter is
Crocodilian. In Iguanodon the muscular arrangements were in the
main Lacertilian, while in Ceratosaurus they were more Crocodilian.
Many herbivorous Dinosaurs, however, used in mastication muscles,
which are only developed among mammals in the Carnivora; and
the Teleosauria show in the sagittal crest, large temporal fossa and
narrow pterygoids, evidence that the temporal muscles were large and
the pterygoid muscles small, or in other words the animals had the
reverse development of these muscles to that seen in Crocodilia. In

* These bones had long been known in fishes, and were described in the Carp by

Mr. Robertson of the Oxford University Museum, and by many other writers.
DECADE 11I.—VOL. IV.—NO. III. 9

130 - Reviews—Noury’s Geology of Jersey.

this matter of the muscles Iguanodon and its allies are termed by M.
Dollo slightly modified types, while Ceratosaurus and Diplodocus
are more specialized ; and just as Professor van Beneden has shown
that since Miocene times the form of the skull in Mystacocete has
undergone a specialization by shortening, so Diplodocus presents
a similar specialization as compared with Iguanodon. Thus, by
muscular modification, the primitive terminal narine comes to occupy
a more backward position. It would take more space than is here
available to discuss these interesting speculations.

On the prelachrymal vacuity M. Dollo observes that, it is small
in Dinosaurs which have the pterygoid muscles feeble, and large
when they are greatly developed. The pterygoid muscles are in-
serted in birds on the anterior border of the pre-lachrymal fossa, so
that it seems possible that the size of the vacuity may depend upon
the volume of the muscle which passes through it.

These papers are but a small fraction of the mass of valuable
memoirs which the author has published. Any one who studies
them carefully will be impressed by the originality and power of the
writer. His method is his own. The memoirs that we have noticed are
a landmark in the history of the group to which they relate, ereatly
adding to our knowledge, and applying the methods of comparative
anatomy for the elucidation of Dinosaurian structures in new ways.
We trust that the time is not distant when the author may be enabled
to issue detailed monographs, like those in which Van Beneden has
so well described the Mammalia of the Antwerp Crag; for the
development of exact knowledge of all Dinosaurians cannot but
be influenced by the data for comparison which such monographs
would afford. When this work is done, we may anticipate that
stringent comparisons of form and measurement of bones will be
made, and that the same canons of determination will be extended
to fossils as have already given to the comparative anatomy and
zoology of living animals many of the attributes of an exact science.

-H. G. Sreey.

IlIl.—Géonociz pz Jersny. Par Le P. Cu. Noury, 8.J. Pp. 178,
with coloured map. Priceds. (Paris, Librairie F’. Savy ; Jersey,
Librairie Le Feuvre.)

HIS book is modestly described as intended principally for

residents and visitors, but it contains matter that may be
useful and interesting to any geologist.

After a notice of previous writers and some general remarks, the
author commences with a ‘Brief Description of the Rocks.” He
describes the nature and distribution of the many varieties of
eruptive rocks, classifying them as granitic, granitoid, porphyry,
diabase dykes, mica-trap dykes, and diorite dykes. The granitic
rocks are subdivided as granite proper, forming the N.W., 8.W.,
and much of the 8.E. corner of the island, and granulite such
as that of the Mont-Mado quarries. “ Granitoid” rocks include syenite
and diorite, the latter occurring in considerable mass on the 8.H.
shore. Along with the porphyry are described the remarkable

Reviews—Noury’s Geology of Jersey. 131

pyromerides (perlitic felstones?), which in one locality named
present immense spherules attaining diameters of as much as a foot.
“ Spherolithes” nearly as large are mentioned as occurring in
one of the diabase dykes, but the description points to these being
spheroidal weathering. The localities of mica-trap dykes are
carefully enumerated. —

The sedimentary rocks are said to be chlorite-schist (the first
notice of its occurrence in Jersey); felspathic schist or grit, includ-
ing by far the largest part; metamorphic schist ; and conglomerate.
The metamorphic schist is divided into “spilites” and “porphyres
argileux,” the distinction made between these is not very clear.
The author seems to regard both as altered forms of the felspathic
schists, but alludes to the possibility of the ‘“spilites” being
eruptive. The metamorphism he thinks mainly due to the eruption
of the porphyries; he does not seem to have considered the
idea that they may be ashes belonging to those eruptions. The
remarkable conglomerate of the N.E. corner is very fully described.

Next comes a chapter on “Contours and Relief of the Island,” in
which its physical geology is treated with admirable completeness.
The caves and clefts, the giants-kettles, pits, and natural tunnels,
are enumerated and explained almost individually: similarly with
the inlets, cliffs, and bays. Specially interesting are his descriptions
of the Pinacle and the Creux de Vis or Trou du diable. The origin
of nearly every valley is discussed, and many valuable remarks are
made on the causes which guided and shaped the channels.

In the chapter on the Past of Jersey the author assumes the
hypothesis of an original granitic crust on which afterwards the
gneisses were deposited in an intensely heated ocean. Sedimentation
in a more normal sea laid down the Jersey rocks which he calls
schists, and to which he assigns a Cambrian age. (The term
schist is not very appropriate to these rocks.) Nothing shows, he
says, whether the true granites are prior to them or not; the other
eruptive rocks are certainly later, and range from Cambrian or
Silurian to Triassic; evidence is to be found in other regions. No
sedimentary rock exists between the Cambrians above named and
the conglomerate ; to this he attributes a Permian age, and he gives
good reasons for regarding it as due to sea-wave, not torrent
action. A section on Quaternary and modern geology contains a
very able discussion of past oscillations of land and sea. After
a careful sifting of the evidence, he concludes that since the Roman
occupation only subsidence has happened: and that probably
Jersey was still joined to Normandy as late as the sixth century.
The discussion of this question contains many interesting remarks
on dunes and their growth, submerged forests and their mode of
origin and destruction, the formation of raised beaches, and other
important points in littoral geology. He adduces reasons for thinking
that some at least of the “raised beaches” of the Channel Islands
are not due to changes of level.

A vein of humour appears here and there: as in the relation of
a stonemason’s belief that building-stones can be corroded by the
moon’s rays.

132 Reports and Proceedings—Geological Institute, Vienna.

The book is a valuable monograph: the topographical indications
are especially full and excellent. It is well printed and furnished
with a good coloured map and some sketch-plans. Only a resident
could have produced such a work. Jersey is to be congratulated on
possessing one both able and willing. HK. Hin1.

REPORTS AND PROCHHDINGS._

——"———
J.—ImprriaL GronocicaL InstitutTE, VIENNA.

September 30th, 1886.—On Cretaceous Crustacea of Mount
Lebanon, by Herr Dames.

Ranina cretacea, sp. n., near the Eocene form R. marestiana ;
Peneus septem-spinatus, sp. n.; Peneus Libanensis, Brocchi; Ibacus
precursor, n. sp. (a post-abdomen) ; Pseudastacus Hakelensis, O.
Fraas, very frequent, generic position not yet clearly ascertained,
as also of Pseudastacus minor, O. Fraas. Sculda Syriaca, sp. 0. ;
Sculda is the representative of a peculiar family, the oldest known
type of Stomatopoda. Sculda levis, Schloth. (=Squilla Lewisi,
Woodw.), is the type of another family and genus— Pseudosculda,
Dames. Pseudosculdide are known to exist in the Upper Cretaceous.
Sculdid@ in the Upper Cretaceous and Upper Jurassic; and genuine
Squillidae (Squilla cretacea, Schloth.) begin in the Upper Cretaceous,
and continue upward to the present time.

Larve of crustaceans—Pseuderichthus cretaceus and Protozoéa
Hilgendorfi, sp. n., are very frequent near Sahel Alma. Limulus
Syriacus, Woodw., Loriculina Noetlingi, Dames, are found at Hakel.
The beds of both localities, Sahel Alma and Hakel, although
possessing a quite different Ichthyological and Crustacean fauna,
appear to be coeval; and, considering the presence of Jurassic and
early Tertiary forms, may possibly be of Upper Cretaceous age.
The fauna of Hakel, notwithstanding the difference of age, offers
striking comparisons with the fauna of the Bavarian Lithographic —
flagstones. It includes a few Post-Cretaceous types, such as Ibacus —
precursor and Ranina cretacea.

IJ.—Gronocicat Socrrry or Lonpon.

(1).—January 26, 1887.—Professor J. W. Judd, F.R.S., President, —
in the Chair.—The following communications were read :—
1. “On the Correlation of the Upper Jurassic Rocks of the Jura —
with those of England.” By Thomas Roberts, Esq., M.A., F.G.S. 4
The author described at length his observations on the rocks of —
the Jurassic system, from the Callovian to the Purbeckian inclusive, —
first in the Canton of Berne. and then in the more southerly Cantons —
of Neuchatel and Vaud. The sections in the former differed mate- —
rially from those in the latter: the following stages were observed:— _

Norrs Disrricr. Sours Disrrict.
Purbeckian. Purbeckian.
Portlandian. Portlandian,
Virgulian, p

Reports and Proceedings—Geological Society of London.

Norrs District.

133

Soutn Disrricr,

Pterocerian. Pterocerian.
Astartian. Astartian.
Calcaire 4 Nérinéés. —————
Corallian. Oolithe Corallienne. —
Terrain a chailles siliceux. Corallian.
., Terrain 4 chailles marno-calcaire. Pholadomian. .
2 ae { Calcaire 4 Scyphies inferieur. Spongitian. } Pee
its Le fer sous- Oxfordien. Supérieur. :
pslov iat: Zone of Amm. macrocephalus. Intérieur. } Callovian.
Beihonian. Dalle nacrée, etc. Dalle nacrée.

Some of the lithological and paleontological differences between

these rocks and the English

Oolites were noticed, and the views of

Oppel, Marcou, Waagen, Blake, and Renevier, as to the relations of

the beds in the two countries, were commented upon.

Tke author

then proceeded to compare the fossils of the Swiss Jurassic beds

with those of their English

representatives, stage by stage, and

finally suggested the following correlation :—

ENGLAND.
( Upper.

PURBECK.< fiddle.
|

L Lower.

Portland stone.
a9 sand, etc.

Upper Kimmeridge Clay.

Clays with Exogyra virgula.

3 3, Ammonites alternans.

Clays with Astarte supracorat-
lina.
3, Ostrea deltordea.

Kimmeridge passage-beds.

LowER
KiMMERIDGE

”

Supracoralline.

Coral Rag.

Coralline Oolite.

Middle Calcareous Grit.

CoRALLIAN.

Hambleton Oolite.

Lower Calcareous Grit.

ER

Clays with cordazz Ammonites.

Clays with ovzatz Ammonites.

OxFoRD
CLAY.

Kellaways Rock.

Cornbrash.

JURA.

Valangian.

Purbeckian.

Portlandian.

Virgulian.

Pterocerian.

Astartian.

Calcaire 4 Nérinées.

Oolithe Corallienne.

CoRALLIAN.

Terrain 4 chailles sili-
ceux.

Pholadomian. ) 5
XFORDIAN.

Spongitian. )

Le fer sous-Oxfordien.

———— nnn

Zone of Amm. macroce-
phalus.

and

Bathonian.

CALLOVIAN.

134 Reports and Proceedings—

2. “The Physical History of the Bagshot Beds of the London
Basin.” By the Rev. A. Irving, B.Sc., F.G.S.

The author, in reviewing the position taken up by him, attempted
to estimate the value of such paleontological evidence as exists, and
insists on the importance of the physical evidence in the first place.
He gave reasons for considering the evidence of pebbles, pipe-
clay, derived materials, ferruginous concretions, percentages of
carbon (ranging in the more carboniferous strata up to nearly 24°/,)
taken together with the evidence of carbon in combination, as
adduced in former papers, freshwater Diatoms (now perhaps recorded
for the first time in the Middle and Lower Bagshot), and the micro-
scopic structure of the sands and clays, as furnishing such a cumu-
lative proof of the fluviatile and delta origin of the majority of the
Middle and Lower Bagshot Beds, as can hardly be gainsaid ; while
he regarded the wide distribution of the Sarsens, taken along with
the absence of such evidence as is quoted above, as indicating, along
with the fauna, a much greater former area for the Upper Bagshot
than for the strata below them.

He referred to the evidence furnished by the Walton section (Q.J.
G. 8. May, 1886), the Brookwood deep well (Grou. Mac. August,
1886), the contemporaneous denudation of the London Clay (Got.
Mage. September, 1886) as affording further support to the view
which he has advocated; gave six new sections on the northern side
of the area, showing (1) the attenuation of the Lower Bagshots
beneath the Middle Bagshot clays, (2) the greater development of
clays towards the margin at the expense of the sands, (3) contempo-
raneous transverse erosion of the London Clay, (4) cases of overlap,
(5) the occurrence of massive pebble-beds at nearly the same altitude
along the northern flank underlying (as at Easthampstead and Bear-
wood) Upper Bagshot sands, and resting either immediately upon,
or in near proximity to, the London Clay ; and added an account of
his observations on the flank of St. Anne’s Hill, Chertsey, which he
takes to be nothing more than an ancient river-valley escarpment.
subsequently eroded by rain-water, the hollows thus formed having
been subsequently filled up and covered over by pebbles and other
débris of the beds in the higher part of the hill, these assuming the ~
character of ordinary talus material. The consideration of the
southern margin of the Bagshot district is reserved for a future paper.

The author considered that his main position, resting as it does
upon physical evidence, remains untouched by the attempt of later
writers to disprove it; while the disproof breaks down even on its
own lines (the stratigraphical), the paper in which this disproof is
insisted upon being characterized by (1) an incomplete grasp of the
problem on the part of its authors, (2) equivocal data, (8) omission
of important evidence, (4) inconsistencies, (5) erroneous statements.

The author (while correcting some errors of stratigraphical detail,
which appeared in his former paper, from insufficiency of data)
maintained that (though occasional intercalated beds with marine
fossils may be met with, as is commonly the case in a series of delta-
and lagoon-deposits) the view he has put forward is, in the main,

Geological Society of London. 135

established; and he proposed the following classification of the
Bagshot Beds of the London Basin :—

Oxup ReEapine. New Reapine.
1. Upper Bagshot Sands = 1. Marine-estuarine Series.
2. Middle Bagshot Sands and Clays | a oa. Fresh wahen Sonne
3. Lower Bagshot Sands mami

(2).—February 9, 1887.—Prof. J. W. Judd, F.R.S., President, in
the Chair.—The following communications were read :—

1. “Evidence of Glacial Action in the Carboniferous and Hawkes-
bury Series, New South Wales.” By T. W. Edgworth David, Esgq.,
E.G.8.

After giving a tabular statement of the sequence of rocks connected °
with the coal-bearing beds in New South Wales, the author passed
in review the notices by previous observers of glacial action in the
Carboniferous beds of that country, terminating with the discovery
by Mr. R. D. Oldham of polished and striated boulders in fossiliferous
marine beds of Carboniferous age at Branxton. The author had since
found another extensive deposit of similar beds at Grass-tree near
Musclebrook, 28 miles N.W. of Branxton, and described the section
there exposed in a railway-cutting. A fine calcareous sandy shale,
reddish to greenish-brown in colour, was crowded with round and
subangular fragments of rock, from pebbles no larger than marbles
up to a third of a ton in weight. The surfaces of these fragments
were in many cases ground and scattered. The parent-rock of some
of the boulders was 30 miles distant.

The evidence of ice-action in the Triassic Hawkesbury series was
also described. This evidence was twofold, and consisted of the
disrupted angular fragments of shale first observed by Mr. Wilkin-
son, and of contemporaneously contorted current-bedding, of which
no account had previously been published. The contortions were
represented on a diagram, and attributed to a lateral thrust such as
would be produced by the grounding of floating-ice.

The discovery by Mr. Wilkinson of polished and striated boulders
in some gold-bearing conglomerates, believed to be of Siluro-Devo-
nian age, was also noticed.

2. “The Terraces of Rotomahana, New Zealand.” By Josiah
Martin, Hsq., F.G.S.

The author, after deploring the recent calamity, proceeded to de-
scribe the White Terrace. Its origin, the Terata Geyser, was situated
in a crater-like escarpment near the centre of a conical hill of steam-
ing and partially decomposed felspathic tuff on the south-east side
of the warm lake, Rotomahana. The Terrace was divided into :—

1. The Upper Terrace, with its long horizontal lines of cups,
steaming and overflowing with hot water.

2. The Middle Terrace, with its massive steps and shaggy fringes,
without basins or receptacles for the overflow.

3. The Lower Plateau, a series of shallow basins and wide, level
platforms.

The great cauldron and the action of the Geyser were described

136 Reports and Proceedings—

in much detail. The following analysis of the water was given in
grains per gallon :—

Silica, free and combined with soda...........sssss0.0e 50
Sodium and potassium chlorides ..........c0.scesseseees 60
Alkali Gs icinietly@icod aehaseeect cece ss \dessnchsenaseoaeesteeens 30
Soctmgs ul pate Me hCemyn steph ws a ase sbecitenesceeenes 10

Totalteaeentet sosccsete cesses <aesinncsccceuinseceeee 150

The amount of rock-material withdrawn in solution would amount
to about 10 tons per day; observations lead to the conclusion that
10 per cent. of the silica would be deposited on the surface covered
by the overflow—equivalent to about 120 tons per annum. Then
followed the description of the three divisions previously defined,
including such local features as the Giant Buttress, the Boar's Head,
and the Broken Basin—the latter a circular pool 12 feet in diameter
and 380 inches deep—the only warm-water basin on the White Ter-
race of sufficient depth to be used as a bath. The central portion of
the Middle Terrace was distinguished by a series of massive, rugged,
and rippled perpendicular steps, many of which exceeded six feet in
height, and were variously ornamented. The margin of the lower
plateau was somewhat undefined towards the lake.

The author observed that the comparative study of local pheno-
mena must precede any attempt to explain the origin of the Terraces.
The phenomena of mud-volcanoes exhibited at the plateau of Roto-
kanapanapa afford to the geologist valuable indications of the pro-
bable appearance of the Te-Tarata cauldron in the earlier stages of its
activity. These phenomena he described, and arrived at the conclu-
sion that the initial activity of Te-Tarata was of a similar nature, and
that the successive periods which mark the history of the formation
of the White Terrace correspond with the increasing activity of its
source. Given a crater-lake of seething mud, as activity increased,
the outer wall of the crater would occasionally be broken down, and
mud-streams would be liberated. Such periodical overflows he re-
garded as having built up the curious and complex terraced series.
This hypothesis he applied in detail, and concluded that deposition
and removal combined to produce the great variety of forms which
existed. Thermal activity within the cauldron having at length
removed the softened rock, the deposition of siliceous incrustation
commenced.

Lastly he gave a short description of the Pink Terrace, and re-
marked that by the catastrophe of June 10th the waters of the lakes
Rotomakirisi and Rotomahana were drawn into the new fissure at
the base of Tarawera, whilst the Terraces were blown away.

3. “The Eruption of Mount Tarawera.” By Capt. F. W. Hutton,
F.G.S.

The paper commenced with a description of the country in which
the eruption took place. From Tongariro to White Island, in the
Bay of Plenty, a distance of 130 miles, there extends a belt, 20 or
30 miles wide, abounding in solfataras, geysers, hot springs, etc.,
and composed of volcanic rocks, chiefly rhyolite, with some augite-
andesite. About the middle of this belt lie the mountain and lake

Correspondence—Mr. J. J. H. Teall. 137

of Tarawera, and two or three miles further south Lake Rotomahana,
the spot where the famous Pink and White Terraces existed. Before
the recent eruption there were no craters on Mount Tarawera, the
form of which was a ridge, apparently due to denudation.

Shortly after midnight on the 10th of June a series of tre-
mendous explosions took place from various parts of the Tarawera
ridge, and columns of steam were thrown up with quantities of red-
hot stones. The whole mountain appeared as if on fire. A column
of steam was then sent up from near Okaro far to the west, and,
finally, a great explosion took place in Lake Rotomahana, and steam
rushed forth to a height exceeding that of the columns from Tarawera.
These eruptions from the plain were not accompanied by any red-
hot stones; the ejecta were of much lower temperature. The
principal eruption, accompanied by violent earthquakes and loud
noises of various kinds, was over by 5:30 a.m., and the mountain
craters ceased to be active within twenty-four hours, but steam with
some stones and mud continued to issue from the Rotomahana and
Okero craters for several days, and steam has ever since been emitted
from Rotomahana.

The results of the eruption in the form of fissures on Mount
Tarawera, the change of Rotomahana from a lake to a crater of
larger dimensions, with precipitous walls, the formation of a new
lake between this crater and Tarawera, and the formation of a
number of small craters about Okaro, were then briefly noticed. The
materials ejected were composed of augite-andesite, and rhyolites,
both compact and vesicular. The mineral structure and distribution
over the surrounding country of various forms of pumice, scoria, and
ash were described, and it was shown that there was a difference in
the substances ejected from the mountain craters of Tarawera and
those from the craters in the plain at Rotomahana and Okaro, the
former comprising pumice and scoria, which were not thrown out
from the latter, and but little steam issuing from the higher craters.
when compared with the enormous volumes emitted from the lower
vents. ‘The cause of the eruption was ascribed to the reheating of old
lava-streams saturated with water. This reheating was apparently
not due to crushing ; for, had it been so, the preceding earthquakes
would have been more violent, but probably to molten rock coming
up from below and heating the rocks near the surface. The eruptions
from Rotomahana and Okaro were purely hydrothermal.

CORRESPONDENCE:
ee
THE LIZARD SERPENTINES.

Str, —As Prof. Bonney has called in question my statement that
felspar occurs in the Rill serpentine, I should like to mention the
grounds on which that statement was based. Of course there is
always a certain amount of inference involved in the identification
of minerals under the microscope. One recognizes a number of
characters, and then one forms the opinion that those characters
indicate the presence of a certain mineral.

138 Correspondence—MUr. J. J. H. Teall.

Now I find in all sections of the Rill serpentine that I have
examined irregular grains of a colourless mineral having the refrac-
tive index of felspar, so far as one can judge of this by the relief of
the section and the character of its surface. This mineral always
polarizes in the neutral tints of the first order in sections in which
olivine and augite would give asa rule chromatic polarization. It
frequently shows, moreover, a fine Jamellar twinning, and
sometimes two sets of parallel lamellae may be seen inter-
secting each other at a high angle. It has been rendered turbid
in. places by granular decomposition products. Now I know of no
mineral except felspar which possesses all these characters. Professor
Bonney vaguely suggests that it is augite or diallage. I am, of
course, aware that augite does show multiple twinning ; but I cannot
possibly regard this mineral as augite. In one case in which the
extinction of the two sets of twin lamelle were approximately
symmetrical with reference to the trace of the face of composition,
the combined angle was 53°. Now, if the crystal were augite,
twinned according to the ordinary law, such a section could not
possibly be cut approximately at right angles to an optic axis ;* and,
therefore, in slides of the thickness used, could not possibly polarize
in the neutral tints of the first order, as it actually does.

Another very important point is the existence of two sets of
lamellz intersecting at a high angle. This is perfectly easy to
understand on the assumption that the mineral is felspar; but, so
far as I know, inexplicable on the assumption that it is augite.

To sum up. As the mineral possesses the refractive power of
felspar, the double-refraction of felspar, the twinning of felspar, and
the mode of alteration of felspar, so far as we are able to judge of
these characters under the microscope, I adhere most firmly to my
original statement.

Section of felspar in the Rill serpentine, showing cross-twinning; Nicols crossed.
Magnified 80 diameters.

In my remarks on the MRauenthal serpentine I have simply

followed Weigand, and I must leave him to take care of himself,
as, no doubt, he is well able to do. JI may remark, however, that
the main point of Weigand’s paper, so far as it relates to the
Rauenthal rock, is to prove that serpentine has been largely pro-
duced by the alteration of hornblende, and that the serpentine so
formed can be distinguished from that produced by the alteration of
olivine. The slides of specimens purchased from Sturtz amply

1 On referring to Fouqué and Lévy (Min. Micrographique, p. 355), it will be seen

that the section in question, if of augite, would be out of the zone 100: 010 and would
make an angle of about 35° with the ortho-pinacoid. ; “ ;

Correspondence—Professor E. Hull. 139

confirm Weigand so far as this is concerned. It must be remem-
bered that Weigand’s paper appeared in 1875, at a time when the
notion that all serpentines were altered olivine-rocks was becoming
very general in consequence of the researches of Sandberger and
Tschermak, published some eight or nine years previously.

I may take this opportunity of referring to Col. McMahon’s
paper in the same number of the Gronocican Magazine. I have
no new facts of any importance to add on the subject referred to,
and I do not think that any useful purpose would be served by my
attempting to remove the objections raised by Col. McMahon.
I cannot explain why foliation has been developed in some cases
and not in others. The apparently capricious manner in which
foliation comes in is equally striking in the Scourie Dyke and in
the Lizard gabbros. If I am right in one case, I am right in the
other; and if I am wrong in one case, I am wrong in the other.
I believe with Col. McMahon that foliation may be produced in
connexion with the intrusion of plutonic rocks; but I cannot
explain the foliation of the Lizard gabbros in this way.

Col. McMahon quotes Prof. Bonney as saying that the serpentine
is “free from all signs of disturbance.” This is true of the serpen-
tine locally, as it is of the gabbro ; but it is not true generally. There
are the same signs of disturbance in the serpentine as there are in
the gabbro. I have a polished slab of serpentine from Porthalla,
which shows precisely the same structural features as the figured
slab of augen-gabbro from Karakclews. Abundant signs of
pressure metamorphism occur also in the serpentine near Mullion

Cove. Jistghe) Fal ain Aaa

BORING AT BLETCHLEY.

Srr,—-The London and North-Western Railway Company have for
some time been carrying out a trial-boring for water; and if they have
not found what they were in search of, they have made a discovery
which is interesting to geologists in reference to the underground
structure of the central and eastern parts of England. I have not
yet the full details before me; but, from the information furnished by
Mr. C. Bowen Cooke, it would appear that the boring-rods, after
-penetrating the Jurassic Clays (called by my informant the “ Oxford
Clay ”’), struck on a very hard rock, of which three sinall specimens
were sent to me for identification. On examining them I had no
difficulty in giving a reply. The specimens appear to consist of
finely-crystalline quartz-felsite, with some green mica, and evidently
form a portion of the old Pre-Triassic ridge, which, as all under-
ground borings combine to prove, underlies the Mesozoic formations
of this part of England.

I hope ere long to have a complete series of the cores brought up
from the boring, and to be able to give fuller details.

Grout Survey or IRELAND, Epwarp Hvtt.
14, Hume Street, Dustin.

140 Correspondence—Mr. E. Wethered, Mr. C. E. De Rance.

THE PEA GRIT OF CLEEVE HILL.

Sir,—I thank Mr. Witchell for his courteous correction of my
figures in the thickness of the Pea-grit, and underlying Ferruginous
Oolite in the Cleeve Hill Section, which I quoted in my letter in the
GrotocicaL Macazine for November last. The error occurred in
the numbers of the beds being inserted as feet, and the three figures
were transferred to the inch column. Mr. Witchell remarks that
“the correct reading confirms my statement, except as regards
the lowest 5 feet.” Hxactly, but the exception makes all the dif-
ference ; if there are only 5 feet of Oolite under the Pea-grit beds at
Cleeve Hill, then Dr. Wright could not make the thickness more,
and as I understand Mr. Witchell, in his paper in the Quarterly
Journal of the Geological Society, he maintains that the basement
beds were overlooked by Dr. Wright. Mr. Witchell in his paper
says, ‘The beds next above the Cephalopoda-bed are usually brown
sandy limestones in two or three beds, varying in thickness from
0 feet at Cleeve Hill.” ?

Now I think it would have been fairer to Dr. Wright if Mr.
Witchell had given a reference to Dr. Wright’s Cleeve Hill section
where that fact was first mentioned. Doubtless in the Stroud area
the basement beds assume a greater importance than Dr. Wright
recognized, but of course he had to be guided by the available
exposures of the strata in his day.

I do not think I need argue the matter further, as Mr. Witchell
seems to me to admit my contention, viz. that the late Dr. Wright
in his sections of Cleeve Hill and Leckhampton showed that there
were Oolitic beds below the Pea-grit proper. HEpwarp WETHERED.

THE COLLINGHAM OR SCARLE BORING.

Srr,—The alternative figures, given by me, as Reporter to the
British Association Underground Water Committee, on the authority
of Mr. W. H. Dalton, are correctly copied from a lithographed copy
of a report by him to the Gainsborough Board of Health, “On the
Water Supply obtained from Underground Sources at Gainsborough,”
handed to me by the Board on the 24th of October, 1884, and now
before me.

On the Ist of November, of that year, I recommended the Board
to sink an artesian boring at Gainsborough to a depth of 780 feet :
this proposal was adopted, and I have to-day learnt by telegraph
that the contractors, Messrs. Timmins, of Runcorn, have penetrated
the Keuper Marls, and reached the Sandstone at a depth of 725 feet
from the surface. C. E. De Rancs.

54, West ParapvE, Ruyt.

FOLKESTONE GAULT.

Sir,—Mr. John Griffiths, of Folkestone, the well-known collector
of Gault fossils, is without resources and is permanently disabled by
rheumatism brought on by exposure in his daily labours, which have

On J. Gy S2 vol. xin. pe267,.

Obituary— Caleb Evans, F.G.S. 141

not only enriched the Museums of Europe and the United States, but
have formed the groundwork of the investigations into the zones and
fossils of the Gault made by myself, and fellow-workers—the Rev.
Professor Wiltshire before my own endeavours, and those of Mr. F.
G. H. Price, F.G.S., and Mr. Starkie Gardner, F.G.S., since. Mr.
F. G. H. Price, of Messrs. Child’s Bank, Temple Bar, W.C., has
kindly undertaken to receive subscriptions for the “ Griffiths Fund.”

H.M. Grotoetcan Survey. C. E. De Ranos, F.G.S.

@ See eOPAS ESR

CALEB EVANS, F.G.S., MEMB. GEOL. ASSOC.
Born Juty, 1831; Diep Spr. 16, 1886.

Tue subject of our present Memoir was a resident of Hampstead.
He was educated at University College School, and so early as in
1846 he entered a solicitor’s office, and was appointed Clerk in the
Chancery Pay-Office in 1852, where he served for 30 years, but
retired on account of ill-health in 1882.

He commenced to study geology about the year 1855, and attended
lectures by Prof. Owen and Dr. Melville. He made no actual collec-
tion of specimens until 1858, but from that time until his health gave
way, he took advantage of his annual official vacations to visit the
various localities of geological interest, especially those of the
South-Hast of England. In 1859 he became a member of the
Geologists’ Association, and in 1867 he was elected a Fellow
of the Geological Society of London. The beds to which he chiefly
directed his attention were those of the English Tertiaries and the
Chalk, and in addition to a large collection from the Isle of Wight
and Hampshire beds, he obtained numerous London Clay fossils by
watching the excavations in various parts of the Metropolis, and more
especially from the main-drainage works in the South of London,
which yielded numerous fossils of the Woolwich and Reading Series,
from strata then exposed for the first time, and which have never been
accessible since in this particular area.

Mr. Evans was author of eleven papers, eight of which appeared
in the Proceedings of the Geologists’ Association, the most important
being that ‘‘ On the Geology of the Neighbourhood of Portsmouth and
Ryde.” But the paper by which he will be best known was that
read before the Geologists’ Association in January, 1870, entitled,
«On some Sections of Chalk between Croydon and Oxtead,” which
was separately published. It was the first attempt made in this
country to subdivide the Chalk into zones according to their fossil
contents, and to correlate these zones with those in other parts of
England and on the Continent.

Mr. Evans constructed several geological relief-maps or models,
based on his own observations; one of the neighbourhood of Hamp-
stead and Highgate; one of the Thames Valley in the neighbourhood
of London ; one of Hastings, one of Sidmouth, and one of England

142 Obituary—J. A. Phillips.

and Wales. Although Mr. Caleb Evans only attained the age of 55°
years, he has left behind him a very excellent record of geological
work achieved by a private individual in the leisure hours of a busy life.

JOHN ARTHUR PHILLIPS, r.r.s., v.p.a.s., F.C.S., M.I.C.E., ETC.

Born NovempBer, 1822; Diep 5 January, 1887.

Tue new year has deprived us not only of an excellent chemist,
mineralogist, and geologist, but of a dear and valued friend. Born
at Polgooth, near St. Austell, where several of his family had been
connected with that important tin-mine, young Phillips inherited
a love of mining and metallurgy which he retained unabated to the
end of his useful and valuable life. His school-days were passed
at St. Austell, but he does not appear to have developed a love for
science until near his 20th year, when the subject of electro-
metallurgy attracted John Arthur Phillips’ attention, and he ex-
hibited some specimens of electro-deposited copper on lace, for which
he received the first prize from the Royal Cornwall Polytechnic
Society in 1842 at Falmouth.

This led to a series of investigations into the formation of mineral
lodes. But the want of more accurate scientific training led him to
Paris in 1844, where he entered as a student at the Ecole des Mines.
Here he passed through the regular course of study, and showed such
proficiency that he obtained the appointment of engineer to one of
the large French Collieries, which he held for some years. On his
return to England, he was engaged by Sir Henry de la Beche and
Dr. Lyon Playfair to carry out experiments at Putney for the
Admiralty, on the various qualities of coal suited for the steamships
of the Royal Navy. Lead-smelting and desilvering works next
occupied his attention. Thence he went to California on an inspection
of the gold-producing regions, and to report upon the machinery and
methods in use in separating the precious metal at gold-mines and
works. On his return to England, he lectured before the Society of
Arts, on May 14th, 1862, on “‘Gold-Mining,” giving the result of
his own experience and observations in America. Mr. Phillips pub-
lished his “ Manual of Metallurgy” in 1852, a second edition in
1854, and a third in 1858. At the time of his death he was engaged
upon a fourth edition assisted by Mr. Bauerman, which we under-
stand will be almost immediately published. Mr. Phillips was also
the author of a work on “The Mining and Metallurgy of Gold and
Silver,” which appeared in 1867. In 1884 he published his
«Treatise on Ore-deposits,” giving all the varied natural phenomena
connected with the occurrence of metalliferous deposits.

For the last sixteen years Mr. Phillips has mainly directed his
attention to the study of petrography, and his paper in the Quarterly
Journal of the Geological Society, “On Concretionary Patches and
Fragments of Rocks found in Granite,” and others of a kindred
nature, are of the greatest value to petrologists.

His communications were not however confined to the Geological

Obituary—. Francois Fontannes. 143

Society, but were made also to the Chemical and the Royal Societies,
and some were published in the Philosophical Magazine. He was
elected a Fellow of the Geological Society of London in 1872, and
of the Royal Society in 1881, and at the time of his death was a Vice-
President of the former Society. He was also a F.C.8., a M.1C.E.,
and an “ Ancien Eléve de l’Ecole des Mines.”

Those who were personally acquainted with Mr. Phillips, while
they lament the loss to science which his sudden death has inflicted,
mourn still more the extinction of a life of singular simplicity,
earnestness, and kindliness. He was a large-hearted and open-
handed man, fond of taking every chance that came in bis way of
doing a good deed and helping every one to whom his help could be
of service.

CHARLES FRANCOIS FONTANNES.

Or the losses by death sustained by Geological Science in the year
1886, none has been greater than that of M. Fontannes. Men of
riper age, and of wider reputation, we may have lost; but when we
consider the value and the amount of the work performed by
M. Fontannes before reaching his 48th year, it will be evident that
the gap left by his death will not be easily filled. Especially will
this be the case with the “ International Geological Congress,” which
is to hold its next meeting in England in 1888.

There are several Secretaries to the Congress at each meeting,
but the bulk of the work falls on one or two. At Bologna, in 1881,
M. Fontannes divided the work with M. Delaire; but in 1885, at
Berlin, M. Fontannes took it almost entirely upon himself. The
“‘procés verbal” of a foreign scientific meeting is very different
from the “minutes” of an English meeting; it is really a full
abstract of the entire discussion, and the prompt preparation of this
is no small test of a man’s powers.

M. Fontannes’ earliest work was a notice of the Museum of Lyons,
1873. This was followed in 1874 by a Note on the Infra-Lias of
Narcel, and by notes taken at Athens. In 1876 he published, with
M. Dumontier, “ Description des Ammonites de la zone & Ammonites
tenuilobatus de Crussol et de quelques autres fossiles Jurassiques
nouveaux ou peu connus” (Mem. Acad. Lyon). In 1879 this was
followed up by a work on the same subject by Fontannes himself,
Dumontier having died meanwhile. In the Introduction to the
later work Fontannes pays a warm tribute to his late master, attri-
buting to his encouragement and influence his own love for geology.
These books made known a new Jurassic Fauna for the South-east
of France.

The most important works by Fontannes were “Les Invertébres
du Bassin du Sud-est de la France—Les Mollusques Pliocénes de la
Vallée du Rhone et du Roussillon,” of which two volumes appeared
(1879-82) ; and “ Etudes stratigraphiques et paléontologiques pour

144 Obituary—Frangois Fontannes—The Earl of Enniskillen.

servir A Vhistoire de la Période Tertiaire dans le bassin du Rhéne”’

(Amn. Soc. Agric. Lyon) ; of this eight parts appeared :—

i. Le Vallon dela Fuly etles Sables 4 Buccins des Environs d’ Heyrieu (Isére) 1875.
ii. Les Terrains tertiaires supérieurs du Haut Comtat-Venaissin (Bolléne. St.
Paul-Trois Chateaux. Visan) 1876.
iii. Le Bassin de Visan (Vaucluse) 1878.
iv. Les Terrains néogéne du Plateau de Cucuron (Cadinet-Cabriéres-d’Aigues), 1878.
v. Description de quelques espéces nouvelles ou peu connues, 1879.
vi. Le Bassin de Crest (Dréme), 1880.
vii. La Région Delphino-Provengale, 1881.
vill. Le Groupe @’Aix dans Le Dauphiné, La Provence et le Bas-Languedoe, 1885.

An active worker in the field and a careful student in the
museum and library, M. Fontannes united in himself the two
important requisites for studying problems of this nature. He
explored the later Tertiaries of the South of France and the
neighbouring regions, wherever known, and traced them into
districts where they were not previously known to exist.

Besides the important works here alluded to, M. Fontannes
published numerous papers on the same or on kindred subjects,
chiefly in the Bull. Soc. Géol. de France and Ann. Soc. Agric. Lyon.
But he also wrote on the Miocenes of Portugal (Ann. Sci. Geéol.
1884) ; on the Constitution of the Subsoil of the Chalk and of the
Plain of Avignon (Bull. Soc. Géol. France, 1884) ; on Borings in the
Isére, Dréme, and Vaucluse (Aun. Soc. Agric. Lyon, 1888). His minor
and miscellaneous papers amount to about forty in number.

M. Fontannes was an Officer of Public Instruction, and of the
Geological Survey of France; Chevalier of the Order of St.
Maurice and Lazare, and a recipient of other Orders conferred by
Foreign Governments. In recognition of his important researches,
the Academy of Sciences awarded him, in 1883, the Grand Prize
of the Physical Sciences. W. Topiey.

THE EARL OF ENNISKIELEN, p.c..., LL.D. F.R:S. RGIS Meer
Born 25 January, 1807; Disp, 12 Novempszr, 1886.

By the death of William Willoughby Cole, third Earl of Ennis-
killen, geological science has lost one of its most earnest supporters.
Edueated at Eton, and afterwards at Christchurch, Oxford, he became
attached to Sir Philip de Malpas Grey-Egerton, Bart., and having
studied geology with him under the Rev. W. Conybeare and Dr.
Buckland, they spent their long vacation with the former at Lyme
Regis, where they made the acquaintance of the well-known Mary
Anning, and commenced to collect Lias fossils. Afterwards, by
advice of Dr. Buckland, they visited Franconia, and explored the
caverns of Kiiloch, Rabenstein, Scharzfeld and Gailenreuth, and
returned laden with spoils of Hyzna, Bear, Lion, Rhinoceros and
other cave-animals. Encouraged by Prof. Agassiz, they took up the
study of fossil Fishes, with which their names will ever remain
associated. It seems only appropriate that the collections made by
these two eminent palichthyologists, whose life-long friendship was
cemented by a common interest, should now rest side by side in the
Geological Gallery of the British Museum (Natural History).

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Geol. Mag.1887. Decade IIL Vol. IV.PL.1V.

West Newman & Co.imp.

ET.N.del.ad nat.

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12 Otter, gab, 2 aele Owl: 6.7, Shoveller Duck.
8,Cormorant.

THE

GEOLOGICAL MAGAZINE.

NEW SERIES DECADE Ill. VOL. IN;
No. IV—APRIL, 1887.

OF LGarNPAS Ain Tr rCinmSs:

I.—NotTE ON SOME RECENT ADDITIONS TO THE VERTEBRATE F'AuNA
or tHE NorFouik “ Pre-GuaciaL Forest-Bep.”

By E, T. Newron, F.G.S., F.Z.S8.
(PLATE IV.)

INCE the publication of my last notes on the Vertebrata of the
Norfolk “ Forest-Bed ” in this MaGazrne,! several new forms
have been identified,” and we are now under obligation to Mr. W.
Barker and Mr. A. Savin, whose diligent search in these beds has
brought to light four species not hitherto recorded ; three of them
are bones of Birds, and therefore especially interesting, as so few
remains of this class have been determined from British Pre-Glacial
deposits. I have to thank Prof. Stewart and Dr. Garson for the
facilities they have afforded me on this, as on other occasions, when
comparing specimens in the Hunterian Museum of the Royal College
of Surgeons ; and for similar assistance at the British Museum I am

indebted to Mr. R. Bowdler Sharpe and Mr. Oldfield Thomas.

Lurra vtiearis (Otter). (PI IV. Figs. 1, 2.)

A left ramus of a lower jaw has been found by Mr. A. Savin in the
“ Forest-Bed”’ exposed on the shore at East Runton, near Cromer,
which enables us to add the above-named species to the Pre-Glacial
fauna of the Hast of England. This specimen has the extreme front
and hinder part broken away; but the alveolar margin is complete
from the socket for the canine to that of the hindermost molar,
leaving no doubt therefore as to the number of cheek-teeth, namely,
five, three premolars and two molars. The large sectorial tooth
(pm. 1) is well preserved, and agrees in all particulars with the same
tooth in the common Otter. The two anterior outer cusps of this
tooth are sharp and show slight facets due to contact with the upper
sectorial tooth ; while the inner cusp is not so high as the median
outer cusp. The hinder part of the tooth is low with the upper sur-
face concave ; and a distinct cingulum extends along the lower part
of the outer surface of the crown. The rest of the teeth are absent;
but the number, position, and size of the alveoli agree exactly with

1 Grou. Maa. Dec. II. Vol. X. p. 433.
2 Vide Quart. Journ. Geol. Soc. vol. xxxix. p. 575 ; vol. xli. p, 248; and vol. xlii.
p- 316.

DECADE 1V.—VOL. IV.—NO. IV. 10

146 E. T. Newton—Fauna of Norfolk Forest-Bed.

those of the Otter; in fact, in every particular, the agreement is so
close there can be no question as to their specific identity.

MEASUREMENTS.
Length of alveolar border for cheek-teeth

Depth of ramus under sectorial tooth ...............--++. 13°5 KS
ILEMEWN Ot FSCWOHIA WOW, > no50000000 passospodeDsdeD0000000 12:0 5H
Width of sectorial t00tD .............-..cs0ceseccocnceseesecnes 6°5

Buso maximus (Hagle Owl). (PI. IV. Figs. 3-5.)

The second specimen, also found by Mr. A. Savin in the “ Forest-
Bed” at East Runton, is a right tarso-metatarsus of a large Owl.
This bone is perfect from the lower extremity upwards to the ridge
for the attachment of the anterior tibial muscles, but the parts above
this are wanting. The most marked characters of this bone are the
deeply grooved hinder surface bordered by sharp ridges, and the
backward extension of the distal articular surfaces for the second and
fourth digits. The last-named peculiarity is such that when the
bone is viewed from its lower extremity as in Fig. 5, it is seen to
form rather more thanasemicircle. The front and sides of this bone
are much flattened, giving a square appearance to the shaft. At the
lower part, in front, between and a little above the articulations for
the third and fourth digits, is the perforation for the tendon of the
adductor muscle of the fourth digit; and immediately above this a
second, smaller foramen. ‘Towards the lower part of the hinder and
inner surfaces, there is a flattened space for the attachment of the
fourth metatarsal.

The only Birds, so far as I am aware, with a tarso-metatarsus of
this form, are the Owls, and some of these agree very closely with
this “ Forest-Bed” specimen, the species which comes nearest to it
being Bubo maximus.

There is a marked difference between the tarso-metatarsi of
different examples of this species; thus in the Bubo maximus in the
College of Surgeons (No. 1602) this bone is not quite so long as our
fossil, but is more robust, the upper part being wider and the shaft
thicker. The example figured by Milne Edwards,’ is not quite so
stout, and therefore comes nearer to our fossil. A third specimen,
in the College of Surgeons (No. 1602 a), is much more slender
than the other two}; it is as nearly as possible the same length as
the fossil, but is even more slender. Possibly these differences may
be due to sex, for the male and female of this species differ in size ;
but, be that as it may, this “ Forest-Bed ” fossil bone is within the
extremes of variation of the tarso-metatarsi of Bubo maximus. The
front of the fossil is flatter than in either of the recent examples
examined ; but as this is due to the sharp muscular ridge on the
outer edge, possibly age may have much to do with it. Length of
bone from distal end to tibial crest, 55 mm. Greatest width of
distal end, 22 mm. Width of shaft in middle, 7-5 mm.

SPATULA CLYPEATA (Shoveller Duck). (PI. IV. Figs. 6, 7.)

A small but perfect left coracoid of a bird, found by Mr. W.
1 Oiseaux fossiles, pl. 189, f. 1.

A. J. Jukes- Browne—Interglacial Land-surfaces. 147

Barker in the Freshwater portion of the “ Forest-Bed Series” at
West Runton, is referred to the above species. A comparison of this
specimen with the series of avian coracoids in the College of Surgeons
leaves no doubt as to its nearest affinity being with the Anatide and
especially with the Ducks; whilst its close agreement in size, form,
structure, and muscular markings with the coracoid of the Shoveller
Duck leaves one no option but to refer it to that species. The greatest
length of the specimen is 44 mm., and the widest part, at the sternal
articulation, is 17 mm.

PHALACROCORAX CARBO (Cormorant). (PI. IV. Fig, 8.)

The last specimen which I have to notice was likewise found by
Mr. W. Barker in the Freshwater-bed at West Runton. This is the
upper part of a bird’s coracoid with a markedly flattened inner surface,
agreeing in this, as in other particulars, with the somewhat peculiar
coracoid of the Cormorant. When comparing this specimen with
recent forms, nothing could be found so nearly approaching it as the
common Cormorant, and no doubt was felt as to its belonging to the
same species. Some allied forms, such as the Shag and other Cormo-
rants, were somewhat like, but P. carbo was certainly nearest and one
might say identically the same. The Gannet, which is nearly related
to the Cormorant, has a different form of coracoid.

Although other avian remains have been found in the “ Forest-
Bed,” some evidently belonging to species differing from those which
have been determined, it has not been possible to identify them.
All the ‘ Forest-Bed” birds at present known are Bubo maximus,
Phalacrocorax carbo, Anser sp., Anas sp., and Spatula clypeata.

EXPLANATION OF PLATE IV.

Fie. 1. Lutra vulgaris, left ramus, outer surface. ‘‘ Forest-Bed,’’? East Runton.
», 2. Same specimen seen from above.
3. Bubo maximus, right tarso-metatarsus, front view. ‘‘ Forest-Bed,’’ East
Runton.
Same specimen, back view.
Same specimen, end view of distal extremity.
Spatula clypeata, lett coracoid, outer surface. ‘‘Forest-Bed,’’ West Runton.
Same specimen, inner surface.
Phalacrocorax carbo, upper end of right coracoid, outer surface. ‘ Forest-
Bed,”’ West Runton.
All the figures natural size.

OND OR

IJ.—Inrer-GuactaL LAND-sURFACES IN ENGLAND AND WALES.
By A. J. Juxes-Browne, B.A., F.G.S.

HE exploration of the caves in the Vale of Clwyd, and the con-
clusions announced by Dr. Hicks at the last meeting of the British
Association, have naturally aroused much interest; for if the facts
are rightly interpreted by Dr. Hicks, and the deposits which are
banked up against the north-western end of the cave are really
of Glacial age, then it is clear that the contents of the cave date
from a time anterior to the great submergence during which those
deposits were formed. The occurrence of a worked. flint-flake in
the cave-earth makes this conclusion of the greatest importance, and

148 A. J. Jukes-Browne—Interglacial Land-surfaces.

revives the question of Man’s first arrival in Britain, carrying this
back to Inter-Glacial, though not necessarily to Pre-Glacial times.

Dr. Hicks’s inferences are, however, disputed by Prof. Hughes,
whose objections may be summed up as consisting of two assertions
—(1) that the deposits concealing the north-west mouth of the
cave are not true Boulder-clays, but consist of rainwash and
re-sorted Drift; (2) that if they did belong to what he calls the
Clwydian Drift, they would still be Post-Glacial, and not Glacial.

Upon the first point it would appear that the majority of those who
saw the excavation are against Prof. Hughes, and as fresh openings
are to be made next June, we may hope that geologists who are
acquainted with the Glacial beds of Cheshire and Lancashire will
visit the place, and give us an authoritative opinion. In the mean
time I may draw attention to the regularly stratified succession of
sands and Boulder-clays in Dr. Hicks’s section (see GnmoLogrcaL
Macazinn, December, 1886, p. 569); this is not the kind of
structure which rainwash deposits usually exhibit.

Prof. Hughes’s second objection is simply an unwarranted assump-
tion ; his only grounds for the statement that the so-called.Clwydian
Drift is Post-Glacial appear to be that it is of marine origin, and
was formed during “the submergence which followed the extreme
glaciation.” Prof. Hughes may choose to assume that Post-Glacial
time commenced with this submergence; but this is not the view
which is usually held, and students of Pleistocene geology will
naturally call upon him to define what he means by the terms
Glacial and Post-Glacial. The latest authorities are agreed in
correlating the Boulder-clays and gravels of the Vale of Clwyd with
the similar deposits which spread over such large areas in Cheshire
and Lancashire, and he must be a bold man who would exclude
these from the category of Glacial deposits.

It is true that the late Mr. S. V. Wood, Jun., made a similar
assumption with regard to the Drifts of Lincolnshire, speaking of a
major and a minor glaciation, and referring the product of the latter
(Hessle Beds) to the Post-Glacial era, because they contained
Cyrena fluminalis, and were in his opinion contemporaneous with
certain river-gravels which are usually called Post-Glacial. I have
elsewhere shown, however, that the Hessle beds are so intimately
associated with the underlying Purple clay that they cannot possibly
be dissociated from it ; and that as both were evidently formed under
glacial conditions, it would be both confusing and illogical to call
any part of the series Post-Glacial.

The fact is, as Prof. Boyd Dawkins has pointed out, the so-called
Glacial period was only an episode in Pleistocene time; the length
of this episode was necessarily different in different parallels of
latitude, and consequently the term Post-Glacial can only have
a local significance. Deposits which are evidently the products of
ice-action must be called Glacial, and Post-Glacial deposits could
not be formed at any given place until glacial conditions had ceased ;
hence it is probable that the Post-Glacial deposits of southern
England are of earlier date than those of northern England, while
in France the term Post-Glacial ceases to have any value at all.

A. J. Jukes-Browne—Interglacial Land-surfaces. 149

In discussing questions of relative age, therefore, it would be
much better to use the terms Older and Newer Pleistocene instead of
Glacial and Post-Glacial, the true test of age being the constitution
of the Mammalian fauna, and not the cessation of glacial conditions.
I can see no reason why the newer Pleistocene fauna should not
have occupied our southern and midland counties before the forma-
tion of the later glacial deposits of Cheshire and North Wales,
provided only there was a time when a land-surface existed that
was sufficiently free from snow and ice to permit of their immi-
gration. If this were the case, Man was probably a contemporary
immigrant; but this would not make him Pre-Glacial: consequently
it is needless to compare the fauna of the Welsh caves with that
of the Pre-Glacial Forest Bed.

The question then is, do the facts, so far as we know them, afford
any evidence in favour of the supposition that there was a land-
surface free of ice anterior to the submergence during which the
later glacial deposits were formed? I think this question may
certainly be answered in the affirmative ; it is indeed a remarkable
coincidence that three separate inquirers, each studying a separate
district lying between the same parallels of latitude, should have
independently arrived at conclusions which favour the above sup-
position. These three districts are (1) Lincolnshire, (2) South
Derby and Nottingham, (3) North Wales.

One of the most striking points in the Pleistocene Geology of
Lincolnshire is the contrast and distinction between the two great
groups of glacial deposits; on this point I agree with the late
Searles Wood, Jun., that the facts indicate the lapse of a very
considerable interval between the formation of the older and newer
deposits. Whether the older Boulder-clay was formed on land
or beneath the sea is of course an open question, though I incline
to the latter opinion; but it certainly seems to have been exposed
to extensive erosion before the deposition of the newer red and
brown clays. The facts favour the idea that a land-surface existed
which was free of ice, but exposed to the action of rain and running
streams, and that the district remained above water long enough for
a distinct valley-system to be produced. Submergence then took
place, the ice-laden waves of the North Sea attacked the coast-line
and cut it back for many miles, forming a plane of erosion which
terminated in a line of cliffs. More rapid submergence ensued, the
cliffs and the wolds sank beneath the sea, and the valleys were
filled up with gravels and Boulder-clays, which bear evidence
of their marine origin in the shells which are found in them up to
heights of 200 feet.! Here, therefore, we seem to have fairly good
evidence of an inter-glacial land-surface.

Again, the Pleistocene deposits of South Nottingham and Derby
have recently been described by Mr. R. M. Deeley, who divides the
series into Older, Middle and Upper, assigning the Hast Anglian
Chalky Boulder-clay to the Middle stage; from his description

1 See Quart. Journ. Geol. Soc. vol. xli. p. 130, and ‘The Geology of East
Lincolnshire,’ Mem. Geol. Survey, 1887, p. 91.

150 A. J. Jukes-Browne—Interglacial Land-surfaces.

of the succeeding Newer Pleistocene epoch I quote the following :—
“The evidence furnished by the deposits of the two previous epochs
favours the assumption that, up to the close of Middle Pleistocene
times, the area under consideration was uninterruptedly submerged
to a greater or less extent . . . The deposits of the Newer
Pleistocene epoch now to be considered indicate the first signs
of subaerial erosion, and the consequent formation of river-gravel.
. . . During this stage the rivers cut down their valleys through
the older Boulder-clays and sands to within about twenty feet
of their present depths, and left their gravels stranded as terraces at
various heights above their present courses. Upon these inter-glacial
gravels, or upon the older rocks, there frequently rests a Boulder-
clay sometimes reaching a considerable thickness.”! This later
Boulder-clay would appear to be contemporaneous with the marine
clays of Staffordshire and Cheshire on the one hand and of Lincoln-
shire on the other, though this point cannot be taken as proved.
Lastly, with regard to the Pleistocene succession in North Wales,
we have the concurrent testimony of Mr. Mellard Reade, Mr. A.
Strahan, and Dr. Hicks. Mr. Strahan sums up as follows :*—
“While, however, there is a general agreement as to the marine
origin of the sand, gravel and associated Boulder-Clays, there is an
equally wide-spread opinion that the tough and very strong base- .
ment-clay seen at Colwyn Bay, Bryn Elwy, Llanefydd and other
places in North Wales is the product of an ice-sheet.” The dis-
tinction between the older and newer Boulder-clays seems therefore
to be as marked in North Wales as it is in Lincolnshire; and if
Dr. Hicks’s views with regard to the relation of the caves to the
newer glacial deposits are confirmed, the Pleistocene record in North
Wales may be read thus :—
(1) Intense glacial conditions; Wales buried in ice, but the relative
level of land and sea not yet known.
(2) Retreat of the ice, exposal of land-surface, and occupation
of the district by Man and the newer Pleistocene Animals.
(3) Extensive submergence, during which the later (marine)
Glacial beds were deposited.
(4) Elevation and re-oceupation of the country by man and animals.
All recent observations tend to show the high probability of
there having been a free land-surface over the greater part of
England in the midst of what is usually called the Glacial period.
During this Inter-Glacial period valleys were excavated, caves were
formed, and a long process of subaerial detrition went on ; the caves
being occupied by Hyenas, while the plains were inhabited by an
assemblage of animals very little different from that which again
occupied the country after the second Glacial episode had passed away.
At present this is little more than a theory, but it will be interest-
ing to see how far future investigations will confirm what I have
suggested, and some geologists may perhaps be stimulated to search
for further evidence bearing upon the question.

1 Quart. Journ. Geol. Soc. vol. xlii. p. 466. 2 Q. J. G. S. vol. xii. p. 386.

J. EH. Marr—The Work of Ice-Sheets. 151

IJJ.—Tue Work oF IJce-Sueers.
By J. E. Marr, M.A., F.G.S.,
Fellow of St. John’s Coll. Camb., University Lecturer in Geology.

ee, occupation of Britain by Ice-sheets in Pleistocene times has
been established by the researches of Sir A. Ramsay, Dr. J.
Geikie, Messrs. Peach and Horne, Tiddeman, Goodchild, and others.
At the time that these inquirers made their observations, the very
complex nature of the phenomena of the Greenland ice-sheet was
hardly recognized, and ‘many difficulties arose, upon which consider-
able light is thrown by a knowledge of the work of a modern ice-
sheet. Under these circumstances it may be well to apply the
information gained in recent years, and published by the Commission
for Directing the Geological and Geographical Exploration of Green-

land * to the clearing up of some of these difficulties.

A few remarks upon the nature of this continental ice, extracted
from the “ Meddelelser,” may not be out of place.

The Greenland ice-sheet is stated to extend probably over an area
about three hundred and fifty times that of all the glaciers of the Alps
taken together, and it may be readily understood that the phenomena
presented by such a mass are very different from those of the small
glaciers so generally known. The difficulties of exploration of this
great continental ice-sheet are very great, and the arduous under-
takings of the Danish explorers must command universal admiration.

Owing to the cold polar current which bathes the eastern coast
of Greenland, an almost impenetrable mass of ice blocks the shores
between latitudes 60° and 69° N., and consequently our knowledge
of that portion of the country is slight. On the western coast, how-
ever, a more favourable set of conditions exists, and the exploration
of the ice-sheet has been undertaken from this side. The southern
part of the country, around Cape Farewell, is occupied by gigantic
glaciers, in the depressions between rugged mountains reaching
a height of about 7000 feet, the summits of which, according to the
observations of Herr Sylow, appear never to have been covered by
moving ice; but north of the latitude of Julianehaab the ice-sheet is
encountered, and the numerous fjords which indent the coast to the
north of this are frequently barred at their inner terminations by
great ice-cliffs which form the ends of huge glaciers projecting like
tongues of ice from the ice-sheet of the interior into the valleys of
the coast-region.

The confinement of the ice to the valleys in this region appears
to be due to the elevation of the mountains surrounding the littoral.
The country rises rapidly from the fringe of islets surrounding the
coast, which have a maximum height of under one thousand feet, to
heights of from 2000 to 4000 feet upon the peninsulas between the
fjords. After this it falls towards the interior of the fjords, and
again rises rapidly inland, so that one meets with summits of 3000
to 5000 feet and more, further inland; but as the ice itself rises in
the interior, these heights become more and more buried in ice,

1 “ Meddelelser om Gronland,’’ parts ivi. Copenhagen, 1879—1883.

152 J. E. Marr—The Work of Ice- Sheets.

their summits standing up from the surrounding ice as islets of rock
known as “ Nunatakker,” until finally nothing is seen but a gently
sloping plain of ice extending into the interior. The “‘ Nunatakker”
of Jensen, situated at a distance of over forty English miles from the
edge of the ice-sheet, have a height of over 5000 feet above the sea.
The ice to the east of them is elevated to a height of 5000 feet,
whilst to the west it is considerably lower, as it becomes heaped up
against the eastern side of the barrier like running water against a
projecting rock. For a considerable distance to the west the ice is
nearly horizontal, and afterwards it slopes downwards at a very
small angle, having at first an average of 0° 49’ and afterwards at
greater angles, which do not exceed 2° 14’.

The effects produced upon the movements of the ice by these
partially buried barriers are most remarkable, and remind one
strongly of the phenomena described by Messrs. Tiddeman and
Goodchild in the area of and around the Pennine Chain.

If we examine the map of the directions of movement of the ice in
Phillips’s Geology of Yorkshire, third edition, part i. p. 9, and read
it in the light of recent discovery, we are at once struck with the
similarity of the conditions to those now presented by Jensen’s and
Dalager’s “ Nunatakker,” as described in part i. of the “Meddelelser.”
This map may be taken to represent roughly the emergence of the
Pennine “‘ Nunatakker ” above the ice about the period of maximum
glaciation. The whole of the low tract to the west of the Pennines
was occupied by the great masses of ice which, as shown by Messrs.
Tiddeman and Goodchild,’ came from the Lake District hills and
from those of the south of Scotland. This ice passed over the Pen-
nines at Stainmoor, and by the low watershed separating the valleys
of the Ribble and Aire further to the south. The Scotch ice and
apparently some of the Lake District ice passed over the low land
between the northern extremity of the Pennine Chain and the
Cheviot Hills, and it is generally recognized that this ice spread out
far and wide over the Yorkshire plains.

This ice is considered by Mr. Goodchild not to have risen much ©
above the 2400 feet contour-line in the Dale district examined
by him, and judging from his map, the highest marks of glacia-.
tion occur here, where the ice would be heaped up against the
Pennine Chain. In the district to the south described by Mr.
Tiddeman, the marks of glaciation occur up to a height of 1400 feet
on Bowland Knotts. The distance from Baugh Fell, where the:
highest marks are found in Mr. Goodchild’s district, to Bowland
Knotts, is over twenty miles, giving a fall of not more than 1 in 110
for the surface of the ice-sheet.

In the case of the Greenland “ Nunatakker,” we find that the
greater part of the ice passes round the buried ridge of rock,
describing a nearly complete circle, but that the upper portion flows
over the depressions which separate the different ‘“‘ Nunatakker,”
and moves over the main mass of ice on the lee-side of the obstruct-
ing ridge, usually at right angles to the course of that ice, and that

1Q. J. G. 8. vol. xxviii. p. 471, and vol. xxxi. p. 55.

J. HE. Marr—The Work of Ice-Sheets. 153

the line of junction between the two is marked by a horse-shoe-
shaped moraine profonde, which has been dragged up the more
inland side of the rocky ridge over the passes, and becomes
exposed as a terminal moraine at the extremity of the tongue
of ice which has flowed over these passes. ‘That this is true
moraine profonde is indicated by the rounded and polished con-
dition of all the stones composing it, showing that they have been
brought from a distance, and not fallen from the Nunatakker to
form superior moraines.!

The conflicting currents assumed by Sir A. Ramsay and others
from an examination of the phenomena presented by the glaciation
of Britain are here actually seen. Just as the great mass of ice
presses against the ‘“‘Nunatakker” of Jensen and Dalager, and is
borne round it, whilst a thin superficial portion is carried over the
passes between the ‘‘Nunatakker,” bearing with it some of the
moraine profonde of the ice-sheet, so the lower part of the Lake
District ice appears according to Mr. Goodchild to have ridden
northwards into the Eden Valley, as shown by the distribution of
erratics along the western side of the Pennines to the north of
Stainmoor, and the northerly pointing scratches near Crosby
Ravensworth, whilst the upper portion flowed at right angles to
this over Stainmoor, bearing with it part of the moraine profonde
of the ice-sheet, including blocks of Shap granite.

Again, the ‘ Nunatakker,” by causing the deflection of the ice,
allow of the formation of a hollow on the lee-side, whilst the main
streams of ice which have been carried on either side of each
“Nunatak” unite some way below the obstruction. ‘This is
shown in the case of “Nunatak” ¢ of Jensen’s group, where
a lake occurs with ice-cliffs towering to a height of 600-800 feet
above it, but especially by the small ‘‘ Nunatak” e situated to the
east of Dalager’s ‘“‘ Nunatakker.” In this case, the moraine profonde
appears at the surface above the “ Nunatak,” and flows ina crescentic
form around it, the horns of the crescent nearly uniting at the
extremity of the hollow, which is filled with water forming a small
lake on the lee-side of the ‘‘ Nunatak.” ? The tendency of this must
be to produce a “‘driftless” area on the lee-side of the obstruction,
up to the point where the two streams of ice re-unite. Such a
driftless area is described by Mr. Dakyns? as occurring on the east
side of the Pennine chain, to the south of the Aire basin, except
where the chain is broken by the Wye and Calder valleys.

Similar driftless areas‘ seem to be indicated by the lines on Prof.
Phillips’ map, as occurring on the east side of the Chain between
its northern extremity and Stainmoor, and between the latter pass
and the pass between the Ribble and Aire valleys. The curves of
the distribution of drift in this map remind us strongly of the
curves taken by the ice in rounding the Greenland ‘“ Nunatakker.”

1 Cf. Meddelelser, part i. plate v. figs. B’, B”, C’, 0”, and OC”.
Meddlelser, part 1. plate v. figs. Dp’ D’.

3 Q. J. G. 8. vol. xxviii. p. 383.

4 i.e. not occupied by Scotch and Lake District drift.

154 J. E. Marr—The Work of Ice-Sheets.

To complete the parallel, the ice seems to have ‘spread out at its
extremity in a fan-like form on the low ground of East Yorkshire,
just as does the Greenland ice to the S.W. of Dalager’s “Nun-
atakker” on similar low ground, forming the great Frederikshaab
glacier.

The moraine-like mound mentioned by Mr. Tiddeman as occurring
on the east flank of Ingleborough, running parallel with the curving
set of scratches, which according to him appear to have been
caused by the ice rounding Simon’s Fell, may be the relic of a
erescentic moraine formed at the end of a small tongue of ice
passing over the depression between Ingleborough and Simon’s
Fell, and sliding over the main mass of ice below in the same way
as the tongues of ice slide over the main masses on the lee-side of
the ridges which form Jensen’s and Dalager’s “ Nunatakker.” This
mound, in any case, merits careful examination.

Another point illustrated by the Greenland ice-masses is the
formation of contorted sands and clays associated with boulder-clay.
Such deposits are usually referred to the action of the sea, or of
running water, and it does not seem to be generally recognized that
similar deposits are actually being formed in the ice itself.

In part iv. of the ‘‘ Meddelelser,” plate iii., bands of stratified
sand and clay are seen interstratified with the ice at the extremity of
a glacier which descends towards the fjord of Umanak, and these
bands are not only overfolded, but also faulted along lines of crevasses
in the ice. Similar bands are seen in plate iv. fig. 8, at the end of
the glacier of Tuapagsuit, and above them, at one part, is a mass of
moraine formed of gravel and large stones with their asperities worn
off. If these masses of ice melted, they would leave contorted beds
of sand and clay, with small faults, associated with morainic matter.
May not some of the remarkable stratified deposits figured by Mr.
Goodchild have been produced in a somewhat similar way ?

The very conspicuous manner in which the Greenland valleys are
stopped up by ice is also worthy of notice in connexion with the
glacial theory of the origin of the Parallel Roads of Glenroy. The
Jacobshavn glacier stops up both ends of a valley running parallel with
its course, converting it into a lake which is separated from the
glacier throughout the greater part of its length by a “ Nunatak.”
The lower end of another valley considerably to the south of this is
stopped by the ice-sheet, and the valley converted into a lake |
(Tasersiak), which is drained by a river running over the col at the
head of the valley into the Strémfjord, just as in the case of the
Marjelen See, only the Greenland lake is much larger than this. A
similar lake drains into the N. Isortok fjord, and another into that of
Alangordlia. Two similar lakes are formed to the east of Sermilik
fjord, and several small ones to the east of Bjornesund. North of
the Frederikshaab glacier is a valley running north and south, the
mouth of which is stopped by the Frederikshaab glacier, whilst a
tongue of ice flows through a col situated half-way up the valley and
bars the valley, one part of the tongue of ice flowing a small distance
to the north, and another to the south, thus causing the conversion of

Dr. H. Hicks—Cambrian Rocks of N. America. 155

the valley into two lakes. On the east of the Frederikshaab glacier
is the lake Tasersuak, bounded on the north by the “Nunatak ”
Kangarsuk, and stopped at its lower end by the Frederikshaab
glacier, and having a tongue of the ice-sheet entering into it at the
upper end.

The erosive power of an ice-sheet is well seen by a glance at the
observations made upon the rivers which flow into the fjords of
Nagsugtok and Isortok, and which have their origin at the ends of
the tongues of ice which occupy the valleys continuous with these
fjords! The river from the first contained only 200—225 grammes
of mud per cubic metre of water in the month of July, whilst the
second in the month of June enclosed 9129 to 9744 grammes. This
is compared with the amount carried by the Aar where it emerges
from the glacier; it there contains only 142 grammes. The great
difference presented by the rivers which fall into the two fjords is
attributed to the fact that the ice moves with much greater speed
towards the fjord of Isortok than towards that of Nagsugtok. It is
calculated that the quantity of fine mud carried into the former of
these fjords amounts to 4062 million kilogrammes per day. This
mud is deposited in the interior of the fjord, which is filled up to
such an extent in its upper portion that even flat boats cannot pass
up it. What a powerful machine for the formation of the fine clay
of “till” is here!

At the time when the Pennine Chain was nearly buried by the
great ice-sheet from the west and north-west, the parts which stood
out above the ice may still have possessed a meagre flora, for plants
are found upon Jensen’s Nunatakker which, as already stated, are
situated about forty English miles from the edge of the ice, and have
an elevation of over 5000 feet. Amongst these plants are Draba
alpina and Potentilia nivea. Herr Kornerup has collected altogether
54 species of plants from various ‘‘ Nunatakker.”

Observations have been taken by members of the various expedi-
tions as to the former extension of the ice, with the result that it is
found to have stretched much further seaward in the period of great
glaciation, but at the same time its height does not appear to have
risen very much above the present level, for the summits of many
mountains along the littoral show no traces of former glaciation.
This seems to indicate that the thickness of the ice depends rather
on the elevation of the country than on the intensity of the cold.

I have written the above slight sketch in hopes of calling attention
to the importance of the results obtained by the Danish explorers in
Greenland, to those who wish to elucidate fully the history of the
ice-sheets of our own country.

TV.—Tue Camprian Rocks or NortH AMERICA.
By Henry Hicxs, M.D., F.R.S., F.G.S., etc.
ONSIDERABLE attention has been given of late years to the
faunas of the rocks in North America considered to be the
equivalents of the rocks usually classed as Cambrian in this country,
1 Meddelelser, part ii.

156 Dr. H. Hicks—Cambrian Rocks of N. America.

and the facts which have been obtained are particularly interesting
to British geologists. Two recent communications by Mr. C. D.
Walcott, Paleeontologist to the U.S. Geological Survey, are especially
deserving of study in reference to the classification of these rocks,’
and many facts of importance bearing on the same question are also
given in papers by Mr. G. F. Matthew, of St. John’s, N.B.?

That the classification found most suitable by the majority of those
who have, during recent years, studied these rocks in Great Britain
should now have been adopted by such experienced geologists in
America, is very strong evidence of its wide applicability, and is a
fact which should, I think, have influence on those who still hesitate
in adopting it as the best means of bridging over the insuperable
difficulties connected with the classifications of the rival schools of
Sedgwick and Murchison.

In his introductory observations Mr. Walcott says,? ‘In using the
name Cambrian in this paper for the series of strata characterized by
the First or Primordial fauna of Barrande, I do not forget the claims
of the name ‘Upper Taconic,’ which Dr. E. Emmons proposed for
the strata now placed under the Middle Cambrian or Georgia
Formation,” and, ‘“‘The term Cambrian is used from the belief that
in so doing I approve of the view of those writers who hold that
each of the distinguished authors, respectively, of the names Silurian
and Cambrian will be fairly recognized, and geologic nomenclature
advanced by the use of the names Cambrian and Silurian for the
divisions of strata characterized by the first and third faunas as
defined by Barrande..... Of the presence of a well-defined
geologic system beneath the strata characterized by the second fauna
of Barrande or the Trenton fauna (including the Chazy and most of
the Calciferous) of North America, on the North American continent,
there is no question. The geologic sections given in this paper show
it to have a total thickness of over 18,000 feet, and that its middle
division has a known fauna of 43 genera, represented by 107 species.
We also know that the Lower Cambrian or Paradoxides fauna has
o2 genera and 76 species; that the Upper Cambrian or Potsdam
fauna includes 52 genera and 212 species; that of the 393 species
now known from Cambrian rocks but very few pass up into the
Calciferous horizon of the Lower Silurian (Ordovician) ; and that
the faunas of the two systems are so distinct in their general facies,
and also in detail, that they are quite as readily separated as the
Silurian and the Devonian or the Devonian and the Carboniferous.
There is no doubt that in certain areas the faunas of the Cambrian
and the Lower Silurian (Ordovician) systems are intermingled ; but
the same is more or less true of all the great divisions of the entire
geologic series from above the great Archean break to the Quater-
nary.”

1 “ Classification: of the Cambrian System of North America,’ Amer. Journal of

Science, vol. xxxii. and ‘‘ Bulletin of the United States Geolog. Survey, No. 30,”
1886.

2 “Tilustrations of the Fauna of St. John’s Group,’”’ Trans. Royal Soc. Canada,
1885, and “ On the Cambrian Fannas of Cape Breton and Newfoundland,” Canadian

Record of Science, Oct. 1886. 3 Bulletin U.S. Geolog. Survey, No. 30, 1886.

Dr. H. Hicks—Cambrian Rocks of N. America. 157

Dr. Sterry Hunt has strongly advocated! the adoption of the term
Ordovician (first proposed by Prof. Lapworth and now used by
many authors in this country) for the American second division
(Lower Silurian), and it is highly advisable that it should be adopted
by American authors, as it would then be possible to know exactly
to which portion of the Lower Paleozoic rocks the author referred.
The tripartite division of the Lower Paleozoic rocks of Great Britain
under the names Cambrian, Ordovician, and Silurian, seems at
present the only means of avoiding confusion, and it is highly satis-
factory, therefore, to find that some American authors are prepared
to accept these terms to designate the primary divisions of the
American Lower Paleozoic rocks.*

On the other hand, it is advisable that groups and series should
still have local names, and the names should be those of places where
the beds were first examined, or are well exposed. The following
table expresses Mr. Walcott’s views on the classification of the various
groups that go to make up the Cambrian system of North America.

CLASSIFICATION oF NortH AMERICAN CAMBRIAN Rocks.

Lower portion of the Calciferous Formation of New
Lower E
GalGforous York and Canada.

‘| Lower Magnesian of Wisconsin, Missouri, etc.

UPPER

CAMBRIAN.| Potsdam. | Potsdam of New York, Canada, Wisconsin, Texas,
Wyoming ; Montana and Nevada; Tonto of Ari-

Knox. zona; Knox Shales of Tennessee, Georgia, and
Albama. The Alabama section may extend down
Tonto. into the Middle Cambrian.

Conn Georgia Formation of Vermont, Canada, & New York.
MIDDLE Teens Limestones of L’anse au Loup, Labrador.
Th Lower part of Cambrian section of Eureka and High-
CAMBRIAN,| p. 7 C land Range, Nevada.
pect | Upper portion of Wasatch Cambrian section, Utah.

St. John. | Paradoxides beds of Braintree, Mass., St. John, New

Braintree. Brunswick.
12 Newfound-| St. John’s area of Newfoundland. Lower portion of
land. Wasatch section, Utah.
CAMBRIAN.| Wasatch. | ‘The Ocoee conglomerate and slates of East Tennessee
: Tennessee ? are somewhat doubtfully included.

1 Trans. Roy. Soc. Canada, 1883, and ‘‘ Mineral Physiology,”’ etc. 1886, p. 528.

2 In a former paper (Grou. Mac. Aug. 1885) I ventured to suggest that the term
“Cambrian,”’ instead of being confined to the lowest rocks, might fairly be extended
as a main term to indicate the whole of the Lower Paleozoic rocks, and that the
name ‘‘ Georgian” (from St. George’s Channel, on the borders of which the lower
rocks are best exposed) would be a suitable term for the lowest rocks. I have since
found that the Middle Cambrian rocks of Franklin County, Vermont, America, had
previously been designated the ‘‘Georgia Group’’; therefore it is evident that the
adoption for a much larger division of the term “‘ Georgian” would only lead to
confusion. It is better, therefore, to confine the term ‘‘ Cambrian”’ as in the present
paper to the rocks underlying the ‘‘ Ordovician.”’

158 J. Starkie Gardner—Development of Dicotyledons.

In Bulletin No. 30, Mr. Walcott treats mainly of the fauna of the
Middle Cambrian rocks and figures and descriptions of a large
number of new genera and species are given. In Great Britain the
fauna of these rocks is comparatively a poor one, and none of the
typical American forms have as yet been discovered in them.

The American Middle Cambrian fauna is said to combine! “the
characters of the Lower Cambrian and Upper Cambrian faunas and
yet is distinct from each of them. . . . The conditions that developed
the Middle Cambrian fauna appear to have been largely peculiar to
the American continent. During the deposition of the St. John’s
series of the Lower Cambrian, or the Paradoxides strata, we learn
from the European and eastern American sections, that the fauna was
essentially of the same type over the entire basin (Atlantic), and,
from evidence known to date, that the fauna did not extend west of
a line passing north-east through Hastern Massachusetts to New
Brunswick and Newfoundland. . . . From the data we now have, I
think that during the existence of the greater portion of the Lower
Cambrian (Paradoxides) fauna, a barrier existed that prevented its
extension westward of the line mentioned; that towards the close of
the time of the Paradoxides fauna that barrier was removed to the
north-east, in the vicinity of Newfoundland, and the descendants
from the Paradoxides fauna entered the westward seas and spread to
the eastern and western basins and formed the Middle Cambrian
fauna. What route was taken by the Middle Cambrian fauna after
passing to the western side of the outer barrier is not yet traced, but
I think from the indications we now have of a continental area,
during Lower and Middle Cambrian time, in the central portion of
the continent, that the fauna passed to the south around the southern
end of the then existing land, and thence north along the west shore.
In the Atlantic basin, the Paradoxides fauna persisted to a greater or
less extent and mingled with the types of the Upper Cambrian fauna,
as in the Upper Lingula Flags of Wales.”

As Mr. Walcott is personally acquainted with the strata from which
the fossils have been obtained, and has studied in the field most of
the sections referred to, the conclusions at which he has arrived
are important and highly deserving of very thoughtful consideration.

V.—Tuer APPEARANCE AND DrveLorpmentT or DicoryLEpons In TIME.
By J. Starxiz Garpner, F.G.8., F.L.S.

T has been acknowledged by botanists that the methods generally
pursued in determining fossil dicotyledonous plants have been
scarcely such as were likely to lead to trustworthy results. Their
study has, or should have, two practical aims. The one, that geo-
logists may be able to determine the ages of strata, when they only —
contain fossil plants, with as much certainty as if they contained the
remains of animals. The other, that botanists may be able to trace
the evolution of the existing genera of plants from the palzonto-
logical record under conditions no less favourable than those at the
disposal of the zoologist.

1 American Journal of Science, vol. xxxii. p. 181.

J. Starkie Gardner—Development of Dicotyledons. 159

Each new discovery should fall into a definite place, fill in some
gap, and serve as a new point of departure.

That this is not the case when new fossil floras are described is
but too apparent. When we sum up and examine the whole of the
knowledge we possess of the ancestral forms of existing Dicotyledons,
we find we are in a state of almost complete ignorance regarding
them. We merely know that in certain formations, which we believe,
from their included marine fauna, to be of Cretaceous age, perfectly
developed leaves of Dicotyledons abound ; but we do not know with
any certainty how far we are justified in assigning them to existing
genera, nor in what way they are linked to these. We know abso-
lutely nothing of the successive steps by which even the leading
existing families have been developed. We know nothing concerning
the evolution of the Leguminose, the Proteacez, the Cupulifere.
We see nothing beyond a more or less vague recognition of the fact
that plants with simpler flowers should have preceded those with
flowers of more compound character. We assume from the absence
of Dicotyledons in older Cretaceous rocks that they must have been
relatively somewhat rapidly developed; but the where, how, and
whence, are still sealed books.

In the first place, we must inquire whether we can be absolutely
certain that the ages of the Cretaceous beds which contain them are
correctly known. Our first impression would be that the age of the
Aix-la-Chapelle series is established on the most unequivocal evidence,
for the beds with plants are intercalated between strata which belong
lithologically and at first sight paleontologically to our Upper Green-
sand and Chalk, yet nevertheless the similarity may be completely
misleading ; and when we compare the faunas together critically, we
shall realize that those of the Aachenian series are relatively con-
siderably the younger. In an area of prolonged and gradual
subsidence, as Europe undoubtedly was throughout the Upper
Cretaceous period, the deep sea, or ancient gulf of the Atlantic,
as represented by the Chalk, would gradually encroach further and
further in every direction as the levels were lowered. At certain
depths blue mud resembling that knownas the Gault, and green mudand
sands, similar to our Upper Greensand, would now be forming. These
require a less depth and are more littoral than the deeper sea deposits
corresponding with our Chalk, and in every area where chalk exists
are seen to underlie it. During the Cretaceous subsidence, where-
ever oceanic waters penetrated, one or other or both of these qualities
of mud must have preceded the deposition of true Chalk. Nothing
could be more erroneous and more liable to beget confusion than to
speak of all the blue mud as of one age, the green mud and green
sand of another, the calcareous mud with chloritic grains as another,
and the finer calcareous ooze as another. Their relative ages must
be judged by the faunas they contain, and the greater or less resem-
blance of the organisms composing these to the existing types now
found in the same qualities of sediment. There is no reason to
suppose that the Cretaceous subsidence extended over Europe syn-
chronously ; it is at all events perfectly obvious that so long as Chalk

160 J. Starkie Gardner—Development of Dicotyledons.

was being formed over any part of its area, the formation of those
qualities of sea-bed called in their upheaved state Gault and Green-
sand must also have been forming synchronously over the lesser
depths nearer land.

There is no physical reason whatever why the Aachenion Danish,
Irish, Scotch, or even Devonshire basins or gulfs, should not have
begun to form contemporaneously with the deposition of the newest
White Chalk in Kent and Sussex, or even with the much newer
chalks that have since been denuded without leaving a trace. Strati-
graphy, or rather petrology, is entirely at fault in this question,
while paleontology tends to show that subsidence travelled outwards
from the South-East of England and the North-East of France, and
thatthe farther we recede from this centre, the younger will be the
relative ages of the Cretaceous series, and the nearer the approach in
themyto what is recognized as a Tertiary fauna. Cretaceous forms
wotld still be present in the newest of them, for it cannot be sup-
Hostd Ahat the extinction of these was sudden, or that they must
Steere be absent from a Cretaceous quality of sea-bed, even
thorgh its deposition was continued into Hocene times, for much of
the lite characteristic of the Cretaceous period is even now living in
the deeper seas. It would on the other hand be very surprising to
find Cretaceous forms in our Eocene muds, as these were formed
under wholly different conditions which precluded the possibility
of the existence of any faunas approaching in character those of
the Chalk. The Aix-la-Chapelle flora, therefore, though overlaid by
Greensand and Chalk with some Cretaceous types, is not necessarily
as old as it appears to be stratigraphically. In countries so distant
as America, we might have had Cretaceous formations in progress
part passu with the formation of our Hocene. ‘The presence of some
extinct or supposed extinct types is no certain proof of antiquity,
for we only know them to be extinct now, but do not know when
they became extinct, because we do not at present recognize the
possibility of any deep-sea, or, in other words, deposits of Cretaceous
aspect, being of Tertiary age. A great number of Cretaceous genera
have been discovered to be not yet extinct; why then should we
suppose that all those that are extinct disappeared simultaneously
with the recession of a Cretaceous-depositing sea from our area, in-
stead of the more rational hypothesis that they disappeared gradually,
dropping out now one, now another, at any time between that period
and the present day. If these considerations were not lost sight of,
we should not find the presence of an Ammonite, Belemnite, or
Inoceramus in a deep-sea deposit of America or New Zealand, held
as proof conclusive that this is as old as our Cretaceous series, for
they may merely be survivals of archaic types, which once swarmed
in every condition of sediment, but which gradually took refuge in
deeper water, to become extinct, no one can know when until our
record of deep-sea deposits be more complete or better understood.

It is thus obvious that the supposed sudden appearance of a num-
ber of highly developed and almost perfectly distinct dicotyledonous
floras during the Cretaceous period, at so many distinct parts of the

J. Starkie Gardner—Development of Dicotyledons. 161

world, may be illusory. The first appearance of Dicotyledons re-
mains, however, in any case remarkably sudden, and we are still
left with very little clue as to how and by what progressive steps
they originated.

The flora of Aachen is, I believe, the most extensive European
Cretaceous flora known. Very little concerning it has been pub-
lished, and neither it nor any other Cretaceous flora with Dicotyle-
dons is adequately represented in any Museum in Great Britain. I
had fortunately, however, an opportunity of going carefully through
Dr. Debey’s collection, and of visiting the quarries whence it had
been obtained and even finding a few specimens. Its great antiquity
is obvious, despite the presence of dicotyledonous leaves, for the
Conifer depart very widely from existing species, or even from
those of the Hocene, and among the Ferns there seem to be repre-
sentatives of two singularly archaic genera, Matonia and Thyrsopteris,
which do not occur in any Tertiary formation in Europe. I did
not see, and am not aware of any good grounds for the supposed
identifications of the Dicotyledons with living genera, such as Oak,
Beech, Fig, Willow, Poplar, Bog-myrtle, nor with any genera of the
Proteaceze and Myrtacez. The leaves are of considerable variety of
form and size, lobed, serrate and simple. There are many other
localities in Europe from which similar Cretaceous floras have been
obtained, but I am not so well acquainted with them.

A more ancient flora is that of Kome in Greenland, from which
a single though apparently perfectly developed dicotyledonous leaf
has been obtained, and referred, upon no ground whatever, except
a fancied resemblance in the form of the leaf, to Populus.

The newer Cretaceous rocks of Greenland are said to contain
species of a large number of existing genera; but these appear, with
trifling exceptions, to be all determined upon the greater or less
resemblance of the fossil leaves to some of the forms of leaf met with
in such genera. The ages of the deposits are apparently very un-
certain, and no specimens have yet found their way to our museums.

Another extensive and supposed Cretaceous flora from Vancouver’s
Island has frequently been referred to; but no specimens, so far as
I know, exist in England.

A yet more extensive flora is that from the Dakota group at the
base of the American Cretaceous series. The leaves are mostly
lobed, resembling those of Piatanus, Sassafras, and Liquidambar,
but seemingly no fruits have yet been identified. A remarkable
fact about this flora is, that while utterly disconnected from any
other supposed Cretaceous flora in Europe, it bears a resemblance
to the English Lower EHocene flora.

Cretaceous rocks containing Dicotyledons are also met with in
New Zealand, but as yet little appears known about their floras.

It is quite apparent that the whole subject is still involved in the
utmost obscurity, and that our actual definite knowledge of Cretaceous
Dicotyledons practically amounts to very little. A man would
indeed be bold who ventured to pronounce upon the precise age of
any Cretaceous rock only from the character of the dicotyledonous

DECADE III.—VOL. IV.—NO. IVY. 11

162 J. Starkie Gardner—-Development of Dicotyledons.

plants found in it. They require, before this can be done, and
deserve, the most profound study.

We have next the supposed Pre-Kocene or Pal-Hocene floras, the
chief of which are from the calcareous tuffs of Sézanne and the
limestone of Gelinden. Large collections from both these localities
have been in my possession, and are now in the British Museum,
The stratigraphical evidence as to the age of the former is inconclu-
sive, and the flora, rich in flowers as well as leaves, is unlike any
other. The Gelinden flora is mainly composed of small and simple
leaves, and is equally unlike any other, though its age seems to rest
on a surer basis. It does not appear so far that the age of any Pre-
Eocene or very old Hocene deposit could yet be recognized with
certainty through its Dicotyledons.

We next come to the true Hocene deposits, and in the first place
I am able to correct the erroneous assumption that no flora in our
latitude comprising such modern and temperate-looking genera as
Platanus, Saliz and Alnus can be Eocene. At Reading, underneath
the true London Clay with its typical marine fauna and the Reading
series, leaves and fruits abound of Platanus as completely differentiated
as existing species. With these are leaves and fruits of at least two
leguminous trees, a large-leaved tree with melon-shaped fruits of the
size of a walnut, and others forming a completely distinct and homo-
geneous flora, easily identifiable, and of perfectly defined age. It
strongly resembles the Dakota flora of America, but does not seem
known elsewhere in Europe. At Newhaven and at Coldam Com-
mon near Winchester, we have some Reading plants mixed with
others belonging to the somewhat higher and also perfectly charac-
terized horizon of Bromley, Lewisham, Croydon and Dulwich.
Platanus here mingles with many new forms of leaf, for the most
part strongly serrate, forming another group of plants quite unknown
out of England. We now reach the well-known flora of Sheppey,
led up to by the Herne Bay flora with Alnus Richardson. The
Sheppey flora is extremely instructive, although it is so utterly
distinct from any other that it is of little value for purposes of com-
parison. Such vast numbers of fruits have been collected from it
that we may safely consider ourselves in possession of all the chief
types, yet, singular to say, though the presence of trees with such
easily recognizable fruits as Quercus, Fagus, Corylus, Castanea,
Juglans, and some Proteaceous genera has been insisted upon in all
the preceding dicotyledonous floras, not a single fruit even re-
motely resembling those of any one of these genera has been found
among them. Ido not yet realize the full significance of the fact,
but so far most of the early dicotyledonous seeds seem to. be clustered
in fruit spikes as in Alnus and Platanus and the Urticee, and few
seem of the nature of single-seeded nuts; nor up to this horizon is
there any indication of winged-seeds such as the Maple, Ash and
Elm. The oldest leguminous pods seem those from Reading. Next
in age, and possibly even to some extent contemporaneous with the
London Clay, is the flora of Alum Bay, also met with in France in
the Grés du Soissonais. It is specially characterized by leaves of

ah a ee

J. Starkie Gardner—Development of Dicotyledons. 163

Myrica, large-lobed leaves referred to Acer, and large simple leaves
referred to Ficus and others, together with leaves of an immense
Fan Palm. None of the determinations seem well grounded except
Myrica, but there are several leguminous fruits, and the flora, as a
whole, is easily and immediately recognizable, and would suffice to
define the age of any beds in which it occurred,

Following in order is the Bournemouth flora, of great variety and
extensively collected. It is very unlike any of the preceding, and
were its age not absolutely known beyond the faintest possibility of
doubt, it would have been referred to the Miocene, though actually
older than the Bracklesham beds. It greatly resembles the Hocene
floras from the South of France and of the Lignitic Series of
America. Its affinity to the Oligocene floras of the rest of Hurope
appears so great that it is doubtful whether any distinct line can he
drawn between them, but a little higher at Hordle, some of the
Older Hocene Reading types seem to mingle with it.

All these Hocene floras are in beautiful preservation, and their
stratigraphical position is definitely ascertained. A careful study of
them will be repaid by much valuable information regarding the
order of appearance of the genera of Dicotyledons, and would enable
us to at once recognize the ages of any Hocene floras of adjoining
countries. We should be able to argue from the known to the un-
known, instead of the reverse as heretofore practised, and to con-
struct for the first time a definite chronological sequence with which
other floras might be contrasted and compared. ‘The series can only
be paralleled by the fossil floras of South-Hastern France, so beauti-
fully described by Saporta.

In utilizing them for comparison with the fossil floras of other
countries, the differences of latitude and longitude must be taken
into account. Nor have we any right to suppose that all the plants
preserved from an immense number of localities grew at the same
elevation above the sea, while they may also have lived on very
different stations, and under relatively dry or moist climates. Any
of these influences, singly or combined, might profoundly modify
floras, which, though perfectly contemporaneous, would then present
very different compositions and aspects. Such considerations are so
very obvious, that it would seem almost unnecessary to insist on
them, yet we find in examining works on the Miocene floras that
they have not been regarded. Floras trom Spitzbergen in the North
to Australia in the South have been classed as Miocene from a very
slender fancied resemblance to those of Switzerland, and great series
of strata have been assigned without sufficient reason to that age,
not only in Central Europe, but in such distant lands as Greece,
Madeira, Borneo and Sumatra, Sachalin and Alaska, and in fact
wherever other evidence of age was absent. The resemblance of
some of these floras to those of Switzerland is in many cases very
shadowy and quite insufficient to justify any conclusion as to their
age; but it is more than doubtful whether many of the supposed
Lower Miocene Floras of Switzerland classed as Aquitanian are not
themselves as old as the Eocene, and others, as the Mayencian, Oligo-

164 J. Starkie Gardner—Development of Dicotyledons.

cene. Hnough has, however, been said to show that no scientific
value can attach ina general way to these determinations, and it
will suffice to select the Greenland floras as an example, and to in-
vestigate the evidence upon which their supposed Miocene age was
originally established. This was stated in 1868 to rest on an assured
basis, when of 70 described species, 20 were alleged to occur in
Miocene beds of Central Europe..

Of these two are Ferns, and appear respectively allied to Osmunda
regalis and Pteris aquilina. 'They are ancient and northern forms
which do not appear in any profusion to the south until Miocene
times, though the Osmunda occurs in the old Eocene of Gelinden.
Of Coniferze two are referred to Sequoia; the first is erroneously
united to S. Couttsie of Bovey, and the second, S. Langsdorfii, is a form
known in the Cretaceous, and to which every fragment of distichous
Coniferous foliage from the Tertiaries, that could not be placed in the
third form, Taxodium dubium, has been at one time or another referred.
The latter genus is found in the Middle Eocene of England. The
sixth plant is merely a rush-like fragment referred to Phragmites.
Of the thirteen Dicotyledons, ten are the most ordinary and wide-
spread forms of leaf, such as occur in every flora, and of the three
that are at all distinctive forms, two, the Platanus and Populus
Zaddachi, are characteristic of the Lower Hocene of Reading, and the
third has only been found elsewhere in the Oligocene of Armissan.
The age of the Greenland formations can hardly be considered settled
on such evidence as this, even were the determinations trustworthy,
which is far from the case. Of course enormous quantities of plant
remains have been described from Arctic formations since then, but
they do not help to justify their reference to the Miocene, and the
significant fact remains, that the most distinctive species belong to
the Eocene floras of Reading and of Gelinden.

But supposing the identity of the floras were satisfactorily estab-

lished, should this suffice to establish contemporaneous growth? -

Could floras of forest trees so closely related to existing species have
grown at so recent a geological period synchronously with 24° of
latitude intervening? This, it must be remembered, is the distance
between Lombardy and Iceland, or Florida and Newfoundland.
There is no reason why Hocene floras should be unrepresented
round the Pole, and all the Eocene formations existing there be
unfossiliferous. A series of sedimentary rocks destitute of fossils,
and sometimes a thousand feet thick, is said to occur between the
uppermost Cretaceous and lowest supposed Miocene, representing
probably the temperate Lower Hocene period, when forests of leafy
trees could no more have grown within the Arctic Circle than they
would at the present day. As the temperature increased towards
the Middle Eocene period, the temperate floras of the Lower Hocene
would have migrated north, and we accordingly find, not fancied
resemblances, but identity established by the presence of such peculiar
and typical species as the Reading Populus Zaddachi, P. Richardson,
Platanus, and the Gelinden McClintockia and Cocculus Kanit.

The Middle Eocene temperature was moreover exactly that re-

J. Starkie Gardner—Development of Dicotyledons. 165

quired, according to Heer, to admit of the growth of the Greenland
floras, for it was above 70° Fahr. in the South of England, lat. 50°,
and 50° Fahr. in Greenland, lat. 70°, the distance, difference in tem-
perature, and difference between the floras being as nearly as possible
equivalent to that existing between Madeira and England at the
present day.

When we reflect that the first dicotyledonous floras of any extent
to be described were from the Miocenes of Italy and of Germany, we
are no longer surprised at the immense relative importance that that
formation assumed in the eyes of subsequent workers. It is small
wonder that Heer was led by comparisons with these and with the
well-known Miocene formation of Oeningen, to class all the dicoty-
ledonous floras of Switzerland as Miocene. As each is in turn
farther and farther removed in age from the horizon of Oeningen,
it is seen to contain a decreasing proportion of true Miocene types.
Thus, of the floras belonging to the Aquitanian stage, only six out of 34
species at Ralligen, 27 out of 193 species at Monod, and seven out of
47 at Paudéze, are common to Oeningen. Yet each in turn, as it came
to be incorporated in the Miocene, has furnished fresh standards for
comparison, each addition approaching more nearly to Eocene types,
and departing more widely from those of the Miocene. By including
the Swiss Aquitanian and Mayencian in the Miocene, and then in
comparing Hocene and Oligocene floras of other countries with them,
the latter would be shown to possess Miocene characters, for there
can be little doubt that the Aquitanian floras are really Eocene, and
the Mayencian are truly Oligocene. We thus get at the root of the
matter, and though I could not induce the lamented Prof. Heer to
understand the grounds of my contention, I have no doubt that had
he lived to investigate our magnificent and typical series of English
floras, he must have modified his views. The process of assimilating
floras with the Miocene became a habit with him, and was always
justified by percentages. He persistently ignored Hocene floras, and
it was only the stratigraphical and overwhelming paleontological
evidence as to the position of the Dakota and other floras of
America that led him to admit the Cretaceous age of the older
dicotyledonous floras.

It was Heer’s privilege to describe the floras of Greenland, and
he called them Miocene. Had it fallen to Saporta’s lot, he would
possibly have assigned to them a Lower Eocene age, on account of
the considerable number common to Gelinden, including the typical
M‘Clintockia, which had not then been found in any other formation.
A student of our Reading flora would have assigned them to that
age. The Greenland flora has in its turn served to identify the
Mull and the Antrim floras as Miocene, and must have absorbed the
Gelinden flora and the American floras, had stratigraphical evidence
not intervened and made this impossible. Not the least remarkable
fact about these determinations is, that wherever the stratigraphical
evidence is nil, as at Antrim, Mull, and Bovey, the floras are Miocene ;
but where there is stratigraphical evidence, we hear of few Miocene
floras to the west of Switzerland.

166 J. Slarkie Gardner—Development of Dicotyledons.

Before quitting the subject, it is well to revert to the danger of
determining the ages of fossil floras in remote parts of the world by
comparing and estimating the percentages common to those of
Europe. Not only have we to keep in mind the similarity that
dicotyledonous leaves belonging to different genera bear to each
other, a likeness increased by the process of fossilization where the
matrices are similar, but the fragmentary condition of the specimens
usually brought from distant countries. In the first five volumes of
the Arctic flora hardly a perfect dicotyledonous leaf is illustrated,
and it is most rare to find them collected with so important a
character as the petiole complete. In addition to this, were we to
take an armful of fallen leaves at random from each country, such as
Siberia, Japan, Sumatra, Australia, New Zealand, Madeira, Scotland,
France, Greece and the United States, and compare them together
after the manner of paleontologists, is it likely that we should find
grounds for supposing that they all belonged to floras growing
synchronously ? The fallacy of such reasoning is even more appa-
rent when we realize that a considerable percentage of the species of
even Hocene floras, including such unmistakable forms as Osmunda
Javanica, are now living on the Hast Coast of Asia, for a comparison
by percentages would make the existing and the Eocene floras
contemporaneous. In like manner we have living Asiatic species at
Mull and Antrim, living Australian species at Bournemouth and
Sheppey. These must have migrated to or from their present
habitats, and might be found imbedded anywhere along the routes
they have passed over, and if so found might be of any age between
the Hocene and the present day.

We are too accustomed to treat these floras as complete exponents
of the vegetation of the past. They are, however, but mere frag-
mentary indications of what existed. The flora of Gelinden
consists of, for instance, some 60 species, but only contains three
Ferns and one Conifer. Can we suppose that Ferns and Coniferee
were not at least as richly represented then as now? And if we
were well acquainted with the bulk of them, how entirely erroneous
our inductions from the few we do know might appear. Bourne-
mouth is a case in point, for on the right of the old river delta,
of which the present cliffs are a section, the flora is completely
different in character to that met with on the left. The latter
is a flora of leafy trees, and had it alone been accessible, the climate
might have been inferred to have been too temperate for the growth
of Palms, for none are found in it. Thus an utterly different view
of the character of the plant world of the Eocene period during the
Middle Bagshot would be deduced by a student of the flora of the
right bank, from that fairly deducible by a student of the left bank.
But, extraordinary to tell, within a few hundred yards of the latter,
still another completely different flora is found, in which occur Fan
Palms in place of Feather Palms, Araucaria Cunninghami, Eucalypt,
Aroids, and a whole host of tropical Ferns. Even now, after years
of collecting, new and astonishing plants are continually coming to
light, such as Hewardia regia, a South American type of Fern, and

Prof. J. W. Spencer—Glacier-erosion in Norway. 167

Stenocarpus, a purely Australian genus, as if to impress the danger
of prematurely drawing inferences. Not deep below we have another
completely different tropical flora on the Alum Bay horizon, with
scarcely a type of plant in common to the horizon above; and again,
separated in this district by only a few hundred feet, we might find
the characteristic flora of the Reading beds with an utterly distinct
assemblage, indicative of a temperate climate. In face of such
amazing facts it is only possible to smile at the glib way in which
temperatures and comparisons for every little handful of fossil
plants are set out, and the physical features of the country which
bore them reconstructed.

These remarks are not intended to discredit those who have
laboriously worked at the task of deciphering fossil floras. They
are simply meant to warn those who have to make use of the facts
arrived at, that the conclusions and the inductions drawn from them
are not based upon foundations as assured as those of other branches
of geology and paleontology. They may or may not prove to be
wholly or partially correct, but what we had best do for the pre-
sent is to abstain from theorizing, and to devote ourselves to the
work of deciphering, more especially those floras whose ages are
definitely stratigraphically known, and by friendly intercourse and
repeated comparisons of actual specimens, to ascertain beyond all
dispute that a species means one and the same plant to each individual
worker.

If at the same time it could be agreed that new species should not
be founded on fragments so obscure and imperfect that no good
specific characters can be obtained from them; that references to
genera founded only on resemblance of foliage should be distinguished
by a special termination ; and that fossil plants found to be still existing
should bear the name of the living plants ; the science would rapidly
command that consideration and respect to which its vast importance
so well entitles it.

VI.—Nores on THE HRostvE Power oF GLACIERS, AS SEEN IN
Norway.

By Professor J. W. Spencer, M.A., Ph.D., F.G.S.

DURING last summer it was my good fortune to visit the three
» largest snowfields in Norway, namely, Folgefond, at the head
of Hardangerfjord, in Southern Norway, whose area is 108 square
miles ; the Jostedalsfond, two degrees to the northward, and beyond
Sognefjord, whose area is 580 square miles, and the largest snow-
field in Europe; and the Svartisen, of nearly equal area, extending
from just inside the Arctic Circle for 44 miles to the northward. All
of these snowfields send down glaciers to within from 50 to 1200
feet of the sea. These snowfields are not basins like those in the
Alps, but are mantles covering the tops of the plateaux from 38000
to 5000 feet or more above the tide, from which great carons sud-
denly descend to the sea, and extend themselves as fjords from 1000
to even 4000 feet in depth. ,

168 Prof. J. W. Spencer—Glacier-erosion in Norway.

2. Many of the Norwegian glaciers are rapidly advancing. In
their progress they do not conform to the surfaces over which they
are passing, but are apt to arch over from rock to rock and point to
point, especially as they are descending the icefalls. Thus are pro-
duced great caverns into which the explorer can often wind his way
for long distances.

3. Beneath the glaciers of Fondal, Tunsbergdal, and Buardal, in
the northern, north central, and south central snowfields of Norway,
as well as under other glaciers, I observed many stones enclosed in
ice, resting upon the rocks, to whose surfaces—sometimes flat and
sometimes sloping steeply—they adhered by friction, and by the
pressure of the superincumbent weight. Although held in the ice
on four sides, with a force pushing downward, the viscosity of the
ice, or the resistance of its molecules in disengaging themselves from
each other in order to flow, was less than that of the friction between
the loose stones and the rock, consequently the ice flowed around
and over the stones, leaving long grooves upon the under surfaces
of the glaciers. (The use here of the word ‘ viscosity ’ is in the sense
of ice moving like a viscous body, irrespective of the cause.) The
first observation made was at Fondalbre, where an angular stone,
whose section was 10 by 18 inches, rested upon the sloping face of
smooth rock. For 20 feet below the stone, the under surface of the
glacier was grooved by the moulding of the ice about the obstacle.
This distance showed the advance of the glacier after the stone had
come in contact with the rock, for it had evidently been completely
buried at the lower end of the groove, before the ice had begun to
flow about it. As the ice between the stone and the rock gradually
disappears, the embedded stone does not suddenly cease to move but
drags, until enough of its surface rests upon the rock to allow
of friction hetween the two granitoid surfaces to overcome the
viscosity of the ice, when the latter flows around the obstacle.
Elsewhere an example of this action was seen. The knife edge of
a wedge-shaped piece of gneiss was protruding beneath the ice and
resting upon the rock. The front end of this stone had moved
beyond the subjacent surface, whilst the posterior end was still upon
it. Yet the sharpness of the edge had scarcely been blunted.

4, Abundant examples were found showing that the flowing of
the ice about loose obstacles was quite the rule. Both large and
small (even an inch in length), angular and rounded masses lying
either upon the rock, or upon morainic matter, were sufficient to
channel the bottom of an advancing glacier.

5. No blocks of rock were seen in the act of being torn loose
from the floor or sides of the valley, and certainly there were no
loose or solid masses being picked up by the advancing glacier.

6. At Tunshergdalbree, whose lower end is 1600 feet above the
sea, a modification of the above-described phenomenon was seen. A
roughly rounded boulder of 30 inches diameter was enclosed in the
convex side of the glacier, which rose above it from 380 to 50 feet in
height. It was resting upon a surface, sloping at 45°, and was held
in place by the ice itself. As the surface of the stone, bearing upon

Prof. J. W. Spencer—Glacier-erosion in Norway. 169

the rock, was small compared with that held in the ice, it should
have been dragged along. But it was being rolled, as shown by the
moulding of its form in the glacier, which was advancing faster than
the stone was rolling down the steep slope. The pressure upon this
stone could not have been merely that of the superincumbent ice,
but a powerful component of the energy of a glacier descending
1500—2000 feet, as if the ice were moving more or less as a fluid.
The energy upon our boulder was sufficient to crush it into one large
and two smaller masses, together with stone dust. When seen these
fragments had hardly begun to part company.

7. The abrasion of the solid rock by the fall of stones, and
detached masses of ice and stones was illustrated at the locality just
named. The two guides and myself succeeded in detaching a large
boulder of about five tons weight, adjacent to the edge of the glacier.
It went rolling and sliding down a hundred feet or more, tearing
away great blocks of ice, which held a considerable amount of
débris, and in its wake the rock was more or less crushed and
scratched.

8. A further example of the ability of the ice to flow like a plastic
body was shown in a cavern 400 feet higher than the end of the
glacier, where the temperature was 4° C., whilst that outside was
13°C. Upon the debris of the floor rested a rounded boulder whose
longer diameter was 80 inches. It could have been rolled over by
one man. A tongue of ice, in size more than a cubic yard, was
hanging from the roof, and pressing against the stone. In place of
pushing the stone along or flowing around it, the lower layer of ice
above the tongue had yielded, and was bent backward at right angles,
as easily and gracefully as if it had been a thin sheet of lead, in
place of one of ice a foot thick.

9. According to the experiments of Pfaff,’ the temperature of ice
has a great deal to do with its flow about obstacles. Below freezing-
point, the movement is scarcely more than appreciable, whilst above
that point, but not below, it may reach 28 inchesaday or more. The
conditions arising from the temperature beneath a glacier are more
or less favourable to the movement of the ice, as the lower surfaces
are never entirely below freezing-point, even in winter. Prof. S. A.
Sexe found that the water flowing from a Folgefond glacier,” in
February, 1861, had a temperature of 1° R., whilst that of the air
was 7° R.

10. The movement or flow of the ice about detached stones has
been observed by Prof. Sexe beneath the Buarbree, and by Prof. J.
W. Niles* beneath the Aletsch glacier. Prof. Sexe illustrates the
sliding of the ice over a loose stone, which was wedged beneath the
glacier by a projection of the rock. My observations were upon
masses not held up by wedges, but upon surfaces often sloping down-
ward. Although Prof. Niles did not record observations showing
that there was definite movement of the stone, yet he concluded that

1 Nature, Aug. 19th, 1875.

2 «Om Sneebreeen Folgefon,’’ af §. A. Sexe.
3 Am. Jour. Sc., Noy. 1878.

170 Prof. J. W. Spencer—Gtacier-erosion in Norway.

there was a differential movement of the ice and the block. What-
ever differential movement there is beyond that referred to, it must
be very inconsiderable even upon the inclined surfaces, and upon the
horizontal plains it must be indefinitely small, as here even the
movement of the ice is reduced to almost zero, as shown by the
measurements of Prof. Tyndall,’ upon the Morteracht, where the
velocity of the surface, some distance from its end, was 14 inches,
whilst that of the tongue of the glacier, as it reached the plain, was
only two inches a day.

11. The most favourable condition for holding stones in ice as
graving tools is low temperature, which impedes its progress, but
this condition beneath the glacier does not generally exist. At
higher temperatures the velocity of the glacier is not great enough
to overcome its plastic movement and to drag along the detached
blocks. However, when the whole mass of ice is charged with
sand and stones, there is no doubt that polishing and some scratching
are effected : but when there are only occasional fragments in the
bottom of the ice, as is commonly the case, the erosion from the
sliding ceases, as soon as the resistance due to friction between the
stones and the rock equals that due to viscosity, which observation
shows to be soon reached. Consequently-we should not expect to
find great troughs or grooves scooped out by the actual glacier.
These I have not seen about the existing glaciers of Norway, which
are not dependent upon atmospheric and aqueous erosion and the
texture of the rock, although their surface may have been sub-
sequently polished. Generally speaking, as shown in the valley
behind the Fondal Gaard, where the glacier is nearly free from sand,
and contains comparatively few stones, as well as at many other
places, the surfaces of the subjacent crystalline rocks, although of
the form of roches moutonnées, with angles mostly removed, are not
smooth, but are as rough and as much weather-worn as similar rocks in
warmer countries where no glaciers have been. Upon these surfaces
it is often difficult to discover any scratches, even where present,
for they are often so faint as to be only rendered apparent by
moistening the rock. Hven the faces of the hammocks are commonly
unpolished. In other places, particularly at Tunsbergdalbre,
which contains much sand along the margin, the rocks are highly
polished and but little scratched. One is everywhere surprised to
find beneath the glaciers the paucity of glaciated stones, and in many
terminal moraines they are scarcely if at all to be found.

12. The insufficiency of glaciers to act as great erosive agents is
further shown at Fondal, where a mass of ice, 30 to 40 feet thick,
abuts against a somewhat steep ridge of rock, 10 feet or less in height.
In place of a stone-shod glacier sliding up and over the barrier, the
lower part of the ice appears stationary (or else is moving around
the barrier), whilst the upper strata bend and flow over the lower
layers of ice.

13. When the barrier to the advance of a glacier is met with,
whether composed of hard rock, or of morainic matter, the ice,

1 Tyndall’s ‘ Forms of Water.”’

Prof. J. W. Spencer—Gilacier-erosion in Norway. 171

provided it be sufficiently high, flows over upon itself, yet when the
sheet is no higher than the barrier, the lateral thrust may push it up
somewhat. The best example of the consequences of such a con-
dition is to be seen at Svartisen glacier, at the head of Holandsfjord,
which descends to within 50 feet of the sea, where it ends in a
morainic lake of considerable size, the northern side of which is filled
with ice. The water of the lake rises, in part, to the level of
the ice, or over it, where the waves of the lake are depositing sand
upon its surface. Part of the ice is not less than 25 feet thick,
and most of it is probably double that thickness. Some of the strata
of the ice are pushed up and rest at 5° from the horizontal. But
the interesting observations are at the end of the glacier, where it
impinges against the morainic barrier. Being unable to advance, the
lateral pressure has forced up an anticlinal ridge, or rather dome, in
the ice, to a height of 15 feet, along whose axis there has been a
fracture and fault. Upon this uplifted dome rests the undisturbed
sand stratified perfectly conformable to the surface which was
formerly just below the level of the lake. As the ice abont the line
of fracture melts, the sand falls over and leaves a sand cone, of which
there were examples, one at the end of the lake, and two in the
centre, but the nuclei of the mounds were of solid ice. By this
lifting process, pockets of loose clayey sand were thrown on top of
the morainic matter, producing thus the appearance of having been
ploughed up by the glacier, to even several yards beyond its termin-
ation.

14. Nowhere is there apparently more ploughing action, and yet
little or none to be seen, than at the Buarbree, which is advancing
rapidly against a high lateral moraine. There is a large ridge
of stone upon a thin snout of the glacier, just as if the ice
were pushing under the boulders or earth, which, however, it
is not doing. The glacier has a steep convex margin, from 20 to
40 feet hi¢h, with many blocks and boulders upon it. These become
detached, and rolling down upon the lower tongues of ice, leave a
deep trough between the ridges thus produced and the side of the
glacier, and delay the melting of the layer of ice beneath, which is
too thin to do any undermining of the moraine.

15. An excellent illustration of a glacier advancing, without any
ploughing action, over a moraine, and at the same time levelling it
into a sort of ground moraine, was seen at the Suphellebre. Here
the glacier was moving up the slight elevation or moraine produced
by the early summer retreat of the glacier, although advancing again
in July. The lower surfaces of the ice tongues were furrowed by the
loose stones of the soft incoherent water-soaked moraine, into which
one’s foot would sink when stepping upon it. The moraine was
being levelled by the constant dripping of the water from the whole
under surfaces of the advancing glacier.

16. This glacier of Suphelle is the most remarkable of its kind,
being a glacier rémanié. From the Jostedalsfond, which, near the
head of Fjzrlandfjord, is 3000 to 4000 feet high, the clear bluish
ice and the consolidated snow fall over a precipice of dark rocks for

172 Prof. J. W. Spencer—Gilacier-erosion in Norway.

about 1000 feet, and at about 1500 to 2000 feet above the sea
re-form into a glacier extending down into and nearly across the
valley of Fjzrland, for a distance of somewhat less than a mile, ‘to
a level of only 175 feet above the sea. The glacier is much crevassed
and covered and filled with débris. In fact, it is the most dirt-laden
glacier known—not excepting the Aar glacier in the Alps. These
materials are wholly derived from the side of the mountain, and
brought down by frosts, and more largely by the fall of ice as it
dashes from one frost-cracked rock to another. One of these great
ice avalanches I witnessed from the other side of the valley—fully a
mile distant. Thousands of tons must have fallen at this time, but
as the ice fell from rock to rock, it was converted into what, seen
from the distance, appeared to be white dust.

17. There are no considerable streams from the upper glacier, but
from the melting ice, below the fall, the volume of water laden with
mud is large. As this glacier is not ploughing up but levelling
down the inequalities of its bed of loose materials, we cannot sup-
pose that the mud comes from any other than the dirt upon and
within the ice, and that obtained by the dripping water as it levels
the terminal moraine. This is only one of the examples everywhere
to be seen showing the erroneous estimate of glacier-erosion, when
based upon the amount of mud carried down by the streams flowing
from the glaciers, for the débris is brought upon their surfaces by
other than grinding action, and, as far as observation goes, it is not
derived from beneath them, at least, to any great extent.

18. Although I have seen some of the sharp angles of the rocks at
2000—38000 feet above the sea, along the sides of the valleys, more
or less rounded, yet the inequalities of the faces have not been
generally removed by erosion of any kind. At numerous places in
Norway as well as in other countries, hammocks of rocks rise above
or out of the glaciers, as the ice flows around them at lower levels—
these channels having been deepened not by glaciers but by sub-
glacial streams.

19. Nowhere are the roches moutonnées so abundant as on the coast
of Norway. In their more perfect form, they are not extensively
developed along the coast more than 250 feet above the sea. At
higher altitudes they are best seen about glacier-falls, farther up the
valleys. But since the Pleistocene days, the coast has been raised
several hundred feet, at least. The form of the hummocks is pre-
cisely like what may be seen in South-Hastern Missouri, and other
states south of the line of northern drift, or like those described in
Ceylon, Brazil, and other tropical countries, to which only are added
the scratches. The forms of the hummocks must be principally
attributed to the atmospheric erosion of the crystalline rocks, where
the débris has been swept away by currents or by ice. We see them
more frequently swept clean upon the coast of either cold or warm
countries than in the interior, where the currents are only those from
rain or local glaciers, for even the sweeping beneath the glaciers is
principally effected by dripping waters or streams. Prof. Kjerulf,
of the University of Christiania, than whom there is no better

Prof. H. A. Nicholson—On Hemiphyllum siluriense, Tomes. 173

authority, regards the production of hummocks and their glaciation
up to a height of 600 feet upon the coast of Norway as the result of
floating-ice.!

20. The absence of transported boulders and striations upon the
surface of many parts of the high plateaux of Norway is doubtless,
in part, attributable to the capacity of ice to flow over loose obstacles,
and the frequent want of higher ridges to furnish material by their
débris falling upon the ice, which might afterwards work through
the mass.

21. The faith in glaciers as great erosive agents has been so
severely shaken, that most geologists who personally study those
still existing do not attribute to them much greater power than that
of removing soft materials, or are even sceptical of this power—
as, for instance, Prof. Penck of the University of Vienna, who has
been misquoted as having proved their great potency.” To this
scepticism, it seems to me that these notes must contribute, especially
when applied to the hypothetical excavation or modification of great
lake-basins, and the transportation of northern materials in the
Boulder-clay over the broad plains of America, as there were no
mountains of adequate height with peaks and screes to supply the
detritus sufficient to furnish the surface of the glaciers with all the
boreal material of the drift, which now covers half a continent.

University oF Missourr, Feb. 1887.

VIl.—On Hevipryiitom situriensz, Tomes.

By H. Atteyne Nicuotson, M.D., D.Sc.,

Regius Professor of Natural History in the University of Aberdeen.

N the Jast Number of the Gsotoeicat Macaztye there is published

a paper by Mr. Robert F. Tomes dealing with two Corals from

the Silurian rocks of Britain. For the reception of one of these

Corals Mr. Tomes proposes to form a new genus under the name of

Hemiphyllum. The single species of this proposed genus he identifies,

somewhat doubtfully, with the form described by M‘Coy (Ann. Nat.

Hist. ser. 2, vol. vi. p. 281, 1850) under the title of Cyathaxonia

siluriensis ; and he therefore describes it as Hemiphyllum siluriense,
M ‘Coy, sp., with a note of interrogation.

I wish, however, to point out, in the first place, that the description
and figures given by Mr. Tomes of this Coral render it perfectly
certain that he has had to deal with a species of the genus Calostylis,
Lindstr., founded long ago, and rightly referred to a position among
the Hupsammide, by Dr. Gustav Lindstrom (Ofversigt af Kongl.
Vetenskaps-Akad. Forhandl. 1868, and Kongl. Svenska Vetenskaps-
Akad. Handl. Bd. ix. 1870). The proposed genus Hemiphyllum,
Tomes, cannot, therefore, be sustained, and the name must simply

1 Discourse before Meeting of Scandinavian Naturalists, Copenhagen, 1873.
2 Grotocicat Magazine, April, 1883.

174 Prof. H. A. Nicholson—On Hemiphyllum siluriense, Tomes.

be added to the long list of synonyms which already afflict the
students of Palzeozoic Corals.

In the second placé, with regard to the specific determination of
Mr. Tomes’s Coral, it may at once be unhesitatingly stated that it has
no relation of any kind to the form which M‘Coy described as
Cyathawonia siluriensis. Of all the troublesome little cup-corals of
the Silurian and Devonian rocks, I do not know one so clearly marked
off and so easily recognized by its general aspect and characters as
this rare form, and I am ata loss to imagine what should have led
Mr. Tomes to suppose that he had to deal with examples of this
species. That Cyathaxonia siluriensis, M‘Coy, is not a species of
Cyathaxonia, Mich., but that it is truly referable to the genus Lind-
stremia has been formerly pointed out by Mr. R. Htheridge, jun.,
and myself (Mon. Sil. Foss. Girvan, p. 82, 1880). Our determination
was based simply upon a macroscopic examination of the species ;
but I have since then examined the species by means of thin sections,
and have completely confirmed our reference of it to Lindstrema. I
shall take an early opportunity of publishing a description and
figures of its internal structure.

The Hemiphylium siluriense of Mr. Tomes is not, however, refer-
able to any recorded species of the genus Calostylis, Lindst. So far
as I am aware, only two species of Calostylis have been previously
described, both of these being from the Silurian rocks. One of these
is O. denticulata, Kjerulf, fully described and figured by Lindstrom,
first under the name of C. cribraria, and subsequently under the
above title (loc. cit. supra). The second species was described, from
British specimens, by Mr. R. Htheridge, jun., and myself (Mon.
Sil. Foss. Girvan, p. 65, pl. v. figs. 2—2c, 1880), under the name of
C. Lindstrémi. Neither of these species agrees in its characters
with the form which Mr. Tomes has had under examination. This
T am the better able to affirm as I have not only fully examined the
two recorded species of Calostylis, but I am well acquainted with the
species here in question. My friend, Dr. George J. Hinde, in fact, pre-
sented me with specimens of this form, from the Wenlock Shales of
Buildwas, some years ago, since which time they have lain in my
cabinet with the MS. name of Calostylis breviuscula appended to
them ; but I have never found time to publish a description of the
species.

Pras! with regard to the Corals to which Mr. Tomes refers under
the name of Cyathaxonia Dalmani, K. and H., I may point out that
Dr. Lindstrém long ago recognized that the Coral so named did not
belong to the genus Cyathaxonia at all. The correctness of this view
was demonstrated by Mr. R. Etheridge, jun., and myself (Mon. Sil.
Foss. Girvan, p. 84, fig. 4), who showed that C. Dalmam, H. & H.,
belonged properly to the genus Lindstremia, Nich. and Hth. jun., a
determination which has been since accepted by Dr. Lindstrom
himself (List of the Fossils of the Upper Sil. Form. of Gotland, p.
19, 1885).

Notices of Memoirs—Excursion in Brittany. 175

NOTICES OF MEMOTRS.

L’Excurston DE LA SocreT& GOLOGIQUE EN Breragne. Par M.
De Larparent. Revue Scientifique, 8 Janvier, 1887.

Tags is an article upon the excursion already described in the

February Number of this Macazine. It gives a general view
of the geological features of the Armorican peninsula, the igneous
and metamorphic rocks occurring there, and certain questions hitherto
controverted on which evidence regarded as conclusive was produced.
Among these were the age of certain granites, the causes of the
metamorphism in certain localities, and the nature of the passage
from Cambrian strata to Silurian. As to this last, the sections in the
Bay of Douarnenez and the succession seen at Gourin are said to
present concurrent indications that in this district the transition is
conformable and continuous.

-Upon the Archzean question the author expresses decided opinions.
To think that the crystalline schists can be excised from the chrono-
logical succession, and to regard them as capable of being produced
out of any strata, whatsoever their age, is, he says, “‘an extension of
the idea of metamorphism which is altogether a misuse of it.” ‘‘ The
facts observed in Brittany seem fatal to this view.” i. H.

aS) da 0 DE aS

GroLogicAL AND NaturaL History Survey oF OanaDa.
Annual Report (New Series), Vol. I. Accompanied by an Atlas
of Maps. Royal 8vo. pp. ix. and 798. With Geological Maps,
Plans, Plates, and Woodcuts. (Montreal, 1886.)

‘ae present volume ushers in a new series, and although entitled

Report for 1885, it includes work done in previous years, and
in the early part of 1886. It begins with the customary “ Summary

Report” (“ A.” pp. la—108a*) by the Director, Dr. A. R. C. Selwyn,

F.R.S., F.G.S. This contains an excellent résumé of the operations

of the Geological Staff in the field, and of the work carried on

at head-quarters (Ottawa) in the museum, laboratory, and library.

- The succeeding reports fully sustain the deservedly high reputa-
tion so long enjoyed by the Canadian Survey. Many important
contributions to the history of the geology and resources of the
country are contained in them; showing how work has heen pro-
secuted “over portions of every province and territory in the
Dominion, from Nova Scotia to the west coast of Vancouver Island.”

Among the varied duties that now fall to the lot of the Dominion
geologists are included the collection of specimens illustrative of the

Zoology, Botany and Hthnology of the tracts explored, in addition
to their Geology and Lithology.

Messrs. Whiteaves and Ami undertake the paleontological and
zoological work, with the occasional assistance of eminent English

1 The Reports being also published separately, each is distinguished by a letter or
letters in the pagination.

176 . Reviews—Geological Survey of Canada.

and American ‘specialists.’ Professor Macoun (Botanist to the

Survey) reports upon the plants collected, while Sir J. W. Dawson
frequently lends his valuable assistance in the department of palzo-
botany. Messrs. Hoffmann and Adams carry on the work of the
chemical laboratory. The staff now numbers 50, viz. 34 “ pro-
fessional,” and 16 “ordinary” members.

Much attention is naturally bestowed upon the mining industries
of the country. In 1885 a survey was commenced by Mr. Bowman
and assistants of the gold-mining region of Cariboo in the interior
of British Columbia. This district, comprising an area of 50 by 75
miles, has yielded in the past twenty-five years about thirty million
dollars of gold by placer mining. The various mining centres in the
Eastern Townships (Province of Quebec, east of the St. Lawrence)
were visited by Messrs. R. W. Ells and N. I. Giroux. The minerals
obtained are gold, silver, iron, copper, and asbestos. In the last of
these a flourishing trade is carried on. The copper deposits are also
extensively worked. Most of these minerals find a market in the
neighbouring States.

Leaving the Summary Report, of which we have given but a very
brief sketch, let us now turn to the reports of the field corps, which
make up the bulk of the volume.

Report B. (pp. 78—1678), by Dr. George M. Dawson, “is intended
as a preliminary geological and general account of that portion of
the Rocky Mountain range included between the 49th parallel on
the south and the upper waters of the Red Deer River (about lat.
51° 30’) to the north. The Rocky Mountain range proper, in this
region, is definitely limited to the south-west by the great Columbia-
Kootanie Valley, which separates it from the Selkirk and Purcell
ranges, while to the north-east the edge of the Paleozoic rocks may
be regarded as its boundary. The width of the range thus naturally
outlined is about fifty miles. The length of the range here treated
of in a north-west and south-east bearing is about 200 miles, while
the approximate total area covered by this report and the accom-
panying map is about ten thousand square miles.” The map spoken
of is geologically coloured, and is on a scale of five miles to one
inch. It contains marginal notes and sections.

Beginning with an account of former geological and geographical
explorations of the region, amongst which the most important were
those of Captain Palliser, Dr. Hector, and Mr. Bauerman, the author
proceeds to describe its orographic features. He explains that the
so-called Rocky Mountains are divisible into four great systems,
which are from east to west as follows :—‘“ (1) The Rocky Moun-
tains proper; (2) Mountains which may be classed together as the
Gold Ranges; (3) The system of Coast Ranges sometimes impro-
perly regarded as a continuation of the Cascade Mountains of Oregon
and Washington Territory; (4) A mountain system which in its
submerged parts constitutes Vancouver and Queen Charlotte Islands.”

Taking up the geology of the district surveyed by Dr. Dawson, we
find that the Cambrian is the basal formation, and consists of
‘“‘quartzites, and quartzitic shales passing into argillites, and occa-

Reviews—Geological Survey of Canada. 177

sionally including limestone or more or less calcareous or dolomitic
materials and conglomerates. Sheets of contemporaneous trap also
occur, probably at “several horizons.”

An instructive section of the Cambrian formation, with a thickness
of about 3000 feet, was met with near Waterton ‘Lake, and in the.
eastern part of the South Kootanie Pass. But between the latter
and the Flat-head River these beds were calculated to have a
minimum thickness of 11,000 feet, and this “included neither the
summit nor the base of the series.”

The similarity both as respects their lithological characters, and
the general absence of life, of the Cambrian of this part of the
Rocky Mountains, to that of the Wasatch Mountains in Utah, and to
the same rocks of the Chuar and Grand Cation Groups of the Colorado
Cation in Arizona, is pointed out by the author. Mr. C. D. Walcott
(Amer. Journ. Sci. vol. xxvi. p. 487) has suggested that the absence
of the Lower Cambrian Fauna in the western part of the Continent
of North America may be due toa land barrier having existed at
that time between the eastern and western portions of the continental
area. But Dr. Dawson remarks that “the body of water in which
the lower portion of the rocks here described were deposited was
a basin separated from the ocean, and, occasionally, if not continuously,
in the condition of a saturated brine, and this may in itself explain
the absence of life of any kind, at least in this particular region.”

Between the Cambrian series and the “ Devono-Carboniferous ”
rocks which succeed, and rest unconformably upon them, there is an
interval which is in part at least filled up in the north-western
portion of the area by a mass of beds of ‘Silurian and possibly
also of Cambro-Silurian [Ordovician] age.”

The ‘“‘ Devono-Carboniterous ” series attains an estimated thickness
of from one thousand to four thousand feet and “forms many of the
most prominent ranges and mountain masses.” This great limestone
series is overlaid unconformably by rocks which are upon strati-
graphical, in the absence of paleontological, evidence deemed to be
of Triassic age, and are here “ probably the northern limit of a great
Triassic mediterranean sea, which extended far to the southward in
the western part of the present continental area.”

The Cretaceous rocks are next in ascending order, and belong to
the lower division of that group, here named by Dr. Dawson the
“ Kootanie Series,” though showing, according to Sir J. W. Dawson,
who examined the plants, consisting of Ferns, Cycads, and Conifers
(with one exception the only fossils collected), affinities with the
Jurassic of the Amur country of Siberia, and of the Lower Creta-
ceous of Greenland, as these floras have been described by Heer.”

The sandstones, shales, and conglomerates composing the Kootanie
Group are estimated to be about 9000 feet in thickness.

Important Coal-bearing rocks occur in this series, and their dis-
tribution is depicted upon a coloured geological map of part of the
“Cascade Coal Basin.” The coal is an anthracite of excellent
quality, and its proximity to the Canadian Pacific Railway line will
cause it to be soon turned to account.

DECADE I1I.—yVOL. IV.—NO. Iv. 12

178 Reviews— Geological Survey of Canada.

The chief development of the Coal-bearing rocks is in the valley
of the Cascade River, a tributary of the Bow, where the Cretaceous
rocks form a “long, narrow, synclinal fold, which, owing to the
immense pressure from the south-westward, has been bodily over-
turned in the opposite direction; the mountain range on the south-
west side being composed of an anticlinal of the limestone series,
similarly compressed and folded over on the Cretaceous rocks.”

Volcanic beds (ashes and agglomerates) occur at an horizon not
far above the summit of the Kootanie Group, which would make
them of the age of the Dakota period. Their maximum thickness
is estimated at 2200 feet.

In a “provisional general section” of the Cretaceous beds of
the mountains of the area explored, their thickness is put down at
13,350 feet, making with that of the Foot-hills and Plains (7490 feet)
a maximum thickness for the Cretaceous of the region of 20,840 feet.

Upon the subject of economic minerals Dr. Dawson informs us
that the recognized gold-mining district is ‘“‘ Wild Horse Creek,”
“but nearly all the streams flowing into the Columbia-Kootanie
valley contain more or less alluvial gold, which should be sought in
those parts of the district which are based on the slaty zones of the
Cambrian.”

The author was much struck with the grandeur and beauty of
the scenery of the mountains, and the excellent engravings with
which the report is illustrated enable the reader to realize in some
degree the physical features of this magnificent tract of country.

Mr. R. G. M°Connell’s Report (pp. 5c—78c) treats of the geology
and resources of the Cypress Hills, Wood Mountains, and adjacent
territory, embracing part of the district of Assiniboia, and covering
an area of about 31,000 square miles. It is accompanied by a
geological and topographical map of the district, together with
photographic and other illustrations.

The most interesting result of Mr. M°Connell’s researches from a
geological point of view was the discovery of thick deposits of con-
glomerates of Miocene age, covering Laramie beds, which have by
this means escaped destruction. ‘The Miocene rests unconformably
on the Laramie, as a rule; but in some places it overlaps and comes
in contact with the Fox Hill beds beneath.

The Miocene beds are characterized by the great quantity of water-
worn pebbles in them, derived from the quartzite formations of the
Rocky Mountains. These beds cover an area of nearly 14,000 square
miles, capping the more elevated parts of the plateaux from the west
end of the Cypress Hills to the east end of Swift. Current Creek
plateau, a distance of 140 miles.

Numerous invertebrate fossils were collected in the Cretaceous
beds, and remains of Reptilia (Testudinata) and Mammalia (Buno-
theria and Perissodactyla) in the conglomerates. The Vertebrates
furnish the subject of a separate report by Prof. HE. D. Cope (Ap-
pendix 1. pp. T9c—85c). 5

Mr. Andrew C. Lawson’s report (pp. 5cc—1ldlcc) is “On the
Geology of the ‘Lake of the Woods’ Region, with special reference
to the Keewatin (Huronian ?) belt of the Archean Rocks.”

Reviews—Ceological Survey of Canada. I)

The beds examined consist of a belt of schistose rocks which runs
through the granitoid gneiss across the northern parts of the Lake
of the Woods, and has been hitherto regarded as of Huronian age.
Mr. Lawson, however, considers these rocks to be older than Sir
W. B. Logan’s typical Huronian. His reasons for coming to this
conclusion are based mainly upon the lithological characters of the
rocks. Thus he finds (1) that Logan’s typical Huronian is essentially
a quartzitic series, whereas in the Lake of the Woods series
quartzites form a very small proportion of the rocks. (2) Logan’s
series is characterized by bedded limestones, but there are none of
these in the Lake of the Woods series. Further, the basal con-
glomerate of Logan’s Huronian on Lake Temiscamang is described
as holding pebbles and boulders, of the subjacent gneiss, from which
they appear to be derived. Mr. Lawson holds that the Lake of the
Woods rocks are not basal conglomerates, but “agglomerates ” of
voleanic origin, the fragments in them being frequently sharply
angular.

Taking these and other facts into consideration, Mr. Lawson is of
opinion that it is best to regard the Lake of the Woods rocks, at
least provisionally, as a distinct series, for which he proposes the
name of “ Keewatin ” 1 series, and adds that they “‘ may be taken as
representative of an important division of the Archean, extensively
developed in parts of the great Laurentian area.”

Mr. A. P. Low’s report (pp. 5p—55p) consists of geological and
meteorological observations in the region of Lake Mistassini.? It
was found by this explorer that with the exception of the compara-
tively small areas of Huronian and Cambrian rocks, in the vicinity
of Lake Mistassini, the Laurentian gneisses and associated rocks
occupied the whole country from the Gulf of St. Lawrence to James’
Bay, along the route taken by the expedition.

Appendices I., II. (pp. 34p—44p) of the report contain lists of
birds and of plants collected at Lake Mistassini, and along the banks
of the Rupert River.

Dr. Robert Bell’s report (pp. 5pp—27pp) contains brief observa-
tions on Geology, Zoology, and Botany, made in his capacity as
Geologist and Naturalist on board H.M.S. “Alert,” on the Second
Hxpedition to Hudson’s Strait and Bay, sent out by the Government
of Canada in 1885.

The opportunities for gathering information were necessarily
limited, and advantage had to be taken of stoppages for the landing
of supplies, etc., to make a few rapid notes. The report embodies
the results of the geological investigations of previous years, dating
from 1870.

Hudson’s Bay, which has an area equal to about half that of the
Mediterranean Sea, occupies the centre of a wide depression in the
great Laurentian area. The Laurentian system of rocks prevails

1 The Indian name for the North-West, or the North-West wind, applied to the
district within which the rocks occur.

2 Formed from two Algonquin words signifying ‘‘big-stone,’’ and so called
because of the large boulders of gneiss that strew the west shore of the lake.

180 Reviews—Geological Survey of Canada.

everywhere in this region; but Paleozoic strata occur in many of the
islands in Hudson’s Bay, and probably extend over much of its bed.
Rocks of volcanic origin were observed in the north-western part of
the Bay.

The report by Mr. R. W. Ells (pp. 5: —71s) gives an account of
the geological formations in South-Hastern New Brunswick, and in
Cumberland and Colchester counties of the adjoining province of
Nova Scotia.

The prevailing rocks of this area are the Pre-Cambrian or
Huronian (?), the Carboniferous and Permo-Carboniferous. The
Pre-Cambrian rocks are typified in the “ Cobequid Series,” which
underlie unconformably the iron-ore belts flanking the Cobequid
mountain range on the south. The Carboniferous system is repre-
sented by the three divisions, Upper, Middle, and Lower, and an
elaborate description of each of these is contained in the report. The
Spring Hill area was especially examined for the purpose of deter-
mining the extension of the thick coal-seams. The famous South
Joggins Coal-measures, made historical through the labours of Logan '
and Dawson,’ are briefly described by Mr. Ells.

The report concludes with a reference to the economic minerals
of the region surveyed. These include Coal (by far the most
important), Iron, Copper, Gypsum, etc.

A coloured geological map ona scale of four miles to one J inch
accompanies the report.

Professor L. W. Bailey contributes a report (pp. 54— 30a) upon
portions of Northern and Western New Brunswick. This also is
illustrated by a geological coloured map, in which the orographic
features of the region are delineated. It is upon the same scale as
that of Mr. Ells.

The following geological systems are embraced in the region
examined :—

Carboniferous. Cambro-Silurian (Ordovician).
Devonian (?). Pre-Cambrian.
Silurian. Crystalline rocks, including granite.

The Carboniferous is of limited extent, and consists of the Mill-
stone Grit, and the lower or marine beds of the system.

Much of the region is too densely wooded to admit of the ex-
amination of the underlying rocks, and their boundaries are therefore
difficult to define with accuracy. Hruptive rocks in the form of
dykes and intercalated masses are met with in many parts of the
Silurian area, notably in the gorge above the Falls of the Aroostook
river, close to the boundary-line of the State of Maine. Connected
with these igneous and trappean overflows are innumerable faults,
and the Silurian rocks are everywhere twisted and folded.

To the south of these rocks portions of the country are occupied
by metamorphosed strata, penetrated by great masses of intrusive
granite, supposed to be of Cambro-Silurian age, while other strata,
apparently connected with these last, furnish in their fossil contents
satisfactory evidence for referring them to that horizon.

1 Report, 1840. 2 Acadian Geology, 1868.

as

Reports and Proceedings—Geological Society of London. 181

The Pre-Cambrians consist typically of crystalline felsites, mostly
obscurely stratified; and hard fine-grained syenites. Intrusive
masses of igneous rocks also occur in the Pre-Cambrian area.

Mr. R. Chalmers furnishes a preliminary report (pp. 5 ¢a—d8 Ge)
on the Surface Geology of New Brunswick, in which he describes
the superficial deposits as consisting of “ Alluviums, or Recent
Deposits,” and “Stratified Sands, Gravels and Clays.” The topo-
graphical features of the Province, agricultural character, forests,
etc., are also particularized, and a table of glacial striz and a list of
Post-Tertiary fossils are added.

Report K (pp. 5k—15x) by Mr. Eugéne Coste, Mining Engineer,
contains valuable observations on “Mining Laws and Mining in
Canada,” in which the writer attributes the failure of so many
mining schemes in the Province of Ontario and Quebec and in the
north-west territory to the defective state of the laws governing such
undertakings.

Speculators are allowed to “purchase very cheaply large tracts of
‘mineral lands,’ which they are not compelled to work, and which
they hold. against the interest of the mining industry and of the
country, awaiting fabulous prices for them, and so preventing bona
fide working companies from developing them.”

To remedy this deplorable state of things, Mr. Coste proposes that
national mining property should be submitted to an administration
similar to that which is in force in France, Prussia, Austria, and
other Huropean countries. He formulates a series of “ principles
which should be followed in determining the conditions under which
mining rights should be acquired and maintained.” These relate
to the leasing of mining property, the prevention of monopoly of
mining rights on too large an area of land; penalties for insufficient
working of mining property ; regulations concerning the purchase of
a sufficient extent of land for the surface requirements of the mine,
and finally, the due inspection of mines by government officers.

The concluding report (pp. 1m—29m), by Mr. G. Christian Hoff-
mann, assisted by Mr. Frank D. Adams, contains a record of assays
and analyses carried out in the Laboratory of the Survey, attention
having been devoted chiefly to such minerals as promised to be of
economic value. ;

A general Index to the volume completes this large and valuable
accession to our knowledge of the physical geography, geology and
material resources of Canada. Artuur H. Foorp.

ees @ be > AN es) a ey © Cae Baas GS

—— +>
I.—Tur Gerotocicat Socrety or Lonpon.
1.—Annvat Geverat Mezrine, February 18, 1887.—Prof. J. W.
Judd, F.R.S., President, in the Chair.
The Secretary read the Reports of the Council and of the Library
and Museum Committee for the year 1886. The Council stated that
they had to congratulate the Fellows upon a continuation of the

182 Reports and Proceedings—

improvement in the state of the Society’s affairs, to which they had
the satisfaction of calling attention last year, although they regretted
that they could not announce any increase in the total number of
Fellows. The number elected during the year was 41, and the
total accession was 46; while the losses by death, resignation, etc.,
amounted to 48, making an actual decrease of 2 in the number of
Fellows. Nevertheless the number of contributing Fellows was in-
creased by 2. The Balance-sheet showed an excess of Income over
Expenditure during the year of £390 5s. 9d. The Council’s Report
further announced the awards of the various Medals and of the pro-
ceeds of the Donation Funds in the gift of the Society.

In presenting the Wollaston Gold Medal to Mr. J. W. Hulke,
F.R.S., the President addressed him as follows :—

Mr. Hulke,—It is a very pleasant duty which I am called upon to perform in
presenting you with the Wollaston Medal, as a recognition of your great services
to the study of Vertebrate Paleontology. A member of that honoured profession
which has given to Geology—and especially to the biological side of our science—
so many diligent and accurate students, you have succeeded, in spite of the labours
and anxieties incident to a very active career, devoted to the alleviation of human
suffering and the training of others for the same duties, in finding time for very
valuable researches among those wonderful forms of Reptilian life which charac-
terize the Mesozoic period. Your hardly-earned vacations have been spent in the
search of fossil bones among the mud-flats of Dorsetshire and the sandy cliffs of
the Isle of Wight ; and in this way you have acquired an exceptional amount of
knowledge concerning the exact geological horizons and the mode of occurrence
of the fossils you have so admirably described. As by successive discoveries you
have been able to add new details to your restoration of the bony framework of
f/guanodon, you must have experienced a joy akin to that of Creation! But though
you are best known to the world by those osteological researches, those who, like
myself, have had the happiness of being associated with you in the work of this
Society, have discovered how wide is the knowledge, how catholic the sympathy,
and how keen the interest with which you follow all the manifold developments of
our Science.

Mr. HULKE, in reply, said :—Mr. President,—I cannot find words adequately
to express how highly I value the distinction which the Council has this day, by
your hands, conferred upon me. The pleasure I experience in receiving it is in no
small degree increased by the words of approbation which have fallen from your
own lips. The Wollaston Medal is so truly great a prize, and the work I have
done to merit it has appeared to me so little in comparison with that accomplished
by the long roll of illustrious men on whom in past time it has been bestowed,
that I have fancied that (as occurred to Sir Philip Egerton on a similar occasion)
in awarding it to myself the Council may also have desired to mark the recog-
nition of the labours of those who, whilst not devoting the chief part of their
time and energy to the culture of that branch of Natural Science for the advance-
ment of which our Society exists, yet endeavour in their leisure hours to do what
in them lies to add to our common stock of knowledge. To you, Sir, to the
Council, and to the Fellows, I tender my warmest thanks.

The President then presented the Balance of the Proceeds of the
Wollaston Donation Fund to Mr. Benjamin N. Peach, F.G.S., and
addressed him as follows :—

Mr. Peach,—In addition to your services to science as an officer of the Geological
Survey of Scotland—and how important those services have been every geologist
in recent years has had an opportunity of judging—you have, in conjunction with
your colleague and friend, Mr. Horne, devoted your holidays to arduous labour in
studying the geology of the Orkneys and Shetlands. Both the glacial and the
volcanic phenomena of those islands have been admirably elucidated by your joint
researches. But besides your work in the field you have devoted much attention
to palzeontological investigations ; and your discoveries concerning the nature of

Geological Society of London. 183

the Carboniferous Arachnids and their allies have justly excited very great interest.
To aid you in the prosecution of such studies the Proceeds of the Wollaston
Donation Fund have been awarded to you, and I feel sure that one circumstance
in connexion with this Fund will make the award specially welcome to you. In
the roll of names of those who have in previous years received this distinction,
will be found one, honoured alike by you and by us, that of your lamented father,
Mr. Charles Peach.

Mr. PEACH, in reply, said:—Mr. President,—I desire to record my cordial
thanks for the honour now conferred upon me. The pleasure derived from the
pursuit of the researches indicated by you has more than compensated for my
labour. It is, however, an additional gratification to me to know that my
eee have been deemed worthy of recognition by the Council of this

ociety.

The President next presented the Murchison Medal to the Rev.
P. B. Brodie, M.A., F.G.S., and addressed him as follows :—

Mr. Brodie,—Never probably has an award of this Society been made to one
who can look back upon so long a record of faithful services to Geology as yourself.
It is now 54 years ago since you became a Member of this Society, at a time when
the Founder of the Medal which has now been awarded to you occupied the
_ Presidential Chair. At the date of your election the ‘ Principles of Geology’ had
but just appeared, while Sedgwick and Murchison had not even commenced their
researches among the Paleozoic rocks of Western Britain. A pupil of the great
Cambridge professor and infected with his enthusiasm, you soon began to contribute
to various scientific journals, our own among the number, and in 1845 your
valuable ‘ History of Fossil Insects ’—the first treatise of the kind published in any
language—made its appearance. A dweller in the provinces, you have shown how
the advancement of our Science may best be promoted under those conditions ;
and in the field-clubs and local societies which have done so much for the study of
geology in the West of England, where your home lay, you have long been a
prominent and very active worker. Your published papers on a variety of subjects
amount to more than 50, and only last year we were glad to welcome a fresh con-
tribution from your pen, and to hear your clear exposition of it, as you stood before
us with eye undimmed and with natural force unabated. The Council of this
Society have adjudged you to be a worthy recipient of the Medal founded by their
President of 1833.

Mr. BRopig, in reply, said :—Mr. President,—I receive, Sir, this mark of the
approbation of the Council with very great pleasure and grateful thanks ; and it
was more gratifying because it took me quite by surprise. After searching the
rocks for more than half a century, and having been a Fellow of this Society for
53 years, it might be expected that I should have done more to enlarge our
knowledge of geology ; but of course my time was not entirely at my own disposal
in this respect, and I could therefore only study Natural Science in the closet and
the field during hours of leisure. As a proof that I have not been altogether idle,
I have made during that time a large collection of fossils, numbering twenty-three
thousand specimens, numbered and arranged, more or less illustrating every
formation in the British Isles. But of course a mere collection of fossils, though
having a certain value, is of little worth without an accurate knowledge of the
rocks and their organic contents.

The award of the Murchison Medal is especially agreeable to me because I have
had many pleasant and instructive days in the field with that distinguished geologist ;
but I do not forget that at Cambridge I was a pupil of the illustrious Sedgwick, to
whom I owe a lasting debt of gratitude for the kind help and encouragement which
that great and good professor was ever ready to give to any student anxious to learn.
In after years, I can with pardonable pride speak of him as my friend. When I
made some of my earlier discoveries of fossil insects and other organisms in the
Wealden Purbecks in the Vale of Wardour, I received a letter from him in which
he said, ‘‘ you have made a good hit, go on and prosper,” and this medal shows
that I have so far done so. It is now more than half a century since I was
admitted a Fellow of this Society, just before I went to college, and I know that
some hesitation, and very properly, was felt whether I should take up geology to
any good or useful purpose. But my kind proposer Mr. Clift, the able Curator

184 Reports and Proceedings—

of the College of Surgeons, to whom I was well known, and where I often went
as a student, would not give.me up ; and this proof of the Society’s favour just
received shows that he was not altogether mistaken.

In my younger days, when I resided in London, I was a regular attendant at the
meetings of this Society, then held in Somerset House, where I was a humble but
(I hope) not inattentive listener to the papers read and the discussions which
followed, and I recall with pleasure the many intellectual combats between the
geological giants of those days. I regret that distance from London and the
higher duties of my profession prevent my attending our meetings so often as I
could wish ; but though now a septuagenarian, I am thankful to say that I can
still hammer the rocks, and that my zeal and love for the noble science we all love
so well has not abated ; but I fear I shall not be able to do much more to elucidate
their history, though, if younger, this Medal would encourage me to make still
further efforts ; and my chief regret is that, for reasons stated, I have not been able
to do more to deserve the honour which the Society has kindly conferred upon me.
I can only hope that the Society will pardon me for saying so much about myself.

In handing the Balance of the Proceeds of the Murchison Geo-
logical Fund to Dr. Henry Woodward, F.R.S., for transmission to Mr.
Robert Kidston, F.G.S., the President said :—

Dr. Woodward,—The balance of the Murchison Fund has been awarded by the
Council of the Geological Society to Mr. Kidston, to aid him in his important in-
vestigations among the fossil plants of the Palzeozoic period. Mr. Kidston’s great
knowledge of the extensive literature and the complicated synonymy of these forms
is borne witness to by the valuable catalogue which he has prepared under your
superintendence, and which was issued only a few months ago by the Trustees of
the British Museum ; a large number of remarkable memoirs have also shown his
capacity for dealing with this difficult and intricate subject. In seeking to extend
our knowledge of the earliest forms of plant-life, Mr. Kidston seems determined to
leave no museum unvisited and no stone unturned, if perchance it should be found
to exhibit any traces of an ancient vegetation. I will ask you to convey to Mr.
Kidston, with this award, the hope of the Council that it may be of some assist-
ance to him in enabling him to prosecute his researches.

Dr. WoopwanrbD, in reply, said :—Mr. President,—It is with much pleasure that
I am permitted to act as Mr. Kidston’s representative here this day, and to receive
for him, at your hands, the award of the Murchison Donation Fund. I am sure
Mr. Kidston would, had it been possible, have been present in person to receive the
award. He writes as follows :—‘‘I desire to express my thanks to the President
and Council of the Geological Society for the honour they have conferred upon me
in acknowledging my labours in Fossil Botany, an honour which I beg to assure
them I fully appreciate ; it is one which will act as a stimulus in my future investi-
gations in Vegetable Paleontology. My aim has always been most carefully to
work out our Palzeozoic flora, and in this spirit I hope to continue my labours,
trusting that the results may be of use to others.”

The President then handed the Lyell Medal to Prof. T. G. Bonney,
D.Sc., F.R.S., for transmission to Mr. Samuel Allport, F.G.S., and
addressed him as follows :—

Prof. Bonney,—It is to me an especially gratifying circumstance that it falls to
my lot to deliver into your hands for transmission to Mr. Allport the Lyell Medal
for the present year. Mr. Allport commenced the microscopical study of rocks at
a time when the workers in that department of science were comparatively few,
and when the road he had to travel was encumbered with difficulties and stumbling-
blocks which have now been, to a large extent, removed by the labours of many
earnest and patient workers. It was at that time my good fortune to know him,
and to have frequent opportunities of admiring the perseverance and energy with
which he carried on his researches. You have yourself from this chair paid a warm
and well-merited tribute to the generosity with which, at that time, he was always
ready to assist his fellow-workers. The establishment of one very important prin-
ciple will always be associated with Mr. Allport’s labours, namely, that the apparent
differences between the igneous rocks of widely different geological periods are, to

Geological Society of London. 185

a great extent, due to the changes which the constituent minerals of the older rock-
masses have undergone since their original formation. His classic papers on the
Archzean rhyolites of Shropshire and the Carboniferous dolerites of various parts
of this country furnish the clearest evidence of the truth of this principle, and in
several thoughtful and logical essays he has very ably enforced it. On a great
variety of other questions connected with Petrology his researches have added
largely to our knowledge; and the fine collection of rock-sections now in the
National Museum, which were made by his own hands, bear striking testimony to
his industry and skill.

Prof. BONNEY, in reply, expressed his regret that Mr. Allport was unable to be
present to receive this Medal from the hands of the President, but said that he
found some consolation in the fact that he had thus an opportunity of most heartily
endorsing what had been said by the President as to the great value of Mr. Allport’s
own work, and of the kind assistance which he was always so ready to afford to his
fellow-labourers in the field of Petrology. Prof. Bonney added that he should best
thank the Society by reading to them a letter received from Mr. Allport, in which
that gentleman wrote as follows :—‘‘I much regret to inform you that I shall be
unable to attend the Anniversary Meeting of the Geological Society in consequence
of the very unsatisfactory state of my health. I venture, therefore, to request that
you will kindly express to the Council my very grateful sense of the honour they
have conferred upon me by the award of the Lyell Medal. It is, I assure you,
most gratifying to me that the name of Sir Charles Lyell should be associated with
this award; for I have not only ever regarded his character and scientific method
with the greatest admiration, but it is undoubtedly to the study of his works that
I am chiefly indebted for what little knowledge I possess of the principles of
geological science.”

The President next presented the Balance of the Proceeds of the
Lyell Geological Fund to the Rev. O. Fisher, M.A., F.G.S., and said:

Mr. Fisher,—The Council of the Geological Society has awarded to you the
balance of the Lyell Fund, in recognition of your great and long-continued services
to our science. Nearly forty years ago you commenced your well-known strati-
graphical investigations among the Newer Jurassics of Dorsetshire and the Older
Tertiaries of the Isle of Wight, your attention being subsequently directed to the
Pliocene and Post-Tertiary beds of East Anglia. Ata very early period in your
career a predilection for the great problems of Physical Geology began to manifest
itself ; and for dealing with such problems your mathematical training gave you
obvious advantages. In these researches, however, which have been recorded in a
number of separate memoirs, worthily crowned by the publication six years ago of
your ‘‘ Physics of the Earth’s Crust,” you have always maintained a just estimate
of the proper sphere and necessary limitations of the mathematical method of
treatment as applied to such problems. Speaking of the processes you have
chosen to employ, you truly remark in the preface to your well-known work,
““ When it is recollected that, for the most part, we can assign only very hypothe-
tical values to our symbols, it would be affectation to seek close results, which
would, after all, have no greater value than those which claim to be only distant
approximations.” In you we rejoice to see that the geologist has not been alto-
gether lost in the mathematician, and that you have always kept in mind in your
_ researches the weakness no less than the strength of the mathematical method.

Mr. FISHER, in reply, said :—Mr. President,—It is no small gratification to me
that the Society, through its Council, has expressed approbation of what I have
done in the favourite study of a long life. I commenced geologizing almost before
I can remember, when my uncle, the Rev. George Cookson, taught me to collect
fossils in the cliffs of my native village of Osmington. My work in the field is
now finished, and I geologize in my arm-chair out of my inner consciousness, but
still, I hope, to some purpose. It appears to be rather these later attempts to un-
ravel some of the physical riddles of our science (although my earlier observations
in the field have not been forgotten) which have been thus handsomely reeognized ;
and, indeed, for my own part I think what I have done in applying mathematical
methods to these geological problems has been my most useful labour. Neverthe-
less I feel assured that my earlier work in the field has been of much service to me ;
for no one can pretend to grapple usefully with the great problems of geology who

186 . Reports and Proceedings—

has not personally studied the actual phenomena. It is in this respect that the
greatest physicists of the day fail to give us the decided assistance which they
might do had they a more accurate knowledge of the questions to be solved.

