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GEOLOGICAL MAGAZINE:
Monthly Journal of Geologn:
WITH WHICH IS INCORPORATED
(hie Gl, OLiOG LS."
NOS. CCCXIX. TO CCCXXX.
EDITED BY
HENRY WOODWARD, LL.D., F.RB.S., F.G.8., F.Z.8., F.R.M.S.,
OF THE BRITISH MUSEUM OF NATURAL HISTORY 5
VICE-PRESIDENT OF THE PALZONTOGRAPHICAL SOCIETY,
MEMBER OF THE LYCEUM OF NATURAL HISTORY, NEW YORE; AND OF THE AMERICAN PHILOSOPHICAL
SOCIETY, PHILADKLPHIA ; HONORARY MEMBER OF THE YORKSHIRE PHILOSOPHICAL
SOCIETY; OF THE GEOLOGISTS’ ASSOCIATION, LONDON; OF THE GEOLOGICAL
SOCIETIES OF EDINBURGH, GLASGOW, HALIFAX, LLVERPOOL, AND NOR-
WICH; CORRESPONDING MEMBER OF THE GEOLOGICAL SOCIETY
OF BELGIUM; OF THE IMPERIAL SOCIETY OF NATURAL
HISTORY OF MOSCOW; OFTHE NATURAL HISTORE
SOCIETY OF MONTREAL; AND OF THE
MALACOLOGICAL SOCIETY
OF BELGIUM.
ASSISTED BY
ROBERT ETHERIDGE, FBS. L. & E., F.G.8., F.CS8., &.,:
wed OF THE BRITISH MUSEUM OF NATURAL HISTORY.
WILFRID H. HUDLESTON, M!A., F.R.S., V.P.G.S., F.L.S., F.C S.
AND
GEORGE J. HINDE, Pu.D., F.G.8., &c.
NEW SERIES. DECADE III. VOL. VIII.
JANUARY—DECEMBER, 1891.
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LONDON:
KEGAN PAUL, TRENCH, TRUBNER\& Oo., Luar, _
PATERNOSTER HOUSE, CHARING CROSS R Oe in . “eg ;
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. SAVY, 77, BOULEVART 8T.-GERMAIN, PARTS:
1891.
THE
GEOLOGICAL MAGAZINE.
DECADE III. VOL. VIII.
JANUARY—DECEMBER 1891.
Stephanella sancta, Hinde, gen. et sp. nov., Utica Shale, Canada
LIST. OF WOODCUTS.
Edinburgh Earthquake, January 18, 1889
Apparatus for Isolating Minerals
Fisher’s Physics of the Earth’s Crust .
Diagram to illustrate the theory of the elevation of the Himalayas
Apical disc of Echinoconus subrotundatus
feltastes Wrightit, and Echinoconus subrotundatus
Humerus and Mandibles of Dendrerpeton Acadianum
Parts of Skull and other bones of D. Acadianum
Outer Tooth and portion of Maxillary Bone of D. Acadianum
LTylonomus Lyelli
°
Cervical vertebrze of Triceratops prorsus, Marsh
Dorsal vertebrze of
Sacrum of
Caudal vertebrze of
Distal Caudal of
29
9?
99
”
Cranium of Bubalus Bainzi, Seeley .-
Hylonomus Wildi, A. S- Woodw., sp. nov.
Right scapula and coracoid of Triceratops prorsus
Right humerus of
Left ulna of
Pelvis of
Pubis of
Femur and tibia of
Metacarpal of
Phalanx of of manus of Zriceratops flabellatus
Metatarsal of
2?
prorsus
Vill List of Woodcuts.
Unsual phalanx of 7yzceralops horridus 9. 4 « « © «© « © «= PAG
Dermal spineolel72cerarops mw
egsil Wensses 5 56) 8 | Be Go) Gd!) ol 6
. Eocene and Cretaceous Fishes’ Teeth, and Tooth
Lelgicus ° e ° ° ° e ry ° e ° ° °
» Dhe/ Gigantic Ceratopside ~~ = -= 3 «. « «=
. Leveillia latidorsata, sp. nov., R. B. Newton . .
. Restoration of 7riceratops prorsus, Marsh . » -«
Remains of Wylonomus Lyell, Dawson . «
. Ichthyosaurus tenuirostris, Conybeare. .» « «© «
. The Lancashire Earthquake, February 10, 1889. .
. Restoration of Stegosaurus ungulatus, Marsh . «
Marsden Quarries, Coast of Durham. . »« =
~ Olenellus, Callaver, Wetails 5. 3 ss ss
Olenellus Callaveit, Restoration .»« »« +» « »« «
e e e e ° I
° e ° e 49
of Bottosaurus
e e e e 385
. Concretions from the Magnesian Limestone of Durham . » « «+ 433
° ° e e 433
Miata OU Lead (yotke q ee Woe A
frontispiece to the GEOLOGICAL MaGazinz, Dec. III. Vou. VIII. No. 1, for Yanuary, 1801.
THE
GEOLOGICAL MAGAZINE.
NEV SERIES, "DECADE Il. “VOLE. VIII:
No. I—JANUARY, 1891.
ORIGINAL ARTICLES.
————
J.—A Geonocist or A Century Aco:
SamMvEL Woopwarp or Norwicu, Antiquary and Geologist.!
(With a Portrait.)
HEOLOGISTS are so accustomed to deal with vast periods of
time, that a century may be deemed by them as equivalent to
the moment-measure of the dial, or the sand-grains of the hour-glass.
Nevertheless a century, in human affairs, especially that just .
expiring, has for us a vastly wider significance, and although its
passage may not have seen the birth, it has witnessed all the growth
and development of Geological science, and a large proportion of
that of her sisters also. It cannot be without interest, therefore,
briefly to record in these pages the name of one who, although
born a hundred years ago, with but scanty opportunities either of
position or education to assist him, yet by sheer force of energy and
perseverance, and attracted by a strong love of Nature, became
a geologist of no mean merit, and left behind him a name honoured
by those who knew him, and a record of work accomplished, worthy
to fill a much longer life.
Samuel Woodward was born at Norwich, on the 8rd October,
1790. His grandfather, Simon Woodward, came from London to
settle in Norwich, where he married and left two children, the
younger of whom, William, born in 1762, married, in 1789, to
Elizabeth Springall, and died in 1795, at the early age of 33 years.
He left a widow and two children, the elder of whom was Samuel
Woodward, the subject of the present Memoir. His father died
before he was five years old, and after attending a day-school for
a short time, he was placed under the care of a relative who was
a shawl-weaver, then one of the staple manufactures of Norwich.
So desirous was the boy to learn that he devoted every spare
moment to study, and read with eagerness every book which came
within his reach. At ten years of age we find him singing, as a
1 Those who are interested in the story of a Norwich boy who became a geologist
may read the fuller account, of which this is but an abstract, in the Transactions of the
Norfolk and Norwich Naturalists’ Society, vol. i. pp. 563-593, 1879, by Horace
B. Woodward, F.G.S. (grandson of Samuel Woodward), and author of the ‘‘ Geology
of England and Wales,’’ one of the best text-books ever written. The portrait is
reproduced by permission from an original sketch, in Indian ink, in the possession
of his daughter, Mrs. T. G. Bayfield of Norwich, drawn from life by his eldest son,
B. B. Woodward.—Epir. Grou. Mac.
DECADE III.—VOL. VIII.—NO. I. 1
2 Life of a Geologist of a Century Ago—
chorister, on Sundays, in St. George’s Colegate, the church of the
parish in which he lived with his mother. Here he was introduced
to Mr. Alderman Herring, a wealthy manufacturer, and at one time
Mayor of Norwich, who kindly took the lad into his warehouse, and
having first placed him in a school for a short time, he afterwards
bound him apprentice to his own business, that of weaving Camlets
and Bombazines. Here he gradually rose to a position of trust
and responsibility ; nor did he, during this period of twelve years,
neglect any opportunity of improving his mind, eagerly availing
himself of the kind permission given him by Mr. Herring to use his
library for study whenever he had leisure to do so. His pursuits
had already assumed the form they retained in later life. He
collected and cultivated flowers, and his room was adorned with
curios and shells which he bought at the old-curiosity shops in
the city.
One of the first geological puzzles he endeavoured to solve was
a mass of flint containing Ananchytes, which he had noticed on a
cottage mantel-piece, where it was kept, well black-leaded, as an
ornament. And one of the books which first excited his attention,
and perhaps directed it to antiquarian and geological studies, was
Verstegan’s “Restitution of Decayed Intelligence, in Antiquities
concerning the most noble and renowed English Nation,” a curious
work, of which the first edition was published in 1605, and in
which the former connection between England and France was then
advocated.
He not only used every opportunity of adding to his own store
of knowledge, but was ready to help others, for he himself taught
in both an evening and a Sunday school. It was whilst thus engaged
that he became acquainted with Joseph John Gurney, who, throughout
his life, proved a true friend to him.
In 1812 Mr. Herring gave up his manufactory owing to the
general depression of business, but in 1814 Samuel Woodward
obtained a clerkship in the Norwich Union Fire Office, which he
held for six years, when he entered the Banking-house of Messrs.
Gurneys’ & Co., where he remained until his death.
In 1815 Samuel Woodward married Elizabeth, daughter of Bernard
Bolingbroke, Hsq., of Hast Dereham, Norfolk, and niece of Nathaniel
Bolingbroke, Esq., formerly Mayor of Norwich, and of Sir John
Yallop, Sheriff of that city. This union resulted in a family of six
sons and three daughters; but one son and one daughter died in
their infancy.
After 1820, he was brought prominently under the notice of
Hudson Gurney, Esq., M.P., of Keswick, and Dawson Turner,
Ksq., of Yarmouth, both Fellows of the Royal Society, and partners
in Gurney’s Bank. It was to their friendly aid and encouragement
that he largely owed the opportunities he enjoyed for the prosecution
of his favourite studies, and also the success which attended his
labours. ‘To them he was particularly indebted for the loan of
books, and for aid in his publications.
The works of Parkinson, William Smith, and, later on, those of
Samuel Woodward— Geologist and Antiquary. 5)
Conybeare and Phillips, became his text-books; while the writings
of Richard Taylor gave an impetus to his local researches. Taylor’s
earliest paper was published in 1822,' and in the following year
Samuel Woodward made his first geological tour of the coast, put
without obtaining any specimens of fossil bones. In 1824 Mr.
Robert Lacy sent him two molars of Elephant from Mundesley,
and soon after he made another excursion from Yarmouth to Cromer
along the beach, and obtained some good specimens; and might, he
says, have obtained some very large and fine bones, but for the
difficulty of conveyance.
From this year and up to the time of his death he maintained a
considerable correspondence with many of the leading naturalists
and geologists of the day. The letters he received, together with
many miscellaneous notes and memoranda, are preserved in eleven
quarto volumes, now in the possession of his youngest son, Dr.
Henry Woodward, F.R.S. During this period of fourteen years he
seems to have kept every scientific letter he received, and it must
be remembered that in those days letter-writing was, as a rule, far
more elaborate and careful than it is now. Many of these letters
are only of value as autographs, and merely relate to inquiries as
to coins, rings, seals, merchants-marks, ancient buildings, and other
antiquarian matters mostly of local interest. Others bear upon
geological topics: amongst them we find letters from William Bean
(of Searboro’), C. W. Peach, R. C. Taylor, Hudson Gurney, Dawson
Turner, the Rev. James Layton (of Catfield); Thomas Amyot
(Treasurer of the Society of Antiquaries), J. W. Robberds, Miss
Etheldred Benett,? Goddard Johnson, H. Denny (of Leeds), Daniel
Stock (of Bungay), Dr. Buckland, Prof. Sedgwick, Dr. Mantell, G.
B. Baker (of Bungay), Dr. Charles Konig (British Museum), Sir R. I.
Murchison, Prof. John Phillips, Dr. James Mitchell, Wm. Gilbertson
(of Preston), the Rev. Thomas Image (of Whepstead), the Rev.
George Munford, the Rev. W. Foulger. There are also short notes
from Fitton, De la Beche, Lyell, Agassiz, Sir Philip Egerton, Eliza-
beth Fry, Harriet Martineau, and Charles Waterton.
Samuel Woodward’s first letter to Mr. Caleb Rose, F.G.S., of
Swaffham, was written in May, 1826, and from that date there was
an uninterrupted correspondence, mostly on geological topics, until
the death of the former in 1838. The enthusiasm of the two friends
seems to have been very great ; every discovery of a new fossil was
at once communicated, while books and specimens were borrowed
and exchanged, in a way that speaks well for the prosecution of
science in those days.
In 1824 he made his first communication to one of the learned
Societies of London. It consisted of a series of maps and plans of
Ancient Norfolk, which he submitted to the Society of Antiquaries
through Mr. Hudson Gurney. One of these maps illustrated the
Roman period, showing the several stations and roads constructed
1 « Fossil Bones on the Coast of East Norfolk,’’ Phil. Mag. vol. lx. p. 132, 1822.
2 Well known to geologists as authoress of ‘‘ A Catalogue of the Organic Remains
of the County of Wilts,’’ 1831; (of Norton House Warminster, Wilts).
4 Life of a Geologist of a Century Ago—
by the Romans; another pictured the great estuary which it was
considered had spread itself as far as Venta Icenorum (Norwich)
before the sands on which Yarmouth was built were left uncovered
by the sea. This latter map was based upon the ancient ‘ Hutch
Map,’ belonging to the Corporation of Yarmouth, with, however,
many inaccuracies as to places and distances corrected.
In 1825 he had already nearly completed two works in MS., one
entitled “Sketch of the Norwich Crag Deposit, with a Descriptive
Catalogue of its Fossils,” a quarto volume containing twenty plates
with outline figures of the species; the other, entitled, ‘‘ Remarks
on the Geology of the County of Norfolk,” 4to. illustrated with
coloured figures of the fossils and coloured sections of the strata.
Both works, however, were commenced and carried out on a plan
far too ambitious and expensive for publication. The projected
“Geology of Norfolk” was to comprise 24 plates, and nearly 1000
figures; he had already drawn about 300, and others were sub-
sequently added; these remain as he left them. The substance of
his observations, and figures of many of the species were, however,
published in his “Geology of Norfolk,” in 1833. The original
drawings of fossils are extremely accurate and very carefully executed
and bespeak considerable native talent. In 1826 he was elected a
member of the Committee of the Norfolk and Norwich Museum
(established in 1824), an office which he held at intervals during the
subsequent years of his life. In 1827 he exhibited before the
Society of Antiquaries, in London, some antiquities found at
Coltishall, which he conjectured to have been a landing-place to the
Romans when navigating the River Bure on their way to Bampton
or Burgh-by-Aylsham. Later in the year he was engaged with Mr.
W. C. “Ewing, in exploring the Barrows at Eaton Heath. The
Bronze Celts and a perfect metal mould obtained there, were ex-
hibited at the Society of Antiquaries, Dec. 6, 1827 (see Archeologia,
vol. xxil. p. 424, 1829). On the Sth Feb. 1828, he was elected
an Honorary Member of the Yorkshire Philosophical Society, at
the suggestion of John Phillips, then Curator of the York Museum,
with whom he frequently corresponded.
In 1828, in a letter to Dr. Fitton, F.R.S., President of the
Geological Society of London (read 2nd January, 1829), he records
the occurrence of Crag at Cromer, and westward at Coltishall, and
around Norwich. ‘To the eastward, instead of marine shells, he
noticed that there occurred a layer of igneous and mammalian
remains reposing on the Chalk. In this, immense numbers of bones
and teeth of the Hlephant, Horse, Deer, etc., mingled with trunks,
branches, and leaves of trees, had been found, extending even to the
distance of twenty miles out to sea, and on the Knoll sands, ete.
(Proc. Geol. Soc. 1829, vol. i. p. 98). In 1829, he communicated a
short sketch of the geology of the county to the “Norfolk Tour,”
in which he states that in what was subsequently termed the
“Forest Bed” there are found a surprising number of vegetable
and animal remains, as trunks, branches, leaves, and stumps of trees
(in situ), etc. He had two years previously (1827) recorded that
Samuel Woodward—G'eologist and Antiquary. 5
in his own collection from the coast were remains of Elephant,
Rhinoceros, Hippopotamus, Horse, Bos, Irish Deer, and three other
species of Deer.’ Many of these were obtained from the oyster-
bank off Hasboro’, which he regarded as an extension of the
blue clay of the cliff. He also observed that “the antlers of the
deer are broken into fragments of from six to eight inches in length,
and three-fourths of them had been shed, indicating that they were
at present not far removed from their original locality, and appeared
to confirm the tradition that this part of the sea, called ‘the
Holmes,’ was originally a forest.”
In a second communication to Dr. Fitton (23rd March, 1829), he
pointed out that “ Wherever a section has been made of the Crag
of Norwich, with one exception, there has been found a layer of
nodular flints from twelve to eighteen inches in thickness reposing
on the Chalk. Reasoning from analogy he concluded that the
Chalk in these instances had been subject to the action of currents
of water previous to the deposition of the (Crag) shells; as the
appearance of the flints perfectly agrees with the like phenomena
going on at Foulness Point, Cromer, and at Trimmingham Beach,
on our coast; .... The Chalk under these flints is perforated as
if by Pholades.” These notes, although not published at the time,
appeared later on in the “ Geology of Norfolk.”
In April, 1829, he sent to Mr. Amyot some “ Fragments illus-
trating the History of Norwich Castle;” and in May,. some
“Observations on the Round Towers of Norfolk,” for the Society
of Antiquaries. At the request of Mr. Daniel Gurney, he directed
his attention, in 1825, to the collecting and publishing of Merchants’
Marks, and later on he exhibited six examples referred to dates between
1409 and 1608, which he had drawn on stone ready for publication.
For some time past his “Synoptical Table of British Organic
Remains” had been in preparation, entailing much research and
correspondence; it appeared on Ist July, 1830, the list of sub-
seribers numbering 155. This work, naturally, has now been out
of date long ago, having been superseded in 1843 by the “Catalogue
of British Fossils,” by Professor Morris, the second edition of which
appeared in 1854, now 386 years since. Happily the Vertebrata
have been brought up to date by Messrs. Arthur Smith Woodward
and C. Davies Sherborn, but the Invertebrata have only been
partially listed in separate works, so that much remains to be done
in order to complete our Catalogue of British Fossils.
In 1832, Samuel Woodward visited Mr. Hudson Gurney in
London, and went the round of the principal learned Societies with
him; making the personal acquaintance of a number of eminent
geologists and antiquaries whom he had previously known by
correspondence. He also attended aconversazione at Mr. (afterwards
Sir Roderick) Murchison’s house, where he met Dr. Buckland and
Mr. (afterwards Sir Charles) Lyell, and others.
The year 1833 saw the publication, on the Ist of May, of his
“Outlines of the Geology of Norfolk,” one of the first works
1 See Rev. J. Layton, Edinb. Journ. of Science, vol. vi. p. 199.
6 Life of a Geologist of a Century Ago—
describing the geology of any English county, and one which in its
plan and scope has not at present been superseded. Much necessarily
requires revision in the classification of both the strata and their
included fossils; but the work has retained its place as a standard
book of reference for Norfolk. He attended the meeting of the
British Association at Cambridge in 18338, in company with his
friend Mr. Caleb Rose, of Swaffham, but they do not appear to
have been much gratified with their visit; for, as his friend after-
wards remarked in a letter, ‘“‘authorities were ponderous,’ and we
were only “insignificant labourers.”
In this year Professor Sedgwick was appointed a Canon of Norwich
Cathedral, and his advent was indeed a happiness to the Norfolk
geologist. Dr. Mantell, writing from Brighton (December 14th,
1854), says: “Believe me you are most fortunate to have such a
man near you; it will more than compensate for your distance from
all the other savants in England. I think Mr. Sedgwick by far the
most talented and splendid man we can boast of. I only wish we
had a Cathedral here, and he had a stall in it.”
During the Professor’s residence in Norwich, they not unfrequently
met, Sedgwick often inviting Woodward to the Close, and coming
occasionally to spend an evening at Grove Cottage, to look over
the treasures in his geological collection.
In February, 1835, he delivered a lecture on “The Antediluvian
Topography of Norfolk” at an evening conversazione of the Norfolk
and Norwich Museum.
About this period his health seems to have been very feeble; he
was suffering from a most trying complaint, diabetes. At times he
had to relinquish his duties at the Bank, and seek in travel and
change of scene, a temporary alleviation from his indisposition.
Thus, on the 18th July, 1835, he went by packet to Yarmouth, and
thence to Hull, where he inspected the Hull Natural History Museum
with Mr. W. H. Dykes, and Mr. John Edward Lee, the Curator of
the Museum. He next proceeded to Beverley, and afterwards to
Scarborough, where he met Mr. W. Bean, Dr. William Smith, and
Mr. Williamson, and was shown the geology of the coast by William
Smith. Thence to York to visit John Phillips and the York Museum ;
afterwards to Leeds, to the Museum and to visit Mr. H. Denny.
Then on to Preston to stay with Mr. Gilbertson, the well-known
collector of Mountain Limestone fossils.1_ Later on he returned via
Liverpool, and made his first railway journey from that city to
Manchester, thence to Nottingham and so through Derbyshire by
Buxton and Matlock to Derby and back to Nottingham, then on to
Newark and so home vii Sleaford, Lynn, and Dereham to Norwich,
a truly formidable journey in those days.
In 1836 we find him again in London, seeking health, though
mostly visiting amongst friends and attending the meetings of
scientific societies.