We pass on the torch from hand to hand. Some of the ideas which I have
tried to work out were suggested by conversations with honoured friends long gone
to rest—Sedgwick, Hopkins, Miller, Phillips, and others. May I hope that when
some one now young, in this assembly, receives a similar recognition of a similar
life’s work, he may think of me as an intermediate link connecting him with those
earlier workers ?>—a link which, whatever may be its intrinsic defects, and however
inferior the metal, you have seen fit to gild with the balance out of the munificent
legacy of the great Lyell.

In presenting the Bigsby Gold Medal to Prof. Charles Lapworth,
LL.D., F.G.S., the President said :—

Professor Lapworth,—The late Dr. Bigsby established a Medal to be awarded to
one “not too old for further work, and not too young to have done much.” That you
admirably comply with the latter qualification every geologist knows ; but that your
age could possibly fall below the limit prescribed by the founder of this Medal,
any One not personally acquainted with you might be pardoned for doubting. In
studying the difficult, but, to geologists, very important group of the Graptolites,
in utilizmg your knowledge of those remarkable fossils for unravelling the strati-
graphical problems presented by the contorted beds of the Scottish Borderland,
and in applying the valuable experience thus acquired to the far more difficult
examples of involved stratigraphy found in the county of Sutherland, you have
exhibited a happy blending of those powers of patient observation and of bold
generalization which are equally necessary for the man of science. Those who
know you best will feel the least doubt concerning those ‘‘ favours to come ”’ in the
shape of further work, the “lively sense”’ of which constitutes the staple of our
gratitude to you to-day.

Prof. LAPWORTH, in reply, said :— Mr. President,—I am deeply sensible of the
distinction which the Council of the Geological Society has conferred upon me in
awarding me the Bigsby Medal; and I am grateful, indeed, for the generous words
in which you have referred to my geological work. If anything could add to the
gratification with which I accept this award, it is that I receive it from the hands
of one who, since the reading of my first paper before this Society, has been a
staunch friend and a sympathetic adviser. I am afraid that the Members of this
Society are a little inclined to rate my geological labours somewhat higher than
they deserve, and I regard this Medal less as a reward for what I have done in the
past than as a stimulus and encouragement for the future. ‘The pursuit of original
research has always appeared to me to be the highest and most pleasurable of
enjoyments—and none the less pleasurable, as it has for years been associated in
my mind with the unfailing interest, sympathy, and friendship accorded me by the
Members of this Society. My leisure and means for work of this kind are, how-
ever, but small; but I am sure that there is no need for me to assure the Society
that such leisure and powers as I possess in the future will be wholly given to the
service of that science to which we are all devoted.

The President then read his Anniversary Address, in which he
gave obituary notices of the following Fellows of the Society who
have died since the last anniversary:—The Harl of Enniskillen,
Sir Charles Bunbury, Mr. George Busk, Mr. John Arthur Phillips,
Mr. Henry Michael Jenkins, Dr. Harvey B. Holl, Mr. Caleb Evans,
the Rev. Willlam Downes, Dr. Frederick Guthrie, and Mr. Arthur
Grote. Also of the late Foreign Member, Dr. Hermann Abich, and
of the deceased Foreign Correspondents, Professor Guiscardi and M.
Cornet. In the Address proper, the President, after congratulating
the Society on its present condition and prospects, and referring to
some of the more notable incidents in the history of Geological
Science during the past year, proceeded to discuss the past and pre-

Geological Society of London. 187

sent relations between Mineralogy and the Biological Sciences. After
insisting that the supposed distinction between living and non-living
matter was not a fundamental one, he maintained that minerals
resemble animals in possessing definite organization, and in going
through regular cycles of change. He further pointed out that, in
the course of its development, Mineralogy was now exactly following
in the same lines which had been already taken by Zoology and
Botany. He expressed his conviction that Geology and Mineralogy
were powerful for mutual help, and that the latter science, now
passing from the classificatory stage, had a great future before it.

The Ballot for the Council and Officers was taken, and the following were duly
elected for the ensuing year :—President :—Prof. J. W. Judd, F.R.S. Vice-
Presidents ; H. Bauerman, Esq. ; Prof. T. G. Bonney, D.Sc., F.R.S. ; A. Geikie,
LL.D., F.R.S. ; Henry Woodward, LL.D., F.R.S. Secretaries: W.T. Blanford,
LL.D., F.R.S., and W. H. Hudleston, Esq., M.A., F.R.S. Foreign Secretary:
Warington W. Smyth, Esq., M.A., F.R.S. Zveasurver: Prof. T. Wiltshire, M.A.,
F.L.S. Council: H. Bauerman, Esq. ; W. T. Blanford, LL.D., F.R.S. ; Prof.
T. G. Bonney, D.Sc., LL.D., F.R.S.; A. Champernowne, Esq , M.A. ; Thomas
Davies, Esq.; Prof. P. M. Duncan, M.B., F.R.S.; A. Geikie, LL.D., F.R.S. ;
Henry Hicks, M.D., F.R.S ; Rev. Edwin Hill, M.A.; W. H. Hudleston, Esq.,
M.A., F.R.S.; J. W. Hulke, Esq., F.R.S.; Prof. T. M‘Kenny Hughes, M.A. ;
Prof. T. Rupert Jones, F.R.S.; Prof. J. W. Judd, F.R.S.; R. Lydekker, Esq.,
B.A. ; J. E. Marr, Esq., M.A.; E. T. Newton, Esq. ; Prof. H. G. Seeley, F.R.S. ;
Warington W. Smyth, Esq., M.A., F.RS.; J.J. H. Teall, Esq., M.A. ; Prof.
T. Wiltshire, M.A., F.L.S.; Rev. H. H. Winwood, M.A.; Henry Woodward,
WEDi EARS:

2.—February 23, 1887.—Prof. J. W. Judd, F.R.S., President, in
the Chair. The following communications were read :—

1. “On the Origin of Dry Chalk Valleys and of Coombe Rock.”
By Clement Reid, Esq., F.G.S.

Whilst engaged in examining the Pleistocene deposits of Sussex,
for the Geological Survey, the author observed that the Coombe
Rock differs from anything commonly seen in the strongly glaciated
districts of the Yorkshire and Lincolnshire Wolds. As in these
localities, the seaward slope of the South Downs is broken by the
line of a partially buried sea-cliff before passing under the low-lying
drift areas. Subsequent to the formation of this sea-cliff a mass of
angular flint and chalk detritus spread out from the Downs over
the low lands, being seldom found far up the valleys. This is the
Coombe Rock, which passes further on into a worthless mixture of
angular flint and loam, and at a still greater distance into almost
clean brick-earth. It is not of glacial origin, neither is it marine,
nor is it a gravel formed by ordinary fluviatile action. A study of
the contours of the Downs may give us, the author thinks, a key to
the mode of formation.

The rolling outline of the Downs and the steep-sided dry valleys
point to conditions which have passed away. However much rain
may fall, the upper parts of these valleys are always dry, and no
running water can be found where the incline of the bottom of the
valley exceeds the slope of the plane of saturation—never more than
60 feet per mile. Three explanations have been offered :—

1. Former submergence and rise in level of the plane of saturation.

188 Reports and Proceedings—

2. Former higher level of the plane of saturation before the valleys
were cut down to their present depth.

3. Increase in the rainfall.

None of these theories is sufficient to account for the origin of
Coombes and the transport of Coombe Rock. There is no evidence
of submergence whilst the Coombes were being eroded ; on the con-
trary, the descent of the Coombes to the sea-level near Rottingdean —
and elsewhere, is suggestive of a slight elevation. The deep trench-
ing of the Downs by valleys, and the consequent lowering of the
plane of saturation, is applicable to many of the slightly inclined
Coombes, but the whole structure of the country shows that the
outlet for the water must have been as clear then as now. Since
the dry chalk valleys play no part in the present superficial drainage,
it would make but little difference in the plane of saturation if they
were filled up again. If springs had formerly existed in the higher
valleys, their gradual failure would have left evidence in the shape
of gravel deposits and terraces. Moreover, as an objection, both to
the first and second theories, it is urged that if valleys had been cut
back by springs, some of them should fall to the north, where most
of the springs occur, whereas the Coombes open to the south. lastly
he finds no traces of the “ hypothetical Pluvial period.”

In suggesting an origin for the dry valleys and Coombe Rock, he
considers that the fauna and flora, both at Fisherton and Bovey
Tracey, point to a great degree of cold, from 20° to 30° lower than
what now prevails in the South of England. The ground would
thus be frozen to the depth of several hundred feet, and the drainage
system of the chalk entirely modified. There would be no under-
ground circulation. The summer rains would immediately run off
any steep slope, often in violent torrents. ‘These would tear up the
layer of rubble already loosened by the frost, carrying down masses
of unthawed chalk too rapidly for solvents to have much effect. No
Coombe Rock is found in valleys that have a greater slope than 100
feet per mile. There is no need of excessive rainfall; it might have
been a dry period corresponding to that of the Loss.

If the time had not been short, all soft rocks in the South of
England would have been planed down to one gently undulating
surface like the plains of Russia and Siberia. Such Tundra-con-
ditions may have occurred more than once.

2. “ Probable Amount of former Glaciation of Norway, as demon-
strated by the Present Condition of Rocks upon and near the Western
Coast.” By W. F. Stanley, Esq., F.G.S.

The observations on which this paper are based were made in June
last, during a voyage along the west coast of Norway. Inland con-
ditions were also noted in the Hardanger and Sogne Fjords, and a
few trips up some of the valleys enabled these inland observations
to be further extended. The author limited his work in searching
for outline evidence of ice-action. The aspect of the coast for hun-
dreds of miles consecutively has a uniform character of jagged and
pointed rocks nearly to the sea-level. At the mouths of the fjords
the rocks are more rounded, particularly at heights less than 100 ft.

Imperial Geological Institute, Vienna. 189

Within the Arctic Circle the Swartisen glacier reaches nearly to the
sea, and here the rocks are more rounded.

He exhibited sketches showing the characteristic forms of the rocks,
and concluded from a study of these that ice had never prevailed
along the entire western coast of Norway, neither had inland ice of
any considerable thickness flowed over this coast in sufficient volume
to wear off the points of the sharply-fractured granite. Hven the
rocks below 100 feet are not more worn than is sometimes the case
in tropical climates. The “shark’s teeth” of the Lofotens have not
been planed down, nor is there any vestige of the great ice-sheet of
our text-books within the Arctic Circle. Even in the fjords there
is no evidence of ice-action until we arrive at the head, where it is
very evident. There can be no better demonstration of the extent
of former glaciation than in the Romsdal valley, where the line of
the worn base extends as high up the rock as 600 feet. He also
instanced the principal glaciers of the Folge Fjord, now about 7
miles from the open water of the fjord, though formerly within 14
mile. The angular character of the low rocky island in front of Odde
shows that it cannot have advanced further.

The author concluded that at no period within geologically recent,
say Tertiary times, has ice extended much further than at present.
Seeing that the morainic matter now in the valleys has been derived
from the hills, there must formerly have been a greater extent of
land above the snow-line, and this would cause a former extension of
glaciers without resort to any extraneous theory or change of climate.
The Great Ice Age has left no trace on the Norwegian littoral.

IJ.—Iwperiat Groxnogican InstirutE, VIENNA.

September 30, 1886. — “On new Neogene Isopoda,” by N.
Andrussow.

Cymodocea Sarmatica, Andr., from the dark-tinted Lower Sarmatian
Clays of Kertch (Crimea), where it is associated with Mactra Podolica,
Hichw., Cardium obsoletum, Hichw., C. papyraceuwm, Sinzoa, C. Fittoni,
D’Orb., C. Barboli, R. Hérn., and several new species, Modiola
navicula, Dub., Tapes Vitaliana, D’Orb., Buccinum Verneuilii, D’Orb.,
B. substriatulum, Sinz., Trochus, several species, Polyzoa, Foramini-
fera, Vertebre of Fishes, and impressions of leaves, is remarkable, as
being the first known undoubted fossil representative of the marine
Spheromida. All hitherto known fossil Spheromide are freshwater
forms, or belong actually to other families or even orders, such as
the Inferior-Oolite species Spheroma Catullii, Zigno. As early as
1868, Prof. Kichwald described Spheroma exsors, from the Sarmatian
Beds of Kijchenew (Bessarabia). Palega Anconitana, Andr., from
the “Schlier” of Ancon, is a counterpart of P. Gastaldii, Sism.,
from the Miocenes of Turin. Besides the above-mentioned two
species, the other known Palege are P. scrobiculata from Karing
(Tyrol), the Eocene P. Catullit, Zigno, sp., two Cretaceous species,
and possibly the Cretaceous Cymatoga Jazikowi, Kichw., from Simbirsk
on the Volga. _4gites Kunthi, Amm., is an Upper Jurassic repre-
sentative of the family Algida.

190 Zoological Society of London.

III.—Zoonogicat Society or Lonpon.

December 7th, 1886.—Prof. W. H. Flower, LL.D., F.R.S., Presi-
dent, in the chair.—The following communication was read :—

“ On the Anatomy and Systematic Position of the Liassic Selachian,
Squaloraja polyspondyla, Agass.” By A. Smith Woodward, F.G.S.

After a brief notice of previous researches, the author attempted
an almost complete description of the skeletal parts of Squaloraja,
as revealed by a fine series of fossils in the British Museum. He
confirmed Davies’ determination of the absence of the cephalic spine
in certain individuals (presumably females), and added further
evidence of its prehensile character, suggesting, also, that the various
detached examples afforded indications of one or more new species.
The cartilages of the skull were, as far as possible, described in
detail, and special attention directed to the palatine region, which
appeared remarkably similar to that of the Myxinoids: there is a
long forwardly-directed process on either side, evidently represent-
ing a pre-palatine element, and if the conclusions suggested by the
present genus can be substantiated by an examination of other forms,
the Selachian antorbital cartilage must fall under the denomination of
post-palatine. A well-marked hyomandibular was noted, resembling
that of typical Rays; and each ramus of the jaw was shown to be
provided with a single dental plate, exhibiting the ordinary Selachian
mode of growth, and having the grinding surface rendered more
efficient by a series of longitudinal rugze; to the latter there pro-
bably correspond some slight sutures, which allow of the shedding
of the outer edge at intervals during growth. The pectoral fin
shows but two basal cartilages, the preaxial being only about one-
fourth the size of the postaxial; and the pectoral girdle is of the
Ray-type. The pelvic girdle is remarkable for the enormous size of
the prepubic process, and there appear to have been no sutures in
the basal cartilage of the pelvic fin, which passes, in the male,
directly into the large clasper of either side. The author concluded
with some general remarks on the affinities of the genus, and pro-
posed to institute the new family of Squaloraiide, which may be
placed near the Pristiophoride and Rhinobatide, and is conveniently
defined as follows :—Body scarcely depressed, elongate. Head pro-
duced into a long flat rostrum, without lateral teeth. Males with a
prehensile spine on the upper part of the snout. Dentition sharply
divided at the symphysis. Pectoral fins with small propterygium,
free.

CORRESPONDENCE.

es

GLACIATED AND FACETTED BOULDERS IN THE PUNJAB.

Sir,—The statement of the case of the glaciated (?) rock-fragments
of the Punjab has been thus far all from one side. As the “arch-
heretic” who ventured to suggest that the four “ Indian geologists,”
who took part in the discussion of the subject at Birmingham, had
overlooked some important physical agencies, when they asserted

Correspondence—Rev. A. Irving. 191

that no agency other than moving-ice could produce the effects
observed, perhaps I may venture to ask for space for a few lines.
I wish to point out that there appears to be considerable confusion
of thought on this matter.

The rock-fragments are described now as “pebbles,” now as
“boulders,” which are surely representatives of very different sets of
mechanical forces. The term “pebble” is certainly a misnomer if
applied to the two specimens which were exhibited at Birmingham.
I saw and handled them both. The felsitic block had portions of
its original surface somewhat smoothed, the sharper lines of its
fracture somewhat rounded off in a fashion suggestive of the way in
which the more flinty sarsens of this district acquire a certain degree
of polish. The striated “facets” on this block are certainly difficult
of explanation by reference to glacial agencies: they seemed to me
very different from the ice-striations of blocks, of which I have had
rather extensive observation in Alpine regions; nor can the necessary
retention of the block in a fixed position in resistance to great and
long-continued pressure be reconciled with the known physical

properties of ice (see Q. J. G. 8. February, 1883, pp. 62 e¢ seq.).

The other block exhibited was more of a basaltic character, and
was no doubt a slightly water-worn fragment of a basaltic column,
as Prof. Carvill Lewis pointed out in the discussion at Birmingham.
I do not recollect that this block was striated.

The question as to how the blocks came into their present position
is entirely distinct from that of the agencies by which their present
surface-character was given to them ; and we have no right to assume
that these agencies acted upon them simultaneously. On the contrary,
Mr. Oldham’s description! of the beds in which they occur affords, I
think, convincing evidence to show that these facets and striations
were produced by some agency or other prior to their deposition in
the beds in which they now occur. This disposes at once of that
writer's objection to the landslip theory (miscalled “soil-cap move-
ment”), which I urged as the most likely explanation of the
phenomena. In the discussion I referred to the objections of so
excellent a physical geologist as Prof. Heim? of Ziirich, to which I
have on a previous occasion drawn attention in the pages of this
Magazine (Decade II. Vol. X. pp. 160 et seq.), where it was also
pointed out that the polishing and striations of the surfaces of
fragments of rock by the slow grinding movement, which often
goes on for years, was worthy of some consideration from their
resemblance to some of the effects of glacial action. As I fail to
see that this explanation has been met as yet by any insuperable
objection, it will not be from mere obstinacy if I still adhere to it
as upon the whole the most probable.

Mr. Oldham remarks on the origin of the name “Olive Group,”
and then a few lines further on says there is not “any sign of
carbonaceous matter in the bed.” Has chemical analysis decided
this ? A. Irvine.

WELLINGTON CoLLEGE, BERKS,

January 8th, 1887.

1 Vide Geou. Mac. January, 1887, p. 32. * « Ueber Bergstiirse.”’

192 Correspondence—Mr. R. S. Herries—Prof. Wiltshire.

THE BAGSHOT SANDS.

Srr,—Mr. Irving commences an article in the Gronocican Mae@a-
zINE for March (p. 111) with the following statement: “The chief
object of this paper is to describe an unmapped outlier of Bagshot
Sand.” I have no desire here to raise the question of the age of the
beds he has described in that article, especially as that subject was
fully discussed on a paper read by Mr. Irving before the Geological
Society in January last. But I wish to point out that, unless I
have greatly misunderstood Mr. Irving’s account of the geographical
position of the outlier which he describes, the Bagshot Sand in
question is neither unmapped nor does it form an outlier. In the
Survey Map the Lower Bagshot Beds are represented as extending
from the main mass westwards, between Barkham and Bearwood
Park, including part of the latter, and sending off spurs to the south-
ward, one of which ‘is crossed by the main road from Arborfield
Cross to Wokingham,” exactly as described by Mr. Irving. The
only difference appears to be that Mr. Irving gives the beds a rather
greater northerly extension than the Map. Moreover, the beds are
not only mapped, they are also described. In the “ Memoirs of the
Geological Survey,” vol. iv. page 314, we find the following :—
“‘ About three-quarters of a mile N.N.W. of Barkham, near Woking-
ham, there is light-brown fine micaceous glauconiferous sand, with
thin layers of pipe-clay towards the top, about 12 feet thick, over a
pebble-bed in whitish micaceous sand.” This may possibly have
been a description of the “ Barkham Pit” described by Mr. Irving
on p. 112. It agrees well enough in position, and the pit is said
(p. 118) to have been “re-opened only last winter, after having
been disused for years.” It is true we find no mention of these
beds in the list of outliers given in the memoir (loc. cit. p. 316) ;
but, as I have stated above, the Survey considers that the sands are
connected with the main mass.

It would seem, therefore, that in the alleged new outlier of
Bagshot Sands, with which he has lately been puzzling those who
are interested in Bagshot geology, Mr. Irving has only discovered
an old friend. R. 8. Herries.

PALHONTOGRAPHICAL SOCIETY.

S1r,—The volume for the year 1886, price one guinea, containing :
(1). Stigmaria ficoides, by Prof. W. C. Williamson, with 15 plates; (2) Fossil
Sponges, Part I. by Dr. G. J. Hinde, with 8 plates ; (3) Jurassic Gasteropoda,
Part I. No. 1, by Mr. W. H. Hudleston ; (4) Inferior Oolite Ammonites, Part I.
by Mr. G. S. Buckman, with 6 plates; (6 ) Pleistocene Mammalia, Part V1. by
Prof. W. Boyd Dawkins, with 7 plates, is now with the binder, and will be issued
to the Members toward the close of the present month,

The volume for 1887, of which nearly all the plates are ready, will be placed in
the printer’s hands at once, and will be distributed before the end of the year.

The new Monographs, on the Fossil Sponges, the Stromatoporoids, the Jurassic
Gasteropoda, and the Inferior Oolite Ammonites, will require many plates for their
illustration, and will be very costly. It would be a considerable aid to the Society
if Members would mention these Monographs to those of their friends who are
interested in such subjects, and if they would try to bring in new Subscribers.

25, GRANVILLE Park, LewisHaM, Tos. WILTSHIRE,

Lonvon, 7th March, 1887. Secretary.

Geol. Mag. 1887.

A.S Foord del. et ith. :

New British Liassic Gasteropoda.

THE

GEOLOGICAL MAGAZINE.

NEW SERIES! DECADE” Ill.’ VOL IV.
No. V—MAY, 1887.

OQ LG EIAs eALR LCrhan Se

agi. |
J.—Britisu Lrasstc GASTEROPODA.
By E. Witson, F.G.S.; Curator of the Bristol Museum.
(PLATE Y.)
INTRODUCTION.

F\HE Gasteropoda, next to the Lamellibranchiate Mollusca, are the
most varied class of organisms found in the Lias. The general
elegance of their forms, and the frequent beauty of their ornamenta-
tion, make these fossils extremely attractive objects; whilst their
limited vertical range gives them a by no means inconsiderable
stratigraphical importance. Notwithstanding these inducements to
their study, the Gasteropoda of the Lias have not received, in this
country, anything like the amount of attention which has been given
to the other leading classes of organisms derived from that formation.
On the Continent, on the other hand, considerable progress had been
made in the investigation of this interesting group of fossil mollusca,
more than thirty years ago. The elaborate Memoirs of Miinster (in
Goldfuss’s “‘ Petrefacta Germanie”’), D’Orbigny (in the “ Paléonto-
logie Frangaise”’), Deslongchamps the elder, Dunker and Terquem,
Chapuis and Dewalque, furnish the basis of our knowledge of the
Gasteropoda of the Lias, whilst in later years Messrs. Eudes
Deslongchamps, Stoliczka and Piette, Jules Martin and Dumortier,
have each and all contributed a large amount of very valuable
information in this department of Paleontology. The above differ-
ence, to our disadvantage, is perhaps to be explained, in part at any
rate, by the more localized distribution of Gasteropodous Mollusca in
the English Lias, by their prevailing small size, and the comparative
rarity of the more conspicuous forms, such as the Pleurotomarie, and.
finally, by their generally more highly mineralized condition, and
the consequent greater difficulty there is, in this country, in extracting
these fossils in anything like perfect condition.’ During recent
years, however, an increasing amount of attention has been given
to the paleontology of the English Lias. In this work a number of
earnest students are now actively engaged, chiefly in the Midlands,
a district which had previously been greatly neglected, and one of

1 Tn the Lias of Luxembourg and Hettange, several Gasteropods have been found,
which are not only perfect in form, but even retain the original colours and markings
of the shells. (See Terquem, “ Paléontologie de Hettange,’? Mem. Soc. Geol.
France, 2"4 ser. vol. v. pp. 219-843, pl. xii.—xxvi.)

DECADE III.—VOL. IV.—NO. V. 13

194 E. Wilson—British Liassic Gasteropoda.

the results of their labours has been to materially add to our know-
ledge of the Gasteropoda of the Lias formation.

The following summarized account will serve to illustrate the
progress which has been made in this branch of Paleontology in
recent times. In the Catalogue of British Fossils (2nd edition),
published by the late John Morris in the year 1854, only six species
of Gasteropoda are quoted from the Lias formation, viz. Pleurotomaria
Anglica, Pl. compressa, Pl. expansa, Trochus imbricatus, Turbo
undulatus, and Dentalium giganteum. In 1872, twenty-three species
had been obtained from the Lias of Yorkshire, but in 1876 this
number was, through the labours of Messrs. Tate and Blake,
increased to 89 (see “ Yorkshire Lias,” p. 331). Mr. E. C. H. Day
in 1863 obtained 40 species of Gasteropoda from the Middle Lias of
Dorsetshire, many of which were new to this country, and appear to
be confined to that district (Q.J.G.S. vol. xix. p. 278, and vol. xxxiii.
p- 167). One of the most indefatigable students of the paleontology
of the Lias at this period was the late C. Moore, who chiefly worked
in the Somersetshire and §. Wales areas. The fruits of the labours
of that very capable geologist are to be seen in the splendid “‘ Moore
Collection” of Lias fossils in the Bath Museum. This collection,
which is, I believe, richer in Lias Gasteropoda than any other in
England, contains 180 named British species, including no less than
90 type forms, many of which are unique both in their interest and
rarity... In 1871 Prof. Ralph Tate, in his “Census of the Marine
Invertebrate Fauna of the Lias,” enumerated 269 species representing
32 genera of British, as compared with 650 species representing 43
genera of Continental Liassic Gasteropoda (Grou. Mag. Vol. VIII.
1871, p. 4). Mr. R. Etheridge, F.R.S., in his Presidential Address
to the Geological Society in 1882, «On the Analysis and Distribution
of the British Jurassic Fossils,” quotes 388 species, which are classed
by him under 51 genera, from the Lias of Great Britain. Of this
large number only six” species are stated to pass up into the Inferior
Oolite, viz. Acteonina pulla, Amberleya capitanea, Cerithium papil-
losum, Natica adducta, Onustus pyramidatus, and Pleurotomaria
princeps, one of which (A. capitanea) survived into. the Forest
Marble (Q.J.G.S. vol. xxxvili. p. 165). In reference to the foregoing
account I would observe, without in any way questioning the general
accuracy of the figures given by my esteemed friend Mr. Htheridge,
or the validity of the conclusions founded thereon, that the number
both of the species and of the genera appear rather too high for what
they respectively represent. It was admitted, for instance, that the
136 Middle Lias names represented only 118 true species, and this,
apart from any similar deduction for duplicated nomenclature in the

1 See Quart. Journ. Geol. Soc. vol. xxiii. p. 449, pl. 14-16; Proc. Somerset Arch.
and Nat. Hist. Soc. vol. xiii. p. 119, pl. 4-6. It is unfortunate that these types
should have been so indifferently delineated. Moore’s sketchy figures give but a poor
idea of the beauty of these fossils, and, in several instances, are so inaccurate as to be
positively misleading as to their form. Students of this group should therefore beware
of too readily trusting to identifications founded solely on comparisons of their
specimens with these figures.

2 This number is certainly capable of increase.

ne

FE. Wilson—British Liassice Grasteropoda. 195

other two divisions of the Lias, would reduce his gross total to 370.
Then again we find some of the genera repeated under different
names : ‘Amberleya,’ ‘Hucyclus,’ and ‘Tectaria,’ for example, are cited
as three instead of as one only, and similarly the synonymous
Acteonina and Orthostoma are apparently counted as two.

I have recently drawn up lists of the British Liassic Gasteropoda
which, exclusive of those now described, comprise 425 species, dis-
tributed provisionally under 51 genera. In these lists care has been
taken to avoid the reduplication of names, but it is probable that a
small number of the species have been counted twice under different
synonyms. These last, however, will, I believe, be more than
balanced by the various new forms now awaiting description. The
number of genera on the other hand is almost certainly too great,
The 425 species are very unequally distributed among the genera.
The dominant Liassic genera are Trochus, Turbo, Cerithium, and
Pleurotomaria. Taking with the last the sub-group Cryptenia, each
of these genera would comprise about 50 species, or together nearly
a moiety of the whole number. Next comes Chemnitzia with some
30 species, and then Amberleya (=Eucyclus) — et@onina (= Ortho-
stoma), Turritella, and Patella, with from 10 to 16 each. The follow-
ing genera are represented by an average of 6 species each: Acteon
(= Tornatella), Alaria, Dentalium, Discoheliz, Eulima (= Niso),
Iittorina, Natica, Neritopsis, Phasianella, Pitonillus (= Rotella),
Solarium, Straparolus and Trochotoma; whereas Cylindrites, Crypt-
aulax, Delphinula?, Euomphalus?, Kilvertia (=Exelissa), Monodonta,
Neriia, Neritina, Onustus, Purpurina, Rimula and Rissoa are repre-
sented by 1 to 3 species each only. The remaining genera, which are
mostly founded on extremely few forms, and in some cases on single
and imperfect or on minute and immature specimens, cannot be con-
sidered to be satisfactorily established at present. These are Chiton,
Conus, Fusus, Nerina, Pterocera, and Pyrula, one if not both of
Moore’s genera Pleuratella and Pterocheilos, and the following
terrestrial and freshwater types:—Ampullaria, Helix, Hydrobia,
Melania, Planorbis, Proserpina, Valvata, and Vertigo. Some of the
foregoing are pretty sure to break down as Liassic genera under closer
scrutiny and the acquisition of more satisfactory material. Indeed,
it is very questionable whether any one of the first six of the above
genera can be maintained; and, before accepting any land or fresh-
water form, as coming from a formation so essentially marine as the
Lias, we must require in each case the most clear and convincing
evidence. The net result of a future revision will probably be to
reduce the number of generic types given above, whereas the species
are probably capable of an appreciable and immediate increase.

The enumeration of 425 species of British Liassic Gasteropoda in
1886 as compared with the trivial number of six only in 1854, is a
striking illustration of the progress which has been made in Paleon-
tology in this country during the last thirty years.

Without further preface, 1 proceed to the main object of the present
communication, which is to describe thirteen species of Gasteropoda.
These are mostly new to science, and all are new to the British Lias.

196 E. Wilson—British Liassic Gasteropoda.

For a full moiety of the material on which the following species are
founded I am indebted to Mr. W. D. Crick, of Northampton, who
has very generously placed a number of interesting specimens at my
disposal for the above purpose, and has also furnished me with much
valuable information as to their precise geological position. I am
under a considerable obligation to the Rev. H. H. Winwood, M.A.,
F.G.S8., for the facilities he has kindly given me for examining the
specimens in the Bath Museum, to Mr. H. E. Quilter, of Leicester,
for assistance with specimens from that county, and to Mr. T. Beesley,
F.C.8., of Banbury, and Mr. B. Thompson, F.G.S., of Northampton,
for useful information on the general subject.

Note.—In the following descriptions, the “sutural angle” is the
greater angle which the suture makes with the side of the spire; and
the “length of the last whorl” is measured axially, and posteriorly
when practicable, from the anterior extremity of the aperture to the
last preceding suture.

Description oF New SPECIES.
Trocuus Daxsiensis, spec. nov. Pl. V. Figs. 1, la, 18, le.

Description.—Shell conical, as broad as high; imperforate ; spiral
angle concave, apex acute; whorls 7, slightly concave, separated by
deep sutures, last whorl very large relatively, squarely angulated at
the periphery. The ornamentation of this very pretty little shell is
as follows :—Numerous slender radial costee commence close to the
posterior suture in a row of fine granulations, apparently formed at
the junctions of the coste with a fine encircling thread, and are
continued forwards rather obliquely across two rows of larger
rounded tubercles, similarly occurring at the decussations of the
coste with fine encircling threads; these two granulated lines
occupy the anterior third of the whorls, and the anterior one of the
two, which is the most prominent, gives a distinct angulation thereto ;
from each of the tubercles of this anterior row two fine threads pass
downwards obliquely across the deep sutural groove, and terminate
in a finely-granulated encircling thread close to the anterior suture.
Base of shell almost flat, very slightly convex, with 12 or more very
finely-crenulated concentric threads, which are closer together towards
the centre and circumference, and wider apart in the intermediate
area. Aperture trapezoidal, transverse and oblique. Outer lip boldly
arched, inner lip almost straight and effuse over the columellar border.

Dimensions. — Length, 8 millimétres; diameter, 8 mm.; length
of last whorl, 5 mm.; spiral angle, 70°; sutural angle, 128°.

Affinities.—This species is somewhat closely related to Tr. Thetis,
Miin. (Goldfuss, Petr. Germ. pl. 179, figs. 10a, 6: and Plate V.
Figs. 2a, b, c). It differs therefrom by its finer ornamentation, the
double row of anterior tubercles, the fine granules over the suture,
and the more numerous concentric striz on the base, also by its
greater spiral angle, larger number of whorls, and more acuminate
apex. Judging by the specimens of this latter species found at
Dalby associated with the foregoing form, Miinster’s figure (loc. cit.)
errs in showing unduly straight coste, want of tubercles on the keel,

/

E. Wilson—British Liassic Gasteropoda. 197

a roundly-furrowed instead of a sharply-ribbed base, and an apparent
and large umbilicus.

Note.—Trochus Thetis seems to be a difficult form to delineate. It
has several times been re-figured, but never drawn with perfect
accuracy. The figures I give (PI. V. Figs. 2, 2a, b, c) are an advance
on most of the previous figures, but the appearance of an umbilicus
is fallacious.

Geological Position and Locality.— Lower Lias, zone of Am.
oxynotus, Railway-tunnel, Old Dalby, Leicestershire.

Trocuus Crick, spec. nov. Pl. V. Figs. 3, 3a, 3b.

Description.—Shell conical, imperforate ; spiral angle regular, very
slightly concave, apex acute; whorls 5-6, quite flat; sutures linear,
only slightly inclined; last whorl obtusely angulated at the circum-
ference ; base almost flat, very slightly convex; columella prominent,
massive and vertical; outer lip imperfect, but the aperture when
complete appears to have been rhomboidal and only a little wider
than high. The whorls are covered with close-set spirals of small
rounded tubercles, the spiral lines and the individual tubercles being
respectively closer together than their interspaces ; on the penultimate
whorl there are 5-6 spirals; the tubercles of the most anterior row
of these are a little the largest, and give a slight tabulation to the
whorls, the row next behind are nearly equally large, then there is a
very fine row, and behind these two rather coarser rows; on the last
whorl 4 rows of coarser tubercles occupy the angular border,
posterior to which are 4 rows of finer tubercles; on the base im-
mediately within the 4 coarse granular lines are 38 finer lines, of
which the outer one only is granular; the rest of the base is smooth.

Dimensions.—Length, 5 millimétres; diameter, 4 mm.; length of
last whorl, 3:25 mm.; spiral angle, 65°; sutural angle, 130°.

Affinities.— This small shell appears to have rather close affinities
with certain small Oolitic Trochi having granulated spires and smooth
bases, such as Tr. monilitectus, Phil., and its allies Zr. Scarburgensis,
Dudl., and 7r. strigosus, Lyc., figured and described by Mr. W. H.
Hudleston, M.A., F.R.S., in his “ Paleontology of the Yorkshire
Oolites” (Gror. Mac. Dee. III. Vol. IL 1885, p. 121, et seq.). It
does not, however, appear to be absolutely identical with any of these.

Obs.—I name this fossil after Mr. W. D. Crick, of Northampton,
whose valuable work on the paleontology of the Lias of that district
has already been acknowledged.

Geological Position and Locality—Middle Lias, zone of Am. mar-
garitatus, Daventry, Northamptonshire.

TROCHUS SAGENATUS, spec. nov. PI. V, Figs. 4, 4a.

Description. — Shell conical, turrited, imperforate; spiral angle
regular; whorls 8 probably (the apex being lost in my sole
specimen), a little concave and slightly imbricating. Hach whorl
bears 3 equidistant encircling raised lines one a little in advance of
the posterior suture, the second a little in front of the middle of the
whorl, and the third forming a slight keel directly overhanging the

198 E. Wilson—British Liassic Giasteropoda.

deeply cut but very narrow suture; these are crossed by numerous
slender, slightly oblique, radial costae, forming with the spiral lines
a neat meshwork, having little nodules at the decussations ; the
radial costes are more slender and more closely set on the last
whorl. Base almost flat, bearing numerous fine encircling threads
with nearly equal interspaces; the radial coste are continued over
the angular border of the last whorl, to which they give a fine
crenation, and then rapidly die away. Aperture depressed, lunate
and oblique, outer lip somewhat thickened, columella inconspicuous.

Dimensions.—Length (restored), 6-75 millimétres; diameter, 4mm. ;
spiral angle, 85°; sutural angle, 110°.

A ffinities.—This form appears to be related to Trochus Holwellensis,
Moore, a fossil derived from the Liassic deposit contained in fissures
of the Mountain Limestone near Frome (Q.J.G.S. vol. xxiii. p. 554,
pl. 17, figs. 1, 2). The types of this species should be in the Bath
Museum, but they are unfortunately missing. Comparison of our
specimen with Moore’s figure, however, shows that whilst the two
fossils agree in general form and ornamentation, Tr. Holwellensis
had a more elongated spire, the whorls of which, instead of im-
bricating each other, were separated by wide and deep sutures, and
bore fewer and coarser radial coste, making prominent “ bosses ” on
the margin of the last whorl. Moore’s type appears also to have had
a small umbilicus. These points of difference seem quite sufficient
to distinguish the two forms specifically.

Geological Position and Locality.—Upper Lias (transition-bed to
Middle Lias), L. and N. W. Railway, Watford, Northamptonshire.

Trocuus NoRTHAMPTONENSIS, spec. nov. PI. V. Figs. 5, 5a.

Description.—Shell conical, imperforate; apex acute; spiral angle,
regular or slightly convex; whorls 7, concave; a prominent and
acute crenulated ridge or carina encircles the anterior portion of the
whorls, and a similar but much less prominent ridge encircles the
whorls close to the posterior suture; between these there is a
concave area occupying two-thirds of the width of the whorl; from
the anterior carina the surface of the whorl falls vertically to the
anterior suture, this portion occupying about a third of its width;
the last whorl is tricarinated, having two anterior crenulated caring,
the posterior of which is the more prominent; broad undulating
costes run somewhat obliquely from the spinose points of the
posterior to those of the anterior carina, beyond which they are
continued vertically to the anterior suture, and on the last whorl,
after connecting the spinose points of the two anterior carine,
are continued in more or less prominent serpentine ridges from the
circumference to the centre of the base. A few faint encircling lines
are discernible in the concave portions of the whorls. The whole
shell is covered with fine close-set radiating flexuous lines, which pass
over the cost and their interspaces, the carinz and the base. The
base is only slightly convex, but prominent in the centre, and marked
with numerous concentric lines, which are either equally distinct and

FE. Wilson—British Liassie Gasteropoda. 199

spaced from circumference to centre, or are much more distinct and
more widely spaced towards the circumference, in addition to the
radial serpentine lines and ridges above mentioned. Aperture trans-
verse, outer lip thin, with an irregular outline; inner lip concave,
with a broad expansion over the massive, axial and somewhat
obliquely produced columella.

Dimensions.—Height, 10-75 millimétres; diameter, 9 mm.; length
of the last whorl, 6:75 mm.; spiral angle, 60°; sutural angle, 125°.

Note.—Figs. 5 and 5a, being drawn from a laterally compressed
Specimen, show a rather greater breadth and spiral angle, and a more.
transversely elongated aperture than this form really possesses.

Affinities—In its general form and ornamentation this shell
appears almost identical with one (viz. fig. 6) of the figures of
DOrbigny’s Turbo subduplicatus (Pal. Fr. Terr. Jur. vol. ii. p. 389,
pl. 329, figs. 1-6), a species which, according to that authority,
is synonymous with TZrochus duplicatus, Sow., Turbo duplicatus,
Goldfuss, Turbo plicatus, Goldfuss, and Turbo Palinurus, D’Orb. We
are, however, confronted with the fact that the Northamptonshire
fossil is certainly not a Turbo, but a Trochus.

The aperture of the particular form (l.c. pl. 329, fig. 6) which
is so like our specimens is not shown, but the author defines its
character in this very variable species of his as “round, with a broad
thickening over the columella.” The question arises, was the aperture.
of this particular shell (lc. pl. 329, fig. 6) hidden or imperfectly.
shown, and has D’Orbigny mistaken its genus in consequence, or has
he and Goldfuss also (Petr. Germ. vol. iii. p. 95, pl. 179, fig. 2) mis-
interpreted the character of this portion of these shells generally,
and thus of the genus, from having had to deal with imperfectly-
preserved specimens?! The description and figure of Trochus
duplicatus, Sow., which give the aperture as quadrangular (Min.
Conch. vol. iii. p. 181, t. 181, fig. 5), indicate that Sowerby’s type
was a genuine Trochus. The species Trochus duplicatus, Sow., is
therefore good, and must stand. If Goldfuss and D’Orbigny were
correct in their respective specific identifications of Turbo duplicatus,
and Turbo subduplicatus, with Sowerby’s type, they have both erred
in their generic appellation. However this may be, I consider the
Northampton fossil distinct from all these, with the probable exception
of the particular shell figured by D’Orbigny as Turbo subduplicatus
(lc. pl. 329, fig. 6), which—relying upon the vertically truncated
whorls and spinose and widely-channelled double-keel—I consider
distinct from the other forms figured by that author (Jc. pl. 329,
figs. 1-5).

Geological Position and Locality.— Upper Lias, zone of Am.
communis, New Railway, Weedon and Dodford, near Daventry,
Northamptonshire.

1 The matter is complicated by D’Orbigny describing a typical Trochus duplicatus,
Sow., in another part of the Pal. Franc. (Terr. Jur. Gast. ii. p. 278, pl. 313, figs. 5-8)
under that name.

200 EF. Wilson—British Liassie Gasteropoda.

Trocuus Nioxtensts, D’Orb. PI. V. Figs. 6, 6a, 6b.
1850. D’Orb. Pal. Franc. Ter. Jur. vol. ii. Gast. p. 282, pl. 315, figs. 5—8.

I recently obtained a little shell from the Marlstone Rock-bed of
Downcliff, near Bridport, Dorset, which in all essential respects
agrees with Tr. Niortensis, described by D’Orbigny as having been
derived from the étage bajocien (Inferior Oolite) of Niort (Deux
Sévres).

Description.—The following is a translation of that author’s descrip-
tion :—‘“ Shell conical, much longer than broad, imperforate. Spire
formed of a regular angle, composed of whorls very much hollowed
out, striated longitudinally, and marked in the lower portion with
oblique coste tuberculated below (i.e. posteriorly). The last whorl
is convex, striated concentrically above and angular over the sides.
Aperture a little depressed and angular. Spiral angle, 49°. Length,
10 mm. ; breadth, 8 mm.” (D’Orbigny, Pal. Fr. l.c. p. 282).

A finities.—My specimen has a less elevated spire than D’Orbigny’s
type, being only a little higher than broad, 6:5, with a decidedly
greater spiral angle, viz. 60°; the three apical whorls and the spiral
angle are a little convex; the cost, too, are more strongly nodulated
at their anterior ends and prominent on the upturned keel; the base
shows radial as well as encircling strie; and the aperture is more.
squarely angulated than in D’Orbigny’s figure. These differences
are of detail rather than of essence, and not more than might
reasonably be expected between individuals of the same species
derived from such widely-separated horizons as the Middle Lias and
the Inferior Oolite. D’Orbigny speaks of the aperture of his Tr.
Niortensis as “ angular,” and in this the description is probably more
correct than the delineation, which, like that of too many of the
figures in the Paléontologie Frangaise, appears to have received an
artistic rounding off or restoration not strictly true to nature.

Obs.—The occurrence of this fossil in the English Lias is of special
interest from its being one of those that range into the Oolite.

Geological Position and Locality—Middle lias, Conglomeratic
Marlstone, zone of Am. spinatus, Down Cliff, near Bridport, Dorset.

AMBERLEYA CALLIPYGE, spec. nov. Pl. V. Figs. 7, Va.

Description.— Shell turbinate, thin, imperforate; spiral angle
regular ; whorls 6-7, only slightly convex, the greatest diameter of
the whorl is attained a little behind the anterior suture, whence it
falls rapidly thereto, thus giving a slight tabulation ; sutures narrow,
but clearly defined; last whorl relatively large, long and inflated ;
base very convex; aperture broadly ovate; outer lip thin, with its
inner margin very finely crenated; inner lip slender, extending
somewhat over the columella, vertical, but arching forwards towards
its angular junction with the outer lip at the anterior margin, which
at this point is patulous and a little effuse. The ornamentation of
this handsome shell is elaborate, the whole surface being covered
with close-set spirals of small rounded tubercles. On the first
4-5 whorls these granular tubercles are much finer than on the

E. Wilson—British Liassic Grasteropoda. 201

last 2. The third whorl bears only 4 of these spirals. The
penultimate whorl bears 7 granular spirals; of these the sixth
from the posterior suture lies on and determines a faint angle, and
the seventh is close to the anterior suture; these two rows consist
of rather coarser tubercles, and speaking generally the granules get
smaller towards the posterior suture; the spirals are separated by
about their own breadth from one another, and the individual beads
of a spiral from a little less up to rather more than their own width.
On the last whorl very finely granulated lines are seen setting in
between the rows of coarser granules; there are eight or nine of each
series counting from the periphery, whilst the base shows a like
number of the coarser spirals (which are more closely set and
somewhat finer than those posterior to the periphery), with indica-
tions of fine alternating spiral lines.

Dimensions.—Leugth, 8 millimétres; diameter, 5°75 mm.; length
of last whorl, 5:75 mm.; spiral angle, 68°; suiural angle, 125°.

Geological Position and Locality.— Middle Lias, zone of Am.
margaritatus, Daventry, Northamptonshire.

Monoponta (Turso) HumILIs, spec. nov. Pl. V. Figs. 8, 8a, 8b.

Description.—Shell small, smooth, spire greatly depressed ; whorls
4, flattened and embracing, with linear sutures and scarcely exsert
(Fig. 8), but occasionally the whorls are a little convex, the sutures
distinct, and the spire slightly raised (Fig. 8a). A shallow sulcus
encircles the whorls posteriorly; this depressed area is most apparent
on the last whorl, and occasionally becomes so marked as to hollow
out its whole upper surface, and give an angulated instead of the
prevailing obtusely rounded border to the shell; the columella is
very short and twisted, it terminates by uniting with a prominent
bluntly triangular tooth, which originates at the edge of the inner
lip in advance of and reflected over the minute umbilicus. Aperture
transversely ovate, rather small and not quite continuous, directed
obliquely forwards, and having its outer border slightly constricted
by the sulcus. Base almost flat, very slightly convex, more or less
wrinkled towards the centre. Under a lens the shell shows numerous
close-set lines of growth.

Dimensions.—Height, 2°50 millimétres. Diameter 5 mm.

Geological Position and Locality.—Lower Lias, zone of Am. oxynotus,
common in the Tunnel waste heaps, Old Dalby, Leicestershire.

Monoponta (Turso) LinDECoLINA, spec. nov. PI. V. Figs. 9, 9a, 95.

Description.—Shell small, thick, transversely ovate ; imperforate ;
spire scarcely exsert, and apex obtuse ; whorls 5-6, convex, embracing
with scarcely visible linear sutures, the last whorl inflated ; ashallow
sulcus bounds the posterior suture; base slightly convex; the umbilical
region, which appears to be covered by a thin shelly callus, is
encircled by a more or less prominent semicircular ridge which runs
nearly from the posterior to the anterior inner margin of the aperture ;
aperture almost exactly circular, oblique, the last whorl slightly

202 G. Dowker— Water-supply of East Kent.

disjoined from the penultimate posteriorly at the aperture; columella
very short, and twisted horizontally, terminating in a prominent
bluntly-pointed tooth, in front of which is a narrow groove. The
shell is smooth and shining, but under a strong lens its whole surface
up to the basal ridge above referred to is seen to be covered with
numerous fine encircling striz, and still finer curved radial strie.

Dimensions. — Height, 4 millimétres; diameters, 5 mm. and
5°75 mm.

Geological Position and Locality—Upper Lias, zone of Am. ser-
pentinus, Lincoln.

EXPLANATION OF PLATE VY.

Fie. 1, a,b,c. Trochus Dalbiensis, spn.—Lower Lias, zone of Am. oxynotus, Old
Dalby. Back and front views and base enlarged
twice, penultimate whorl enlarged six times.

» 2,a,b,¢c. Trochus Thetis, Miin.—Lower Lias, zone of Am. oxynotus, Old Dalby.
Back and front views and base enlarged twice,
penultimate whorl enlarged six times.

» 98,a,b. Trochus Orickt, spm.—Middle Lias, zone of Am. margaritatus,
Daventry. Back and front views enlarged three
times, penultimate whorl enlarged six times.

op ah Ee Trochus sayenatus, sp. n.—Upper Lias, Watford. Back and front

views. enlarged three times.

op» Gy Bo Trochus Northamptonensis, sp.n.—Upper Lias, zone of Am. communis,
Weedon. Back and front views enlarged twice.

» 6,a,b. Trochus Miortensis, d’?Orb.—Middle Lias, zone of 4m. spinatus, Down
Cliff. Front and basal views enlarged three times,
penultimate whorl enlarged six times.

np Up iB Amberleya Callipyge. sp.n.—Middle Lias, zone of Am. margaritatus,
Daventry. Front and back views enlarged three
times.

» 8,a,b. Monodonta humilis, sp. n.—Lower Lias, zone of Am. oxynotus, Old
Dalby. Front, back, and apical views enlarged
four times.

» 9,a,b. Monodonta Lindecolina, sp. n.—Upper Lias, zone of Am. serpentinus,
Lincoln. Back and front views enlarged twice,
portion of penultimate whorl enlarged six times.

FLO sats Cerithium trigemmatum. sp n.—Lower Lias, zone of Am. oxynotus,
Old Dalby. Back and front views enlarged six times.

jy JUL) Bo Acteonina ferrea, sp. n.—Middle Lias. zone of Am. spinatus, Tilton.
Back and front views enlarged three times.

i) 2) Ble Cylindrites equalis, sp. n.—Middle Lias, zone of Am. spinatus, Tilton.
Front and back views enlarged twice.

nq es Alaria Hudlestoni, sp. n.—Lower Lias, zone of Am. Bucklandi, Bitton.
Front view enlarged three times.

ao es Alaria semicostulata ? Piet et Hug. Desl.—Upper Lias, zone of Am.
serpentinus, Dodford. Back view enlarged twice.

» 15. D0 7 P—Upper Lias, Chipping Warden. Front view

enlarged twice.
(To be continued.)

I].—Tue Warer-Suprpry or East Kent, 1x Connection WITH
NatTuRAL Springs AnD Drer WELLS.
(Being the substance of a Paper read before the East Kent Natural History Society.)
By Gzorcz Dowker, F.G.S.

ee numerous demands made upon our underground water-supply,
both for sewage and sanitary as well as brewing purposes,
render the subject of my paper a matter of deep and serious im-

portance.
I shall set forth in the first place the rise and course of the rivers,

a ed a

G. Dowker— Water-Supply of East Kent. 203

and in the next place the wells, especially the deep ones in the Chalk
area; and I propose to show the connection between the height of
the springs and the rainfall of the district.

Although I have chosen for the title of this paper “'The Water-
supply of Hast Kent,” I must premise that the area to which I shall
confine my remarks is chiefly Hast Kent as represented by a line
from West Hythe to Whitstable and eastwards, and generally to that
part of Kent included in the new one-inch maps, numbered Sheets
273, 274, 289, 290, 305, 306, which combined will forma a very good
map of reference to my paper.

The well-sections are many of them unpublished, but my remarks
will chiefly be directed to their water-level rather than their geolo-
gical features.

The section I have constructed from West Hythe to the north of
Canterbury will show the general dip of the beds of the whole area,
and define approximately the thickness of the underlying beds:
I say approximately, for the beds below the Chalk vary in relative
thickness, and between the Gault and the Wealden beds we may
expect to find (after the facts revealed in the deep well-section at
Dover Convict Prison, where the Lower Greensand is only repre-
sented by 381 feet of clayey sand) no certainty as to thickness or
character.'

The bed called Upper Greensand between the Gault and Chalk
Marl is barely represented in Hast Kent, and the base of the Chalk
Marl, which (in all the sections I have met with) has been so squeezed
and contorted that no definite thickness could be assigned to it, and
some 50 feet of the Lower Chalk resting on the Gault is an alterna-
tion of sand and clay which for the most part retains water. It is
from this bed, probably the upper part of it, that we find the springs
thrown out all along the southern edges of the escarpment of the
Chalk. For the details of these beds Mr. Hilton Price’s paper on the
beds between the Gault and the Upper Chalk may be consulted.’

The rivers of this district are the Stour, the Little Stour, and the
Dour.

The Stour has two branches, which both take their rise from
numerous springs which issue from the Chalk escarpment of the
Weald, mostly between the Chalk and Chalk Marl, or the latter and
the Gault. The southern source of the Stour is close to Postling
Church, where a strong spring rises at about the elevation of 530
feet above Ordnance Datum. Thence it flows in a north-westerly
direction receiving various tributaries; strong springs at Horton Park,
Stouting, and Brabourne, the strongest springs in each case rising at
the level of 300 and 350 feet. The water is highly charged with car-
bonate of lime, and travertine (calcareous tufa) is deposited. Thence,
flowing westward by Ashford, it is joined by another branch, rising
near Lenham Church and Westwell, and so flowing in an opposite
direction to Ashford. Here the united streams cut through the Chalk
escarpment, and flow as oneriver between Wye, Godmersham, Chilham,

1 See Quart. Journ. Geol. Soc. vol. xlii. p. 36.
2 Quart. Journ. Geol. Soc. vol. xxxil. pp. 431.

204 G. Dowker— Water-supply of East Kent.

Chartham, and Canterbury. Here the river is fed by several strong
Springs issuing from beneath the drift gravel and clay beds of the
Stour and lateral valleys. At Canterbury, and thence towards the
Isle of Thanet, there are many springs, which rise in the alluvinm
of the valley on either side, in the form of circular deep conical pits,
which are locally called “‘ Nicker-pits”—a name of Saxon or perhaps
Celtic derivation. As the water from these pits is highly calcareous,
it probably is likewise derived from the Chalk, or flows between the
Chalk and Lower Tertiary beds. Such springs occur at Chartham
and at Canterbury, where one goes by the name of the Silver Hole,
and is situated near White Hall. It was proposed by Mr. Pilbrow,
the engineer, to utilize this spring for the water-supply of Canter-
bury. Again, at West Bere, on either side of the river, like springs
are met with.

The Little Stour, which in the upper part of its course constitutes
the Nailbouwrne, takes its rise at a very short distance from the
source of the Great Stour, at Postling Church, is derived from the
same range of hills, and has its first spring at Etching Hill, which is
about one mile south of Postling Church; thence it flows through
the Elham Valley, by Lyminge, Elham, Barham, Bishopsbourne,
and Beaksbourne, where it forms a permanent stream, flowing thence
to Wingham, through Littlebourne, Ickham and Wickham. At Wing-
ham it is joined by a branch stream fed by strong springs (‘‘ Nicker-
pits”) at Danbridge, and by another stream running along the
Tertiary escarpment by Ash towards Woodnesborough ; at the latter
place there are large ‘‘swallow-holes”’ which absorb the water from
the surface and convey it some distance underground. Passing
Wingham these streams unite their waters in the Little Stour, which
flows parallel with the Great Stour, till their waters finally unite
at Stourmouth ; from which place the Stour (formerly the Wantsum)
flows in a very circuitous course round to Sandwich, where it bends
upon itself and flows out to sea at Pegwell Bay.

The Dour, the next river, has two heads, one a little above Ewell,
at a place called ‘Little Waters,” and another southward towards
Alkham, which rises at an elevation of about 300ft.O.D. The
Alkham Valley receives the drainage of the higher hills, running as
a “ Nailbourne,” these two streams unite at River, and thence, as
the Dour, flow out to sea through Dover Harbour. The waters of the
Dour are highly calcareous, and deposit travertine. Large quantities
of this substance have been found in the Dour Valley, which formerly
appears to have received a much larger quantity of water.

To the north of Canterbury in the Tertiary area of the district the
chief stream is one which rises, in the Blean Woods near Dunkirk, at
an elevation of about 200 ft. O.D., and flows in a north-easterly
direction to Chislet, where it flows through a valley called the
Nethergong, and thence out to sea northwards by Reculver.

A similar small stream, rising near the same place as the last,
flows northward out to sea at Swalecliffe, and a third stream issues
from the Blean Woods, and flows into Whitstable Bay by the
Graveney marshes. :

G. Dowker—Water-supply of East Kent. 205

Over the Tertiary area from Deal to Sandwich are several strong
springs, which are partly used in the Delf, an artificial water-course,
constructed to supply the town of Sandwich with water. One of
these rises at Northbourne, receiving there the drainage of the Chalk
valleys which run from west to east: this Northbourne stream
empties into the Stour near Sandwich Haven. At Hastry another
similar spring occurs, flowing in a like direction, and receiving in
the same way the underground drainage from the Chalk valley
running towards Dover.

In the Isle of Thanet there are no streams of any importance; but
one occurs at “Great” and “ Little” Brooks End, and runs north-
west into the sea near St. Nicholas, while another small brook is
found eastward of Minster, emptying into Pegwell Bay; springs
issue near the “Sportsman,” and from the Thanet beds of Pegwell
Bay cliff, in these instances apparently from the Tertiary beds.

Between West Hythe and Folkestone, south of the Chalk hills, are
several springs. I would particularize those at Sandling Park and
Saltwood, taking their rise from the Lower Greensand strata, and
flowing out to the sea at Hythe. Similar smaller streams are met
with at Newington and Cheriton, while another occurs at Lymne.

By the seaboard from Folkestone to Deal many springs are tapped
by the sea-cliffs. Among these I would mention a strong spring at
Lydden Spout, which issues from the Chalk Marl, about 15 feet from
the base of the cliff, which is about 400 ft. in height. The bed from
which this water issues is No. V. bed in Mr. Price’s section, 48 feet
above the Gault... At St. Margaret’s Bay are some very strong
fresh-water springs below high-water mark.

The way in which the Chalk strata absorbs, retains, and gives out
the rainfall is strikingly illustrated in the wells and “ Nailbournes”
of the Chalk, to which I wish here to draw attention. Details of
the Petham Nailbourne are to be found in the Proceedings of this
Society for 1880.2 I have before mentioned the source of the Lesser
Stour as taking the character of a Nailbourne from Etching Hill to
Beaksbourne. After a wet season the springs rise, as is apparent
by the increase of water in the wells; those situated on the highest
level being the first to show it, then successively the springs rise
in the wells lower down the valley, till they overflow, or discharge
their waters as a periodical stream; this stream runs down the
course of the before-mentioned valley till it joins the permanent
stream at Beaksbourne. After excessive wet seasons the stream
comes from the highest level, but at other times lower down. It is
evident, however, that the water is flowing as an underground
stream long before and and after it appears at the surface. In proof
of which I would mention the following facts. After a very wet
season the stream flows all the way down the valley from Etching
Hill Pond ; at other times it flows only above ground from Lyminge
Pond; while at dry seasons it flows above the ground only low
down the valley at Beaksbourne. After some wet winters the

1 Q.J.G.S. vol: xxx. p. 431:
* See Mr. Hammond’s paper, E. K. Nat. History Society, 1880.

206 G. Dowker— Water-supply of East Kent.

Nailbourne may run for two years in succession ; on other occasions
it may not appear for two, three, or four successive years.

Matthew Beli, Esq., writes to me to the effect that in dry seasons
his ponds became dry when the Nailbourne was not running, and
being convinced that all the time at Bourne Park the water was
finding its way down below ground, he caused a trench three feet
wide to be sunk across the valley, through the underground stratum
of gravel {which he then ascertained to be about 12 to 15 feet in
thickness), into the Chalk below, and then filled this trench with
stiff puddle, forming an underground dam, The water, as he
expected, immediately began to rise, and the sheet of water opposite
his house has never been dry since. A reference to the section which
I have prepared to illustrate this paper will perhaps explain the
action of this Nailbourne better than a mere verbal description.
Tt will be seen that the beds dip at a considerable angle from south
to north; at the former the impervious beds of Chalk Marl and
Gault Clay cause the water to gravitate in the porous Chalk strata
from south towards the north. The water from the Chalk is derived
in the first instance from the rain falling on its surface. This takes
a considerable time to find its way down to the impervious bed; and,
after doing so, to spread laterally through the surrounding strata.
It is evident that when the Chalk is saturated with water, the
water-level is correspondingly raised. It happens that it is some
time after the abnormal rainfall, before it affects the water-level
of the wells, and consequently before the lower strata become
saturated with water. When this is the case, the water finds its way
out at the surface, and runs down the valley. It may at first sight
appear strange that springs should break out at Postling and Horton,
as the beds dip in the contrary direction to the flow; but if you con-
sider that the impervious beds of clay there come to the surface, and
the rainfall takes a long time to expand laterally through the Chalk,
you will understand that it will here find vent where there is the
least resistance.

An examination of the section will show also that the water-level
by no means corresponds with the height above the sea-level (a very
prevalent error). It will be seen that the water-level in the wells at
Acrise, Horton, Elmsted, and Wootton, stands at a level some two
hundred feet or more above those at Canterbury. These well-sections
are placed to scale at their respective heights, and the water-level of
the wells is shown by a shaded line. Most of these wells are dug in
the Chalk, not bored, and many of them have been deepened in dry
seasons, so that in this case the well depths represent pretty nearly
the ordinary water-level in dry seasons; for it is impossible to get
these wells sunk to any considerable depth below the point of
saturation or water-level in the Chalk. For instance, Mr. Collett, of
Elmsted Rectory, who has dug a well 277 feet deep, states: “The
springs rise and fall here in a wonderful way; they are usually
highest in May, and fall till January, when they begin to rise again.
In 1884, Jan. 13, the weil was dry, next day it rose 14 feet; the
water varies in height from 138 to 68 feet.” Mr. Metcalfe, of Upper

G. Dowker—Water-supply of East Kent. 207

Hardres Rectory, writes, “‘ This well was formerly 300 feet deep, but
failed in the dry seasons of *56 and °58, when it was deepened
60 feet. The water-level lowers in autumn from 20 to 30 feet.”

The Chalk area is by far the largest in this district, and, exclusive
of the Isle of Thanet, equals about 296 square miles. While the
area of the Tertiary beds is about 158 square miles.

The rainfall of the district is subject to considerable variation, and
more statistics on this head are needed. At Sheldwich the average
rainfall for three years 1883 to 1885 equalled 25-99 in. At Canter-
bury for 1884 it was equal to 20°83 in. At Ramsgate for three years
from 1883 to 1885 = 21-81 in. While at Horton Park I have for
1883 above 30-00 in. It must be remembered that the last three
years were exceptionally dry ones.

One inch of rainfall represents about 100 tons of water to the
acre. A portion of this is lost by evaporation, and some passes away
underground to sea; the remaining portion constitutes our available
supply in rivers and wells.

A consideration as to the permeability of different beds, and their
capacity for retaining water, will form an important element in our
calculation. We may consider the Chalk area as the most important,
not only as the chief water reservoir, but as constituting by far the
largest portion of the district, and it will be found that it is through-
out its extent extremely permeable when not saturated with water,
down to a short distance from the Gault. The large supplies of
water required for the Canterbury Waterworks, the Chartham
Asylum, the Canterbury Breweries, the wells for drinking water at
Ramsgate, Margate, and Dover, are all derived from this formation.
In the case of the deep boring for the Convict Prison at Dover, made
during this year, when strata were pierced to the depth of over 900
feet (penetrating both Gault and Lower Greensand), the water-
supply was chiefly, if not entirely, derived from the upper three
hundred feet, all in the Chalk. The time taken by the water to
reach the line of saturation in this Chalk area appears to be about
three or four months, and the height of the springs varies in propor-
tion to the rainfall.

The Chalk area is in some places capped by impermeable beds of
clay, as at Swingfield Minnis, but the clays and gravels over the
Chalk are for the most part permeable. North of Canterbury, over
the Tertiary area, the permeable beds are the sandy portions of the
Old Haven, Woolwich, and Thanet beds; the lower parts of the
latter, however, are impermeable. Above these the London Clay
and the clay and gravel beds of the Blean district are impermeable.

A narrow tract of land below the escarpment of the Chalk Downs,
stretching from Folkestone to Wye, is composed of impervious
Gault and pervious beds of the Lower Greensand. In many of the
wells, after piercing the Gault, the water flows up to, or over the
surface. In this area the water from the Sandgate beds of the Lower
Greensand is bad, being largely impregnated with iron. I have very
few data relating to the wells of this district, which is, however,
of little importance in the general survey of the water supply.

208 G. Dowker— Water-supply of East Kent.

Mr. W. Whitaker, B.A.Lond., Assoc. Inst. C.E., F.G.S., of H.M.
Geological Survey, has kindly placed at my disposal some well-
sections not before published, chiefly that of the Herne Bay Water-
works at Ford and the Whitstable Waterworks, which are in the
Tertiary area north of Canterbury. But it is not certain from these
data whether the water is derived from the Thanet Beds or the
Chalk. In the case of Whitstable, at a height of 48 feet above
Ordnance Datum, the well, 400 feet deep, pierced the London Clay
at 69 feet, the Tertiaries at 240 ft., and penetrated the Chalk 160 feet.
The water-level is stated to be 35 feet down, and the yield 220
thousand gallons daily. And in the case of Ford, reaching a total
depth of 260 feet, piercing the Lower Tertiaries at 110 feet, and
penetrating the Chalk 50 feet—the water-level standing 26 feet
down. From which facts it seems that the Chalk in both cases was
the source of the supply.

The well-sections in the Isle of Thanet, which have (with the
exception of one at Mr. Cobb’s Brewery, Margate) been’ sunk but
little below the sea-level, have only yielded water at about that
level. In the case of Mr. Cobb’s well, which reached a depth of
317 feet, no spring was met with. Artesian wells at Minster at
a low level, piercing the Thanet Bed to some 20 feet or so into the
Chalk, yielded water springs flowing to the surface.

The permeability of the Chalk in Kent was shown some years
ago by an old member of our Society, Mr. Bland, of Sittingbourne,
in some tables which he published showing how one well was
influenced by another, and how they all fluctuated with the rainfall
of the seasons. Mr. Prestwich has in his memoirs! made use of it,
and I am indebted to the Rev. C. J. Wimberley, of Sibertswold
Vicarage, for a copy of this interesting paper. His conclusions with
respect to the permeability of the Chalk have been corroborated in
all the observations I have made, and the truth cannot be too often
repeated to those who are engaged or interested in sanitary matters.
It must be of the first importance to consider this in relation to the
sewage and health of towns. Sewage matter will contaminate a
large area of Chalk, if precautions are not taken.

The section I have made would show how regularly the lower
beds dip towards Canterbury ; but if I had continued the section to
Whitstable nearly in the same line, it would be apparent that the
Gault must rise, or there would be an enormous thickness of Chalk
to be accounted for had the Gault continued at the same dip. It is
assumed that the bore at the Chartham Asylum touched the Gault.
Mr. Whitaker places the bottom of the bore at that horizon. From
the specimens I have seen at the Canterbury Waterworks, I doubt if
they quite reached the Gault. There seems also to be a slight
synclinal of the Thanet beds in the valley of the Stour east of
Canterbury—the Isle of Thanet being on an anticlinal.

It would seem as if the Lower Greensand in this neighbourhood
cannot be reckoned upon asa source of water-supply, firstly, because

1 «<The Water-bearing Strata of the Country round London,’’ and ‘‘ Manual of
Geology.”’

we - —— Gets

G. Dowker—Water-supply of East Kent. 209

the water is not good, and secondly, because there is no high land
of this formation to receive the rainfall, nor is it certain that it
would be met with in any thickness east of Dover.!

The slight anticlinal ridge of the Thanet Chalk has yielded water
for the present supply of Ramsgate, Margate, and Broadstairs ; but
in dry seasons the supply has not equalled the demand, and supple-
mentary wells have been sunk ; these, however, all derive their supply
from the exceedingly porous beds of the Upper Chalk, the wells not
reaching much below the sea-level, about which point the line of
saturation of the Chalk is there reached. From the fact that one of
these, the Southwood Waterworks near Ramsgate, became brackish
from the influx of sea-water, the engineers of these waterworks
appear to have been afraid to sink deeper in the Chalk. It is pro-
verbially foolish to prophesy unless you know; but I would
venture to suggest that the future water-supply of Thanet must be
sought for in a well reaching down nearly to the Gault. For though
there is every appearance that the whole depth of the Chalk strata of
Kent are to be found here (the Thanet beds reposing on the higher.
beds at Margate, St. Peter’s, and Broadstairs), yet there should be
no difficulty in piercing the Chalk, and I should expect an unlimited
supply of good water would be found in the Lower Chalk. Should
such be the case, there would be no danger of its being contaminated
with sea-water, if a site were chosen not too near the sea, or
directly in a line of fault. If the stratum pierced was in a state of
saturation, there would be no reason to fear that sea-water would
replace the fresh.

One great advantage of the water derived from deep Chalk strata
is its great purity, the only drawback being its exceeding hardness,
from the presence of bicarbonate of lime; this may, however, be got
rid of by adopting the admirable method employed at Canterbury, of
passing lime water in certain proportions into the fresh pumped
water, which, uniting with the excess of acid in the bicarbonate of lime
in solution, precipitates it as an impalpable powder, and at the same
time killing all organic impuritiesand precipitating them with the lime.

it now only remains for me to explain the supplementary section
and well notes which have been placed at my disposal. Mr. Bland’s
paper, already alluded to, is entitled, ‘‘ Measurements of the Altitudes
of the Hills and Valleys and the Depths of Wells through a Part of
Kent, undertaken for the purpose of ascertaining the Height of the
Springs above the Sea-level,” and referring chiefly to the Chalk in and
around Sittingbourne in the years 1827 and 1828, with the rainfall
and state of the weather from 1819 to 1829. Privately printed at
Sittingbourne. For the loan of this interesting paper I am indebted
to the Rev. C. J. Wimberley, Sibertswold Vicarage.

Notes on the Petham Nailbourne from 1772 to 1869. Communi-
cated by Mr. James Reid, of Canterbury. ‘The Nailbourne came
into Shamford Street, Feb. 22, 1772, and continued to run through
the street till June 16, 1772. It came into the street again, March
7, 1774, and continued running till June 28, 1774. It came into

1 See section in Mr. Whitaker’s paper, Quart. Journ. Geol. Soc. vol. xlii. p. 36.

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212 Col. McMahon—Granite of the Himalayas.

the street again Jan. 12, 1775, and again Feb. 26, 1776. This
Nailbourne ariseth at Dean, in the parish of HElmsted, and at Duck
Pit in the parish of Waltham. This by Thos. Page.” From other
data this Nailbourne ran in Jan. 1860, Feb. 1861, 1864, to June,
1865, and slightly in 1866, 1869, and Jan. 18753.

Notes on a Well at Elmsted Vicarage. Communicated by Rev. G.
A. Collett. “This well was sunk in the Vicarage garden in 1884, at
an elevation of 500 feet O.D. Water was first reached at 180 feet.
Waiting for this to lower, the well was continued to 243 feet, where
a good head of water was met with. The strata met with were firstly,
11 feet of diluvial matter, stones, clays, etc., called locally ‘ clay
pillars.’ All below this, Chalk without flints, with joints few and
far between, the Chalk so hard that it had to be blasted with gun-
powder, no need to ‘steen.’ We sent up at 58 feet some palatal teeth
of fish, and lower down fragments of Inocerami. Below 220 feet
the Chalk was more jointed and easier worked. The springs rise and
fall here in a very wonderful way, they are usually highest in May
and fall till January, when they begin to rise again. In December,
1884, I ran my well dry, but kept sounding it in January, 1886,
expecting water. On the 13th it was dry, next morning I found
fourteen feet of water, which soon increased to 40.”

In the tabulated list of wells appended, I have given the height
above O.D., the depth of well, and the water-level (where this
information is given), but in most cases, especially in bored wells,
the latter is not very conclusive. For other particulars of well-
sections I must refer my readers to the Memoirs of the Geological
Survey, vol. iv. pt. 1, by Mr. W. Whitaker, B.A., F.G.S., and the
Quarterly Journal of the Geological Society, vol. xlii. p. 26. I have
confined my observations chiefly to the water supply.

I am indebted to those gentlemen whose names appear in the
Appendix of Well-sections (p. 211) for much valuable information.

II].—Tue Gneissose-GRANITE oF THE HIMALAYAS.
By Colonel C. A. McManon, F.G.S.
Introduction.

YHE cause, or causes, which result in the foliation of igneous
rocks is a subject which at present occupies the attention of
many geologists, and seems likely, in the near future, to lead to some
discussion. In view of this, a short account of the foliated granite
of the Himalayas may be of interest. It may be as well, however,
to preface my remarks by saying that I believe that foliation may be
produced in several distinct ways, and the explanation which I offer
of the mode in which the foliation of the Himalayan granite has been
brought about is only intended to apply to the case of that granite.
Tn the following pages I propose to give a brief summary only of
some of the more important results worked out in detail in a series
of papers published in the Records of the Geological Survey of India;
and to add thereto a brief consideration of the question whether the
foliation of the gneissose-granite of the Himalayas was, or was

Col. McMahon—Granite of the Himalayas. 213

not, produced by pressure-metamorphism, a point not touched on in
my published papers.

As the Himalayas cover a large area, I shall limit my remarks
almost exclusively to the rocks in the neighbourhood of Dalhousie,
a sanitarium in the mountains nearly due east from Lahore, the capital
of the Panjab. Want of space obliges me, however, to make my
observations on the stratigraphy extremely brief. Any one requiring
more detailed information will be able to find it in the volumes of
the Records of the Geological Survey of India.

In the neighbourhood of Dalhousie the gneissose-granite appears
in two bands striking in a north-westerly direction. The inner
band at Dalhousie itself is six miles and a half in thickness;
further to the south-east the thickness increases to eleven miles,
and this broad belt extends for some hundreds of miles in a south-
easterly direction. In its north-westerly extension from Dalhousie
the band suddenly contracts to a width of two hundred and fifty
yards: but twenty-one miles further on it expands again as abruptly
as it contracted.

This outcrop is in contact along both margins with Silurian rocks ;
those along its eastern margin being older, and those along its
western margin younger Silurians. The interpretation which I
have put on this section is that the granite has risen through the
axis of a flexure that resulted in an overfold fault.’

The outer band of gneissose-granite, roughly speaking, runs a
course parallel to the western margin of the inner band, being
divided from it by a broad belt of Silurian beds. To the south of
Dalhousie it dies out altogether. Its general width is between four
hundred and five hundred feet; but to the north-west of Dalhousie
it widens out to several thousands of feet in thickness. Along its
eastern margin it is in contact with Lower Silurian, or Cambrian,
mica-schists (no fossils have ever been found in them, so their precise
age cannot be determined); and along its western margin with
limestone and slaty beds of Carboniferous age. The latter are not
greatly altered rocks; the limestones are never more than sub-
crystalline; and though the slaty rocks have often a thin micaceous
glaze, they are sometimes shaly in appearance ; and are frequently
so highly charged with carbonaceous material, and so coal-black
in colour, that they have from time to time, in various parts of the
Himalayas, raised fallacious hopes of finding coal in the minds of
non-geologists.

The strike of the Silurian and Carboniferous beds conforms to
that of the granite, following all its curves. The beds in contact
usually dip into the granite ; but occasionally dip away from it.

The Gneissose-Granite.
The gneissose-granite is almost always decidedly porphyritic,
though it occasionally passes into a fine-grained non-porphyritic rock.
The matrix is usually a granite of moderately large grains (it is

1 A geological map of the Dalhousie area and diagrammatic sections explaining it
will be found at page 110, vol. xviii. Records Geol. Survey of India. .

214 Col. McMahon— Granite of the Himalayas.

never coarse-grained), but occasionally it becomes so extremely fine-
grained that the rock assumes, to the unaided eye, the appearance of
a felspar porphyry. In the perfectly granitic varieties the porphyritic.
crystals of felspar, which sometimes attain a length of from three
to three and a half inches, orient in all directions, and present
sharply rectangular forms. From the porphyritic-granitic and non-
-porphyritic-granitic varieties the rock passes by gradual transitions -
into a more or less foliated granite. The passage from one variety
to the other is often apparently capricious; but even in the most
perfect granitic masses a tendency towards foliation may generally
be observed at its edges.

Speaking generally, the granite of the inner outcrop is foliated
along both margins; and the foliation becomes intense where the
band contracts, on the north side of the river Ravi, to a width of
two hundred and fifty feet. At this point it passes, on its western
margin, into what, from its macroscopic aspect, would be called a
mica-schist.

The outer band of gneissose-granite is intensely foliated. It does
not indeed pass into a mica-schist; but it not unfrequently looks,
viewed macroscopically, as if it had been flattened under a steam
roller.

Joints are abundant; and they frequently simulate bedding; but
true bedding is not to be seen.

The granite is composed of orthoclase, plagioclase, microcline,
quartz, biotite, and muscovite. In some localities biotite pre-
dominates—in others muscovite. Magnetite, garnets, and apatite are
sometimes present; whilst schorl is rarely absent from the granitic
varieties. The presence of ilmenite may also be inferred from the
occasional existence of leucoxene. ~

Mircoscopic characters of the Gneissose-Granite.

Under the microscope the granite yields abundant evidence of
strain, pressure, and shear or traction. The twinning planes of the
triclinic felspars are sometimes bent ; felspars are frequently cracked,
fractured, and occasionally the pieces are pushed over like books on
a shelf; whilst crumpled micas may be seen which have been com-
pletely bent and one end folded over on the other like a sheet of
note-paper preparatory to being placed in an envelope.

A prominent characteristic of every variety of the Dalhousie
gneissose-granite, even the most granitic, is the presence of what I
have called in my papers by the short term of crypto-crystalline
mica. -It is mostly a form of muscovite, though the imperfectly
crystallized material of biotite is occasionally present in ropy masses.
This crypto-crystalline mica varies from a pale-buff to a pale-grey
colour, and it has a superficial resemblance to the base of some
felsites and rhyolites. In its typical form, though its double refraction
is strong, no definite crystals of mica can be made out; and the
leaflets, under polarized light, melt into each other and exhibit no
definite shape. This crypto-crystalline mica passes into a micro-
crystalline condition, in which the leaflets, though of extreme micro-

Col. McMahon—Granite of the Himalayas. 215

scopic size, have a distinct individuality of their own. Both varieties
will, in the following remarks, be referred to under the term erypto-
crystalline mica.

This crypto-crystalline mica is present in all varieties of the
Dalhousie granite. It is to be seen in every thin slice under the
microscope ; and in the foliated specimens it traverses them in
strings ; sometimes extremely attenuated; at other times widening
out into comparatively broad lake-like expanses. It does not run in
straight lines, but flows in curves like those of rivers on a map ; now
approaching each other; now diverging widely ; bending sharply at
one turn, and making a wide sweep at another. It frequently leads
up to, or embraces in its streams, large crystals of muscovite, quartz
grains, and other minerals; and it occasionally traverses large
felspars. I shall have to allude to this crypto-crystalline mica
further on.

Another striking characteristic of all varieties of the Dalhousie
granite is what I have termed in my papers fish-roe quartz; that is
to say, quartz in grains of microscopic size clustered together in a way
to suggest the roe of a fish. This polysynthetic or fish-roe quartz
behaves very much as the crypto-crystalline mica behaves; that is
to say, in the foliated specimens it flows about in streams round the
larger minerals ; fills the interstices between larger grains of quartz ;
and stops the fractures in felspars. I shall have to allude to this
further on.

The most important questions which arise in connection with the
rock above described are: Is it an igneous eruptive rock? and if so,
was the foliation produced prior. or subsequent, to its final consolida-
tion? I propose to consider each point separately.

Evidence of the eruptive origin of the Gneissose- Granite.

In the first place it seems necessary to meet the objection of those
who may be disposed to hold the view that it is an ancient, possibly -
Pre-cambrian rock, which suffered erosion before Silurian times.
It would be impossible to discuss this position in detail in a brief
article that only proposes to give the results of the author’s investi-
gations ; but I may say that I carefully considered this point in the
field at a time when I had formed no theories about the Dalhousie
rock in my own mind, and that I could not discover any evidence
to support it. Two considerations seem to offer serious obstacles to
the acceptance of this theory. In the first place, erosion which
reduced the gneissose-granite from a thickness of eleven miles to
that of two hundred and fifty feet would hardly have left a long
stretch of this slight thickness without having cut through it alto-
gether ; secondly, if this crystalline rock represents an ancient and
eroded land-surface, the granite to the north of the Ravi, where its
thickness is only two hundred and fifty feet, ought to be a fair sample
of the granite two or three miles to the south of the Ravi, where
its thickness is six miles and a half; but, on the contrary, the former
is a much more intensely foliated rock than any portion of the latter.
The thin band of granite north of the Ravi has evidently been sub-

216 Col. Mc Mahon—Granite of the Himalayas.

jected to much more intense squeezing than the massive portion,
and field observations favour the conclusion that the intensity of
the foliation and the narrowness of the outcrop are directly connected
with each other.

Without pausing to discuss this question further, I pass on to
state briefly the evidence which the rock presents of eruptive
origin.

Stratigraphical evidence.—First, the granite has produced a certain
amount of contact metamorphism on the rocks touching it. The
slates exhibit a marked increase in induration and they pass more
or less into a crystalloid condition as they approach the granite.
Schorl, garnets, dark mica, muscovite, and magnetite have been
formed in the slates by contact action; foliation has sometimes
resulted from that action—at other times “spotted schists” have
been formed.

Secondly, tongues and intrusive veins have been sent from the
granite into the adjoining rocks: in other places the granite appears
in sheets between the beds of the sedimentary rocks at some distance
from the junction of the latter with the main mass of the granite ;
and in some cases these sheets, or dykes, have cut through the beds
and passed from one horizon to another.

Thirdly, the main mass of the granite appears at different geolo-
gical horizons.

Fourthly, the granite contains veins similar to those caused by
shrinkage on cooling in granites of admittedly eruptive origin.

Fifthly, it contains fragments of slates and schists imbedded in it.
A striking photograph, or rather a print produced by the helio-
gravure process from a photograph, of a schist enclosed in the main
mass of the granite, half a mile from its contact with the slates, will
be found at p. 175, Records Geological Survey of India, vol. xvii.
(with a paper thereon ); which, in conjunction with the evidence
afforded by the microscope, completely sets at rest any doubts that
might have existed, previous to the discovery of this specimen, as to
whether or not these inclusions are true fragments of foreign rocks
caught up in the granite. .

Microscopic evidence.—The evidence afforded by the study of
numerous thin slices under the microscope confirms the conelusion
arrived at by the stratigraphical evidence, and indicates the eruptive
origin of the gneissose-granite. I select the following instances for
enumeration :—

First, the presence of microliths containing contraction cavities
precisely similar to those in microliths to be seen in undoubted erup-
tive rocks. As an illustration I would point to fig. 11 of the plate
at page 158, Records G.S.I. vol. xvi., which gives the sketch of a
microlith seen in one of the Aden lavas, but which serves equally
well as an illustration of some of those seen in the gneissose-granites ;
vide Records G.S.I. vol. xvii. p. 60.

Secondly, cracks in microliths formed by contraction on cooling.
In some cases the fractured portions have been floated to a little dis-
tance from each other. Fig. 5 of the plate at p. 72, Records G.S.L.

Colonel McMahon—Granite of the Himalayas. 217,

vol. xvii. affords a striking illustration of a microlith thus ruptured.
Cracks of the character alluded to do not in any case extend from
the microlith into the matrix.

Thirdly, opacite embracing and riding on the backs of previously
formed microliths. As illustrations I would point to the right-hand
figure of fig. 6, plate ii. p. 144, vol. xvi., compared with fig. 13 of
plate at p. 158, vol. xvi. Records G.S.I. The former is a representa-
tion of a microlith in a Himalayan gneissose-granite, and the latter
of one in an Aden lava. The last-mentioned illustration could be
exactly matched by numerous illustrations from the gneissose-granites.

Fourthly, stone cavities,’ in which mineral matter has been depo-
sited on cooling. Compare fig. 18, plate, p. 72, vol. xvii. (a
Dalhousie specimen) with figs. 4 to 10, inclusive, plate, p. 158, vol.
xvi. Records G.S.I., Aden lava specimens. The presence of clusters
of minute microliths sticking to and fringing the outside of the
Dalhousie stone cavity shows conclusively that this is not a case of
schillerization.

Fifthly, stone cavities in which either crystals have been deposited
on cooling, or in which mineral matter has caught up and enclosed
previously formed crystals. Illustrations, figs. 1, 6, and, possibly,
the upper portion of fig. 18, plate, p. 72, vol. xvii. Records G.S.I.

These instances, which are selected by way of sample of the kind
of evidence applicable, indicate I think that the gneissose-granite at
one period of its history was in a condition of what may be termed
—roughly speaking—igneous fusion. That water was, however, to
a considerable extent mixed up with the constituents of the rock
when it was in a plastic state, and that its condition may be more
correctly described as one of igneo-aqueous fusion, is made plain by
the examination of thin slices under the microscope. Liquid cavities
abound in the quartz of the granite; whilst, it is important to observe,
they are entirely absent from the slates in contact with it. The heat
produced by contact with the granite appears to have been sufficient
to drive the water out of the quartz of the slates and of the siliceous
rocks brought within its influence. An interesting illustration of
this was afforded by an examination of the crystals of schorl found
in the slates in contact with the granite. When these crystals were
first formed, they appear to have contained inclusions of air, gas, or
liquid ; but as the heat increased, and the included matter expanded
under its influence, the included gas, or liquid, was forced out to the
surface of these crystals and driven off. An interesting illustration
of this will be found at fig. 7, pl. ii. p. 144, vol. xvi. Records G.S.1.

Cause of the foliation of the Gneissose-Granite.

A realization of the eruptive character of the rock described in
the above pages removes many difficulties from the way of the
Himalayan geologist. “Despite the wonders performed by flexure
of strata in mountain regions,” wrote Mr. Medlicott, the Director of
the Geological Survey of India, in his Annual Report for 1883, “the

1 This is an awkward term; but, as it was introduced by Sorby, I retain it: micro-
scopists know what it means.

218 Colonel McMahon—Granite of the Hi imalayas.

structural features presented by this rock in certain cases were
impossible of satisfactory explanation on the supposition of its being
a really stratified gneiss.” But if the eruptive origin of the gneissose-
granite be admitted, the further question arises whether the foliation
observed in it was produced prior, or posterior, to the consolidation
of the rock. In considering this question, I leave out of sight
altogether evidence of fluxion structure as being really irrelevant
to the question at issue, though I think it material to state that the
rock does show very decided evidence of fluxion. Without laying
any stress on this fact, however, I think the following consider-
ations prove that the foliation was not produced by pressure acting
on the rock after its consolidation.

First, the granite is not always foliated at its contact with the
rocks into which it has been intruded ; on the contrary, though still
porphyritic, it is not unfrequently decidedly granitic along its margin.
This fact presents no difficulty to the acceptance of the hypothesis
advocated below, but I think it offers an insuperable barrier to the
acceptance of the view that the foliation was produced by pressure.
Simple pressure will not do: that would not explain the crumpled
micas and the very decided evidence of flow or fluxion. Pressure
resulting in shear, motion, the development of heat and concomitant
chemical and mineralogical action, might possibly account for the
fluxion structure; but if shear and motion were established on the
grand scale required after the consolidation of the rock, the granitic
portions along the margins could not possibly have escaped the effects
of this action.

Secondly, the apparently capricious passage from a granitic to a
foliated structure in the main mass of the granite is another serious
impediment in the way of the acceptance of the theory of dry
pressure.

Thirdly, the conjunction of the outer band of gneissose-granite at
Dalhousie with the Carboniferous series presents another almost
insuperable difficulty. The outer band is the most intensely foliated
of all the Dalhousie granite. Parts of it look as if it had been
rolled under a gigantic steam roller. Unquestionably it has been
subjected to very great pressure, and to either traction, or shearing ;
and yet this rock is chock and block with little altered black Car-
boniferous rocks. He who would apply the dry-pressure theory
to explain the intense foliation of the outer band of granite, would
have to invent a new set of conditions out of his imner conscious-
ness and bring some other rock into position next the granite before
he applied the squeeze.

Fourthly, the condition of the long tent-peg-like splinter of
schist included in the granite, alluded to above, shows conclusively
that the granite at the point where the inclusion was found was not
subjected to extreme pressure of the character under consideration
after its consolidation. Had it been, the splinter of schist would

1 T use this expression as a short term to indicate pressure applied after the con-

solidation of a rock, though, of course, I am aware that pressure so applied may
produce heat and even fusion.

Colonel McMahon —Granite of the Himalayas. 219

have been flattened to a wafer. A mere glance at the plate, a photo-
graph reproduced by the heliogravure process, will show this at once.

Fifthly, neither the crypto-crystalline mica, nor the fish-roe quartz,
described ante, can possibly have been produced by the grinding
down of the mica and the quartz in the consolidated rock, or by any
analogous process; for, besides the crypto-crystalline mica, and the
fish-roe quartz, we have very numerous large crystals of muscovite,
biotite, and quartz. The muscovite and biotite are large and beauti-
ful specimens of these minerals, and they orient in ail directions and
at every angle up to a right angle to the strings of crypto-crystalline
mica. Mechanical action potent enough to have reduced mica to the
pulpy condition of the crypto-crystalline mica would not have left the
larger micas untouched. Similarly, the fish-roe quartz not only fills
cracks in felspars, and forms a sort of setting to quartz grains, but
it meanders about in the interior of large quartz grains, and termi-
nates abruptly inside them, in a way that does not suggest to the
observer that he is looking at cracks stopped with micro-crystalline
quartz, but rather that the crystallization of the quartz was brought
to a comparatively rapid termination towards its close.

Indeed, properly considered, I think the crypto-crystalline mica,
and the fish-roe quartz, furnish a clue to the riddle. I may mention
in passing that I have observed ina felsite patches of material closely
resembling the crypto-crystalline mica mixed up with the quartz and
the ordinary felsitic base; but I desire more particularly to refer to
a series of rocks which occur in the peninsula of India about eighty-
five miles nearly due west of Delhi. We have there a very interest-
ing group ranging from felsites, quartz-porphyries, and granite-por-
phyries to almost true granites. The felsites appear to be true lavas ;
and: the others, though merging gradually into rocks of plutonic
character, are probably more or less directly connected with them.
These rocks never show any trace of foliation, or give any indication
of crushing. But what is important to note is, that the gradual
genesis, so to speak, of the fish-roe quartz may be observed in these
rocks. The quartz gradually becomes more and more developed in
the felsitic base ; it begins to crystallize out in grains of microscopic
size, and the grains increase in number, until at last the whole base,
or ground-mass, of the granite-porphyries partakes closely of the
characters of the fish-roe quartz of the Dalhousie granite. The true
explanation of the foliation of the latter rock I believe to be briefly
as follows :—The rock had partially consolidated before it was moved
into place: large porphyritic crystals of felspar, and numerous micas
and quartz grains had formed ; it was very much in the condition of
a felspar-porphyry, or a granite-porphyry ; when, in the course of
the earth-movements that were contorting, crumpling, and folding
the strata of the Himalayas, this imperfectly consolidated granite-
porphyry was forced through the faults that had been formed along
the axes of over thrust-folds; the semi-plastic mass was subjected to
enormous pressure; the mica was crumpled; the crystals of felspar
were cracked and ruptured ; and so much of the micaceous siliceous
materials as remained unconsolidated were forced into the rents made

220 J. H. Collins—Cornish Serpentinous Rocks.

in the already formed minerals. The final consolidation took place
under conditions of continued strain; but before it was actually
accomplished minor and subsidiary eruptions took place which
forced new supplies of the granitic material into fissures formed in
the previously injected rock, and this fresh material consolidated under
conditions somewhat different from those of the first eruptions.

I think this view meets all the difficulties of the case, and that the
intelligent reader will with its aid be able to harmonize all the facts
stated above without detailed exposition on my part.

IV.—On THE Geronogican History or THE Cornish SERPENTINOUS
Rocks.

By J. H. Cotttys, F.G.S.
(Continued from Grou. Mag. Decade III. Vol. III. 1886, p. 366.)

III. Rocks Exursitine put A Moprrate Amount oF SERPENTINOUS
CHANGE.

Botallack Mine.—-The dark hornblendic slates of the sea-border of
the parish of St. Just are known to many geological tourists. They
have been well described by the late Mr. J. A. Phillips,! who regards
them as consisting of altered killas; and the justice of this conclu-
sion will not I think be questioned by any who have studied the
rocks in situ; traces of an original lamellar structure are visible even
in hand-specimens. Phillips (op. cit. p. 322) gives the following
analyses of the rock, a being from near the surface, and 6 from a
depth of 180 fathoms, or far below the sea-level; while c is the
analysis of atypical Cornish killas (from Polgooth Mine, 100 fathoms
from surface) : —

a. 6. Cc.

hygros. °39 4-12 200 ?
Water Se ang | 3-13 a L 11-09 { ae 3-26
STINGER DE Ane hares Mare aman ie S26 | 4\())292) ee ee 32°98 50°92

Phosphoric acid ............... BOO) po alias sisted TEACE eee —
INGTON EXCL osccneadcnsadoscecce O15) Sees tracey. oe trace
AUT Aeon ota cc acon (ease eeee QAO vo tcans Oe) eens 20°79
Ferrous oxide: ...........-..06: ILL °73 (ha RE LST ees 4-92
Ferric oxide ..............000. 4hoS CEUs irs TW — sascee 13°41
Times (etic escsceaee cette nee AD re... vader ees A*Q90, yescnteg 1°62

WAGIESEY ssoqguqsacoduasadenguescs GOD es cicinssains 113520 - Asa —
POhASht ss eee occ ase een ere GY |e Locrecaemee hoe Aare 93
NOGAe: wecnstee caerenece eee SO, WaMecsccesa 763°) OL A 4:08
99-52 99°31 99-938
Spe Gry acerca ease 2°95 2°82 2°73

Evidently a and b are ina highly-altered condition; but assuming
that they were originally of similar composition, approximating to e,
it would seem that the deeper-seated rock has been much more
altered than the other in the direction of serpentine ; it is also softer,
lighter, and more serpentinous in aspect. The following is its
appearance under the microscope, as stated by Mr. Phillips or as

1 Quart Journ. Geol. Society, 1875, vol. xxxi. pp. 319-343.

J. H. Oollins—COornish Serpentinous Rocks. 221

observed by myself. The base is green and transparent; it includes
many minute acicular or fibrous crystals of hornblende or asbestos
crossing each other in all directions, some in bundles with parallel
axes, as if from the partial destruction of a cleavable crystal. In
some instances the hornblendic bundles are replaced by a greenish
mineral which is possibly chlorite, and there is always present more
or less crystalline magnetite. Mr. Phillips says, “It is worthy of
notice that while the slates of Botallack are highly magnesian, the
sea-water which percolates through them into the workings of the
mine has lost three-fourths of its magnesium. Similar effects
appear to be produced at Huel Seton, where the amount of magnesia
in the rock bounding the great cross-course, which is traversed by
the modified sea-water constituting the well-known ‘lithia spring,’
is twice as large as it is in the normal killas of the locality. The
magnesium of the sea-water has in this case almost entirely dis-
appeared.” !

Terras, St. Stephens.—This is a band of dark and fine-grained
rock used locally for roadstone, which is not marked on the 1-inch
Geological Map. It is very tough, and often platy in character,
owing to an incipient pseudo-cleavage which I take to be an indica-
tion of an original bedding now almost obliterated. It has all the
appearance of a compact hornblende schist. Thin veins of an
asbestiform mineral are often seen in the joints, and occasionally the
fibres of this mineral are so interlaced as to result in a kind of
*‘rock-leather”’ or ‘“‘ rock-felt”? sometimes as much as half an inch in
thickness. Some of the joints, however, are lined with thin films of
serpentine, and in such cases the rock itself exhibits serpentinous
change to a depth of an inch or more, so as to be almost indistinguish-
able from the Botallack rock above referred to. In thin sections,
and under a moderate magnifying power, it is seen to be made up of
a transparent greenish serpentinous base full of matted crystals of
hornblende. The original laminar character of the rock is indicated
by many crystals of magnetite and minute patches of viridite.
Occasionally, too, fibres of asbestos are visible, and, rarely, minute
prisms of apatite.

I made a partial analysis of this rock in 1872, with results as
follows :—

HOSSOMPISTULLOTIN eee eeeP ERE EEEEE eee sdsee cea seccesee 92
SiC aie oS... iene ee RR eee sais c acs nese otlncdes 45:20
PAVING, (2,2 eer eee ECR ER Eh cic <eawcceesseaceki 19°80
Ma gNetite” sets. asec ee eee sciecses nace stsiens caste 5°01
Herr Ous{OXtd E)i he eaee MRR E RE eey ter eek hes 7°35
1 DIBOTY OB IPR RB ance Gcconb obs cosococ CALC ere RRR RTE EEE Eee 8°00
IETS TESTE NE mond} ppcaccbqcood ponec eb ag cee REE EE eR eReeen 6°20
Not) determine dia PeMeeeee a... cetccssccesdeseaeee 7°52

100-00

A very similar rock, probably an extension of the same bed, was
opened up some years since at Terras Mine, and described by Mr.
J. A. Phillips as a greenstone (Q.J.G.S. vol. xxxii. p. 175).

1 Loe. cit. See also “ On the Composition and Origin of the Waters of a Salt-
spring in Huel Seton Mine,’’ Phil. Mag. July, 1878.

222 J. H. Collins—Cornish Serpentinous Rocks.

At this locality I obtained in 1872 a number of interesting crystals
of pharmacosiderite, scorodite, and olivenite, which were noticed in
the Mineralogical Magazine, vol. i. pp. 16 and 17. I regard this
rock asa slightly serpentinized and otherwise much altered horn-
blende schist.

St. Cleer Downs.—On these downs there are several broad bands
of hornblendic rock, mostly lying in the line of strike of the asso-
ciated slates, and graduating in places into them. The chief mass
extends about one mile from east to west, and nearly half a mile from
north to south, dipping to the south-south-west. It is usually more
or less decomposed, and in a quarry now filled up near the church,
asbestos in fine silky fibres was obtained by Canon Rogers in 1818.

Mr. J. A. Phillips gives the first two of the following analyses of
this rock : !—

a. Slaty. b. Crystalline. c. Selected.

Water sk. ccmances cman O53) 0. asos6deee 190s Getiseemenee 7:8
ila a eacesmace cee Ey Gy:E «) SR a eeeeee B32: my eeenek 42-2
JNiusantit, — Seecbosn0600 2 32S OMe ea. sc s.6 TSO) Oo ce eeasanae 76
Ferric oxide ......... DCA: | ana Gedits (? caelmeaeee 41
Ferrous oxide......... AC SAAN mocaccacss TT), 4 has. ee }
Tin mene sa eee SOMO Weenee bas SeQa ol) sss esteee 3:3
Magnesia ..........68 DOU Mpg acces a's EOD It) Sateen 33°6
Potash and Soda ... 95:06 ......... 3°80) eee eee oF

99-93 100°34 99°3

S105 (CER caoceasne 25S O Meee ic oe 2°90

e is an analysis of selected portions by myself.

Both a and 6 contain free quartz—hence the high percentage of
silica. This rock seems to be a partially altered hornblende slate,
or else an altered diorite; but the serpentinous change has not
proceeded very far. I have often seen thin films of serpentine in
the joints, and by breaking up masses of the more highly altered
portions of the rock, and selecting the more serpentinous grains, I
have obtained a substance with the composition given inc. The
relative proportions of silica, magnesia, and water in this are pretty
near what they are in pure serpentine, if we consider that it was.
impossible to completely separate all the crystals and grains of
magnetite, fibres of asbestos, crystals and grains of unaltered or
partially altered augite, felspar, hornblende, ete. The approximation
is indeed remarkable if we compare the analyses given of the general
rock-masses.

Under the microscope, using a low power, it seems to be composed
of a green fibrous granular ground-mass, filled with distinct fibres
of asbestos ; the ground-mass is very slightly dichroic, and includes
some crystals and grains of magnetite, with some irregular masses
having ill-defined and shadowy boundaries, which I think are highly
altered augite. Using the 1” power, the ground-mass is resolved
almost completely into a network of fibres, while the magnetite
appears as a congeries of rounded grains. In some instances horn-
blende crystals are seen, which appear to be changing very slightly

1 Quart. Journ. Geol. Soc. 1878, vol. xxxiv. p. 487.

J. H. Oollins—Oornish Serpentinous Rocks. 223

into asbestos. The following is an analysis of some of the larger
asbestos fibres carefully separated :—

Silica? ye eae eeeer kei ccsccbees Clea 45-22
Alumina and a little Ferric oxide ...... 30°09
Lime Be eee esa ga odeak aie 8:00
Midoniesiat a.m aeceeee aries s oct) isis esciele aise 10°19
Potash! oc - 1s cee een eas a caiace seca 1:12
"Wiaterih eee Mee Meee nel esicceeis selcuees 5°20

99°82

Tregerla.—This rock, which occurs in the neighbouring parish
(Menheniot), and under very similar conditions, much resembles the
preceding.

Catacleuse.—This is a somewhat altered dolerite which has been
extensively used in North Cornwall for the ornamentation of ancient
pulpits, fonts, etc.; and the interesting tomb of Prior Vivian in
Bodmin church, which has been so well described and illustrated
by the Rev. W. Jago in the “Journal of the Royal Institution of
Cornwall,” is made of it. It is only slightly serpentinous, yet the
change is distinct, especially near the joints, and in the less compact
masses. It is often mistaken for Polyfant stone,’ but it is much
harder. The following are analyses of the rock,—l, of an ordinary
mass; 2, of a fragment specially selected as being more highly
altered than usual :—

1 2

SILT CAN tee sec oe sacs oa eae e oe A596) 1) uate eases 40°38
PAU IMINI AY Ae ei wwckhaneseeeeeee OSODQ I Acasa 10°2
Herrous OXIME) ..i..002) soseeeeee (Gea a MARE Nos Aascac 4°5
IFlerrichOxIde) s2.2sassoedeenees BeOS d vem saee. see cee WAH
AIGITIMVG D5 scan ese dooce cee Geshe oersoscecuaaee 5:0
IMiomesia’ .U.a..ovesseencomtene B44 ues aietdenste 23°5
AW GIG AAPA SEE Ea daincoosoc D2.0 | WPS OEE ae 5°4

100°37 101-6

Here in 1 serpentinous change is hardly if at all recognizable, while
in 2 serpentinous matter exists to a very considerable extent.

Altered eruptive rocks exhibiting serpentinous change occur in
a great many other localities in North Cornwall, and especially at
Cant Hill near St. Minver. My acquaintance with the rocks of this
district dates from the year 1871, and I can quite confirm the
observations made by Mr. F. Rutley in his paper. He gives the
following examples from this locality :—

No. 1. Eastend, at top of hill—“ bands and small knots of felsitic
matter (microcrystalline), separated by bands of translucent greenish-
yellow or brownish-yellow serpentine,” also “a thin vein of greenish-
yellow to brownish-yellow serpentine which is traversed by opaque
rust-coloured strings,” the bands and the vein being continuous.
We seem here as in many other instances to have evidence at once

1 See Grou. Mac. Dec. III. Vol. IIT. 1886, p. 365.
2 Eruptive Rocks from the Neighbourhood of St. Minver,’’ by F. Rutley, F.G.S.,
Quart. Journ. Geol. Soc. 1886, vol. xlii.

224 J. H. Collins— Cornish Serpentinous Rocks.

of “segregation” and of “selective metamorphism” in one and

the same slide, the result in each case being serpentine.’ .

No. 2, same locality. Here the serpentine is associated with
chalcedony and “‘a yellowish-white matter, apparently kaolin.”

No. 4, same hill, west end. Here there is ‘a large proportion of
serpentinous matter ; so large, indeed, that by burnishing a smoothly-
cut surface of the rock with an ivory paper-knife, a fairly good
polish can be communicated to it. When we examine a section of
this rock under the microscope, we find some of the original glassy
basis has to a large extent been converted into serpentine, especially
along lines which seem to indicate fluxion-structure. There is in
addition to the serpentine a large proportion of kaolin present.”

Nos. 5 and 6, east side, foot of hill. These also contain a very
considerable admixture of serpentine; and the author concludes—
“There seems then no doubt that the upper portion of Cant Hill,
which has been mapped as ‘Greenstone,’ is really composed of a
basic lava of a once vitreous character, but so altered that its original
mineral constitution cannot be inferred with precision.” * Mr. Rutley
goes on to speak of the occurrence of serpentine in other eruptive
rocks in the locality, and especially at Carlion near Cant Farm. .

The occurrence of kaolin in Nos. 2 and 4 connects them with the
Duporth rock already referred to,* where also very extensive kaolin-
ization of felspathic matter has taken place.

TV. Exampies rrom DErvonsHIreE.

Greston Bridge.—The serpentinous rock of this locality is figured
(No. 27) and described by Mr. Rutley in his excellent account of
the eruptive rocks of Brent Tor, which is published at a prohibitive
price by Her Majesty’s Stationery Office. It is very incompletely
serpentinized, and no analysis has been published or made so far as
I know. A similar rock exists at Dunterton.

Anstey’s Cove, near Torquay.—This is a coarsely crystalline rock
of a dark green colour, and consists of augite, small prisms of triclinic
felspar, apatite and magnetite. Some of the augite is but slightly
altered; there is a little pale-green serpentine disseminated through-
out the mass. In some parts it is very largely serpentinous,
much more so than the specimens which Mr. Allport describes would
appear to be. The rock occurs distinctly as a dyke cutting through
Devonian rocks. No analysis of the rock has been made to my
knowledge.

1 In a note Mr. Rutley says: ‘‘ Prof. Bonney, who favoured me with an opinion
upon these sections, regards much of the substance which I have here called
serpentine as a palagonitic material.” But palagonite is a constituent of recent
volcanic tufa, and hardly likely to be found in so old a rock as this. Moreover, it is
fusible, while this mineral, like serpentine, is very infusible. Further, Mr. Rutley
says the serpentinous matter has a hardness of 3 or slightly less, while the hardness
of palagonite is from 4 to 5.—J. H. C. .

2 Op. cit. p. 397.

3 See Groz. Mac. August, 1886, p. 362.

4 Allport, ‘‘ Metamorphic Rocks surrounding the Land’s End Mass of Granite,”
Quart. Journ. Geol. Soc. 1876, vol. xxxil. p. 423.

J. H. Oollins—Cornish Serpentinous Rocks. 225

Babbacombe Bay.—This, like the last, is intrusive in Devonian
rocks. ‘There are here two principal varieties of dolerite—one
rather fine-grained and of a uniform grey colour; the other of
a lighter shade and porphyritic texture, having conspicuous crystals
of felspar scattered through it. Both varieties are highly altered ;
the secondary products are serpentine and calcite.”! Much of the
original augite of this rock seems to have been converted into
hornblende, as in cases already mentioned. No analysis of the rock
has been made.

Serpentinous change has been observed in a great many other
localities within the two western counties, but probably these will
suffice as illustrations.

The methods of the changes which have taken place in these various
rocks have been already adverted to (Gron. Mac. 1885, Dec. III. Vol.
II. pp. 298-802). It would occupy too much space to discuss these
changes completely, as the inquiry is complicated by the great diversity
of composition indicated by the various analyses. In comparing
these, the very variable amount of iron in its two states of oxidation,
of alumina, and of lime, arising from the presence of included
erystals and grains of various substances, cannot fail to be noticed ;
and of course these greatly varying proportions affect those of the
water and silica, and especially those of the magnesia. The diversity
of composition, however, is more apparent than real, and is owing
in some instances to the irregularly porphyritic character of the
original rock, and in others to subsequent infiltration and crystalliza-
tion. Thus the alumina may be generally traced to the presence
of still undecomposed crystals of felspar, or else to kaolin resulting
from such; to augite, or hornblende; the iron to magnetite or to
flocculent masses of peroxide of iron; and the lime either to felspar
or else to patches or veins of calcite. Take away these, and the
serpentinous ground-mass will often be found to consist of nearly
pure serpentine.

ConcLusion.

I have thus shown that serpentinous change is extensively met
with in both stratified and intrusive rocks in many parts of the two
western counties of England. The rocks sometimes change as a
whole—as at Botallack and Clicker Tor—or in certain of their folize
—as at Cant Hill—or thin films of serpentine are produced, bounding
the numerous joints which divide the rock into angular fragments,
still purer serpentine, with or without asbestiform matter, being
deposited wherever the joints are sufficiently open—as at Terras.
Crystals of augite, olivite and hornblende all appear to have been
frequently changed into serpentine—-with or without intermediate
changes—while felspar crystals, if present, are either converted into
saussurite, or else are more or less completely kaolinized. In the
ease of the hornblende crystals, the change begins by loss of
dichroism. Then, as in the case of augite also, the crystal breaks
up into a fibrous mass of acicular crystals; and finally amorphous

1 Allport, ibid.
DECADE III.—vVOL. IV.—NO. VY. 16

° 226 =©Reviews—Dr. Bornemann—Cambrian Fossils of Sardinia.

serpentine without trace of fibrous structure is produced. The next
stage is a general hydration of the whole ground-mass, the disap-
pearance of alumina from its composition, and the oxidation of
magnetite into peroxide of iron.

Such changes are analogous to those observed by Prof. Heddle in
the serpentinous marbles of Tyree, Lewis, and other places in the
North of Scotland, where augite has been converted into serpentine ;
as well as in the picrolite of Balta and the erysotile of Fetlar, where
forms of hornblende have been so changed ; it is very similar to that
which he observed at Beauty Hill near Aberdeen,. where waxy
labradorite (a mineral closely resembling the felspathic component
of the Porthalla stone) ‘‘7s seen to pass within a space of about an
inch into this mineral” (an aluminous serpentine or pseudophite)
“by insensible gradation.” he italics are all the Professor’s. For
the full discussion of the processes of change in these different
circumstances, which to me is perfectly conclusive, I must refer to
the original paper in the Proceedings of the Royal Society of
Edinburgh. On the whole, it seems to me that serpentinous change
in hornblendic and augitic substances is little less common than the
kaolinization of felspar; and these two modes of metamorphism are
not unfrequently to be seen in the same rock-mass, as at Duporth
(see Min. Mag. vol.i.), Cant Hill (see supra), and many other places.

Beye) ae SES VV GS

I.— Die VERSTEINERUNGEN DES CAMBRISCHEN SCHICHTENSYSTEMS
DER InsEL SARDINIEN, NEBST VERGLEICHENDEN UNTERSUCHUNGEN
UBER ANALOGE VORKOMMNISSE AUS ANDERN LANDERN. Von Dr.
J. Gzorc Bornemany, M.A.N. Erste Abtheilung. Mit 33 Tafeln,
No. ii—xxxiti. Nova Acta der Ksl. Leop.-Carol. Deutschen
Akademie der Naturforscher. Band LI. No.1. (Halle, 1886.)
THe Fosst~ts OF THE CAMBRIAN STRATA OF THE ISLAND OF
SARDINIA, WITH A CoMPARATIVE STUDY OF SIMILAR FORMS FROM
otrr Countrizs. By Dr. J.G. Bornemann. Ist part, 4to. pp.
83, and 33 plates.

HE present is the first portion of a work in which the author
i: proposes to give a complete description of the fossils from the
Cambrian strata of Sardinia, which he has collected during succes-
sive visits to the island. Owing to the extremely complex manner
in which the strata have been disturbed, it has not been possible to
make out in detail the succession of the beds; but the oldest fossil-
iferous rocks near Canalgrande on the west coast of the island, con-
sist of a series of clay-schists, rich in Trilobites, quartzitic sandstones
with sponge (?) remains, and dark crystalline, and in part oolitic,
limestones. ‘These are succeeded by a great thickness of massive
limestones, followed by successive alternations of shales with Lingula,
sandstones with Trilobites, and limestones containing large numbers
of the peculiar Coral-like fossils known generally as Archeocyathus.
Associated with these Coral (?) bearing limestones and marbles are
coarse sandstones filled with Cruziana.

ia

Reviews—Dr. Bornemann—Cambrian Fossils of Sardinia. 227

The Trilobites of the lower zones are stated by the author to pre-
sent a general resemblance to Paradoxides and Olenus, though for
the most part they are specifically and even generically distinct from
any forms yet described ; in a somewhat higher zone examples of
Lilenus are associated with survivors of the older forms.

The description of the Trilobites is, however, reserved for another
part: the fossils treated in the present one are ranged under the heads
of Plante, Spongiz and Archeocyathine. The forms described as
plants are, at the best, doubtful. Thus the author, accepting the
views of Lebesconte, de Saporta, and Delgado, places Cruziana as a
genus of Algz. In Sardinia, as elsewhere, there is not a trace of
organic structure in these fossils, and there is nothing to controvert
the striking arguments of Nathorst (whose name is not even men-
tioned by the author) that they are most probably tracks or im-
pressions.

A new genus, Phytocalyx, is proposed for conical or hemispherical
bodies, which weather out of a sandstone rock in considerable abun-
dance. No structure whatever is preserved. They are regarded
as Algz analogous to Fucoids or Siphonee ; but, judging from the
description and figures, it seems to be equally as probable that they
may be inorganic concretionary bodies or infilled casts of hollows
made by burrowing organisms.

Another new genus, Hpiphyton, is stated to consist of fan-shaped
groups of cells which are regarded as formed by -a lime-secreting
Alga allied to the Siphonez.

Another form, growing in small rounded masses, like Nullipores,
and consisting of an agglomeration of minute curved tubes, is
extremely abundant, forming in places whole beds of rock. The
author regards it as a new genus of calcareous Alga, and finds a re-
semblance in the form, arrangement, and dimensions of this Cambrian
marine fossil to a species of existing Alga which grows on the
surface of calcareous rocks in Switzerland. Some of these Jand-
Algee also secrete lime, and form hard stony crusts, and the author
thinks there is reasonable ground for placing the fossil in the same
group with the recent form !

We may here point out the fact, that this genus, which the author
names Siphonema, is by no means new, as he supposes, since it was
clearly described, and the typical form figured, by Nicholson and
Htheridge, jun., nine years since, in their Monograph of the Silurian
Fossils of Girvan, under the name of Girvanella (Lc. p. 28, pl. ix.
fig. 24). As the writer has had the opportunity of seeing both the
specimen described by Dr. Bornemann, as well as that which has
received the name of Girvanella, he can confidently state that they
are generically identical.

Singularly enough, the same fossil occurs at a similar geological
horizon in the United States, and it has lately been described by
Prof. H. M. Seeley as a genus of free calcareous sponges under
the name of Strephochetus (American Journal of Science, vol. xxx.
1885, p. 855). Thus for this same fossil we have the following
references :—

228 Reviews—Dr. Bornemann—Cambrian Fossils of Sardinia.

1878. Girvanella, Nicholson and Eth, jun. Probably Rhizopods.

1885. Strephochetus, H. M. Seeley. Calcareous Sponges.

1886. Siphonema, Bornemann. Algve allied to living subaerial forms.
Whatever may be said in favour of the alliance of this genus to
Rhizopods, on which the writer is not competent to pronounce an
opinion, it is quite certain that it has not the least resemblance to
Calcisponges, and its affinity to living subaerial Aloz seems very
problematical. It is clear, however, that these bodies should retain
the generic name first applied to them, and the two later names must
be suppressed.

In the class Spongiz the author proposes a new genus, Palao-
spongia, to include smal] cylindrical branching bodies, from 1 to 5 mm.
in thickness, which in places fill beds of slaty rock, and are exposed
in relief on their weathered surfaces. ‘These forms now consist, for
the most part, of angular quartz grains; but it is stated that, in
microscopic sections, siliceous spicules arranged parallel with each
other to form fibres can be distinctly seen, and between the spicules
are grey and dark lines, regarded by the author as indications of the
keratose materials of the organism, by which, when in the living
state, the spicules were held together! The genus is regarded as
allied to existing monactinellid sponges, and a photograph of a section
of the existing Awinella polypodioides is given to show the resem-
blance between it and sections of these Cambrian fossils! We must
confess our inability to perceive this asserted likeness, and we think
that the few, scattered, crooked linear bodies shown in the figure,
which the author supposes to be spicules, may be otherwise explained.
It would indeed be astriking fact, if sponges of this character, which,
owing to the fact that their component spicules are only held together
by perishable horny material, are of extremely rare occurrence in
newer undisturbed strata, should in these disturbed Cambrian rocks
be preserved in great abundance.

The author further states that the forms described by Billings as
marine plants, under the name of Palgophycus, have a remarkable
resemblance to his Palgospongia. In our own opinion the forms
known as Palg@ophycus, Bill., are most probably the infilled tracks and
burrows of marine organisms, and we think that Palgospongia may
have a similar origin. It is to be hoped that, to clear up, if possible,
the doubts as to the real nature of this genus, the author will submit
his specimens to some one acquainted with the characters of fossil
sponges.

The peculiar cylindrical, cup- or funnel-shaped fossils, of which
the genus Archgocyathus, Billings, may be taken as the type, are
placed by the author as a distinct class of Coelenterates, in proximity
to Sponges, Anthozoa, and the Medusoid Polyps. Fossils of this
group are present in great abundance in the massive Cambrian Lime-
stones of Sardinia, but they are, for the most part, not well preserved,
and can only be studied in microscopic sections. Of these the author
prepared a large series, and photographs of them are given in the
accompanying plates.

In addition to Archeocyathus, Bill., the author proposes two new
genera, Coscinocyathus and Anthomorpha. In the former, regular

Reviews—T. Mellard Reade—On Mountain Ranges. 229

transverse tabule are present, as well as the vertical lamelle, whilst
in the latter, the transverse structures are irregular. Associated with
the ordinary forms of Archgocyathus, a peculiar fossil, consisting of
anastomosing, apparently homogeneous fibres, frequently occurs. It
is believed by the author to be the vegetative state of development
from which the complete cups of Archgzocyathus originate, and thus
to indicate a true alternation of generations in these Cambrian fossils !
To this form, though not regarded as an independent genus, the name
Protopharetra is given.

An equally surprising statement is, that delicate threads or fibres
of calcite present in the interspaces of the walls of some examples
of Archeocyathus and Coscinocyathus are the fossilized remains of
such soft organic structures as sarcode-threads, muscle-fibres and
tentacles. The author thinks it possible that these structures may
have been inclosed by the ooze, and then replaced by calcite!

Though the author has described in detail numerous species, it can
hardly be said that our knowledge of the true nature and affinities of
Archeocyathus and its allies has been increased. The author doubts
the correctness of the observation of Billings as to the spicular
nature of the walls of Archeocyathus, and thinks that the spicules
figured were accidental intrusions.

Though we regret our inability to accept most of the determinations
and conclusions of the author, we nevertheless readily admit the
value of the work which he has done in bringing to light and
describing the organisms in these unpromising Cambrian rocks of
Sardinia. It is of great interest to know that many of the forms are
closely similar to those recorded by Billings from the so-called
Calciferous rocks of the Mingan Islands and other localities bordering
the St. Lawrence, and this similarity will probably be further shown
when the Trilobites and other fossils are described. It may also be
mentioned that this work has a direct bearing on questions connected
with British geology, since Archeocyathus has lately been discovered
by members of the Geological Survey of Scotland in the Durness
limestones. The specimens, though not uncommon, are but frag-
mentary and in a poor state of preservation ; but, in spite of this,
Mr. B. N. Peach, F.G.S8., has been able to ascertain from them some
important conclusions respecting the relations of Archgocyathus to
Calathium, Bill., which it is hoped will soon be published.

G. J. Hip.

IJ.—Tue Orictn or Movntary Rayeus. By T. Metrarp
Reape, C.E., F.G.S., F.R.LB.A. (London, Taylor & Francis,
1886.)

ee is a handsome octavo volume of 359 pages, profusely illus-

trated with forty-two full-page or folding lithographic plates.

The short final chapter contains the author’s main conclusions ;

and these are further condensed into its first two sentences.

‘“‘ Mountain-ranges are ridgings-up of the Harth’s crust, which take

place only in areas of great sedimentation. The exciting cause of

the various horizontal and vertical strains, ending in the birth of a

230 = Reviews—T, Mellard Reade—On Mountain Ranges.

mountain-chain, is the rise of the isogeotherms, and consequent
increase of temperature” [and expansion | “ of the new sedimentaries,
and that portion of the old crust that they overlie” (p. 326). It
will therefore be seen that the theory is founded on what has
been termed the Herschel-Babbage hypothesis, that, where thick
deposits are laid down, the rise of the isogeotherms into them must
needs cause their expansion; coupled with the observation of
American geologists, that in general a mountain-range occupies an
area where sedimentation has gone on undisturbed, until the deposit
has attained a great thickness, and that the event, next in sequence
there, has been the elevation of that very tract into a mountain-
range. ‘The Americans have attributed this subsequent elevation to
the contraction of the Earth’s volume through secular cooling,
acting upon the newly-deposited matter as a weak place. But
Mr. Reade rejects this supposition. In this rejection I agree with
him. I think the question may be put simply thus. If any mass
contracts equably in all its parts, the rate of shortening of every
dimension must be the same. If then the whole Harth had
cooled down to the present temperature of the surface, every
dimension would have contracted equably, and there would be
formed neither wrinkles nor cracks. But in fact the crust has
cooled more than the interior. Therefore the circumference of the
crust must have contracted in a greater ratio than the radius of the
nucleus, which it envelopes. Its tendency would therefore be to
crack ; and, although the weight of its parts might close up the
cracks as they tended to be formed, still no compression would take
place, unless we throw more than its proper share of cubical
contraction into the vertical dimension.! It does not seem that this
conclusion will be much affected by the condition of the interior,
whether it be solid or liquid.?

Accepting the theory of a solid globe, and the view, that the
matter of which it consists becomes fluid on the pressure being
reduced, the author thinks that this matter is subject to local
fluctuations of temperature, a property which it is not easy to
reconcile with solidity. Rocks at a depth of two miles and over,
whether originally soft mud or clay, may be treated as solid matter.
“‘Solid by compression, but ready to flow, one way or other, as the
pressure may be reduced or increased’”?’—a very accommodating
condition, but difficult to understand, because, if solid only by
compression, one would imagine that increased pressure would make
them more obstinate to move.

There seems a difficulty in accounting for the accumulation of

1 In a paper upon the subject, which I have lately contributed to the Phil. Mag.
(Feb. 1887), I have thrown the whole contraction into the vertical, a supposition,
as I have expressed it, “‘ too highly favourable.”’

2 Jn considering the possible causes of contraction of the nucleus, perhaps enough
has not been made of the evisceration of the interior by volcanic action of various
kinds. How much must have been vomited forth to form the great basaltic flows—
and the pumice-covered floor of the deep oceans—and the dust clouds, which must
often and often in geological ages, for months and years at a time, have covered the
sky all round the globe! 3 p. 91.

Reviews—T. Mellard Reade—On Mountain Ranges. 231

thick deposits on the theory of a solid globe. They cannot make
a cavity for themselves, because the increase of pressure due to their
weight would increase the rigidity of the sea-bed. The cavity must
therefore somehow be already hollowed out, and it must conveniently
border a continent, to be within reach of the sediment. This isa point
which needs to be explained. But suppose that done; and conceive
the sediment to be in process of accumulation. A second difficulty pre-
sents itself. Mr. Reade appears to consider that the hollow would be
first filled up, and that the heat would subsequently be conducted
from below into the sediments, and that they would swell up into a
mountain region. But asa fact the heat would enter them concur-
rently with their deposition, so that the swelling up would begin at
once. When the top of the deposit had reached the sea-level,
deposition must cease; and it would be only the balance of heat
remaining to be made up after that time, which could be effective
towards raising the deposits above the sea-level. If deposition was
a rapid process, the larger part of the heat might remain still due,
and therefore available to raise the tract above the sea-level. But
it is a very slow process—so slow that Mr. Reade thinks forty-two
millions of years not too long for the deposition of the matter from
the Carboniferous upwards in Western North America. Surely in
that time the sediments would be almost quite warmed up before
they got above the sea-level.

A valuable part of Mr. Reade’s work consists of the experiments
he has made upon the rates of expansion of different kinds of rock.
His results agree closely with those obtained by Mr. Adie long ago;
giving, as he puts it, 2°77 feet per mile per 100° Fah. He has not
referred to Mallet’s experiments upon molten slag, of which I have
given an account in my “Physics of the Harth’s Crust.”! It is
satisfactory to learn that, even at the high temperatures examined
by Mallet, the coefficient of expansion keeps fairly near that deter-
mined by Adie, and now by Mr. Reade, for lower temperatures.
Applying his result to masses of the size contemplated, the linear
expansion of 1000 miles raised 1000° Fah. (which he takes as the
mean increase of temperature for the new deposits and of the old
crust under them) would be about 54 miles. At p. 158 he assumes
a lenticular mass, measuring 1000 x 500 miles, and 20 miles deep in
its thickest part, raised to a mean of 1000° F. above its previous
temperature. Lying in a rigid dish of crust, the entire cubical
expansion would be effective to elevate the surface. The lower
strata, being heated more than the upper, expand more, and become
crumpled, because their periphery is confined by the rigid crust.
They then burst up the superincumbent less-expanded beds, which
gape at the anticlinals. Into these the lower heated rocks are
intruded, and form plutonic cores. The interstitial differential move-
ments give rise to foliation, and similar phenomena; and in places
the hot solid rock beneath, finding weak places, and “ strugeling” to
escape, intrudes itself into dykes, and becoming more and more liquid
as it reaches regions of less and less pressure, at last appears at the

1 p. 68, note.

232 Reviews—T. Mellard Reade—On Mountain Ranges.

surface in volcanic manifestations. Such is an outline, as I understand
it, of the theory.

If the two preliminary difficulties can be disposed of, the theory
seems well suited to explain the formation of elevated plateaux.
But for producing the intense corrugation, which characterizes most
mountain ranges, the amount of horizontal expansion which it affords
appears inadequate; especially when we consider, that much of the
compression would be expended in deforming the material upwards,
without rotation of the parts. The scale is made appreciable if one
takes a metre rule, and-compares five millimetres with the entire
length—or a yard measure with less than a quarter of an inch.
The corrugation arising from compression on such a scale must be
very small. Many of the numerous and interesting sketches given
from nature make one feel rather the inadequacy of the theory to
account for the disturbances shown. Altogether this part of the
theory needs more reasoning out quantitatively.

Chapter xxi. on the connection of volcanic action with mountain-
building, is worth studying. The subject is an obscure one, but it is
so intimately connected with every manifestation of force in the
Harth’s crust, as cause with effect, that they cannot be separated.
Mr. Reade’s leading idea seems to be, that the reservoir of magma
is solid, but that it exerts expansive stress to find escape. Being
solid, it does not transmit liquid pressure from one vent to another;
so that lava can stand at different levels in them.

The experiment represented in figs. 1 and 2 of plate xlii. and the
description of it (p. 431) are interesting. Several strips of paper
were laid upon each other, and lines were drawn across the edge of
the block so formed. It was then bent into folds. The inclination
assumed by the lines now indicated the manner in which the strips
had slidden longitudinally over one another in the process of folding.
I may mention that the position taken by these cross lines exactly
agrees with that of the “planes of less perfect cleavage” in Mr.
Sorby’s well-known diagram of a contorted bed in slate rock at
Ilfracombe.! This shows that the cleavage follows the lines of
distortion, not those of shear; for the latter would, in the experi-
ment, have been along the surfaces of the sheets of paper.’

Mr. Reade, in plate xxxviii., gives a good demonstration of the
extension that necessarily accompanies the compression of strata
into close chevron folds, which, from what has been said in the
preceding paragraph, would lead one to expect such folds to be in
general affected by cleavage inclined at an angle across them.

There is throughout the book a certain want of precision in
scientific language. ‘“ Heat” is sometimes used where the word
should be “temperature”; ‘‘strain”’ where it should be “ stress.”
At p. 308, having been told that mechanical denudation from the
Mississippi basin is one foot in 6000 years, we read, “If we add the

1 Edin. New Phil. Journ. vol. lv. p. 138, 1853; and Lyell’s Students’ Elements,
p- 577; also Prestwich’s Geology, vol. i. p. 264.

2 Rev. O. Fisher on Cleavage and Distortion, Gronr. Mac. Decade III. Vol. I.
p- 400, line 5, 1884.

Reports and Proceedings—Greological Society of London. 238

matters removed in solution, I have shown that we must reduce the
time to one foot in 4500 years.” To take notice of a verbal slip,
confounding time with feet-per-year, may be making a mountain
of a molehill. If I have done that, at any rate I have achieved a
success in mountain-building.

In chapter x. our author gives very good reasons for considering
the globe to contain a sufficient supply of heat for all the purposes
of his theory. But he has made a mistake in supposing (as by
working out his figures he seems to have done) that, if the tempera-
ture of the whole were reduced to zero Fah., all its heat would be
exhausted. To accomplish that result, it would need to be reduced
460° Fah. lower still. O. FisHer.

SLITS OuReeS FVaNlb, JSssxelOamam Sse iS

—>—_
GrotocicaL Society or Lonpon.
I.—March 9, 1887. — Professor J. W. Judd, F.R.S., President,

in the Chair.—The following communications were read :—

1. “On Chondrosteus acipenseroides, Ag.” By James W. Davis,
Ksq., F.G.S.

Sir P. Egerton described two species of Chondrosteus from the Lias
of Lyme Regis, viz. C. acipenserordes, Ag., and C. crassior, Eg. The
author describes an unusually fine specimen from the same locality,
44 inches long, the head, trunk, and tail being exceptionally complete,
whilst a considerable portion of the elements of the vertebral column
is preserved.

The head is proportionately large and deeper than the body of the
fish. It has an almost circular outline with a diameter of about
9 inches, but the snout has been broken off during extraction. The
cranium was protected by dermal bones or scutes. The anterior
portion of the head, beneath the orbit, does not exhibit any traces of
external defence, thus differing from existing Sturgeons. The frontals,
postfrontals, parietals, mastoid, and some of the occipital plates
are present: all these bones are united by sutures. The external
surface of the dermal plates is coarsely striated or ridged; the ridges
radiate for the most part from the centre towards the margin, the
surface being covered by strips of ganoine. The orbit is oval. The
base of the skull is formed by bones more completely ossified than
in the existing Sturgeons: these are more extensive than in the
Teleostean fishes, being the equivalents of the sphenoid bones of the
latter. Sir P. Egerton, in his description of the genus Chondrosteus,
states that the elements of the scapular arch, which in recent
Sturgeons are three in number, are reduced to two in the fossil
genus by the coalescence of the scapula and the coracoid. The
author describes it as composed of a series of three bones, supra-
scapula, scapula, and coracoid (or clavicula). The last is united
with the pectoral fin by two bones, apparently representing the
radius and ulna of Owen (coracoid and scapula of Parker). The
pectoral fin is large and comprised forty-two rays. The mandibles
and maxillaries are large and well ossified, in this respect differing

204 Reports and Proceedings—

from existing species; there is no evidence of teeth. From the
position of the respective maxillary and premaxillary bones in this
specimen there can be no further doubt that the small bifurcated bone
of C. acipenseroides, Ag., described as the maxillary bone, is really the
premaxillary.

Bony neurapophyses are preserved in the anterior portion of the
body. There is no trace of the vertebral column nor of ribs or
heemapophyses, except in the caudal fin, where hamapophyses support
the lower lobe. The neurapophyses extend from the occipital region
of the skull to the base of the dorsal fin, 13 inches. In this length
there are preserved thirty-five neurapophyses, representing the same
number of vertebree. ‘The first ray of the dorsal fin is inserted above
the thirtieth vertebra; the total number of vertebra in the spinal
column would be from eighty to eighty-five. The caudal fin is very
large and was a powerful organ of propulsion; its upper lobe, as in
the recent Sturgeon, is the longer of the two.

The specimen is nearly twice the length of those described by
Egerton, and the author indicates the differences in some detail.
The division of the scapular arch into three parts, the suprascapula,
the scapula, and the coracoid, appears to be undoubted, whilst in
the specimens previously described the scapula and coracoid are said
to be united. The two latter ossifications of the shoulder-girdle are
separate in the existing Sturgeons, and in the Ganoid fishes this is
also generally the case.

The author then refers to the opinion expressed by Sir P. Egerton
as to the homology of the cranial plates of fossil Sturgeons when
compared with recent ones and also with Teleosteans, and to the
confirmation of these views by Prof. Parker, who concludes that,
although the Sturgeons cannot be said to occupy an intermediate
position directly between the Selachians and the Bony Ganoids, yet on
the whole that is their position.

Lastly, the author states his belief that there is no specific
difference between C. acipenseroides, Agassiz, and C. crassior, Egerton.

2. ‘On Aristosuchus pusillus, Ow., being further Notes on the
Fossils described by Sir R. Owen as Potkilopleuron pusillus, Ow.” By
Prof. H. G: Seeley, F.R.S., F.G.S. ;

A Wealden fossil, comprising certain dorsal, sacral and caudal
vertebrae, with some associated bones belonging to the pubic region,
formerly in the collection of the Rey. W. Darwin Fox, but now in
the British Museum, was described by Sir R. Owen in 1876 as
Poikilopleuron pusillus. In the present paper the author showed
that the presence of a peculiarly-shaped medullary cavity in certain
vertebre, a character upon the strength of which the bones were
referred to Povkilopleuron, Desl., was not peculiar to that genus, but
had been found in Megalosawrus and in other Dinosaurian reptiles,
whilst the characters of the sacrum in ‘ Povkilopleuron pusillus”
differed from those of any Crocodilia. The species was clearly not a
Poikilopleuron, but was apparently a Dinosaur belonging to an un-
described genus, for which the name of Aristosuchus was proposed.

The pubic bones were described and shown to resemble those
noticed by Prof. March in Allosaurus, Ceratosaurus, and Celurus, and

Geological Society of London. 235

the specimen itself has been referred by Prof. Marsh to the last-named
genus. The genera named were, however, placed in distinct Dinosaurian
suborders, and consequently it was evident that the pubic bones by
themselves were insufficient for generic determination, whilst the
dorsal vertebra of the Wealden fossil had the texture usually found in
- Dinosauria, and not that peculiar to Celurus. The mode of attachment
of the ribs was also different. The sacrum of Celuwrus was unknown,
but was probably very different from that of Aristosuchus. In the
latter the transverse processes or sacral ribs were given off from each
individual vertebra, as in certain American forms, and not as in
LIyuanodon, Hyleosaurus, Megalosaurus, etc., from the junction between
two centra.

The five sacral vertebre of the fossil and their apophyses were then
separately described in detail, and also an associated fragmentary
caudal vertebra; and the conclusion was expressed that Aristosuchus
- was a Dinosaur nearly related to certain imperfectly-described American
types, such as Adlosaurus.

‘“On Patricosaurus merocratus, a Lizard from the Cambridge
=n preserved in the Woodwardian Museum of the University
of Cambridge.” By Prof. H. G. Seeley, F.R.S., F.G.S.

No Lacertilian has hitherto been described from the Cambridge
Greensand. The only remains of Lizards known to the author as
haying been derived from that bed consisted of the two bones now
described, the proximal end of a femur, and a sacral vertebra with the
processes broken away. The former exceeded in size the corresponding
bone of the largest living Monitor, and differed from the femora in all
recent Lizards in so many respects as to indicate subordinal distinction.
The vertebra was not found with the femur, and may have belonged
to a different species; but there being nothing in the characteristics
of the two bones inconsistent with their having belonged to one
specific type, both were fully described as types of a new genus and
ae

4. *©On Heterosuchus valdensis, Seeley, a proccelian Crocodile from
the Hastings Sands of Hastings.” By Prof. H. G. Seeley, F.R.S.,
F.G.8.

An ironstone nodule from the Hastings Sands was acquired by the
British Museum from Dr. Mantell’s collection. The specimen measured
10 centimétres by 6, and displayed on its water-worn surface several
proceelian vertebra of a small Crocodilian, together with some other
bones, perhaps belonging to a different reptile. These other bones
appeared to comprise portions of a skull with peculiarities not hitherto
recognized in proccelian Crocodiles, and a pubis and ischium exhibiting
distinct Lacertilian characters, and of comparatively very small size,
but still situated in proximity to the sacral vertebre.

The vertebre were described in detail in the paper, and referred to
a new genus and species. They included one late cervical vertebra,
eight dorsal, and two which might be considered as sacral. All
appeared to be mature, and were more completely ossified than
the same bones in living Crocodiles. The body of each centrum was
compressed laterally, the neural arch comparatively depressed and
thrown out laterally above by the inferior V-shaped approximation

236 Reports and Proceedings—

of the side of the centrum. Several other peculiarities were also
pointed out.

The paper concluded with notes on other vertebree of similar
character from Tilgate and Brook, and attention was called to a
Crocodilian cervical vertebra with the proccelian cup from the Purbeck
beds.

5. “On a Sacrum, apparently indicating a new type of Bird
(Ornithodesmus cluniculus, Seeley), from the Wealden of Brook.”” By
Prof. H. G. Seeley, F.R.S., F.G.S.

After some remarks on the characters of the sacrum in Birds,
Ornithosauria, and Dinosauria, the author proceeded to describe a
sacrum composed of six vertebree in the Fox collection, now at the
British Museum, and then to compare the fossil with the corresponding
bones of the three groups named. The resemblance to the Dinosaurian
and Ornithosaurian sacral vertebree was less than those which connected
the fossil with birds. From the latter it was distinguished by the
smaller number of vertebrae in the sacrum, the absence of sacral
recesses for the lobes of the kidneys, and the form of the articular
face of the first sacral vertebra. But the small number of sacral
vertebre in Archaeopteryx, the want of renal recesses in ehthyornis,
and the characters of the articulation in the Solan Goose showed
that these differences were not essential; and the author concluded
that the fossil belonged to a true Bird, but that it formed a link
with lower forms, and approximated more to Dinosaurs than did any
other Avian type hitherto described.

II.—March 23, 1887.—Prof. J. W. Judd, F.R.S., President, in the
Chair.—The following communications were read :—

1. ‘‘ Notes on the Structures and Relations of some of the older
Rocks of Brittany.” By T. G. Bonney, D.Sc., LL.D., F.R.S., Pro-
fessor of Geology in University College, London, and Fellow of St.
John’s College, Cambridge.

These notes are the results of a visit to some of the more interesting
geological sections in Brittany, in the autumn of last year. The author
is greatly indebted for information to the Rev. E. Hill, who took part
in the summer excursion of the Société Géologique de France, and to
Dr. Charles Barrois, who has for long been engaged in investigating
the geology of Brittany.

(1). The author briefly noticed the glaucophane-amphibolites and
the associated schists of the Ile de Groix, which have been already
admirably described by Dr. C. Barrois. He considered the evidence
to be on the whole in favour of the view that the former were originally
igneous rocks intrusive in the latter, but modified by subsequent
pressure (the marks of which are very conspicuous in the schists), and
by mineral change, which probably produced the glaucophane, the
garnets being anterior to the mechanical disturbance.

(2). The next part of the paper treated of sections in the district
about Quimperlé. Cases were cited of granite, modified by pressure
so as to result in a gneissoid rock, and of banded gneisses also modified
by subsequent pressure, but, in the author’s opinion, indubitably
banded gneisses anterior to the mechanical disturbance, and exhibiting

Geological Society of London. - 237

structures which, in his opinion, lend themselves more readily to a
theory of some kind of original stratification of the constituents than to
any other. The amphibolites in this region are undoubtedly of igneous
origin (intrusive), but subsequently modified. In one part of the
district are granitoid gneisses, but little modified by subsequent
mechanical action, which in structure differ greatly from the granites,
and much resemble the older Archean gneisses of other regions.
A “‘halleflinta” to the north of Quimperlé proves to be in part
a rhyolitic rock, modified by subsequent pressure; part, however, may
be an indurated tuff of similar composition.

(3). In this part of the paper were noticed the crystalline rocks of
Roscoff, and (more briefly) the Paleozoic strata about Morlaix, with
the mineral and structural modifications due to pressure and to the
action of intrusive igneous rocks. The author pointed out that, in the
latter case, the results either of pressure-metamorphism or of contact-
metamorphism differ much from the crystalline schists, which, both in
Brittany and elsewhere, are regarded as of Archean age; and that
here in the north at Roscoff, we have a series of banded gneisses, less
modified by subsequent pressure than in the south, the structures of
which are very difficult to explain on any theory of a ‘rolling out”
of a complicated association of igneous rocks, but which are such as
would naturally result from some kind of stratification of the original
constituents.

The result of the author’s work is to strengthen the opinion which
he has already expressed, that while the structures of some foliated
rocks may be regarded as primarily due to pressure operating on
suitable materials, the structure of others seems opposed to this explana-
tion. At any rate the latter rocks appear to have assumed a crystal-
line condition with a semblance of stratification in Pre-Cambrian
times; so that, whatever may be their genesis, they are rightly called
Archzean gneisses and schists.

2. “The Rocks of Sark, Herm, and Jethou.”’ By Rev. E. Hill,
Ma AG eb. GS.

The author described the island of Sark, about three miles long by
two broad, with the smaller areas of Little Sark and Brecqhou. Little
Sark is attached to Great Sark by a narrow ridge (the Coupée), which
the weather is rapidly degrading, while Brecqhou is completely
separated by a narrow strait. The greater part of these islands consists
of dark hornblendic banded rocks, which closely resemble those of the
Lizard, and show by their alternation of materials and their phenomena
of current-bedding that they have originated by some kind of deposition.
These were shown to lie unconformably on a gneiss, seen only at the
eastern extremity of the island, in and around the Creux Harbour.
Over this the beds lie in a dome, and as they slope away on the N..,
W., and S., they pass under a highly-crystalline rock, which has been
called a metamorphic gneiss. This rock was described, and evidence
given to show that it is really a granite,—an igneous rock which has
overflowed the hornblendic beds.

Veins and dykes were briefly noticed ; they include a dyke of mica-
trap. The islands of Herm and Jethou, lying between Guernsey and
Sark, were also described. Jethou contains a fine raised beach. They

238 Correspondence—Rev. O. Fisher.

consist of granite which presents signs of an EH. and W. dip. A pro-
bability was shown that this granite is part of the mass overlying Sark.

Finally, the age of these rocks was shown to be Archean, and
attention was called to the evidence they give that some at least of the
Archean rocks did not originate out of igneous masses by crush, but
were formed by some process which, if not aqueous sedimentation, at
all events was some kind of successive deposition.

3. ‘‘Quartzite Boulders and Grooves in the Roger Mine at Dukin-
field.” By James Radcliffe, Esq., F.G.S.

Quartzite boulders have from time to time been found imbedded in
the roof of the Roger Mine coal-seam. Similar boulders had previously
been described from coal-seams both in Leicestershire and the Forest of
Dean. The composition of the Roger-Mine boulders was shown by
notes furnished by Prof. Bonney to be quartzose grit and quartzite,
containing some grains of felspar, epidote, and tourmaline and flakes of
mica. This composition resembled that of some of the pebbles in the
Bunter conglomerate of the Midland counties, and also that of some of
the Loch Maree quartzites. The boulders varied in weight from 166
pounds to 4 pounds, and appeared to have been dropped into the coal,
one boulder having been found standing edgeways. ‘They were half
imbedded in the seam, half inclosed in the overlying grey shale.

In the upper surface of the coal in the same mine, grooves were
found running about S. 50° E., the mean direction of faults, slips, ete.,
being S. 26° W. The sides of these grooves were raised, as if by
pressure, and each depression commenced as a small groove, then
increased in depth and breadth, and finally died out.

C6 @iz eS © IND saa:

—

INTERGLACIAL LAND AND MAN.

Srr,—As an item of evidence in favour of the existence of an
interglacial land surface, so ably maintained by Mr. Jukes-Browne
in this Magazine for March, and of the presence of Man in this
country at the time, I send an extract out of a letter (Sept. 80, 1861)
from the late Dr. Bowerbank to the late Dr. Bree, of Colchester,
which has not, I think, been published. The occasion of its being
written was that Dr. Bree had shown him the cut deer’s horn from
Clacton, described by me in the “ Geologist,” Aug. 1861, and figured
in plate ix. ‘I have in my possession remains of a human skull,
that was found mixed with bones of extinct animals at the bottom
of a deep dyke on an axis of elevation, covered by the detritus of
“the Magnesian Limestone to about one-third of the height of the
great crack, and the remainder then covered by the Red Drift of
Yorkshire ; so that it is fair to infer that it was deposited in the
crack, or dyke, before the submergence of that country beneath the
sea, and again elevated after being covered by the great northern
Drift. This would appear to give an immense period to the existence
of Man. The finding of these bones are (sic) so well authenticated,
that there can be no reasonable doubt of their being in every

Correspondence—ev. Prof. Bonney. 239

respect genuine. I have often thought of publishing these facts,
and I think I shall do so ere long.”

What became of Dr. Bowerbank’s collections ?

J am quite aware that, as a rule, a geologist will not trust any one
to observe correctly except himself. But on questions of this kind,
where the evidence is destroyed in the process of being obtained,
autopsy is impossible. We are therefore obliged to rely upon
cumulative evidence, the weight of which depends upon the circum-
stance, that it is highly improbable that every observation should be
erroneous, while at the same time a single correct one is sufficient to
prove the point at issue. O. FisHEr.

Hartton, CamBriner, 4th April,

FELSPAR IN THE LIZARD SERPENTINE.

Srr,—May I be permitted to state, as briefly as possible, the
reasons why the characters described by my friend Mr. Teall in his
letter on “The Lizard Serpentines,” fail to convince me that the
mineral in question, which occurs in the Rill rock, is really felspar ?
As he rightly says, the identification of a mineral under the micro-
scope is often more or less a matter of inference. Hence it is
occasionally quite possible for two observers, both of some experience,
to take different views. I do not then attribute a mistake to him in
the ordinary sense of the word, nor wish in any degree to detract
from the value of his work. The point is one of considerable
interest, where there is ample room for two opinions.

To prevent any misunderstanding, let me say that I do not in the
least deny that felspar may occur as an accidental constituent in a
peridotite, and, if it occurred anywhere in the Lizard Serpentines, I
should expect it, as will be seen from my remarks on that of Gue Graze,
in the serpentine of the Kynance-Mullion district.' The difficulty of
determining this particular mineral is not a new one to me, as I had
to consider it nine years ago when preparing the above-named paper.

The following are my reasons, so far as they can be expressed on
paper :—

1. The texture and aspect of the mineral in question, seen under
the microscope, do not appear to me exactly identical with those of a
felspar, but remind me rather of a pyroxenic mineral.

2. The brown earthy decomposition of the mineral seems to differ
slightly from that of a felspar, and I find a similar decomposition in
some grains of decomposing hornblende (mineral identified by
cleavage and extinction) in the serpentine of Lower Pradanac, also
in that of Mullion and Helston Road. I have also seen a similar
decomposition in bastite or enstatite.

3. As to the tints seen between crossed Nicols. Low neutral tints
are not rare in enstatites. I have noted them in augites, when some-
what decomposed, and in certain hornblendes. In my slides from
Lower Pradanac the hornblende generally shows chromatic polar-
ization, but some grains exhibit these low neutral tints. JI believe it
indicates incipient decomposition. As we have lately heard much

1 Quart. Journ. Geol. Soc. vol. xxxiii. p. 918.

240 Correspondence—Rev. Prof. Bonney.

about the life of minerals, we may say that the flush of health is
being replaced by the pallor of approaching death.

4. As regards the twinning, which is no doubt a very strong
argument, I‘ find a rather similar lamellar twinning (as it appears)
in hornblende (serpentineof Mullion and Lower Pradanac). These seem
to be produced by the formation of a mineral (doubly refracting but
with different extinction) along the cleavage planes parallel to P,
but Iam by no means sure that this is the explanation of every
case. In my slide (of 1878) from the Rill it occurs in a mineral
which much more resembles a variety of enstatite than felspar. In
the slide cut from Mr. Teall’s specimen the twinning both lamellar
and in two directions at high angles occurs in minerals which I
cannot distinguish from the low-tinted pyroxenes (I use the name
generically) in the other slides. Further, the twinning is produced
by narrow bands such as one obtains in the almost microlithic
felspars of lavas, not in those of holocrystalline rocks such as
picrites, gabbro, etc., and the outline of the grains is not that usual
in felspars, but curiously irregular. Moreover, I find in a slide cut
from the Carn Sparnack serpentine, both lamellar twinning and cross
twinning in the less highly altered part of the pyroxenic constituent.
I have measured the extinction angles of some of these compound
grains, but to discuss the result would unduly extend this letter, so
that I must content myself with affirming that these bear as much
resemblance to the twinning of a plagioclase felspar as those noted
by Mr. Teall, while they occur to such an extent that, if the mineral
were felspar, the rock could not fail to give macroscopic indications of
its presence. So, though I have endeavoured to approach the subject
with the ‘open mind’ of some modern statesmen, I remain after
repeated examination of the question of ‘the same opinion still’
that the mineral is not felspar. My suggestion as to its name was
‘vague’ designedly, for two reasons: (a) that it is very often easier
to say what a mineral is not than what it is; (b) that I] am by no
means sure that these characteristics are exhibited by one mineral
only ; I believe it, however, to be always a member of the pyroxenic
group, viz. some variety of augite, hornblende, or enstatite.

In conclusion, may I add that Mr. Teall appears to have slightly
misunderstood the drift of my remark quoted by Colonel McMahon.
Whether or not there is evidence of mechanical action on the serpentine
at Porthalla is hardly germane to the question. Of course I should
say that to assign the banded structure in this rock to pressure is at
present just as much an hypothesis as it is in regard to the banded
gabbro. But, apart from this, the difficulty, which I had felt and to
which Colonel McMahon referred, was this—that, when the gabbro
is so remarkably banded, then the serpentine shows little or no sign
of mechanical disturbance. Porthalla is some miles from both
Karakelews and the Landewednack district, and, so far as I know,
gabbro does not occur in association with serpentine either there or
near Mullion Cove. T. G: Bonney.

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THE

GEOLOGICAL MAGAZINE.

NEW) SERIES, .MEBGCADE Ill... VOL. AIN.

No. VI—JUNE, 1887.

Oi Gari AS AS EL Cl aS.

i’
I.—American Jurassic Mammats.
By Professor O. C. Marsu, M:A., LL.D., F.G.S.

(PLATES VI. anp VII.)

N previous publications the writer has announced the discovery
of Jurassic Mammals in America, and has given brief descrip-
tions of the more important forms brought to light.t Since the last
article on this subject, a large amount of new material has been
secured, including representatives of several hundred individuals.
The remains consist not of lower jaws alone, but of various portions
of the skull, and not a few vertebre, limb bones, and other parts of
the skeleton.

These fossils, although fragmentary, are usually well preserved,
but owing to the peculiar conditions under which they were
entombed, no two bones of the skeleton are as a rule found together.
This fact, taken in connection with the very diminutive size of the
animals themselves, and especially with the present brittle nature
of the teeth and jaws, has rendered their investigation a work of
great difficulty. The importance of the subject, however, and the
fact that all the known remains of mammals from the Jurassic of
America are in the collection made by the writer, have led to a
careful study of the whole material, and the results will be brought
together in a Memoir now in preparation for the United States
Geological Survey.

Some of the results of this investigation, and notices of several
new forms recently discovered, are given below in the present
article.

In connection with this work, the writer has also examined the
“more important specimens from the Jurassic of Europe, and, like-
wise, the few specimens known from the Trias, in both Europe and
America.

The American Jurassic Mammals hitherto found are all from
essentially the same geological horizon, in the Atlantosaurus beds, of
the Upper Jurassic. The principal locality is in Wyoming, on the
western slope of the Rocky Mountains, and remains of two or three
hundred individuals have been obtained at this place alone. At
other points in the same region, a few remains have been found. A

1 American Journal of Science, vol. xv. p. 459, 1878; vol. xviii. pp. 60, 215, and
396, 1879 ; vol. xx. p. 235, 1880; vol. xxi. p. 511, 1881; and vol. xxxiii. p. 327,
1887. See, also, Proceedings British Association, Montreal Meeting, p. 734, 1884.

DECADE III.—VOL. IV.—NO. VI. 16

242 =Prof. O. C. Marsh—American Jurassic Mammals.

second locality of importance is in Colorado, about three hundred
miles south of the most northern known limit of these remains.

The other vertebrate fossils from this horizon are mainly Dinosaurs,
many of them of gigantic size, but some scarcely larger than the
mammals. Crocodiles, Turtles, small Lizards, and Fishes, are also
well represented. A single Bird (Laopteryx), and one small Ptero-
dactyl, have likewise been recognized from these deposits. More
recently, various bones of small, anourous amphibians (Hobatrachus
agilis) have been found, the first detected in any Mesozoic formation.'
The deposits are lacustrine, as shown by the fresh-water shells they
contain.

In investigating these American Jurassic Mammals, it was neces-
sary to compare them, first of all, with those from the same
formation in Hurope. On this subject, the elaborate memoir of
Owen, on British Mesozoic Mammals, was taken as the main
authority.?

The first specimens discovered in America proved to be very
near allies of Huropean forms, and most of those since found show
a remarkable resemblance to others described by Owen. Some
fragmentary specimens cannot indeed be distinguished from the
English fossils, but where the remains are more complete, various
differences are seen, which appear to be distinctive. A few well-
marked American genera have no known representatives in Kurope,
while some forms found in Europe are unknown in America.

One difficulty in the investigation of the remains from the two
widely-separated regions arises from the necessity of relying mainly
upon figures for comparison. Again, these minute, delicate fossils
are often embedded in a matrix from which they cannot be removed
‘without great danger of injury or destruction. Hence, the jaws and
teeth in many cases must be examined and described from the single
side exposed. If the opposite side of a similar jaw should be shown
in another specimen, the two may easily be regarded as distinct.
This may also be the case where upper and lower jaws are found
separately. Hence, a large amount of material becomes necessary
for even a proximate correlation of the closely-related forms.

PLAGIAULACIDA.

One of the first American specimens discovered resembled strongly
the minute lower jaws first described by Falconer, under the name
Plagiaulax, and since investigated by Owen, Flower, and others,
whose discussion of the habits and affinities of those peculiar mam-
mals forms a well-known chapter in the history of paleontology.
Of this genus, only the lower jaws were known, and this is one
reason for the wide divergence of opinion as to the nature of the
animals they represent. The lower jaws found in America were
regarded by the writer as indicating a distinct genus, Ctenacodon,
two species of which he has since described.

1 Proceedings British Association, Aberdeen Meeting, p. 1033, 1886.

2 Monograph of the Fossil Mammalia of the Mesozoic Formations, Palzonto -
graphical Society, vol. xxiv. London, 1871.

Prof. 0. OC. Marsh—American Jurassic Mammals. 248

Among the separate upper jaws found in the Jurassic of England
were two or three described by Owen, under the generic name
Bolodon, but with no suspicion that they were in any way related
to Plagiaulaxv. From American deposits, also, somewhat similar
jaws were obtained more recently, and as they were apparently
quite distinct from Bolodon, they were described by the writer as
representing a new genus, Allodon. The molar teeth in one
Specimen resembled those of Plagiaulax, and the writer in his
description expressed the opinion that Allodon should probably be
placed in the Plagiaulacide. A natural inference was that Bolodon
was the upper jaw of Plagiaulax, and Allodon, of Ctenacodon. How-
ever this may be in regard to the European forms, the specimens
now known make it clear that the American genera are quite distinct.

The molar teeth of Allodon and Ctenacodon are of the same general
type, and it is still difficult, if not impossible, to distinguish them
when detached from the jaws. The premolars, however, and
especially the incisors, differ in the two genera, and when well
preserved may often be separated with certainty.

ALLODON.

In Allodon, the superior dentition on each side appears to be as
follows :—Incisors 3; canine 0; premolars 5; molars 2.

The lower dentition is uncertain, but is probably the following :—
Incisors 1; canine 0; premolars 4; molars 2.

The upper molar series in the type specimen of Allodon is well
shown in Plate VI. Figures 1 and 2. The five premolars have
tuberculate crowns, and all appear to be inserted by two fangs.
The first and second have each one external, and two internal cones.
The third premolar has a small additional cusp. These three pre-
molars diminish in size from before backward. The next premolar,
or fourth, is much larger, and has its crown flattened on the inner
side. There are three tubercles on the outer border, and four on
the inner margin. The fifth in the series is still larger, and has
a more rounded crown. There are three lobes on the outer side,
and the same number on the interior face.

The two true molars have low crowns, which are divided into an
outer and inner half, by a deep-worn groove. Hach half bears three
low tubercules, of nearly equal size. The last molar has its longi-
tudinal groove on a line with the inner margin of the other teeth.

The superior incisors of this genus now known are represented
in the detached premaxillary of Allodon fortis, Plate VI. Figures
7-10. The first incisor was very smal]. The second was the main
front tooth, much larger than the third. In the type specimen of
Allodon, represented in Plate VI. Figures 1 and 2, no suture is
visible behind the first small tooth (a), hence this may possibly be
a weak canine instead of the third incisor. In Allodon fortis,
Fig. 7, and also in the type of Bolodon, Owen, the suture between
the premaxillary and maxillary is distinct.

The large second incisor of Allodon is a peculiar tooth, and was
evidently exposed to the full wearing action of a strong lower incisor,

244 Prof. O. C. Marsh—American Jurassic Mammals.

somewhat similar to that of a Rodent. This lower tooth has not been
found in place, but the one represented in Plate VI. Figures 14 and
15, may, with considerable probability, be referred to this position.
The remaining lower teeth have not been found associated with the
upper jaws, but they evidently resembled those of Ctenacodon, in
some of their most important characters.

In comparing Allodon with Bolodon, we evidently have two nearly
related forms. So far as at present known, Allodon has three incisors
instead of two, a larger number of teeth in the premolar and molar
series, and likewise shows other differences of less importance.

The affinities of these peculiar mammals and the inferences in:
regard to their habits and food, which may be drawn from the
specimens now known, will be fully discussed by the writer else-
where.

Attopon Fortis, Marsh.

The present species appears to be generically identical with the
type specimen of Allodon laticeps, but is represented by remains of
much larger size. The premaxillary shown on Plate VI. Figures
7-10, may be taken as the type specimen. A number of upper
molar teeth, and the large lower incisor (Figures 14 and 15 of the
same Plate), are also referred to this species.

The first incisor in this premaxillary was very small, and situated.
close to the median line. It is wanting in the present specimen, but
its size and position are indicated in the above figures. The second
incisor is large and prominent, and is the principal front tooth. It
has a distinct crown, which is covered with enamel, and consists of
one large main cusp, with a small posterior cone. The lower surface
is much worn, evidently by an opposing lower tooth which bore:
directly against it, from its apex to the small posterior prominence.
The sides of the crowns show no signs of wear. The third and last
incisor is much smaller, and is separated from the second by a short
diastema. It has a distinct crown covered with enamel, but shows.
no marks of attrition. It is situated a little in advance of the suture:
with the maxillary, shown in Figure 7, s, Plate VI.

A second specimen referred to this species is shown in Figures
11-18, Plate VI. It is a portion of a left upper jaw containing
three premolars, apparently the first, second, and third. The first
two of these have a single external cone, and two inner cones, and
the second tooth is larger than the first. The third premolar is still
larger, unlike the corresponding tooth in Allodon laticeps, and has a.
second exterior cone behind the main one. Above this tooth, there.
is a large cavity, apparently the entrance of the antorbital foramen.
This is shown in Figure 11. f, Plate VI.

The large lower incisor which met the prominent one above is
probably represented in Figures 14 and 15. This tooth is faced with
enamel in front, and grew from a persistent pulp, like the incisor of
a Rodent. The summit is incomplete, and hence the shape of the
worn surface cannot be determined.

The specimens here described indicate that Allodon fortis was the

Prof. O. O. Marsh—American Jurassie Mammals. 245

largest mammal of this group hitherto discovered in the Jurassic.
In bulk, it was three or four times as large as Allodon laticeps, and
about the size of a Rat.
The only known remains of this species are from the Atlantosaurus
beds of the Upper Jurassic, in Wyoming.

CrENACODON.

The genus COtenacodon was based upon lower jaws, one of which
is represented in Plate VII. Figure 1, and others in Figures 4, 7,
and 8. The single, long, pointed incisor, the four, compressed,

. cutting premolars, and the two, minute, tubercular molars, form
together a peculiar dentition. The long, sharp incisor shows no
signs of wear whatever, and hence could not be opposed to the large
upper incisor of Allodon. Its position was close to its fellow, and
the two evidently acted together, as indicated in Figure 9, Plate VII.
The four premolars form a close-set series, with their upper margins
on a curve, all more or less notched. Some specimens, at least, show
distinct marks of wear on the outer sides of the crowns, which are
sometimes worn to a uniform surface. The two small tuberculate

_ molars are of the Microlestes type, with a deep longitudinal groove
on the upper surface of the crowns.

The entire upper dentition of Céenacodon is not known with cer-
tainty, but it probably corresponded in its main features to that of
Allodon. A portion of the upper jaw, with typical premolars, is

_ shown in Plate VII. Figures 2 and 3. The posterior premolars,
_ especially the last two, show strong marks of attrition on the inner
sides of the crowns, and these were opposed to the compressed pre-
molars below, forming together a most effective apparatus for cutting.

Some of the lower jaws at present referred to Ctenacodon appa-

rently show no signs of wear on the premolars, and as the large
incisor is not preserved, it is impossible to say definitely that they
may not pertain to Allodon. It is likewise quite probable that some

_ of the lower jaws considered as Plagiaulax may belong with some

_ of the specimens now known as Bolodon. The exact correlation of
the two forms cannot be determined with certainty until the upper
and lower jaws are found together in position.

Cienacodon may be distinguished from the type of Plagiaulax (P.
Becklesii) in having four premolars instead of three. The summits
of these teeth alone are notched, and the sides smooth, not obliquely
grooved as in Plagiaulaz. The condyle, moreover, is separated from
the angle of the jaw, not confluent with it. Ctenacodon, also, has
the angle of the jaw not only strongly inflected, but its outer margin
efflected into a wide horizontal shelf, making this one of the most
peculiar features of the genus.

_ The vertical posterior condyle in Céenacodon implies a strong post-
glenoid process, that would confine the jaw to a vertical motion.

In Ctenacodon, the mental foramen is large, and situated below the
middle of the diastema. The dental foramen is under the last molar,
but its entrance is partially concealed by a ridge descending from the

‘ base of the tooth to the inflected border of the angle.

246 Prof. O. C. Marsh—American Turassie Mammals.

In none of the specimens of Ctenacodon preserved is there any
trace of a mylohyoid groove.

CrENACODON PoTENS, Marsh.

A third species of Ctenacodon, much larger than C. serratus, is
represented by several jaws and isolated teeth, discovered since the
first species was described. The most important of these specimens,
which may be taken as the type, is the right upper jaw represented
in Plate VII. Figures 2 and 38. The lower jaw with incisor, figured
on the same Plate, may also be referred to this species. A second
lower jaw in better preservation, but without the incisor, may like-
wise be included, although somewhat larger in size.

The upper jaw above mentioned agrees in its general shape with
that of Allodon. It indicates a short, broad skull, with strong,
expanded, zygomatic arches. There is a small antorbital foramen,
as in Allodon. The four premolars present increase in size from
before backward. The first and second are of the Allodon type.
The last two have strong marks of attrition on the inner surface of
their crowns, as shown in Figure 2 of the same Plate. They differ
from the corresponding teeth in Allodon, in being more compressed,
and adapted to cutting. There were apparently two true molars,
which are wanting in the present specimen, but their position and
size are similar to those of the same teeth in Allodon.

The left lower jaw represented in Figures 7, 8, and 9 shows that
the incisor in this species was very large in size, and a most effective
weapon. It grew from a persistent pulp, and its massive base
extended back under the fourth premolar. The crown is oval in
outline at the margin of the jaw, somewhat more compressed above,
and sharply pointed at the apex. There is a shallow groove on the
outer surface of the lower half of the crown, and a corresponding
depression along the middle of its inner face. A careful examination
shows no signs of wear on any part of the crown.

The premolars are separated from the incisor by a long diastema.
The first premolar is small, without serrations, and is placed close to
the second. The latter is larger, inserted by two fangs, and has the
summit faintly notched. The third premolar was still larger, but is
so much fractured in the present specimen that its form and dimen-
sions are uncertain. The fourth premolar is very large, notched at
the summit, and with its outer face showing distinct marks of wear.

The first true molar is small, and its crown much inclined back-
ward. The second true molar is wanting, but its alveoli show that
it was also small, and placed below the first molar.

In this species, the series of four lower premolars is placed on a
curve, and acts as a single cutting blade against the compressed
upper premolars. This curve is completed behind by the two molars,
which have their crowns inclined outward.

The second and larger lower jaw referred to this species gives
some additional characters. The third and fourth premolars show

* A somewhat similar tooth of M:ecrolestes is figured by Owen in Mesozoic Mammals,
plate i. fig. 16, Mon. Pal. Soc. vol. xxiv. 1871.

Prof. O. C. Marsh—American Jurassic Mammals. 247

distinct traces of wear on their outer surfaces. The first true molar
is placed obliquely, as in the previous specimen, and has been sub-
jected to much attrition. The last true molar was situated lower
than the first, and was also oblique. In Ctenacodon serratus, the two
lower molars are nearly on a level. The present specimen shows
that the angle of the jaw was strongly inflected, and there was like-
wise a ridge on the opposite outer margin. The coronoid process
had its front border more nearly perpendicular than in Ctenacodon
serratus. There is no trace of a mylohyoid groove.

The known specimens of this species are from the Upper Jurassic
deposits of Wyoming.

EXPLANATION OF PLATES VI. anp VII.

PLATE VI.

Left upper jaw of Adlodon laticeps, Marsh; outer view.
The same specimen ; seen from below.
Left upper jaw of same species; inner view.
The same specimen ; seen from below.
Left upper jaw of same species ; outer view.
The same specimen; seen from below.
Right premaxillary of Al/odon fortis, Marsh; outer view.
The same specimen ; seen from below.
The same specimen; seen from in front.
:» 10. The same specimen; inner view.
» 11. Portion of left upper jaw of Allodon fortis ; outer view.
5, 12. The same specimen; seen from below.
», 13, The same specimen; inner view.
», 14. Lower incisor of Adlodon fortis ; side view.
», 15. The same incisor; seen from in front.
a, last incisor; a”, second premolar; 0, fourth premolar; 2’, third premolar ;
e, second true molar; ¢’, first molar; f, antorbital foramen ; m, malar arch ;
8, suture with maxillary.

Figures 1-4 are four times natural size; 5 and 6, six times natural size; 7-16,
three times natural size.

.

(CONES OUR Oo bo

PLATE VII.

Fig. 1. Right lower jaw of Ctenacodon serratus, Marsh ; outer view.
The small figure is natural size, and the larger one is magnified four diameters.

Fic. Right upper jaw of Ctenacodon potens, Marsh ; inner view.
The same jaw; seen from below.

Left lower jaw of Ctenacodon serratus ; inner view.

Incisor, probably of same species ; seen from in front.

The same incisor ; seen from the side.

Left lower jaw of Ctenacudon potens ; outer view.

The same jaw ; inner view.

The same jaw; front view, with its fellow restored in place.

$0 1 DID OVE Ob

In Figures 2 and 3, a, first premolar; 4, fourth premolar; ¢, second molar ;
m, malar arch. In the lower jaws, a, incisor ; 6, condyle; ¢, coronoid process ;
m, molar ; 7, root of incisor ; s, symphyseal surface.

Figures 2, 3, 5 and 6, are four times natural size, and Figures 4, 7, 8 and 9, are
three times natural size.

(Zo be continued.)

248 Dr. Rk. H. Traquair—On Chondrosteus acipenseroides.

IL—Notss on CHzowbDROSTEUS ACIPENSEROIDES, AGASSIZ. -
By Dr. R. H. Traquair, F.R.S., F.G.S.

TYNE now well-known Liassic Acipenseroid fish Chondrosteus

acipenseroides was named by Agassiz in 1843, but not described
by him.’ It subsequently formed the subject of an elaborate memoir
by Sir Philip Grey-Egerton, Bart.,? in which, besides giving a minute
account of the structure of the genus, he named two additional species
—C. pachyurus and C. crassior. Putting the results of Sir Philip’s
investigations as briefly as possible, he maintained that while “in
all essential points” Chondrosteus resembled the recent Sturgeon,
nevertheless in certain others, and notably in the structure of the
opercular and hyoid regions, it constituted a transitional form towards
the more ordinary Ganoids. Moreover, the skin of the body pre-
sented the same naked condition seen in the recent Polyodon.

Hight years afterwards Professor Young read a paper on the
subject before the Geological Society of London, of which only an
abstract of six lines* is given in the Quarterly Journal. The object
of the paper was to show that Chondrosteus was a Holostean, not
a Chondrostean, because it “possesses a well-ossified basioccipital,
and the lateral walls of the cranium are composed of bones answering
to the cartilage bones of ordinary Teleostei.”

In 1877 I placed the family “‘Chondrosteide” (including Chon-
drosteus) in the “‘ Acipenseroid ” suborder of Ganoids, between the
Spatularide and the Paleoniscidee, which latter family, along with
the allied Platysomide, I proposed to include in one great group
with the Sturgeons.*

On the 9th March of the present year, Mr. J. W. Davis read a
paper on Chondrosteus acipenseroides before the Geological Society
of London, of which an abstract has been published. In this paper
Mr. Davis interpreted the appearances presented by a single fine
specimen in his own collection, and besides giving a detailed account
of its anatomical structure, expressed his belief “that there is no
specific difference between C. acipenseroides, Agassiz, and C. crassior,
Egerton.”

Mr. Davis does not seem, however, to have made use of the
magnificent suite of specimens of Chondrosteus in the British
Museum, which contains not only the types of Sir Philip Hgerton’s
figures, but also a splendid array of additional examples, mostly
also from the Egerton and Enniskillen Collections. For the privi-
lege of examining these, and of noting several new and interesting
details presented by them, I am indebted to Dr. Woodward, F.R.S.,
Keeper of the Geological Department, and my thanks are due also
to Dr. Geikie, F.R.S., and Mr. E. T. Newton, F.G.S., for kindly per-
mitting me to take notes of the specimens in the Museum of Practical
Geology, Jermyn Street. In the present paper I propose to give an

1 Poissons Fossiles, t. ii. pt. 2, p. 280.

2 Phil. Trans. vol. 148 (1858), pp. 871—885.

3 Q. J. G. S. vol. xxii. (1866), p. 596.

4 Ganoid Fishes of the British Carboniferous Formations, Pt. I. Paleoniscide,
p. 42, Pal. Soc. 1877.

Dr. R. H. Traquair—On Chondrosteus acipenseroides. 249

outline of the results derived from the study of the specimens in both
Museums.

Cranial Shield.—The elements of the main portion of the cranial
shield have been recognized by Sir P. Egerton and by Mr. Davis, the
former of whom enumerates “the parietals, the mastoids, the frontals,
and the prefrontals,’—the latter stating that the “ frontals, post-
frontals, parietals, mastoid, and some of the occipital plates are
present.” This cranial shield is exhibited in many of the British
Museum specimens, but in none have I seen it better displayed than
in one belonging to the Museum of Practical Geology, from which
Fig. 1 has been taken. Here we have two oblong parietals (p.)

Fic. 1.—Cranial shield of a specimen of Chondrosteus in the Museum of Practical
Geology, Jermyn Street. On the left side the displaced operculum (op.) is seen
overlapping the post-temporal (p¢.) and outer supra-temporal (s¢.).

joining each other in the mesial line, and each is flanked externally
by a rather larger squamosal (sqg.), the “‘mastoid” of a bygone

250 = =Dr. R. H. Traquair—On Chondrosteus acipenseroides.

nomenclature. In advance of the two parietals are two large
Jrontals (f.), also in apposition mesially, while posteriorly, and
externally, each of them also touches the squamosal of its own side.
Then, occupying a corner between the hinder part of the external
margin of each frontal and the anterior external margin of the
corresponding squamosal, is a rather small posterior frontal (p./f.).
In no specimen which I have seen are the plates in advance of
the frontals in sufficiently good preservation to enable one to map
out or describe them: the outline of the snout as given in the
restoration (Fig. 5) is therefore conjectural. Behind the posterior
margins of the parietals and squamosals, and between these and the
post-temporal elements of the shoulder-girdle, is a transverse row
of five small plates (s.¢.). One of these, of a rudely polygonal shape,
is median, and placed just at the union of the two parietals, and is
flanked on each side by another plate, of which the right is larger,
the left smaller than itself. External to each of the latter is the
remaining plate of each side, of considerably larger size, of an
irregularly triangular shape, and placed between the posterior
margin of the squamosal and the post-temporal (p.t.), which latter
it largely overlaps. These are certainly the plates which in other
Ganoid fishes (Lepidosteus, Polypterus) have sometimes been called
“supra-occipitals”’ and ‘“epiotics,” but they are mere scale-bones,
and occupy the place of the supra-temporal chain in Teleostei.

A very distinct suborbital bone (s.o. Fig. 5) is seen in a large
number of specimens. It consists of two limbs—an upper and
longer vertical one meeting below at nearly a right angle with a
shorter horizontal portion, the bone being considerably expanded at
the junction. Above, the suborbital was suspended trom the post-
frontal region of the cranial shield,—below, it comes in contact with
the middle of the maxilla. This suborbital is the bone which Sir
Philip Egerton has interpreted as the “ premaxilla” in his memoir.

All these plates are externally marked with pores, and often with
furrows and ridges radiating from the centres of ossification ; often
also the surface becomes corrugated, sometimes almost granulated ;
but I have seen no positive traces of ganoine upon the surface.

Internal Cranial Bones. —'There is a large parasphenoid much
resembling that of Acipenser in shape; but, unlike Prof. Young, I
can find no remains of ossification in the chondrocranium, which can
be described, or even relied upon as being such. Although such
ossifications may very likely have existed, it seems very improbable
that they attained any considerable dimensions. :

Hyoid Arch.—-The most easily recognized bone of the entire head
is the hyomandibular (h. m. Figs. 2 and 5), which passes from the
squamosal region obliquely downwards and backwards. It is shaped
much ag it is both in Acipenser and Polyodon, being constricted in
the middle and flattened anteroposteriorly in its upper part, laterally
in its lower. In one specimen in the British Museum there is an
appearance as of an ossified symplectic, extending from the lower
extremity of the hyomandibular towards the articulation of the
mandible ; this I do not insist upon, as it is not corroborated by any

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below and affords an excellent view of the shoulder-
and inner surface of a portion of the cranial shield

girdle, opercular apparatus, roof of the mouth,

i

en obliquely from

In this specimen the head is se

252 Dr. R. H. Traquair—On Chondrosteus acipenseroides.

other specimen, though the existence of a cartilaginous one may be
safely assumed considering the large space between the lower
extremity of the hyomandibular and the articulation of the lower
jaw.

The ceratohyal (c. h. Figs. 2, 8,and 5) is also very easily recog-
nizable, and requires no special description.

Fic. 3.—Head of Chondrosteus (British Museum, P. 2048), seen obliquely from
below, showing the position of the mouth and the symphyses of both maxille and
mandibles. The suboperculum and branchiostegal rays are somewhat injured.

Opercular apparatus.—The opercular flap is principally supported
by a large, broad, somewhat irregularly rhombic plate (s. op. Figs.
2, 8, and 5), overlapping, with its anterior superior angle, the
posterior inferior part of the hyomandibular, and leaving a consider-
able space between its upper concave margin and the edge of the
cranial shield. This is the bone which has hitherto been called
“operculum” in Chondrosteus, and it certainly corresponds exactly
in position to the so-called operculum in Polyodon. It is, however,
equally clear that it corresponds also in position, as well as in general

Dr. R. H. Traquair—On Chondrosteus acipenseroides.. 253-

shape, with the suboperculum of Palgoniscus ;+ and that this is its
true interpretation is proved by the discovery of the proper oper-
culum (op.) lying above it and between it and the cranial shield
(Figs. 2, 3,5). The shape of this operculum may be aptly likened
to that of an inverted comma, the tail passing upwards and forwards
to the cranial shield, the convex margin being posterior and the
concave one anterior, a considerable space in front of the bone and
above the suboperculum being still left uncovered. The opercular
flap is continued downwards and forwards by a series of ten
imbricating branchiostegals (br.), which are broad and _ plate-like
where they immediately follow the suboperculum, though anteriorly
they become narrow and slender.

Jaws and palato-quadrate apparatus.—The maxilla (ma.) is a
tolerably stout bone, tapering anteriorly and somewhat expanded in
its posterior third—the posterior margin looking very obliquely
upwards and backwards. As is well shown in Figures 2 and 3, it
is curved inwards in front to meet its fellow of the opposite side in
a perfect symphysis; there cannot, therefore, be a true premaxilla
here any more than in Acipenser or Polyodon. Articulated to the
oblique posterior margin of the maxilla is a small flat plate (7), whose
shape somewhat reminds one of a boot, the sole being in apposition
with the maxilla, while the leg is directed upwards and backwards
towards the anterior margin of the suboperculum (see Fig. 4, /).
This is clearly the homologue of the little bone which in the recent
Sturgeon is called “ praeoperculum ” by Mr. W. K. Parker,? although
it seems to me and others to be the same “jugal” element which
we find appended to the maxilla in Amia, Salmo, etc. In the Sturgeon
it has also been called “ maxilla” by some who looked upon the real
maxilla as a “ premaxilla,”* and this seems to have been Sir P.
Egerton’s view when he assigns a preemaxilla as well as a maxilla to
Chondrosteus. But an examination of the original specimen repre-
sented in pl. lxix. of his memoir shows that his “ premaxilla” is the
suborbital bone, and that his maxilla—the small bifurcate bone
behind it—appertains to the palate, and will be described immediately
as a pterygoid element! The real maxilla in this specimen is inter-
preted by Sir Philip as a mandible, while to this jugal plate he has
assigned the name and position of hypotympanic (=quadrate).

Within the space bounded by the maxille, the roof of the mouth is
principally composed of two plates (m. pt. Figs. 2 and 4) of a some-
what oval or ovoid contour, narrower behind than in front. Ante-
riorly, these plates are placed behind the symphysis of the maxilla;
mesially, they articulate with each other along a portion of their
internal margins, while externally each comes into contact with

! Described as ‘‘ interoperculum ”’ in my Memoir on the Structure of the Paleo-
niscidee. I have, however, abandoned that view, and now consider the plate inter-
calated between it and the operculum in such genera as Rhabdolepis to be not a sub-
operculum, but merely an accessory element.

* *«On the Structure and Development of the Skull in Sturgeons,” Phil. Trans.
vol. 173 (1881), p. 172.

° See Stannius, “‘ Handbuch der Zootomie der Wirbelthiere,” erster Theil, Die
Fische, p. 53.

204 Dr. R. H. Traquair—On Chondrosteus acipenseroides.

the maxilla of its own side for the anterior half of its length, behind
which the margin recedes inwards, the little bone pé. being placed
just where the recession takes place. These plates were recognized
by Sir Philip Egerton as “ palatine,” and are undoubtedly the repre-
sentatives of the two plates occupying a corresponding position in

Drawn

mesoptery-

,in the British Museum. m. pt.

+ side of head of Ohondrosteus, seen from above.
pterygoid, or ectopterygoid.

killen Coll. No, P 3367
jugal. pt.=

paratus of lef

mnis

goid. mx.=maxilla. /.

Fig. 4.—Palatal ap

from specimen in the E

Acipenser, and which, although formerly usually reckoned as “ pala-
tines,” are designated as ‘“ pterygoids” by Prof. W. K. Parker.1 To
my mind it seems to correspond more with the mesopterygoid of other
fishes, and I have lettered it accordingly.

Placed at the middle of the outer edge of this last described bone,
and articulating both with it and with the maxilla, is a small

E Op. cut. po LGt

Dr. R. H. Traquair—On Chondrosteus acipenseroides. 255

bone (pét.) which bifurcates posteriorly, one limb being placed
along the middle, the other along the mesopterygoid palate-plate.
This is the bone which Sir Philip Egerton has interpreted as
“maxilla” (op. cit. pl. lxix. 21), but whose true relations are most
clearly seen in a large number of specimens in the British Museum.
These relations are not obscure even in the specimen figured by
Sir Philip; but here, as already explained, he unfortunately mistook
the real maxilla for the lower jaw. As the position of this little
bone is about the middle of the maxilla and behind the suborbital,
we may feel a little surprised at the following statement in the
published abstract of Mr. Davis’s paper :—“‘ From the position of the
respective maxillary and premaxillary bones in this (Mr. Davis’s)
specimen, there can be no further doubt that the small bifurcated
bone of C. acipenseroides, Ag., described as the maxillary bone, is
really the premaxillary.”

Fie. 5.—Profile of head of Chondrosteus, restored.

But if we inquire what this little “bifurcated bone” really
is, | answer that it seems to me to occupy, as regards the maxilla
and the great palate-plate, a position quite analogous to that of the
small bone in Acipenser lettered as “palatine” by Professor W. K.
Parker, but which I have come to look upon as a pterygoid or
ectopterygoid, for the same reasons which have induced me to regard
the great palate-plate as a mesopterygoid, and as such I have
accordingly marked it.

I have seen no evidence of ossified quadrate or metapterygoid
elements. There can be no doubt that the bone interpreted by Sir
Philip Egerton as a combined “‘mesotympanic” and ‘“ hypotympanic”’
(symplectic and quadrate of modern nomenclature), is that external
plate appended to the hinder extremity of the maxilla, which I have
already described as the jugal.

The mandible is stout, and anteriorly is, like the maxilla, strongly
curved inwards to meet its fellow of the opposite side in a symphysis:
its outer surface presents a well-marked longitudinal groove, which

256 Dr. R. H. Traquair—On Chondrosteus acipenseroides.

approaches close to the superior margin about the middle of its
extent, and then diverges downwards and backwards towards the
angle. Sir Philip Egerton describes the mandible of each side
as a single bone, and no doubt it is mostly composed of a large
dentary element (d. Fig. 3). But at its posterior extremity two other
elements are undoubtedly present, of which one, the upper, may be
reckoned as articular, while the other beneath it is unquestionably
the angular (ag.).

No trace of teeth can be seen in connection with either jaw;
Chondrosteus in this respect, as in so many others, resembling the
recent Acipenser.

Branchial skeleton.—Abundant remains of ossified cerato-branchials
(Fig. 2. c. b.) are seen in many of the specimens, but we need not be
detained at present by entering into detail as to this part of the
skeleton.

Shoulder-girdle. — Sir Philip Egerton states that whereas in
Acipenser three bones are present in the shoulder-girdle, viz. supra-
scapular (post-temporal), scapular (supra-clavicular), and coracoid
(clavicle), in Chondrosteus the “scapula” and “coracoid” have
coalesced. In Acipenser there are, however, at least four membrane
bones of the shoulder-girdle; the post-temporal being however
immoveably articulated with the cranial shield, while the fourth
element is the large infra-clavicular plate. And Mr. Davis, as regards.
Chondrosteus, is undoubtedly right in maintaining that the “scapula”
and ‘“coracoid” are not fused, though, as he enumerated only three
elements in the shoulder-girdle, he seems not to have observed the
infra-clavicular.

The post-temporal (Figs. 1 and 2, p. ¢.) is a somewhat three-cornered
plate placed behind the posterior margin of the cranial shield, and
having its anterior margin overlapped by the supra-temporal bones.
This is followed by the supra-clavicular (Fig. 2. s. cl.), an oblong
bone passing obliquely downwards and backwards, and having its
upper extremity obliquely perforated by the side-canal. Its distinct-
ness from the clavicle is obvious in every well-preserved specimen.
This clavicle (Figs. 2 and 38, el.) differs from that of the Sturgeon in
not being so much developed inferiorly, so that the next element, the
infra-clavicular (i. cl.) articulates to its lower margin, extends higher
up, and comes to be opposite a considerable portion of the origin of
the pectoral fin. There is still another plate (Fig. 3, p. cl.), though
it is a very small one, appended to the posterior margin of the
clavicle, and this we may recognize as corresponding to the post-
clavicular of Polyodon and the Palezoniscide.

I have seen no evidence of ossification in the scapulo-coracoid
cartilage, nor does any specimen afford a view of the base of the
pectoral fin, though in some a few dislocated radials may be seen in
this position. It is probable that the arrangements here resembled
those in Acipenser, and I own lam somewhat at a loss to understand
the “two bones” to which Mr. Davis alludes as “ apparently repre-
senting the radius and ulna of Owen (coracoid and scapula of
Parker).”’

Dr. R. H. Traquair—On Chondrosteus acipenseroides. 257

The limits of the present paper hardly permit my entering into
detail as to the rest of the structure of Chondrosteus. So far as the
internal skeleton is concerned, its remains indicate a structure very
similar to that in Acipenser, while the fins in shape and arrangement
much resemble those of Polyodon.

Conclusion.—Although there is no evidence of any long snout,
Chondrosteus resembled Polyodon in the general shape of the body,
in the form and arrangement of the fins, and, above all, in the absence
of scales on any part, save the prolongation of the body-axis along
the upper lobe of the very heterocercal tail. In other respects its
affinities are more with Acipenser.

How like the corresponding parts in Acipenser are the suborbital
bone, the edentulous jaws, the jugal bone, and indeed the palatal appa-
ratus, though that has also its own peculiarities ; while it seems highly
probable that the mouth was protrusible as in the living Sturgeon.

But where the resemblances to Acipenser become weaker, they come
to point in another direction, namely, that of Palgoniscus, and of
course through the Palzoniscide to the truly ‘ teleosteoid” Ganoids.
This is in the first place well seen in the cranial shield (Fig. 1)
where the parietals and frontals are mesially in contact with each
other for their whole length, where there is a well-marked supra-
temporal chain, and where the post-temporal is moveably articulated,
—whereas in Acipenser the frontals are entirely separated by an inter-
calated plate, and the post-temporals and two of the median body-
plates are immoveably joined to, and form a part of the cranial
buckler itself. LHypecially paleeoniscoid is, however, the aspect of
the opercular and branchiostegal apparatus, as will be seen if the
reader will compare the restored drawing (Fig. 5) with the figures
of the heads of Palgoniscus and Nematoptychius given in my account
of the Paleoniscide, although in Chondrosteus there is no preoper-
culum and the series of branchiostegal rays of the two sides may not
have met in the middle. The special resemblance of the shoulder-

_ girdle to that of Palconiscus is also very striking, especially in the

form of the post-temporal and supra-clavicular bones.

In my already-quoted essay on the structure of the Paleoniscide,
I pointed out certain strange and previously unrecognized resem-
blances which Palgoniscus bore to Polyodon, especially in the internal
skeleton, the shoulder-girdle, and the jaws and palato-quadrate
apparatus (even although there are premaxillary bones and there is
no evidence that the palato-quadrate elements met in the middle line

‘infront). Ialso remarked that the resemblances between Palgoniscus

and Acipenser are of course much less prominent. Here, however,
is a form which in many of its features presents strong Palzoniscoid
resemblances, but whose affinities are, nevertheless, more with Aci-
penser than with Polyodon !

The affinities of Chondrosteus seem, therefore, to radiate in three
directions, towards Acipenser, towards Polyodon, and towards the
Palzoniscidee, and certainly, of all the three directions, the distance
towards Acipenser is the least.

DECADE III.—VOL. IV.—NO. VI. 17

258 E.. Wilson—British Liassie Gasteropoda.

IJI.—Britisa Liasstc GASTEROPODA.
By E. Witson, F.G.S8.; Curator of the Bristol Museum.

(Concluded from p. 202.)
CERITHIUM TRIGEMMATUM, spec. nov. PI. V. Figs. 10, 10a.

Description.— Shell conical, turrited; apex acute; spiral angle
regular, whorls 8-9, angularly carinated anteriorly; sutures wide
and deep; each whorl bears 3 spiral rows of equally spaced but
unequal neatly rounded tubercles ; the anterior of these, which are
much the largest, are set on the carina; the middle row consists of
fine granules, whilst the nodules of the posterior row, which adjoin
the posterior suture, are intermediate in size and half-way between
the other two. Fine, close-set curved strie of growth cross the
whorls transversely, but are scarcely discernible even with a lens,
except on the last whorl of well-preserved specimens. Last whorl
bicarinated by a fourth very finely granular raised line, between
which and the coarsely nodulated carina is a plain encircling thread ;
base flattish, bearing a few concentric raised lines. The aperture is
imperfect in all the specimens I have examined, but is roundly ovate
in form, and occasionally shows slight indications of the commence-
ment of an anterior canal. I therefore assign this species to the
genus Cerithium.

Dimensions.—Length, 7-5 millimétres; diameter, 2°5 mm.; spiral
angle, 22°; sutural angle, 97°.

Geological Position and Locality. — Lower Lias, zone of Am.
oxynotus, Railway-tunnel, Old Dalby, Leicestershire.

ACTONINA FERREA, Spec. nov. Pl. V. Figs. 11, 11a.

Description.—Shell pyriform, smooth and shining ; spire depressed
near the shoulder of the last whorl, but presenting a small pyramidal
elevation in the centre; this portion of the shell is badly preserved,
but the total number of the whorls appears to be 5; anarrow groove
encircles the shoulder of the last whorl above (posterior to) the
rectangulated keel. The aperture is almost entirely concealed in my
sole specimen, but it widens out somewhat towards the anterior
extremity, and the inner lip is thin with a sharp edge anteriorly,
without any fold or thickening over the columellar region. A few
(5 or 6) fine encircling striz are discernible on the anterior portion
of the last whorl.

Dimensions.—Length, 7°5 mm.; diameter, 5 mm.; length of last
whorl, 6-75 mm.

Geological Position and Locality.—Middle Lias, Marlstone Rock,
zone of Am. spinatus, Hast Norton Embankment, derived from
Tilton, Leicestershire.

CYLINDRITES HQUALIS, spec. nov. Pl. V. Figs. 12, 12a,

Description.—Shell ovately and regularly fusiform ; spiremoderately
elevated, obtusely conical; apex acute; whorls 4, slightly convex,
embracing, with narrow ill-defined sutures. A narrow impressed line

é

EE. Wilson—British Liassic Gasteropoda. 209

encircles the whorl a little in front of the suture, between which
there is a narrow raised encircling band; the aperture is, unfortunately,
not well shown; it occupies five-sixths of the length of the last
whorl, the anterior extremity is acutely angulated, with thickened
margins, and there is a distinct spiral fold on the columellar border
anteriorly. The shelly matter has disappeared, but the surface
appears to have been originally smooth.

Dimensions.—Length, 11°5 millimetres ; diameter, 5°75 mm. ;
length of last whorl, 10 mm.

Geological Position and Locality.—Middle Lias, Marlstone Rock,
zone of Am. spinatus, Hast Norton Embankment, derived from Tilton,
Leicestershire.

Bririsa Liasstc ALARIZ.

It has often been supposed that the section of winged shells
Aporrhaide, and genus termed Alaria by Lycett, but more clearly
defined by Piette, did not appear in the British area until the
commencement of the Oolitic period. This is certainly a mistake.
Although extremely rare in the Lias, there are undoubted instances
of the occurrence of Alarig even in the Lower division of that
formation. Messrs. Tate and Blake do not record this genus from
the Yorkshire Lias. In his valuable “Contributions to the Paleon-
tology of the Yorkshire Oolites,’ Mr. W. H. Hudleston, F.R.S.,
referring specially to the Yorkshire area, observes that “It was in
the Lower Oolite that the genus Alaria first began to flourish, and
we find that it became tolerably well represented as low down as the
Inferior Oolite or Bajocian subdivision” (Grou. Mac. Dee. III. Vol. I.
p. 145, 1884). In the year 1867 the late Charles Moore described
three species of Alaria from the Upper Lias of Somersetshire, viz.
A. unispinosa, Moore; A. coronata, Moore, and A. angulata, Moore.
The first of these certainly, and the last two probably, are true
Alarig. Since then other examples of this genus have been found
in different portions of the English Lias. Mr. T. Beesley, F.C.S.,
whose valuable labours in the Lias of Oxfordshire are widely known,
informs me that he has obtained the moulds of two Alarig, which he
takes to be A. coronata and A. angulata, from the Upper Lias shales
(lower portion of zone of Am. communis?) of Bloxham, Oxon. Mr.
H. A. Walford, F.G.S., of Banbury, records an Alaria (A. unispinosa,
query A. semicostulata) from the Upper Lias of Chipping Warden,
Northamptonshire. Mr. B. Thompson, F.G.8., has shown me
imperfect specimens of an Alaria, which may be A. unispinosa, from
the Upper Lias (zone of Am. serpentinus) of Alderton, Gloucester-
shire, and Mr. W. D. Crick has recently forwarded me specimens
from the Upper Lias of Chipping Warden, and of Burrow Hill,
Dodford, Northamptonshire, which are very closely allied, if not,
indeed, identical with A. semicostulata, Piet. et Eug. Desl. Last
year I had myself the good fortune to find a single well-marked
example of this genus in the Lower Lias of Bitton, near Bristol,
Gloucestershire.

In his classical paper on ‘Abnormal Secondary Deposits in the

260 Li. Wilson—British. Liassic Grasteropoda.

West of England,” the late Charles Moore described two incomplete
shells from the Lower Lias coralliferous conglomerate of Brocastle,
Glamorgan, under the names Alaria rudis, Moore, and A. fusiformis,
Moore (Q.J.G.8. vol. xxiii. p. 566, pl. xiv. figs. 24, 25). Having
lately examined these specimens in the Bath Museum, I would
question very seriously the generic appellation given to these fossils.
In their general proportions both these shells are very unlike typical
Alarie, and seeing that they show no distinct canal or trace of
digitation, their identification as such must be considered doubtful.
On the other hand, there are a few forms in the “ Moore Collection ”
at Bath, at present ascribed to other genera, which may eventually be
shown to belong to the genus Alaria. For the present, the little
shell from the Lower Lias of Bitton, Gloucestershire, must, I believe,
be considered the earliest definitely established British Alaria, if not
indeed the earliest known example of that genus.

Aparia Hupuestont, spec. nov. Pl. V. Fig. 13.

Description.—Shell turrited, scalariform ; apex acute; spiral angle
slightly concave; whorls 8-9, quadrangular and rectangularly
bicarinated, with wide and deep sutures; the carinz each bear a
finely-granulated thread over the angle, the posterior of which is
rather more prominent, and causes this keel to project a little more
than the anterior one; the posterior carina is encircled anteriorly by
a narrow impressed line; the whole of the spire and apparently also
the base is covered with fine oblique radial lines; in the earlier
whorls the anterior carina is submedian and much more prominent,
and is coronated over the angle by vertical coste, whilst the posterior
carina is much less prominent; the base of the shell is almost flat,
it bears 8 or 4 widely-separated concentric raised lines. The wing
consists of a single digitation, which has a general direction at right
angles to the axis of the shell; this is wide at its origin, directly
below the anterior carina of the last whorl, after proceeding a short
distance it suddenly narrows, and then soon tapers away to its
rather blunt and slightly recurved extremity. Canal unknown, the
canal-sheath being broken off at its origin.

Dimensions.—Length of shell without the canal, 7-5 millimétres ;
diameter of last whorl, 4mm.; breadth of same, with wing, 8 mm. ;
spiral angle, 30°; sutural angle, 105°.

Obs.—I name this interesting fossil after Mr. W. H. Hudleston,
M.A., F.R.S., who has contributed so largely to our knowledge
of the Gasteropoda of the British Oolites.

Geological Position and Locality.—Lower Lias, zone of Am. Buck-
landi (lower portion), Stout’s Hill, Bitton, near Bristol, Gloucester-
shire.

ALARIA SEMICOsSTULATA? Piet. et Hug. Desl. Pl. V. Figs. 14 & 15.
1864. <Alaria semicostulata, Piet. et Kug. Desl. Pal. Fr. Terr. Jur. Gast. vol. iii.
p. 18, plate 1. figs. 7—9.

The following description of the more perfect of Mr. Crick’s
specimens will be found to agree pretty closely with that given by
Piette (Uc.).

ogee

E. Wilson—British Liassie Glasteropoda. 261

Description. — Shell turrited, fusiform; spiral angle regular ;
whorls 9 or thereabouts, convex, very feebly carinated a little anterior
to the middle line, and ornamented by several fine spiral threads of
unequal thickness. In one specimen (Fig. 14), which is the more
complete of the two, but is imbedded in the rock so as not to show
the aperture, there are on the penultimate whorl 11-12 threads. Of
these four are coarser than the rest; two of those which are most
prominent and subcentral in position determine the faint keel; the
other two are anterior to these; between the second and third, and
also between the third and fourth, of these coarser threads, counting
from the anterior suture, there is a fine line; posteriorly to the fourth
coarse thread there are two threads of medium coarseness with a fine
thread between them, and there are two or three more fine threads

between the last of these and the posterior suture. Crossing these
are numerous inconspicuous curved radial lines of growth. The
earlier whorls are badly preserved, but enough remains to show that
they bear strong straight radial costee; these coste disappear on the
later whorls, and there are no signs of them on the last two or three.
The canal-sheath, uniformly slender from its origin, is prolonged in
a straight line axially to its termination ; it is striated by fine oblique
lines. (In Piette’s type the canal was broken off short, so that the
character of its termination could not be given.) The aperture and
ultimate wing (Vaile définitive) are not shown, but the character of
the latter is indicated by a single longish slender spine, which
originates from the posterior line of the keel, making an angle of
68° with the axis of the spire.

Dimensions.—Height, including the canal, 19 mm.; height, without
the canal, 14 mm.; greatest breadth of last whorl, exclusive of the
wing, 8 mm.; spiral angle, 25°; sutural angle, 115°.

Geological Position and Locality.—Upper Lias, zone of Am. serpen-
tinus, Burrow Hill, between Dodtord and Norton, Northamptonshire.

The other specimen (Fig. 15) is much less perfect, but it agrees
pretty closely with the foregoing in its general form and ornamenta-
tion. The whorls, however, appear to be more convex, with deeper
sutures, and are even less perceptibly carinated; they are crossed by
widely spaced slender curved radial cost, which taper away towards
the sutures, and almost disappear on the later whorls; a short spinous
process remains at the opposite side to the aperture, from which
point a single angular and moderately prominent keel is continued
forwards: the base as well as the apex of the shell having suffered
considerably, we cannot say for certain whether any more spinous
processes were developed on the keel or what were the characters of
the canal and the wing.

Dimensions.—Spiral angle, 25°; sutural angle, 120°.

Geological Position and Locality.—Upper Lias (transition-bed to
Middle Lias), Chipping Warden, Northamptonshire.

Obs.—There are minor differences in form, and in the number
and arrangement of the spiral lines, between the above shells
and between each of them and Piette’s figure of Alaria semi-
costulata. The shell from Burrow Hill (Fig. 14) evidently does not

262 _ dod. BE. Marr—Glacial Deposits.

exhibit its full growth, so that it is impossible to say whether an

angular carina sets in on the last whorl or not. Judging by its

general agreement with our other specimen, I am inclined to think it
would, and in that case the chief difference between this shell and
Alaria semicostulata disappears. Again, in the Chipping Warden
specimen (Fig. 15) the whorls are more rotund and more deeply
sutured than in the enlarged figure of A. semicostulata, given by
Piette, or in the first above-described specimen. Slight variations
in the convexity of the whorls, in the depth of the sutures, spiral
angle, and arrangement of the spiral lines, are not by themselves
characters of specific value amongst otherwise similar Alarie; so
that in face of the general agreement of these shells with 4. semi-
costulata, and failing definite proof of any important distinction in
the keel, the carinal spines, or the canal, I consider it safest to
relegate both of the above specimens to that type.

[For the Plate and the Explanation thereof, see the May Number, p. 202.]

IV.—Tue Guactan Deposits or Suppury, SUFFOLK.

By J. E. Marr, M.A., F.G.S.,
Fellow of St. John’s College, Cambridge.

HE accumulations of drift in the vicinity of the town of Sudbury
have been described by Mr. Whitaker in the Geological Survey
Memoir upon the N.W. part of Essex and N.E. part of Herts, ete. ;
and additional notes are given by the same author in the Memoir upon
the Geology of Ipswich, etc. Since the appearance of these memoirs
the sections have altered considerably, and one of the exposures is
of such interest, that a record of it seems to me desirable, as in a
few years it will be doubtless destroyed, and one more link in the
chain of facts which have to be considered in attempting to account
for the mode of formation of these drifts will have disappeared.
I wish to express my indebtedness to Dr. J. 8. Holden, F.G.S.,
who has kindly accompanied me to the principal exposures, and
furnished me with much information.

Fic. 1.—Section in Mr. Green’s Pit N.E. of Sudbury.
S. Length of Section about 100 feet. IN

A. Chalk. 1. Boulder-clay. D. Gravel dug over and filled in.
B. Thanet Sands. 2. Gravel and sand. T. Talus.
C. Red Crag. 3. Loam.

C’. Red Crag caught up in drift.

The section to which I would call special attention is seen im
Mr. Green’s pit, about a quarter of a mile N.E. of Sudbury Town Hall.
The accompanying Figure (Fig. 1) shows its appearance at the

J. EB. Marr—Glacial Deposits. 263

present time (March, 1887). The Chalk, which is worked to a
depth of many feet, is succeeded by the clayey green sand with green-
coated flints, referred by Mr. Whitaker to the Thanet Sands. The
bed is partly removed at one point, near the north end of the section,
but elsewhere it hag its full thickness, which is ascertained where
the green sand is succeeded by an upper deposit resting conformably
upon it; this is the red clay, B® of Fig. 2, which only occurs in one
part of the pit underneath a remarkable ridge of Red Crag to be
now described. The ridge is marked C in Fig. 1, and an enlarged
sketch of it is given in Fig. 2. The lower part consists of the

Fic. 2,—Enlargement of the Crag Ridge in Fig. 1 (Mr. Green’s Pit).

A}, Chalk. 1. Boulder-clay.
1
as oe ae Thanet Sand. 2. Sand and gravel,
C'. Pebble bed. 3. Loam.
C?. Hard dark brown very ferruginous gravel a. Iron staining from Crag
0%. Bleached (yellow-green) sand Red Ridge.

C°, Rust-red sand, very finely laminated in drift.
C®, Bleached (yellow-green) sand in the drift z. Marked divisional plane
(fault ?).

pebble-bed with phosphatic nodules described by Mr. Whitaker
(Q.J.G.S. vol. xxx. p. 401). This is marked C’in Fig. 2. Next
above it is a coarse sandstone CO? with a few pebbles, the whole being
hardened by a ferruginous cement which gives the rock a very
dark-brown colour. The united thickness of these beds is about 2 feet
6 inches. The main part of the ridge is formed of about 8 feet of
fine incoherent quartz-sand, stained rusty red at the summit, but
bleached to a pale yellow-green hue at the base. The bleached part
C* and the lower portion of the unbleached part C* are devoid of
lamination planes, though some planes of deposition are visible ; but
the top of the ridge C* is formed of a finely-laminated sand, the
laminz being quite regularly inclined at a very low angle towards
the south. It will be seen that not only are the bedding planes
between the Chalk and the Thanet Sands, and between the latter
and the Red Crag, quite regular, but that the divisional planes of
stratification and lamination in the latter, which stands up as a ridge
in the middle of the drift accumulations, are absolutely undisturbed.

C4. Rust-red sand, not laminated | Crag y. Fragmentof Bed C* included

264 J. H. Marr—Gilacial Deposits.

Very different is the condition of the overlying drifts. Before
proceeding to describe them, I may refer to the section fig. 17 of the
Geological Survey Memoir on the Geology of N.W. Essex, ete.
This section is described by Mr. Whitaker as occurring on the foot-
path to Chilton; it would therefore lie somewhere to the east of the
section now under consideration. The structure of the Crag ridge
and the disposition of the overlying drifts would seem to indicate
that there was a continuation of the ridge now visible in Mr.
Green’s pit, in which case the ridge probably has a general H.—W.
direction, as may indeed be gathered from an examination of Mr,
Green’s pit itself. The section figured by Mr. Whitaker is now
destroyed.

The ridge in Mr. Green’s pit increases in height and breadth
towards the west, as shown by comparing a photograph which I
caused to be taken at the end of the year 1885 with the present
exposure, several feet of the face of the cliff having been cut away
in the interval.

The description of the drift deposits of this pit is not quite so easy
as that of the older formations. Mr. Whitaker describes the Boulder-
clay in the pit on the footpath to Chilton as filling up a hollow in
the gravel, but the section as drawn by him is explicable also upon
the supposition that the gravel fills up a hollow in the Boulder-clay.
In the case of Mr. Green’s pit, I came to the conclusion that the
latter was the case, and have therefore taken the Boulder-clay as the
deposit which would under ordinary circumstances be the lowest.
This may be the case here, even if the Boulder-clay in the pit on
the footpath to Chilton is above the gravel, as Mr. Whitaker shows
that there are two Boulder-clays in the area. The succession, as
gathered from a careful examination of Mr. Green’s pit, appears to be
as follows :—

1. Boulder-clay.

2. Coarse sand and gravel.
3. Fine loam.

And this is the order in which I shall describe the accumulations.
The Boulder-clay 1—Figs. 1 and 2—consists of a very stiff brown
or leaden-blue clay, having at the south end of the pit a series of
wavy divisional planes. Besides this, it in places contains very
close-set divisional planes, reminding one strongly of the ‘ fluxion-
structure ” of igneous rocks. Along some of these carbonate of lime
has collected, giving the deposit here and there a marked banded
appearance. The deposit is full of boulders, mostly small, the
greater number being of white chalk (often striated) and flint, but
blocks of sandstone also occur, especially a port-wine red sandstone.
In the north part of the pit a small patch of Boulder-clay occurs in a
depression of the Thanet Sands, but separated from them by gravel.
This clay forms a horizontal tongue a yard or two long, and 2 ft.
Gin. high. At the bottom of the clay, and resting on the gravel,
are patches of red clay, clayey green sand, and a mixture of the two,
evidently torn off from the rocks close by. The Boulder-clay
probably owes its position here to a fault which appears to run

;
&

J. E. Marr—Gtacial Deposits. 265

almost horizontally from the upper portion of the Crag ridge, and
which brings the deposits below against beds above inclined at
quite different angles. The whole arrangement of the drifts at this
part of the pit is extremely difficult to comprehend.

The gravel and sand 2— Figs. 1 and 2—are stratified and frequently
false-bedded. They contain a considerable intermixture of argilla-
ceous material. The boulders are similar to those in the Boulder-clay,
mainly chalk and flint. I noticed two small fragments of red
chalk. The carbonate of lime has collected along divisional planes,
as in the case of the Boulder-clay and of the loam. In the central
part of the section the gravel undoubtedly does at present overlie
the Boulder-clay, and though it is underneath it at the south end,
this seems to be due to the thrusting of a trough of gravel and loam
under the Boulder-clay.

The gravel is arranged around the Crag ridge in two loops, and
in the northerly one a mass of sand (Fig. 1, C’) is involved; this
sand is almost certainly a piece torn off from the Crag. It is
entirely different from the gravels and loams, and resembles
precisely the bleached portion of the Crag ridge, being, like it, a
pale yellow-green quartzose sand, devoid of lamination; moreover,
here and there a few brown patches show parts that have escaped
the bleaching, as is also the case with the Crag of the ridge.

The drift-gravel is in one place coloured red, viz. along a line
(Fig. 2) proceeding from the northern edge of the Crag ridge. This
is possibly due to subsequent infiltration, but it is also possible that
small particles of the Crag have been carried down along this line.
The latter certainly seemed to me to be the case on examining the
coloured seam closely.

Immediately below this stained line occurred a fragment of the
bed C? (y. Fig. 2) caught up in a small patch of loam in the centre
of the gravel.

The loam 38—Figs. 1 and 2—is a stiff yellowish-brown clay,
sometimes sandy, and containing comparatively few boulders. It is
very finely laminated throughout. It occurs in the loop just south
of the Crag ridge, and in the centre of the loop now underlying the
Boulder-clay in the southern portion of the pit-face. It again occurs
in a very narrow loop to the north of the Crag ridge; this expands
above the plane, which is, as I have suggested, possibly a fault
plane, and is then continued along this plane as a very narrow seam,
sometimes only a couple of inches in thickness, above the patch of
Boulder-clay before referred to, and beyond it for some yards to the
extreme north end of the section.

In a pit to the east of Mr. Green’s, a considerable mass of the
ferruginous sands of the Crag is seen, succeeded by coarse gravels,
above which comes contorted loam, in some cases bent into long
horizontal loops, but no Boulder-clay is now visible. Here again
the Crag sands are absolutely undisturbed, notwithstanding the
violent contortion of the drifts immediately above.

. Two important sections occur near the town upon the right bank
of the Stour. One of these is near the summit of Balingdon Hill

266 J. EH. Marr—Glacial Deposits.

(Fig. 38). The pit here is mainly cut in the ferruginous sands of the
Crag, which show a total thickness of 30 feet here, without any
signs of approaching the base. The beds are quite like those of the
Crag ridge in Mr. Green’s pit, save that they are here markedly
false-bedded. The surface is perfectly even except in one place,
where a rounded ridge rises up five feet above the surface of the:
surrounding sand (C', Fig. 3). The Crag is succeeded here by
Boulder-clay, which is at the top an ordinary blue laminated
Boulder-clay, with the usual scratched chalk boulders, as. well as
others of flint, oolitic limestones, sandstones, ete., and below this
two feet of a sandy laminated Boulder-clay, of a reddish colour, the
sand being evidently derived from the underlying Crag.

Fic. 3.—Pit on Balingdon Hill.

—— EL

: S SSSSSSSSSSS=

= ZA LZ BZ
eee SSIES I ESTE =<

——=_

SSS

SS a LLL

C. False-bedded sands, ferruginous above, bleached at base, 25 feetseen ) Red
C’. Ditto bleached, projecting into drift, 5 ft. ) Crag.
1. Sandy laminated Bonlder-clay, 2 ft.

1’. Blue laminated Boulder-clay, to 10 ft.

The last section I shall notice is in Mr. Allen’s pit, close to the
river-side, and about half a mile south-east of the last-mentioned
exposure. This appears to be the pit described by Mr. Whitaker as
the ‘Grove.’ It is of interest as showing two Boulder-clays (cf.

Fic. 4.—S8. end of Mr. Allen’s Pit, Sudbury.

1. Lower Boulder-clay, 20 ft. seen. 3. Loam, to 15 ft.

2. Sand and gravel, 10-12 ft. 4, Upper Boulder-clay, to 16 ft.
Fig. 4). The lower one is a leaden-blue clay, often very dark,
laminated, and with many chalk boulders, twenty feet beimg seen,
and Mr. Allen informed me that below it a hard sandy rock occurred
with a band of round pebbles below, almost immediately underlain
by the Chalk. The hard sandy rock and pebble bed are most
probably the beds of the Crag which are seen at the bottom of the
ridge in Mr. Green’s pit. It will be noticed that the base of the
drift is here about 150 feet below its position on Balingdon Hill.

The Lower Boulder-clay is succeeded by sand and gravel, altogether

like that of Mr. Green’s pit, so that description is unnecessary.
The same may be said of the succeeding loam, which is here rather:
more sandy than on the left bank of the Stour.

J. E. Marr— Glacial Deposits. 267

The Upper Boulder-clay is lighter than the Lower, but otherwise
altogether like it; but it contains thin seams of gravel and loam.
A large number of boulders were lying in the pit, probably from
both clay and gravel, and consisting of various schists, granites,
fragments of basaltic columns, limestones, sandstones, ete.

The sands, gravels, and loams in this pit are, as in the case of
those on the left bank of the Stour, very extensively contorted.

So much for the facts. It remains to be considered what light, if
any, they throw upon the origin of these particular drifts. That we
do want some light is evident, when we find some writers assigning
a marine origin to the East Anglian drifts, others a terrestrial one,
whilst Mr. Searles Wood, jun., in his last communication concerning
these drifts (Q.J.G.S. vol. xxxvi. p. 457), calls into play the agency
of both land-ice and the sea. I wish it to be understood that the
following remarks apply only to the actual Sudbury sections.

The great difficulty connected with the above-described sections is
the occurrence of intensely-contorted drifts upon an irregular surface
of absolutely undisturbed Tertiary beds, which are now, with one
exception (the top of the Crag pebble bed), in a soft and incoherent
state. 'Two questions suggest themselves :

1. Were the contortions produced in the area in which the
contorted beds now lie, or were the contorted deposits borne from a
distance ?

2. If the former, why are not the incoherent beds, on which these
contorted deposits rest, themselves disturbed ?

In answer to the first question, it may be confidently stated that
the contortions were produced in the beds in the area in which they
now lie, firstly, because the contortions adapt themselves to the
irregularities of the surface on which the contorted beds rest, as
seen in the case of the Crag ridge in Mr. Green’s pit, and of a section
figured by Mr. Whitaker as occurring on the east side of a chalk-pit
about half a mile east of St. Peter’s Church (Geol. of N.W. Hssex,
etc.), where the drifts are looped into a hollow in the Chalk;
secondly, because the contorted deposits have been largely derived
from the local rocks. Thus we find many fragments of Crag, large and
small, in the gravel north of the Crag ridge in Mr. Green’s pit, and
fragments of the green Thanet Sand scarcely even re-made in the
patch of Boulder-clay in the northern part of that pit just where
the green Thanet Sand has been scooped out. Similarly, at the top of
Balingdon Hill, the base of the Boulder-clay contains much Crag
material. Again, Mr. Whitaker describes the passage of re-made
green Thanet Sand into the actual deposit, so that the line of junction
is not to be ascertained. Mr. Penning, in the same Memoir, p. 59,
remarks that “the main substance of the [Boulder-]|clay indeed
consists of material received from rocks at no great distance from
the point where it may be observed,” and Mr. Dalton adds that
“some parts of the Boulder-clay consist almost entirely of chalk.
Where it lies directly upon the London Clay, it is often mainly
composed of the latter, being a blackish or reddish-brown clay with
a few pieces of chalk or other rocks.” It is clear then that the

&

268 J. BE. Marr—Glacial Deposits.

contortion was actually produced in the Sudbury area, and con-
sequently we are led to ask the second question, why are not the
incoherent beds below also disturbed ?

Four suggestions have been made to account for the contortion of
drift deposits :

(i.) The pressure of material from an adjoining elevation, either
rock or ice.

(i.) The removal of soluble material, as chalk or ice, from the drift.

(iii.) The grounding of true or false icebergs.

(iv.) The pressure of superincumbent land-ice.

The first explanation is inapplicable here. Not only do contortions
occur in the drifts which occupy the valley bottoms, but they are
also found in the accumulations which lie on the summits of ridges,
as at Mr. Green’s pit, and the pits near the Cemetery. As the
summits of these ridges are covered with these drifts, it is clear that
no higher land occurred here in Glacial times.

The second cause seems inadequate to produce the intense con-
tortion observed in many of the pits. The amount of chalk removed
cannot be very great, for the drifts are still very calcareous. A great
quantity of interstratified ice may have disappeared, but would this
produce such violent folds as that seen at the southern end of Mr.
Green’s pit? Overfolds of this nature are produced by lateral
pressure, but it is difficult to see how the removal of interstratified
material could cause the folding of one deposit nearly horizontally
over another for distances of several yards.

In both of these cases, we have no explanation of the undoubted
fact that the drifts are largely derived from the underlying rocks.
The third explanation requires fuller consideration. Local rocks
might undoubtedly become churned up and included in the drifts by
the grounding of icebergs, and no doubt contortion can be caused
thereby, though we should also expect partial obliteration of the
lamination planes. Several difficulties confront us if we adopt this
explanation. Firstly, the derivation of a great part of the material
from local sources. If this material was denuded by icebergs,
whence comes its lamination? If, on the other hand, the deposits
are ordinary marine accumulations, how are we to account for the
absence of fossils? The loam, which is admirably adapted for
the preservation of organisms, contains patches of lignitic material,
which are apparently boulders derived from some earlier forest bed,
but no marine organisms. Of course, the sea might be too cold
for the existence of Molluscs, but the bones of Seals ought to occur.
The Greenlanders thaw out the seals which have been frozen in
winter whilst diving below the ice, and other seals are taken in
nets below the ice (K. J. V. Steenstrup, ‘“‘ Meddelelser om Gronland,”
part iv. p. 99). The great difficulty in the way of accepting the
view that the drifts of this area were contorted by icebergs is the
fact that the incoherent Tertiary rocks immediately underneath the
violently folded Glacial deposits are never contorted even when standing
up in ridges (such as that in Mr. Green’s pit), around which the drifts
have been folded. It seems absolutely impossible that they should

J. BE. Mavr—Glacial Deposits. 269

escape such contortion, unless they were themselves consolidated,
and their nature is such that they can have been consolidated only
by being frozen, which could not occur over large areas at the
bottom of the muddy sea, in which according to this view the ice-
bergs were drifted.

The conformation of the ground around Sudbury is of such a
nature that it is extremely difficult to account for the stranding of
icebergs in some of the spots where the contorted drifts occur, as, for
instance, at the bottom of the Stour valley.

We come now to the last suggested cause of the production of
contortion, viz. by the passage of land-ice. This agency is con-
sidered by Mr. Searles V. Wood, jun. (Q.J.G.S. vol. xxxvi. p. 479),
to have produced the Chalky Boulder-clay with which the so-called
Upper Boulder-clay of this district is identified. The map No. 4 of
Mr. Wood (Q.J.G.S. vol. xxxviil. plate xxvi.) shows the ice which
produced this clay blocked by the British ice to the north, and
spreading over Hast Anglia parallel with the southern trend of this
clay, #.e. in a general east and west direction. Could not such a mass
of ice produce all the phenomena which are observable in the Sudbury
area? The difficulty of accounting for the undisturbed state of the
Tertiary rocks disappears at once upon this view. If the area over
which the ice passed was a land-surface, it would be frozen so hard
- that the now incoherent rocks would be solid, and would be treated
in a similar way to the harder rocks of other districts. Such seems
to be the case. We find a series of ridges having a general E.—W.
trend, composed of Crag sands, with intervening depressions some-
times cut deeply into the Chalk, as in the case already referred to,
and figured by Mr. Whitaker. These ridges would be veritable
roches moutonnées, which accords well with the appearance presented
by that on Balingdon Hill. The fragments torn off and included in
the drifts, being frozen, would not be crushed, but retain their form
of large and small subangular boulders, such as that seen in Mr.
Green’s pit. Only on this view is the regular bedding of the torn
Tertiary beds comprehensible.

Next, the contortion of the drifts, the relationship of the folds
to the inequalities below, the large quantities of local material which
enters into their composition, and the absence of marine organisms,
is satisfactorily explained upon this supposition. I have already
referred to the similarity of the divisional planes to those of the
fluxion-structure of igneous rocks, which is not to be confused with
the fluxion-structure described by Mr. Hugh Miller (Rep. Brit. Assoc.
1884, p. 720) as occurring in Till. Moreover, the great overfolds
in the drift, as above remarked, seem to require the occurrence of
considerable lateral pressure to produce them. That lateral pressure
does produce a similar structure in the stratified deposits of land-ice
is apparently indicated by the case figured in the “ Meddelelser om
Gronland,” part iv. pl. ili., where a glacier ending in a narrow valley
has its stratified sand and clay thus overfolded where the ice has
been compressed against the sides of the valley. That this sand and
clay may be interstratified with Boulder-clay produced by the same

270 k. Lydekker and G.A. Boulenger—Notes on Chelonia.

agent as the bedded deposits is shown in a figure on the next plate
of the same work, where a mass of Boulder-clay overlies such
materials in the ice. The moraine profonde (including under this
term all the drifts carried at and towards the base of the ice, whether
derived from upland districts, or caught up from an ancient sea-floor
over which the ice passed) coming from the flat tracts of the extreme
East of England and the North Sea would be driven through the
lateral valleys of the Sudbury area, and compressed laterally owing
to the smaller space necessarily occupied by the lower parts of the
ice under these circumstances. In this manner the contortion would
be produced, accompanied by the small faults which are so common
in these drifts, and so difficult to account for except upon the view
that the drifts were solid at the time of faulting. Upon the melting
of the ice, the drifts of this moraine,—Boulder-clays, gravel, and
loam,—would be left standing upon the undisturbed beds of the
irregular floor, once frozen, but resuming their incoherent condition
upon the passing away of the cold.

In this way, and apparently in this way only, can we account for
the phenomena of the Sudbury district, and the explanation has the
advantage that it brings into play an agent which we know, from the
researches of the Danish explorers upon the Greenland ice, does
produce similar features at the present day, whereas all other
explanations require the operation of agents, whose asserted mode
of procedure is purely hypothetical.

V.—Nores oN CHELONIA FROM THE PURBECK, WEALDEN AND
Lonpon-ciay.

By R. Lypexxer B.A., F.G.S., and G. A. Boutuncrr, F.Z.8.

Introductory.—The writers having had occasion, in company with
Mr. Davies, to examine the greater number of the remains of English
fossil Emydine and Pleurodiran Chelonia in the collection of the
British Museum, with a view both to their rearrangement in the
cases and the determination of their affinities, and having in the
course of such examination been enabled to add several genera to
the British fauna, as well as to make certain emendations in regard
to the age and affinity of some of the previously-described forms,
have thought it advisable to put their observations on record.
Several of these observations are, indeed, only supplemental to those
already published by Prof. Riitimeyer, of Basle, in the invaluable
memoirs quoted below, but the writers have been able in some
instances to add to his conclusions, owing to facts with which the
learned Professor was necessarily unacquainted.

The reference by M. Dollo, of the Brussels Museum, of three of
the Lower Eocene English species described by Sir R. Owen under
the generic name of Chelone to a distinct genus Pachyrhynchus, has
been already noticed by one of the present writers in last year’s
volume! of this Magazine. The term Pachyrhynchus is, however,

1 Page 521. I must apologize to M. Dollo for having in this notice misinterpreted
him as retaining Prof. Cope’s family Propleuride. In the same notice I have quoted

English forms under the generic names assigned to them by Owen, not having at that
time entered on the question of the correctness of their determinations.—[R. L.]

se

R. Lydekker and G. A. Boulenger—Notes on Chelonia. 271

preoccupied ; and Prof. Cope had previously applied the generic
term Puppigerus to several of Owen’s species; some of which may,
however, belong to other North American genera.’ At least one
of the carapaces of the Chelonians from the London Clay has
nine costal bones, which is a character of Cope’s Propleuride.’ This
group does not, however, form the proper subject of the present
communication.$

Purbeck and Wealden.—The first genus for consideration is
Pleurosternum, in which there appears a considerable amount of
confusion. In their ‘Monograph of the Chelonian Reptilia of the
London Clay’ (Pal. Soc. 1849) Owen and Bell figured in pl. xxi. a
Chelonian plastron under the name of Platemys Bullocki, the specific
name‘ dating from 1842. This specimen, now in the British
Museum, is characterized by the presence of a mesoplastral bone,
and also by an intergular epidermal shield. Owing to the former
feature Prof. Riitimeyer’ pointed out that the specimen could not
have belonged to Platemys, but must be referred to the genus
Pleurosternum of the Purbeck; he was, however, necessarily unaware
that the specimen is really from the Purbeck, and not from the
London Clay as stated by Owen and Bell. A comparison of this
plastron with other Purbeck examples of Pleuwrosternum shows that
it cannot be distinguished from the form figured by Owen in his
Purbeck and Wealden Reptilia (Mon. Pal. Soc. 1853) under the
name of Pleurosternum ovatum, with which the specimen figured in
pl. vii. under the name of P. emarginatum appears also specifically
identical ; under these circumstances the name Pleurosternum Bullock,
as being the earliest, must be adopted for the common Purbeck
form.’ It should further be observed that it has been stated by Prof.

1 See Amer. Nat. vol. xx. p. 968 (1886).

2 Cope (loc. cit.) states that his Proplewride is identical with Dollo’s Pachyrhyn-
chide. The type species of the latter is, however, expressly stated to have only
eight costals, which Cope makes a character of Puppigerus.

3 It is usual among English writers to term the bony parts of the Chelonian shell
‘¢plates,’’ and the horny epidermal covering “scutes ’’ ; but Prof. Huxley, ‘‘ Anatomy
of Vertebrated Animals,’’ Ist edition, pp. 197, 200 (1871), uses the former term for
both. Since, however, the term ‘“‘scute’’ is applied to the dermal bones of the
Crocodilia and of the Armadillos (vide Huxley, op. cit. pp. 250, 338), which are
homologous with some of the bony elements of the Chelonian shell, this use is cer-
tainly objectionable ; and in previous works I have reversed the application of the
two terms. This application is not, however, thought advisable by Mr. Boulenger,
who usually employs the terms in their older sense; as a compromise, in the present
paper the bony elements will therefore be alluded to as “ bones,” and the elements of
the epidermal layer as ‘‘ shields.’’—[R. L.]

“ Rep. Brit. Assoc. for 1841, p. 164 (1842).

5 Verh. Nat. Ges. Basel, vol. vi. p. 121 (1873),

6 Specimens of Purbeck Chelonia in the Cambridge Museum have been referred by
Prof. Seeley (Index to Aves, Ornithosauria, etc., in the Cambridge Museum, pp. 86,
87 [1869] ) to Plewrosternum, under the names of P. Sedgwicki, P. Vansittarti, P.
Oweni, and P. typocardium. These specimens have, however, not been figured, and
cannot therefore be compared with those in the British Museum; some of them may
nemeps belong to Plesiochelys, while the distinction of others from P, Budllocki is not
clear.

272 R. Lydekker and G. A. Boulenger—WNotes on Chelonia.

Cope’ that the plastron of Pleurosternum has no intergular shield,’
and the genus is accordingly referred by him to the Cryptodira;
whereas its true position, as was pointed out by Prof. Riitimeyer, is
with the Pleurodira; and with that group—the Pelomeduside and
Peltocephalide of Gray—characterized by the presence of eleven,
instead, of nine, plastral bones.

With regard to the carapace figured by Sir R. Owen in pl. iv. of
his “Wealden and Purbeck Reptilia,” under the name of Pleuro-
sternum emarginatum (of which it is the type), it appears from the
emargination of the anterior border that the specimen does not
belong to that genus at all; and it is highly probable that it should
be referred to Plesiochelys, although, as only the ventral aspect of
the carapace is visible, this cannot be definitely determined ; the other
specimen figured by Sir R. Owen under the same name cannot
apparently be distinguished from Pleurosternum Bullocki. Another
carapace from the Purbeck has been figured by Sir R. Owen in pl. 1.
of the above-mentioned work under the name of Pleurosternum
latiscutatum, which differs from P. Bullocki by the notch in its
anterior border, in the presence of a nuchal epidermal shield, and
in the narrowness and length of the neural (vertebral) bones. A
specimen of both carapace and plastron in the Museum (No. 25624)
from the Wealden, which is evidently specifically identical, shows
that there was no mesoplastron, and the species may apparently
therefore be referred to the genus Plesiochelys.2 A second Hnglish
species of that genus is indicated by an imperfect shell from the
Wealden in the collection of the Museum (No. 28967) which
evidently belongs to the group containing the Upper Jurassic P.
Soluthurnensis and P. Sancte-Verene of Riitimeyer,* and agrees so
closely with the latter that it may apparently be referred to the same
species; a younger shell of the species (No. R. 583) from the
Wealden near Hastings is also contained in the collection. Two
plastra from the Purbeck (No. 45937) have a large central vacuity,
and thereby agree with P. Htalloni, Riitimeyer.’ Prof. Riitimeyer ®
has already observed that the fragmentary remains from the Wealden
figured by Sir R. Owen’ under the name of Platemys and Chelone
costata do not belong to those genera, and he has suggested that they
may be Thallasemydians, but there seems no reason why they should
not be referred to that group of Plesiochelys in which there is a large
plastral vacuity. The occurrence in the English Wealden and
Purbeck of several species of Plesiochelys apparently closely allied
to those of the Upper Jurassic of the Continent is a matter of con-
siderable interest.

1 Proc. Amer. Phil. Soc. 1882, p. 1438.

2 The presence of an intergular shield is distinctly mentioned on page 5 of Owen’s
‘¢ Wealden and Purbeck Reptilia,” although it is not shown in a complete state in
any of the figured specimens.

3 Mr. Boulenger takes this view.—[R. L. ]

4 Neue Denks. schweiz. Ges. Nat. vol. xxv. pls. xii. xiii.

5 Ibid. pl. xi.

6 Verh. Nat. Ges. Basel, op. cit. p. 166.

7 Wealden and Purbeck Reptilia, pls. viii. and ix.

R. Lydekker and G. A. Boulenger—WNotes on Che’onia. 273

A crushed and broken shell with several of the bones of the
pectoral and pelvic girdles, obtained by the late Mr. Fox from the
Wealden of Brook, in the Isle of Wight, and now preserved in the
Museum (No. R. 171), together with another crushed specimen (No.
48349) from the Wealden, and the anterior portion of a plastron
(No. 46325) from the Purbeck, belong to the genus Tretosternum,
and enable us to arrive at a conclusion as to the affinities of that
genus. These specimens show, moreover, that the Chelonian remains
from the Wealden of Bernissart in Belgium, described by M. Dollo,!
under the name of Peltochelys Duchastelii, are not separable from the
English Tretosternum Bakewelli (Mantell? sp.). M. Dollo was led to
separate the Belgian form because Sir R. Owen® has suggested that
Tretosternum may have had incomplete marginals ; which the present
specimens show is not the case. The suggestion of Sir R. Owen #
that Tretosternum had a permanent plastral vacuity is shown by
these specimens to be incorrect, although a small one exists in the
young. M. Dollo places the genus in the Pleurodira, a view which
is not supported by the examination of the remains in the Museum.

As may be seen from M. Dollo’s figure, and still better from
the Museum specimens, the anterior border of the nuchal bone
is broadly emarginate, a character which occurs in none of the
Pleurodira, for the reason that the head takes shelter on the side;
but is found in all Cryptodira in which the head is particularly large
and non-retractile, with the temporal fossz roofed over by bone, as
in Chelydra, Platysternum, Chelone, etc. Another peculiarity shown
by the nuchal before us lies in the presence of a costiform process
on each side, as in Chelydra; a process which, judging from Dollo’s
figures, is also shown in the young specimens from Bernissart.
Important again is the fact, shown by our specimens, that the plastron
articulates with the carapace by gomphosis, exactly as in Chelydra,
and does not send off any axillary and inguinal peduncles like those
so highly developed in all known Pleurodira. The plastron is essen-
tially of the Dactylosternine-type of Cope. M. Dollo has, it is true,
recognized the presence of an intergular shield, a character which has
hitherto been regarded as infallibly diagnostic of the Pleurodiran
group; this shield is also well shown in the type-specimen of Treto-
sternum. A careful examination shows, however, that this intergular
is, in addition to only five pairs of plastral shields, exactly as in

1 Bull. Mus. R. Hist. Nat. Belg. vol. iii. p. 78 (1884). The name itself is not
very happily selected, since Prof. Seeley (Quart. Journ. Geol. Soc. vol. xxxvi. p. 412,
1880), has proposed the name Peltochelyide for an entirely different group of Chelonia.

2 Geology of S.E. of England, p. 255 (1833)—Trionyx. Tretosternum punctatum,
Owen, dates from 1842.

3 Rep. Brit. Assoc. for 1841, pp. 165-7 (1842). Sir R. Owen’s words are, ‘‘ The
entire and rounded margins of the truncated and expanded extremities of the ribs,
beyond which there is not the slightest trace of projecting tooth-like processes,
strongly indicates that the marginal plates [bones] were either wanting or rudimental,
as in the genus Cryptopus [ Trionyx].”’

4 Op. cit. p. 167. The generic name was given upon the assumed existence of this
feature ; since, however, the vacuity occurs in the young, no reasons can be adduced
for changing the name.

DECADE III.—VOL. IV.—NO. VI. 18

274 RK. Lydekker and G. A. Boulenger—Notes on Chelonia.

certain specimens of Dermatemys, instead of the six pairs of all
recent Pleurodira; and we think too great importance has hitherto
been attached to the disposition of the epidermic plastral shields, as is
shown by a specimen of Macroclemmys Temminckii in the Museum,
which exhibits an intergular shield situated within the margin of
the plastron, exactly as in the Australian Chelodina. Again, the
number of plastral shields of Zietosternum, viz. 11, is that of a
Cryptodiran, and not of a Pleurodiran. In addition to the above
arguments, the remains before us give elucidation on a point which
is in itself decisive; v2z. the attachment of the pelvis. Two bones
only are preserved, but they will suffice for our purpose; these are
a sacral vertebra and a pubis. The former bone shows a large
articular surface for a sacral rib, which was therefore present, and
gave attachment to the ilium. In the Pleurodira, in which the ilium
anchyloses with the carapace, sacral ribs are either atrophied or
disappear altogether in the adult. The pubis, of a rather peculiar
shape, owing to the great elongation and distal expansion of the
inner or symphysial branch, is intact and shows that the extremity
of the outer process was thin and compressed, and did not anchylose
with the plastron.'

In the absence of any remains of the caudal vertebral column, it is
impossible to say for certain that Tretosternum belongs to the family
Chelydride, but we may surmise that such was probably the case.
As far as can be judged from a comparison with Leidy’s figure of
Anostira, the two genera were very closely allied.

The last of the Chelonians from the Wealden and Purbeck that
we have to notice is a small cordiform carapace from the latter
formation (B. M. No. 40676), which may confidently be referred to
the Thallasemydes of Prof. Riitimeyer (Hurysternide of Dollo), and
may probably be referred to the genus Hurysternum.”

London Clay.—The first specimen from this formation that calls
for notice is the hinder portion of a carapace in the Museum (No.
40099), which evidently belongs to the genus Pseudotrionyx, Dollo,?
from the Middle Eocene (Bruxellian) of Belgium, and is apparently
specifically identical with the typical P. Delheidi, Dollo. This genus
is included by its founder in the Chelydride, but from the absence of
epidermal shields may probably be regarded as belonging to a distinct
family.*

The next species for notice is founded on the shell figured by
Owen and Bell® under the name of Platemys Bowerbanki ;° in regard

1 On this occasion it may be well to observe that Ritimeyer’s statement, made
with due reserve, but since repeated by others as an admitted fact, that, in some
recent Plewrodira, the ischium anchyloses with the plastron before the pubis, was
derived from the examination of figures accompanying one of Gray’s memoirs ; and
that an investigation of the actual specimens which gave rise to this statement has
proved it to be erroneous.—[G. A. B.]

2 = Acichelys = Aplax = Paleomedusa = Achelonia = Euryaspis = Parachelys.

3 Bull. Mus. R. Hist. Nat. Belg. vol. iv. p. 96 (1886).

4 The suggestion made in the above-quoted notice in the GronocicaL MAGazINE
that the genus might perhaps be referred to the Trionychide will not hold.—[R. L.]

> Reptilia of the London Clay, pt. i. pl. xxiii,
& Rep. Brit. Assoc. for 1841, pp. 163 (1842).

wd

:

be
Os

R. Lydekker and G. A. Boulenger—Notes on Chelonia. 275

to which Prof. Riitimeyer + has already pointed out that the specimen
figured by the same writers” under the name of Hmys levis is merely
the young of the former, and that owing to the presence of a small
mesoplastral bone the reference to Platemys is incorrect, and it is
suggested that the species may probably belong either to Podocnemis
or Peltocephalus. The type is unfortunately not in the ‘collection of
the Museum, but the figure shows that the length of the bony union
between the carapace and plastron is comparatively long, from which
its affinity appears to be rather with the former than the latter, and
it may accordingly be provisionally referred to that genus.

With regard to the large Chelonian figured by Owen * under the
name of Hmys Conybeari, which appears specifically identical with
the younger specimen figured as Hmys Delabechi, Bell,* Professor
Riitimeyer® has observed that it is difficult to say whether these
forms belong to the Hmydide or the Chelydide, but this difficulty has
now been decisively solved. The best preserved and larger of the
two specimens, or that figured under the name of H. Conybeart,
shows both carapace and plastron, and exhibits in the latter distinct
mesoplastral bones like those of Podocnemis. he matrix between the
carapace and plastron has recently been chiselled away, and the
characteristic Pleurodiran anchylosis of the ischium and pubis to
the plastron is thus exhibited. In the number of the neural (verte-
bral) bones, in the flatness and general contour of the carapace, in
the shape of the plastron and the relative length of the bridge
uniting the latter with the carapace, and in the absence of a nuchal
epidermal shield, the specimen accords so well with Podocnemis, that
it may be pretty safely referred to that genus, under the name of
P. Delabechi. 'The presence of two epidermal pygal shields differ-
entiates it from the allied genus Peléocephalus ; the vertebral shields
agree in form very closely with those of Podocnemis Dumeriliana,
although the contour of the carapace accords more closely with that
of P. expansa. With regard to the so-called Emys bicarinata ® from
the same formation, a cutting-away of the matrix shows no trace of
the pelvis, which was probably, therefore, of the Cryptodiran type,
and the species may accordingly, in the absence of any evidence to
the contrary, be included in the genus Clemmys. 'The occurrence of
Podocnemis in the London Clay indicates that the Pleurodira, which
are now almost entirely relegated to the Southern Hemisphere, were
dominant forms at that period in the Huropean area, as they also
were in the corresponding epoch in India, where there were repre-
sentatives of both Podocnemis and Platemys in the Lower Hocene.’

i Verh. Nat. Ges. Basel, p. 121.

2 Op. cit. pl. xxii.

3 Reptilia of London Clay, Supplement, pls. xxviii. A, B.

£ Tbid. pl. xxviii.

5 Verh. Nat. Ges. Basle, op. cit. p. 121.

6 Owen and Bell, Reptilia of the London Clay, pt. i. pls. xxv. xxvi.

7 These species will be described in a forthcoming memoir in the “ Palzontologia
Indica,”’ ser. 10, vol. iv. pt. 3.—[R. L.]

276 Reviews—Prof. Credner—On Branchiosaurus.
ReV Lew s.

———

1.—Proressor Dr. Hermann CrREDNER ON THE DEVELOPMENT
oF BRANCHIOSAURUS.!

N this valuable communication to Palzeontological science Prof.

Credner gives us the result of his observations on the. life-

history of a single species of Labyrinthodont, or Stegocephalian,
based on the study of no less than 76 specimens.

The paper commences with a discussion of nomenclature and
synonymy; but here we regret to say that we cannot quite agree
with the author’s conclusions. Prof. Credner states that in 1881
he described the skeleton of a small Labyrinthodont from the
‘Rothliegendes’ of Saxony under the name of Branchiosaurus.
gracilis, while on a subsequent page of the same memoir he described
a second specimen as B. amblystomus. Subsequent ‘finds’ showed
that the former is but the larval condition of the latter, and Prof.
Credner proposes to adopt the name B. amblystomus for the species.
He proceeds, however, to mention that Messrs. Geinitz and Deich-
miller have pointed out that B. gracilis is probably identical with
Protriton petrolei of Gaudry, from the Permian of France and
Thuringia, and he therefore concludes that the latter is also a larval
form, of which the adult may be perhaps still unknown, or may be
the so-called B. amblystomus. So far no objection can be taken to
Prof. Credner’s views; but when he proceeds to observe that the
name Protriton petrolei, as being founded on a larval form, ought to
be withdrawn, we cannot agree with him. There appears, indeed,
to be no doubt that Messrs. Geinitz and Deichmiiller are right in
regarding Branchiosaurus and Protriton as generically the same, and
there is also a very strong presumption that B. gracilis (B. ambly-
stomus) and P. petrolet are also specifically identical. Now the
generic name /rotriton was first published (with figures of the
type specimen) by Gaudry in the “ Bull. Soc. Géol. France,” sér. 3,
vol. iii. p. 800 (March 29, 1875); the type specimen having been
previously recorded under the name of Salamandrella petrolei in
the “Comptes Rendus,” vol. Ixxx. p. 442 (Feb. 15th, 1875), the
earlier generic name being withdrawn on account of being pre-
occupied. The term Branchiosaurus was first published by Fritsch
in the ‘“Sitz. k. bohm. Ges. Wiss.” (19th March, 1875),’ p. 72;
but was not figured till 1879, in the “Fauna der Gaskohle,” etc.,
pt. 1, p. 69, pl. i-iv. The generic name Protriton is therefore,
strictly speaking (if we count from the date of the reading of the
memoir), of ten days’ later date than Branchiosaurus; but since
the date of figuring gives no less than four years’ advantage on the
side of the former, we think that the generic name Protriton ought

1 «Die Stegocephalen aus dem Rothliegenden des Plauen’schen Grundes bei
Dresden,’”’ VI. Theil.-—Zeitschr. deutsch. Geol. Ges. pp. 576-633, pls. xvi—xix.
(1886).

2 Fritsch (Fauna der Gaskohle, etc., pt. i. p. 69 [1879]) totally ignores his.
previous preliminary notice of the genus, and expressly states that it should date
only from the time of figuring (1879). .

1

Reviews—Prof. Credner—On Branchiosaurus. PG

to stand; and if P. petrolei be identical with B. gracilis, there can
be no question as to the right of the former specific name to
supersede the latter.

Coming to the proper subject of the paper under consideration, it
appears that the youngest specimen which came under the author's
notice was about 25mm. in length. In this stage the animal was
aquatic, and breathed by gills, which were supported by four pairs of
branchial arches. The cartilaginous dorsal segments of these arches
were furnished with small calcified denticules; and the ventral
segment of the first was ossified. By the time, however, these
animals had attained a length of from 60 to 70 mm., they cast their
branchial arches and became air-breathers ; their development being
thus analogous to that obtaining among the Salamandride of the
present day. The adults measure from 100 to 130 mm. in length.

This metamorphosis from a water- to an air-breather was accom-
panied by the following changes in the structure of the skeleton.
The short and wide skull of the larva becomes relatively narrower ;
the proportion of the transverse to the longitudinal diameter being
2 to 3 in the larva, whereas these two diameters in the adult are
subequal. The relative increase in length is mainly confined to the
anterior cranial bones; and the orbits, and more especially the
parietal foramen, do not enlarge at the same rate as the surrounding
bones. In the pectoral-girdle,’ while the coracoid and supra-clavicle
only increase in size proportionately with the general growth of the
animal, the median element (interclavicle) of the ventral buckler,
which is very minute in the larva, attains a length of 8 or 9 mm.
and forms a pentagonal bone, interpenetrated by slits from the
anterior border. The lateral bones (clavicles) of the shield in the
larva are small and in contact with each other in the median lines ;
but as development advances they become relatively broader, and
separate. In the vertebral column it has been found that while in
the larva the presacral vertebra are 20 in number, they are 26 in the
adult, this being accompanied by a diminution in the relative length
of the tail in the former. This remarkable change Prof. Credner
explains by a gradual backward shifting of the pelvis as the animal
increases in age, from which it necessarily follows that the sacral
vertebra of the larva become lumbar in the adult. With the
lengthening of the presacral vertebral column the bones of the limbs
do not keep pace; so that the limbs of the adults are relatively much
shorter than those of the larva. During the above-mentioned
changes the dermal and epidermal skeleton is likewise undergoing
evolution; and in the adult the ventral surface of the body is
protected by a complete and complex covering of dermal scutes, of
which the author has succeeded in tracing out the arrangement ;
while in the young larva this covering is totally wanting.

Prof. Credner is indeed to be congratulated on having traced in

1 Prof. Credner employs a nomenclature of the elements of the shoulder-girdle
different from that adopted by many writers; but the equivalent terms are noticed
on p. 607 of his memoir. In this notice we employ the terms used in the ‘‘ British
Association Report’’ on the Labyrinthodontia.

278 Reviews—Dr. G. M. Dawson’s Borings in Manitoba.

this able and interesting manner the development of a water-breathing
naked larva of the Palzeozoic epoch into an air-breathing adult, clad
in a strong coat of mail; and we shall welcome with much interest
future work on kindred subjects. BK. hh.

IJ.—On Certain Borines 1x Maniropa aNnp THE NoRrTH- WEST
Territory. By Grorczr M. Dawson, D.Se., A.R.S.M., F.G.S.
[From the Transactions of the Royal Society of Canada, vol. iv.
1886.] Montreal, 1887.

ARIOUS useful purposes are subserved by boring operations,

such as the procuring a supply of pure water in arid regions ;

the search for useful minerals, petroleum, etc., in which case boring

may be regarded ‘as an expeditious, and, upon the whole, economical

method of prospecting ; and finally, as a means of gaining a know-

ledge of the nature of the subjacent strata when these are concealed
by drift deposits.

We shall dwell more particularly upon the results of these borings
from the geological standpoint, as being that which is most likely
to interest the readers of this MaGazinr.

We have then 1, “ Boring at Rosenfeld Station.” This is a station
on the South-Western Branch of the Canadian Pacific Railway,
about fifteen miles north of the 49th parallel and ten miles west
of the Red River Valley. In this boring, which was undertaken by
the C. P. Railway Co., a depth of 1037 feet was attained by means
of an ordinary percussion drill.

The nature of the beds passed through, with their probable geolo-
gical age, is indicated in the accompanying slightly abridged section :

FErEt. ForMATIONS.
erBlackssoil aq nen, (ese cee fics | rose
Prtine siltor Clava c. ees «ALLL
3. Sand and gravel . 300). Gore lO)
4. Boulder- clay («‘hard- -pan my odo ame ameons |. 12)
5. Boulders oe os 6 Dus acti eee
6 to 9. Grey and red shales and Timestone ee. OF :
10 to 13. Theis sandstone, and red shale 260 Maquoketa shales.
14. Cream-coloured limestone... ... ... ... 305 Galena limestone passing
15. Redshale ... 2... 2... .2 2. ... ... 75 below into Trenton.
16. Soft sandstone Pe ie senn .. 50 St. Peter Sandstone
17 to 20. Red, ern blue, and d grey shales... 110 L. Magnesian limestone (?).
21. ‘* Granite 9 cae 2 Laurentian.

Totals 24 eee: So LOSy

A detailed analysis here follows, which may be thus briefly sum-
marized :—The soil was of the character common in that region, and
consisted of the underlying silts mixed with vegetable matter.
“The silts are those of the ancient lake which, about the close of
the Glacial Period, occupied the Red River Valley, and which has
been called ‘ Lake Agassiz’ by Mr. Upham.” * The gravel consisted
of rounded Laurentian and limestone pebbles. ‘The ‘ hard-pan,’

1 See Gronocican Magazine, 1883, p. 427, ‘‘ Lake Agassiz; a Chapter in
Glacial Geology,” by Warren Upham.

Reviews—Dr. G. M. Dawson’s Borings in Manitoba. 279

while evidently representing the Boulder-clay, is unusually pale in
colour, being apparently composed of limestone debris.”

Passing on to the consideration of the beds underlying the drift,
we learn that their geological age was considered by the author to be
doubtful, owing to the entire absence of paleontological evidence or
of any outcrops in the vicinity of the boring, by which the result of
the operations might have been checked.

However, pretty strong presumptive evidence seems to have been
elicited regarding the age of the beds supposed to represent the
“‘ Maquoketa shales,’ so named by Dr. C. A. White, in Iowa. In
Iowa these shales are about 75 feet in thickness, and consist of
bluish and brownish shales with calcareous layers. In Wisconsin,
they average about 200 feet in thickness, and are composed of grey,
green, blue, red, purple, buff and brown shales with thin limestones.
These beds are met with also in Minnesota, but owing to the want
of complete sections they could not be compared with those of the
Rosenfeld boring. But at Stony Mountain, Manitoba, fifty-eight
miles north, strata determined by their fossils to be of the horizon
of the Hudson River were met with. A section made at this locality
showed that the rocks consisted of dolomitic and other limestones,
and red and yellow shales, resembling very closely those referred to
the Maquoketa Shales (Nos. 10 to 18 in the section) in the Rosenfeld
boring.

The limestone (No. 14) underlying the Maquoketa shales is
assigned to the horizon of the Galena limestone of the west, which
it was found to resemble in character; while the red shale at the
base (No. 15) was supposed to be the equivalent of the Trenton.

«The Galena limestone of the West, which is nearly equivalent
to the Utica of the New York series, is about 180 feet thick in
Minnesota; 250 feet thick in Wisconsin; and from 100 to 250 feet
thick in Iowa.

“The Trenton in Minnesota consists of flaggy limestones, with
interbedded greenish shales, and is nearly 160 feet in thickness. In
Jowa it consists of clayey shales and shaly and compact limestone,
200 feet in thickness. The reddish colours of the Rosenfeld shales.
and their apparently more complete separation from the limestone
and want of interlamination with it, constitute the chief point of
dissimilarity. The massive buff limestones of Selkirk and Stone
Fort in Manitoba, resemble the Rosenfeld bed in character, and are
known by the evidence of fossils to represent the Galena.”

No. 16 in the section, an “‘ unconsolidated sand-bed,” is described as
resembling precisely the “St. Peter Sandstone,” as typically developed
near St. Paul, Minnesota.

Assuming that the geological horizons of the preceding beds have
been accurately determined, then it is held that beds 17 to 20 (both
inclusive) must be referred to the ‘Lower Maguesian Limestone,”
equivalent in age to the Calciferous [Tremadoc] of the New York
section. This limestone in Iowa and Wisconsin has a thickness of
65 to 250 feet. In Minnesota it is a magnesian rock, sandy towards
the top, and with beds of greenish shale. At Rosenfeld there is no

280 Reviews—Dr. G. MU. Dawson’s Borings in Manitoba.

limestone, and Dr. Dawson concludes, therefore, that we have here
“a littoral formation directly overlying the subjacent Laurentian, and
marking the limit at this place of the Lower Magnesian Sea.”

The most remarkable feature of the Rosenfeld well was the strong
flow of brine which issued from it, especially at the level of the St.
Peter Sandstone, whence it rose in a pipe to a height of 18 feet
above the surface of the ground. The author calls attention to the
great age of the rocks yielding the brine. ‘‘It appears,” he says,
“not improbable that the shoaling of the Cambro-Silurian sea
evidenced by the widespread littoral deposit known as the St. Peter
sandstone resulted in the enclosure of salt lagoons in this portion of
the interior basin, while it merely produced an increased land area
further south in Iowa and Wisconsin.”

The brine is said to be well adapted for the manufacture of salt.

Another fact of geological importance was elicited by the Rosen-
feld boring, viz. “the comparatively thin covering of Paleozoic
rocks which here overlaps the Archean, and the very gradually
shelving character of the surface of the latter westward.”

Passing over the records of borings at various places (numbered
2 to 6) in which there appears to be nothing worthy of special note,
we reach No. 7 :—“ Boring at Langevin Station.”—This place is
also on the line of the Canadian Pacific Railway, 35 miles west of
Medicine Hat, on the South Saskatchewan River, at an elevation of
2471 feet above the sea-level. Two borings were made here, the
one attaining a depth of 1155 feet, and the other 1400 feet. The
result of these operations was somewhat unexpected, and, in the first
case disastrous, a heavy flow of combustible gas having been dis-
charged from the bore-hole, and this becoming ignited, destroyed the
works at the surface. This boring had consequently to be abandoned,
and another undertaken, the gas being now utilized for working the
engine.

This second boring showed (1) Drift deposits, estimated at 88 feet
in thickness ; with (2) about 223 feet of beds consisting probably of
the lower part of the ‘Belly River Series”? (Upper Cretaceous)
underlying them. Beneath the latter there were found beds aggre-
gating 1099 feet in thickness; these are considered by Dr. Dawson
to be probably of the age of the “Lower Dark Shales,” ? passing
down into the “ Fort Benton Group” (?) (Lower Cretaceous).

The result of the operations at Langevin proves the existence of
a large quantity of combustible gas in the district ; a matter of great
economical importance. The supply of gas comes from the sandy
layers of the “‘ Lower Dark Shales” at depths of 900 feet and over,
and is derived, in the opinion of the author, from the decomposition
of the organic matter of the dark Carbonaceous shales.

-Arruur H. Foor.

* See Geol. Surv. of Canada, Report of Progress, 1882-83-84, p. 112¢.
* Loc. cit. p. 42¢.

Reports and Proceedings—Geological Society of London. 281

REPORTS AND PROCHHDINGS.

SS
GrotocgicaL Society or Lonpon.
I.—April 6, 1887.—Prof. J. W. Judd, F.R.S., President, in the

Chair.—The following communications were read :-—

1. “On the Rocks of the Malvern Hills.” Part I. By Frank
Rutley, Esq., F.G.S.

The details of the microscopic examination of the rocks constituted
the principal part of the present paper. The author finds that the
truly eruptive rocks are more plentiful in the range than he was at
first led to suppose. In all 33 rock-specimens were described, and
in some cases Mr. Timmins’s analyses were quoted. The author
commenced with the rocks of the North Hill and concluded with
those of the Raggedstone Hill. Rocks between a little south of the
summit of the Worcestershire Beacon on to Wind’s Point, those of
Midsummer Hill, and those of Keys Hill were not collected. The
following are the general results :—

ERUPTIVE. FouraTeD. STRATIFIED.
Nori Ha +. Hornblende-gabbro. | Gneissic Syenite. Altered Tuff ?
Diorite. Gueissic Diorite.

Quartz-syenite.
North Hill (above

West Malvern).| Mica-diorite. Biotite-gneiss.
North Hill (The :
ingle) ye s.....- Mica-diorite.
Werestestie)) Granite
Granite.
Diorite.
Epidotite ?
oo \ Eucrite. Hornblendic Gneiss. | Diabase-tuff?
eacon.......
Basalt.
Devitrified Obsidian.
Swinyard’s Hill..| Pegmatite. Biotite-gneiss.
Hornblende-pegmatite| Biotite-muscovite.
Diorite. Gneiss.
Hollybush Pass...| Diabase. [stone.
Raggedstone Hill} — ......... Mica-schist. Altered Sand-
Micaceous Quartzite-
schist.

In the first instance a separation must be effected of rocks showing
foliation or lamination, or of which the origin has been sedimentary,
from those which show no such structure, and which must be
regarded as eruptive: there is, in fact, a banded and an unbanded
series. The gneisses are altered volcanic tuffs or sedimentary rocks
of eruptive material derived from the disintegration of rocks of
dioritic or syenitic character.

The rocks of the North Hill, as may be gathered from the tabular
classification, are truly eruptive in many cases; whilst the foliated
varieties are made up of the débris of rocks rich in hornblende,
which may have had an eruptive origin. The rocks of the Here-

282 Reports and Proceedings—

fordshire Beacon are chiefly gneissic: the eucrite-basalt occurs at a
buttress of the hill. The pegmatite of Swinyard’s Hill has apparently
been faulted into its present position. South of Midsummer Hill
fine-grained gneissic rocks, quartzite-schists, etc., are met with.

There is no reason to suppose that the alteration of any ordinary
sedimentary rocks could have resulted in such a vast amount of
hornblende as is found in these gneisses. The gneissic rocks of the
Malvern Hills may be composed of the detritus of eruptive rocks.

The rocks of the Malvern Hills show in their structure but little
resemblance to the foliation induced by shearing, the crystals seldom
exhibiting any marked lenticular form, while there is but little like-
ness to the pseudo-fluxion structure described by Lehmann, etc.

The author.concluded that the rocks of the Malvern Hills represent
part of an old district consisting of plutonic and, possibly, of voleanic
rocks associated with tuffs, sedimentary rocks composed mainly or
wholly of eruptive materials, and grits and sandstones; that the
structural planes in these rocks (sometimes certainly, at others
possibly) indicate planes of stratification, and that the foliation, in
many cases if not in all, denotes lamination due to deposition either
in water or on land surfaces, probably more or less accentuated or
altered by the movements which produced the upheavals, subsidences,
and flexures prevalent in the range.

2. ‘On the alleged Conversion of Crystalline Schists into Igneous
Rocks in County Galway.” By C. Callaway, Esq., D.Se., F.G.S.

This paper was an inquiry into the theory, held by many Irish
geologists, that granite and other igneous rocks are the last term in
a progressive series in the metamorphism of aqueous sediments.
The evidence collected by the author was regarded as entirely hostile
to this view. In Knockseefin, the typical section, he found diorite
intrusive in gneiss and granite intrusive in the diorite, but no passage
between any two. The igneous veins sometimes displayed a foliated
structure. At Shaunarea the phenomena were similar; but the
granite in contact with the gneiss was much crushed and decomposed.
In the region south of Glendalough the intrusion of granite in
diorite and schist gave rise to the peculiar mixtures which had been
described as “metamorphosed conglomerate.” The granite was
intruded along the joints of the diorite, sometimes separating the
joint-blocks from each other, and completely enclosing them. It
was noticed that when schists were penetrated by granite isolated
folia often retained their parallelism, and this was accounted for
partly by the slowness of the intrusion, partly by regional pressure.
Even when mere flakes of the schist were enclosed in granite there
was no passage between the two. The granite, both in masses and
veins, was often foliated, but the blocks of included diorite were not;
and this seemed to suggest that the foliation of the granite was

acquired before complete congelation of the larger masses. There -

was also a foliation concentric to included blocks of diorite.

At the town of Galway the “metamorphic sedimentary” rocks
were a coarse-grained hornblendic gneiss of Hebridean aspect, and
in some parts of it was a structure similar to that of the ‘“‘ metamor-

Geological Society of London. 283

phosed conglomerate”; but the included blocks of diorite had
acquired a definite orientation, apparently due to pressure. An
igneous origin for some of the coarser gneisses was thus suggested.
It was concluded that there was no proof of the conversion of schists
into igneous rocks, the evidence collected tending to show, on the
other hand, that igneous rocks were sometimes converted into schists.

3. “A Preliminary Inquiry into the Genesis of the Crystalline
Schists of the Malvern Hills.” By C. Callaway, Esq., D.Sc., F.G.S.

The author’s researches amongst the crystalline rocks of Con-
naught had suggested certain lines of investigation which had sub-
sequently been followed out in the Malvern district. He had satisfied
himself that many of the Malvern schists had been formed out of
igneous rocks; but at present he limited himself to certain varieties.

The materials from which these schists were produced were diorite
(several varieties), granite, and felsite.

The metamorphism had been brought about by lateral pressure.
Evidence of this was seen in the intense contortion of granite-veins
and in the effects of crushing as observed under the microscope.

The products of the metamorphism were divided into two
groups :—

A. Simple schists, or those formed from one kind of rock. The
varieties described were the following :—Hornblende-gneiss, or diorite
which had been crushed and modified. Mica-qgneiss, formed from
granite. In the first stage of the crushing, the quartz and felspar
lay in lenticular fragments, separated from each other by cracks, the
fragments and cracks being roughly parallel. As the metamorphism
proceeded, the cracks became less evident, and the respective minerals
were flattened out into comparatively uniform folia. Mica gradually
came in, at first in the form of a partial coating to felspar crystals,
and, at a further stage, in regular folia. Mica-schist, formed from
felsite. The felsite gradually acquired a parallel structure. Pari
passu with this mechanical alteration, a mineral change was observed.
Mica at first appears in very small quantity, either filling cracks or
accentuating the parallelism. In a more advanced stage, the mica
lies in imperfect folia, and sometimes forms a partial coating to
grains of quartz. At last there is little left but quartz and mica,
the latter in folia, and enveloping individual quartz granules.

B. Injection schists, formed by the intrusion of veins, which had
acquired parallelism by pressure. Veins of diorite in diorite pro-
duced duplex diorite-gneiss, and veins of granite in diorite originated
granite diorite-gneiss.

It was further noted that

(1). Generally the particular varieties of schist occurred in the
vicinity of the igneous masses to which they were most nearly
related in mineral composition.

(2). The mineral banding of the rocks in the field was more like
vein-structure than stratification.

The author accepted the received view of the age of the schists.
The parallel structure was clearly antecedent to the Cambrian epoch,
and the occurrence of similar rocks as fragments in the Uriconian

284 Reports and Proceedings—

conglomerate of Shropshire seemed to indicate that the Malvernian —

schists were older Archean.

IJ.—April 27, 1887.—Professor J. W. Judd, F.R.S., President,
in the Chair.—The following communications were read :—

1. “On the London Clay and Bagshot Beds of Aldershot.” By
H. G. Lyons, Esq., R.E., F.G.S.

The author first described the section from Thorn Hill on the
N. to Redan Hill on the §., plotted from the 6-in. Ordnance Survey
on a scale of 6 in. to 1 mile horizontal, and 12 in. to 1 mile vertical.
This section comprises beds from the Woolwich and Reading series
to the Upper Bagshot inclusive. He showed a dip of 22° to the N.
which is regular or nearly so throughout. A few feet of Upper
Bagshots occur on Thorn Hill (865 feet); at the base of these the
Pebble-Bed crops out, forming also much of the surface of the South
Camp. The Middle Bagshots on the south slope of the hill are
estimated from the South Camp boring at 53 feet, with a marked
clay-bed at the base; and below these a few feet of the Lower
Bagshots are exposed in the intervening valley. The greater part of
Redan Hill (364 feet) is made up of Lower Bagshots; but towards
the top a few feet of the basal clays of the Middle Bagshots have
been exposed by a recent trench. Although the elevation is prac-
tically the same as that of Thorn Hill, the rest of the Bagshot series
is cut out owing to the northerly dip. These results differ from
those of previous observers, e.g. the Geological Survey carry the
Lower Bagshots to the top of the Redan Hill, as do Messrs. Monck-
ton and Herries; whilst of the anticlinal, alleged by Mr. Irving to
exist in this traverse, there appears to be no trace. The author
also observed that the arguments for overlap of the upper beds and
for the erosion of the London Clay are not borne out by the facts.

The second section described runs from Gravel-Pit Hill on the N.
to Ash Green on the S. It was drawn to the same scale, and showed
the beds from the Chalk to the Middle Bagshots inclusive. Dip
northerly 24° to 2° 50' at south end. A spur of the Fox Hills
(Gravel-Pit Hill) is seen to consist of Upper Bagshots of the normal
type down to the lower shoulder of the spur, which is capped by the
Pebble-beds marking the junction of the Upper and Middle Bag-
shots. The Ash-station well shows the basement-beds of the Lower
Bagshots, of a character very similar to those in the Brookwood and
South-Camp deep boring. The position of the outcrop of the London
Clay also is in favour of a regular and persistent northerly dip,
corresponding in degree with that given at Hast Wyke farm by
Messrs. Monckton and Herries. The thickness of the London Clay
was calculated at 880 feet, which is about the same as at South
Camp, leaving no margin for its erosion before the deposition of the
Bagshots.—The third section was drawn, also on the same scale,
through Aldershot town, showing the beds from the Woolwich and
Reading series to the Middle Bagshots inclusive. The dip is 24°
to the N., and regular, as in the other two cases. The following
thicknesses are given :—

Geological Society of London. 285

Middle Basshots’’\..° (25) Ae.” di.) ws 2 about (55 feet:
Lower Bagshots ANGER tL) iss 08 Gees pone LUG es
Hondon Clay... %:. 13 ae Le BB Din ags

It was inferred fan various Pe dations, as also from direct obser-
vation, that the thickness of the London Clay shows no diminution
throughout the section, being nearly the same also at Ash and at
Aldershot Place.

In ‘‘Ceesar’s Camp” the Pebble-bed occurs at altitudes ranging
from 500 to 550 feet.

The author concluded that wherever we can fix the top or base
of the London Clay, we get a northerly dip of 24° to 3°, showing a
fairly constant thickness of from 3380 to 340 feet. The same thing
occurs from Odiham on the west to Ash on the east, whilst at
Brookwood the London Clay is thicker. He also assumed the exist-
ence of a passage from the London Clay up into the Bagshot beds in
the deep wells or borings at Wellington College, at Brookwood, and
at South Camp. Hence at these points there can have been no great
erosion or unconformity. The overlying Bagshots le conformably
on the London Clay and on each other.

2. “Supplementary Note on the Walton Common Section.” By
W. H. Hudleston, Esq., M.A., F.R.S., Sec.G.S.

The principal object of this paper was to point out the ocourrence
of certain beds of clay or loam in what are usually known as the
“Lower Bagshot Sands” of West Surrey. It was shown that the
sandy series, No. 8, of the previous paper is overlain by a second
clay series, No. 4, whose mode of occurrence and lithology were
described. This is again succeeded by a third sandy series, No. 5,
which, it is believed, is maintained throughout the remainder of the
cutting as far as the River Wey, with occasional clay patches
deposited in small basin-shaped hollows of the sand.

The nature and geological position of the brick-earth of Hatch
on Woburn Hill was next described. This forms a portion of the
“clays most extensively developed between Addlestone and Chert-
sey, referred by Professor Prestwich to his Middle Bagshots, and
mapped as such by the Geological Survey. The clay is seen to
occur as a lenticular mass, 21 ft. thick at its maximum, in a hollow
of loose yellow sand; the current-bedding of the upper loamy layers
is very marked towards the north end, with a strong false dip to the
south, 7.e. towards the centre of the basin.

Accepting as the true datum line for the base of the Middle
Bagshots in this district, “the foliated clays, more or less sandy,
having a thickness of 14 ft.,” which are shown by Prof. Prestwich
to be typically developed in the railway-cutting on Goldsworth Hill,
it was contended that the Hatch brick-earth cannot be correlated with
these. The true basal beds of the Middle Bagshots in this district
differ somewhat in their physical characters; but it was on strati-
graphical grounds mainly that the author endeavoured to show
that the Hatch brick-earth should, despite its argillaceous nature,
be assigned to the Lower Bagshots. A diagrammatic section from
St. George’s Hill (245 ft.), through Woburn Hill (92 ft.), to St.

286 Reports and Proceedings—

Ann’s Hill (230 ft.), was given, and the possible existence of a trough
or synclinal towards the centre of the section discussed. It was shown
from the position of the Hatch brick-earth that if the Lower Bag-

shots retain anything like the mean thickness of, say, 120 ft., which

prevails in this district, the London Clay surface must here be 60 ft.
below O.D., on the supposition that these beds represent the basal
clays of the Middle Bagshots ; whereas, at Chertsey, in the valley of
the Thames itself, the London clay surface coincides with O. D.

In conclusion, it was held (1) that the more we study the Bagshot
beds of this area, the less likely are we to see a passage between the
curiously diversified Lower Bagshots and the much more uniform
and homogeneous London Clay; (2) that, until we realize the
considerable though sporadic development of clays in the Lower
Bagshots, we shall be in danger of referring beds to the Middle
Bagshots which do not belong to them, and thereby give encourage-
ment to a speculative stratigraphy which can only mislead.

TII.—May 11, 1887.—Prof. J. W. Judd, F.R.S., President, in the
Chair.—The following communications were read:— _

1. “Further Observations on Hyperodapedon Gordon.” By Prof.
T. H. Huxley, LL.D., F.RB.S., F.G.S.

The author briefly noticed the circumstances under which he
first described the occurrence of Lacertilian and Crocodilian fossils
in the Elgin Sandstones, and the confirmation which his views as to
the Mesozoic age of these remains had received from the discovery
of Hyperodapedon in English Triassic rocks and in India. The
original type of Hyperodapedon Gordoni from Elgin was, however,
in bad condition, and the receipt at the British Museum of a second
much better preserved skeleton, found in the Lossiemouth quarries
of the same neighbourhood, had enabled him to add considerably to
the known characters of the genus, and to compare it more thoroughly
both with the recent Sphenodon (or Hatteria) of New Zealand and
with the Triassic Rhynchosaurus articeps, several specimens of which
are in the British Museum paleontological collection.

The recently-discovered Hyperodapedon-skeleton was of nearly
the same size as that formerly described, and must have belonged
to an individual about 6 or 7 feet in length. The specimen was
exposed by the splitting of a large block of sandstone, and comprised
the skull, the vetebral column as far as the root of the tail, all the
bones of the left and of part of the right fore limb, and those of the
right hind limb, the whole almost in their original relations.

The bones were described in order and compared with those of
Sphenodon, the most important differences in Hyperodapedon being
the following :—

1. The centra of the presacral vertebre are ossified throughout and more or less

opisthoccelous, especially in the cervical region.
2. The anterior cervical vertebree have long and strong ribs.

3. The external nares are not separated by bone.

4. Conjoined premaxillary bones form a long, conical, curved, pointed rostrum,
which is received between the rostral processes of the mandible. All these
were devoid of teeth and probably sheathed in horn.

a le

.
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:

Geological Society of London. 287

5. The palatal area is very narrow in front and wide behind, with strongly curved

lateral boundaries.
_ 6. The posterior maxillary and palatal teeth are multiserial.
7. The rami of the mandible are united in a long symphysis, behind which they
diverge widely, and the dentigerous edges are strongly concave upwards as

well as outwards.
8. The mandibular teeth in front are set into a close, apparently continuous
palisade, and become distinct and conical only at the posterior end of the

series.
9. The fore foot is remarkably short and stout, with metacarpals of equal length.

The relations of Rhynchosaurus to Hyperodapedon and Sphenodon
were then dealt with, the first-named being shown to occupy in
some respects an intermediate place between the two others. The
skull of Rhynchosaurus resembles that of Hyperodapedon in its single
anterior nasal aperture, its premaxillary and mandibular rostral
processes, and in having more than one series of palatal teeth ;
but in general form and in the shape of the maxilla, palatal bones,
and rami of the mandible, it departs far less from Sphenodon than
Hyperodapedon does. Some comparisons of limb-bones were also made.

The three genera mentioned were shown to form a particular
group, which, however, had no claim to ordinal distinction, and
appeared to form a family, Sphenodontide, of the Lacertilia, com-
prising two subfamilies, Rhynchosaurine (including Rhynchosaurus
and Hyperodapedon) and Sphenodontinz.

The fact that in this Lacertilian group the highest known degree
of specialization, as shown in Hyperodapedon, was attained as early
as the Triassic epoch, showed that in Permian times, or earlier,
Lacertilia existed which differed less from Sphenodon than either of
the Rhynchosaurine did. Not only was the Lacertilian type of
organization clearly defined in the Triassic epoch, but it attained a
degree of specialization equal to that exhibited by any modern lizard.

2. “Rocks of the Essex Drift.” By Rev. A. W. Rowe, M.A., F.G.S.

The rocks of the Essex drift are of great variety. There is a
remarkable absence of granite of any kind, and only two specimens
of syenite have been found. Quartz-porphyrites and quartz-tourma-
line rocks are fairly abundant, felsites are rarely met with, but felspar
porphyrites are very abundant; trachytes also are found, but there is
some reason for suspecting that these do not really belong to the drift,
but have been imported in very early times. The most abundant of
the igneous rocks are the dolerites; but all the coarser dolerites
and those of a true ophitic character are wanting. Many of the
specimens are of subophitic texture, and bear a general likeness to
the subophitic dolerites of Central England. Some specimens, how-
ever, are strikingly like the rocks of the Whin Sill, in certain special
points. The dolerites of trachytic texture, or basalts, do not at all
resemble those of the North of England, but some of them are almost
identical with certain Scandinavian basalts. One or two specimens
deserve special mention, and among them a hypersthene-bearing
dolerite that is more nearly ophitic than any of the others. Two
specimens of granulite containing hypersthene are interesting as
belonging to a well-characterized type. The crystalline schists are

288 Reports and Proceedings— Geological Society of London.

not abundant; among them is a hornblende schist containing abun-
dance of tourmaline. The sandstones, some of which are of very
large size, belong chiefly to the Carboniferous series, and, as a rule,
are unfossiliferous. Two blocks of fossiliferous sandstone have been
identified with the sandstone of the Lower Neocomian series in
Lincolnshire. Of the limestones there are a great number of blocks
of a hard grey crystalline limestone of the Carboniferous series
containing some very perfect specimens of Foraminifera; and
two specimens from the Rheetic beds, which are of peculiar interest
if, as it is said, the Rhzetic beds do not now come to the surface any-
where in the North of England. The greater number, however, of
the limestones belong to the Jurassic series; there are also many
lumps of very hard chalk which have been identified with the hard
chalk of Cambridgeshire. The microscopic sections of the Chalky
Boulder-clay show that amid grains of quartz, sand, etc., there are a
great number of minute Foraminifera still wonderfully well pre-
served. The way in which the Chalky Boulder-clay and the gravels
lie was well shown in a railway-cutting near Dunmow some short
time ago, and happily a small photograph of the section was taken
at the time, for that part of the cutting has now been covered in.
It is possible that this attempt at classifying and describing the rocks
of the drift may be of some assistance to those who are considering
the general question of the glacial drift.

3. “On Tertiary Cyclostomatous Bryozoa from New Zealand.” By
Arthur W. Waters, Esq., F.G.S.

The Cyclostomata noticed in this paper were from the same
collections as the Chilostomata described in the last volume of the
Quarterly Journal, and this part was kept back a short time, in the
hope that the publication of the Report of the “Challenger” ex-
pedition might throw some light upon this unsatisfactory suborder ;
but the results are very disappointing in this respect, as only thirty-
three species are recorded, and these for the most part well known
and common ones.

It was proposed to subdivide the Cyclostomata into two sections,
namely :—1, those in which the surface of the zoarium is to a
considerable extent formed of the lateral walls of the zocecia, as
Entalophora, etc.; and 2, those in which the zocecia or cancelli open
for the most part at right angles to the axis, or surface of the zoarium,
or subcolony, of which Heteropora and Lichenopora are typical.

The author recorded the preservation of the extremely delicate
and fragile rays or “hair-like teeth” in the interior of the fossil
Entalophora intricaria.

Out of the twenty-eight species or varieties eighteen are known
living, and this part of the collection agrees with the former in indi-
cating that it is comparatively recent. The number of these fossil
Bryozoa is now brought up to 106. The new species described
by the author were :—Entalophora wanganuiensis, Tubulipora tubipora,
Lichenopora wanganuiensis, Reptocavea aspera, Heteropora napierensis,
and Crassohornera waipukurensis ; and he also noted a new variety,
perangustu, of Diastopora sarniensis.

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AMERICAN JURASSIC MAMMALS.
* ie a g ute

DecavE III. Vou. IV. Pt. ee

‘

AMERICAN JURASSIC MAMMALS.

THE

GEOLOGICAL MAGAZINE.

NEW SERIESS @BECADE Ill. VOL. INV.
No. VIIL—JULY, 1887.

@©AE GEE IN Ase Are TES ea Se

2
J.—Amerioan Jurass10o Mammats.
By Professor O. C. Marsu, M.A., LL.D., F.G.S.
(PLATES VIII. anv IX.)
(Concluded from page 247.)
DRYOLESTID.

HE first American mammal found in the Jurassic, and a large
proportion of those since discovered, belong to a peculiar family
which the writer has called the Dryolestide. It includes several
genera and numerous species from America, and is likewise repre-
sented among the forms found in Europe.

The type species of the group, Dryolestes priscus, was based upon
a characteristic lower jaw, although the specimen was imperfect.
A nearly complete lower jaw of the species is represented on Plate
VIII. Fig. 2. An allied species, Dryolestes vorax, is shown on the
same Plate, by Figures 8 and 4. Stylacodon, Asthenodon, and Laodon,
other genera of this family, are likewise represented on the same
Plate.

The upper jaws of several genera of this family are now known
with tolerable certainty, and these will be figured and described
fully in the Memoir now in preparation.

All the genera of this family have more than the typical number
of teeth (44), and the general characters of the inferior dentition
are well shown in Plate VIII. The lower teeth form a close-set
series, without diastemas, or marked interspaces.

There are three, or four, incisors, and in those preserved, each
has a distinct crown, and the series diminishes in size from in front
backward. The canine is inserted by two fangs, more or less
distinct, and in most forms its crown is prominent and trenchant.
Three or four premolars follow, increasing in size backward, with
the last usually very prominent, and in some forms larger than the
canine. These premolars all have two roots, and a compressed
crown. All have one main cusp, and a small posterior heel. There
is usually a small anterior cusp, especially on the posterior teeth.

The molar teeth are from six to eight in number, and are essen-
tially identical in form, and usually distinct from the premolars.
The crown consists of one main external cone, high and pointed,
and three internal cusps, which vary much in development in the
different genera. Seen from the outside, these teeth appear to be

DECADE III.—YOL. IVY.—NO. YII. 19

290 Prof. O. C. Marsh—American Jurassic Mammals.

inserted by a single fang, but, in most cases, each has two roots,
although these are nearly or quite connate. When the jaw is
imbedded in the matrix, and the diminutive teeth uncovered as far as
safety will permit, the features of one side only of the molars can
be determined. Thus in Figure 1, Plate VIII. the outer exposed
side of one lower jaw (Stylacodon) is shown, while in Figure 2, the
inner side of another jaw (Dryolestes) is represented. In Figures 3
and 4, the two sides of the same jaw are placed together, and the
main characters of the lower molar teeth of Dryolestes are thus made
evident.

There are seven superior molars, and these have one main inner
cone, and three outside cusps that vary in size and proportions in
the different genera.

DRYOLESTES AND STYLACODON.

The two genera most nearly allied in dentition are Dryolestes and
Siylacodon, typical examples of which are shown on Plate VIII.
The number of lower teeth in the best preserved specimens appears
to be the same in each, while the incisors, canine, and four premolars,
show no marked differences. In Dryolestes, the eight molars which
follow are all of one type, and differ but little except in size. All
have the inner middle cone of the crown as high as, or higher than
the outer main cone. In Stylacodon, the first two of these teeth
resemble the anterior premolars in shape, and like them show from
the outside double fangs. The main external cone is quite as high
as the opposite cusp.

In Dryolestes, moreover, the lower jaw is comparatively short and
massive, deep below the molar teeth, with its lower margin strongly
convex. The condyle in the best-preserved specimen is concave
transversely, and has its lower margin nearly on a line with the
summits of the molar teeth.

In Siylacodon, the lower jaw is long and slender, and constricted
in front of the coronoid process, which slopes well upward and
backward. The condyle is convex transversely, and placed con-
siderably above the line of the teeth. The jaw is shallow below the
molars, scarcely exceeding the height of the teeth themselves, while
the lower border in this region is nearly straight. ‘These differences
may be readily seen in the two specimens shown on Plate VIII.
Figures 1 and 2. The mylohyoid groove is well developed in both
genera, and its position is essentially the same in each.

In Dryolestes, the mental foramen is below the first premolar.
The dental foramen is beneath the front margin of the coronoid
process, and at this aperture, the mylohyoid groove begins.

ASTHENODON.

The genus Asthenodon, the type species of which is described
below, agrees with the above genera in the more important characters
of the lower dentition, but differs, in having the entire series of
teeth much more uniform in size, and but eleven teeth behind the
canine. The type of this species is the lower jaw shown in Plate

~

Prof. O. C. Marsh—American Jurassic Mammals. 291

VIII. Figure 7. A second specimen referred to this species is the
anterior part of another jaw, shown in Figure 6. The former jaw
shows a weak canine (a), followed by three premolars, each with
two fangs. Behind these, in place of the large, trenchant premolar
seen in Dryolestes and Stylacodon, is a small tooth, which from its
shape may be regarded as the first molar. The remaining teeth
agree in their more important characters with the corresponding
molars of Dryolestes. The second specimen, Figure 6, shows a
similar weak canine, and in front of it, the four incisors in place,
increasing rapidly in size forward, the front one being larger than
the canine.
ASTHENODON sEGNIS, Marsh.

In the genus Asthenodon, the inferior dentition on each side is as
follows :—Incisors 4; canine 1; premolars 3; molars 8.

The largest tooth in the entire lower series is the first incisor,
Plate VIII. Figure 6,,. The remaining incisors decrease in size
backward, as shown in the same Figure, ., ;, and, The canine (a)
is small and weak, and its crown resembles that of the incisors. It
is implanted by two roots, which are nearly connate. The three
premolars behind the canine have each two fangs, and increase in
size from first to last, as shown in Figure 7 of the same Plate. The
following seven teeth, judging from the shape, are molars, and
behind them is the alveole of one more. These molars agree in
general form with those of Dryolestes. The form of the lower jaw
also is similar in the two genera. The upper jaw of this genus is
not known.

The specimens representing this species indicate an animal about
the size of a Weasel. They are from the Atlantosaurus beds of
Wyoming Territory.

Laopon.

A fourth genus, Laodon, while agreeing in the general type of
lower molar teeth with the above forms, differs widely from them in
other respects. The molars in this genus have the outer main cone
high and pointed, as in the above genera, but the inner opposite
cusp is greatly reduced in size, as shown in the type specimen
represented in Plate VIII. Figure 5. There appear to have been
eight molar teeth, six of which are well preserved. In front of
these, are two premolars of nearly equal size, and between these
and the canine, there were apparently three more, each with two
fangs, making thirteen teeth in the premolar and molar series. The
canine had two roots, and the last incisor was placed closely in
front of it.

In this specimen the dental foramen is situated below the summit
of the coronoid process. Its aperture is placed obliquely, opening
backward and upward, and from its outer margin, the deep
mylohyoid groove extends forward and downward, rapidly desceud-
ing below the lower border of the ramus.

This lower jaw is intermediate in form between Dryolestes and
Stylacodon. It has the slender straight ramus of Stylacodon, with

292 Prof. O. C. Marsh—American Jurassic Mammals.

even a stronger constriction behind the molar teeth, but the jaw is
deeper below the molar series, and the lower margin is convex, as
in Dryolestes. Yhe molar teeth resemble those of Peraspalax, Owen,
but in that genus there is a less number of teeth, and other features,
not seen in the present specimen.

The upper jaw of this genus has not yet been identified.

Laopon venustus, Marsh.

In the type specimen of this species, the inner side only of the
lower jaw is shown. ‘The alveolar border is nearly straight, while
the lower margin is strongly convex. The anterior portion of the
ramus is very shallow, but little, if any, deeper than the crowns of
the teeth it contained. There is a well-marked mylohyoid groove,
which begins at the dental foramen, and extends forward and down-
ward, until it is lost below, directly under the second molar. The
angle of the jaw extends well backward, and was not inflected,
although somewhat thickened along the lower margin. The ptery-
goid fossa is deep and wide. The coronoid process was large, but
its exact form cannot be determined.

The type specimen of the present species is from the Upper
Jurassic deposits of Wyoming.

DIPLOCYNODONTIDZ.

A third group of Jurassic Mammals is known at present from
three genera, which have been found only in America. The most
typical form, Diplocynodon, is represented on Plate IX. Figure 3, by
the specimen first described. This fossil indicates one of the largest
mammals yet found in the Jurassic. In this genus, there were at
least three lower incisors, directed well forward. 'The canine is
very large, elevated and trenchant, and inserted by two strong fangs.
Behind this, there are twelve teeth, all essentially of the same type,
so that, from the outer side alone, it is difficult, if not impossible,
to distinguish the premolars from the molars. The crowns of these
teeth are composed of a main external cone, with a small, elevated
lobe in front, and a lower one behind. This is repeated on a
reduced scale on the inner side, except that the posterior cusp is
rudimentary, or wanting. The antero-posterior faces of the crowns
are deeply excavated, and grooved.

The jaw is elongate, and gently curved below. The coronoid
process is large and elevated. The condyle is placed very low,
nearly on a line with the teeth. The angle of the jaw is produced
into a distinct process (d), the lower margin of which bends out-
wards, although the process as a whole has a slight inward direction.

An upper jaw referred to this species contains the canine and
eight succeeding teeth in excellent preservation. The canine is
very large, and has two distinct fangs. The molar teeth have one,
main, external cone, and two lateral cusps, which rise from a strong
basal ridge. On the inner side, there is one main cone, with a small
posterior heel. The outer face and the sides of the upper molars
are deeply sculptured with irregular grooves.

Prof. O. O. Marsh—American Jurassic Mammals. 298

The Huropean genus Amphitherium may possibly belong to this
family, but the lower canine has only a single root, and the molars
appear quite different from those of the American forms.

Docopon.

Another genus (Docodon) of this family may be distinguished
from Diplocynodon by having, in the lower jaw behind the canine,
eleven teeth instead of twelve. The canine has two fangs, as in the
latter genus, and the molar teeth correspond closely in form. The
symphysis is very long, and the mylohyoid groove extends forward
to its upper border. The type specimen of this genus is shown in
Plate IX. Figure 2.

ENNEODON.

A third genus, Enneodon, described below, is represented by two
specimens, one of which is shown on Plate IX. Figure 4. The
lower jaw is comparatively short and robust, and contained only
nine post-canine teeth, all of the same type.

The canine in Enneodon is large, and, as in other genera of this
family, is inserted by two well-separated fangs. Seen from the
outside, its crown resembles that of a true molar, but the anterior
lobe is wanting. The second premolar is larger than the first, not
smaller, as in the type of Diplocynodon. The premolars, although
of the same general form as the molars, have the surface of the
crown more grooved, or striate.

A second specimen of this genus agrees with that last described
in the main features of its dentition, but the lower jaw is less robust.
The canine is also more slender, and there is a small diastema
behind it. The first three premolars increase in size backward, but
are all of similar form. The angle of the jaw is considerably below
the lower margin of the ramus.

The fossils on which the two species of Enneodon are based were
found in the Atlantosaurus beds of the Upper Jurassic, in Wyoming.

SPALACOTHERID.

The type genus of this family is Spalacotherium of Owen, but it
is probable that he included more than one generic form under this
name, in the various specimens described. In America, one well-
preserved jaw has been found, which appears to indicate a distinct
genus (Menacodon), and is described below. ‘This specimen is
represented on Plate IX. Figures 5 and 6.

In the typical specimens of Spalacotherium, the premolars and
molar teeth are ten in number, and of the same general form. The
crown consists of one, main, external cone, high and pointed, and
two, short, inner cusps, nearly equal in size, in front of and behind
the main cone. The canine has two fangs, and there is little or no
diastema behind it.

In Menucodon, the molars have the same general form, but there
appear to be but seven in the post-canine series. The crowns also
are shorter and more robust. The canine is small, and has two roots.

294 Prof. O. C. Marsh—American Jurassic Mammals.

Menacopon rarus, Marsh.

In this species, the lower jaw is comparatively slender, and its
inferior border is strongly convex, longitudinally. The canine was
small, and directed well forward. The first three premolars are
separated slightly from the canine, and from each other. The three
following teeth, which may be regarded as true molars, are larger
and more elevated, and behind these was the last molar, somewhat
smaller in size.

In the type specimen of Menacodon, there is no sharply defined
mylohyoid groove, but a shallow depression takes its place, as
indicated in Plate IX. Figure 6.

In Spalacotherium there is a well-defined mylohyoid groove.

The unique specimen on which the present species is established
was found in the Upper Jurassic of Wyoming.

TINODONTIDZ.

This family is well represented by American forms, one of
which, the type species of Tinodon, is shown on Plate IX. Figure 1.
Phascolotherium, Owen, appears from its dentition to be an allied
form, but differs in several important points, and may yet be found
to represent a distinct family. The premolar and molar teeth have
nearly the same form in both genera, but in Zinodon, there is a larger
number of post-canine teeth. The coronoid process, also, is vertical,
and the angle of the jaw is not inflected. The premolars have
the same general shape as the molars, the crowns being composed
essentially of three pointed cusps, one, main, outer cone, and two,
smaller cusps, one in front and one behind, on the inner side.
There is a strong cingulum on the inner surface, which may develop
into an anterior lobe, or posterior heel. The mylohyoid groove is
distinct. The condyle in Tinodon is rounded, and somewhat trans-
verse, and is separated from the jaw by a distinct neck.

In Zinodon bellus, the dental foramen is large (Plate IX. Fig. 1,/),
and looks downward and backward. It is placed somewhat behind
the anterior margin of the coronoid process, and somewhat above
the middle line of the ramus. The deep mylohyoid groove (g)
leads from this opening, forward and downward.

TRICONODONTID&.

Another family related to the one last described is represented by
the genus Zriconodon of Owen, and by one or two American forms,
In this group, the premolars are unlike the molars. The latter
are large, and their crowns are composed of three, nearly equal,
trenchant cusps. The premolars are compressed and trenchant, but
lack the anterior cusp. There is apparently more than one genus
included under the specimens referred by Owen to Triconodon, but
more specimens will be required to separate them.

PrRiacopon.

One of the American forms, which appears to be generically
distinct from the type of Triconodon, is represented below, on
Plate IX. Figure 9, under the name Priacondon ferox. ‘The type

eo

Prof. O. C. Marsh—American Jurassie Mammals. 295

specimen, on which it is based, was originally placed by the writer
in the genus Tinodon, and the species named Tinodon feroz. This
Specimen is a right lower jaw, with most of the teeth in position.
There are three premolars, and four molars. The premolars have
one main cone, pointed and compressed, with a low cusp in front,
and a larger one behind. The last premolar is large. The penulti-
mate molar has four distinct cones instead of three. The canine
was large, and directed well forward. The coronoid process is high,
and inclined backward. The mylohyoid groove is nearly parallel
with the lower margin of the jaw, and extends forward to the
symphysis. The latter is strongly marked.

PAaURODONTIDE.

A peculiar genus, Paurodon, widely different from any form
hitherto found in America, or Europe, is represented at present by
a single specimen, a left lower jaw. This is shown on Plate IX.
Figures 7 and 8. The entire premolar and molar series consists of
only six teeth, the main features of which are seen in the figures
cited. The canine is large, nearly erect, and is apparently inserted
by asingle fang. There is a distinct diastema between this and the
first premolar. The latter is small. The lower jaw is short and
massive, and there is a deep mylohyoid groove (q).

The molar teeth of Paurodon appear to agree in the general
features of their crowns with those of Achyrodon and Peralestes, but
the figures given by Owen of the specimens described under these
names show them to be quite distinct from the present genus.

PavrRopON VALENS, Marsh.

In this genus there were apparently two lower premolars, and
four molars, all separated somewhat from each other. The premolars
have a single main cusp, and a low posterior heel. Hach is
implanted by two roots. The molars have a single main external
cone, and two low inner cusps. The mylohyoid groove extends
from the pterygoid fossa to the symphyseal surface, which is large.
The mental foramen is below the diastema between the canine and
the first premolar.

The upper jaw of this peculiar fossil is not known.

The type specimen of this unique form is from the Upper Jurassic
deposits of Wyoming Territory.

The main object of the present article is to present a typical series
of the remains of known American Jurassic mammals. A discussion
of the closer relations of these to the mammals from the same
formation in Europe, as well as to both older and more recent forms,
will be reserved for the Memoir now in course of preparation.

The vertebre, limb bones, and other parts of the skeleton of
mammals, found with the jaws and teeth here described, cannot yet
be definitely associated with the latter, but an attempt to do this
will be made in the Memoir.

The genera and species of American Jurassic mammals now
known are given in the list below. All have been described by the

296 Prof. O. C. Marsh—American Jurassic Mammals.

writer, in the American Journal of Science. One figure, at least, of
atypical form of each new genus proposed, has also been given,
either in the original description, or in the present article.

The list is as follows :—

PLAGIAULACIDE.
Allodon laticeps. Amer. Journ. Sci., vol. xxi. p. 511, 1881.
ty fonts. 36 3 » XXxll1. p. 331, 1887.
Ctenacodon serratus. ,, He », Xvi. p. 896, 1879.
AH nanus. i aA » XXi. p. 612, 1881.
5 potens. ,, a »» XX&ill. p. 833, 1887.
DRYOLESTID#. 7
Dryolestes priscus, Amer. Journ, Sci. vol. xv. p. 459, 1878.
3 _WOrak. yy 3 »» Xvill. p. 215, 1879.
99 arcuatus. ,, ap », Xvi. p. 897, 1879.
99 obtusus. 4, 5 », XX. p. 287, 1880.
5 gracilis. ,, ‘9 » Xxi. p. 613, 1881.
Stylacodon gracilis. ,, Ap », Xvili. p. 60, 1879.
> validus. ,, - », XxX. p. 236, 1880.
Asthenodon segnis. ,, _ », XXxilil. p. 336, 1887.
Laodon venustus. A 6 » XXxlil. p. 337, 1887.
DipLocyNoDOoNTID#.
Diplocynodon victor. Amer. Journ. Sci. vol. xx. p. 235, 1880.
Docodon striatus. 90 . bp Ody Dn OMA, UisKsil
Enneodon crassus. ,, 33 » XXxil. p. 339, 1887.
* afinis. ,, aa », XXxui, p. 339, 1887.
SPALACOTHERID&.

Menacodon rarus. Amer. Journ. Sci. vol. xxxiii. p. 340, 1887.

TINODONTID B.
Amer. Journ. Sci. vol. xviii. p. 216, 1879.
,, Xvili. p. 397, 1879.
», XVill. p. 398, 1879.

Tinodon bellus.
9 robustus. op 7
» lepidus. 56 39

TRICONODONTIDZ.

Triconodon bisulcus. Amer. Journ. Sci. vol. xx. p. 237, 1880.
Priacodon ferox. 08 ») XXXl. p. 841, 1887.
(Tinodon feroz). ,, a », XX. p. 236, 1880.

PAURODONTID#.
Paurodon valens. Amer. Journ. Sci. vol, xxxiii. p. 342, 1887.

Nearly all the mammals older than the Tertiary, judging from
their dentition alone, may have lived mainly upon insects, with
such accessory diet as modern Insectivores affect. The Plagiaula-
cid@, however, show evidence of marked adaptation to some peculiar
food, whether animal or vegetable cannot yet be determined with
certainty. Now that the upper teeth of Ctenacodon are known, and
trenchant teeth are found opposed to the lower cutting premolars,
and tubercular molars to those below, the problem is simplified, but
not solved. The evidence at present points to an animal, rather
than to a vegetable, diet for all the Allotheria.

It is not improbable that there was a gradual change in diet in
the later forms, until vegetable food predominated. The fact that
the Tertiary genus Neoplagiaulaz, Lemoine, has only a single lower

aye O. OC. Marsh—American Jurassic Mammals. 297

premolar coincides with this view, and if Hypsiprymnus is a still
later descendant, the additional molars, and other herbivorous
features, may be the result of this gradual change.

The few mammals known from the Trias may be placed in two
families, Dromotheridg, including the American specimens, and
Microlestide, those of the old world. They are all quite distinct
from any of the Jurassic forms, either those found in America or in
Europe. Below the Trias, no Mammals have hitherto been dis-
covered ; and none are known with certainty from the Cretaceous.

Mesozoic Mammals have very generally been referred hitherto
to the Marsupialia. An examination of the known remains of
American Mesozoic Mammalia, now representing upwards of two
hundred distinct individuals, has convinced the writer that they
cannot be satisfactorily placed in any of the present orders. This
appears to be equally true of the Huropean forms which the writer
has had the opportunity of examining. With a few exceptions, the
Mesozoic Mammals best preserved are manifestly low generalized
forms, without any distinctive Marsupial characters. Many of them
show features that point more directly to Insectivores, and present
evidence, based on specimens alone, would transfer them to the
latter group, if they are to be retained in any modern order. This,
however, has not yet been systematically attempted, and the known
facts are against it.

In view of this uncertainty, it seems more in accordance with the
present state of science, to recognize the importance of the generalized
characters of these early mammals, as at least of ordinal value,
rather than attempt to measure them by specialized features of
modern types, with which they may have little real affinity. With
the exception of a very few aberrant forms, the known Mesozoic
mammals may be placed in a single order, which the writer has
named Pantotheria.1 Some of the more important characters of this
group are as follows :—

(1.) Cerebral hemispheres smooth.

(2.) Teeth exceeding, or equalling, the normal number, 44.?
(3.) Canine teeth with bifid or grooved roots.?

(4.) Premolars and molars imperfectly differentiated.

(5.) Rami of lower jaw unankylosed at symphysis.

(6.) Mylohyoid groove on inside of lower jaw.

(7.) Angle of lower jaw without inflection.

(8.) Condyle of lower jaw near horizon of teeth.

(9.) Condyle vertical or round, not transverse.

The generalized members of this order were doubtless the forms
from which the modern, specialized, Insectivores, at least, were
derived.

Another order of Mesozoic mammals is evidently represented by
Allodon, Bolodon, Ctenacodon, Plagiaulax, and a few other genera.
These are all highly specialized, aberrant, forms, which apparently
have left few, if any, descendants later than the Tertiary. This

1 American Journal of Science, vol. xx. p. 239, 1880.
2 The genus Pawrodon may be an exception.

298 Prof. O. C. Marsh—American Jurassic Mammals.

order, which the writer has termed the Allotheria,’ can be distin- -
guished from the previous group by the following characters :—

(1.) Teeth much below the normal number.

(2.) Canine teeth wanting.

(8.) Premolar and molar teeth specialized.

(4.) Mylohyoid groove wanting.

(5.) Angle of lower jaw distinctly inflected.

These characters alone do not separate the Plagiaulacide and
Microlestide from some of the Marsupials, and the facts now known
seem to prove that they belong to that group, where they represent,
at least, a well-marked sub-order.

Of the two families of Triassic Mammals now known, the Dromo-
theride may be placed in the order Pantotheria, and the Microlestide
in the Allotheria. According to present evidence, the former were
probably placental, and the latter non-placental, and marsupial.

The modern Placental mammals were evidently not derived from
Marsupials, as is generally supposed. Lach group has apparently
come down to the present time, by separate lines, from primitive
oviparous, forms, of which the living Monotremes may be the more
direct but specialized representatives. Among the diversified mem-
bers of Placental mammals, the Insectivores are probably the nearest
to the early type, and hence they show many features seen in the
Jurassic and ‘Triassic mammals of the order Pantotheria.

Among the various existing Marsupials, the Rat-Kangaroos
(Hypsiprymnide) appear to be nearest to the oldest known forms
represented in the order Allotheria, but future discoveries may, at
any time, bring to light new Mesozoic mammals allied to other
Marsupials.

So far as at present known, the two great groups of Placental and
Non-placental mammals appear to be distinct in the oldest known
form, and this makes it clear that, for the primitive generalized
forms (Hypotheria), from which both were derived, we must look
back to the Paleozoic.

EXPLANATION OF PLATES VIII. anp IX.
PLATE VIII.

Fie. 1. Left lower jaw of Stylacodon gracilis, Marsh; outer view.
», 2 Left lower jaw of Dryolestes priscus, Marsh; inner view.
» 98 Left lower jaw of Dryolestes voraxz, Marsh; outer view.
» 4. The same jaw; inner view.
», 9. Left lower jaw of Laodon venustus, Marsh; inner view.
», 6. Left lower jaw of Asthencdon segnis, Marsh; anterior part, outer view.
», ¢. Right lower jaw of same species; outer view.

a, canine; 6, condyle; ¢, coronoid process; d, angle; g, mylohyoid groove ;
s, symphyseal surface.

All the Figures are three times natural size, except Figure 5, which is four times
natural size.

PLATE IX.

Fie. 1. Right lower jaw of Tinodon bellus, Marsh ; inner view.
», 2 Right lower jaw of Docodon striatus, Marsh ; inner view.
», 98 Right lower jaw of Diphocynodon victor, Marsh; outer view.

1 American Journal of Science, vol. xx. p. 239, 1880.

Grenville A. J. Cole—Rhyolites of the Vosges. 299

Fie. 4. Right lower jaw of Znneodon crassus, Marsh; outer view.
», 9. Left lower jaw of Menacodon rarus, Marsh; outer view.
» 6. The same jaw; inner view.
>» 7. Left lower jaw of Pawrodon valens, Marsh; outer view.
>, 8. The same jaw; inner view.

», 9. Right lower jaw of Priacodon ferox, Marsh ; inner view.

@, canine; 6, condyle; c¢, coronoid process; d, angle; f, dental foramen ;
g, mylohyoid groove; s, symphyseal surface.
Figures 2 and 3 are twice natural size, and the others three times natural size.

Yate Cottece, New Haven, March 26, 1887.

Il.—Tue Ruyoures or WueENHEIM, VOSGES.

By Grenvittz A. J. Corz, F.G.S.,

Demonstrator of Geology in the Normal School of Science and
Royal School of Mines.

N a paper recently read before the Geological Society,’ I ventured
the conclusion that the bulk at least of the “pyromerides” of
the Continent would be found to be altered lavas of an originally
glassy character. The careful drawings and descriptions of various
petrographers formed a strong chain of evidence; and the observa-
tions of Mr. T. Davies* on materials from Bouley Bay, Jersey,
seemed to establish beyond a doubt the connection between rocks
authoritatively styled pyromerides and those regarded in this country
as ancient rhyolites. Last autumn I visited one of the most typical
continental localities, the richly-wooded Tiefenbach valley west of
Wuenheim in the Vosges, and a few notes on specimens then

collected may possibly be of interest to workers in a similar field.

It is at once apparent in the steep cliff-like exposure, with old
slaty and sandy rocks towards its base, situated just beyond the
junction of the roads from Wuenheim and Sulz, that one is dealing,
not with a massive “porphyry,” but with materials as diverse as
those of the famous quarry near the Wrekin. Thus one rock is distinctly
banded in tints of grey and yellow-brown, and proves under the micro-
scope to be a devitrified perlite, an old obsidian rather than a stony
rhyolite ; while the “ globular” types, made famous, since their dis-
covery by M. Koechlin-Schlumberger, through the detailed investi-
gations of Delesse,*? occur in considerable variety, as may be seen
even in the metal of the neighbouring roads. In some instances the
spherulites, 5 millimetres to 1 centimetre in diameter, are purple-red
in a yellowish matrix; in other cases they have a grey and flinty
aspect. Many have become chalcedonic in the centre, and may have
passed through a hollow stage before this final alteration. Radial
structure is visible in the spherulites to the naked eye, and the sur-
rounding material is evidently perlitic.

So much did the spherules at the time of their origin partake of
the character of the matrix from which they were derived, that the
larger lines of perlitic jointing pass frequently from one into the

1 Quart. Journ. Geol. Soc. vol. xlii. p. 188.
2 Min. Mag. vol. ui. p. 118.
3 Mémoires de la Soc. géol. de France, 2me série, tome iv, p. 308, etc.

300 Grenville A. J. Cole—Rhyolites of the Vosges.

other, and aid doubtless in bringing about the alteration of the
spherulites. It is to this admixture of glass and this slight differentia-
tion from it that I would prefer to ascribe the absence of double
refraction in so many incipient spherulites of modern date, rather
than adopt the view held by some petrographers that such bodies
may largely consist of opal.

Delesse, with his usual perception, detected in the matrix of the
rock of Wuenheim the perlitic jointing, the “structure fendillée et
globuleuse entrelacée,” explaining it as a product of contraction when
the mass had become practically solid. Microscopic sections would
have revealed it to him in exceptional completeness, and the former
glassy condition of these dull felsitic rocks may be considered as
proved by the presence of the structure in such perfection. The
spherulites, whether grey or red, are alike brown in section, and
resemble the well-known type, the ‘felsospherites” of German
authors; while their minute globulitic constitution seems to be still
retained, despite the secondary granulation visible under polarised

Fia. 1.—Section of rock of Tolesya, showing disturbance of the lines of flow between

the components of the large irregular spherulites. x 80.
Fic, 2.—Section of altered perlitic lava of Wuenheim, showing rays belonging to
two large ‘“skeleton-spherulites.’’ x 18.
light. Vogelsang,! indeed, comments on the “surprising resem-
blance ” between the structures of the rock of Wuenheim and certain
Hungarian lavas; and it is interesting to note that Faujas de St.-
Fond ? described, eighty years ago, the similar pyromeride of Corsica
under the name of Roche porphyroide rather than porphyre, stating
his belief that the constituents had consolidated more rapidly than is
the case in the latter class of rocks. '
The most remarkable rock from the “globular” series of Wuenheim
is one of limited occurrence, in which the spherulites, about 1 centi-
metre in diameter, are closely crowded together, apparently to the
almost complete exclusion of the matrix. Instead of being compact
and homogeneous, these spherulites are seen on broken surfaces to
be composed of alternating red and lighter rays, suggesting the

1 Die Krystalliten, p. 168. 2 Essai de Géologie, tome ii. p. 245.

Grenville A. J. Cole—Rhyolites of the Vosges. 301

presence of a coarse granophyric structure. Under the microscope,
however, while the red rays resemble in constitution the ordinary
spherules, the intervening matter proves to represent the matrix,
now petrosiliceous, it is true, but retaining the characteristic perlitic
curves, marked out often by ferruginous stains and granular products
of alteration. The spherulites are, in fact, imperfect, being con-
structed of radially-grouped rods, circular in cross-section, stretching
outwards from a more compact and normal centre. That the alter-
nating and more transparent layers consist, not of original quartz,
nor chalcedony, but of a devitrified glassy matrix, the specimen
figured leaves, I think, no room for doubt. (Fie. 2.)

Further alteration might convert this material into the semblance
of chalcedonic veinules, or might even replace it by bands of
secondary quartz. The frequent mention by older writers—Mon-
teiro,’ for example—of interlamination of “quartz and felspar” in
the nodules of pyromerides makes one certainly prepared for the
development of granophyric structure in such masses on a handsome
scale. Delesse* even held that the “quartz” in the rock of
Wuenheim exerted some influence on the globular forms of the
spherules at the time of their development, and that the alternating
bands were due to a primary separation of the constituents. But in
another place* he shows that the more siliceous fibres are probably
chaleedonic, since the etching of polished surfaces of the rock with
hydrofluoric acid destroys them more rapidly than the felspathic rays.
M. Michel Lévy,‘ accepting the siliceous rays and veinules in the
pyromeride of Gargalong as consisting of chalcedony, believes them
to be primary, and to characterise a distinct type of rock, peculiar
to Permian and Triassic days; that is, a rock intermediate in
structure between the micropegmatites with their radial quartz and
the modern lavas with spherules largely made of opal.

The example from Wuenheim, however, recalls forcibly a structure
occurring in glassy rocks of comparatively recent date. Von Richt-
hofen °® noted in the perlites of Tolesva and Erdobenye in Hungary
certain groups, one or two inches across, of radially divergent rays,
interpenetrated by the homogeneous magma, and regarded them as
coarse spherulites extended outwards in this open fibrous manner
until they were checked by coming into contact. Vogelsang,® seek-
ing for an explanation of this abnormal mode of growth, observed
that the general direction of flow of the rock, as indicated by the
lines of trichites, was the same in the spherulitic rays as in the
matrix, but that local disturbances in this arrangement occurred in
the glassy interspaces, where the trichites seemed even to follow the
outlines of the several rays. He was thus led to the conclusion

1 Journal des Mines, tome xxxy. (1814), pp. 347 and 407.

2 Bull. de la Soc. géol. de France, tome ix. p. 177.

3 Mem. de la Soc. géol. de Fr. 2me série, tome iv. p. 313.

4 Bull. de la Soc. géol. de Fr. 3me série, tome iii. (1875), p, 226. Cf. Noury.
“‘ Géologie de Jersey,” p. 33.

5 Jahrbuch der k.k. geol. Reichsanstalt, vol. ix. (1860), p. 180.

6 Die Krystalliten, p. 148; also plate xvi. fig. 1.

302 Grenville A. J. Cole—Rhyolites of the Vosges.

that the spherules had originally been formed as compact and normal
aggregations, but that the rock had undergone a second fusion ; the
glass had then penetrated the spherulites along their lines of radial
structure, corroding but not destroying them, nor yet disturbing, by
shifting of their parts, the parallelism of the earliest-formed crystal-
lites within. Each spherule became thus split up into a bundle of
diverging and rounded rays; and Vogelsang remarks in a later
passage! on the similarity between this structure and that of certain
felsospherites in the “kugelporphyr” of the Vosges, in which the
place of the glass, however, is taken by a granular siliceous aggre-
gate affecting polarised light.

That Vogelsang’s explanation will not satisfy certain cases, while
it may probably in others be regarded more as an ingenious than an
inevitable deduction, is clear from sections of Hungarian “ strahlige
sphaerolithe ” in the collection of the Normal School of Science and
Royal School of Mines. In the instance figured (Fig. 1), the fluidal
structure of the obsidian passes continuously through the matrix
and the spherulitic matter, and is merely disturbed, not broken, in the
interspaces between the rays. While this continuity excludes the idea
of a second fusion, the local disturbances must have arisen from the
opposition offered by the rays themselves. In a glassy lava moving
with some rapidity, large spherulites are impossible, the separated
globulitic materials being carried out into parallel bands. As the
movement becomes slower, however, and as consolidation proceeds,
nodular aggregations appear locally along this banding, and, if the
crystallisation is finally arrested at this stage, their outer margins
are seen to be ill-defined and ragged, set with, in fact, irregular but
fairly radial rays.? It is conceivable that as we frequently meet in
rocks with the mere skeletons of crystals planned on a scale too
ambitious for the time occupied in the consolidation of the mass, so
even skeleton-spherulites may arise, the whole product being similar
in structure to the arrested external layers of the instances above
described. The diverging rays, set at all angles to the direction of
flow, will gradually interfere, after the manner of embedded crystals,
with the further uniform progress of the glass; and the last move- -
ments in the mass, together with the pressure of upper layers, will
serve to distort the lines of crystallites between the rays, or even to
break them through and rearrange the particles into local lines of flow.

In some of the Hungarian cases examined, the interstitial matrix
has itself become finally spherulitic, but on a minute and delicate
scale, showing a mosaic of dark-cross areas when viewed between
crossed Nicols. In the rock of Wuenheim, however, it seems for
the most part to have remained glassy until the period of its
secondary alteration into granules. The individualised fibrous
structure of the spherulitic rays, which are well compared to axiolites
by Rosenbusch,’ would in itself assign to them an origin independent
of one another in all but the tendency to develope in groups about

1 Ibid. p. 168 2 See Quart. Journ. Geol. Soc. vol. xli. plate iv. fig. 1.
3 Mikroskop. Physiogr. 2nd edit. (1886), p. 395.

. A. S. Woodward —Eocene Siluroid Fishes. 3038

certain centres. The second, third, or fourth series of spikelets attach-
ing themselves to one of the rays of a skeleton-crystal of magnetite
may be considered as independent of the similar additions, whether
simultaneous or not, made during consolidation to the other primary
arms. One arm, moreover, in such examples frequently attains to
a much greater development than the rest, and corresponding pheno-
mena may be expected among skeleton spherulites.

I would submit these few observations as further evidence in
favour of regarding the pyromerides as the altered representatives
of the rhyolites of to-day, of which they reproduce, not only the
familiar, but also some of the rarer types. It is interesting to
observe that, equally with those of Jersey, the Wuenheim lavas are
held to be of Permian age.

In the microscopic work relating to this subject, I have been
much indebted to preparations made in the Geological Laboratory
of the Normal School of Science and Royal School of Mines.

T1I.—On Some Remarns oF Siuuroip Fisues From British Eocenzt
ForRMATIONS.

By A. Smita Woopwarp, F.G.S., F.Z.S.,
of the British Museum (Natural History).