In September, the Marquis of Northampton, who was much
interested in geology, visited him at Grove Cottage, Lakenham, in
1 Whose collection, like William Smith’s, is now preserved in the British Museum
(Natural History).
Samuel Woodward—Geologist and Antiquary. ii
order to see his collections ; also Mr. Joseph Prestwich, jun. (after-
wards Professor Prestwich, F.R.S.) who, paid his first visit to the
Thorpe Crag-pits under Mr. Woodward’s guidance, and there obtained
a fine molar of Hlephas meridionalis, now in the Norwich Museum.
Although his bodily powers failed him, his mental energies never
ceased to display their activity, and even at the last he occupied
himself with numerous archeological subjects, and with the prepara-
tion of a new work, “Theoretical View of the Geology of the Norfolk
Coast,” a MS. which was never published.
He was also engaged in the preparation of his “History and
Antiquities of Norwich Castle,” edited, after his death by his eldest
son, B. B. Woodward, F.S.A., in 1847; and in gathering materials
for the “Norfolk Topographer’s Manual,” revised, augmented, and
edited by W. C. Ewing, and published in 1842. Nothing could
exceed the sympathy and kindness shown to Mr. Woodward during
his last illness by all his friends, but his malady baffled medical
skill, and he died on the 14th January, 1838, in his 48th year.
Thus ended a life of devotion to science, a life whose published
works form but a partial memorial of the indefatigable industry of
their author. “I believe,” writes Prof. Sedgwick, “it is not too
much to say that his life has been cut short by his devotion to
science, and by his continuing (after the laborious duties of the
day) to spend hours in study, which ought to have been given to
rest.” ‘His memory,” writes his eldest son, ‘‘remains an object of
reverence to his children, whose paths, by his patience and toil,
have been made so easy and pleasant compared with his own, and
of unfeigned respect to all who were acquainted with his character
and his acquirements.”
LIST OF WORKS BY SAMUEL WOODWARD OF NORWICH.
1829.—1. Geology of Norfolk. In ‘‘A General History of the County of Norfolk
intended to convey all the Information of a Norfolk Tour.’ [By J.
Chambers.] 2 vols. 8vo. 1829.
2. A Letter [to Dr. Fitton] respecting some remarkable fossil remains found
near Cromer, in Norfolk. [Read Jan. 2nd.] Proc. Geol. Soe. vol. i.
pp. 93, 94.
3. Musical Snails. Mag. Nat. Hist. vol. ii. p. 244.
4. [Notes on some Antiquities found in Norfolk.] Archeeologia, vol. xxii.
pp. 422-424,
1830.—5. On the Hydra, or Freshwater Polypus. Mag. Nat. Hist. vol. iii. p. 348.
6. A Synoptical Table of British Organic Remains: in which all the edited
British Fossils are systematically and stratigraphically arranged in ac-
cordance with the views of the Geologists of the present day; anda
reference given to their localities, strata, and engraved figures. 8vo. and
4to. London and Norwich.
1831.—7. Observations on the Round Church Towers of Norfolk; and on the
materials employed in constructing the early religious buildings in that
County. [Read May, 1829.] Archeologia, vol. xxii. pp. 7-9.
8. A Descriptive Outline of the Roman Remains in Nortolk, accompanied
by a Map of the County. [Read Dec. 1830.] bid. pp. 358-373.
9. A Copy of an Ancient Plan of the Chalk Vaults near St. Giles’ Gates,
Norwich: made by John Bond, 1571; exhibited, with notes, by Mr.
Samuel Woodward. Jbid. pp. 411-412.
19. Natural History Collection. Mag. Nat. Hist. vol. iv. p. 177.
11. Luminosity of the Sea. bid. p. 284.
12. Atites or Eagle Stones. did. p. 468.
8 R. D. Oldham—Essays in Theoretical Geology.
1832.—13. Trichiosoma lucorum, the Pupa and Imago of, a Habitat of, and the
destruction of by one of the Ichneumonide. Mag. Nat. Hist. vol. v.
. 85, 86.
Gl uaduens of the Sea. did. vol. v. pp. 302, 303.
15. Origin of the Crag Stratum of Norfolk. did. vol. v. pp. 544, 545.
16. Sir John Byerley’s Theory of verifying Dates by calculations on the
Precession of the Equinoxes. did. vol. y. p. 761.
1833.—17. An Outline of the Geology of Norfolk. 4to. and 8vo. Norwich.
18. The Natterjack in Norwich. Mag. Nat. Hist. vol vi. p. 447.
19. Remarkable Meteor seen from Norwich, Dec. 19th, 1832. Ibid. p. 463.
[Also Letter in ‘ East Anglian,’ 1832, on this subject. |
1834.—20. Drawing of Two Steelyard Weights, one of which was found at Catton ;
exhibited by Mr. Samuel Woodward. [Communicated Feb. 2nd, 1832.]
Archeologia, vol. xxv. p. 589.
21. An Account of certain Judicial Proceedings at Norwich, at the com-
mencement of the Usurpation, copied from a Manuscript written about
1675, im the possession of Edward Steward, Esq., of Norwich. Com-
municated by Mr. Samuel Woodward. [April 12th, 1832.] Jdid.
pp. 591-594.
22. Sketch of an Ancient Sword, found in the Bed of the River Yare, at
Thorpe. [Communicated Dec. 12th, 1833.] bid. pp. 618, 619.
1835.—23. Some Remarks upon the Crag Formation of Norfolk and Suffolk.
Phil. Mag. series 3, vol. vii. p. 353.
1836.—24. On the Crag Formation; in answer to Mr. Charlesworth’s ‘‘ Reply.”
Ibid. vol. viti. p. 138.
25. An Account of some Discoveries made in excavating the Foundations
of Wymondham Abbey, with a Plan and Description of the Religious
Establishment. [Communicated December, 1834.] _Archeologia, vol.
XXvi. pp. 287-299. [Also Letter on this subject to Editor of “ Norwich
Mercury,’’ dated 30th December, 1833.]
26. Modern Conglomerate at Cromer. Mag. Nat. Hist. vol. ix. p. 47.
27. Evidence in argument that remains of Mastodon giganteus and Mastodon
latidens have been found in the Tertiary Beds of Norfolk. Ibid. p. 161.
1838.—28. Ancient Swords, found near Norwich. [Communicated November 16th,
1837.] Archzologia, vol. xxvii. pp. 485-487.
1842.—29, The Norfolk Topographer’s Manual: being a Catalogue of the Books
and Engravings hitherto published in relation to the County. The whole
revised and augmented by W. C. Ewing. 8vo. London.
1847.—30. The History and Antiquities of Norwich Castle. Edited by his Son
[B. B. Woodward]. 4to. London and Norwich.
IJ.—Essays 1n TurorericaL, Gronoey.
By R. D. Oxpuam, A.R.S.M., F.G.S.,
of the Geological Survey of India.
3. Tor AcE anp Origin oF THE HIMALAYAS. WITH ESPECIAL REFER-
ENCE TO THE Rey. O. Fisuer’s Torory or Mountain Formation.
Introductory.
ie has become one of the truisms of geology that India, like Gaul,
is divided into three parts, the Peninsular, the Extra-peninsular,
and the Indo-gangetic alluvium.
Of these the first, the Peninsular, has been dry land since the
Paleozoic period at least. It consists of a core of highly metamor-
phosed and contorted gneiss, on which are the remains of a skin of
sedimentary rocks of various ages, and a vast expanse of trappean
outbursts. Except in the Aravallis, the beds are but slightly dis-
turbed, and the whole area has evidently been in a state of quiescence
LR. D. Oldham—Essays in Theoretical Geology. 9
throughout the greater part of the period which has elapsed since
the commencement of the sedimentary period. The region seems |
to have undergone but little oscillation of level, and such oscillations
as have taken “place never brought more than the margins of the area
beneath the level of the sea. With the exception of the Aravallis
before mentioned, there is no structural mountain-range in the
Peninsular area, and such tracts as, from their elevation, deserve the
name of mountains, owe their limitations to the action of subaerial
denudation.
In contrast with this the Extra-peninsular area, if we except the
Upper Tertiary beds at the top of the sequence and the Archean
gneisses at the base, contains few sedimentary rocks which are not
of marine origin. Almost everywhere they are intensely disturbed,
and the area is essentially one of structural mountain ranges, that is,
of ranges whose general direction is closely connected with, and
caused by, the disturbance the beds have undergone. Of this area
we are at present concerned with the Himalayas, that system of
mountains which rises abruptly from the plains of Upper India,
range beyond range, to the snow-clad summits forming the highest
spots on the surface of the Earth.
In the contour of the two areas there is a vast difference. The
surface of the Peninsular area shows rounded outlying and gentle
slopes, except where the outcrop of hard or massive beds has led
to the formation of scarps; the gradients of the streams are flat, their
beds sandy, and seldom do they show signs of active erosion of
their channels; in fact, the Peninsular area shows all the features
of an ancient land-surface, long exposed to subaerial denudation,
in which the streams and hill-slopes have alike gone far towards
reaching a condition of equilibrium.
The Himalayas, on the contrary, are a region of deep, steep-sided,
valleys and gorges; nearly everywhere the streams and rivers alike
are torrents flowing over a bed of coarse boulders, everywhere, with
but local exceptions, they are evidently eroding their channels,
while the steep slopes and sharp crests of the ridges, no less than
the constant landslips and general instability of the soil, betoken
a country in which the action of rain and frosts on the hill-sides has
not been able to keep pace with the deepening of the stream-beds
by erosion.
Equally striking is the contrast in the nature of the boundary of
the two areas with the Indo-gangetic alluvium. To the north the
Himalayas rise abruptly from slopes of recent gravels at their base,
and, though there are irregularities of detail, the boundary as a
whole sweeps in a crescent curve from one extremity to the other,
while there are no outliers of the Himalayan beds surrounded by
alluvium, nor are there any long tongues of the latter running up
into the Himalayan area. To the south the rocks slip imperceptibly
under the alluvium, so much so that different observers have differed
by miles in the boundary they drew between the alluvium and the
older rock; the boundary exhibits every variety of irregularity,
long tongues of alluvium run up the various river valleys far into
10 R. D. Oldham—Essays in Theoretical Geology.
the rock area, and, to crown all, there are outliers innumerable of
the peninsular rocks standing up from the alluvial plain.
These last contrasts between the two areas are shown even on
a good topographical map; but that now to be mentioned, the most
important of all, can only be seen on one that is geologically
coloured.
Along its southern boundary the alluvium is in contact with rocks
of various ages; but to the north, with the exception of a short
distance in Sikkim, a zone of rocks of Tertiary age separates the
alluvium on the one hand from the pre-Tertiary rocks of the
Himalayas on the other. In a word, the southern boundary is due
to the freaks of denudation and alteration of level, while the
northern is a structural boundary; and this will be made still
more evident when we come to consider in more detail that band
of Tertiary deposits which forms the southern margin of the
Himalayas, and has so important a bearing on the subject with
which this paper deals.
Part I. The Facets.
The Tertiaries of the outer Himalayas present a marked similarity
of type along the whole extent of the range, but the sequence is
not everywhere equally complete. In the extreme north-west there
is a great series of beds, ranging from the marine Nummulitics at
the base to the subaerially deposited Pliocene conglomerate sand-
stones and clays at the summit. ‘They were divided by Mr. Wynne,
who examined this country, as follows : !—
1. Upper Siwalik, about 4000 feet; brown drab or reddish clays, soft grey sand-
stones, conglomerates.
2. Lower Siwalik, about 10,000 feet; soft grey sandstones and brown and grey
clays, many red clays.
3. Murree beds, average 7500 feet; harder grey sandstones with soft zones, red
or purple clays.
4. Nummulitic, upper 800 feet; greenish grey and purple sandstones, grey, olive-
brownish, red and variegated clays with masses of gypsum.
5. Nummulitic limestones with shales and coal at base.
The series is said to be parallel and conformable from the pale
limestones upwards to the top of the Siwaliks.
The series in the Jamu” (Jummoo) hills appears to be practically
the same, except that the Nummulitic Limestone is much less
developed.
In the Simla region the Tertiaries are divided into two distinct
areas, in which the beds are of different ages, though they may
slightly overlap each other. The first area forms part of the lower
Himalayas and the beds constitute the so-called Sirmur series,
divided into
1, The Kasaoli group; grey sandstones, sandy shales, and shales containing plant-
remains.
2. The Dagshai group ; hard, fine-grained sandstones and red or purple nodular
shales, the former prevailing in the upper and the latter in the lower part of the
group.
* Records Geol. Surv. India, vol. x. p. 112 (1877).
* Mem. Geol. Surv. India, vol. xxii, chap. vy. (1883).
R. D. Oldham—Essays in Theoretical Geology. 11
3. The Subathu group; olive green, grey and red shales and subsidiary bands of
sandstone and argillaceous limestone, with a coal-seam and a peculiar ferruginous
bed at the base. It contains Nummulites and other marine fossils.
The second area, forming part of the sub-Himalayas, is divided
from the Sirmur series by a great fault, and, in many places, by
a narrow strip of pre-Tertiary beds; the series may be divided as
follows:
1. Upper Siwalik ; soft sandstones or sandrock, conglomerates and some clays.
2. Lower Siwalik; soft sandstones or occasionally pebbly sandstones, and clays
mostly grey, but sometimes tinged with red, especially in the lower part of the group.
3. Nahan group; firm or hard sandstones interbedded with clays generally nodular
and of a bright red colour, which are more abundant in the lower part of the group
than in the upper.'
The series in the two areas combined appears to be much the same
as in the Murree hills. The Nummulitic Limestone is not developed,
and the marine deposits are much less in thickness; but there can
be no doubt that the Subathu group represents the Nummulitic
groups of Mr. Wynne. The Dagshai and Murree groups corre-
spond so closely in mineral character and stratigraphical position
that there can be no risk of error in correlating them, while the
two upper groups in the north-west are evidently the equivalents
of the three groups in the sub-Himalayas of the Simla region and
possibly in part of the Kasaoli group of the Sirmur series.
To the east of the Ganges there are a few small outliers of the
Subathu group faulted and folded among the pre-Tertiary beds near
their southern boundary ; but with this exception the only Tertiary
beds known here or to the eastwards are confined to the Nahan and
Siwalik groups.’
Besides these Tertiaries of the Outer Himalayas, beds of the same
age are known to exist at several places to the north of the main
snowy range; but it is only in Cashmere territory that they have
been examined in any detail. In the Upper Indus Valley the
Nummulitics may be briefly described as consisting, at the base, of
coarse-grained sandstones, arkose beds and conglomerates, considered
by Mr. Lydekker to be of glacial origin; they are certainly of
littoral origin, and indicate the close proximity of the original limit
of deposition. Above these come red, and green and grey shales, of
very similar type to those of the Subathu group, interbedded with
limestones: while at the top the series consists of a great thickness
of beds, mainly volcanic in their origin and basic or ultrabasic in
composition.?
The coarse-grained beds of littoral origin are confined to the
north-eastern boundary of the exposure, whose south-western
boundary is marked by great disturbance, and is in effect a faulted
one. It seems then that to the north-east the original limit of
deposition was not far removed from the present boundary, but
' Comp. Medlicott, Mem. Geol. Surv. India, vol. iii. part 2, chaps. i. and iii. ;
also Manual of Geology of India, vol. ii. chap. xxii.
* Oldham, Rec. Geol. Sury. India, vol. xvii. p. 161 (1884); Middlemiss, Mem.
Geol. Surv. India, vol. xxiv. part. ii. 1890.
3 Mem. Geol. Sury. India, vol. xxii. chap. v.
12 R. D. Oldham—Essays in Theoretical Geology.
to the south-west there is no indication of the original limit of
deposition ; and the small outlier in the Singhe La, between Zanskar
and the Indus Valley, is described by Mr. La Touche as consisting
of a foetid limestone, resting directly on the Secondary quartzites
without the intervention of any beds of a littoral or shallow-water
origin. From this it is evident that the land-surface must have
been far to the southwards, and it may be that the sea extended
over the whole of the Himalayan area between this and the outcrops
of the Subathu group, as it certainly must have done over a con-
siderable portion of it.
Having briefly reviewed the geology of the Himalayas so far as
is necessary to make what follows intelligible, we must now enter
into a detailed consideration of the evidence. It is not, however,
intended to give here anything resembling a complete account of
the geology of the Himalayas, for such would be impossible in the
space available, but merely to notice such points as have a special
connection with the age and elevation of the Himalayas.
The first, most important, most palpable and unmistakeable point
that stands out is that, at the commencement of the Tertiary period,
the Himalayas did not exist as a distinct mountain range, or at
least that, if the Himalayan system of disturbance had commenced,
it had not extended north-west of a line, drawn transverse to the
range, through the debouchure of the Ganges. This is amply
proved by the occurrence of marine nummulitics in the heart of the
Himalayas, in the Upper Indus Valley and in Zanskar, at heights of
19,000 to 20,000 feet above the level of the sea.
But besides this the nature of the contact between the Nummu-
litic and pre-Tertiary beds points to the same conclusion. In the
Upper Indus Valley the Nummulitics rest directly on an eroded
surface of, presumably, Archean gneiss; in the outer hills, however,
they rest on limestones or slates,and Mr. Medlicott has noticed how,
both near Subathu and in the Jamu Hills,” wherever the boundary
is one of original contact, there is no perceptible divergence of dip
between the Tertiary and pre-Tertiary formations. The same appears
to be the case with the outliers in Garhwal, and this shows that,
though the older rocks had been denuded before the Nummulitics
were deposited, they had not at that time been seriously disturbed,
and that their position was practically one of horizontality.
It is true that, in his recently published memoir, my colleague,
Mr. Middlemiss, has shown good reason for believing that, at the
commencement of the Tertiary period, the pre-Tertiary beds were
not everywhere so slightly disturbed as the contact with the
Nummulitics would indicate.? But the Himalayan area is a large
one, and it would be unnatural to suppose that there had been no
disturbance of any part of it before the commencement of the
Tertiary period; while the evidence produced by Mr. Middlemiss
1 Rec. Geol. Surv. India, vol. xxi. p. 161.
2 Rec. Geol. Surv. Ind. vol. ix. p. 54.
3 Mem. Geol. Surv. Ind. vol. xxiv. p. 184.
R. D. Oldham— Essays in Theoretical Geology. 13
shows that the pre-Tertiary disturbance was transverse, and did not
belong to that which has resulted in the elevation of the Himalayas.
It may be that in Kumaon and Garhwal this last had already
commenced when the Nummulitics were being deposited and only
extended to the north-west at a later period; but there is no
evidence to show that it could have commenced before the end of
the Secondary period; and the early Paleozoic or still earlier date,
to which Mr. Middlemiss would seem inclined to refer the first
origin of the Himalayas as a mountain range, is, to say the least,
extremely improbable.
Besides the stratigraphical evidence of the absence of disturbance,
there is everywhere, from the Jamu Hills to the outliers east of the
Ganges, a peculiar pisolitic, ferruginous bed, which invariably occurs
at the base of the Subathu group. In mineral and chemical character
this closely resembles the laterite of the Peninsula and the laterite
beds, which occur interbedded with the Nummulitics of Cutch and
Sind, and must probably be referred to the same source of origin.
The origin of the laterite of the Peninsula is still a vexed question,
which has been much complicated by the very loose manner in
which the term has been used; but the balance of evidence seems
to show that the true laterite is in some way or other connected
with the Deccan Traps, and is directly or indirectly the result of
an alteration of them or their detritus. If this same source of
origin is accepted for the ferruginous bed at the base of the Subathu
eroup, it follows that the present distinction between Peninsular and
Extra-peninsular areas had not been established in Hocene times,
and, consequently, that the system of disturbance of which it is the
result must, at the outside, only have commenced when the Subathu
group was being deposited.
In this connection the occurrence of Gondwana rocks of Penin-
sular type in Sikkim and the Eastern Himalayas is important.
Unfortunately nothing is known of the great area of Nepaul, which
occupies the middle third of the length of the Himalayas; but
Sikkim cannot in any way be regarded as a terminal area, and the
occurrence of Peninsular beds of latest Palaeozoic or early Secondary
age’ shows that the present limits between the Peninsular and
Himalayan areas cannot have been established until the Secondary
period at the earliest.
A further insight into the history of the commencement and
progress of the elevation of the Himalayas may be derived from a
study of the structure of the sub-Himalayan ranges.
In the region west of the Jhelum the structure of the ground
does not enable us to decide with certainty at what date the
Himalayan system of disturbance invaded that area; but, so far.
as can be judged, the beds appear to have undergone but little
compression till towards the end of the Tertiary period.
In the Jamu Hills we find the typical sub-Himalayan structure
1 Mallet, Mem. Geol. Surv. India, vol. xi. part i.; see also Godwin-Austen,
Journ. Asiatic Soc. Bengal, part ii. vol. xxxviii, p. 151; La Touche, Records Geol.
Surv. India, vol. xvii. p. 121.
14 R. D. Oldham—Essays in Theoretical Geology.
has commenced, though not so fully developed as further to the
south-east. Next to the pre-Tertiary rocks of the Himalayas proper
comes a broad zone, principally formed of the Murree group,
at the outer margin of which rise some inliers of pre-Tertiary
(Carboniferous ?) limestone, overlaid by the marine Subathu group,
while near the inner boundary, with the pre-Tertiary rocks, there
are some outliers of Upper Siwalik clays and conglomerates. The
general section from 8.W. to N.H. is therefore an ascending one,
and both boundaries of this zone are, in effect, great faults with
an upthrow on the Himalayan side. Between this zone of Murree
beds and the alluvium of the plains there comes a band of Upper
Tertiaries, which, on the only published maps, are divided into an
inner, older, and an outer, newer zone; but there is no indication of
the nature of the boundary.