MONG the early Tertiary Fishes in the British Museum, there
are a number of detached spines and cranial fragments from the
Middle and Upper Eocene beds of Bracklesham and Barton, which
are undoubtedly referable to extinct members of the family of
Siluride. With the exception, however, of three specimens figured
and briefly noticed by Dixon in his work on the fossils of Sussex,}
all have remained hitherto undescribed; nor is it an easy task to
base any satisfactory identifications upon such fragmentary materials.
But as it has sometimes been asserted that no traces of this family
have yet been discovered in European formations,—and, as moreover,
at least one important generalization has been based upon the
supposed fact,’—it will perhaps be of interest to offer a few notes
upon these fossils, to show that their non-recognition is due rather
to the imperfection of the geological record, than to their actual
absence in the rocks. And some slight notice is all the more
desirable, since Dixon’s reference of the Bracklesham specimens to
the temperate genus Silurus is obviously erroneous, and the mistake
has escaped correction in the second and revised edition of his great
work.

It is impossible, of course, to attempt any precise specific diagnoses
equivalent to those recognized by the zoologist among living forms ;
for no evidence is yet forthcoming as to the arrangement and
proportions of the fins, which constitute so prominent a character
of note in systematic works. But there is very good reason to believe

1 F. Dixon, “ Geology and Fossils of Sussex,’’ 1st edit. 1850, p. 204, pl. xi.
figs. 11-12 [2nd ed. p. 244, pl. 11, figs. 11-13. ]

2 “The Siluroids . . . . came into existence after the Cyprinoids, fossil remains
being known only from Tertiary deposits in India, none from Europe.”’ (A. Giinther,
“‘ Study of Fishes,’’ 1880, p. 216.)

304 A. Smith Woodward—Eocene Siluroid Fishes.

that the fossils indicate two distinct types, and it therefore seems
advisable to adopt the usual palzontological expedient of applying
a provisional name to each, merely for convenience of reference;
and in the first case, at least, there can be little doubt that the
present determination will prove well founded.

Arius Eerrroni, Dixon sp.
1850. Silurus Egerton’, F. Dixon, Geol. and Foss. Sussex, p. 204, pl. xi. figs. 11-13.

Pectoral Arch and Spine.—The finest specimen figured by Dixon
among the types of this species is a right pectoral spine in natural
association with the clavicular element of the supporting arch (Brit.
Mus. No. 25612). A triangular dermal plate, ornamented with
irregularly-disposed, large conical tubercles, is firmly merged with
the clavicle in its middle portion, and extends backwards for a
distance equalling half the length of the spine; and the bone is
evidently preserved as far upwards as its sutural connection with
the supra-clavicle, though unfortuately mutilated near the rigid
lower symphysis. ;

Of the spine itself, the National Collection comprises several
examples, which render it possible to define its characters completely.
These specimens vary considerably in size, though agreeing in every
other respect, and the beautiful fossil already mentioned is much the
largest, while one of the smaller ones (B. M. 25736) was originally
selected to show the form of the proximal articulation. All are of
the ordinary laterally-compressed shape, and, when well preserved,
exhibit an ornament of closely-approximated, short irregular ridges,
rising at intervals into small conical bosses. In the distal half of
the spine, the denticles upon the edges are large and recurved, but
more proximally they become much smaller, and the points incline
in the opposite direction.

3

Fres. 1 and 2. Arius Egertoni, Dixonsp., M. Kocene, Bracklesham Bay, Sussex, etc.
Fic. 3. Arius ? Bartonensis, sp. nov., U. Kocene, Barton Cliff, Hampshire, etc.
a, median view of proximal articular end of Fig. 3.

Dorsal Spine, etc.—The dorsal spine, associated by Dixon with
“ Silurus Egertoni,” corresponds so closely in the character of its
ornamentation with the pectoral appendage already referred to, that
there can be little doubt as to the correctness of the correlation.

A. Smith Woodward—Eocene Siluroid Fishes. 305

But the British Museum does not appear to possess any example
sufficiently large to have pertained to a fish of the dimensions
indicated by the pectoral arch No. 25612; and the fossil figured by
Dixon (No. 25735a) is one of the finest and best preserved. The
spine is remarkably straight, neither the anterior nor the posterior
border exhibiting more than the slightest curvature, and the distal
tapering is but gradual. The lower end shows the usual facettes
for its connection with the interspinous bones, and there is the
ordinary ‘shackle joint.” The row of denticles upon the anterior
edge is prominent in unabraded specimens, and they are largest in
the middle, diminishing towards either extremity ; those at the
base are merely minute tubercles, but those still higher are well-
defined hooklets, with the points at first directed upwards and
finally downwards.

The short blunt spine, with bifurcating base, situated in front of
the larger weapon, and serving as a kind of “bolt” or fulcrum,
has also been met with at Bracklesham, and is shown of the natural
size in Fig. 1. There are likewise some fragments of the modified
interspinous bones, though these exhibit no special features of
interest.

Cranial Bones.—But the most satisfactory materials for discussion
consist in a number of fragments of the cranium, which were long
ago labelled by Sir Philip Egerton and Mr. William Davies as
pertaining to the present species, though no description of them
seems to have been hitherto published. These bones are ornamented
externally in a very similar manner to the clavicular plate already
noted, and their size is such that they may well have belonged to
the fishes indicated by the detached fin-spines. The only element,
however, that is capable of certain determination, is the supra-
occipital bone—fortunately one of the most characteristic bones in
the Siluroid skull—and of this four good examples are preserved:
the finest is shown of the natural size, viewed from above, in
Fig. 2. Anteriorly, there is a small median process dividing the
posterior ends of the frontals; on either side, the sutural connections
with the successive laterally-placed bones are more or less dis-
tinguishable, and the greatest breadth is attained between the
squamosals; and posteriorly, where the lateral borders are free,
the element exhibits scarcely any tapering, and has a comparatively
abrupt termination. The upper surface is raised into a median
longitudinal keel in the hinder half of the bone, and from the
anterior extremity of this there diverge two well-marked mucus-
canals, which appear to extend towards the point of junction of
the frontal and postfrontal on each side. On the inferior aspect,
the most noteworthy feature is the strength of the septum between
the lateral muscles, below the post-cranial extension of the bone.
There is no trace of a supraoccipital fontanelle.

Systematic PositionFrom the foregoing facts, it is obvious, that
the Siluroid species under consideration was characterized (i.) by the
presence of a strong dorsal fin-spine in addition to the pectorals ;
{il.) by a large, ornamented dermal plate attached to the scapular

DECADE III.—VOL. IY.—NO. VII. 20

306 A. Smith Woodward—Eocene Siluroid Fishes.

arch; and (iii.) by the ornamentation of the upper cranial bones,
which are evidently not covered with more than a very thin skin.
In all these respects, the present species differs widely from the
Silurus-ty pe, and the first two characters alone, which were originally
indicated by Dixon, are quite sufficient to exclude it from the genus
just mentioned. Sir Philip Hgerton, indeed, seems to have already
recognized the fact, and has labelled some of his specimens as
Pimelodus. But a careful comparison of the supraoccipital bone
with the corresponding element in the large series of recent Siluroids
in the British Museum can leave little doubt that the fossil really
belongs to the well-known genus Arius, or to some closely allied
form which cannot be distinguished upon present evidence. There
is the most striking similarity in the few points as yet known, and
it is scarcely likely that any great divergence will be noted in the
other structures still to be revealed.

If such a conclusion be substantiated by future discoveries, the
fact will become of considerable interest, as showing that this
Siluroid fish belonged to a type now characteristic of tropical waters,
instead of representing an existing form (Silurus) that rarely trans-
gresses beyond the temperate zone; and this circumstance, of course,
is in harmony with all the indications of the associated fauna.
Nothing, however, can be said as to its having its nearest ally in
the forms now inhabiting any particular region, for the living
species of Arius have an extraordinarily wide distribution, and are
scattered throughout the freshwaters and littoral areas in almost all
tropical parts both of the Old World and the New.

Formation and Locality.— Middle Eocene: Bracklesham Bay,
Sussex. Probably also Upper Hocene, Barton Cliff, Hampshire.
[ Egerton Collection, B. M. p. 1894a. |

ARIUS? BARTONENSIS, Sp. NOV.

The second species of Siluroid is indicated by some small spines
from the Barton Clay of High Cliff, near Christchurch, Hampshire,
but in this case it is impossible to determine the genus even approxi-
mately. It may belong to Arius, or may represent some other
generic type; and the name by which we venture to designate it
is, therefore, as provisional as those already applied to detached
examples elsewhere. The dorsal spine has a very characteristic
curvature, being gradually arched backwards for three-quarters of
its length, and assuming a more upward direction in the distal
fourth,—a peculiarity shown in the accompanying Fig. 3, though
still more marked in two other less perfect specimens: and the
largest example is almost twice the size of the one here represented.
The sides are ornamented with irregular, delicate longitudinal ridges,
exhibiting but the slightest traces of the thickenings or nodose
expansions so conspicuous in the ruge of A. Hgertoni. The anterior
edge is provided in its lower part with a short series of small, blunt
tubercles; and towards the distal extremity, which becomes much
compressed and sharp, there are little downwardly-directed denticles
both in front and behind, imparting to the tip somewhat of a

R. Lydekker—Hordwell and other Crocodilians. 307

“‘barbed-arrow ” appearance. Posteriorly, the denticles are almost
destroyed in the figured specimen, but another fossil shows that
they are largest in the middle, decreasing towards either end, and
the points are all inclined downwards.

The only pectoral spines that can be associated with this species
are, unfortunately, too imperfect for description. They seem to
have been considerably arched, and have an ornamentation similar
to that of the dorsals.

Formation and Locality—Upper Eocene: Barton Cliff and High
Cliff, Hampshire.

Such, unfortunately, is the most complete evidence of early
Tertiary Siluroids that appears to have been hitherto discovered
in the European area. Among Continental works, I have only
succeeded in meeting with the single description of a dorsal fin-ray
(“second”) and a fragment of a pectoral spine, from the Hocene (?) —
Beds of Austria,’ in addition to a brief notice of the presence of the
family in the Belgian Hocenes.2 And from rocks of still earlier
date, only one fish seems to have yet been referred to the same
systematic position—the Telepholis acrocephalus of von der Marck,
from the Upper Cretaceous of Westphalia ;* and this determination,
it must be admitted, is scarcely placed beyond all doubt.

TV.—Norr on THE HoRDWELL AND OTHER CROCODILIANS.
By R. Lyrpex«er, B.A., F.G.S.

HE two admirable summaries of our knowledge of fossil Croco-
dilia recently published by Mr. A. Smith Woodward—the one
relating to British forms, in this Macazinz,* and the other, com-
prising the whole order, in the “Proceedings of the Geologists’
Association ” ’—render it a comparatively easy matter to find out what
is known concerning any particular species or genus; and I may
accordingly at once proceed to the proper subject of this paper.
Hordwell Crocodiles.—In the above memoirs Mr. Woodward‘ follows
the original suggestion of Sir R. Owen—more fully confirmed by
Prof. Huxley—that the Crocodilian remains from the Upper Hocene
(Lower Oligocene) of Hordwell described under the names of
Alligator Hantoniensis and Crocodilus Hastingsie belong to one and
the same species. The author adopts for this species the trivial
name /astingsie (although Hantoniensis has the priority), and
retains it in the genus Crocodilus; remarking, however, that it
presents characters which under certain circumstances might entitle
it to rank as generically distinct. Sir R. Owen, in his original
description of the so-called C. Hastingsie, remarked that the skull

1 Pimelodus Sadleri, J. J. Heckel, “ Beitrage zur Kentniss der fossilen Fische
Oesterreicher,’’ i. (1849), p. 15, pl. ii. fig. 3.

2H. Le Hon, ‘‘ Préliminaires d’un Mémoire sur les Poissons Tertiaires de
Belgique,’’ 1871, p. 16.

3 W. von der Marck, ‘‘ Neue Fische und Krebse aus der Kreide yon Westphalen,”
Paleontogr., vol. xv. p. 276, pl. xlii. figs. 6, 7; also 7d. vol. xxxi. p. 248.

4 Supra, Vol. II. pp. 496—510 (1886).

5 Vol. ix. No. 5 (1886). 6 Gzou. Mag. op, cit. p. 509.

308 R. Lydekker—Hordwell and other Crocodilians.

presented many Alligatoroid features (which are of course enhanced
by the inclusion of A. Hantoniensis in the same species), and that
it was difficult to say whether the species should really be included
among the Crocodiles or the Alligators. Prof. Huxley’s observations,
which proved the existence of a ventral dermal armour, showed that
the Hordwell Crocodilian in this respect differed decidedly from
all known members of the genus Crocodilus; but since such an
armour is present in some species of Alligator (including * Cayman
and Jucare) and absent in others, this feature would not of itself
necessarily exclude the species from the former genus. Professor
Huxley showed, moreover, that in having the upper teeth more
numerous than abe lower, the species differed from Alligator and
agreed with Crocodilus ; while the usual presence of a notch in the
skull for the reception of the fourth lower tooth is a character of the
latter genus. It will suffice to mention here that the cranium is
characterized by the peculiar circumstance that the premaxillz are
united superiorly, and thus separate the nasals from the anterior
nares.

The reader’s attention must now be directed to the genus Diplo-
cynodon, which was founded by Pomel? upon the lower jaw of an
Alligatoroid Crocodilian from the Lower Miocene (Upper Oligocene)
of Allier, which presented the peculiar feature of having the third
lower tooth nearly as much enlarged as the fourth—from which
feature the generic name was chosen. To the type specimen Pomel
applied the name D. Rateli, and subsequently ° referred to the same
genus the so-called Alligator Huntoniensis. Subsequently again
H. von Meyer? identified with this D. Rateli both a Crocodilian
mentioned by Bravard from Allier under the name of Crocodilus
elaverensis, and also others from the equivalent beds of Weissenau
and other places in the Mayence basin to which he had previously
applied the names C. Rathi, C. Bruchi, C. medius, and C. Brauniorum.
At the same time Meyer observed that this form agreed with the
so-called Crocodilus Hastingsie in the peculiar relations of the
pre-maxillz and nasals; and he consequently came to the conclusion
that both were very closely allied, if not specifically the same.

At a much later period M. Vaillant® described the Crocodilian
remains from Allier and proposed for one form, in which the nasals
reach the nares, the name of Diplocynodon gracilis; retaining that
of D. rateli for the type mandible, which he regarded as probably
distinct from his D. gracilis. His researches proved that Diplocynodon
was furnished with ventral dermal armour.

In 1877 Herr Ludwig® described and figured the Crocodilians
from the Mayence basin, and re-named the form in which the nasals
did not reach the nares Alligator Darwini (including in that species the

1 T follow the views of Dr. Giinther in this respect.

2 Bull. Soc. Géol. France, ser. 2, vol. iv. p. 383 (1847).
3 Catalogue Méthodique, p. 124 (1853).

4 Neues Jahrbuch, 1857, p 538.

5 Ann Sci. Géol. vol. iii. art. 1 (1872).

& Paleontographica, suppl. vol. iii. pt. 4.

R. Lydekker—Hordwell and other Crocodilians. 309

four above-mentioned names previously applied by Meyer) ; while
to another form, in which the nasals reach the nares, he gave the
name of Orocodilus Ebertst. Both forms show the enlarged third
lower tooth characteristic of Diplocynodon, and from the equivalence
of the Mayence and Allier deposits and the specific identity of many
of their Mammals, the prima facie presumption is that they are
respectively identical with the two Allier forms.

Turning once more to the Hordwell Crocodilian, an examination of
the skull figured by Owen in pl. vi. of his “‘ Crocodilia, ete., of the
London Clay ” (Mon. Pal. Soc.), now in the British Museum (No.
30393), shows that it has the enlargement of the third lower tooth
characteristic of Diplocynodon ; and also that the smaller upper teeth
bite on the‘ outer side of the lower ones as in the Alligators, instead
of interlocking with them as in the Crocodiles; and I therefore
come to the conclusion that Pomel’s reference of this species to
Diplocynodon is correct, and consequently that it should be known as
D. Hantoniensis. I should observe, moreover, that I think there is no
doubt but that Diplocynodon is a valid genus, presenting the peculiar
feature of the enlargement of the third lower tooth, but otherwise
intermediate between Alligator and that group of Crocodilus com-
prising the existing Indian C. palustris and the fossil C. Sivalensis.
As I shall allude more fully on a subsequent occasion to the dis-
tinctive features of the genus, I will only observe here that if it be
not adopted it would be necessary to include both it and Alligator in
Crocodilus.

With regard to the so-called Aliigator Darwini, I cannot observe
from the characters of the figured imperfect skulls any characters by
which it can be distinguished from D. Hantoniensis ; but since it
occurs on a higher horizon it may be entitled to specific distinction,
and I therefore propose that it should be provisionally known as D.
Darwini ; the specific name being adopted in preference to either of
the four proposed by Von Meyer, which were never properly described
or figured. With this form D. Rateli, Pomel, is probably also identical,
but the unsatisfactory character afforded by the type renders it in-
advisable to adopt thisname. With regard to the so-called Crocodilus
Ebertsi the figured cranium appears to me to show no characters by
which it can be specifically distinguished from the younger type
cranium of D. gracilis from Allier ; the difference in the contour of
the two being apparently merely due to the different ages of the two
specimens.

It will be apparent from the above that all the so-called fossil
Alligators of the Old World really belong to the genus Diplocynodon;
and since the Crocodiles (C. palustris and C. Sivalensis) which
approach nearest to this genus in the structure of the cranium and
form of the maxillo-premaxillary suture on the palate are confined to
India,’ it becomes an interesting question to know whether the exist-
ing Alligator recently described from China may not show signs of
affinity with Diplocynodon.

‘ See Lydekker, “ Palzontologia Indica’? (Mem. Geol. Surv. Ind.), ser. 10, vol.
iii. p. 216 (1886).

310 ht. Lydekker—Hordwell and other Crocodihians.

London Clay Crocodilians.—Having concluded what I have to say in
regard to Diplocynodon, I may mention that a comparison of the
type skulls of the so-called Crocodilus champsoides and C. toliapicus,
Owen, from the London Clay, has convinced me that these forms
are nothing more than young and old individuals of a single species,’
for which we should therefore adopt the original name C. Spencer,
Buckland.? The so-called C. Arduini, Zigno,? from the Nummulities
of Verona, appears to be specifically indistinguishable from the
English form.

The Wealden genus Hyleochampsa.—In his sixth supplement to the
Reptilia of the Wealden and Purbeck (Mon. Pal. Soc. 1873), p. 1,
Prof. Sir R. Owen applied the name of Hylzochampsa to the imperfect
posterior part of the cranium of a small Crocodilian from the
Wealden of Brook, which was figured in pl. v. figs. 23-25 of the
preceding supplement of the same monograph. ‘This specimen is
new in the British Museum (No. R. 177), and differs from all other
English Wealden Crocodilians by the extremely backward position
of the posterior nares, which are situated immediately in advance of
the pterygoids; and by the supratemporal fosse being decidedly
inferior in size to the orbits. It is further characterized by the
orbits communicating freely with the lateral temporal fossee* as in
recent Crocodilia, instead of being completely shut off from them as
in the Teleosauride. Now the above features being those given by
M. Dollo® as characteristic of his so-called Bernissartia,® the type of
the family Bernissartiide, from the Wealden of Belgium, it becomes
necessary to consider in what respects that form differs from Hylgo-
champsa. On page 322 of his memoir M. Dollo observes that
Bernissartia is distinguished from “ Hyl@ochampsa par l’absence de
tout échancrure orbito-latéro-temporale”; but as this statement is
entirely erroneous,’ the one point of distinction which he indicates is
invalid. As far, indeed, as I can see, the cranium of Hyleochampsa
appears to agree exactly not only in form, but also in size with that
of Bernissartia, and I accordingly regard the two as specifically
identical ; in which opinion I have the support of my friend Mr. G.
A. Boulenger, who has been good enough to compare the type speci-
men with M. Dollo’s description and figure.’ Under these circum-
stances the name Bernissartia Fagesi must apparently give way
to that of Hyleochampsa Vectiana. The perfect preservation of

' Analogous modifications in a still more marked degree are exhibited in the three
crania of the existing long-nosed C. intermedius figured by Liitken in the ‘‘ Vidensk.
Meddell,’’ 1884, p. 61, pl. v.

2 Woodward, Gzou. Mac. op. cit. p. 508.

3 Mem. Ac. R. Lincei, ser. 3, vol. v. p. 67, pl. i. (1880).

4 The “ échancrure orbito-latéro-temporale ”’ of Dollo.

> Bull. R. Hist. Nat. Belg. vol. ii. p. 334, pl. xii. (1883).

6 Ibid. p. 222.

7 M. Dollo’s statement was probably derived from Sir R. Owen’s figures, but fig.
24 shows most clearly the vertical bar occurring in the middle of this vacuity; the
rims of the parieto-frontal and quadrato-jugal regions having been broken away.

8 The onus of proving any distinction between Hyleochampsa and Bernissartia
now rests entirely with M. Dollo. i

R. Lydekker—Hordwell and other Crocodihans. dll

the Belgian specimens renders our knowledge of the affinities
and structure of Hyleochampsa almost as well known as that of
recent Crocodilians; and this we owe to M. Dollo’s careful description.
The hinder portion of a Crocodilian skull with attached cervical
vertebree and dorsal scutes from the Wealden of Brook, preserved
in the British Museum (No. 28966), appears to indicate a genus
hitherto unknown in Britain. The vertebree are amphiccelous, the
scutes apparently without a peg-and-socket articulation, the orbits
communicating with the lateral temporal fossee, the posterior nares
placed as in Goniopholis, the orbits only slightly smaller than the
supratemporal fosse, and the few remaining teeth small and slender.
The whole contour of the skull is essentially Garial-like, and I have
little doubt that it was produced into arostrum. As far as I can see,
it apparently agrees precisely with the skull figured in Dunker’s
“Mon. norddeutsch. Wealden,” under the name of Macrorhynchus
Meyeri (of which it is the type), although the palate of the latter is
unfortunately not shown. Dr. Koken, who regards! Macrorhynchus
as identical with -Pholidosaurus, of the German Wealden, has,
however, been good enough to send me a sketch of the palate of
Pholidosaurus Schaumburgensis, which shows that the English
specimen is generically identical with that form. The generic term
Macrorhynchus, Dunker, which dates from 1844, is of later date
than Pholidosaurus, and as it is preoccupied by Lacépede (1880) for
a genus of Pisces, it cannot stand. Under these circumstances I
propose to provisionally refer the English specimen to the second
German species, which should be known as Pholidosaurus Meyert
(Dunker). This genus appears to bear the same relation to the
existing Garials as is presented by Goniopholis to the Crocodiles
and thus connects the former group with the typical Teleosauride ;
and I propose to include in the family Goniopholidide all the
Amphiccelian forms (e.g. Hyleochampsa, Theriosuchus, Goniopholis,
Petrosuchus, and Pholidosaurus) in which the orbit communicates
with the lateral temporal fossa; such family being divided into
groups according to the position of the posterior nares, the form of
the skull, and the nature of the armour; and occupying an inter-
mediate position between the Crocodilide and the Teleosaurid .
Classification.—In conclusion, I may observe, that since observa-
tions made subsequently to the publication of Prof. Huxley’s classic
memoir on the “‘ Evolution of the Crocodilia” have tended to approxi-
mate his suborders Eusuchia and Mesosuchia, and to accentuate the
distinction of the two from the Parasuchia, it appears inadvisable to
continue to divide the Crocodilia into these three groups, which are
certainly not of equivalent value; and I accordingly think it would
be preferable, while retaining the suborder Parasuchia for those
extremely generalized Crocodilians which show many points of kin-
ship to other orders, to unite the other two groups in a single sub-
order which might be termed Crocodilia Vera. For the two sub-

1 Zeitschr. deutsch Geol. Ger. vol. xxxv. p. $24, note (1883). The suggestion
here made that the vertebree are proccelous has proved unfounded.

312 EH. Westlake—Terebratula from the Upper Chalk.

divisions of the latter, since it would perhaps be inadvisable to
retain the names Eusuchia and Mesosuchia in a minor sense to their
original usage, and as it is in many cases important to have a
classification not depending solely upon cranial characters, I would
adopt the earlier Owenian names to form a Proccelian and an
Amphiccelian series. The former series would be characterized by
the possession of procoelous vertebrae, and at least usually by the
union of the pterygoids in a palatal plate below the narial canal. I
add the saving clause in the last paragraph because it is highly pro-
bable that in some of the proccelous Crocodilia of the Cretaceous the
pterygoids did not unite inferiorly.

The following table gives the grouping of the families under
this scheme; the definition of the various groups being reserved for
a future occasion.

Order Crocopitia.

A. Suborder Crocopin1a VERA.

a. Proccelian series.
Crocodilide.

6. Amphiccelian series.
Goniopholidide.
Teleosauride.

B. Suborder Parasucuia.
Belodontide.
Parasuchide.
Stagonolepidide.

P.S.—Since the above was in type I have received a memoir by
Dr. Koken on the Crocodilia of the German Wealden (Palaonto-
logische Abhandlungen, vol. iii. pt. 5, 1887), in which the skull of
Pholidosaurus (Macrorhynchus) is figured. In this memoir the
author has proposed precisely the same classification as that given
above, although he adopts one or two more families, and has not
proposed a name for the first suborder.

V.—On A TEREBRATULA FROM THE Upprr CHALK OF SALISBURY.
By E. Westiaxe, F.G.S8.

HE two specimens figured below are from the collection of Mr.
C. J. Read, of Salisbury, who obtained them from the Upper
Chalk (Senonian) of the neighbourhood. Some uncertainty has
attached to the exact locality, Mr. Read having told me that he had
found them in the Mucronata-Chalk of Clarendon ; but he now writes,
18th Jan. 1887—“ My belief, on thinking the matter over, is that
the right locality is the ‘Devizes Road,’ as they were originally
marked.” The locality referred to is Old Camp Down lime-pit,
three miles N.W. of Salisbury on the Devizes Road. This pit is
characterized by an abundance of Micraster coranguinum and Echino-
conus conicus; but Terebratula semiglobosa, Sow., usually present in
this zone, does not occur, and the only Terebratulee we have found
there are the two specimens figured. As the pit is seldom worked
and we have no prospect of obtaining others, it has seemed best to
describe them.

E. Westlake—Terebratula from the Upper Chalk. 313

Mr. Thos. Davidson, who examined them, wrote to me, 28th Feb.
1884—“ These specimens are peculiar and puzzle me. They are not
T. carnea, nor T. semiglobosa, and I am uncertain as to their proper
identification. They approach most in shape to some specimens of
Ter. semiglobosa, but I would not like to refer them to that species.
They almost look to me a new species.”

1 la 2 2a

Terebratula obesa, Sowerby, var. cuneata.

Enlarged about nine-tenths natural size. The figures are photo-facsimiles. The
fine surface-marking is due to the process employed (Dallastint).

Dimenstons—Fie. 1. length 23-9, width 1971, depth 10:2, foramen 1-6 mm.
Ere Qu) OCT GDM {o-B°4F 2 Topp ott TO sare) so

Shell obtusely pentagonal, elongated, depressed, slender and thin ;
dorsal valve nearly flat; beak projects ‘8 mm. in front of the
deltidium, stands off from the dorsal valve ‘5 mm., and is obliquely
truncated by a circular edged foramen 1:6 mm. in diameter. The
pieces of the deltidium are about ‘5 mm. in width. Front margin
very slightly undulated.

In the British Museum are twelve specimens of ‘‘ Terebratula obesa,
Sow., from Greenhithe,” (B. M. 20289) identical with the above,
excepting that the dorsal valves of the B. M. specimens are rather
more convex. The Chalk of Greenhithe contains M. coranguinum
and Echinoconus conicus. From this zone in Hampshire I have
about a thousand Terebratule, all of which, however, are referable to
T. semiglobosa or T. carnea. I have not yet met with T. obesa in the
Hampshire Basin.

Affinities and Differences.—Their large foramen and flattened
dorsal valve include them in the Ter. biplicata group, which is repre-
sented in the Middle and Upper Chalk by T. obesa. With this species,
and more especially with the large form from the Norwich Chalk,
the specimens figured agree in most respects. They differ chiefly in
their flatter dorsal valve and in the absence of lateral plaits, both of
which may be characters of young shells. On the other hand, the
same form having occurred elsewhere on the same horizon, it may be
convenient to distinguish them as a variety. They differ from T.
Ciplyensis, von Hanstein, by their thiner shell, flatter dorsal valve,
more recurved beak, and smaller foramen.

314 Reviews—H. B. Woodward’s Geology of England and Wales.

RAVIEwWS.

I.—Tne Gerotocgy or Eneranp anp Waters. By Horace B.
Woopwarp, F.G.S., of the Geological Survey of England and
Wales. Second Edition, pp. 670, with Geological Map and 103
Illustrations. (London: George Philip & Son, 1887.)

Mor than ten years have elapsed, as the author reminds us, since

the first edition of this work was published. During the interval
a considerable amount of new material had accumulated, so that the
geological public were quite prepared for the revision of the original
work which had been so fully appreciated that it was already well
nigh out of print. A comparison of the two editions may be said to
afford an outline of the progress of geology during the last decade
in the Old Country, which still continues to furnish useful matter
to investigators, notwithstanding the more colossal features of con-
tinental and trans-Huropean areas, which have lately been brought
to light. ‘The original plan of the book has not been altered, but
the volume has attained a larger size, owing to the many additions
necessary to do justice to the subject. Nor is this increase surprising
when it is remembered that, sixty-five years ago, the excellent and
in great measure original ‘Outlines of the Geology of England and
Wales,’ by Conybeare and Phillips, filled 531 pages; and only the
first part of that work was published. The aim of the present
work is to afford a book of reference, useful not only to students of
the scientific aspect of the subject, but also to engineers and others
in its practical applications.”

On the question of Nomenclature and Classification Mr. Woodward
observes that, in the absence of a definite scheme formulated on the ’
part of the International Geological Commission, the classification in
the previous edition has been in the main retained. ‘As before,
alternative groupings are stated, and, wherever possible, old and
well-established names of formations are employed, while the
synonyms are also mentioned. Numerous tables are given with the
view of explaining more clearly the relations of the various divisions
of the stratified rocks. An attempt has been made to give some
historical value to the work by indicating the labours of the many
geologists to whose observations our present knowledge is due.”
He also alludes to the assistance rendered by many of the leading
geologists of the day ; and expresses his indebtedness to the Councils
of the Geological Society and the Geologists’ Association, as also to
the Editor of the Gonogrcat Magazine in the matter of reproducing
illustrations. These bave been further supplemented by some
effective etchings by Mr. Alfred Dawson of scenery in the Isle of
Purbeck, which seem to take the place of the woodcuts of the pre-
vious edition borrowed from Mackintosh’s “ Scenery of England and
Wales.” Thus we lose the illustration of the action of atmospheric
disintegration afforded by the Millstone Grit of Brimham rocks
(1st ed. p- 90), to have it replaced by an etching of the Agglestone
near Studland, an isolated remnant of Lower Bagshot beds, locally
hardened, which tells the same story (2nd ed. p. 607).

Reviews—H. B. Woodward’s Geology of England and Wales. 315

This is a book without chapters. The Introduction contains a few
pages explanatory of the principles of geology, with a brief history
of English geologic research. There is a very neat section across
England and Wales about the parallel of Lincoln, which shows the
outcrop of the Coal-measures in three distinct Coal-fields, together
with their relations to the Lower Paleozoics of Wales and to the
Lower Carboniferous of the Pennine anticlinal.

Part I. is devoted to the Patmozoric, which is made to include the
Archean, the term now adopted instead of the Lewisian, or Laurentian,
of the previous edition. So much has been done during the last ten
years below the region of ascertained life that this portion of the
second edition is altogether new. ‘The determination of the
Archean rocks in England and Wales is mainly due to the researches
of Dr. H. Hicks, Prof. T. McK. Hughes, Dr. C. Callaway, and Prof.
T. G. Bonney.” As some portions of the evidence have been con-
troverted by Dr. A. Geikie, the author proceeds to point out the
differences of opinion which have been expressed on this most
disputed subject, more especially in Pembrokeshire. ‘‘ These differences
in the interpretation of this ancient ‘ Geological Record ’ are serious,
but perhaps not quite so serious as they at first appear. It is admitted
that the rocks termed Pebidian underlie the oldest fossiliferous
Cambrian strata, and rest on the rocks termed Arvonian. The rela-
tive position and origin of the Dimetian granitoid rock are the main
points in question. It may be mentioned, however, that in other
areas, where Archean rocks have been identified, two main divisions
are recognized, one of coarsely crystalline rocks (Dimetian), and the
other of eruptive rocks (Pebidian).”

The readers of the first edition of Mr. Woodward’s Geology of

England and Wales will bear in mind that he fully identified himself
with the Sedgwickian view of the classification of the Lower Palzo-
zoic rocks. Hence, for him, the Cambrian system includes every-
thing to the very top of the Balabeds. According to this arrangement
his Middle Cambrian consists of the Tremadoc Slates and Lingula
Flags: and further on he says, ‘“‘The Middle Cambrian rocks introduce
many forms of Graptolites.” This is not exactly the case. The
point perhaps is not one of much importance; but when we bear in
mind the great change in life-forms which occurs between the
Tremadoc series and the Arenig series, we must confess that the
Sedgwickian is apt to minimize this biological hiatus, just as the
‘opposite side desires to minimize the local unconformity in connection
with the Llandovery series.
_ Thecorrelation of the Lake-district rocks with those of Wales is very
fully treated. We miss the section by Harkness at the foot of the Cross
Fell range ; but on the other hand there is an interesting generalized
section across the Lake-district by Goodchild. Speaking generally,
however, the junction line of the Skiddaws and the Volcanics
should be somewhat more excavated than is there represented.

The Old Red Sandstone and Devonian, and the question of their
relations to each other, are ably treated by the author, whose personal
experience in surveying some of these districts lends additional

316 Reviews—H. B. Woodward’s Geology of England and Wales.

weight to his conclusions. ‘The relations between the Old Red
Sandstone and the underlying Silurian and overlying Carboniferous
rocks have been long since established. In both instances a perfect
conformity exists. But only in recent years has it been fully
realized that there is a great unconformity between the Upper and
Lower Old Red Sandstone.” In the Devonshire area there is a con-
formable sequence in the strata, and the Middle Devonian (marine)
bridges over the interval between the Upper and Lower Old Red
Sandstone in Wales, ete. In Scotland also, as pointed out by Dr.
Geikie, the Old Red Sandstone must be placed in two divisions with
a complete discordance between the two, the lower passing con-
formably into the Silurian, the Upper graduating into the Carbon-
iferous. In the district of the Cheviot Hills, however, owing to the
accumulation of volcanic material, a marked discordance is shown in
Mr. Goodchild’s section (fig. 16) between the ‘‘Cheviot Series ”
(Lower Old Red Sandstone) and the underlying Silurian, but this
is evidently an exception.

When a system is thus weakened by internal discordance, whilst
its extremities exhibit a disposition to amalgamate with their respec-
tive neighbours, a period of annexation seems to be at hand. At
present the fossiliferous Devonian maintains a firm front against all
comers, though there are not wanting geologists who would hand it
over to the Silurian by way of compensation for the loss of the
Ordovician rocks.

Grouping the Upper Old Red Sandstone with the Carboniferous
System, the latter is held to comprise the following formations :—

Upper Coal Measures.
Carboniferous, Millstone Grit.

Upper Limestone Shales and Yoredale
Rocks. Bernician and Calci-

Lower Carboniferous and Mountain Limestone. ferous Sandstone
Carboniferous. 2 Lower Limestone Shales and Tuedian Series.
Beds.

Basement Conglomerate and Upper Old
Red Sandstone.

Nearly sixty pages are devoted to this most important system, and
there are nearly a dozen sections, by way of illustration, from
various authors. ‘To begin with, there is a very effective section by
J. W. Davis, showing the separation of the Yorkshire from the

Lancashire Coal-fields by means of the Pennine anticlinal. The_

various “edges” of the Millstone Grit on the Yorkshire side are
particularly well brought out. This originally appeared in the
Grou. Mag. (1878, p. 504) in a paper on the Valley of the Calder.
The following sections also occur :—Draughton Quarry near Skipton
(Dr. C. Ricketts), to show contortions in the Carboniferous Lime-
stone; across the Eglwyseg Rocks. Denbighshire (Prof. A. H. Green),
to show an ascending sequence; across part of Charnwood Forest
(Prof. EK. Hull), to show Carboniferous strata lying on the edge of
the older rocks ; across the Mendips (H. B. W.), to show position of
the Carboniferous rocks on either side of the anticlinal; across
Ingleborough (J. G. Goodchild), to show relations of the Carbon-

ee

‘
P
:
|

Reviews—H. B. Woodward’s Geology of England and Wales. 317

iferous beds to the ‘‘Cambrian” rocks, and how they are affected by
the Craven faults: from Durdham Down to the City of Bristol (R.
Htheridge), to show the relations of the Carboniferous Limestone,
Millstone Grit and Coal-measures to the Mesozoic rocks; ideal
section across the S.W. extremity of the Pendle Range (Prof. H.
Hull), showing, inter alia, the position of the Wigan Coal-field:
southern side of the South Wales Coal-field (Sir W. HE. Logan):
generalized section from Dartmoor to Great Haldon (H. B. W.), to
show the position of the Culm Measures..

Lastly, the author devotes a few pages to the possible existence of
the Coal-measures in the Hast and South-Hast of England. Figure
31 is an interesting diagram, which shows the probable curvatures
of the Paleozoic beds beneath the Mesozoic rocks; but, since the
undoubted discovery of the Great Oolite beneath London and
Richmond, that portion of the diagram may require some recon-
sideration.

Amongst the economic products, he fails to give an account of the
celebrated Harrogate waters, but at p. 539, under the head Mineral
Springs, we find the sulphuretted springs of Harrogate duly recorded
as issuing from a deep source along an anticlinal axis of the Carbon-
iferous rocks.

Part IJ. Mesozorc.—The Permian rocks are grouped along with
the Trias under the general title of New Red Sandstone. Doubtless
there are some advantages in this arrangement, but it does seem
strange to find, for instance, the Magnesian Limstone of Durham
with its rich store of Palzozoic fossils being classified under this
heading. That the Permian, in England, should be placed with
the Secondary rather than with the Paleozoic rocks is reasonable;
since there seems to have been considerable identity of physical
conditions throughout the Permio-Triassic period. This indeed was
one of revolution and decay, during which, but for the most part in
other areas, the elements of the World’s Middle Life were being
slowly evolved. As a matter of fact the author’s New Red Sand-
stone, or Poikilitic (Conybeare). to a certain extent stands alone,
although biologically its lower division inclines to the Paleozoic and
its Upper to the Mesozoic. The Rheetic or Penarth beds are also
included here.

Mr. Woodward divides the Jurassic into Lias and Oolitic, and
with the latter he includes the beds originally called by Mr. William
Smith “The Sand of the Inferior Oolite.’” In adopting Phillips’
name of “ Midford Sands” for this group, we are not sure that the
author is on very safe ground. What is the evidence that the
Sands of Midford represent the zones of Am. opalinus and of Am.
Jurensis? At this village the Parkinsoni-zone is seen to rest directly
on certain sands of the Inferior Oolite. If the Cephalopoda-bed of
the Cotteswolds occurs immediately below the junction, the name
holds good; otherwise the age of the upper part of the sand is
uncertain.

Nearly 100 pages are devoted to the Jurassic rocks, which have
lately enjoyed a special share of the author’s attention, and sections

318 Reviews—H. B. Woodward’s Geology of England and Wales.

are given by himself, Sir A. Ramsay, Messrs. Dalton, Topley, Sharp,
Hudleston, Blake, Damon, Weston, and Bristow. The table on
p- 286, showing the subdivisions of the Lower Oolitic rocks, may
not meet the views of every geologist; but at any rate it grapples
with a very difficult piece of correlation throughout this variable
series in different parts of England. The Middle and Upper Oolitic
beds are also very fully treated.

The Cretaceous occupy rather over 70 pages, and include sections
by the author, Messrs. Topley, Bristow, Prestwich, Whitaker,
Strahan, Hughes, and Dowker. The following are the divisions

adopted :
Chalk
Upper
Cretaceous ippee Greensand

Neocomian
Lower |S Greensand

of

Cretaceous ) Wealden Beds some Authors

It is almost unnecessary to add that both as regards lithology
and paleontology this system is most thoroughly dealt with; the re-
searches of Dr. Hinde meet with frequent mention, and in addition
to the names already quoted in this connection we find those of
Messrs. Price, Meyer, Penning, Jukes-Browne, Barrois, and many
others. As regards the Chalk itself there is a table (pp. 402, 403)
showing the distribution of life zones in Yorkshire, Norfolk, Cam-
bridgeshire, Bedfordshire, Surrey, Kent, and the Isle of Wight.
The determination of these zones is due, he says, to the researches
of Prof. Hébert and Mr. Caleb Evans, and particularly of Dr. C.
Barrois. These have been followed out in various parts of England
by several geologists. “But Mr. Whitaker has remarked that
although they are very valuable when applied to particular sections,
yet their application to great inland stretches of country without
continuous sections, and when the structure of the deposits could be
seen only in occasional pits, was by no means safe.” As a surveyor,
always on the look out fora feature, Mr. Whitaker prefers lithological
divisions such as the Chalk Rock, the Melbourn Rock, and the
Totternhoe Stone, which themselves appear to mark certain zones for
a considerable distance.

Parr III. Ca@wnozoro.—This is divided into Tertiary and Quater-
nary. The Tertiary rocks include all, from the Thanet Sands to
the Cromer Forest Bed inclusive, and are illustrated by sections
from the author and Messrs. Whitaker, Bristow, Holmes, and
Prestwich. The Quaternary he divides into Pleistocene and Recent.
“The Pleistocene period, so named by Lyell in 1880, includes
Terrestrial, Alluvial, Estuarine, Marine, and Glacial accumulations ;
and the organic remains found in certain Caverns and River-deposits,
being associated with relics of Paleolithic Man, these deposits are
sometimes regarded as of Paleolithic age.” Then follows a list of
the Mammalia characteristic of the Pleistocene Beds such as Ovibos
moschatus, Bison priscus, etc. The Glacial Beds are illustrated by
sections from the author, Sir A. Ramsay, and Messrs. De Rance,
Mellard Reade, Ussher, Searles Wood, Lamplugh, Jukes-Browne,

\

Reviews—H. B. Woodward’s Geology of England and Wales. 319

Clement Reid, Rev. O. Fisher, whilst illustrations of the Victoria
Cave and of the Coygan Cave are borrowed from the works of
Messrs. Tiddeman and Hicks respectively.

Under the head of Recent, besides the various deposits of Modern
Age, he partly includes the Cave deposits, and under the sub-
division Terrestrial Phenomena, refers to Springs, Swallow Holes,
Tufa, Blown Sands, and Soils; and under the subdivision Marine
Deposits, to Sea Beaches and Raised Beaches.

There is a supplementary section on Hruptive and Metamorphic
Rocks, in which he refers to the progress in their study of late, par-
ticularly alluding to the works of Allport, Forbes, Sorby, Phillips,
Rutley, Clifton Ward, Bonney, Davies, Teall, and Cole. A very
useful, condensed account of these rocks has been furnished by Mr.
Rutley. A “chapter” on Mineral Veins and Metalliferous Deposits,
and one on Denudation and Scenery, complete the work. Appendix
No. 1 records some of the more important well-sinkings and borings
in England and Wales; and Appendix No. 2 gives a Synopsis of
the Animal Kingdom by Mr. HE. T. Newton. There is a very copious
index—a matter of considerable importance in a work so compre-
hensive and so full of references.

A geological map 24 in. x 19°5 in. accompanies the volume. It
is no longer attempted, as in the map of the previous edition, to
show the Hast Anglian Boulder-clay and Gravels. The colours are
less vivid than in the old map, and more in accordance with estab-
lished usage. By colouring all the Cretaceous beds below the Gault
as one, the difficulty of deciding which is Wealden and which Lower
Greensand is avoided. In the same way by colouring the Trias and
Permian as one, not only is the definition of their boundary avoided,
but their general relations to the Carboniferous rocks of the great
Pennine massif is made exceedingly clear and effective. We regret
that the South Yorkshire Coal-field, the least exhausted in Britain,
has not been differentiated from the Millstone Grit; but this is one
of those accidents in printing which are apt to befall the most careful.!
The two great volcanic areas of the Cheviot and of the Lake-
district are well shown, and the chartographer judiciously colours
the Archean and Metamorphic alike. The map bears the name of
Mr. Goodchild, and does him much credit.

The entire work must be regarded as a most complete compen-
dium of English geology. The author has brought to bear upon
his task an assiduity in labour and an impartiality in judgment
alike remarkable. To these qualifications he adds a grasp of the
subject, which years of experience in the field and in the study
could alone produce. Not only is the information conveyed of
the greatest utility and interest to every student of English
geology, but whosoever wishes to pursue any particular subject
further may obtain in this book many of the references required. Bear-
ing in mind the enormous and varied mass of material thus sifted, it
is not surprising that the publication has been a little delayed.
The artist (p. 24) shows how blithely the field geologist may set

aes are informed that this omission has been corrected in the later-issued copies.
—Epir.

320 Reviews—A. Guillier’s Geology of the Sarthe.

about his task; but ere the consummation is reached (p. 670),

ere those innumerable volumes have been consulted and annotated, °

the work seems to have told its tale. At the same time we hope
that the author may survive to give us a third edition in due course.

W. iH. H.

Il.—Grotogiz pu Départmenr pe ta Sarrue. Par ALBERT
GuILLieR. 4to pp. xii. and 430, with numerous Woodcuts.
Published at Le Mans and Paris, 1886. Price 16 franes.

Ae monograph is published by the local authorities of the

Department, and is intended as an explanation of the Geological
Map of the Department, which is founded on the work of M. Triger,
An Agricultural Map is also published by the same authority, and
notes on the soils prodnced by the various rocks are given in this
volume.

All this is very creditable to the local government, and one
wonders if we shall ever have a similar county government in
England, viz. councils by which local county affairs might be
managed and from which scientific knowledge might be disseminated.
During the last few years the Geological Survey has issued many
descriptive memoirs, at reasonable prices, which contain much useful
information, but neither the maps nor the explanations of the Survey
are so well known throughout the country as they ought to be,
because no steps are taken to make people in the country aware of
their existence.

The Department of the Sarthe has a varied geological structure,
for it possesses representatives of the following systems ;—

9. Quaternary. 5. Carboniferous.
8. Eocene and Miocene. 4, Lower Devonian.
7. Upper Cretaceous. 3. Upper Silurian.
6. Jurassic. 2. Lower Silurian.

1, Cambrian (or Archzean).

Full descriptions are given of the rocks and their stratgraphical
relations, with lists of the fossils found in them. ‘There are also
diagrammatic sections, but we wish that the vertical scale of these
had not been so greatly exaggerated; this is a fault which the French
are only slowly learning to correct.

In his first chapter M. Guillier refers to the Murchison and
Sedgewick controversy, but he has hardly grasped the details of the
Cambrian question, and seems to think that Murchison had inde-
pendently given the name of Cambrian to rocks that were older than
his Lower Silurian. He therefore applies the term Cambrian to
rocks which are older than Barrande’s Primordial Silurian; but these
in modern nomenclature are the Pre-Cambrian or Archean rocks.
The strata actually referred to are the Phyllades de St. Lo and the
Ardoises de Parennes, and it so happens that Prof. Hebert and Dr.
Ch. Barrois are now at variance on the very question of whether
these Phyllades should be referred to the Archean or to the Cambrian.
M. Guillier’s view is that recently advocated by Prof. Hebert, though
‘it would not appear so from his nomenclature.

Reviews—A. Guillier’s Geology of the Sarthe. 321

Under the head of Primordial Silurian he ranges a series of schists
and flagey beds with bands of dolomite, which are stated to occur in
certain localities between the Phyllades and the Grés Armoricain ;
but the only fossil hitherto found is a Lingula which Dr. Davidson
identified with ZL. crumena, and this same Lingula is found in the
overlying series.

The representatives of the Lower Silurian (Ordovician) are the
following :—

3. White sandstones without fossils (? Grés du May).
2. Shales with Calymene Tristani.
1, The Armorican sandstone and red shales.

The two lower stages are probably of Arenig age, No. 2, contain-
ing also Calymene arago, Asaphus nobilis, Illenus giganteus, Placoparia
Tournemmei, and Cheirurus Guillieri.

The beds of true Silurian age are (1) Sandstones and Carbonaceous
Shales with Graptolithus colonus ; (2) Shales with Cardiola interrupta.
We may notice that neither here nor in treating of the other Paleeozoic
groups are any estimates of their thicknesses given.

Of the Devonian system only the lower portion is found, and this
consists of (1) Sandstone; (2) Shales; (3) Limestone, the last
being rich in fossils.

A great break then supervenes, neither Middle nor Upper Devonian
nor the lowest part of the Carboniferous being represented. The
Devonian Limestone is succeeded by a series of sandstones and shales
which include beds of workable anthracite and a band of limestone
containing Producta gigantea—a series which is referable to the
upper part of our Carboniferous Limestone. No true Coal-measures
occur nor any strata of Permian or Triassic age.

The succeeding beds are Jurassic and belong to the Middle Lias
(limestone with Pecten equivalvis, 18 feet) and to the Upper Lias
(marls and limestones with Am. bifrons and Am. serpentinus, thickness
24 feet).

The Oolitic series is well represented, as shown by the following
tabular view :—

KIMERIDGIEN. Limestone with Astarte minima.
Sandstone with Trigonia.
Oolitic Limestone.

Ferruginous sands.

CoRALLIEN.
| Clay and Limestone of Aubigné.

OXFORDIEN. Clay and Limestone of La Vacherie.

Ferruginous Limestone with Am. coronatus.
Clay and Limestone with Am. macrocephalus.
( Montlivaltia Limestone.
| Marls with Terebratula cardium.
BATHONIEN. < Oolite of Mamers.
| Lithographic Limestone.
(| Oolite with Rhynch. spinosa.
Oolite with Am. Parkinsoni.
{ Oolites with Ter. perovalis.

The Cretaceous rocks of Sarthe possess a peculiar interest because
they include the type of D’Orbigny’s Cenomanien stage ; the beds
composing this stage are evidently shore deposits of the Cenomanien
sea and beds of sand with Rhynchonella compressa, Terebratella

DECADE III.—VOL. IV.—NO. VII. 21

CALLOVIEN.

Basocien.

322 Reviews— Geological Surrey of Minnesota.

Menardi, and Ammonites navicularis occur near the top of the division,
showing that these species continued to exist along the shores
throughout the Cenomanien stage. The local succession, however,
is just as clear as our own, and according to M. Guillier the arenaceous
beds pass laterally into the ordinary chalky facies or Normandy type,
the parallelism being as follows :—

6. Marne a Ostrea biawriculata. (raic A eBIRIOTE
. Sables & Rhynch. compressa. zt gece
. Sables et grés du Mans passing into Craie de Theligny,

both with Lurrilites costatus.

. Sable a Perna lanceolata.
. Craie et argile glauconieuse 4 Pecten asper.
. Glauconie a Ostrea vesiculosa=Gaize des Ardennes.

In this he differs from Prof. Hebert, who does not admit the
synchronism of the Grés du Maine and the Craie de Rouen. He
also differs from the same authority in regarding the Cenomanien as
succeeded conformably by the Turonien, which is divisible into three
ZONES.

Craie de Rouen.

rm bo OO we OV

3. Craie a Terebratella Bourgeoisit.
2. Oraie 4 Inoceramus problematicus (mytiloides).
1. Craie a Terebratella Carentonensis.

These are succeeded by Chalk with Spondylus truncatus, which is
classed as Senonien. —

At the base of the Hocene are placed certain sands and clays with
flints, but English geologists would probably doubt the evidence of
stratigraphical succession and the propriety of classing them as
Hocene. ‘The true Kocene strata are as follows :—

4. Clay of La Bosse.

3. Freshwater Limestone of St. Aubin.
2. Sands with Sabalites.

1. Conglomerates.

The conglomerates and sands are correlated with our Middle
Bagshots and the limestone with the upper part of the Calcaire
Grossier (Bracklesham).

A small area of Faluns (Miocene) comes into the Department.
Lastly the so-called Quaternary deposits are described, and there are
short chapters on Metamorphic and Hruptive Rocks, on Building
Stones, and Mineral Waters, while a Bibliography and Index com-
plete the volume.

We regret to find that the author died before its publication, so
that the revision of the latter part was performed by one of his
pupils.

IJ].—Tur Grorocicat and Narurat-History Survey oF Minne-
sota. The Thirteenth Annual Report, for 1884, pp. 196; the
Fourteenth Annual Report, for 1885, pp. 358, Svo. (St. Paul’s,
1885 and 1886.)

ITH the exception of some valuable information to farmers

and others as to Insects injurious to the Cabbage, by O. W.
Oestlund, some Notes on the Mammals of Big-Stone Lake, by C. Li
Herrick, and a paper on Minnesota Geographical Names derived

Reviews—Geological Survey of Minnesota. 323

from the Dakota Language, by Prof. A. W. Williamson, the whole
of the Thirteenth Report is devoted to Geology. After a few notes
on reconnoitering trips into Pope County, and to Vermilion Lake,
we come to a paper on the Vermilion Iron-ores of Minnesota. Full
details are given of the various mines, with a table showing that in
ten years the gross product of metal has been 6,831,285 tons. Some
important analyses of the hard hematites are given. The crystalline
rocks of Minnesota, which appear to consist of gneisses and “ soft
red granites,” are treated of at pp. 36-38. Information as to the
Humboldt Salt Well in Kittson Co. is given, with details of a boring
to a depth of 644 feet; “it remains for the future to determine
whether these salt-deposits shall become economically of importance
to the North-west.” Details of other wells are given, bored appa-
rently for fresh water, one reaching a depth of 1800 feet (p. 54),
and a second 1160 feet (p. 57). The geological formations through
which these two wells pass are not given, but the latter begins
about 90 feet below the top of the St. Lawrence limestone. Two
interesting finds are those of Lingula Calumet and Paradowides
Barberi, in the blood-red catlinite of the Great Pipestone Quarry in
Pipestone Co., a rock of Huronian age (pp. 65—72). Figures of
these interesting but rather obscure organisms are given in plate 1.
A catalogue of the specimens registered in the General Museum in
1884 occupies nine closely-printed pages and contains many interest-
ing specimens of local and other rocks. Mr. Warren Upham (pp.
88—97) gives some notes on the geology of Minnehaha Co., Dakota,
where Potsdam quartzite seems to predominate. Professor H. W.
Winchell’s valuable paper on ‘‘The Crystalline Rocks of the North-
west”’ (pp. 124—140), read before the American Association in
1884, is here printed. The peat, clay, and “‘Cretaceous ” leaves of
Blue-earth Co. are noticed; anda fossil Elephant tooth, from Winona
Co., is described and figured (pl. ii.) as being probably EH. primi-
genius. ‘The glacial deposits receive a due share of attention. Dr.
G. M. Dawson has a paper on the microscopic structure of some
Boulder-clays, and the organisms found in them (pp. 150—169).
He seems to have recognized certain minute bodies as Annelid jaws,
and compares them with those described by Dr. Hinde in the
Silurian and Devonian Rocks of Canada. Foraminifera are also
abundant, and a special paper by Messrs A. Woodward and B. W.
Thomas on some specimens from the Boulder-clay of Meeker Co.
is given at pp. 164—177. These fossils were found in fragments
of shale derived from the Cretaceous beds of Pembina Mountain,
in Manitoba, whence Dr. G. M. Dawson obtained similar specimens.
Two plates are given (pl. iii. and iv.), but they are unfortunately
very inferior to the plates usually seen in American Governmental
Reports.

The first paper with which we are concerned in the Fourteenth
Report is on some deep wells in Minnesota, by N. H. Winchell, with
an appendix at p. 348. The second is by H. O. Ulrich on Lower
Silurian Bryozoa (pp. 57-103), mostly obtained from the Trenton -
Shales. A list of 92 species is given, and of these about 50 are

324 Reviews—Greological Survey of India.

described, but not figured. The Survey, however, proposes to
publish a monograph of the Silurian Polyzoa before long. Mr.
Ulrich also contributes a paper on Crinoidea, and describes three new
genera, Cremacrinus, Deltacrinus, and Halysiocrinus (pp. 104-113).
The list of specimens acquired by the Museum in 1885 fills ten
pages, and shows, we should imagine, a very satisfactory state of
_ thmgs. Some new fossils are described at pp. 313-318 (pl. i. and

ii.), by Prof. Winchell, one of them being a specimen of the peculiar
form, Cryptozoon, described recently by Prof. James Hall. Mr.
Winchell also writes upon a peculiar ore and the Cambrian rocks of
the State of Minnesota (pp. 819-337). The most bulky contribution
to this Report is “‘ The Bibliography of the Foraminifera,” by Prof.
Anthony Woodward (pp. 167-312). His work having been antici-
pated by Mr. H. B. Brady’s bibliography in the ‘‘ Challenger” Report,
so well known to workers on the subject, Prof. Woodward has
rearranged the results of his own work with the materials of the
published list, and has given it in alphabetical order in groups under
countries. His work, though, as he truly says, incomplete, is useful ;
but unfortunately it is marred by very numerous typographical and
bibliographic errors. The page and a half of errata for the list stop
hopelessly at seventy pages from its end. Such errors as occur un-
noticed in the references will prove serious hindrances to the utility
of his work. Instances taken at random,—such as duplicate entries
and wrong dates given with Dawson, at p. 180; with Jones at pp.
184 and 202, and with Ehrenberg at pp. 193 and 194; errors at
p- 271, “‘ Bisherigebnisseder Tiefbohrung,” etc.; p. 252, Tregnem ;
p. 245, Milne-Hwards ; p. 286, Summersetshire, etc., make the reader
regret that so useful a work should have been printed without
correction. Hozoon has a separate bibliography ; and Recepiaculites
is included in the general list.

Besides a few pages of matter relating to geological and chemical
research not mentioned above, there is Mr. O. W. Oestlund’s “ List
of the Aphidide of Minnesota, with descriptions of some new
species” (pp. 17-56), unfortunately without figures; also Concho-
logical Notes, by U. 8. Grant (pp. 114-124). T. R. J.

IV.—Puysicat Grotocy or West British GARWHAL, witH NoTES
on A Route TRAVERSE THROUGH JAUNSAR BAWAR, AND TiRI-
Garwuat. By C. 8. Mipptemiss, B.A. Records of the Geologi-
cal Survey of India, vol. xx. Part i. 1887, pp. 26-40, with 2
maps and plates of sections.

HE second and most important part of this memoir deals with
the geological structure of a tract situated 120 miles N.E. of

Delhi, and bordered on the N. and 8. by the Sub-Himalayan boundary

and the Nyar river, and E. and W. by the Ganges at Hardwar and

Ghungti mountain. It is illustrated by a small-scale map of the

whole area and its N.W. corner by one on the one-inch scale. In the

district are found Tertiary strata (Nummulitic and Sub-Himalayan),

Mesozoic grits and impure limestones, both fossiliferous; massive

unfossiliferous limestones, purple slates and volcanic breccia, and

Reviews—The Essex Field Club. 325

a schistose series, all of uncertain age. Mr. Middlemiss designated
the oval tract of schistose rocks running N.W. and §.E. as the Inner
Formation, and the oval rings of the other formations which sweep
round it the Outer Formations. He finds that the outer formations
at every point dip into and under the central tract, and that the
schistose rocks themselves are arranged in an elongated quaquaversal
so as to complete the appearance of a synclinal whose highest rocks
are the schists. That the whole area is not inverted is proved by
the constant sequence of the fossiliferous horizons (Mesozoic below
Nummulitic), and as these are in their proper place, the massive
limestone and volcanic series are pretty certainly in their right order
beneath. What then is the true place of the schists? At some
spots Mesozoic beds dip directly beneath the schists, but at others
the Nummulitic intervenes and is found actually in contact with
schists and quartzites ‘“‘ without any semblance of what can be called
a transition rock.” ‘To satisfy a condition of this kind the most
glaring case of selective metamorphism would be totally inadequate ; ”
and therefore the whole set of outer formations must be younger
than the inner formations. The author then urges that the constant
infraposition of the outer formations must be more than a coincidence,
indeed a necessary concomitant of the Post-Nummulitic mountain
building of the Himalayas, in which the rocks were compelled to
take up less horizontal room by sigmoidal-flexure and over-faulting ;—
it is the story of the Highlands told in a new country. The Scotch
work of Lapworth and the Alpine work of Heim are bearing good
fruit in India, and we may be sure the Himalayas will do their share
in elucidating the principles of mountain structure and earth-move-

ment. W. W. W.

V.—Tue Essex Fretp Cuvs.

MONG the most enterprising of our local scientific societies is
the Essex Field Club. Like the Cumberland Association, its
aim is to record facts of local importance; but its publications, while
illustrating the Natural History, Geology, and Pre-historic Archzo-
logy of Essex, include some essays and memoirs of much wider
interest. In 1885 the first of a series of special memoirs was
published, and this, the work of Prof. Meldola and Mr. William
White, was a Report on the Hast Anglian Earthquake of April
22nd, 1884. It contains a list of British Earthquakes which have
caused structural damage, and full particulars of the last important
earthquake which originated beneath the surface of Hssex, and was
attended by so much damage to buildings. The report should be in
the hands of all those interested in Earthquakes; it is a model upon
which other reports might be based, and furnishes many suggestions
on what to observe in connection with the catastrophes. Of great
interest also is the Presidential Address delivered by Mr. T. V.
Holmes at the annual meeting of the Club in 1886; it deals with
British Ethnology, being a review of the evidence of characteristics
and race-affinities of the various settlers in the British Islands, and

the extent of their probable survival at the present day.

326 Reports and Proceedings—

The Council of the Essex Field Club have resolved now to issue
their “Transactions” and “ Proceedings” combined in the form of a
monthly periodical under the name of the ‘‘ Essex Naturalist.” This
periodical should command an extensive circulation, for it includes
many short notes of interest connected with the county, as well as
papers read before the club ; among the illustrations is a reproduction
of Norden’s Map of Hssex, printed in 1594.

VI.—Transactions oF tHE Lezps GEonocicaL AssociaTron.
HIS Geological Association, which has been established twelve
years, commenced in 1885 the publication of its Transactions. The
first part contained the papers read during the sessions 1883-85,
and the second part (just received) contains the record of the Pro-
ceedings during 1885-86. The papers are printed only in abstract,
and they include the Inaugural Address of the President, Mr. C. D.
Hardcastle, on the Geology of Ingleton and the neighbourhood ; an
account of Recent Discoveries of Carboniferous Vegetation in York-
shire, by the Hon. Secretary, Mr. S. A. Adamson ; notes on the Drift
of the North of England by Prof. Green: and various other papers.
There are also reports of Field Excursions, which contain informa-
tion of much local interest.

ER AEG @ aes aS) ACN) > ee @ Gib ED aie Ss
Mito!
GEOLOGICAL Society oF Lonpon. ;
I.—May 25, 1887.—Prof. J. W. Judd, F.R.S., President, in the
Chair.—The following communications were read :—
1. “On the Remains of Fishes from the Keuper of Warwick and
Nottingham.” By H. T. Newton, Esq., F.G.S.; with Notes on

their Mode of Occurrence by the Rev. P. B. Brodie, M.A., F.G.S., |

and E. Wilson, Esq., F.G.S.

This paper gave an account of two series of fossil fishes which
have been discovered in British Triassic strata. ‘The specimens are
very fragmentary, but the rarity of Ganoid fish-remains in the
English Trias lends considerable interest to these discoveries. The
first series noticed were obtained by the Rev. P. Brodie in the
Upper Keuper of Shrewby, and consist of some half dozen portions
of fish, all small and much broken. The characters of the scales and
the positions of the fins, together with as much of the form as can be
made out, point to their belonging to the genus Semionotus. ‘The
second series were obtained by Mr. EH. Wilson, F.G.S., of the Bristol
Museum, from Keuper Beds near Nottingham. A large number of
specimens were in this case collected ; but all of them are too much
broken and crushed out of shape to allow anything very definite
to be said about them. Some of these also appear to be Semio-
notus ; they agree in size, as well as in some other particulars, with
the Shrewby fishes, and may perhaps belong to the same species ;
but others, on account of their strongly heterocercal tail and orna-
mented scales, seem to belong to the Paleeoniscide. The presence
of a third form among these Nottingham fishes is indicated by

ee ee Se

Geological Society of London. 327

masses of larger scales. The Rev. P. B. Brodie and Mr. Hdward
Wilson each appended notes on the Triassic beds from which the
fishes were obtained.

2. “Considerations on the Date, Duration, and Conditions of the
Glacial Period with reference to the Antiquity of Man.” By Prof.
Joseph Prestwich, M.A., F.R.S., F.G.S.

After showing how the discoveries in the valley of the Somme and
elsewhere. 28 years ago, led geologists who had previously been
disposed to restrict the age of man, to exaggerate the period during
which the human race had existed, the author proceeded to discuss
the views of Dr. Croll on the date of the Glacial epoch. Dr. Croll,
who had at first referred this to an earlier phase of orbital eccentricity,
commencing 980,000 years ago, subsequently regarded it as coinciding
with a minor period of eccentricity that commenced 240,000 and
terminated 80,000 years since. This last estimate was chiefly sup-
ported by the amount of denudation that had subsequently taken place.

The efficacy of the increased eccentricity of the earth’s orbit in
producing the cold of the Glacial epoch was shown to be very doubt-
ful; for as similar changes in the eccentricity had occurred 165 times
in the last 100 millions of years, there must have been many glacial
epochs in geological times, several of them much more severe than that
of the Pleistocene period. But of such glacial epochs there was no
valid evidence. Another inference from Dr. Croll’s theories, that
each glacial epoch consisted of a succession of alternating cold and
warm or interglacial phases was also questioned, such alternations
as had been indicated having probably been due to changes in the
distribution of land and water, not to cosmical causes. The time
requisite for such interglacial periods as were supported by geological
evidence was more probably hundreds than thousands of years.

Recent observations in Greenland by Professor Helland, Mr. V.
Steenstrup, and Dr. Rink, had shown that the movement of ice in
large quantities was much more rapid, and consequently the denuda-
tion produced much greater than was formerly supposed. The
average rate of progress in several of the large iceberg-producing
glacers in Greenland had been found to be 36 feet daily. Applying
these data and the probable accumulation of ice due to the rainfall
and condensation to the determination of the time necessary for the
formation of the ice-sheet, the author was disposed to limit the
duration of the Glacial epoch to from 15,000 to 20,000 years, includ-
ing in this estimate the time during which the cold was diminishing,
or Postglacial time.

Details were then given to show that the estimate of one foot on
an average being removed from the surface by denudation in 6000
years, on which estimate was founded the hypothesis of 80,000
years having elapsed since the Glacial epoch, was insufficient, as a
somewhat heavier rainfall and the disintegrating effects of frost
would produce far more rapid denudation. It was incredible that
man should have remained physically unchanged throughout so long
a period. At the same time the evidence brought forward by Mr.
Tiddeman, Dr. Hicks, and Mr. Skertchly of the occurrence of

328 © Reports and Proceedings—

human relics in preglacial times, had led the author to change his
views as to the age of the high-level gravels in the Somme, Seine,
Thames, and Avon valleys, and he was now disposed to assign these
beds to the early part of the Glacial epoch, when the ice-sheet was
advancing. This advance drove the men who then inhabited
western Europe to localities such as those mentioned which were
not covered with ice. Man must, however, have occupied the
country but a short time before the land was overwhelmed by the
ice-sheet. The close of the Glacial epoch, i.e. the final melting of
the ice-sheet, might have taken place from 8000 to 10,000 years since.
Neolithic man made his appearance in Europe 3000 to 4000 years
B.c., but may have existed for a long time previously in the east, as
in Egypt and Asia Minor civilized communities and large States
flourished at an earlier date than 4000 B.c.

3. “Notes on some Carboniferous Species of Murchisonia in our
Public Museums.” By Miss Jane Donald. Communicated by J. G.
Goodchild, Esq., F.G.S.

The paper gave a history of the genus Murchisonia, an account
of the relations between it and Pleurotomaria, and of the resem-
blances to it afforded by certain recently discovered species of
Purritella. The synonymy and a new description of the genus
followed, and then of the species M. angulata, M. Kendalensis, M.
Verneuilliana, and four forms, for which new names were proposed,
were described and discussed, with notes on the localities where
each had been found and the museums in which the specimens
described were preserved. The new species were named :—WM. pyra-
midata, zonata, spherulata, and tenuissima.

IJ.—June 8, 1887.—Professor J. W. Judd, F.R.S., President, in
the Chair.—The following communications were read :—

1. ‘A Revision of the Echinoidea from the Australian Tertiaries.”
By Prof. P. Martin Duncan, M.B., F.R.S., F.G.S.

After calling attention to a previous paper by himself published
in the Society’s Journal for 1877, and to additions to the fauna
made by Prof. R. Tate and Prof. M‘Coy, the author proceeded to
give notes on the characters, relations, and nomenclature of the
following 29 species of Echinoidea :—

Cidaris (Liocidaris Australia).
Cidaris (Liocidaris), sp.
Gontocidaris, sp. spines.
Salenia tertiaria.

Holaster Australia.

H. difficilis (Rhynchopygus dysa-
sterovdes).

Micraster brevistella.

Psammechinus Woodsi.
Ortholophus lineatus.
Puradoxechinus nodus.
Clypeaster folium, var. elongata.
C. yippslandicus.

C. (Monostichia) australis.
C. (Monostichia) Lovent.
Echinobrissus Australia.
Catopygus elegans.
Pygorhynchus Vassalei:
Echinolampas ovulum.

Maretia anomala.
Megalaster compressus.
Pericosmus gigas.

P. Nelsoni.

P. compressus.
Lovenia Forbest.
Euspatangus rotundus.
E. Laubei.

EE. murrayensis.

LH. Wrighti.
Schizaster ventricosus.

Geological Society of London. 329

A few notes were added on the relations between this fauna and
that now inhabiting the Australian seas, also on the connexions
with the Tertiary Echinoidea of New Zealand, Sind, etc.

2. “On the Lower Part of the Upper Cretaceous Series in West
Suffolk and Norfolk.” By A. J. Jukes-Browne, Hsq., B.A., F.G.S.,
and W. Hill, Esq., F.G.S.

The district described in this paper is that of West Suffolk and
Norfolk, and is one which has never been thoroughly examined ; for
no one has yet attempted to trace the beds and zonal divisions which
are found at Cambridge through the tract of country which lies
between Newmarket and Hunstanton. Until this was done the
Hunstanton section could not be correlated definitely with that of
the neighbourhood of Cambridge. It was the authors’ endeavour to
accomplish this, and the following is an outline of the results
obtained by them.

The paper was divided into six parts :—(1) Stratigraphical, (2)
Paleontological, (3) Microscopical, (4) Chemical Analyses, (5) Faults
and Alteration of Strike, (6) Summary and Inferences. In the first
four parts separate lines of argument were followed, and each led
to the same set of conclusions.

The chief interest of the paper probably centres in the Gault, and
its relation to the Chalk Marl and the Red Chalk. Quite recently
the very existence of Gault in Norfolk has been disputed, but the
authors think the facts they adduce and the fossils they have found
will decide that point. The Gault at Stoke Ferry is about 60 feet
thick, and in the outlier at Muzzle Farm Ammonites interruptus occurs
plentifully in the form of clay-casts with the inner whorls phos-
phatized. At Roydon a boring was made which showed the Gault
to be about 20 feet thick, the lower part being a dark blue clay, above
which were two bands of limestone enclosing a layer of red marl, and
the upper 10 feet were soft grey marl; the limestones contained
Amm. rostratus, Amm. lautus, Inoceramus sulcatus and Inoc. concen-
tricus (?), while the marls above contained Belemnites minimus in
abundance. At Dersingham another boring was made which proved
the grey marl (2 feet) to overlie hard yellow marl, passing down into
red marl which rests on Carstone. The grey marl thins out north-
ward, and as the red marl occupies the position of the Red Chalk,
the authors believe them to be on the same horizon, an inference
confirmed by the presence of Gault Ammonites in the Red Chalk.

Another point of importance is the increasingly calcareous nature
of the Gault as it is followed northward through Norfolk. This
was regarded as evidence of passing away from the land supplying
inorganic matter, and approaching what was then a deeper part of
the sea; this inference is borne out by the microscopical evidence.

As regards the Chalk Marl, it also becomes more calcareous: at
Stoke it is still over 70 feet thick, and its base is a glauconitic marl
which can be traced to Shouldham and Marham, but beyond this
the base is a hard chalk or limestone, which is conspicuous near
Grimston and Roydon, and passes, as the authors believe, into the
so-called ‘‘ sponge bed ” at Hunstanton.

330 Reports and Proceedings—Geological Society of London.

The Totternhoe Stone is traced through Norfolk, but is thin at
Hunstanton (2 feet); its existence, however, enables the limits of
the Chalk Marl to be defined, with the result that some 18 feet of
the hard Chalk at Hunstanton must be referred to that subdivision.

The Grey Chalk also thins northward, and from 90 feet near
Cambridge, is reduced to about 380 at Hunstanton. The Belemnite-
marls are traceable in Norfolk, but either thin out or are replaced
by hard white chalk near Heacham.

The Melbourn Rock is continuous, and maintains similar charac-
ters throughout.

The total diminution in the thickness of Lower Chalk is from 170
feet at Newmarket to 55 feet at Hunstanton, viz. 115 feet. An
endeavour was made to estimate the amount and extent of Gault
removed by erosion from Arlesey and Stoke Ferry.

3. “On some Occurrences of Piedmontite-schist in Japan.” By
B. Koté, Esq. Communicated by Frank Rutley, Esq., F.G.S.

The occurrence of mangan-epidote or piedmontite in connexion
with the glaucophane-bearing rocks, in the crystalline schists of
Japan, had already been indicated by the author. But the “ mura-
saki” or violet-rock contains it as an essential component. This
is well developed near Tokusima, and its geological range has been
traced further. ‘The piedmontite occurs in this rock along with fine
quartz-grains under a schistose arrangement, the accessories being
muscovite, greenish-yellow garnet, rutile, some felspars, iron-
glance, etc.

The crystals of piedmontite are elongated, cracked, and much
striated, and occur with the orthopinacoid parallel to the planes of
schistosity. The crystal faces are, as a rule, well developed, thus
differing from common epidote, regarded as a rock-forming mineral.
Twinning is rare; cleavages upon the base and orthopinacoid are
sometimes observed. The clino-pinacoidal sections of the mineral
show the most intense colours; the polarization-colours are magni-
ficent. The following is the analysis :—

SiOs (a2ck WAS, GES LARAEY Ocho PO ORIG
ATS O si icpah Cea coins, ve ow erage | ccm me eo,
(SENOR DL, RM nia oO S,
MnO (AG, TOT ie Bites
CAOKE. SERRE. (255 OFS GRE OOR 05
Ne OVKoO Ne sORMe) o.. 2-b eevee ONS
FOV eed... .. ce ae neg

100°53

The chemist expresses a doubt as to whether the iron exists in
the state of sesquioxide or monoxide. The author then alludes to
the difference of opinion as to the state of oxidation of iron in the
Swedish and Alpine piedmontites, and suggested that the Japanese
mineral supplies a missing link between the two. The Japanese
mineral was originally mistaken for tourmaline, and the rock called
Tourmaline-schist by E. Naumann. Although comparatively rare
both in Piedmont and Sweden, in certain parts of Japan it is so

Correspondence—C. D. Sherborne, A. J. Jukes-Browne. 381

abundant as to constitute a rock-forming mineral, whilst as an
accessory it occurs also in the glaucophane-schist.

The author further describes a peculiar epidote, containing iron,
from the glaucophane-schist, and also a peculiar garnet, occurring in
rhombic dodecahedra about the size of a pea, which includes many
other minerals, but no glaucophane. The garnet is of a deep yellow
colour, and is anisotropic, a circumstance probably due to strain from
the interposition of other minerals.

CORRESPOND HIN CEH.

NORWEGIAN “RHOMBEN-PORPHYR” FROM THE CROMER
BOULDER-DRIFT.

Sir,—In 1884 I collected some erratics from the cliff-sections
near Hast Runton, amongst which was a specimen which proves to
be exactly similar to the well-known ‘ Rhomben-Porphyr” of
Southern Norway and elsewhere. It will be interesting, perhaps,
to put on record the occurrence of this uncommon and local rock.
A small piece of this specimen has been sent to the Mineral
Department, British Museum (Natural History).

540, Kine’s Roan, Lonvon, 8S. W. Cuas. D. SHERBORNE.

THE GLACIAL DEPOSITS OF SUDBURY.

Srr,—As one of those who believe that sea-ice was the main agent
in the formation of the Hast Anglian Drifts, allow me to enter a
protest against the conclusions drawn by Mr. J. E. Marr in his paper
on the Sudbury sections in the June Number of this Macazinz.

He entirely omits to consider the action of coast-ice on a sinking
shore, though he must be well aware that this agency has been
prominently referred to as concerned in the formation of Boulder-
clay.

He asks the question, “‘ Why are not the incoherent Tertiary beds,
on which the contorted Glacial deposits rest, themselves disturbed ? ”
and he thinks that this fact is incapable of explanation except by the
theory which invokes the passage of land-ice over the Hast of
England. I perfectly agree with him on the point that the incoherent
Tertiary beds could only escape contortion by being frozen hard so as
to behave like the harder rocks of other districts; but is it, I would
ask, only on an actual land surface that such sands could be frozen
into a solid mass? JI am writing in the country away from books of
reference, but think I am correct in saying that the sand on the
shores of Siberia is frozen into a perfectly hard and solid mass for
some distance below the water, and I think the fact is mentioned in
Nordenskiéld’s ‘‘ Voyage of the Vega.”

Mr. Marr dismisses the agency of icebergs because he thinks the
deposits could not be frozen “over large areas at the bottom of the
muddy sea in which the icebergs were drifted ;” this is probably
true of those parts of such seas in which large and massive icebergs

332 Correspondence— W. H. S. Monck.

would ground, but it is not true of the shallower parts near the
shore on which the coast-ice acts and on to which floe-ice and pack-
ice is often driven with immense force,—agencies which seem to
be quite as capable of carrying with them the masses of partially
frozen materials and of pushing them over a floor of solid frozen
sand as Land- or Glacier-ice could be.

Mr. Marr refers to a recently-described case where a glacier
traversing a narrow valley seems to have overfolded certain deposits
of stratified sand and clay; thus comparing what may happen in
a narrow valley with the phenomena of a district of which he him-
self says “‘not only do the contortions occur in the drifts which
occupy the valley bottoms, but they are also found in the accumu-
lations which lie on the summits of ridges.” Are we to suppose
that so able a geologist as Mr. Marr thinks an ice-sheet over-riding
a ridge will act in the same way as a glacier pushing itself through
a narrow valley ?

The sections round Sudbury are exceedingly interesting, and Mr.
Marr deserves our thanks for calling further attention to them and
for recording new aspects of the changing pit-faces, but in his charge
to the jury he has not put all the possible alternatives, and conse-
quently his summing-up is biassed in favour of one explanation.

JUNE 6, 1887. A. J. Juxes-Browne.

THE CAUSES OF GLACIATION.

Str,—I ask leave for a few remarks on the question of the causes
of glaciation, as there are some points connected with it on which I
think sufficient stress has not hitherto been laid.

The total amount of direct solar heat received at any place is
admittedly nearly constant whatever be the eccentricity of the earth’s
orbit. ‘The amount indirectly received through the medium of air-
currents, clouds, and ocean-currents may vary; but if the variations
of this indirect heat are ascribed to the raising or lowering of the
temperature, the causes of this raising or lowering must be sought
for in the distribution of the direct heat. We come, therefore, to the
question, What distribution of direct heat over the various seasons
(the total amount being unaltered) is most favourable to glaciation ?

In the first place, then, it seems clear that the Glacial period could
not have been produced by the freezing of water in situ. A snow-
cap or ice-cap reaching an elevation of hundreds or thousands of
feet over the sea-level could only have resulted from falls of snow.
The former question is therefore resolved into the following, What
distribution of direct heat is best calculated to increase the annual
snow-fall ?

In answering this question, two principles must be borne in mind.
First, that snow will not fall, or at least will not lie, if the tempera-
ture is much above freezing-point. In such cases either rain would

take the place of snow, or else the snow would melt at once. Second,

that very little snow falls when the temperature is very low. Great
cold preserves the snow that has fallen, but it seems necessary for a

ae

Correspondence—W. H. S. Monck. 330

heavy fall that the temperature should not be much below freezing-
point.

I now distinguish three cases.

1st. Where the mean temperature is above freezing-point. Here,
if we could distribute equally throughout the year, no snow would
fall. Unequal distribution might, however, produce a considerable
snow-fall, though not a permanent snow-cap. In mountainous
districts extensive glaciers might be produced in this way.

2nd. Where the mean temperature is below, but not much below,
freezing-point. Here an equal distribution of heat throughout the
year is most favourable to the formation of a snow-cap. Snow
would fall at all seasons of the year, and the melting-point being
rarely, if ever, attained, the snow-cap would continue to accumulate.

ord. Where the temperature is much below freezing-point. Here
an unequal distribution of heat is most favourable to glaciation,
because we must bring the temperature nearly up to freezing-point
at one season of the year in order to obtain the heavy falls of snow
which are required to form a snow-cap or ice-cap of considerable
thickness.

If these principles are correct, they lead to the following results.
A high eccentricity of the earth’s orbit when the earth is in aphelion
at mid-winter is favourable to glaciation in two regions of the
Northern Hemisphere, one immediately round the pole and the
other much further south (where, however, the result would be
rather extensive detached glaciers than general glaciation). But
between these two regions there is an intervening one in which the
conditions for glaciation would be unfavourable, the snow-fall being
less than if the distribution of heat was equable, while a good deal
of this lessened snow-fall would be melted by the increased quantity
of heat received during the summer. If the earth was in perihelion
at mid-winter, this state of things would be reversed. ‘The polar
snow-cap would be diminished, but there would be more glaciation
in the southern portion of the Arctic region and the northern portion
of the Temperate Zone. As far south as Switzerland, however, the
glaciation might perhaps again diminish.

In confirmation of these views, I may add that I do not see how
the snow-fall could be increased over the entire region from, say, the
fiftieth degree of North Latitude to the Pole at the same time. For
high eccentricity would not, I apprehend, increase the difference of
temperatures between the Equatorial and Polar Regions. It would
produce a summer and winter at the Equator—the former when the
earth was in perihelion and the latter when the earth was in aphelion ;
but when the Equatorial and Polar summers and winters synchronized,
the contrast of temperatures would not be greater than at present.
During the long cold northern winter, on which Dr. Croll lays so
much stress, there would also be winter at the Equator, and if we
regard the Equatorial region as the generator of vapour or steam and
the Polar region as the condenser, the apparatus as a whole would not
be more powerful but less powerful than before. There would be
no increase in the quantity of aqueous vapour available for the

334 Obituary— Edward Townley Hardman.

production of falls of snow in the higher northern latitudes, and,
therefore, an increased snow-fall in one portion of these latitudes
must be compensated by diminished snow-fall in another portion.

I have omitted to notice the effects which might be produced when
the snow-caps thus formed were set in motion. Moving masses of
ice or snow might considerably alter the general phenomena of
glaciation. If we take the most southerly portion of our hemisphere
in which permanent glaciation is possible, the snow-cap would form.
most readily if the irruption of northern ice commenced about the
same period when the conditions for local glaciation were becoming
favourable. These latter conditions would, I apprehend, be most
favourable when the earth was in aphelion at midsummer; but the
Polar Pack would not attain its full dimensions until some time after
the mid-winter aphelion, and in its slow southward motion it might
not begin to overrun the northern portion of the Temperate Zone
until a still later period. The invasion of Polar ice might nearly
coincide with the commencement of the local glaciation produced by
very different causes, and a Glacial period would result.

13, BELVIDERE Priacr, Dusutin, W. H. S. Moncx.

May 77TH, 1887.

OBITUARY.

EDWARD TOWNLEY HARDMAN, F.C.S., F.R.G.S.1., ETC.
Born 6TH Aprit, 1845; Diep 30TH Aprin, 1887.

EOLOGICAL science has suffered a serious loss in the early

KN ©6death, from typhoid fever, of Mr. Hardman, of the Irish
branch of the Geological Survey of the United Kingdom.

Descended from an old and respected Drogheda family, Mr.
Hardman received his early education at that town. Having by his
ability won a Government Exhibition and entered the Royal College
of Science, Dublin, in 1867, he obtained a diploma in mining,
etc., as well as numerous prizes, and in 1870, he was appointed to
the staff of the Geological Survey of Ireland. In 1871 he was
elected a Fellow of the Geological Society of Ireland, and in 1874 of
the Chemical Society of London.

He examined, and prepared a Memoir upon, the Geology of the
Coal-fields of Kilkenny and Tyrone, and prepared a list of papers.
on the Geology of the North of Ireland. Mr. Hardman was also an
active and earnest antiquary, and communicated several papers to
the Royal Irish Academy.

In 1883 he was selected by the Colonial Office to examine and
report upon the geology and mineral resources of the Kimberley
district of the colony of West Australia. Here he was attached to
a local surveying expedition, under the direction of the Hon. J.
Forrest, C.M.G., Crown Surveyor General to the Colony, and set
out for the North-East Territory. Having a camera, he was enabled
to photograph numerous points of interest, and also to make sketches
of characteristic geological sections. The most important practical

Obituary— Edward Townley Hardman. BI319)

result of his investigations was the discovery of an extensive gold-
field in the vicinity of the Napier Range in the Kimberley district,
where by actual experiments he was able to attest the presence of
auriferous deposits at various points.

There is no doubt that Mr. Hardman’s work was performed
in such an efficient and satisfactory manner that he would have been
at once appointed as geologist to the Colony, but for the difficulties
raised by the Legislative Council on the subject of expenditure.
His engagement having terminated, he returned home in October,
1885, bearing however the assurance that he would certainly be
appointed if the post was created.

Last year he was called upon to assist in the arrangement of the
rocks, fossils, and minerals sent by West Australia for the Colonial
and Indian Exhibition in London.

He had returned to his duties on the Irish Survey, and in March
last he inspected a district in the Wicklow Mountains and adjacent
country, with the view to compiling a second Survey Memoir thereon ;
his constitution no doubt suffered owing to the inclemency of the
weather and frequent exposure to swnostorms and rain amongst the
hills, so that when attacked by fever he was too reduced in health to
withstand its effects, and he passed away after only a few days’ illness,
leaving a widow and two young children quite unprovided to face
the struggle for existence deprived of a father’s protection and
support.

It is all the more sad to think that had he lived the long-desired
post of geologist to West Australia would have been offered to Mr.
Hardman, the financial difficulties in the way of his appointment
having been removed just before he died.

A considerable reward had been offered by the Government for
the discovery of gold in the colony, and Mr. Hardman was at the
time of his death a claimant for the prize. It is earnestly to be
hoped that the Legislative Council will be pleased to award at least
a part of such premium to the widow of the man who discovered
the Kimberley Gold-field.

The following is a list of the papers of which Mr. Hardman is
the author :-—

1. On the Analysis of Trachyte Porphyry from Tardree Quarry near Antrim. Roy.
Geol. Soc. Ireland, May 10, 1871.

2. On the Analysis of a Limestone compared with that of the same rock where it is
in close proximity to a Doleritic Dyke. R.G.S.I., June 14, 1871.

3. On the Occurrence of Gypsum in Keuper Marls near Coagh, Co. Tyrone.
R.G.S.I., June 12, 1872.

. On the Recent state of Coal Mining in the County of Tyrone. Roy. Dub. Soc.,
Nov. 18, 1872.

. List of Geological Papers on North of Ireland. Mems. G. Sur. I., 1872.

. On the Occurrence of Silicious Nodular Brown Hematite (Gothite) in the Car-
boniferous Limestone beds near Cookstown, Co. Tyrone. R.G.S.1., May 14,
1873.

7. On Analysis of White Chalk from the Co. Tyrone; with Notes on the occurrence

of Lime therein. R.G.S.I., June 11, 1873.
8. Notes on a Small Raised Beach at Tramore Bay, Co. Waterford, showing traces of
severe oscillatory movements during the recent period. R.G. S, I., Dec. 10, 1873.

Qo

306 Obituary—Edward Townley Hardman.

9. On the Substitution of Zinc for Magnesium in Minerals. Roy. Irish Acad. vol.

10.
ll.
12.
13.

14.
15.
16.
17.
18.

19.
20.

21.
22.

28.
24.
25.

26.
27.

28.
29.

30.
él.
32.
33.

i. 1870, p. 533; Guon. Mac., May, 1874.

Further Researches on the supposed Substitution of Zinc for Magnesium in

Minerals. R.I.A., vol. ii. p. 146.

On Bones discovered in a Cave of Dunmore, Co. Kilkenny. Proc.R.I.A., 1870-

1879, p. 354. “a

On Two new Deposits of Human and other Bones discovered in the Cave of

Dunmore, Co. Kilkenny. P.R.I.A., February 22, 1875.

On the Age and Mode of Formation of Lough Neagh, Ireland; with Notes on

the Physical Geography and Geology of the surrounding country. R.G.S.L.,

January 13, 1875.

On the Origin of Anthracite, with suggestions as to the possible Correlation in

time and manner of Production of the Anthracite of Southern Ireland, Wales,

Devonshire, and France. R.G.S.1., 1875.

On the Sub-Glacial Theory of Gravels. Guzou. Maa., April, 1875.

Analysis of Coals and Ironstones from the Dungannon Coal-fields, Co. Tyrone.

R.1.Acad., February 28, 1876.

A Contribution to the History of Dolomite (with plates), R.I.Acad. (xli. and

xlii.) vol. i. p. 708.

The Dolomites of the Carboniferous Limestones of Ireland. R.I.A., May 8,

1876.

Fossiliferous Pliocene Clays. Grou. Mac. Dec. II. Vol. III. p. 556, 1876.

On a Triple System of Post-Miocene Faults in the Basaltic Region around Lough

Neagh. R.G.S.I., April 11, 1877.

Memoir on Tyrone Coal-field. Mems. G.S.I., 1877.

Chemical Notes in Connection with Prof. Hull’s paper on the Nature and Origin

of the Beds of Chert in the Upper Carboniferous Limestone of Ireland.

R.G.S8.1., May 9, 1877.

On the Barytes Mines near Bantry. R.G.S.I., January 21, 1878.

On Hullite: a hitherto undescribed mineral : a hydrous Silicate of peculiar com-

position from Carnmoney Hill, Co. Antrim, with analysis. R.J.Acad., June 24,

1878.

Preliminary Report on Soundings in Lough Gill, Co. Sligo. R.I.A., vol. iii.
. 473.

Momerr on the Kilkenny Coal-field. Mems. G.S.I., 1881.

First Report to Government on the Geology of the Kimberley District, West

Australia, 1884.

Second Report to Government on the Geology of the Kimberley District, West

Australia. 1886.

Notes on a Collection of Flint Implements and other Weapons, ete., from

Tropical Western Australia. R.I.A. (in course of publication). Read 22

February, 1886.

Catalogue of the Geological Survey (Ireland) Library (for private official use).

1886.

Notes on some Habits and Customs of the Natives of Kimberley, West Australia.

R.1.A. (in course of publication). Read 10 January, 1887.

Memoir on the Geology of the Country in Sheets 148-49 Geol. Surv. Ireland.

Mems. G.S.I. (in the press). 1887.

Note on Professor Hull’s paper with reference to Dr. Hinde’s paper on Beds of

Sponge Remains ; Greensand. Royal Society, Lond., April 28, 1887.

A. B. W.

Ir is with deep and sincere regret that we record the death, on the

5th June, of our friend and fellow-worker in geology, ArTHUR
Cuamprrnowne, Esq., M.A., F.G.S., of Dartington Hall, Totnes,
S. Devon, aged 48 years. We hope to publish a notice of his life
and work in our next Number.—Epir. Gro. Mae.

a

ae
; oe
Boi

eol. Mag. 1887.

5

E C Woodward ael,et lith

Phohdophorus, Purbeck, Dorsetshire.

West Newman & Co. imp.

a

THE

GEOLOGICAL MAGAZINE

NEW SERIES. DECADE Ill. VOL. IV.
No. VIII—AUGUST, 1887.

Oeste Aste, |; Ave ane S tra Ss

I.—On New Species or PHOLIDOPHORUS FROM THE PuRBECK BrEpDs
oF DoRSETSHIRE.

By Witiram Daviss, F.G.S.,
of the British Museum (Natural History).

(PLATE X.)

EW genera of Fossil Fishes contain so large a number of well-
defined species as Agassiz’s widely-distributed and well-known
genus Pholidophorus. Above forty species have been more or
less fully described by Agassiz and subsequent authors; the geologi-
cal range extending from the Rhetic to the Purbeck Beds inclusive.
The group consists mainly of small or moderate-sized fishes, but few
that can be termed large; and with the exception of one species (P.
maximus), the generic identity of which is doubtful, it contains no
fishes of magnitude. Fifteen species have hitherto been recorded as
occurring in British rocks by Agassiz* and Egerton ® respectively, the
geological distribution being as follows:—Two species from the Rheetic
Beds at Aust; nine from the Lower Lias (Lyme Regis; Street; and
Barrow-on-Soar) ; one species from the Inferior Oolite of Blisworth ;
one from the Great Oolite, Stonesfield ; and lastly, two from the
Purbeck Beds of Swanage, namely Pholidophorus ornatus, Ag., and
P. granulatus, Hgert. These last are fishes of moderate size; with
crenulated and otherwise ornamented scales. The fishes which form
the subject of this article differ in some important characters from
the above-named species; inasmuch that they are diminutive in size,
have smooth unornamented scales with entire free margins, another
feature being the reduced number of the vertical series covering the
flanks. They are apparently rare, the specimens here described
being the only examples that have come under my observation.
They comprise two forms, one short and deep, the other more
elongate.

PHOLIDOPHORUS PURBECKENSIS, sp. nov. (Plate X. Fig. 2.)
This species is founded upon two specimens, one in the private
cabinet of Mr. Damon, of Weymouth, who has kindly submitted it

to me for examination, the other on counterpart slabs in the National
Collection (B.M. 40685). They are elegant fusiform fishes, less

1 Agassiz, ‘‘ Rech. Poiss, Foss,’’ tom. ii. p. 287.
2 Op. cit. tom. i. 3 Mem. Geol, Surv. Decades vi. and viii.

DECADE III.—YOL. IY.—NO. VIII. 22

338 Wilkam Davies—New Purbeck Pholidophorus.

than 84 inches (85 mm.) in length. Unfortunately the head in each
Specimen is so much crushed, that, with the exception of the oper-
cular plates, the component elements are too indistinct for separate
description; but its form and relative proportions are fairly well
preserved. The orbits are of moderate size; the operculum is
oblong, the upper margin being slightly convex, and the sub-oper-
culum is triangular in form. The head forms one-fourth of the
entire length of the fish, and is equal to the depth of the body a
little in advance of the ventral fins. The scapular arch is nearly
concealed by the opercular plates. The paired fins are imperfect,
afew rays of each only being preserved, which suffice to indicate
their position. The ventrals are placed midway between the attach-
ment of the pectorals and the anterior ray of the anal fin. The
latter fin is also imperfect, insomuch that the distal bifurcated
extremities of the rays are wanting. It consists of ten strong and
unarticulated rays, and is 9 mm. in length; no fulcral scales are
preserved on either specimen. ‘The dorsal fin rises from the middle
of the back and opposite the interspace dividing the anal and ventral
fins. It is short but incomplete, the few rays preserved are
moderately thick, the anterior ray being strengthened by several
imbricating and elongate fulcra. The caudal fin is deeply cleft and
equilobed, like the tail of the contemporary P. ornutus. There are
sixteen articulated rays, eight in each lobe, preceded by acutely
pointed fulcral scales, those on the upper lobe being the largest.
The scales on the Museum specimen are all more or less broken, but
the characteristic or principal series covering the flanks are well
preserved on Mr. Damon’s specimen.! These form four rows of
high and narrow scales which gradually diminish in height as they
approach the tail, and are completed by smaller scales above and
below. The upper or dorsal row of large scales are slightly curved,
the anterior series of the other rows are nearly rectilinear in form.
Those of the second, or lateral line series of scales are the largest,
being four times as high as they are broad, whilst in the next series
these proportions are as three to one. There are from 32 to 34
scales in each longitudinal row. The lateral line is prominent and
continuous, with a slight curve, from the operculum to the caudal
fin. The side scales show the peg and notch articulation, and are
strengthened on the inner surface by the continuation of the peg as
a mesial vertical ridge to the articulating depression on the lower
margin of the scale. The scales are coated with shiny ganoine, upon
which may be seen with a lens a few striz, or lines of growth, and,
compared with most species of Pholidophorus, the scales are relatively
thin, hence their imperfect preservation. The specimens are from the
Lower Purbeck Beds of the Isle of Portland.

PHOLIDOPHORUS BREVIS, sp. nov. (Plate X. Fig. 1.)

The little fish I have thus designated is in the National Collection
(P. 1074), and is readily distinguished from the preceding species

1 See Plate X. Fig. 3. The entire fish has been drawn (but not yet published), for a
new edition of the Supplement to the Geology of Weymouth and the Isle of Portland.

Nicholson and Marr—On. the Lake-district. 339

by its shorter and deeper body. In shape and relative proportion it
resembles P. granulatus, and might be taken for its young form: ~
but the unornamented scales with entire margins preclude its being
referred to that species. The extreme length is 77 mm. (8 inches)
of which the head occupies the fourth part; between the hinder
margin of the operculum and the insertion of the caudal fin the body
measures 40 mm., and the depth in front of the ventral fins is 25 mm.
The head is crushed, and but little of the external surfaces of the
bones are preserved. The orbits are not large, nor are any teeth
visible. There is not the slightest evidence by depression or other-
wise of the presence of the notochord. The fins appear to have
been small and the rays few. The insertion of the dorsal fin is a
little in advance of the opposite anal fin. Long acute imbricating
scales cover the front ray of both fins. The caudal fin is composed
of about 20 strong and jointed rays with several fulcral scales above
and below, and is not deeply cleft. The structure and general form
of the scales are the same as in P. purbeckensis ; namely, high and
narrow scales on the flanks, which gradually decrease posteriorly,
with small scales on the dorsal and abdominal regions. Most of
the larger scales are either wanting or broken; but well-marked
impressions of the outer surfaces of those missing are preserved on
the matrix. On another fragment of a larger individual (B. M.
P 3607), the scales are in better position, and also show the inner
side. Both specimens are from the Upper Purbeck Beds at Upway,
near Weymouth; and formed part of the Egerton and Enniskillen
collections respectively.

It is deserving of remark that Pholidophorus is found associated
with Lepidotus in many of the marine formations of the Jurassic
period, and also in the estuarine deposits of the Purbecks, proving
that species of both genera frequented estuarine waters.

DESCRIPTION OF PLATE X.

Fie. 1. Pholidophorus brevis. British Museum (P 1074).
», 2+ Lholidophorus purbeckensis, drawn from the two slabs in the British
Museum (40635).

Spe Bs 25 3 enlarged external view of the flank scales on
Mr. Damon’s specimen.
Sree bs 5 restored inner view of the same scales showing

the medial ridge.

I].—On tHe Occurrence or A New Fossittirerous Horizon IN
THE ORDOVICIAN SERIES OF THE LaKe-DistRict.

By H. Atteyne Nicwonson, M.D., D.Sc., F.G.S., and
Joun KE. Marr, M.A., F.G.S.

ELOW the “Coniston Limestone Series ’’—if we include under
this general title not only the Coniston Limestone proper, but

also the “Style End Grassing Beds” of Long Sleddale and the
“Dufton Shales” of the Cross Fell area—no fossiliferous beds have
hitherto been detected in the Lake-district till the horizon of the
Upper Skiddaw Slates (Llanvirn Series) is reached. Between these
two horizons are placed the thick and varied volcanic rocks which

340 Prof. H. A. Nicholson wal a ove

have usually been grouped together under the name of the ‘“‘ Borrow-
dale Series” (the “‘Green Slates and Porphyries” of Prof. Sedg-
wick); though it may be taken as certain that this name covers
more than one series of volcanic ejecta. Up to the present time, no
strata containing fossils have been detected in connection with
any of the rocks which have been included under the general title
of the “ Borrowdale Series.” The object of the present communi-
cation, however, is to draw attention toa group of fossiliferous shales
which we have found to be associated with certain of these volcanic
rocks.

The shales in question occur on the north side of the great mass
of the Skiddaw Slates of the Lake-district, in what has been spoken
of as the “Caldbeck Fells Area’; and their general position will be
made clear by the accompanying sketch-map.

iT

BRU GHRABN GIN GOL LIA saa

: 4
SS = Mosedale.

Sketch-map of Carrock Pike and the district immediately round it, on the scale of
one inch to a mile. (The boundaries of the intrusive igneous rocks are in part
taken from Mr, Clifton Ward.) S. Skiddaw Slates, for the most part highly
metamorphosed; d. Drygill Shales; e¢. Lavas and ashes (‘‘ Hycott Series ”’) ;
e. Carboniferous rocks; g. Granite. G. Gabbro (the ‘‘hypersthenite’”’ of Mr.
Ward) ; D. Intrusive diorite (?) ; F. Spheerulitic felsite.

The main area of the Skiddaw Slates in the Lake-district, as 1s
well known, is followed to the south by the main area of the so-

New Fossiliferous Horizon in the Lake-district. 341

called Borrowdale rocks, while it is flanked on the north and north-
east by a narrow strip of volcanic rocks which runs from Eycott
Hill near Troutbeck Station, through the range of the Caldbeck Fells,
to Binsey Crag and Torpenhow Common. The upward sequence of
the volcanic rocks of the Caldbeck Fells is concealed from view by
the overlapping Carboniferous Limestone. On the other hand, the
relations which these rocks bear to the Skiddaw Slates to the south
of them have not hitherto been precisely ascertained, partly from an
insufficiency of sections, and partly owing to the intercalation
between the two series at the eastern end of the range of the great
intrusive igneous masses of Carrock Pike and Great Lingy.

The strata to which we wish to direct attention here are situated
immediately to the north of the intrusive masses just spoken of, and
are, therefore, of special interest as lying between the Skiddaw
Slates on the one hand and the volcanic rocks of the Caldbeck Fells
on the other hand; though it cannot be said that their stratigraphical
relations with either of these are absolutely clear. They occupy the
summit of the valley between High Pike and Carrock Pike, and are
fully exposed in the course of Drygill Beck, the head tributary of
Carrock Beck. We shall, therefore, speak of them as the “ Drygill
Shales.” The following is the section seen in Drygill in descending
the stream. The ridge from which Drygill Beck flows north-east-
wards is probably composed of intrusive igneous rocks, but the
summit of the ridge is covered with peat, and no rock is seen in
place. The first rocks seen in the highest part of Drygill are pale
drab-coloured shales, which dip at tolerably high angles to the S.S.W.
and strike W.S.W. and E.N.E. No fossils were detected in these
beds ; but a more prolonged search would probably bring organic
remains to light. These are succeeded below by blue-grey shales,
weathering white, and similarly coloured mudstones, with iron-
stained joints, containing ill- preserved Brachiopods and other fossils.
These beds are best seen in Drygill itself, but are also exhibited in
the western fork of the stream.

The beds just spoken of abut against a mass of intrusive igneous
rock, which occupies both sides of the stream for some little distance
below the point where the eastern and western forks unite. This
rock decomposes by exposure to the weather to a soft brownish-
green ashy-looking rock, but it seems really to be very similar to the
intrusive mass which occurs in Brandy Gill, and which Ward has
spoken of as a “ diorite.” Very probably the mass in Drygill is only
an offshoot from this.

Below the preceding, the stream cuts through a series of dark
blue-grey or nearly black mudstones, crowded with fossils, which
are fairly preserved, though slightly distorted by cleavage. The
general strike of the beds here varies from §.W. to W.S.W., the dip
still being southerly ; and the whole series is much broken and inter-
sected by mineral veins. These beds rest upon a series, of no great
thickness, of remarkable contemporaneous volcanic rocks in the
form of breccias with associated bands of quartz-felsite, which are
unlike the ordinary lavas and ashes of the Lake-district in their

342 Prof. H. A. Nicholson and J. E. Marrv—

nearly white colour. Lastly, these volcanic beds are underlaid by
a final mass of dark fossiliferous mudstones, full of Brachiopods and |
Trilobites. .
The following is a list of the fossils which we have obtained from
the Drygill Shales :—
Ampyx rostratus, Sars. Beyrichia complicata, Salt.
Calymene cambrensis, Salt. | Leptena sericea, Sow.
Lichas laciniatus, Wahl. ? Obolella ?
Stygina Murchisonie, Murch. Orthis testudinaria, Dalm. (abundant).
Trinucleus favus, Salt. P

The strata above described are not exposed elsewhere in the Cald-
beck Fells, to our knowledge, nor are we acquainted with any rocks
in the Lake-district which can be precisely paralleled with them.
Moreover, the relations of the strata of this small, disturbed, and
shattered area to the rocks in the immediate neighbourhood are not
at all clear. Their northern boundary is probably a faulted one,
since the whole series is dipping in a southerly direction, whereas
the general dip of the volcanic rocks of the Caldbeck Fells is
northerly. No actual junction, however, is seen between the lowest
mass of the Drygill Shales and the volcanic rocks in question.
Below the lowest exposure of Drygill Shales is an interval of barren
ground, followed by an exposure of a hard grey lava. Then there is
a long interval in which no rock at all is exposed to view, and,
finally, the lower part of Carrock Beck is excavated in a series of
lavas which may be regarded as a direct continuation of those of
Eycott Hill, with which they agree in all essential particulars.

The relations of the Drygill Shales to the south are still more
obscure, since no rocks of any kind are exposed between the head of
Drygill Beck and the head of Brandy Gill (see sketch-map). Here
we meet with a mass of an imperfect granite, with the general aspect
of a felsite. Following the stream downwards, this is seen to be
succeeded by a mass of intrusive igneous rock, which Mr. Clifton
Ward identified with some doubt asa diorite (Quart. Journ. Geol.
Soc. vol. xxxii. p. 16). Southwards of this, again, is the westward
continuation of the gabbro (“ hypersthenite ” of Ward) of Mosedale
Crags. This, finally, is succeeded to the south by the highly-altered
Skiddaw Slates which occupy this portion of the valley of the
Caldew, and which appear to be cut off from the igneous rocks on
the north by a great fault.

The stratigraphical relations of the Drygill Shales are, thus,
obscure. So far as we are aware, the only published notice of these
beds is the incidental mention of them by the late Mr. Clifton Ward
in his memoir on “The Granitic, Granitoid, and Associated Meta-
morphic Rocks of the Lake District” (Quart. Journ. Geol. Soc. vol.

1 From a remark made by Mr. Ward (Quart. Journ. Geol. Soc. vol. xxxii. p. 24),
we should be disposed to infer that this observer regarded the peculiar characters of
these beds as due to extreme weathering. Mr. Teall has been good enough to examine
for us a specimen of one of the felsitic bands associated with these light-coloured
breccias, and informs us that it exhibits porphyritic quartz and felspar in a crypto-
crystalline ground-mass, Assuming it to be a lava, he would consider it to bea
slightly altered liparite.

New Fossiliferous Horizon in the Lake-district. 343

xxxil. pp. 17 and 24). This gifted observer considered the Drygill
Beds as being referable to the Skiddaw Slates. He was, in fact, of
opinion that we had here an instance of a passage between the
Skiddaw Slates and the Volcanic Series, by the intercalation of the
highest portion of the former with the base of the latter in alternat-
ing succession—a phenomenon of which he believed he had found
instances in other localities in the Lake-district. It is certain, how-
ever, that, as regards the rocks here in question, this conclusion
could not have been arrived at by a geologist of such experience
except under the influence of a preconceived theory. Lithologically,
the Drygill Shales do not at all resemble any members of the
Skiddaw Series, and they do not precisely resemble any rocks which
are known to us as occurring in the Lake-district. They are of
the nature of mudstones, with a rough cleavage; and of all the
Ordovician rocks of the North of England, it is, perhaps, the
“‘Dufton Shales” which they most nearly resemble. Some of the
_ beds are also very like parts of the “Skelgill Series.” Apart,
however, from the comparatively unimportant character of their
lithological nature, the Drygill Shales swarm with fossils—of few
species certainly, but of great abundance as individuals—which leave
no doubt at all as to their general position in the Ordovician Series.
The presence in abundance of such fossils as Orthis testudinaria,
Dalm., Leptena sericea, Sow., and Calymene cambrensis, Salt., Ampyx
rostratus, Sars., and Stygina Murchisonie, Murch., renders it certain
that the Drygill Shales are of Llandeilo-Bala age. Upon the whole,
the general characters of the fossils would lead us to refer the
Drygill Shales to about the horizon of the Llandeilo Limestone, or
to a slightly higher point in the series.

As regards the Lake-district succession, the paleontological
evidence renders it absolutely certain that the Drygill Shales are
younger than the Upper Skiddaw Slates and older than the Coniston
Limestone proper. They agree most nearly with the ‘‘ Dufton
Shales” as regards their fauna, but they differ from these in the
predominance of Orthides of the type of O. testudinaria, Dalm., and
in various other points. On the other hand, it is not at present
possible to decide positively as to the relations which the Drygill
Shales bear to the Volcanic Series. From their general position
between the Skiddaw Slates on the one hand and the lavas and
ashes (‘‘ Hycott Series”) of the Caldbeck Fells on the other hand,
we should be led to conclude that they occupy a place low down
in the latter series. It is quite certain that they do not belong to
any part of the Skiddaw Series; and there is, in fact, no evidence
that the series of the Upper Skiddaw Slates is present at all in this
particular area. On the contrary, the Skiddaw Slates of the Caldew
Valley appear to be faulted down against the igneous rocks to the
north of them, and it is probable that the Upper Skiddaws are thus
completely cut out. Again, the Drygill Shales are lithologically
and palzontologically distinct from any of the fossiliferous rocks
which can clearly be shown to lie above the Volcanic Series. It
would thus seem almost certain that, though their present position

344 T. F. Jamieson—Changes of Level in the Glacial Period.

is probably largely affected by faulting, they must be referred to
the Volcanic Series itself.

In corroboration of our view that the Drygill Shales form part
of the Volcanic Series, we may draw attention for a moment to
tbe unequivocal occurrence of bands of mudstone—unfortunately
apparently not fossiliferous—in the lavas and ashes of this series in
another locality. The locality alluded to is Falcon Crag, near
Keswick, selected by Mr. Ward as affording a typical section of the
Volcanic Series (Geology of the English Lake-district, p. 13), though
he does not mention the particular feature here in question. Above
the lowest lava in this section, as seen in Cat Gill, we find a series
of unaltered ashes and breccias, sometimes fine, sometimes of coarser
grain, which alternate with thin bands of grey shaly mudstone.
These alternating beds are sometimes so mixed and blended together
at their lines of junction, that it is clear that the ashes were from
time to time abundantly showered into the sea in which the grey
mud of the shales was in course of deposition. The mudstones have
no resemblance lithologically to the Skiddaw Slates, and they are so
much squeezed and jointed that all attempts to detect fossils in them
have hitherto proved abortive. They are, however, full of ferruginous
stains and cavities which may possibly represent organic remains
now destroyed. We have here, then, an unquestionable instance of
tke occurrence of contemporaneous mudstones among the lavas and
ashes of the Volcanic Series; and this would so far support our
reference of the Drygill Shales to the same series. At the same time,
it should be added that we are not disposed to regard the mudstones
of Falcon Crag as being the precise equivalent of the Drygill Shales.
On the contrary, the latter not only have a vastly greater thickness,
but are associated with a peculiar type of volcanic ejecta, of which
we find no representative in the section at Falcon Crag.

IJ].—On Somer Cuances oF LeveL purInNG THE GuActAL Prriop
AND THEIR SUPPOSED CAUSE.

By T. F. Jamrzson, F.G.8., Ellon, Aberdeenshire.

T the close of the Glacial Period in North America the basin of

the Red River was occupied by a large lake which has received

the name of Lake Agassiz. It extended from what is now Lake

Winnipeg southward for some hundreds of miles to the watershed

of the Minnesota River. The bottom of this old lake now forms an

extensive level plain famous for its fertility and the fine crops of
wheat it produces.

At present the drainage of the Red River Valley flows northward
into Lake Winnipeg and from thence along the Nelson River into
Hudson’s Bay ; but during the existence of the lake in question this
outlet is supposed to have been blocked by the great glacier which
formerly covered all the region to the north, and which was then
slowly retreating owing to the advent of a milder climate. As the
drainage of the glacier went into the lake, there must have been
an ample supply of water to keep it constantly brimming. The

T. F. Jamieson—Changes of Level in the Glacial Period. 345

quantity of water it discharged, and the length of time the lake
existed, is further shown by the size of the channel which the river
flowing out of it has cut through the thick bed of drift to the south-
ward. This channel forms a long trough, from 100 to 225 feet in
depth, commencing at Lake Traverse and extending for about 250
miles along the course of the Minnesota River to its junction with
the Mississippi. The fact. of the excavation of this remarkable
trough being due to the outflow of the lake which formerly filled the
basin of the Red River was pointed out by Gen. G. K. Warren in
1868.

The beaches left along the margin of the vanished lake are still
quite distinct, and have lately been made the subject of careful
examination by Mr. Warren Upham, of the U. 8. Geological Survey.’
He has executed a series of levellings along the uppermost beach for
a distance of 142 miles, extending from its outlet at Lake Traverse
northward to Maple Lake, which is about 20 miles east of Crookston,
and one interesting result of his work is to show that the beach does
not form a horizontal line, but slopes gradually upwards from south
to north along the whole distance he carried his levels. Its height
at the south end is about 85 feet above the present level of Lake
Traverse, or 1055 feet above the sea; while at Maple Lake, where the
levelling stopped, it is 1180 feet above the sea, showing a gradual
rise of 125 feet in the course of 142 miles. ‘‘' Through this distance,”
says Mr. Upham, “the upper beach clearly marks one continuous
shore-line, and the accuracy of our levelling is attested by close
agreement with railroad surveys at five widely-separated points.”

The ascent of this beach from Lake Traverse northward is at the
rate of about 345 of a foot per mile for the first 60 miles. Further
north, through the next 80 miles, its rate of ascent is somewhat
greater, varying from three-fourths of a foot to 14 foot per mile.
The portion of the upper beach thus examined extends through
a prairie region very favourable for exploration and levelling.
Further on it turns to the HE. and N. through a trackless forest
with impassable swamps, where it would be difficult to trace its
‘course.

There are two other beaches, at lower levels, left by the lake as
it gradually subsided, owing to the wearing down of its outlet.
These also have been examined by Mr. Upham with somewhat
similar results. Both are found to have a gradual upward slope to
the north, as compared with the surface which a sheet of water would
now have if confined in this valley. The second beach, in the space
of 150 miles, rises about 70 feet with a nearly uniform slope of a
little less than half a foot per mile. While the third or lowermost
beach was found in the course of 135 miles to rise northward to the
extent of 50 feet, and at a later period of the lake’s existence to half
that amount.

Assuming these levellings to be correct, and assuming also that
each of the supposed beaches does actually represent one of the old

1 W. Upham, Lake Agassiz, Bulletin of the Minnesota Acad. of Nat. Science,
vol. ii. p. 290, 1882.

346 T. F. Jamieson—Changes of Level in the Glacial Period.

water-lines at which the surface of the lake formerly stood, we have
here a very interesting question presented to us. How is it that
these old beaches are not now horizontal, but rise gradually as we
follow them to the north? Has the ground risen to the northward
since the lake disappeared, or did the surface of the lake form a
plane which was not horizontal, while the land remained all along
stationary as itis? The latter is the explanation Mr. Upham adopts.

According to the law of gravitation, matter of all kinds exerts an
attractive force in proportion to its mass, and varying inversely as
the square of its distance from the body it attracts. Mr. Upham,
therefore, supposes that the glacier, by virtue of this attractive force,
drew the water towards it, so that the lake rose to a higher level
near the glacier than it did farther off. The northern barrier of the
lake, he says,’ “was the receding Continental glacier. All the
differences of the once (?) level lines of Lake Agassiz from our present.
level-line would be produced by the gravitation of the water of the
lake towards this ice-sheet. At first this attraction had a large effect
upon the lake-level, because of the nearness of a great depth of ice
on the east in Northern Minnesota, and northward in British America ;
but it was gradually diminished to a comparatively small influence
when these ice-masses had been melted and the attracting force pro-
ceeded from the region far north between Lake Winnipeg and Hudson
Bay.”

Whether we can agree with Mr. Upham in this explanation or not,
we are certainly much indebted to him for the discovery of a very
remarkable and interesting fact. Another explanation, however,
may be offered.

If, as some geologists believe,” the outer crust of the earth reposes
at no great depth upon a stratum of mineral matter in a state of
fusion, we may without violence suppose that the addition of a heavy
load upon the surface would cause the crust to press deeper down
into this soft stratum and drive part of it away to where the pressure
was less. Then, if the load was afterwards removed, and the pressure
on the surface thereby relieved, the subterranean fluid or semifluid
matter would tend to return towards the place it formerly occupied,
until an equilibrium of pressure was restored, thus causing the
surface of the depressed tract to rise again. In accordance, there-
fore, with this notion we may conceive that the weight of the great
glacier had caused a depression of the northern region on which it
lay, and that afterwards, when the ice melted, the land, being relieved
from its load, gradually rose again, so that the old beach, which was
formerly horizontal, now presents an upward slope to the north, such
as Mr. Upham has found.?

Both explanations would account for the facts. In either case the
result would be that the old shore of the lake would now rise
towards the place where the glacier formerly existed. To the one
theory it may be objected that it overestimates the attractive force of

1 Joc. cit. p. 313.

2 See O. Fisher, Physies of the Earth's Crust, p. 223, and elsewhere. |
3 See T. F. Jamieson, Grou. Mac. Sept. 1882.

T. F. Jamieson—Changes of Level in the Glacial Period. 3847

the ice, to the other that it overestimates the flexibility of the earth’s
crust. Here both causes operate to produce the same result; but if
we could find a case where we could test the two under conditions
where the results would be different or opposite, then it might be
seen which would prevail.

Such a case would seem to be found in another great lake called
Lake Bonneville, which formerly existed in the salt desert of Utah
during the Quaternary period. This lake arose from achange in the
climatic conditions of that region. Now it is so dry that the water
has evaporated from the greater part of the basin, leaving it a salt
desert; but formerly the precipitation of moisture was so much
greater that the basin was filled by a body of water as large as Lake
Huron, and nearly 1000 feet deep. Here, then, we have a tract of
ground which formerly sustained the pressure of a heavy load of
water that has now disappeared. If the surface of Lake Bonneville
was influenced by the attraction of surrounding masses, its waters.
should have stood highest at their margin, where they adjoined the
mountain ranges which encompassed them, and its shore-lines (which
are still remarkably distinct) ought to find their greatest altitude in
such places. On the other hand, if the land rose in any degree
when the load of water was taken off it, the old beaches should now
be highest towards the centre of the basin where the water was
deepest and the load heaviest. Whereas, at the outer rim of the
lake, where the water was shallow, no material rise might be expected.
This, I think, is a fair inference in regard to both theories. Now,
what do we find ?

According to Mr. G. K. Gilbert,! who has devoted much time and
labour to the exploration of the locality, the answer would seem to.
be decidedly in favour of the latter supposition. There were
numerous islands in this old lake, and its shore-line encircles them
so distinctly that its level can be ascertained not only round the
margin, but also in the midst of the basin. This shore-line is not
now level, but rises higher in some parts than in others. A map
of the lake was made, its shore-lines carefully traced, and the
altitudes marked upon the map. The final result of the whole
survey went to show that the highest parts of the beach lie within
the area of the main body of the lake, while the lowest ones are at
the extreme north and south ends, and the general expression of the
deformation of the surface indicated a low broad dome of elevation
to have taken place, having its crest situated over the centre of the
main body of the lake. The difference of level between the margin
of the main body of the lake and its centre is not less than 100 feet,
but including observations on outlying bays it amounts to 168 feet.
Gilbert, therefore, believes that the bottom of the lake has risen
since the water disappeared, and he seems to think it probable that
the cause of this is to be found in the removal of the load of water
that formerly lay upon it. He discusses two other theories, but finds
them both inadequate to account for the facts.

1 G. K. Gilbert, ‘‘ On the Inculeation of Scientific Method by Example,’’ Amer.
Journ. of Science, vol. 31, April, 1886.

348 C. Davison—Least Age of the Stratified Rocks.

I am far, however, from wishing to lay too much stress on this
-case of Lake Bonneville. Its outline is intricate and extensive, and
it may be that a more exhaustive survey would modify the results
arrived at by Mr. Gilbert. It is quite possible also, as he himself
remarks, that the deformation of the old shores may be due to sub-
terranean movements proceeding from an entirely different cause.
But, so far as the Survey has gone, it certainly fails to show that
there was any notable gravitation of the lake-waters towards the
high mountains on the East, such as might have been expected upon
the hypothesis that a strong attractive force was exerted by these
mountain-masses.

Assuming, for the present, that the bottom of the lake has actually
risen 168 feet in consequence of being relieved from the pressure of
1000 feet deep of water, we may use this result to ascertain what
might be the effect produced by the disappearance of a like depth of
ice. Taking the specific gravity of glacier-ice at 875 as compared
with water at 1000, the result would be arise of 147 feet—or say
in round numbers 150 feet for a thousand feet of ice. This would
agree tolerably well with some of the changes of level that have
been observed in regions formerly occupied by large glaciers.

IV.—On a Meruop or Determrninc A Lower Limit to tHe AGE
OF THE STRATIFIED Rocks.

By CHARLES Davison, M.A.,
Mathematical Master at King Edward’s High School, Birmingham.

THE following is an attempt to determine a lower limit to the

» time required for the accumulation of the stratified rocks. It
is not supposed to be an accurate estimate, for the data on which it
is based are confessedly imperfect ; but it is thought that the method
employed may be of some little use when more exact determinations
can be made of the physical constants involved.

The first part of the method is founded upon the observed fact
that most, if not all, of the stratified rocks, throughout the period of
their formation were deposited in shallow water ; the latter part on
the law of secular cooling deduced by Sir W. Thomson for the case
of a solid earth, though not on the value of the initial temperature
used by him. As a consequence of secular cooling the outer parts
of the earth’s crust are folded by lateral pressure, the rocks above
the troughs gradually subsiding as the troughs of the folds deepen,
by reason of the weight of the rocks, and of the sediment, if any,
deposited above them.

2. The fact that stratified rocks are chiefly shallow-water deposits
indicates that the rate of sedimentation is generally, and on the
whole has been, greater than the rate of subsidence.1 Now, the
sediment brought down by ariver is used: first, for keeping the
level of the delta-surface close to the level of the sea; secondly, for
extending the delta laterally by means of the surplus sediment.

1 The rate of subsidence at any time is here measured with respect to the level of
the sea at that time.

C. Davison—Least Age of the Stratified Rocks. 349

Let V be the number of cubic feet of sediment brought down by
a river every year, and A the area of its delta in square feet. If the
whole of the sediment were spread over the present delta, so as to
keep its surface close to the surface of the sea without enlarging the
area of the delta, the average rate of subsidence would be V — A feet
per year. If, however, as is generally the case, the sediment is.
spread over a larger area, increasing the delta laterally, then the
average rate of subsidence must be less than V~ A feet per year.
Thus, the volume of sediment brought down by a river in a@ year,
divided by the area of the delta, gives a superior limit to the average
rate of annual subsidence in the region of the delta.

As the area of the delta increases, this limit decreases, continually
approaching the true mean rate of subsidence. The true mean rate
would also of course be known, if we could ascertain the amount of
surplus sediment used for increasing the area of the delta, and there-
fore the amount left for keeping the delta-surface in shallow water.

It should be noticed that the mean rate of subsidence is indepen-
dent of the recurrence of glacial periods and of all changes that
may take place in the intensity of the denuding forces. True, in
estimating its superior limit, we have left out of account the materials
derived from littoral erosion and from some volcanic eruptions that
may be swept by currents into the delta-area; but we cannot err
greatly in neglecting them.

As an example, let us take the case of the Mississippi. Dr. A.
Geikie states that the area of its delta is 12,300 square miles, or
342,204,520,000 square feet; and that the volume of sediment
brought down by the river every year is 7,459,267,200 cubic feet.!
Hence, the average rate of subsidence throughout the area of the
delta cannot be greater than 7; of a foot per year, or, more exactly,
2°18 feet per century.

Now, the mean rate of subsidence is not uniform throughout the
whole period of formation of a fold, for it is evidently zero at the
very commencement and also at the epoch when subsidence changes
to elevation, and there may be pauses in the process. But, in
different parts of the earth, there must be folds in different stages of
formation; and the average of the mean rates of subsidence of all
known areas of sedimentation will give the true mean rate of sub-
sidence for the present time. Not having the necessary data, how-
ever, for river-deltas other than that of the Mississippi, we may
assume the highest value of the mean rate of subsidence at the
present time to be xs of a foot per year, which, it is worth noticing,
is of the same order of magnitude as the estimated rate of elevation
of the north coast of Scandinavia.

3. The mean rate of subsidence over the whole earth has not,
however, been uniform throughout geological time; and it remains
for us to determine, as nearly as we can, the law according to which
it changes. This, I believe, it is possible to do, if we accept the
hypothesis of a solid globe cooling from a high initial temperature.
In a paper lately read before the Royal Society, I have shown that.

1 Text-book of Geology, pp. 389, 444.

350 C. Davison—Least Age of the Stratified Rocks.

the following laws are very nearly true, and that they do not depend
on the initial temperature of the earth (except in so far as the rate
of conductivity of rock may vary with the temperature) :—

(a.) Folding by lateral pressure takes place only to a limited
depth from the earth’s surface, below this depth giving place to
stretching by lateral tension; and the depth at which folding
changes to stretching varies directly as the square root of the time
since consolidation. Also, the rate at which the unstrained surface
recedes from the surface of the earth varies inversely as the square
root of the same time.

(b.) The total amount of rock folded in any given interval also
varies inversely as the square root of the time since consolidation.*

On both accounts, then, it would seem probable, though not, it
should be remembered, actually proved, that the mean rate of sub-
sidence, due to folding by lateral pressure, should vary according to
the same law.

Assuming this to be the case, let the total amount of subsidence

in z years be « feet, so that = measures the rate of subsidence at

the time t. Also, let a feet be the average thickness of the stratified
rocks deposited throughout geological time, and 7 years the time
required for its deposition.
Then, S = — , Where X is a constant; and # = 2A1/#, no
constant of integration being required, for x and # vanish together.
dx 1
But, when t = T, we have « =a, and “el =a eee
the mean rate of subsidence at its highest value ;

taking

so that v= ye

4G”
: = Vr ee :
23 23
i man

If we knew the average thickness of the sediment deposited
throughout the whole of geological time, the value of T obtained
from the last equation would give a lower limit to the length of
time required for the formation of the stratified rocks; but unfor-
tunately, the necessary data are not to be had. The maximum
thickness of the sedimentary rocks has, however, been estimated by
Dr. 8. Haughton and Prof. E. Hull, at 177,200 feet; and I cannot
think we shall be far wrong if we take this as the average thickness

1 On the Distribution of Strain in the Earth’s Crust, resulting from Secular
Cooling; with special reference to the Growth of Continents and the Formation of
Mountain Chains,” read May 5, 1887.

i ee ee

Dr. C. Callaway—Parallel Structure in Rocks. 351

of the sediment deposited within the limited delta-areas,’ remember-
ing:—(1), that all stratified rocks are largely formed from the
denudation of those previously existing, and (2), that there may
have been intervals between successive geological periods represented
by formations now unknown to us or not included in the above
estimate.

Putting, then, a = 177,200 feet in the last equation, we find
T = 23 x 177,200 = 4,075,600 years,

i.e. just half what it would have been had the rate of subsidence
been uniform and equal to the rate at the present time.

But, if we may have over-estimated the average thickness of the
stratified rocks, we have, on the other hand, taken a superior limit
to the rate of subsidence. Also, in the above calculation, it was
supposed that sedimentation, like subsidence, began as soon as the
earth solidified ; whereas, it is possible that a considerable interval
elapsed, thereby postponing the formation of the stratified rocks to
a time when the rate of subsidence was slower than at first.

We may conclude, therefore, on both accounts, that for the formation
of the sedimentary rocks a time is required of not less than four
million years, and possibly of a period very much longer than this.

V.—On PaRaAttet Structure IN Rocks AS INDICATING A SeEpI-
MENTARY ORIGIN.

By Cu. Cattaway, D.Sc., M.A., F.G.S.

GNEOUS rocks and crystalline schists are often associated with
each other in such a manner as to compel the conclusion that
either the igneous rocks have been formed out of the schists or the
schists out of the igneous rocks. There are other cases in which the
two kinds of rock are less intimately related; parallel structure is
wanting, the junctions are sharply defined, and there is no evidence of
an original mineral gradation. These are examples of the ordinary
irregular intrusion of igneous rocks in schists. But there is a third
group in which the characters are intermediate. In these rocks,
structural parallelism is more or less distinct, and there is often a
partial blending of the two kinds of rock at the line of contact ;
but other indications forbid the belief that the schists have been
elaborated out of the associated igneous masses. The question then
arises: Are we here dealing with cases of intrusion, or are we
driven to conclude that the igneous rocks have resulted from the
fusion of schists? The answer to this question has obviously an
important bearing upon the genesis of the crystalline schists.

The conversion of schists into granite and the like is maintained
by the officers of the Geological Survey of Ireland,” and I have dealt
with their evidence in a paper published in the Journal of the

1 Dr. Croll has very clearly shown that there may be a considerable difference
between the maximum and average thicknesses of a formation; but it will be
remembered that he calculated the average over a belt 100 miles broad round the

whole coast-line.—Gzon. Mac. 1871, Vol. VIII. p. 101.
2 Survey Memoirs, Nos. 93, 94, 95, 104, 105, 113, 114, passim.

302 Dr. C. Callaway—Parallel Structure in Rocks—

Geological Society, and in a second communication read before the
Society on the 6th of April last. My contention is that in the dis-
tricts examined there is no gradation whatever between schist and
granite; but that, on the other hand, the igneous rocks frequently
acquire a foliated structure. My chief object in writing, however,
is to call attention to a series of articles by Prof. J. D. Dana, which
appeared in this Macazine* in 1881. These papers deserve special
notice, not only for the interest of the facts described, but because
they present the case for the sedimentary origin of igneous rocks
with exceptional force.

Prof. Dana’s theory is expressed in the title of his memoir :—
‘On a Case in which various massive Crystalline Rocks including
Soda-Granite, Quartz-Diorite, Norite, Hornblendite, Pyroxenite, and
different Chrysolitic Rocks, were made through Metamorphic
Agencies in one Metamorphic Process.” The district described is
in the township of Cortland, to the north of New York City, and
lies on both sides of the River Hudson. Associated with the above- .
named plutonic rocks are gneiss, mica-schist, and limestone. Minute
details of the various rocks are unnecessary for my present purpose.

The argument of Prof. Dana is arranged under the following
heads :—

“1. Hvidences of more or less Complete Fusion.”’—The evidence in
this section simply goes to prove that the igneous rocks have ecrystal-
lized from a state of fusion. So far from affirming a passage between
these and the schists, the author states that at Cruger’s Point, ata
junction between schist and soda-granite, the former “bears evidence
of partial fusion and exhibits other contact-phenomena.” If there
are ‘“contact-phenomena,” there cannot be a gradual transition.

“2, Evidences as to Condition of Fusion.’”’—Were these rocks fused
in situ, or were they erupted from below? Prof. Dana considers
that in the former case the results of fusion “are likely to vary at
comparatively short intervals, because sedimentary beds often vary
thus.” ‘Sediments .. . are liable to frequent and sudden changes
as to material, which igneous outflows cannot imitate.” Here I
must distinctly join issue with Prof. Dana. Some of the banded
gneisses of the Malvern Hills show alternations of different kinds of
mineral matter as ‘‘frequent and sudden” as of any sedimentary
strata in the world. Thin red seams in a black groundmass form
a banding as clear and vivid as the stripes in the American flag.
But the seams are granite and the groundmass is diorite, and the
rock with this parallel banding passes, sometimes abruptly, into
ordinary diorite with irregular veins of granite. In illustration of
the singular way in which igneous rocks mimic sedimentaries, I
may refer to the so-called “conglomerates” * in the crystalline
region west of Galway. Granite veins, intruded into jointed diorites,
have lapped round and enclosed joint-blocks in such numbers as to
suggest the inclusion of pebbles in sediment. Where the rocks have

1 May, 1888, p. 221.

2 Feb. p. 59; March, p. 110; April, p. 162.
3 Described in my paper read before the Geological Society on April 6th.

As Indicating a Sedimentary Origin. BBs)

been exposed to regional pressure, there is produced a rough paral-
lelism amongst the fragments, and this enhances the sedimentary
appearance.

“3. Special Facts from the Cortland Region.”—I shall confine
myself to the essential points, omitting those which, though not
irrelevant, would count for little if my main contentions are sustained.

Some interesting contact-phenomena are seen near Cruger’s Point
(p. 114). The mica-schist towards the north comes to an end against
soda-granite and quartz-diorite. Approaching the igneous rocks,
the schist “becomes increasingly staurolitic and garnetiferous, and
passes in places into a true gneiss.” Pari passu with this mineral
change, the schist becomes more and more contorted, and is “inter-
laminated with nodose-lines of quartz, vein-like in origin.” At
the junction, “the schist is mostly a garnet rock containing much
fibrolite and staurolite, and the latter is in some places granular-
massive ina small way. Just below the granite, the layers are a
compact body of flexures, and in the soda-granite’ there is another
flexed layer rather faintly indicated.”

Assuming the accuracy of Prof. Dana’s data, which I am doing
throughout this paper, I find myself unable to accept his inferences.
He considers that the phenomena just described confirm his theory ;
but, with deference to the opinion of so eminent a scientist, I venture
to maintain that they more justly fit the theory of intrusion. It is
not unusual for schists to undergo increased contortion at the contact
with a large intrusive mass. I have described cases of this in my
paper on Donegal.? This fact suits me quite as well as Prof. Dana.
The production of secondary minerals I have also noticed at and
near the contact of granite and schist (loc. cié.). The composition of
these minerals would of course depend upon the composition of the
surrounding masses, but at Dunlewy one of the contact-minerals
was “allied to kyanite,” and therefore not far removed from stauro-
lite. Heated waters, soaking through granite or schist, could hardly
fail to give rise to chemical changes in the other rock, and these would
under favourable conditions reach to a considerable distance from
the line of contact. Mica-schist could obviously cause little change
in other rocks; but the felspar and hornblende in the granite and
diorite would readily furnish materials for the production of such
minerals as kyanite, staurolite, and some garnets. The abundance
of quartz-veins tells strongly in favour of my view, the silica set
free in the genesis of the basic minerals being redeposited.

The ‘flexed layer rather faintly indicated” demands special atten-
tion. According to Prof. Dana, it is a bed which originally “approached
somewhat the granite in character, but which, owing to the nature
of its material, was not wholly obliterated.” To the enquiry whether
such masses may have been fragments of schist entangled in the
granite, Prof. Dana replies that “they lie so conformably to the
flexures of the” main body of “schist as to suggest a negative reply.”
He rightly attaches great importance to this parallelism of strike,

1 The italics are Professor Dana’s.
? Quart. Journ. Geol. Soc, May, 1885, pp. 225, 226.
DECADE Il.—vVOL. 1V.—NO. VIII. 23

304 Dr. C. Caliaway—Parallel Structure in Rocks.

He sees that it is the key of his position. Referring (p. 163) to
certain masses of schist in granite, he says :—“‘ Since it is obviously
impossible that the inclusions taken in and carried up by rocks
erupted through deep fissures should be beds of schist 100 to 200
feet long, and a series of such beds separated by the fused rock
retaining together their parallel position, we have to admit that these
indications of bedding are of unobliterated! bedding.”

In the year of the publication of these views (1881), I first saw
the tremendous Highland earth-thrusts, and every succeeding season
has taught me more of the wonderful results of earth-pressures.
Other workers have been under instruction in the same school; so
that some things which seemed impossible in 1881 have, in 1887,
become not only possible, but credible. In the light of recent dis-
covery, I venture to suggest that the parallel structure described by
Prof. Dana is susceptible of explanation on the theory of intrusion.
Igneous rocks forced upwards by tangential pressure would neces-
sarily follow the lines of least resistance. ‘These lines might be
planes of cleavage or jointing, or, in the case of some schists, seams
of soft mineral matter, such as mica or chlorite. We are here con-
cerned with mica-schists, in which we should naturally expect
intrusion to correspond with foliation. From this consideration
alone, it would therefore seem that the strips of schist lying between
intrusive bands would be approximately parallel. But we have not
taken into account the horizontal pressure. This cause would pro-
duce parallelism even if it did not previously exist. It would
compel flattened fragments, lying pell-mell in a plastic ground-mass,
to arrange themselves in planes parallel to each other. The size of
the fragments would be quite immaterial. The forces which, in the
North of Scotland, sent a mass as large as the County of Rutland
sliding up-hill for more than a mile, would take small account of
little strips, “100 to 200 feet long,” lying immersed in a granitic
magma.

But I am not indulging in mere speculation. In Donegal, I often
saw outlying masses of schist immersed in granite, and in some
districts their foliation was regularly parallel to the foliation of the
region. In these cases, Prof. Dana’s theory was clearly inapplicable ;
for the junctions between schist and granite were quite sharp, and
the mineral variations sometimes observed at junctions indicated, not
a gradation of conditions, but contact alteration. Similar cases were
also seen in Connemara. Even in hand-specimens, the parallelism
of mineral folia was conspicuous; but, under the microscope, the
boundaries of the schist-fragments were perfectly defined. Con-
siderable changes, however, had been produced in the enclosing
granite, secondary mica and other minerals having originated at the
junctions.

Many other points of great interest are discussed in Prof. Dana’s
papers; but some are not essential to my argument, and others are
hardly ripe for adequate debate.

1 The italics are Prof. Dana’s.

A. Smith Woodward—New Miocene Fish from Malta. 355

VI.—On a New Spercies or Hozocenrruu From tHe Mi0cEnE
oF Matra; wits a List or Fosstz Berycipm HITHERTO
DEscRIBED.

By A. Smira Woopwarp, F.G.S., F.Z.S.,
of the British Museum (Natural History),

ERY little information has hitherto been published in regard to
the fossil fishes of the well-known Miocene formation of the
Maltese Islands. Dr. Leith Adams enumerates! seventeen species
in his latest contribution to the subject, but these are almost exclu-
sively founded upon detached teeth. It is, therefore, of considerable
interest to be able to place on record the discovery of a new and
tolerably complete fish, obtained from an excavation made some
months ago for new docks in the harbour of Valetta.

The fossil in question has lately been received by the British
Museum from the Marquis of Lorne, who is of opinion that it was
derived from a horizon referable to division No. 4 of the section
described in Leith Adams’ “ Notes of a Naturalist in the Nile Valley
and Malta,” p. 138. The right side of the fish is exposed to view,
showing the general outline of the body ; and its salient features are
sufficiently well displayed to allow of its certain determination.
Unfortunately, however, the bones of the head and pectoral arch are
almost entirely broken away ; and the right pectoral fin is likewise
destroyed, while the left remains inextricably buried in the matrix.
One of the pelvic fins, and the right “pelvic” bone, are beautifully
preserved. The caudal fin is equally well shown, and the dorsal
and anal, though somewhat mutilated, are also recognisable. For
a small extent anteriorly, there is a good view of the external surface
of the scales of the right side, but posteriorly both the scales of
this side and the axial skeleton are removed, so that the left dermal
covering is extensively exposed from within.

The specimen must have originally measured about 0:33 m. in
total length, and its greatest depth, beneath the anterior part of the
dorsal fin, is 0:125m. The deep, laterally compressed body rapidly
narrows posteriorly, leaving a long caudal pedicle, which commences
just behind the termination of the dorsal and anal fins, and is about
0:04 m. in length.

Proceeding to the more technical points, there is nothing worthy
of note in the axial skeleton, which has mostly been destroyed. Of
the appendicular skeleton, the right “ pelvic” bone may be observed :
it is very robust, gradually widening proximally, and exhibits a pro-
minent median longitudinal rising on its exterior lateral aspect.
Correspondingly robust is the pelvic fin. The most anterior ray is
a strong spine, sharply pointed at the extremity, and marked by
well-defined, more or less obliquely placed ribs. This is followed
by seven, or perhaps eight, equally powerful rays, similarly orna-
mented at their base, but divided distally.

Of the median fins, the dorsal seems to have been divided into two

1 A. Leith Adams, ‘‘ On Remains of Mastodon and other Vertebrata of the Miocene
beds of the Maltese Islands,’’ Quart. Journ. Geol. Soc, xxxv. (1879), pp. 527-529.

856 =A. Smith Woodward—New Miocene Fish from Malta.

portions, the anterior being the longer and spinous, the posterior con--
sisting entirely of soft rays. ‘The spines are remarkably stout, orna-
mented with oblique ridges, and diminishing backwards; and at
least six are preserved, though appearances are suggestive of others:
having been broken away in front. Of the soft rays, seven can
be distinguished, and these were evidently succeeded by a few
more now slightly indicated. Both parts of the fin are compara-
tively low, but the soft rays originally exceeded the height of the
spinous portion. The anal fin is only shown partially, and as a faint
impression. Anteriorly there are traces of powerful ribbed spines,
supported upon strong interspinous bones, and these are succeeded
by at least ten other rays, probably all soft and divided. The total
length of the fin is 0:06, and it seems to terminate exactly opposite
the posterior extremity of the opposing dorsal. At the base of the
caudal fin, both above and below, there are two or three small
smooth spines; and in each half of the fin, which is but slightly
forked, there are thirteen dichotomous rays, which become closely
jointed and commence to branch near the base, ending in very
delicate terminal filaments.

Impressions of opercular bones show that these were ornamented
to some extent with fine ridges, and small backwardly-directed
spines; and the exposed enamel-like surface of each scale is marked
anteriorly by a slight rugosity, passing behind into radiating furrows,
with intervening ridges, which terminate in the points of the ctenoid
border. The scales are very large and thick, having a vertical.
measurement, in the front portion of the body, of 0-:025—0-028, and
a total breadth of 0-012. They are deeply overlapping, the covered
surface being destitute of the enamel layer, and exhibiting delicate
concentric lines of growth.

Such being the main characters of the fossil, it remains to deter-
mine its systematic position.

The nature of the dorsal and anal fins, and the situation of the
pelvics, are features at once referring the fish to the Acanthopterygian
suborder. The relations of the median fins, moreover, and the
presence of more than five divided rays in each of the pelvic pair,
indicate its affinities still more precisely, and prove it to belong to
the family of Berycide.

The characters of the dorsal fin determine, further, the generic
position of the fish. The separation of the spinous portion of the
dorsal from the soft portion, is a feature only met with in two known
genera of the family in question, namely, Myripristis and Holocentrum.
From the former, the Maltese fossil differs in having the two.
divisions more closely approximated, and in this respect it agrees
exactly with Holocentrum. Its general aspect, also, is very suggestive
of the latter genus, and the impression of the anal fin may well be —
interpreted as showing a great development of the third spinous.
ray. We may, therefore, safely conclude that we are dealing with
a Miocene representative of this well-known surface fish of the
present tropical seas.

With regard to specific’ characters, a careful comparison soon

A. Smith Woodward—New Miocene Fish from Malta. 357

reveals a divergence from all the forms of Holocentrum as yet known.
Only one extinct species appears to have been hitherto described,
namely, the little H. macrocephalum, de Blainv. (=H. pygmeum, Ag.),
from the Hocene of Monte Bolca, near Verona. This is readily
distinguished by its more elongated shape, relatively smaller scales,
and the presence of a large spine in advance of the soft rays in the
posterior division of the dorsal fin. Twenty-four of the twenty-six
‘recent species enumerated by Dr. Gtinther ' are also separated, among
other characters, by the greater elongation of the body and the
relatively smaller size of the scales; and the remaining two short-
bodied types—H. spinosum and H. retrospinis, from West Indian
seas—though very similar in proportions, and apparently with a
corresponding opercular armature, have much more strongly serrated
scales, and are of considerably smaller dimensions. It is proposed
accordingly to designate the Maltese species H. melitense.

In conclusion, it may be of value to append a list of the fossil
‘Berycidee hitherto described. Since the earlier works, numerous
emendations and additions have been made to our knowledge of the
subject, and some genera and species at first supposed to be rightly
placed with this family, are now known to be truly referable to
other groups. The determinations here enumerated are such as are
adopted in the latest memoirs, and to each species is added the name
of the formation and country or district whence the type-specimen
was obtained.

ACROGASTER, Agassiz.
brevicostatus, v. der Marck, Palontogr. vol. xi. p. 24, pl. 7, fig. 2.
Cretaceous, Westphalia.
minutus, v. der Marck, ibid. p. 23, pl. 7, fig. 1. Cretaceous, Westphalia.
parvus, Ag., Rech. Poiss. Foss. vol. iv. p. 134, pl. 17, fig. 2. W. v. der
Marck, Paleontogr. vol. xi. p. 23. Cretaceous, Westphalia.
Berycorsis, Dixon.
elegans, Dixon, Geol. and Foss. Sussex (1850), p. 372, pl. 35, fig. 8.
Cretaceous, England.
Brryx, Cuvier.
dalmaticus, Bassani (Steindachner), Denkschr. Math.-Naturw, Cl. kais.
Akad. Wiss., vol. 45 (1882), p. 70. Originally described in error as
obtained from the Isle of Lesina, under the name of B. Jesinensis,
Steind., Sitzb. kais. Akad. Wiss. vol. 47 (1863), pt. 1, p. 128, pl. 1.
fig. 1. Cretaceous, Dalmatia.
dinolepidotus, Fischer de Waldheim, Bull. Soc. Imp. Nat. Moscou, 1841.
p- 465, pl. 8. Cretaceous, Russia.
insculptus, Cope, Proc. Amer. Phil. Soc. 1869, p. 240; and ‘‘ Vert. Cret.
Form. West,’’ 1875, pl. 52, fig. 4. Cretaceous, United States.
lewesiensis: Zeus lewesiensis, Mantell, Geol. Sussex, 1822, p. 234, pls. 35,
36. Beryx ornatus, Ag. op. cit. iv. p. 115, pl. 14a; pl. 144, figs. 1
and 2; pl. 14e, figs. 1-6; pl. 14d. Also Dixon, op. cit. p. 871, pl. 36,
fig. 3; pl. 34, figs. 1, 4 and 5. Cretaceous, England.
microcephalus, Ag. op. cit. iv. p. 119, pl. 14, figs. 3-6; pl. 14e, fig. 10.
Dixon, op. cit. p. 372, pl. 34, fig. 3. Cretaceous, England.
ovalis, J. W. Davis, Trans. Roy. Dublin Soc. [2] vol. iii. 1887, p. 508,
pl. 27, fig. 4. Cretaceous, Lebanon. }
radians, Ag. op. cit. iv. p. 118, pl. 144, fig. 7; pl. 14c. figs. 7-9. Dixon,
op. cit. p. 371, pl. 36, fig. 4. Cretaceous, England.
subovatus, Bassani, Denkschr. Math.-Naturw. Cl. kais. Akad. Wiss. vol. 45
(1882), p. 34, pl. & fig. 4. Cretaceous, Isle of Lesina, Dalmatia.

1 A. Gunther, Cat. Fishes Brit. Mus. vol. i. pp. 28-60.

358 A. Smith Woodward—New Miocene Fish from Malta.

BERYx vexillifer, Pictet, Poiss. Foss. M. Liban, 1850, p. 8, pl. 1, fig. 1. Pictet
et Humbert, Nouv. Rech. Poiss, Foss. M. Liban, 1866, p. 30, pl. 2,
figs. 1-3. Cretaceous, Lebanon.

Honocentroum, Artedi.

macrocephalum, de Blainville, Nouv. Dict. d’Hist. Nat. vol. 27 (1818),

p- 849. HH. pygmeum, Ag., op. cit. iv. p. 107, pl. 14; pl. 16, fig. 1.
Hocene, Monte Bolea, Verona.
melitense, A. S. Woodw., 1887. Miocene, Malta.
Homonorus, Dixon.
dorsalis, Dixon, op. cit. p. 372, pl. 35, fig. 2. Cretaceous, England.
pulcher, Davis, loc. cit. p. 519, pl. 25, fig. 3. Cretaceous, Lebanon.

HopiLopreryx, Agassiz.

antiquus, Ag. op. cit. iv. p. 181, pl. 17, figs. 6-8. W. v. der Marck,
Paleontogr. xi. pp. 18, 14, pl. 1, fig. 4; pl. 2, fig. 1; cbid. xxxi.
p. 243. Cretaceous, Westphalia.

gibbus, y. der Marck, Paleeontogr. xi. p. 15, pl. 1, figs. 5, 6. Cretaceous,
Westphalia.

oblongus, Davis, loc. cit. p. 515, pl. 25, fig. 1. Cretaceous, Lebanon.

spinosus, Davis, loc. cit. p. 516, pl. 28, fig. 1. Cretaceous, Lebanon.

superbus, Davis, loc. cit. p. 514. Beryx superbus, Dixon, op. cit. p. 372,
pl. 36, fig. 5. Cretaceous, England.

syriacus, Davis, loc. cit. p. 514. Beryx syriacus, Pictet et Humbert, op.
cit. p. 28, pl. 1. Cretaceous, Lebanon.

Zippei, Davis, loc. cit. p. 514. Beryx Zippei, Ag. op. cit. iv. p. 120,
pl. 15, fig. 2. Reuss, Verst. bohm. Kreideform. 1845, pt. 1, p. 12,
pl. 1; pl. 2, fig. 1. Fritsch, Rept. u. Fische bohm, Kreideform. 1878,
p. 41, pl. 5, fig. 1. Cretaceous, Bohemia.

Myrtpristis, Cuvier.

homopterygius, Ag. op. cit. iv. p. 112, pl. 15, fig. 3. ocene, Monte
Bolca, Verona.

leptacanthus, Ag. op. cit. iv. p. 111, pl. 15, fig. 4. Eocene, Monte Bolea,
Verona.

PristiGENYS, Agassiz.

macrophthalmus, Ag. op. cit. iy. p. 186, pl. 18, fig. 2, Eocene, Monte
Bolea, Verona.

PsEupoBERYX, Pictet et Humbert.

Botte, Pict. et Humb. op. cit. p. 34, pl. 2, fig. 7. Cretaceous, Lebanon.

grandis, Davis, loc. cit. p. 510, pl. 28, fig. 4. Cretaceous, Lebanon.

longispinus, Davis, loc. cit. p. 511, pl. 25, fig. 2. Cretaceous, Lebanon.

syriacus, Pict. et Humb. op. cit. p. 33, pl. 2, figs. 4-6. Cretaceous,
Lebanon.

SPHENOCEPHALUS, Agassiz.

cataphractus, v. der Marck, loc. cit. xi. p. 18, pl. 8, fig. 1; pl. 7, figs.
3-5. Oretaceous, Westphalia.

Jissicaudus, Ag. op. cit. iv. p. 129, pl. 17, figs. 8-5. W.v. der Marck, doc.
cit. Xi. p. 17, pl. 3, fig. 2. Cretaceous, Westphalia.

Srenostoma, Dixon.

pulchella, Dixon, op. cit. p. 373, pl. 36, fig. 2. Cretaceous, England.

Among other forms originally included in the Berycide may be
particularly mentioned the genera Platycormus, Acanus, Podocys, and

Rhacolepis. The type-species of the first of these was described by

Agassiz under the name of Beryx germanus, and removed to the

Squamipinnes, in 1858, by W. von der Marck,’ under the new

generic title. The most recent researches upon Acanus and Podocys’

1 W. v. der Marck, ‘“‘ Ueber einige Wirbelthiere, Krusten, und Cephalopoden der

Westfalischen Kreide,’’ Zeitschr. deutsch. geol. Gesell. vol. x. 1858, p. 251. See

also papers in Paleeontographica, vols. xi. XV. XXX1.

2 A, Wettstein, ‘‘ Ueber die Fischfauna des Tertiaeren Glarnerschiefers’’? (Mém.
Soc. Pal. Suisse, 1886), pp. 62, 69. ,

Prof. von Ettingshausen—Australian Tertiary Flora. 359

appear to show that the first is a true Percoid, and the second
probably the same; while there can be no longer any doubt that
Rhacolepis is a physostomous fish, having its nearest living ally in
the clupeoid genus Elops.' It may also be added that Beryx niger,
Costa,? from the Cretaceous of Mount Lebanon, is undoubtedly a
Pycnosterina.®

VII.—On tar Tertiary Fiora or AUSTRALIA.

By Dr. Constantin Baron von Hrrinesuausen, F.C.G.S.,
Professor of Botany, University of Graz, Austria.

R. C. §. WILKINSON, Government Geologist for New South
alu Wales, had the kindness to entrust his collection of Australian
Tertiary plant-remains to me, for which I now express my most
sincere thanks to him. I laid the results of my investigations before
the Imperial Academy of Sciences of Vienna, in a Memoir, entitled:
“Contributions to the Tertiary Flora of Australia, Part II.,” which
- follows a Memoir already published under the same title, Part I., in
the forty-seventh volume of the “ Denkschriften” of the same
Academy.

It is highly satisfactory to me that the general results I obtained
from my first efforts were not alone strengthened, but materially
completed by the second Part. The 128 species of fossil plants
described and figured in it mostly come from Vegetable Creek, near
Emmaville, in New England, N.S. W. ‘Twenty-one species have
been collected from Elsmore, and only five species from Tingha, in
New England. Mr. Wilkinson, who has examined these localities,
referred them to the Lower Tertiary formation. The species are
distributed into 86 orders and 72 genera. Of the former 35, and of
the latter 52, are also represented in the Tertiary Flora of Europe.
Respecting the principal sections of the Vegetable Kingdom the
Cryptogame contain 2 species, the Gymnosperme 12, the Monoco-
tyledons 2, the Apetale: 56, the Gamopetale 11, and the Dialypetale
40. Of the orders represented by several species, the Proteacez
contain 20 species, the Cupulifere 14, the Conifere 11, the Myrtacezs
10, the Laurinez 7, the Leguminose 6, whereas the Morez, Apocy-
nacez, and Celastrinez contain 5 species each.

The results respecting the character of the Flora confirm Mr.
Wilkinson’s statement. We cannot find any reason for supposing
the above-named localities to be different in age. It is at first
sight evident that the character of their flora (especially of that
of Vegetable Creek and of Elsmore) deviates strikingly from the
character of the living Australian Flora. According to the latter
difference, which indicates a greater divergence of age between both
these floras, as well as regarding the close relationship of some

1 Smith Woodward, ‘“‘On the Fossil Teleostean Genus Rhacolepis,’ Proc. Zool.
Soc. June 28rd, 1887.

2 O. G. Costa, “‘ Descrizione di alcuni Pesci fossili del Libano,’? Mem. R. Acad.
Sci. Napoli, vol. ii. 1855, p. 100, pl. ii. fig. 1.