After leaving the Jamu Hills, the zone of Lower Tertiaries
becomes much restricted in width, till we reach the Simla region.
Here the Lower Tertiaries, forming the Sirmur series, are distinctly
separated from the Upper Tertiaries or Nahan and Siwalik groups.
The boundary is a great reversed fault, and along nearly the whole
length of it the two divisions are not in contact, but separated by
a band of pre-Tertiary slates and limestones. The beds of the
Sirmur series have partaken of the intense disturbance of the
pre-Tertiary beds, with which they are folded up in the most com-
plicated manner, and the northern boundary is no longer a single
well-defined fault, to the north of which there are no outliers. But
the most important point to notice is that in the area occupied by
the Sirmur series there is no trace of the Upper Tertiary groups,
which were either never deposited or have been completely removed
by denudation. :
Still further to the south-east, the small outliers in Garhwal only
exhibit the remains of the Subathu group, no representative of the
two Upper groups of the Sirmur series being found.
The explanation of these facts, which has been adopted by every
observer of the ground in question, is that the disturbance of the
Himalayas gradually advanced from 8.E. to N.W., and that the |
missing upper groups were never deposited over the outliers owing to
the elevation resulting from this disturbance. There is ample
corroborative evidence to prove the truth of this hypothesis; but
the same result is arrived at even if we suppose that the full
sequence of deposits was formed everywhere alike, for the condition
of the Simla area is such as would result from a greater elevation
and denudation of the Jamu area, while the outliers in Garhwal
might result from a still further extension of the same processes.
But as both elevation and denudation take time, and as the con-
ditions of the three areas with regard to denudation at least are
substantially similar, we reach the same conclusion as before, that
the elevation, and consequently the denudation of the Garhwal area
must have commenced before that of the Simla area, and this again
before that of the Jamu Hills.
Before passing on to a consideration of the evidence of the
R. D. Oldham—Essays in Theoretical Geology. 15
Siwalik groups, it will be well to briefly examine the nature and
distribution of the deposits now being formed along the foot of the
Himalayas. Along the outer margin of the hills there is every-
where a zone of gravel and boulder deposits; near the debouchure
of the great rivers this consists of well-rounded fragments of
crystalline rocks, quartzite, and some limestone; where there are
no large rivers, the fragments are less rounded, and consist of the
rocks exposed within the drainage-area of the streams flowing down
from the hills. The similarity of these gravels to those brought
down at the present day, and the fact that their diversity is matched
by that of the gravels of the existing streams, leaves no room for
doubt that they deposited the gravels even in those districts where
they have since cut deep channels through their old deposits.
Outside the zone of boulders and gravel comes a region of sands,
of various degrees of fineness, and outside this again the clays and
fine silts which form the bulk of the Gangetic alluvium.
It must not be understood that this division into three zones is
absolute. Sand and clay are occasionally found close up to the foot
of the hills, even near the debouchures of the great rivers, but none
the less it truly represents the general disposition of the recent
deposits. The width of the zones is not constant, and the boulder
and gravel zone in particular expands opposite the debouchures of
the great rivers. With all these local variations the main fact
remains, that on any line drawn transverse to the boundary of hill
and plain, the deposits, omitting minor variations and local excep-
tions, decrease in coarseness as we pass away from the hills, that the
coarse deposits of gravel and boulders are confined to the immediate
neighbourhood of the boundary, and that it is only near the debou-
chure of the principal rivers that these are composed of large and
well-rounded fragments of hard crystalline and metamorphic rocks.!
Returning now to the Siwalik deposits, we find that the same
relation between the composition of the gravels and the existing
drainage system which is exhibited by the recent deposits of the
northern margin of the plains, has also been noticed by every
observer in the conglomerates of Upper Siwalik age.
In the neighbourhood of the Jumna and Ganges rivers we find
a great development of conglomerates, composed of well-rounded
boulders of crystalline and metamorphic rocks. East of the Ganges,
there comes a tract where the watershed is only a few miles removed
from the edge of the hills, and coincident with this there is a narrow-
ing of the Siwalik zone, and a cessation of the thick deposits of
sandstone and conglomerate, till the Ramganga and Kosi rivers
are reached. Here the Siwalik beds again attain a great width and
thickness, and there is a large development of conglomerates.’
In the country between the Ganges and the Jumna the con-
glomerates are largely developed and extend for some little distance
1 Boulder gravels composed of well-rounded blocks of hard rock are also found
in the beds of streams draining from the Upper Siwalik conglomerates ; but such
exceptions are obvious.
* Middlemiss, Mem. Geol. Surv. India, vol. xxiv. pt. 2.
16 R. D. Oldham—Essays in Theoretical Geology.
west of the Jumna: but further west, in the country south of Nahan,
the conglomerates not only decrease in thickness, but change their
character. The well-rounded boulders of crystalline rocks cease,
and, in their place, we find imperfectly rounded fragments of lime-
stone, slate, and quartzite derived from the Lower Himalayas, mixed
with a large proportion of fragments of Lower Tertiary sandstones.
Where the Sutlej] passes out through the Siwalik area, there is
again a large development of Upper Siwalik conglomerates and the
same features of a prevalence of conglomerates near the great rivers,
and their absence away from them, continues all the way to the
Jhelum."
This peculiarity in the distribution of the Siwalik conglomerates
shows that not only are the Siwalik beds of subaerial origin; but -
that, when they were formed, the Himalayas existed as an elevated
region whose main features of hydrography had already been marked
out, and further the occurrence of coarse conglomerates, which could
only have been deposited in the immediate neighbourhood of the
limit of hill and plain, shows that the southern margin of the
former must at that time have been approximately the same as the
present boundary between the rocks of the Himalayas and of
the Siwalik series.
Taking all these considerations into account, the conclusion becomes
inevitable that the Siwalik beds were deposited subaerially and under
conditions similar to those of the recent deposits along the foot of
the Himalayas; that the latter existed as a mountain range, com-
parable to that now existing, in which the main features of its
hydrography had already been marked out; and consequently that
the original northerly extension of the Siwaliks cannot have very
far overstepped their present northern boundary.
The thickness of these subaerially formed beds varies considerably,
but is always great; from ten to twenty thousand feet and perhaps
more in places; and as they now, after having been compressed,
disturbed and elevated, do not occur at a height of more than a few
thousand feet above the sea, it is evident that they must have been
deposited in an area of continuous subsidence, which approximately
kept pace with the deposition. On the other hand, the Himalayan
area, as I shall subsequently show, has been in a state of continuous
elevation throughout the Tertiary period, and this elevation has more
than kept pace with the denudation of the surface. We have con-
sequently two parallel regions, one of elevation accompanied by
denudation ; the other of deposition accompanied by subsidence,
and we will now investigate the nature of the boundary between
them.
Everywhere along the Himalayas the present boundary, between
the Upper Tertiary beds and those of pre-Tertiary age, is a gigantic
reversed fault. It is one of the most conspicuous structural features
of the Himalayas, and, except for the outliers of Lower Tertiary
beds in the Simla district and in Garhwal, and the inliers of pre-
Tertiary rocks in Jamu, forms an absolute line of demarcation between
1 Medlicott, Rec. Geol. Surv. India, vol. ix. p. 57.
R. D. Oldham—Essays in Theoretical Geology. 17
the Tertiary and pre-Tertiary formations. In Mr. Medlicott’s memoir
this great fault was called the ‘main boundary ”—a name which has
been found so convenient that it has frequently since been used in
the publications of the Geological Survey of India, and will be
retained here in the sense indicated above.
This main boundary fault is almost everywhere a clean cut
fracture, generally reversed, and as a rule the rocks on either side
show little or no signs of that crushing which one would expect to
have accompanied so great a displacement. As we have seen, it
marks, approximately at least, the limit between what was, in
Siwalik times, an area of subsidence and an area of elevation, and
it is not unreasonable, on this ground alone, to suppose that it was
the actual boundary, and formed pari passu with the deposition of
the beds to the south.
But the main boundary is not the only fault of its kind, though
the most remarkable ; for, both in the Himalayan and sub- Himalayan
areas, there are similar great faults with an upthrow on the
Himalayan side, which have been held to mark successive stages
in that southerly advance of the margin of the hills, which is
sufficiently proved by the elevation of the Siwalik beds, originally
deposited in the plains along the foot of the Himalayas.
This supposition derives considerable support from a consideration
of the nature of the boundary between the disturbed Upper Siwaliks
and the recent deposits of the plains. With a few exceptions where
uppermost Siwalik conglomerates dip towards and under the recent
gravels, the boundary is a well-defined one, and the undisturbed
recent gravels are in contact with disturbed sandstones from which
several thousand feet of overlying strata have been removed by
denudation. There are no great irregularities of the boundary or
deep embayments of the recent deposits, such as would result from
a subsidence of the hills and an encroachment of the recent deposits,
such, in fact, as are seen on the southern margin of the alluvium.
The beds of which the hills are formed are precisely similar in
character, and were deposited under circumstances identical with
those of the present submontane deposits; and this, taken in con-
junction with the outline of the boundary, leads one naturally to the
conclusion that the latter is a structural one, and that the hills
have slowly and contemporaneously been undergoing elevation and
denudation. At the same time the greater bulk of the débris
washed down from them has been deposited near their foot, and, to
make room for this vast quantity of débris, the latter area must
have been slowly subsiding. We have consequently, in close
contiguity with each other, an area which has been subject to
elevation, and one which has been subject to depression, the
boundary between the two being necessarily analogous to those
faults with an upthrow to the north which intersect the sub-
Himalayan region, and to the great boundary fault which limits it
on the north.
1 This question is more fully treated by my colleague, Mr. Middlemiss, in his
recently published memoir, Mem. Geol. Sury, Ind. yol. xxiv. pt. il.
DECADE IfI.—VOL. VIII.—NO. I. 2
18 R. D. Oldham—Essays in Theoretical Greology.
In all the sections of the sub-Himalayan beds there is a marked
and steady increase in coarseness of texture as we ascend the section.
This feature is everywhere observable in the sub-Himalayan sections,
and even in the Sirmur series of the Simla Hills there is a steady
increase in the proportion of sand to shale from the purely argilla-
ceous Subathu group to the chiefly arenaceous Kasaoli group. This
gradual upward increase in coarseness of texture on any one section
is an inevitable result of the gradual southward extension of the hill
area; for by it the region of fine-grained silts is brought within
reach of the sand, and, finally, of the shingle deposits. But besides
the increase in coarseness of texture on each section, it is an indubit-
able fact that the texture of the coarsest beds of each group or
division increases with its decrease in age, and this appears to me to
be due to a gradual increase in the average size of the debris brought
down by the Himalayan streams.
I have already shown that in Hocene times the North-West
Himalayas did not exist, and that in Siwalik-Pliocene times there
was a mountain range whose hydrography agreed with that of the
present day in its main features, and that, to judge by the nature of
the burden carried by the rivers, this range must have been com-
parable in elevation and extent to the present Himalayas. During
the Tertiary period, then, the Himalayas were in process of elevation,
and it is natural to suppose that, during the earlier part of this
process, the gradients of the streams and their powers of trans-
portation would be less than at a later period, and that, consequently,
no great deposits of coarse gravel could be found. This supposition
derives great support from the fact that throughout the great thickness
of the Dagshai and Kasaoli groups, and of the Murree group, not a
single pebble has been found, while with one very doubtful excep-
tion’ no conglomerates of Nahan age are known.
In the foregoing passages it has been tacitly assumed that elevation
has always been accompanied and caused by disturbance of the beds
elevated, and such, in the main, is the case. There are, however,
recent undisturbed gravels which rise, in the sub-Himalayan region,
to heights of 500 feet above the present river-beds and seem to
indicate that there has been a certain amount of elevation unaccom-
panied by disturbance of the horizontality of the beds elevated. So,
too, the fossiliferous Pleistocene deposits of Hundes have probably
been elevated without disturbance to some extent, though not so
much as was supposed by the earlier observers.?, With these sub-
sidiary exceptions, which do not affect the general principle, it is
true that, in the Himalayas, elevation has always been a result of
the compression and disturbance of the beds elevated.
* Mem. Geol. Survey India, vol. iii. part ii. p. 135.
® Lydekker, Rec. Geol. Survey of India, vol. xiv. pp. 178-183 (1881).
(To be continued.)
|
:
J. G. Goodchild—Motion of Land-ice. 19
JJl.—Tur Morton oF Lanp-1cer.
By J. G. Goopcutip, F.G.S., of H.M. Geol. Survey,
Lecturer on Geology and Paleontology at the Heriot-Watt College.
MONGST the many useful tables given in Prof. Prestwich’s
of “Geology” is one on the expansion and contraction of ice
under variations in temperature (vol. i. pp. 139 and 188). The table
in question is abbreviated from one of greater length, which was
published in the year 1845 by Carl Brunner von Wattenwyll in the
Annales de Chimie et de Physique, 8"° ser. tome 14, pp. 869-878,
under the title of ‘ Hxpériences sur la densité de la glace a différentes
températures.” The author of the paper referred to made an ex-*
tensive series of observations upon the contraction of ice under
various temperatures below the freezing-point ; and he proved con-
clusively that, under these circumstances, the contraction of ice
exceeds that of all other solid bodies that had (up to the date of
the paper) been studied in this connection. Taking the density
of pure water at 0° Centigrade as unity, then the contraction in
question for a fall of each degree Centigrade is expressed by the
decimal figures in the right-hand column of the following table
(op. cit. p. 878) :—
Temperature. Density of Ice. Temperature. Density of Ice.
0° Centigrade. 0:91800 —11 Centigrade. 091924
—1 0-91812 2a 0°91935
—2 0°91823 —13 0°91946
—3 0°91834 —14 0:°91957
—4 0:91845 —15 0-°91968
—d 0°91856 —16 0°91980
—6 0°91868 —17 0°91991
—T 0°91879 —18 0°92002
—8 . 0-91890 —19 9°92013
—9 0°91901 —20 0°92025
—10 0°91912
In connexion with this table the author adds that the mean
contraction for a fall in temperature of every degree Centigrade is
0:0000875, or sstvs
If the density of the ice increases from 0:91800 at the freezing-
point to 0-92025 as the temperature falls to —20° Centigrade, then,
of course, the density will diminish, or, what is the same thing,
the bulk will increase, proportionately, as the temperature of the
ice rises.
M. Brunner’s testimony does not stand uncorroborated ; for Prof.
Prestwich adds to his summary of the paper (Geology, vol. i. pp.
139, 140) some important observations by Dr. Rae upon the ice of
the Arctic American lakes, which bear upon the same question.
These observations prove, beyond the possibility of doubt, that ice
does contract greatly under low temperatures; and, also, that as
the temperature rises towards zero Centigrade, the ice does undergo
a corresponding increase in volume.
20 J. G. Goodchild—Motion of Land-ice.
Professor Prestwich, in summarizing the results of these obser-
vations, points out the importance of their bearing upon theories of
glacier motion; but in doing so he takes into account the effects
of changes of temperature of ice arising only from what one may
term subaerial causes. These causes, diurnal, or seasonal, etc.,
variations of temperature must, of course, play a very important
part; but their effects are most marked at or near the surface, and
cannot directly affect the movements of the lower parts of the ice to
any appreciable extent.
But differences in temperature of large bodies of land-ice are
not by any means necessarily connected with the effects of solar
heat, or of other causes acting from the upper surface of the ice
downwards. However low the surface temperature of a thick
mass of ice may fall, its internal temperature will not every-
where be the same as at the surface. Observation and experiment
alike have proved that the cold-waves (those below 0° Centigrade)
affect the surface layers most, and that their effects become less
and less marked as the cold-waves are propagated further into
the ice. Eventually, the cold-waves travel downwards to a zone
where they hardly lower the temperature of the ice at all. The
position of this zone in relation to the surface varies, of course,
with the degree of cold prevailing at the particular place under
observation. There is thus within every thick mass of land-ice
a zone below which diurnal or seasonal variations of temperature
may be said to produce no appreciable effect. Above that zone,
when the temperature falls below the freezing-point, contraction
takes place. Where the cold is most felt, z.e. at the surface, the
contraction is greatest, and there the ice snaps, unless the downhill
flow of the adjoining ice at a higher level is sufficient to relieve the
tension. From the surface such cracks extend downward, gradually
diminishing in width as the downward effects of the cold-waves
diminish, until they die out altogether and terminate downward in
unbroken ice. Water flows into the cracks, freezes, and the expansive
force thus exerted helps to thrust forward the ice on the downhill
side, or wherever else may happen at that spot to be the direction of
least resistance; and in this way the ice is made to flow. A rise of
temperature brings about a general expansion of the upper part
of the ice, and, consequently, also forces it to flow in the direction
of least resistance from this cause as well as from the others.
But a flow of the surface layers of ice—extending downward at
the most perhaps not more than a few hundred feet—will hardly
satisfy the requirements of those geologists who are familiar with
the effects of ice-action in well-glaciated regions. Every field-
geologist who has spent many years in, say, North Wales, the North
West of England, or in Scotland, must feel that, somehow or other,
the bottom of the Ice-sheet must have flowed, and must have moved
steadily, and with nearly-uniform directions of movement, long
enough to admit of the stone-shod sole of the Ice-sheet scoring deep
and wide grooves upon the surfaces of even the toughest of rocks.
M. Brunner did not follow up his researches; but his conclusions
J. G. Goodchild—Motion of Land-ice. 21
should do much to convince even those who are not field-geologists
that the lower parts of masses of land-ice really do move forward,
and are therefore quite competent to score the rock-surface over
which they pass, and to score it to almost any extent.
Let us consider what happened with any of the larger affluents
of the Ice-sheet in, say, North West Yorkshire, or in Cumberland
and Westmorland. During the Glacial period every one of the
valleys in those parts was filled to the brim with masses of ice,
which, in most cases, can be shown to have moved outwards from
the mountain centres towards the lowlands. The inland and uphill
movements, which affected certain parts, were exceptional, and took
place only at or near the climax, just before the Ice-sheet began to
melt away, and long after most of the glacial erosion had been
accomplished. There is reason for believing that for a long period
the thickness of the ice in places was not less than two thousand
feet. All the rock previously carried seaward by subaerial denuda-
tion from those valleys was thus replaced, as it were, by a solid
mass of other material,—ice. Doubtless, in those days, as is the case
with the smaller glaciers of to-day, the surface layers were slowly
impelled downhill and seawards by the alternate expansion and
contraction of the ice, aided by the expansive action of water
freezing in crevasses, as well, of course, by the pressure of the
higher masses of ice behind. All these forces, acting separately or
in combination, tend to make the line of swiftest flow coincide with
the centre line of the upper layers of each stream.
The tendency to flow most rapidly nearest the surface is, however,
counteracted by other causes. KHvery one seems to have overlooked
the fact that when a deep valley is filled by ice, that ice tends to
act in much the same way in conducting terrestrial heat outwards
towards the surface as if there were rock there in the valley instead
of ice. The isogeotherms in such a case, instead of following nearly
the contour of the valley as they would do if the ice were absent,
would be carried to a higher level, whose exact position would vary
with the thickness of the ice and with the surtace-temperature for
the time being. In other words, the lines of equal subterranean
temperature of the rocks forming the sides of the valley would
enter the adjoining ice itself, and would connect the isogeotherm of
one side of the valley with its corresponding line on the other by
_ a downward curve, which would run through the Jower part of the
ice, instead of through the rock below upon which it lay.
While the surface-temperature and the terrestrial-temperature
were alike in degree, it seems possible that there might be no
movement of the ice at all, except that due to the downhill impulse
derived from heavier masses at a higher level. Where the surface
conditions were such as those described near the commencement of
this paper, then the locus of swiftest flow tended to the surface.
But when, as must generally have happened during the Glacial
period, the surface of the ice was kept in a prolonged state of
contraction through extreme cold, the higher temperatures prevailing
in the parts of the ice nearer the bottoms of the valleys caused the
22 Dr. G. J. Hinde—On a New Fossil Sponge.
ice there to expand more than the colder ice overlying, and therefore
to move in the direction of least resistance. That direction of least
resistance must, under these circumstances, usually remain near the
bottoms of the valleys, and it must tend to be modified (1) by the
form of the surface adjoining; (2) by the position of the main
feeders of that particular ice-stream ; and (3) by the situation of the
terminal portions of the glacial stream itself,
Another factor comes in here. The movement of a thick mass of
ice under enormous pressure (25 tons per square foot for every
thousand feet of thickness of ice) must result in the conversion of
part of the force so exerted into heat. This in its turn brings
about a still further expansion of the parts of the ice im direct
contact with the rock, and thus contributes still further to the
erosion that is being accomplished by these means. Indeed, it
appears to me more than likely that, when once the movement of
the lower strata of the ice is set up, terrestrial radiation on the
one hand, and the heat generated by the enormous friction on the
other, tend to impel the sole of the ice forward with much more
regularity, and with much greater evenness of motion, than can be
shown to obtain in any part of the surface of any ginge: that has
yet been carefully examined.
It appears to me that this view of the causes that determine the
flow of land-ice will enable us readily to understand the origin of
many phenomena of denudation which northern field-geologists
have long agreed to refer to glacial action, although no one has
explained satisfactorily how those results were accomplished. lake
basins; the remarkable terraces and scars of Wensleydale, ete.; the
corries or coums so characteristic of glaciated districts; the great
glacial ruts so well seen near Appleby, for example, or near
Edinburgh, can each and all be readily enough accounted for if we
extend M. Brunner’s observations to their proper conclusion, and
assume that the flow of a large mass of land-ice is not limited to
its upper parts, but extends also to the bottom layers in contact
with the rock.
IV.—Nores on a New Fossin Seonce From THE Utica SHALE
Formation (Orpovictan) av Orrawa, CanabDa.
By Gzorce Jennines Hinpe, Ph.D., F.G.S.
R. H. M. AMI, F.G.S8., of the Geological Survey of Canada,
who has devoted special attention to the fauna of the Utica
Shale in the neighbourhood of Ottawa, lately sent me for examination
several fragments of slabs of this rock containing some peculiar
sponge remains, which seem to me to be worthy of notice, although,
from their mode of preservation, no decisive determination as to the
character of the sponge to which they belong can be arrived at.
The fossils in question appear to the naked eye as so many
circular, or, in some instances, fan-shaped, faintly-marked rusty
patches on the surtace of the black shale, each consisting of delicate
Dr. G. J. Hinde—On a New Fossil Sponge. 23
lines or markings radiating from a centre. These patches are so
numerous as in places to cover the surface, and their margins overlap
each other, so that their individual outlines cannot in all cases be
distinguished ; further, it can be seen that they are not limited to
a single surface layer, for the rock to the thickness of about a
millimétre consists of several distinct successive films or layers,
each covered with similar rusty patches of radiating lines. Hxamined
with a lens or under a microscope, these lines are seen to be in
reality very fine, delicate needle-like spicules radiating horizontally
from a centre. The spicules are not all of the same length, so that
the outer margin of each patch is uneven, and the general appearance
of these circles impressed on the rock-surface calls to mind the
nimbus or halo which in old religious books is depicted round the
heads of saints.
The circular patches are from 18 to 24 mm. in diameter; the
spicules of which they are formed are straight, simple, apparently
smooth, and nearly of an even thickness throughout their length,
which appears to be from 8 to 10 mm., whilst they are only about
‘035 mm. in thickness. In some instances the spicules radiate from
the centre of the patch, in others there is a small free central space,
and occasionally they are disposed in the shape of a fan. In all
cases the spicules form an extremely thin layer. The spicules are
for the most part pyritized, in some instances they are reduced to
Stephanella sancta, gen. et sp. nov.; Utica Shale (Ordovician), Ottawa, Canada.
rusty peroxide. This change of the original silica to pyrites and
peroxide of iron seems to be of very general occurrence wherever
siliceous sponges have been preserved in black bituminous shales ;
well-known instances are those in the Cambrian shales of St. Davids,
South Wales, and those lately described by Sir J. W. Dawson from
the black Ordovician shales at Métis, Lower St. Lawrence (Trans.
Roy. Soc. Canada, vol. vii. 1889, p. 31).
It may be taken for granted that each of the numerous circular
patches in this rock indicates the basal portion of a distinct sponge;
but it is hardly likely that it represents the entire skeleton of the
organism, and it is insufficient to determine conclusively the nature
of the sponge. It has been suggested by Sir J. W. Dawson,’ who
has seen some of the specimens, that they may be the root-spicules
of Hexactinellid sponges. As a rule, however, the anchoring-
spicules in this group of sponges consist of a more or less compact
1 Notes on Specimens, Peter Redpath Museum, 1888, p. 59.
24 Dr. G. J. Hinde—On a New Fossil Sponge.
bundle of elongated spicules which extend downwards from the
base of the sponge and anchor it in the mud, consequently very
different from the horizontal radial disposition of the spicules in
these specimens. Further, if they were the anchoring appendages
of hexactinellid sponges, one would naturally expect to find some
traces of cruciform or typical six-rayed spicules characterizing the
bodies of these sponges, more particularly as the great regularity in
which the free radial spicules forming these circular patches have
been preserved in their natural position indicates the absence of
currents to remove the body-portions from their bases. But on
the slabs I have examined, I do not recognize any distinctive
hexactinellid spicules. At the same time it is not altogether
impossible that these fossils may be a peculiar modification of the
anchoring appendage of hexactinellid sponges, and this view derives
some support from the fact that a species of this group, Cyathospongia
reticulata, Walcott, sp., occurs in this Utica Shale, though Mr.
Ami has not yet discovered any specimen of it in the vicinity of
Ottawa.
There are however certain recent siliceous Monactinellid and
Tetractinellid sponges, inhabiting deep water, which possess basal
structures of slender radiating spicules, very similar in character
and arrangement to those forming these fossil impressions. Thus in
the genus Radiella, O. Schmidt! (=Trichostemma, Sars”), there is
a basal layer of long straight, styliform or pin-shaped spicules
radiating from a centre and forming a definite fringe round the
sponge, whilst the spicules of the body of the sponge are smaller
and less likely to be preserved as fossil. Again in Tethya easula,
Carter,® there is a well-marked basal fringe of spicules, but in this
case the spicules have trifid head-rays and consequently differ in
character from those in our fossils. As pointed out by Sars, and
more particularly by Ridley and Dendy,’ the basal fringe of elongated
spicules in these sponges serves not so much to anchor the sponge
as to support it on the surface of the soft yielding mud of the
sea-bottom.
There seems fair ground for supposing that. these patches of
radiating spicules likewise served as basal supports to sustain the
sponges, which lived in dense colonies, om the surface of the ooze.
Whether these sponges were hexactinellid or monactinellid must
for the present remain an open question; but it may be desirable
to give a name to them, and I propose to call them Stephanella
sancta.°
The specimens were collected by Mr. H. M. Ami from the Utica
shale, at Ottawa itself, and in the adjoining township of Gloucester.
* Spongien Fauna Atlantischen Gebietes (1870), p. 48, pl. 4, fig. 6.
* Remarkable Forms of Animal Life (1872), ine i. p. 62.
3 Ann. and Mag. Nat. Hist. ser. 4, vol. viii. (1871), p. 99, pl. iv. figs. 1-9.
4 «Challenger ’ ” Report, Zoology, vol. xx. (1877), p. D16, Dl. xiii.
6 eran, a wreath, dimin.
A. H. Foord & G. C. Crick—On Nautilus Neocomiensis. 25
V.—Nore on tHE Ipentity or Nauritus Neocourensis, SHARPE
(non D’OrBIGNY) with WauTizus DestonecHaMpPstaNus, D’ORB.
By Artuur H. Foorp, F.G:S. ;
and G. C. Crick, Assoc.R.S.M., F.G.S.,
Assistant in the Geological Department, British Museum.
ie 1853, in bis “ Description of the Fossil Remains of Mollusca
found in the Chalk of England” (Mon. Pal. Soc.), Sharpe
described and figured a specimen under the name of Nautilus
Neocomiensis, d’Orbigny. He states (loc. cit. p. 15), “« We have only
seen one small specimen from the Grey Chalk, which we can refer
to this species; it is from Urchfont near Devizes, in the Collection
of Mr. Cunnington, and is 2 inches in its greatest diameter and 1}
inch in breadth; although a good deal broken, it shows all the
peculiar characters of the species. The species is more common in
the Lower Greensand of Dorking, Atherfield, Sandgate, etc., where
it sometimes reaches above 7 inches in diameter. M. dOrbigny
quotes it as common in the lower beds of the Middle Division of the
Neocomian Formation in France.”
The specimen referred to is now in the British Museum (No.
88640). Itis a natural cast and in its badly preserved state the
flexuous ribs appear to be rounded. A close examination of the
fossil, however, reveals distinct traces of fine longitudinal lines
between the ribs, a character which suggests affinities with Nautilus
Deslongchampsianus, dOrbigny. Moreover the remains of the body-
chamber, the posterior portion of which Sharpe has représented in
his plate v. fig. 3c, show, on either side, at a short distance from
the umbilicus, the keel so characteristic of the same species. The
area between the keel and the umbilicus is also marked by faint,
raised, longitudinal lines. The umbilical portion of the remainder
of the specimen is too much broken to show the keel distinctly.
The rest of the characters of the specimen, viz., the general form,
the form of the sutures and the position of the siphuncle, all agree
perfectly with Wautilus Deslongchampsianus, and there can be no
doubt that the specimen referred by Sharpe to Nautilus Neocomiensis
is only a small, much-broken and badly-preserved specimen of
Nautiius Deslongchampianus. The locality and horizon of the fossil
also support this conclusion.
Erratum—In Gxrot. Mac. December, 1890, p. 551, fourth line from top of
page, insert Mot before the paragraph beginning ‘1853. Nautilus pseudoelegans,
Sharpe,”’ and ending ‘‘ figs. 2a, 20.”’
VI.—A Catatocur or BritisH Fossin VERTEBRATA.
SUPPLEMENT For 1890.
By Arruur Smith Woopwarp, F.G.S., F.Z.S.,
and CuHartes Davies Suerzorn, F.G.S., F.Z.S.
N the Paleontology of the Vertebrata, so much progress is made
in various directions in Britain, that it seems advisable to
attempt to bring up to date the record of the subject prepared and
published by the writers a year ago. The following list may thus
26 A. 8. Woodward and C. D. Sherborn’s Catalogue—
be regarded as the first supplement to the work in question ; and if
is hoped, by the courtesy of the Hditor, to issue such a list of additions
annually in the GrotocicaL Macazine.
With regard to general corrections it must be remarked, that the
memoir of Mr. J. Ward, forming Vol. X. of the Trans. N. Statfts.
Inst. Mining Engin., frequently quoted in connection with Carboni-
ferous fishes, was not issued until February 1890, the publication
having been delayed by unforeseen circumstances. Mr. J. Weston,
of Fenton, should have been mentioned as the collector of a fine
series of fishes from the Staffordshire Coal-measures, which will
shortly become the property of the British Museum. In connection
with the Carboniferous fishes of the Edinburgh Coal-field, the writers
also regret to add that they failed to distinguish between the private
and public collections made and extended by Dr. R. H. Traquair, as
Keeper of the Natural History Department in the Edinburgh
Museum. In this case, however, it is not possible to rectify the
error at present, there being no list or catalogue of either of these
collections.
A few names applied by Owen to London Clay Teleosteans, in
the Cat. Foss. Rept. Pisces Mus. R. Coll. Surgeons, were also over-
looked; but most of these refer to species already recorded under
the MS. names of Agassiz, and it is thus proposed to defer entering
them until the synonymy has been investigated.
PISCEs.
Acanthodes ,Mitchelli, Ag.: remarks and outline-figure by Traquair in Ann. Mag.
Nat. Hist. [6] vol. vi. 1890, p. 481, woode. 2, under name of Mesacanthus
Mitchelli.
Acanthodes sulcatus, Ag.: Traquair, Proc. Roy. Soc. Edinb. vol. xvii. 1890, p. 392,
and Ann. Mag. Nat. Hist. [6] vol. vi. 1890, p. 481, woode.1. Fife and
Midlothian.
Wardi, Eg.: Ward, Trans. N. Staffs. Inst. Min. Engin. vol. x. 1890, p.
157, pl. v. f. 2.
Acrodus minimus, Ag.: Portlock, Rep. Geol. Londonderry, 1843, p. 469, pl. xiv.
f.18 (? 17). Rhetic; N. Ireland.
Acrolepis Hopkinsi, M‘Coy : Traquair, Proc. Roy. Soc. Edinb. vol. xvii. 1890, p.
398 (to include 4. Rankini).
ortholepis, R. H. Traquair, Proc. Roy. Soc. Edinb. vol. xvii. 1890, p.
398, and Ann. Mag. Nat. Hist. [6] vol. vi. 1890, p. 492 (olim Elonichthys
ortholepis) .
Rankini (Ag.) : synonym of A. Hopkinsi.
semigranulosus [n. sp.], R. H. Traquair, Proc. Roy. Soc. Edinb. vol. xvii.
1890, p. 898. Calcif. Sandst.; Straiton. [Scales; Edinb. Mus. ]
Anodontacanthus attenuatus [n. sp.], J. W. Davis, Proc. Yorks Geol. Soc. vol. xi.
(2), 1890, p. 883. [? Plewracanthus]. Carbonif.; Cultra, Co. Down.
[Spine ; C. Bulla Coll., Belfast. ]
Aspidorhynchus crassus [n.sp.], A. S. Woodward, Proc. Geol. Assoc. vol. xi. (1890),
p- 296, pl. iii. f. 11-15 (includes A. sp. (1888), Belonostomus flexuosus, and
Sauropsis mordax).
sp., A. 8S. Woodward: v. A. crassus.
Asteracanthus Stutchburyi, Ag.: synonym of A. verrucosus (E. Wilson, Gzou. Mac.
1890, p. 366). [Type,—Bristol Mus., probably from Purbeck Beds, Swanage. |
verrucosus, Ke.: includes A. Stutchburyi, Ag.
Belonostomus flecuosus, Phillips : = ? maxilla of Aspidorhynchus crassus, A. 8. We
——— leptosteus, Ag.: A. S. Woodward, Proc. Geol. Assoc. vol. xi. (1890), p. 296.
Caturus pleiodus [n. sp.], A. S. Woodward (ex. Ag.), Proc. Geol. Assoc. vol. xi.
(1890), p. 294, pl. in. f. 10 (genus uncertain).
British Fossil Vertebrata. Dib
Centrolepis, Eg.: A. 8. Woodward, Ann. Mag. Nat. Hist. [6] vol. v. 1890, p. 430.
———_ asper, Eg. (ex Ag.): A. 8S. Woodward, ibid. p. 430, pl. xvi. f. 1.
Ceratodus Phillipsi, Ag.: A. 8. Woodward, Proc. Geol. Assoc. vol. xi. (1890), p.
292 Pople tits 10.
Chirodopsis Geikiet, Traq.: Traquair, Ann. Mag. Nat. Hist. [6] vol. vi. 1890, p. 494.
Chirodus crassus [n. sp.], R. H. Traquair, Proc. Roy. Soc. Edinb. vol. xvi. 1890,
p- 400. Carb. Limest.; Abden and Beith. [Scales; Edinb. Mus. ]
Chirolepis Trailli, Ag.: recorded from Achanarras, Caithness, by Traquair, Ann.
Mag. Nat. Hist. [6] vol. vi. 1890, p. 485.
Coccolepis liassica [n. sp.|, [us], A. 8. Woodward, Ann. Mag. Nat. Hist. [6] vol. v.
1890, p. 435, pl. xvi.f. 2-4. Lower Lias; Lyme Regis. [Fish; brit. Mus. ]
Coccosteus, Ag.: A. v. Koenen, Grou. Mac. 1890, p. 191.
decipiens, Ag.: Traquair, Ann. Mag. Nat. Hist. [6] vol. v. 1890, p. 125,
pl. x. and Grou. Mae. 1890, p. 236.
sp., J. HK. Lee, Gzon. Mac. 1880, p. 146, pl. v. f. 3. U. Devon. ;
Chudleigh, 8. Devon. [Median dorsal plate; Brit. Mus.]
Celacanthus Phillipsi, Ag.: J. W. Davis, Grou. Mae. 1890, p. 159.
sp. [n.], J. W. Davis, Proc. Yorks. Geol. Soc. vol. xi. (2), 1890, p. 334.
Carbonif. ; Cultra, Co. Down. [Bones; C. Bulla Coll., Belfast. ]
Cosmolepis, Eg. : synonym of Oxygnathus.
Egertoni, Kg.: v. Oxygnathus Egertoni.
Cosmoptychius, Traq.: synonym of Elonichthys.
striatus (Ag.): v. Llonichthys striatus.
Ctenodus interruptus, Barkas: A. S. Woodward, Ann. Rep. Yorksh. Phil. Soe.
1889 (1890), p. 37, pl. i. f. 2; R. H. Traquair, Grou. Mae. 1890, p. 249.
Form. and loc. are Carb. Limest. and Calcif. Sandst., Fiteshire and Midlothian
(not English Coal- Meas.)
Murchisoni, Ag. MS.: first described by J. Ward, Trans. N. Staffs. Inst.
Minmg Engin. vol. x. 1890, p. 166. Additional locality is Longton, N.
Staffordshire.
caudatus, Barkas: v. Sagenodus caudatus.
corrugatus, Atthey: v. Sagenodus corrugatus.
obliquus, Atthey: v. Sagenodus inequalis.
obliquus, var. guinquecostatus, Traq.: v. Sagenodus quinquecostatus.
obtusus, Barkas: vy. Sagenodus obtusus.
—— octodorsalis, Barkas: v. Sagenodus octodorsalis.
Ctenolepis cyclus, Phillips (ex Ag.): A. 8S. Woodward, Proc. Geol. Assoc. vol. xi.
(1890), p. 301. There is an early fig. of this sp. in C. Prevost, Ann. Sci.
Nat. vol. iv. 1825, pl. xviii. f. 21.
Dapedius dorsalis (Ag.): M. Browne, Trans. Leicester Lit. and Phil. Soc. n. s. vol.
(1890), p. 196 (includes Dapedius monilifer).
monilifer (Ag.) : synonym of D. dorsalis.
Diplopterus Agassizi, Traill: Traquair, Ann. Mag. Nat. Hist. [6] vol. vi. 1890, p.
484, woode. 3.
Drydenius [n. g.], R. H. Traquair, Proc. Roy. Soc. Edinb. vol. xvii. 1890, p. 399.
msignis [n. sp.], R. H. Traquair, did. Carb. Limest.; Loanhead.
_ [The type species, founded on jaws, etc. ; Edinburgh Mus. }
Elonichthys, Giebel: to include Cosmoptychius, Traquair, Proc. Roy. Soc. Edinb.
vol. xvii. 1890, p. 396.
Dunsi, Traq.: synonym of E. nemopterus (Ag.), Traquair, ibid. p. 395.
[v. £. Robisoni ].
mtermedius, Traq.; synonym of EH. nemopterus (Ag.), Traquair, ibid.
[v. E. Robisoni].
multistriatus [n. sp.], R. H. Traquair, Proc. Roy. Soc. Edinb. vol. xvii.
1890, p. 396. Carb. Limest..; Gilmerton and Loanhead [ Fragments ;
Traquair Coll. |
nemopterus [Ag.]: Traquair, ibid. p. 394 (to include EZ. Duns, inter-
medius, ovatus, Robisoni, striolatus, tenuiserratus). |v. HE. Reson. |
ortholepis, Traq.: synonym ot Acrolepis ortholepis.
ovatus, Traq.: synonym of ZL. nemopterus (Ag.), Traquair, Proc. Roy.
Soc. Edinb. vol. xvii. 1890, p. 396. [y. EB. Robdisoni.]
Robisoni (Hibb.) : referred with several other supposed species to Z.
nemopterus by Traquair, as noted above. Pal@oniscus Robisoni, however,
28 A. 8S. Woodward and C. D. Sherborn’s Catalogue—
being described by Agassiz before the so-called Amblypterus nemopterus, the
specific name originally suggested by Hibbert must be adopted.
Elonichthys striatus (Ag.): Traquair, Proc. Roy. Soc. Edinb. vol. xvii. 1890, p. 396
(olim Cosmoptychius striatus).
striolatus (Ag.): synonym of EH. nemopterus (Ag.), Traquair, Proc. Roy.
Soc. Edinb. vol. xvii. 1890, p. 395. [v. #. Robdisoni. |
tenuiserratus, Traq.: synonym of E. nemopterus (Ag.), Traquair, ibid.
[v. EL. Robisoni].
Hogaleus toliapicus, R. Owen, Cat. Foss. Rept. Pisces Mus. R. Coll. Surgeons, 1854,
p- 133. London Clay; Sheppey. [Vertebree; Mus. R. Coll. Surgeons. |
Eurycormus grandis, A. 8. W.: A. 8. Woodward, Proc. Geol. Soc. 1890, p. 8, and
Gxou. Mac. 1890, p. 289, pl. x. f. 1-8.
Eurynotus crenatus, Ag.: Traquair, Proc. Roy. Soc. Edinb. vol. xvii. 1890, p.
400 (to include Z. fimbriatus, Ag.)
Jimbriatus, Ag.: synonym of H. crenatus, Ag., Traquair, ibid.
microlepidotus [n. sp.|, R. H. Traquair, Proc. Roy. Soc. Edinb. vol. xvii.
1890, p. 400. Carb. Limest.; Loanhead. [Imperfect fish ; Traquair Coll. ]
Ganodus, Ag.: A. S. Woodward, Proc. Geol. Assoc. vol. xi. (1890), p. 290, pl. ii. f. 4.
Ganopristodus, Traq.: synonym of Uronemus.
splendens, Traq.: v. Uronemus splendens.
Glyptolepis Flemingii, H. Mitchell and J. Powrie: v. Holoptychius Flemingi.
Glyptolepis paucidens (Ag.): Traquair, Ann, Mag. Nat. Hist. [6] vol. vi. 1890, p. 483.
Gyrolepis Albertii, Ag.: Portlock, Rep. Geol. Londonderry, 1843, p. 469, pl. xiv.
f. 12-14 and f. 11 (G. tenwistriatus). Rheetic: N. Ireland.
Gyronchus oblongus, Ag.: v. Mesodon oblongus.
Gyrosteus mirabilis, A. S. Woodw.: A. S. Woodward, Naturalist, 1890, p. 101.
Helodus simplex, Ag.: synonym of Pleuroplax Rankina.
Holophagus, Kg.: A. 8. Woodward, Ann. Mag. Nat. Hist. [6] vol. v. 1890, p. 436.
Holoptychius Flemingi, Ag.: includes Glyptolepis Flemingti, H. Mitchell, Geologist,
1863, p. 43; J. Powrie, idid., p. 96.