3 Pictet and Humbert, ‘‘ Nouv. Rech. Poiss. Foss. Liban,’’ p. 43.

360 Prof. von Kittingshausen—Australian Tertiary Flora.

of the species to those of the Eocene and of the Cretaceous period,
we may conclude that the Fossil Flora described in the above-men-
tioned memoir might be referred to the Lower EHocene. vi

When we take into consideration only those fossil species which
are represented by fruits, seeds, and characteristic forms of leaves, —
we obtain new and sufficient proofs concerning the view which I
have brought forward in the first part of these contributions, that
the elements of the floras are mixed together in the Tertiary Flora
of Australia. These proofs consist of facts relative to the common
appearance of the genera endemic in Australia with genera we find
represented in other floras, but which are strange to the Australian
one. For example, there occur in the Fossil Flora of Vegetable
Creek and Hlsmore the following genera of the Australian: element:
Phyllocladus, Casuarina, Santalum, Persoonia, Grevillea, =Hakea,
Lomatia, Banksia, Dryandra, Callicoma, Ceratopetalum, Pomaderris,
Boronia and Eucalyptus. On the other hand we find here, intermixed
with the former, types belonging to: Sequoia (California), Myrica
(Europe, North America, Asia, South Africa), Alnus (Northern
Hemisphere), Quercus (Northern Hemisphere), Cinnamomum (Asia),
Sassafras (North America and Hast India), Aralia (North America,
Japan and New Zealand), Eleocarpus (Tropical Asia), Acer (Northern
Hemisphere), Copaifera (Tropical America). In Part I. of the
Contributions quoted above I have already stated that the elements
of the floras are united not only in the Tertiary Flora of Hurope, of
the Arctic Regions, of North America and of Australia, but also in
the Tertiary Floras of the other portions of the globe. The above-
mentioned facts confirm this even more strongly. Besides, 1 am
able to state the same result from facts which I obtained by examin-
ing the Tertiary Flora of New Zealand, with collections of which
Prof. (now Sir) Julius von Haast and Prof. T. J. Parker have kindly
forwarded to me}

There is now scarcely any doubt that the general character of all
Tertiary Floras of the globe is one and the same in regard to the
mixture which they exhibit, and continued so until the separation of
the elements of floras into the existing special floras towards the
commencement of the present period.

The relationship of all the Tertiary Floras of the globe to one
another is based upon the common elements of floras. The com-
parison of the Australian Tertiary Flora to the European one shows
at once not only many orders and genera which are common to both,
but also many species of the one are more or less corresponding to
species of the other. For example the following species are closely
related ; Callitris prisca is closely related to C. Brongniarti, Sequoia
Australiensis to 8. Langsdorfii, Podocarpus pre-cupressina to P. elegans,
Casuarina Cookii to C. sotzkiana, Alnus MacOoyi to A. Kefersteinii,
Quercus Wilkinsoni to Q. chlorophylla, Q. Hartogi to Q. drymeja, Fagus
Benthami to F. Feronie, Ficus Gidleyi to F. arcinervis, F. Solanderi to

1 A Notice of the Paleo-Botanical Investigations of the Fossil Flora of New
Zealand will follow.

Prof. con Ettingshausen—Australian Tertiary Flora. 361

F, Reussii, F. Willsit to F. Jynx, Cinnamomum polymorphoides to C.
polymorphum, C. Leichardtiit to C. spectabile, C. Nuytsti to C. lanceo-
latum, Grevillea proxima to G. heringiana, Banksia Lawsoni to B.
Deikeana, B. Hovelli to B. heringiana, B. myricefolia to B. Ungeri,
Dryandra Benthami to D. acutiloba, Callicoma primeva to C. panno-
nica, Ceratopetalum MacDonaldi to C. bilinicum, Eleocarpus Muellert
to EH. Albrechti, Acer sub-productum to A. trilobatum, A. sub-integri-
lobum to A. integrilobum.

I have selected the following few from among numerous new
forms, as possessing greater interest. A remarkable Anomozamites-
species, related to an Anomozamites of Greenland, indicates some
affinity of the flora to that of the Cretaceous period. Heterocladiscos,
a Cupressinea, shows dimorphous branchlets, the primary ones being
cylindrical, their leaves lanceolate, close to one another in spiral
order; the secondary ones being four-edged and their leaves rhom-
boidal-ovate, imbricate and set in four rows. Thus this remarkable
plant combines the facies of Glyptostrobus with that of Thuites
Mengeanus, a Cupressinea from the amber. Most remarkable is the
appearance of Pseudo-Pinus, a representative genus of Pinus, which
perhaps might be even a subgenus of Pinus. Cones, seeds, leafed
branchlets, rachis of branchlets and single leaves have been found at
Vegetable Creek. The cones are smaller than those of any living
Pinus-species. The size and form of the leaves, as well as their arrange-
ment, and the shape of the branchlets, remind us of Pinus canadensis.
Besides Phyllocladus two separate genera bearing phyllodes also
occur at Vegetable Creek, Palgzocladus, the primary branchlets of
which are also phyllodineous, and Ginkgocladus, a genus common also
to the fossil flora of New Zealand, and combining the facies of
Phyllocladus with that of Ginkgo. A Sassafras-species has affinity
to Cretaceous species as well as to an Hocene one of the Huropean
Tertiary Flora, and points to an early state of the Tertiary Flora to
which our flora belongs. The same fact may be admitted respecting
some Aralia-species. Hxamples regarding the attachment of our
(Australian) flora to that of the Cretaceous period appear, however,
to be only isolated when we take into consideration its numerous
analogies to known Tertiary plants. Diemenia, a peculiar genus of
Laurinez, uniting the facies of Cinnamomum with that of other
Laurinez (Laurus, Persea), occurs in Hlsmore, where two species
have been collected.

Besides Proteaceze showing their Australian type, the appearance
of Rhopala, a genus of tropical America, is remarkable. It is repre-
sented in the beds of Vegetable Creek by two species. Not less
worthy of note is the appearance of Banksia-types exhibiting leaves
which are acuminate at their apex, and thus are closely allied to the
Banksia-species of the Huropean Tertiary Flora. Two species of
Boronia, an Australian genus, have been found, one of which unites
distinctly the characters of two living species. Doubtlessly they
have been differentiated from this ancestral species. A calyx in
some degree corresponding to those of Getonia of the European
Tertiary Flora possesses a special interest.

3862 Prof. von Ettingshausen—Australian Tertiary Flora..

It may be worthy of notice that Fagus, distributed over both
Hemispheres, is represented in Vegetable Creek not only by types of
the Southern, but also by one of the Northern Hemisphere. Whilst
the former, belonging to the section Notofagus, exhibits coriaceous and.
persistent leaves, the latter closely corresponds to Fagus ferruginea,
a species of. the section Hufagus, bearing membranaceous and
deciduous leaves. In accordance with these facts the representation
of Quercus in the Tertiary Flora of Australia might be considered
not less interesting. ‘They have collected in Vegetable Creek leaf-
fossils of Quercus, belonging to species which are analogous to species
now living in North America, in Mexico, on Lebanon, in Hast India,
in Japan, and in the Isle of Hong-kong. Whilst types of Fagus are
still existing in the present flora of Australia, those of Quercus seem
to be quite extinct there.

Although the Tertiary Flora of Australia deviates very much from
the living one, we find numerous points of connexion between them.
A species of Callitris closely approaches the C. robusta, R. Brown ;
a Dammara-species is very near to D. australis, Lamb.; a Phyllocladus-
species, which on one side unites the characters of all the three living
ones, is allied on the other side to types of Mesozoic, especially
Cretaceous floras; the genera Casuarina, Santalum, Boronia, Huca-
lyptus, the Proteaceae, Saxifragacea, etc., are represented by species,
more or less closely related to living Australian forms.

A: brief synopsis of the conclusions drawn from the general results
which the investigation of the Tertiary Flora of Australia have
offered may be given as follows :—

Firsily.—The geographical distribution of plants in Australia at
the Tertiary period deviated in many respects from the present one.
Therefore, the materials for comparison obtainable from the present
flora of Australia are not at all sufficient for the investigation of the
Tertiary one, and must consequently be completed from other floras
of the globe.

Secondly.—Types of plants of the Southern as well as of the
Nortuern Hemisphere of the globe are associated together in the
Tertiary Flora of Australia.

Thirdly.—The flora-elements represented in the Tertiary Flora of
Australia chiefly contain Phylones (ancestor-types), which are also
common to other Tertiary Floras of the globe. The character of
the Tertiary Flora of Australia cannot therefore be considered
essentially different from that of the latter.

Fourthly.—The Australian Tertiary Flora, in accordance with the
preceding statements, is but a part of one and the same Original-
flora upon which all living floras of the globe are founded.

Fifthly.—The comparison of this Original- flora to the present
floras of the globe shows that in Australia the differentiation of the
Phylones has reached its highest degree.

Stathly.—Many analogies to the Tertiar y Flora are nevertheless to.
be found in the living Australian Flora.

Prof. von Ettingshausen—New Zealand Fossil Flora. 363:

VIII.—Own tue Fosstz Fiona or New ZEeawanp.

By Dr. Constantin Baron von Errincsuausen, F.C.G.S.,
Professor of Botany, University of Graz, Austria.

T was my good fortune in 1884 to receive two interesting collec-.

tions of fossil plants from New Zealand, for which I am indebted

to the kindness of Professor (now Sir Julius) von Haast, of Christ-

church, and Professor T. J. Parker, of Dunedin. In these collections

seventeen localities of fossil plants are represented which belong to

three formations: the Tertiary, the Cretaceous, and the Triassic
formations.

The relation of the living flora of New Zealand to its Tertiary
one has already formed the subject of a paper submitted by me to
the Imperial Academy of Sciences in Vienna, under the title
“Genetische Gliederung der Flora Neuseelands” (Sitzungsberichte
vol. 58, part i. p. 953). I have pointed out in it that the endemic
New Zealand flora not only contains types which may probably
descend from the principal element of its Tertiary Flora, but also
such ones probably being derivable from some accessory elements
of the latter flora.

Only a brief time has elapsed since my attention has been again
drawn to the subject, and I have been enabled by the examination of
the above-mentioned collections to lay a Memoir before the Vienna
Academy, entitled: ‘Contributions to the Fossil Flora of New
Zealand” (Denkschriften, vol. 53, part 1, 1887), of which I now
have the pleasure to give a brief account.

The Tertiary Flora of New Zealand, collected from eight localities,
as Shae Point, Dunstan, Landslip Hill, Malvern Hills, Racacliff
Gully, Weka Pass, Amuri and Murderer’s Creek, comprises till now
as far as investigations could bring to light, 52 species which are
distributed into 39 genera and 26 families. Of these species 3 are
Cryptogame, 11 Gymnosperme, 2 Monocotyledons, 22 Apetale, 3
Gamopetalz and 10 Dialypetale. Regarding the general character
of the flora, it by no means essentially deviates from that of the
hitherto known Tertiary Flora. We find here the same mixed
character as in the Tertiary Flora of Europe, of North America, and
of Australia, the analogies of which to the New Zealand Tertiary
species may easily be surveyed in a table appended to the above-
mentioned Memoir.

Although the Tertiary Flora of New Zealand is very different
from the living one, yet with regard to several species a close
relationship is clearly indicated between them. Thus, Aspidium
tertiario-zelandicum and A. Nove-Zelandie, Dammara Oweni and
D. australis, Lamb., Podocarpus Parkeri and P. Totara, Don., Decry-
dium pre-cupressinum and D. cupressinum, Sol., etc., are closely allied.
Besides several genera, for instance, Fagus, Hedycarya, Santalum,
Loranthus, ete., are represented in both, whereas others seem to be
in a genetic relation to living ones, and the latter may in some
degree be transmuted from the former. Thus, Daphnophyllum or

064 Prof. von Kttingshausen—New Zealand Fossil Flora.

Laurophyllum may have been evolved from Nesodaphne, likewise
Apocynophyllum from Parsonsia, Aralia from Scheflera, Sapindus from
Alectryon, etc. On the contrary, we miss in the recent endemic flora
of New Zealand a considerable series of genera belonging to its Tertiary
flora, for instance: Lomariopsis, Sequoia, Araucaria, Seaforthia,
Casuarina, Myrica, Alnus, Quercus, Ulmus, Planera, Ficus, Cinnamo-
mum, Dryandra, Diospyros, Aralia, Acer, Sapindus, Eleodendron, ete.

According to the preceding statements, the principal results of my
memoir are as follows :—

Firstly.—In New Zealand there exists a gence relationship
between its Tertiary and its living flora.

Secondly.—The Tertiary Flora of New Zealand contains the
elements of floras.

Thirdly.—The Tertiary Flora of New Zealand is a part of that
universal Original-flora from which all living floras of the globe
descend.

Fourthly—In New Zealand only one part of its Tertiary Flora
has changed into its living flora, the other has become extinct.

I proceed now to give a brief record of the fossil plants occur-
ring in the above-named localities.

I. Of all the localities ascribed to the Tertiary formation, that of
Shag Point is the richest and most interesting. Of Cryptogame two
Species of Aspidium, and of Cycade@ one specimen, betraying some
resemblance to Zamites tertiarius, Heer, have been found there. Of
Coniferze 10 species have been discovered there, belonging to 7 genera.
Of Monocotyledons one Caulinites species, and of Dicotyledons a
considerable series occur there, namely :—One Casuarina species ;
two species of Myrica, the one allied to M. integrifolia, Ung., of the
European Tertiary Flora, the other similar to M. quercifolia, L., a
native of the Cape of Good Hope; one Alnus species, closely allied
to the Huropean Tertiary, A. Kefersteinii, as well as to the Australian
Tertiary A. MacCoyi, M.; four Quercus species, one of them related
to Q. macranthera, native of the Caucasus, another allied to the
European Tertiary Q. lonchitis, Ung.; two species of Fagus, the
one related to F. procera and F. alpina, both natives of Chili; the
other very similar to F. Deucalionis, Ung., as well as to the North
American F. ferruginea. One Ulmus and one Planera species, both
analogous to species of the European Tertiary Flora; one Ficus
species corresponding to F’. lanceolata of the Huropean Tertiary, and
to F. Burkei, m., of the Australian Tertiary Flora; one Hedycarya
species, analogous to the Tertiary H. ewropee, as well as to the
Australian Tertiary H. Wickami; one Cinnamomum species, closely
allied to C. polymorphum and to C. polymorphoides; two Cassia
species, the one closely related to C. phaseolites and C. phaseoli-
toides, the other to C. Memnonia. Besides, species of the genera
Santalum, Diospyros, Aralia, Loranthus, Acer, and Carpolithes, their
analogues being represented in the Tertiary of Hurope, North
America, and Australia having been found there.

From the flora of the above-mentioned locality we may safely
eonclude that it, and probably also the following localities belong to

Prof. von Ettingshausen—New Zealand Fossil Flora. 865

the Lower Tertiary. As many species of this flora are closely
allied, or at least analogous to Hocene species, I refer it to the
Hocene Period.

II. From Dunstan the following species are now before us :—One
Lomariopsis species, analogous to L. bilinica from the Hocene strata
of Kutschlin, near Bilin, and related to L. triquetra, a native of
Nepal; the Aspidium species which has also been collected from the
preceding locality; and one Seaforthia species, analogous to S.
Mellingit of the fossil Flora of Hibiswald, and to S. robusta, R.
Brown, living in Australia.

III. From Landslip Hill the following came :—The Sequoia species
also found at Shag Point; one Dryophyllum species, being analogous
to D. lineare from the Hocene Flora of Sézanne ; two Apocynophyllum
species, the one corresponding to 4. helveticum of the European
Tertiary, and to 4. MacKinlayi of the Australian Eocene Flora, the
other related to A. Tabernemontana of the fossil Flora of Radoboj ;
one Hlgodendron-species corresponding to H. helveticum of the
European Tertiary Flora and H. curtipendulum, a native of Norfolk
Island.

IV. At Malvern Hill I., the following species have been found :—
An Araucaria and a Dammara species, both also occurring at Shag
Point; a Myrica, representing the widely-spread Tertiary Myrica
lignitum; a Quercus-species coming also from Shag Point; a Fagus
corresponding to F. Wilkinsoni of the Australian Tertiary ; a Planera
which appears also at Shag Point and at Murderer’s Creek; a
Cissophyllum, approaching the genera Cissites and Ampelophyllum.

VY. At Racacliff Gully the following fossil plants have been found:
—An Alnus and a Quercus, both also occurring at Shag Point; a
Sapindus, corresponding to S. falcifolius of the Kuropean, and to S.
caudatus of the American, as well as to S. Gossei of the Australian
Tertiary Flora.

VI. From Weka Pass, a Daphnophyllum-species, related to D. ellip-
ticum, Heer, has been collected.

VIL. At Amuria fragment of wood has been discovered. I referred
it to Dammara Oweni, a species occurring also at Shag Point and at
Malvern Hills I.

VIII. At Murderer’s Creek the following fossils have been obtained :
A Quercus, a Planera, a Cinnamomum, and a Cassia, all also collected
from the preceding localities I.—V.; a Dryandra, closely related to
D. acutiloba of the European and to D. Benthami of the Australian
Tertiary Flora.

Taking into consideration that although only a few species have
been found at each of the localities Nos. IJ.—VIIL, the plurality of
the species is common to them, especially to Shag Point, we may
conclude that their flora is to be referred to the same period, being
already determined as Hocene.

The strata containing remains of Dicotyledons in New Zealand
having been collectively called the “‘ Cretaceo-Tertiary Formation,” I
have pointed out that some of the strata must be referred only to the
Tertiary, and the others only to the Cretaceous formation. Whilst

366 8©Prof. von Ettingshausen—New Zealand Fossil Flora.

the former have already been taken into consideration in the preceding
exposition, I proceed now to explain the results of my investigations
of the fossil Flora of the Cretaceous formation.

The Cretaceous Flora of New Zealand has up till now been col-
lected from four localities, as, Pakawau, Grey River, Wangapeka
and Reefton. It contains 37 species, distributed into 29 genera and
17 families. Of these species 4 are Cryptogame, 8 Conifers, 4
Monocotyledons, 13 Apetale, and 8 Dialypetale. The Gamopetale
are wanting here. Several species seem to be the ancestors of
Tertiary ones, particularly of the genera Aspidium, Podocarpus, Da-
crydium, Quercus, Fagus, Cinnamomum, Dryandroides, Ceratopetalum,
Cupanoides, etc. According to the closer relationship of some of
these species to Tertiary ones, we may refer the above-mentioned
localities to the Upper Cretaceous formation.

I. Pakawau, Nelson, the richest locality of the four, contains well-
preserved fossil plants. Its flora is characterized by species of ferns
exhibiting the facies of Cretaceous ferns; by the genera of Coniferze
Podocarpium and Dacrydinium; by a peculiar genus of Musacez,
Haastia, related to Musophyllum; by Ulmophylon, a genus comprising
the ancestor-species of Tertiary Ulmus and Planera-species ; by a
Dryophyllum and by a Grewiopsis-species analogous to species of the
American Cretaceous formation; and by species of Cinnamomum and
Dryandroides, corresponding to European Cretaceous species. There
have also been found a Bambusea, a Casuarinites, a peculiar Fagus-
species and a Cupanites.

II. Gery River, Westland, a locality which offers many but not such
well-preserved fossils. There have been disvovered a Flabellaria,
related to /. longirhachis, Ung., from the Cretaceous beds of Muth-
mannsdorf, Austria ; two species of Quercus, one species of Celastro-
phyllum and one species of Palgocassia, all corresponding to species
of the Cretaceous Flora; a Dalbergiophyllum reminds us of a Dalbergia-
species of the same flora. There also have been found, a Knightio-
phylium and a Ceratopetalum, both peculiar to this locality, whilst a
Bambusea, a Casuarinites and a Cupanites, which also occur at the
former locality, have been collected.

III. Wangapeka, Nelson, showing a flora which agrees with that
of the preceding localities, inasmuch as some of its species are com-
mon to the latter. Of the several forms of fossil plants peculiar to
this locality, the following are worthy of notice: Two genera of
Conifers, the one intermediate between Cephalotaxus and Torreya,
the other uniting Ginkgo with Phyllocladus; two Quercus, one Fagus
and one Ficus-species, all corresponding to Cretaceous forms; a Sapin-
dophyllum analogous to Sapindus prodromus, Heer, from the Cretaceous
strata of North Greenland; a Dalbergiophyllum and a Poacites.

IV. Reefton, Nelson.—Only Casuarinites Cretaceous has been found
here, a species which also occurs at Pakawau and at Grey River.

The collections of Sir Julius von Haast and Prof. Parker also con-
tain numerous fossil plants from localities which I refer to much
lower Mesozoic strata. They are Mount Potts, Haast Gully, Malvern
Hills II., Mataura and Waikawa. A greater difference of age of
these localities is excluded by some common species which they

Reviews—Mark W. Norman’s Geology of the Isle of Wight. 367

contain. The species mostly are analogous to Triassic ones. I may
therefore not be far wrong in supposing that all the last-named
localities belong to the Trias formation.

A brief record of their flora follows :—

I. Mount Potts. Here have been collected :—EHquisetum microdon,
m., a species corresponding to an Huropean-Triassic one ; Teniopteris
pseudo-vittata, m., closely allied to T. vittata from the European
Trias-flora ; Asplenium Hochstetteri, Ung. sp.; Palissya podocarpoides,
m., analogous to P. Braunii, Endl. ; Baiera australis, m., also corre-
sponding to an European species of that flora; Phyllodes of Thinn-
feldia australis, m., and of Protocladus lingua, m.

II. At Haast Gully (also called “Clent Hills’) have been found :
—Sphenopteris amissa, m., 8S. Clentiana, m., Pecopteris proxima, m.,
Teniopteris pseudo-simplex, m., all more or less related to Triassic
species, Teniopteris pseudo-vittata, Camptopteris Haastii, m., Asplenium
Hochstettert, Equisetum microdon, Palissya podocarpoides, and Baiera
australis.

Til. Malvern Hills II. (not to be confounded with the above-
named Tertiary locality Malvern Hills I.). Pecopteris proxima, m.,
Teniopteris lomariopsis, m., both related to Triassic species, Asplenium
paleo-darea, m., A. Hochstetteri, Podozamites Malvernicus, m., and
Protocladus lingua have been collected there.

IV. Matura and V. Waikawa. There have been found :- Spheno-
pteris Palgopteris, Ung. sp., Hymenophyllites australis, m., Teniopteris
pseudo-simplex, T. lomariopsis, Asplenium Hochstetteri, Macro-Tenio-
pteris affinis, m., Lycopodites pal@o-selaginella, m., Nilssonia Zeelandica,
m., Zamites Mataurensis, m., Pierophyllum Dieffenbachi, m. The
fossil plants are well preserved there, and the species bear more or
less the facies of those of the Triassic Flora.

In concluding this brief notice, I have to remark that I am unwill-
ingly compelled to disagree with the view expressed by Sir James
Hector, and published by him in “ New Zealand Court,” Catalogue
Indian and Colonial Exhibition, London, 1886, p. 60, namely, that there
occur Mesozoic plants in New Zealand, as, for instance, species of Ale-
thopteris, Tenopteris, etc., together with leaves of Tertiary Dicotyledons
in one and the same strata. I have not seen any trace of such a con-
nexion in the rich material the above-mentioned collections offer.
Sir James Hector’s statement may be based on some mistake; perhaps,
he has taken specimens of Camptopteris for leaves of Dicotyledons, an
error easily possible when the specimens are not well preserved.

REVLEWwS-

T.—A Porutar GuIDE To THE GEOLOGY oF THE IsLE oF WIGHT,
wits A Nore on 17s RELATION TO THAT OF THE IsLE oF PURBECK.
By Marx W. Norman. 8vo. pp. 240, Map, Sections, and 15
Plates of Fossils. (Ventnor, 1887.)

M* MARK NORMAN, who some years ago contributed a

paper on the Greensand formation of the Isle of Wight
to the GxroLocicaL Macazinz, now presents us with a popular

3868 Reviews—Prof. C. Lapworth’s Canadian Graptolites.

Geological Guide to the Island. Basing his views upon the ex-
cellent works of Mantell, Forbes, Bristow and others, Mr. Norman
has incorporated in his volume many descriptive notes and sugges-
tive observations, the result of thirty years’ experience and work
amongst the Downs and Coast sections of his interesting district.
Hach geological formation is reviewed in turn, and lists and
illustrations of the principal fossils given. Notes on the best
collecting grounds, and much information of an instructive and
useful kind, both to the collector and visitor, as well as to amateurs
and students, will also be found in his pages. After reviewing the
various divisions in ascending order, Mr. Norman devotes one
chapter to the consideration of ‘‘ Denudation and Landslips,” and
another to ‘The Human Period.” In an appendix he discusses ‘the
Relation of the Geology of the Isle of Wight to that of the Isle of
Purbeck.” Some notes on the Ventnor Museum and a list of the
Economie Products of the Island complete the volume.

Although the book is essentially a Geological Guide, Mr. Norman,
has rendered it useful to other visitors, for he points out the most
interesting features in the landscape, and gives much general infor-
mation touching the antiquities of the Island and other objects.

A map, sections, and fifteen plates of fossils accompany the text,
and we must congratulate the author on having so careful a draughts-
man as his friend Mr. Ryan, the plates being much superior to those
usually seen in Guide-books. Several typographical errors on the
plates and others in the text seem to have escaped the notice of the
author. The numerous plates and figures together with the low
price should recommend this book to ail, and it should especially
find a place in the equipment of the tourist and the visitor, who is
interested in the Geology of the Isle of Wight.

IJ.—Pretiminary Report on some GRAPTOLITES FROM THE LOWER
Patmozoic Rocks on THE SourH SrpE oF THE St. LAWRENCE,
From Care Roster tro .Tartigo River, From THE NortH
SHORE OF THE ISLAND OF ORLEANS, ONE MILE ABOVE CaP
Rouge, AND FROM THE Cove Fintps, Quessc. By Prof. Cuas.
Lapwortn, LL.D., F.G.S. [From the Transactions of the Royal
Society of Canada, Section iv. 1886. ]

N his brilliant Memoirs on the Moffat Series and the Girvan
Succession, Professor Lapworth completely established the high
importance that should be attached to the study of life-zones for the
elucidation of the true sequence of fossiliferous rocks. Wherever
these rocks are contorted into frequent foldings and ‘their original
position disturbed by faults, stratigraphical evidence alone can
seldom be relied upon to assign them their place in the series. In
such cases the testimony afforded by fossils even of such lowly
organization as that of the Graptolites becomes of almost incalculable
value.
In complicated areas such as those of the Girvan District, the
eastern townships of Lower Canada, and the regions treated of in
the Report now before us, a minute and patient investigation of the

Reviews—Prof. C. Lapworth’s Canadian Graptolites. 369

life-groups, as they occur in each stratum, is the only method open
to the geologist who aspires to lay the foundations for an enduring
scheme of classification.

The collection of Graptolites treated of in this Report was for-
warded to Prof. Lapworth by Dr. A. R. C. Selwyn, F.R.S., Director
of the Geological Survey of Canada, the material having been accu-
mulated by various members of the Staff of the Survey at different
periods dating from 1876.

The Graptolites were found to belong to several distinct zones,
each corresponding with a distinct zone in Great Britain and Western
Hurope, and ranging from the British Tremadoc Slates to the middle
of the Bala or Caradoc Formation of Wales and the West of
England.

The Graptolite zones are here briefly described :—

Zone I.—Cape Rosier Zone: Zone of Dictyonema sociale and

Bryograptus.

This is the oldest represented, and it occurs at the Barrasois
River, Cape Breton Island, and at Cape Rosier, Gaspé; as well as
at other points along the south shore of the St. Lawrence. In
Europe it occurs in the Tremadoc of Wales and the Tremadoc and
Ceratopyge Beds of Norway (Brégger) and Sweden (Tullberg). It is
of Upper Cambrian age.

Zone II.—Ste Anne Zone: Zone of Phyllograptus Anna; Grap-

tolites from Rocks three miles above Ste Anne des Monts.

This zone contains the following four species of Graptolites ;
Tetragraptus bryonoides, Hall; T. fruticosus, Hall; Phyllograptus
Ama, Hall; Didymograptus extensus, Hall. ‘These are all well-
known Point Levis species, according to the classical monograph of
Prof. Hall,’ and they also occur together upon the corresponding
Arenig-Skiddaw horizon in Europe, in the Shelve Arenigs, in the
Skiddaw Slates, and in the Phyllograptus beds of Norway and
Sweden.”

The author remarks upon the absence of this Ste Anne Phyllo-
graptus zone in the collection among the fossils eastward of the
Ste Anne River, though the lithological characters of these strata
point to the persistence of such a zone for great distances.

Zone Ill.—Griffin Point or Marsouin River Zone: Zone of Ceno-

graptus gracilis.

This supplies the largest number of species in the collection.

The most characteristic forms are Didymograptus sagittarius (Hall,
non Hisinger); Cenograptus gracilis, Hall; Dicellograptus sextans,
Hall ; Zasiograptus mucronatus, Hall; Climacograptus antiquus, Lap-
worth; Diplograptus Whitfieldi, Hall, “and the presence of a single
one of these species is sufficient to settle the age of the rock in Great
Britain, and in all likelihood in America.” But there are associated
with them a few species which enjoy a more extended range in time,
such as the well-known Hudson River form, Dicranograptus ramosus,
Hall. i

1 Canadian Organic Remains, Decade ii. 1865, ‘‘ Graptolites of the Quebec
Group.”’

DECADE IIIl.—VOL. IV.—NO. VIII. 24

370 =©=©§ Reviews—Prof. C. Lapworth’s Canadian Graptolites.

The most important and interesting point in connexion with this
Marsouin River zone is its identity with that of the Norman’s Kill
shales in the Hudson River valley, near Albany, described by Prof.
James Hall in the “ Paleontology of New York.’’!

The New York geologists have always held that the Norman’s
Kill beds are of the age of the Hudson River (Lorraine Shales), or
of that of the Utica Slate; but Prof. Lapworth observes, “not a
shadow of paleontological evidence has yet been adduced to show
that these Norman’s Kill or Marsouin Rocks are newer than the
Trenton.” On the whole he regards the Marsouin zone provisionally
as coming between the Chazy (holding Muclurea Logani and Ophi-
leta compacta) and the Trenton Limestone in America, and therefore
answering roughly to the Cenograptus gracilis zone in Britain, “in
age as well as in fossils.”

As a result of his analysis of the three Graptolitic zones above
detailed, Prof. Lapworth finds that there are two grand faunas
represented, viz.:—(A) The so-called Quebec fauna of the Calcifer-
ous-Chazy formations of Cape Breton, Cape Rosier, Point Levis
and Ste Anne, which answers to the fauna of the British Upper
Tremadoc and Arenig rocks and their European equivalents; and
(B) the Griffin Cove, Marsouin River, and Norman’s Kill fauna,
which answers to the fauna of the middle zones of the Huropean
Ordovician or Cambro-Silurian rocks.

In each of these grand faunas are found two subfaunas, those of
the lower faunas being the more distinctly separable :-—

A. QUEBEC OR Curorous. Cuazy Fauna.—Subfauna I.— Cape
Rosier and Barrasois River Zone, of Calciferous age = Tremadoc
Rocks of Great Britain and Ceratopyge and Dictyonema Beds of
Norway.

Subfauna II.—Ste Anne River Zone, of Point Levis age = typical
Arenig of Great Britain; Phyllograptus Beds of Scandinavia, ete.

B. Trentonian, Marsovurin River, or Norman’s Kirt Fauna.
Subfauna A.—The Cenograptus Zone of Griffin Cove and the
Marsowin River, answering to the Middle Llandeilo Beds of
Great Britain, to the Glenkiln Beds of Scotland, etc.

Subfauna B.—The Cove Fields and Orleans subfauna ; apparently
destitute of Cenograptus gracilis, and answering to the highest
Llandeilo or lowest Caradoc Beds of England.

The last of these subfaunas shows evidence of a transitidn into the
Utica-Lorraine Graptolitic fauna of the Mohawk Valley, New York,
and of Lake St. John, Canada.”

The author next presents a “Possible Ascending Succession of
Strata, on the South Side of the St. Lawrence, from Cape Gaspé to

Tartigo River,” which includes
Pre-CAMBRIAN.
(4). Metamorphic Rocks of the Shickshock Ranges [in the Gaspé Peninsula].
CaMBRIAN.
(B). Cambrian Formations.
ORDOVICIAN.
(€). Ordovician or Cambro-Silurian Formations.

1 Vol. i. 1847,

Reports and Proceedings—Paleontographical Society. 371

(1). Lower or Quebee Group of Logan.
(2). Middle Division, or Trenton and Black River Rocks of Hall and

Logan.
(3). Upper Division, or Hudson River and Lorraine Rocks of Hall

and Logan (apparently wanting).

The lithological characters of these groups are described with
much minuteness, and their stratigraphical relations discussed. Into
these details our space forbids us to enter, but we cannot refrain
from quoting from the paragraph in which Professor Lapworth con-
cludes this interesting and suggestive study of Canadian Graptolites.

“Jn the careful study of the geographical and geological distribu-
tion of the several horizons of these Graptolites in the extensive
convoluted rock series of the Hastern Townships, lies the solution
of the great geological enigma of the Quebec Group and its puzzling
associates. We shall not be able to parallel the eastern and western
series, formation for formation, until we know more of the Grapto-
litic fauna of the Chazy, Black River, Trenton, Utica and Lorraine
formations themselves, where they lie flat and undisturbed, and can
compare them with those of their European equivalents. This is
a work that ought to be at once taken up by American geologists,
and carried on, stage by stage, with the study of the equivalent
rocks of the convoluted eastern areas. ‘Till this is done, all our
correlations of these eastern deposits must be regarded simply as
provisional approximations, liable to inevitable modification and
improvement in the light of future discovery.”

The last few pages of the Report are devoted to a “ Provisional
list of Fossils [7.e. Graptolites], with localities,’ together with two
useful tables; Table A. ‘Showing the various Horizons, approximate
Geological Age, and American and European Equivalents of the
several Graptolitic Zones,” etc. Table B. “Showing Vertical Range
of Graptolites from Rocks between Cape Rosier (Gaspé) and Cap
Rouge (Quebec).” INS Jel We

ep Om ES | Aap PROC DENGS-
———>—_—_

I.—Tue PatmonrocrapuicaL Socrrty or Lonpon.

Report oF THE CoUNCIL READ AND ADOPTED AT THE ANNUAL
GENERAL Mererinc, HELD AT THE APARTMENTS OF THE G£Eo-
LoGioaAL Socrrry, Burztinaton Hovsz, 17tuH June, 1887, Dr.
Henry Woopwarp, F.R.S., Vicn-Prestpent, IN THE CHaIR.

ee Council in presenting their fortieth Annual Report take the
. opportunity of inviting the attention of Members to the publi-
cations of the Society and to the faithful manner in which the
wishes and purpose of its founders are being carried into effect.
Since the last meeting was called, a volume has been issued—one
every way equal to its predecessors, so far as the valuable scientific
information contained in it and the beauty of its illustrations are con-
cerned. This book (the return for the Members’ subscriptions due
in 1886) contains five distinct subjects, four of which form the
commencement of new monographs, and one is the continuation of

372 Reports and Proceedings—Paleontographieal Society.

a Memoir begun twenty years previously. The first on the list, that
on the Morphology and Histology of Stigmaria ficoides, by Prof.
W. C. Williamson, LL.D., F.R.S., is a complete summary of the
latest information on the roots and rootlets of the great Carboniferous
Sigillaroid trees, and devotes fifteen plates to their aspect, as seen by
the aid of the microscope as well as by the unassisted vision. All
the plates are examples of high artistic skill, and of excellent
lithographic printing.

The second monograph on the list, viz. that on the Fossil Sponges,
by Dr. George J. Hinde, F.G.S., deals with a general introduction,
and gives much information with regard to the structure and forms
of Palzozoic Sponge-spicules. The eight plates accompanying
Part I. of this Memoir are fine specimens of careful drawing. In
the third work, treating of the Jurassic Gasteropoda, by Wilfrid H.
Hudleston, M.A., F.R.S., F.G.S., the variations in the strata of the
Inferior Oolite at numerous localities in Dorsetshire and Somersetshire
are dwelt upon (the beds themselves being carefully defined), so
that when the description of species commences, as will be the
case in the next volume, the different horizons can be rigorously
indicated. In the fourth Monograph, by S. S. Buckman, F.G.S.,
the Ammonites of the Inferior Oolite are taken in hand, and five
species, illustrated by six admirable plates, are described with
much care, an earnest of the nature of the parts that will follow.
In the fifth and last work the continuation of the Mammalia of the
Pleistocene period, by Professor W. Boyd Dawkins, M.A., F.B.S.,
F.\S.A., F.G.S., the horns of some of the Deer belonging to that era
are delineated by seven fine plates.

The cost of this grand volume has exceeded five hundred pounds,
and has been more in amount than the sum contributed by the
subscribers for the year to which the book relates.

The volume for the year 1887 is with the printer, and will contain
the continuation of the Monographs on the Paleeozoic Sponges, the
Jurassic Gasteropoda, and the Inferior Oolite Ammonites; it will
introduce, in addition, a new Monograph on the Paleozoic Phyllo-
poda, by Prof. T. Rupert Jones, F.R.S., and Dr. H. Woodward, F.R.S.

Dr. H. Woodward has promised, at an early date, a Monograph.
on the Insects of the Coal-period, for which he has been for some
time collecting materials.

Active then as is the Society for the promotion of Paleeontological
Science, it is a matter of regret, that Geologists in general do not
more readily enroll themselves as members. A hundred additional
subscribers would materially advance the issue of the Monographs,
seeing that several of the latter cannot at the present moment be
proceeded with for want of funds. The aim of the Society is essen-
tially national, and is deserving of national support. For forty
years the Society has laboured and has outlived all but a very few of
its founders and early friends; nevertheless the present year finds it:
still at work, striving to spread abroad a knowledge of the vast
stores of fossil treasures existing in the strata of Great Britain.
Since the days that its original promoters met together, many Free

Reports and Proceedings— Geological Society of London. 378

Libraries, local Geological Societies, and Naturalists’ Field-Clubs
have risen into being, but the number of these institutions that
have joined the Society is very small.

Cannot the lovers of geological science be induced to combine and
replenish the void places caused, to so large an extent of late years,
by the hand of death in the once long list of members of this useful
and important Society, whose work cannot be said to be fulfilled so
long as any British fossils remain unfigured and undescribed ?

TI.—Groroercan Socrery oF Lonpon.
June 28, 1887.—Professor J. W. Judd, F.R.S., President, in the

Chair.—The following communications were read :—

1. “On Nepheline Rocks in Brazil, with special Reference to the
Association of Phonolite and Foyaite.” By Orville A. Derby, Esq.,
F.G.S.

The author refers to the phonolites and associated basalts of
Fernando Noronha, a deep-sea island off the north-eastern shoulder
of the Continent of South America. Nepheline rocks of a somewhat
different character are abundantly developed on the mainland, and
under conditions favourable for throwing light on the relations
existing between the granitic type, foyaite, and the other members
of the group. There are some mountains near Rio de Janeiro
composed of these rocks, as is also the peak of Itatiaia, 83000 metres
high, the loftiest mountain of eastern South America. A cursory
examination of some of these localities having shown an apparent
relation between foyaite, phonolite, trachyte and certain types of
basalt, Mr. Derby determined to visit the Caldas region, where a
railway under construction gave unusual facilities for examining
this series. A fine development of foyaite, phonolite and tuff was
found, associated with several types that have not yet been met
with in the other localities. The existence of a leucite basalt was
recognized.

The bulk of the paper was devoted to a detailed description of these
railway-sections, and the following deductions are drawn :—

1. The substantial identity, as regards mode of occurrence and
geological age, of the Caldas phonolites and foyaites.

2. The connexion of the latter through the phonolites with a
typical volcanic series containing both deep-seated and aerial types
of deposits.

3. The equal, if not greater antiquity of the leucite rocks as~
compared with the nepheline rocks, whether felsitic, as phonolite, or
granitic as foyaite.

4, The probable Paleozoic age of the whole eruptive series.

2. “ Notes on the Metamorphic Rocks of South Devon.” By Miss
Catherine A. Raisin, B.Sc. Communicated by Prof. T. G. Bonney,
D.Se., LL.D., F.R.S., F.G.S.

This communication consisted mainly of detailed observations,
supplementary to those published by Prof. Bonney in the Society’s
Journal for 1884, on the slaty and metamorphic rocks of South

374 Reports and Proceedings—

Devon in the neighbourhood of Salcombe estuary. In the first part
of the paper details were given of the sections exposed around the
estuary, at Hope Cave to the westward, and in several localities to:
the eastward as far as Hall Sands, all confirmative of Professor
Bonney’s views, and showing that the slaty beds to the northward
do not pass into the mica and chlorite schists to the south, but are
separated from the latter by a line of faults.

Descriptions were then given of microscopic slides from various
parts of the metamorphic rocks. Some of these showed the action
of secondary forces. The effects of lateral pressure in producing
cleavage-planes and a kind of jointing were also commented upon.

An attempt was also made to determine the succession of chlorite-
mica- and micaceo-chloritic schists around Salcombe estuary. The
beds appeared to succeed each other in the following order, com-
mencing from the northward :—

1. (a) Interbanded series south of Halwell Wood, etc.

(6) A thick band of chlorite-schist at Scoble, Snapes Point, ete:

2. (a) Mica-schist north of the side estuary.

(6) Interbanded series south of the side estuary.

3. Mica-schist of Portlemouth Ferry.

4, Chlorite-schist of Bickerton.

3. “On the Ancient Beach and Boulders near Braunton and
Croyde in North Devon.” By Prof. T. McKenny Hughes, M.A.,
F.G.S.

The author observes that amongst the raised beaches of 8.W.
England we generally find included the sand cliffs of Saunton Down
and Middleborough on the coast west of Barnstaple. These de-
posits possess a further interest owing to the occurrence at their
base of large boulders. In 1866 Mr. Spence Bate, in opposition to.
the prevailing view, concluded that the so-called raised beach is the
undestroyed remnant of an extensive district of wind-borne sand
similar to that which now exists on Braunton Burrows. The points
to which attention was invited are as follows :—

1. Is this deposit on the southern slope of Saunton Down a
raised beach ?

2. Were the above-mentioned boulders carried to their present
position by ice ?

The paper was fully illustrated by diagrams, showing the relations.
of the recent deposit, and by figures showing the mode of occurrence
of three of the most remarkable boulders. ‘The conclusions were :—
(1) That the ancient beach of Saunton Down and Croyde is not a
raised beach in the ordinary acceptation of the term. The top is
subaerial talus, the middle part is blown sand, the base only marine,
and the marine part is not above the reach of the waves of the sea
at its present level. (2) The boulders of granite and felsite which
occur at the base of the ancient beach were transported to their
present position by the waves of the sea. Such as are of local
origin could have reached the sea by the ordinary processes of de-
nudation ; such as are possibly of northern origin could have been

Geological Society of London. 370

carried down the Irish Channel on bergs, and been thrown up by
the sea to their present position at any period subsequent to their
transportation southwards by ice ; but their presence does not imply
any local glaciation. .

4. “Notes on the Formation of Coal-seams, as suggested by evi-
dence collected chiefly in the Leicestershire and South Derbyshire
Coal-field.” By W.5S. Gresley, Hsq., F.G.S.

The author’s principal object in this paper was to bring forward
evidence in opposition to the view now generally accepted that coal-
seams were formed from vegetation growing on the spot.

He showed that during a very extensive experience he had only
once or twice detected stems passing into a bed of coal and con-
nected with the Stigmaria-roots in the underclay. If, as was
generally stated, the Stigmariz were the roots of the trees that
formed the coal, such instances ought to be common. Not only,
however, were they very rare, but the abundance of the Stigmariz was
extremely variable, and these roots, instead of becoming more thickly
matted together in the uppermost part of the underclay, as they
should be if they were roots of the coal-forests, were generally dis-
tributed, as a rule, throughout the clay in a manner that showed
them to have been in all probability independent organisms. Stig-
marian roots, when found connected with a stem, were more often
on the top of the coal-seam than at the bottom.

Other reasons assigned for rejecting the hypothesis that coal-
seams were formed of plants that grew upon the spot were the
occasional absence of underclays, the sharp division between the
coal-seams themselves, and the beds above and below them; the
distinct lamination of every seam and its division into layers of
different mineral character that are persistent over large areas; the
presence of foreign bodies in the underclay, and especially of pebbles
and boulders transported from a distance; the presence of similar
fish, etc., in the coal itself; and the circumstance that many coal-
seams are impregnated with salts, and are associated with beds
containing marine fossils.

5. “Note on some Dinosaurian Remains in the Collection of A.
Leeds, Esq. Part I. Ornithopsis Leedsti. Part I. Omosaurus, sp.
By J. W. Hulke, Esq., F.R.S., F.G.8.

Part I. Ornithopsis Leedsii, nov. sp., from the Kimmeridge Clay
of Northamptonshire.

The author described a pelvis, vertebrae and coste referable to
this genus, of a stature far surpassing that represented by the
pelvis in the Fox Collection from the Isle of Wight Wealden, which
he brought under the notice of the Society a few years since. The
ilium has a very long preacetabular process. A rib is three times
as large as the largest rib of an elephant of average stature. The
trunk vertebrze show the characteristic large chamber opening in
the side of the centrum, under the platform supporting the neura-
pophyses. There is no post-pubis. The pubis and ischium diverge ;
their close resemblance to those of Ceteosaurus oxoniensis, figured by
J. Phillips, in the ‘Geology of Oxford,’ is obvious when each figure

376 Reports and Proceedings—

is reversed, their true position being misrepresented in that author’s
diagram, a very excusable error.

Part II. described a sacrum, with ilia, vertebre, a femur, etc.
The neural arches of the sacral vertebrae are synostosed, and so form
a continuous roof (simulating the vault of a cranium) of the dilata-
tion of the neural canal, which enclosed the sacral swelling of the
spinal cord. The transverse processes are long. The ilia offer a
general resemblance to those of Osmosaurus armatus (Owen), but
differ from those of this species in the relatively greater length and
narrowness of the preacetabular process. The similarity of con-
struction of this sacrum to that of Stegosaurus, described by O. C.
Marsh, and the very close resemblance of their ilia were noticed.
The author considered that an extremely close affinity exists between
these two genera, and is prepared to find that, upon the acquisition
of more materials, their identity may even be established. For the
present, he preferred to refer the Peterborough Dinosaur to Omosaurus,
and proposed for its specific name durobrivensis, having reference to
that of the old Roman settlement in that locality.

6. “Notes on some Polyzoa from the Lias.’ By Hdwin A.
Walford, Esq., F.G.S.

The author briefly reviewed the work of Etheridge, Vine, and
others in the tabulating of the British Liassic Polyzoa, and mentioned
also the labours of Terquem and Piette, Dumortier, and others in the
same direction in France and Germany. He directed attention to a
species described by Prof. Tate from the Lias of May, Normandy,
under the name Spiropora liassica, and described specimens in his
own collection from a similar horizon in the Midlands, with which
it had been confounded. The English forms have very varying
modes of growth; sometimes foliaceous after the fashion of the
Diastopora proper of Haime, at other times ramose and cylindrical,
like Entalophora. 'The latter habit, together with the long, and often
partly free, zocecia, suggest the relationship of the species with the
Tubulipore. The exceptional state of preservation of the specimen
is such as to show the cells in a perfect condition, with solid circular
calcareous closures within the orifice of the zocecial tubes, a feature
common to both the foliaceous and the cylindrical forms. The
surface-pores are unusually well preserved, and appear to be similar
to those of the recent Cyclostomatous Polyzoa. The name of Zubu-
lipora inconstans is proposed for the species.

Mention was also made of other fragments of Polyzoa of doubtful
relationship occurring in the same beds.

7. “On the Superficial Geology of the Southern Portion of the
Wealden Area.” By J. Vincent Elsden, Hsq., B.Sc. Communicated
by the President.

The author, after referring to Sir R. Murchison’s paper, published
more than thirty years ago, on “The Distribution of the Flint Drift
of the 8.E. of England,” proceeded to give in detail his observations
on the angular flint-deposits of the Arun, Adur, Ouse, and Cuckmere
basins, He also noticed a sandy or loamy deposit containing angular
fragments of ironstone, and generally a few small angular flints that

Geological Society of London. od

oceurred on the surface of the Lower Greensand, and to a small
extent on the Weald Clay. A block of granite, weighing between
© and 6 lbs., was found on the chalk escarpment at Kilhurst Hill.

The angular flint-drift occurred mainly on the higher parts of the
area, and was wanting in the river-valleys, where, however, river-
gravels derived from the denudation of the older deposits were abun-
dantly developed. This distribution of the angular drift was shown
to be incompatible with the theory of its origin advocated by Sir R.
Murchison and some other geologists, who attributed it to a violent
and transitory current. The author showed that not only in the
Wealden area, but throughout many of the neighbouring districts,
the angular drift consisted of the undenuded remnants of a deposit
formed before the present river-valleys were cut, and that many of
the river-gravels, though newer than the angular drift, were
deposited when the valleys had been less excavated than they now
are. This was Mr. Topley’s view with respect to the northern
portion of the Wealden area. Mr. Searles V. Wood’s marine theory
of the origin of these gravels was discussed, and shown to be refuted
by their mode of occurrence. It was, moreover, contended that the
drift, although composed of local materials, was probably of sub-
aqueous origin, and not merely subaerial. The discovery of a granite
boulder might, if confirmed by other discoveries, lead to a modifica-
tion of the views generally held as to the physical character of the
area during the Glacial period.

8. “Report on Palzo-botanical Investigations of the Tertiary
Flora of Australia.” By. Dr. Constantin Baron von Httingshausen,
For.Corr.G.S. (‘This paper appears in full in this Macazine.)

9. “On some new Features in Pelanechinus corallinus.” By T.
T. Groom, Esq. Communicated by Prof. T. M‘Kenny Hughes, M.A.,

The discovery by the author, in the Coral Rag at Calne, of an
additional and well-preserved specimen of the Echinoderm originally
described by Dr. Wright as a Hemipedina, but subsequently made
the type of a new genus, Pelanechinus, by Mr. Walter Keeping,
afforded an opportunity of adding considerably to the known
characters of the type. The test proved to be flexible, as in the
Echinothuride, a point already noted by Mr. Keeping.

A number of details as to the interambulacral and ambulacral
areas, the imbricating peristomial plates, pedicellariz, and teeth
were given. Pedicellarize did not appear to have been previously
observed in fossils.

The genus appeared to occupy an intermediate position between
the Echinothuride, Echinidee, and Diadematide, and must form the
type of a distinct subfamily, perhaps referable to the last named. A
new description of the species was added.

10. “On Boulders found in Seams of Coal.” By John Spencer,
Ksq., F.G.8.

The discovery of a boulder weighing 6 Ibs., and composed of

378 Reports and Proceedings—Zoological Society of London.

granite, in the Gannister or Mountain-Mine seam of the Rossendale:
district, at Old Meadows Pit, near Bacup, Lancashire, had led the
author to call attention to the occasional occurrence of similar
boulders in various parts of Lancashire and Yorkshire. Such
boulders were always isolated, and sometimes imbedded in the seam,
sometimes in its upper surface. They were always waterworn and
rounded, and were composed, so far as had been observed, of granite,
gneiss or quartzite foreign to the district.

After considering the various suggestions that had been made as
to the means by which such boulders had found their way into the
coal, the author gave the preference to the action of floating-ice,
both because the presence of fragments from a distance would thus.
be more readily explained, and because ice-scratched rocks have been.
found in situ in the Millstone Grit within three miles of the place
whence the boulder mentioned was obtained.

The next Meeting of the Society will be held on Wednesday, 9th
November.

III].—Zoonoaicat Society or Lonpon.

May 17th, 1887.—Prof. W. H. Flower, LL.D., F.R.S., President,
in the Chair.—The following communications were read :—

1. “On the Presence of a Canal System, evidently Sensory, in the
Shields of Pteraspidian Fishes.” By A. Smith Woodward, F.Z.S.

A broken specimen of Péteraspis Crouchii in the British Museum
adds an interesting fact to our knowledge of the structure of the
shield in the Pteraspidian fishes. In his well-known monograph
on this ancient group, Prof. Ray Lankester described a number of
pits or depressions arranged in rows upon the external surface
of certain well-preserved examples, and considered that they were
connected with the ‘lateral line” system of the fish, probably
lodging the sensory organs situated in an enveloping soft integu-
ment. The same feature was again described in Holaspis in 1873.
(Grou. Mag. Vol. X. p. 243, Pl. X.) It now appears that these
curious depressions are really the openings of a canal system,
traversing the middle layer of the shield, and quite comparable to
the canals of the lateral line in many ganoids and teleosteans. ‘The
branches have the remarkable ‘“feather-barb” arrangement, so well
seen in the living Pleuronectide.

2. “Note on the ‘Lateral Line’ of Squaloraja.” By A. Smith
Woodward, F.Z.S.

In his description of the genus Squaloraja, recently published, the
author had failed to recognise traces of the lateral line. He now
showed that these canals were supported by numerous minute, in-
complete, calcified rings, exactly similar to those well known in
recent and fossil Chimeroids. The fact probably implied that the |
sensory organs were placed in open grooves, and thus added one
more feature to those already noted as connecting the old Liassic
Selachian with the Holocephala.

Reports and Proceedings—Zoological Society of London. 879

2. June 28rd, 1887.—Prof. W. H. Flower, LL.D., F.RB.S., Pre-
sident, in the chair.—The following communications were read :—

1. “Note on a Fossil Species of Chlamydoselachus.” By James
W. Davis, F.G.S.

The author showed that some teeth described and figured about
ten years ago by R. Lawley (‘‘ Nuovi Studi sopra ai Pesci, ete.,”
Florence, 1876, p. 87, pl. i. figs. 1, a-c) were truly referable to the
newly-discovered Japanese Shark, Chlamydoselachus, Garman. These
fossils were obtained from the Pliocene of Orciano, Tuscany, and
their original discoverer was naturally perplexed in determining their
relationships ; he left them incertw sedis, and refrained from pro-
posing aname. Mr. Davis suggested that the new species be known
as C. Lawleyi.

2. “On the Fossil Teleostean Genus Rhacolepis, Agassiz.” By
A. Smith Woodward, F.Z.S.

This communication contained a detailed description of the
Brazilian fossil fish briefly noticed by Agassiz under the name of
Rhacolepis, and concluded by discussing the systematic position of
the genus. The original determination was founded upon a collec-
tion of fossils obtained by Mr. G. Gardner, about 1840, from Barra
do Jardim, Serra de Araripe, North Brazil, and brief notes were
published in the “ Edinb. New Phil. Journ.” 1841, and the “Comptes
Rendus,” vol. xviii. p. 1007. An early figure, without name, was
also given in the Atlas accompanying Spix and Martius’ “ Reise in
Brasilien,” 1825. <A large number of specimens now in the British
Museum display the principal characters of the skeleton, and also
show well-preserved traces of the gills and the lateral muscles of
the trunk. The body exhibits but slight lateral compression, and
the abdomen is rounded; the snout is acutely pointed, and the roof
of the skull flattened. The margin of the upper jaw is formed both
by the premaxillz and maxille, and the clett of the mouth is nearly
horizontal; the cheek is covered by the expanded posterior circum-
orbital bones; there is a narrow preoperculum, a triangular inter-
operculum, and a relatively large suboperculum. The branchiostegal
rays are numerous, about ten, of considerable size, being attached to
the epihyal, and an equal number of smaller ones to the ceratohyal.
There is a single dorsal fin in the middle of the back; the pelvic
fins are abdominal in position, opposite the dorsal, and each consists
of about 12 soft rays; the anal is situated half-way between the
pelvics and the caudal; and the latter is deeply forked. The scales
are cycloid and beautifully marked with delicate radiating ruge ;
thin scales also appear upon portions of the dorsal and caudal fins.
A distinct ‘axillary appendage” is observable above the pectoral
fin. ‘Three species can be distinguished, and are separated by the
form of the body, and the proportions of the operculum and posterior
circumorbital bones; they were respectively named by Agassiz,
R. brama, R. bucealis, and R. latus, and many of the National fossils
bear his MS. labels. The newly-determined characters show that
Rhacolepis is not a Percoid or Berycoid, as originally supposed, but
a truly Physostomous fish, The author concluded that it was an
Elopine Clupeoid.

380 Correspondence—Mr. W. Davies—Prof. Bonney.

CORRESPONDENCE.

NOTES ON CHELONIA.

Srr,—In the interesting “‘ Notes on Chelonia from the Purbeck,
Wealden, and London-clay,” by Messrs. Lydekker and Boulenger,
in the May Number of this Macazine, the authors refer to the generic
identity of the plastron named by Prof. Sir R. Owen Platemys
Bullockii, supposed to have been obtained from the London-clay at
Sheppey, and the plastra of the same author’s genus Pleurosternon
from the Purbecks. In regard to which will you allow me to state,
that when arranging the fossil Chelonia, some fourteen or fifteen
years ago, in the Museum cases at Bloomsbury, I observed that the
structural characters of the plastra of Platemys Bullockii and of
Pleurosternon were the same, and that the two genera must be merged
into one. This conclusion was further confirmed by a closer exami-
nation of the matrix adherent to the former, which proved it to have
been derived from the Purbecks, and not as stated from the London
clay. The specimen has ever since been exhibited in the Museum
eases with the following label attached, “ Plewrosternon (Platemys)
Bullockii, Owen, Purbeck beds, Swanage.”

Though the locality is not positively known, there can be little
doubt that the specimen was found in the “Isle” of Purbeck, and in
the neighbourhood of Swanage. Prof. Riitimeyer’s remarks upon
the same subject were, I am sorry to admit, unknown to me until
very recently. Wm. Davis.

THE LIZARD SERPENTINES.

Siz,—It appeared to me that, in regard to the existence of felspar
in the Rill serpentine,' lately in dispute between Mr. Teall and
myself, the evidence of a chemical analysis of the rock would do
much to clear up the question. Through the kindness of Dr. S.
Rideal, a partial analysis of this serpentine has been made in the
Chemical Laboratory at University College with the following
results in two cases :—

I II.

SiOn car ce et AOnTOn tae ele eet ORGS
IATORN EF Sie EY RTO) SME Sepa gs
Bes Osii tonuss lee MGT; (0B eae anes
CRON nen e) Ce ERY Bune)
MoO peer.) ce 08) 0. ey BeuiSeae

86°39 87°13

The water, alkalies, etc., were not estimated, as I had said that
probably the silica, alumina, and magnesia would suffice for my
purpose. At first sight this analysis appears conclusive in favour of
Mr. Teall’s contention, that there is felspar in the rock. It is the
analysis of a picrite, so far as such a variable rock can be said to
have a typical analysis. Indeed, the proportion of alumina is large
even for a picrite. But I still feel perplexed, for on consideration
of the analysis it appears to me to “prove too much.” Suppose the
alumina all present in the felspar, and that to be anorthite; for

1 See Grou. Mac. Feb. 1887, p. 69, and March, 1887, p. 137.

Correspondence—Rev. A. Irving. 381

rough calculations take the alumina as 14 per cent., and use the
proportions given by Nicol in his Mineralogy : then there will be in
anorthite #2 x 14 of silica, and 2% x 14 of lime, i.e. the amounts of
silica and of lime in the felspar will be nearly 16-3 and 7:6 respec-
tively. But the amount of CaO in the analyses is only 3-05 or 3:22.
Moreover, the total of the constituents in the anorthite would be
nearly 37; or more than a third of the rock would be felspar, which
is certainly far too much for any slide that I have seen. If the
amount be calculated from the lime, 5:5 of the alumina would be
needed, and 6°5 of the silica, and the felspar would be 26 per cent.
of the rock,—still too much, and there would be 8:5 of the alumina
left. In both these cases also there is not magnesia enough for the
remaining silica, if, as seems certain, another principal constituent
has been olivine. Suppose, however, the felspar be labradorite; then,
calculating in the same way, and supposing all the lime to be a
constituent of that mineral, we require 8 per cent. of the alumina,
leaving 6 per cent., so that the rock should be rather rich in such a
mineral as spinel, which it is not. In this case also the proportionate
amount of felspar seems considerably in excess of the amount of the
mineral which has been claimed. I have made various other trial
calculations from the analysis, and in no case can I obtain results
which seem to accord with the microscopic structure of the rock,
even in matters on which I believe we should be in agreement.

I may indeed add that I have more than once found a similar
apparent discrepancy between the microscopic and the chemical
analysis of a picrite, and had reason to suspect that the alumina was
mainly present as the constituent of a mineral other than felspar.
So, notwithstanding the apparently conclusive evidence of the
chemical analysis, on which I frankly admit Mr. Teall is entitled to
claim a verdict in his favour, I still feel very strongly the difficulties
as to the identification of the mineral alleged in my former commu-
nication, and am not sure that the question is even yet decided
beyond all appeal. T. G. Bonney.

THE BAGSHOT SANDS.
Str,—I do not think Mr. R. 8. Herries (Gnon. Mac. April, 1887,

p- 192) has found such a ‘mare’s nest’ as he seems to imagine.
The note he has quoted from vol. iv. of the Memoirs of the Geo-
logical Survey, of a pebble-bed somewhere near Barkham, has long
been familiar to me; but I have never succeeded in finding the pit
to which the description would apply. Short of the identification
of the pit, which I have described in my paper in the Grou. Mac.
for March last, by the original writer of the note quoted, I cannot
admit its application to the case in question. If the author of that
note is prepared to vouch for the supposed identification, the in-
accuracy of the description will go far to vitiate the evidence of
similar notes from the same source. I leave my critics to choose
between the horns of this dilemma.

In speaking of an “unmappped outlier,” it was simply intended
to imply that the beds under consideration had not been mapped out

382 Obituary—Arthur Champernowne, F.G.S.

as an outlier. A portion of them had been mapped, as I knew
perfectly well; but, as I think, wrongly. As a matter of fact, they
are found to extend half a mile further to the north, than the
boundary-line drawn on the map. When Mr. Herries shall have
made as complete and close an examination of the locality as I have
made, I shall be glad to welcome further criticisms from him on my
paper; meanwhile I do not feel quite justified in filling up the
pages of the Gzorogican Macazine in recording “glimpses of the
obvious.” A. Irvine.

WELLINGTON CoLLEGE, BERKS.

@23E irA: eae

ARTHUR CHAMPERNOWNE, M.A., J.P., F.G.S.
Born Marcy 197n, 1839; Diep May 22np,! 1887.

HY and anon as we press forward in life’s journey we are
4) confronted with the loss of some valued friend and comrade,
in whose removal we seem to suffer a far greater hardship than any
other we have had to bear. To many of us such a feeling arises
when we recall the keen sorrow of a few weeks since at the loss of
our fellow-worker in geology, Arthur Champernowne.

He was the eldest son of Henry Champernowne, Hsq., of Dart-
ington Hall, Totnes, South Devon, and belonged to one of the oldest
families in Devonshire. His father died in 1851, whilst Arthur was
only 12 years of age. He was educated at Eton, whence he passed
to Trinity College, Oxford, where he graduated as M.A. In 1870 he
married Helen, daughter of M. L. Melville, Esq., of Hartfield Grove,
Sussex.

Soon after he settled down in Devonshire, he became acquainted
with William Pengelly, F.R.S., of Lamorna, and John Edward Lee,
F.G.S., of Villa Syracusa, Torquay, the latter of whom was the
intimate friend of Prof. John Phillips, of Oxford, whose lectures
Arthur Champernowne had attended. The interest these geologists
aroused in his mind caused him to look around his own county and
try to understand, and finally to map, probably one of the most
complex pieces of country in the whole of England.

Mr. Champernowne never enjoyed robust health, but his earnest-
ness and enthusiasm in whatever he undertook carried him through
successfully. He was an excellent artist, and when travelling for
his health in Italy, he made many sketches; but after he took up
geology he only used his pencil to prepare sections and draw fossils,
which he executed with great skill and fidelity.

He geologised in Spain, and in order the better to comprehend his
native county, he made repeated expeditions to the Devonian rocks of
the Eifel, on one occasion with Mr. John Edward Lee, of Torquay,

1 The 5th June was by an error the date quoted in the July Number Gzor. —
Mac. —Eprr.

Obituary—Arthur Champernowne, F.G.S. 383

spending some time at Priim and Gerolstein. He also geologised at
Paffrath and in other parts of Germany and Belgium. His last
foreign trip to Belgium was particularly interesting to him, and he
was enabled to confirm many of his views as to the geology of
South Devon by what he saw in the Meuse Valley. In this visit
he was greatly assisted by M. Dupont, the Director of the Geological
Survey, who desired M. Alphonse Le Duc to accompany Mr.
Champernowne over much of the ground he wished to see and study.

He took the greatest interest in the Devonian Corals, in the work-
ing out of which he never seemed to tire. He was the first who
discovered the Calceola Limestone, and obtained specimens from the
cliff-section immediately below Daddy-hole-plain, Torquay—in
front of Mr. Lee’s house. He also obtained the fine Homalonotus
from the Devonian of the “New Cut,’ Torquay (figured in the
Grou. Mac. 1881, Pl. XIII. p. 489), and named after him by the
writer. So keen was he in the field that wherever he geologised he
invariably was the first to discover fossils, and usually the best
specimens fell to his own hammer.

During his Devonian researches he discovered in the “ Pit-Park
Quarry ” near the Hall, a vast number of Stromatoporoids, which led
him to enter into an earnest correspondence and have frequent
interesting conversations with Dr. H. J. Carter, F.R.S., of Budleigh
Salterton, Devon, who had taken much interest in this group of
organisms. Mr. Champernowne with great diligence extracted large
numbers of these fossils from the Limestone, and had numerous
sections cut and polished at his own cost to illustrate their internal
structure, and he most liberally distributed these to various museums
and individuals interested in their examination.

Prof. Nicholson writes, “ Mr. Champernowne took a special interest
in the Stromatoporoids, and gave me throughout the most unselfish
and ungrudging help in the work I had undertaken, namely, to
prepare a Monograph on this group of organisms for the Paleeon-
tographical Society. He not only placed at my disposal the whole
of his splendid collection from the British Devonians, but he freely
laid before me the results of his own studies in these difficult fossils ;
indeed, I owe more than I could easily measure to his friendly
criticisms on my work, and his wise suggestions as to the particular
lines of research which it would be wise for me to follow. With
this feeling, I cannot but recognize in the death of Arthur Champer-
nowne that a heavy loss has befallen the small band of British
Palzontologists of which he was so excellent a type. It is not
only a gifted scientific observer that has gone from amongst us, but
a genuine man and a loyal and true-hearted friend.”

With Mr. Horace B. Woodward, Mr. W. A. E. Ussher, of the
Geological Survey, and Mr. Frank Rutley, he was in frequent cor-
respondence ; and when the former Surveyors were at work in his
area, it afforded Mr. Champernowne the keenest pleasure to join”
them in the field and share his knowledge of the country with them.

The visit paid to Devonshire by Prof. Dr. Ferdinand Roemer, of
Breslau (the Geological Historian of the Devonian rocks of the

304 Obituary—Arthur Champernowne, F.G.S.

Hifel) afforded Mr. Champernowne the utmost gratification, as con-
firming the views which he had arrived at, together with Mr. John
Edward Lee, on the Upper Devonian Goniatite Limestone in Devon-
shire (see Grou. Mace. 1880, Pl. V. p. 145) and other kindred.
subjects. — |

Mr. Champernowne was at the time of his death a Member of the
Councils of the Geological and of the Palzontographical Societies, in
both of which he took the warmest interest. He was a frequent
contributor to the Quarterly Journal of the former Society as well
as to the GrotocicaL MaGazinr.

Mr. Horace B. Woodward frequently refers to Mr. Champernowne,
and acknowledges his great indebtedness to him for revising the
Devonian chapters of his ‘‘ Geology of England and Wales” (2nd
edition just published).

The Director-General of the Geological Survey, Prof. Geikie, told
the writer, “ When I saw Mr. Arthur Champernowne’s detailed
geological colouring on the Ordnance Maps of his own area, I was
delighted with the beauty and clearness of the work, and after going
over the ground with him, I was equally convinced of its careful
accuracy.

«When I proposed to him that he should allow me to incorporate
his work on the Survey Sheets, he was greatly pleased, but so
modest and diffident was he, that after spending years on this area,
he expressed his anxiety to go over it all again before allowing me,
to accept it as quite complete.”

It was after attending the Council Meeting of the Geological
Society on May 11th, that he hurried down to Dartington intent on
setting to work at once upon a revision of his maps, and having
gone abroad in unfavourable weather, and suffering from a severe
cold, he caught a chill which developed into inflammation of the
lungs, under which he gradually sunk.

Mr. Champernowne was connected with every work of benevolence
and public usefulness in his own district. As a Magistrate he was
most conscientious in the discharge of his duties; as a Landlord he
was most generous, and lived upon the best terms with all his.
tenantry, his constant aim being to promote their welfare. His
death was felt as a common sorrow, and his funeral was attended by
representatives of all ranks of society each of whom seemed to feel
that in the deceased he had lost a personal friend.

Mr. Champernowne leaves a widow and ten children, the eldest,
a boy of only fifteen years, to deplore his early loss.

Like shadowy watchers by some misty shore,
We stretch our arms towards the silent main,

And sigh for those we ne’er shall look on more,
Whose hand-clasp we may never feel again.

There is no fear that the name of ArTHUR CHAMPERNOWNE will
be soon forgotten, either in his home-circle, or in that wider
scientific circle of friends, to be associated with whom as a fellow-
worker he always esteemed to be his greatest happiness.—H. W.

GEOL. MAG 1887. DECADE IILVOL IV.P1.XI._

]
,
%
,

EC Kon ght lith. West, Newman & Co.imp.

Ostracoda from the London Clay. —

THE

GEOLOGICAL MAGAZINE.

NEW "SERIES; 1DECADE III, .VOL.-IV,

No. IX—SEPTEMBER, 1887.

ORIGINAD ARTICLIAS.

——+—__.

I.—Furruer Notes on THe Tertiary EnTomostTraca oF ENGLAND,
WITH SPECIAL REFERENCE TO THOSE FROM THE LONDON Clay.

By Professor T. Rupert Jonzs, F.R.S., and C. Davies Suerzorn, F.G.S.
(PLATE XI.)

HE Tertiary Entomostraca (Ostracoda) of England, at first
treated of ina monograph for the Palzeontographical Society in

1856, were revised in the Grotocgtcat MaGazinz, 1870, pp. 155-159.
The researches of G. O. Sars and G. 8. Brady, elucidating the
relationships of the genera and species, gave effect in a great degree
to that revision ; and their continued labours have further helped us.

Since the publication of the Revision, fifteen years ago, besides
there being some additional corrections to be noticed, several
new species have come to hand, late research in the fossiliferous
deposits of Tertiary age having enabled our friends to add to the
collections we have made for ourselves, so that the known English
Tertiary forms are now nearly eighty in number. The British Post-
Tertiary species are still more numerous.!

We therefore offer these “Further Notes” as of interest to
workers on Fossil Ostracoda.

Besides new species, those requiring some remarks as to new
occurrence or corrected nomenclature are noticed in this communi-
cation. We especially take this opportunity of drawing attention to
the Ostracoda lately found in the London Clay from an excavation
in Piccadilly, London ; and with them we group in this paper all
the species known to occur in that formation, giving illustrations of
these London Clay forms in one plate, so as to present their facies at
a glance,—with the exception of two species which reached us after
the plate was finished, but figures of which are given in the text.
The order of description is arranged according to the natural grouping
of genera sabe by Dr. G. 8. Brady i in his latest memoirs on recent
Ostracoda.

Cypripga, Bosquet, 1852.

This genus is described at large in the Quart. Journ. Geol. Soc.
vol. xli. (1885), p. 836. Remarks on the possible alliance existing
between Cypridea and Chlamydotheca have been made by G. S.

1 See the “Monogr. Post-Tert. Entom.”” by Brady, Crosskey, and Robertson,
Paleont. Soc. 1874.

DECADE III.— VOL. IV.—NO. Ix. 25

386 Jones and Sherborn—Tertiary Entomostraca.

Brady, in the ‘ Proceed. Zool. Soc. Lond.,’ 1886, p- 90; and in the
‘Journ. Linn. Soc.,’ vol. xix. (1886), pp. 200, 201.

1. Cypripga spinicera (Sow.).

This is referred to at pp. 316, 333, 334, Quart. Journ. Geol. Soc.
vol. xli. as a species common in the upper part of the Weald Clay ;
and we now find that it occurs in Tertiary beds at Hempstead in the ©
Isle of Wight. Specimens, young or imperfect, from this locality
were figured in the “Geological Survey Memoir on the Isle of
Wight,” 1856, as a sub-reniform Ostracod with a sharp spine on each
valve, Cytherideis unicornis (Jones). Careful examination of a
further series of specimens leaves no doubt that it is the same species
as that found in the Wealden beds. The Hempstead specimens are
not so well preserved as those in the Wealden Clays, nor are they so
abundant ; but, with the many individuals that have come under our
notice, we have been able to match old and young perfect examples
from the Tertiary and Wealden formations.

2. CYPRIS INCONGRUENS, Ramdohr.
Cypris setigera, Jones, Monogr. Tert. Entom., 1856, p. 12, pl. i. fig. 6.
Candona compressa (Koch), Grou. Mac. 1870, p. 155.

To the localities of Berkshire and Cambridgeshire mentioned in
the Monograph, 1856, we have to add the Valley-drift of Fisherton
at Salisbury (Dr. Blackmore’s Collection), Portland raised beach
(Prestwich), and lacustrian bed near Hitchin (W. Hill).

3. PoTAMOCYPRIS TRIGONALIS (Jones) ; and var. LEVIS, nov.

We have two examples of this species from Mr. Clement Reid’s
Collection,—one from the Norwich Crag at Bramerton,—and one
from the Weybourn Crag at Hast Runton.1 The latter specimen,
being larger and smooth, may be distinguished as var. LHVIS.

4, AGLAIA? CYPRIDOIDES, sp. nov.

The genus Aglaia, G.S. Brady (1868), one of the Cypridida, has here
a fossil form provisionally referred to it on account of the similarity
of shape and condition of the valves. The muscle-spot, however,
is like that of Bairdia. Our example is from the Norwich Crag of
Bramerton, and was collected by Mr. Clement Reid, F.G.S. It has
the usual curved form, and is delicately pitted. It is too broad in
shape for either A. ? glacialis, G. S. Brady, ‘“ Post-Tert. Hntom.,”’

1 Mr. Clement Reid, F.G.S., has given a detailed account of the Norfolk Deposits
in the ‘‘ Mem. Geol. Survey; The Geology of the Country around Cromer,’ 1882.
The Weybourn Crag is described at pp. 11—19; and the Entomostraca from that
deposit are mentioned at p. 66. See also Prof. Prestwich’s Memoir on the Crag
Beds of Suffolk and Norfolk; Quart. Journ. Geol. Soc. vol. xxvu. p. 457, 460, ete. ;
and H. B. Woodward’s ‘‘ Geology of England and Wales,’’ 2nd edit. pp. 465-474,
for Bramerton, Weybourn, ete. The Bramerton Crag is also treated of in H. B.
Woodward’s ‘‘Geol. Surv. Mem. ; The Geology of the Country around Norwich,’
1881, pp. 38-55, 82, ete. The list of Ostracoda from Weybourn referred to above
does not agree with our determination in all respects. Thus we have not found
Cythere tuberculata, Sars, nor C. pellucida, Baird, among the specimens we have seen ;
and probably C. concinna, Jones, is represented by the set of the closely allied C.
angulata, Sars, which we have met with. Other species in our series are not indicated
in the printed list referred to.

Jones and Sherborn—Tertiary Entomostraca. 387

p. 132, pl. xi. figs. 54-56; or A.? obtusata, G. 8. Brady, ‘“ Report
Challenger Ostrac.,” p. 35, pl. xxx. fig. 8.

5. ByTHOCYPRIS SUBRENIFORMIS, sp. nov.

In the genus Bythocypris, determined by G. 8S. Brady, in “ Report
Challenger Ostrac.,” 1880, the left valve is described as much
larger than the right, and overlapping it above and below. In this
character, and other features, a specimen from the “ Belosepia-bed ”
at Bracklesham (Science Schools Coll.) coincides. It approaches
Cytherina abbreviata, Reuss, “‘ Haidinger’s Nat. Abh.,” vol. iii. p. 52,
pl. viii. fig. 10 ; but itis too short and too high, and is not so reniform.
It has the usual kidney-shape, and is also near B. reniformis, G. S.
Brady, “Report Challenger Ostrac.,” p. 46, pl. v. fig. 1; but this
figured form is too short, and more incurved on the ventral edge
than is our specimen.

6. Pontocypris (?), sp.

A single, small, pitted valve, of uncertain alliance, but approxi-
mately like some members of the genus Pontocypris, G. O. Sars,
occurs in a collection from the Tertiary beds at Colwell Bay.

7. Barrpra suppEttormpea (Minster), Jahrbuch fiir Min. etc. 1830,
p- 64; and 1838, p. 446.
(For synonyms see Monogr. Tert. Entom, p. 52.)

As mentioned in the Grontogican Magazine for 1870, p. 157, the
little Bairdia from the Crag (‘ Monogr. Tert. Entom.,’ 1856, p. 52,
pl. iv. fig. 2) may be B. fusea, G. S. Brady, ‘Trans. Zool. Soe.’ vol. v.
p- 364, pl. lvii. fig. 9; and the fine species from the London Clay
{‘ Monogr.’ p. 52, pl. vi. fig. 1) is probably B. subtrigona, Bornemann,
‘Zeitschr. deutsch. geol. Ges.,’ vol. vii. p. 857, pl. xx. fig. 4.

We have now from the Bracklesham Belosepia-bed (Science
Schools Coll.), a very fine example of the real subdeltoidea, which we
have compared with authentic specimens from Osnabriick, sent by
Count Miinster to London many years ago.

With the Bracklesham specimen is a smaller individual, relatively
thicker and rounder; it may belong to a different species, but for the
present we leave it as a variety.

8. Bairdia subtrigona, Bornemann. Pl. XI. Fig. 1.

B. subdeltoidea, Jones, Monogr. Tert. Entom., 1856, p. 52, pl. vi. fig. 1.
This specimen from the London Clay is re-figured from the above-
mentioned Monograph. As mentioned in our description of B.
subdeltoidea, we now refer this species to Bornemann’s B. subirigona.

9. Barrpra Lonpinrensis, sp. nov. Pl. XI. Fig. 2.

This is a small neat Bairdia, of a not unusual form, but not
exactly matching in shape any species known to us; it is moreover
denticulated at the end margins, and punctate all over with very
distinct, roundish, close-set pits. This valve is stained with nume-
rous bright orange-irony spots, which possibly may be traces of the
original colouring of the shell.

388 Jones and Sherborn—Tertiary Entomostraca.

From the London Clay, Piccadilly ; collected by Messrs. Sherborn
and Chapman.*

10. BarrDIA RHOMBOIDEA, sp. NOV.

A stiff-looking Bairdia ; broadly angular in front; nearly parallel
above and below ; narrow behind, with a curve on the ventral, and
a slope on the dorsal edge of this end. The antero-ventral margin
is suddenly constricted, leaving a projection behind the antero-ventral
slope. The surface is very delicately punctate.

From the White (Coralline) Crag of Sutton, Suffolk.

‘11. Barrpra ovorpea, sp. nov. Pl. XI. Fig. 3.

A very small roundish Bairdia, pitted, rosetted at the muscle-spot,
of a rather unusual pattern. It is like fig. 2, pl. iv., Monog. Tert.
Entom., but much less of a subdeltoidal shape, being well rounded
before, and slopingly curved behind, with the greatest fullness in the
front moiety; hence, though both ends are somewhat obliquely
rounded, the anterior half of the valve is broader than the hinder
portion.

From the London Clay, Piccadilly. Collected by Sherborn and
_ Chapman.

CytHERE, Miller, 1875.

Valves unequal (left valve usually somewhat larger than the
other), oblong-ovate to quadrate in shape, smooth or rough, mostly
highest in front; hinge with teeth and sockets at anterior and pos-
terior angles, variously developed.

The quadrate and rough forms have been classed as Cythereis
(‘ Monogr. Cretac. Entom.,’ 1849, p. 14) ; and, although this group
will not hold its own as a true genus, Dr. G. 8. Brady having shown
that the animals do not differ from other Cythere, yet it is a very
convenient grouping for paleontologists, who have to study the
valves only of these small fossil Crustacea.

12. CyTHERE RECURATA,” sp. Nov.

Oblong-reniform, nearly equal at the ends in the outline, but
thickest posteriorly, as seen in edge view. Approximating to fig. 7g,
of G. S. Brady’s C. demissa, in pl. xii. of the “Report Challenger
Ostracoda,” but more even in outline. Coarsely punctate; the pits
somewhat in lines, but with a tendency to assume a concentric
arrangement on the front half of the valve. Others are of the same
outline, but differ in the ornament.

From the “ Norwich Crag” of Southwold.

13. CyTHERE VENUSTULA, Sp. nov.

Oblong, rounded at the ends, broadly oblique in front, semi-circular
behind; straight on the ventral margin, oblique dorsally by the

1 In the ‘Journ. R. Micros. Soc.’ ser. 2, vol. vi. p. 740, this specimen was
doubtfully collated with Sowerby’s Cypris barbata (‘ Trans. Geol. Soc.,’ ser, 2, vol.
y. 1834, p. 181, pl. ix. fig. 1), but this was probably a Cythere.

2 6¢ Finished in a workman-like manner.”’

Jones and Sherborn—Tertiary Entomostraca. 389

swelling of the anterior hinge-joint. Depressed on the front half, but
more convex behind. Surface ornamented with a neat open network
of delicate meshes, lying obliquely from the postero-dorsal to the
antero-ventral region.

From the Belosepia-bed at Bracklesham. (Science Schools Coll.)

14. Cyruere Rerp1t, sp. nov.

Valves sub-oblong, obliquely rounded at the ends, broader in
front than behind, straight on the back, slightly sinuous below,
nearly flat ; rising into a median knob in the anterior third. Surface
with rather coarse punctation, making a rough reticulation. Named
after Mr. Clement Reid, F.G.S., who collected this and many other
undescribed Ostracoda from the Crag beds of Norfolk. From the
Weybourn Crag of Hast Runton. (Museum of Practical Geology.)

15. CyTHERE RETIFASTIGIATA, Jones.

Mr. Clement Reid has met with a good example, with less pro-
minent ridges than in the figure in the ‘ Monograph,’ 1856 (pl. iii.
fic. 7), and with a smaller, neater, and closer punctation. Weybourn
Crag. (Mus. Pract. Geol.)

16. CyTHERE LACRYMALIS, sp. NOv.

One of the sub-oblong punctate Cythere, of a not uncommon
shape, but rather more oblique anteriorly than usual. Surface
slightly convex, swelling at the anterior third, and posteriorly
bearing two separate, short ridges, which rise near the middle of the
valve, and end each in a strong knob at the posterior border, thus
forming two long tear-shaped eminences, instead of the more usual
pair of posterior swellings, such as we see in C. bidentata, Bosquet,
Tert. Entom., 1852, p. 72, pl. iii. f. 9, and several other Tertiary
Cythere. From the Norwich Crag, Bramerton, collected by Clement
Reid, F.G.S. (Mus. Pract. Geol.)

17. CyrHEerr picryostema, Jones.

This was not figured in the ‘ Monogr. Tert. Entom.,’ 1856, p. 33 ;
but we hope to figure it shortly. We may remark that some of Dr.
G. S. Brady’s illustrations of his Oythere mutabilis, ‘Trans. Zool.
Soc.,’ 1866, p. 377, pl. lix. fig. 14 (C. tuberculata, G. O. Sars, Brady,
etc., Post-Tert. Entom., p. 164), approach very near to C. dictyosigma.

18. CyrHzre ancuxata (G. O. Sars), var.
Cythere angulata, G. 8. Brady, Trans, Linn. Soe. vol. xxvi. p. 409, pl. 26, figs. 89-42.

In some of their more important characters our little specimens
agree with Dr. G. 8. Brady’s definition of C. angulata ; but in them
we also see a strong affinity to C. limicola, Norman; C. globulifera,
Brady, and OC. concinna, Jones, as described in full by G. 8. Brady,
are also near allies.

Our specimens were obtained by Mr. C. Reid from the Norwich
Crag of Bramerton, and the Weybourn Crag of Hast Runton ; and
are in the Mus. Pract. Geology.

390 Jones and Sherborn— Tertiary Entomostraca..

19. CyrHmrr CHARLESWORTHIANA, Sp. nov.

A neat small Cythere, oblong, with front end rather obliquely
rounded, and the posterior nearly square. Ventral edge slightly
incurved, dorsal faintly arched. Broadest at the anterior third near
the front hinge-joint. Surface ornamented with very delicate elon-
gate pits, arranged in lines lengthwise, but curving in front, parallel
with the margin. The anterior margin is neatly denticulate, espe-
cially on its dorsal third. This differs from our Cythere recuratw
in being truncated posteriorly and denticulated in front, and also in
its ornament. The form nearest to this that we know of is C. tenera,
G. 8. Brady, Trans. Linn. Soc., vol. xxvi. p. 399, pl. 28, fig. 29-382 ;
but in shape and ornament it differs.

From the Weybourn Crag of East Runton, collected by Mr.
Clement Reid. (Mus. Pract. Geol.)

In memory of his early researches in the Crag, we name this
species after Mr. H. Charlesworth.

20. CYTHERE viLLosA, Sars. B. C. and R., Monogr. Post-Tert. Hntom.
1874, p. 157, pl. iii. figs. 7-18.

Subtriangular, straight on the ventral, and obliquely arched on the
dorsal and front edges, but somewhat truncate behind. Surface
bearing a concentric reticulation of coarse angular pittings. Three
tubercular swellings affect the valve just within its thickened rim,
two behind, such as are frequent in this group of Cythere, and one
in the antero-ventral third. The greatest convexity of the valves is
central, making the edge-view acute-oval.

From the Weybourn Crag of East Runton. Collected by Mr.
Clement Reid. (Mus. Pract. Geol.)

With this species we connect a variety from the “ Norwich Crag”
of Southwold, in which the tubercles are not so definitely marked.
The places of the two near the ventral margin are occupied by
irregular swellings, and the postero-dorsal tubercle is ill-defined.

21. CyTHERE Las, sp. nov.

Ovate-oblong, straighter on the ventral than on the dorsal edge.
Close to the ventral margin is a broad, longitudinal, somewhat sinuous
ridge, widened, or rather doubled, with an oval interspace at its
posterior third, and irregular at the anterior third. In one specimen
the surface is coarsely reticulate with angular meshes; in the other,
the ornament consists of a smaller mesh-work. In this latter indi-
vidual the edge-view is less convex than in the other.

Norwich Crag, Bramerton. Collected by Mr. Clement Reid. (Mus.
Pract. Geol.)

22. CyrHERE WooDWARDIANA, Sp. nov.

Sub-trigonal; obliquely rounded in front, nearly semicircular
behind ; broad across the anterior third by the projection of the
hinge-joint. Surface slightly convex; ventral surface somewhat
flattened. Superficial ornament a coarse irregular pitting.

We name this species after Dr. Samuel Woodward, one of the
earliest workers in these late Tertiary deposits.

Jones and Sherborn—Tertiary Entomostraca. 391

From the Weybourn Crag, Hast Runton. Mr. C. Reid. (Mus.
Pract. Geol.)

23. CyrHeRE Aarenosa, Bosquet. Pl. XI. Fig. 4.

This is one of the papulated forms of Cythere, the surface having
low, tubercular, and obscure meshes, which in other instances form
strong tubercles. In some cases these become ragged warts (C.
scabra, Miinster ; see Bosquet, Entom. Tert., p. 103, pl. v. fig. 7) ;
in others they pass into spines (C. ericea, C. irpex, and others; G.
S. Brady. “Challenger Ostrac.,” pl. xvii. and xviii.) ; we have also
a passage-form. The above and two following forms have a subovate
edge-view. They were found in the London Clay of Piccadilly,
London, by Messrs. Sherborn and Chapman.

24, CYTHERE SCABROPAPULOSA, Jones. Pl. XI. Fig. 5.

This specimen from the London Clay of Piccadilly is more
uniformly convex and more rounded posteriorly than the Brackle-
sham specimen figured in the Monograph, 1856, pl. v. fig. 16.
Moreover, the anterior margin is strongly denticulated, but the
dorsal edge is not quite so roughly tuberculate as seen in the valve
from Bracklesham.

Dr. G. S. Brady’s “ C. scabropapulosa” from the Antwerp Crag
(Trans. Zool. Soc. vol. x. p. 393, pl. Ixvi. fig. 2), beng much rougher
and more warty, is nearer to OC. scabra, Miinster, and might be
regarded as C. scabropapulosa, var. rudis.

25. CYTHERE SCABROPAPULOSA, Jones, var. ACULEATA, NOV.
Pies Hic: 6.

This is a well-grown valve of OC. scabropapulosa becoming hispid,
by the tubercles ending with a sharp prickle or spine. A further
development of this spinose condition is seen in C. irpex, Brady, as
above mentioned. This also is from the London Clay of Piccadilly.

26. CYTHERE GYRIPLICATA, Sp. NOV.

Narrow-suboval in outline, hinge-line slightly convex, but distinct.
Ends rounded; narrow behind, somewhat oblique in front. Surface
sculptured with delicate longitudinal ridges, arranged concentrically
towards the margins, and united by smaller transverse ridges.

From the Belosepia-bed of Bracklesham. TT. R. Jones’ Collection.

The nearest species we know of is Bosquet’s C. multicostata, Entom.
Tert., p. 59, pl. ii. fig. 12 ; but this is very much coarser and broader,
and without any sign of reticulation.

27, CYTHERE DELIRATA,! sp. nov.

A Cythere of the not uncommon sub-oblong form, but with the
rare ornament of slight furrows diverging up and down from the
median line of the posterior region, and becoming more or less
concentric or confused anteriorly. Edge view long-oval.

From the Fluvio-marine beds of Headon Hill, Isle of Wight.
(Fred. Edwards’ Collection in the British Museum.)

1 Ploughed with divergent furrows.

392 M. Dollo—Belgian Fossil Reptiles.

EXPLANATION OF PLATE XI.
(OstRacopA FROM THE -Lonpon Cuay.')

Fie.
1. Bairdia subtrigona, Bornemann.
2. 30 Londiniensis, sp. nov.
3. rs ovoidea, sp. NOY.
4. Cythere arenosa, Bosquet.
6. ue seabropapulosa.
6. is os var. aculeata, Nov.
i. i. scalaris, sp. Nov.
8. ; scrobiculoplicata, Jones.
9. Cythereis Bowerbankiana, Jones.

10,a,6. 4, aranea, sp. nov. ; 0, ventral aspect.

11, a,b. ,, Prestwichiana, sp. nov.; 0, transverse section.
12. Cytheridea perforata (Roem.), var. insignis, Jones.
‘ glabra, Jones.

14, a, 6. Krithe Londiniensis, sp. nov.

15, a, 6. » glacialis, B. C. and R.

16. Cytheropteron triangulare (Reuss).

17. Cytherella fabacea, Bornemann.

18. 9p Beyrichi (Reuss).

19. 5p compressa (Minster).

(Zo be continued.)

IJ.—On some Beteran Fossin Repriues.

By Lovis Dotto, C.E.,
Assistant Naturalist in the Royal Museum of Natural History of Belgium,
Brussels.
HAVE read with much interest the two articles which Messrs.
G. A. Boulenger and R. Lydekker have recently published in
the GroLtocican Macaztnz,” and I should be very much obliged
if you would permit me to make an addition, which appears to me
useful, and which I should be glad to see published.

I. Psruporrionyx.*—1. I have remarked with satisfaction that
it has been possible for the above-named naturalists to refer to
P. Detheidi, a Tortoise of the London-clay. This discovery is doubly
interesting, in the first place because it shows the existence of the
Belgian fossil in England, in the second place, because it establishes
the existence of the Bruxellian (Middle Eocene) Chelonian in the
Ypresian epoch (Lower Hocene).

2. I do not, however, believe that the absence of the horny scutes
in Pseudotrionyx would be sufficient to create a new family.* In
fact, I think, for reasons which I shall explain elsewhere,’ that
the Zhecophora® without horny scutes (Gymnoderms) proceeded
from types which possessed them (Lepidoderms). I believe also that

1 See also woodcuts in the text.
_ ® R. Lydekker and G. A. Boulenger, ‘On Chelonia from the Purbeck, Wealden
and London Clay,’ Grou. Mac. June, 1887, p. 270. R. Lydekker, ‘ Notes on Hord-
well and other Crocodilians,’ Grou. Mac. July, 1887, p. 307.

2 L. Dollo, ‘ Premiére Note sur les Chéloniens du Bruxellien (Eocéne moyen)
de la Belgique,’ Bull. Mus. Roy. Hist. Nat. Belg. 1886, t. iv. p. 75.

4 R. Lydekker and G. A. Boulenger, ‘ Chelonia,’ ete. p. 274.

5 L. Dollo, ‘Premiére Note sur les Chéloniens oligocénes et néogénes de la
Belgique,’ Bull. Mus. Roy. Hist. Nat. Belg. 1887, t. v. (in the press).

6 L. Dollo, ‘Chéloniens du Bruxéllien,’ ete., p. 79.

M. Dollo—Belgian Fossil Reptiles. 399

the disappearance of the scutes has taken place by a progressive
diminution of their rigidity, a diminution in consequence of which
the skin has been gradually moulded upon the subjacent bone,
taking exactly its reliefs and hollows. At this stage it must have
already possessed a vermiculated external surface of the carapace (as
happens with the Thecophora, which have a soft skin, Zrionyx for
example), but the dorsal tegument was always divided into distinct
areas, leaving their trace upon the above-mentioned external face.
Such is perhaps Anostira,! and probably Chelonia Suyckerbuyki.
Afterwards, these different areas have disappeared, and with them
their lines of demarcation on the skeleton: take Trionyx and
Pseudotrionyx as examples. We may then find, by future researches,
all the passages between the gymnoderm and lepidoderm Thecophora,
and I do not understand, consequently, how the presence or the
absence of horny scutes could suffice alone to characterize a family.

TI. Pacnyrayncuus.2—l. As Messrs. Boulenger and Lydekker
have pointed out,? this name has already been employed; it
will therefore be necessary to change it. Ina paper at present in
the press‘ I have proposed to substitute for it Hrquelinnesia, to
recall the locality in which the curious Chelonian has been dis-
covered, and where it is so common.?

2. As Messrs. Boulenger and Lydekker admit,’ and contrary
to the statement of Mr. E. D. Cope,7 my Pachyrhynchine* are
quite distinct from the Propleurid@® of the celebrated Professor of
Philadelphia, since the latter have nine pairs of costal plates,
whereas the Chelonian of Erquelinnes has only eight.

3. Mr. Cope, notwithstanding the assertion to the contrary of
Messrs. Boulenger and Lydekker,’ does not refer, at least in the
paper meutioned by them," any of the species of Sir R. Owen
to Puppigerus.” Besides, as I have said in a former paper,”
Erquelinnesia is, without any doubt, generically different from the
American type, since the latter has the xiphiplastrons united by

1 J. Leidy, ‘Contributions to the extinct Vertebrate Fauna of the Western
Territories,’ Rep. U. 8. Geol. Surv. Territories (F. V. Hayden), Washington, 1873,
p. 174 and 174, pl. xvi. fig. 1 and 2. E. D. Cope, ‘The Vertebrata of the
‘fertiary Formations of the West’ (book i.), Rep. U. S. Geol. Surv. Territories (F.
V. Hayden), Washington, 1883, p. 112. L. Dollo, ‘Chéloniens du Bruxéllien,’ ete.

. 95. :

2 L. Dollo, ‘ Premiére Note sur les Chéloniens landéniens (Eocéne inférieur) de
la Belgique,’ Bull. Mus. Roy. Hist. Nat. Belg. 1886, t. iv. p. 129.

3 R. Lydekker and G. A. Boulenger, ‘ Chelonia,’ etc., p. 270.

4 L. Dollo, ‘ Chéloniens oligocénes et néogénes,’ etc, (Vv. supra).

5 L. Dollo, ‘ Chéloniens landéniens,’ ete., p. 129.

6 R. Lydekker and G. A. Bouleger, ‘ Chelonia,’ etc., p. 271.

7 E. D. Cope, ‘Dollo on Extinct Tortoises,’ American Naturalist, November,
1886, p. 968.

8 L. Dollo, Chéloniens landéniens,’ etc., p. 139.

9 KH, D. Cope, ‘Tertiary Vertebrata,’ etc., p. 111.

10 R, Lydekker and G. A. Boulenger, ‘Chelonia,’ etc., p. 271.

11 KE. D. Cope, ‘ Dollo on Extinct Tortoises’ (v. supra).

12 HE. D. Cope, ‘ Tertiary Vertebrata,’ etc., p. 112.

18 L, Dollo, ‘ Chéloniens landéniens,’ etc., p. 131.

394 M. Dollo—Belgian Fossil Reptiles.

sutures. The Turtle of the New World, which the Belgian reptile
resembles most, appears to me, as well as to Mr. Cope, to be
Euclastes.; But I shall return to this subject on another occasion.

III. Pevrocurnys.*—Whatever may be the position of this form
in classification, I do not believe that it can be identified with
Tretosternum, as Messrs. Boulenger and Lydekker think.* In fact,
with regard to Zretosternum, according to the naturalists just named,
“the plastron is essentially of the Dactylosternine type of Cope.’’*
Now I can assert that I have not seen the least trace of “more or
less open digitations”’® in the plastron of Peltochelys.

TV. Bernissartia.°—According to Mr. Lydekker,’ with whom
Mr. Boulenger agrees,* Bernissartia = Hyleochampsa,® tor there
would exist in the latter an orbito-latero-temporal notch.

1. In the first place, I beg leave to point out to these
naturalists that Sir Richard Owen says plainly: “The orbits in
Hyleochampsa are circular and better defined by the postfrontal
from the lateral outlets of the temporal fosse than in Crocodilus,.
and herein they more resemble the orbits in Zeleosaurus,”” which
agrees with the figure given by the celebrated paleeontologist.
And, on the other hand, I can assert that, in Bernissartia, the
orbito-latero-temporal notch is as clearly marked as in any living
Crocodilian. The difference which I have pointed out is therefore
quite real, although perhaps less strongly marked than I have stated.

2. In the second place, I will add that a naturalist peculiarly
competent in the question under consideration, and who has also
seen the type of Hyl@ochampsa, Mr. A. 8. Woodward, is inclined”
to consider it rather as a Teleosaurian, which supports what I have
just said, and removes the English Crocodilian from Bernissartia.

3. However this may be, and until I shall have described in a
more complete manner (and with numerous figures) the Crocodilians.
of Bernissart, I may add, to the character which I have already
indicated, the following differences between Bernissartia and Hylao-
champsa.

1 E. D. Cope, ‘Synopsis of the Extinct Batrachia, Reptilia and Aves of North
America,’ Trans. Amer. Philos. Soc. Philadelphia, 1871, p. 147 and pl. vi.

2 L. Dollo, ‘ Premiére Note sur les Chéloniens de Bernissart,’ Bull. Mus. Roy.
Hist. Nat. Belg. 1884, t. iii. p. 76.

3 R. Lydekker and G. A. Boulenger, ‘ Chelonia,’ etc., p. 273.

4 R. Lydekker and G. A. Boulenger, ‘ Chelonia,’ etc., p. 273.

> K. D. Cope, ‘ Tertiary Vertebrata,’ etc., p. 111.

6 LL. Dollo, ‘ Premiére Note sur les Crocodiliens de Bernissart,’ Bull. Mus. Roy.
Hist. Nat. Belg. 1883, t. ii. p. 309.

7 R. Lydekker, ‘ Crocodilians,’ ete., p. 310.

8 R. Lydekker, ‘ Crocodilians,’ etc., p. 310.

® R. Owen, ‘Monograph on the Fossil Reptilia of the Wealden and Purbeck
Formations,’ Supplement, No. VI. Crocodilia (Hyleochampsa), Wealden, Paleon-
tographical Society, London, 1873.

10 R. Owen, ‘ Hyleeochampsa,’ etc., p. 8.

1 R. Owen, ‘ Hyleochampsa,’ etc., pl. ii., fig. 24.

2 A. S. Woodward, ‘On British Fossil Crocodilia,’ Grou. Mac. Nov. 1887,.
p- 504. A.S. Woodward, ‘ The History of Fossil Crocodiles,’ Proc. Geol. Assoc. Feb.
1886, p. 318.

M. Dollo—Belgian Fossil Reptiles.

395

CHARACTERS,

5
Ornamentation
the cranium.

of

2.
Orézts.

Interorbital space.

Hyt#xocuAmpsa.!

“The outer surface of the cranial bones
shows a different pattern of sculpture
from that in Gonzopholzs; instead of
small circular pits, there are short irre-
gular ridges, which, at some parts, the
post-frontal, forexample, havea tendency
to diverge from a reticulate centre; a
number of short ridges and clefts radiate
from the raised part of the border of the
temporal outlet; but all these accentua-
tions of the surface are rather feeble’’
(pp. 1 and 2).

BERNISSARTIA.

Ornamentation very accentuated and
consisting in small circular pits.

A. “Circular”? (p. 3),

B. Antero-posterior diameter shorter
than the corresponding one of the
supratemporal fossz; transverse dia-
meter longer than the corresponding one
of the supratemporal fosse.

C. Orbits neither horizontal, nor ver-
tical, but intermediate between the two.

Forming very distinctly, in its narrowest
part, more than the half of the trans-
verse diameter of an orbit.

4.
Supratemporal
Soss@.

5.
Intersupratem-
poral space.

6.
Posterior border of
the superior surface
of the crantune
seen from above.

as
Pterygo-palatine
vacurties.

Form very elongated, ‘‘ teleosauroid ”’
(p. 3)-

A. No; having the form of the figure
8 of which the anterior circle has a much
smaller diameter than the posterior one,
but being equally weli accentuated.

B. Antero-posterior and _ transverse
diameters much greater than the corre-
sponding ones of the supratemporal
fossz.

C. Orbits horizontal.

Forming, in its narrowest part, very
distinctly less than the half of the trans-
verse diameter of an orbit.

Form more rounded.

At the narrowest part, at least a third
inferior to the transverse maximum dia-
meter of a supratemporal fossa.

With three notches of which one is
median.

Slight, very narrow and elongate.

8.
Interpterygo-
palatine septum.

Q.
Choanes.

I0.
Szze.

Much thicker, at its narrowest part,
than the transverse diameter of one of
the pterygo-palatine vacuities.

Perceptibly equal, in its narrowest
part, to the transverse maximum diameter
of a supratemporal fossa.

With two symmetrical notches and a
point on the median line.

Enormous and much broader in pro-
portion to their length.

Much thinner, at its narrowest part,
than the transverse diameter of one of
the pterygo-palatine vacuities,

A. Rounded.

B. Situated very distinctly nearer the
occipital condyle.

A. Elongated in the direction of the
longitudinal axis of the cranium.

B. Placed very perceptibly more an-
teriorly.

At least 3, if not 3, greater than that of
our greatest specimen of Berzzssartia.

The entire cranium of our largest
specimen of Bernzssartza is not greater
than the preserved portion of that of
Hyleochampsa.

1 The figures between brackets, in this column, indicate the pages of the Monograph of Sir

R. Owen.

396 S. S. Buckman—On Jurassic Ammonites.

To conclude, from the preceding remarks, I think that Bernis-
sartia cannot be considered as a synonym of Hyleochampsa, and,
that consequently, the name of the Crocodilian of Bernissart ought to
be retained, instead of placing it in a list of synonyms.

II.—On Aumuowires sprpenrinus, REINECKE, AM. FALCIFER, SOWB.,
Au. ELEGANS, Sows., Au. ELEGANS, YOUNG, ete.
By 8. 8S. Buckman, F.G.S.

I HAVE had occasion lately to thoroughly investigate these and

other allied Ammonites, partly because it has been important
to me that I should know the true affinities of these species, partly
because my attention was directed to certain still obscure points
with regard to their identification, and partly on account of the
statement by the late Dr. Wright that Am. serpentinus and Am.
falcifer were the same species. In pursuing my investigations I
have received a great deal of assistance from Dr. E. Haug’s Beitrige
zu einer Monographie der Ammoniten-gattung Harpoceras,! which
I am pleased to acknowledge, although I do not find myself able to
agree with him in one or two small points which I will presently
mention. Meanwhile, by the aid of a few references to well-known
works, I will indicate the Ammonites so that they may be understood.

HILpoceras ? SERPENTINUM (Reinecke).

1818. Argonauta serpentinus, Reinecke, Maris protog., p. 89, fig. 74-75.

21822. Ammonites Strangewaysi, Sowerby, Min. Conch. t. 254, fig. 1 and 3.
Non Am. serpentinus, D’ Orb. (figure reduced), Wright, Bayle, etc.

This Ammonite seems to be extremely scarce. What has been
called by D’Orbigny, Wright, and others, Am. serpentinus, and is so
labelled in museums and private collections, is the Ammonites falcifer
of Sowerby, which has been erroneously supposed to be the young
state of Am. serpentinus (Reinecke). Oppel, in his Juraformation,
p. 243, noticed that this was not so, and keeps both species distinct ;
and Dr. EH. Haug, in his Beitrige Monog. draws pointed attention
to the fact of falcifer having been generally figured for serpentinus.
Dr. Haug corrects this error, and separates the Am. serpentinus totally
from Am. falcifer, placing Am. serpentinus in the group of Am. bifrons,
and consequently in Hyatt’s genus Hildoceras. The form of the
inner margin, the general outline of the ribs, obscure, it would
seem, on the inner part of the whorl, seem to warrant this; but at
- the same time it lacks the furrows on each side of the keel present
in Hild. bifrons. Of its suture-line I can say nothing, but the suture-
line of Hild. bifrons is very distinctive. Tio whatever genus the
true Am. serpentinus belongs, I feel convinced it does not belong to
the same genus as Am. falcifer; and that Am. falcifer does not belong
to the genus Hildoceras is very clear, on account of the suture-line,
the shape of the inner margin, etc., but especially on a distinctive
structural difference in the keel. The keel of Hildoceras bifrons is
filled by the mould, and is the same shape in reference to the ventral

1 Neues Jahrbuch fiir Mineral. Beil. Bd. iii. 1885.

S. S. Buckman—On Jurassic Ammonites. 397

area when the test is present or absent; but the keel of Am. falcifer
is separated from the mould by an inner layer of shell; and the two
sides of the keel and this layer form a triangle inclosing a hollow
space, which has become filled with mud. Where, therefore, the test
is absent, the mould of Am. fulcifer becomes rounded on the ventral
area. This kind of keel is well shown by Dr. Haug, Beitrige
Monogr. Harpoceras, plate xi. fig. 1, for Am. variabilis ; and it is to
be seen in the genera Hammatoceras, Sonninia, etc.; but this structure
of the keel is not shown in the genera Hildoceras, Ludwigia, Lioceras,
ete. It therefore seems right to separate Am. falcifer generically,
and since Dr. Haug has proposed to restrict Waagen’s genus Harpo-
ceras to a small group of which Am. falcifer is the type, we desire to
follow such a good suggestion.

Genus Harpoceras, Waagen, emend. Haug.

Ribs sickle-shaped, much produced on ventral area. Keel distinct
and hollow, separable from the mould; ventral area of mould
rounded when keel absent, no furrows on either sides of the keel,
inner margin square; large accessory lobe in siphonal saddle; large
and much branched superior lateral lobe; inferior lateral and
auxiliaries retracted.’

HarpocERAS FALCIFERUM (Sowerby).

1822. Ammonites falcifer, Sowerby, Min. Conch. t. 254, fig. 2.

1846. —— serpentinus, D’Orbigny (non Reinecke), Pal. fr. t. 55.
1878. Lioceras serpentinum, Bayle, Explic. carte géol. iv. t. 87, figs. 2-3.
1882. Harpoceras serpentinum, Wright, Lias Am. t. 58.

The above list of references will at once show how this Ammonite
has been misunderstood. D’Orbigny, Wright, and other authors
have extinguished Sowerby’s names of Strangewaysit and falcifer,
considering them to be the same and also equivalent to Reinecke’s
serpentinus. In this they were perhaps right as far as Am. Strange-
wayst is concerned, which is very near to Reinecke’s Am. serpen-
tinus; but Sowerby was certainly correct when, having the two
specimens in front of him, and putting them for comparison on the
same plate, he made them two different species ; and it is singular
that D’Orbigny, Wright, etc., should have figured as Reinecke’s
serpentinus what is really Am. falcifer, for a comparison of the inner
edges of the whorls should have shown this to be a mistake.
Sowerby distinctly says of Am. Strangewaysi, ‘inner edges of the
whorls obliquely flattened,” and of Am. falcifer that it differs from
Am. Strangewayst by “wanting the flat surface of the inner margin
of the whorl,” and Reinecke distinctly shows the section of his
serpentinus (fig. 75) with the inner margin obliquely flattened. Again,
the coiling is very different. In Reinecke’s serpentinus it is regular
throughout; in Wright’s figure it is irregular, that is, the inclusion
becomes less with every whorl. Reinecke’s serpentinus, which is

1 Compare genus Hildoceras. Mould showing shape of keel; ventral area flattened
or furrowed ; inner margin subconcave, sloping. Very broad siphonal saddle, small
accessory lobe, superior lateral lobe little branched, inferior lateral and auxiliaries
produced.

398 S. S. Buckman—On Jurassic Ammonites.

3 inches 4 lines in diameter, has four whorls at least. Wright’s
serpentinus at the same diameter has barely three. Taking the
diameter of Reinecke’s figure as = 100, the breadth of the outer
whorl is 29-6, whilst taking the same diameter on Wright’s figure
(3 inches 4 lines), we find the breadth of the outer whorl at that
size is 40-7. I think it is therefore clear that Sowerby’s Am.
faleifer is not Reinecke’s Am. serpentinus.

HARPOCERAS ELEGANS (Sowerby).

1815. Ammonites elegans, Sowerby, Mineral Conch. vol. i. table 94, upper figure.
1884, Harpoceras bicarinatum, Wright (non Zieten), Lias Ammonites, Pal. Soc. 1884,
plate 82, figs. 9 and 10 (non 11).
Non Am. elegans, Young and Bird, non Harpoceras elegans, Wright.

Sowerby describes his species in the following terms :—

“Spec. Char. Involute, much depressed, acutely keeled; volutions
about three, inner ones about two-thirds concealed; radii twice
curved, numerous, equal; keel distinct, entire; aperture acutely
triangular ; internal angles truncate.

“A delicate species with a thin shell; thickness about one-sixth
of the largest diameter ; it gradually lessens towards the edge, which
is rather obtuse, with a sharp keel placed upon it. The septa are
tolerably close with their sinuous margins much plaited: the
siphuncle slender within the keel.”

Sowerby’s type-specimen is not in the British Museum collection,
and so nnfortunately we cannot refer to it; but although the species
has been much misunderstood, I think that if the figure and the
description be accurately studied, we shall be able to arrive at definite
conclusions about it. One thing is perfectly certain, that the Am.
elegans of Young and Bird is not Sowerby’s elegans. Dr. Wright
has figured on plate 63, Harpoceras elegans, Sowerby, but has
corrected this in his text, page 447, to Young, and he further states :
“‘Some authors refer this species to Am. elegans, Sowerby. but none
of the specimens I have examined correspond with Sowerby’s
figure, which does not appear to be a Lias shell at all.” . However,
on p. 462 he places Am. elegans of Sowerby as a synonym of Harp.
bicarinatum, and in this matter J think he was so far correct that I
think his Harp. bicarinatum, plate 82, figs. 9,10, are really Sowerby’s
Am. elegans, and certainly not 4m. bicarinatus of Zieten, plate 15,
fig. 9, which has a far smaller centre.

Dr. Haug, on page 680 of his Beitriige Monog. Harpoceras, is
mistaken in supposing Dr. Wright to have figured Sowerby’s 4m.
elegans on plate 68, and Dr. Wright himself corrects this. Sowerby’s
Am. elegans, does not belong to the group of Am. opalinus as Dr.
Haug has placed it, though undoubtedly Am. elegans, Wright, does.
Therefore we have this position:—The Am. elegans, Sowerby, I
consider to have been figured again by Wright as Am. bicarinatus,
and not to be Zieten’s Am. bicarinatus, and that it is also a distinct
species in itself. Further, that it belongs to the restricted group of
Am. falcifer, which is now erected into a genus, and therefore must
be called Harpoceras elegans, Sowerby. On the other hand, the

S. S. Buckman—On Jurassic Ammonites. 399

name of Am. elegans, Young, ought in reality to be cancelled ; but
we know from Young that it has a concave inner margin, and
Wright has given a very good figure of a shell of this kind, which
agrees with Young’s description, and as this shell of Wright’s would
belong to a different genus, and possesses no other name, perhaps it
is as well to retain this one. Also, since it belongs to the genus
Lioceras, it would be correctly stated as Inoceras elegans (Young,
or Wright), and would be well distinguished from Harpoceras
elegans (Sowerby).

There is one point about this latter species, namely, that Sowerby
states that the siphuncle is within the keel. As Harpoceras in its
restricted definition is distinctly not so, we think he may have mis-
taken the hollowness for the siphuncle, as he did in his figure of Am.
Sowerby, pl. 213.

Harpoceras EXARATUM, Wright.
1822. Ammonites exaratus, Young and Bird, Geol. Surv. Yorks. p. 266.
1882. Harpoceras exaratuwm, Wright, Lias Am. Pal. Soc. pl. 62, fig. 1.

As Young does not give any figure of his species, we cannot say
what it may be, and therefore accept Wright’s figure as the type of
the species. It seems, judging from the figure, to belong to the
genus Harpoceras. It is certainly not, as Wright has mentioned
in his synonyms, Am. complanatus of D’Orbigny, which has a very
different sectional view and smaller centre. This species has thesame
sized umbilicus as Harp. elegans (Sow.), but differs in the sectional
view, the sides being less sloped towards the ventral area. If there
are no other differences, I should be inclined to regard this shell as
merely a variety of Sowerby’s H. elegans.

HaARPOCERAS SUBPLANATUM (Oppel).

1844. Ammonites complanatus, D’Orb., Terr. Jur. p. 353, pl. 114, figs. 1-2.
1856. subplanatus, Oppel, Juraf. p. 244.

Dr. Wright has given Am. complanatus, D’Orb., as a synonym of
Harp. exaratum; but I think that a comparison of the centres and
the section of D’Orbigny’s and Wright’s figures will show this to be
a mistake, and Dr. Haug (p. 619) has wisely separated the two
species. Dr. Haug has included both of these species in the group
of Am. falcifer, and also Am. discoides; but I am inclined to think
that Am. discoides should be separated. It has a likeness in regard
to its ribbing, but it has in reality no keel, only the ventral area
sharpened, and, judging from the suture-line, I consider that it does
not belong to Harpoceras at all, but should be classed in proximity
with Oppelia. Harp. subplanatum occurs in England; by the kind-
ness of Mr. B. Thompson, F.G.S., I have been able to examine a
specimen from Northamptonshire.

We have, therefore, in the genus MZarpoceras, Harp. falciferum,
Sow., Harp. elegans, Sow., Harp. exaratum (Young), Wright, and
Harp. subplanatum, Oppel; whilst Am. serpentinus, Reinecke,
perhaps belongs to the genus Hildoceras, and as the species was not

400 A. Strahan—Explosive Slickensides.

figured by Wright in his Monograph, a good figure of it in its
various stages would be an advantage.’

Besides these species, we have Am. elegans, Young, which belongs
to the genus Lioceras, and we have Am. bicarinatus, Zieten, which is
distinct from any we have mentioned on account of its smaller centre
and furrows on the ventral area, and in all probability belongs to
another genus. I do not know if it has really occurred in England.

It may be interesting to notice the sizes of umbilicus in these
various species taken from the figures given. The diameter = 100,
the umbilicus of Harp. falciferum is, youth (Sowerby) 31:9; adult
(Wright) 40-5, showing the decrease of inclusion I have mentioned.
Harp. exaratum (Wright’s figure) 20-5 and Harp. elegans (Sow. figure)
20:7. (These two have a different sectional view.) Harp. subplana-
tum (D’Orb. pl. 114) 16-76, Am. bicarinatus (Zieten’s figure) 12-2.
Whilst Wright’s Am. bicarinatus, pl. 82, fig. 9, which I contend is
Sowerby’s Am. elegans, has, umbilicus 19:00, which is almost exactly
the same as Sowerby’s figure at the same diameter. I have given
these measures exactly from the figures. Of course in ordinary work
care would have to be taken as to the amount of body-chamber
present, and the size of the specimen; but if allowance is made in
the present instance for these, it will not account for the variation
in the umbilicus in these species.

P.S.—If Sowerby’s Am. Strangewaysi be really Reinecke’s Am.
serpentinus, | should much doubt, from the indications of suture-
lines given by Sowerby, if it be correct to class it in the genus
Hildoceras. Etymologically, as Dr. Haug wrote to me when making
his suggestion, Harpoceras is very aptly applied to the true Faleifert.
It is an important matter to assign a correct place to Waagen’s genus
which had been partly forestalled by Hyatt’s genera Zropidoceras,
Hildoceras, Lioceras, Grammoceras, Hammatoceras, and to another
section of which Bayle gave the name Ludwigia. In accordance
with these genera the restriction of Harpoceras becomes a necessity.

IV.—On Exptosive SLICKENSIDES.
By Ausrey Strawan, M.A., F.G.S.
(Communicated by permission o{ the Director-General of the Geological Survey.)

URING a recent examination of the lead-mines of Derbyshire, I
was interested in some accounts of explosions which had taken
place, which were not due either to any material used by the work-
men or to fire-damp. Though at first inclined to believe that the
accounts were exaggerated, I soon found that not only was the
evidence of such explosions having constituted a real danger to the
men overwhelming, but that accidents are still liable to occur from
this cause. The explosions are connected with the structure known
as slickenside in the veins. The vein-stuff, consisting generally of
galena, cale-spar, heavy spar (sulphate of baryta), and fluor-spar, is
divided by the planes of slickenside into more or less vertical sheets

1 Wherever Dr. Wright has mentioned the zone of Harp. serpentinum, it must
probably be taken to indicate the zone of Am. falcifer.

A. Strahan—Explosive Slickensides. 401

or slabs. Such sheets, when bared in the mining operations, fly
to fragments with explosive violence on being struck, or even
scratched by a miner’s pick. The following extracts from old
authors, and from communications on the subject that I have
received, will serve to illustrate the nature of the explosions and the
manner in which the danger was met by the men. The accounts
relate chiefly to the mines near Eyam, but explosions occurred also
in the Odin Mine near Castleton.

The earliest reference to the subject: which I have met with is by
Dr. Short :—

“On the North Side of this Mountain [Hucklow Edge, near
Byam]... is a Mine which cannot be wrought; for in picking
or striking the Ore, the sudden shaking of the Metal gives such a
violent Motion to the Sulphur, that it makes an Explosion like fired
Gunpowder, or a Blast in a Rock, so as great Lumps rise up and fly
about along with a Kind of Terre Motus, or Earthquake.” !

_ Pilkington,’ writing fifty years later, remarks that “the crackling
and explosions caused by scraping these slickensides with a pick-axe
are well known, but hitherto not satisfactorily accounted for. They
are said to lose the above property very soon after they are taken
out of the mine. In regard to their external appearance, their
smooth side greatly resembles black lead very thinly spread over
the surface of any smooth body. But the rough side looks very
much like to common limestone.”

But the most detailed account is furnished by John Whitehurst,°
and is, I think, of sufficient interest to be reproduced here in full :—

«‘T purpose giving some account of an extraordinary phenomenon
which has frequently happened in Haycliff and Ladywash Mines at
Hyam, and in Oden Mine at Castleton: the former are thus circum-
stanced.

“J, The minerals are contained in the fissures of the limestone,
covered by a stratum of shale and grit, which retain their full thick-
ness of sixty fathoms each.

‘2. The minerals contained in the above mines are blended together
so as to produce the appearance of white Italian marble clouded with
black, and are so extremely hard and compact as to require blasting
with gunpowder, to separate them from the general mass.

«3. Those in the Ladywash veins are divided in two equal parts
parallel to the sides of the fissure. They may be compared to two
slabs of marble, whose polished surfaces are absolutely in contact
with each other without the least degree of cohesion.

“4, These naturally polished surfaces are not truly flat, but in
some degree waved, as if formed by a carpenter’s plane, consisting
of various members.

“5, The two surfaces are generally coloured with lead ore, thinly

1 The History of the Mineral Waters of Derbyshire, Lincolnshire, and Yorkshire,
by Thomas Short, M.D., 4to., London, 1734, p. 96.
2 A View of the Present State of Derbyshire, 1789, vol. i. p. 195.
3 An Inquiry into the Original State and Formation of the Earth, by John
Whitehurst, 3rd edition, 1792, London, p. 218, et seg., plate i.
DECADE III.—VOL. IV.—NO. IX, 26

402 A. Strahan—Explosive Slickensides.

laid on, as if only rubbed over with black lead, though sometimes
thicker.

«6, The vein in Haycliff Mine contains two of the above seams,
and therefore may be compared to three slabs of marble, the middle
one polished on both sides and in contact with the other two.

“Thus are the above veins circumstanced. Now what is yet more
remarkable is this: if a sharp pointed pick is drawn down the vein
with a small degree of force, the minerals begin to crackle, as sulphur
excited to become electrical by rubbing; after this in the space of
two or three minutes, the solid mass of the minerals explodes with
much violence, and the fragments fly out, as if blasted with gun-
powder. ‘These effects have frequently happened, by which many
workmen have been wounded, but none killed, both in the Hyam
Mines, and in that called Oden, at Castleton.

“In the year 1758 a prodigious explosion happened in the mine
called Haycliff. The quantity of two hundred barrels of the above
minerals were blown out at one blast; each barrel, I presume, con-
tained no less than three or four hundredweight. At the same time
a man was blown twelve fathoms perpendicular, and lodged upon a
floor, or bunding, as the miners call it, in one of the shafts.

“‘ When the above explosion happened, the barrel, or tub, in which
the minerals, etc., are raised to the surface, happened to hang over
the engine shaft, which is nearly seven feet in diameter, and 448
yards distant from the forefield, or part, where the explosion happened ;
this barrel, though of considerable weight, was lifted up in the hook
on which it was suspended; and the people on the surface felt the
ground shake, as by an earthquake.

‘“‘Such are the effects which have frequently been produced in all
the above mines; but from what cause they proceed, I have not yet
been able to discover, nor even the least traces towards it. The
substance having been analized, is found to consist of fluor and the
ore of lead, but the cause of explosion still remains equally mysterious,
though some attempts have been made to obtain a knowledge of this
curious phenomenon.

‘These curious observations I received from Mr. Mettam, of Lyam,
overseer of the mines, who also addressed the following account of
them to Mr. George Tissington, of Winster, principal agent of the
works.

“ Hyam, 2 July, 1768. Sir,—I send you by the bearer, two speci-
mens of our slickensides, containing all the variety of minerals
where the explosions happen ; they fly out in such slappits,* smooth
on one side. The explosions are sometimes heard to the surface, and
felt like an earthquake; they frequently blow out all the candles in
the mine, and split the stemples* into splinters as small as the twigs
of a birch besom, to the distance of thirty or forty yards from the
forefield;* others are broke, and some of them become too short

1 Slappits, fragments of the minerals burst out of the vein.

2 Stemples, joists laid across fissures, when the minerals are cut out, by way of
making a floor, on which rubbish is deposited, to save the expense of raising it to the
surface. 3 Forefield, that part of the vein under workmanship.

A. Strahan—Explosive Slickensides. 403

and drop out. The smooth sides lie face to face, and have the
appearance of being shot with a plane, consisting of various members.
There is generally two of these divisions in our forefield at Haycliff,
about eight or ten inches asunder, and a seam of white kebble’ in
the middle of that space, half an incb thick, in which the miners
rake down a sharp pointed pick until the crackling ceases ; then they
run away, knowing that the explosion will follow in a minute or two.
Sometimes a noise is heard like the beating of a church clock, after
which the greatest explosions happen.—I am, yours, etc., William
Mettam.—To Mr. George Tissington, Winster.”

John Mawe also writes in 1802 that in the Odin Mine “is found
that singular variety of lead ore, called slickenside. This galena
presents a smooth surface, as if plated. Sometimes it forms the sides
of cavities, and on being pierced with the minevr’s tool, rends with
violence, and explodes with a crackling noise. The cause of this
phenomenon has not been fully explained. I have seen a man, when
he came out of the mine, only a few minutes after the explosion,
who, regardless of the danger, had pierced the sides of this substance,
and was much hurt, and cut violently, as if stabbed about the neck
and other places with a chisel, whence he was unable to return to
the mines for two weeks.” *

“Sometimes the vein-stuff is found perfectly divided vertically,
throughout, and the surfaces polished ; and these are called Slicken-
sides or Cracking-whole, which usually are ribbed or slightly fluted,
horizontally: the appearances are very similar to those of faults,
but extraneous matters do not usually accompany them, the sides
being mostly in very close contact; and often, after one side is
removed, so as to give room, especially if the surface be pecked or
broken, large Slapits, Spels, or fragments fly off, sometimes with
loud explosions, and continue so to do for some days or longer, until
the gate or passage in such vein is greatly enlarged thereby: this is
the case in Gang Mine, in Cromford, where the hard 1st Toadstone
also, in the gates and shafts, thus spels off, until they want timbering
often, to support the roof and sides. I could not learn, that the
Slickensides in the Mines about Eyam explode now, on mere
scratching, as they were said to do in the late Mr. Whitehurst’s time.” °

“Tn Gang Mine, where a Slickenside runs through the Vein, the
Miner avails himself of a curious property attending such Veins, by
drawing laces, stoops, or nicks, at about six inches apart and four
inches deep, with the point of his Pick, from top to bottom of his
face of work, when he then leaves for several hours, and on his
return, finds all the Vein-stuff so furrowed, spelled, or slappeted off,
and laying on the sole ready got to his hands.” *

“‘When their edges occur in the face of the vein, on the miner
striking his pick into the vein they separate, in some districts without,

1 Kebble, a white opaque spar, calcareous, but not apt to break into rhomboidal
forms.

2 The Mineralogy of Derbyshire, by John Mawe, 8vo. London, 1802, p. 48.

3 General View of the Agriculture and Minerals of Derbyshire, by John Farey,
8yo, London, 1811, vol. i. p. 250. 4 Ib. p. 367.

404 A. Strahan—Explosive Slickensides.

in others with a slight report; and in some of the mines in the
neighbourhood of Eyam, in Derbyshire, with loud reports, particu-
larly in Cracking-hole vein, in Haycliffe title . . . . where in the
centre of the vein, termed a shack vein, was a small white impalpable
(not effervescing) powder, called a mallion, a quarter of an inch thick,
which on being scratched, a loud explosion immediately ensued,
before which explosion a singing kind of noise was heard. By
setting a blast in the vein at a short distance from the mallion, after
the blast was fired, in a few minutes an explosion took place, when
a large quantity of the vein fell down. In the year 1790, a loud
explosion took place from a slide joint of Slickensides going across,
but not into the cheeks of the vein containing the mallion, which
caused on its being stirred the loudest explosion and the largest
quantity of vein materials to come down.... . The last great
explosion was in the year 1805. It has sometimes happened that
persons have been maimed or even killed by this phenomenon ;
which, however, has not been noticed from Slickensides where no-
shale is incumbent.” *

In writing of the mines on Hucklow Edge, William Wood refers
to the Hay Cliff, as “a mine distinguished for having contained in
great abundance, that extraordinary phenomenon in the mineral
world, provincially called Slickensides. . . . The effects of this
mineral are terrific: a blow with a hammer, a stroke or scratch with
a miner’s pick is sufficient to blast asunder the massive rocks to
which it is found attached. . . . A person named Higginbotham once
narrowly escaped with life, by incautiously striking this substance
in the above mine. Experienced miners can, however, work where
it greatly abounds without much danger. It is also known by the
name of Cracking-whole.” ?

The phenomenon is referred to by W. Adam also, who supposes
that the slickenside has been produced by the rubbing of the rocks
against one another. ‘The intense heat generated by the motion of
such vast masses (expanding the air in its pores) may account for
its exploding when broken into, similar to lumps of glass when
suddenly cooled, which explode on being scratched or slightly
broken.” °

“To avoid the danger attendant on working in its immediate con-
tiguity, the miners use the precaution of merely making a small
incision or aperture, with the point of the pick, and then retire to
a place of safety, awaiting the result. In case of an explosion, it
generally takes place in ten or fifteen minutes, and by the force
attendant on which, considerable masses of ore, and even stuff, are
detached.” *

Sir Charles Lyell, referring to this subject in the 6th edition of

1 An Account of the Explosion of Slickensides, by W. Watson, Edin. Journ. Sci.

new ser. vol. ii. p. 186, 1829. i

2 The History and Antiquities of Eyam; with a minute account of the Great
Plague, which desolated that village in the year 1666, by William Wood, 8yo.,
London and Derby, 2nd ed. 1852; 8rd ed. date not stated.

3 The Gem of the Peak; or, Matlock Bath and its Vicinity, etc., by W. Adam,
London, 1845, p. 419, footnote. ;

4 Mining Almanack for 1850, by W. English, London, p. 220,

A. Strahan—Ezxplosive Slickensides. 405

his Elements of Geology in 1865, remarked, ‘these phenomena and
their causes (probably connected with electrical action) seem scarcely
to have attracted the attention they deserve.” In subsequent editions
this suggestion of a connection with electrical action was omitted.

Mr. Leonard Maltby, of the Mill Dam Mine, Great Hucklow,
informs me! that he has had experience of the explosion of slicken-
sides. The explosions take place at the present time in the vein at
the Cockersfield Shaft; pieces of mineral burst from the face with
a loud noise and with great force, so as to necessitate great care on
the part of the men when working. ‘There are also several other
places in the Mill Dam Mine where slickensides of an explosive
tendency have occurred, as well as in the Silence Mine on the same
vein, and in a vein near Hyam, called the Brookhead Vein. At the
Lady Wash Mine also, on the eastern range of the vein worked at Mill
Dam, the miners noted the same phenomenon. Its prevalence in
this neighbourhood leads Mr. Maltby to infer that slickensides will
explode more or less, while being cut, wherever they occur. He
remarks further that where slickensides occur, the vein is always as
hard and fast as it is possible to be, and seems to be under great
pressure. “When we work with a pick, cutting one side of the
vein, as soon aS we have made a little opening, it seems then that
the air gets in, and the mineral swells and bursts off with loud noises,
and where the vein is hardest and most nipped, the explosions are
strongest. It always bursts off just as far as the opening is made.”
He considers both the slickenside and the explosions to be the result
of pressure.

Though some of the veins in which explosions have occurred con-
tain much fluor-spar, yet the phenomenon has been more frequently
observed in the hard and tight veins which contain cale-spar, heavy
spar (sulphate of baryta) and galena. Fluor-spar, as Mr. Maltby
informs me,” occurs more commonly in soft veins, such as that at
the Dusty Pits, near Eyam, where it was very abundant. In this
vein no slickenside was seen and explosions were unknown.

The late Mr. J. A. Phillips, F.R.S., F.G.S., etc., informed me that
he had known of several instances of the flying off of fragments of
mineral from the slickensided face of a vein, with a sharp report.
In one case a fragment was thrown off with sufficient force to break
the leg of a man who was passing. The explosions occurred after a
portion of the vein had been undercut. Mr. Phillips suggested that
the removal of one side of a vein would leave the remaining side in
a condition of strain, resembling that of a strung bow, with a
tendency to bulge outwards into the workings. The undercutting
would free, so to speak, one end of the bow.

Mr. W. Bowman, of Alport, writes* that he has seen pieces of
limestone in the Hcton Mine fly off with a sharp small crack, some
short time after it has been broken by blasting. In one instance, in
1885, two miners were drilling a hole by hand in the Clayton Adit-
level, when a piece of rock burst from the face with a loud report,

1 In a letter dated 22nd October, 1886.

2 In a letter dated 23rd November, 1886.
3 In a letter dated 15th October, 1886.

406 A. Strahan—Explosive Slickensides.

throwing the men to the ground, and bruising them considerably ;
the thickness of the fragment was equal to the depth of the drill-
hole, namely, ten or twelve inches. The toadstone also has been
known by Mr. Bowman to break off with a little noise soon after it
has been relieved of pressure by excavation. Hcton Mountain is
composed of the upper beds of the Carboniferous Limestone, sharply
contorted and crushed.

I may refer here also to the description by Mr. W. H. Niles,’ of
the movements of rocks resulting from lateral pressure, and ex-
hibited in quarries. It was found at Monson that the rock has been
brought into a compressed condition by a powerful lateral pressure
acting in a north and south direction, and that, when opportunity is
presented, the compressed rock expands with great energy, often
bending, folding, and fracturing the beds, and sometimes producing
sudden and violent explosions, and occasionally throwing stones into
the air. The expansion became apparent on cutting trenches in the
rock in an east and west direction.

At Lemont, Illinois, the bed of rock forming the floor of a quarry
was gradually bent up into the form of an anticlinal, trending east
and west, and running for about 800 feet with an elevation of six to
eight inches. The elevation had taken place in consequence of the
removal of the overlying rock, and had been attended by explosive
sounds, and sometimes fragments of the rock had been thrown into
the air. In the same quarry it was observed that drill-holes bored
through two layers of stone became displaced, the upper parts of the
holes being no longer vertically over the lower parts. ‘The effects
of this force have been noticed at five different localities, ranging
over five and a half degrees of longitude.

Mr. Niles refers also to explosions which have sometimes occurred
in making railway-tunnels and other excavations, and which could
not be accounted for as the results of any artificial power.

The tradition among miners that knockings may be heard under-
ground, where ore exists, is well known, and has often led to the
expenditure of much money. ‘That subterranean noises are not
uncommon has been proved beyond doubt, and the following
account by a working miner is not without interest.”

“J have heard some Miners say that it is a Knocking they hear,
Striking much like as when one in Boreing, not constantly but
resting by Fits, and always seem to be at a distance from him... .
I once Worked in a Groove not many Years ago, where two more
Men wrought, they worked by yards at a deeper Level than I wrought
at... One day I having some leasure at Work, it struck into my
Head to go down to them, . . . but coming there I found no Body,
which T did much Wonder at, since I well knew that no Body else
wrought within my hearing. Next Day I told the Men how I was
mistaken ; see you there says one of them to the other, it is what

1 The Geological Agency of Lateral Pressure exhibited by certain Movements of
Rocks, Proc. Boston Soc. Nat. Hist. vol. xviii. p. 272 (1876) ; see also 20. vol. xiv.
and Proc. American Assoc. for the Advancement of Science, vol. vill. p. 285, and
vol. xxii. part il.

? The Miner’s Dictionary, by William Hooson, 8vo. Wrexham, 1747 (under the:
head Knocker).

A. Strahan—Exzplosive Slickensides. 407

we are used to hear; after some little Discourse, they told me that
they had heard it very often, and (says they) not long before you
came here, we was both at Work and heard a Noise, and we concluded
it could be nothing but somebody coming down the Shaft, and in a
little while, about the time they might be got to our first Sump-head,
we presently heard as we thought, them throwing the Corves down
the Sump; we heard ’em rattle so plain against the hard Sides, and
amazed at such folly we came in hast up, where we found all things
as we had left them when we came down without the least alteration,
as we could discerne. Thus the Men.

“One Instance more may be of the same kind, where I have been
acquainted, and ’tis this: I with others wrought in a certain Work
about eighty Yards deep, the Shaft was Sunk in a great and loose
Shack of Chirts, which sunk down to the Soles and much further
for any thing we know, being exceeding loose, and not any openess
seen throughout the whole Work, but the ways that were cut; the
loosness of this Work was all the care to keep it up; yet what I
Remark is, that the Workmen themselves, but more especially the
Labourers, at the Sump-heads and in the Gates, have been often
affrighted with such a Noise and dismal Rattle, as if sometimes the
Shaft had run in, and at other times the Gates or Sumps; I have
heard it my self, and have thought by the Noise, we had been all
made fast, but by God’s Blessing, never found one Stick of Timber
disordered or out of its Place; one would think that the Noise
might be caused by something running in some openness, or great
Shack, but there was never any such seen in the whole Work; for
altho’ there were large and wild shaken Places, yet they were all
full of loose small Chirts to the Day; . . . what these Noises are,
we miners know not, but must leave them to the Disquisition of such
learn’d Men as deal in those profound Matters ; I mention it because
Miners say that the Knocking is some Being, that Inhabits in the
Concaves and Hollows of the Earth; and that it is thus kind to
some Men of suitable Tempers, and directs them to the Ore by such
its knocking, etc.”

In some of the mines near Eyam, which have been referred to
above, explosions of fire-damp have occurred from time to time,
especially in those which were sunk through the Yoredale Shale into
the Carboniferous Limestone, and in the water-levels which were
driven long distances through the Millstone Grit and Yoredale Shale
to drain the mines. References to such explosions occur in most of
the authors quoted above, and in such terms as to show that they
were clearly recognized as distinct from the explosions due to slicken-
sides. Jam therefore disposed to believe that the great explosion
described by Whitehurst as having occurred in 1788 was due to
slickensides, but that in the fifty years which had elapsed before
Whitehurst wrote, the account of the effects had become considerably
exaggerated, or more probably confused with the account of some
explosion due to fire-damp.

It is difficult to understand the lifting of the barrel in the shaft,
and the blowing of a man twelve fathoms perpendicularly, except

408 A. Strahan—Explosive Slickensides.

by an explosion of violent expansive power. It will be noticed that
the cause of the great explosion of 1790 is distinctly stated by Mr.
W. Watson, though writing nearly forty years after the event, to have
been a slide joint of slickensides going across a vein.

By the kindness of Mr. Maltby I have been supplied with some
specimens of the explosive ore from the Cockersfield Shaft of the
Milldam Mine at Great Hucklow, near Eyam. The specimens
consist of sulphate of baryta and galena arranged in more or less
vertical but irregular ribs. The planes of slickenside are beautifully
polished, so much so in places as to possess the reflective power of
a looking-glass, but they show also the usual ribbing or striation
which so strongly conveys the idea of slickenside having been pro-
duced by the rubbing of two surfaces together. The planes of
slickenside were clearly formed after the filling in of the vein by
the minerals mentioned above. They cut through the galena and
baryta impartially, nor in any of the specimens in my possession
is there any appearance of a rearrangement of the minerals having
resulted from the existence of the plane of slickenside, except that
the slickenside surfaces are slightly stained by iron oxide, or coated
by a microscopically thin film of galena.

The spar in these specimens has the granular appearance of white
lump sugar, and readily crumbles into a gritty powder. Whether
this granular structure is the result of the explosions by which the
specimens were detached, there is no evidence to show. The speci-
mens themselves average from half an inch to three inches across,
and are of all shapes. Attempts have been made to prepare
microscopic sections across the planes of slickenside, but up to the
present without success.

The first explanation that suggested itself to me was that the
mass of rock, separating two planes of slickenside, was comparable
to a huge sheet of very brittle glass, placed on its edge; a slight
blow on the lower part of which might bring down the whole mass
in fragments. This, however, provides no explanation of the
explosive power, which is so clearly brought out in the above
quotations.

Secondly, it will be familiar to all who have been in mines, that
newly bared shale swells and crumbles on exposure to air and
moisture. This is probably due in many cases to chemical processes
set up in the mass of the rock, principally no doubt in connection
with the salts of iron. It seemed conceivable that such processes,
taking place within a brittle rock, might place it in a condition
of strain, under which it would fly to pieces with a mere touch. But
there is no sign of any chemical alteration having taken place in
these explosive spars.

The explanation, which perhaps best satisfies the requirements of
the problem, appears to be that the spars are in a state of molecular
strain, resembling that of the Rupert’s Drop, or of toughened glass,
and that this condition of strain is the result of the earth-movements,
which produced the slickensides.

Alfred Harker—Some Anglesey Dykes. 409

V.—Woopwarpian Musnum Notes: on some AnGursey Dyxas. I.

By Atrrep Harker, M.A., F.G.S.,
Fellow of St. John’s College.

N the Woodwardian Museum is a collection of nearly a thousand
rock-specimens made by Professor Henslow to illustrate his
“Geological Description of Anglesea” (1821, Trans. Camb. Phil.
Soe. vol. i. pp. 859-452, plates xv.-xxi.). Specimens of the principal
dykes were submitted to the examination of Professor Cordier, and
his remarks on them are quoted in Henslow’s paper. As Cordier’s
determinations date from a time when thin slices of rocks were
unknown, and but little attention has since been given to the dykes
of Anglesey, it is believed that brief notices of some of the typical
rocks from localities easily identified may have an interest for
British geologists. As regards the mode of occurrence of the dykes
and their effects upon the adjacent strata, little can be added to the
accurate descriptions of Henslow, written at a time when the igneous
origin of dykes was a proposition to be proved. ‘The specimens are
referred to by number in the memoir, and these numbers will be
cited below in brackets [ ].

We begin with a few specimens from the numerous dykes exposed
on the shores of the Menai Straits. In spite of some interesting
variations, these rocks possess many characters in common. ‘They
strike usually in directions varying from §.H. to H.8.E., and often
coincide with lines of faulting, which are at right angles to the
general strike of the strata. The only direct evidence of their date
-of intrusion is that they sometimes cut through Carboniferous beds ;
but if it is allowable to correlate these dykes with others having
a similar direction in the Anglesey Coal-field, we may infer from Sir
A. Ramsay’s reasoning that the whole are of pre-Permian age
(Geology of North Wales, 2nd ed. p. 264).

Beginning near Beaumaris, we find in the green contorted schists
between Gallows Point and Garth Ferry an enormous number of
small dykes of generally compact appearance. The majority of
them are not more than a foot or two in breadth, but some attain to
about twenty feet. They frequently ramify, but show on the whole
a parallel arrangement with an average bearing about $.H. by H. In
some cases a certain relative movement of the rocks on opposite sides
of a dyke can be verified. Making allowance for the varying sizes
of the dykes and the modifications due to more rapid cooling near
the edges, the rocks present a general community of megascopic
characters ; only two of Henslow’s specimens have been selected for
closer examination.

Dykes between Gallows Point and Garth Ferry.

[640.] Augite-andesite—The hand-specimen shows a black, com-
pact ground-mass containing numerous clear felspars in the form of
parallelograms. These crystals are’ very flat, and have a marked
parallel arrangement, as noticed by Cordier and Henslow. Under
the microscope they are seen in cross-sections of elongated shape,
‘0-1 to 0-15 inch in length, and their fluxional arrangement is very

410 Alfred Harker—Some Anglesey Dykes.

evident. The faces which give the felspars their tabular habit are
the brachypinacoids, while the other forms present may be the
macropinacoid and basal planes. The usual albite-twinning is seen,
combined with the Carlsbad type: the extinction-angles seem to
indicate labradorite. The crystals are often bent and partially
fractured, but I have not observed any relation between these dis-
turbances and the twin-lamellation. Besides the felspars are abun-
dant crystals of magnetite; and the ground-mass is composed of
felspar microlites, magnetite, and rounded granules of augite
decomposing into a pale-green substance. In both the grownd-mass
and the larger constituents, the magnetite seems to be of rather
earlier formation than the felspar.

[642.] Augite-andesite-—Henslow mentions this rock as “more
remarkably fine-grained and tough than any other which I have met
with in Anglesea.” It is a contact specimen with a fragment of the
green schist firmly adhering to it. Here the scattered felspars are
smaller and occur more sparsely ; they show little of the tabular
habit and parallel disposition so striking in the preceding slide.
The ground-mass too is a little finer ; but with these exceptions the
same description will suffice.

To illustrate the modifications of texture in different parts of one
dyke, two specimens collected by Prof. Hughes have been sliced,
They are from a dyke just south-west of Gallows Point.

Augite-andesite from marginal portion of dyke.—This is inter-
mediate in texture between [640] and [642], and has the same
general characteristics. The scattered felspars, however, have inclu-
sions of magnetite, disposed chiefly along the twin-planes.

Dolerite from central part of the same dyke.—The slide exhibits
rectangular sections of felspar, mostly lath-shaped and about 0-1 inch
in length, magnetite in crystals giving quadrangular sections and in
rods, and decomposed augite in ophitic plates. There is no ground-
mass. The felspars show twinning by different laws. In some
cases a crystal is divided by a line which may represent Carlsbad
twinning into two halves, of which one shows lamellation on the
albite and the other on the pericline type. The lamelle are often
interrupted.

Another of Prof. Hughes’ specimens, from a dyke north-east of
Garth Ferry House, may be styled a porphyritic dolerite——This
rock bears a close resemblance to the preceding, but differs from it
in the fact that the magnetite occurs in imperfect crystals of later
formation than the felspar. Besides the rectangular felspars there
are a few of larger dimensions giving squarish sections. This rock
shows more advanced decomposition than the others mentioned
above. The augite, which appears to have formed ophitic plates, is
entirely destroyed and replaced by the usual pale-green substance
with confused scaly structure, and polarizing in low tints of grey
and indigo. Patches of this ‘viridite’ inclose crystalline grains of
calcite. Grains of secondary quartz are also plentiful, as well as
magnetite dust and ferruginous specks. The felspars are almost
opaque.

Alfred Harker—Some Anglesey Dykes. 411

Cordier pronounced some specimens from this part of the Straits
to be “dolerite. The pyroxene very evident, with fer titané.” In
the slides examined, however, the iron-ores never show forms
characteristic of ilmenite, and no leucoxene occurs. The compact
rocks are named “ basaltic lava.”

Cadnant dyke.—Between Garth Ferry and Menai Bridge we meet
with the first large dyke, which occurs on the right bank of the
little stream at Cadnant. This dyke is not marked on the Maps of
the Geological Survey, but Henslow traced its course among the
schists for some distance inland. He also found it on the Carnarvon-
shire shore, where it cuts Carboniferous strata. In the latter place
the rock is less compact in texture than on the Anglesey side, and
Henslow states that ‘‘none of the dykes which intersect the lime-
stone and shale attain to so great a degree of compactness as the
generality of those which are found among the schist.” Three
dykes having a similar strike to that at Cadnant are marked on the
Survey Map south of Bangor Station, and a slide from one of these,
at Glan Adda, has been examined. Cordier identified the Cadnant
rock as ‘‘a true dolerite, having the ingredients, pyroxene, fer
titané, and felspar well characterized.”

[545.] Dolerite; a typical specimen from Cadnant.—To the eye
the rock shows a moderately coarse-grained aggregate, in which the
augites are conspicuous, moulding elongated crystals of felspar.
Under a low objective the structure is seen to be holocrystalline and
ophitic. The felspars occur in mostly elongated sections, showing
a rather fine albite-twinning, combined with a concentric zonary
banding, and sometimes twinning on the pericline law. From the
extinction-angles they should be andesine or oligoclase. This rock
exemplifies a character found in most other similar dykes in North
Wales ; the felspars appear to be of two generations, of which one
is older, and the other newer than the bulk of the magnetite. The
later felspars are distinguished by their imperfectly defined outline
and more equal dimensions, their more marked zonary banding, and
their greater clearness: their twin-lamellz are usually very narrow
and rather wide apart. A few prisms of apatite are seen. The
magnetite in this slide is plentiful, and builds crystals of intricate
branching shapes. The augite has the pale-brown tint common to
that mineral in almost all North Welsh rocks. It moulds the other
constituents, and never shows crystal boundaries. The prismatic
cleavages are strongly marked, and there are ill-defined interpositions
arranged in branching lines or planes. The chief secondary product
is a yellowish-green, doubly refracting mineral, which pseudomorphs
augite: secondary granular magnetite accompanies it in places. The
dominant felspar is often almost opaque owing to alteration-products.

Porphyritic dolerite: Glan Adda, south of Bangor Station.—This
dyke occurs on the same line as that at Cadnant, and may be briefly
referred to for comparison. Here the earlier felspars have lath-
shaped sections: the later ones are more equi-dimensional, and show
the zones of different chemical composition very distinctly. The
augite moulds the older felspars, but is of earlier formation than the

412 Alfred Harker—Some Anglesey Dykes.

second generation, and sometimes shows crystal-outlines, the prism
and pinacoidal planes. IJron-ores are abundant, chiefly magnetite ;
fine needles of apatite occur in the felspars; small scattered flakes
of biotite are sparsely present. The latter mineral is met with in
the Cadnant dyke [525], ‘‘a circumstance of rare occurrence in the
dykes of Anglesea,” (at least in those of the Menai Straits). The
Glan Adda dyke has pink porphyritic felspars, which under the
microscope show large squarish sections, much decomposed.

It will be noticed that all these dolerites correspond in character
more closely to the andesitic than to the basaltic family: olivine I
have not yet observed in the above rocks, though it may possibly be
lost among the decomposition-products. This mineral occurs, how-
ever, in the Plas Newydd dyke described below.

[546.] Dolerite: near Four Crosses, on the north-western pro-
longation of the Cadnant dyke.—This specimen, to illustrate the
more compact type of rock, is taken from the outer portion of the
dyke, though not from the actual contact, where the andesitic habitus
prevails. The magnetite is mostly older, but partly newer, than the
felspar ; it occurs in crystals showing the cube or octahedron, and in
complex shapes related to those forms. The minuter grains often
appear in star-like aggregates with sections exhibiting three bilobate
rays: these are sometimes surrounded by a ring of finely granular
magnetite. The felspars give elongated rectangular sections: the
larger ones are often simple or once twinned, but fine twin-lamellation
is also found. The pale-brown augite, in ophitic plates of varying
extent, is mostly destroyed. As secondary products occur the usual
“viridite,” finely granular calcite, and clear quartz.

The dykes in the neighbourhood of Menai Bridge have not been
sliced. ‘They are dolerite, often with porphyritic felspars: They
appear to be much decomposed, and contain a considerable amount
of calcite and pyrites.

Plas Newydd dyke.—The largest dyke in this part of the island
cuts through the lower beds of the Carboniferous Limestone series a
little south of Plas Newydd, the seat of the Marquis of Anglesey.
This dyke, 184 feet wide, occupies a probable line of fault bearing
in a south-easterly direction: it is met with again on the opposite
side of the Straits. In the nomenclature of Cordier’s day the rock
was described as “indubitable basalt, consisting of felspar and
pyroxene,” but the normal type is holocrystalline and granular.

[485.] Olivine-Dolerite; typical rock of the Plas Newydd dyke ;
a rather coarse-grained dolerite with marked ophitic structure.—The
microscope reveals olivine in abundant rounded grains included in
the augite. There is much secondary magnetite dust resulting from
its decomposition. Magnetite occurs also in crystals, usually imper-
fect cubes; this and the olivine are the earliest formed constituents.
The chief felspars are in elongated crystals showing finely repeated
twinning and often concentric zoning; the extinction angles are
moderately high, and would agree with labradorite. There is some
slight bending of the crystals, which may perhaps affect the twin-
lamellation. Sometimes cross-twinning, presumably on the pericline

Alfred Harker—Some Anglesey Dykes. 413

law, is observed. There is also, as in the Cadnant dyke, a later
generation of felspars, shapeless, but broader than the others. They
are simple or once twinned, and between crossed Nicols show strong
zonary shading: as usual they are clearer than the earlier felspars.
The augite is in light-brown plates, moulding the dominant felspars :
it shows branching layers of interpositions. The chief secondary
products in this slide are a yellowish-green structureless substance
and a ferruginous staining; both seem related to the augite.

[486.] Dolerite ; the more compact portion of tne dyke; a fine-
grained ophitic rock with abundant magnetite, closely resembling
[546] from the Cadnant dyke. The felspar is in elongated prisms,
with mostly repeated albite-twinning and fairly wide extinction-
angles. It is clear except for some granular calcite and fine viridite
strings, following for the most part, the basal cleavage-cracks.
Magnetite is plentiful in crystals, skeletons, and rods; and is slightly
posterior to the felspar. The apparent rods, which are probably
sections of plates, have a parallel disposition, and are arranged trans-
versely to felspar crystals which they surround. A similar relation
of magnetite to olivine is described by Reusch from the basalts of
Jan Mayen.’ The present rock contains also minute rings (spherical
shells) of magnetite dust surrounding nuclei of the same. The augite,
always allotriomorphic, has the same characters as in the preceding
slide. Chloritic decomposition-products and clear secondary quartz
occur.

The metamorphic effects of the Plas Newydd dyke upon the
adjacent Carboniferous strata, as described by Henslow, possess
considerable interest. On the south-west side a bed of calcareous
shale, abutting upon the dyke, is converted into a kind of lydianite,
containing calcite and clusters of garnet and analcime crystals.
Henslow’s specimens [511 to 528] show the development of these
last-named minerals in every stage from mere whitish concretionary
spots in the hardened shale to perfectly formed crystals. These are
closely clustered together along particular bedding-planes, and some-
times the valve of a Productus, converted into crystalline calcite, is
seen to be studded over and penetrated by globules or crystals of
analcime.

The garnet occurs in crystals up to 0:7 inch in diameter, showing
the faces of the rhombic dodecahedron (110), sometimes truncated
by narrow planes belonging to the form (211): they have often
a marked concentric zonary structure. They vary from yellowish-
green to olive-brown, with a resinous lustre. “Their specific gravity
is 3:353,” and their hardness under 7. These characters indicate
a variety approaching grossularia; Lyell* gives the percentage of
lime as 20. A slice (cut from a specimen in the Sedgwick collection)
shows a number of crystals in various stages of development, closely
packed together, and the interstices filled with crystalline calcite.
The crystals are not all isotropic: they contain a large amount of
foreign material. The readiness with which garnets of considerable

1 Cf. also Prof. Judd’s basalt from Mull, Q.J.G.S. vol. xlii. p!. vi. fig. 7, 1886.
* Student’s Elements of Geoloxy, 2rd ed. p. 515.

414 Alfred Harker—Some Anglesey Dykes.

size are formed by contact alteration is evidently connected with
this capacity of the mineral for including in its crystals a large
quantity of foreign matter. The same remark applies to disthene
and chiastolite.

The analcime crystals, where they are best developed, show the
faces of the trapezohedron (211), and have a concentric zonary
structure. The specimens were analyzed by Cumming, who pro-
nounced them to be “analcime with excess of iron.” His figures,
however, differ widely from published analyses of the mineral in
question, and can only be reconciled by supposing the analcime to
be partially changed into prehnite, a mode of alteration known to
take place occasionally.1. Assuming the iron to be present as ferric
oxide, and replacing it by alumina, Cumming’s analysis is represented
by column I. below. The second column gives the composition of
analeime calculated from the formula H, Na, Al, Si, O,,; the third
prehnite from the formula H, Ca, Al, Si; O,, Column IV. is the
mean of II. and III.

I. IL. III. IV.
SHUN), < Godesonocsns AQ ek. OAS4 LN S436) Senn AOL 0)
AN WNTUIDE, Sooconcse Atte ocd ee aaah 409 asl BQ 4c
MC aes ee 19h" eas — sore wD pice aw Ialteasrae
SO aie cach decane 9 TRADI oes — ae 7:05
Water’ .ihccbeece 5 8:1 Bot ov cee 6:20

99 100:0 99:9 99°95

Tt will be seen that the Plas Newydd mineral agrees fairly well
with the composition of analcime half-converted into prehnite. That
such a mineral as analcime should be formed as a true contact-
alteration product appears at first very improbable, but the whole
process of development can be seen in the specimens, and is precisely
similar to that of the garnets.