Ischyodus sp. [n.], A. 8. Woodward, Proc. Geol. Assoc. vol. xi. (1890), p. 290, pl.
ii. f. 3. Great Oolite; Northampton. [R. palatine; Jesson Coll. ]
Leedsia, A. 8S. Woodward, Grou. Mac. 1890, p. 292 (substituted for Leedsichthys).
problematica, A. S. Woodward, ibid. p. 292, pl. x. f. 9, 10 (olim
Leedsichthys problematicus) .
Lepidotus maximus, Wagner: Spherodus neocomiensis {Ag.), W. Keeping, Foss.
Upware, 1883, p. 81, pl. i, f. 4. Neocomian; Cambridgeshire and Bed-
fordshire.
tuberculatus, Ag.: = suboperculum of L. wnguiculatus, Ag. (A. S. Wood-
ward, Proc. Geol. Assoc. vol. xi. (1890), p. 298).
unguiculatus, Ag.: A. S. Woodward, ibid. p. 292, pl. ii. f. 7, 8.
(Includes L. tuberculatus and Pycnodus rudis).
Leptolepis disjecta [n. sp.], [-us], A. 8. Woodward, Proc. Geol. Assoc. vol. xi.
(1890), p. 295, pl. 11, f. 16-19. Stonesfield Slate. [Preop., op., max., and
dentary bones; Brit. Mus. }
Macrosemius brevirostris [n. sp.], A. S. Woodward (ex Ag.), Proc. Geol. Assoc.
vol. xi. (1890), p. 293, pl. iii. f. 9. Stonesfield Slate. [Mandib. ramus ;
Brit. Mus. ]
Megalichthys levis [n. sp.], R. H. Traquair, Proc. Roy. Soc. Edinb. vol. xvii.
1890, p. 394. Calcif. Sandst.; Straiton. [Imperteet fishes; Edinb. Mus. ]
Mesacanthus, Traq. : genus maintained by Traquair, Ann. Mag. Nat. Hist. [6] vol.
vi. 1890, p. 481. v. -Acanthodes Mitchelli.
Mesodon biserialis [n. sp.], A. 8. Woodward (ex Ag.), Proc. Geol. Assoc. vol. xi.
(1890), p. 300, pl. ii. f. 28. Stonesfield Slate. [Mandib. dentition :
Brit. Mus. ]
Bucklandi (Ag.): A. S. Woodward, ibid. p. 297, pl. iii. f. 20-22: the
scales of ‘‘ Gyrodus perlatus’’ are also figured in the same paper (pl. ili. f.
30, 31). New locality :—Great Oolite of Northampton.
Couloni (Ag.): Pycnodus Couloni (Ag.) W. Keeping, Foss. Upware,
1883, p. 82, pl. i. f. 5. Neocomian ; Cambridgeshire and Bedfordshire.
Damoni [n. sp.], A. 8. Woodward, Grou. Mac. 1890, p. 158. This is
the 1. sp., Woodward and Sherborn, Cat. Brit. Foss. Vert., 1890, p. 121.
Daviesi [n. sp.], A. S. Woodward, Proc. Zool. Soc. 1890, p. 381, pl. xxviii.
f.5. Purbeck; Swanage. [Fish: Brit. Mus.]
—
British Fossil Vertebrata. 29
Mesodon ? discoides [n. sp.], A. S. Woodward (er Ag.), Proc. Geol. Assoc. vol. xi.
(1890), p. 300, pl. i. f. 32. Gt. Oolite; Oxford. [Vomer; Brit. Mus. ]
— latidens, A. S. W.: misprint for IZ. tenwidens.
oblongus (Ag.): Gyronchus (Scaphodus) oblongus, L. Agassiz, Poiss.
Foss. vol. i. (1844), p. xlii. (ame only). Gyronchus oblongus, EK. Wilson,
Gxou. Mae. 1890, p. 367.
rugulosus (Ag.): A. 8. Woodward, Proc. Geol. Assoc. vol. xi. (1890), p.
98, pl. ui. f. 23-27. (Includes WZ. trigonus.)
sp., Woodward and Sherborn, Cat. Brit. Foss. Vert. 1890, p. 121: v.
IM. Damoni.
tenuidens [n. sp.], A. S. Woodward, Proc. Geol. Assoc. vol. xi. (1890),
p- 300 (/atidens, misprint), pl. ii. f. 29. Stonesfield Slate. [R. splenial ;
Brit. Mus. |
trigonus (Ag.) : synonym of IZ. rugulosus.
Mesolepis rhomba [n. sp.|, Traquair, Ann. Mag. Nat. Hist. [6] vol. vi. 1890, p. 4938.
Calcif. Sandst.; Eskdale. [Fish ; Edinbur gh Mus. ]
tuberculata ‘Tn. sp. |, Traquair, ibid. p. 493. Calcif. Sandst. ; Eskdale.
[Fish ; Edinburgh Mus. ]
Mesopoma (un. g.], Traquair, Ann. Mag. Nat. Hist. [6] vol. vi. 1890, p. 493 (in-
completely defined).
macrocephalum [n. sp.], Traquair, ibid. p. 493.
Rhadinichthys macrocephalus, Traquair, Proc. Roy. Soc. Edinb. vol. xvii.
1890, p. 398. Calcif. Sandst.; Pumpherston, Edinburgh. [Fishes ;
Traquair Coll. |
politum, Traquair, Ann. Mag. Nat. Hist. [6] vol. vi. 1890, p. 493 (olim
Canobius politus).
pulchellum, Traquair, ibid. p. 493 (olim Canobius pulchellus).
Nemacanthus brevis, Phillips: A. 8. Woodward, Proc. Geol. Assoc. vol. xi. (1890),
p. 289, pl. ii. f. 1.
Nematoptychius gracilis, Traq.: synonym of NV. Greenock.
——— Greenocki, (Ag.): Traquair, Proc. Roy. Soc. Edinb. vol. xvii. 1890,
398. (Includes NV. gracilis and also Pygopterus elegans, C. W. Peach, Rep.
Brit. Assoc. 1871 (1872), p. 109, name only.)
Oligopleurus vectensis [n. sp.], A. 8. Woodward, Proc. Zool. Soc. 1890, p. 346, pl.
xxviii, f. 1-4, pl. xxix, f.1,2. Purbeck; Swanage. Wealden ; I. of Wight.
[Head ; Brit. Mus. }
Ophiopsis Flesheri (Ag.): A. S. Woodward, Proc. Geol. Assoc. vol. xi. (1890), p. 293.
Oracanthus Milleri, Ag.: O. minor, K. Wilson, Grou. Mace. 1890, p. 368.
Osteolepis microlepidotus, Pand.: Traquair, Grou. Mac. 1888, p. 516, and Ann.
Mag. Nat. Hist. [6] vol. vi. 1890, p. 484.
Oxygnathus, Kg.: A. 8. Woodward, Ann. Mag. Nat. Hist. [6] vol. v. 1890, p.
431 (includes Cosmolepis and Thr issonotus).
Egertoni (Eg.): A. 8S. Woodward, Ann. Mag. Nat. Hist. [6] vol. v.
1890, p. 482 (olim Cosmolepis Egertoni).
ornatus, Kg.: Traquair, Paleoniscide (Pal. Soc. 1877), pl. u.f.2; A.S.
Woodward, Ann. Mag. Nat. Hist. [6] vol. v. 1890, p. 432 (includes Thrissonotus
Colei).
Paleospondylus [n. g.|, Traquair, Ann. Mag. Nat. Hist. [6] vol. vi. 1890, p. 485.
—— Gunni [n. sp.], Traquair, ibid. p. 485, woode.4. L. Old Red Sandst.,
Achanarras, Caithness. [The type species, Kdinburgh Mus. |
Phaneropleuron, Huxley: Traquair, Proc. Roy. Soc. Edinb. vol. xvu. 1890, p. 393.
Phiyctenaspis [n. g.], R. H. Traquair, Grot. Mac. 1890, p. 144. (Olim
Phlyctenius [preoccupied Zittel, Spongida]).
——— Anglica, Traq.: Traquair, ibid., p. 144, (olim Phlyctenius anglicus).
Includes Cephalaspis Salwey yi Lankester (in part), Fishes O.R.S. pt. 1
(Pal. Soc. 1870), pl. viii. f. 2
Phiyctenius, Traq.: preoccupied, v. Pik yctenaspis.
Pholidophorus minor, Ag.: A. 8S. Woodward, Proc. Geol. Assoc. vol. xi. (1890),
. 293.
Ee. A. 8. Woodw.: J. W. Davis, Ann. Mag. Nat. Hist. [6] vol. v. 1890,
p- 291, pl. xin.
Rankini, H. and A.: J. W. Davis, ibid. p. 291, pl. xii. (includes Helodus
simplex) .
30 A. S. Woodward and C. D. Sherborn’s Catalogue—
Pristacanthus securis, Ag.: A. 8. Woodward, Proc. Geol. Assoc. vol. xi. (1890), p.
290, pl. iii, f. 2.
Psammosteus; The types of P. granulatus and P. vermicularis are now in the Dublin
Mus. Sci. and Art.
Pterichthys Milleri, Ag.; recorded from Achanarras, Caithness, by Traquair, Ann.
Mag. Nat. Hist. [6] vol. vi. 1890, p. 483. There is also a specimen from
this locality in the Worcester Museum.
Piychodus mammillaris, Ag.: A.S. Woodward, Ann. Rep. Yorks. Phil. Soc. 1889
(1890), p. 39, pl.i. f. 8-14.
polygyrus, Ag.: A. 8. Woodward, ibid. p. 40, pl. i. f. 16-20.
Pyenodus Coutoni, Ag.: v. Mesodon Couloni.
rudis, Phillips: synonym of Lepidotus unguiculatus.
Pygopterus elegans, Peach: v. Nematoptychius Greenocki.
Rhadinacanthus, Traq.: genus maintained for Diplacanthus longispinus, Ag., by
Traquair, Ann. Mag. Nat. Hist. [6] vol. vi. 1890, p. 483, but essential
part of original definition admitted erroneous and none substituted.
Rhadimichthys carinatus (Ag.): Traquair, Proc. Roy. Soc. Edinb. vol. xvii. 1890,
p- 397 (includes typical R. Geikier).
delicatulus, Traq.: synonym of R. elegantulus.
elegantulus, Traquair, Proc. Roy. Soc. Edinb. vol. xvii. 1890, p. 398, and
Ann. Mag. Nat. Hist. [6] vol. vi. 1890, p. 492 (ncludes &. delicatulus and
so-called R. Geikiei from Eskdale).
Geikiei, Traq.: synonym of &. carinatus and R. elegantulus.
lepturus, Traq.: synonym of R&. ornatissimus.
macrocephalus, Traq. [n. sp.|: v. Mesopoma macrocephalum.
ornatissimus (Ag.): Traquair, Proc. Roy. Soc. Hdinb. vol. xvii. 1890, p.
397 (includes R. lepturus).
Sagenodus, Owen: This genus must be accepted for the so-called Ctenodus obliquus
and allied species. It is first defined under the name of Hemictenodus, R. H.
Traquair, Grou. Mac. 1890, p. 251, andis in part equivalent to Hemictenodus,
O. Jaekel, Sitzungsb. Ges. naturf. Freunde, 1890, p. 7.
caudatus: correct name of Ctenodus caudatus.
- COrrVUgatUs: 4, oH) 9 » corrugatus.
inequalis, Owen: the correct name of Cltenodus obliguus, with synonyms
as already quoted in the Catalogue.
obtusus: correct name of Ctenodus obtusus.
octodorsalis: correct name of Ctenodus octodorsalis.
quinguecostatus, Traquair, Proc. Roy. Soc. Edinb. vol. xvu. 1890, p. 387.
Hemictenodus guinquecostatus, Traquair, Grou. Mac. 1890, p. 251 (olim
Ctenodus obliquus, var. quinquecostatus).
Saurichthys acuminatus, Ag.: 8. apicalis, Portlock, Rep. Geol. Londonderry, 1843,
p. 470, pl. xiv. f. 19. Rheetic: N. Ireland.
Sauropsis mordax, Ag.: maxilla of Aspidorhynchus crassus.
Scaphodus, Ag. MS.: E. Wilson, Grou. Mace. 1890, p. 367; A. 8. Woodward,
Proc. Geol. Assoc. vol. xi. (1890), p. 300.
heteromorphus [n.sp.], A. S. Woodward (ex Ag.), p. 300, pl. iii. f. 33, 34.
oblongus, Ag.: v. Mesodon oblongus.
Strepsodus minor [n. sp.], R. H. Traquair, Proc. Roy. Soc. Edinb. vol. xvii. 1890,
p- 398. Calcif. Sandst.; Pitcorthy. [Scales: Edinb. Mus. ]
Strobilodus Bar [n. sp.], A. 8. Woodward, Proc. Zool. Soc. 1890, p. 330,
|. xxix. f. 4.
Ser Fasc nbeinas R. H. Traquair, Ann. Mag. Nat. Hist. [6] vol. vi. 1890, p. 492
(undefined).
fulcratus, R. H. Traquair, ibid. p. 492 (olim Holurus fulcratus, Traq.)
Calciferous Sandstones, Tarras Foot (not Glencartholm).
Tarrasius problematicus, Traq.: R. H. Traquair, Ann. Mag. Nat. Hist. [6] vol. vi.
1890, p. 494. Locality is Glencartholm (not Tarras Foot, as originally
stated). :
as Ag.: synonym of Oxygnathus.
Colet, Ag.: v. Oxygnathus ornatus.
Thynnus scaldisiensis [n. sp.], R. Storms, Mém. Soc. Belge Géol. ete. vol. iti. (1889)
p- 163, pl. vii. f. 17-22; A. S. Woodward, Ann. Mag. Nat. Hist. [6]
vol. y. 1890, p. 294. White Crag: Suffolk. [Caudal vertebre; Brit. Mus. |
British Fossil Vertebrata. OL
Thynnus thynnus (Linn.): KE. T. Newton, Grou. Mac. 1890, p. 264. Forest
Bed: E. Runton. [Vert. centrum; Savin Coll. ]
Undina (?) barroviensis [n. sp.], A. S. Woodward, Ann. Mag. Nat. Hist. [6] vol. v.
1890, p. 436, pl. xvi. f. 5. L. Lias.; Barrow. [Fish: Brit. Mus. ]
(?) sp. A. S. Woodward, Proc. Geol. Assoc. vol. xi. (1890) p. 292, pl. iii.
f. 6 [also figd. by Prevost, Ann. Sci. Nat. vol. iv. 1825, pl. xviii. f. 20].
Stonesfield Slate. [Jugular and pterygo-quad.: Brit. Mus. ]
Uronemus, Ag.: Traquair, Proc. Roy. Soc. Edinb. vol. xvii. 1890, p. 393 (includes
Ganopristodus) .
magnus, Traq.: = tail of Ctenodus or Sagenodus, Traquair, Grou. Mac.
~ 1890, p. 252.
splendens, Traquair, Grou. Mae. 1890, p. 262 (olim Ganopristodus splen-
dens) .
AMPHIBIA.
Anthracosaurus Russell, Huxley: Lydekker, Cat. Foss. Rept. B.M.1 pt. iv. 1890,
p- 158
Anthracerpetum crassostewm, Ow.: Lydekker, Cat. Rept. pt. iv. 1890, p. 214.
Erpetocephalus, Huxley: synonym of Ichthyerpetum.
——— rugosus, Huxl.: v. Ichthyerpetum Bradleye.
Ichthyerpetum, Huxley: Lydekker, Cat. Rept. pt. iv. 1890, p. 168 (includes
Erpetocephalus).
Bradleye, Huxl.: Lydekker, ibid. p. 169 (includes ZLrpetocephalus
TUGOSUS) . ;
Lepidotosaurus Dufi, Hanc. and Howse: Lydekker, Cat. Rept. pt. iv. 1890, p. 214.
Lepterpetum sp. Lydekker, Cat. Rept. pt. iv. 1890, p. 199. Coal Meas.: Jarrow.
[Skeleton : Brit. Mus. 1]
Loxomma Allmani, Huxley: Embleton, Rep. Brit. Assoc. 1889 (1890), p. 580;
Lydekker, Cat. Rept. p. iv. 1890, p. 164, fig. 38.
Macromerium Scoticum [n. sp.|, R. Lydekker, Quart. Journ. Geol. Soe. vol. xlvi.
1890, p. 291, pl. xi. f. 1, and Cat. Rept. pt. iv. 1890, p. 162.°Carb. Limest. ;
Gilmerton. [Mandib. ramus: Brit. Mus. ]
Ophiderpetum Brownriggi, Huxley: Lydekker, Cat. Rept. pt. iv. 1890, p. 206.
Pholidogaster pisciformis, Huxley: Lydekker, Cat. Rept. pt. iv. 1890, p. 195.
Urocordylus reticulatus, Hance. and Atth.: synonym of U. Wandesfordi.
Wandesfordi, Huxley: Lydekker, Cat. Rept. pt. iv. 1890, p. 196 (includes
U. reticulatus).
REPTILIA.
Bothriospondylus suffossus, Owen: Lydekker, Cat. Rept. pt. iv. 1890, p. 242.
Calamospondylus Foxi, Liyd.; Lydekker, Cat. Rept. pt. iv. 1890, p. 243, f. 54.
Camptosaurus Leedsi, Lyd.: Lydekker, Cat. Rept. pt. iv. 1890, p. 258, f. 61.
Cardiodon rugulosus, Owen: Lydekker, Cat. Rept. pt. iv. 1890, p. 236. (Crown of
tooth ; Gt. Oolite, Cirencester.)
Cimoliosaurus portlandicus (Owen): Lydekker, Quart. Journ. Geol. Soc. vol. xlvi.
1890, p. 47, f. 5, and Cat. Rept. pt. iv. 1890, p. 274. (Cerv. vert.; Mid.
Purbeck, Isle of Portland: Brit. Mus.)
—— Richardsoni, R. Lydekker, Cat. Rept. pt. iv. 1890, p. 276, f. 66.
Celosaurus, R. Owen, Cat. Rept. Mus. R. Coll. Surg. 1854, p. 15. [Genus founded
on a mutilated centrum of a dorsal vertebra washed out of an oolitic stratum
and from the drift of West Norfolk: Mus. R. Coll. Surg. ]
Cryptodraco eumerus (Seeley) ; Lydekker, Cat. Rept. pt. iv. 1890, p. 256.
Gontopholis carinata: first described by R. Owen, Cat. Rept. Mus. R. Coll. Surg.
1854, p. 12, and stated to be from the Great Oolite of Cirencester.
Goniopholis minor, Koken: Lydekker, Cat. Rept. pt. iv. 1890, p. 229. Wealden:
Isle of Wight. [Portions of Skeleton ; Brit. Mus.]
Ichthyosaurus communis, Conyb. : Lydekker, Cat. Rept. pt. iv. 1890, p. 270.
Conybearei, Lyd.: Wilson, Grou. Maa. 1890, p. 365.
intermedius, Conyb. : Lydekker, Cat. Rept. pt. iv. 1890, p. 271, f. 65.
thyreospondylus, Owen: Wilson, ibid. p. 365; Lydekker, Cat. Rept. pt.
iv. 1890, p. 270 (Portland Oolite, I. of Portland: centrum).
1 Subsequent references to this work are briefly entered ‘‘ Cat. Rept.”’
32 A. S. Woodward and C. D. Sherborn’s Catalogue—
Iguanodon Dawsoni, Lyd. : Lydekker, Quart. Journ. Geol. Soc. vol. xlvi. 1890, p.
38, f. 1 B, and Cat. Rept. pt. iv. 1890, p. 259. :
———_ jittoni, Lyd.: Lydekker, ibid. pp. 38, 43, f. 1 c, and ibid. p. 260.
hollingtoniensis, Lyd. : Lydekker, ibid. p. 40, f. 1B, 2, and ibid. p. 262.
cervical vertebra of : Lydekker, ibid. p. 44, f. 3.
Megalosawrus Dunkeri, Koken: Lydekker, Quart. Journ. Geol. Soc. vol. xlvi. 1890,
p- 46, f. 4, and Cat. Rept. pt. iv. 1890, p. 244. Wadhurst Clay ;
Hastings. [Metatarsus: Brit. Mus. ]
—— Oweni, Lvd.: Lydekker, ibid. p. 47, and ibid. p. 245.
Metriorhynchus Moreli, Desl.: Lydekker, Quart. Journ. Geol. Soc. vol. xlvi. 1890,
_ 285, f. 1.
ey superciliosum (Blainy.): liydekker, Cat. Rept. pt. iv. 1890, p. 232.
Ophthalmosaurus icenicus, Seeley: Lydekker, Cat. Rept. pt. iv. 1890, p. 267, f. 62.
Pleydelli [n. sp.], R. Lydekker, Cat. Rept. pt. iv. 1890, p. 268, f. 63.
Kimmeridge Clay: Billingham [Humerus ; Dorset Mus. |
Peloneustes, Lyd.: Lydekker, Quart. Journ. Geol. Soc. vol. xlvi. 1890, p. 49.
Ewansi (Seeley): Lydekker, ibid. p. 52 (olim Pliosawrus Hvansi).
Pelorosaurus Oonybearei (Mant.): Lydekker, Cat. Rept. pt. iv. 1890, p. 240, f. 53.
humerocristatus (Hulke): Lydekker, ibid. p. 241.
Leedsi (Hulke): Lydekker, ibid. p. 242.
Manseli (Hulke) : liydekker, ibid. p. 241.
Plesiosaurus dolichodirus, Conyb. : Lydekker, Cat. Rept. pt. iv. 1890, p. 277.
Pleurocelus valdensis, Lyd.: Lydekker, Quart. Journ. Geol. Soc. vol. xlvi. 1890, p.
182, pl. ix.
Pliosaurus a aus Owen: Lydekker, Cat. Rept. pt. iv. 1890, p. 271. (Teeth;
Kimmeridge, I. of Portland. Head of ischium and propodial ; Portland Oolite,
I. of Portland.)
Evansi, Seeley: v. Peloneustes Evansi.
-— ferov, Sauv.: Lydekker, Cat. Rept. pt. iv. 1890, p. 272.
Rhamphorhynchus jessoni [n. sp.], R. Lydekker, Cat. Rept. pt. iv. 1890, p. 226, and
Quart. Journ. Geol. Soc. vol. xlvi. 1890, p. 431, f. 1-4. Oxtord Clay;
St. Ives. [Bones; Brit. Mus. |
Steneosaurus brevidens (Phill.): Lydekker, Cat. Rept. pt. iv. 1890, p. 234. New
locality is Great Oolite ; Northampton.
—— Boutilieri, Desl.: v. S. robustus.
robustus, R. Owen, Cat. Foss. Rept. Mus. R. Coll. Surgeons, 1854, p. 11.
M. Oolite; Oxfordshire. [Skull and mandible; ? Oxford Mus.] [Includes
S. oxoniensis and S. boutilieri, according to G. A. Boulenger, in /itt. |
Streptospondylus Meyeri, R. Owen, Cat. Rept. Mus. R. Coll. Surgeons, 1854, p. 16.
Wealden; Brook. [Dorsal vertebrae, probably of Igwanodon bernissartensis ;
Mus. R. Coll. Surgeons. |
Suchodus (n. g.], Lydekker, Quart. Journ. Geol. Soc. vol. xlvi. 1890, p. 288.
- durobrivensis [n. sp.], Lydekker, ibid. p. 288, f. 2, 38. Oxford Clay ;
Peterborough. [Mandib. symphysis; Leeds Coll.] The type species.
Syngonosaurus macrocercus, Seeley: Lydekker, Cat. Rept. pt. iv. 1890, p. 264,
f. 60. [Vertebre ; Cambridge Greensand. |
Teleosaurus brevirostris, KR. Owen, was first described in Cat. Rept. Mus. R. Coll.
Surgeons, 1854, p. 8, as from ‘‘ Oolite; Chipping Norton.’’? [Skull and
mandible ; ? Oxford Mus. |
Thecodontosaurus platyodon (Riley and Stutch.): Lydekker, Cat. Rept. pt. iv. 1890,
p- 246. (Two crowns of teeth ; ? Keuper, Somersetshire.)
[Genus non det.] Axis vertebra and intercentrum of Dinosaur: Lydekker, Cat.
Rept. pt. iv. 1890, p. 245, f. 55. (See Woodward and Sherborn, Cat.
Brit. Foss. Vert. 1890, p. 296.)
“ Horn-like Dinosaurian Bone,’’ R. Lydekker, Quart. Journ. Geol. Soc. vol. xly.
(1890) p. 185. fig. [? Ungual phalanx. ]
““Tchnites,”” T. P. Barkas, Rep. Brit. Assoc. 1889 (1890), p. 565. (Carboni.
Sandst. ; Northumberland.)
Lydekker, Cat. Rept. pt. iv. 1890, p. 215.
AVES.
Fulica atra, Linn.: A. Milne-Edwards, Oiseaux Foss. vol. ii. 1871, p- 160. Fens;
Cambridge.
British Fossil Vertebrata. 33
Haliaetus pelagicus (Pall.): The type is a tibia, not humerus.
Phalacrocoraz carbo (Linn.): A coracoid in Brit. Mus. has been referred to as =
- Graculus carbo? by A. Milne-Edwards, Oiseaux Foss. vol. i. 1868, p. 277,
vol. ii. 1871, p. 592.
Lithornis vulturinus, Owen: The type is in Mus. Coll. Surgeons, not in Brit. Mus.
Tetrao urogallus, Linn.: A. Newton and H. Saunders, in Yarrell, Hist. Brit. Birds,
ed. 4, 1882-4, vol. iii. p. 47. [Bones; Cave, Teesdale. ]
MammMatta.
Ailurus anglicus, Dawk.: Newton, Quart. Journ. Geol. Soc. vol. xlvi. 1890, p. 451,
pl. xvii. f. 9. [Molar from nodule-bed (Red Crag), Boyton; Mus. Pract.
Geol.
Alces ee (John.): The type of Cervus booides is a portion of skull, with beam ;
Norwich Mus.
machlis, Ag.: The type of A. palmatus, Ow., is metacarpus, antibrachium
and humerus, Brit. Mus.
Bos taurus, var. longifrons, Owen: The type of B. longifrons is a frontlet and
horn-core; Mus. R. Coll. Surgeons. This was first named Bos brachyceros
by Owen, and subsequently Bos latifrons by Wilde. It is also the ‘‘ Small
ox’’ of Wood; see Woodward and Sherborn, Cat. Brit. Foss. Vert. 1890,
p- 822. The type of Bison minor is a metatarsal ;? Mus. R. Coll. Surgeons.
var. primigenius (Bo].): recorded from Crofthead by J. Geikie, Grox.
Mae. 1868, p. 393. The type of Bos giganteus, Davies, is a cranium ;
Brit. Mus.
Capra ibex, Linn.: A. Newton, Zool. Ancient Europe, 1862, p. 13, footnote. Pleist. ;
Fulbourne, Cambridge. [* Horns; Camb. Mus. ]
Cervus elaphus, Linn.: The type of Strongyloceros speleus, Ow., is a base of antler,
Brit. Mus.
giganteus (Blum.): The type of Megaceros hibernicus is skeleton ; Mus.
Coll. Surgeons. This is also the type of the genus Megaceros. In the
addenda to Woodward and Sherborn’s Catalogue, p. 396, ‘‘ page 333,”’ the
word ‘‘ tooth ”’ should read ‘‘ portion of antler.”’
Dacrytherwim ovinum (Owen): v. Xiphodon platyceps.
Didelphys Coichesteri, Owen: There are some notes on these teeth in E. Charles-
worth, Mag. Nat. Hist. n. s. vol. iv. app. pp. 44-72.
Felis brevirostris, Croiz. and Job.: Laing, Rep. Brit. Assoc. 1889 (1890), p. 582.
Creswell Caves.
Hippopotamus amphibius, Linn.: The type of H. major, Ow., was a lower jaw,
olim Miss Anna Gurney Coll.
Hyracotherium leporinum, Owen: W.H. Flower was the first to identify Pliolophus
vulpiceps, Ow., with this species. See Cat. Mus. Vert. R. Coll. Surgeons,
1884, p. 380, and Ency. Brit. vol. xv. 1884, p. 428. [R.L.]
Leucippe Oweni, A. Pomel, Cat. Méth. Vert. Foss. 1853, p. 10. A name used for
genus and species of English fossil bat: Pomel refers to Geol. Journ. London,
without page or other reference.
Lutra dubia (Blainy.): E. T. Newton, Quart. Journ. Geol. Soc. vol. xlvi. 1890,
p. 444, pl. xvii. f. 1. Red Crag: Woodbridge. [R. mandib. ramus; E. C.
Moor Coll. ]
Reevei [n. sp.], E. T. Newton, ibid. p. 446, pl. xviii. f. 2. Norwich
Crag; Bramerton. [Lower sectorial molar ; Reeve Coll. |
Macherodus crenatidens [n.sp.| E. Fabrini, Boll. Com. Geol. Ital. vol. xxi. 1890,
p- 162. (Refers Backhouse and Lydekker, Quart. Journ. Geol. Soc. vol. xli.
1886, p. 309, pl. x. to this form.)
Mesoplodon Floris [n. sp.], E. T. Newton, Quart. Journ. Geol. Soc. vol. xlvi. 1890,
p- 448, pl. xvii. f. 7 a-c (olim UM. Floweri, Flower (ex Canham MS.) non v.
Haast).
Floweri, Fl.: v. IM. Floris.
scaphoides [n. sp.], E. T. Newton, ibid. p. 450, pl. xvii. f. 8. Red Crag;
Woodbridge. [Rostrum ; Mus. Pract. Geol. ]
Microtus amphibius (Linn.): Newton, Grou. Mac. 1890, p. 453. [Records mandib.
fragment from Ilford in Mus. Pract. Geol.and says others are known from
Crayford and Erith.—Pleistocene. ]
ECDADE III.—VOL. VIII.—NO. I. 3
84 =~ Notices of Memoirs—Prof. Capellini—On Italian Gharials.
Microtus ratticeps (Keys. and Blas.): Newton, ibid. p. 453, f. 1, 2. [Records
remains from Crayford and Erith in Mus. Pract. Geol. and F. C. J.
Spurrell Coll.]
Myodes lemmus (Linn.): Newton, Grou. Mac. 1890, p. 455, f. 7, 8. [Recorded
from Erith Pleistocene: mandib. ramus and teeth, F. C. J. Spurrell Coll. ]
torquatus (Desm.) : Newton, ibid. p. 454, f. 3-6. [Recorded from Erith
Pleistocene: r. mandib. ramus, F. C. J. Spurrell Coll. |
' Newrogymnurus, Filhol. Prof. Rosenberg, of Dorpat, points out that this name,
though invariably adopted, is a misprint for Vecrogymnurus.
Phoca Moori [n. sp.], K. T. Newton, Quart. Journ. Geol. Soc. vol. xlvi. 1890, p.
446, pl. xvii. f. 8. Red Crag: Woodbridge. [L. humerus; E. C. Moor Coll. ]
Phocanella minor, P. J. van Beneden: EK. T. Newton, Quart. Journ. Geol. Soc.
vol xlvi. 1890, p. 447, pl. xviii. f. 4. Red Crag: Woodbridge. [Humerus ;
KE. C. Moor Coll. ]
Platycherops Richardsoni, Charlesw.: [R. Lydekker] Ann. Rep. Yorks. Phil. Soc.
1889 (1890), p. 35, pl. 1, f. 1.
Trogontherium minus [n. sp.], KE. T. Newton, Quart. Journ. Geol. Soc. vol. xlvi.
1890, p. 447, pl. xvii. f. 5 (? 6).? Includes incisor from Sizewell Gap,
Norwich Crag, in Geol. Soc. Mus. (Owen, Brit. Foss. Mamm. 1846, p. 192).
Red Crag; Woodbridge. [R. maxilla; E. C. Moor Coll.] ? Norwich Crag ;
Suffolk.
Xiphodon platyceps, Flower: ‘‘ May be Daerytherium ovinum,”’ R. Lydekker, Cat.
Foss. Mamm. B.M. pt. ii. 1888, p. 187.
N.B.—General information on the distribution of Pliocene and
Pleistocene Fossil Vertebrata will also be found in the following
works :—
W. Wuirtaxer, “ The Geology of London and of Part of the Thames
Valley,” 2 vols. 8vo., London (Geol. Survey), 1889.
C. Rerp, “The Pliocene Deposits of Britain,” 8vo., London (Geol.
Survey), 1890. W. and 8S.
IN @2rGzaS | Ore) Vila E@ ieee Se
————————
J.—Pror. CapeLirnt on A Fossit Irartan Species oF Tomistoma.
G. Capruurni. Sunt Coccopritiano GaRIALOIDE (TomIsToMA
CALARITANUS), SCOPERTO NELLA CoOLLINA DI CaGLraRI NEL 1868.
Mem. Ac. Line. (4) Vol. VI. 1890, 4 Plates.
VILL within the last few years the existing Schlegel’s Gharial, of
Borneo, was the only known representative of the genus
Tomistoma, the skull of which is readily distinguished from that of
the Gangetic Gharial (Garialis gangeticus) by the forward extension
of the nasals to join the premaxille in the long snout. Within
that period fossil remains of this genus have, however, been
determined from the Miocene of Malta (7. champsoides) and
Lower Austria (T. eggenburgense), while it has been suggested that
Blainville’s Crocodilus macrorhynchus, from the Cretaceous Pisolite
of France, might also be included in the same genus. In the
memoir before us the learned Professor of the University of
Bologna makes us acquainted with a third species from Italian
strata, for which he proposes the name TY. calaritanus.. This
species is described upon the evidence of a skull, somewhat
imperfect posteriorly, which was obtained in 1868 from beds at
1 T. calaritanum would appear to be more correct.
Notices of Memoirs—Dr. Dames on Nothosauria. 39
Cagliari, which are probably of Miocene age. Prof. Capellini first
gives us a plate illustrating the specimen in the condition in which
it was obtained from the quarry, and then a larger plate showing
the skull completely extracted from its matrix. All the characteristic
features of the genus Tomistoma are displayed in these plates, so
that there is no doubt as to the correctness of the generic determina-
tion. The general characters are also very similar to those of the
Austrian T. eggenburgense (which the author considers is rightly
included in Tomistoma, although originally described as Gavialo-
suchus) ; but the snout is relatively shorter and thicker, and the
supratemporal fossee are more nearly circular.
The gradually accumulating evidence of the abundance of Tomistoma
during the Tertiary period in Europe shows conclusively that the
solitary existing species of the genus is one of the many instances of
the survival in the Oriental region of ancient European types.
We may mention in passing that the author adopts the amended
name Garialis in place of the ordinary and incorrect Gavialis.
R. L.
II.—Dr. Orro Jaxet on Prerroratine Funer in Fossin Enasmo-
BRANCH TEETH.
“Gane von Fapenpiuzen (Mycelites ossifragus, Roux) in DEenTIN-
BILDUNGEN.” By Orro Janke. ([Sitzungsb. Ges. naturf.
Freunde, 1890, pp. 92-94. |
URING the microscopical examination of sections of the fossil
rostral teeth of Pristiophorus, Dr. Jaekel observed the minute
branching tubes of a boring organism. The latter he regards as
a fungus already described by W. Roux as infesting bones and teeth.
Similar borings are recorded in “ Sphenodus ornati,” Coraxz heterodon,
Acanthias orpiensis, Notidanus primigenius, and a new extinct species
of Trygon. We would add that similar borings have already been
noticed in fish-scales from the English Chalk.
IilI.—Dr. W. Dames on a NoruosauriAN REPTILE FROM THE
MuscHELKALK.
“ Anarosaurus pumilio, nov. gen., nov. sp.” By Prof. W. Damzs.
[Zeitschr. deutsch. geol. Ges. 1890, pp. 74-89, pl. 1. ]
TY\HE author describes the remains of the head, neck, and abdominal
region of a small Nothosaurian, from the Lower or Middle
Muschelkalk of Remkersleben, west of Magdeburg. The specimen
is preserved in the Royal University Museum, Gottingen, and it is
well shown with its counterpart, of the natural size, in the plate
accompanying the memoir. At first sight the reptile appears to be
a miniature Vothosaurus, but it is considered to be generically
distinguished by the club-shaped form of its lower side-teeth, and
by the total absence of a cleft in the glenoid border of its coracoid.
Anarosaurus (as the new genus is termed) is also distinguished
from Lariosaurus by its dentition, and differs from the type species
of the latter in the slenderness of its ribs and femur, and in the
36 Reviews—Dr. Ristori on Italian Apes.
relatively greater length of the neck. Pachypleura (or Veusti-
cosaurus) has no front teeth such as characterize the form now
described, and there are differences in the limbs. Dactylosaurus is
also excluded from comparison both by its short, stout, cervical
vertebrae, and by the absence of an epicondylar foramen in the
humerus. Dr. Dames’ study of the subject leads him to conclude,
that all the Triassic Vothosaurus-like reptiles may well be comprised
within a single family, that of Nothosauride; while the remarkable
Mesosauridz ought not to be regarded as very closely related.
AS Sane
TV.—On tHe Mexican MErerorITES, WITH ESPECIAL REGARD TO THE
SUPPOSED OCCURRENCE OF WIDE-SPREAD Murxroritic SHOWERS.
By L. Furrcuser, M.A., F.R.S., with maps of the region.
Mineralogical Magazine, Vol. 1X. No. 42, pp. 91-180.
JN this most important contribution to Meteoritic Literature, Mr,
Fletcher first points out that the ‘‘ prevalent belief in wide-
spread meteoritic showers” is ‘‘as regards the desert of Atacama,
based on insufficient evidence,” and then goes on to make observa-
tions, from which it would appear that he includes Mexico in this
statement. Mr. Fletcher notes the Meteoritic falls actually observed
(only seven in number) ; the localities in which Meteoritic masses
have been found ; the distribution in each locality ; the transporta-
tion of masses ; the natural or artificial dispersion of masses belonging
to a single type; and the facts which seem to him to prove that
many of the masses probably belong to a single fall. Numerous
other points are also carefully considered and the history of each
known mass is treated in detail, the actual locality being shown on
the maps appended. Although dealing with the Meteoritic falls
in a limited district, this paper throws a great light on the general
subject and will be found most instructive to all those who are
interested in cosmical phenomena.
RAV Lew Ss.
I.— Dr. Risrori on Fossit Irauran Apss.
Ristori, G. Le Scrmmiz Fosstur Iratiane. Boll. Com. Geol. Vol.
VII. Nos. 5-8 (1890).
N this communication the author affords us some important
il and interesting information as to the affinities of the fossil Ape
from the Miocene of Monte Bamboli known as Oreopithecus bambolit.
This Ape was originally described by Gervais on the evidence of an
imperfect lower jaw of an immature individual; and was then
regarded as being a true anthropoid. Quite recently, however, Dr.
Max Schlosser came to the conclusion that the genus has nothing
to do with that group, but was very closely allied to Cynocephalus.
Dr. Ristori now describes and figures a number of imperfect jaws,
and considers that while there are undoubtedly some signs of affinity
with the Cercopithecide, as represented by Semnopithecus and
_ Reviews — Prof. von Zittel’s Paleontology. 37
Cynocephalus, yet there are others of fully equal importance con-
necting it with the Simiide, the characters being, indeed, so equally
balanced that the author appears to be undecided to which family it
should be referred. Among the characters allying Oreopithecus to
the inferior apes are the great length of the dental series, and the
elongation of the last molars—especially those of the lower jaw.
On the other hand, anthropoid affinities are displayed in the short-
ness of the face, the rounding of the chin, and the contour of the
molars, in which the tubercles are arranged diagonally, and do not
exhibit the complete cross-crests of the Simide. The species was
of somewhat larger size than a Gibbon; and it appears highly
probably that the author is right in considering this interesting form
as one of the ancestors of the existing anthropoid Apes.
The remainder of the paper is devoted to the consideration of
Semnopithecus monspessulanus and Macacus (Inuus) florentinus of the
Pliocene of the Val d’Arno. The latter was originally described by
Cocchi as the type of a distinct genus, under the name of Aulaxinuus ;
and it appears that Dr. Forsyth Major’s Macacus ausonianus is merely
a synonym of this form.
Weare much interested to learn that this memoir is one of a series
intended to illustrate the whole of the Mammalian fauna of the
Italian Tertiaries, if the necessary funds are supplied by the Govern-
ment. The importance of such a series cannot be overestimated,
not only to the students of Italian paleontology, but likewise to
those of other countries—and more especially England. We there-
fore most earnestly hope that the Italian Government will be induced
to afford the supplies necessary to continue this most important
work, which we feel sure will be well carried out under the direction
of Professor Stoppani. Re i:
I].— Dr. K. A. von Zrrret’s Hanpsook oF PALMONTOLOGY.
Hanpsucu per Panmonrotogie—Patmozoo.oeis, Bann III. Lier. 4.
By Karu A. von Zirren. pp. 633-900, woodcut figs. 561-719.
(R. Oldenbourg, Munich and Leipzig, 1890.)
HE fourth part of the third volume of this work, relating to
Paleozoology, has just been issued, and extends to the end of
the section Aves. The index and title-page of vol. iii. are also added,
and there is a short list of Corrigenda, chiefly in connexion with
the class Pisces. The Order Crocodilia occupies the first fifty pages,
and is regarded as comprising the three suborders of Parasuchia,
Pseudosuchia, and Eusuchia; the second being founded for the
reception of the remarkable Triassic genera Aetosaurus, Zypothoraa,
and Dyoplax, while the third includes both the Eusuchia and
Mesosuchia of Huxley’s classification. Few of the illustrations are
new, but the selection of published figures is such as to render Dr.
von Zittel’s account the most completely illustrated synopsis of the
order that has hitherto appeared. The number of genera with
appended queries shows how much scope for investigation still
remains for any one able to undertake an extended review of available
38 Reviews —Prof. von Zittel’s Paleontology.
materials; and there will doubtless be much difference of opinion
upon some of the author’s views of synonymy. The difficult task of
presenting an impartial and comprehensible résumé of the Dinosauria
(as they are still termed) is accomplished in Dr. von Zittel’s best
style. Several pages are devoted to the history of the classification
of the order, with an outline of its principal osteological characters ;
and considerable space is then occupied with a detailed account of
each of the principal types. Three subordinal divisions—Sauropoda,
Theropoda, and Orthopoda—are adopted, and of the numerous illus-
trations no less than two-thirds are the fine woodcuts published in
the well-known memoirs of Prof. Marsh. In contributions to
knowledge of this order, indeed, Europe sinks into insignificance,
except as regards the Iguanodontide, Compsognathide, and
Zanclodontide. As in the case of the Crocodilia, some of the
nomenclature adopted will not meet with general approval, especially
in the New World; but Dr. von Zittel has wisely selected for special
prominence a series of the most satisfactorily preserved types,
recording them under the names they received in the original
memoirs, thus enabling the student and general reader to obtain a
clear idea of the subject without becoming involved in the perplexi-
ties of synonymy, which none but a specialist, with the actual
materials before him, can understand. The Pterosauria constitute
the last order of Reptiles discussed, and are illustrated by several
fine figures of remains from the Bavarian Lithographic Stone. The
author’s well-known memoir of 1882 forms the basis of much that
has scarcely been incorporated in a text-book previously ; and the
introduction of the graphic restored figure of Rhamphorhynchus,
originally adorning that memoir, is a new feature in the present
« Handbuch.”