Moel-y-don and Plas-Coch dykes.—Several dykes, one forty feet in
width, were noted by Henslow at Moel-y-don, opposite what is now
Port Dinorwic. These are not marked by the Geological Survey,
and I have failed to find any exposures on the shore. Others occur
inland on about the same line, near Plas-Coch.

[563.] Amygdaloidal dolerite from one of the minor dykes, south
of Moel-y-don: a medium-grained ophitic dolerite, with numerous
spherical cavities, averaging 0-1 inch in diameter, filled with
secondary minerals, and others larger and more irregular in shape.
Under the microscope the dominant felspars are seen in elongated
sections with ragged ends due to some of the twin-lamellz project-
ing beyond others. Between crossed Nicols they show for the most
part finely repeated albite-twinning, and some zonary shading.
Some sections perpendicular to the twin-plane give extinction-
angles up to about 38°, indicating anorthite. The smallest crystals
are once twinned, and in several places have a radiate arrangement
about a centre. Besides these earlier-formed felspars, there is a
second generation, less abundant and, judging roughly from their

1 Blum., “‘ Pseudomorphosen,’’ p. 100, etc.

Alfred Harker—Some Anglesey Dykes. 415

extinctions, of a more acidic species. These are untwinned, and
show the zones of growth very clearly. They are without crystal
boundaries, and sometimes include little crystals of the older genera-
tion. Magnetite occurs in small cubes of later formation than the
first set of felspars: it is not very abundant. The augite in pale-
brown patches moulds or completely includes the felspars of the
earlier generation. In some places it is crowded with short black
rods, probably of magnetite, disposed parallel to two definite direc-
tions: this appears to be a secondary phenomenon connected with
the decay of the augite. The usual feebly polarizing ‘viridite’
patches replace this mineral, and there is some calcite dust in the
slide. The infilling of the vesicles has taken place in several
distinct stages. First a zeolitic mineral has been deposited at points
on the wall, in fan-like bundles of imperfect crystals. The interior
of the cavity, thus reduced in size, has been stained by a greenish-
yellow substance, and then lined with chalcedony in the usual
mamillary coating. ‘The remainder of the vesicle has finally been
filled with calcite, not in one mass, but as a mosaic of distinct
crystalline grains, mostly untwinned. In some cases a little clear
quartz occurs with the calcite.

Llanddwyn dykes.—Henslow collected specimens from two dykes
in the island or peninsula of Llanddwyn, westward of the opening
of the Menai Straits. They do not agree in position with those
marked on the Survey Map. The rock is much decomposed, and
only one slide has been prepared.

[684.] Porphyritic dolerite from Llanddwyn.—This is a fine-
grained, much-weathered rock inclosing liver-coloured felspars more
than an inch in diameter. One of these is shattered, but the parts
still remain in proximity to one another. The microscope shows
abundant cubes of magnetite, small felspar prisms much altered, and
augite replaced by the characteristic pale-green product with some
calcite. There is a small vesicle filled by a deposit of quartz
followed by calcite with polysynthetic twinning. The large porphy-
ritic felspars are deeply affected by an apparently saussuritic altera-
tion. In some places, however, they are clear enough for their finely
repeated twinning to be made out, and the extinction-angles are
such as would be given by labradorite. Similar felspars occur in the
Glan Adda dyke already mentioned.

All the dykes of the Menai Straits, with perhaps the exception of
the olivine-bearing rock of Plas Newydd, are intermediate rather
than basic in their affinities. The characters of the augite are in
accordance with this; so also the frequent cross-twinning in the
larger felspars and their very pronounced zones of growth, the
abundance of magnetite to the exclusion of ilmenite, and the nature
of the ground-mass where it occurs. The rocks are all ‘ porphyritic ’
in the sense of Rosenbusch, since they contain felspars of more than
one generation. When the later felspars occur as microlites forming
part of a ground-mass, I have used the name augite-andesite. Rocks
of more holocrystalline type, in which the two sets of felspars are
of about equal size, have been called dolerites, as distinguished from

416 Reviews—J. W. Davis—Lebanon Fishes.

diabases, which are characteristic of larger intrusive masses, and
exhibit the ‘granular’ structure of Rosenbusch. The term porphyritic
dolerites has been applied to those containing larger scattered felspars,
making in all three generations.

The dykes of the central and northern portions of Anglesey and
of Holyhead Island differ widely from those described above, and
may furnish the subject of further notes.

ReV Tew Ss.

T.—Tuet Fossit Fishes or THE CHauK or Mount Lepanon, 1N
Syria. By James W. Davis, F.G.S., F.L.S., ete. Scientific
Trans. Royal Dublin Soc., series 2, vol. ili. pp. 457-636, pls.
Xiv.-xxxvill. (April, 1887.)

GAIN we have to welcome from the pen of Mr. James W. Davis

an important contribution to our knowledge of the paleontology

of Fishes. Nearly four years ago (Grou. Mac. Nov. 1883) we
received an exhaustive monograph upon the fossil fish-remains of the

Carboniferous Limestone of Britain, in which were figured and

described a number of teeth and spines, indicative of types previously

unknown to science ; and on the present occasion, a still more sub-
stantial contribution is made in the form of figures and descriptions
of a large series of the most perfectly preserved fossil fishes that have
hitherto been discovered. The author treats of the palichthyology of
the Upper Cretaceous rocks of the Lebanon, as revealed by the
researches of the Rev. Prof. E. R. Lewis, formerly of the Syrian

Protestant College, Beyrout, whose magnificent collection was acquired

some years ago by Mr. R. Damon, of Weymouth, and a large portion

of which has now been purchased by the British Museum. This
memoir, like the previous one, was communicated by the late Harl of

Hnniskillen to the Royal Dublin Society, and is printed and published

in the excellent style for which that Society’s Transactions are so

well known.

On glancing over the pages, we are led to admire the industry and
untiring energy of the author, who succeeds, in the midst of business
avocations and at so great a distance from works of reference, in
turning hours of leisure to such profitable account. Nearly all the
more important memoirs bearing upon the subject have been consulted
and are referred to, and, in addition to notes upon forms already
known, no less than ten genera and sixty-six species are described as
new to science. At the same time, the pursuit of scientific study
under such conditions must necessarily render one liable to errors
arising out of the very difficulties surrounding work requiring so
much research as the present; and to this cause must probably be
ascribed certain misapprehensions that will doubtless be criticized
adversely by ichthyologists more favourably situated for interpreting
these remains.

Mr. Davis prefaces his work with a concise and appropriate intro-
ductory section, historical and geological. This is mainly based

Reviews—J. W. Davis—Lebanon Fishes. 417

upon the resumé already published by Pictet and Humbert, with the

addition of a notice of works that have subsequently appeared. By |
some singular mishap, however, there is no reference to Prof. Lewis's

own interesting account of the geology of the Lebanon, which

appeared in the Grorocrcan Macazine in 1878; and the omission

is all the more unfortunate, since the observations contained in

this paper were made while collecting the fossils which chiefly

form the subject of the memoir before us.*

Proceeding to the systematic portion of the work, the author
wisely decides to follow some definite published classification, and
selects that of Dr. Giinther employed in the well-known “Study of
Fishes.” We can scarcely agree with Mr. Davis, however, when he
states that this system “embraces the most recent work of modern
embryologists and anatomists;” and we venture to think that some
of the new facts revealed by the Lebanon fishes themselves will
combine with other recent discoveries to demonstrate the illogical
nature of the arrangement.

The descriptions of the Selachian fishes occupy 24 pages and seven.
plates, and relate to a magnificent series of specimens representing
9 genera and 16 species, of which 2 genera and 12 species are con-
sidered tobe new. A very fine nearly complete example of Notidanus
is made known under the name of WV. gracilis. Two new Scylliidee
are referred to Thyellina. Of the Spinacide, there are remarks upon
Spinax primevus, and the description of a novelty, Centrophoroides
latidens, closely related to Centrophorus; but the author unfortun-
ately fails to appreciate the essential characters of this family, and
includes a remarkable new genus, Rhinognathus, which is described
as possessing a distinct anal fin. The teeth of the latter, if found
isolated, would have been unhesitatingly referred to Lamna, and the
discovery of the complete fish to which they belong is thus of
especial interest. - Among Rays, the Rhinobatide are believed to be
represented by six species of Rhinobatus, of which five are new and
most beautifully preserved; a large Cyclobatis is described as C.
major; and a diminutive fossil from Sahel Alma is doubtfully
assigned to Raja. The Chalk of Mount Lebanon has thus yielded
one of the most important series of Sharks and Rays ever discovered
in a single formation, and the accession of new forms is unusually
great. On reading the letterpress, however, accompanying the
plates, we cannot but regret the want of scientific precision in regard
to anatomical points. The branchial arches, for example, are con-
tinually described as “ branchiostegal rays”; the basal pterygia of
the pectoral fins are referred to as part of the scapular arch, being,
in Rhinobatus, “ divaricating osseous plates,” and in one case ‘‘ pro-
tecting the gills”; the shagreen is regarded as a “ euticular ”
covering; and in the description of the fine skull of Rhinobatus
ienuirostris on p. 488, the most evident features are overlooked.

Some interesting novelties are made known among the Ganoids,
which comprise two species of the Pycnodont Paleobalistum, and

1 See The Fossil Fish Localities of the Lebanon by the Rev. Prof. E. R. Lewis,
M.A., F.G.S., 1878, Decade II. Vol. V. pp. 214-220.

DECADE IiI.—VOL. IV.—NO. Ix. 27

418 Reviews—J. W. Davis—Lebanon Fishes.

two forms perhaps having some affinity with Amia. In the deter-
mination of Palgobalistum Goedelii, Heckel, the author has appa-
rently followed Mr. William Davies’ labelling of the National fossils
without consulting Heckel’s original description; for there is no
reference to the latter, and it is wrongly assumed (p. 496) that the
species was not at first described from the Lebanon. With the
exception of certain head bones, almost the complete skeleton of this
fish is shown in the new specimens; and there is also good evidence
of a second species, which Mr. Davis names P. ventralis. The two
remaining Ganoids are known only by portions of the caudal region,
and so cannot be satisfactorily placed; they are described as Spathi-
urus dorsalis and Amphilaphurus major. With the same order are
also associated a decidedly Teleostean caudal fin, curiously deter-
mined to be “ Chondrosteus ?’’ and another small fish ‘‘ Microdon ?
pulchellus,” which does not appear even remotely connected with the
Pyenodonts.

Passing to the Teleosteans, there are some brief remarks upon the
Sparoid genus, Pagellus, and then follows a most interesting account of
the Berycide. One new species of Beryx, two of Pseudoberyx, two of
Hoplopteryx, and one doubtful species of Zomonotus, are described ;
and the author adds some appropriate remarks upon the mixture of
extinct fishes originally referred to the first of these genera. He
shows (so far as we are aware, for the first time) that the so-called
Beryx Zippei, B. superbus, and B. syriacus, ought all to be placed in
the genus Hoplopieryx; and this is an important advance towards
the philosophical arrangement of the extinct members of the family.

The only representatives of the Carangide are referred to Plataz,
and of this genus two species are distinguished, the one named
P. minor by Pictet and Humbert, and the other new, described as
P. brevis. Some family-headings, however, have been accidentally
omitted from the text, and Petalopteryx, Cheirothrix, and Sphyrena,
thus fall under the section Carangide. Of the first of these, Mr. Davis
has only observed a single specimen, referable to a new species; but
of the second, some five examples are described. The latter are said
to have no less than fifty vertebra, and other features combine to
render their association with the Gobioids somewhat problematical.
Sphyrena Amici, Agassiz, is rightly dismissed as founded upon
uncertain evidence.

Of the Fistulariide, a fine specimen of “ Solenognathus” lineolatus,
Pict. et Humb., is figured; but the author omits to substitute a new
generic name for the one it bears, so long pre-occupied. Next suc-
ceeds a lengthy account of the characteristic Lebanon Cretaceous
genus, Pycnosterinz. Mr. Davis agrees with Pictet and Humbert in
placing this form with the Chromides, and recognizes five species in
addition to the six already known. These are mostly described
in detail; but it would have been interesting to have further infor-
mation regarding the fish named P. latus (pl. xxvii. fig. 2), which
appears to possess a remarkably primitive tail. In the same family
is also placed Imogaster auratus, Costa, of which a beautiful new
Species is made known ; and another example of the Italian Professor's
Omosoma Sahel-Alme is referred to the Stromateide.

Reviews—J. W. Davis—Lebanon Fishes. 419

The Physostomous fishes are placed in the families of Siluride,
Scombresocidee, Esocide, Halecidee, Hoplopleuride, and Murzenide.
The first of these becomes a convenient “refuge” for two remarkable
genera, whose characters appear to be unique. Coccodus has already
been so determined by Pictet, and the new materials described by
Mr. Davis add very materially to our knowledge of the skeleton of
the fish. There is an anteriorly directed spine upon the top of the
head; the body seems to have been scale-less; and the notochord
persistent. Another fish, known only bya single specimen, destitute
of the head, is named Xenopholis carinatus, and presents very
different characters. The body is covered with imbricating bony
‘scutes ; the dorsal and anal fins are long and opposite, and the latter
possesses two small robust spines in front; while the pelvic fins are
abdominal, consisting of 12 or 18 rays, all soft.

Of the Scombresocide, a small flying fish is described under the
new generic name of Hxocetoides, and considered to be closely allied
to the living Hxoccetus. Beautiful specimens are figured, showing
all the more characteristic features of the genus. Another interest-
ing novelty is a well-preserved example of Istieus from Sahel Alma,
—a form hitherto only discovered in the Upper Cretaceous of West-
phalia. This is named I. lebanonensis, and Mr. Davis follows Agassiz
and W. von der Marck in assigning the genus to the Hsocide.

The great families of Salmonide and Clupeide are next treated
together under Agassiz’s convenient name of Halecide. Six new
species of Osmeroides are determined; one of Sardinius; one of
Opistopteryx ; five of Clupea; and one doubtful species of Engraulis.
There are also two new forms of Spaniodon. The section upon
Osmeroides commences with a general notice of the genus, particu-
larly referring to the important researches of W. von der Marck,
but unfortunately omitting a reference to Laube’s recent remarks
upon the skeletal anatomy of the first (Denkschr. Akad. Sci.
Wien). The species are then carefully described in detail, with
numerous illustrative figures; and two specimens are interesting as
showing well-preserved ova, though the author does not appear to
have recognized these, merely noting them as “masses of rounded
granular substance spread over the abdominal region.” Sardinius
crassapinna is another important new member of the Lebanon Chalk
fauna; and the type specimen of Opistopteryx curtus exhibits the
skeleton of the latter genus in an unusually perfect state. Proceed-
ing to the long series of species of Clupea, we hardly feel convinced
of the propriety of assigning some of the forms described to this
genus; C. Lewisii, for example, has a remarkably Hlopine aspect,
and there are others whose connection with Clupea does not, at first
sight, seem well established. Closely related to these is Leptosomus,
of which Mr. Davis has found nothing to add to the original
descriptions. Some notes on Chirocentrites follow, and then an
interesting detailed account of the species of Spaniodon, and of a
nearly allied fish believed to represent a new genus, Lewisia.

The remainder of the Halecide are referred to this group with
more hesitation. The author removes to this position the remarkable

420 Reviews—H. P. Malet—“ Sunlight.”

genus Hurypholis, from its more usual place in the Hoplopleuride,
adding one new species, and showing that Pictet’s H. longidens must
be regarded, at least in part, as representing a hitherto unrecognized
genus, for which he proposes the name of Hurygnathus. This is a
fish of extreme interest, as are also two others referred to new genera,
Pantopholis and Phylactocephalus. These forms belong to a type
apparently well represented in Cretaceous seas, and are suggestive
of some interesting considerations in regard to the affinities of the
primitive Teleosteans of later Mesozoic times, to which, it is to be
hoped, the author will return in greater detail on some future occa-
sion. We would wish to know something further, for example,
concerning the obvious connection between Eurygnathus and En-
chodus—especially as Prof. Cope, so long ago as 1875, showed that
the latter was a truly Physostomous fish, having no affinities with
the Trichiuride, as previously supposed, and is still erroneously
maintained in the monograph before us.

A large number of fine specimens of Rhinellus are described,
indicating no less than six new species, and the author then proceeds
to consider an equally unique series of Leptotrachelus, representing
the family of Hoplopleuride. These fossils are preserved in the
British Museum, and reveal almost all the hard parts of the fish.
LL. triqueter is described in great detail, and Mr. Davis makes known
a new variety of this form, in addition to another, which is con-
sidered specifically distinct. He also gives reasons for concluding
that no true Dercetis has been found in the Lebanon Chalk, and that
Pictet’s D. linguifer was probably founded upon a fragment of
Leptotrachelus triqueter. A figure of Aspidopleurus cataphractus is
likewise added, and this genus included in the same family.

In conclusion, Mr. Davis makes an important contribution to
philosophical ichthyology by bringing forward the first evidence
hitherto discovered of a-Mesozoic eel. Two species, referred to
Anguilla, ave figured and described, the one from Hakel and the
other from Sahel Alma; and the specimens are fortunately suffi-
ciently complete to leave not the slightest doubt as to their family
relationships.

As will be gathered from this brief resumé, the author is to be
congratulated on having contributed to fossil Ichthyology one of the
most extensive works of recent years; and its value is doubly
enhanced by the careful drawings of Miss H. C. Woodward, who has
executed the fine series of illustrative plates. A. 8. W.

I.—Sunuicutr. By the Author of “Tue Inrurior or THE Harru.”
Second Hdition. pp. 180. (London, Triibner and Co., 1887.)
dt this little work the author (Mr. H. P. Malet) asks for the

“serious consideration” of his “simple suggestion, that lght
was the first cause of the creation of this earth, acting on a nebulous
mass that held in it gases or material sensitive to, absorptive, and
retentive of that light.” ‘In other words, a nebulous, chaotic mass
was converted into air, water, and solids by the action of sunlight
on gases sensitive to that force.” He finds that there is actually no

Reviews—H. P. Malet —“ Sunlight.’ . 421

proof of heat in the sun, nor that this earth was ever hot; but that
the “solids contracted and subsided in their necessary gravitation, |
and the waters certainly subsided with the bed they rested on. As
the entire solid body could not possibly sink into a smaller space
than it occupied, it followed that the water sank into the lower
levels of its bed, and left ridges and islands all round the sphere to
form the dry land.” This sinking of the ocean-bed is one of the
main contentions of the author: “the process has been going on
ever since organic life began; therefore we find the relics in our
quarries, mines, and on our mountain tops.” It is needless to
criticize these statements, for although made by one who has read
or consulted some standard geological works, he has evidently failed
to grasp the principles and philosophy of the science. We can only
lament the publication of books of the class to which “ Sunlight ”
belongs, for they are calculated to do much harm to those who
cannot discern fact from fiction. The author, quoting remarks of
Mr. Froude, asks, ‘How many times must we outsiders learn our
science and then unlearn it? ach generation of philosophers
laughs at the conclusions of its predecessors.” In questions relating
to Cosmogony science is naturally speculative, and the most eminent
men differ on many points; but it is curious to find the author
quoting from that “lover of truth,” Dr. Kinns, and criticizing some
of his statements about the early history of the earth.

We do not find so much fault with the author for his quotations
to show how various geologists ‘‘ancient and modern” differ one
from the other on speculative matters; we find most fault with his
own geological (?) teachings. The following quotations will suffice
to justify our lamentations. “It is asserted that rocks are scratched,
grooved, and polished by ice-friction.” And the author proceeds as
follows, “I have examined many of these places, and take a type in
Lucerne. The polishing was all done by running water ; the small
scratches and the larger grooves were all done first by sand and
water; then as they increased in size gravel and pebbles made them
into grooves. Some of these follow bends in the rock, which ice
could not have done.” Again, in reference to Caverns, the author
remarks, ‘To prevent any confusion, I divide caves into three heads
—-First, those that have been excavated by man or beast ; secondly,
those that have been washed out by water ; thirdly, those that have
been built on a centre or nucleus.” In reference to the third cause
for caves he goes on to say, “They are built as a nucleus on a
centre support, and are similar in history, but not in extent, to those
coal-fields which have ocean deposits over each seam.” While, how-
ever, we take exception to these and many other statements, we
entirely sympathize with one sentence in the work before us, “ We
require correct data to start from, before puzzling students of natural
history by one thing to-day and another to-morrow, thus throwing
cosmogony into chaos, and making scientific teaching untrustworthy.”

422 Reports and Proceedings—Geologists’ Association.

REPORTS AND PROCHHDINGS.
(2 Se
VisIT OF THE GroLocists’ AssociaTIoN To THE HrsToRIcAL AND:
Type CoLiections in THE GxroLocicaL DEparrmMEent, BRITISH
Museum (Naturat History), Cromwent Roan, S.W.

N Saturday afternoon, the 12th of March, 1887, the Members of
the Association, accompanied by their President, F. W. Rudler,
Hsq., F.G.8., their Secretaries Dr. J. Foulerton, F.G.S., and B. B.
Woodward, Esq., F.G.S., assembled in the Central Hall of the
Natural History Museum, Cromwell Road, whence they proceeded,
under the guidance of Dr. Henry Woodward, F.R.S., the Keeper of
the Department of Geology, to visit a newly-opened Gallery (No. 11),
in which had been arranged, in seventeen cases, a series of nine
Collections of historical and paleontological interest, bearing upon
the early history of the British Museum and the study of Geology
and Paleontology in this country. Dr. Woodward addressed the
members as follows :—

Taking the exhibition cases in chronological order, the earliest is
the “Sloane Collection.” This is the most ancient portion of the
Geological Collection, having formed a part of the Museum of Sir
HansSloane, Bart., F.R.S8., acquired by purchase forthe Nation in 1758.

The geological specimens are stated to have consisted ‘‘in what
by way of distinction are called extraneous fossils, comprehending
petrified bodies, as Trees or parts of them; Herbaceous plants ;.
Animal substances,” etc., and reported to be “the most extensive
and most curious that ever was seen of its kind.” Until 1857 the
Fossils and Minerals formed one collection, so that a large part of the
“Sloane Collection” consisted probably of mineral bodies and not
organic, but in any case only about 100 specimens of invertebrate *
fossils can now be identified with certainty as forming part of the
original Sloane Museum. Hach specimen in the Sloane Collection
had originally a number attached to it, corresponding to a carefully
prepared Manuscript Catalogue, still preserved, which contains many
curious entries concerning the various objects in the Museum. In
the course of more than 130 years, many of these numbers have
been detached from the objects or obliterated by cleaning. But as
all fossils at this early date were looked upon merely as curiosities,
but little attention was paid to the formation or locality whence they
were derived. Historically, the collection has immense interest to.
us, marking the rapid strides which the science of Geology has made
of late years, especially as tegards its more careful and systematic
methods of study.

The next Collection in chronological order is the “ Brander Col-
lection,” and is the earliest one in which types of named and described
species have been preserved.

This Collection was formed by Gustavus Brander, F.R.S., F.S.A.,.
in the earlier half of the last century, and an account of the same,
with eight quarto plates, was published in 1766, entitled, “ Fossilia

* And some few vertebrate fossils which have not been separated from the General
Collection.

Visit to the British Museum. 423

Hantoniensia Collecta, et in Muszxo Britannico deposita.” The
descriptions of the species given in the work were written by Dr.
Solander, one of the Officers of the British Museum. ‘They were
“collected in the County of Hampshire, out of the cliffs by the sea-
coast between Christchurch and Lymington, but more especially
about the cliffs by the village of Hordwell, nearly midway betwixt
the two former places” (op. cié. p. 111).

Only a small number out of the original 120 figured specimens,
are now capable of being identified, the rest having become, in the
course of 120 years, commingled with the far more numerous and
later Eocene Tertiary acquisitions, and so have lost their connection
with this admirable Memoir. The engravings of the shells are equal
to any modern published work descriptive of the fossils of the Hocene
formation; but the names given by Dr. Solander are in many
instances incorrect, according to our present knowledge of the genera
of Mollusca.

The next series to which I would direct your attention is the
Collection of William Smith, LL.D. This Collection, which was
commenced about the year 1787, was purchased by the Trustees in
1816, a supplemental Collection being added by Dr. Smith in 1818,

Jt is remarkable as the first attempt made to identify the various
strata forming the solid crust of England and Wales by means of
their fossil remains. There had been other and earlier Collections
of fossils, but to William Smith is due the credit of being the first to
show that each bed of Chalk or Sandstone, Limestone or Clay, is
marked by its own special organisms and that these can be relied
upon as characteristic of such stratum, wherever it is met with, over
very wide areas of country.

The fossils contained in this Cabinet were gathered together by
William Smith in his journeys over all parts of England during
thirty years, whilst occupied in his business as a Land Surveyor and
Engineer, and were used to illustrate his works, “Strata Identified
by Organized Fossils,” with coloured plates quarto (1816; four parts
only published): and his “Stratigraphical System of Organized
Fossils ” (quarto, 1817).

A coloured copy of his large Geological Map, the first Geological
Map of England and Wales, with a part of Scotland, commenced in
1812 and published in 1815—size 8 feet 9 inches by 6 feet 2 inches
wide, engraved by John Cary—is exhibited in the last Wall-case on
the right hand side of this Gallery, at the north end. It is well
worthy of careful inspection.

_ William Smith was born at Churchill, a village of Oxfordshire,
in 1769; he was the son of a small farmer and mechanic of the
same name, but his father died when he was only eight years old,
leaving him to the care of his uncle, who acted as his guardian,
William’s uncle did not approve of the boy’s habit of collecting
stones (‘ pundibs” = Terebratule, and “quoit-stones” = Clypeus
sinuatus) ; but seeing that his nephew was studious, he gave him a
little money to buy books. By means of these he taught himself
the rudiments of geometry and land-surveying, and at the age of

424 Reports and Proceedings— Geologists’ Association.

eighteen he obtained employment as a land surveyor in Oxfordshire,
Gloucestershire, and other parts, and had already begun carefully
and systematically to collect fossils and to observe the structure of
the rocks. In 1798 he was appointed to survey the course of the
intended Somersetshire Coal-Canal, near Bath. For six years he
was the resident engineer of the canal, and, applying his previously-
acquired knowledge, he was enabled to prove that the strata from
the New Red Marl (Trias) upwards followed each other in a regular
and orderly succession, each bed being marked by its own character-
istic fossils, and having a general tendency or ‘dip’ to the south-east.

To verify his theory he travelled in subsequent years over the
greater part of Hngland and Wales, and made careful observations
of the geological succession of the rocks, proving also, by the fossils
obtained, the identity of the strata over very wide areas along their
outcrops.

His knowledge of fossils advanced even further, for he discovered
that those in situ retained their sharpness, whereas the same
specimens derived from the drifts or gravel-deposits were usually
rounded and water-worn, and had reached their present site by
subsequent erosion of the parent-rock.

In 1799 William Smith circulated in MS. the order of succession of
the strata and imbedded organic remains found in the vicinity of Bath.
His large Geological Map of England and Wales is dated 1815.

On June 1, 1816, he published his “ Strata identified by Organized
Fossils,” with illustrations of the most characteristic specimens in
each stratum (4to.).

In 1817 he printed “A Stratigraphical System of Organized
Fossils,” compiled from the original geological collection deposited
in the British Museum (4to.).

In 1819, he published a reduction of his great Geological Map,
together with several sections across England.

These have just been presented to the forse by Wm. Topley,
Hsq., F.G.8.

Mr. Smith received the award of the jirst Wollaston Medal and
fund in 18381, from the hands of Prof. Sedgwick, the President of
the Geological Society.—“ As a great original discoverer in English
geology, and especially for his having been the first, in this country,
to discover and teach the identification of strata, sal to determine
their succession by means of their imbedded fossils.”

In June, 1832, the Government of H.M. King William the
Fourth awarded Mr. Smith a pension of £100 a year, but he only
enjoyed it for seven years, as he died 28 Aug. 1839.

In 1885 the degree of LL.D. was conferred upon Mr. Smith by
the Provost and Fellows of Trinity College, Dublin.

Perhaps the highest compliment paid him was that by Sedgwick,
who rightly named him “the Father of English Geology.”

The bust above the case which contains William Smith’s collection
is a copy of that by Chantry surmounting the tablet to his memory
in the beautiful antique church of All Saints at Northampton, where
his remains lie buried.

=

Visit to the British Museum. 425

We come next to a collection, the very name of which betrays the
antiquity of its origin. It is known as “ Sowerby’s Mineral Conch-
ology.”

This Collection was begun by Mr. James Sowerby, prior to 1812,
and continued by his son, Mr. James de Carle Sowerby, F.L.8., during
the preparation of their great work entitled, “The Mineral Conchology
of Great Britain,’ which appeared in parts, between June, 1812,
and December 1845, and forms six volumes octavo, illustrated with
648 plates.

The value of the work consists in ahi fidelity and accuracy of the
figures given, and also that most of the specimens drawn are here
named and described for the first time. They comprise fossils from
all parts of England and from every Geological formation.

The small green labels mark the specimens actually figured in the
work. The Collection was purchased by the Trustees from Mr.
J. de Carle Sowerby, January, 1861.

It may be interesting to record that many of the latter parts were
illustrated by plates drawn by the late Mr. J. W. Salter, A.LS.,
F.G.8., for so many years paleontologist to the Geological Survey.
When a youth, Salter was apprenticed to Mr. J. de Carle Sowerby,
F.L.S., who was at that time both a naturalist and an engraver.
The youthful apprentice afterwards married his master’s daughter,
and became, as is well known, one of the most brilliant paleeontolo-
gists in this country.

Another curious, but small series represents the ‘types’ or
‘figured specimens’ of ‘“ Konig’s Icones Lossilium Sectiles.”

This illustrated work, on miscellaneous fossils in the British
Museum, was prepared by Mr. Charles Konig, the first Keeper of
the Mineralogical and Geological Department, after its separation
from the general Natural History Collections in 1826.

The engravings are rough, but characteristic, and the first
“Century ” (or 100 figures of fossils), is accompanied by descrip-
tions ; the plates of the second “Century” have names only, but no
descriptions are published with them.

A far more important Collection is that known as ‘“ The Gilbert-
son Collection.”

In 18386 Prof. John Phillips published Vol. II. of his ‘“ Illustrations
of the Geology of Yorkshire,” which is devoted to the ‘‘ Mountain
Limestone District.” In the Introduction he writes as follows :—
«My greatest obligation is to Mr. Wm. Gilbertson of Preston, a
naturalist of high acquirements, who has for many years explored
with exceeding diligence a region of mountain limestone, remarkably
rich in organic remains. ‘The collection which he has amassed from
the small district of Bolland is at this moment unrivalled, and he
has done for me, without solicitation, what is seldom granted to the
most urgent entreaty; he has sent me for deliberate examination,
at convenient intervals, THE WHOLE OF HIS MAGNIFICENT COLLECTION,
accompanied by remarks dictated by long experience and a sound
judgment.” He (Gilbertson) had proposed to publish on the
Crinoidea himself, but his sketches as well as his specimens were

426 Reports and Proceedings—Geologists’ Association.

all placed at Prof. Phillips’s disposal. Phillips adds—‘ An attentive
examination of this rich collection rendered it unnecessary to study
minutely the less extensive series preserved in other cabinets ... .
most of the figures of fossils are taken from specimens in Mr. Gilbert-
son’s Collection, because these were generally the best that could
be found.”

The Gilbertson Collection was purchased for the British Museum
in 1841.

The collections which follow mark a distinct era in the annals of
Geological Science.

Some forty-seven years ago a little society was founded by a few”
London geologists, namely—Dr. J. Scott Bowerbank, F.R.S., Searles
V. Wood, F.G.S., Prof. John Morris, F.G.S., Alfred White, F.L.S.,
Nathaniel T. Wetherell, F.G.S., James de Carle Sowerby, F.L.S.,
and Frederick EH. Edwards, F.G.8., for the purpose of illustrating
the Hocene Mollusca, and entitled the “‘ London-Clay-Club.”

They met at stated periods at each other’s houses, and after a time
they said, ‘“ Why should we not illustrate all the fossils of the
British Islands, and from every formation?” No sooner proposed.
than a society was founded, called the Paleeontographical Society,
in the year 1847 (just forty years ago). The first volume, issued
in that year, was “The Crag Mollusca, Part I., Univalves,” by Mr.
Searles V. Wood, F.G.S. (with 21 plates).

You have here before you the actual “Searles Wood Crag Collec-
tion.” This collection was commenced in 1826, and occupied about
30 years in its formation. It represents the Molluscan fauna of
the Red and Coralline Crags of the neighbourhood of Woodbridge,
and from Aldborough, Chillesford, Sudbourn, Orford, Butley, Sutton,
Ramsholt, Felixstow, and many other localities in Suffolk, also from
Walton-on-the-Naze in Hssex. The specimens so collected were
employed by Mr. Searles Wood in the preparation of his Monograph
on the Crag Mollusca, published by the Paleontographical Society
(1848-1861); with supplements in 1871, 1873, and 1879, illus-
trated by seventy-one quarto plates. Hach figured specimen is
indicated by having a small green label affixed to it.

A geological description of the Crag formation by Mr. 8. V. Wood,.
jun., F.G.8., and Mr. F. W. Harmer, was issued by the Palzonto-
graphical Society in 1871 and 1873.

The collection was presented by Mr. 8. V. Wood to the British
Museum, January, 1856, and a supplementary collection was given
by Mrs. Searles V. Wood in 1885.

The next ‘“ Paleontographical Collection” is of nearly equal
antiquity and fully of equal merit. It is the Eocene Molluscan
Collection formed by the late Frederick N. Edwards, F.G.S., about
the year 1835, and was continually being added to, until a few years.
before his death, which happened in 1875. It was acquired for the
nation by purchase in 1873.

Originally intended to illustrate the fossils of the London Clay,
Mr. Edwards extended his researches over the Eocene strata of
Sussex, Hampshire and the Isle of Wight, where, assisted by Mr.

Visit to the British Museum. 427

Henry Keeping, he made the most complete collection ever attempted
by any geologist, and it still remains unrivalled.

Mr. Edwards contributed six Memoirs to the Paleontographical
Society, 1848-1856, also separate papers to the “ London Geological
Magazine,” 1846, the “ Geologist,” 1860, and the ‘“ Geological
Magazine,” 1865, descriptive of the Hocene Mollusca in his collection.

Mr. 8. V. Wood continued the work for Mr. Edwards, describing
and figuring the “ Eocene Bivalves” in the annual volumes of the
Palzontographical Society for 1859, 1862, 1870, and 1877. Hach
Specimen which has been figured is specially marked.

About 500 species have been described and figured, but the col-
lection is very rich in new and undescribed forms.

The last Collection is that of a Naturalist who devoted his entire
life to the study and illustration of a single class of organisms,
namely, the Brachiopoda. It was formed by the late Mr. Thomas
Davidson, LL.D., F.R.S., F.G.S., V.P. Pal. Soc., ete., (formerly of 9,
Salisbury Road, West Brighton, and Muir-house, Midlothian) ;
between the years 1837 and 1886, with the object of illustrating his
great work on the “ British Fossil Brachiopoda,” published by the
Paleeontographical Society, in six large quarto volumes, between the
years 1850 and 1886, comprising 2290 pages of text, and 234 plates,
with 9329 figures, and descriptions of 969 species.

Dr. Davidson was also the author of the Report on the recent
Brachiopoda collected by H.M.S. “Challenger” (vol. i. 1880) ; of
the article “ Brachiopoda,” in the Encyclopedia Britannica, Ninth
Kdition, 1875; of a Monograph of Recent ‘“ Brachiopoda” (Trans.
Linnzean Society, 1886 and 1887), and of more than fifty other
separate Memoirs mostly bearing upon Brachiopoda both Recent and
Fossil, printed in the Transactions and Journals of the various
learned Societies, etc.

His collection, both of Recent and Fossil Brachiopoda, together
with all Dr. Davidson’s original drawings, his numerous books and
pamphlets were presented by him to the British Museum through
his son William Davidson, Esq., February, 1886. By his direction
the entire collection of recent and fossil species are to be kept
together in one series, for the convenience of reference of all men of
science who may wish to consult the same.

At the conclusion of Dr. Woodward’s remarks Mr. William Topley,
F.G.S., kindly added some valuable information with reference to
William Smith’s maps and sections and his geological work in
various parts of England.

The President then returned thanks to Dr. Woodward, and
expressed the interest which, he said, he and all the members present
felt in this very important addition made to the exhibition-series of
the Galleries devoted to Geology and Paleontology. After a further
examination of the Collections the Members separated, well pleased
with their visit to this deservedly popular Museum.

428 Correspondence—Mr. A. B. Wynne.

CORRESPONDENCE

———

RECENT DISCOVERIES IN THE SALT RANGE OF THE PUNJAB.

Str,—Having already trespassed upon your space with regard to
this subject, 1 beg leave to add a few necessary words, because the
discoveries already noticed (Grot. Mac. March and May, 1886) have
since extended to further recognition, by Dr. Warth and Mr. R. D.
Oldham, of the continuation of the boulder beds of the original
“ Olive Group” westwards—these being identified by their Conularia-
containing pebble layer in a position entirely different from that
which my own acquaintance with the Range would have led me to
expect.

My contention has been that the boulder beds with the Conularia
layer in the east of the Range, occupying a position immediately
beneath the Hocene limestone, occupied a different horizon from that
of other boulder beds of somewhat similar and somewhat different
character, in the west of the Range, which had their place with the
lowest members of the series amongst Silurian or other old Paleozoic
rocks.

The recent discovery of the same Conularia-layer underlying a
group of sandstones, next below the Carboniferous Limestone, must
modify my previous views, and I feel the more inclined to abandon
the contention above stated, were it even to involve identification of
the eastern and western boulder-beds as upon one arid the same
horizon, in consequence of the probability that a coincident uncon-
formity, till quite lately undetected, intervenes between these boulder
beds and the older groups of the Range, its place being traceable by
means of the boulder-beds with Conularia pebbles.

Without the evidence of the subsequently-discovered fossiliferous
layer, or that of the associated discordance, the extension of a part of
the original “ Olive Group” westwards at the higher level appears
to have been taken by me as representative of the whole, there being
another dark-coloured zone amongst the lower groups, to which soft
dark rocks could be referred when low down in the series.

The correction which it is expected will now be applied to previous
classifications of the Salt Range rocks is of great interest in con-
nexion with the geology of the Punjab, and I refer to it, so far as
my own published views to the contrary are concerned, gladly
accepting new light thrown upon the subject from reliable sources,
but as far as possible refraining from forestalling the full announce-
ment of details to be looked for from those who have added these
important discoveries to our knowledge of the Salt Range series, a
series of such complexity that additional facts of detail cropping up
here or there might almost have been anticipated. A. B. Wynne.

June 10th, 1887.

P.S.—Since writing the above I have seen Dr. Warth’s account of
his discovery alluded to (Records Geol. Surv. Ind. vol. xx. pt. 2,
p- 117), and find therein much with which I can agree.

Correspondence—Ur. A. J. Jukes-Browne. 429

THE PALHONTOGRAPHICAL SOCIETY.

Sir,—By the publication of the Council’s Report in your last
Number, the attention of your readers is once more drawn to the
Paleontographical Society, and its need of a larger number of
members in order to find the necessary funds for carrying on its
excellent work.

I think I shall be doing the Society a service if I briefly point out
some facts which may partly account for the falling off in the number
of its members. The Council regret that “ geologists in general”
do not more readily enroll themselves as members, and they remark
that since the formation of the Society, many free libraries, local
geological societies, and field clubs have been established, ‘but that
the number of these institutions that have joined the Society is
very small.”

I venture to think that one reason of this backwardness may be a
feeling that the subjects of the Monographs issued by the Society
are not always of general geological interest, and that many of them
are not such as would be practically useful to the members of local
societies.

It is said that a guinea a year is very little to pay for such a
splendid series of books, and so it is; but if the intending subscriber
feels that half the contents of the volumes are not likely to be of
use to him (or to the society he represents), he is apt to think that
the money could be more usefully spent in other ways, or perhaps
he purchases second-hand copies of those monographs which he does
find are frequently wanted, such as Davidson’s Brachiopoda, Wright’s
Hchinoderms and Ammonites, Wood’s Crag Mollusca, etc., etc.

I feel a difficulty in expressing my meaning more plainly without
appearing to depreciate the value of many excellent and valuable
monographs which have been published by the Society; but every
one admits that there are certain classes of fossils which are of great
practical use to the geologist, and that there are others which are of
much less geological importance, though biologically they may be
equally interesting. In the first category we place the Mollusca,
Brachiopoda, Echinodermata, Corals, and certain orders of Crustacea ;
among the less useful we must class Plants, Sponges, Cirripeds,
Entomostraca, Polyzoa, Insects, Fishes, Reptiles, Birds, and Mammals.
This being so, it is surely desirable that prominence should be given
to the more important groups, and until these have been fully
described and figured, very little space should be given to those of
less general value; particularly should the delineation of large
Vertebrate remains be postponed in favour of the Invertebrate fossils,
which occupy so much less space, and a knowledge of which is so
much more generally useful.

I know that there are difficulties in the way of applying these
principles, and probably the Council would not consider themselves
justified in refusing an offered monograph because it deals with one
of the less geologically important classes, but I think they should
have regard to the effect which the publication of such monographs
may have on intending subscribers. Let us consider the monographs

430 Correspondence—Ur. J. FE. Marr.

in the recently issued volume for 1886. I imagine there are very
few general geologists who desire to possess 15 plates of one species
of plant, however curious and interesting that plant may be. Again,
the appearance of seven plates devoted to the horns of Deer is not
likely to be welcomed by any but a few experts. These 22 plates
would have illustrated 50 or 100 species of Mollusca, and there are
many hundreds of such fossils awaiting illustration.

Why are the Mollusca so neglected? It is true that in this
volume we have the first parts of two memoirs on Jurassic Mollusca,
but one of these parts is wholly taken up with stratigraphical details
which, though unquestionably useful, might perhaps have been
condensed or printed elsewhere; this, however is a minor point,
and every one will welcome Mr. Hudleston’s Monograph. Cannot
the Council induce other palzeontologists to prepare similar mono-
graphs on the Cephalopoda, Gasteropoda, and Pelecypoda of the
Cambrian, Ordovician, Silurian, Devonian, Carboniferous, Cretaceous,
Eocene, and Oligocene formations ?

I can testify that the synonomy of some of the commonest Chalk
fossils is in the utmost confusion; and that Monographs of the
Cretaceous Mollusca would be welcomed by many amateur and
professional geologists. When will Mr. Wiltshire give us his
promised contribution ? I feel sure that if this and other Molluscan .
Monographs were produced, and if those relating to fossil plants and
bones were deferred, the publications of the Society would be used
by a much larger number of persons, and consequently that many
more geologists and local institutions would decide to become sub-
scribers.

Harwett, Berns, August 5. A. J. Juxes-Browne.

THE GLACIAL DEPOSITS OF SUDBURY, SUFFOLK.

Sir,—I owe an apology to Mr. Jukes-Browne for having omitted
any reference to the action of coast-ice in my paper upon the Glacial
Deposits of Sudbury in the June Number of the MaGazinr (pp. 262-
270). In considering the suggestions made to account for the con-
tortion of drift deposits, I should have mentioned the grounding of
true or false icebergs, or of coast-ice. Nevertheless, it seems to me
that the arguments I brought forward against the contortion having
been produced by icebergs apply equally to the case of coast-ice.

Unless we are prepared to admit that the drifts were actually
frozen into the coast-ice at the time that the contortion was produced
in them (and I fail to see how such could be the case, considering
the uniformity of succession and characters of the drift over a con-
siderable area), we must suppose that they were deposited on the
sea-floor before the exertion of pressure by this ice. If so, it is
difficult to see why the drifts were not frozen as well as the under-
lying Tertiary rocks, for these drifts are of some thickness, and
considerable time must have elapsed during their formation. If they.
were so frozen, the Tertiary beds ought to be affected in the same
manner as the drifis, which is not the case.

Correspondence—Mr. Alfred Harker. 431

If the drifts were not frozen, I cannot understand the production
in them of overfolds of considerable horizontal extent (such as that
shown at the south end of Mr. Green’s pit), without any obliteration
of the planes of deposition.

Mr. Jukes-Browne speaks of the drifts as being pushed along in a
‘partially-frozen state.’ Hven if contortion can be produced by coast-
ice in deposits under such conditions, I cannot conceive that the order
of succession of the deposits should be so constant as it is in the
Sudbury area, upon this hypothesis. Surely the incoherent portions
of the drift would become churned up, so that we should find masses
of boulder-clay, gravel, and loam mingled together, and having
their divisional planes obliterated. I have seen no signs of such in
the area under consideration.

In asserting that contortions occur “in the accumulations which
lie on the summits of ridges,” IJ used the term ‘ summits’ not for the
highest points, but for the upper portions of the major ridges, and I
referred to Mr. Green’s pit and the pits near the cemetery. These
pits are situated at the upper parts of major ridges, and the contor-
tions are seen in Mr. Green’s pit to lie against a minor ridge. At the
same time I do not wish to assert that all the contortions were caused
by the inequalities close to which they now lie.

I regret that my summing up should appear biassed in favour
of one explanation. I visited the Sudbury area with little practical
knowledge of the Hast Anglian drifts. Having read much of the
literature bearing upon these drifts, including Mr. Jukes-Browne’s
lucid papers, I started my examination with a strong bias in favour
of their marine origin. As I was gradually led to abandon this view,
I considered it worth while to state the evidence which weighed
with me, but brought forward my reasons as an advocate, and not as
a judge. I should certainly not venture to make a charge to a jury
with the evidence derived from so limited an area.

I take this opportunity of calling attention to one or two inaccu-
racies in Fig. 1 of my paper. The Crag mass C’ should be separated
from the filled-in ground D by a little gravel; the junction of the
Thanet sand and chalk in the isolated patch at the south end of the
pit should be in the same straight line with that of the main portion,
and the top and base of the Thanet sand layer are much more even
than represented in the diagram. Joun BE. Marr.

St. Joun’s Couu., CAMBRIDGE.
Aug. 6, 1887.

THE CORTLAND ROCKS.

Sir,—Dr. Callaway, in combating the ‘metamorphic’ origin of
the rocks of the ‘Cortland Series,’ does not appear to be aware that
Prof. Dana has materially modified his earlier opinion on this point.
After examining some new railway cuttings, he was convinced that
the hornblendic and augitic rocks are of true eruptive origin, and
although he does not find that the new sections throw any light on
the origin of the ‘soda-granite,’ his former line of argument is
evidently much weakened (Amer. Journ. Sci. 8, vol. xxviil. p. 384,.

432 Obituary—Sir Julius von Haast. -

1884). Mr. G. H. Williams, who is publishing a series of petro-
logical studies on the whole of the rocks in question, reserves to the
last any general conclusions concerning their origin; but he states
that the area “‘is quite sharply separated from the gneisses, mica-
schists and limestones which surround it, showing none of the
gradual transitions into these rocks which Hermann Credner, in his
description of this district written in 1865, supposed to exist.”
(Ibid. 3, xxxi. p. 27, 1886.) ALFRED HarKkeEr.

Sr. Joun’s Connece, Cameripcr, Avg. 5th, 1887.

OBITUARY.

SIR. ve cke WULIUS | VON BAAS

Sir Jonn Francis Junius von Haast, K.C.M.G., Ph.D., F.R.S.,
F.L.S., F.G.S., Ord. Fr. Jos., Ord. Coron. Ferr. Austr. Coron. Ital.,
etc., etc., Director of the Museum, and Professor of Geology in
Canterbury College, New Zealand.

It is with deep regret that we learn, through a Reuter’s telegram
from Wellington, that our friend and fellow-geologist, Sir Julius
von Haast, died suddenly of heart disease, on the 15th August. It
seems but yesterday that he was here with us, and although com-
plaining of rheumatic gout, which he attributed to the severe work
and endless engagements arising out of the duties he was called
upon to fulfil last year, as Commissioner in charge of the New
Zealand exhibits at the Colonial and Indian Exhibition, he appeared
to have many more years of good work lying before him.

Sir Julius von Haast has done excellent service to science in New
Zealand, not only in connection with its Geology, in which he took
an active part, but also in the discovery and collection of remains of
the great extinct Wingless Birds of those Islands with which the
Museum of Christchurch (N.Z.), and those of nearly all the prin-
cipal European and American Museums, have been enriched.

Sir Julius recetyed the honour of Knighthood in recognition of his
services in connection with the Colonial and Indian Exhibition ; but
so far back as 1867, he had been elected a Fellow of the Royal
Society in recognition of his services to science. Upwards of thirty
memoirs are credited to him in the Royal Society’s list of scientific
papers, mostly on the Geology and Extinct Birds of New Zealand.
His loss will be keenly felt in the Colony where he has laboured so
long and diligently.—H. W.

PROFESSOR LAURENT-GUILLAUME DE KONINCK.

Prof. C. Malaise informs us of the recent death (on 16 July last)
of our venerable friend, Prof. de Koninck, For. Memb, Geol. Soe.
Lond., late Professor of Chemistry and Paleontology in the Univer-
sity of Liége, Belgium. Prof. de Koninck’s labours on the Fauna
of the Carboniferous rocks of Belgium, England, Australia, etc., are
well known. We hope to give a notice of his life in a later Number.—
Eipir. Gro. Mac.

Geo].Mag.1887. Decade IIL Vol. \V. PL XU

5)

GM .Woodward del. ct lith, . West, Newman & Co.imp.

Carboniferous Cockroaches. ‘i

ERRATA.

P. 435, line 5 from below, for fine read free.
Ae 5. 19) “55 3 53) “these? 5, «theres

THE

GEOLOGICAL MAGAZINE.

NEW. SERIES. DECADE Ill. YQE. IN.
No. X—OCTOBER, 1887.

SnStiGahinpIhy /NISjba(@ Abas

eed

I.—On tur Discovery or THe Larvat STAGE ofr A CocKROACH,
EirostaTtina Pract, H. Woopw., FROM THE CoAL-M¥EAsuURES
or Kitmaurs, AYRSHIRE.

By Henry Woopwarp, LL.D., F.R.S., F.G.S.,
British Museum (Natural History).

(PLATE XII.)

Y the kindness of Mr. B. N. Peach, F.R.S.E., F.G.S., of the
Geological Survey of Scotland, I have been permitted to examine
a very interesting insect-remain enclosed in a light-brown nodule
of Clay-Ironstone, obtained fram Kilmaurs, Ayrshire.
In February last! I had the pleasure to describe three new forms
of British Carboniferous Cockroaches, viz. :—

1. Htoblattina Johnsoni, H. Woodw., Coal- Measures, goer, near Dudley.
2. Leptoblattina exilis, H. Woodw. do.
3. Lithomylacris Kirkbyi, H. Woodw., U. Coal- see “Meithil, Fife.

Mr. 8. H. Scudder, of Boston has described no fewer than 30
species from the Coal-Measures of N. America, whilst 41 species
have been described by Goldenberg, Heer, Germar, Scudder, and
others from the Coal-Measures of Europe, so that this group of
Orthopterous insects was perhaps almost as well represented in the
Coal-period as at the present day, and nearly as widely distributed
geographically.

The present example from the Coal-Measures of Kilmaurs makes
us acquainted with another entirely new form, measuring 28 milli-
métres in length, by 14mm. in breadth, and exhibiting the minute
head sunk in the rounded pronotum, a pair of rudimentary wing-
covers, and a pair of rudimentary wings, which, as in other fossil
cockroaches, are not differentiated from one another as they are
in the modern Blattarie.

The abdomen exhibits nine segments with broadly-expanded free-
edges to their terga remarkably unlike the abdomen of most modern
cockroaches.

The 8th and 9th segments are as large in proportion as those
preceding them, thus differing markedly from living species, in which
the terga of these segments are very narrow and are greatly over-
lapped by the 7th segment.

The 10th abdominal segment cannot be made out, but was probably
present between the free-edges of the terga of the 9th segment.

Save the wings, no appendages are preserved.

1 See Grou. Mac. 1887, Decade III. Vol. IV. pp. 49—58.
DECADE III.—VOL. IVY.—NO. x. 28

434. Dr. H. Woodward—On Etoblattina Peachit.

Detailed description.—The pronotum is nearly semicircular in out-
line, its anterior border being rounded and its posterior border
straight. It is twice as broad as it is long.

The head is seen occupying a small rounded indentation in the
centre of the anterior border of the pronotal shield. The epicranial
plate is divided longitudinally down the centre; there is also a trans-
verse furrow probably indicating the ocular and genal divisions.

Behind this notch in which the head lies, the pronotum is orna-
mented with two small slightly-raised prominences, and two small
rounded depressions. Breadth of pronotum, 12 millimétres, length
5mm. The wing-covers and wings, which are nearly alike in form
and size, are each about 10 mm. in length, and about 5 mm. in
greatest breadth. The mediastinal vein is seen in all 4 wings, also
the veins of the Anal and the Internomedian area. The wings
appear to conceal the whole of the mesonotum and the greater part
of the metanotum. The length of the mesonotum and metanotum
together is 6 mm.

The abdomen is 12 mm. in length by 10 mm. in breadth at its
broadest anterior part. The segments 9 in number diminish in
breadth rapidly, being only about 34 mm. in breadth at the posterior
border. Fully half the breadth of the segments consists of the free-
edges (epimera) of the terga, the body itself being not more than
5 mm. in breadth at the widest part, the terga making up the remain-
ing 5 mm.

Compared with other fossil Cockroaches, the wings in this fossil
Blatta have a close resemblance to those of Blattina insignis,’ Gold.
(Pl. XII. Fig. 3), from the Coal-Measures of Saarbriick (Rhenish
Prussia) ; also to Leptoblattina eailis, H. Woodw., from the Coal-
Measures of Coseley, near Dudley (Pl. XII. Fig. 2).?

I mention in my description of L. ewilis (op. cit. p. 57) that “there
is evidence of epimeral pieces to 3 of the segments,” which would
have greatly increased their width.

Compared with recent Cockroaches, there seemed at first but
small hope of finding any form amongst living Blattine which
would serve for comparison with this remarkable fossil; but
through the kind assistance of Mr. W. F. Kirby, of the Zoological
Department (British Museum of Natural History), I was referred to
the figures and description of Blattarize given by Brunner de Wat-
tenwyl,* from the West Indies and Brazil, and particularly to one
named blabera atropos, by Stoll. This form, of which Brunner
figures the male and female, and also the larva, presents in its larval
stage * a close approach to our fossil example, not only in the rudi-

1 « Fauna Sarepontana Fossils,” Die fossilen Thiere aus der Steinkohlenformation
von Saarbrucken von Dr. Frederick Goldenberg; Saarbruck, 1878. 4to. 1st Heft,
mit 2 Tafelen (Taf. ii. fig. 14).

? See ‘*Some New British Carboniferous Cockroaches,’ by Henry Woodward,
Gzot. Mag. 1887, Dec. III. Vol. IV. Pl. IL. Figs. 2 and 3, pp. 56—58.

3 Noveau Systéme des Blattaires, par Charles Brunner de Wattenwyl, Vienna,
1865, p. 375-6 and tab. xii. 55, A—G.

4 Op. cit. tab, xii. 55, F.

Dr. G. J. Hinde—Organic Origin of Chert. 435

mentary wings, but also in the great development of the free-edges
(epimera) of the terga of the abdominal segments, so marked a
feature in the fossil before us. (Compare Figs. 1 and 4, Plate XII.)

The Kilmaurs specimen, however, differs from the larva of Blabera
atropos (Stoll), in the presence of the anterior notch of the pronotum
in which the head is visible; in the larger size of its wings and the
ornaments on the segments of the abdomen in the living form and
the difference in the ornament on the pronotum.

In the character of the neuration of the wings in the adult of
Blabera atropos one cannot but be struck with its resemblance to
the neuration of Htoblattina amongst Coal-measure forms of Blattarie.

Seeing that there can be little doubt that we are here dealing with
a larval form, it may be well to place it provisionally under the
genus LHtoblattina, and I cannot think of a more suitable specific
name to propose for it than that of the geologist from whose hands
I received it. I therefore name it Etoblattina Peachit, after that most
able naturalist and geologist, Mr. B. N. Peach.

EXPLANATION OF PLATE XII.

Fic. 1. Etoblattina Peachii, H. Woodward, sp. nov. (enlarged three times), Coal-
Measures, Kilmaurs, Ayrshire.

. Leptoblattina exilis, H. Woodward, Coal-Measures, Coseley, near Dudley.

. Blattina insignis, Goldenberg, Coal-Measures, Saarbriick, R. Prussia.

. Larva of Blabera atropos, Stoll, Brazil, view of upper side.

. The same larva seen from beneath.

Or co bo

I].—On THE ORGANIC ORIGIN OF THE CHERT IN THE CARBONIFEROUS
Limestone SERIES oF IRELAND, AND ITS SIMILARITY TO THAT IN
THE CoRRESPONDING STRATA IN NorrH WALES AND YORKSHIRE.

By Groree Jennines Hinpz, Ph.D., F.G.S., ete.}

HE first references in any detail to the nature of the Chert in
Carboniferous rocks appeared in 1878,” when Messrs. Hull and
Hardman published a joint paper on the subject, treating more
particularly of the Chert in the Upper Carboniferous Limestone of
Ireland. Prof. Hull gave a general description of the distribution
and mode of occurrence of the Chert, and a detailed notice of its
microscopic structure, as shown in fifteen thin sections of the rock
from various localities in Ireland. The author reached the conclusion
that the Chert is essentially a pseudomorphic rock, consisting of
gelatinous silica replacing limestone of organic origin, chiefly
foraminiferal, crinoidal, and coralline ; the replacement was believed
to have taken place before the shales overlying it were deposited,
whilst the limestone was in a more or less plastic condition, admitting
the fine percolation of water holding silica in solution. The sea
was believed to have been largely charged with silica in solution,

1 Paper read before the British Association at Manchester.
* Scientific Transactions of the Royal Dublin Society, vol. i. n.s. 1878,
pp. 71-94, pl. iii. ;

436 Dr. G. J. Hinde—Organic Origin of Chert.

and the chemical process was accelerated by the warm surface waters:
of a shallow sea. The origin of the Chert from the siliceous skeletons
of Diatomacez, Polycystine, and the spicules of sponges is distinctly
denied, and it is affirmed that it can only be considered as a secondary
product due to the replacement of lime-carbonate by silica.

Mr. Hardman gave, in his part of the paper, the results of numerous
analyses of the rock, showing that it consisted principally of
anhydrous silica, reaching up to 95:5 per cent., with a varying
admixture of carbonate of lime, iron, and a few other minerals.
Judging from its chemical constitution, Mr. Hardman considered
that the formation of Chert can only be accounted for by a process
of pseudomorphism in limestone, and “supposing that the ocean in
which the limestone was being formed contained an unusually large
percentage of silica, it is but natural to suppose that the water would
elect to dissolve small portions of the more easily soluble carbonate
of lime and in their place to deposit equivalent portions of the less
soluble silica in the gelatinous state” (op. cit. p. 92).

Shortly after the appearance of the paper just referred to, M.
Alphonse Renard, of Brussels, published, in a paper entitled?
“¢ Recherches lithologiques sur les Phthanites du Calcaire Carbonifere
de Belgique,” the results of an examination of the same kind of
rock in the Carboniferous Limestones of Belgium. This author
very carefully studied the macroscopic and physical characters of the
Chert, and he reached nearly the same conclusion respecting its
origin as that of Messrs. Hull and Hardman, viz. that the phthanites
(as the Chert beds are technically termed) have been formed by the
silicification of the organic and inorganic calcareous elements which
composed the limestones, and that this more or less complete pseudo-
morphosis has taken place at an epoch when the sediments, although
retaining a certain amount of plasticity, already possessed the
structure which may be seen in the normal Carboniferous Limestone.
The author further adds, that it is impossible to explain the formation
of phthanites by the .accumulation of organisms with siliceous
skeletons, and there” was nothing to prove that the silica which had
infiltrated into the limestone was derived from the decomposition of
the spicules of sponges or the frustules of diatoms.

I may just remark that the observations of M. Renard on the
characters of the Chert or phthanites appear to have been very
carefully and thoroughly worked out, and it is not to these but
to the theoretical conclusions as to the inorganic origin of the
silica of the Chert that I venture to take objection.

Since 1878, no special memoir on the nature of the Carboniferous
Chert has appeared, but a curious commentary on the statement
of Prof. Hull that this Chert was not derived from siliceous organisms
such as the spicules of sponges, was afforded by the discovery by
Prof. Sollas,? that some of the very sections described and figured
in Prof. Hull’s paper were so constituted of sponge-spicules that

1 Bulletin de l’ Académie Royale de Belgique, 2 s. t. 46, pp. 471-498, pl. 1.
2 Op. cit. p. 498.
3 Ann. and Mag. Nat. Hist. vol. vii. (1881) p. 141.

Dr. G. J. Hinde—Organie Origin of Chert. 437

they made up the larger part of the Chert. Another fact, also
bearing on the probable organic character of the Irish Carboniferous
Chert, was the discovery by Messrs. Wright and Stewart of Belfast
of beds of siliceous clay, apparently resulting from decayed Chert,
which were described by Mr. H. J. Carter, F'.R.S.,’ as in some
parts nearly entirely composed of sponge-spicules.

In a paper? showing the derivation of the Chert in the Lower
and Upper Greensand of the South of England from the remains
of siliceous sponges published in the Phil. Trans. for 1885, I ventured
to suggest that the facts above stated justified the conclusion that
the Carboniferous Chert of Ireland would be found to be likewise
of organic origin, and that therefore Messrs. Hull and Hardman
were probably wrong in regarding it as of inorganic derivation.
This suggestion has been warmly combated by Messrs. Hull and
Hardman in two short papers brought before the Royal Society,®
and lately published in its Proceedings. Prof. Hull states, in the
paper referred to, that there is absolutely no evidence that the
silica of the Irish Carboniferous Chert has been derived from
sponge-spicules; that there is only a fanciful analogy between
the Carboniferous Chert-beds and the sponge-beds of the Cretaceous
formation ; that as sponges were rare in the Carboniferous rocks,
it is clear that they could have taken no important part in the
formation of the Chert-bands in the Carboniferous Limestone; and
the assertion I made is therefore unfounded, and I must have
mistaken sections of crinoid stems for sponge-spicules. Prof. Hull
still maintains and reasserts his original proposition, that the beds
and nodules of siliceous material in the Carboniferous Limestones
of Ireland have been formed by a direct replacement of the original
calcareous substance of the limestone itself by silica held in solution
in the sea-water, without the intervention of siliceous organisms.

It is somewhat remarkable that neither Prof. Hull nor Mr. Hard-
man make any mention whatever in these papers of the fact,
published by Prof. Sollas, that in at least two of the specimens of
Chert in Prof. Hull’s own possession, sponge-spicules make up the
larger part of its substance. This fact alone is quite sufficient
foundation for the assertion I made, and Prof. Hull was in duty
bound to give some explanation of it, before accusing me of making
a statement on absolutely no evidence. It is manifest that * Prof,

1 Ann, and Mag. Nat. Hist. s. 5, vol. vi. (1880) p. 218.

2 On Beds of Sponge-Remains in the Lower and Upper Greensand of the South of
England, Phil. Trans. pt. 1, 1885, pp. 405-453, pls. 40-45.

3 Proc. Royal Soe. vol. xlii. p. 304, et seq. !

4 J regret to have to make another serious complaint against Prof. Hull of having
misquoted a passage from my published paper in the Phil. Trans., leaving out words
essential to its meaning, and then stating that he has quoted the entire passage to
avoid the possibility of misinterpretation, and that it is altogether unintelligible !
The passage in question, at the bottom of page 432 in my paper, is as follows,
<< Thus Dr. Bowerbank held that the sponges imbedded in the Chert of the Greensand
possessed horny and not siliceous skeletons, and that the silica of the Chert in which
they were imbedded was attracted from the exterior medium by the animal matter
and not secreted therefrom by the living sponge.’’ In Prof. Hull’s quotation the
last paragraph runs thus, ‘‘ The silica in the Chert in which they were imbedded was

438 Dr. G. J. Hinde—Organie Origin of Chert.

Hull had clear evidence in his own possession; that its nature had
been publicly pointed out by Prof. Sollas; and that he has entirely
ignored it in his reply to my statement.

As I have been engaged during this last year in an investigation
of the character of the Carboniferous Chert of Yorkshire and North
Wales, which proves to be unequivocally of the same organic
nature as the Chert in the Cretaceous strata of the South of England,
this emphatic denial of the organic origin of the Carboniferous
Chert in Ireland by the Director of the Irish Geological Survey
made me desirous of examining for myself the character of the
rock in question, and with this end in view, I visited during this
last July the various localities in Ireland in which, according to
Prof. Hull, the Chert in the Carboniferous series is best developed,
and I propose now to give a short notice of the observations I made
in the field, and also of a microscopic examination of the specimens
I collected. Time has not allowed me to work out fully the results.
of my studies of the English and Welsh Carboniferous Chert, and I
shall only make a brief reference to these rocks at present; but the
specimens I have brought will enable any one to see how close is
the resemblance in general characters between the same rock from
the different countries.

Before starting on my search, I called at the Office of the Geolo-
gical Survey in Dublin, and through the courtesy of Prof. Hull,
for which ] tender him my best thanks, I was allowed to examine
under the microscope the series of sections of Carboniferous Chert
prepared for his original description of the rock, including the two,
in which, according to Prof. Sollas, sponge-spicules make up the
larger part of the Chert. I can fully substantiate this statement
of Prof. Sollas, not only as regards the specimens which he examined,
but in others as well; the sponge-spicules in the slides are mostly
shown in transverse section and their characters are unmistakeable.

It is somewhat strange that with specimens filled with sponge-
spicules before him Prof. Hull should not in his paper have made
a single mention of these structures beyond denying that they had
anything to do with the structure of the rock. If we compare the
original specimens with the descriptions given of them, the mistake
made by Prof. Hull is at once apparent. Thus, for example, the
section of the brownish and banded Chert from Ballymote, County

Sligo, represented on fig. 4 of the plate, is stated to contain.

“circular disks of crinoids, sometimes with dark central nuclei,

attracted from the exterior medium by the animal matter, and not secreted from the
living sponge.’? In the original I distinctly state that the living sponge secreted
the silica now forming the Chert from the exterior medium (7.¢, the sea-water). In
the quotation, Prof. Hull omits the important words ‘these’ and ‘éy,’ and then
accuses me of not stating that the silica was originally derived from the sea-water !

Again, Prof. Hull on page 305 of his paper gives as a quotation from my paper,
between inverted commas, the following passage, ‘‘ The beds and irregular masses of
Chert have been derived solely from the silica of the sponge-remains, instead of
from that held in solution by the sea-waters themselves.’’ This passage, quoted as
a verbatim extract, does not occur in my paper, and is not even a fair representation
of my meaning, which will be seen by furning to pages 482, 3, to be, that the silica
of the Chert was not derived directly from that held im solution in the sea-water.

a

Dr. G. J. Hinde—Organic Origin of Chert. 439

obscure forms of foraminifers in section, coralline structures? and
bivalves (brachiopods) with crystalline silica in interiors,” etc. In
the original of the figure, however, sections of crinoid stems do not
appear, and it is evident that the forms described as “ circular disks
of crinoids with dark central nuclei” are really transverse sections
of sponge-spicules, and the central nuclei are sections of their axial
canals! These are abundant enough in the section. A similar
mistake vitiates the descriptions of the other sections, and the
supposed Crinoidal stems are, in most instances, the spicules of
sponges! When a chance section of the ossicle of a Crinoid does
occur in Prof. Hull’s slides, the distinction between it and a sponge-
spicule is readily apparent, for not only is the Crinoid fragment
much larger, but it also exhibits the minute cribriform structure
peculiar to Hchinodermal organisms, which is so well known to
every tyro in the microscopical study of organic rocks, and serves
to mark them off from sponge-remains. Prof. Hull has charged me,
and erroneously, with mistaking sections of Crinoids for sponge-
spicules, but it is evident that he was himself really committing
the converse mistake of describing the sponge-remains in his own
specimens as portions of Crinoids!

As Prof. Hull’s specimens were selected without any reference
to their composition, and as they have been brought forward as
evidence of the inorganic origin of the silica of the Chert, the fact
that some are found filled with siliceous spicules may fairly be
taken as a strong argument from a perfectly independent source
that the Carboniferous Chert is really derived from the silica
of sponge remains.

The Chert in the Irish Carboniferous Limestone is mainly
developed in the Upper Division or Upper Limestone, which’ Prof.
Hull regards as the equivalent of the upper portion of the Carbon-
iferous Limestone in England, the shale beds intervening between
this Upper Limestone and the Millstone Grit being considered by
him as the representatives of the Yoredale beds of Yorkshire. As
a fact, however, the Yoredale series in its typical region mainly
consists of beds of limestone associated with beds of Chert, often of
considerable thickness; these limestone and chert beds are of a
similar character to those of the so-called Upper Limestones of the
Irish series, and it is therefore reasonable to conclude that these
Chert-bearing Upper Limestones are the equivalents in the geological
scale of the Chert-bearing limestones in the Yoredale series of
Yorkshire and North Wales.

According to the reports of the Ivish Geological Survey, beds of
Chert are very generally distributed in the Upper Limestones of the
south-western districts of Tipperary, Limerick, Kerry, and Cork,
but I had no opportunity of visiting these counties, and my obser-
vations were limited to the Chert in the Limestones in Queen’s
County and Kilkenny to the south, and in the Counties of
Fermanagh and Sligo to the north-west of Ireland, from whence
Prof. Hull obtained the specimens on which he has founded his

EN LOGNCie. De Toe

440 Dr. G. J. Hinde—Organie Origin of Chert.

theory of its inorganic origin. I also examined the Chert in the
Carboniferous Limestones in the vicinity of Dublin, which, though
coloured in some of the Geological Survey Maps as belonging to the
Upper Limestone series, forms part, as I was informed by Prof.
Hull, of the Middle division, or Calp series.

The mode of occurrence and the physical characters of the Chert
are in the main similar both in the south and in the north-west
of Ireland. It is usually exposed on the flanks and summits of
some of the principal hills which have partially escaped the severe
glacial erosion to which the country has been subjected, and their
preservation may, in part at least, be attributed to the compact
resistant nature of the Chert and Cherty-limestones of which they
are composed. The Chert often occurs as nodular masses of irregular
form, inclosed in beds of hard bluish Limestones, and following the
planes of bedding, much in the same way as the flints in the Upper
Chalk; but unlike the flints, these nodular masses are not sharply
delimited from the Limestones in which they are interbedded, but
there is a gradual passage from the Chert to the Limestone.

More frequently, however, the Chert exists in definite beds, from
one to five inches (-025--12m.) in thickness, which intervene at
irregular intervals between beds of Limestone. These beds some-
times occur also as well-marked layers in the central portions of
beds of Limestone. Both the nodular aggregations and the
horizontally-bedded Chert usually occur in the same series of rocks ;
the particular mode of deposition probably depends on the extent to
which the sponge-remains (of which it will be shown the Chert
consists) are present in the respective areas.

Owing to this irregular mode of deposition, it is difficult to arrive
at an estimate of the total thickness of the Irish Carboniferous

Chert. Nowhere have I seen a continuous series of beds like those —

in North Wales and Yorkshire; the Chert in Ireland was more
interrupted by the deposition of Limestones, but its aggregate
thickness may not fall much short of the beds in Yorkshire.

On the sides of the hill of Knock-na-Rea, near Sligo, Chert
occurs at frequent intervals, both in beds and nodular masses
throughout the series of Limestone, about 800 feet (240m.) in
thickness, forming the upper portion of the hill, and at Ben Bulben
to the North of Sligo Bay, the Limestones, in the higher slopes,
about 600 feet (180m.) in thickness, also contain an abundance of
Chert. I should estimate the Chert to vary from one-tenth to one-
fifth of the total thickness of these beds. On the sides and summit
of the hill of Benachlan, Florence Court, near Enniskillen,’ Prof. Hull
estimates that the Chert-bands in the Upper Limestone series may
have a thickness of 150 feet (45m.) out of a total thickness of 400
feet, but from my own observation I should judge that this estimate
is considerably too high. In the South of Ireland the upper portion
of the Upper Limestone series consists, according to the reports of
the Geological Survey,? nearly entirely of a mass of Chert from

1 Proc. Royal Soe. vol. xlii. p. 306.
2 Explanation of Sheet 128 (1859), p. 11.

Dr. G. J. Hinde—Organie Origin of Chert. 441

30 to 50 feet (9 to 15m.) in thickness. As the total thickness of the
Upper Limestone series, in which the Chert is mainly developed,
is from 600 to 800 feet, there is probably an aggregate thickness of
100 to 150 feet of Chert (30-45m.), and in addition to this there
is a considerable thickness of Chert in the Middle or Calp series of
Limestone.

There is considerable uniformity in the character of the Chert in
the Carboniferous series of Ireland. It is, for the most part, a
compact, dark rock, it breaks with a conchoidal or splintery fracture,
is too hard to be scratched with a knife, and, as a rule, gives no
action with acid. The fractured surfaces are usually dull, sometimes
with a faint lustre, resembling the so-called JLydian Stone.
Horizontal lines of banding are not often shown in it. The beds
are sometimes traversed by minute thread-like fissures, now infilled
with quartz. The upper and under surfaces of the beds weather into
a light grey or whitish siliceous crust, in some cases nearly an
inch (20mm. ) in thickness, of a porous granular material, harsh to the
feel, and adhesive to the tongue, which strikingly contrasts with the
black compact Chert of the central portion of the beds. In cases
of extreme weathering, the entire mass of the Chert is converted
into this porous rock, it then has a pumice-like aspect, and is
relatively very light.

In the case of cherty limestones, in which the shells of Brachio-
pods, Crinoid stems and other calcareous organisms have been
imbedded, the calcareous structures are entirely removed by weather-
ing, and the impressions of the fossils are distinctly shown in the
siliceous matrix.

In some cases the Chert has a light brownish tint; it is equally
as hard as the black Chert, and weathers out in a similar manner.
In Queen’s County and Kilkenny some of the nodular masses,
and beds of Chert as well, are of a grey or bluish grey tint, the
beds are much jointed, and thin films of calcite have formed in the
joint-planes. Occasionally the siliceous rock occurs in the granular
porous condition in the limestones, it does not appear to have
reached the stage of compact Chert. When treated with acid or
when weathered out naturally, the siliceous portions stand out from
the limestone in the same way as the porous crust on the solid
Chert.

I have not had any chemical analysis of the Chert prepared, those
carried out by the late Mr. Hardman’ being sufficient to show
its mineral composition. In several of these analyses the proportion
of insoluble silica varied from 90 to 95 per cent., the residue con-
sisting of carbonate of lime, iron, alumina and magnesia. In less
pure Chert the proportion of silica diminished, whilst that of
carbonate of lime increased, and some of the rocks analyzed were
rather limestones than Chert. Prof. Hull states from his micro-
scopic observations that the silica of Chert occurs in a gelatinous
or colloid condition.» The chemical analyses of Mr. Hardman®

1 Scient. Trans. Royal Dublin Soe. vol. i. 1878, pp. 86-91.
2 Op. cit. p. 84. 3 Op. cit. p. 92.

442 Dr. G. J. Hinde—Organie Origin. of Chert.

show, however, that in all cases the silica present is in the insoluble
form, and he seems to have been puzzled to reconcile this fact
with the preconceived notion that it was in the amorphous or
soluble condition. The sections of the Irish Chert which I have
examined between crossed Nicols all show the optical characters
of chalcedony and quartz, and thus substantiate the accuracy of Mr.
Hardman’s analyses; it is therefore probable that Prof. Hull’s
statement that the silica is now in a colloid condition is founded
on some mistake.

In order fairly to ascertain the microscopic structure of the Chert
I had sections prepared, from specimens obtained from every locality
JI visited, including Dublin. The localities comprised Dunamase,
near Maryborough, in Queen’s Co.; Bonnet’s Rath, near Kilkenny ;
Keishcorran, near Ballymote; Knock-na-Rea, and Ben Bulben in
the County of Sligo, and also Benachlan, Florence Court, near
Enniskillen. !

Nearly all the sections were prepared from the prevalent dark
Chert. This, when viewed by reflected light under the microscope,

showed a diffused, cloudy, bluish-white reticulation on a dark

ground. By transmitted light the bluish portion becomes trans-
lucent, and when the section is very thin, transparent. It is
resolved into microscopic sponge-spicules, confusedly intermingled
together, whose individual outlines can be traced with varying
degrees of clearness. In transverse section the spicules appear as
well-defined circles, with, in many cases, a central spot indicating
the axial canal of the spicule. In longitudinal section, the larger
spicules exhibit two parallel lines with a clear space between them,
but viewed in this direction the individual forms are much less
distinct than when seen transversely. In most of the sections under
examination, sponge-spicules are the only organisms visible, in some
there is a slight admixture of specimens of the genus Fenestella and
other Polyzoa, the cells of which are now filled with either chalce-
dony or quartz, rarely also there are fragments of minute Brachiopod
or Entomostracan shells, and one or two microscopic ossicles of
Crinoids, but I have not recognized Foraminifera in my sections.
The dark material in the Chert is for the most part disposed in
wavy bands, following the plane of bedding. Some of it consists of
very minute opaque crystals, but for the most part it has a cloudy
appearance. It appears to me to be partly of a carbonaceous and
partly of a ferruginous character. As already mentioned, this dark
material disappears in the weathered outer crust of the Chert, and
even the central portion of black Chert beds becomes bleached after
exposure.
Sections of the light-brown Chert from Benachlan contain, in
addition to spicules, numerous well-defined microscopic cubic and
rhombic crystals, either entirely or partially transparent or opaque ;
they vary from 02 to ‘(075 mm. in diameter; similar crystals are
also present in the dark Chert, but in fewer numbers. In this brown
Chert the spicules have a brownish cloudy aspect in transmitted
light; their outlines are extremely jagged, showing that solvent
action has reduced them to mere skeletons of their original forms.

Dr. G. J. Hinde—Organie Origin of Chert. 443

In all the sections of Chert which I had prepared sponge-
spicules are present; in some their traces are indistinct and objection
might be raised that the few forms visible are insufficient to justify
the conclusion that the rock has been derived from these organisms.
In other slides of precisely the same kind of rock in outer appear-
ance, the spicules are so abundant that it must be conceded that, as
Prof. Sollas remarked of some of Prof. Hull’s specimens, they make
up the larger part of the Chert. But even in the best-preserved
specimens of the Irish Chert, the spicules have suffered from the
influences of fossilization, and many are passing into various stages
of dissolution, and there are good grounds for supposing that in the
specimens which only show the spicules faintly, they have become
nearly obliterated through subsequent changes in the rock.

I have discovered evidence strongly confirmatory of this view, in
the nature of the porous crust, which, as already mentioned, results
from weathering action on the surfaces of beds of Chert. In most
cases, this crust appears to consist only of minute siliceous grains,
but under favourable conditions of preservation, it is seen to be
_ composed of innumerable minute rod-like sponge-spicules, inter-
. crossing, and as it were felted together irregularly in the plane of
the bedding of the rock. Also the layers of porous siliceous rock,
which, as already noticed, in some cases appears to take the place
of the compact Chert in the limestone, are likewise seen to consist
of matted masses of minute spicules.

In the cases just mentioned, the evidence in favour of the view
that the silica of the Chert is derived from the accumulation of
the skeletal elements of siliceous sponges, and not as a direct deposit
of this mineral from solution in sea-water, is demonstrable and
conclusive. We can see in these instances that the silica of. the
Chert is distinctly of organic origin; the sponges have by vital
action secreted the silica to form their spicules, and whilst some of
these still retain their forms, others have been partially or com-
pletely destroyed to form the siliceous matrix. These spicular
erusts also prove the presence of these bodies in the central mass
of the beds of Chert, even when they cannot be distinguished in
microscopic sections.

The preservation of the sponge-remains in the Jrish Carboniferous
Chert is much less favourable than in the corresponding Chert-beds
of the Yoredale series in Yorkshire and North Wales; the spicules
are far more eroded, and consequently it is more difficult to determine
their characters. They appear to be nearly entirely minute acerate
and cylindrical spicules varying from ‘3 to ‘9mm. in length, and
from :017 to -12 mm. in thickness. Most of these spicules probably
belong to the Monactinellidee, though some of the larger forms may
be those of Tetractinellid sponges. Occasionally slender filiform
spicules are present which attain a length of 2 mm., though only
°05 mm. in thickness.

Not a single entire sponge has, as yet, been discovered in any of
the Chert-beds referred to, and though masses of rock reaching, as
we have seen, an estimated thickness of 100 to 150 feet (30-45 m.)

444 Dr. G. J. Hinde—Organie Origin of Chert.

are built up by these organisms, the portions preserved do not suffice
to determine satisfactorily a single species. The sponges, like those
in the Cretaceous rocks, have lived for successive generations on the
areas of these Chert-beds, and after the death of the animal and
the decay of the soft structures, the microscopic spicules of their
skeletons have gently fallen and intermingled together on the sea-
floor. When the sponges have existed continuously and nearly
exclusively in the same area for long periods, massive beds of Chert
have been produced by the accumulation and partial solution of their
spicules; where, however, the sponges have grown in association
with Crinoids and Polyzoa, then the Chert is in nodular aggregates,
or the interspaces between the Crinoidal and other calcareous
structures have been filled up by the silica resulting from the partial
solution of the sponge-remains producing Cherty limestones.

Under certain conditions, however, when the calcareous portions
of the rock much exceed the sponge-remains, these latter are
frequently partially or entirely dissolved and replaced by calcite.
This substitution has taken place in some of the dark limestones of
the Calp series near Dublin, in which by the aid of a simple lens
numerous spicules can be detected, but on treating the rock with ©
acid, the spicules are dissolved away equally with the limestone
matrix, leaving only a few small hollow fragments in the residue.
The spicules in this limestone are considerably larger than those in
the Chert-beds, and appear to belong mostly to Tetractinellid sponges.

It is not my intention to enter now into a detailed comparison of
the Irish Carboniferous Chert with that in the Yoredale series
of Yorkshire and North Wales; it will suffice to state that in all
essential features the rocks from these different localities are very
similar, so that in many cases it would be impossible to distinguish
hand-specimens of the Irish from the Welsh Chert. The organic
nature of the English and Welsh Carboniferous Chert, as produced
from sponge-remains, is far more distinctly shown than in the case
of the Irish beds, for the spicules are much better preserved, and
the beds have been less altered by fossilization. Sponge-life also
has been more continuous in the Yorkshire and North Wales areas,
or, at all events, these organisms have been less intermingled with
Crinoids and other animals possessing skeletons of carbonate of
lime, so that their remains form continuous series of Chert-beds.
In some of the Yorkshire areas there are beds of Chert 18 feet
(5'4m.) in thickness without a break, and in North Wales there is a
continuous series 350 feet (105m.) in thickness, without the inter-
vention of Limestones. I hope shortly to give a detailed notice of
these remarkable and hitherto unequalled sponge-beds, which, alike
with those in the Irish Carboniferous rocks, conclusively show that
in the interval between the Carboniferous Limestone proper and the
Millstone Grit, siliceous sponges existed in greater force and played
a more important part as rock-builders, than at any subsequent
geological period.

The organic nature of these Carboniferous Chert and siliceous
rocks, though strenuously denied by some geologists, has been

Dr. G. J. Hinde—Organie Origin of Chert. 445

frequently suspected by others, but no satisfactory proof has been
‘heretofore brought forward to decide the question. I think, however,
that the evidence which I have now collected from so many
quarters will be found sufficiently conclusive to set at rest all
objections to their organic origin.

I am not in a position to discuss how far the British Cherts cor-
respond with the phthanites of the Carboniferous strata of Belgium,
but judging from the careful description given of the latter by
M. Renard, the resemblance is very close, and in my opinion the
phthanites will be found to have the same origin as our Cherts.
I have some grounds for this belief from the fact that in sections
of a hand specimen of phthanite from the Carboniferous rocks at
Namur, which was kindly sent to me by Dr. C. Barrois, there are
abundant remains of sponge-spicules, and in transverse sections
they correspond closely with those figured by M. Renard in illus-
tration of his paper. Most of these spicules, however, are now
so fragmentary and altered, that they would not be recognized as
such by any one unfamiliar with the changes produced in them by
fossilization.

I wish in conclusion shortly to notice some of the arguments
brought forward by Messrs. Hull and Hardman and by M. Renard
in favour of what may be called the chemical theory of Chert,
which is that the silica of which it is composed is a direct deposit
from the stores of this mineral held in solution in the sea-water,
without the intervention of organic life. According to the explana-
tion given by M. Renard,’ at certain intervals the waters of the
Carboniferous sea, holding in solution carbonic acid, a solvent of
calcite, attacked the calcareous material, the silicic acid being infil-
trated into it, and taking its place in proportion as it was decom-
posed. Prof. Hull distinctly states that the Chert is essentially
a pseudomorphic rock consisting of gelatinous silica replacing lime-
stone of organic origin.

I am unable to recognize the evidence for the statement that the
silica of the Carboniferous Chert is a pseudomorph after limestone.
In the beds of pure Chert, that is, when there is scarcely any
admixture of carbonate of lime, hardly any traces of organisms other
than sponge-spicules can be distinguished. According to the trans-
mutation theory these Chert-beds were originally organic limestones,
and should now show in silica the forms of their original structures;
but, unfortunately for the theory, there are scarcely any present in
them. In the Cherty limestones, calcareous organic structures are
plentiful, but curiously enough, even here, there has been little
replacement. Silica has indeed infilled the vacant spaces in the
cells of the Polyzoa and the stems of the Crinoids, but it has not, as
a rule, replaced the calcareous structures themselves. This is clearly
shown when the Cherty limestones are exposed to atmospheric in-
fluences by which the calcareous structures in them are dissolved
away and removed, leaving perfect moulds of their forms in the
siliceous matrix, which is now in the form of rottenstone. If they

* Bullet. de l’Acad. Roy. de Belgique, 2me s. t. 46 (1878), p. 497.

x

446 F. A. Bather—Growth of Cephalopod Shells,

had been replaced by silica on the transmutation theory, they would
not thus be dissolved out. I fully admit that the substitution of
silica for calcite is of common occurrence, but in the case of these
Carboniferous Cherty limestones it does not seem to have taken place
to any great extent. Phy

The main argument brought forward by Prof. Hull,’ in his lately
published paper, against the derivation of the Chert from sponge-
remains, is stated to be “based on the fact that the development of
sponge-life in the Carboniferous period was insignificant, and quite
inadequate to account for the existence of bands and masses of Chert,
sometimes constituting almost a half or third of the entire mass of
the Upper Limestone.”

But in what manner did Prof. Hull set himself to ascertain the
fact that the Sponge-life in the Carboniferous seas was insignifi-
cant? With great pains he compiles lists of the numbers of species
and genera of sponges and calcareous organisms in the Carboniferous
and Cretaceous formations respectively, and he finds an ‘‘ enormous
proportion of siliceous sponges in the Cretaceous as compared with
those in the Carboniferous period.” Further, in the Carboniferous
period, “the species of siliceous sponges might almost be counted
on the fingers of the two hands; both in genera, species and indi-
viduals they are quite unimportant as compared with the calcareous
organisms of that period, and totally inadequate to supply materials
for the formation of such beds of Chert as are formed in the Carbon-
iferous Limestone formation.”

It seemed to me, however, that this method was rather an unsafe
one to determine a question of this character, and that even in the
hands of a Director of the Geological Survey, in his own field of
investigation, a satisfactory result would not be obtained by figuring
up lists of species, and then doing a rule-of-three sum with the totals.
I ventured to think that it would be more satisfactory to ask the
question whether sponge-life was insignificant in the Carboniferous
period, of Nature herself, and so, with the limited time and resources
at my disposal, I went to the rocks in Ireland and collected the
evidence which has been brought forward in this paper. I leave it
to the reader to determine whether my plan, or that of the Director
of the Irish Survey, is most to be relied on, and whether, as Prof.
Hull states, there is absolutely no evidence beyond a fanciful analogy
for the organic origin of the Carboniferous Chert of Ireland.

III.—Tue Growts or CrpHatopop SHELLS.
By F. A. Baruer, B.A., F.G.S.,
of the British Museum (Natural History).

HE shells of Cephalopods form an evolutionary series, traceable
| to an ancestor unknown, but nearly related to not yet coiled
forms of the Cambrian. In all descendants from this common stock
homologous parts are discerned. Hence facts regarding the growth
of any one form may be applied to all. Of Cephalopods with
chambered shells only Nautilus, Spirula, and Sepia exist. Spirula is

1 Proc. Royal Soc. 1887, vol. 42, p. 306.

F. A. Bather—Growth of Cephalopod Shells. 447

so rare and its shell so retrograde that no theory has yet been built
onit. Hxamination of Nautilus gave rise to the Secretion-hypothesis,
shortly stated as follows :—As the animal grows, the adherent muscles
and the cincture gradually advance, the siphuncle lengthening in
proportion ; thus a cavity is formed between the last septum and the
surface of the visceral hump: this latter then deposits calcareous
matter, beginning at the sides of the shell and proceeding towards
the siphuncle round which it is continued backward. During the
advance of the animal the anterior portion of the mantle secretes
calcareous matter, which it deposits in successive layers on the margin
of the aperture (Edwards and Wood).

Microscopical examination of the fresh Sepion has led Dr. H.
Riefstahl to propose what may be called the Intussusception-hypo-
thesis :—That each new septum is absolutely developed from the
preceding, and is removed therefrom by growth of the intervening
zone of the outer shell wall; which growth is effected, not by
apposition, but by intussusception (The Sepion and its relations to
Belemnites, Paleeontographica, Bd. 82, 1886). Startling though this
be, the minuteness of the investigation demands attention. His paper
consists of (a) description of minute structure of the Sepion; ()
conclusions as to its mode of growth; (y) establishment of homo-
logies with the Belemnite, thus bringing those conclusions to bear
on external shells.

Fic. 3.

uncalei jet
ERT 7 AEC
—Dm— Tics of The
= ee cal In

IES brah
Be ney

SVS Trelehed

iN munbranes.
a / .
ell mm
te

Fic, 1. Sagittal section, posterior end of young Sepia shell. Diagram after Riefstahl.

Fic. 2. Sagittal section, anterior margin of Sepia shell: the partitions not shown.

Fic. 8. Development of sinuous partitions. Diagram after Riefstahl. The thick-
ness of the free membranes is exaggerated.

(a) The Sepion is a complex of conchyolin membranes, impreg-
nated with lime in varying degrees: in accordance with the extent
and mode of calcification three parts are distinguished (Fig. 1.)—
i. Middle plate ; calcification slight and not extended to the margin ;
i. Outer portion, dorsal; membranes parallel and overlapping,

448 F. A, Bather—Growth of Cephalopod Shells,

stiffened in definite tracts by calcareous discs to form an anterior
“shagreen field” and a posterior ‘‘mucro”; iii. Inner portion,
ventral; chiefly consists of the so-called ‘“‘spongioid tissue”; in
sagittal section the organic membranes forming this are seen to be in
groups ; in each group the ventral membranes lie close together and
are supported by a calcareous lamina of prismatic structure, thus
forming a ‘“‘lamella” ; the remaining membranes are stretched freely
at regular intervals; between the lamelle, at right angles to them,
are calcareous “sinuous partitions,’ which radiate towards the
margin; through these the free membranes pass, and are by them
supported: decalcification shows that all the membranes are con-
tinuous with those of the Middle plate (Fig. 2).

(8) The Outer portion is secreted by the mantle; its form
is determined by that of the Inner portion. Secretion does not
explain the growth of the Inner portion: the last formed lamellze
lie more closely on one another than do those of earlier age;
the spaces between the freely-stretched membranes are not
smaller, but the number of those membranes is less, they are
absent from at least the hinder edge of the last formed lamella;
hence the partitions are shorter, and the space between the insertion-
lines of the two last lamellze is less than in other parts of the shell
(Fig. 2); each partition is bifid ventrally, this end is the first to
appear. It follows that the membranes are separated from the
lamellee, not secreted by the mantle; and the calcium carbonate is
only deposited on the inner, i.e. dorsal, side of the conchyolin
(Fig. 8): the subsequent sundering of the lamelle is accounted for
by intussusceptional growth of the shell.

(y) The Outer portion equals the Belemnite guard; the Inner
portion the phragmocone, the lamellz being septa; the Middle plate
was represented by an epicuticula of the phragmocone: this is con-

firmed by fresh details. Hence in all chambered shells the hinder .

end of the body is in continuous contact with the youngest septum,
and the subsequent sundering of the septa is effected by the growth
of those zones of the shell-wall that lie between the sutures.

Thus far Riefstahl.

Undeniably there are objections to the Secretion-hypothesis,
such as the complex structure of nacre, especially when freely-
stretched membranes are present. But neither alternate secretions
of lime and gas or, as in Sepia, liquid, nor alternate deposition of
lamellee and partitions are so absurd as Riefstahl maintains. Despite
their regularity, due to advance of structure and function, we need
not think the septa of Cephalopods originally different from those of
some Gasteropods. Still the chambers of a Nautilus have, thanks to
the siphuncle, a vitality denied to the septate portion of a Bulimus ;
here Riefstahl’s conclusions harmonize with those of F. Miller on
shell formation in Lamellibranchs: “The shell is no product of
secretion, but has independent life, and grows by intussusception ”’
(Zool. Beitr. Breslau, 1885, p. 206). Yet the avascular nature of the
shell renders it hard to credit elaboration of lime in parts removed
from the animal, nor is it to be thought that the latter is wholly idle ;

.
}

F. A. Bather—Growth of Cephalopod Shells. 449

in Sepia the inner surface of the mantle covering the lamellz is formed
of columnar cells, which at the anterior margin, where growth is
most vigorous, are extremely long; removing this, there are seen on
the ventral side of the last-formed septum, especially at the margin,
developing sinuous partitions, over which I have been unable to
demonstrate any such conchyolin membranes as are shown in Fig. 2.
Further, this hypothesis requires subsequent growth of the septum
as well as of the wall.

In the adult Nautilus, Ammonites, and Spirula the last septum
is always nearer the penultimate septum than the regular increase
in the depth of the chambers would lead one to expect; this also
obtains in Belemnites so far as our fragmentary specimens allow one
to judge, and, as Riefstahl has shown, in Sepia. The Intussuscep-
tion-hypothesis demands (i) that this should be also the case in the
young; (ii) that, in any one species, the body-chamber should at all
ages be of the same depth in proportion to the length of the whorl.
Riefstahl and his reviewer in Naturforscher (April 80, 1887) assume
these facts and adduce them as arguments. But in smaller and
presumably younger specimens of Sepia the last-formed lamella does
not always seem to be nearer the penultimate, while the spaces
between the insertion-lines are regular: it is easy to be deceived by
the fact that all the lamellee approach one another at their posterior
borders. In Nautilus sections through undoubtedly young shells
show that the last-formed chamber is actually larger than the pre-
ceding. In such young shells a distinct nacreous ring often indi-
cates the first formation of a fresh septum. Had it been completed,
the chamber enclosed by this septum would, without any interstitial
growth, have been of increased size: the ratio of the body-chamber
to the whorl, as compared with other specimens, is less or greater
according as this half-formed chamber is counted in or not. The
evidence from Ammonites is often vitiated by fracture ; granting that
the last chamber in small specimens is sometimes of relatively little
depth, it is not so always, and in adults there may be seen, though
rarely, a small air-chamber between two of normal size. In Wautili
the 8th chamber is always less deep than those preceding, for the
increased breadth and height of the cone makes up for loss of depth:
examination of shells with only 8 or 9 chambers would therefore be
deceptive. Riefstahl says that his fixed point is the hinder end of
the animal’s body: this does not explain the lines of advance so
clearly seen in the muscle-scars.

So far facts do not confirm the Intussusception-hypothesis, some of
those here brought forward favour the old view. Still Dr. Riefstahl
deserves our gratitude for re-opening an interesting question, which
is not likely to be settled without further investigation."

1 As bearing upon the subject of this Article, see a paper ‘* On the Structure of
Camerated Shells’? by Henry Woodward, Popular Science Review, 1872, vol. xi.
pp. 118-120, pl. Ixxxi.

DECADE III.—VOL. IV.—NO. X. 29

450 Jones and Sherborn—Tertiary Entomostraca.

IV.—Fourrtuer Notes on THe Tertiary ENtomMostTraca oF ENGLAND,
WITH SPECIAL REFERENCE TO THOSE FROM THE LONDON CLAY.

By Professor T. Rupzrt Jonzs, F.R.S., and C. Davizs Suerzorn, F.G.S.!
(Continued from p. 392.)
28. CYTHERE COSTELLATA (Roemer), var. TRIANGULATA, NOv.

The specimen under notice is relatively shorter, broader (higher),
more triangular, and with sharper ridges than the figure in the
‘Monograph,’ 1856, pl. vii. f. 21. The anterior hinge is more pro-
minent, and the front margin rather oblique. It is also narrower
behind, ending with three small spines or denticles. The edge view
is acute-ovate. From the Belosepia-bed, Bracklesham. T. R.
Jones’ Collection.

This variety of C. costellata is figured and described in the
‘Monogr. Post-Tert. Entom.’ 1874, p. 152, pl. xvi. figs. 18-15, from
Selsey, and there recognized as being probably of Tertiary date,
though found in the superficial mud.

29. OyrHeRE piicata, Miinster.

We have a narrow and compressed carapace, contracted posteriorly,
from the Belosepia-bed, Bracklesham. T. R. Jones’s Collection.
This species is noticed in the Grout. Mac. 1874, p. 479, as having
been found in the London Clay of Copenhagen Fields, with two
species of Chara.

30. CYTHERE LATIMARGINATA, Speyer.

Cythere latimarginata, Speyer, Tert. Ostrac. Casell., 1863, p. 22,'pl. ii. fig. 3.
Cythere abyssicola, G. O. Sars, Overs. Norg. Mar. Ostrac., 1865, p. 1638.
Cythere latimarginata, Brady, coe and Robertson, Monogr. Post-Tert. Entom.,
1874, p. 163, a xvi. fig. 6
Cythere latimarginata, G 4135 Brady, Trans. Zool. Soc., vol. x. p. 389, pl. xiv. fig. 8.
Following Dr. Brady’s determination of this species in the papers
above mentioned, we refer this specimen to Speyer’s species. The
figure in the “ Monogr. Post-Tert. Entom.” comes nearest to our
form, but is furthest from Speyer’s original figure, to which the
figures of the Antwerp-Crag specimens in ‘Trans. Zool. Soc.’ nearly
approximate.
One valve; White (Coralline) Crag. 'T. R. Jones’s Collection.

31. CYTHERE ANGULATOPORA (Reuss).

oe angulatopora, Reuss, Haidinger’s Nat. Abth. vol. iti. 1854, p. 86, pl. x.
g. 32.

An oblong valve, with parallel dorsal and ventral margins, and
rounded ends. Surface with numerous small, more or less angular
pits, arranged in parallel rows. A series of pits independently of
the other ‘ornament, follows the semicircular outline of the anterior
end, just within the margin. The hinder margin is toothed. A
single valve, associated with Nummulites elegans, in a bed regarded as
at the top of the Bracklesham series, Hunting Bridge, New Forest.

Collected by Mr. Keeping. TT. R. Jones’ Collection.
1 For Plate XI. see September Number Grou. Mae. facing p. 389.

ee

—————

ee

aes

{
:
;

Jones and Sherborn—Tertiary Entomostraca. 451

The specimens figured and described as C. angulatopora, in the
“Monogr. Tert. Entom.,” 1856, p. 34, are not referable to that
species. Figs. 17 and 18 of plate iv. correspond with the form (No.
‘83) to which we have here given the name C. sealaris; and fig. 18,
pl. vi. figured by Bosquet (we think, erroneously) as C. angulatopora
of Reuss, we now regard also as a new species, and have named
it C. Bosqurriana (No. 32).

32. CyTHERE BosQueETIANA, sp. nov.
Cythere angulatopora (not Reuss), Bosquet, Entom. Tert. 1852, p. 68, pl. iil. fig. 5.
Cythere Pohennce (not Reuss), Jones, Monogr. Tert. Entom., 1856, p. 34, pl. vi.
£. .

One of the oblong species of Cythere, with rounded ends, well-
marked hinges, and convex valves, ornamented with a strong
reticulation, the longitudinal meshes of which are stronger than
the transverse. Just in front of the centre of the valve the meshes
show an inclination to assume a concentric arrangement. This is
strongly marked in fig. 18, pl. vi. of the Monogr. 1856.

One valve, occurring with Nummulites elegans, in the “ uppermost
bed” of the Bracklesham Series, at Hunting Bridge, New Forest.
Collected by Mr. Keeping. T. R. Jones’ Coll. ,

33. CYTHERE SCALARIS, sp. nov. Pl. XI. fig. 7.
Cythere CE ie (not Reuss), Jones, Monogr. Tert. Entom., 1856, p. 34, pl. iv.
gs. 17, 18.

Another oblong Cythere with nearly equal ends, but the front
margin, sloping to the strongly marked anterior hinge, is more
oblique than the other. The surface has longitudinal ridges, which
on the hinder moiety of the valve are connected by transverse riblets,
making irreeular square meshes. The disposition of the ridges vary
as to their parallelism.

A fine series of allied forms, from Gaas, near Dax, have been
described and figured by Reuss (‘Sitz. k. Ak. Wiss. Wien,’ vol. lvii.
1868, pp. 38-40, pl. vi. figs. 8, 4, 5, and 7); but the differences are
sufficiently apparent.

Two or three examples, London Clay; Islington. T. R. Jones’
Coll.

o4, CYTHERE POLYPTyCHA (Reuss), var.

Somewhat trigonal-obovate; the antero-ventral angle and the
opposite hinge both well developed. Anterior border nearly semi-
circular; the posterior somewhat contracted. Surface puckered
with nearly parallel, but irregular, longitudinal ridges, with inter-
mediate rough, but obscure reticulation. The central region swollen
into a round boss. Except that this specimen is less quadrate,
possesses a boss, and is less distinctly reticulate, it closely resembles
Reuss’ original figure, Haidinger’s ‘Nat. Abth.,’ vol. iil. 1854, p. 83,
pl. x. fig. 22, from the Tertiary of Bohemia.

This Cythere belongs to a group of which C. pusilla, Bosquet,
‘Entom. Tert., p. 85, pl. iv. fig, 7, may be taken as a type; possibly
embracing the species referred by G. 8. Brady, Trans. Zool. Soc.,
vol. v. 1866, p. 376, pl. lix. fig. 10, to Reuss’ C. clathrata (which

452 Jones and Sherborn— Tertiary Entomostraca.

does not appear to us to be at all identical), and also ©. pumila, G.
S. B., op. cit., p. 878, pl. lx. fig. 7. The latter, though near to our
specimen, has far more irregular ridges.

One valve, from the “ Norwich Crag” of Southwold. 'T. R. Jones’
Collection.

35. CYTHERE SOROBICULO-PLICATA, Jones. Pl. XI. Fig. 8.

A figure of this species is reproduced from “ Monograph Tert.
Entom.,” 1856 (p. 33, pl. vi. figs. 4 and 6), as one of the forms
belonging to the London Clay of Finchley and Copenhagen Fields;
the species also belongs to the Barton Clay, in which deposit it
occurs in greater abundance than in the London Clay.

36. Cyturre Harrisiana, Jones. Woodcut Fig. 1.

Cythereis interrupta, Jones. Monogr. Oretac. Entom., 1849, p. 16, pl. ii. f. 6.
Cythere Harrisiana, Jones. Gxou. Mac., 1870, pp. 75, 76.

This form was found with C. spinosissima, here-
after described, while looking over for a second time
some washings of London Clay. We have only this
one valve, which agrees so closely in every particular
with valves from the Gault, presenting the same
isolated prickles and the pursed-up posterior end with
its flattened margin, that we cannot separate them.

Skerborn and Chapman Collection; from Picca- arrisiana, Jones.
dilly, London.

o7. CyTHERE ForBESII, sp. nov.

A subquadrate form, approaching the more definitely squared
Oythere, for which we conveniently keep the subgeneric name of
Cythereis. The valves are well-rounded in front and behind, with
nearly straight lower and upper margins, the latter marked with
well-defined hinges. The posterior margin is usually denticulate.
The surface bears 6 or 7 crenulate and fenestrate ridges; those on
the ventral region being more continuous than those on the dorsal.
. The interspaces of the ridges are deeply reticulated. This distinct
and well-defined species we dedicate to the late Edward Forbes,
whose investigations into the fossil fauna of the Isle of Wight
Tertiaries will ever be gratefully remembered.

Specimens numerous, from the Fluvio-marine beds of Headon, Isle
of Wight. EF. Edwards’ Collection in the British Museum.

38. CyTHEREIS BowrRBANEIANA, Jones. PI. XI. Fig. 9.
Monogr. Tert. Entom. 1856, p. 38, pl. vi. figs. 7 and 8.

A figure of this quadrate species, characteristic of the London
Clay, is here reproduced in illustration of the group. It has been
found at Copenhagen Fields and Wimbledon Common (Jones), and
at Whitecliff Bay (Sherborn).

39. CYTHEREIS SPINOSSISSIMA, sp. nov. Woodeut, Fig.2.
A right and left valve of this form were lately found, with C.
Harrisiana, in some washings of the London Clay from Piccadilly.
They are oblong, with the front margin broader and more semi-

Fic. 1.—Cythere

Jones and Sherborn—Tertiary Entomostraca. 458

circular than the hinder. Surface coarsely reticulate; the reticulations
becoming more shallow and indistinct as they reach the central area.
Many of the ridges of the meshes are pinched up at their junctions,
and in most cases thus form bluntly-pointed spines; these spinous
prolongations are partly the cause of the confusion of the reticula-
tion in the centralarea. Approaching the margins, the
spines become longer and more defined ; and the
anterior area bears, in addition to its marginal row of
Spines, a second row just within the other. In this
form, related to C. Bowerbankiana, on the one hand,
and to ©. horrescens on the other, we note that the
characteristic ventral ridge of spines, which is pre
sent in both these forms, is absent, being merely re-
presented by scattered spines, not arranged in a
definite order except on the anterior area. The Fic. 2.—Cythe-
reticulation is also much more distinct,—a marked 728 ‘Spimossis-
feature in the new form. tk ke

To this same group belongs a rather common recent and Post-
Tertiary species, namely, Cythereis Dunelmensis, Norman (the refer-
ences are given in full in the “ Monogr. Post-Tert. Entom.” 1874,
p- 168). The chief differences between this and the older form from
the London Clay are in the shape of the posterior margin, which is
elliptically rounded in the latter instead of being square, and a more
definitely spinose, instead of foliaceous, condition of the ornament,
especially towards the margins.

Two valves only: from Piccadilly. Sherborn and Chapman Col-
lection.

40. CYTHEREIS ARANEA, sp.nov. Pl. XI. Fig. 10a, 100.

Oblong, with the front margin broader and rounder than the
hinder, both more or less denticulate. The surface ornamented with
a delicate raised network of irregular meshes, which extend over the
flat ventral area. ‘T'wo ridges, over which the network is traceable,
are present. One, shorter than the other, occupies the median line
from about the centre to the edge of the posterior slope, which makes
a strong depression at the hind margin. The other and longer ridge
commences in a curve inside the front margin, rises as it borders the
ventral region, and dies out at the posterior slope, like the other.
The ventral aspect of the carapace is cuneiform or almost sagittate.
C. Haidingeri, Bosquet, ‘'Tert. Entom.,’ p. 125, pl. vi. fig. 10, is
near to this species in general characters; but its more angular
shape, and more symmetrical network distinguish it. So also C.
Edwardsvi (Roemer), Reuss, ‘Haidinger’s Nat. Abth.’ vol. i. p. 84,
pl. x. fig. 24, is like it to some extent; but its ridges extend the
whole length of the valve, joining fore and aft, and, as figured by
Bosquet, ‘Entom. Tert.’ p. 94, pl. iv. fig. 14, it appears still coarser
or stronger, and with still more marked features.

Several specimens from the London Clay; Piccadilly, London.
Sherborn and Chapman Collection.

454 Jones and Sherborn—Tertiary Entomostraca.
41, CytHerris PResTWIcHIANA, sp. nov. PI. XI. Figs. 11a, 116.

A very small neat Cythereis, with well-developed marginal rim
in front, which, passing along the ventral region, gradually rises
higher, and ends in a sharp rectangle. A similar, but lower, ridge
follows the dorsal edge. Both are more or less crenulated. There
is a central boss, and a short ridge behind it, ending, like the others,
at the sudden posterior slope, which terminates in a narrow, produced,
flat, and toothed edge. The surface of the valve is somewhat
depressed, and is covered with a distinct lace-like reticulation.
Hdge-view, subsagittate.

‘This form is clearly related to that figured in the “ Monogr. Cre-
taceous Entom.,” 1849, pl. v. fig. 13b., which we propose to remove
from C. ornatissima (Gro. MacG., 1870, p. 75). We now have closely
allied forms from the Chalk of other localities of the British Islands,
and the distinctness of this new species, named after Prof. Prest-.
wich, becomes more and more apparent.

Two valves from the London Clay of Whitecliff Bay, Isle of
Wight. Collected by C. D. Sherborn.

42. Cyrnerris Horrnust, Speyer.
Cytherella Hoernesi, Speyer. Ostrac. Cassel. Tertiar., 1863, p. 82, pl. i. fg. qe
pl. iv. fig. 1.

Oblong; swollen into a distinct boss in the centre; ends pial
the front margin semicircular and deeply fenestrated, the hind
margin depressed and slightly toothed. Surface reticulated, orna-
mented with two prominent ridges, the dorsal and most striking of
which, strong, fenestrated, and somewhat convex, partly obscures
the hinge-line, and curves forwards and downwards below the front
hinge. “The ventral ridge is not so strong; both are sharply angular
posteriorly.

The only marked difference between our specimen and that figured
by Dr. Speyer is—that the dorsal ridge in the former is much better
developed, being higher, thinner, donee ntte. more delicate, and
ending posteriorly ina much sharper angle.

A single valve from the White (Coralline) Crag. T. R. Jones’
Collection.

43, CYTHEREIS CORRUGATA (Reuss), var.

This valve is rugosely reticulate, with the longitudinal: meshes
stronger and more persistent than the transverse. Several allies of
this form are figured in plates xxi. and xxii. of the “Report
Challenger Ostracod.,” 1880. Of the previously published forms we
find that C. corrugata, Reuss, Haidinger’s Nat. Abth. vol. iii. p. 79,
pl. x. fig. 14, is the nearest to ours, although it varies in being
squarer, stronger, swollen at centre, and strongly rimmed on the
front margin.

One specimen, collected by the late F. Edwards from the Fluvio-
marine beds, Headon, Isle of Wight. British Museum.

44, CYTHEREIS CORNUTA (Roemer).
Three or four specimens of this form from Bracklesham, of which

9 an

i
:
i
|

Jones and Sherborn—Tertiary Entomostraca. 455

one is here figured, differ individually from those previously figured
in the Monogr. 1856, and elsewhere, in their narrowness, the paral-
lelism of their upper and lower margins, and in the replacement of
the curved dorsal ridge by a uniform marginal rim. The very faint
markings seen along the ventral ridge, in the figures in the Monograph
of 1856, are more distinct in the specimens now under consideration,
and are evidently due to alternate thick and thin rod-like divisions,
forming minute, light and dark, squarish areas. The slight trans-
verse dorsal notch in fig. 19 is also traceable in our present specimens,
when carefully illuminated and strongly magnified.
Bracklesham. 'T. R. Jones’ Collection.

45, CYTHERIDEA PERFORATA (Roemer).

This specimen is like figure 14a, pl. iv. in the ‘ Monogr.’ 1856, but
is rather less triangular, much more coarsely punctate and strongly
marked at the front hinge.

It was found with numerous normal valves in some washings from
the clay at Barton.

T. R. Jones’ Collection.

46. CyTHERIDEA PERFORATA, var. InsIqnis. Pl. XI. Fig. 12.
Monogr. Tert. Entom., 1856, p. 46, pl. vi. fig. 3.
This fine variety is reproduced in the accompanying Plate from
the original monograph. It was found in the London Clay of Copen-
hagen Fields.

47. CYTHERIDEA GLABRA, Jones. Pl. XI. Fig. 13.
Cytheridea perforata, var. glabra, Jones. Monogr. Tert. Entom., 1856, p. 46,
pl. v. fig. 24.

This angular and smooth form, related to C. perforata, should now,
we think, be regarded as a species. It came from the London Clay
of Copenhagen Fields.

48, CYTHERIDEA PUNCTILLATA, Brady.

One damaged valve we refer to this species, which has been
described and figured in full in the ‘Monogr. Post-Tertiary Entom.,’
1874, p. 177, pl. vi. figs. 1-11. Our specimen, however, approaches
most closely to another figure of the same species in Dr. G. 8. Brady’s
paper, ‘ Trans. Linn. Soc.,’ vol. xxvi. (1868), p. 424, pl. xxvi. fig. 36.

From the “Norwich Crag” at Southwold. T. R. Jones’ Col-
lection. !

49, CYTHERIDEA PINGUIS, Jones.

We have this species from the Weybourn Crag; collected by Mr.
Clement Reid at East Runton. Dr. G. §. Brady figures it from the
Antwerp Crag, ‘Trans. Zool. Soc.,’ vol. x. p. 397, pl. Ixil. fig. 3.

50. CYTHERIDEA DEBILIS, Jones.

We have seen a right valve (opposite to. that figured in the
Monograph, 1856), apparently belonging to this species from the
Belosepia-Bed, Bracklesham. Science Schools Collection.

456 Jones and Sherborn—Tertiary Entomostraca.

51. CytuHrripEa nLoneata, Brady.
C. elongata, G. 8. Brady. Monogr. Recent Brit. Ostrac., Trans, Linn. Soc. 1868,
vol. xxvi. p. 421, pl. xxviii. figs. 13-16 ; pl. xl. fig. 6; Monogr. Post-Tert.
Entom., 1874, p. 181, pl. ix. figs. 10-13.

Numerous specimens from the Weybourn Crag of East Runton,
varying slightly in individuality of growth and sex, are referable to
Brady’s Oytheridea elongata. Collected by Mr. Clement Reid, F.G.S.
We have it also, not rare, in the Crag of Southwold (Norwich Crag).

52. Krirae @iaciatis, B.C. and R. Pl. XI. Fig. 15a, 150.
B. ©. and R. ‘Monogr. Post-Tertiary Entom.,’ Pal. Soc., 1874, p. 184, pl. vi.
figs. 21-24.

A smooth specimen of Krithe from the London Clay of Piccadilly
is so extremely close in every feature to K. glacialis from Scotland
and Norway, except in the apparent pitting of the latter, that we
eannot separate it from this later form. Sherborn and Chapman Coll.

538. Kriraz Lonprinensis, sp.nov. Pl. XI. Fig. 14a, 140.

Carapace narrow obovate, not quite semicircular in front, subacute
posteriorly. In edge-view the anterior third is compressed and
wedge-shaped, the middle is swollen, and the posterior third is com-
pressed, and ends in the usual notch formed by the produced ends of
the two valves. Surface smooth and shining. In this last feature if
resembles other forms of this genus, but in its outlines it differs
from any we know. From the London Clay of Piccadilly. Sherborn
and Chapman Collection. Bornemann’s Bairdia pernoides (Zeitschr.
D. g. Ges. vol. vii. 1855, p. 858, pl. 20, fig. 7) is a somewhat similar
Krithe of this geological age.

54, XusTonEBERIS AURANTIA (Baird), 1835; var.

Xestoleberis aurantia, Brady, Crosskey and Robertson, ‘ Monogr. Post-Tert. Entom.,’

Pal. Soc. 1874, p. 191, pl. xvi. figs. 32, 33. (Full synonymy is here given.)

Except in being minutely punctate, and not distinctly papillose,

this specimen (from Headon) closely resembles the recent X.

aurantia, above quoted. From the Fluvio-marine deposits of Headon

Hill, Isle of Wight. Collected by the late F. E. Edwards, and now
in the British Museum.

55, XESTOLEBERIS COLWELLENSIS, Sp. NOV.

Carapace ovate in outline, and subovate in edge-view, with spinu-
lose surface. This is near X. aurantia (Baird), but blunter
anteriorly.

From the Tertiary of Colwell Bay. 'T. R. Jones’ Collection.

56. CyTHERURA PRESTWICHIANA, Sp. NOV.

This belongs to the same type as Cytherura nigrescens, B. C. and R.,
‘Post-Tert. Entom.,’ p. 192, pl. xi. f. 28-32, but differs in its greater
compression anteriorly, and in being less strongly notched behind.
Allied forms are known to us from several Jurassic strata. From
the Belosepia-bed, Bracklesham. ‘'T’. Rupert Jones’s Collection.

Named after Professor Prestwich, of Oxford, who has so greatly
advanced our knowledge of the Tertiary deposits.

lis

Jones and Sherborn—Tertiary Entomostraca. 457

57. CyTHERURA CLATHRATA, G. O. Sars.
Cytherura clathrata, G. O. Sars. Brady, Trans. Linn. Soc., vol. xxvi. 1868, p. 446,
pl. xxix. figs. 43-46; B.C. and R., Post-Tert. Entom., Pal. Soc. 1874,
p- 204, pl. x1. figs. 1-4
In this small and interacene form, the oval carapace is somewhat
sharper behind than before, and more compressed in front than
behind. It has the surface ornamented with a strong median ridge,
branching freely off towards the margin. ‘The main branches in our
specimen keep their entirety, but Dr. G. 8. Brady figures individuals
in which the branches lose themselves in a rough general reticulation
over the surface. From the Weybourn Crag of East Runton ; col-
lected by Mr. Clement Reid, F.G.8.

58. CYTHEROPTERON TRIANGULARE (Reuss). PI. XI. Fig. 16.
Cythere triangularis, eae ieee e Deutsch. geol. Ges. vol. vii. 1855, p. 279,
x. fig. 3.
33 ae Monogr. Tert. Entom. 1856, p. 25, pl. vii. fig. 5.
» ctenuicr istata, Reuss, Sitzungsb. k. Ak. Wiss. Wien, vol. lil. 1865, p- [23]
plate, fig. 12.

This well-marked form has already been well described, as also
have several allies, namely, Cytheropteron mucronalatum, Brady, “Chal-
lenger,” 1880, p. 140, pl. xxxiii. fig. 8; C. fenestratum, Brady, Ibid.
p- 1389, pl. xxxiv. fig. 6; and C. sphenoides (Reuss), Denkschr. k.
Ak. Wiss. Wien, vol. vii. p. 141, pl. xxvii. fig. 2.

From the London Clay of Piccadilly ; Sherborn and Chapman Coll.

09. CYTHERIDEIS GRACILIS (Reuss).
Cytherina gracilis, Reuss, Haidinger’s Nat. Abh. vol. iii. 1850, p. 52, pl. lui. fig. 3
Cytherideis gracilis, Brady, Trans. Zool. Soc., vol. v. 1866, p. 367, pl. lvii. f. la-d.

To this neat form, already described by Reuss and others, the
following are more or less allied :— C. arcuata (Bosq.), Tert. Entom.,
1852, p. 32, pl. i. fig. 14; C. lithodomoides (Bosq.), Ibid., p. 36, pl. il.
fig. 3; C. Bairdia difficilis (Reuss), Sitzungsb. k. Ak. Wiss. Wien,
vol. vii. 1868, p. 55, pl. v. fig. 7.

The figure given in the “ Fonds de is Mer” (8vo. Paris, 1867-71),
nae ee 1868, p- 94, pl. xii. figs. 1, 2, of Brady’s Aglaia pulchella
reminds us of this form.

We have one small specimen from a Tertiary bed at Colwell Bay.
In the closed carapace the right valve is the smallest; it is faintly
toothed on the anterior margin. The longitudinal lines on the ventral
surface are distinct, though faint.

CyTHERELLA, Jones (sub-genus), 1849.

The members of this genus are separable with difficulty as to
their probable specific identities (Monogr. Carbonif. Entom., Part I.
No. 2, Pal. Soc., 1884, pp. 57-69). For the recognition of the
Tertiary forms, with which we are at present concerned, we propose |
to keep certain types in view, referring our specimens to one or
the other of the several groups.

Group I—Typified by Cytherella compressa (Miinster), as figured
by Egger, ‘ Ostrak. Ortenburg,’ Neues Jahrb., 1858, p. 404, pl. i.
fig. 2, with its wedge-like ends and flat parallel sides. To this we

458 Jones and Sherborn—Tertiary Entomostraca.

must relegate C. Londiniensis, Jones, ‘ Monogr. Tert. Entom.’ p. 54,
pl. v. figs. 20 [reproduced here, Pl. XI. Fig. 19] and 22, besides,
“ C. compressa, var. 2,” Fig. 19 of the same Plate.

Group II. Cytherella Muensteri (Roemer). These carapaces have
their greatest convexity near the middle or towards the hinder part
of the valves. One of our specimens from Bracklesham belongs to.
this group ; but we know of none exactly like it, in its symmetrical,
broad, and oblong outline, with nearly equally rounded ends,
median convexity toward the ventral edge, and broadly ovate edge-
view.. We call it C. Remert. Another is near Roemer’s original
figure, ‘Neues Jahrbuch, fiir Min. etc.’ 1888, p. 516, pl. vi. fig. 13,
in shape, though not so strongly punctate. In the ‘Monogr. Tert.
Entom.,’ p. 56, pl. v. fig. 18, is a smooth variety ; but fiy. 12 is even
more strongly pitted than is Roemer’s fig. 18, and was termed var..
rectipunctata in the Grou. MaG., 1870, p. 157. Some allied forms,
smooth and having the convexity more definitely in the hinder third
of the valves, are remarkably ovate in outline, and lanceolate in
edge-view. These may be regarded as belonging to a new species
to be called C. Reussii, after the eminent micrologist of Prague and
Vienna. In the ‘Monogr. Tert. Entom.,’ p. 54, pl. v. figs. 21 [re-
produced in our Pl. XI. Fig. 17] and 23 are also smooth, and belong to.
this group: but they are obovate in outline, like Bornemann’s C.
fabacea, ‘ Zeitschr. Deutsch. geol. Ges.,’ vol. vii. 1855, p. 355, pl. xx.
fig. 2, to which they must be referred, as in Grou. Mac. 1870,
p. 157. Another of our Tertiary Cythereile is ovate-oblong, lanceo-
late in edge view, with acute-ovate end-view. This also we believe
to be new, and name it C. Dixoni, in memory of one of the most
enthusiastic workers on the geology and fossils of Bracklesham,
whence all but one of the Cytherelle described as new in this paper
have been obtained.

A very small Cytherella, smooth, snbovate, and with lanceolate
edge-view, belongs apparently to Group II. It was found by Mr.
Clement Reid in the Weybourn Crag of East Runton.

Group III. The type is Cytherella Beyrichi (Reuss).

Cytherina Beyrichi, Reuss, Zeitschr. Deutsch. geol. Ges., vol. ii. 1851, p. 89, pl. vii.
fic. 65.
Cytherella Beyrichi, Bornemann. bid. vii. 1855, p. 354, pl. xx. fig. 1.
»» compressa, var. 1, Jones. Monogr. Tert. Entom. 1856, p. 55, pl. v. fig. 18.
[Reproduced here, Pl. XI. Fig. 18.]
», Beyrichi, Speyer, Ostrac. Cassell. Tertiar., 1863, p. 54, pl. i. fig. 1.
», Beyrichi, Brady, Trans. Zool. Soc., vol. vy. 1866, p. 362, pl. lvil. fig. 3.
tis . Jones, Gzou. Mag. 1870, Vol. VII. p. 157.

In this group the carapaces vary from round-ended oblong to ovate-
oblong, with a partial flattening of the anterior portion, giving a.
compressed wedge-shaped edge-view. In most cases the posterior
end is full and truncate, herein also differing from the members of
Group II. Generally the surface is pitted, but we have a smooth
example of this form. The last may be termed C. Beyrichi, var.

levis; but we consider that the others do not offer differences sufficient

to separate them from the type as named varieties.

a Fe

Jones and Sherborn—Tertiary Entomostraca. 459

Referring especially to the specimens from the London Clay, we
conclude that they should stand as follows:— _

60. CyTHERELLA FABACEA, Bornemann. PI. XI. Fig. 17.
Cytherella compressa, Jones (not Minster), Monogr. Tert. Entom. p. 54, pl. 4, fig. 21.

61. CyrHereLta Bryricut, Bornem. PI. XI. Fig. 18.
Cytherella Beyrichi (?), Jones, Monogr. Tert. Entom. p. 55, pl. v. fig. 18.

62. CyrHsretta compressa (Miinster). Pl. XI. Fig. 19.

Cytherella Londiniensis, Jones, Mon. Tert. Entom. p. 55, pl. v. fig. 20.
C. compressa, var. 2, Jones, ibid. fig. 19.

The last is very near to the other, but is rather more oblong and
is somewhat punctate.

63. In Mr. Clement Reid’s Collection we have seen the following.
Freshwater Ostracoda from the uppermost Pliocene Formations.

Mounpestey Unto-sep.!

Cypridopsis obesa, B. & R.
Darwinula Stevensoni, B. & R.
_Cythere concinna, Jones, var.

SIpDESTRAND UNIO-BED.

Candona candida (Miller).
Cypridopsis obesa, B. & R.

Cypris reptans (Baird).
»» gtbba, Ramdohr.
Candona candida (Miller).

Cypris reptans (and)
», Browniana (?), Jones.*
», gibba, Ramdohr.

64. Mr. C. Reid, F.G.S., has lately sent from the Isle of Wight :—
1. Candona Forbesii, Jones, from the Hempstead beds of *Park-
hurst Forest (Bore-hole, No. 32).
2. Cytheridea Muelleri and its variety, torosa, Jones; from Bore-
hole No. 5, east bank of the Medina, one mile north of Newport.
65. In his notice of some of the Post-Tertiary deposits, associated’
with the Raised Beach at Portland (see Q.J.G.S. vol. xxxi. 1875,
p- 89) Prof. Prestwich mentions two species (Cypris Browniana and
Candona candida) as occurring there. We can now add Cypris gibba,
Ramd., and C. incongruens, Ramd., besides an undetermined species.

66. We here add a list of some Post-Tertiary Entomostraca, which
we find in a Chara-deposit from near Hitchin.

Collection of W. Hill, Esq., jun., F.G.S.
Cypris Browniana, Jones. Cypris reptans (Baird).

»» mmeongruens, Ramdohr. Candona candida (Miller).

The following are Lists of the species of Ostracoda treated of in
the foregoing Memoir :—

WeyBourn Crac.
8. Potamocypris trigonalis, Jones, and |, 20. Cythere villosa, Sars.

var. /evis, nov. 22. », Woodwardiana, sp. nov.
14. Cythere Reidit, sp. nov. 49, Cytheridea pinguis, Jones.
15. » retifastigiata, Jones. dl. », elongata, Brady.
18. >» a@ngulata, Sars, var. 57. Cytherura clathrata, Sars.
19. °',, Charlesworthiana, sp. nov. Cytherella, sp.

1 See also Trans. Norf. Norw. Nat. Soe. vol. iii. p. 631.

2 Dr. G. S. Brady informs us that he has lately received C. Browniana from Loch.
Fadd, near Rothesay, and that it will be described and figured in a forthcoming
Report of the Scottish Fisheries Commission.

460 Jones and Sherborn —Tertiary Entomostraca.

SouTHWoLD ORrac.

48. Cytheridea punctillata, Brady.
51. », elongata, Brady.

12. Cythere recurata, sp. NOV.
20. 5, villosa, Sars.
34. >, polyptycha, Rss., var. nov.

BRAMERTON ORraG.

4. Aglaia ? cypridioides, sp. nov. 18. Cythere angulata, Sars, var.
16. Cythere lacrymalis, sp. nov. 21. » lesa, Sp. NOY.
SUFFOLK CRraG.
10. Bairdia rhomboidea, sp. nov. | 30. Cythere latimarginata, Speyer.
17. Cythere dictyosigma, Jones. 42. Cythereis*Hoernesi, Speyer.

Hempsteap, Iste or WIGHT.
1. Cypridea spinigera (Sow.).
Heapon Hint, Istz or Wieut.

27. Cythere delirata, sp. nov. | 43. Cythere corrugata, Rss., var.
37. 54, Forbesii, sp. nov. 54. Xestoleberis aurantia (Baird).

CotwrELt Bay.

6. Pontocypris (?) sp. 59. Cytherideis gracilis (Reuss).
55. Xestoleberis Colwellensis, sp. NOV. |

Hontine Bripce.

31. Cythere angulatopora (Rss.). | 32. Cythere Bosquetiana, sp. Nov.
Barton.
45. Cytheridea perforata (Roemer).
BRACKLESHAM.

5. Bythocypris subreniformis, sp. Noy. 56. Cytherura Prestwichiana, sp. Nov.

7. Bairdia subdeltoidea (Munster). Cytherella Muensteri (Roem.).
13. Cythere venustula, sp. nov. 55 Beyrichi (Rss.) var. levis, n.
26. » gyriplicata, sp. Nov. 99 a 3 var.
28. >, costellata, Roem., var. trian- >, Lemeri, sp. NOY.

gulata, Nov.
29. », plicata, Minst.
44. Cythereis cornuta (Roem.)
50. Cytheridea debilis, Jones.

Lonpon Cuay. (Figured and described in this paper.)

», Lteussit, sp. NOV.
>, Dixoni, sp. nov.

8. Bairdia subtrigona, Bornem. 40. Cythereis aranea, sp. Nov.

9. », Londinensis, sp. nov. 41. », Lrestwichiana, sp. Nov.
11. >, ovotded, sp. nov. 46. Oytheridea perforata (Roem.), var.
23. Cythere arenosa, Bosq. insignis, Jones.

24. », scabropapulosa, Jones. Mis on ler, VOWS.

25. 55 5 var. aculeata, nov. | 52. Krithe glacialis, B. C. & R.
33. >, scalaris, sp. Nov. 53. », Londiniensis, sp. nov.
35. 5 scrobiculoplicata, Jones. 58. Cytheropteron triangulare (Rss.)
36. ,, Harrisiana, Jones. 60. Cytherella fabacea, Bornem.
38. Oythereis Bowerbankiana, Jones. 61. ;, Beyrichi (Rss.)

39, >, Sspinosissima, sp. Nov. 62. », compressa (Munster).

Apprnpix.—It is advisable to make the following emendations
in the paper in the Guor. Mac. 1870:—Page 155, for No. 9 read
No. 19, and transfer the paragraph to p. 156. Pages 157 and 159 for
Tlyobates read Krithe. Page 158, 2* var. tumida, should come under
2 Cypris Browniana.

For later alterations in generic and specific names, see the present

paper.

R. D. Oldham—Gneissose Rocks of the Himalaya. 461

V.—Tue Gyetssos—E Rocks or tHe HIMaLaya.
By R. D. OtpHam, A.R.S.M., F.G.S.,
of the Geological Survey of India,

T had not been my intention to publish anything on this subject
at present, as I have in preparation a review of the present state
of our knowledge of Himalayan geology; but as Col. McMahon has
started the subject, and his paper is not exhaustive, I trust the follow-
ing outline of that part which relates to the gneissose rocks may
prove of interest.

The gneissose or granitoid rocks of the Himalayas may be divided
into three groups :—

(1) The fundamental or “ Centeall ” oneiss of Dr. Stoliczka.

(2) The orthoclase, usually porphyritic and gneissose, granites.

(3) The oligoclase granite.

The last of these appears to be distinct from and of later date than

the first two, and will not be further referred to here.

The fundamental, or, to use the term under which it was first
described, the central, gneiss consists of a great thickness of crystal-
line rocks. In the little disturbed sections of the Upper Pabar
Valley in Bissahir it is seen to unconformably underlie rocks which
I have little doubt are the equivalents of Dr. Stoliczka’s Babeh series
of Silurian age. Both by lithological structure and mode of occur-
rence, these beds are shown to be of metamorphic, as opposed to
intrusive origin; they contain beds varying from almost pure
felspar to almost pure quartzite or mica-schist, but felspar is seldom
altogether absent; some of the beds are augen gneiss, the eyes being
lenticular in form, lying in accord with the planes of foliation, and,
as regards their internal structure, consisting of a single twinned
crystal of orthoclase.

On the section over the Babeh Pass, that first examined by Dr.
Stoliczka, the beds are more disturbed and more metamorphosed.
Highly foliated beds are rare, and the rock is for the most part a
more or less fine-grained granitoid gneiss: some beds are augen gneiss,
in which the eyes still maintain their lenticular form, though, as
a rule, they have more or less acquired an outline in conformity with
their crystalline structure; these crystals, however, still lie along
the planes of foliation or very slightly oblique to them.

There can be little doubt that it is from the fusion of these beds
that the gneissose granite was derived. Typically this rock consists
of a somewhat fine-grained, slightly-foliated matrix, through which
porphyritic crystals of orthoclase are scattered ; the crystals exhibit-
ing no definite orientation, but being scattered about with their axes
pointing in every direction, as described by Col. McMahon. It
occurs in large intrusive masses, or in veins of various thickness,
usually intruded parallel to the bedding planes; the former usually
show very slight signs of foliation, except near their boundaries,
while the latter are almost, if not quite, invariably distinctly foliated.
As the veins are traced away from their parent masses, the
larger crystals of felspar appear to be left behind, and the rock

462 R. D. Oldham—Gneissose Rocks of the Himalaya.

gradually ceases to be porphyritic, and sometimes contains merely
a small proportion of felspathic material. How complete is the
assumption of a gneissose and loss of the granitic structure may be
judged from the fact that specimens from one exposure, which can
be shown to be intrusive, have been examined by Col. McMahon,
and declared by him to be a true gneiss showing no signs of
intrusive origin.’

Col. McMahon has shown that the microscopic structure of this
rock, as well as the inclusions of mica-schist, prove its intrusive
nature. J may add that the same is shown by its mode of occur-
rence, by the manner in which it cuts across the bedding of the
rocks among which it occurs, and by the invariable occurrence of
contact metamorphism in the neighbourhood of any large mass of it.
The intrusion, in many cases, does not seem either to have caused
or been accompanied by any considerable disturbance, but to have
taken place by a fusion (or solution) and absorption of the rocks
which it has replaced. These often continue with a perfectly steady,
low dip right up to a large mass of the gneissose granite, and end
abruptly there; yet the intrusive nature of the granite is shown
by the presence of included masses of these very rocks. The same
thing is indicated by a study of the intrusive sheets; they con-
stantly thin out and thicken without any disturbance of the border-
ing beds, which simply run up to the edge of the gneissose granite,
and stop there abruptly ; the granite itself too becomes more mica-
" ceous or more quartzose (according to the prevailing type of rock it
has passed through) and less felspathic the further it is traced from
its source, indicating a gradual increase of impurity. But the most
conclusive proof I know of is exhibited by the sections on the
eastern side of the Chor Mountain. The southern sections show a
considerable thickness of volcanic beds, altered to more or less
schistose hornblende rock; while on the northern sections these
hornblende rocks are absent, but the granite has become so highly
hornblendic that the ground-mass is of a dark green colour, throwing
up the porphyritic crystals of white orthoclase in a most conspicuous
manner.

Before passing on, it will be well to explain how these two
distinct rocks came to be confused with each other. In the Sutlej
Valley, between Simla and the Wangtu bridge, there are extensive
exposures of gneissose rocks ; these are almost all the gneissose
granite, but owing to similarity of lithological appearance and abso-
lute continuity of outcrop, they were (erroneously) confounded by
Dr. Stoliczka with the granitoid gneiss which is exposed almost to
the exclusion of intrusive granite on the ascent from the Wangtu
bridge to the Babeh pass. In 1877 Col. McMahon published a
paper on the “Central gneiss” of the Simla Himalayas, in which he
(correctly) identified the rock of the Chor and the gneissose granite
intrusions south of the Sutlej with the rock of the Sutlej Valley.
In 1883 he showed that while the rock of the Dhaoladhar, which he
had identified with that of the Chor, could not in a single case be

1 Rec. Geol. Surv. India, vol. xvii. p. 60; vol. xix. p. 86.

R. D. Oldham—Gneissose Rocks of the Himalaya. 463

shown to be a true gneiss, it presented all the characters of an
igneous rock. In this paper he dropped the term granitoid gneiss
in favour of gneissose granite, and added that “it is for consideration
whether the term ‘central gneiss,’ introduced by the late lamented
Dr. Stoliczka, and since used to denote the ‘granitoid gneiss’ of the
North-West Himalayas, should not be discontinued in future.”
Consideration is entirely in favour of this proposition, but against
the total abandonment of the term “ central gneiss,” which may still
be conveniently used for the fundamental gneiss, the oldest rock,
in the Himalayas.

The separation of these two rocks in the field will often be a
matter of difficulty, and not always possible, except where the
gneissose or the intrusive characters are well developed ; the micro-
scope will not aid in this, for, as I have remarked above, in one case
it has declared what can be shown to be an intrusive rock to be a
metamorphic gneiss, while some of the more granitoid forms of the
central gneiss show so little foliation and are so granitoid as seen in
a hand specimen, that I doubt whether even microscopic examination
would give a decided answer as to whether they are granite or gneiss.
The general result then is the satisfactory one (for it is always more
satisfactory to confirm than to refute a previous observer) that Dr.
Stoliczka was correct in describing the oldest rock he observed as
a gneiss, while Col. McMahon is equally correct in maintaining that
the rocks of the Sutlej Valley and the Dhaoladhar are granite. I
may now pass on to consider the cause of the foliation of this granite.

In considering this question, it is necessary to distinguish between
the large, slightly foliated masses and the distinctly foliated sheets.
In the former case the obscure foliation is probably in the main a
form of fluxion structure, but the well-developed foliation of the
thin sheets, which are occasionally sufficiently fissile to be used as
flags or roofing slates, cannot be solely due to this cause.

When we find intrusive sheets of a few feet, or even a few tens of
feet, in thickness, extending for miles without more than mere local
variations of thickness, it must be evident that their fluidity cannot
have been in any great degree due to excess of temperature ; in the
case of the thinner sheets I do not think that it can have been in any
degree due to this cause, but rather to a difference of composition
which enabled the granite to maintain some degree of fluidity, while
the rocks into which it was intruded remained solid. Whatever this
temperature may have been, it was sufficient to metamorphose the
sedimentary beds which have always been converted into more or
less perfect schists, that do not exhibit any marked increase of meta-
morphism near the sheets of gneissose granite intruded into them.!

1 Contact metamorphism is only conspicuous in the case of large intrusive masses.
The statement in the text may seem inconsistent with that of Col. McMahon regard-
ing the slightly metamorphosed condition of the slates in contact with the outer band
of gneissose granite in the Dalhousie region ; but the particular slate§ referred to are
everywhere characterized by a much greater power of resisting metamorphism than
those above and below them. I have more than once observed the total absence of

metamorphism, or the mere development of a micaceous glaze on the bedding-planes,
where associated beds were converted into distinct schists.

464 R. D. Oldham—Gneissose Rocks of the Himalaya.

The exact causes productive of foliation are not thoroughly under-
stood, but it appears to be in some way related to the parallel
structure due to stratification or cleavage, as the case may be. In
the case of an intrusive sheet of granite, there would be neither
stratification nor cleavage; but friction against the sides of the
channel it flowed in would be sufficient to produce a slight parallel
structure in a viscid mass; while it is not inconceivable that the
very fact of the minerals, in the rock on either side, arranging them-
selves in a laminated structure, would induce similar rearrangement
of the minerals in the gradually cooling granite. In short, I believe
that the very slight foliation of the larger masses is principally a
fluxion structure, while the more developed structure of the thinner
bands, and near the margins of the larger masses, was produced in
the solid but still heated granite by the same causes—whatever they
be—that led to the foliation of the adjacent sedimentary beds."

Before leaving this subject, there is one point that may be referred
to with advantage. In Mr. Lydekker’s memoir on the geology of
Cashmir it is stated, both on the map and in the text, that part of
the gneiss of that region consists of metamorphosed Silurian strata ;
this statement will not, I fear, be borne out by a more detailed
examination of the ground. I have had a tolerably extensive, if
fragmentary experience of the Himalayas, during which I have
never seen a case of beds, which occur elsewhere as slates, having
been converted into gneiss ; but I have seen sections, similar to those
described by Mr. Lydekker, where there appears to be a gradual
passage from slate to gneiss. It appears not to be uncommon that
near the boundary of a crystalline area there should be sections
showing a considerable thickness of gneissic rocks, with small
intercalations of non-gneissic beds. which can occasionally be
recognized as belonging to some definite horizon in the slaty series.
The sections, at first sight, seem to indicate an extreme metamorphism
of the beds, a few of which have so far escaped metamorphism as
still to be recognizable. Apart, however, from the fact that the
gneiss exhibits those features especially characteristic of the gneissose
granite, where I have been able to trace the horizontal extension of
the rocks into unaltered slates, the change has not been by a gradual
diminution in the metamorphism of the rocks as a whole, but by a
gradual diminution of the gneissose beds, those which remain being
as distinctly crystalline as before, till, where they have diminished
in thickness and the schistose beds prevail, they can be distinctly
recognized as intrusive gneissose granite. The sections indicate,
not an extreme degree of metamorphism of the slaty rocks, but their
more or less complete obliteration by gneissose granite. ;

In Western Garhw4l there is a considerable development of
arkose beds which have become foliated, but are still recognizable as
foliated arkose. It is quite conceivable that similar beds might be so
metamorphosed as to be undistinguishable from gneiss, but with this

1 In 1884 Colonel McMahon seems to have held an opinion somewhat similar to

this (see Records Geol. Surv. India, vol. Xvil. p. 72), but so far as I can understand.
his paper in the May Number of this Macazine, he has now abandoned it. ;

Notices of Memoirs—British Association Meeting, 1887. 469

exception (which could not be called a true metamorphic gneiss as
the felspar was provided ready made), I do not think that any beds
belonging to the slaty series of the Himalaya have been converted
into gneiss; whether they could be is a matter to be decided by
chemical analysis.

Ose S = Cra Ie VE@imE S-

ee

I.—Britrish AssociATION FOR THE ADVANCEMENT OF SCIENCE.
Firry-sEvEntH Merrinc, Mancuester, 1887.

Section C.—Gerotoey.
President: Henry Woopwarp, LL.D., F.R.S., F.GS.

Titles of Papers Read September 1st to 7th, 1887.

. Address by the President.

. Prof. W. Boyd Dawkins—On the Geography of the British Isles

in the Carboniferous Period.

. Prof. W. Boyd Dawkins.—On the Structure of the Millstone

Grit of the Pennine Chain.

4, Mark Stirrup.—Foreign Boulders from Coal Seams.

5. Dr. G. J. Hinde.—On the Organic Origin of the Chert in the
Carboniferous Limestone Series of Ireland, and its similarity to
that in the corresponding strata of North Wales and Yorkshire.

6. Robert Law and James Horsfall.—On the Discovery of Carboni-
ferous Fossils in a Conglomerate at Moughton Fell, near Settle,
Yorkshire.

7. Dr. H. Crosskey.—Report on the Erratic Blocks of England,
Wales, and Ireland.

8. Prof. EH. Hull.—Note on a few of the many remarkable Boulder
Stones to be found along the Hastern Margin of the Wicklow
Mountains.

9. Prof. H. Carvill Lewis.—The Terminal Moraines of the great

_ Glaciers of England.

10. Prof. H. C. Lewis —On some important Extra-Morainic Lakes in
England, North America, and elsewhere, during the period of
Maximum Glaciation; and on the Origin of HExtra-Morainic
Boulder Clay.

11. Hugh Miller.—A comparative study of the Boulder Clay in the
Glaciated Districts of Hurope—Britain, Norway, Switzerland,
Low Germany, and the Pyrenees.

12. Dr. H. Hicks.—Report on the Cae Gwyn Cave, North Wales.

13. J. W. Davis.—On an Ancient Sea-Beach near Bridlington, con-
taining Mammalian Remains.

14. Dr. H. Woodward.—On the Discovery of a Larval Cockroach,
Hioblattina Peachii (H. Woodw.), from the Coal-Measures of
Kilmaurs, Ayrshire.

15. Dr. H. Woodward.—On a new form of Eurypterus com the

Lower Carboniferous Shales, Glencartholme, Eskdale, Scotland.

DECADE I1l.—yOL. 1V.—NO. X. 30

ao bdr

466

16.
17.
18.
19.
20.
al.

22.

23.
la
25.
26.
27.
28.
29.
30.
dl.

32.

42.

43.

Notices of Memoirs—British Association Meeting, 1887.

Dr. H. Woodward.—On a new Trilobite (Conocoryphe) from ihe
Upper Green Slates, Penrhyn Quarry, near Bangor.

Prof. T. Rupert Jones.—Report on the Fossil Phyllopoda of the
Paleeozoic Rocks.

Prof. H. G. Seeley.—¥vidence on the Mode of Development of
the young of Plesiosaurus.

Prof. H. G. Seeley.—On the reputed Clavicles and Inter-
Clavicles of Iguanodon.

Prof. H. G. Seeley.—On Cumnoria, an Iguanodont Genus founded
on Iguanodon Prestwichi, Hulke.

Prof. H. G. Seeley.—The Classification of the Dinosauria. °

Prof. Vilanova.—Sur la calcedoine enhydrique et la roche dans
laquelle se trouve a Salto Oriental (Uruguay) avec exhibition de
Vechantillon.

Prof. W. Boyd Dawkins.—On the Schists of the Isle of Man.
Prof. G. A. Lebour.—On Thinolite and Jarrowite.

W. W. Watts.—A Shropshire Picrite.

Vaughan Oornish and Percy F. Kendall.—On the Mineralogical
Constitution of Calcareous Organisms.

Sir J. William Dawson.—On New Facts relating to Hozoon
Canadense.

Dr. T. Sterry Hunt.—Gastaldi on Italian Geology and the
Crystalline Rocks.

Dr. T. Sterry Hunt.—Elements of Primary Geology

Prof. T. G. Bonney.—Preliminary Note on Teaccee of the
Western and of the Hastern Alps, made during the summer of
1887.

J. H. Marr.—Some effects of Pressure on the Sedimentary Rocks
of North Devon.

Prof. J. F. Blake.—Report on the Microscopic Structure of the
Older Rocks of Anglesea.

. Dr. C. Callaway.—Notes on the Origin of the Older Archzan

Rocks of Malvern and Anglesea.

. J. J. H. Teall.—The Origin of Banded Gneisses.
. Howard Fox and Alex. Somervail.—On the occurrence of Por-

phyritic Structure in some rocks of the Lizard district.

. Prof. W. J. Sollas.——Some Preliminary Observations on the

Geology of Wicklow and Wexford.

. G. H. Kinahan.—On Archean Rocks.
. W. Pengelly.—Recent Researches in Bench Cavern, Brixham,

Devon.

. Prof. J. W. Judd.—The Natural History of Lavas, as illustrated

by the materials ejected from Krakatoa.

. Dr. H. J. Johnstone-Lavis.—Report on the Volcanic Phenomena

of Vesuvius and its neighbourhood.

. Prof. J. Milne.—Report on the Volcanic Phenomena of Japan.

Dr. T. Sterry Hunt and James Douglas.—The Sonora Earthquake
of May 3, 1887.

Thos. Ward.—The History and Cause of the Subsidences at
Northwich and its neighbourhood in the Salt Districts of
Cheshire.

Notices of Memoirs—British Association Meeting, 1887. 467

. Prof. J. H. Panton.—Places of Geological Interest on the Banks

of the Saskatchewan.

. Rev. # Hill.—The Disaster at Zug, on July 5, 1887.
46.
. Prof. W. C. Williamson.—Report on the Carboniferous Flora of

Dr. A. Fritsch.—On the Permian Fauna of Bohemia.

Halifax.

. A. Sinith Woodward.—On the Affinities of the so-called Torpedo

(Cyclobatis, Egerton) from the Cretaceous of Mount Lebanon.

. Prof. J. F. Blake.—Description of a New Star Fish from the

Yorkshire Lias.

. C. EH. De Rance.—Report on the Underground Waters in the

Permeable Formations of England.

. Prof. Vilanova.—Notice du Dinotherium, deux especes, trouvées

en Hspagne.

. A, H. Foord.—On the Genus Piloceras, Salter, as elucidated by

examples lately discovered in N. America, and in Scotland.

. J. S. Gardner. — Report on the Fossil Plants of the Tertiary

and Secondary Beds of the United Kingdom.
A. Bell.—Report on the “ Manure” Gravels of Wexford.

. R. G. Bell.—The Pliocene Beds of St. Erth, Cornwall.
. J. 8. Gardner.—Report on the Higher Hocene Beds of the Isle

of Wight.

. W. A. EH. Ussher.—The Triassic Rocks of West Somerset.
. W. A. E. Ussher.—The Devonian Rocks of West Somerset on

the Borders of the Trias.

. Prof. H. Carvill Lewis.—The Matrix of the Diamond.
. Prof. T. G. Bonney.—Observations on the Rounding of Pebbles

by Alpine Rivers, with a Note on their Bearing upon the
Origin of the Bunter Conglomerate.

. Prof. W. Boyd Dawkins.—The Present State of the Channel

Tunnel, and the Boring at Shakespeare’s Cliff, near Dover.

2. Prof. Otto Torell.—On the Extension of the Scandinavian Ice

to Eastern England in the Glacial period.

. Prof. H. Carvill Lewis.—On the Terminal Moraine of the Irish-

Sea Glacier, near Manchester.

. E. P. Quinn.—Upon a Simple Method of Projecting Microscopic

Rock Sections upon the Screen, both by ordinary and by polar-
ized light.

List of Papers bearing upon Geology read in other Sections.

Section A.—MarnematicaL AND PuysicAL SCIENCE.

Prof. EH. Hull.—On the Effect of Continental Lands in Altering the

Level of Adjoining Oceans.

4. C. RusseliimwOn some Variations in the Level of the Water in

Lake George, New South Wales.

E. Douglas Archibald.—The Direction of the Upper Currents over

the Equator in connexion with the Krakatoa Smoke-Stream.

Section B.—CurmicaL Screncz.

Ff. W. Clarke-—The Chemical Structure of Natural Silicates.

468 Notices of Memoirs—k. G. Beli—St. Erth Beds.

. Section D.—Bronoey.
Discussion on the arrangement of Museums (in conjunction with

Section C), Opened by Dr. H. Woodward, F.R.S., F.G.S.

Section E.—GroGrapHy. ;
W. Brindley.—A Visit to the Porphyry Quarries of Gebel Dukhan.
Second Report of a Committee for inquiring into the depth of the
permanently frozen soil in the Polar Regions.
Prof. Boyd Dawkins.—The beginning of the Geography of Great
Britain.
G. Skelton Streeter—The Ruby Mines of Burma.
Josiah Pierce, jun.—On the United States Geographical and Geological
Survey.

Section F.—Economic Screncre AND STATISTICS.

W. Topley.—On the Future Production of the Precious Metals (at a:
Joint Meeting with Section C).

Srotion G.—MrcHanicaL SCIENCE.
Jeremiah Head.—The Iron Mines of Bilbao.
F. Ransome.—Portland Cement Manufacture.
T. A. Walker.—Severn Tunnel.

Srction H.—ANTHROPOLOGY.
Sydney B. J. Skertchly.—On the Occurrence of Stone Mortars in the
Ancient (Pliocene ?) River Gravels of Butte County, California.
Report of the Committee on the Pre-historic Inhabitants of the
British Isles.
Dr. Henry Hicks.—The Migrations of Pre-glacial Man.
Dr. H. Colley Marsh.—The Early Neolithic Floor of Hast Lancashire.
W. Pengelly.—On Recent Researches in Bench Cavern, Brixham,
Devon.

Papers Read at the Meeting of the British Association, Manchester, in
Section (C), Geology.
Ti.—Tue Puiocent Bens or St. Err, Cornwatt. By Ropert
Guorce Bett, F.G.S.

{INCE the publication of the paper read before the Geological
Society of London in February, 1886, a good deal of work
relating to the geological surroundings and to the special fauna of
the deposit has been undertaken. Considerable excavations were
made, and much examination given to the sands and clays, with the
result that the section given on p. 202, “Quarterly Journal of
Geological Society,” for May, 1886, was completely verified.

The clay deposit is not, however, uniformly fossiliferous, nor is it
uniform in the distribution of its fossil contents as a rule. Cerithia
are found in great numbers at the base of the blue clay, while the
larger Nasse and Turritelle are generally distributed in that bed.
A great feature of interest is the large number of the smaller species
of mollusea, especially of Gasteropods, which embrace more than
three-fourths of the total amount. ;

Notices of Memoirs—R. G. Beli—St. Hrth Beds. 469

Of these small shells the genera Rissoa and Odostomia are the
most plentiful, in species and numbers; about twenty species of the
former (including the Hydrobias) and eighteen of the latter genus
are present, some being living inhabitants of the British and Medi-
terranean seas, while others appear new to science, and will have to
be described. The Trochi are nearly all extinct, three only being
Crag and living forms. Of Nassa about eight species are present,
Nassa serrata being by far the most common, and is nearly identical
with the general form of Nassa reticosa, Sowerby, so plentiful in
the coprolite pits of the Boyton district in Suffolk; there are also
other well-known Crag species of this family.

The carnivorous Gasteropods are, however, not otherwise plentiful ;
one should be noticed, a large fragment of Buccinum undatum, but
no traces of Fusus antiquus or F. gracilis; all the Pleurotomas are
scarce except P. brachystoma, and there are two species of Pisania or
Lachesis; all these last are southern forms.

Of the bivalves not much can be said; few species were obtained,
and these mostly in a fragmentary condition. It is still a difficulty
to afford an adequate explanation of this fact, for while the deposit
of clay is so well calculated to preserve the shells, as shown by the
perfect state of the univalves, the bivalves (if we except the oysters
and some minute species) have universally suffered. Some explana-
tion other than that of the physical character of the deposit must
be sought for, and none has yet appeared sufficiently satisfying.

The opinion expressed in the earlier reports upon this deposit, as
to the southern facies of its fauna, has been amply justified by fresh
researches ; a large quantity of the fossiliferous clay has been care-
fully washed and examined, and no trace of northern forms, except
Buccinum undatum, and the two small species noticed in the paper
previously referred to, has been found, while greatly increased
evidence confirming what has been already said is present. Had
there been any connection with northern seas or colder waters, it
would be difficult to understand the entire absence of those forms of
Pleurotoma (Bela) so abundant in the Boreal seas of the Crag period
and the present age, as well as the equally characteristic bivalves,
Astarte and Cyprina.

Some conflict of opinion exists upon the depth of water in which
the St. Erth clays were deposited.

In a letter to “Nature,” of August 12, 1886, a very competent
authority on Pliocene phenomena, Mr. Clement Reid, F.G.S., gave it
as at least forty or fifty fathoms, founding his view on the evident
fact of its deposition in still water, which he maintains could not be
found in a district exposed to Atlantic swells at less depth. To this
the writer must take serious exception. Undoubtedly the clays
exhibit an entire absence of such a disturbing cause as the influence
of great wave action, but it remains to be proved that such a great
depression as Mr. Reid describes did occur at the western end of
Cornwall, and as far as I have been able to observe there is little
indication of such a fact. Some depression, of course, must have
happened, sufficient to submerge the low-lying land near St. Erth,

470 Notices of Memoirs—Prof. Bonney—Alpine Geology.

causing a strait or gulf, dividing the Land’s End from the maim
eastern portion of the county.

In this shallow strait the clays and sands were deposited, and just —
such an assemblage of mollusca is found as will bear out this view..
Scarcely any of the shells which are of living species are known to
inhabit such deep water as Mr. Reid indicates, while the majority
show the presence of a laminarian zone, extending to not more tham
fifteen fathoms. This bathymetrical range is the chosen habitat of
the Rissog, who are all vegetable feeders, and of the Nass, which
are predatory and always plentiful just below low-water mark 3.
and what appears still more conclusive is the number of Hydrobia,
which have a close connection with Littorina and indicate shallow
depth and close proximity to shore.

It is hoped that a more detailed examination of the mullusca fauna
may soon be completed, and the whole series added to the National
Collection.

Ti].—Pretiminary Notr on TRAVERSES OF THE WESTERN AND OF
THE HasterN ALPS MADE DURING THE SummuR oF 1887. By
Prof. T. G. Bonney, D.Sc., LL.D., F.R.S., F.G.S.

HE first traverse was made along the line of the Romanche from
near Grenoble to the Col du Lautaret, and thence by Briangon
over the Mont Genévre and the Col de Sestriéres to Pinerolo at the
edge of the Italian plain. The second went from Lienz, across the
central range of the Tyrol to Kitzbiihel, and the rocks of this range
were also investigated at other places, During both traverses the
author had the advantage of the assistance of the Rev. Hi. Hill, who
had accompanied him on a similar journey in 1880.

The results of their examination fully confirm the views already
expressed by the author as to the nature and succession of the
crystalline rocks of the Alps.

(1.) The lowest group consists partly of modified igneous rocks
(which indeed occur at all horizons), partly of gneisses of a very
ancient (Laurentian) aspect.

(2.) The next group, up to which there seems a gradual passage,
consists mainly of more friable gneisses and moderately coarse
mica-schists (Lepontine type). This group is commonly less fully
developed in the above districts than in the Central Alps, having
probably been removed by very ancient denudation.

(3.) The third group has an enormous development. It forms:
a large part of the Cottian and Graian Alps, and it flanks the central
axis of the Eastern Alps on both sides, often passing beneath the
ranges of Secondary strata, which here form the northern and
southern ranges. It has been traced almost without interruption
from east to west for more than fifty miles on the southern, and
eighty on the northern side of the central range. It has a very
close resemblance in all respects to the uppermost group of schists,
in the Central Alps, found to some extent in the Lepontine and yet
more largely in the Pennine Alps, and the author fully agrees with
the Swiss and Austrian geologists in regarding it as in the maim

Notices of Memoirs—Dr. H. Hicks—Cae Gwyn Cave. 471

a prolongation of the same series. It is charactérized especially
by rather dark-coloured mica-schists, often calcareous, sometimes
passing into fine-grained crystalline limestones, with occasional
intercalated chloritic schists, especially in the lowest part, and
with (rarely) quartz schists.

(4.) The Carboniferous and Secondary strata infolded or overlying
in the Western Alps section, and the Paleozoic (? Silurian) and.
Secondary strata succeeding the metamorphic rocks in the Hastern
Alps, are comparatively little altered, and are each readily to be
distinguished from the above.

(5.) The succession of strata in the third group is inexplicable,
unless it be due to stratification; in the second this explanation
appears highly probable, and in the first not more difficult than any
other.

(6.) As groups of rocks with marked lithological characters occur
in like succession over a mountain chain measuring above 400 miles
along the curve, and sometimes at distances of 40 miles across ins
as these groups correspond with rocks recognized as Archzean else-
where, which exhibit like characters and sometimes a like order of
succession, the author thinks a classification of the Archean rocks
by their lithological characters (using the phrase in a wide sense),
may ultimately prove to be possible.

(7.) The views already expressed by the author as to the distinct-
ness of cleavage-foliation and stratification-foliation have been fully
confirmed by the examination of the above districts. He believes
that the failure to recognize this distinction is the cause of the
contradictory statements with regard to the relation of foliation and
bedding which have been made by so many excellent observers, and
lies at the root of much of the confusion which exists on the subject
of the so-called metamorphic rocks.

TV.—Srconp Report oF THE ComMITTEE, CONSISTING OF PROFESSOR
T. McK. Hucurs, Dr. H. Hicks, Dr. H. Woopwarp, anD
Messrs. H. B. Luxmoors, P. P. Pennant, Epwin Morean, ann
G. H. Morton, APPOINTED FOR THE PURPOSE OF HXPLORING THE
Caz Gwyn Cave, Nortu Wats. Drawn ur By Dr. H. Hicks,
SECRETARY.

| Ni main object that the Committee had in view this year was to
extend the excavation which had been made in front of the
new entrance to the cavern, discovered last year, so that a clear
section of the deposits which covered that entrance might be exposed.
Work was commenced on June 6, and continued to the 18th,
when it was decided that sufficient excavation had been made, and
work was for the time suspended. It was deemed advisable to
postpone the shoring up of the sides and any filling in that may be
required until August, so that an opportunity may be given to
any one interested in the exploration to examine the section exposed.
The excavation was visited daily by some members of the Committee,
and all, excepting Dr. H. Woodward, were able to be present on

472 Notices of Memoirs—Dr. H. Hicks—Cae Gwyn Cave.

several occasions. The section has also been examined by Prof.
Boyd Dawkins, F.R.S., Messrs. C. E. De Rance, F.G.S., R. H.
Tiddeman, F.G.8., Clement Reid, F.G.8., A. O. Walker, F.L.S.,
H. C. Beasley, and others.

It was found necessary to remove much of the timber placed last
year to support the face in front of the entrance, so that the section
might be clearly exposed, and the cutting was widened here
sufficiently to show a vertical face of undisturbed deposits. The
timber supporting the north-east face of the cutting was allowed to
remain, as that portion had been well exposed last year, and it was
thought that the excavation in front and to the south-west would
yield all necessary evidence without incurring that additional trouble
and expense. The cutting was carried in a _ south-south-west
direction from the mouth of the cavern, and beyond the dip in the
field supposed to indicate the line of an old fence; the length from
the timber on the north-east face to the commencement of the dip in
the field being about 30 feet and the width varying from 5 to 10
feet; the narrowest part being at the furthest point from the cavern.
In the face exposed in front of the entrance, and for a distance in the
cutting from there of about 25 feet, the soil varied in depth from
18 inches to 2 feet, but at the slope supposed to indicate the line of
the old fence it thickened considerably. Underlying this throughout
the whole length of the cutting and in the field beyond this point,
a boulder clay of reddish-brown colour was exposed. This boulder-
clay contained thin seams of sand, which were traceable generally
at the same horizon along the whole section.

At a depth of about 7 feet from the surface, in a continuous band
of reddish sandy clay, numerous fragments of marine shells and some
perfect ones were met with, and these have been recognized by Mrs.
McKenny Hughes ‘to belong to the following species, viz. Ostrea sp.,
Mytilus sp., Nucula nucleus, Cardium echinatum, C. edule, Cyprina
islandica, Astarte borealis, Artemis exoleta, Venus gallina? Tellina
balthica, Psammobia ferréensis, Donax? Mya truncata, Littorina sp.,
Turritella terebra, Buccinwn undatum. Below the boulder-clay at a
depth of about 9 feet from the surface, there was exposed some sandy
gravel and fine banded sand with a total thickness of over 6 feet,
and under the latter a well-defined band of finely laminated
reddish clay.

Below the laminated clay the brecciated bone earth was found to
extend as far as the cutting was made in front of the entrance, and
also for a distance of 7 feet in a southerly direction from the entrance.
This year only a few fragments of bone and bits of stalagmite were
obtained from this earth, though it will be remembered that last
year it yielded many teeth as well as the flint flake which was
discovered near the entrance. The limestone floor under the bone
earth was found to rise gradually outwards from the mouth of the
cavern for some distance, forming a shallow basin-shaped space in
front of the entrance. In the bone earth in this space there were
several large angular blocks of limestone.

It was not thought necessary to dig down to the floor along the

ee

Reviews—Howorth’s Mammoth and the Flood. 473

whole length of the cutting, but it was traced for 7 feet in that
direction by the side of the cliff against which the deposits abutted.
Beyond that point the cutting was made deep enough to reach the
sandy gravel under the boulder-clay, and at different parts test-holes
were sunk still deeper into the gravel and sand. One hole was also
sunk in the field in front of the cutting at a distance of over 35 feet
from the entrance to the cavern. The deposits here were found to
be similar to those in the cutting and in front of the cavern, but the
depth of the soil over the boulder-clay was only from one foot to 18
inches. A very large number of smoothed and ice-scratched boulders
were found, many of considerable size; the majority being fragments
of Wenlock shale from the neighbourhood, and Lower Silurian rocks
from the Snowdonian area. Amongst them also were fragments of
granite, gneiss, quartzites, flint, diorites, basalts, Carboniferous
rocks, ete.

V.—Tue Disaster at Zue on Jury 5, 1887. By tan Rev. H.
Hitt, M.A., F.G.S., or St. Jonn’s Cottecu, CAMBRIDGE.

()* July 5, 1887, at the town of Zug, in Switzerland, a portion of

the shore gave way and sank into the lake. About three hours
later another much larger adjacent area also suddenly subsided, so
that in all an area considerably over two acres, with half of one of
the principal streets, was submerged to a depth of about 20: feet.
It can be seen that the subsoil consists of coarse gravel and sand,
followed after a few feet by soft wet sand and fine mud. According
‘to Professor Heim, this fine mud or sludge reaches to a depth of
nearly 200 feet, and the disaster is shown to be due to a flowing out
into the lake of this mobile sludge from under the superincumbent
weight of buildings and firmer ground. The buildings collapsed as
they sank. The catastrophe must have been long impending; the
exact cause which precipitated it is indeterminate, but a low level of
the lake and tremors from pile-driving for new quays are suggested
as contributories. On the English coast the incessant changes of
pressure from tides probably render impossible such instability of
equilibrium.

aEy San eee TEG VVi I S-

Tae Mammora anp THE Froop. An AttTEemMpr To CONFRONT
THE Turory oF UNIFORMITY witH THE Facts oF Recent GroLoey.
By Henry H. Howorrts, M.P., F.S.A., M.R.A.S. 8vo. pp. xxxil.
464, (London, 1887, Sampson Low, Marston, Searle, and
Rivington.)

sl ae desire to find harmony between the Geological record and the

first chapter of Genesis, laudable enough when Science was in
its infancy, has ceased now-a-days to cause much anxiety. Geological
chronology, like human history, can only be separated into epochs
that are marked by local breaks or ‘‘ landmarks ” in the continuity
of events; so that no system of subdivision that applies to one
tract of the earth’s surface will be equally applicable in all countries.

474 Reviews—Howorth’s Mammoth and the Flood.

Even when such terms as Silurian, Jurassic, and Cretaceous are em-
ployed in all quarters of the globe, it must not be inferred that the
periods embraced can be limited in the same way as they are in this.
country. With the later epochs of Pleistocene and Recent, it is
possible, however, to speak more confidently, though in a general
way, of contemporaneous forms of life.

Mr. Howorth candidly dismisses the first chapter of Genesis as
“absolutely valueless in geological discussion ”; but, granting this
to be the case, he adds, “there is no reason whatever why sub-
sequent chapters which profess to report, not how things arose before:
man appeared, but the traditions of man himself, should be
discarded.” Thus approaching his subject, the author continues,
“To speak more definitely, the Flood, as reported in the Bible, is
undoubtedly a very old tradition, it is in correspondence with similar
traditions among widely separated peoples, between whom there has
been no intercourse, so far as we know, at least since the first dawn of
history. These traditions generally agree in placing a great cata-
strophe, involving widespread destruction to animal life, at the verge
of human memory. Such widespread and continuous traditions
need explanation.” At the outset we are disposed to question the
value of the traditional evidence, so far as it suggests “a deluge
apparently unparalleled in extent and completeness in any other
geological period” ; for the words we have placed in italics indicate
a flaw in that evidence, as the ideas held by the various peoples may
have been transmitted from one independent source, and not have
originated simultaneously all the world over. Be this as it may, the
main object of the work before us is to bring forward facts to prove
that a very great cataclysm or catastrophe occurred at the close of
the Mammoth period, by which that animal with its companions,
were overwhelmed over avery large part of the Earth’s surface ; that
this catastrophe constitutes the gap which is almost universally
admitted to exist in Northern Europe between so-called Paleolithic
and Neolithic man ; and that while this flood was exceedingly wide-
spread, considerable areas escaped, and from these insular areas man,
animals, and plants spread out again and reoccupied those districts
which had been desolated.

We may pass over those portions of the work that deal with the
etymology of the word Mammoth and its identity with Behemoth ;.
or that review the old records of fabulous beasts and giants, based
on the discoveries of huge bones. These accounts, together with
the speculations on the origin of the bones, furnish a good deal of
interesting matter.

The author is evidently quite “at home” with ‘the Mammoth in
Siberia,” and he gives full and instructive accounts of the discoveries
of bones and frozen carcases (“ Mammoth Mummies”) ; of the trade
in fossil ivory ; and of the physical features of the land. The larger
portion of Northern Siberia, as is well known, consists of flat tracts,
known as tundras, upon which few if any trees will grow. The
areas are covered with moss, and they are swept by icy winds. The
ground is in parts frozen to a depth estimated at 630 feet, although

Reviews—Howorth’s Mammoth and the Flood. 475

in the summer season it may be thawed to a depth of three feet.
In several cases Mammoth carcases have been found standing
upright in the ground, as if they had sunk down and been frozen in
that position ; in other cases remains of various animals are com-
mingled in the frozen soil and must have been drifted some distance,
before being embedded in the black earth, sand, or icy clay. There
is evidence also of much drift wood, as well as of large tree-stems, to
indicate that the climate formerly was more favourable to vegetation
than it now is. The animals represented by the frozen carcases,
must have been overwhelmed and have been rapidly enveloped in
mud and gravel, and the ground must have become frozen, and
remained so until the present day. There appears no escape from
this conclusion, though it is difficult to say in what way the animals
were overwhelmed and how long they have been embedded. As
Mr. Howorth remarks, no Russian naturalist holds the view that
the Mammoth lived on to Recent times in Siberia.

The facts pointed out by our author are opposed to the view that
the Mammoth and other animals were, as a rule, drifted far from
the south, for the remains are found not only on the banks of the
long rivers, but also abundantly on the borders of the very short
ones, and in nearly all parts of the tundra. Mr. Howorth concludes
that the Mammoth and his companions lived for the most part where
their remains occur in northern as well as in southern Siberia, but
under different climatal conditions. He says (p. 96), ‘* We cannot
postulate a separate climatic cataclysm for each individual case and
each individual locality, but we are forced to the conclusion that the
now permanently frozen zone in Asia became frozen at the same
time from the same causes.” While we feel with the author that
diluvial agents may reasonably be inferred in order to account for
the remarkable entombment of many organic remains, yet we are
not prepared to go so far as he does, and to regard the phenomena
generally as “the result of one of Nature’s heeatombs on a grand
and wide-spread scale, when a vast fauna perished simultaneously.”

The fact is, our author would lead us all round the world, and
taking the Pleistocene fauna, which we admit in a general way to
be contemporaneous, he would have us believe that the bulk of the
animal remains were smothered up at one time in “ the Great Flood.”
Not only were the remains of Mammoth and Rhinoceros found in
brickearth and gravel and in Cave-earth, over the north of Europe,
entombed by this cataclysm ; but the bulk of the Pleistocene remains
in North and South America, in Australia, Tasmania, and New
Zealand were covered up at one and the same time! In other words
the Mastodon and Elephant, the Megatherium, the Diprotodon and
Nototherium, and the Moa also, perished in one general catastrophe!

The author bases his views partly on the general mode of oc-
currence of the fossil animal remains, their abundance in certain
places, and the commingling of various genera; but as he observes
the present volume only deals with one-half of the problem, namely,
that illustrated by paleontology and archeology. In interpreting
this or any other geological record, the stratigraphical evidence is of

476 Reviews—Houworth’s Mammoth and the Flood.

the highest importance, but that is not now put before us, the author
hoping to treat the geological side of the case fully and completely
in a subsequent volume, when he will discuss the cause of the
catastrophe and its extent. In the meantime he observes that “This
vast effort seems from inexorable evidence to have been due to the
exertion of some cataclysmic force by which the Harth’s crust was
greatly disturbed, not merely locally, but over a large part of its
surface. It was in consequence of this dislocation that the loose
watery envelope which covers a large portion of the world was set
in motion, and sweeping over the land drowned and then buried
deep in gravel, loam and clay, hecatombs of living beings.”

All this is of course very vague and hypothetical. The relations
of the Mammoth and its companions to the Glacial period form an
exceedingly important subject, but the questions that Mr. Howorth
raises concerning them cannot be discussed until his second volume
comes to light. He however so far anticipates himself as to speak
of the Mammoth age as the true Glacial epoch, and to remark that
he is “completely opposed to the extreme views urged in recent
years by Agassiz, Croll, James Geikie,” and others, whose views he
regards as a “ glacial nightmare.”

Nevertheless, whatever opinions be held with regard to the
relative influence of land-ice, coast-ice, and icebergs, there can be no
reasonable doubt that all agents have acted a part in the history of
the Glacial period. Moreover, that epoch must have lasted thousands
of years. The records of tumultuous deposits are interwoven with
those of quiescent deposits, and in a broad and general—we might
say poetic—way it would not be very rash to speak of this period as
Catastrophic. Compared with what is now going on in this country,
no doubt the Glacial period was decidedly catastrophic, and we feel
convinced that excessive denudation and deposition must have taken
place far and wide over the surface of our land. Indeed, we believe
with Mr. Howorth, that the Glacial period coincides generally with
that of Paleolithic man; and it is not unreasonable to suppose, as
Mr. Tiddeman has suggested, that extensive floods in those days
gave rise to the tradition of a Universal Deluge. More than this we
are not prepared to admit, nor can we agree with the author when ~
he says that “over much the largest portion of the earth’s surface
which is covered and protected by herbage or forest, denudation is
not going on at all, but on the contrary humus is being deposited in
a more or less slow fashion.” This is a very misleading statement,
inasmuch as the author entirely neglects the effects of subterranean
denudation: for we need only point to the solid matter carried
away in solution and suspension by springs and rivers, much of
which sedimentary matter is derived from lands covered and protected
by herbage. here can be no doubt that the level of the land is in
places gradually lowered without the general surface contour being
visibly affected.

Another point on which the author places considerable stress, 18
that remains of animals are not now-a-days preserved to the extent
they were during “the Great Flood.” The facts that “in Spitzbergen

Reviews—Howorth’s Mammoth and the Flood. 477

it is easier to find vertebree of a gigantic Lizard of th e Trias than
bones of a self-dead Seal, Walrus, or Bird,” or that in the forests of
Ceylon remains of Elephant are rarely if ever found, simply show
that conditions for the preservation of the bones did not locally exist.
At Lyme Regis it would be easier to find Saurian remains in the
Lias, than Mammoth bones in the old gravels of the neighbouring
valleys, or than remains of Bear, Wolf, and species of animals
still existing, in the more recent Alluvial deposits. We should be
surprised rather than otherwise to find bones preserved on the
surface ‘“‘in subaerial layers,’ excepting those bones which have
been buried, and it is far from strange ‘that the plough, in cutting
through virgin soil,” seldom meets with them. Throughout the
history of all our stratified rocks fossils are more abundant at
particular spots even in the same stratum, just as we find recent
shells abundantly on our beaches at some localities, while they are
absent at others. Mr. Howorth might visit many a section in our
older Thames Valley deposits and return home without any osteological.
reward ; and he might meet with similar experience in searching for
bones in the Norwich Crag, or even in the Cromer Forest Bed.

In other instances bones are locally very abundant, and sometimes
represent animals in various stages of growth. This again is quite
natural, for land-animals that die of old age would, as a rule, perish
in situations where their bones would not be preserved. We are,
however, quite disposed to agree with the author when he maintains
that “The occurrence of immense caches in which the remains of
many species of wild animals are incongruously mixed together
pell-mell, often on high ground, seems unaccountable, save on the
theory that they were driven to take shelter together on some point
of vantage, in view of an advancing flood of water, a position which
is paralleled by the great floods which occur occasionally in the
tropics, where we find the tiger and its victims all collecting together
on some dry place, and reduced to a common condition of timidity
and helpiessness by a flood which has overwhelmed the flat country.”

Most of the Pleistocene Mammalia found in this country have
been obtained in deposits that occur in caverns or in the drainage
areas of modern rivers; and we dispute the statement, that in many
places in this country, “we find the caches of bones in positions
entirely out of the reach of any possible rivers or river-floods.”
Nor is it generally the case that the beds in which Paleolithic imple-
ments occur are found in situations where no river flows, and where
no river that we can postulate as possible ever could have flowed.

These dogmatic statements are certainly inconsistent with the
general tenor of the author’s remarks, and we hope in his second
volume he will not be led to quote exceptional and disputed cases
in support of his particular views.

From the facts brought before us in this volume, we cannot discern
any immediate connection between the accumulations formed by the
direct agency of ice, such as the widespread deposits of Boulder-
clay and the entombment of the various Pleistocene mammalia.
And this view is in concord with Mr. Howorth’s statement (p. 100)
that “Speaking roughly, remains of the Mammoth are absent or

478 Correspondence—Prof. H. G'. Seeley.

exceedingly scarce in the area bounded on the east by Lakes Onega
and Ladoga, an area where the Boulder-drift prevails.” That floods
of considerable magnitude may have taken place, again and again
during the Glacial period, is more than likely ; but the stratigraphical
and physical evidence in support of the Great Flood, as pictured by
Mr. Howorth, has yet to be made known.

Mr. Howorth has given lists of the Pleistocene Mammalia from
various parts of the world, a task which we can readily admit has
given him a great deal of patient labour. Nor was his task at all
lightened by the uncouth names so profusely applied to the genera
and species. On this subject he seeks to comfort his troubled mind
by remarking, “Surely we are nearing a time when the man who
coins a new species without abundant excuse will be deemed a
scientific criminal, and when the ambition to flood text-books with
lists of names of one’s own invention will cease to be called science,
and be treated as mere child’s play.”

In addition to the Mammalia, other organic remains, including
the Plants of Pleistocene times, are more or less fully recorded.

The author loses no opportunities of entering and repeating his
protests against “the creed of English Uniformitarians.” In this
respect he is not alone, we think, in somewhat needlessly spending
a good deal of energy ; his views, after all, as he points out, coincide
with those advanced by Prof. Huxley more than eighteen years ago
in an address to the Geological Society of London. Moreover, the
elementary facts to which Mr. Howorth alludes (p. xv), such as the
sudden creation and rapid disappearance of the submarine island
near Santorin, are clearly not opposed to the teachings enunciated
by Lyell, and they do not “strain the theory of Uniformity to the
breaking point.” Geologists do not argue “that the present forces
which are busy with the Harth’s crust are the measure of what.
they have always been,” but they do hesitate to introduce
*“‘abnormal” causes, or tools that are not known to exist in
Nature’s workshop, to explain phenomena that can be accounted
for by known agents.

Notwithstanding our objections to the very sweeping conclusions
drawn by Mr. Howorth, his work will be of great value as a
storehouse of facts on the fauna and flora of Pleistocene times.
The book is well printed on thick paper and neatly bound. Its
value, however, as a work of reference is seriously damaged by the
lack of an index: but perhaps the author can remedy this when he
brings out his second volume.

CORRES PON DENCE.

in ae
NAMES OF BONES REVISED.

Sir,—In “The Ornithosauria,” 1870, pl. xii. figs. 12, 18, I gave
two views of a fragment of bone, which is described as follows:
“‘ Undetermined [? pterygoid end of palatine bone].” This fragment
J now know to be the radial crest of an Ornithosaurian humerus.

In the Quarterly Journal of the Geological Society, 1877, vol.
XXxil. p. 716, is an account of Pliosaurus Evansi. A bone in that

Obituary—Edwin Witchell, F.G.S. 479

paper, which is described and figured as a left ischium (pp. 721-3,
figs. 7-9) is the left coracoid.

In the Grotocrcan Magazinu, February, 1887, p. 84, the humerus
of Pelorosaurus is referred to Cetiosaurus. I had previously, in the
Quarterly Journal of the Geological Society, 1882, vol. xxxviii.
p- 871, regarded the same bone as referable to Ornithopsis, and to
that determination I adhere. Cetiosawrus is well known to be allied
to Ornithopsis, but I am aware of no evidence of the presence of
Cetiosaurus in the Wealden deposits, in which the type is repre-
sented by species of Ornithopsis. . H. G. Seerzy.

‘24th August, 1887.

PARALLEL STRUCTURE IN IGNEOUS ROCKS.

Srr,—I am obliged to Mr. Harker for the information given in his
letter in your August Number. I do not see the American Journal
of Science, and was not aware that Prof. Dana had partially modified
his views, or that Mr. G. H. Williams had by observations on the
ground come to the conclusion that the igneous rocks of Cortland
were sharply separable from the adjacent crystalline schists.
It need hardly be pointed out that this coincidence of opinion
between Mr. Williams and myself is of considerable evidential
value. Cu. CaLLaway.

WELLINGTON, SHROPSHIRE, September 17th, 1887.

@i= eae ASE ays"

EDWIN WITCHELL, F.G.S.,

TREASURER OF THE Correswotp Narurauists’ Firnp Cuvs.

Ir is with deep regret that we have to announce the sudden death,
on the 20th August last, of Mr. Edwin Witchell, solicitor, of Stroud,
at the age of sixty-four. Mr. Witchell was a son of Mr. Edward
Witchell, of Nymphsfield, a well-known and _highly-respected
yeoman, and was born in June, 1823. His tastes from early boy-
hood led him more to the study of books than to the cultivation of
the soil; at the early age of thirteen years he was placed in the
office of Mr. Paris, of Stroud, the chief local solicitor of those days.
Later on he was articled to that gentleman, and ultimately succeeded
to his practice in 1847. He was at one time very fond of hunting,
and used frequently to accompany the late Mr. Paul Hawkins Fisher
in some of the most memorable runs of the adjacent packs of fox-
hounds. This exhilarating sport doubtless contributed to his then
robust health; but as years crept on, Mr. Witchell gave up his
hunter and applied himself assiduously to rambles in pursuit of his
favourite science of Geology. About five years ago, when climbing
in a dangerous part of the cliffs at Lyme Regis, heart trouble set
in, and for three or four years he has suffered from angina pectoris,
but had not been incapacitated from business, nor deterred from
carrying on his geological work. And it was while engaged in
collecting fossils from the Inferior Oolite at Swift’s Hill, near
Stroud, that Mr. Witchell overtaxed his strength, and fell amidst
the rocks to which he had devoted so much study. In the neigh-

480 — Obituary—Edwin Witchell, F.GS.

bourhood of Stroud the loss will be long felt, for Mr. Witchell was
much esteemed ; a man of kindly, genial nature, he was essentially
a peacemaker, and was never known to say a harsh or unkind word
of any one.

Mr. Witchell no doubt owed his early love of geological study
to his long association with the late Mr. George Poulett Scrope, for
many years M.P. for Stroud. Mr. Witchell was for a long period
the trusted agent and friend of Mr. Scrope. In 1861 he was elected
a Fellow of the Geological Society, and had since contributed papers
to its Quarterly Journal. The last of these, on “The Basement
Beds of the Inferior Oolite of Gloucestershire,” was read for him on
the 24th of February last year, his health at that time rendering
a journey to London undesirable. Mr. Witchell was for many years
an active member of the Cotteswold Naturalists’ Field Club, and
contributed many valuable papers to its Proceedings. For several
years he was treasurer to the Club, and this year was elected one
of its vice-presidents. No geological discussion at the meetings of.
the Club was considered complete until Mr. Witchell had taken part
in it, when his stores of geological knowledge would be given out
with his characteristic enthusiasm and ability. His last contribution
to the Cotteswold Proceedings, on the “Genus Neringa,” appears in
the part last issued, and was illustrated by his own hand with a series
of beautiful and accurate drawings. Mr. Witchell took an active part
in all matters pertaining to scientific education in Stroud, and helped
to support the various institutions that succeeded the first Mechanics’
Institution more than thirty-five years ago. He read papers, gave
lectures,-and not seldom took parties of members for Geological
field-work on the neighbouring Cotteswolds. He was always most
anxious to see a local museum formed in Stroud, and his own large
and complete collection of local fossils was a great attraction to all
geologists visiting the district. It will be remembered that last
Whitsuntide the members of the Geologists’ Association visited
Stroud, when Mr. Witchell conducted them to Rodborough and
Minchinhampton, an excursion which will long be a pleasant recol-
lection to them. The following is a list of the principal papers con-
tributed by Mr. Witchell to the Proceedings of the Cotteswold Club :

1. ‘‘Sections of the Lias and Sands exposed in the Sewage Works.”’

2. “A Deposit on Stroud Hill contaming Flint Implements, Land and Fresh-

water Shells.”
3. “On a Section of the Lias and Recent deposits in the Valley of the River
Frome at Stroud.”

. ‘On the Denudation of the Cotteswolds.”’
. “On a Bed of Fullers’ Earth at Whiteshill, near Stroud.’’
. *©On the Angular Gravel of the Cotteswolds.”’
“On a Pechon of Stroud Hill, and the Upper Ragstone’Beds of the Cottes-

wolds.
. On the Pisolite and Basement Beds of the Inferior Oolite of the Cotteswolds.”

. On the Genus Nerinea and its Stratigraphical Distribution in the Cottes- —
wolds.”’

In 1882 Mr. Witchell published an excellent work on ‘The
Geology of Stroud,’ which contains a large amount of original
information ; and at the time of his death he was collecting materials
for the publication of another work.—Stroud News, Aug. 16, 1887.

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THE

GEOLOGICAL MAGAZINE.

NEW TSERIESH SDECADE: ilily VOLoaelv;

No. XI—NOVEMBER, 1887.

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==

J.—On a NEw Species oF Huryrprzerus FRoM THE LoweER CARBONI-
FEROUS SHALES OF GLENCARTHOLM, EskpALE, SCOTLAND.

By Henry Woopwarp, LL.D., F.R.S.
(PLATE XIII.)

OME time since, in the summer of 1884, Mr. Jex, a collector of
fossils employed by Mr. Robert Damon, F.G.S., of Weymouth,
obtained from the Lower Carboniferous Shales of Eskdale, a new
and most interesting form of Merostomatous Crustacean belonging
to the genus Hurypterus. It has been secured for the Geological
Department of the British Museum (Natural History), and I now
propose to submit a brief description of this very interesting
specimen.

In my Monograph of the order Merostomata (Part IV. 1872,
pp- 1883—1389, pls. xxv.—xxvii. see also p. 180) I described the
only previously-known British Eurypterus from the Carboniferous
Limestone series, Kirkton, near Bathgate, West Lothian, named
Eurypterus Scouleri; a specimen doubtfully referred to the same
having been since discovered at Cape Breton. Another species not
determined was noticed by Salter from the Carboniferous of Nova
Scotia. A form doubtfully referred to H. Scouleri from the Upper
Devonian of Kiltorcan, Ireland, and one named by Salter E. pulicaris
from the same horizon, St. John’s, New Brunswick, and two from
the Lower Devonian of Arbroath, namely HE. Brewsteri and E. pyg-
meus, complete the Carboniferous and Devonian series.

But in the Upper Ludlow beds (U. Silurian) no fewer than 17
species have been described, 10 being from Russia and N. America,
and seven from Ludlow, Kendal, and Lanarkshire ; but the most
perfectly preserved are those from New York and the Island of
Oesel in the Baltic.

Description of the Specimen.—The specimen is preserved with its
dorsal aspect exposed upon the surface of a much-jointed bluish-
grey mudstone; owing to shrinkage and the want of tenacity
between the matrix and the fossil, much of the black and glistening
organic surface of the carapace and segments has been lost in
transit. The counterpart however of a portion of the fossil is
preserved, and assists us in the interpretation of the appendages, ete.

The head, which is semicircular in outline, is very tumid, and
strongly and irregularly tuberculated; the general surface being
coarsely squamose and scabrous. The eyes are not visible; but

DECADE I1I.—yOL. IV.—NO. XI, 31

482 Dr. H. Woodward—On a New Carboniferous Eurypterus.

this I believe to be owing to an unfortunate series of fractures, which
intersect the middle of the carapace just where in other specimens
these organs are usually situated. There is a distinct and rather
wide and smooth margin to the head-shield, which can be traced
for about three-fourths of its circumference, but it is broken away
upon the right side by the protruding appendages.

Three almost entire jointed appendages, furnished with numerous
spines at their articulations and with smaller spinelets along their
edges, are preserved in situ on the right side of the head. A portion
of a fourth is seen on the right anterior border of the carapace; and
portions of the corresponding limbs are shown on the left side of the
head. The appendages where best preserved show six articulations,
the 1st or coxal joint (making 7 articuli) being hidden beneath the
carapace. ‘The two body-segments which follow next after the
head-shield are unusually large, being one-third as deep as they are
broad, and very strongly squamose, the squame lying very close to
one another and becoming more elongated near the margins of the
segments; the posterior angles of each segment were slightly
produced, the points being directed backwards. Portions of five
other segments following the Ist and 2nd are seen in place on the
right side of the specimen, three of which are also partly preserved
on the left side.

These show that the 3rd, 4th, 5th, 6th, and 7th segments were
much narrower than the preceding two, their depth being only one-
seventh of their breadth ; the surface-ornamentation too undergoes a
considerable change, being sparingly covered with small irregular
tubercles.

Scattered irregularly over the somites may be seen a number of
small circular disc-like bodies, having a radiating fibrous structure,
which I at first mistook for some small polyzoon or other minute
sessile parasite, fixed to the surface of the Crustacean. A more
careful investigation—in which Dr. G. J. Hinde was so kind as to
give me his valuable assistance—showed me that these bodies were
actually enclosed within the chitinous substance of the terga, and
are in fact deposits of calcite forming part of the crust of the
segments themselves.

Under the description of Anthrapalemon Parki (Peach), from the
Carboniferous series of Langholm, Dumfriesshire, Mr. B. N. Peach
writes as follows! :—

“The test is very thin, and probably contained very little calcium

carbonate, as it is apt to be filled with calculi,? such as that now

found in the common shrimp. Where the test is thin these are
mere scales; but in the spines and thickened portions they are
semi-globular, the rounded part being mammilated. In every case,
however, they have a central nucleus from which radiations proceed.

1 See Trans. Roy. Soc. Edinburgh, 1880, vol. xxx. pt. 1, p. 80; see pl. ix. figs.
4g, 4h.

2 «*Globular calcite.’”? Prof. Huxley informs me that he has noticed this deposit
as constantly present within the chitinous test of every Palemon and Crangon which
he has examined.——H. W.

.
;
:
j

Dr. H, Woodward—On a New Carboniferous Eurypterus. 483

The above remarks are equally applicable to all the Crustacea
described in the present paper. Sometimes these calculi are
sporadic, at other times they fill the whole tests of the creatures,
forming an irregular polygonal net-work, which destroys the
character of the test and gives it a granulated appearance. Even
in this case the nucleus and radiations are observable.” These
calcareous deposits are most carefully figured by Mr. Peach in plate
ix. of his memoir, figs. 4g and 4h. They agree exactly with those
observed in the specimen of Hurypterus now under description.

In a detached piece, obtained with and forming a part of this same
specimen, is preserved the left margin of four other body-segments
which must have been parts of the 8th, 9th, 10th, and 11th
segments, so that we only need evidence of the 12th segment and
the telson to complete our knowledge of this specimen.

These posterior segments give clear evidence of becoming
narrower and deeper as they recede from the head—the 9th
being about five times as broad as deep; the 10th being about
four and a half times as broad as deep; the 11th being about twice
as broad as it is deep. There is the mould of a raised longi-
tudinal subcentral ridge, one evidently of a pair of ridges no doubt
present on each of the posterior body-segments as seen in Hurypterus
remipes (De Kay) from North America.

The fifth pair of broad spatulate swimming-feet answering to the
maxille, or to the maxillipeds of the higher Crustacea, are not
preserved in this fossil; but as they have been found with nearly
all the species of Hurypterus hitherto described, there is little
doubt that this form also possessed them when entire. Certainly
the other appendages reproduce with only slight modification in
their style of ornamentation those of the Russian, the American,
and the Lanarkshire Huryptert already described and figured by
Hall, Schmidt, and myself. Certain delicate brown leaf-like bodies
can be observed lying on the left side of the head. There can be
no question that these are the remains of the branchiz, such as I
have figured from Lanarkshire, and such as are frequently found
lying detached on pieces of shale from Eskdale, and which have
been considered by Mr. Peach to have belonged to some form of
Arachnide ?

Prof. Geikie indeed states that ‘“‘Mr. Peach’s researches go to
show that the Carboniferous Hurypterus was almost certainly a
gigantic Arachnid and not a Crustacean. Some splendid specimens
of its scorpion-like combs and feet have been obtained from the
Lower Carboniferous rocks of the South of Scotland” (Geikie’s
Text-Book of Geology, p. 724, Second Edition, p. 723.)

The scorpion-like combs I have not seen, but I cannot for a moment
doubt that the feet of this specimen are those of a true Hurypterid,
and although the pair of swimming-feet are not preserved, the form
of the body-segments and their squamate ornamentation proves that
this was a true aquatic form, and that the fragmentary leaf-organs
lying beside it were remains of its branchial lamelle.

Of course—if the branchiated aquatic forms of the Merostomata,

484 J. J. H. Teall—Origin of Banded Gneisses.

are to be relegated to the same division as the terrestrial tracheated
forms of the Arachnida, there is no need to offer any further evidence ;
but at present I deny, with other Carcinologists, that Professor Ray
Lankester has proved his position, or that such an arrangement is
consistent with sound zoological classification.

It is extremely interesting to record the fact that in 1881 Mr. J.
F. Mansfeld communicated an account, with a woodcut, of a fine
fossil Hurypterus found by him in the shale immediately beneath
the Darlington Cannel Coal-bed, Lower Productive Coal Measures, -
Darlington, Pennsylvania, U.S.A. (See Amer. Phil. Soc. Proce. vol.
xix. p. 152, April 1st, 1881.)

The figure I have seen, being only a sketch, and roughly executed
—without scale—does not admit of accurate comparison ; but so far
as Iam able to judge, this American Eurypterus must have been
extremely closely related to our Eskdale species.

As it is convenient to have a name for a new form, T propose to
designate this our second Scottish Hurypterus from the Carboniferous
series as E. scabrosus.

Dimensions of Specimen.—Head 5% inches broad, by 44 inches in
length. Length of body (including head to seventh segment) 10
inches, perfect appendage 8 inches in length, widest part at third
segment of body 64 inches broad. Total length estimated at about
20 inches, including the telson.

EXPLANATION OF PLATE XIII.
Eurypterus scabrosus, sp. nov.

Fie. 1. Larger slab containing the head with three of the gnathopodites in place
on the right side ; and the 1st to the 7th somites more or less perfectly preserved.
Fragments of the branchial leaves (dr.) are seen on the left side of the head.
Prof. Huxley (who kindly looked at the original specimen) has suggested that
the: portion of an appendage, with a row of small tubercles along its border
near the small figure 2, on the right side of the head, may possibly have been
a part of a chelate appendage ; Dut it is very obscure. Other fragments are
seen on the left side of the head (near 5) similarly ornamented.

Fic, 2. A fragment of same specimen showing portions of the 8th to the 10th somites.

I].—On THE ORIGIN OF CERTAIN BANDED GNEISSES.
By J. J. H. Treat, M.A., F.G.S.
(PLATE XIV.)

HE term gneiss as generally used by geological writers signifies

a rock of granitic composition in which a parallel structure in

the arrangement of the constituents is more or less apparent. For
our present purpose it is important to note that other plutonic rocks
besides granite (e.g. diorite, gabbro, and peridotite) have their
gneissose equivalents, so that, ‘if we use the term eneiss in a structural
rather than in a mineralogical sense, we may speak of diorite-gneiss,
gabbro-gneiss, and so on.!_ Now the parallel structure of gneissose
1 Roth has recently (Sitz. d. k. preuss. Akad. d. Wissen. Ueber den Zobtenit, vol.
XXxil. 1887, p. 611) proposed that Leopold von Buch’s term Zobtenfels should be

revived under the form Zobtenite for those gabbros which are associated with crystal-
line schists and are often foliated.

Grou. Mac. 1887. DECADE UI) VOle DVien Bis ol.

Fic. 2.—The “ Granulitic Series,’? Pen Voose, the Lizard.

To illustrate Mr. J. J. H. Teall’s paper on Banded Gneisses.

J. J. H, Teall—Origin of Banded Gneisses. 485

rocks is of two kinds. It may consist (1) of a parallel arrangement
of certain constituents (e.g. mica plates or porphyritic felspars), or
(2) of an alternation of bands of varying chemical and mineralogical
composition. It is agreed on all hands that a parallel structure of
the first kind may be due either to the deformation of a mass of
half-consolidated plutonic rock at the time of intrusion, in which
case it is strictly analogous to the flow structure in many volcanic
rocks, or to deformation produced by earth-stresses operating on the
mass after consolidation. As regards the origin of the second kind
of parallel structure there is no such general agreement, and many
writers regard it as due to some process akin to sedimentary deposi-
tion. The object of the present paper is to show that just as the
first kind of parallel structure may be and in certain cases actually
is due to the plastic deformation of what may be termed homo-
geneous’ plutonic masses, so the second kind of parallel structure
(banded structure) may be and in certain cases actually is due to the
deformation of heterogeneous plutonic masses.

In the first place let us inquire what kind of deformation is
necessary in order to produce parallel banding in a heterogeneous
mass. A moment’s consideration will show that if any heterogeneous
mass of fairly uniform dimensions in the different directions be
deformed into a flat sheet or narrow ribbon, then the individual
portions will be similarly deformed and the mass as a whole will
show a banded structure. This was clearly realized by Mr. Poulett-
Scrope in 1824, who not only explained in this way the parallel
banding of the Ponza liparites, but also suggested that the similar
appearances in gneiss and schist might be due to the same cause.” A
very simple experiment will serve to illustrate the important fact
just referred to. Take pieces of differently coloured clays (say
ordinary potter’s clay and clay which has been intimately mixed
with the blue used by laundresses) ; bring them together in any way
you please so as to make one lump and deform the lump into a thin
sheet or narrow band by squeezing or rolling. Then fold the sheet
or ribbon on itself two or three times and, if you like, repeat the
process of rolling it out. In this way the most perfect parallel
banding may be produced and by varying the conditions in ways
which readily suggest themselves (as for example by using clays of
different degrees of plasticity and inserting fresh pieces after the
deformation has progressed to a certain extent) it is easy to produce
many of the peculiar structures seen in banded gneisses.

It is important to note that the result will differ according as the
mass is deformed into a flat sheet or narrow strip. In the former
ease the strain-ellipsoid will be an ellipsoid of revolution with its
short axis in the direction in which the stress was applied, in the
latter case the strain-ellipsoid will possess three unequal axes,
the least axis lying approximately as in the former case, and the
greatest axis lying at right angles to this and in the direction of

1 Not homogeneous in the strict sense of the term, but homogeneous in the sense
that the different mineralogical constituents are uniformly mixed throughout the mass.
2 Geology of the Ponza Isles, Trans. Geol. Soc. London, 2nd ser. ‘vol. ii. p- 228.

486 J. J. H. Teall— Origin of Banded Gneisses.

the length of the strip, 7.e. in the direction of stretching. The idea
of a strain ellipsoid is of course only applicable to those masses or
portions of a mass which have been subjected to a uniform strain.’
If the different coloured clays yield differently to the deforming
stresses the phenomena will be highly complex.

Now before we are justified in looking favourably on the theory
I am endeavouring to illustrate, it is necessary to show, (1) that
banded gneisses are on the whole identical with plutonic rocks in
composition, (2) that masses of plutonic rocks are often heterogeneous,
and (3) that heterogeneous masses, if such exist, may be deformed
in the manner required to produce banded structures.

To establish the first point it is only necessary to refer to Roth’s
elaborate collection of rock analyses.?, No one who has studied these
analyses can doubt for a moment that the banded gneisses are
essentially identical with plutonic rocks so far as chemical composi-
tion is concerned. The resemblance, however, is not limited to
chemical composition, it extends to mineralogical composition and
in a certain sense even to structure. Hach plutonic rock has its
equivalent in the banded gneisses.

We pass on now to consider the second point. When large
masses of plutonic rock are examined they are often found to vary
considerably in composition. They frequently contain patches which
differ from the main mass. These have been investigated by Mr.
Philips, so far as the granites are concerned, and have been shown
by him to be in general more basic in composition than the rock in
which they occur. Again, every one is familiar with the phenomena
of contemporaneous or segregation veins. These appear to be in
general more acid than the rock in which they occur. Sometimes
two or more varieties of plutonic rocks interlace in the most intricate
manner. Cases of this kind have been described by Prof. Judd® as
occurring in the Isle of Rum, where basic and ultra-basic rocks are
concerned; by Messrs. Peach and Horne‘ as occurring in the Shet-
land Isles, where granite and diorite are concerned; and by Herr
Lossen* in the Hartz, where granite (granitite) and gabbro are
concerned. ‘The last-mentioned observer states that both granitite
and gabbro occur in the same dyke, and that the acid rock either
surrounds or penetrates masses of the basic rock in the form of
veins—the relations of the two rocks being such as to suggest that
the two magmas were intruded simultaneously (or nearly so) rather
than that the fluid granite-magma was injected into solid gabbro.

Diorite and granite may be seen in intimate relation in the ridge

1 A mass is said to have been strained uniformly when every portion has been
strained alike.

2 Beitrage zur Petrographie, etc. Abh. d. k. preuss. Akad. d. Wissen. fiir 1869,
18738, 1879, and 1884.

3 On the Tertiary and older Peridotites of the West of Scotland,’ Q. J. G. 8.
vol. xli. p. 358.

4 The Old Red Volcanic Rocks of Shetland, Trans. Royal Soc. Edinburgh, vol.
XXxki. partii. p. 378.

> On the Eruptive Rocks of the Hartz, Jahr. d. preuss. Geol, Landesanstalt fur
1882, p. xxi.

J. J. H. Teall—Origin of Banded Gneisses, 487

of crystalline rocks running E. and W. a few miles south of Haver-
fordwest, in Pembrokeshire, and similar rocks show similar relations
in the Lizard peninsula, The last-mentioned case will shortly be
described at greater length.

We have now to consider the question of deformation. No one
will doubt that deformation necessary to produce banded structures
in heterogeneous plutonic magmas may take place in connexion
with intrusion. The only question that can arise is whether many
banded gneisses have originated in this way. At present I have no
definite opinion on this point. There is, however, another way in
which the necessary deformation may be produced, viz. by the
operation of the earth-stresses of which we have such striking
evidence in mountain-regions. With reference to this mode of
deformation I will content myself by referring to the work of Heim
and Baltzer in the Alps, of Reusch in the Bergen peninsula, of Leh-
mann in the granulitic region of Saxony, and of Lapworth and the
Geological Survey (Messrs. Peach and Horne) in the north-west of
Scotland. It will not be doubted by any one who has studied the
writings of these authors, and is at all familiar with the phenomena
they describe, that large masses of country have been profoundly
modified by the earth-stresses. It may be a long time before we
become acquainted with the precise nature of the movements and
deformations, but that they are adequate to convert a heterogeneous
plutonic mass into a banded gneissic series is to say the least highly
probable. It must of course be remembered that sedimentary rocks
may also be involved in the movements, so that the occasional
presence in a gneissic series of bands having the composition of
sedimentary rocks is no proof that the whole series is of sedimentary
origin.

Having by these general remarks established, as I believe, the
@ priori probability of the theory I am endeavouring to illustrate, I
will now refer to what appears to me to be a case in point. In the
Lizard district of Cornwall we find two or three rock-types occurring
as portions of an igneous complex and as portions of a banded
eneissic series. Where they exhibit the relations of igneous rocks
(Fig. 1, Plate XIV.), they may be termed granite, diorite and gabbro ;
where they occur as portions of a banded gneissic series they possess
the same specific gravity, but usually show a more or less marked
parallel structure and in certain cases differ in mineralogical com-
position. Consider first of all the petrographical characters of the
different rock-types.

Granite.—This rock never occurs in large independent masses, but
only as comparatively small veins and dykes. It is found in gabbro
(north of Pen Voose), serpentine (Kynance) and diorite (Pen
Voose). It is present also, in a somewhat modified form, in the
banded eneissic series—the “ granulitic series” of Prof. Bonney.!
The least modified rock is a fine-grained granular aggregate of
quartz, felspar and dark mica. The felspar is mostly unstriated,
but a striated variety also occurs. Both felspar and quartz are

1 Quart. Journ. Geol. Soc, vol. xxxix. (1883), p. 1.

488 J. J. H. Teali—Origin of Banded Geisses.

present for the most part in irregular grains. Sometimes, however,
we find more or less rounded grains of quartz inclosed in the
felspar, so that the quartz was not always the last mineral to form.
The mica is deeply coloured. It occurs in detached scales and also
in aggregates composed of several individuals. Sections parallel to
the vertical axis appear a pale yellowish-brown when viewed with
rays vibrating at right angles to the cleavage cracks, and opaque or
a deep reddish brown when viewed with rays vibrating parallel to
these cracks. The mineral is biaxial with a very small optic axial
angle. It evidently contains a considerable amount of iron, for the
rock in which it is abundant often assumes a deep red colour by
weathering. The mica of the weathered rocks has been replaced by
chlorite with which iron-oxides are associated.

_ The more modified rocks, and these are by far the most abundant,
are characterized by the presence of a fine-grained granulitic aggre-
gate of quartz and felspar and a more or less marked parallel
structure. The granulation of the quartz and felspar is, I believe,
a secondary phenomenon due to the dynamic metamorphism which
has operated upon the district. It may be developed merely at the
margin of the original grains, in which case we have the mortar-
structure of Tornebohm '—the relics of the original grains then lie in
a fine-grained granulitic paste like stones in mortar—or it may
replace entirely, or almost entirely, the original quartz and felspar.
The development of white mica does not appear to be a common
feature. It may, however, be observed in what I am inclined to
regard as a schistose granite from Porthalla, where it occurs along
the planes of schistosity. In this rock the secondary granulitic
aggregate forms a large portion of the mass.

A very interesting variety of gneissose rock occurs in the serpentine
near Kynance. It forms only a thin band, and is, I believe, a granitic
vein which has been profoundly modified by the regional meta-
morphism. Sections at right angles to the foliation show a
magnificent micro-flaser structure. The secondary aggregate of
quartz and felspar winds in and out amongst the relics of the
original grains, and possesses in some places a crypto- rather than a
micro-crystalline structure. The rock does not possess any very
definite schistosity and white mica is absent. It appears as if the
development of white mica were connected with movement along
definite planes—where the mass has been deformed in a plastic
manner white mica is absent.

‘The specific gravity of the rocks of the granitic type lies between
2:6 and 2:7

Diorite.—This rock, like the granite, never occurs in large in-
dependent masses. It is generally veined by the granite or mtimately
banded with it in the gneissic series. It may also be found in the
gabbro. The rocks to which I here apply the term diorite vary in
composition and specific gravity. Some belong to the intermediate,
others to the basic series. At the one end of the series we have a

1 Naagra ord om granit och gneiss. Geol. Foren. i Stockholm Forhandl. 1881,
pp. 166 u. 2388,

J. J. H. Teall—Origin of Banded Gneisses. 489

rock which may be termed a mica-diorite, with a specific gravity of
about 2:75; at. the other end of the series we have a rock which may
be termed hornblende-diorite (basic diorite, or possibly an epidiorite)
with a specific gravity of 2°99; between the two extremes we
find intermediate forms which may be termed mica-hornblende-
diorites. The specific gravity of one of these is 2°83.

The more important minerals of the dioritic group of rocks are
felspar (mostly striated in the least modified rocks), dark mica, green
hornblende, sphene, iron-ores, and apatite. The felspar of the least
modified rocks is often somewhat turbid, and the turbid portion
frequently forms a kind of kernel in the centre of a comparatively
unaltered individual. This points to an original zonal structure.
Some of the diorites are porphyritic, and traces of the forms of the
porphyritic crystals (felspars) are preserved even in the foliated
rocks.

The mica is similar to that of the granite. It occasionally contains
minute granular inclusions (probably zircon) which are surrounded
by very dark borders. The sphene is a very interesting and im-
portant constituent of the diorites. It occurs in perfect crystals and
also as grains. The grains in certain rocks form a border to the
opaque iron-ores. ‘This is a feature which may be observed in some
of the gneissic rocks of Sutherland and the Malvern Hills. Iron-
ores are comparatively rare in the mica-diorites, but they become
abundant in the basic diorites. Apatite is very common in some of
the mica-hornblende-diorites.

The felspars of the diorites show the same tendency to granulation
as those of the granite and the individual grains in the granulitic
ageregates are mostly untwinned. In the foliated diorites of the
banded gneissic series striated felspar is comparatively rare.

Gabbro.—As this rock and the modifications which it undergoes
when subjected to regional metamorphism were described at the last
meeting of the British Association,’ it will be unnecessary for me to
enter into details on the present occasion. Suffice it to say that
every gradation from a massive rock to a gabbro-schist may be
observed in the district. Unaltered gabbros are, however, very rare,
just as unaltered granites and diorites are rare. Since my last paper
was read I have isolated the felspar and augite of the unaltered
gabbro from Coverack, and Mr. Player has kindly analyzed them
for me in my laboratory ; the former is a somewhat basic labradorite ;
the latter possesses *6 °/, of chromic oxide, and is therefore a chrome-
diopside. The hornblende of the gabbro-schist from Pen Voose has
also been analyzed by Mr. Player. It possesses over 10°/, of
alumina and differs from the augite also in containing more magnesia
than lime. It contains, however, decided traces of chromium. The
analyses, therefore, so far as they go, point to the conclusion that the
hornblende differs from the augite or diallage in composition, so that
the disappearance of the pyroxene and the development of horn-
blende cannot be ascribed to simple paramorphism. The specific
gravity of the chrome-diopside is about 3:22, that of the hornblende

1 Guot. Mac. Decade III. Vol. III. p. 48.

490 J. J. H. Teali—Origin of Banded Gneisses. .

is about 3-05. With regard to the so-called saussurite, I am able to
state that malacolite, felspar, and minute granules of sphene often
occur as constituents. The malacolite has been isolated and analyzed
by myself, so that no doubt exists as to its identification, though it
often occurs only in minute grains without form or cleavages. The
doubtful substance which appears white by reflected and brown by
transmitted light and which is a constant feature in the Lizard
saussurite has not been identified.

Fic. 3.

We have now to consider the mutual relations of the different
rocks above described. At Kennack Cove and at Pen Voose, near
Landewednack, granite may be seen veining diorite, often in the
most intricate manner (see Fig. 1, Plate XIV.). At Pen Voose,
veins of both granite and diorite occur in the gabbro, Fig. 4. The
three rocks are therefore of igneous origin. They exhibit the
relations of igneous rocks, and they possess the composition of
igneous rocks; moreover, it is possible to find here and there portions
which have escaped the influence of the dynamic metamorphism,
and which show the normal structure of igneous rocks. But the
same rock types occur as integral portions of a banded gneissi¢
series in the same localities. ‘The bands are in some places as re-
gular as layers of sediment in a stratified rock-mass, in other places
they are crumpled and contorted (Fig. 3); in others we observe
“eyes” and lenticles of diorite surrounded by streaks and bands
of a granitic rock (see Fig. 2, Plate XIV.)

As a rule the banded gneissic series is formed only of granitic
and dioritic rocks, but we occasionally find eyes and streaks of
gabbro and gabbro-schist. One large specimen, to which I wish to
direct special attention, shows a crumpled band of gabbro-schist in
mica-diorite.

Another mass much too large to carry away showed the appearance

J. J. H. Teall—Origin of Banded Gneisses. 491

represented in Fig. 5. It consisted of parallel bands and narrow
lenticles of foliated gabbro, granite and diorite. Fig. 6 represents
the relations of granite, diorite, and gabbro in a mass which ex-
hibited no parallel structure. In Figs. 5 and 6 the space left clear
represents granite, or at any rate a rock of granitic composition ; the
dotted portions represent diorite, and the portions indicated by fine

Fic. 4. Granite in Gabbro, Pen Voose. Block 6 feet long.

lines gabbro or gabbro-schist. Fig. 5 represents a mass four feet
and Fig. 6 one three feet in height.

I submit, therefore, that the rocks of the Lizard District referred
to in this communication, and which constitute the greater portion
of Prof. Bonney’s granulitic series, are of igneous origin and that
the parallel structure which characterizes many of them has nothing

Fig. 6.

to do with stratification in the ordinary sense of the word, but is
a consequence of the deformation to which the original rock -masses
have been subjected. It is undoubtedly true, as Prof. Bonney
has pointed out, that many of the rocks are largely composed of
broken crystals, and may be said therefore to possess a clastic
structure if we use the term clastic in its etymological sense. But
this is no proof that the fragments have been deposited as such.
The original minerals may have been broken during the deformation
of the rock-masses. This I believe is what has actually taken place.

ES GAS
SETUV AN Nee

Parn Voose i ocally k
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Cove, : Pen*Voose

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Geological Map of Coast near Landewednack. Scale 25 inches to the mile.
To illustrate Mr. J. J. H. Teall’s paper.

Prof. T. Sterry Hunt—Elements of Primary Geology. 493

The structures are of the kind for which Prof. Kjerulf* has pro-
posed the term cataclastic.

I doubt whether any true clastic (epiclastic*) rocks occur in the
Lizard District south of St. Keverne.

EXPLANATION OF ILLUSTRATIONS.

The map is merely intended to enable readers to form some idea of the relations of
the rocks in the district especially referred to in the latter part of the paper, and to
fix the exact localities from which the illustrations are taken. The actual phenomena
are too complicated to be accurately represented even on the 25 inch scale At the
point marked A an ‘‘eye”’ of gabbro foliated at the mazgin and measuring about
five or six feet in length may be seen in the ‘‘ granulitic”’ series. Figs. 2 and 3 are
reproductions from photographs taken at B. Fig. 5 represents a portion of the cliff
face about nine feet in height; Fig. 6 another portion about four feet. The crumpling
of the bands is well seen in the negative, but has not been very successfully reproduced
in the figure. Fig. 1 is froma photograph taken at C, where the banded gneissic
series and the gabbros are seen in juxtaposition. It represents a portion of the cliff
about 8 feet in height. The line representing the boundary between the gneissic
series and the gabbro should have been brought to the point C. This figure
illustrates very well the manner in which the light-coloured granitic rock veins the
dark-coloured diorite. It must be remembered that Figures 1, 2, and 3 represent
portions of the same rock mass. If the rocks are igneous at C as seems to be
proved by Figure 1, they must also be igneous at A and B. The point C is the
point where a granite vein is indicated on the geological map of the district.

IIl.—Etements oF Primary Gronoey.?®
By T. Srerry Hunt, M.A., D.Sc., LL.D., F.R.S.

1. NDER the general terms of Primary and Original, given by

Werner and others, to the early crystalline rocks, have been
included various mineral aggregates which may be classed under
three heads: 1. The great stratiform masses of aqueous origin,
essentially granitic, and formed by slow deposition at the earth’s
surface, which I have called Indigenous rocks. 2. Those lesser
crystalline masses which were formed under similar conditions to
the last, but within veins or fissures in pre-existing rocks, and may
therefore be cailed Endogenous. 3. Rocks resembling the last in
their geognostic relations, and often confounded with them, but
distinguished by the fact that they have come into their present
positions not by deposition from solution, but by displacement in a
more or less fluid or plastic state. These Exotic or erupted masses,
whether ancient or modern, are in a sense Primary, since they
sustain, in one way or another, intimate relations to the more ancient
rocks to which this name was first given.

1 Grundfjeldspsrofilet ved Mjqsens sydende, Nyt Magazin, 1885, p. 214.

2 Some modification in the use of the term clastic is rendered necessary by recent
discoveries. I venture to suggest that it should be applied to all rocks which consist
largely of mineral fragments and that we should distinguish between the three types
of clastic rocks at present recognized by using the terms epiclastic, cataclastic, and
pyroclastic. Epiclastic—Rocks formed of fragments resulting from the breaking up
ot older rocks occurring won the earth’s surtace. Cataclastic—Rocks largely com-
posed of fragments produced during the deformation of older rocks by the earth-
stresses. Pyroclastic—Fragmental rocks of voleanic origin. The same terms may
be applied to the structures which characterize the rocks in question.

3 Paper read before Geological Section, British Association, Manchester, 1887.

494 Prof. T. Sterry Hunt—Elements of Primary Geology.

2. The history of the origin of all these rocks is one of evolution
through successive differentiations. The transformations of the
primitive igneous material of the earth’s crust, through the action
of air and water, aided by internal heat, present a mineralogical
evolution not less regular, constant and definite in its results than
the evolution apparent in the organic kingdoms. The nature of
this very complex operation, and its various stages, the writer has
elsewhere endeavoured to set forth at length, and the object of the
present note is to state concisely, and in an elementary form, some
conclusions and generalizations reached after forty years of study;
referring the reader for details to his recently published volume
entitled Mineral Physiology and Physiography. It may, however, be
said in a few words that the protoplasmic mineral matter —which we
may define as the superficial portion of a cooling globe solidifying
from its centre—was, so soon as its surface became sufficiently re-
frigerated, the subject of a double series of processes. These included
(1) the removal from its mass by solution, through permeating
waters, of the elements of the Neptunian, or as I have elsewhere
named them, the Crenitic, crystalline and colloidal or porodic agere-
gates ; (2) the modification of the residue by this watery lixiviation,
removing silica, alumina and potash, and when sea-water intervened,
bringing in lime, magnesia and soda in exchange ; and farther by the
crystallization and partial differentiation through the influence of
gravity, and by eliquation, of more or less altered portions of this
primitive mass, resulting in the production of various types of
properly igneous or plutonic rocks.

3. The continued removal therefrom of the elements of the great
succession of crenitic rocks, which were laid down upon its surface
alike as indigenous and endogenous masses, caused a progressive
diminution in volume in this water-impregnated primitive plutonic
stratum; which must not only have produced a profound corrugation
of its earliest crenitic envelope, but through the succeeding ages of
the duration of this operation, have given rise to that generally
folded and inclined attitude, with frequent discordances, which
characterizes the Primary stratified rocks, while it is only occasional
and accidental in Secondary strata. With the decline of crenitic
action the weight of accumulated strata apparently brought about the
plutonic and pseudoplutonic eruptions; which appear to have been
rare in the earlier periods, but in later times to have replaced the
previously continuous upward transfer of matter from the primitive
plutonic substratum by the process of aqueous solution. In thus
indicating what must have been in early periods a potent agent in
producing corrugation and disturbance of strata in the crenitic rocks,
it must not be forgotten that from the beginning to the present time
the contraction of the terrestrial anhydrous nucleus from secular
refrigeration has also doubtless been a factor therein not to be over-
looked.

4, The crenitic masses present in successive ages marked variations
in mineral type, which furnish the basis of a chronological classifi-
cation having regard especially to the relative proportions of silica,

Prof. T. Sterry Hunt—Elements of Primary Geology. 495

alumina and alkalies in the masses. In the study of these rocks
as members of great succeeding groups, it is however necessary to
take account of the products, SIS soluble and insoluble, of the
subaerial decay of previously exposed masses, both crenitic and
plutonic, of the frequent intervention of sea-water bringing mag-
nesian salts, and also of the direct and indirect intervention of
products of organic life; all of which have caused at different
periods variations in the constitution of the rock-masses generated.
From these considerations it will be apparent that no series of
deposits subsequent to the ancient granitoid gneisses can ever have
possessed the same degree of uniformity and of universality as they.
Variations from causes already assigned appear also in the constitu-
tion of the plutonic rocks of successive ages.

do. Types of silico-aluminous :crenitic rocks which are rare at a
given period become more abundant in a later time, and subsequently
disappear. ‘The earlier types recur locally and less well character-
ized in later ages. From this it results that in the mineral as in
the organic world, generalizations as to chronological classification
must be based upon the mineral characters of the group considered
as a whole, and not on those of individual varieties. Rocks not
including aluminous silicates,—such as quartz, carbonate of lime,
iron-oxyds and protoxyd silicates,—recur with slight variations at
very widely separated periods in geologic time.

6. The operations of solution and deposition, and those of sub-
aerial decay and disintegration during the earlier ages went on
under geographic conditions not very much unlike those of later
periods, so that in the great series of crenitic rocks certain groups
are often absent; in some cases from non-deposition, and in others
from subsequent erosion connected with movements of elevation and
depression. From these causes, as well as from the universal con-
traction of the underlying plutonic stratum, due to the crenitic
process, stratigraphical breaks and discordances exist among the
crenitic strata as among the sedimentary rocks of later ages. All
such phenomena in stratigraphy, at whatever period recurring, are
however but local and accidental interruptions of the normal order
of mineralogical development.

7. The great groups of stratiform crystalline rocks, which every-
where appear as the substratum of the uncrystalline sediments,
are essentially neptunian or crenitic in origin, and the few plutonic
masses of pre-Paleeozoic age have no other significance in the litho-
logical history of these groups than that which comes from the fact
that portions of these plutonic masses, or the results of their
subaerial decay, occasionally intervene in the formation of the
crenitic rocks, Their importance as factors in primary geology
is so small that their exclusion therefrom by Werner and his school
was an error much less grave than those of the endoplutonic and
exoplutonic schools, and especially of the latter; which, in its extreme
and logical form, assigns an eruptive origin to the whole category
of crenitic rocks, including gneisses, samtics, steatites and SEES,
and even quartzite, iron- oxyds and limestones.

496 Prof. T. Sterry Hunt—LElements of Primary Geology.

8. If we restrict the term eruptive to such rocks as have
evidently come in a fused or plastic condition into their position
among and above previously formed masses, we may on miner-
alogical grounds divide them into two classes.

I. Rocks consisting essentially of basic silicates, including much
alumina, lime, magnesia, and férrous oxyd, of which dolerite is
the type. These we regard as portions of the primitive plutonic
mass, which however, as already explained (§ 2), has, through
successive ages, become more or less modified alike by additions
and subtractions through the crenitic process, and by crystallization
and partial eliquation, thereby giving rise to the considerable
variations in composition met with in these basic rocks in different
areas and in different periods. The stratiform arrangement of the
elements of these, due to movements of flow, occasionally met with
in such masses, simulates, as is well known, the structure of
stratified crenitic masses. This has led some theorists to assign
to these plutonic rocks an aqueous and so-called metamorphic
origin; while the same resemblance has been, alike by endoplu-
tonists and exoplutonists, made an argument for maintaining
a plutonic origin for all stratiform crystalline rocks.

II. Besides the basic eruptive rocks, which are to be regarded
as truly plutonic, are those mineralogically very unlike masses
which resemble in composition the predominant type of the earlier
crenitic rocks, and are often confounded with them. Such are the
trachytes and the clearly eruptive granites, which, it is maintained,
are but softened and displaced portions of older crenitic masses,
and may be designated pseudoplutonic rocks.

9. Besides these masses of once softened and plastic material
—whether plutonic, or pseudoplutonic and of crenitic origin—
which have been erupted after the manner of lavas, there are two
other kinds of rock-masses, which, from their geognostic relations,
are frequently regarded as eruptive. Of these the first is the
veinstones or endogenous rocks—alike quartzose, calcareous and
granitic—already mentioned (§1), themselves of crenitic origin,
and formed, although in fissures or cavities, under chemical con-
ditions not unlike those which gave rise to the greater masses of
non-plutonic primary rocks. As regards the second kind of masses
above referred to, it often happens that disrupted portions of crenitic
rocks have, without softening or change of state, been forced, as the
result of local movements, among softer and more yielding strata.
Such intrusions of rigid amongst plastic masses have in many cases
caused the former to be regarded as rocks erupted after the manner
of lavas.

10. In the case of crystalline or colloidal rocks evidently posterior
to the enclosing material, the question will therefore arise whether
a given mass may be (1) a truly plutonic rock; (2) a crenitic deposit
im situ, aS a granitic veinstone; (3) a crenitic mass from a lower
horizon, which by softening and displacement has assumed a pseudo-
plutonic form; or (4) a portion of rock, either crenitic or plutonic
in origin, which, without having itself been softened, has been forced
among soft and yielding materials, displacing these.

Prof. T. Sterry Hunt—Elements of Primary Geology. 497

These various cases, it is evident, introduced certain apparent
perturbations into the normal order of crenitic rocks, and should be
carefully borne in mind. The many evidences of the displacement
of previously formed crenitic rocks, alike in rigid masses, and in a
softened and plastic condition, are especially worthy of a critical
study. A more careful investigation than has generally been made
alike of the chemical, mineralogical, and geognostical history of the
various silicated rocks, keeping in view all of the above considerations,
will, it is believed, serve to correct some of the extreme views
of certain geologists of the metamorphic schocl, as well as those
of the plutonists.

11. The process of mineral evolution seen in the succession of
the earlier and later indigenous crenitic rocks, and in the veinstones
or endogenous rocks of still later periods, has continued, though with
progressively diminished activity, through Palzozoic and still later
ages down to the present time, as evidenced by the indigenous
silicates sometimes found in Paleozoic rocks, and éven in the
deep-sea ooze and the deposits of certain thermal waters. The
transition from the earliest fundamental granite to the predomi-
nantly uncrystalline sediments of the Paleozoic age is marked
by gradations, so that it is not easy to define the respective limits of
what were originally designated Primary, Transition, and Secondary
rocks. The terms Azoic, Eozoic, and Paleozoic, are for a different
reason equally vague. While organic life undoubtedly existed long
before what is called Palaozoic time, we have no evidence that it
had appeared when the fundamental granite, that is to say, the basal
granitoid gneiss, was laid down; although it is apparent that the
formation of certain crystalline silicates was still active in later
Transition times, contemporaneous with organic life.

A failure to grasp this conception has led geologists of the
Huttonian school to an undiscriminating use of the vague and ill-
defined term metamorphism, which, in the interest of a more exact
science, it would be well to banish from the language of geology.
The extremists of that school have maintained, and still maintain,
that the chemical and mineralogical constitution of the crenitic silico-
aluminous rock-masses has no constant and definite relation to their
age, and that large areas of Secondary sediments have, by a subse-
quent metasomatic change, been converted into mineral masses un-
distinguishable from the crystalline strata of the earlier Primary
periods. Without referring to the fact that recent and careful
geognostical studies have at every point shown the fallacy of the
stratigraphical evidences adduced in favour of this assumption, it may
be remarked that the whole metamorphic hypothesis is an attempt to
substitute a constant intervention of miracle for the orderly and
systematic evolution which appears in the mineralogical history of
the earth’s crust.

The transition above referred to introduces a difficulty into our
terminology, since among the crenitic indigenous masses are included
both Kozoic rocks and others which are apparently pre-EHozoic. Both
the Primary and the Transition of Werner are also included therein.

DECADE III.—VOL. IV.—NO. XI. 32

498 Prof. T. Sterry Hunt—Elements of Primary Geology.

For this reason the often used word Archzan, from its very vagueness
and indefiniteness, is perhaps, in the present state of our knowledge,
the most convenient term to designate the more or less completely
crystalline or colloidal rocks which preceded the essentially detrital
rocks of Secondary time, and by their decay and disintegration
furnished the chief part of the material of these.

12. As a result of all these considerations, the author has been led
to attempt a subdivision of the Archean indigenous rocks into
several chronological groups, which he has often described elsewhere,
and which, in his Mineral Physiology and Physiography, are concisely
treated in a chapter entitled A History of Pre-Cambrian Rocks. It
will therefore be sufficient for the present purpose to recall briefly
the great subdivisions there advocated.

I. Under the name of Laurentian are comprised the gneissic rocks
of the Laurentides, the Adirondacks, the Highlands of the Hudson,
- and much of the Rocky Mountains in North America. These rocks
are divided, so far as known, into a lower granitoid series, often but
obscurely stratified, and without included limestones or quartzites
(the Ottawa gneiss) and an apparently unconformable series of
gneisses, much resembling the last, but with interbedded quartzites,
limestones and iron-oxyds (the Grenville series). The name of
Laurentian was originally (in 1854) made to include both of these,
without regard to the subdivisions; which were, however, pointed
out in 1847, and which we may provisionally designate as Lower
and Upper Laurentian. The latter term, afterwards applied by
Logan to a succeeding series, otherwise called Labradorian, having
been superseded by Norian, the name of Middle Laurentian, which
some have erroneously applied to the Grenville series, or upper
division of the Laurentian, becomes meaningless.*

II. The Norian series, in which stratiform crystalline rocks,
granitoid in structure, nearly or quite free from quartz, and com-
posed essentially of basic feldspars, of which labradorite is the type,
constituting the rocks known as norite, is our next great division.
It, however, includes also occasionally quartzose and gneissic
rocks, together with crystalline limestones, and iron-oxyds, generally
titaniferous. From the resemblance of these gneisses to those of
the Laurentian, and from the few contacts observed, this Norian
division is assigned the second place in the succession. ‘The
characteristic rocks of this series are often called gabbro, but are
widely distinct from the euphotide of the Huronian or Pietre-verdi
series, to which this name was first applied.

III. At the base of the Huronian appears in many regions a great
series essentially composed of petrosilex, often becoming a quartz-
iferous porphyry, and occasionally interstratified with an indigenous

1 Inasmuch as these distinctions were first devised and announced by the Canadian
Geological Survey, it may here be said that its earliest printed reports on the ancient
rocks of the country (those for 1845 and 1846, published in 1847) were prepared from
the notes and collections of Logan and Murray, by the present writer after his
connection with that Geological Survey in February, 1847, and that all subsequent

matters relating to lithology in its reports up to 1872, were either prepared by him
or under his direction.

Prof. T. Sterry Hunt—Elements of Primary Geology. 499

diabasie rock, with sericitic schists, quartzites, iron-ores, and more
rarely with limestones. This, which in concert with Dr. Henry
Hicks, I have called Arvonian, is the Lower Huronian of C. H.
Hitchcock.

IV. The Huronian, which in many regions rests unconformably
upon the Laurentian, or upon the Arvonian, constitutes the great
greenstone or Pietre-verdi group of the Alps, with its characteristic
euphotides, serpentines and chrysolitic and amphibolic rocks. In this’
series the intervention of sea-water is more evident than in the
preceding periods, perhaps for the reason that the sea had become
more magnesian from the results of the subaerial decay of erupted
plutonic masses.

V. The great series of tender fine-grained gneisses passing into
granulites on the one hand and into quartzose mica-schists on the
other, makes what I called in 1871 the White Mountain or Montalban
series. This in many regions rests directly upon the Laurentian,
but it is believed in others to overlie chronologically the Huronian.
I say this with all deference to my honoured colleague, C. H. Hitch-
cock, who, recognizing the fact that the Arvonian and the Huronian
are wanting in many regions between the Laurentian and the
Montalban, and finding above the latter a series of schists which he
refers to the Huronian, maintains that the division is younger than
the Montalban. To this I would reply: First, that my observations
in the Alps, which are in accord with those of Von Hauer, Gastaldi,
and others, are to the effect that the true Pietre-verdi or Huronian
comes chronologically between the older and the younger gneisses,
which two divisions are there indistinguishable from the Laurentian
and Montalban respectively. Secondly, that the Taconian (or Lower
Taconic) series, which alike in the Alps and in North America
overlies the younger gneiss, has in portions a considerable litho-
logical resemblance to parts of the Huronian, to which its schistose
portions are related in character, somewhat as portions of the younger
gneisses with mica-schists of the Montalban are to the lower or
Laurentian gneisses. Hence it was that Murray, Credner, and for
a long time the present writer (who gave the name of Huronian in
1855), confounded the Huronian and the Taconian on Lake Superior..

VI. The great series with quartzites, crystalline marbles, and the
iron-bearing schists of that region which, in 18738, I called the
Animikie series, is, as ] have elsewhere endeavoured to show, identical
with the Taconian, for which it was long ago claimed by Emmons,
and is distinct from the Huronian alike in geographical distribution
and in lithological characters. This Taconian series extends in
eastern North America from the Gulf of St. Lawrence to Alabama,
including not only quartzites and marbles, but siderite and limonite,
and much of the magnetite of Pennsylvania; where it embraces
alike the “ Primal slates” and the so-called “ Altered Auroral and
Matinal strata” of H. D. Rogers. It is also the Itacolumitic series
of Lieber, in the Carolinas, and constitutes, so far as known, the
youngest member of the great succession of crystalline schists.
While parts of the Taconian have thus been confounded with

500 Prof. T. McKenny Hughes—Brecciated Archean Rock.

Huronian, there are not wanting portions of its more schistose
strata which have a resemblance to certain Montalban rocks. Hence
it was that at an early period in the writer’s studies he attempted to
group Montalban and Taconian under the name (soon after abandoned)
of Terranovan. For a detailed account of the whole Taconic con-
troversy, see the author’s Mineral Physiology and Physiography, and
for a more concise statement, but with more new light, “The
Taconic Question Restated”’ in the American Naturalist for 1887.

13. The name of Taconian was given to the Lower Taconic of
Emmons to distinguish it from his Upper Taconic, which is essentially
uncrystalline, and, as shown by its trilobitic fauna, and recognized by
Emmons himself, is clearly Cambrian, and is in some regions directly
overlaid by Ordovician strata. Beneath the recognized Cambrian, in
parts of the North American continent, is a great body of uncrystalline
sediments, which I have designated Keweenian. While newer than
the Taconian, their relation to the unconformably overlying Cambrian
is as yet uncertain.

It is not claimed that the above indicated division of the great
pre-Paleeozoic or Archeean succession is complete. Further study will
probably show that there are other groups, and furnish grounds for
subdividing those here proposed. They are, with small help from
without, chiefly from the generalizations of a single observer during
a period of forty years, and as such are offered as a first attempt at a
classification of the stratified crenitic rocks, and as illustrations of
the process of mineralogical evolution. It must be remembered
that for reasons already assigned (§ 2), none of these groups save
the fundamental granite can be supposed to possess the characters
of uniformity and universality.

TV.—Own Some Brecciatep Rock In tor ARCHHAN OF MALVERN.

By T. M‘Kenny Hueuss, M.A., F.G.S.,
Woodwardian Professor, Cambridge.

Whe question of the origin of the Archean rocks is one of such
great interest that it will not be thought unimportant on the
one hand to record any facts that may bear upon it, and on the other
to examine somewhat severely all the evidence that may be from
time to time brought forward on the subject. Among the facts
which may be adduced in support of the view that the Archean
rocks are altered sedimentary strata, the occurrence of breccias and
conglomerates may well claim a foremost place; and a vast amount
of superincumbent theory must rest on a very shaky foundation if
there be any doubt whether some of those ancient fragmental beds
be true conglomerates or not. The manner of occurrence, the mode
of formation, and the character of pseudo-breccias and pseudo-
conglomerates become therefore questions of first importance.

What one would be at first inclined to accept as evidence of
the conglomeratic character of a bed would be that the included
fragments were rounded, and that they were of a different character
from the mass in which they were imbedded. I have on a former

Prof. T. McKenny Hughes—Brecciated Archean Rock. 501

occasion! discussed this point, and given examples of rocks made
up of fragments differing more or less in character from the
surrounding matrix in cases in which I was able to offer abundant
evidence that these rocks owed their fragmental character to breccia-
tion in place. I explained the pebble-like form of the fragments
by the rounding off of the corners which usually accompanies
infiltration from the joint surfaces, and further pointed out how the
apparent matrix was derived from the alteration of the more finely
comminuted portions of the brecciated mass, and from the decom-
position of the outside portion of the larger fragments.

I am now able, as the result of observations made at various times
on the Archean rocks of the Malvern Hills, to supplement and
extend these remarks.

It might be argued that the modification induced by chemical
change within the mass would be likely to affect equally adjoining
fragments of the same size, composition, etc., and therefore, that, if
the apparently included fragments were of different nature, not
only from the matrix but also from one another, this must be accepted
as evidence that the mass was made up of bits transported from
different rocks and various: localities, especially if the pieces could
be matched among the members of the underlying series.

It would be pointed out that a volcanic brecciated conglomerate
often seems made up of fragments of rock belonging to the very
series in which the agglomerate occurs.

In the Archean rock which rises abruptly from the level of the
New Red west of Malvern Link, near the quarries, there are some
bands of rock (Fig. A B) answering these conditions, which might
easily be taken for a brecciated conglomerate. The included frag-
ments are of various kinds, different from the matrix, and also unlike
one another. Some are coarse light-coloured crystalline syenite,
others close-grained pink felsitic rock. The matrix is a claret-
coloured earthy, homogeneous, felspathic paste, with here and there
a coarser or crystalline structure, or a few imperfect felspar crystals
and grains of quartz. ‘The fragments are often quite rounded, like
shore pebbles. Following the band along its trend we find varia-
tions in the size of the fragments, and in the proportion of the
different kinds, but otherwise its general character prevails as far as
it is exposed.

If, however, we trace this fragmental mass across its trend into the
adjoining part of the rock, we find that the fragments cease to be
round, and their sides are bounded by the continuation of the joints
which affect the whole rock. The claret-coloured matrix disappears,
being represented first by thin bands along the outside of the
angular fragments, then by mere lines of colour along the joints.
The pink felsitic fragments run together, and are at last seen
united in a vein (C D) of compact pink felspar-rock, such as is so
common in the Malvern Archean. Where the vein has got much
broken up and displaced, we find sometimes, on the margin and at

1 Grou. Mac. Vol. X. 1883, p. 306, ‘On the Brecciated Bed in the Dimetian of
St. Davids.”

502 Prof. T. McKenny Hughes—Brecciated Archean Rock.

the sharper folds, even a commingling of fragments of the vein and
surrounding rock.

When, moreover, such fragmental beds are observed to coincide with
the trend of the ridges, and with the larger divisions of the series
which are supposed to represent original differences in the succession,
this may be urged as an argument in favour of the conglomeratic
character. But in any folded rock the chief crush is apt to run
along and be confined to the central portions of the folds, so that
the bands of breccia caused by it must necessarily coincide in direc-
tion with the trend of the ridge and the strike of the succession of
rocks of which the mass is made up, and any rock having a different
texture in successive portions, whether original or superinduced, will,
during earth-movements, behave just like a sedimentary rock in
which there is a succession of beds of different powers of resistance.

In the Malvern Hills, as so often elsewhere, the axes of folding
of the older rocks run slightly oblique to the trend of the ridge.

. ie
wig ean
me igo

goa KC

Diagram sketch of part of band of pseudo-agelomerate in the Archean rocks
of Malvern.
A.B.—Band of brecciated rock. C.D.—Vein of pink felsite.

The margin against which the New Red abuts on the east of the
Malvern Hills was probably determined by pre-existing lines of
weakness, due to faults and crushes in the Archean, but the now
more important but originally less intense movements which took
place after the deposition of the New Red have determined the
existing boundary of that series. But the principal divisional planes
and sequences indicating the direction of the great folds in the
Archean rock run into the ‘hill obliquely to the margin in the
locality to which these observations chiefly refer, namely, the
quarries west of Malvern Link. Along these axes, and therefore
coinciding with what looks most like strike in the Archean, run the
bands of fragmental rock, and thus, if it had not been that we were
able to examine the surrounding rock sufficiently to satisfy ourselves
that the conglomeratic character was deceptive, and to see that the
breccia passed into jointed rock, we might easily have taken this
band as an ancient shingle or agglomerate, to the great confusion of
the evidence already sufficiently difficult to unravel.

Thus it is clear that we may in certain cases have a conglomera-

G. H. Kinahan—Archean Rocks. 503

tic-looking mass composed of rounded pieces of rock differing in
lithological character both from the matrix and from one another,
occurring along what looks like the strike of the rocks, and yet may
be able to make out that it is entirely a superinduced structure due
to brecciation in place and subsequent decomposition of the broken
rock.

From these observations we may also learn another lesson, viz.
that crushing may take place without producing any effects analogous
to metamorphism properly defined, and may act in aid of true meta-
porphism or other chemical change, chiefly by comminuting and
preparing the rock for chemical reaction.

V.—Arcuman Rocks.

By G. H. Kryanan, M.R.I.A., ete.
(Read before the British Association, Manchester, 1887.)

ye the present time the American geologists, both those of the

United States and the Dominion of Canada, are at variance
as to the groups the Archean should be divided into; it is however
unnecessary to enter into this controversy, as the strata may be con-
veniently grouped, as in Selwyn’s map (1884), into Norzans or
Labradorians, excessively coarse gneiss or other granitic rocks ;
Laurentians, gneiss and granite; and Huronians, schists with sub-
ordinate gneiss.

Some of the authorities both in the States and the Dominion
would have us believe that the Archeans originally accumulated as
erystalline foliated rocks; that is, the minerals were deposited by
chemical action from solution. Others, however, hold that at one
time they were ordinary sedimentary rocks, which during one or
more successive periods of metamorphic action were changed into
their present conditions. The present school of English Archean
geologists seem from their writings to coincide with the Americans,
who believe in originally crystalline accumulations.

The facts in favour of the first theory seem to be obscure; we
are indeed told that “chemistry forbids” an ordinary sedimentary
rock changing into a schist, gneiss or granitic rock; yet in the field
we can walk along beds that change from unaltered rocks through
schist into gneiss, and thence into metamorphic granite. Such a
change may be quite contrary to the chemical laws laid down by
such Archzan geologists for their own guidance, but they are patent
facts effected by the Grear Cuemist, and to be ocularly learnt by
any ordinary observer who carefully works out any large tract of
metamorphic rocks.

In connection with this subject the value of lithological charac-
teristics may first be mentioned. It is now generally well known
that any rocks, no matter to what period they belong, from the
newest Tertiaries to the Archean, if they have been subjected
to sufficient metamorphic action, will be changed into schist and
gneiss; that is, that foliation will be developed in them, although
originally they may have been ordinary sedimentary rocks, volcanic

504: G. H. Kinahan—Archean Rocks.

rocks, or even granite. Of course rocks that have once been metamor-
phosed, may again be so placed that they are subjected to a second,
third, or even more periods of action; each, if not too excessive, further
developing the foliation. The American rocks called Norians or
Labradorians have excessively coarse foliation, some of the measured
plates being at least a foot in length; these rocks at one time were
considered on account of their structure, to be the oldest Archzean :
but further research has demonstrated that they are as young, if
not younger, than the associated rocks: as they originally were
protrudes or intrudes, generally the latter, possibly of granite,
into their associated rocks, and that their present structure is
solely due to metamorphic action at successive times. In Ireland
intruded courses and tracts of granite in the Castlebar District, Co.
Mayo, and near Glenties, Co. Donegal, have been altered into a very
coarse gneiss by metamorphic action, while in Slieve Croob, Co.
Down, the margin of the granite intrude has also by a similar process
been changed into gneiss. It therefore appears evident that if any
kind of rock, by sufficient metamorphic action, can be changed into
crystalline foliated rock, such structure or composition by themselves
cannot be taken as a test of the age of the rocks.

Dana, Le Conte, Selwyn, George Dawson, and other American
authorities specially point out that between the American Archean
and the later rocks there are the distinct records of a vast lapse of
time. In the Dominions this is most conspicuous, the unaltered
fossiliferous Primordial or Cambriam rocks lying unconformably
on the Laurentian gneiss, and the Huronian schists; the old rocks
having been tilted, crushed up, metamorphosed and afterwards
excessively denuded, prior to the Primordial or other later rocks
having been deposited on them.

In Europe alone there are in different places representatives of
the different Passage Beds between the different geological groups ;
there are, as Passage Beds between the Cambrian and the Ordovicians,
the Arenig group; between the Ordovicians and the Silurians, there
are the Llandovery or Mayhill Sandstone group; between the Silurians
and Carboniferous, there are the Devonians or Old Red Sandstone, and
so on upwards ; it is therefore natural to suppose, that somewhere on
the face of the globe there are rocks that represent the equivalents of
the Passage Rocks between the Archean and the Primordial; but if.
such rocks occur in England or Ireland, which to me appears very
questionable, they are not the equivalents of any of the American
Archeans, and ought not to be so called, but should be grouped as
‘“‘ Passage Beds” under a new and distinct name.

Except in Scotland, where it has been demonstrated by Murchison,
there are no authentic records of a great lapse of time between the
so-called Archzans and the later rocks. Circumstances have prevented
the writer from being intimately acquainted with the English tracts
now declared to be of Archean age; but he has visited some of them,
and in fact believes he was the first to suggest that the rocks in one
of them might possibly be Archean. Now, however, since the real
Archean rocks have been seen and studied, such a suggestion in refer-

G. H. Kinahan—Archean Rocks. 505

ence to them, or any other tract of English metamorphic rocks, would
bemuch more cautiously given. With respect to the Irish metamorphic
rocks, however, statements can be more confidently made, and to
him it would appear that no rocks in that island are the representatives
of the American Archean, or even of the at present unnamed, or un-
recognized, * Passage Beds” between the Archeans and the Primordial.

Prior to 1878, as has been pointed out in papers published by
the Royal Dublin Society and the Royal Geological Society of Ireland,
first Jukes and Sterry Hunt, and afterwards Murchison and the
writer, pointed out that the equivalents of the Laurentian rocks might
exist in places in the provinces of Connaught and Ulster (Cos.
Antrim, Tyrone, Donegal, Leitrim, Sligo and Mayo). Subsequently
Hicks suggested that my supposed Cambrians in Tyrone (Slieve
Gallion District) were more probably of Archxan age; while still
more recently Drs. Callaway and Hull have stated “that they have
proved the existence of Archean rocks in different places. But
none of the tracts so exalted have the characteristics considered
essential by Dana, Le Conte, etc., as nowhere in Ireland are there
records of a great lapse of time between the accumulation of the strata
said to be Archean and those of Cambrian or Ordovician ages.

As to the rocks at Greenore and Kilmore, Co. Wexford, said to be
Archean, the first are evidently a metamorphic protrude of exotic
rocks, and the second are interstratified with their fellows; the
rocks in both cases being so intimately intermingled that it is
absurd to attempt to separate them; here therefore there is no
record of a vast lapse of time between the Archzans and Primordials.

In North-west Ireland, that is, the portions of the Provinces of
Connaught and Ulster, between Galway Bay and the eastern boun-
daries of the Cos. Londonderry and Tyrone, there was one large
tract of metamorphic rocks. This has now on it, in places, patches
of Silurian and Carboniferous rocks, thus dividing it up into subor-
dinate tracts; yet the connection between all of them is very
conspicuous and can be easily traced out.

In Ulster there is an unconformability in these angemmerpits
rocks; but some of the strataabove and below this unconformability
have general characters so similar that it is disputed by some; the
so-called Archean are a portion only of the rocks below the uncon-
formability. In places both in Ulster and Connaught portions of
both the older and later rocks are unaltered, and contain fossils or
markings that are considered to be fossils.

In North-west Galway and South-west Mayo, in the unaltered
portions of these rock-tracts, there are fossils of Llandeilo
types, and after tracing the equivalents of these fossiliferous rocks
northward and north-eastward through North-east Mayo, Sligo,
and Leitrim, into Donegal, Tyrone, and Londonderry, it induced
the opinion, published some years ago (1878), that the later rocks in
Ulster, that is, those above the unconformability, represented the
upper portion of the Irish Ordovicians (Volcanic and Slate Series),
and perhaps in part the Llandovery (Passage Beds between the
Ordovicians and Silurians) ; while the strata below the unconformability

506 G. H. Kinahan—Archean Rocks.

are the equivalents of the Arenig (Passage Beds between the Ordo-
vician and Cambrian) and part of the Cambrian; the lower portion
of the Ordovician (Dark shale series) being absent. And if the
markings near Fintown, Co. Donegal, in the black shales belonging
to the rocks below the unconformability (gneiss and schist series), which
were exhibited at the British Association Meeting, Birmingham
(1886), turn out to be Graptolites of Arenig types, as some consider
them, such evidence ought to prove the correctness of this sugyestion.
This classification originally was made from petrological or strati-
graphical evidence.

The Galway area, declared to be of Archean age, is as follows.
To the south-east granitic-gneiss with metamorphic and intrusive
granite; these are margined by gneiss and schist; while in the
western portion of the area there are rocks, principally argillaceous,
very slightly altered, with intrudes of granite. The south-east
granitic-gneiss can be traced, first northward, then north-westward,
through schist into the ‘“‘Doolough bed,” in the neighbourhood of
Killary Harbour; the latter rocks having in them fossils of Llandeilo
types; while westward this granitic-gneiss can be traced through
schist into the slightly-altered rocks margining the western coast.
The latter rocks have all the characteristics of the “ Doolough beds,”
although fossils have not as yet been found in them.

The supposed boundary of the Archean area is an arbitrary line
drawn nearly westward from Clifden to Oughterard; while both
north and south of this line the major portion of the rocks are
lithologically identical. Therefore there are no records of a vast lapse
of time. Stratigraphically it seems proved, that the so-called Archeans
of Galway, instead of being the oldest rocks of the country, are the
equivalents of the latest Ordovicians.

‘In North-west Mayo (Hrris) the tract that has been given a brevet
rank isa patch of granite and gneiss, in sub-metamorphic rocks. Here
there is a marked distinction between the lithological character of
the rocks ; but there are no records of a lapse of time, as there is
no basal conglomerate in connection with the sub-metamorphic
rocks, which the description given in the Geological Survey Memoir
has led some to believe. The rocks in this tract have undergone
much more metamorphism than those in the adjoining county,
which led Griffith to believe they were older; possibly they may be
of Archean age—or the still-unnamed Passage Beds; but it seems
more probable that they are of the same age as the rocks in North-
east Mayo and South Donegal, which are as much, if not more altered,
and whose age probably is either Arenig or Cambrian.

In North-east Mayo, Sligo, Leitrim, and Donegal, there are no
hard boundaries to the tracts of the so-called Archeeans; as the
rocks in general graduate one into another, except in a few
places where faults or intrudes occur. So gradual is the change,
that the supposed boundaries have several times been changed. In
fact, they are like the rolling fences of a farm adjoining a common,
one time here and another time a quarter of a mile or more away ;
yet, in reference to the Archean boundary, each successive line is

G. H. Kinahan—Archean Rocks. 507

said to be an “undoubted line of a double hiatus!!! the rocks on
one side being Archean, and on the other the equivalents of
the Ordovicians.” Yet on both sides of such boundaries there are in
places identical rocks; this difficulty has, however, been got over by
mapping all rocks inside the lines as gneiss, and those outside as
schist—regardless of their lithological characters.

If the Fintown markings are not fossils, all the rocks below the
unconformability may be of any age, from Arenig to Archean, but all
must be included, as they are portions of one regular series. They,
however, cannot be the American Archean, but, possibly, under such
circumstances (that is, the Fintown markings not being fossils), they
may represent the unnamed passage beds between the Archzans and
the Primordial.

In the Co. Tyrone, the rocks of the Slieve Gallion district are
more or less similar, lithologically, to the Huronians of Ontario. To
the south of them there is a well-marked break in time between
them and the fossiliferous “ Pomeroy beds” (Llandovery ?). North-
ward they are bounded by schistose rocks that lie on them uncon-
formably ; yet, but for this unconformability, the rocks above and
below it are lithologically so similar, that they might be con-
sidered as belonging to one group. These Slieve Gallion rocks,
although having lithological and other characters that might possibly
suggest an Archean age, are evidently, as has been pointed out in
previous writings, the eastern extension of the rocks of the Pettigoe
District, South Donegal, in which case they belong either to the
Arenig or the Cambrian. The Pettigoe rocks in the new classification
have not been given a brevet rank, but are said to be the equivalents
of the Ordovicians.

The most northern portion of Ireland, Innistra Hull, off Malin
Head, Innisowen, Co. Donegal, consists of gneiss. Possibly this
may be a bit of the Laurentian Hills, separated by a convulsion of
nature and strayed away, to be stranded and find a home off the
coast of Ireland. More probably, however, it is of Arenig age.

It should be mentioned that the natural unconformity in the meta-
morphic rocks of Ulster is treated very cavalierly ; as in some places
it is recognized and pointed out as “the undoubted proof of the
Archean age of the rocks below it,” while in all places where its
position proved that the gneiss and schists below it must be portions
of one and the same series, it is ignored and is said not to exist. It
may also be interesting to record, that the two advocates for the
presence of Archzeans in Ireland are at variance; as the one rejects
the idea of there being Archzeans in South-east Wexford, while the
other seems to say that there cannot be Archzeans in Donegal, as the
so-called ‘“‘ Laurentian gneiss” is an intrusive mass.

508 A. Smith Woodward—A ffnities of Cyclobatis.

VI.—Norrt on THE AFFINITIES OF THE SO-CALLED “'ToRPEDO”
(CyctozaTis, HGERTON) FROM THE CRETACEOUS OF Mount
LEBANon.!

By A. Smire Woopwarp, F.G.S., F.Z.S.,
of the British Museum (Natural History).
i a paper read before the Geological Society in 1844,” Sir Philip

Egerton made known an interesting fossil Selachian from the
Cretaceous beds of Mount Lebanon, which he named Cyclobatis
oligodactylus, and referred to the Torpedinide, in consequence of its
apparently unarmed skin and the resemblance between its general
form and that of the familiar electric Torpedo. Six years afterwards
Pictet* figured and described a second specimen of the fish, adding
some further particulars of the skeleton, and adopting Egerton’s
determination of its affinities. And quite lately,t Mr. James W.
Davis has made another contribution to our knowledge of the genus,
by describing a larger and more robust species under the name of
C. major. The fish is again relegated to the Torpedinide, and, so
far as I have been able to discover, the same original determination
has been universally adopted up to the present time.

The fine series of specimens now in the British Museum, however,
appear to afford conclusive proof that the imperfections in Sir
Philip Egerton’s original fossil led to an erroneous interpretation.
I have recently determined that the skin was far from unarmed ;
and a comparative study of the fins has shown that they are totally
distinct in character from those of all known genera of Torpedos,
while they approximate in a striking manner to those of the ‘‘ Sting-
rays” or Trygonide. There seems, indeed, to be no doubt whatever
that Cyclobatis is truly a member of the last-named family; and
there are four principal reasons why this position should be assigned
to it rather than that to which it has hitherto been referred. ‘These
reasons may be concisely stated as follows.

1. The pectoral fins are uninterruptedly continued to the end of the
snout, and were thus probably confluent in front. This, as is well
known, is one of the main characters of the Trygonide, but it is a
condition apparently never met with among the Torpedinide. I
have examined species of all the genera of the latter family, except
Discopyge, and find that, in no case, do the cartilages of the pectoral
fin extend in advance of the antorbital.

2. The pelvic arch is placed far forwards, and the rays of the pelvic
jins scarcely extend posteriorly beyond the extremity of the pectorals.
Though perhaps not of such fundamental importance as No. 1, this
peculiarity is much more suggestive of the Trygonide than the
Torpedinide, the living examples of the former often exhibiting it,
but the latter rarely or never.

1 Read before Section C, British Association, Manchester, 1887.

Sir P. Egerton, ‘‘ Description of a Fossil Ray from Mount Lebanon (Cyclobatis
oligodactylus),’’ Proc. Geol. Soc. vol. iv. pp. 442-446, pl. 5.

°F. J. Pictet, ‘‘ Poissons fossiles du Mont Liban,’’ 1850, p. 54, pl. x. fig. 4.

4 J. W. Davis, “The Fossil Fishes of the Chalk of Mount Lebanon, Syria,’
Trans. Royal Dublin Soc. [2], vol. iii. (1887), p. 491, pl. xxi. fig. 1.

A. Smith Woodward—A fiinities of Cyclobatis. 509

3. There are no traces of median fins.—In the Torpedinide, these
fins are always more or less developed, one or two dorsals being
invariably present, except in Temera, and in this genus the caudal
fin is well represented. In the Trygonide, on the other hand, the
presence of median fins is an exception to the general rule, dorsals
never being met with, though sometimes replaced by barbed spines.

4. The skin is armed with spinous tubercles. Though not previously
observed, the National fossils demonstrate very clearly that the
dorsal surface of Cyclobatis was provided with at least one median
row of prominent spines, and there are numerous minute prickles
scattered both over the trunk and fins.

The larger tubercles are best seen in the type-specimen of C.
major (the rough impressions of a few being shown in Miss Wood-
ward’s drawing, loc. cit.) ; in another fossil (B. M. No. 49514) which
Mr. J. W. Davis has also labelled as pertaining to the same species ;
and in an incomplete specimen of C. oligodactylus (No. P. 99). The
first of these shows that the series was continued forward almost
as far as the pectoral arch, though the tubercles in advance of the
pelvic arch appear to have been much smaller than those behind,
and they succeed one another at short intervals. Each of these
dermal defences is oval in form, rising into a sharp spine; and those
placed more anteriorly have the base radially crimped, while the
posterior examples seem to have been smooth, with the spine much
more laterally-compressed and thorn-like, and the apex directed
backwards. In one small fossil (No. 49557), of doubtful species,
the tail has the appearance of being completely encased in rows of
the tubercles.

The minute, irregularly-scattered prickles may be most satisfactorily
studied in Nos. 49556, 49557, and 49514, their shape and characters
being best displayed by the first-named, and their distribution by the
two latter. Hach of them seems to consist of a small erect, or back-
wardly-directed, spine, fixed upon a rounded, radially-marked base,
being, in fact, a miniature of a larger tubercle, but higher in
proportion to its size. There are some indistinct traces of these
structures in Egerton’s original specimen of C. oligodactylus; and
the example of C. major (No. 49514) already referred to shows
them densely arranged upon the margins of the pectoral fins. I
have discovered no other dermal calcifications, except the teeth;
and the “small hexagonal shining dermal ossicles,” mentioned by
Mr. Davis (loc. cit.), are evidently the superficial calcified tesserze of
the endoskeletal cartilage.

None of the living “electric rays” are known to have the slightest
trace of dermal asperities, whereas the presence of these is a marked
feature of certain Trygonide—especially the genera destitute of
barbed caudal spines; and the facts just recorded are therefore
corroborative of the inferences drawn from the three previous
considerations, namely, that it is to the Trygonide rather than to
the Torpedinide that Cyclobatis must be referred.

It would thus appear that there is still no evidence of the existence
of Torpedoes in times anterior to the Eocene; and the earliest

510 Clement Reid—Isle of Wight Tertiaries.

undoubted members of this family hitherto discovered, are the
species made known by Volta* and Baron de Zigno’ from the fish-
beds of Monte Bolca, near Verona.

VII.—Tue Extent or rae Hempstead Beps 1n THE Isum or WIGHT.
By Crement Reztp, F.G.S.
(Communicated by permission of the Director-General of the Geological Survey.)

WING to the impossibility of making an accurate Survey of

many of the flatter and Drift-covered portions of England, in

the absence of sections, the light boring tools so extensively used

by the Geological Survey of Belgium have been experimentally

tried during the last few months in the Isle of Wight. The results

arrived at are of so much interest that the Director has requested me
to draw up this preliminary notice.®

The Hempstead Beds, which were thought to be confined to the
outlier at Hempstead Cliff and another of unknown extent in Parkhurst
Forest, prove to be much more important, indeed they occupy about
half the Tertiary area of the Isle of Wight.

To find their limits series of borings were made, radiating in different
directions from the highest points in Parkhurst Forest. These proved
that the whole of the deposits there represented belong to the
lacustrine Middle and Lower Hempstead Beds, for there was no trace
anywhere of the Corbula or Cerithium plicatum zones. The ‘“‘ White
Band” was met with in several places in the lower part of the
Forest, but the outcrop of the “Black Band” (the base of the
Hempstead Series) is a long distance away. It was found—with
abundance of its characteristic fossils—less than half a mile from
the Chalk, at Gunville, one mile west of Newport, and was traced
eastward through Newport to Brading, always parallel with the
Chalk, and dipping at high angles away from it. The northern limits
pass near Ryde, Wootton, Osborne, and across the Medina to Gurnard,
Newtown, and Hempstead.

Though no Hempstead Beds seem previously to have been noticed
in the East Medina, they are very well represented there, and must
be nearly 200 feet thick. At Wootton there is a small outlier, over
20 feet thick, of the higher estuarine beds full of Cerithium plicatum,
C. elegans, and Melania inflata; but I have not yet succeeded in
finding any relic of the Corbula Beds. Below this are mottled clays
with Unio, ete., for about 50 feet, resting on thick sands, which in
the Hast Medina seem to represent the base of the Middle Hempstead
Beds. Beneath the sands is another series of mottled clays with
Paiudina lenta and Cyrena semistriata. These are about 80 feet thick,
and have at their base the “Black Band.” 'The Black Band and
shales immediately above are very fossiliferous at Newport and

1 Volta, ‘‘ Ittiolitologia Veronese,” 1796, p. 251, pl. 61.

2 A. de Zigno, “‘ Annotazioni Paleontologiche,” Mem. R. Istit. Veneto, vol. xx.
(1877), p. 452, pl. xvii.

3 Full details will be given in the new editions of Mr. Bristow’s ‘‘ Geology of the’

Isle of Wight,’’ and of the Geological Map—which, however, cannot appear for
some months.

Prof. T. McKenny Hughes-—Bursting Rock-surfaces. 511

Wootton, and are full of the characteristic Hydrobia Chastellii, H.
pupa, Neritina tristis, Modiola Prestwichii, ete.

Borings on each bank of the Medina prove that the Hempstead
Beds cross the river unaffected by any fault, as also does the
Bembridge Limestone at Cowes. The singular rise of the Osborne
Beds at East Cowes, which has always been taken to indicate a fault,
is caused by the intersection at right angles of two undulations, which
produce a skew dip. Building operations at East Cowes show that
the Limestone falls from Osborne to the bank of the Medina, where
it can now be examined on the foreshore nearly opposite the
exposure on the left bank of the river.

The Bembridge Marls also prove to be of considerably greater
thickness than was formerly thought; they probably average about
120 feet.

VIII.—Burstine Rock SurFaczs.
By Prof. T. McKrnny Huecuss, M.A., F.G.S.

‘ee interesting note by Mr. Strahan in the Gxon. Mace. for
September, 1887, on explosive slickensides, reminded me of
some similar phenomena which were not of unfrequent occurrence
near Dent Head and Ribble Head in Yorkshire.

In the limestone quarry from which the black marble of Dent is
procured the workmen found that, when they were quarrying the
lower beds and struck the rock with a pick or bar, fragments flew
up into the air with greater force than could be due to their blow
and in an unexpected direction.

Also, when the tunnel was being made above Ribble Head, and
the workmen were engaged upon the bed of rock which formed the
floor of the tunnel, pieces used to burst off with a loud noise, so
that some thought they had discovered a detonating shale.

The explanation in both these cases seemed to be that the bed
which was apt to shell off in that unexpected manner rested on shale
which yielded to the superincumbent weight on either side, and
produced in the tunnel, or in the quarry, where the overlying rock
had been removed, what would be called in a coal-mine a “creep”
(see Woodcut).

Diagram showing the manner of occurrence of Bursting rock at Dent Head and
Ribble Head in Yorkshire. a@ rock. 6 shale; the arrows denote the direction of
the pressure.

The shale behaves as a thick fluid or viscous mass, and transmits
the pressure and motion. But in the cases to which I refer, a thin
bed of the solid rock was left above the shale. This was not com-
pressible, but, where, in the tunnel or in the centre of the quarry,

512 R. Lydekker—On Hyleochampsa.

the weight of the overlying rock had been removed, it rose in a
slight arch over the upthrust shale, and was thrown into a state of
tension, so that when struck, chips and flakes, and sometimes larger
pieces, would fly off. These pieces were in themselves quite sound.
It was not that the whole mass was like Rupert’s drops in a state of
molecular unstable equilibrium, as suggested by Mr. Adam, and
supported by Mr. Strahan in the case of the explosive slickensides,
but it was rather analogous to the effect of drawing a knife across
the outside curve of a bent stick; when jagged ends spring off and
stand out straight in the original direction of the unbent stick—only
in this case the fibrous character of the material prevents the pieces
breaking away altogether as if it were rock. That the conditions in
the case of the explosive slickensides were similar to those at Dent
Head Quarry and the Ribble Head tunnel seems probable from the
observation of Watson that “this phenomenon has not been noticed
from slickensides where no shale is incumbent,” and also from the
suggestion of Phillips, “that the removal of one side of a vein would
leave the remaining side in a condition of strain resembling that of
a strung bow, with a tendency to bulge outwards into the workings.
The undercutting would free, so to speak, one end of the bow.”

But the observations at Dent Head Quarry and Ribble Head tunnel
would show that it was not merely a bringing down of the mass of
the vein stuff when undercut that was remarkable, but rather the
tendency to shell off in chips and flakes over the whole surface.
The beds at Dent Head and Ribble Head were approximately hori-
zontal. Also it would appear from analogy that what the vein stuff
did was not to offer a material more readily burst up, but a mass of
the form and extent which could be bent by settlement of the sur-
rounding rock so as to be thrown into a state of tension all over the
exposed surface.

In connection with these inquiries we must always remember that
time is an element in the bending of rocks, and that it is the rapidity
of the action due to the artificial removal of the overlying mass that
causes the rock to break rather than to sag and retain its curved
form, as we see so commonly among the contorted strata where
nature has applied the pressure more gradually.

ITX.—NorTE on HytxocHAMPsA.
By R. Lyprxxer, B.A., F.G.S.

i ie my paper on Crocodilia in the July Number of the GronocicaL

Magazine, pp. 310-311, I expressed my opinion that the
characters given by M. Dollo in his description of the Belgian
Bernissartia did not appear to me to afford grounds by which that
form could be distinguished from Hyleochampsa, and I accordingly
observed in a note that the onus of proving the distinctness of the
former rested with its describer. In a note published on pp. 394—
396 of the September Number of the Macazinz, M. Dollo replies
to this criticism, and shows conclusively that the Belgian form is
entitled to specific, and very probably to generic distinction from the
larger English one.

kh. Lydekker—On Hyleochampsa. 513

In respect, however, to the serial position of Hylwochampsa, there
is no question whatever but that it must be regarded as one of the
most specialized members of the Goniophiloid Crocodiles, and from
the backward position of the posterior nares and the small size of
the supratemporal fosse that it is probably allied to Bernissartia.
In my original paper I purposely refrained from quoting Sir R.
Owen’s description of the orbito-temporal region of Hylaeochampsa,
because, either from being misled by the broken edges of the bones
in this region, or from not having at that time directed his attention
to the importance of the features of this part, the Professor’s descrip-
tion is not altogether satisfactory ;1 but the fact is undoubted that
Hylzochampsa has the orbit in as complete communication with the
lateral or infratemporal fossa? as in Crocodilus itself.

Assuming that Hyleochampsa be distinct from Bernissartia, the
question will then arise whether the proccelous vertebre of a small
Crocodilian from the Wealden both of Sussex and the Isle of Wight
described by Prof. Seeley in the Quart. Journ. Geol. Soc. vol. xiii.
p- 212, pl. xii. figs. 7-8, under the name of Heterosuchus valdensis,
may not belong to the former genus. This view occurred, indeed,
to me at the time of writing my above-mentioned paper; but being
then unable to distinguish Hylgochampsa from Sernissartia (in
which the vertebrae are amphiccelous), it could not be advanced.
In favour of it we may observe that it is highly improbable that the
transition from the amphiccelous to the proccelous type of vertebrae
precisely synchronized with the union of the pterygoids beneath the
narial passage, and therefore that it is highly probable that Hylgo-
champsa, in which the posterior nares are only one step removed
from the most specialized type, may have had proccelous vertebre.
I cannot, of course, put forward this suggestion as anything more
than a possible, or perhaps probable, contingency; but it clearly
shows how undesirable it is (as 1 hope shortly to show on another
occasion) in the case of any particular group to form one genus on
portions of the skeleton which are totally unknown in one already
described.

Finally, I may observe that in the scheme of classification given
on page 312 of my paper I proposed the name Crocodilia Vera for
the united Husuchia and Mesosuchia of Prof. Huxley; on further
consideration, however, the term Eusuchia appears such a convenient
one in opposition to Parasuchia, that I think it preferable to retain
this old and well-known name in a wider sense, than to substitute
for it the new one proposed.

' In his reply, M. Dollo enlists Mr. A. 8S. Woodward on the side of the Teleosauroid
nature of Hyleochampsa ; but I am authorized to state that the latter writer merely
followed the lead of Sir R. Owen in this respect, and that having examined the
specimen with me when I was writing the original paper, he was fully convinced of
the relation of the orbit to the infratemporal fossa being of the type obtaining in the
Crocodilide.

* By an inadvertence on p. 310, line 29 from top, of my paper, the words “ chez
celut-ci” are omitted at the conclusion of the quotation from M. Dollo; an omission
which alters the sense of the whole passage. ‘

DECADE III.—VOL. IV.—NO. XI. 33

514 Notices of Memoirs—W. Pengelly— Bench Cave, Brixham.

INROMEITCHtS| Cn ivospVconsSS-

T.—Recrent Researcues in Bence Cavern, Brrxuam, Devon.
By Wiii1am Pencewty, F.R.S., F.G.S8., ete.

S long ago as 1839 the workmen in a limestone quarry on the
southern shore of Torbay, and adjacent to the town of Brixham,
laid bare at the back of the quarry the greater part of a vertical
dyke composed of red earth and angular pieces of limestone. The
quarrying operations, then discontinued, were resumed in 1861, when
the entire dyke was disclosed, and among the materials of an
incoherent part of it which fell down, were found some hundreds of
osseous remains, including skulls, jaws, teeth, vertebrae, portions of
horns, bones, and pieces of bones, identified by Mr. W. A. Sanford,
F.G.S., as relics of the Cave-Hyzna, Wolf, Fox (2 species), Bear,
Wild Bull, Reindeer, Hare, and Arvicola (2 species). The Hyena
was by very much the most prevalent form; but there was nothing
indicating that he found a habitual home there. Not a coprolite was
met with, nor was there a single bone scored with his teeth-marks,
or broken after any of his well-known modes. The entire absence
of anything betokening the existence of man was equally marked.
It must be remembered, however, that the finds then met with were
all from a mass of heterogeneous material which had filled a fissure
nowhere more than two feet wide, and in places not more than a
very few inches—not from a cavern in the proper sense of that term.
Adjacent to the left bottom corner of the dyke was the mouth of
a low narrow tunnel, having a floor of stalagmite and extending
into the hill to an unknown distance, but certainly upward of 30
feet. The proprietor of the quarry declined to allow any scientific
investigations to be made, stating that he meant to make such
researches himself; but this was never done.

In September, 1885, Mr. W. Else, Curator of the Museum of the
Torquay Natural History Society, obtained permission from the
gentlemen into whose hands the property had passed, to make such
explorations as he might find desirable both in the dyke and in the
tunnel; and from that date he has spent on the work all the odds
and ends of time he has been able to command. His more recent
researches have been mainly carried on in the tunnel, where he
found the stalagmite floor, from 6 to 12 inches thick, formed on
a reddish cave-earth, having a maximum thickness of 14 inches, and
lying on a continuous limestone basis. Beyond a few remains of
Hyena nothing of interest occurred in the stalagmite, but the con-
tents of the cave-earth were more numerous and interesting. In
July, 1887, 24 specimens of bone selected from Mr. Hlse’s finds—
21 being from the cave-earth in the tunnel and 3 from the dyke—
were forwarded for identification to Mr. H. T. Newton, of the Geolo-
gical Survey of England, who at the end of a very few days
returned them with a list containing not only the names of the
species to which they belong, but also those of the bones themselves.

Of the 21 from the*tunnel one is a relic of a Fox, while all the

Notices of Memoirs—Prof. Lewis—Eztra Morainic Lakes. 515

others are those of the Cave-Hyena. The three from the dyke
represent the Cave-Bear, Rhinoceros tichorhinus, and a species of Deer.
Among the tunnel finds there were also three coprolites and a solitary
part of a left lower jaw of Hyzna divested of its lower border—two
facts indicating that the Hyzena occasionally visited the tunnel.
Here also was found one, and but one, flint-flake tool. It has the
white colour so prevalent in the tools found in the cave-earth of
Kent’s Hole, and was met with under circumstances admitting of no
doubt of its having been made and used by a human contemporary
of the Cave-Hyzena in Devonshire.

IJ.—On Some Important Extra-Morainio Lakes In CENTRAL
Enouanp, Norta AMERICA, AND ELSEWHERE, DURING THE PERIOD
oF Maximum GLACIATION, AND ON THE ORIGIN OF Extrra-Morainic
Bouuper-ciay. By Professor H. Carvitt Lewis, M.A., F.G.S."

HE lakes so characteristic of all glaciated districts are due to
several causes. Some few are due to an actual glacial scooping
out of the rock floor, many to an irregular deposition of the drift,
by which former watercourses are obstructed, and still others to the
terminal moraine or to the glacier itself. These latter, known as
morainic lakes, may be divided into inter-morainic lakes, moraine meres,
and extra-morainic lakes, according to their position—back of, in,
or outside—the moraine. Hxtra-morainic lakes, if dammed up by
the ice front, are temporary in character, disappearing with the
retreat of the glacier; but, as they may be of enormous extent if the
glacier is large, they may produce deposits of much geological
importance. Instances of such lakes occur in Switzerland, and
ancient examples occur as well in Northern Germany, Asia, North
America, and Central England. They are to be expected wherever
a glacier advances against or across the drainage of a country. Mr.
Belt supposed that Northern Asia was covered by a lake of this
character, caused by the Polar glacier obstructing the rivers flowing
north.

In North America, where the terminal moraine has been accurately
mapped for thousands of miles, deposits of boulder-clay and erratics
occur outside of the moraine, and have been supposed to be due to
an older glacier in the first glacial epoch. But the general absence of
strie or of glacial erosion or moraines in this district prove that a
glacier was not the agent of deposition. Nor are there any traces of
marine life in the deposits. This extra-morainic boulder-clay is
narrow in Pennsylvania, where the author has called it ‘the Fringe,”
but west of the Missouri is 70 miles wide; and in British America,
between the great moraine called the ‘‘ Missouri Coteau” and the
Rocky Mountains, is 450 miles wide and over 1000 miles long. It
only occurs where rivers had flowed toward the glacier, and is
explained as the deposit of great temporary freshwater lakes dammed
up by the ice front, the erratics having been dropped by icebergs.

Similar deposits occur in England outside of the terminal moraine,

1 Abstract of a paper read at the Manchester Meeting of the British Association,
September, 1887.

516 Notices of Memoirs—Prof. Lewis—Ezxtra Morainic Lakes.

and have been the subject of much discussion ; being held by some
to be proof of marine submergence, by others to be the ground-
moraine of a glacier. The ‘great chalky boulder-clay ” is the best
known of these deposits. There are serious objections to the two
theories heretofore advanced to explain this, whilst the hypothesis of
extra-morainic freshwater lakes, dammed up by the glaciers, is
sustained by all observed facts. The most important of these lakes
was one caused by the obstruction of the mouth of the Humber by
the North Sea glacier, whose terminal moraine crosses that river at
its mouth. This large lake reached up to the 400 feet contour line,
and extended southward nearly to London, and westward in finger-
like projections into the many valleys of the Pennine Chain. It
deposited the “ great chalky boulder-clay,” and erratics were floated
in all directions by icebergs. It was bounded in the Vale of York
by the Stainmoor glacier, and Charnwood Forest was an island in it.
At its flood period it overflowed south-westward by torrential streams
into the Severn Valley and elsewhere, carrying the ‘“‘ Northern Drift ”
into the south of England. Other glaciers in England were bordered
by similar but smaller lakes wherever they advanced against the
drainage. Three such lakes were made by the Aire glacier, the
largest of them extending to Bradford. The Irish Sea glacier caused
many similar lakes high up on the west side of the Pennine Chain, and
at its southern end north of Wolverhampton. The overflow streams
from the most southern of these lakes joined those issuing from Lake
Humber in the Birmingham district, characterized by a ‘‘com-
mingling of the drift,” otherwise inexplicable. An examination of the
supposed evidences for glaciation, and for a great marine submergence
in Central and Southern England, shows that neither theory is
sustained by the facts. Thus, the supposed striz on Rowley Rag
prove to be rootmarks or ploughmarks ; those reported at Charnwood
Forest to be due to running water or perhaps icebergs; the supposed
drift on the chalk wolds to be a local wash of chalk flints; the high
level gravels on the Cotteswold Hills to be pre-glacial; the shells
at Macclesfield, Moel Tryfaen, and Three Rock Mountain to be
glacier-borne, and not a proof of submergence; the drift on the.
Pennine plateau of North Derbyshire to be partly made by icebergs
floating in Lake Humber, and partly a decomposed Millstone Grit
or Bunter Sandstone ; and the Welsh erratics on Frankley Hill at a
height of 800 feet to be due to a more ancient glaciation.

The conclusion that the glacial phenomena of England are due
neither to a universal ice-cap nor to a marine submergence, but to a
number of glaciers bordered by temporary fresh-water lakes, is in
accordance with all the observations of the author in England and
elsewhere.

Postscript.—Since the paper was read, of which the above is an
abstract, I have found traces of the existence of a very much older
series of glaciers than those here described. Since the period of
these ancient glaciers, which in many places were more extensive
than the modern ones, earth movements have occurred and erosion
has removed almost all their deposits and generally obliterated the

Notices of Memoirs—Thos. Ward—Subsidence in Cheshire. 517

strie, so that the region subject only to the older glaciation now .
resembles a non-glaciated area. ‘The glaciers and their bordering
lakes described above should therefore be considered as belonging to
the second or last glacial epoch.

III.—Tue History anp Cause oF THE SuspsrpENcES AT NorTHWICH
AND Its NEIGHBOURHOOD, IN THE Sat Disrrict oF CHESHIRE.
By Txos. Waxp, Esq.

lies frequent occurrence of subsidences in the neighbourhood of
Northwich makes it desirable to learn their history and cause.

Northwich overlies extensive beds of salt. These occupy about
three square miles. The first or ‘top’ rock-salt lies at a depth of
about fifty yards from the surface, and is covered by Keuper marls,
and these by the drift sands and marls. Between the two beds of
salt there are 30 feet of indurated Keuper marl. The second, or
‘bottom’ rock-salt, is over 30 yards in thickness. These beds of
salt occupy the lowest portion of an old Triassic salt lake.

The first bed of rock-salt was discovered in 1670, the second in
1781. From about 1730, at which date the river Weaver and the
Witton brook were rendered navigable, until after 1781, all the
rock-salt mines were in the ‘top’ bed, and the whole of these with
one exception have been destroyed, and in almost every case by
water, leaving funnel-shaped nearly circular holes. These are now
filled with water and are known as ‘rock-pit’ holes. The rock-salt
mines are now in the lower bed and very rarely fall in. When
worked to the boundary, water and brine, either or both, break in
or are let in, and the mines are utilized as huge reservoirs.

The falling in of a rock-salt mine is a very rare occurrence, and
subsidences of this kind do not give rise to the reports which are
met with in the newspapers. The first reported destruction of
a mine was in 1750, and from that date to the end of the eighteenth
century every two or three years a mine collapsed. In the present
century, at considerable intervals of time, collapses of mines have
occurred, but these with scarcely an exception were old abandoned
‘top’ mines.

The subsidences which are so destructive in the town of North-
wich and the neighbourhood are entirely caused by the pumping of
brine for the manufacture of white salt. It was only about 1770
or shortly afterwards that the first sinking was noticed; since that
date subsidence has gone on very rapidly, and much destruction of
property has resulted. Large lakes or ‘flashes,’ one of more than
100 acres in area, and of all depths up to 45 feet, have been and are
being formed. Prior to 1770 not more than’ 30,000 tons of salt
were sent down the Weaver navigation ; by the end of the century
it reached 100,000 tons, and in 1880 had increased to 1,087,000 tons.
The whole of this salt was taken off the surface of the first bed of
rock-salt by the solvent action of water. In fact, water is the
instrument used to mine and carry off the salt to the pumping
centre. The brine pumps set up a circulation of the salt water
or brine lying on the rock-salt, which flows to the pumping centres.
The brine thus removed -is replaced by fresh water, which on its

518 Notices of Memoirs—Fox & Somervail—Lizard Porphyrites.

passage to the pump saturates itself taking up sufficient salt to make
a solution containing about 26 per cent. of salt. This continual
removal of salt from the surface of the rock-salt lowers it, and the
overlying earths either follow the diminishing surface continuously,
or else after remaining suspended for a time suddenly fall into the
cavity from which the water has extracted the salt. The brine
currents on their way to the pumping centres form deep valleys
or troughs, and the surface of the ground overlying forms a facsimile
of these hollows. The property on the sloping sides of the valleys
is pulled to pieces and destroyed; the windows and doors all get
out of form owing to the unequal sinking of the various portions of
the house. When, owing to the different nature of the marls and
the abundance of sand overlying them, a sudden sinking takes place,
the hole extends to the surface and swallows up anything upon
the surface—as a horse in a stable, barrels of beer in a cellar, or
water butts and other utensils in a yard. The damage done to
property is enormous, but thus far no human life has been lost.
The most serious part of the matter is that the brine-pumper takes
not only his own salt in solution, but that of all his neighbours over
whose salt beds the water flows, and neither asks their consent nor
pays them for the salt thus obtained. Worse even than this, the
owner of the property overlying the brine ‘run’ suffers most serious
damage to buildings, etc., but can obtain no compensation, because
amongst the number of brine-pumpers he cannot prove who is doing
the particular mischief complained of. This peculiar phenomenon
of subsidence in the salt districts is worthy of more consideration
than it has hitherto received from scientific men.

IV.—On tHE Occurrence or PorpHyritic STRUCTURE IN SOME Rocks
or THE Lizarp Disrrict.! By Howarp Fox and ALEX. SoOMERVAIL.
ROF. BONNEY has described a porphyritic diabase which is
seen on the shore at Polpeor; it cuts, in an intricate manner,
through micaceous and hornblendic schists. The authors have
traced this rock further, and have recognized a porphyritic structure
in many dykes and intrusions along the coast which cut through the
serpentine, and also in the darker bands of Professor Bonney’s
‘granulitic group.’

Descriptions of these various localities were given and illustrative
specimens exhibited. The crystals of felspar are found to be most
numerous in those rocks which lie in the closest proximity to
the gabbros and serpentine. They have their long axes at various
angles, and are mostly small except at Parn Voose, Cavouga, and
Green Saddle. The felspathic and hornblendic lines often circle
round the crystals.

Without discussing any theory as to the true nature and origin of
the whole of the schists, the authors think that the porphyritic
structure so prevalent in the dark bands of the ‘ granulitic group,’
in many of the micaceous and other rocks, as also in the later
intrusions cutting the serpentine, indicate an igneous origin for
many rocks hitherto regarded as schists.

_ 1 See Mr. Teall’s paper, ante, pp. 484-493.

Mr. T. W. Shore—Discovery of Bos primigenius. 519

CO aS] © aN sa Saar

REMAINS OF BOS PRIMIGENIUS RECENTLY FOUND AT
SOUTHAMPTON.

Str,—During the progress of the excavation for the purpose of
forming a new deep water dock of eighteen acres at Southampton,
a fine specimen of the horn cores and part of the skull of os
primigenius has been found.

The river mud with which the excavation begins is of a thickness
varying from ten to fifteen feet, below which a bed of peat resting
on dark angular flint gravel occurs. Both the peat and the gravel
vary in thickness, as the gravel is found more or less in ridges, in
the hollows of which the peat attains its greatest depth. It was
from one of these thick masses of peat that the remains of Bos
primigenius were met with at a depth of nearly twenty feet below
the surface of the mud, which formed the bed of the tidal estuary at
this spot.

The skull was found in one piece, and includes the frontal,
occipital, temporal, sphenoid (with both wings), and tympanic
bones, with fragments of the pterygoids, and of the ethmoids.

The temporal fossz are preserved, and the roof of one orbit, and
part of the other; the zygomatic arches are incomplete.

The breadth of the forehead, across the centre, is ten inches, and
between the orbits about twelve inches. The length of the forehead
as preserved is eleven inches, and the length from the frontal crest
to the base of the occipital bone is ten inches. The circumference
of the cores of the horns at their roots is sixteen and a quarter
inches, and the length of the cores round the curvature about
twenty-nine inches. The width apart of the horn cores from tip to
tip is thirty-four and a half inches.

The specimen has been placed in the Museum of the Hartley
Institution, Southampton. T. W. Sore.

PALHZONTOLOGICAL NOMENCLATURE AND THE TRINOMIAL
SYSTEM.

Str,—An answer given not very long ago in an Examination
paper was as follows, “Physical Geography is the work of God,
Geology is the work of man.” No doubt the candidate who wrote
this answer failed to receive full marks; but since the matter was
brought to my notice, it has frequently occurred to me that the reply
was not altogether inappropriate. Geology and Paleontology are
suffering from such an infusion of new and hard names that the
ordinary reader and even the hard-working student are often
bewildered and baffled in their efforts to comprehend the progress of
knowledge. It is not my intention now to discuss any of the new
terms applied to our formations and their subdivisions; suffice it to
say that most of the suggestions to replace old and well-understood
names would, if adopted, be more likely to place obstacles in the
path of the inquirer than to assist or encourage his studies. What
even more paintully stirs me at the present time is the multiplication

520 Ur. k. W. Haddow—Names of Fossils.

of generic or subgeneric names of Ammonites, and the confusion
that appears to have arisen concerning what have hitherto been
regarded as recognizable species.

It is indeed difficult for the “general geologist” to understand
and remember the subgeneric names of Ammonites, especially when
the form known as Harpoceras concavum has been recently changed
again to Lioceras concavum, and H. Murchisone has become Ludwigia
Murchisone. One cannot help wondering what other changes may
be in store for us. It is, however, still more perplexing to be told
by one who has devoted especial attention to the subject, and who is
in every way qualified to speak with authority, that the form which
is “called by D’Orbigny, Wright, and others Am. serpentinus, and is
so labelled in museums and private collections, is the Ammonites
faleifer of Sowerby.” (See 8. S. Buckman, Grox. Mae. Sept. 1887, |
p- 396.) What is then to become of our “ Serpentinus-beds” ?
Again, the same paleontologist tells us that the occurrence of
Ammonites Jurensis in England is doubtful, in fact he has never yet
ascertained its presence in our strata. (Proc. Cotteswold Club,
vol. ix. part 2, 1887.) What then is to become of our “ Jurensis-
beds” ? Once more, the recognition of the true Ammonites Sowerbyt
appears to be a source of great difficulty to judge by the remarks
made in a recent volume of the Paleontographical Society.
(Hudleston, Introduction to Gasteropoda of the Inferior Oolite.)
Even the “ Sowerbyi-beds ” are in trouble!

The question that perhaps naturally arises to an outsider is this,
cannot these well-known specific names he applied in a sufficiently
comprehensive way to include the forms which the older authorities
recognized under the names of A. serpentinus, A. Jurensis, and A.
Sowerbyi, respectively ?

To go further, would not the adoption of the trinomial system
meet all requirements, and be the means not only of doing justice to
the more minute and exceedingly important observations made now-
a-days, but also of placing the results of this detailed work in a
manner more intelligible to the “general geologist”? It would
seem likely under present circumstances that some collective group-
ing of the many species now made must eventually take place, if
any individuals except the specialists in each department are to
follow the progress of paleontology, or attempt the naming of their
fossils: and this grouping might be done under the trinomial system,
better, it appears to me, than under the system which introduces
subgeneric names. So far as the geologist is concerned, he simply
requires a definition of specific characters, and a key to the distribu-
tion of each species in time and space. Where particular varieties
are confined to special horizons, he can obtain this precise information
on the trinomial system. Moreover, the adoption of that system
would fulfil all the requirements of the biologist. No doubt many
more specimens are available now for study than was formerly the
case, and it becomes more and more difficult to draw rigid lines ;
but there seems to be a tendency to confine specific characters within
narrower limits than heretofore, and this perhaps is the real source

Mr. G. H. Kinahan—Irish Carboniferous Rocks. 521

of the difficulty. I should feel much grieved if these remarks
appeared to convey any slight whatever on the careful work of
modern paleontologists; but my impression is that the object of
their labours will be to a serious extent frustrated if their results
are published in too complex a form for the “general geologist.”
Having said so much about changes of names, perhaps I may be

pardoned if I sign myself, Ros. W. Happow.
Banzury, 8th Sept. 1887.

CHERT IN IRISH CARBONIFEROUS ROCKS,

Sir,—Chert is not, as supposed by Dr. Hinde, a definite character-
istic of the Irish Upper Carboniferous Limestone (see chapter v.
Manual of the Geology of Ireland, C. Kegan Paul & Co., 1878).
Where this limestone is fully represented as in Co. Limerick, ete.,
the “lower cherty zone” is there best developed; and it occurs i
the lower limestone, between the “lower shaly limestone ” and the
“ Fenestella Limestone.” A second conspicuous zone for chert lies
between the Fenestella Limestone and the upper limestone, when of
the “ Calp type.” In the upper limestone of Cork and Kerry there
are layers and nodules of chert, but in Limerick, Tipperary, and
part of Galway it is rare, while in the rest of Galway and in Clare
it is more common. In part of Leinster, between the upper lime-
stone and the Coal-measures lower shales, there is a cherty zone,
but in the rest of Leinster and in Munster in all the known sections
of the junction of the Limestone and Coal-measure shales, this
cherty zone is absent. In Ulster, however, especially Fermanagh,
where sections can be seen, this cherty zone is well developed and
of a character similar to that described by Dr. Hinde as characteristic
of the Yoredale Series, Yorkshire.

According to my experience chert is as frequent, if not more so,
in the Lower, as in the Upper Irish Carboniferous Limestone. When
it occurs in zones, it is usually accompanied by shaly beds, and is
more or less friable; but when in compact limestones like those of
the “Burren type,” it stands out conspicuously like the nodules,
lentils, and layers of flint in the chalk, as can be seen in innumerable
places in Cork, Kerry, Clare, Sligo, Fermanagh, etc.; near Athenry,
Co. Galway, in a railway-cutting, there is a thick bed.

As Dr. Hinde has been making researches as to the origin of
chert, I would specially direct his attention to the chert lentils
perpendicular to the stratification in Benmore, Co. Fermanagh, to
which attention was first drawn by Thos. Plunkett, M.R.I.A., of
Enniskillen, in a paper read before the Royal Dublin Society. Those
mentioned in his paper occur in Benmore, but I have since observed
them in Belmore and other places in that county. They are lenticular
masses in height and depth, and have all the appearance of ordinary
chert. I take it that they are the filling in of shrinkage fissures
along a line of partial rupture. JT would also draw his attention to
the lower and middle cherty zones in the Co. Limerick, both of which
are remarkable Paleozoic breaks, as in the intervening rock, ‘“ Fenes-
tella Limestone,” the fossils are quite distinct and much more

522 Mr. W. 8S. Gresley—Explosive Slickensides.

abundant than in the strata above (Calp) and below (lower limestone
with shale partings). I would also draw his attention to the papers
published by the Boston Society on the island of Cuba, which I
suspect might throw some light on the subject. As suggested in
previous writings I suspect that the cherty zones in the Irish
Carboniferous Limestone, especially that between the Fenestella
Limestone and the Calp, must have some connection with vulcanicity.

Years ago Jukes got chert from Queen’s Co., Limerick, Clare, etc.,
examined by Sorby, and I think I remember that he published about
them.

GxEoLogicaL SuRvEY oF IRELAND. G. H. Kinawan.

RE “EXPLOSIVE SLICKENSIDES.” 1

Str,—I should like, if I may, to add a few facts which seem to
closely bear upon the subject of Mr. A. Strahan’s interesting article
in the August Number of your Macazine. They are these :—In
driving, exploring, or “opening-out” headings in certain seams of
coal, loud reports are very frequently heard, which are often accom-
panied by the bursting-off from the sides of the excavations of large
blocks or masses of coal. The noise made by such ‘“ explosions” or
reports may be likened to artillery, and often causes men to run out
of the place with alarm. Now, these ‘“‘ bumps,” as the miners term
them, generally occur in situations where the strata are much faulted —
by dislocations, and increase in importance with depth or thickness
of cover. They probably happen most frequently and loudest in
single drifts or headings, or those formed in advance of the general
workings of the mine; and it is where these excavations are formed
in the lower part of the coal-seam that the “bumps” are heaviest
and produce greatest effects. Such an instance occurred a few years
ago in one of the pits of the Moira Collieries close here, when a
sudden and very severe bump completely displaced and shattered
a single-brick “ brattice’-wall (or partition, dividing the excavation
longitudinally for ventilating purposes) for a length of about 24 feet.
This wall was, as it were, completely blown out, and the men in the
place were “‘jumped-up ” off the floor, but not hurt. The wall was
about three feet high and built with mortar. Again, in excavatimg
the main roadways in the solid coal in the thicker seams of South
Staffordshire, very severe bumps take place, and have been known
to suddenly displace hundreds of tons of coal, by throwing them off
the sides into the road. But in the ordinary course of coal-getting,
especially by the method called the ‘‘ Longwall”’ (i.e., where all
the seam is extracted by one operation), loud reports with bumps
are of every-day occurrence, and now and again they have the effect
of knocking out the props and sprags (wooden supports to roof and
sides) and bring down a quantity of stuff. Also, during the
operation of ‘‘holing” (under-cutting the coal-seam preparatory to
breaking it down), the coal will keep on bursting itself off in little
fragments from the face of the excavation with loud explosive reports,
often putting the men’s candles out. When the coal does this, it is
said to have plenty of “life” in it, or “it keeps talking to you.”

1 See Prof. T. McKenny Hughes’ article, ante, pp. 511-512.

Mr. W. H. S. Monck—Date of the Ice Age. 523

When in the mine alone and all work is suspended, I have frequently
heard strange and unearthly (?) sounds, such as rattlings, scratchings,
knockings, etc.—noises called ‘‘nackings” by the men. In York-
shire I have heard of bumps of such magnitude taking place as to
throw down large areas of roof in worked-out parts of the pit, and
which created a blast in the air of the mine strong enough to knock ~
men over, upset tubs, blow open doors, put out lights, and cause
much havoe.

Subterranean rumblings, as is well known, have for several years
been heard, and felt too, beneath and in the vicinity of the town of
Sunderland ; but these are considered to be due, not to coal-mining,
but to the dissolution of the magnesian limestone by water which is
constantly being pumped through it.

Now, it appears to me, that there is one common cause for all
these ‘‘ explosions,” “ bumps,” “ nackings,” etc., which is simply this:
the upsetting, by the excavation, of the equilibrium of the strains or
pressures holding everything fast and firmly together—the removal
of the support thereby causing the rocks to get relief and to fly off
or apparently to explode. I look upon the phenomena as minature
earthquakes in fact. I question very much whether gas has anything
to do with these bumps, etc., even in coal-mines, but that they act
upon the gas is exceedingly probable. The phenomena are certainly
often very striking, and would seem to be worthy of much more
attention than they have received. With Mr. Strahan’s last paragraph
I quite agree. W.S. Grustey, F.G.S.

OVERSEAL, 8 Sept. 1887.

THE DATE OF THE ICE AGE.

Srr,— Some time ago you inserted a letter of mine in which I
contended that a high eccentricity of the earth’s orbit and winter
aphelion would not produce all the effects which Dr. Croll assigned
to them. I venture now to give some reasons for thinking that the
Glacial Period did not occur so long ago as Dr. Croll’s theory
supposes. His principal maximum of eccentricity took place 800,000
years ago, while the last large maximum was about 210,000 years
ago. Can the Ice Age have been as remote as this ?

I have just returned from a visit to the Lake District, the glacial
phenomena of which have been very fully described by Mr. J.
Clifton Ward. The traces of ice-action along the sides of the
mountains bordering the Valley of Borrowdale are remarkably
numerous and well-defined. The sides of these mountains are
usually steep and pretty bare, and the rainfall of the district is
enormous. At Seathwaite, situated at the head of the valley, Sir
John Herschel gives the annual rainfall at 141 inches, and Ramsay
at 118 inches. No doubt the rocks are hard volcanic rocks which
would stand a good deal of wear; but would the ice-markings be as

1 T recollect seeing it stated in a newspaper a few years ago that the wife of the
colliery manager was disloged from her seat in the house in Nottinghamshire at the

same moment that a very heavy ‘‘ bump ”’ occurred in the workings of the colliery
below, which at the time was, by some, attributed to an earthquake.

524 Prof. EL. Hull—Origin of Chert.

distinct as they are if these steep mountain-sides had been exposed
to annual rainfall of 100 inches for the last 200,000 years ? )

Above Grasmere there is a small lake, know as Hasdale Tarn,
which seems to have been partly formed by a terminal moraine,
while earlier ice-markings down the valley seem to indicate that the
glacier formerly pursued the same course which the stream from the
tarn now follows. Though the drought of the season had been
remarkable this stream was not a very small one, yet the work of
erosion done by it since the Glacial period was not of a very startling
description. It was not what I should expect a rapid mountain-
stream (though checked by a small tarn) to effect in 200,000 years.

Such phenomena are by no means peculiar to the Lake District.
The great fall of Niagara seems to be an example. There is, I
believe, no trace of an earlier post-glacial river-channel. On the
contrary, the ice-markings almost down to the water’s-edge above
the fall seem to show that the glacier followed the same track as
the river. The river must, therefore, have commenced cutting out
of the gorge as soon as the ice-cap cleared away. But Sir Charles
Lyell estimated the time necessary to cut out this gorge at 35,000
years, while others have placed it as low as 12,000. Professor
Winchell has estimated the time required to cut out the gorge below
the falls of St. Anthony at 8000 to 10,000 years. I am not aware
that there is any reason to think that this excavation did not com-
menee until long after the close of the Ice Age.

Man probably existed on the earth in the Glacial, if not the
Pre-Glacial, era. But is there any reason to suppose that he existed
for at least 200,000 years without making any solid progress in
civilization, and then suddenly made the great advances (emanating
apparently from more than one centre) which has taken place in the
last 10,000 (or perhaps 6000) years? It is not a case of an
anthropoid ape slowly developing into a man during a period of
200,000 or 800,000 years; for the earlier skeletons appear to be
those of fully-formed men.

For these reasons I think Dr. Croll refers the Ice Age to too
remote a period. Further researches on the amount of post-glacial
erosion and the erosive power of the streams or rivers engaged in
it ought, I think, to enable us to decide the question one way or the
other with a tolerable degree of certainty.

Dvsuin, Sept. 5th, 1887. W. H. 8. Moncx.

DR. HINDE ON THE ORIGIN OF CARBONIFEROUS CHERT.

Str,—Permit me to reply to the article by Dr. Hinde, F.G.S.,
which appears in the GrotogicaL Magazine for the present month
(No. 280, p. 485). As I had an opportunity when attending the
meeting of the British Association in Manchester of hearing the
paper read in Section C, and as I had previously had the pleasure of
a visit from its author in this city, 1 was not unprepared for the
onslaught which afterwards took place. I have no wish to maintain
a position which subsequent investigation has shown to be untenable,
or which requires readjustment; and I am, therefore, quite ready

Prof. E. Hull—Origin of Chert. 525

now to admit, what I stated in Manchester, that in examining the
slides of chert under the microscope, I had, at least in many instances,
mistaken forms of sponge-spicules for those of Crinoid stems. Nor
was this, I submit, at all surprising when we recollect that these
organisms are often very vague, and that the bands of chert occur
intercalated with beds of limestone abounding in stems, ossicles,
and plates of Crinoids. It was not unnatural, therefore, that I should
have supposed the little discs seen in the chert-sections under the
microscope to be minute cross-sections of these stems or ossicles.}
Dr. Hinde’s great experience in the examination of the sponge-
structures of the Cretaceous beds has given him an advantage
in this line of investigation which certainly has not fallen to my lot ;
consequently, when on examining my slides in this office, he stated
that the forms were those of sponge-structures, I accepted his state-
ment without question.

Dr. Hinde’s recent investigations undoubtedly show that siliceous
sponge-structures enter far more largely into the composition of
Carboniferous chert than has hitherto been suspected, and even,
that they exceed in numbers other organic forms; all this I now
willingly concede. But I am not prepared to go to the full length
of Dr. Hinde’s demands, as I understand them, nor to abandon as
untenable the proposition that much of the silica of Carboniferous
chert has been derived by a transmutation process from the waters
of the ancient seas. Not only are there to be found forms, such as
those of Corals, Brachiopods and Polyzoa and ossicles of Crinoids,
originally calcareous, now occurring silicified in the chert, but the
amorphous cementing material of the organic structure which may
be supposed to have originally been calcareous has now been trans-
muted, or may have been directly deposited from the waters under
such favourable conditions as those supposed by Mr. Hardman and
myself in our original memoir.? A similar conclusion has been
arrived at by Prof. Renard by a process of investigation analogous
to, though quite independent of, that pursued by ourselves. Whatever
doubt I might have entertained in regard to my own conclusions, I
cannot extend to those of so competent an observer as Prof. Renard.
Let meask Dr. Hinde, does he deny the possibility of siliceous bodies
‘or masses having been formed by the transformation process? If so,
he is confronted by the evidence of a large number of the ablest
observers, both British and Foreign, amongst whom may be mentioned
Bowerbank, Rupert Jones, Sullivan, Sterry Hunt, and Bischof.* If
so, it is Hinde contra mundum; and let me say that these observers
appeal to Nature as well as does Dr. Hinde himself.

I feel obliged to Dr. Hinde for having called my attention to the
fact that Professor Sollas had previously identified siliceous sponge-
spicules in the chert-sections which I had forwarded to him for

* From what Dr. Hinde has stated in his original paper (Phil. Trans. 1885, note,
p- 433), it would appear that a more competent “observer than myself has fallen into
a similar error; from which it will be inferred that it is a matter of much difficulty,
and requiring great experience to distinguish the one from the other.

2 Scientific ‘Transactions, Roy. Dublin Society, vol. i. new ser. (1878).
3 Bischof: ‘* Chemical and Physical Gevlogy,”’ Cavendish edit. vol. i. p. 486, e¢ seg.

526 Obituary—John Edward Lee, F.S A., F.G.S.

examination. When I wrote my paper for the Royal Society, I
had altogether forgotten this circumstance, which I much regret; a
copy of the paper itself had been carefully laid aside by me for
reference, and suffered the fate of most such papers. Having, how-
ever, now referred to this document, I will put it in evidence on the
question now discussed, and the reader will hear what Prof. Sollas
has had to say. The author examined five of my slides of chert-
sections under the microscope, and states as the result of his examina-
tion; “‘ in the first place, to completely confirm his (Prof. Hull’s)
clear descriptions of the appearances presented by them (the chert-
sections) ; and next, to establish the truth of my supposed detection
of sponge-spicules,” as shown in the plate accompanying my original
paper. ‘This is very valuable testimony.

As to the question of the geological position of the so-called
“‘Yoredale Series,” I have only to say that I have used the term as
it is understood on the Geological Survey throughout the wide
district where, in conjunction with some of my colleagues, I mapped
these beds some years ago in South Lancashire, Cheshire, Derbyshire,
and the adjoining parts of Yorkshire, an area of not less than 2000
square miles. What may be the exact relations of these beds to
those of the Valley of the Yore as described by Phillips, I am not
prepared to say. It is well known that the Lower and Middle
Carboniferous strata undergo considerable alteration both in character
and thickness as we proceed northwards from Derbyshire and
Cheshire ; and I can only now refer Dr. Hinde to my paper on the
Classification of the Carboniferous Rocks published in the Quarterly
Journal of the Geological Society, vol. xxxiii. for my views on this
subject.

In conclusion, I have to add, that if I have misquoted Dr. Hinde,
as he affirms, 1 can only express regret, as I took special care not to
do so, as will be seen by referring to my paper in the Proc. Roy. Soc.
vol. xlii. p. 805. My late valued colleague, Mr. Hardman, whose
name occurs in this controversy, is not now with us to take his share
therein, but I feel convinced he would have concurred in what I
have written. Epwarp Hvtit.

GroLocicaL Survey Orrice, Dustin, 7th Oct. 1887.

OS EAU ALR.

JOHN EDWARD LEE, F.S.A., F.G.S., ETC.
Born DercEmMBer 21st, 1808; Dizp Avcust 18TH, 1887.

DervonsurirE has lost another excellent geologist and antiquary
in Mr. John Edward Lee, of Villa Syracusa, Torquay. Mr. Lee
was born at Newland, Hull, Dec. 21st, 1808. His father having
died when he was very young, he was brought up by two uncles,
Avison and John Terry, and at sixteen he entered their shipping
office in Hull. From the earliest period of his life he took an
interest in science, beginning with Entomology, and while living

1 Prof. Sollas's paper was published in the Annals and Magazine of Natural
History for February, 1881.

Obituary—John Edward Lee, F.S.A., F.G.S. 527

at Hull he took an active part in the Royal Institution there ;
frequently at the end of the day’s work, he would shut himself in
the Museum, and stay far into the night arranging the specimens it
contained.

His health failing, he travelled abroad, first in Norway and Sweden,
afterwards in Russia and other parts of the continent. During these
tours he sketched, and also mastered French and German thoroughly.

In 1841 he entered the Iron Works (J. J. Cordes & Co.) of
Newport, Monmouthshire, where he spent the best years of his life.

In 1846 he married Miss Gravely, of Torquay, and they resided
at the Priory, Caerleon, till 1868, when anxiety for Mrs. Lee’s
health decided his removal to Villa Syracusa, Torquay ; but he still
constantly went back to Monmouthshire for many years.

During all the years of his residence at Caerleon, and later at
Torquay, until failing health compelled him to abandon many of his
cherished pursuits in life, he worked steadily and uninterruptedly at
various branches of science, principally at Geology and Archeology.

He was one of the founders of the Monmouthshire and Caerleon
Antiquarian Society, to the Proceedings of which he frequently con-
tributed. He also aided in the formation of the Museum at Caerleon,
publishing, under the title of “ sca Silurum,” an illustrated catalogue
of the Roman remains discovered at Caerleon, the ancient capital of
the “ Silures.”

He exchanged fossils with geologists in all parts of the world, and
carried on a large correspondence with many foreigners, who had
either visited his collection at Caerleon or Torquay, or whom he had
met during his numerous continental travels, or others in America
and elsewhere with whom he had no personal acquaintance. AlII his
journeys were undertaken with a scientific object, and he was in the
habit of carrying small sketch-books with him when travelling, the
contents of which he utilized in his publications, many of his
sketches appearing in “The Note-Book of an Amateur Geologist,”
published in 1881.

His principal work was a translation and revision (assisted by the
author) of Dr. Keller’s Lake Dwellings of Switzerland, printed in
1866, and a second edition (in two volumes) in 1878; all the plates
for this work, 206 in number, were drawn by Mr. Lee for the
English edition, and illustrate more than two thousand five hundred
objects, obtained from between two and three thousand separate lake-
dwellings.” Mr. Lee’s other works are, ‘“ Roman Imperial Photo-
graphs ” and ‘Roman Imperial Profiles ” (the latter being a series
of more than 160 lithographic profiles enlarged from coins), both
published in 1874.

A translation of Conrad Merck’s Excavations at the Kesslerloch,
near Thayingen, Switzerland, a cave of the Reindeer period, followed
in 1876; and an English version of Prof. Roemer’s Bone-cave of
Ojcow in Poland in 1884.

One of Mr. Lee’s most interesting geological expeditions was
made to Italy in 1868, in company with one of his earliest friends,

Prof. John Phillips of Oxford, to study the phenomena of Vesuvius,
then in active eruption.

528 Obituary—Sir William Vernon Guise, Bart., F.G.S.

Ten years later (1878) the writer of this notice had the pleasure
to accompany Mr. Lee to the Hifel district, where, being happily
ioined by Prof. Ferdinand Roemer, of Breslau, the historian of the
Devonian rocks of this region, a delightful fortnight was spent in
collecting the fossils of Gerolstein, Priim, and other localities.

Mr. Lee contributed several important papers to the GroLocrcaL
MaGazinx on points in Devonian geology which he had worked out;
he was the original discoverer of many fossils described by the late
Mr. J. W. Salter, F.G.8. (as Homalonotus Johannis, etc.)

He gave his most valuable and extensive collection, contained in |
31 cabinets and comprising upwards of 21,000 specimens, to the
British Museum (Natural History), in 1885. This collection not
only embraces a large series of British fossils from all formations,
many of which have been figured and described, but a most valuable
and instructive collection from almost every important Huropean
locality where fossils abound.

Although his bodily powers began of late years to fail, his intellect
remained bright, especially on all matters of science, to the last, and
after he failed to write. he dictated and signed many letters, giving
clear and accurate scientific information to correspondents, and he was
full of plans and ideas for the furtherance of science up to the end.

Mr. Lee was a Member of the British Association, a Fellow of
the Society of Antiquaries, and a Fellow of the Geological Society
of London.

SIR WILLIAM VERNON GUISE, BART., F.L.S., F.G.S.
Born 1816, Diep 1887.

Sir Wriiam Guise was the eldest son of the late Gen. Sir John
Wright Guise, Bart., one of the most distinguished Peninsula officers,
by his marriage with Charlotte Diana, daughter of the late John
Vernon, Esq., of Clontarf Castle, County Dublin. He was born in
the year 1816, and succeeded to his father’s title in 1865. He was
a Magistrate and Deputy-Lieutenant for Gloucestershire, and served
as High Sheriff of that county in 1872. He was also a retired
Lieutenant-Colonel of the Royal South Gloucestershire Militia. Sir
William married in 1844, Margaret Anna Maria, daughter of the
Rev. D. H. Lee-Warner, of Walsingham Abbey. He is succeeded
by his eldest surviving son, William Francis George, who was born
in 1851.

Sir William Guise was elected a Fellow of the Geological Society
in 1841; and although not a founder, was for many years one of the
most active members of the Cotteswold Naturalists’ Field Club.
Only last year he retired from the office of President, which he had
held for 28 years. He had a wide general knowledge of Geology,
Conchology, Botany, and Archeology, and there were few objects or
places of interest in Gloucestershire with which he was not acquainted :
thus he was eminently qualified to direct the Excursions of the Club,
while his hearty and genial manners contributed much to the enjoy-
ment of the meetings. Sir William Guise died on the 24th September,
at his residence, Elmore Court, near Gloucester.

eee a Me)
ghee a’

Geol Mag. 1887. ' - Deeade II Vol IV. PLXV.

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Solaster Murchisoni, Mn. sp.

Yorkshire Lt LAs.

THE

GEOLOGICAL MAGAZINE.

NEW (SERIES DECADE. Wily VOL. Ive

No. XII—DECEMBER, 1887.

Oi GareINE Ae) AS eye Se een Se
————

I.—On a New Specimen or Sozaster Murcuisoni FRoM THE
Yor«KSHIRE Litas.

By Prof. J. F. Buaxe, M.A., F.G.S.

(PLATE XV.)

HE specimen to which the following description applies was

found by the Rev. G. Crewdson, F.G.S., of Kendal, at the base

of the cliff at Huntcliff. The block in which it lay was separated

from the parent rock, and had doubtless fallen from above. The

occurrence in the same slab of a portion of an arm of Ophioderma

Milleri and the general character of the stone leave no doubt that it
is derived from the “Star-fish”’ bed of the Capricornus Zone.