The preliminary chapter to the class Aves is of the usual concise
and complete character ; and in the systematic description the three
orders of Saurure, Ratite, and Carinate are recognized. Owen's
original figure of Archgopteryx is not dispensed with, as often
happens now, to make way for an illustration of the beautiful fossil
in Berlin; but both are given, the one made to supplement the other.
Hochstetter’s restored portrait of Dinornis is as effective as the sketch
of Rhamphorhynchus already mentioned, and forms a well-chosen
contrast to the dry bones on the succeeding pages. The genera
Meitonornis and Palapteryx are admitted as distinct from Dinornis,
but the so-called Euryapteryx becomes a synonym of the second, as
determined by Hutton and Fiirbringer. The Odontolez are referred
to the Ratite, and the Odontorme to the Carinate; and the
numerous recent families of Carinate with extinct representatives
are arranged in sixteen suborders, the latest researches of Furbringer
being especially taken into consideration. Most of the genera are
simply recorded, but a brief statement of characters or distribution
is given in the case of some of the principal types; and the only
important omission in the references to literature we notice is
Symington Grieve’s work on the Great Auk.
The index to the volume, comprising both genera and species,
Reviews—Proceedings of Geologists’ Association. 39
occupies thirty-four pages of three columns each, and both students
and investigators in the Paleontology of the Lower Vertebrates will
feel that at last they have some definite and satisfactory basis to
work upon. Dr. von Zittel is to be congratulated upon the com-
pletion of another part of his laborious undertaking, and the most
gratifying reward that the Professor can receive must be the very
evident improvement in the respective authors’ knowledge of the
literature of the subject in recent contributions to the Paleontology
of Fishes, Amphibians, and Reptiles. JNotSb MVE
IiI.—Dr. Orro JaeKent on THe Systematic Posrrion anD Fossin
Remains oF Pristiophorus.
“ UEBER DIE SYSTEMATISCHE STELLUNG UND UEBER FOSSILE RuESTE
DER GATTUNG Pristiophorus.” By Orro JarKen. [ Zeitschr.
deutsch. geol. Ges. 1890, pp. 86-120, pls. ii.—v. ]
HIS is a valuable contribution to our knowledge of an interesting
Selachian family, of which few traces have been met with
among fossils. Six-sevenths of the memoir relate to the skeleton
of the existing species, comprising observations made in the Berlin
and British Museums; and the remaining pages are devoted to a
description of the fossil remains regarded by the author as pertaining
to the same type. Prof. Carl Hasse has already recorded vertebree
of Pristiophorus from the Molasse of Baltringen, Wiirtemberg ; and
Dr. Jaekel now describes rostral teeth from the same formation and
locality, considered to justify the establishment of a new species,
Pristiophorus suevicus. The fossils from the Amuri Beds of New
Zealand, determined by J. W. Davis to be caudal spines of a new
species of Trygon (T. ensifer), are now shown, from microscopical
characters, to be rostral teeth of another extinct form of Pristiophorus.
The remarkable Sclerorhynchus, from the Upper Cretaceous of Mount
Lebanon is also discussed and considered to be a subgenus of
Pristiophorus. As, however, a discovery in the British Museum
a year ago (Proc. Zool. Soc. 1889, p. 450) suggested, and probably
proved, that the trunk of the Lebanon genus had been erroneously
described under the name of Squatina crassidens, it may be well that
Dr. Jaekel should reconsider the subject. There is a fine example
of the so-called S. crassidens in the Noetling Collection at Berlin,
which will probably be available for study and comparison.
Ne Sa
TY.—Proceepines or THE Geotogists’ AssocraTion, Vol. XI. No. 8.
November, 1890. ,
MONG the many papers in this number, that of Mr. B. B:
A. Woodward, on the Pleistocene (non-marine) Mollusca of the
London Basin seems to be the most valuable. It is this kind of
contribution that we like to see, this collecting together, and adding
to, of all available information on one subject. Indeed in these days
of unlimited writing, the author who takes the trouble to sift the
wheat from the chaff deserves as much, or even more thanks, than
he who adds scrappy notes to the mass. Mr. Woodward has pre-
sented to us, in some fifty pages, the results of all researches in the
40 Reviews—Geological Survey of New South Wales.
subject, and further he has crammed his paper with observations
and notes of such value, that it must constitute the principal source of
reference to future workers. The paper is well illustrated and it is
highly creditable to the Association that they have devoted so much
space to this, and so assisted the reader and rendered the work of
greater service. A list of the Pleistocene (non-marine) Mollusca is
appended, with the correct nomenclature, but such great confusion
still exists in the question of priority, that no doubt two of the
genera will be changed in the addenda to the completed volume.
A full report of the Excursion of the Association to the Italian
Volcanoes, by Dr. Johnston Lavis follows, and should be of material
service to those who could not avail themselves of Dr. Lavis’ per-
sonal guidance, on that interesting occasion.
Professor Boulger contributes a paper on Capulus, containing
the description of a new species, illustrated by a coloured plate.
Other papers of great interest by Dr. Wheelton Hind, Major-Gen.
McMahon, T. P. Moody, H. W. Monckton, G. F. Monckton (Gold
Deposits of Nova Scotia), H. M. Klaassen, and W. J. Lewis Abbott,
complete this bulky number, but space does not permit us to notice
all these contributions in detail.
V.—Recorps or THE GrEoLocicaL Survey oF New Soura WALEs.
Vol. II. Part 1, pp. 1-86, with 3 tables, 2 plates and a map.
(Sydney, Department of Mines, 1890.)
J. Mr. T. W. Hpeeworrsa Davin publishes a proposed “ Petro-
logical Classification for the Rocks of New South Wales,” giving the
terms, lettering and signs to be employed by the Survey.
II. Under the name T. Lonsdalei. Mr. R. Evrurripes, jun.,
describes a new species of Tryplasma, Lonsdale (Pholidophyllum,
Lindstrom), from the Upper Silurian of N.S. Wales. The “pores ”
described by Lonsdale, the existence of which was doubted by
Lindstrom, are explained as impressions of the thorn-like septa in the
matrix filling the inter-tabular spaces. In the same paper Mr.
Etheridge assigns doubtfully to Diphyphyllum a new species, D.
Porteri, from the Devonian limestones near Tamworth, N.S.W. The
Specimens show interesting structural features, and suggest the
existence of an inner wall.
III. Mr. W. Anprerson has some notes of considerable practical
value “on the Tertiary Deep Lead at Tumbarumba,” an auriferous
river-bed covered by lava-flows. The paper is accompanied by a map.
IV. In a paper of anthropological rather than of geological interest
Mr. R. ErueripeGr, jun., describes and figures “The Aboriginal
Rock-Carvings at the Head of Bantry Bay, Middle Harbour, Port
Jackson,” which he thinks “formed a portion of a Bora-ground, the
spot set apart for the performance of the initiatory mysteries attending
the entrance of youths into manhood’s estate.”
V. isa note on Dromornis Australis, Owen, by the same writer.
Possibly the low price of this publication—ls. 6d.—is held to
excuse the misprints that disfigure it: the Government printer should
have his attention drawn to these, especially in Article II.
Reports and Preceedings— Geological Society of London. 41
Fee Ores ASIN) se OC raa aN GS
i
GroLogicaL Society or Lonpon.
J.—Nov. 12, 1890.—Dr. A. Geikie, F.R.S., President, in the Chair.
The Presipent reported that Mr. L. Belinfante had been tem-
porarily appointed by the Council to the Office of Assistant-Secretary.
The following communications were read :
1. “On the Porphyritic Rocks of the Island of Jersey.” By
Prof. A. De Lapparent, Foreign Correspondent of the Society.
(Communicated by the President.)
The author had some years ago described as Permian a series of
porphyritic rocks, of which specimens had been sent to him from
Jersey. He had since been led to believe that this view of their
age, arrived at from what he knew of similar rocks in France, was
erroneous, and in a recent visit to the island had satisfied himself
that the English observers who had assigned to these rocks a much
higher antiquity were in the right. He now found that the igneous
rocks in question underlie the Rozel conglomerate, which must be
placed at the very base of the Silurian formations. He reserved his
detailed statement for a communication to the Geological Society of
France ; his present object being to do justice to English geologists,
whose views he had formerly opposed.
2. “On a New Species of Trionyx from the Miocene of Malta, and
a Chelonian Scapula from the London Clay.” By Rk. Lydekker,
Esq., B.A., F.G.S.
(i.) The anterior portion of a carapace from the Miocene of Malta
exhibits a divided neural between the first pair of costals, as in the
Indian species of Trionyx, and in Chitra. The author describes this
Maltese fossil, and discusses its relationship to Trionyx and Chitra,
and names it Trionyx melitensis.
He notes the interest of finding another Oriental form in the
Miocene of the Maltese Islands, which has already yielded a species
of Tomistoma.
(ii.) A large scapula from the London Clay of Sheppey is referred
to Eosphargis gigas, and is considered to support Dr. Baur’s view as
to the intimate affinity between the Dermochelyide and Chelonide.
3. “Notes on Specimens collected by W. Gowland, Esq., F.C.S.,
in the Korea.” By Thomas H. Holland, Esq., of the Geological
Survey of India, late Berkeley Fellow of the Owens College.
(Communicated by Prof. J. W. Judd, F.R.S., F.G.S.)
The southern half of Korea traversed by Mr. Gowland is of a
hilly character. The rocks forming the hills are chiefly crystalline
schists—egneisses with graphite, garnet, dichroite, and fluor occurring
in considerable abundance, and the whole group is probably part of
the great Archean mass of North-east China. The autkor describes
these metamorphic rocks in detail.
Stratified rocks, probably of Carboniferous age, lie unconformably
upon the schists in the south-eastern part of the peninsula, and
petrographical notes of these are given in the paper. Through the
42 Reports and Proceedings—
crystalline schists and stratified rocks various igneous rocks have
been erupted as dykes or in large masses. Amongst these the most
conspicuous rock is granite. Biotite- and muscovite-granite are
most widely distributed, and in places are cut by dykes of eurite
and veins of quartz and pegmatite. The more basic class of rocks
is represented by diorites, propylites, andesites, basalts, dolerites,
and gabbros. Interesting cases of the gradual passage between the
so-called intermediate and basic rocks are found, and various stages.
in the devitrification and decomposition of andesitic lavas represented.
These are described in detail by the author, and compared with
similar cases in other regions; and full descriptions of the intrusive
rocks are furnished.
There are now no active voleanoes; and there is a notable lack of
mineral wealth in the southern part of the Korea.
4, ‘Further Notes on the Statigraphy of the Bagshot Beds of the
London Basin (north side).” By the Rev. A. Irving, D.Sce., F.G.S,
1. The author brings forward new evidence from well-sections,
clay-pits recently opened, and excavations, confirming the reading of
the country between Wellington-College and Wokingham Stations
on the 8.H. Railway, as put forward by him in 1887 (Q. J. G38.
vol. xlili. and figure 1 of the paper). We have now actual data for
the gradients of the clay-beds, and the thinning-out of both the
Lower (fluviatile) Sands and of the Middle green-earth series; the
latter, when taken into account, bringing the clays in the Wokingham
outlier into stratigraphical alignment with the basal clays of the
Middle Group. Certain clays at California are also shown to be in
alignment with these; and a sketch-section from Ambarrow to
Barkham Hill shows the relative gradients of certain horizons to be
such as to justify the relegation of the Pebble-bed there to the base
of the Upper Sands; while a microscopical examination of the sands
above it brings out the lithological identity of these and of the sands
capping Farley Hill with the basal beds of the Upper Sands at
Wellington College and on Finchampstead Ridges. The accidental
occurrence of thin seams of pipe-clay is rejected as a test of horizons,
as affording only ambiguous evidence.
2. A similar succession is shown in a section drawn from Wel-
lington College Well through the sand-pit at the brick-yards by
Ninemile Ride (base of the Middle Clays exposed), Hasthampstead
Church Hill (with more recent data), and Bill Hill (Easthampstead),
to the S.W. Railway at Bracknell, bringing the higher beds of those
two hills into the horizon of the Upper Sands. Further notes are
also added to those of the author’s 1888 paper (Q.J.G.S. vol. xliv.)
on the Ascot Hills, Englefield Green, and Windsor Park, where the
transgressive relation of the Bagshot Beds to the London Clay is
maintained.
3. In conclusion, the author points out that the new well-sections
confirm the trustworthiness of that at Wellington College as a
vertical datum-line ; he criticises the views of previous writers and
maintains that, with the aid of Lieut. Lyons’ recently published
contour-map, we can now discriminate between the effects of con-
Geological Society of London. 43
temporaneous and post-Hocene earth-movements in the area; and
that the physical history of the Bagshot Beds, which he has himself
propounded, is substantiated by the stratigraphical evidence.
IL.—Nov. 26, 1890.—A. Geikie, F.R.S., President, in the Chair.
—The following communications were read :—
1. “Account of an Experimental Investigation of the Law that
Limits the action of Flowing Streams.” By R. D. Oldham, Ksq.,
A.R.S.M., F.G.S., Deputy Superintendent of the Geological Survey
of India.
The author brings forward evidence derived from experiments in
support of the views expressed in a paper submitted to the Society
in 1888. His apparatus consisted of a sloping trough, through
which various amounts of water containing definite percentages of
sand could be sent. The lower end of the trough issued on to a
semicircular platform.
In three experiments with the trough at a slope of 1 in 20, and
with the same work to be done in each case, the resulting slopes
after sand had accumulated in the trough were as follows :—With
one part of sand to 42 of water, a slope of 1 in 40; with 1 of sand
to 28 of water, 1 in 20; and with 1 of sand to 14 of water, 1 in 18:3.
These slopes were obtained when a condition of equilibrium had
been maintained so that the water was just able to transport its
burden. By increasing the supply of water from 14:1 to 42:1, the
original slope was eventually obtained.
On the fan formed on the horizontal platform variations in the
water supply did not produce nearly so marked an effect as in the
confined channel, and the slope varied considerably in different
directions.
After a time a channel was cut back into the fan, and its sand
swept forward and deposited as a secondary fan in front of the first ;
and as this grew, it cut back into the reach above, and this in turn
eut back towards the head of the fans, and sometimes into the
trough. In some cases other secondary fans were formed on the
margin of the main fan, but the apparatus was not large enough
for further formations. The general slope of the fans, both primary
and secondary, was ‘06, and that of the reach only -04, while at the
head of the reach, where it was cutting back into the face above,
there was a gradient of -08
The general tendency of the experiments supports not only the
specific conclusions as to the normal form and behaviour of a river
which has attained a state of equilibrium, but to a greater degree
the fundamental assumption that a river will adapt its channel to
such a slope and form as will enable it to just transport a solid
burden cast upon it.
2. «On the Rocks of North Devon.” By Henry Hicks, M.D.,
FE.R.S., Sec.G.S.
During a recent visit to North Devon the author obtained evidence
which has led him to believe that far too little importance has
hitherto been assigned to the results of movements in the Harth’s
44 Reports and Proceedings—.
crust as affecting the succession of the rocks in that area. The sup-
posed continuous upward succession from the rocks on the shore of
the Bristol Channel to those in the neighbourhood of Barnstaple,
including, according to some authors, no less than ten groups, and
classed into three divisions under the names Lower, Middle, and
Upper Devonian, is, the author believes, an erroneous interpretation.
The beds, he says, have been greatly plicated and faulted, and con-
sequently several times repeated, and instead of being one continuous
series, they occur folded in more or less broken troughs. In the
Morte Slates, previously considered unfossiliferous, the author found
a Lingula, and he believes that these slates are the oldest rocks in
' the area, and formed the floor upon which the Devonian Rocks were
deposited unconformably. As the result of movements in the Harth’s
crust, the Morte Slates have been brought to the surface and thrust
over much newer rocks, producing a deceptive appearance of over-
lying the latter conformably. The Morte Slates mark the dividing
line between the two main troughs. On the north side in ascending
order are the Hangman (or Lynton), Combe: Martin Bay, and IIfra-
combe Beds, and on the south side the Pickwell Down, Baggy Point,
and Pilton Beds. Those on the south side of the Morte Slates are,
the author believes, a repetition of the beds on the north side. The
paleontological evidence is not antagonistic to this view, for an
analysis of the Brachiopoda, the only group of fossils in the beds on
the south side, which hitherto have been systematically examined,
shows that of the twenty species mentioned by Mr. Davidson and
others as occurring in the Pickwell Down, Baggy Point, and Pilton
Beds (the so-called Upper Devonian rocks), no less than thirteen
have already been found in the Middle or Lower Devonian rocks on
the north side of the Morte Slates. Four others are recognized
Middle Devonian species in other areas; and the three remaining
are either doubtful species or ones which have a great vertical range.
These facts show that the so-called Upper Devonian rocks in this
area do not contain a distinguishing fauna of any importance; and
the stratigraphical evidence is opposed to the view that they are
a series of rocks distinct from those on the north side of the Morte
Slates, which have been classed as Middle and Lower Devonian.
TII.—December 10, 1890.—Dr. A. Geikie, F.R.S., President, in
the Chair.—The following communications were read :—
1. “On some Water-worn and Pebble-worn Stones taken from
the Apron of the Severn Commissioners’ Weir erected across the
River at Holt Fleet about eight miles above Worcester.” By Henry
John Marten, Esq., M.Inst.C.E., F.G.S., ete., Engineer to the Severn
Commissioners.
The Weir referred to in the paper was built in 1844 of soft red
sandstone, and some of the stones composing the apron of the Weir
showing signs of decay were removed in 1887. The average quan-
tity of water passing over each square foot of the stones composing
the apron has been estimated at about 2000 gallons per minute. A
Geological Society of London. 46
large proportion of the stones had been drilled through and through
by the action of the current upon small pebbles lodged in hollows or
between the joints of the stone; and the author estimates that as a
result of 43 years of erosion, six of the stones of the apron, which
may be taken as a sample, had lost the following amounts respec-
tively :—45, 60, 48, 50, 37, and 58 per cent.
2. “On the Physical Geology of Tennessee and adjoining Districts
in the United States of America.” By Prof. Edward Hull, M.A.,
LL.D., F.R.S., F.G.S., late Director of the Geological Survey of
Ireland.
The area described in the paper is occupied by the Unaka or Blue
Ridge, which may be regarded as one of the parallel ridges of the
Alleghanies, and the prolongation of Prof. J. D. Dana’s “ Archean
Protaxis.” It runs in a general south-westerly direction, and attains
an elevation of 6760 feet. At its base, and to the north-west of it,
is the Valley of Hast Tennessee, about 40 miles wide, and furrowed
by north-east and south-west ridges and depressions, parallel to the
strike of the Cambrian and Silurian beds. Through this runs the
Tennessee River, which, instead of running south to the Gulf of
Mexico, turns to the north-west, some distance below Chattanooga,
and cuts through the Cumberland table-land, a prolongation of the
Appalachian mountains, and flows into the Ohio River.
The Cumberland table-land has an average height of 2000 feet
above the sea, and 1350 feet above the Tennessee River at Chatta-
nooga. It consists of a synclinal of Carboniferous rocks resting
conformably upon the Devonian beds, and is bounded along the Hast
Tennessee Valley by a curved escarpment; a similar though more in-
dented escarpment forming its north-western margin, and separating
it from the Silurian plain of Nashville. The table-land is about 40
miles wide, and is intersected by the valley of the Sequachee River,
running in a north-easterly direction along a subsidiary anticline
from near Jasper for a distance of sixty miles.
From the base of the Cambrian beds, the whole Lower and Upper
Paleozoic formations succeed each other in apparently conformable
sequence, except at the junction of the Upper and Lower Silu-
rian series, where a probable discordance occurs. The prolonged
period of subsidence and deposition at length gave way to elevation ;
acting with the greatest effect along the Alleghanies. Under these
circumstances, denudation proceeded most rapidly along the tract
bordering the Protaxis, whilst the synclines were protected from
erosion to a greater degree; and as the elevatory movement was
more rapid along the Unaka range, the flow of the streams was
generally westward. At a later period the Cumberland plateau
began to be formed by backward erosion of the strata in the
direction of the dip; so that it owes its development to the erosion
of the Tennessee and Clinch Rivers on the one hand, and to the
Cumberland River on the other. Where the Tennessee River flows in
a north-westerly direction through the Cumberland plateau, the divide
between it and the Gulf of Mexico is only 280 feet above the river-
bed, whilst the table-land is 1400-1500 feet above. The author
46 Correspondence—Mr. Alex. Somervait.
infers, therefore, that when the river began to erode its channel, the
plateau was relatively lower than the tract to the south of the
present course of the stream, but that by denudation the relations
have been reversed, whilst the river has never left its originally
selected course.