The only other known examples of polyradial star-fish from the
Yorkshire or any other Lias are figured on plate v. of Dr. Wright’s
Monograph of Oolitic Asteroidea in the Paleontographical Society’s
volume for 1861, issued in 1863. These are named Plumaster
ophiuroides, and Luidia Murchisoni respectively. That our fossil is
not the same as the former is very evident from its possessing 22 arms
instead of 14, and other differences are soon observed. On com-
parison with the latter, as represented by its figure and description,
it appears very closely allied; but this is described as a Lwidia.
The principal difference between a Ludia and a Solaster, that can
be observed on such examples, is that in Luidia the ventral surface
of the arms has one medial row of ossicles, with the pores on either
side, whereas in Solaster there are a pair: a circumstance that
results in dried specimens of the latter opening along the ventral
side of the rays, while in the former the rays remain intact. Now,
on examination of our specimen, it is immediately evident that in
this respect it agrees with Solaster. Therefore, if the specimen
described by Dr. Wright is a Luidia, this cannot be the same. This
‘was my opinion when I exhibited the specimen at the British
Association at Manchester in September last. But on that occasion
Prof. Williamson, who found the specimen figured by Dr. Wright,
and also provided the description, considered the new specimen so
like the old, that a comparison became necessary. Through the
kindness of Mr. J. Woodall, I have been enabled to examine the
other specimen in the Scarborough Museum, as it was found to be
in too fragile a condition for safe carriage. The result of that

DECADE III.—VOL. IV.—NO. XII, 34

530 Prof. J. F. Blake—On Solaster Murchisoni.

examination is that they are undoubtedly of the same species, and that
therefore they both belong to the genus Solaster.

The new example, however, is so much better preserved, and
renders the possible description so much fuller and more accurate,
that it is worthy of as much consideration as if it had been a new
species. I shall therefore describe it fully.

Soraster Murcuisont, Williamson (sp.).

Syn. 1836. Luidia Murchisoni, Williamson, Mag. Nat. Hist. vol. ix. p. 426.

», 1855. Solaster polynemia, Simpson, Fossils of the Yorkshire Lias, p. 135.

», 1863. Lwidia Murchisoni, Wright, Paleontographical Soe. p. 111, pl. v. fig. 2.

Diagnosis.—Diameter 4-6 in. Central aperture ¢ diameter. Rays
20-22. Angle-plates long, triangular. Ambulacral area with a pair
of ossicles, anvil-shaped.. Pores large. Interambulacral area half
clothed, ossicles 5 on ventral surface, each with a spine, terminal one
with two. Dorsal surface with branching ossicles loosely netted.

Description.—The new specimen is about 4 in. in diameter. It
has been buried in the stone with its ventral surface downwards,
by which means an external cast has been produced of the ventral
surface of its arms. Upon this has been pressed down the dorsal
surface which covers over and hides the central opening, and shows
sharply marked triangular, or bent impressions irregularly scattered,
which are interpreted as the casts of a loose network of dorsal
ossicles. ‘The arms are 22 in number (see Fig. 1). Someare broken,
but most are complete, and come to a rather blunt termination.
Along the centre of each (see Fig. 2) is seen a raised band, cor-
responding to a depression: in the animal. This band is threefold,
the centre line is the interval between the ambulacral ossicles, which
are like anvils placed back to back, as seen in the depressions of the
cast. The pores are large and form the two outer bands, occupying
the concavity of the ambulacral ossicles. Each of these ossicles is
continued outwards and also somewhat radially by a subtriangular
ossicle—and then by four others—all of the interambulacral series.
Each of these four had a spine in its centre, and the outermost an
additional larger one at the end. These latter clothe the sides of
the rays with a layer of spines. It is possible there were smaller
spines also on the softer part which intervened between each of
these rows of interambulacral ossicles and the next. These rows
form cross lines in the cast, with a gentle concavity in the radial
direction, and each ray has nearly 50. In one spot a fragment of
a ray has been reversed and its dorsal surface is seen. This shows
the insertions of the spines at the sides; but the remainder is so
smooth that the paxilles must have been very small. This is all that
can be learnt from this specimen, which is beautifully preserved in
a fine micaceous, earthy sandstone, well suited to retain impressions.

The original specimen, now in the Scarborough Museum, under
the charge of Mr. Phillips, who gave every facility for its examina-
tion, is in a shaly matrix, which, in spite of preserving materials,
has cracked, and is very liable to shale off entirely. It shows
20 arms and the central aperture is well-preserved, being about + of
the whole diameter. The inner ends of the rays open out in the

Dr. T. Sterry Hunt—On Italian Geology. 531

ambulacral line, and on either side is found a projecting triangular
ossicle, whose cast is well preserved. These are thus arranged in
closely opposed pairs in the interambulacral line (see Fig. 4). The
features of the ventral side of the rays are not well preserved ; but
in four places at least the casts of the pair of ambulacral ossicles are
‘seen, and they are of the same shape as in the new specimen (see
Fig. 3). The somewhat separated rows of interambulacral ossicles
are preserved as grooves, in the base of which are seen the pits
which indicate the spines. The larger ones at the ends are also
marked by the marginal pits, and the casts of the spines themselves
are seen diverging from them. ‘Towards the margin of the central
aperture is seen the madreporiform tubercle which, with the exception
of the casts of a few ossicles, is the only relic of the dorsal surface
that is preserved. This is beautifully shown, it is of the ordinary
type with radiating pores, and it is about +> inch in diameter (see
Fig. 5). :

It is thus seen that in all comparable points the two specimens
agree, while each contributes something special to the description,
which between them is rendered about as complete as we can well
expect in the case of such an ancient relic of the group. The new
Specimen is now one of the ornaments of the Kendal Museum, whose
development the discoverer has done so much to promote.

_ DESCRIPTION OF PLATE Xy.

Fic. 1. New specimen of Solaster Murchisoni, in the Kendal Museum. Found by
Rey. G. Crewdson in the Capricornus beds of Huntcliff. Natural size.

- Portion of a ray of the same restored. Enlarged.

. Ambulacral ossicles of the type specimen. Enlarged.

. Angle plates at the inner ends of the rays of the type specimen.

. Madreporiform tubercle of the type specimen. Enlarged.

2?
2?
?

Ore CO bO

2?

II.—GastTatpi on ITALIAN GEOLOGY AND THE CRYSTALLINE Rocks.!
By T. Sterry Hunt, M.A., D.Sc., LL.D., F.R.S.

TP\HE present writer in 1883 reviewed the history of the rocks of

the Alps and the Apennines with especial reference to the
geological relations of serpentine and its associates, in a paper which
appeared in the first volume of the Transactions of the Royal Society
of Canada, and is reprinted, revised and with some additions, as the
tenth chapter of his volume entitled “‘ Mineral Physiology and
Physiography” (Boston, 1886). Therein he gave a somewhat detailed
account of the labours in Italian geology of the late Professor
Bartolomeo Gastaldi, of Turin, a list of whose publications on that
subject from 1871 to 1878, so far as known to the writer, will there
be found, including his letter to Quintino Sella, in 1878, on the
general results of explorations made in 1877 (loc. cit., 458). In
doing this the present writer said, “I feel that Iam both rendering
a veritable service to science and paying a tribute to the memory of
my honoured friend and correspondent of many years,” stating at the

1 Read before the British Association for the Advancement of Science, Section C,
Manchester, Sept. 4, 1887.

532 Dr. T. Sterry Hunt—On Italian Geology.

same time that “the work of Gastaldi, interrupted by his death in
1878, was unfortunately left incomplete.” This statement was not
quite exact in one particular, since he survived till January 5, 1879,
when there passed away, universally honoured and beloved, one
who brought to the study of geology, with a spirit of complete
devotion, a rare genius and a breadth of view which will assure him
a first place among the geologists of our time.

In the chapter above mentioned the writer proceeded to consider
the history of the so-called Tertiary serpentines of Monte Ferrato in
Prato (Tuscany), and those of parts of the Ligurian Apennines
which he had personally examined, and, in opposition to the opinion
of most Italian geologists, and some others who have studied them,
maintained that they were really but portions of the ancient pietre
verdi zone, identical with that of the Alps, underlying, in the regions
in question, the beds of Eocene age; which latter, by subsequent .
terrestrial movements, have been disturbed, broken and even inverted,
so as to seem to pass beneath the serpentinic rocks. The indigenous
and neptunian character of serpentine, maintained on stratigraphical
evidence in North America by E. Emmons, by Logan, and by the
present writer, was not only held by Gastaldi and Delesse, but is
maintained by Stapff, by Lotti, and by Dieulefait. The hypothesis
of a plutonic origin has moreover been so much modified by recent
Italian geologists, as Taramelli, Capacci, Issel, and Mazzuoli, that
instead of supposing them to have been erupted like basalts, they
now conceive that serpentines, and the associated rocks of the
ophiolitic group, were formed by submarine eruptions, in Tertiary
time, of magnesian and feldspathic muds, of unexplained origin but
of no very elevated temperature; which subsequently consolidated
and crystallized into euphotide, diorite, and serpentine, with their
associated feldspars, enstatite, chrysolite, and other minerals.

In the change of chrysolite into serpentine, as I have elsewhere
shown, “one hundred parts by volume of the former species, with
a specific gravity of 3:33, if converted into serpentine of specific
gravity 2°50, without change in its content of silica, must lose one-
eighth of its weight of magnesia, and acquire the same amount of
water instead, while at the same time its volume will be augmented
one-third, or to one hundred and thirty-three parts.” That such a
change takes place in some instances, probably through the action of
carbonated waters removing a portion of magnesia from chrysolite,
and leaving behind the more stable hydrated and colloid silicate,
serpentine, is evident. Until, however, the precise conditions under
which this may take place are better understood, we cannot explain
why in some cases chrysolite is exempt from such change. I have
long since described in the vicinity of Montreal, in Canada, cutting the
limestones and pyroschists of the Ordovician series, great masses of
a granitoid chrysolitic dolerite, itself of Palaeozoic age, in which the
chrysolite, in large crystals, often predominates, and is still unchanged,
hard, and anhydrous. The assumption, lightly made by some plutonists,
that chrysolite is always of plutonic origin, and serpentine always
a product of epigenesis, rests upon a slender foundation, and is in

Dr. T. Sterry Hunt—On Italian Geology. 533

contradiction with a great number of facts. While the production
of chrysolite from mixtures in a state of igneous fusion is well |
known, and while the chrysolitic rocks just mentioned are, as I have
endeavoured to show, the result of crystallization and partial eliqua-
tion in a truly plutonic mass, it is not less certain that to other chryso-
litic rocks a neptunian origin must be assigned; as was maintained
by the writer in 1879, for the so-called lherzolite or chrysolite-rock.
which, accompanied by enstatite, serpentine, and chromite, is inter-
stratified with the younger gneissic and mica-schist series in North
Carolina. The same may be said of the similar chrysolite rocks in
Norway, which, like these, are gneissic in structure and interstratified
in crystalline schists. In this connection I have also elsewhere
noted the variety of chrysolite known as glinkite, found in nodules
in talcose or micaceous schists in the Urals, and that purely
magnesian chrysolite or forsterite which occurs abundantly in
crystalline limestone in eastern Massachusetts. It appears evident
that chrysolite, like pyroxene, feldspars, spinel, and many other
species, is generated alike by plutonic and by neptunian agencies.

As regards serpentine, while it may occur as a product of the
decay of chrysolites either of igneous or of aqueous origin, no one
who has intelligently studied the mode of its occurrence in grains,
nodules, interstratified layers and beds, sometimes hundreds of feet
in thickness, in the crystalline limestones and dolomites of Archean
rocks alike of Laurentian and of Taconian age, and even in Palzeozoic
strata, can doubt the direct formation of serpentine and its accom-
panying silicates, in such cases, by aqueous deposition. Its separation
from solutions is also made apparent by the frequent occurrence of
veins carrying the species marmolite and chrysotile (which are but
crystalline forms of the same silicate as serpentine) either with or
without calcite, traversing ophiolitic rocks, and even, as noticed by
Gastaldi, in serpentinic breccias of comparatively recent date.’

Gastaldi had already, in 1871, expressed in general terms his
opinion that “all the serpentinic masses of the Tuscan and Ligurian
Apennines,” as well as the similar rocks in Calabria, are but
prolongations of the great pietre verdi zone of the Alps, in which
he included what are known as the Apuan and the Maritime Alps.
To the same horizon also he referred the so-called ophitic rocks
of the Pyrenees. From my~own observations in Italy in 1881, I
could not doubt the correctness of these earlier generalizations of
Gastaldi, who however apparently did not verify his conclusions by
personal observations of the so-called Hocene serpentines of Liguria
and Tuscany until 1878, a few months before his death, when he
examined both of these regions with especial reference to the
question. His final conclusions thereon, a fortunate circumstance
now permits me to give to the world.

There lies before me a letter of eleven pages, to my address, from

1 For a detailed discussion of the questions here raised as to serpentine and related
silicates, see The Genesis of Serpentine, in the author’s Mineral Physiology and
Physiography, pp. 497-509; also further for analyses and description of the
chrysolitic dolerite, iid. pp. 211-213.

534 Dr. T. Sterry Hunt—On Italian Geology.

Gastaldi, written in French, and dated Turin, July 20, 1878, which
reached me in London in due time. After reading the first and last
pages of this epistle, concerning matters which demanded and received
an immediate answer, it was put aside for careful perusal, and by a
curious chance was mislaid, and believed to be lost until recovered
during the present year (1887). As it is the last recorded word of
Gastaldi with regard to various geological problems which had
occupied many years of his life, and moreover sustains fully my
own opinion formed three years later regarding the rocks in question,
as set forth above, I have thought it well to translate into English
this precious letter, omitting only those portions which have no
reference to the subject before us,—premising that with the exception
of the references to the regions then lately examined by him, the
conclusions, for the greater part, are already embodied in his
previously published papers and in the present writer’s summary of
them :—
‘« Turin, July 20, 1878.

“Dear Friend anp Corteacuz,—On returning from a long
campaign in the Apennines of Prato (Tuscany) and the Apennines
of Liguria, I was agreeably surprised to receive your letter from
Montreal of June 25, announcing your speedy departure for England.
-..- lam very glad that you are about to give us a historical and
critical work on the Azoic rocks of North America, respecting which
it has not been easy to get clear ideas, on account of the extent of
the literature and the difficulty of procuring it. I agree with you
that we are now enabled to place on a solid foundation the classifica-
tion of the Azoic rocks, and you may rely on my support of your
views which you will lay before the International Geological Congress,
where your skill in exposition will be more effectual, because the
facts are evident. I cannot myself attend the Congress, for at that
time it is necessary that I should be in the high valleys of the
Maritime Alps; besides which please consider that I am sixty-one
years of age, and cannot put off labours which involve great fatigue,
and of which I may not be capable another year. . . .

“You propose to give in your volume my conclusions as to the
crystalline terranes of the North of Italy. For this I thank you
with all my heart, and demand permission to set forth a summary
of my observations. As to crystalline rocks, I am even more radical
than you; for me all crystalline rocks are stratified; for me there is.
no plutonism; for me volcanic activity commenced only with the
lavas of the Lower Tertiary; at least I know no intrusive rocks in
the Alps; the porphyries there are, to my eyes, sedimentary.’ I

1 The volume here referred to was that on Azoic Rocks, being Report KE. of the
Second Geological Survey of Pennsylvania, 1878 (8vo. pp. xxi. and 253), and was.
already printed at that date, a poimt which I had apparently not made clear to
Gastaldi, who sent the notes for the volume in question, as well as for use at the
Geological Congress of 1878, where, however, the time had not yet come for their
presentation. The volume on Azoic Rocks contains a brief summary of the views
of Gastaldi, drawn from his published papers.

* I have elsewhere remarked that Gastaldi, misled by his too exclusive Werner-
ianism, appears to have included under the name of porphyry both stratified

neptunian rocks and intrusive plutonic or pseudoplutonic rocks of more than one
kind.

Dr. T. Sterry Hunt—On Italian Geology. 535

divide the crystalline rocks into two great zones; the lowest con-
sisting of the oldest rocks of the Alps, and probably of the globe, is
that of the central, ancient, or primitive gneiss. It is emphatically
the zone of the orthoclase feldspar, and is very poor in minerals.
The other zone is that of the pietre verdi, or green rocks, and is
especially the zone of the triclinic feldspars, like those of the diorite,
euphotide and apenninite. The granites themselves of this zone—and
I cite those of Elba, of Baveno, of Mont Orfano, and of Alzo, ete.—
although characterized by the beauty of their crystals of orthoclase,
are rich in albite. Ihave cited apenninite, which will be new to
you, so that I give the following explanation. Our geologists have
long recognized in the Apennines of Savoy the presence of a great
body of protogine or protogine-like gneiss. This rock is composed
of quartz and feldspar, in nodules rather than in crystals, and of
chlorite. A rock of the same character has been recognized by
Giordano in the Grand Cervisa. Now the feldspar of this rock,
which in the Ligurian Apennines, as well as in the Pennine Alps,
occupies a large surface, is in part soda-bearing, and I have thought
best to distinguish it from the true protogine, the feldspar of which
is orthoclase, by the name of apenninite.

“In a great many localities in the Alps we see the pietre verdi
resting against the central gneiss, but in others the same series is
found lying nearly horizontally thereon. In the latter case meteoric
agencies destroy this superimposed series, and thus extend more
and more the area of the ancient gneiss, already widely exposed.
Were the rocks of the pietre verdi zone thus made to disappear
from the Alps, the height of these in many places would be much
reduced (thus, for example, the Grand Cervisa and the Grivola are
formed of this zone) ; and when at last these rocks were destroyed,
we should find the region entirely occupied by the ancient gneiss.
In a word, the mass of the Alps is formed of the ancient or primitive
gneiss, here and there overlain by the rocks of the pietre verdi zone.”

[For illustration of these different relations two figures are given
in the letter, one of which is along the valley of Lanzo, showing the
stratified pietre verdi series resting at a considerable angle upon the
ancient gneiss (the stratification of which is not indicated), and over-
laid by more recent sediments. The other section, in the valley of
Chisone, represents the ancient gneiss overlaid by a stratum of
Therzolite, one of serpentine, and one of diallagic euphotide, the
attitude of all three being nearly horizontal. |

“The ancient gneiss is very poor in minerals, but includes a
limited number of other rocks, such as quartzite, amphibolite, and
crystalline limestone. The zone of the green rocks or pietre verdi,
on the contrary, is very rich in minerals, as well as in varieties of
rocks. Whence have come the minerals of this zone, since they
have not [apparently | traversed the gneiss? Whence the porphyries
and the granites of this same zone, which we nowhere find intersecting
the gneiss? We must conclude—and direct observation of the
facts demonstrates it—that the masses, the veins, and the so-called
bedded veins in which the zone of the pietre verdi is so rich, are

5386 Dr. T. Sterry Hunt—On Italian Geology.

characteristic elements of these rocks, and do not come from great
depths. The porphyries and the granites, which are found so
frequently in this zone, are not intruded rocks, since they do not
traverse the underlying gneiss, but of sedimentary origin, like the
limestones, the calcareous and argillaceous schists which accompany
them. These are points upon which it seems to me important to
insist.

“At Chaberton, a mountain of the Cottian Alps, I found resting
directly upon the serpentinic series a semi-crystalline limestone
holding organic remains. Not then suspecting a hiatus in the
succession, I was led to suppose that these fossils, which were badly
preserved, might be very ancient, and my friend Michellotti, who
was so good as to study them, thought like myself that they were
Lower Paleozoic forms. Upon these fossils I have published two
papers.’ It appears, however, that our notion of the existence of
Silurian [Cambrian] forms in the Alps was an illusion.? I sub-
sequently discovered more complete sections in the valley of the
Macra, and in that of the Stura de Caneo (Maritime Alps), and in
these, in limestones which appear to be a continuation of those of
Chaberton, we have found a good number of fossils which have been
described by Messrs. Zittel and Giimbel, and show the existence in
the Alps, above the zone of the pietre verdi, of various Mesozoic and
Czenozoic terranes. Resting upon the crystalline rocks we have, first
a quartzite alternating with a semi-crystalline limestone, then a
compact limestone with layers of anthracite, followed by another
compact limestone of Triassic age, with Encrinurus liliiformis, and
finally by a series of limestones, Liassic, Jurassic, and Cretaceous ;
the whole overlain by Nummulitic and more recent Tertiary strata.
The complete succession is then (1) The ancient central or primitive
gneiss, with quartzite, crystalline limestone, graphite, etc. (2) The
pietre verdi series, principally formed of serpentine, lherzolite,
euphotide, diorite, variolite, porphyry, calc-schists, apenninite, ete. ;
(3) The anthracitic series; (4) Triassic; (5) Liassic ; (6) Jurassic ;
(7) Cretaceous; (8) Nummulitic, Miocene, Pliocene.” [This is
illustrated in the letter by an ideal section. |

“The excursions which J have lately made in the Apennines of
Prato in Tuscany, and in the Ligurian Apennines, had for their
object to study the serpentines of these regions. Some geologists
of my acquaintance have lately given themselves much labour and
pains to confute my views of the age and the nature of the serpentines.
They wish to establish that these are eruptive rocks, in many cases
interstratified with the beds of the Upper Eocene—a proposition
which is wholly untenable. The serpentines as well as the other
rocks of the pietre verdi series are ancient rocks, pre-Silurian in age,
and are of types which have not been formed in later times. In
regarding these from this point of view, the geology of all those

' Sul fossili del caleare dolomitico del Chaberton ; Roma, 1876. Su alcuni fossili
paleozoici delle Alpi marittimi et dell’ Apennini ligure; Roma, 1877.

? Tn Sardinia, however, Lower Paleozoic forms, both Cambrian and Ordovician, are
met with ; Mineral Physiology and Physiography, p. 476.

Dr. T. Sterry Hunt—On Italian Geology. 537

regions in which the pietre verdi series plays an important part
becomes easy to understand; but it is, on the contrary, extremely
complicated if we consider the rocks of this series as intrusive. In
a great many parts of the Alps we see these rocks rising into con-
siderable elevations, as in Monte Viso; elsewhere again they are
overlain by the anthracitic series, by the Trias, or by still more recent
terranes. Thus in the valleys of the Bormida, and the Erro, and in
other valleys of the Ligurian Apennines, they are directly covered
by the Miocene; and again, as in the Apennines of Bologna, of
Florence, etc., are overlain by the Eocene or the Upper Cretaceous.
The separation of the two chains, Apennine and Alpine, is but a
geographical fiction; it would be absurd to attempt to separate them
geologically. I have visited the valleys and the depressions along
which geographers have drawn the lines of separation, and have
there found nothing but Alpine rocks, serpentine, apenninite, calc-
schists, etc. a .

“'T'o-morrow I leave for the Maritime Alps, where I shall remain
for about a month in order to visit the valleys of the Macra and the
Stura, that of Geno and that of the Vermagna, making for the third
time this journey, which is a weary and a painful one, especially for
the valley of the Macra, where one is forced to undergo many
privations. I am delighted to think that our literary correspondence
is renewed, and regret very much that circumstances deprive me of

the pleasure of being with you at the Congress in Paris. . .
« Affectionately yours,
“To Mr. T. Sterry Hunt. B. GASsTAaLptI.”

As regards the pietre verdi series, of which he has here so well set
forth the importance, I have in the volume already quoted (Mineral
Physiology and Physiography) shown that Gastaldi not unfrequently
employed it, as in the foregoing letter, to designate the whole suc-
cession of crystalline schists above the ancient or central gneiss—
speaking of these collectively as the “newer crystalline series.” This
however, includes a great body of younger gneiss and mica-schists
above the group characterized by serpentine, euphotide, diorite, ete.,
which he has here so clearly defined as resting upon the ancient
gneiss. Neri, in his sections in north-western Italy, distinguishes
above the ophiolitic or pietre verdi horizon, a group of mica-schists
with granites, while Gerlach described the same as recent gneiss
and granite, followed by gneissic mica-schists. Gastaldi himself,
in more detailed accounts, used the term pietre verdi in the same
restricted sense as Neri. Thus in 1874 (Studii geologici sulli Alpi
occidentale, part 2) he speaks of “the pietre verdi properly so-called,”
and declares it to be comprised between “the ancient porphyroid and
fundamental gneiss,” and “the recent gneiss, which latter is finer-
grained and more quartzose than the other.” He elsewhere in this
same memoir speaks of this higher portion of the ‘“‘ newer crystalline
series” (oftentimes, as in the above letter, comprehended in his
*‘pietre verdi zone”) as a mica-schist,—a gneissic mica-schist,—as
recent gneiss and mica-schist,—and also.as a very micaceous gneiss,
often passing into mica-schist and sometimes hornblendic. He says

538 Dr. T. Sterry Hunt—On Italian Geology.

farther, ‘‘I will not assert that when specimens of this newer gneiss
are confusedly mixed with those of the more ancient, it would always
be practicable to distinguish them petrographically ; but I do not
hesitate to affirm that their distinction in the field is not difficult ; on
account of the frequent alternation of the younger gneiss with the
other characteristic rocks of the upper series [ micaceous and horn-
blendic schists, etc.], while the older gneiss, however wide its
extent, is generally unmixed with other rocks.”

Above this recent gneissic and mica-schist division, but below the
anthracitic group, and included in the ‘‘newer crystalline series” of
Gastaldi, there is a considerable thickness of crystalline schists, often
soft and unctuous, and variously described as argillaceous, talcose,
and micaceous, or as grey lustrous schists, which are sometimes
sericitic. These, moreover, include quartzite, karstenite, dolomite,
and banded and statuary marbles, with occasional serpentines and
amphibolic rocks. Serpentines are also met with in intimate asso-
ciation with the younger gneisses, and hence Gastaldi often spoke of
the whole triple group of the newer crystalline series above the
ancient gneiss as the “ pietre verdi zone.” To each of these three
divisions he, in common with other Alpine geologists, assigns a
thickness of several thousand metres.

While these great divisions of the crystalline rocks were thus
being defined in the Western Alps, Von Hauer had already, in
1868, shown the same succession further to the eastward, in the
Lombardo-Venetian Alps, where he distinguished, first, the ancient
gneissic and granitic rocks, called by him the central gneiss;
second, a great thickness of green rocks or pietre verdi, including
serpentine, euphotide, and diorite, with various amphibolic and
chloritic rocks, together with saccharoidal limestones; and, third,
a recent gneiss and mica-schist series. Gastaldi, at an early
date in his studies, recognized in the older or central gneiss the
Laurentian series of North America, and in the succeeding green
rocks, or pietre verdi proper, the group which I had in 1855 called
Huronian. It was not until 1870 that I attempted to define as a
distinct and newer series the group of younger gneisses and mica-
schists in North America, called by me subsequently, in 1871, the
White Mountain or Montalban series, and corresponding both
lithologically and stratigraphically to the récent gneiss and mica-
schist series already recognized in 1868 by Von Hauer in the Eastern
Alps, indicated by Gerlach in the Western Alps in 1869, and
described more at length by Gastaldi in 1871. The work of none of
these was known to me when, in 1870, IJ first set forth the distinctness
of this great group of younger gneisses and mica-schists in North
America, and also indicated their existence in the Scottish Highlands.

I had, in 188i, an opportunity of examining this upper gneissic
series in the Western Alps, near Biella in the province of Novara,
and in company with Quintino Sella (who with Berutti had carefully
mapped the region), of going over a section which had been studied
and described alike by Gerlach and by Gastaldi. Here, besides the
ancient gneiss, with included graphitic and pyroxenic limestone, the

Dr. T. Sterry Hunt—On Italian Geology. 539

whole indistinguishable from the Laurentian of North America, and
also the characteristic serpentinic or proper pietre verdi group over-
lying it, I found the recent gneiss and mica-schist series apparently
overlying transversely both of these, and seemingly identical with
the Montalban or younger gneissic series of the White Mountains
and of Philadelphia in North America. An absence of the ophiolitic
or true pietre verdi group between the older and the younger gneissic
series, which is apparent elsewhere in the Alps, and in many places
in North America, may be due either to non-deposition or to erosion.
The existence of conglomerates holding rolled pebbles in the younger
eneissic series, both in Europe and America, shows erosion to have
played an important part in Archean as in later times, and is in
harmony with the observed stratigraphical discordances in the
crystalline rocks, each one of the upper divisions in turn being found
to rest upon the ancient gneiss.

The younger gneissic or Montalban series I have found well dis-
played in Mont St. Gothard and in the Ticino basin in Switzerland.
To it also apparently belong the granulite rocks and the mica-schists
of the Mittelgebirge in Saxony, with their dichroite-gneiss, lherzolite,
and garnetiferous serpentine, and also the micaceous gneisses of the
Erzgebirge, with their included limestones and amphibolic rocks, and
their overlying mica-schists. In these latter are found the remark-
able conglomerate beds described by Hauer in 1879, the pebbles of
which are apparently derived from the ancient or central gneiss, of
which they have the characters.’

While thus referring the younger gneisses and mica-schists alike
of Saxony and of the Alps to the Montalban, I have maintained that
the uppermost division of the newer crystalline series of Gastaldi is
to be regarded as the equivalent of the Taconian or Lower Taconic
of North America, designated by Lieber the Itacolumitic series; a
great group of strata which is traced from the Gulf of St. Lawrence,
with some interruptions, nearly to the Gulf of Mexico, and westward
to the basin of Lake Superior and beyond. This series should be
carefully distinguished from the Upper Taconic, a younger uncrystal-
line series, different in geographical distribution, and containing a
well-defined Cambrian fauna. The Taconian or Lower Taconic,
whose real stratigraphical relations were already clearly defined
more than fifty years ago by Amos Haton, has since, by various
theorists of the metamorphic school, been alternately regarded as
altered Cambrian, altered Ordovician, altered Silurian, altered Car-
boniferous, and in part even as altered Triassic;* a history which
recalls that of the similar strata of the Apuan Alps, including the
marbles of Carrara and Massa, which have by different writers been.

1 See for a detailed discussion of the questions here involved, the author’s “‘ Mineral
Physiology and Physiography,’’ on The Geology of the Alps and the Apennines, pp.
457-482 ; The Serpentines of Italy, pp. 482-496; and further, The Metamorphic
Hypothesis, pp. 654-673.

2 For a detailed acconnt of the Taconic controversy see the author’s ‘‘ Mineral
Physiology and Physiography,’’ 517-686 ; also, more concisely and with new facts,
“‘ The Taconic Question Restated,’’ Amer. Naturalist, Feb. Mar. and Apl. 1887.

540 Dr. T. Sterry Hunt—On Italian Geology.

referred to various horizons from Cretaceous down to pre-Paleeozoie,
at which latter they are placed by Gastaldi, in the upper part of his
“newer crystalline series,” as also by Jervis in the second volume of
his valuable treatise, I Tesoro Sotteranei dell’ Italia.

This Taconian or newest crystalline group embraces in North
America besides quartzites (sometimes in flexible elastic layers) and
crystalline limestones affording both banded and statuary marbles, —
large deposits of iron-ores, alike magnetite, hematite, and limonite,
the latter being formed by epigenesis, in some cases from pyrites and
in others from siderite. It also includes a great mass of argillites,
and of soft unctuous schists, often described as talcose, and though
more generally sericitic, sometimes containing chlorite and tale, |
together with occasional amphibolic and feldspathic rocks, massive
serpentines and ophicalcites, and bearing throughout a marked
resemblance to the upper division of the newer crystalline series of
the Alps.

As the writer has elsewhere pointed out, the chemical and
mineralogical conditions of the underlying pietre verdi horizon
weré repeated, though with diminished intensity, at this later time
in the history of the newer crystalline series, producing in the
younger rocks thereof such resemblances to the older that the
Taconian strata were not unnaturally confounded with the Huronian.
Thus, to the south of Lake Superior, Emmons having in 1846
recognized the Taconian, he was led, when the Huronian was
announced in 1855, to maintain (in an unpublished paper) that it
was in no way distinct from his Lower Taconic. On the other
hand, the present writer, in common with Murray, Credner, and
others, included these same Taconic rocks in that region with the
Huronian, and it was not until after a prolonged study of the
Taconian in the more eastern regions of North America, that he was
enabled to show that the two series had really been included in the
Huronian as defined in the vicinity of Lakes Superior and Huron;
where also the recent gneisses and mica-schists are met with, as well
as the ancient or primitive granitoid gneiss. In like manner, as we
have seen, Gastaldi was led, from such lithological likenesses, to
include the upper and lower division of his newer crystalline series,
with their intervening recent gneisses and mica-schists, under the
comprehensive name of the pietre verdi zone. These partial resem-
blances between the crystalline rocks of succeeding divisions serve
to illustrate the different stages in the process of evolution of the
crystalline rocks in successive ages by chemical agencies from an
originally undifferentiated mineral matter, as I have endeavoured to
set forth in a recent paper on “The Elements of Primary Geology.” }

1 GzrotocgicaL Macazine, November, 1887.

A, H. Foord—On the Genus Piloceras. 541

IJJ.—On tue Genus Pitoceras, Sauter, as ELvorATep BY
EXAMPLES LATELY DISCOVERED In NortH AMERICA AND IN

Scornanp.!
By Antuur H. Foorp, F.G.S.

PP\HE genus Piloceras was founded by J. W. Salter in 1859? upon

the siphuncle of a shell closely allied to Endoceras. It was
supposed by Salter that the invaginated sheaths observed in the
siphuncle of Piloceras ‘represented the siphuncle and septa
combined,” the septate part of the shell not being preserved in the
specimens described by him.

A year after the appearance of Salter’s memoir, E. Billings (at that
time Palzeontologist to the Canadian Geological Survey) described a
fossil from the Calciferous Sandstone (= Tremadoc) under the name
of Piloceras Canadense.* This exhibited the septate part of the
shell in conjunction with the siphuncle.

The general form of this species was well characterized by Billings
as that of a “short, thick, curved Orthoceratite.”

This appears to have been the first discovery of the septa of
Piloceras, associated with its siphuncle, for the generic identity of
Salter’s and Billings’s species is now put beyond all doubt.

Again, in 1881 Sir William Dawson‘ described a new species of
Piloceras (P. amplum) from the Calciferous Sandstone of Lachute,
near Montreal, which threw much new light upon the internal
structure of the shell.

But the most complete examples of Piloceras hitherto met with
were collected in 1885 by Messrs. Seeley and Brainerd, at Fort
Cassin, in the State of Vermont, from rocks considered to be of the
age of the Birdseye Limestone (= the Lower Llandeilo, nearly).
These fossils were described and beautifully illustrated by Professor
R. P. Whitfield, of New York,® who was enabled to show by means
of almost perfect specimens, the body-chamber, septa, siphuncle
(in place), and even the test of the species, which he very appro-
priately named Piloceras explanator.

M. Barrande,® whose information about Piloceras was very scanty,
constituted it a subgenus of Cyrtoceras, on account of its curvature,
and Professor Blake’ disposes of it in the same way, though only
provisionally, for he remarks, “The organism, whatever it is, must
wait further elucidation by materials not yet extracted from the
rocks.”

Finally, about four years ago, Mr. B. N. Peach, of the Geological
Survey of Scotland, found specimens of Piloceras at the typical
locality, Durness, Sutherlandshire, in which both septa and siphuncle

1 The substance of this paper was read before the British Association at Manchester,
in September last.

* Quart. Journ. Geol. Soc. vol. xv. p. 376.

5 Canadian Naturalist and Geologist, vol. v. p. 171.

* Canadian Naturalist, new ser. vol. x. No. 1.

5 Bull. Amer. Mus. Nat. Hist. vol. i. No. 8, p. 323, pl. xxviii. New York, 1886.

6 Syst. Sil. de la Bohéme, vol. ii. Texte, v. 1877, p. 900.

7 British Foss. Cephalopoda, pt. i. p. 186.

542 A. H. Foord—On the Genus Piloceras.

were preserved, though in a very imperfect condition. These speci-
mens have been very kindly entrusted to me for description by Mr.
H. H. Howell, Director of the Geological Survey of Scotland.

They consist of a large number of the detached siphuncles of
Piloceras, belonging most probably to more than one species. Many
of them exhibit more or less distinct traces of the attachment of the
septa in the form of encircling ridges, which give them a ringed
appearance.

i
ms

'

Fic. 1.—Piloceras invaginatum?, Salter; S, S, remains of septa; S2, siphuncle, a
little restored in the lower part, with ridges marking the attachment of the septa.
(One-half natural size).

(
I
(iW)

One of them shows the siphuncle in its natural position (Fig. 1).
This is probably the Piloceras invaginatum of Salter. The septa
must have been extremely thin and fragile, as in most cases they
have been broken away from the siphuncle, which is usually found
completely detached from them.

In the specimen I have figured the septa appear as delicate lines
upon the weathered surface of the rock. They are from 14 to 3}
lines distant from each other, measuring them from the narrower to
the broader end of the siphuncle. The latter is apparently marginal,
as in P. explanator, Whitf. 'The exact rate of tapering of the shell |
cannot be ascertained, owing to the absence of the shell-wall on one
side of the specimen, but it may be assumed to have been high.

Another example, showing obscure traces of the septa in contact
with the siphuncle, is most probably the small species referred to
by Salter in his paper above mentioned, but it is too imperfect to
characterize.

Many of the detached siphuncles in Mr. Peach’s collection differ
from each other in their rate of tapering, and distance of septa
(estimated by the distance of their encircling ridges) ; but I do not
feel justified in creating another species out of such imperfect
material. 'The smallest siphuncle in the collection measures 8 lines

A. H. Foord—On the Genus Piloceras. 543

in length and 4 lines in its greatest diameter: the largest 44 inches
in length, and 12 in its greatest diameter. Neither of the specimens
measured are perfect. The walls of the siphuncles are usually
composed of chalcedony of a minutely concretionary structure.’
In comparing the structure of VPiloceras with that of other
Cephalopods, we are at once reminded of Hndoceras, and the
resemblance between these two forms did not escape Salter’s
experienced eye. In both genera the siphuncle is very large in
proportion to the shell, and in both it is furnished with a series of
conical or funnel-shaped sheaths, which apparently communicate
with one another by means of a small central tube, the “endosiphon”’
of Hyatt (Figs. 2, 3). This tube is regarded by Hyatt as analogous

to that which has long been known in Actinoceras, and science is
indebted to that able observer for its discovery in Endoceras.*

Fie. 2. Fig. 3.

epese =

Maye
Lo

aoee>
oom C4
not) er aa
(2077 ‘
O 2
—_

7

/

Fic. 2.—I. Section of siphuncle of Piloceras, sp., showing two of the funnel-
‘shaped sheaths, s; ¢, the endosiphon, with 7, remains of former sheaths?; m, matrix
filling what remains of the cavity of the siphuncle; qg, quartz infillmg. II. Posterior
extremity of another siphuncle much eroded, but showing an aperture, @, at the apex
by which the endosiphon may have communicated with the initial chamber; w, wall
of the siphuncle, and g, quartz forming the infilling between this and one of the
sheaths. III. Transverse section of another siphuncle showing in the centre the
endosiphon e, and what appears to bea partition p, representing perhaps the septum
or ‘‘ central shelly plate’’ of Dawson. (All the figures are of natural size.)

Fic. 3.—Vertical section of an imperfect siphuncle, with a few of the septa
attached, of Piloceras amplum, Dawson, cut in the direction of the shorter diameter of
the shell, which was of an elliptical form, judging by that of the siphuncle. s w, shell-
wall; s c, siphuncular cavity; s #, sheath; w, internal wall of siphuncle; s, s,
septa; 4, broken extremity of siphuncle; 7 and e, same as in Fig. 2. The dotted

lines are restorations. (Slightly reduced from Dawson's figure, which is itself a
little smaller than the original specimen.)

' This form of chalcedony used to be called beekite, but it differs so slightly in

composition from ordinary chalcedony that that name is no longer employed for it
by mineralogists.

Proc. Boston Soc. Nat. Hist. vol. xxii. April 4, 1883, p. 261.

544 A. H. Foord—On the Genus Piloceras.

Professor Hyatt, whose conclusions regarding the present genus
are based upon Principal Dawson’s paper, explains the origin of the
sheaths in Piloceras to be due to the widening of what he terms the
“fleshy siphuncle”’ near the body-chamber. The sheaths lie some-
what loosely in the siphuncle, and they are supposed by Dawson,
upon the evidence of the specimen described by him (Fig. 3), to
have existed only temporarily, and to have been successively absorbed,
the last one only becoming completely calcified. In the Durness
specimens, however, it is not an uncommon thing to find two or
three of the sheaths preserved, their walls standing out in relief
from the surrounding matrix, which has been removed by weathering.

A series of short, upwardly projecting lines are observed to spring
from the sides of the endosiphon (Figs. 2 and 3), where it is slightly
swollen. ‘These lines are conjectured by Dawson to be the remains
of the membranous or fleshy sheaths which have become absorbed,
as suggested by Hyatt. The close correspondence of these structures
in the Scotch and Canadian species is very apparent in Figs. 2 and 3.
It is also noticeable that above the sheath whose apex is perforated
by the endosiphon there is another one, in a somewhat shrunken
condition ; this appears also to be perforated, presumably for the
passage of the endosiphon, if indeed that organ extended beyond the
apex of the larger sheath below, but of this I have no proof, as no
vestige of it can be seen above where it is figured. There is every
reason to suppose, though I am not able to demonstrate the fact, that
the endosiphon opened into the initial chamber, or at least into one
of the earlier of the septal chambers, since in all specimens in which
the apical extremity of the siphuncle is preserved, it is found to be
perforated.

It should be mentioned that Principal Dawson in his description
of P. amplum refers to the endosiphon as a “vertical partition”
crossing the lower part of the siphuncle; but Hyatt, recognizing its
tubular character in the figure, interpreted it in the manner already
described. Nevertheless there seems to have been an internal septum
extending upwards from the lower part of the siphuncle, between
the wall of the latter and that of the sheath into which the endosi-
phon opens. This septum shows itself in some transverse sections
of the siphuncle in the manner indicated at p, Fig. 2, III., and
it can be traced for some distance upwards in the vertical section of
this and of other specimens. I am unable, however, to give any
satisfactory account of it, owing to its imperfect condition. I venture
to think that Sir William Dawson, seeing this septum at the broken
end of his specimen (Fig. 3, b), concluded that the endosiphon (e, é)
above it was its upward continuation.

As regards the infilling of the siphuncle in Piloceras, it seems
obvious that the space between the inner wall of the siphuncle and
the first permanent sheath was not originally solid, because it is not
filled with the matrix, but either with calcareous, or dolomitic, or
siliceous matter, introduced by infiltration. Something was there-
fore required to give support to the sheaths, and this was supplied, in
part at least, by the endosiphon, and perhaps also by the “ septum”
above mentioned.

A. H. Foord—On the Genus Piloceras. 545

Whatever the functions of the endosiphon may have been, I do
not imagine that it played such an important part in the vital
economy of the animal as did the same organ in Actinoceras. ‘The
large endosiphon in the latter gave off tubuli which passed through
the membranous walls of the siphuncle by means of foramina.! Sir
Richard Owen conjectured that these tubuli served “for the passage
of blood-vessels to the lining membrane of the air-chambers.”? At
any rate, a vital connection was maintained between the endosiphon
and each of the septal-chambers in Actinoceras, which was wanting
in Piloceras.

The genus Piloceras may now be thus redefined :—

Shell more or less broadly conical; slightly curved ; somewhat
compressed laterally ; elliptical in section. Septa rather numerous.
Siphuncle formed by the prolongation and conjunction of the necks®
of the septa; marginal; very large; partaking of the curvature of
the shell; provided internally with one or more conical, or funnel-
shaped sheaths, which are united at the top with its margin. These
sheaths apparently communicated with one another by means of the
endosiphon, which perforates the apex of the siphuncle. The
endosiphon originated in one of the earlier of the septal-chambers,
if not in the initial chamber itself.* f

Five species of Piloceras have now been described, viz :—

P. wnvaginatum, Salter. P. amplum, Dawson.
P. Canadense, Billings. P. explanator, Whitfield.
P. Wortheni, Billings.

Thus, nearly all the structures in the siphuncle and some of those
of the chambered portion of the shell of Piloceras described by
Dawson and Hyatt are demonstrable in the splendid series of
specimens brought together by Mr. Peach.

The great desideratum now is to obtain a specimen which will
disclose the connection between the apex of the siphuncle and the
chambered part, of the shell. For this purpose a tolerably perfect
specimen would be required. Perhaps some of the material so
ably dealt with by Professor Whitfield may supply the want? One
can scarcely expect to find sufficiently perfect specimens in the
Durness rocks.

From a geological point of view Piloceras is interesting on account
of its association in Scotland and in eastern North America with a
little group of fossils in which several species appear to be common
to both countries.

1 These are beautifully preserved in many examples of Actinoceras in the British
Museum (Nat. Hist.).

2 Paleontology, 2nd ed. 1861, p.102. See also L. Saemann, Ueber die Nautiliden,
Palzontographica, Band iii. 1845, p. 121, Tab. xviii.

3 Called “funnels’? by Prof. Hyatt. ‘‘ Siphonalduten”’ of the Germans ;
“ soulots ” of the French.

* Hyatt in his definition of Piloceras (loc. cit. p. 266) states that it is “ often
annulated,” but this is evidently an inadvertence, because the outer shell was
unknown when he wrote, and remained so until the specimens described by Prof.
Whitfield saw the light, and these showed only ‘‘a few transverse wrinkles of
growth.””? He probably had in his mind the detached siphuncles, which have an
annulated appearance caused by the adherent remains of the septa.

DECADE IlIl.—vVOL. IV.—NO. XII. 35

046 Alfred Harker—On some Anglesey Dykes.

Salter enumerates amongst others the following American species
in the Durness Limestone ; some of which, however, are too imperfect
for accurate identification :—

Orthis striatula, Emmons [non Schlo- | Orthoceras arcuoliratum, Hall. -

theim]. ——— wndulostriatum, Hall. -
Ophileta compacta, Salter. — vertebrale ? Hall [very doubt-
Maclurea matutina ? Hall. ful].

In addition to these, there are among the fossils I received from
the Geological Survey of Scotland, specimens of Endoceras in a very
fragmentary condition, but resembling certain small (?) species
with very closely approximate septa, described and figured by
Billings from the Calciferous group of Canada.!

A Cyrioceras, very probably the Oncoceras ? referred to by Salter,
is also in a condition unfit for determination.

Though the Durness fossils are by no means well preserved, yet
it can hardly be disputed that their general facies, as Salter affirmed,
is American rather than European. The testimony of the fossils, so
far as it goes, is supported by that of the rocks, for we learn from
Mr. Peach? that in the order of succession of the beds in the North-
west Highlands of Scotland an almost exact counterpart is presented
of the strata “exposed along the axis of older Paleozoic rocks,
stretching from Canada through the Hastern States of North
America.”

“In the latter region,” continues Mr. Peach, “the Silurian strata
of Sutherlandshire are represented by (1) the Potsdam Sandstone,
always described as being vertically piped by Scolithus, like the
“pipe-rock”’; (2) the Calciferous group; and (8) part of the
Trenton Limestone.

He further argues, that the beds in these widely-separated areas,
though probably not contemporaneous, were homotaxial, and he
supposes that the species migrated from one province to the other
“along some old shore-line or shallow sea,” some barrier separating
them from Wales and Central Europe.

IV.—Woopwarpi4n Museum Nores: on some ANGLESEY Dyxzs. II.
By Atrrep Harxer, M.A., F.G.S.,
Fellow of St. John’s College.

N the northern half of Anglesey occur several intrusions of dark
hornblendic rocks, some specimens of which were placed by
Henslow in the collection made by him for the Woodwardian
Museum. These rocks present a type unusual in Britain, and show
some peculiarities which are of considerable interest.
A few years ago Professor Bonney found on the south-west coast
of the island some boulders of a rock which he described* under the

1 Canadian Naturalist, 1859, vol. iv. p. 361.

2 Presidential Address before the Royal Physical Society of Edinburgh, Noy. 1885.

3 Q. J. G. 8. vol. xxxvii. p. 137, 1881: vol. xxxix. p. 254, 1883: vol. xl.
p- 515, 1885. See also Teall, ‘‘ British Petrography,” pp. 81, 82; plates iv.
‘and vi. 1886.

Alfred Harker—On some Anglesey Dykes. 547

name of Hornblende-picrite. It was subsequently pointed out by
Professor Hughes that the probable source of these rocks was to be
found in certain intrusive masses near Llanerchymedd, and indeed
such boulders are scattered about rather abundantly in that neigh-
bourhood and to the south-west. The rock in question seems,
however, to be the common type of the larger eruptive masses in
_the north of Anglesey, and brief notes on slides cut from selected
specimens taken in place may be found not unprofitable. The rocks
were noticed and megascopically described in Herslow’s Memoir."

There are three localities in each of which similar varieties occur.
The first lies to the north and north-east of the town of Llanerchymedd,
where the map of the Geological Survey shows nine intrusions.
These masses, not properly dykes, have an oval or elongated form,
with lengths of from 200 yards to three-quarters of a mile, their
long axes running generally with the strike of the adjacent strata.
These beds, Arenig according to Professor Hughes,” are baked at
the junction, but not extensively altered. On Henslow’s map no
attempt is made to separate the several patches, which are marked
as one area of “greenstone.” I have collected specimens from the
six masses lying between Rhodogeidio and Llandyfrydog, but am
not able to state whether the three patches to the north of the latter
place are of similar characters.

A large irregularly-shaped mass appears on the western slope of
Llaneilian Mountain, in the north-eastern corner of Anglesey. ‘This
has been mentioned by Professor Hughes and examined micro-
scopically by Professor Bonney. It too pierces rocks probably of
Arenig age, as well as the debatable Amlwch series. Our specimens
are from Pengorphwysfa.

The third area is situated to the east of Llanbabo, among the
alluvial deposits of the River Alaw. The exposures here are,
according to Henslow, “not well exhibited,” and they have escaped
the notice of the Survey; but the locality is verified by Professor

- Hughes, who obtained a similar rock from south-west of Glas-grug.

Rocks having many points in common with these occur as parts of
some large dykes in Holyhead Island; but they will be more con-
veniently considered apart, and our present description. will apply
only to the three groups of intrusive masses mentioned above. ‘The
-specimens are selected as follows :—

J. Hafod-in-in dyke (A 130, 181) ;
Rhodogeidio dyke (A 182) ;
Llys Hinion dyke (A 86, 91, 94, 1384, and Hughes Coll. 38) ;
Maen Chwynt dyke, probably (Sedg. Coll. 37) ;
Llandyfrydog dyke (Henslow [695 ]) ;
II. Llaneilian Mountain intrusive mass (A 35, 87, and Hughes
Coll. two slides), = — Pengorphwysfa near Amlwch ;
also Henslow [71
III. Dykes or masses ie of Llanbabo (Henslow [711, 712]).
Besides these, a large number of hand-specimens from all the
localities have been examined.

1 Trans. Phil. Soc. Camb. vol. i. 1822. ? Q.J.G. 8. vol. xxxviii. p. 26, 1882.

548 Alfred Harker—On some Anglesey Dykes.

The constituent minerals of these rocks are apatite, ilmenite,
pyrites, magnetite, olivine, felspar, augite, hornblende, and biotite ;
besides leucoxene, serpentine, calcite, quartz, chlorite, epidote, and
other secondary products.

Apatite is often abundant in slender prisms, and seems to be
always the earliest formed constituent.

Tron-ores are almost always among the original minerals, and
sometimes magnetite and ilmenite are recognizable in the same slide.
Ilmenite when best developed shows in skeletons of intersecting
rods choked with grey leucoxene; in other places the presence of
a titaniferous mineral can only be inferred from these cloudy grey
masses. Magnetite sometimes forms rods, but more usually imperfect
cubes. There is also secondary granular magnetite resulting from
the alteration of the iron-bearing silicates. In some of the original
grains a scarcely perceptible brown translucency may indicate
picotite.

Olivine is rarely abundant, and for the most part not detected.
Occasionally rounded and oblong patches of serpentine show the
characteristic mesh-structure ; but the bulk of this substance met
with in the slides can be clearly traced to the decomposition of
pyroxene and amphibole minerals, and is usually mixed with chlorite.
The rocks east of Llanbabo, however, show plenty of olivine.

Felspar of the lime-soda series seems to have been a universal
constituent, and locally abundant. In most of the slides this mineral
is replaced by calcite, chlorite, and quartz. Where the felspar is
fresh enough to exhibit its original characters, it seems from its low
extinction-angles to be never a very basic variety : it may be referred,
if this test is trustworthy, to andesine and oligoclase. 'Twin-lamel-
lation on the albite-law is almost always seen, but the pericline
twinning rarely. The felspar is usually later than the ilmenite, and
earlier than the augite and hornblende, which it penetrates; but in
some slides from Llys Hinion the felspar partly penetrates and partly
moulds the hornblende.

Augite is not always present, but it is probable that this mineral
has been essential in all these rocks, and has been in great part
replaced by hornblende. In some slides from the Llys Hinion and
Llanbabo dykes the process of conversion can be traced. The two
minerals have the orthopinacoids and the clinopinacoids parallel:
they are most intimately associated, with an extremely irregular line
of division, and the augite often remains as a core surrounded by
brown hornblende.

Hornblende is the most abundant mineral in these rocks, and
occurs in several distinct varieties. It is the prevalence of one or
other of these varieties, as much as any essential diversity of con-
stitution in the rocks, that gives rise to the difference of aspect observ-
able in hand-specimens.

Original hornblende is found in well-formed crystals, usually
from one-eighth to half an inch in length. The terminal planes are
probably in most cases the usual (011) and (101), but the basal
plane also occurs (001), and a very oblique one which may be (201).

Alfred Harker—On some Anglesey Dykes. 549

The cross-section always shows the prism form (110) well developed,
often truncated by the clinopinacoid (010), and sometimes the
orthopinacoid (100). Twinning on the usual law is common. The
prismatic cleavages are well-developed, and rarely the clinopinacoidal
cleavage is nearly as well marked. The colour is usually brown,
with strong pleochroism, vibrations parallel to the axes of elasticity
giving: y, deep chestnut brown; f£, a less deep brown; a, a pale
brown. The absorption is then y > 8 >> a; more rarely it is
y= B>> a. Sometimes, however, this original hornblende is
brownish-green, the vibrations parallel to the y-axis giving a pale
grass-green, and perpendicular to it a very pale brown. The larger
erystals occasionally present a mode of alteration different from the
ordinary chloritic and serpentinous changes, and consisting sometimes
of a brown coloration, sometimes a decoloration and decomposition
into a granular substance. These alterations affect the hornblende
along certain planes, which are not parallel to the prismatic cleavage,
but to the clinopinacoid, and are perhaps to be regarded as ‘ solution-
planes” (Lésungsflichen).

Another kind of hornblende, probably also original in the usual
sense, is often present in the dykes to the north of Llanerchymedd.
A cross-section of a brown hornblende crystal is seen, showing the
prism and clinopinacoid faces, but upon the latter a later accretion of
green hornblende-substance, in crystalline continuity with the brown,
has reduced or entirely built over the clinopinacoids, extending the
prism-planes at their expense. From its relation to surrounding
minerals and from its always presenting definite crystal boundaries,
this later growth of green hornblende seems to have originated
before the final consolidation of the rock.

Next comes the hornblende resulting from the alteration of
original augite. The “paramorphic” origin of hornblende from
pyroxenic minerals has received so much notice in recent years,
that there is no need to enlarge upon it here, further than to remark
that the term “ paramorphism ” is strictly applicable only when the
two minerals yield identical analyses, which is probably an unusual
case. In the present instance it is most likely that some chemical
as well as physical change is involved. The hornblende thus produced
is brown, compact, and well-cleaved : in fact a study of the Anglesey
dykes, as well as rocks from several localities in Carnarvonshire,
bears out the conclusion of Lossen and others, that neither colour
nor structure affords any reliable criterion for discriminating between
original hornblende and that resulting from the amphibolisation of
augite. It is possible that some of the hornblende may be derived
from a rhombic pyroxene, and indeed the slides from the rocks east
of Llanbabo have a mineral resembling altered enstatite. Professor
Bonney has noticed the same in the Llys Hinion dyke and boulders.

Some slides (e.g. from the Hafod-in-in dyke) contain a consider-
able quantity of a rather pale, dull, brownish-green or greenish-
brown hornblende without crystal boundaries. Compared with the
foregoing varieties, it is seen to be less clear and less strongly
coloured, to give lower polarisation-tints, and to have its cleavage-

550 Alfred Harker—On some Anglesey Dykes.

traces often less pronounced. It is later than the original brown
hornblende, which it includes. It also includes augite, without any
definite crystallographic relation to it, and so is probably not
‘paramorphic.’ On the whole, it seems likely that this dull-coloured
hornblende is a secondary growth posterior in date to the consolida-
tion of the rock, though this cannot be regarded with certainty, as
in the following case.

Lastly, we have hornblende, sometimes green, but more commonly
colourless, forming a sharply-defined border to original hornblende
crystals, and filling the interstices between them. A study of the
slides leaves no doubt that this new growth of hornblende-substance
has taken place subsequently to the consolidation of the rock. In
some cases it can be verified that the new hornblende extends into
the space formerly occupied by felspar crystals. Again, the inter-
space between two or three original or paramorphic hornblendes is:
found to be filled by colourless substance, which between crossed
Nicols breaks up into distinct portions in crystalline continuity with
the several adjacent crystals. This is exactly analogous to the
cement of secondary quartz observed by Dr. Sorby and others
between the grains of certain quartzites. Sometimes a well-bounded
original crystal has a sharply-defined border of greener horn-
blende, and outside this a margin of colourless hornblende-
substance with ragged outline abutting upon patches of calcite dust,
etc., which probably represent destroyed felspar. In such a case
the double border is all in crystalline continuity with the original
crystal. The secondary hornblende here described gives rather
higher polarisation-tints and a slightly wider extinction angle than
the other varieties of the mineral.

Mr. Van Hise, who was the first to notice the “secondary
enlargement of hornblende fragments” in conglomerates, has re-
cently described’ a like phenomenon in altered diabases from
Michigan and Wisconsin, and he cites similar results arrived at by
Becke*® in 1883. I am not aware that this secondary growth of .
hornblende on the margins of pre-existing crystals has been recog-
nized in British rocks, although Prof. Bonney, referring to the rocks
now under discussion, has remarked on the sudden transition from
dark brown to almost colourless hornblende, and has figured a very
characteristic case in a similar rock from Little Knott in Cumberland.*
The Rhodogeidio and Llys Hinion dykes furnish the best examples.

The only remaining mineral that calls for special notice is the
brown mica, which has been mentioned above as biotite, although
its characters are not easy to make out very definitely. It is not
abundant except in some specimens from Llandyfrydog, which have
to the eye almost a lamprophyric aspect. In his specimen [695]
especially Henslow remarks the presence of “small shining plates,
apparently diallage.” These are the flakes of mica, and their
peculiar lustre is explained on examination under the microscope.

1 Amer. Journ, Sci. May, 1887, 8rd ser. vol. xxxiii. p. 885.

® Tscherm. Min. u. Petr. Mitth. vol. v. part ii. 1883.
° Q. G. G. S. vol. xli. plate xvi. fig. 2, 1885.

Alfred Harker—On some Anglesey Dykes. 551

The slide appears at the first glance totally unlike all the others,
showing only numerous flakes of mica in a confused mass of
decomposition products, without any trace of augite, olivine or
hornblende. The mica is less strongly coloured and_ less pro-
nouncedly dichroic than is usual in biotite, except in the bleached
mineral often met with in the lamprophyres and some peridotites.
It gives, however, a moderately deep or rather light brown for
vibrations parallel to the cleavage-traces, and a paler brown in the
direction at right angles to this. ‘The extinctions are sensibly
parallel and perpendicular to the traces, and a cleavage-flake is dark
between crossed Nicols. The plates are split into thin lamelle
separated by lenticular grains and layers of a colourless, doubly
refracting mineral. The interposition of calcite lenses between the
folize of biotite has been noticed by Zirkel, Hussak, and Williams,
but here the mineral is not calcite. Each lenticular grain consists
of portions differently oriented, and there is sometimes a radial
fibrous appearance suggestive of a zeolitic mineral. The mica
includes also a large quantity of granular magnetite. A slide [711]
from the Llanbabo mass contains precisely similar flakes of mica,
though in much less quantity, and the mineral appears to be closely
connected with the brown hornblende, as if resulting from its
alteration. This slide probably shows the beginning of a process of
which the Llandyfrydog specimen represents the final stage. The
secondary production of biotite in place of hornblende is seen also in
the Pen-y-rhiwiau and Penarfynydd rocks mentioned below, and in
some other Welsh rocks, such as the syenite of Llanfaglen near
Carnarvon.

The structural variations of each dyke have not been studied in
detail. As Henslow and Professor Hughes have pointed out, the
megascopic characters often change largely in a very short distance,
though the microscope shows that these variations do not always
import any considerable difference in constitution. The more
felspathic type of rock sometimes occurs as segregation-veins in the
darker and more hornblendic.’ The dykes grow rather finer-grained
at the immediate margin, and these portions are more susceptible to
destructive weathering action than the coarser rock. A slide (A 134)
from Llys Hinion, close to the junction with the shales, shows
advanced decomposition ; but besides the calcite, ‘ viridite,’ etc., there
remains an abundance of felspar in good crystals, and partly bleached
brown hornblende in crystals and ophitic plates, the latter bordered
by colourless fringes of the usual secondary growth.

The coarse black type of rock, with its cement of secondary
hornblende, is very durable, and, as has been remarked, the erratics
are mainly of this variety. The dykes themselves form prominent
features in the country, which doubtless led Henslow to map the
whole district north of Llanerchymedd as consisting of these rocks.
The smaller dolerite dykes of southern Anglesey, on the other hand,
make but little show at the surface, and are difficult to find; a fact
indicated on the Survey Map, where the greater part of the dykes
marked are on the sea-shore.

502 J. R. Gregory—New French Meteorites.

The affinities of the rocks described above have been discussed by
Prof. Bonney, who points out their close resemblance to that of Pen-
y-rhiwiau near Clynnog-fawr, Carnarvonshire, and the so-called
Diorite of Little Knott in Cumberland. With the latter I am not
acquainted, but a number of slides cut from selected specimens of
the Pen-y-rhiwiau mass show the closest resemblance to these
Anglesey dykes, especially those of Rhodogeidio, Llys Hinion and
Hafod-in-in. There are the same minerals associated in the same
manner,’ the amphibolisation of the augite, the secondary marginal
growth of colourless amphibole, and the apparent conversion of the
brown hornblende into biotite being all well exhibited. There is
more olivine than in the Anglesey ‘ dykes,’ although this constituent
is variable in amount, anda few other differences are to be noted ;
but the rocks may well be classed together. Bearing in mind the
comparatively small quantity of olivine found, the constant presence
of felspar, and that not of a basic variety, the common occurrence of
original iron-ores, and the general structure of the rocks, they seem
to find their most natural place among the olivine-bearing horn-
blende-diabases, rather than with rocks of ultrabasic type.

The mode of occurrence of these masses is different from that of
the beautiful hornblende-picrite of Penarfynydd, which forms a
massive bank 200 or 300 feet in thickness, and of very uniform
character. It is worthy of note that the intrusions of Llys Hinion
and Llaneilian Mountain, as well as Penarfynydd, occur in Arenig
strata, and the slates at Pen-y-rhiwiau are referred to the same age:
I do not know with what degree of probability the Skiddaw slates of
Little Knott can be assigned to the Arenig also.

V.—Two New Frencu Meteorites.
Preliminary Notice by Jamzms R. Grecory.

1 ie Meteorites from France have recently come into my possession

from a private source, one of which, though not of a recent fall
(1836), has neither been described nor chemically examined, and
which I now briefly bring to notice, it being of a most rare type.
The other is of a much more recent fall (1875), and is of a much
more ordinary character, being similar to many other meteorites of
the same class; this stone also appears not to have been described,
nor has any notice of it been published. It is somewhat a remark-
able coincidence that these two stones should have fallen in the
same Department, although at such widely different dates, and from
the data and notes I have received from careful inquiries, 1 now
bring forward the following details of these two aerolites.

I. Avsres, Commune or tax Canron or Nyons (Dréme), FRANCE.
This meteoric stone fell on September 14, 1886, at 3 p.m., in calm
weather and blue sky, at Aubres, Commune of the Canton of Nyons,
in the department of Dréme, France. It fell on a hard and pebbly
* The resemblance eyen extends to the ‘ solution-planes ’ in the brown hornblende,

parallel to the clinopinacoid (010). The slides from Pen-y-rhiwiau, however,
contain an abundance of pale grass-green actinolite in blades and fan-shaped bundles.

J. R. Gregory—New French Meteorites. 553

road, near to a tree under which a shepherd named Favier had taken
refuge. This man hearing—to use his own words—“ something
snore which came from the heavens,” observed the fall and found
the stone, which had forced itself in spite of the hardness of the
road into the soil, it is not stated to what depth—probably no great
distance, owing to the fragile character of the meteorite; he after-
wards drew it out with his stick, the end of which was stated to
have been burnt by the heat. This is probably a fancy, as the nature
of the stone would preclude the idea of any great heat being present,
it being essentially a stony meteorite, containing apparently no free
nickel-iron, and consequently less likely to be hot, or so hot as
meteorites containing much metallic particles, they being better
conductors of heat. The man states that having allowed it to cool
he took it to his master’s house, where it was broken to find out
what was inside, and then seeing it was ‘‘a stone like other stones,”
it was thrown upon a shelf and forgotten. In 1845 the Pasteur
Muston of Bordeaux, who was interested in mineralogy, happening
to hear of the circumstances of the fall, went and examined it,
afterwards purchasing it, and who had retained it, till it came into
my possession. No other stone was found, or believed to have
fallen, nor has any public notice appeared of the circumstances
attending its fall. It was found by simple peasants who saw
nothing very wonderful in it.

This very interesting stone at present weighs 567 grammes,
though probably at the time of its fall it must have weighed about
800 grammes, a portion being broken off by the shepherd who
secured it, and which is probably lost. It is of an extremely fragile
nature and more like that very rare type the Bustee meteorite. It
has a highly crystalline structure, exhibiting broad cleavages of an
almost white mineral, it has also a very brecciated appearance, but
does not seem to contain any of the peculiar mineral named osbornite
by Prof. Maskelyne, who first described this mineral in the before-
named stone of Bustee; it contains certain small brown patches
which may prove to be osbornite on careful examination. The
crust is extremely thin, of a pale brown colour, and somewhat
vitreous and sufficiently translucent to show the brecciated structure
of the stone within, in this respect it also resembles the Bustee
meteorite ; some parts of this crust exhibit a slight iridescence.
In form it is somewhat oval, rather flattish, and pitted with the
frequent pittings characteristic of many meteorites as well as meteoric
irons.

II. Commune or Mornans (Drome), FRANCE.

This meteorite fell in September, 1875, in the Commune of
Mornans, Canton of Bordeaux, Department of Dréme, France, the
exact date apparently is not known; it is said to have fallen in calm
clear weather, and followed an explosion which was preceded by a
gust of wind, and gave during its fall a harmonious sound compared
to that of an organ; many minute details seem to have either been
forgotten or were not observed at the time of the fall.

The stone probably weighed about 1300 grammes, and when it

004 Robert G. Bell—Notes on Pliocene Beds.

came into my possession weighed 1170 grammes. In form it is
rather rectangular, with rounded angles and prominences, being
thicker in the middle of the stone. The interior is of a fine-grained
granular structure of a bluish-grey colour, and contains several of the
veins or faults like the meteorite of Chateau Renard and others, and
belongs to the chondritic class of meteorites; it contains a compara-
tively small amount of iron, which is evenly disseminated through-
out the mass, the crust is of a moderate thickness and of a dull
black colour; about one-half of which is covered with a brownish
stain, probably where it rested on the soil, a character frequently
observed in other meteorites. A single stone apparently only fell, at —
least no others were found. The fragment broken off was said to
be for the purpose of analysis, but the result is not known, as no.
public notice has been made of this fall.

VI.—Notrs on Puiocene Beps.
By Rosert Grorce Bett, F.G.S8.

| Eva some years past the Upper Tertiaries of England have not.

received such a liberal share of attention as was bestowed on
them at one time by the older geologists, probably in part because
of the impression unwittingly encouraged by some of the authorities
in science, that little original work in the way of discovery can now
be done in connection with the organic contents of the Upper
Tertiary deposits, the number of species already recorded being
very large.

Other considerations, such as the comparative shortness and
insignificance (geologically considered) of the period of time during
which these deposits were forming, have also doubtless tended to
divert the attention of the younger students of geology to the more
difficult and less known faunas in older formations.

And yet the termination of the discovery of new species would
seem to be as far off as ever. Very little is actually known of the
fossil forms of many of the lower classes of organisms; indeed,
excepting in the Mollusca, the information that has at present been
published is extremely meagre, our knowledge of the Annelids,:
Echinoderms, Polyzoa, and many other groups of the Invertebrata,
in which the Pliocenes of Britain are very rich, is in fact astonish-
ingly behind that which has been attained as regards Mollusks and
Vertebrates.

Independent of fresh discoveries, there is a line of research which
may with advantage be followed by the paleeontologist dealing with
material already identified, and about which much is known. He may
seek to trace out the life history in time and space of a species or
group of species, which, having appeared in some antecedent
period, has lived on to our own time. For such purpose the present
generation possesses many advantages, the numerous recent deep-
sea explorations having revealed facts respecting geographical and
bathymetrical distribution which help to elucidate the condition of
the Tertiary seas, and thus to enlarge our acquaintance with the
zoological history of many fossil forms.

Robert G. Bell—Notes on Pliocene Beds. 555d:

Research on similar lines was advocated some years ago by the
late Edward Forbes to the zoologists of his day. He remarks that
“to get at the causes of such phenomena (the distribution of species),
we must trace the history of the species backward in time and
inquire into its connection with the history of geological change.”
It is evident that such a course of investigation as that suggested by
Forbes must prove to be equally beneficial to paleeontological students,
and its wisdom has been often manifested of late years, during which
experience has shown how dependent each line of study is upon the
other.

The earliest indication of the Pliocene period in Britain seems to
be the strongly ferruginous deposit at Lenham near Maidstone,
occupying the so-called pot-holes of the Upper Chalk surface, and
spreading over a considerable extent of the North Downs; at this.
place the impressions of shells in this hard rock are plentiful, and so:
far as present observation goes are of Pliocene forms. The locality
has never been thoroughly examined, and would well repay patient
exploration. The latest list of the species, which, however, is not
exhaustive, is in a communication by Mr. Clement Reid, F.G.S., to
“Nature” (No. 876, August 12th, 1886), and contains some which
have not yet been found in our Crags. The age of this Lenham bed
is now generally regarded as that of the similar Diestien deposit in
Belgium.

Mr. Reid holds that this deposit is contemporaneous with our
Coralline Crag. However that may be, the writer must strongly
demur to the association of either of these deposits with those found
in the well-sinkings near Utrecht, the fossils of which are so well
identified and delineated by Dr. J. Lorié, in the paper referred to
by Mr. Reid.

The high northern character of many of the Mollusca found in
these beds is unmistakeable, and is closely correspondent with that
of the fauna of the upper deposits of the Red (Butley) Crag. It is.
significant that no such Arctic forms as several of those mentioned by
Dr. Lorié have ever occurred either in the Lenham or Coralline beds.

The fauna of these earlier deposits indicate a warmer temperature
and a nearer relation to Miocene times than that possessed by the
Red Crag. The Cassidarias, Pyrulas, Volutes, and other shells,
Fusus alveolatus and F. consociale, for instance, all of semi-tropical
character, occur in certain zones of the earlier Crag in some
profusion, and generally in perfect condition; indeed, where the
matrix is dry, they may compare favourably with the French
Tertiary shells. In the later Crags the southern species thin out
and fast disappear as we rise higher in the series, and in the case of
species which are not uncommon to both, e.g. Voluta Lamberti, the
condition is rarely perfect, and the fine sculpture observable in the
Coralline Crag shells is always absent ; even those shells which un-
doubtedly lived in both formations, such as Buccinopsis Dalei, have
materially altered in shape and size after the advent of the Red Crag,
and appear in greatly increased numbers.

The changes both in diversity of climate and of life have doubtless

006 Robert G. Bell—Notes on Pliocene Beds.

been very great in the Hast Anglian area during the Pliocene period ;
the species quoted above are a few examples among many which
exhibit these alterations. Do not such facts imply that a much
longer time than is generally allowed, is necessary to account for
the variation and extinction of species, which occurred during the
formation of the Crags ?

At Walton-on-the-Naze, the Red Crag is shown (as the late Mr.
Searles Wood always insisted) in its earliest and purest condition; it
is the most instructive section at present visible, and contains by far
the largest number of species, especially of Mollusca, of which about
235 have been recorded up to the present time; yet many of the
genera of the older Crag, particularly those of southern habit, are
absent, and others exist only in a dilapidated or fragmentary state.

An examination of the deposit shows that it was formed in a
shallow depression of the London Clay, in the central and deepest
part the Crag beds being almost horizontal and undisturbed. Here a
number of Pectunculi may be found, with their valves united, and in the
position in which they lived and died. Just above this bed the
large Almond Whelk, Fusus antiquus, makes its first appearance in
geological history, and so far as evidence is concerned this seems to
have been its birth-place; it comes in as it were with a rush (as at
a much later date did Tellina Balthica), the deposit at this spot being
full of them in the finest and most perfect condition. :

The appearance of this shell in our Pliocenes may be taken as one
of the best indications of the great change of climatic conditions
which had occurred since the close of the Coralline Crag; it may be
seen in plenty in the Red Crag beds overlying the Coralline at
Sutton (the best and almost only instance where the superposition
can be seen) ; but it has never been observed in an earlier deposit,
either here or on the Continent.

Another striking evidence of change of condition in the Hast
Anglian area is that this shell is the first and best representative of
a family or section (Neptunea) of the old Linnean genus Murex, which
is almost exclusively confined to the Boreal and Arctic regions of the
world. Not only this species, but the whole of this particular section
(if the doubtful subgenus Sipho is excepted) had, so far as has been
ascertained, no previous existence to Red Crag times, since which
period it has continued with undiminished vitality, and in recent
seas it is as plentiful in suitable places as formerly, and exhibits still
more variety than in the limited Crag area.

The sculpture of the earliest form agrees in its fine striation with
that almost universal with these shells round the coasts of Great
Britain, and more particularly with those on the sandy flats round
the mouth of the Thames. Only in St. George’s Channel off the
Irish coast does the carinated variety occur in any number. Several
other northern forms of Mollusca have been found here at various
times, some quite recently, as Fusus Islandicus (Chemnitz), and it
would seem to point to the existence there of one of those old boreal
outliers mentioned by Edward Forbes as among the indications of
a former glacial climate.

Robert G. Bell—Notes on Pliocene Beds. 557

The shells of Fusus antiquus found in the lower beds of the
deposit at Walton are invariably sinistral ; but in the middle zones of
the Red Crag about Sutton the dextral shell occurs plentifully, and
both forms are often carinated; but in the upper horizon in the
- neighbourhood of Butley, and in the Norwich Crags, these carinations
are more pronounced, and the reversed shells generally fewer. It is
here that the Boreal and Arctic Mollusca are most numerous, and
that the number and size of shells having southern affinities dwindle
into smaller proportions.

The contention of Mr. Searles Wood that this species first appeared
in the reversed state, afterwards becoming dextral in the course of
time, certainly appears to agree with known facts. In the grey
sand at Walton, as in the Belgian equivalents of this zone, no dextral
-forms have been found, although in the upper Red Crag at this section
two broken and worn specimens have rewarded a long continued
search.

How to account for this important variation of form is more
problematical: is it dependent on alteration of climate? Perhaps
the gradually cooling condition of the Crag seas was prejudicial to
the original state of the shell, the dextral variety may be a hardier
form gradually superseding the other, until it has become the rare
exception only occasionally found. The cold seas of the Arctic
climate certainly possess two Molluscs, Buccinum deforme, Midd.,
and B. Harpa, Morch. (Heliotropis, Dall.), which are always sinistral,
and Middendorf mentions the reversed F. antiquus as found in the
Polar Sea and Russian Lapland, and Woodward as from the Sea of
Ochotsk ; but these examples must be extremely rare, and altogether
it seems that the sinistral condition of any of the shells of Mollusca,
whether that condition be normal or not, is much less frequent in
cold than in warm or even temperate seas. In Great Britain it is
doubtful whether the reversed Fusus has been found living anywhere
except in the neighbourhood of the German Ocean, where among
many thousands of others an example closely approaching the
Walton type is occasionally seen; but in Vigo Bay, in the north of
Spain, a small colony still lingers, the late Mr. McAndrew having
collected it with a number of other shells of Celtic character. The
specimens do not seem to differ materially from other coarsely
striated forms, and are certainly identical with those from the
Pleistocene deposits of Sicily; but there is no certain authority for
its existence in the Mediterranean.

The small reversed form from the Wexford gravels may be men-
tioned here; it is different from any other known to the writer,
being very thick and quite smooth; it is said to be associated with
many southern shells. So little, however, is accurately known with
regard to the position or contents of the various beds of marine
gravels in Ireland, that at present any conclusions must be premature.

The variety of form and sculpture exhibited by this species in the
Red Crag is more than equalled by its divergence in modern times,
The Fusi found in the Northern. Hemisphere no doubt present great
differences, but in their general characters most of them have a

008 T. Mellard Reade—The Dimetian of St. Davids.

strong resemblance to one another, and, considering the long lapse of
time Fusus antiquus has lived, the many geographical positions it has
occupied, the different conditions, climatal and otherwise, in which it
now exists, is there not reason to conclude that it is the original
parent stock from which most of the species now inhabiting the
Northern Hemisphere have branched forth ?

The New England shell called Fusus tornatus by Gould (Inv.
Mass. 2nd edit. p. 87) closely resembles some examples collected at
Bramerton, near Norwich; it is recognized by him as resembling the
Crag fossil; its relation to Fusus despectus, lL. (which again it is
almost impossible to divide from the carinated form of F. antiquus)
is acknowledged by later authorities, such as Verrill, Sars, and Friele.

-In the Red Crag, however, the carinations are seldom, if ever,
shown so sharply as in the last-named shell, possibly from abrasion
as in the case of most Crag Gasteropods; in their present aspect with
their strong coarse carine, they nearly resemble the older shells of
fF. liratus, Martyn, a native of Behring Sea. FF. fornicatus of Linné,
which has the carine coarse and undulating, has not been met with
in the Crag, although sought for diligently by the late Mr. Wood.

On the Pacific Coast of North America Fusi are scarce in number,
fF. iabulatus of Vancouver not having much resemblance to our shell ;
but on the opposite coasts of North-Eastern Asia varieties of the
common form occur in the seas of North Japan. The Aleutian pro-
moutory and group of islands probably deflecting many of the Arctic
Molluscs inhabiting deep water to the Asiatic side, where they are
carried south by the main current of water which sets that way.

The fragmentary character of the geological record is very apparent
in the Pliocenes of Northern Europe, but their total absence in North
America, and our limited knowledge relating to any of these deposits
(small in extent as they are) outside the British Islands, imposes great
difficulty and consequent imperfection in such life studies as have
been attempted above.

Vil.—Tue Dimertan or Sr. Davips.
By T. Mztiarp Reapsg, F.G.S.

AVING been lately at St. Davids, I made some observations in

relation to the Porth-lisky granite or Dimetian of Dr. Hicks,

which may be worth recording in the pages of the GuoLogicaL
MaAGazINE.

Perhaps it may be well for me to state that previous to my
examination I had no bias whatever in favour of any of the explana-
tions of the geology of St. Davids which have been offered by
Hicks, Geikie, or Blake.

With Dr. Hicks’s map in hand? I examined many of the contacts
of the granite with the surrounding rocks, but could see no evidences
of any faulting sufficient to justify its title to be recognized as a
distinct Archzean formation.

The evidences I did collect, as will be seen in the sequel, tend to

1 Pre-Cambrian Rocks of Pembrokeshire, Q.J.G.8. vol. xl. p. 560.

T. Mellard Reade—The Dimetian of St. Davids. 009

show that the rock is not in any sense Archean, but is post-Cambrian
and intrusive.

First, a few words with regard to the nature of the faults required
on Dr. Hicks’s hypothesis to entitle the granite or granitoidite to be
considered the oldest of the Archean series he has sought to establish
at St. Davids.

The bedded rocks surrounding the granite boss have a high dip
often approaching the vertical. On the one side to the south and
in contact with it lie the admittedly Cambrian rocks, and on the other
to the north-west also in contact, the underlying volcanic series or
“ Pebidian ” of Hicks. Now as the “ Dimetian” (granite) is in Dr.
Hicks’s view older than either series, yet occurs between them,
it cannot have been placed in its present position by the folding
which tilted the Cambrians and volcanics. It must therefore have
been pushed through these highly-inclined rocks as a sort of plug,
consequently Dr. Hicks in his map has shown the granite cut off
from the surrounding rocks by a set of boundary-faults. To establish
the existence of such a remarkable phenomenon would require the
most complete and reliable evidence—such evidence as I venture to
think has not yet been given.

If we consider the throw required in this way to bring the
“ Dimetian ” into its present position, we shall find that it will have
to be estimated by thousands of feet. Does any geologist venture
to assert that the so-called junction faults represent any such a
movement? On the contrary, had such tremendous displacements
occurred, I hold that geologists would have universally recognized
them, whereas some dispute the very existence of the junction-faults.
Unless some one holding Dr. Hicks’s view can frame a consistent
theory by which the “ Dimetian”’ can be got into its present position
without the aid of these great throws, I shall continue to hold this
reasoning unassailable.

It may be said that these are mere general considerations that are
not conclusive, or at least do not carry conviction to some minds.
Let us see if there are evidences of another class which support this
contention.

In the much-examined junction of the granite and Cambrian con-
glomerate on the right bank of the Alan at Porth-clais, of which
there is a wood-cut in Dr. Hicks’s paper! the granite shades off into
the conglomerate, here not much more than a coarse grit, in a way
to make their separate recognition difficult. The conglomerate in
consequence of a reversed dip lies upon the green Cambrian shales
or sandstones,” which dip under it and the granite to the north at an
angle of about 62°.

The conglomerate is seen also above the granite, but probably this
is only the junction face disclosed through the granite having been
removed from the front of the conglomerate. To explain myself

1Q.J.G.8S. vol. xl. p. 582.

* The rock is very like the grauwackes of Wigtonshire. Hicks calls it greenish sand-
stone, Geikie green shale ; it is of an intermediate constitution, but I adopt the term
shale.

060 Notices of Memoirs—Prof. EL. Hull—Irish Boulders.

fully would require a plan and sectional elevation ; but so much has
already been laid before the geological public with regard to this
particular junction that I refrain from the infliction.

The Cambrian rocks to the south of this junction strike across the
harbour of Porth-clais nearly due east and west, and on the left or
east. bank the granite is directly in contact with the green Cambrian
shales. The conglomerate is not to be seen. Ata distance of about
30 feet north of this contact, and embedded in the granite, is a vein * of
green shale about 18 inches across, and another about 10 feet nearer
to the contact about 6 inches across. Both these veins of shale, but
especially the thinner one, have a rudely columnar structure at right
angles to their direction. Excepting that this shale is a little more
indurated and more like slate in its constitution, it is similar to the
Cambrian green shales that overlie the basal conglomerate. These
veins are in my view undoubtedly part of the Cambrian shale
entangled in the granite, so that the granite must be post-Cambrian.

I cannot see any way of escaping from this conclusion. I may
add that the conglomerate in contact with the granite, as before
described on the opposite side of the valley, is converted into an
extraordinarily tough rock. Though I saw no veins of granite
penetrating the adjoining rock, I have little difficulty in recognizing
these alterations as ordinary contact phenomena. —

Jn the face of this strong evidence to the contrary, it appears to
me that the presence of “dirty quartz” in the conglomerate like
that in the granite, a resemblance that may be accidental or fanciful,
but is much insisted upon by Dr. Hicks, has no great weight in
proving that the conglomerate is largely made up of materials from
the granite, and that therefore the granite is pre-Cambrian.

NOTLICGCHS Of MEIMOLERS:

I.—NotTE oN A FEW OF THE MANY REMARKABLE BoOULDER-STONES
TO BE FOUND ALONG THE HasterN Marcin or THE WICKLOW
Mountains. By Proressor Epwarp Huu, LL.D., F.B.S.,
DIRECTOR OF THE GEOLOGICAL SURVEY OF IRELAND.’

MONGST the evidences of the former existence of an extensive

sheet of ice descending from the Wicklow Mountains towards
the shores of the Irish Sea is the occurrence of boulder-stones,
chiefly formed of granite or granitoid gneiss, derived from the
mountainous range to the westward, of a size seldom equalled
—probably not surpassed—amongst the British Isles. As the
Association includes in its labours the task of collecting details
regarding erratic blocks, it may prove of interest, if I record a few
cases which have come under my own notice.

1. The Motiha Stone.—This remarkable boulder is perched on
the summit of Cronhane Hill, above Castle Howard, and is a
conspicuous object from all directions. It consists of grey granite,

1 T use the term ‘‘vein’’ because it best describes the form in which these remnants

of the shale occur.
2 Read before Section C. (Geology), British Association, Manchester, Sept. 1887.

_Wotices of Memoirs—Prof. H. G. Seeley—On Iguanodon. 561

and rests upon Lower Silurian slate. Its dimensions are nearly
as follows:—length, 14 feet; height, 9 feet; breadth, 9 feet.
It contains about 35 cubic yards of matter, and its weight would
be about 70 tons. From the site of the Mottha Stone, at a level
of 816 feet above the sea, the eye ranges westward along the
magnificent valley of Glenmalure, to the flanks of Lugnaquilla,
at a distance of about ten or twelve miles, whence, as we may
Suppose, the granite block started on its journey. In its course
it must have crossed the deep hollow of the Avonmore valley,
which extends just below the feet of the observer transversely
to the path of this remarkable erratic block.

2. Castle Kevin.—In the valley between Castle Kevin and
Moneystown, where large boulders are numerous, there lies a block
of granite, partially imbedded, of which the dimensions are :—
length, 15 feet; breadth, 10 feet; height, 9 feet (imbedded portion
—probably 3 feet—is not included in above). This block contains
about 50 cubic yards of matter, and is about 100 tons in weight.
The birthplace of this boulder was probably the mountainous tract
about Mullaghcleevann, 2783 feet in height, lying at the head
of the valley in which is situated the deep waters of Lough Dan.
and it probably travelled a distance of eight or nine miles in an
H.S.E. direction.

3. The last boulder-stone that I shall mention is the largest
I have met with in co. Wicklow—perhaps in the British Islands.
It stands behind a cottage by the roadside, near Roundwood Church,
and is quite as large as the cottage itself, to which it forms a good
protection from the storms descending from the mountains behind.
This boulder consists of granitoid gneiss, resting on Lower Silurian
slate and grit. Its dimensions are (q. p.) :—length, 21 feet; breadth,
14 feet ; height, 12 feet. Its form is somewhat oval, and it contains
about 120 cubic. yards of matter, and is about 240 tons in weight.
The source of this block, which lies at an elevation of about 800 feet
above the sea, was probably in the same locality with that of the
Castle Kevin boulder, and the distance travelled was about six or
seven miles.

The blocks above noticed, with many others of smaller size,
do not belong to any of the local glaciers which once filled the
valleys towards the close of the glacial epoch, and which have left
numerous well-formed moraines in nearly all the principal valleys
descending from the Wicklow range. They are to be referred,
in all probability, to the earlier stage of intense glaciation, in which
the whole district was covered with perennial snows and ice, moving
eastward into the hollow now occupied by the waters of the Irish Sea.

II.—On tue Repurep Cravicies AND INTERCLAVICLES OF I¢vanoDoy.
By Professor H. G. Surrey, F.R.S."
HE author showed, by superimposing a figure of the reputed
clavicle upon the bone figured by Mr. Hulke as clavicle and
interclavicle of Iguanodon (Quart. Journ. Geol. Soe. vol. xli. pl. xiv.),
1 Abstract of a paper read before the British Association, Manchester, Sept. 1887.
DECADE III.—VOL. IV.—NO. XII. 36

562 Notices of Memoirs—Prof. H. G. Seeley.—On Reptilia.

that the supposed sutures are fractures, and that the supposed inter-
clavicle has no existence, except. as an ossification posterior to the
reputed clavicles. Then it was urged that these bones are un-
paralleled by any vertebrate clavicles, while the reputed pubes of
Crocodiles and pre-pubes of other animals offer a more probable
analogy.

The ossification in front of the pubis in Ornithosaurus is of similar
form in several genera. And in Crocodiles the ossification of the
fibrous extension which connects the reputed pubes with the sternal
ribs would produce a bone like the supposed interclavicle of
Iguanodon. Hence it was urged that these bones in Iguanodon are
pre-pelvic, and the author identified them with the pre-pubice bones.

IIJ.—Tue Cuassiricarion of THE Drinosaurta. By Professor H.
G. Ssxxny, F.R.S.!
HE author discussed the structure of the animals named Dinosauria,
and concluded that the group had no existence, the constituent
animals belonging to two orders which have no affinity; they are
named Omosauria and Cetiosauria, the former with a sub-avian pubis
and ischium; the latter with those bones sub-lacertilian.

The Omosauria is defined as having the ventral border of the
pubic bone notched out so that one limb is directed backward parallel
to the ischium, while the other limb is directed forward. The ilium
has a slender prolongation in front of the acetabulum.

The Cetiosauria is defined by having the pubes directed forward
with a median symphysis, but with no posterior limb to the bone.
The anterior prolongation of the ilium has a vertical expansion.

TV.— On tae Mopror DeveLopment or THE Young In PLEsiosaurus.
By Professor H. G. Srunny, F.R.S."

HIS paper was descriptive of a specimen submitted to the author
by J. F. Walker, Esq., F.G.S. It is a phosphatized nodule

from he Lias of Whitby, measuring about 10 cm. by 7, by 5: On
its surface are four more or less complete specimens regarded as
foetal Plestosauri, together with fragments of at least three others.
They are remarkable for having the flesh mineralized with phosphate
of lime, and still show many characters of the external form of the
body, but slightly distorted by decomposition. Only one individual
has the head preserved, its extreme lengthisabout14mm. The nares
are terminal, like those of an emydian chelonian. The superior aspect
of the head behind the frontal bone is occupied by muscular substance.
The skull rests on one side against the matrix, so that its transverse
width is not clearly shown, but it was wider than the neck,-and
narrows in front of the orbit towards the nares, which curve a little
downward. The eyes look obliquely upward and outward, and have
a diameter of two millimetres. The neck has a length of 4:5 centim.
Behind the head it is about 4 millim. deep, and as wide; it widens
to a centim. where the expansion takes place at. the shoulders, and
there the depth is about 8 mm. A sharp median ridge down

1 Abstracts of papers read before the British Association, Manchester, Sept. 1887.

Notices of Memoirs—E. P. Quain—Rock-Sections Exhibited. 568

the middle of the neck divides its superior aspect into two oblique
moderately convex surfaces. Other individuals show that this ridge
was prolonged down the back and tail, but less elevated. The body
is about as long as the neck. On the right side it has suffered some
abrasion and injury in cleaning, and is not quite symmetrical, being
a little larger on the left side. It is about 2:4 centim. wide, convex
from side to side, and less convex in length. The expansion from
the neck is rapid, and attenuation posteriorly is marked so that the
body has a long ege shape. The tail appears to be short and conical,
and curves rapidly downward in every specimen. The height of the
body was not more than half its width. The limbs are imperfectly
preserved. ‘The distance between them on the left sideis 2°4 centim.
The anterior limb appears to be the larger. The entire length of the
Specimen is 12-5 centim.

This individual lies over the neck of another specimen which was
larger, and appears to have measured 15 centim. without the head.
It shows the fore limbs to have been very wide relatively to their
length, and to have measured in the antero-posterior direction 1:1
centim. at the junction with the shoulder on the right side; it is
flattened, extended horizontally, imperfect distally, and curved some-
what backward, but evidently short as compared with the adult.
The hind limbs of this specimen are not seen.

Other individuals are smaller, and have the body only about half
as wide. ‘They are very narrow in the anterior part of the body,
and there appears to be only a slight budding of the fore limbs.

Hence, I regard this specimen as showing that the Plesiosaurus
was viviparous, and that in one species from the Lias many were
produced at one birth. The species was probably a long-necked one,
and may have been P. homalospondylus, since the head in young
animals is relatively large, and here it is 3 of the total length of the
animal,

V.—Upon a Smmpte Mertruop or Prosectinc UPON THE SCREEN
Microscopic Rock Sections BoTH BY ORDINARY AND BY POLARIZED
Licut. By E. P. Quatn.}

NOWING the difficulty experienced in pointing out to students
-any particular crystal in a rock-section when viewed with the
microscope direct, I attempted to project the images on the screen,
and by the aid of comparatively simple apparatus met with very
gratifying success, both with ordinary and with polarized light.
The tube of the microscope was screwed out and replaced with
a cork, through which a hole had been cut to carry the ordinary
one-inch micro-objective and behind it the analyser of the micro-
scope. The polariscope and rock-section occupied their usual
position, as when used with the microscope in the ordinary way.
The microscope stand being inclined into the horizontal position was
placed in front of the object-lens of the lime-light lantern. The
object-lens of a lantern usually consists of a combination of two
lenses. If so, the back lens is taken out, and the front lens only

1 Abstract of a paper read before the British Association, Manchester, Sept. 1887.

564 Notices of Memoirs—MUr. Gardner’s Report.

used, acting as an extra condenser, concentrating the light upon the
rock-section, and causing it to pass through the polariser and the.
analyser. A little adjustment of the light was required to get it
well through both polariser and analyser, but this with a little care
was soon done, and a bright picture several feet in diameter was.
projected upon the screen, showing the crystals well defined, and
exhibiting very strikingly the changes of colour, etc., characteristic
of the crystals when viewed by polarised light, and in such a manner
as to be well seen by a number of people at once, and also allowing:
the lecturer to readily point out any particular crystal or crystals to.
which he desires to draw the attention of his audience.

As the optical axes of the lantern and microscope did not coincide,
the lantern was placed on a board provided with four levelling
screws with which the necessary adjustments were readily made.

Much better effect may be got if the ‘‘ Joblowsky ” form of prisms
made by Zeiss are used instead of the usual Nicols prisms, on account.
of their greater aperture and shorter length.

VI.—Taxe Permian Fauna or Bouemta. By Prof. Dr. Anton
Fritscu, Director of the Royal Bohemian Museum in Prague."

ROF. Dr. Anton Fritsch, of Prague, Bohemia, read a paper on

the Permian Fauna of Bohemia. After having mentioned the 73:
species of Labyrinthodonts, of which he has given figures in his
work ‘‘Fauna der Gaskohle,” and of which he exhibited the electro-
types and restored models in the galleries of the Owens College, he
communicated the discovery of a very peculiar genus Naosaurus
(Cope). He then explained some unpublished plates of Ctenodus,
Orihacanthus, Hexacanthus, and a new Ganoid Fish, Trissolepis with
three kinds of scales. He proved Acanthodes to be very near to.
Selachians, and lastly he drew attention to the gigantic fish (Am-
blypterus) 113 cm. long exhibited in the galleries.

VII.—-Report on tHe Fossizn Puants oF THE TERTIARY AND
Srconpary Beps or tHE Untrep Kinepom. By J. 8. GaRDNER,

Tag Dysh, 1D (Enss

HE small balance carried forward from last meeting has been
expended in visiting the localities in which fossil plants have
previously been met with. The beds near the Pier at Bournemouth
seem more than usually inaccessible, but a fall from the cliff has
brought down some of the dark clays, and in these were parts of
a large feather Palm and other leaves. I was fortunate enough,
however, to secure at the west end of the cliffs a new species of
Acer and a fine leaf of Dryandra acutiloba, really a Myrica, a rare leaf
at Bournemouth, and one of the few that extend upward from the
Lower Bagshot into the Bournemouth horizon.

I have again visited Alum Bay, but the pipe-clay on the shore
has become still more diminished, and there is no hope that any
more fossil plant-remains will be obtained there in our time. No
distinct plant-remains are obtainable from the same horizon at

1 Abstracts of papers read before the British Associition, Manchester, Sept. 1887.

Reviews—E. Daubrée—Subterranean Waters. 565

Whitecliff Bay, though I had some hope that this might be the case.
The drought was unfavourable to collecting at Barton and Hordwell,
where most interesting fruits are washed out during heavy rains,
and I procured no plants during my visits there this year; but it
favoured, on the contrary, collecting at Lough Neagh, by lowering
the level of the lake; and I am able to add a new Pteris, an ex-
quisitely preserved fruit, and many Dicotyledons to the Flora, and
a Paludina to the Fauna.

No plant-remains are obtainable this year at Reading, nor do any
of the other brick-pits in which plant-remains have occurred seem
in exactly a favourable state, at the moment, for collecting, so that
it appears undesirable to ask for further grants for this purpose at
present. The Lower Eocene Floras are, however, still insufficiently
known, and excavations at Bromley or elsewhere in the Woolwich
horizon would, I anticipate, yield especially important results. In
the mean time, an enormous mass of material has now been ac-
cumulated, which will require years of patient research to digest.
Advantage has been taken of the presence of that distinguished
Paleobotanist, the Marquis de Saporta, at our meeting, to go
through the drawings, numbering more than a thousand, that I have
already made of the plants so far collected. He is completely
astonished at the richness of our Hocenes, and considers them to be
unrivalled. The Reading and Bournemouth horizons contain plants
which do not appear in Europe until much later Tertiary times,
seeming to have passed very slowly across Europe towards Hastern
Asia, which may be considered their present home, their chief affini-
‘ ties being with floras indigenous to that part of the globe, rather
than with those of America and Australia, as hitherto supposed.

In conclusion, it may be mentioned, that although, owing to the
drought and other causes, already referred to, the results of this
year’s labours have been but small, when contrasted with the
magnificent collections obtained in former years; yet, notwith-
standing these adverse circumstances, several important additions
have been made by me to the paleophytological collections in the
British Museum which will doubtless prove of good service in
elucidating the Eocene flora of Britain.

BES San V6 Se Ea VV =

Les Bavux SOUTERRAINES AUX fPoquES ANCIENNES. Par A.

_ Davprix, etc. One Vol. pp. 448, with numerous Illustrations.
(Vve. Ch. Dunod, Editeur, Paris, 1887.)

5 (re work treats of the part which underground waters have
played in the origin and modification of the substance of the
Tarth’s crust. In the preface Mons. Daubrée alludes to the ideas of
Bernard Palissy and others as to the analogy which exists between
what we should call organic and inorganic bodies, and to the belief
that the latter possess a sort of quasi-vitality. Questions bearing on
this subject have lately attracted the attention both of the President
of the Geological Society and the Editor of this Magazin. It is

566 Reviews—EH. Daubrée—Subterranean Waters.

quite sufficient for our present purpose that water should be deemed
an important agent in causing “stones to grow.” But a few years
have elapsed since a celebrated geological chemist declared that the
alkahest, or universal menstruum, was neither more nor less than
water, aided by heat, pressure, and the presence of other substances.
The author of the work now under consideration has already de-
monstrated in his celebrated “‘ Ktudes synthétiques”’ the important
part played by underground waters charged with various substances
in the formation of minerals; and he now proceeds to point out how
their history furnishes us with a remarkable example of the continuity
of operations past and present. Even in places where they no longer
flow, these underground waters have left us indications of their
movements and their chemical energy, so that we are enabled to
follow them in all the details of their “régime.”

Of all mineral substances which have been formed in the wet way,
zeolites are amongst the most obvious, and Mons. Daubhrée has else-
where observed that these may be regarded as a kind of extract of
the rocks, which have themselves been subjected to continued lixi-
viation. Entering more fully into this question in the present work,
he gives examples of their development and mode of formation,
together with that of the associated minerals, quartz, agate, and
chalcedony. Thére is no lack of appropriate illustrations: the
section of an agate is particularly fine. He still seems to regard the
canal shown by some of them as an inlet of infiltration. The zeolitic
minerals of Plombiéres are discussed at some length: sections of
the zeolite-bearing bricks are given, effective alike for showing the
“minerals themselves as well as the structure of the brick. The
bricks thus transformed present considerable resemblance to certain
altered volcanic rocks. The siliceous products of the bricks resemble,
he says, the acid rocks, whilst the zeolites and globules of palagonite
in these same bricks recall the basic rocks. All these changes have
been effected since the days of the Romans by waters of a moderate
temperature.

The study of the formation of metalliferous deposits affords still
more remarkable testimony alike to the solvent and depositing
powers of underground waters. Substances, which under ordinary
conditions are regarded as insoluble, have been deposited in various
ways, as in veins, segregations, beds, etc. A propos of this subject
Mons. Daubrée does not fail to point out the celebrated instance at
Bourbonne-les-bains, so well described in the “ Etudes synthétiques,”
where old Roman coins by their decomposition have yielded metallic
sulphides under the action of warm mineral waters.

This branch of the question is a very large one, and has received
ample treatment both from Mons. Daubrée, and also from the late
John Arthur Phillips, in his excellent treatise on ‘Ore Deposits.”
One cannot fail to perceive that these authors are disposed to ascribe
the bulk of the phenomena, as regards veins, segregation-veins,
beds, etc., mainly to the action of waters, warm or cold. It is true
that such actions are often the most powerful in the neighbourhood
of eruptive rocks, which are frequently accompanied by veins

Reviews—E. Daubrée—Subterranean Waters. 567

having a concretionary structure, either metalliferous or sterile.
“This is not so much an immediate product of the rocks themselves |
as a gentle and prolonged deposit proceeding, some from gaseous
emanations, others and these the most numerous from powerful
mineral and thermal springs, whose first origin must be attributed to
the appearance of the eruptive masses, and whose circulation is
effected by the aid of the cracks or fractures of the ground” (Daubrée,
op. cit. p. 143). There can be no better proof of the intimate con-
nection between mineralizing waters and metallic veins than is
afforded by the wonderful phenomena of the Steamboat Springs in
Nevada, of which a notice was given in the Quarterly Journal of the
Geological Society by William P. Blake as long ago as 1864.
Since then the whole of this Comstock region has been the subject
of numerous memoirs. According to Mr. Phillips (Ore Deposits,
p- 002), these rocks have been carefully assayed, with the results
that the neighbouring diabase contains a notable amount of the
precious metals, of which the larger proportion is contained in the
augite; that the decomposed diabase contains about one-half as much
of these metals as the comparatively fresh rock ; and that the relative
quantities of gold and silver, both in the fresh and decomposed
diabase, correspond fairly well with the known composition of the
Comstock bullion. There does not seem any reason why these -facts
should exclusively favour the theory of lateral secretion, but they
serve to confirm the notion as to the eruptive rocks being, in this
ease, the primary source of the metallic wealth of the. country,
which has been extracted and concentrated, as it were, for the benefit
of miners by the aid of heated and mineralized waters, in such
fissures as the Great Comstock Lode, where the process may still, to
a certain extent, be in operation.

The replacement of limestone by ironstone, and the phenomena
connected with iron deposits generally, are also fully treated by
the author, who reproduces some of Mr. Kendall’s sections showing
the mode of occurrence of hematite in Cumberland and North
Lancashire.

Next comes the question of the change in rock-masses on a large
scale—and firstly, as to the mineralization of fossils, and the for-
mation of nodules (rognons), etc. There can be no difficulty in
believing that water, in conjunction with dissolved salts and gases,
has replaced shell substance by a more or less pure mineral calcite,
and that sometimes the replacing substance has been silica, carbonate
of iron, or other mineral, even specular iron, as some bivalves he
mentions in the Lias. The numerous silicified woods also find a
place here. The flints of the Chalk he treats as concretionary
bodies, and he gives a telling figure of orbicular silex as developed
in the shell of a Gryphea. The chemical alteration of silicated
rocks is next dealt with; and here Mons. Daubrée observes with
regard to the kaolinization of felspar, that this has not in all cases
been effected by surface agents; he suggests aqueous and other
emanations in connection with the deposits « of tin-ore.

A considerable number of pages are devoted to the great question

568 Reviews—EH. Daubrée—Subterranean Waters.

of metamorphism. With respect to contact metamorphism, it is not
quite clear how far the results, in all cases, have been brought about
through the agency of water. Of course, where quartz and numerous
anhydrous silicates have been developed in a limestone, which itself
has become crystalline in the vicinity of an eruptive rock ; supposing
such a limestone to have been a nearly pure calcareous rock originally,
the ingredients of so many silicates have in all probability been
introduced by the agency of waters which owed their impregnation
in part to the eruptive rock itself. In dealing with the far more
important subject of regional metamorphism, we gather in the first
instance that the author excludes the great fundamental gneisses.
Although the subject is very fully treated, it is not easy to assert
what part water is considered to have played in producing the results ;
undoubtedly heat, pressure, and and chemical solvents are required in
addition to mere water. After the admirable experiments detailed in
the ‘‘ Ktudes synthétiques,” and repeated here with excellent illus-
trations, it has been abundantly shown that anhydrous silicates can be
produced in the wet way. Perhaps this is even more than is required
in some cases, since the phyllades of the Ardennes are largely composed.
of such hydrous minerals as sericite and chloritoid, or chlorite, in addi-
tion to quartz. We have also the general statement (p. 875) that the
water enclosed in clays, combined and fixed, has had a “‘ preponderating
action in the development of metamorphic phenomena.”

* Lastly, Mons. Daubrée considers the light which past and present
phenomena are able to throw upon each other. He alludes to the
great vertical and horizontal extent over which the course of ancient
waters is often discernible. Measured by the standard of historical
time, existing hot springs enjoy a great stability, though in general
the old thermal springs, which have brought the metallic minerals
and their gangues into the veins of so many regions, are now dried
up. ‘The relative geological age of ore-deposits is discussed, ranging
from the great iron-masses of Scandinavia contemporary with the
gneiss, to the Tertiary deposits of Comstock, associated with trachytic
greenstone.

He concludes as follows:—“It is thus that water has played a
unique part throughout all time in the earth’s crust; aided, it is true,
by secondary substances, it has been the chief mineralizer, even for
minerals such as quartz and the anhydrous silicates in whose pre-
sence it is altogether inactive at temperatures which prevail on the
surface of the globe, and whose origin for this reason was for long
time considered beyond its influence.

‘However, this does not concern the past merely. There is
nothing to prove that operations of this nature are arrested. On the
contrary, it is more than probable that, as each day goes by, similar
actions are contributing to the formation of new minerals; but these
take place in interior regions which are not accessible to our obser-
vations. In descending but a few métres from the surface we find
silicates of the family of the zeolites and combinations of sulphides
similar to those of metallic veins. Unfortunately we cannot observe
the products of reactions which take place of necessity lower down

Reports and Proceedings— Geological Society of London. 569

in the ascending conduits of these springs or in proximity to the
laboratories of volcanoes. Superheated water, which betrays itself
outside by thermal springs and volcanic exhalations, must produce
slowly and silently in the interior of the globe effects both considerable
-and permanent and, as formerly, give birth to various minerals.

“Jn its ceaseless circulation subterranean and deep, and by its
work principally chemical, water simulates a kind of vital action
which is perpetuated in the earth’s crust throughout the ages of our

planet.” W. H. H.

sea ieee SS AINE) 2>s © Cla nD a eS

—_——_—_
GeEoLoGicaL Socrmty or Lonpon.

November 9, 1887.--Prof. J. W. Judd, F.R.S., President, in the
Chair.—The following communications were read :—

1. “Note on the so-called ‘Soapstone’ of Fiji.” By Henry B.
Brady, F.R.S.

The Suva deposit, which has a composition very similar to that
of the voleanic muds at present forming around oceanic islands in
the Pacific, is friable and easily disintegrated. The colour ranges
from nearly white to dark grey, the mass being usually speckled with
minerals of a darker hue. Under the microscope the rock presents
the character of a fine siliceous mud with crystals of augite, etc.,
together with the sparsely scattered tests of Foraminifera. Tlie
approximate chemical composition of typical specimens is :—Silica,
00 per cent.; alumina, 18 per cent.; lime and magnesia, from 5 to 6
per cent.; ferric oxide, from 3 to 8 per cent.; water, 16 per cent.
with a small proportion of alkalies, chiefly potash, and but small
trace of carbonates.

The author’s attention was chiefly directed to the common grey
friable rock, which may be softened in water and washed on a Sieve,
the residue consisting mainly of Foraminifera with a few Ostracoda.
Of three plcemmcus examined, 1 is a light-grey rock from close to
the sea-level; 2, of a lighter colour, from about 100 feet elevation ;
3 is nearly wilite and somewhat harder, and was derived from an
intermediate point. So far as the Mienoaga are concerned, the first
two present no differences which might not be observed in dredgings
from the recent sea-bottom, taken at similar depths a little distance
apart. The third appears to have been deposited in somewhat deeper
water. There is a marked scarcity of arenaceous Foraminifera.

Then followed notes on the rarer and more interesting species,
together with a list of the 92 species of Foraminifera found. Of
these, 87 are forms still living in the neighbourhood of the Pacific
islands. Two of the remaining 5 are new to science, and the rest
extremely rare. The author concluded that these deposits are of
Post-Tertiary age, formed at depths of from 150 to 200 fathoms in
the neighbourhood of a volcanic region. The following new or
little-known species were selected for illustration :—Ellipsoidina
ellipsoides, var. oblonga, Seguenza; Haplophragmium rugosum, D’Orb.;
Ehrenbergina bicornis, nov.; Spheroidina ornata, nov.

570 Reports and Proceedings—

2. “On some Results of Pressure and of Intrusive Granite in
Stratified Paleozoic Rocks near Morlaix, in Brittany.” By Prof.
T. G. Bonney, D.Sec., LL.D., F.R.S., F.G.S.

The author briefly described the banded Paleozoic slates in the
neighbourhood of Morlaix, and gave a general account of their
microscopic structure. They are greatly contorted and folded, and
have evidently undergone very severe pressure. The result of this,
as it appears to him, has been the development of minute scales of a
light-coloured mica, especially in the darker (originally argillaceous
bands) and certain corresponding changes in the more quartzose
layers. The cleavage-planes often cut the surfaces of bedding and
of this micro-foliation, which are parallel, at high angles, and so are
of the nature of “ Ausweichungsclivage.”

In certain places these banded slates, after they have attained the
aforesaid condition, have been affected by intrusive granites. The
result has been the intensification of the changes which were already
incipient. The quartz granules have been doubled in size, the flakes
of mica have become four or five times as large, the black material
of the argillaceous bands has been gathered into larger granules,
and seemingly reduced in quantity (probably by partial oxidation
of the carbon), and in some cases andalusite crystals or grains of
considerable size have been developed. The rock has become com-
paratively hard, instead of friable, and the cleavage-planes are
‘‘soidered up” by the development of mica along them. In its
general aspect one of these banded rocks (where free from anda-
lusite) bears considerable resemblance, macroscopic and even micro-
scopic, to one of the less coarsely crystalline, distinctly banded
mica-schists, supposed by many to occupy a rather high position in
the Archean series. |

3. “On the Position of the Obermittweida Conglomerate.” By
Prof. T. McK. Hughes, M.A., F.G.S.

The author gave an account of a visit to the section at Ober-
mittweida, 50 miles §.W. of Dresden, where there is an apparent
intercalation of conglomerate and sandstone in a gneissic series.
West of the stream at Obermittweida there is seen a crushed but not
much altered conglomerate of felsite and other pebbles, above which —
gneiss and mica-schist rest, apparently in true sequence numerically.
Below the conglomerate no rocks were seen, but at a little distance
to the eastward coarse flaked muscovite-schists and gneissic rocks
were exposed, apparently underlying it. By a diagram the author
showed how the conglomerate might belong to much newer beds
caught in a synclinal fold of the schists, and he advanced various
arguments in support of this explanation.

4 “On the Obermittweida Conglomerate: its Composition and
Alteration.” By Prof. T. G. Bonney, D.Sc., LL.D., F.B.S., F.G.S8.

The author is indebted to Professor Hughes for the opportunity
of examining a fine series of specimens of this rock, collected by the
latter. The pebbles vary from well-rounded to subangular, some
of the smaller fragments occasionally being practically unworn.
The matrix is sometimes granular to the unaided eye, sometimes

Geological Society of London. 571

very fine. The whole mass has evidently been subjected to con-
siderable pressure.

The associated gneiss is a moderately coarse gneiss, containing
two micas and garnet. It has a general resemblance to rocks which,
in the Alps, appear to occur about or rather below the middle of the
crystalline series. ~

The fragments consist of various kinds of rocks. Those examined
microscopically are referred to granitoid rock (3 varieties), mica-
schist, quartz-schist, quartzite, halleflinta (?).

The matrix is almost wholly composed of quartz and mica (two
species, but mostly brown). with some felspar. The materials appear
to have undergone a certain amount of metamorphism, by augmen-
tation of the original fragments, and to some extent by development
of new minerals. The author is of opinion that the materials are
rather more altered than is usual in Paleozoic greywackes and con-
glomerates, but that the comparatively small amount of alteration,
and the character of the included fragments, render it highly im-
probable that the conglomerate is in stratigraphical sequence with
the above-described gneiss, or with any similar series of rocks; and
so, if Archean, it must belong to one of the latest epochs in that
period.

5. “Notes on a part of the Huronian Series in the Neighbourhood
of Sudbury (Canada).” By Prof. T. G. Bonney, D.Sc., LL.D.,
BELS., 2.G.S.

The specimens noticed by the author were in part collected by
him in the sammer of 1884, when the Canada Pacific Railway was.
in process of construction, and in part subsequently supplied to him
by the kindness of Dr. Selwyn, Director-General of the Geological
Survey of Canada.

The eastern edge of the district assigned to the Huronian consists.
of rocks, which may possibly be part of the Laurentian series modi-
fied by pressure. But after crossing a belt of these, barely a mile
wide, there is no further room for doubt. All the rocks for many
miles are distinctly fragmental, except intrusive diabases or diorites.
- These fragmental rocks are grits, conglomerates, and breccias, which

are described as far as about two miles west of Sudbury. The
included fragments in these rocks appear to have undergone some
alterations subsequent to consolidation: these are described. In
some cases the changes appear to be anterior to the formation of the
fragments. The matrix also has undergone some change, chiefly
the enlargement of quartz grains, and the development or completion
of mica-flakes, as in the Obermittweida rock.

The author gave some notes on other specimens collected by him
along the railway, further west, and on those supplied to him from
near Lake Huron by Dr. Selwyn. As a rule these are but little
altered. Some contain fragments of igneous rocks, apparently lavas.

The author discusses the significance of the changes in these rocks,
as bearing on general questions of metamorphism, and states that, in
his opinion, the name Huronian, at present, includes either a series
of such great thickness that the lower beds are more highly altered

O72 Correspondence—Prof. E. D. Cope.

than the higher, or else two distinct series; and he inclines to the
latter view. Both, however, must be separated from the Laurentian
by a great interval of time, and neither exhibits metamorphism
comparable with that of a series of schists and gneisses, like the
so-called Montalban. The newer reminds him often of the English
Pebidians.

€@ 2 ARe SS se @aN a> se aN@ sea

LYDEKKER, BOULENGER, AND DOLLO ON FOSSIL TORTOISES.

Sir,—I have read with interest the notes on the above subject
which appeared in the GroLoeicaL Magazine for June and September,
I find that the two first-named gentlemen have overlooked a paper of
mine, which will relieve me of the charge of erroneous treatment of
the genus Pleurosternum which they make. The paper was published
in 1870,’ and prior to those of Professor Riitimeyer which they cite
as authority for determination already made by me. The learned
authors quote me as stating that in the genus Pleurosternum there is
“no intergular shield, and the genus is accordingly referred by me
to the Cryptodira ; whereas its true position, as was pointed out by
Prof. Riitimeyer, is with the Pleurodira; and with that group—the
Pelomedusidze and Peltocephalidee of Gray—characterized by the
presence of eleven, instead of nine, plastral bones.” Ona subsequent
page (274-5) they consider the Platemys Bowerbankii, of Owen and
Bell, “in regard to which Prof. Ritimeyer has already pointed out
that the specimen figured by the same writers under the name of
Emys levis is merely the young of the former, and that owing to
the presence of a small mesoplastral bone, the reference to Platemys
is incorrect, and it is suggested that ihe species may probably belong
either to Podocnemis or Peltocephalus.” ?

In my paper of 1870 I remark, “The genus Platemys as adopted
[in Maack’s work] may be cited. It embraces nine species according
to the present work, the genus Pleurosternum of Owen being referred
to it. This is done because the additional pair of thoracic bones
which characterizes it is found in a rudimental condition in Platemys..
Bowerbankii; and Platemys Bullockii of Owen presents the inter-
marginal scuta of Plewrosternum, and because of the general
resemblance in specific characters between the latter and the Pl.
concinnum. ‘To us, however, the genus Pleurosternum appears to be
Cryptodire, not Pleurodire, as it lacks the intergular scutum of
the later suborder, and to represent a peculiar family of that group
characterized by the possession of ten instead of eight sternal bones.
Platemys Bullockii, P. Bowerbankii, and Hmys levis, Owen and Bell,
appear on the other hand to be Pleurodira, and to be referable to
two families of that suborder. The Pl. Bullockii, on account of its
five pairs of sternal bones, to the Sternotheeride, and on account of

1 Die bis jetzt bekannten Schildkérten, u. d. bei Theilheim in Hannover neu
afgetunden altesten Arten derselben; von Dr.G. A. Maack; a review by E. D. Cope,
Amer. Journal Sci. Arts, 1870, L. pp. 136.

* “ The figure shows that its affinity appears to be rather with the former than the
latter, and it may accordingly be provisionally referred to that genus.’

Correspondence—Prof. T. G. Bonney. 573:

its intermarginal scuta to a new genus, which I call Digerrhum.
The last two in their rudimental fifth pair of sternals, resemble
many Plewrodira, and cannot be distinguished from the genus.
Podocnemis now living in the Amazon.”

In this paragraph I have made the references adopted by Riitimeyer,
Lydekker and Boulenger, but I did not use the name Pleurosternum:
for the Pl. Bullockii. Believing that the Pl. concinnum represented
that genus, I removed the Pl. Bullockii from it. It now remains to.
ascertain the characters of the Pleurosternum concinnum, since no
reference is made to it by the authors of the paper on which I am now
commenting, but who regard the Pl. Bullockii as typical of the genus.

M. Dollo well remarks (September Number) that the absence of
dermal sutures cannot alone place a genus of Tortoises in a separate
family from forms which possess such sutures. He regards
Erquilenesia as most resembling Huclastes, but not to belong to the
Propleuride. But I think Euclastes is one of that group, and I
suspect that Dollo’s characters of the skull define the group better
than the number of costal bones, which will however distinguish the
- genera. H. D. Cops.

ORIGIN OF CERTAIN BANDED GNEISSES.

Str,—Mr. Teall’s paper on the origin of certain banded gneisses
(p. 484) is a contribution of the utmost value to the discussion of a
very difficult subject. But, as Iam responsible for another theory
concerning these gneisses, may I be allowed to say, that though [
admit the importance of the hypothesis, I still see great difficulties in
the way of accepting it. These gneisses of the Lizard must not be
regarded alone; a hypothesis which might alleviate our difficulties
here (and they are undoubtedly great) might increase them else-
where—and thus, did I assign an igneous origin to all the crystalline
rocks south of St. Keverne, I should find it difficult to know where
to stop in applying the explanation to other regions. Moreover, if
we are to explain these banded gneisses as the rolling or crushing
out of a complex of igneous rocks, not only must the flexibility of
the rocks have been very great, but also this complex originally must.
‘have been a very intricate one. Now I have had a fairly large
experience in the habits of igneous rocks, and, so far as this goes,
such complications as would be required here are both rare in
occurrence and limited in extent. Yet at the Lizard the banded
series is of considerable thickness, and can be traced along the coast
for full two miles. I admit, however, that when I wrote my two
papers, I sometimes failed to distinguish between structures signifi-
cant of original constitution and those due to subsequent mechanical
action, for our knowledge of the latter is of very recent date; but
to what extent I will not venture to say until I can again examine
the whole district. This I hope todo, but for various reasons must
defer the pleasure for a time. Probably it will be some years before
we can fairly determine the claims of conflicting hypotheses ; mean-
while it is well for science that Mr. Teall has advanced one with so
much moderation in statement, and clearness in reasoning. Perhaps

574 Obituary—Rev. W. S. Symonds, M_A., F.G.S.

one day he may claim me asa thorough-going convert; but at present
I anticipate that it will be my ultimate fate here, as in other things,
to maintain that truth lies between opposite extremes.

As I am writing, I may as well briefly notice another criticism on
some work of mine in the south-west. In the Transactions of the
Devonshire Association a paper has recently appeared (p. 349),
advocating the oid view of a gradual transition between the slaty
and the crystalline series in the Start and Bolt Head districts. As
the writer has “to confess to much ignorance as to the methods and
results of microscopic research,” and the question is one in which
such methods are essential in order to distinguish real differences,
and avoid being misled by superficial resemblances, I cannot admit
that he is qualified to investigate the subject, or waste time by dis-
cussing it with him, and will only say, that, though since I wrote
the paper I have frequently examined my specimens and slides, I
have seen no reason to alter my opinion as to the separateness of the
two groups of rocks. Moreover, a paper will shortly appear in the
Quarterly Journal of the Geological Society, by a careful observer in
the field and worker with the microscope, in which much additional -
evidence is brought forward in favour of my view. It would be
thought strange if any one were to enter into a dispute as to the
interpretation of a corrupt passage in a chorus of a tragedy of
Aschylus, without a preliminary study of the niceties of the Greek
language ; yet this is the course which some persons follow in
petrology, and seem to think that thereby they are doing a service to
science. T. G. Bonnzy.

OS see ORAS a

REV. W. S. SYMONDS, M.A., F.G.S.
Born 1818; Diep 1887.

Forry years ago, the promotion of Natural Science throughout the
country was mainly entrusted to the agency of the various local:
Field Clubs and Natural History Societies, amongst the most active
and useful of which may be mentioned the Malvern Natural History
Field Club, the Woolhope Naturalists’ Field Club, and the Cottes-
wold Club. It was in the districts over which these clubs held
sway that the subject of our present notice passed the best years of
his life and carried on those geological labours with which his name
will always stand associated.

Mr. Symonds was born at Hereford in 1818, being the son of
William Symonds, Esq., of Elsdon, Herefordshire. After passing
through his school-days with Mr. Allen at Cheltenham, and reading
with the Rev. J. P. Sill, he was sent to Christ’s College, Cambridge,
where Sedgwick was then in the height of his popularity as a geological
lecturer. He took his degree in 1842, and in 1843 he was appointed
Curate of Offenham, near Evesham, where he became acquainted with
Mr. Hugh Strickland, from whom he received many of his first
lessons in Natural History. In 1845 he was presented to the
Rectory of Pendock, near Tewkesbury.

Obituary—Rev. W. S. Symonds, MA., F.GLS. 55)

Mr. Symonds married, in 1840, Hyacinth, daughter of Samuel
Kent, Esq., of Upton-on-Severn, and had issue three sons and one
daughter; the latter only now survives him, and is married to Sir
J. D. Hooker, K.C.S.L, F.RB.S.

From an early date Mr. Symonds became the friend and associate
of Sir William Vernon Guise, Bart., of Elmore Court, near Gloucester,
and it is significant that the two attached friends died within a few
days of one another, viz. 15th and 24th Sept. (see Gron. Mac,
Nov. 1887, p. 528).

Mr. Symonds assisted in the foundation of the Woolhope Naturalists’
Field Club, and was elected its President in 1854. He was also
President of the Malvern Naturalists’ Field Club from 1858 and for .
many years subsequently.

In 1857 he visited Dublin, in order to attend the Meeting of the
British Association, and availed himself of the opportunity to make
a geological tour through Ireland (see Geologist, 1858, pp. 292-296
and 380-535). In this year he also published a work entitled
“Stones of the Valley.”

In 1858 we find him busy in the field exploring the bone-bed of
the Upper Ludlow rocks and their characteristic fossils (Geologist,
1858, p. 15). Mr. Symonds examined in 1859 the reptiliferous
sandstone near Elgin (see Edinburgh New Phil. Journ. 1860, vol.
xl. p. 99), and in the year following he was watching the results of
the geological sections exposed in the Malvern and Ledbury Tunnels
with Mr. A. Lambert (Geologist, 1861, p. 148). In 1865 he made a
geological ramble through Wales, an account of which he communi-
cated to the Worcester Nat. Hist. Soc. Trans. 1864. A new edition
of his book entitled ‘“‘Old Bones, or Notes for young Naturalists,”
was issued in 1864, the first edition having appeared in 1859.

In the summer of 1866, accompanied by his friend Sir W. V.
Guise, Bart., Mr. Symonds visited Belgium, and under the guidance
of Prof. Dupont, explored the Bone-Caverns of the Valley of the
Lesse, and gave an interesting description of the same to the Wool-
hope Naturalists’ Field Club (Groz. Mac. 1866, pp. 564-570).

Jn 1871 Mr. Symonds published, in Dr. H. Woodward’s Mono-
graph on the Merostomata, some interesting Notes on Silurian
localities in the West of England where these fossil Crustacea occur
(see Pal. Soc. Mon. Brit. Foss. Crustacea, 1871, part ili. pp. 92-104).
In the same year Mr. Symonds explored the Hyzna-Den (known as
King Arthur’s Cave) on the Great Doward, Whitchurch, Ross (see
Guo. Mage. Vol. VIII. p. 483).

In the year following (1872) he brought out his ‘‘ Record of the
Rocks,” an excellent and readable handbook for students of the
Geology of the West of England.

The autumns of 1874, 5, and 6, were spent in company with Sir
Wm. Guise, Mr. Lucy, and others, in exploring the volcanoes and
tracing the ancient glaciers of Auvergne and those of the Haute
Loire and the Ardéche (see the Pop. Sci. Rev. vol. xv. 1876, and
N: Ser. vol. i. pp. 1, 250, 329, 1877).

In 1880 Mr. Symonds published a second edition of his book

576 Obituary—Oount Marschall.

entitled ‘Old Stones,” and also his romance of ‘Malvern Chase,”
which reached a third edition in 1883. In this year he issued two.
more works, namely, ‘‘ Hanley Castle,” a romance; and the “ Severn
Straits,” a geological work. Althogether he was the author of more
than forty papers which have appeared in various scientific journals.

The main object of Mr. Symonds’ active and useful career, and to the
furtherance of which all his best energies were directed, was the pro-
motion of a love for Geological, Botanical, and Archeological pursuits
and studies, amongst the very large circle of educated people in
the West of England by whom he was surrounded, whose tastes
he strove to elevate and direct, and whose leisure hours he endeavoured
- to occupy with healthful and intellectual pursuits. f

Although a clergyman and a Justice of the Peace for the county
of Worcestershire, he was above all things an ardent Naturalist and
Geologist, and he was never so happy as when conducting the
members of his own Naturalists’ Field-clubs over some classical region
in “ Siluria,” with every spot of which he was familiar.

For several years before his death he had been compelled by ill-
health to withdraw from his parish duties, but he remained as full
of interest in all scientific matters as ever to the last.

Mr. Symonds died on the 15th September, at Cheltenham.

His loss, like that of his friend Sir W. V. Guise, will long be felt
in the West of England, where the services and presence of both had
exercised so beneficial an influence over a very wide and intelligent
community for nearly half a century.— H.W.!

Aveust Frieprich Count Marscuatt, of Burgholzhausen and
Tromsdorf, who has frequently contributed to the GxronogicaL
Magazine, as well as to the Quart. Journ. Geological Society, notes
on Geology and Paleontology, especially from the researches of his
Colleagues in Vienna, died suddenly on the 11th of October, in his
83rd year. He was a Foreign Correspondent of the Geological
Society of London, and Correspondent and Member of many other
learned Societies,—also Hereditary Marschal in Thuringia, Imp.
Roy. Chamberlain, and formerly Archivist of the Imp. Roy. Geo-
logical Institute of Vienna. His frequent communications on papers
read at the Academy, Institute, and other Societies, forwarded by
him to various European friends and periodicals, were continued with
his usual industry (his motto being ‘‘ Nunquam otiosus”) to within
a short time of his death. His “ Nomenclator zoologicus,” combining
both recent and fossil genera, published by the Zoologico-Botanical
Society of Vienna in 1878, is a very valuable book of reference ;
and the ‘‘Ornis Vindobonensis,” 1882, is written in conjunction
with Dr. A. von Pelzeln, also bears evidence to our deceased friend
Count Marscuatt’s scientific zeal and usefulness.—T. R. J.

1 ‘We regret to record the death, on October 4th, at Tonga, of Mr. H. F. Symonds,
only remaining son of the late Rev. W. 8. Symonds. He was Consul at Samoa and
Deputy Commissioner of the Western Pacific. He was only 32 years of age and a
man of great promise.

INDEX.

ACR

CRODUS, on some Post-Liassic
species of, IO!.
levis, A. S. Woodw., 102.
Acteonina ferrea, Wilson, 258.
Affinities of Cyclobatis, 508.
Aglaia? cypridoides, Jones, 386.
Alaria fudlestoni, Wilson, 260.
Allodon fortis, Marsh, 244.
Amberleya callipyge, Wilson, 200.
America, North, Cambrian Rocks of,
TSS
American Jurassic Mammals, 241, 280.
Anatomy of Sgualoraja polyspondyla,
190.
Ancient Beach and Boulders
Braunton, 374.
Andrussow, N.,
Isopoda, 189.
Anglesey Dykes, 409, 546.
Annual General Meeting of Geological
Society, 181.
Appearance in time of Dicotyledons,
159.
Archzean Rocks, 500, 503.
Ardtun Leaf-bed, 91.
Aristosuchus pusillus, Ow., 234-
Arius? Bartonesis, A. S. Woodw.,
306.
- Asthenodon segnis, Marsh, 291.
Australia, Tertiary Flora of, 359.
Australian Tertiary Echinoidea, 328.

near

On new Neogene

BRAcsHOT Beds and London Clay,
III, 284.
aE Sands, 192, 381.
Bairdia Londiniensis, Jones, 380.
ovoidea, Jones, 388.
rhomboidea, Jones, 388.
Banded Gneisses, Origin of, 484.
Barkly, A., Letter from, 41.
Bather, F. A., On the Growth of
Cephalopod Shells, 446.
Beds containing the Gelinden Flora,
LOV. >
Belgian Fossil Reptiles, 392.
Bell, R. G., Pliocene Beds of St. Erth,
468 ; on Pliocene Beds, 554.

DECADE III.—VOL. IV.—NO. XII.

CAR

Bench Cavern, Brixham, 514.
Bernissart, Dinosaurian Fauna of, 80,

124.

Blake, J. F., on Solaster Murchisoni,
520.

Boulder-stones from Wicklow, 560.

Bonney, T. G., on the Rauenthal Ser-
pentine, 65; on the Rocks of Brit-

tany, 236; Felspar in the Lizard
Serpentine, 239; on Lizard Ser-
pentines, 380; Traverses of the

Western and Eastern Alps, 470; on
Stratified Palzeozoic Rocks, 570; on
the Obermittweida Conglomerate,
570; on the Huronian Series, 571 ;
Origin of Banded Gneisses, 573.

Brady, H. B., on ‘‘ Soapstone” of Fiji,
569.

Branchiosaurus, The Development of,
276.

Brecciated Archzean Rocks, 500.

British Association, Papers read at the,
38, 78, 117, 465, 514, 560.

British Carboniferous Cockroaches, 49,
433-

Eocene Siluroid Fishes, 303.
Liassic Gasteropoda, 193, 258.
Brittany, Visit to, 59.

Bucke, E. W., on the Geysers of New
Zealand, 39.
Buckman, S. S.,
monites, 396.

Bursting Rock-Surfaces, 511.
Bythocypris subreniformis, Jones, 386.

on the Jurassic Am-

(CECE SOUS Grit, new Ophzu-
rella from the, 97.

Callaway, C., on Crystalline Schists,
282, 383; on Parallel Structure in
Rocks, 351, 497.

Cambrian Fossils of Sardinia, 227.

Rocks of North America, 155.

Canal System in Shields of Pteraspidian
Fishes, 378.

Carboniferous Lurypterus from Esk-
dale, 481.

37

578

CAR

Carboniferous Cockroaches, 49.
— Larval Cockroach, 433.
—— Limestone of Flintshire,

120,

— Murchisonia, 328.
Myriapods, I, 116.
Carvill Lewis, H., Genesis of the Dia-

mond, 22; Studies in Glaciation, 28.
Causes of Glaciation, 332.
Subsidences at Northwich,

517.

Cephalopod Shells, Growth of, 446.

Cerithium trigemmatum, Wilson, 258.

Chalk Marl and Gault of West Norfolk,
72,

Red, in Suffolk, 24.

of Salisbury, Zerebratula from
the, 312.

Sear onne, A., Obituary of, 336,
382,

Chlamydoselachus Lawleyi, Davis, 379.

Changes of Levelin the Glacial Period,

344.
Chelonia from the Purbeck, etc., 270.
Chert, Irish Carboniferous Rock, 521.
— Organic Origin of, 435.
‘Chilostomatous Bryozoa from New
Zealand, 55.
Chondrosteus acipenseroides, 233, 248.
Classification of Carboniferous Series,
117.
. Cockroaches, New Carboniferous, 49,

433-
Cole, G. A. J., on the Rhyolites of
the Vosges, 299.
Collingham on Scarle Boring, 48, 140.
Collins, J. H., Cornish Serpentinous
Rocks, 220.
Comparative Studies in Glaciation, 28.
** Cone-in-Cone,” 17.
Cope, E. D., on Fossil Tortoises, 572.
Cornish Serpentinous Rocks, 220.
Correlation of Upper Jurassic Rocks,

134.
Courtland Rocks, 431.
Credner, H., on the Development. of
Branchiosaurus, 270.
Cretaceous Crustacea of Lebanon, 132.
Dinosaurian Vertebrz, 93.
Echini, of the Narbada
Region, 92.
— Series of Norfolk and Suffolk,
320.
Crocodiles from Hordwell, etc., 307.
Ctenacodon potens, Marsh, 246.
Culm-Measures of Devonshire, Io.
Cumberland and Westmoreland Asso-
ciation, 80.
Cyclobatis from the Lebanon, 508.
Cyclostomatous Bryozoa from New
Zealand, 288.

Index.

DIN

Cylindrites equalis, Wilson, 258.
Cythere Bosquetzana, Jones, 451.
Charlesworthiana, Jones, 390.
costellata, var. triangulata,
Jones, 450. ;
delirvata, Jones, 391.

Forbesit, Jones, 452.
eyroplicata, Jones, 391.
lacrymalis, Jones, 389.
lesa, Jones, 390.
recurata, Jones, 388.
Reid, Jones, 389.
scabropapulosa, Var.
Jones, 391.

scalaris, Jones, 451.
— Woodwardiana, Jones, 390.
— venustula, Jones, 388.
aranea, Jones, 453.
Prestwichiana, Jones, 454.
Cythereis spinosissima, Jones, 452.
Cytherura Prestwichiana, Jones, 456.

aculeata,

[DALTON, W. H., on Scarle Boring,
8.

Dames, W., on Cretaceous Crustacea,
132.

Date of the Ice Age, 523.

Daubrée, on Subterranean Waters, 565.

David, T. W. E., on Glacial Action, 135.

Davies, W., on a New Species of
Pholidophorus, 337; Notes on Che-
lonia, 380.

Davies, J. W., on Chondrosteus acipen-
seroides, 233; ona Fossil Species of
Chlamydoselachus, 379 ; on Lebanon
Fishes, 416.

Davison, C., on the Age of Stratified
Rocks, 38, 48.

Dawson, G. M., on Borings in Mani-
toba, 278.

Deep Borings in Kent, 93.

De Koninck, Prof. L.G., Death of, 432.

De Lapparent, Excursion of the Geo-
logical Society in Brittany, 175.

Delgado, J. F. N., on the Palzeozoic °
Rocks of Portugal, 89.

Denudation of West Kent, 121.

De Rance, C. E., on the Collingham
Boring, 140; on the Folkestone
Gault, 140.

Derby, O. A., on Nepheline Rocks in
Brazil, 373.

Development of Dicotyledons, 159.

Development of young in Pleszosaurus,
562.

Devonshire, Culm of, 10.

Diamantiferous Peridotite, 22.

Dimetian of St. Davids, 558.

Dinosauria, Classification of the, 562.

Dinosaurian Remains, 375.

Index. 579

DRI

Drifts of the Vale of Clwyd, 42.
Dollo, L., Dinosauria of Bernissart, 80,
124; on Some Belgian Fossil Reptiles,

392.
Donald, J., on Carboniferous AZurchi-
Sonia, 328,
Dorsetshire, Pholidophorus from, 337.
Dowker, G., on Water-Supply, 202.
Duncan, P. M., on a New Genus of
Madreporaria, 43; on Cretaceous
ag 92; on Australian Echinoidea,
328.

FLEMENTS of Primary Geology,

493-
Elsden, J. V., Superficial Geology of
the Wealden Area, 376.
Enniskillen, Earl of, Obituary of, 144.
Entomostraca, Tertiary, 340, 385.
£guus, Molar of, go.
Erosive Power of Glaciers, 167.
Eruption of Mount Tarawera, 136.
Essex Field Club, 325.
Ltoblattina Fohnsoni, H. Woodw., 53.
—_. Peachiz, H. Woodw., 433.
Ettingshausen, C., Tertiary Flora of
Australia, 359; Fossil Flora of New
Zealand, 363.
Eskdale, New Species of Auryfterus
from, 481.
Essex Drift, Rocks of the, 287.
Lurypterus scabrosus, A. Woodw., 481.
Luphoberia ferox, Note on, 116.
Evans, Caleb, Obituary of, 141.
Explosive Slickensides, 400, 522.
Exploration of Cae-Gwyn Cave, 471.
Extent of the Hempstead Beds, 510.
Extra-Morainic Lakes, 515.

f4 ACETTED Pebbles
Punjab, 32, 190.
Fauna of the Norfolk Forest-Bed, 105,
145.
Felspar in the Lizard Serpentine, 239.
Ffynon Beuno Cave, 94, 105.
Fisher, O., on Interglacial Land and
Man, 238.
Fishes from the Keuper of Warwick,
“20:
Foliation of the Lizard Grabbro, 74.
Foord, A. H., on the Genus P2loceras,

from the

541.
Fossil Flora of New Zealand, 363.
Fossil Reptiles, 80, 93, 124, 270, 307,
392, 512.
Fossil Tortoises, 572.
Fontannes, Charles F., Obituary of, 143.
Fox and Somervail, on Porphyritic
- Structure, 518.

GUI

French Meteorites, 552.
Fritsch’s Permian Fauna of Bohemia,

564.

({A85RO, Foliation of the Lizard,

74-

Gabbros and Hornblende in Rocks of
Baltimore, 87.

Gardner, J. S., on the Ardtun Leaf-
bed, 91; on the Gelinden Flora,
107 ; on the Development of Dico-
tyledons, 159; Report on the Fossil
Plants, 564.

Gastaldi, on Italian Geology, 531.

Gasteropoda, British Liassic, 193, 258.

Gault and Chalk Marl of West Nor-
folk, 72.

Gelinden Beds, 108.

Genesis of Crystalline Schists, 283.

of the Diamond, 22.

Geology, Elements of Primary, 493.

— of England and Wales, 314.

of Jersey, 130.
of the Isle of Wight, 367.
of the Wealden Area, 376.

Geological Society of London, 41, 89,
132, 181, 233, 281, 326, 373, 569.

—— Survey of India, 324,

of Canada, 175.

of Minnesota, 322.

Visit to Brittany, 59.

Geologists’ Association, 422.

Geysers of New Zealand, 39.

Glacial Action in the Carboniferou °
Series, 135-

Deposits of Sudbury, 262, 331,

Soo ee de

Period and Antiquity of Man,
327-

— Changes of Level in
the, 344.

Glaciation of Norway, 188.

Studies in, 28.
Glacier-erosion in Norway, 167.
Glyphastree, New Genus of, 43.
Gneisses, Origin of Banded, 484, 573.
Gneissose Rocks of the Himalaya, 461.
Granite of the Himalayas, 212.
Gregory, J. R., on New French Meteor-

ites, 552.

Gresley, W. S., on ‘‘ Cone-in-Cone,”
17; Formation of Coal-seams, 375 ;
Explosive Slickensides, 522.

Groom, T. T., on Felanechinus coral-
linus, 377.

Growth of Cephalopod Shells, 446.

Guise, Sir William Vernon, Obituary of,
528.

Guillier, A., Geology of the Sarthe,
320.

580

-HAA

AAST, Sir Julius von, Obituary
of, 432.
Haddow, R. W., on Paleontological
Nomenclature, 519.
Hardman, Edward T., Obituary of,

334-

Harker, A., Woodwardian Museum
Notes, 409, 546.

Harris, G. F., on the Gelinden Beds,
108.

Herbert M., on the Older Rocks of
France, 40.

Flemiphyllum, Tomes, New Genus, 98.

—— siluriense, 176.

Herries, R. S., on the Bagshot Sands,
192.

Fleterosuchus valdensis, Seeley, 235.

Hicks, H., on the Fauna of Ffynnon
Beuno Cave, 105 ; on the Cambrian
Rocks of N. America, 155; on the
Exploration of Cae-Gwyn Cave, 471.

Hill, E., Geological Visit to Brittany,
59; onSark, Herm and Jethou, 237 ;
Disaster at Zug, 473.

Hill, W., and Jukes Browne, on Gault
and Chalk Marl, 72.

Himalayas, Gneissose Rocks of the,
461.

Himalayas, Granite of the, 212.

Hinde, J. G., Organic Origin of Chert,
435-

History of Cornish Serpentines, 220.

Harker, Alfred, on the Courtland Rocks,
431.

Flolocentrum melitense, A. S. Woodw.,

355.

““Hope” specimen of Luphoberia ferox,
116.

Hordwell and other Crocodilians, 307.

Howorth, H. H., The Mammoth and .

the Flood, 473.

Hudleston, W. H., on the Walton
Common Section, 285.

Hughes, T. M‘Kenny, on Caves and
Cave-deposits, 42; Ancient Beach
and Boulders near Braunton, 374 ;
on some Brecciated Archzean Rocks,
500; Bursting Rock-Surfaces, 511 ;
on the Obermittweida Conglomerate,

570.
Hulke, J. W., Dinosaurian Remains,

375.

Hull, E., on a Boring at Bletchley,
137; Origin of Carboniferous Chert,
524; Irish Boulders, 560.

Hunt, T. Sterry, Elements of Primary
Geology, 493; on Italian Geology,
531

Hutton, F. W., on the Eruption of
Mount Tarawera, 136.
Huronian Series, 571.

Index.

LEP

Huxley, T. H., on Ayperodapedon
Gordoni, 286.

fyleochampsa, Note on, 512.

flyperodapedon Gordoni, Huxley, 286.

[CE-SHEETS, the work of, 151.
Iguanodon, Clavicles and Inter-

clavicles of, 561.

Igneous Rocks in County Galway, 282.

Interglacial Land and Man, 238.

————_— — surfaces, 147. =

Irving, A., on Bagshot Sands, 111, 381;
on Facetted Boulders, 190.

Isle of Wight, Tertiaries of the, 510.

Italian Geology, 531.

AMIESON, T. F., on Changes of
Level, 344.

Jenkins, H. M., Obituary of, 95.

Jones, T. R., Notes on WMummulina
elegans, 89.

—- and Sherborn, on Tertiary En-
tomostraca, 340, 385.

Jukes-Browne, A. J., Red Chalk in
Suffolk, 24; Interglacial Land Sur-
faces, 147; The Cretaceous Series
in W. Norfolk, 329 ; Glacial Depo-
sits, 331; The Paleeontographical
Society, 439.

Jukes-Browne and W. Hill on Gault
and Chalk Marl, 72.

Jurassic Ammonites, 396.

— Mammals, 241, 289.

EEPING, H., on the Osborne
Beds, 48 ; Zone of Mummulina
elegans, 70.
Kinahan, G. H., on Archzean Rocks,
503; Irish Carboniferous Rocks, 521.
Koto, B., Piedmontite-Schists in Japan,

330.
Krithe Londiniensis, Jones, 456.

[_AND-SURFACES, Inter-glacial,
14

Laodon venustus, Marsh, 292. ’
Lapworth, C., on the Ordovician Rocks,
78; on Paleozoic Graptolites, 368.
Larval Cockroach, from the Coal-
measures, 433.

Least Age of Stratified Rocks, 348.

Lebanon Fishes, 416.

Lebour, G. A., on Salt-measures of
Durham, 39.

Lee, John Edward, Obituary of, 526.

Leeds Geological Association, 326.

Le Neve Foster, C., on Manganese
Mining, 38.

Leptoblattina exilis, H. Woodw., 56.

Index.

LEW

Lewis H. Carvill,
Lakes, 515.

List of Papers read at British Associa-
tion, 465.

Lizard Serpentines, 137, 380.

London Clay Chelonia, 270.

Lydekker, R., Miocene Insectivora, 47 ;
Pliocene type of Agus, 90; Dino-
saurian Vertebrata, 93; Notes on
Chelonia, 270; Hordwell and other
Crocodilians, 307; Note on Ayleo-
chantpsa, 512.

Lythomylacris Kirkbyi, 1. Woodw., 55.

Lyons, H. G., London Clay and Bag-
shot Beds, 284.

Extra-Morainic

ALVERN, Archean Rocks of,
500.

Manganese Mining, 38.

Mammals, American Jurassic, 241, 289.

Mammoth and the Flood, 473.

Manitoba, On Certain Borings in, 278.

Marr, J. E., on the Lower Paleozoic
Rocks, 35 ; the Work of Ice-Sheets,
151; on Glacial Deposits of Sud-
bury, 262, 430.

Marsh, Prof. O. C., American Jurassic
Mammalia, 241, 289.

Martin, J., on the Terraces in Rotoma-
hama, 135.

McMahon, Col. C. A., on the Lizard
Gabbro, 74; on the Granite of the
Himalayas, 212.

Mellard Reade, T., Origin of Mountain
Ranges, 229; the Dimetian of St.
Davids, 558.

_ Menacodon rarus, Marsh, 294.

Metamorphic Rocks of the Malvern
Hills, 44.

of South Devon,

373-
Meteorites, New French, 552.
Microscopic Physiography of Massive
Rocks, 122.
Microscopic Rock Sections, 563.
Middlemiss, C. S., Physical Geology,

i)

Miller, H., on the Carboniferous Series,
117.

Miocene Insectivora, 47.

Monck, W. H. S., Causes of Glacia-
tion, 332; on the Ice Age, 523.

Monodonta (Turbo) humilis, Wilson,
201.

Lindecolina, Wil-

son, 201.

Morlaix, Rocks near, 570.

Morton, G. H., on the Carboniferous
Limestone, 120.

Myriapods, Carboniferous, I.

581

ORI

NAMES of Bones revised, 478.
Natural Springs and Deep Wells,
202

Neogene Isopoda, 189.

Nepheline Rocks in Brazil, 373.

New Features in Pelanechinus coral-
linus, 377.

New Fossiliferous Horizon in the Lake
District, 339.

New Species of olocentrum
Malta, 355.

Newton, E. T., on the Ffynon Beuno
Cave, 94; on Keuper Fishes, 326;
on the Norfolk ‘‘ Forest Bed,” 145.

New Zealand Fossil Flora, 363.

Nicholson, Prof. H. A., on Hemz-
phyllum Siluriense, 176.

and Marr, on a New Fossil-
iferous Horizon, 339.
Norfolk ‘‘ Pre-Glacial Forest-Bed,”

from

Tice

Norman, Mark, Geology of the Isle of
Wight, 367.

Note on Hyleochampsa, 512.

Notes on New Chelonia, 380; Chon-
drosteus acipenseroides, 248; the
Formation of Coal-seams, 375 ; Ter-
tiary Entomostraca, 340, 385; Eastern
and Western Alps, 470.

Noury, S. J., Geology of Jersey, 130.

Nummulina elegans, Notes on, 89.

Zone of, 70.

() BERMITTWEIDA Conglomer-
ate on the, 570.

Obituary of Arthur Champernowne,
336, 382; Caleb Evans 141 ;
Earl of Enniskillen, 144; Charles F.
Fontannes, 143 ; Sir William Vernon
Guise, 528; Sir Julius von Haast,
432; Edward T. Hardman, 334;
Henry M. Jenkins, 95; Prof. de
Koninck, 432; John Edward Lee,
526; Count Marschall, 586; John
Arthur Phillips, 142; Rev. W. S.
Symonds, 574; Edward Witchell,
479.

Observations on Ay perodapedon Gordoni,
286.

Occurrence of Piedmontite Schist in
Japan, 330.

Older Rocks of France, 40.

Oldham, R. D., Pebbles from the
Punjab, 32; Gmneissose Rocks of the
Himalayas, 461.

Ophiurella nereidea, Wright, 97.

Ordovician Rocks of Shropshire, 78.

Series of the Lake District,

33):
Origin of Banded Gneisses, 484.

082

ORI

Origin of Chert, 435, 524.
Dry Chalk Valleys, 187.
Mountain Ranges, 229.
Ornithodesmus cluniculus, Seeley, 236.
Ornithopsis Leedsit, Hulke, 375.
Osborne Beds, 48.
Outlier of Upper Bagshot Sands, 111.

ALAONTOGRAPHICAL — So-
ciety, 192, 371, 429.
Palzeontological Nomenclature, 519.
Paleozoic Graptolites, Report on, 368.
Madreporaria, 98,
Rocks of Portugal, 89.
——_ Settle, 35.
Parallel Structure in Igneous Rocks,

479.

Rocks, 351-

Patricosaurus merocatus, Seeley, 235.

Paurodon valens, Marsh, 295.

Pea Grit of Cleeve Hill, 140.

Leckhampton, 46.

Pengelly, W., on Bench Cavern,
Brixham, 514.

Permian Fauna of Bohemia, 564.

Phillips, J. A., Obituary of, 91, 142.

Pholidephorus purbeckensis, WW. Davies,

337-
——__ brevis, W. Davies, 337.
Phosphatic Nodules in the Salt Range,
India, 95.

—-—- Lower Green-

sand, 46.
Piloceras, on the Genus, 541.
Player, J. H., on Igneous Rocks, 40.
Pliocene Beds of St. Erth, 468.
Pliocene Beds, Notes on, 554.
Prestwich, Prof. J., on the Glacial
Period, 327.
Polyzoa from the Lias, 376.
Porphyritic Structure in Lizard Rocks,

518.
Position of Salt Measures in South
Durham, 39.

Post-Lias Species of Acrodus, 101.

Primary Geology, 493.

FPtychodus, Dentition and Affinities of,
9o.

UAIN, E. P., on Microscopic
Rock Sections, 563.
Quartzite Boulders in Roger Mine, 238.

RADCLIFFE, Iles
Boulders, 238.
Raisin, C. A., Metamorphic Rocks of
South Devon, 373.
Rauenthal Serpentine, Note on, 65.

on Quartzite

Index.

SUN

Red Chalk in Suffolk, 24.

Reid, Clement, on Dry Chalk Valleys,
187 ; ; on the Hempstead Beds, 510.

Researches in Bench Cavern, 514.

Rhacolepis, on the Fossil Genus, 379.

““Rhomben-porphyr” from Cromer,

331.

Rhyolites of Wuenheim, 299.

Roberts, T., on Correlation of Jurassic
Rocks, 134.

Rocks, Archzean, 503.

of the Malvern Hill, 281.

of Sark, Herm, and Jethon, 237.

Rock-Surfaces, 511.

Rosenbusch, H., Microscopic Physio-
graphy, 122.

Rowe, A. W., on Essex Drift, 287.

Rutley, F., on Metamorphic Rocks,
44; on Rocks of the Malvern Hills,
281.

GALT District of Cheshire, 517.
Salt Range of-the Punjab, 32, 428.

Sarthe, Geology of the, 320.

Seeley, H. G., Avéstosuchus puszllus,
Owen, 234 ; Patricosaurus merocatus,
235; Heterosuchus valdensis, 235 ;
Ornithodesmus cluniculus, 236; No-
menclature of Bones revised, 478 ;
on Clavicles and Interclavicles of Zo-
wanodon, 561; Classification of the
Dinosauria, 562; Development of
the young in Plestosaurus, 562.

Sedimentary Origin of Rocks, 351.

Serpentine, Note on the Rauenthal, 65.

Settle, Lower Palzeozoic Rocks near, 35.

Shore, T. W., on Remains of Bos pri-
migenius, 519.

Silica, in an Igneous Rock, 4o.

Siluroid Fishes from the Eocene, 303.

Slickensides, Explosive, 400.

Solaster Murchison, Williamson, 529.

Spencer, J]. W., on Glaciers, 167.

Spencer, John, on Boulders found in
Coal Seams, 377.

Spurrell, F. C. J., on West. Kent
Denudation, 121.

Sgualoraja, on the Lateral Line of, 378.

Stanley, W. F., on the Glaciation of
Norway, 188. 3

St. Davids, Dimetian of, 558.

St. Erth, Pliocene Beds of, 468.

Strahan, A., on Explosive Slickensides,

400.

Stratified Rocks, Age of, 348.

Structure of ‘‘ Cone-in-Cone,” 17.
of Rocks of Brittany, 236.

Subterranean Waters, 565.

Sudbury, Glacial Deposits of, 262.

Sunlight, 420,

Index.

TEA

ah BALL, J. J. H., on Banded
Gneisses, 486; on Lizard Ser-
pentines, 137.

Terebratula from the Upper Chalk, 312.

Terraces of Rotomahana, 135.

Tertiary Flora of Australia, 359.

Tomes R. F., on Palzeozoic Madre-
poraria, 98.

Traquair, R. H., on Chondrosteus acipen-
seroides, 248.

Trinomial System, 519.

Trochus Dalbiensis, Wilson, 196.

Crickt, Wilson, 197.

sagenatus, Wilson, 197.

Northamptonensis, Wilson, 198,

SSHER, W. A. E., on the Culm
of Devonshire, 10.

ERTEBRATE Fauna of Norfolk
““Forest Bed,” 145.
Visit to British Museum, Natural His-
tory, 422.
Vosges, the Rhyolites of the, 299.

yj ALFORD, E. A., on Polyzoa
from the Lias, 376.
Walton Common Section, Note on the,
376.
Waters, A. W., on Cyclostomatous
Bryozoa, 288; on Fossil Bryozoa,

45.
Water-Supply of East Kent, 202.
Ward, T., Subsidences in Cheshire, 517.
Wealden Chelonia, 270.
Westlake E., on Chalk 7evebratula, 312.

583

YOR
Whitaker W., on Deep Borings in Kent,

93:
Whitecliff Bay, Mummulina elegans at,

O.

Williams, G. H., on the Gabbros of
Baltimore, 87.

Wilson, E., on Liassic Gasteropoda,
193, 258. .

Witchell, E., on Red Grit, 46, 140;
Obituary of, 479.

Woods, H., Phosphatic Nodules, 46.

Woodward, A. S., on Affinities of
Ptychodus, 90 ; Post-Liassic Species
of Acrodus, 101 ; Sgualoraja poly-
spondyla, 190; Siluroid Fishes, 303;
a new Species of Holocentrum, 355 ;
Canal System in Pteraspidian Fishes,
378; ‘Lateral line’ of Sgualoraja,
378; on the Genus PRhacolepis, 379 ;
on Cyclobatis of Egerton, 508.

Woodward, Henry, on Spined Myria-
pods, I ; Carboniferous Cockroackes,
49; on Luphoberia ferox, 116; on
Etoblattina Peachi, WH. Woodw.,
433; New Species of Zurypterus, 481.

Woodward, H. B., Geology of England
and Wales, 314.

Woodwardian Museum Notes, 400, 546.

Work of Ice-Sheets, 151.

Wright, T., New Ophiurella from
Dorset, 97.

Wynne, A. B., on Phosphatic Nodules,
95; Salt-Ranges of the Punjab, 428.

ESTOLEBERIS
Jones, 456.

Colwellensis,

ORKSHIRE Lias, Solaster from
the, 529.

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