The author compares the state of things with that which must
have occurred in the case of the northerly rivers running from the
centre of the Wealden axis; but mentions that Prof. Safford and
Mr. J. Leslie account for the Cumberland plateau by faulting, though
he thinks that the well-defined escarpment along the valley of Hast
Tennessee seems to show that this cause is insufficient.
In conclusion, he believes that the denudation was accelerated
during the pluvial or ‘‘Champlain” period, and calls attention to
the ‘Columbia formation” on the east side of the Alleghanies, and
to the deposit of red loam by which the surface of the country of the
valleys of the Tennessee and Sequachee is overspread, and which is
probably referable to a similar stage.
3. “On certain Ornithosaurian and Dinosaurian Remains.” By
R. Lydekker, Hsq., B.A., F.G.S.
The author is indebted to Professor O. C. Marsh for the correct
determination of the bones described in the paper.
1. Ornithosaurian Quadrates.—The reptilian bones in the British
Museum, Nos. 48034, 44183, and 41179, are Ornithosaurian quad-
rates. The two latter belonged to the right side of the skull. The
distal extremity of each forms a deeply grooved oblique trochlea,
above which is a nearly quadrangular shaft. To the inner side of
this shaft is attached, by suture, a flattened plate of bone, concave
internally, and convex externally, representing part of the pterygoid ;
so that the relation of the quadrate to the pterygoid in the Ornitho-
sauria is the same as in the Rhynchocephalia.
The smaller quadrate would agree approximately in relative size
with the so-called Pterodactylus Manseli, Owen, and the larger more
nearly with the so-called Pt. suprajurensis, Sauvage, both of which
may be provisionally referred to Rhamphorhynchus.
2. Tibia of Coeluroid Dinosaur.—The author would provisionally
refer the right tibia of a small Dinosaur from the Wealden of the
Isle of Wight, which had been incorrectly referred to Hypsilophodon,
to the species originally described, from an examination of two
vertebree, as Calamospondylus Foxit, but which he would now name
Calamosaurus Foxit. It presents striking avian affinities.
CORRESPONDENCE.
Oe
PROF. BONNEY AND GENERAL McMAHON ON THE GEOLOGY OF
THE LIZARD DISTRICT.
Str,—In your last issue, Prof. Bonney in his characteristic style
refers to my late work in this district. He, however, at once, falls
into error as to the number of my communications to the MaGazine.
there being five, not four as stated by him. The one he overlooks
Correspondence—Report of Congress.— Rev. O. Fisher. 47
being that “On the Schists of the Lizard District,” April, 1890,
perhaps the one he likes least.
As to the points in his letter under his figures 1, 2, 3 and 4, I
have no doubt but that Prof. Bonney will in good time demonstrate
these assertions; but in the meanwhile they are only assertions.
J will freely and gladly admit the errors, both in my observations
and inductions, when proofs are forthcoming. J was much amused
by General McMahon’s letter. I am well aware (perhaps before
the General was) of the apparent sequence of the various rocks laid
down by the masterly mind of De la Beche, and also (perhaps)
I have seen more of the true dykes in the Lizard District than has
fallen under the observations of General McMahon. There are
dykes, however, that I regard as of contemporaneous or segrega-
tion origin.
Independent of the sequence of the rocks referred to, I think them
the product of eruptions of one geological period, that intermittent
action is noticeable, and that there is a decided passage of the main
masses into each other, and that the same magma, cooling under
different conditions, has given rise to many varieties of rock. My
communications were intended to lead up to this point.
As to my theory of the origin of the ‘banded structure,” let
it with the others ‘sink or swim.” I care not which survives.
As to the close of General McMahon’s letter, I much regret having
to say, that I think it is quite uncalled for.
Torquay, 9TH December, 1890. ALEXR. SOMERVAIL.
REPORT OF THE INTERNATIONAL GEOLOGICAL CONGRESS.
Str,—I am periodically asked by friends who joined the last
Geological Congress how it is that the promised report to which
each member was said to be entitled has not yet appeared, although
some of us paid an additional subscription to expedite its production.
Ought not the eminent geologists whose names appeared on the
circular inviting support to that Meeting to be asked to furnish some
explanation for this unaccountable delay ? (B. V)?.
ON DYNAMO-METAMORPHISM.
Srr,—I certainly had no thought of “rolling back the develop-
ment of chemical theory a few decades at least,” when I wrote of
energy taking ‘‘the molecular forms of heat and chemical action.”
Dr. Irving in his criticism of this expression leaves out my reference
to heat. I conclude therefore that he has no objection to that part
of the statement. As to the assertion that part of the energy, which
previously existed in the molar form, was converted into the ‘“ mole-
cular form of chemical action,” I was unable to know whether Dr.
Irving’s stricture expressed the generally received views upon the
subject, owing to my imperfect acquaintance with chemistry. I
have, therefore, consulted the highest authority on such questions
to whom I could apply and on whose opinion I can place reliance.
With respect to Dr. Irving’s apparently general statement, that
‘chemical combination must generate heat,” he replies, that, “when
48 Correspondence—Mr. Alfred Harker.
carbon is heated in carbonic acid gas, C O is formed with a disap-
pearance of heat; and, when nitrogen and oxygen are sufficiently
heated together, an oxide of nitrogen is formed with a disappearance
of heat; and, that in these cases the heat which has disappeared has
become chemical energy in the molecules of C O or N O. Whether
it be atomic energy or not is not at present known, but as the mole-
cule includes the atoms, it is certainly ‘‘ molecular ” as distinguished
from ordinary mechanical, or molar energy. Since many chemical
changes, which only take place at very high temperatures, appear
to be attended with a disappearance of heat, it is at least not im-
probable that some of the changes, by which minerals are formed
in the interior of the earth, may also be attended with a storage of
energy.”
“Perhaps Dr. Irving takes exception to the supposition that
mechanical energy may be directly transformed into chemical
energy. If so, you may reply that the known effects of pressure
upon chemical changes, when those changes are attended by a
change of volume, afford support to the supposition. Recent obser-
vations on the influence of surface tension on chemical change by
Liebreich, J. J. Thomson, and others, lead in the same direction,
so that it cannot be said that the supposition is unreasonable, even in
the light of recent advances in physical chemistry.”
Finally I am told that the assertion that “chemical combination
must generate heat” is certainly incorrect, and that the examples CO
and NO to the contrary are “only two out of an immense number.”
Harton, Camprivce, 13 Dee. O. FisHumr.
DYNAMOMETAMORPHISM.
Str,—I must apologize to Dr. Irving for having overlooked the
observations to which he refers. Unfortunately I had not read the
work in question at the time when I wrote my letter.
As regards the main subject of his letter in your December num-
ber, I would offer only a few words. In assuming that the whole
of the work done in the compression, deformation, and friction of
rock-masses passes into heat, Dr. Irving misses the idea which
underlay the whole of my remarks, and was more explicitly stated _
in Mr. Fisher’s article. The direct correlation of mechanical and
chemical energy was, I believe, first mooted by Dr. Sorby in 1863 ;
but the practical verification’ of it rests on such experiments as those
of Cailletet, Pfaff, and Spring. To take an example: Spring sub-
jects a mixture of sulphur and copper filings to a pressure of 5000
atmospheres, and finds it converted into crystallised copper sulphide.
The operation is conducted slowly, and the temperature of the
apparatus kept constant. In other words, so much of the mechanic-
ally-developed energy as takes the form of heat is carefully removed;
but chemical combination still takes place. It follows that the
energy absorbed in this combination comes directly from the me-
chanical work done, without the intervention of heat.
St. Joun’s Contece, CAMBRIDGE, ALFRED Harker.
Geol, Mag 1891.
Geo.West & Sons del.lith.ectimp.
FOSSIL ESTHHPRIA.
THE
GEOLOGICAL MAGAZINE.
NEW ISERIES, IDECADE, Ill., VOL.. Vill
No. II.— FEBRUARY, 1891.
Ore en Ae Aa en as ese Se
—_—_
I.—On some more Fossit Esturriz.
By Professor T. Rupert Jonzs, F.R.S., F.G.S., ete.
(PLATE II.)
Introduction.
Estheria membranacea of the Old Red, Orkney.
Estheria Andrewsii of the Purbeck, Wilts.
Estheria Hindet of the Trias, Pennsylvania.
LEistheria minuta (Germari?) of the 'l'rias, Saxony.
var. Brodieana of the Trias, Cheshire.
Estherielia.
Estheriella costata
Estheriella nodocostata \ of the Trias, Saxony.
Bibliographic history of the Estherielle.
N the September Number of the Grotocican Magazine, 1890,}
I offered some notes on certain Triassic Estherie of North.
America and Bavaria, and on an Estheria from the Purbeck strata
of Wiltshire. An interesting example of EH. membranacea from the
Old Red of Orkney was figured, but not described. We have
now the Rev. W. R. Andrews’s other Purbeck Estheria, referred to
at p. 389, ready for description; another Triassic Estheria from
Pennsylvania; and some most interesting specimens of the rare
Estheriella, instituted as a subgenus by the late Professor Dr. Ch.
Ernst Weiss.
Seeing the account of Estheria Lewisti in the Grou, Mace., loc. cit.,
Dr. G. J. Hinde, F.G.8., remembered some specimens he had
collected in Pennsylvania, and these I find to be from the same
place (Phoenixville) as supplied Mr. C. M. Wheatley with a series
for my Monograph in 1862; but Dr. Hinde’s examples show
structure not seen in any of the others.
Having met with a peculiar structure in some Carboniferous
Estherie from Scotland, which seemed to correspond with the
descriptions of that in Estheriella, I asked the late Prof. E. Weiss
for information on the subject; and, though confined to bed by
illness, he most courteously gave his attention to my request, and
not only sent me (in February, 1890) some specimens of the rare
fossil, but obtained permission, from the Director of the Geological
Institute and Mining Academy at Berlin, for me to have on loan
some of the best specimens from the Geological-Survey Museum, to
figure and describe. I deeply regret that we have to bring out the
1 Decade III. Vol. VII. pp. 385-390, Pl. XII.
DECADE III.—VOL. VIII.—wNO. II. 4
50 Prof. T. Rupert Jones—Fossil Estherie.
results of the examination without consultation with Prof. Weiss,
whose death a large circle of friends and admirers had to deplore
last summer.
Of Estheria minuta and some other forms of that genus I] gave
some notes in the Grou. Mac. Decade II. Vol. V. 1878, pp. 100-102,
Pl. III. Figs. 1, 2, and now, besides the notices referred to above,
I have to make mention of Mr. C. E. De Rance’s discovery of this
species in the lower part of the “Keuper Marls” of Cheshire,—
a lower horizon for England than had been previously known.
1. EsTHERIA MEMBRANACEA (Pacht). Grou. Mac. September, 1890.
Pl. XII. Fig. 9.
Jones, Monograph of the Fossil Estherie, Pal. Soc. 1862, pp. 14-22, pl. i. figs. 1-7.
Length 6 (hinge-line 5), height 4 mm.
This little fossil has been noticed by P. N. Wenjukoff in his
Memoir “On the Fauna of the Devonian System in North-western
and Central Russia,” S8vo. St. Petersburgh, 1886, pp. 225-4 (in
Russ). In the synonymy he gives Posidonia aspera, Kutorga, 1852,
instead of ‘‘ Posidonomya rugosa, Kutorga,” of the list at p. 14 of
the ‘“‘Monograph Foss. Hstheriz.” We may note that Raimund
Pacht in the “Archiv Natur. Liv.-, Ehst- und Kurlands,” vol. 11.
2nd part, 1859 (“ 1861” in Wenjukoff’s list, op. cit. p. 224), treating
of the Devonian Limestone in Livland (Livonia), describes and
figures E. membranacea, at pp. 290-291, and in figs. Ta, b, ¢, of the
plate (not numbered), as “‘ Posidonia membranacea, n. sp.=P. rugosa,
Kut., auf der Karte des St.-Petersb. Gouv.”
It was remarked at p. 21 of the “ Monogr. Foss. Esth.” that in
the Russian (or rather Livonian) specimens ‘the thin upstanding
concentric riblets are better preserved than in the flagstones of
Caithness.” Some individuals, however, from Orkney, collected by
Mr. Jex, and now in the Tanah Museum, show the ornamentation
so clearly that Fig. 9 of Pl. XII. in the Grou. Mac. for September,
1890, was specially given, though not described at the time, only
alluded to at p. 390. This figure not only shows the longer, or
more oblong, shape of the valve, referred to in the “ Monograph” at
pp. 14 and 15, but a very delicately reticulate interstitial sculpturing,
such as was supposed (at pp. 15 and 19) to have been modified by the
impress of sand grains in the matrix at Caithness.
2. Estuert1a ANDREWS, sp. nov. Pl. I. Figs. 1-4.
Fig. 1.—Length 8-5 (hinge-line 6), height 6 mm.
Jas A UI (Cs Ns by OC tau
These specimens, from the Purbeck beds of the Vale of Wardour,
as also those described in the Guon. Mag. for September, 1890, p.
389, Pl. XII. Figs. 1, 2, were collected by the Rev. W. R. Andrews,
F.G.S., in a quarry at Teffont-Ewyas, Wilts, but in a different
stratum of the Middle-Purbeck formation, namely, in a dark shaly
clay, containing Cypridea fasciculata and C. punctata, five feet below
the horizon of the EHstheria referred to above.
The former specimens were referable to H. subquadrata (Sow.),
Prof. T. Rupert Jones— Fossil Estherie. 51
by their shape and ornament; but those now under notice are larger ;
one individual is approximately subquadrate in shape (Fig. 1), but
the other is more elongate (Fig. 2); both have the umbo further
from the anterior extremity, and otherwise differ from E. subqua-
drata and E. elliptica in being less fully curved at the antero-ventral
region and in being higher behind than in front. Further, they
have a delicate reticulation for the interstitial ornament (Fig. 3).
This finely punctate sculpture, however, belonging to the super-
ficial layer of the test, gives an impression on the matrix, at some
places, of a delicate linear granulation, making very small, vertical,
interrupted strize; whilst the inside of this outer layer shows a
coarser pitting (Fig. 4).
Specimens numerous, squeezed flat, but fairly well preserved, on
the thin lamine of a bluish grey, soft shale, with brownish partings,
and with white patches of the decomposed Cypridee.
3. Hstuerta Hrnpet, sp. nov. Pl. Il. Figs. 5-8.
Length 7 (hinge-line 5), height 4-5 mm.
An elegant suboblong Estheria, boldly rounded in front, narrower
behind ; rather more than half egg-shaped in a longitudinal aspect.
Umbo at the antero-dorsal corner. Concentric riblets (15 visible)
strong and far apart, and at some spots seen to be neatly beaded,
but rarely so regularly and distinct as in Fig. 6. The interspaces
are bare of ornament; but the inner layer of the test in some
instances shows irregular vertical rows of small lumpy elevations
(Fig. 7), which are probably exaggerations (in the older part of the
valve) of small vertical irregular bars (Fig. 8), in the interspaces
elsewhere. This last-mentioned columnar ornament is analogous
to that shown in fig. 37, pl. 11. of the Monogr. Foss. Estheriz, and
referred to at page 387, Guou. Mac. September, 1890.
The specimens under notice are numerous in a hard, black,
thinly-laminated Triassic shale, from Phoenixville, Pennsylvania
(Dr. G. J. Hinde’s Collection), like some of that described at p. 99,
“ Monogr. Foss. Hstherie,” as having been supplied by Mr. C. M.
Wheatley from the same locality. Some are better preserved
as to shape; but others more distinctly show the structure of
the valve. The selected specimen, Fig. 5, is like one of the
“narrower” examples mentioned at p. 98 op. cit.; and, as with
many others, there is no interstitial ornament. In some shiny,
black, filmy valves we have the features shown in Figs. 6,7,8. The
last two belong to the inner layer of tests of apparently different
ages, but covered with the outer layer, in which the ornament
became obsolete. Hence neither figs. 29 and 30, nor fig. 31 of
pl. ii. “Monogr. Foss. Esth.” must be taken by themselves for
specific characters, though suggested at p. 386 of the Grou. Mag.
Sept. 1890.
These specimens from Pennsylvania certainly differ from Hstheria
ovata of the “Monogr. Foss. Esth.” p. 84, pl. ii. figs. 26-28, being
proportionally longer, and having a less fully semicircular ventral
outline. They are larger and proportionally higher (broader) than
52 Prof. T. Rupert Jones—Fossil Estherie.
E. Lewisii, Grou. Mae. Sept. 1890, p. 385, Pl. XII. Fig. 8, with the
umbo further forward and a different ornament. Otherwise these two
species, as well as EH. multicostata (Emmons), “‘ Monogr. Foss. Hsth.”
p- 86, fig. 6, and H. ovalis (Emmons), op. cit. p. 87, fig. 8, are
evidently allied forms, though the last two have most probably
been badly drawn.
4. Esrueria mrnura (Alberti), 1832. Pl. II. Fig. 12.
Jones, Synonymy in the ‘‘ Monograph of the Fossil Estheriz, Paleont. Soc. 1862,”’
p- 42; F. von Alberti’s ‘‘ Ueberblick tiber die Trias,’’ etc., 1864, pp. 191
-and 192; Jones, Gzonocican Macazine, Dec. III. Vol. VII. 1890, Pl. XII.
Figs. 4-8.
Length 3-0 (hinge-line 2-0), height 1-9 mm.
This is a specimen occurring in the Lower-Bunter shale at
Diirrenberg, in Saxony, with Estheriella costata, Weiss. It is very
much like it, as seen in Fig. 9, but is smaller and has no radial strie.
It has the same number of concentric lines, and therefore cannot be
the young of the larger form; and the occurrence of the radii is too
persistent among the many Estherielle in the shale, to allow of the
supposition that they constituted merely a casual feature and were
not always present in the same series of valves. Fig. 12 may be
compared with fig. 8 of pl. v. and fig. 29, and even with fig. 28,
of pl. i. of the “ Monogr. Foss. Esth.” as a specially straight-backed
form of the species.
Fig. 12 may possibly be Estheria Germari (Posidonia, Beyrich,
Zeitsch. D. g. Ges. vol. ix. 1857, p. 377), from the Bunter at the
Steinberg, north of the Hartz, and at Halle and Diirrenberg, both
in Saxony. Andrae, in the Explanation of the Geological Map of
Halle, 1850, p. 67, referred to it as P. minuta. It is characterized
by having a long and straight hinge-border; and according to
Prof. Weiss it has no radial markings.
Besides the authors treating of the occurrence of Estheria minuta
in the German Trias that are enumerated in the ‘‘Monogr. Foss.
Hsth.” pp. 44 et seq., we should mention C. von Schauroth, Zeitsch.
D. g. Ges. vol. ix. 1857, p. 99 (Coburg).
4*, Estueria minuta (Alberti), var. Bropreana, Jones.
Pip ios
Monogr. Foss. Estheriv, 1862, p. 69, pl. ii. figs. 8-15, and pl. v. fig. 10; Gzon.
Mae. Dee. 3, Vol. VII. 1890, p. 388, Pl. XII. Fig. 6.
Length 3 (hinge-line 2), height 2°5 mm.
Lately Mr. C. E. De Rance, F.G.S., has obtained from the “ Old
Alderley Quarry,” at Alderley Edge, Cheshire, a small shoal-like
group of Estherig in a soft, dull red, finely micaceous shale, belonging
to the upper part of the ‘Keuper Marls,” f. 6 of the Geological
Survey Map, and a thousand feet lower down in the Trias (being
below the waterstones, f. 5) than any of the English examples of
F. minuta yet found.
The specimens occur both as single valves and in open pairs;
Prof. T. Rupert Jones—Fossil Estherie. 53
they are much crushed, and Fig. 14 shows one of the best. It is
very much like the German specimen figured in the Grou. Maa. for
September, 1890, Pl. XII. Fig. 6, and nearly matches fig. 9 of pl. ii
“ Monogr. Foss. Hsth.”
E. minuta, var. Brodieana, has been reported by Ferd. Roemer as
having been found in the Keuper of Upper Silesia. This, and some
other notes on the occurrences of H. minuta published since 1862,
are given in the Gon. Maa. Dee. I. Vol. V. 1878, p. 102.
E. minuta, var. Karpinskiana, Jones, related to var. Brodieana,
was obtained by Dr. Karpinsky from the Triassic or Rheetic strata
of Troizk, on the eastern side of the Ural. See Ann. Mag. Nat. Hist.,
October, 1883, p. 244, pl. vi. fig. 1.
HstHertetya, Weiss (as a subgenus, 1875).
Similar to Estheria, excepting that the valves bear radial riblets
or slight ledges crossing the concentric striz from near the umbo
to the ventral border.
5. EstHERIELLA costata, Weiss, 1875. PI. II. Figs. 9, 10, a, b.
Posidonomya Wengensis, Giebel (non Wissmann). Zeitsch. gesammt. Naturwiss.
Halle, 1857, p. 308, pl. i. fig. 6.
Estheria ? Wengensis, Alberti. Ueberblick Trias, etc., 1864, p. 192. note.
Estheria (Estheriella) costata, Weiss. Zeitsch. D. g. Gesellsch. vol. xxvi. 1875,
p- 711, note.
Estheriella costata, Zittel. Handbuch der Palzontologie, vol. i. Lief. 8, 1885, p. 568.
Fig. 9.—Length 3-7 (hinge-line 2°7), height 2-4 mm.
Valves like those of Estheria minuta, such as those shown by pl. i.
fig. 29, and pl. v. figs. 8 and 9, “Monogr. Foss. Esth.,” that have
markedly straight backs, a more or less definite postero-dorsal angle,
and strong concentric lines of growth (about 18 visible). Modifica-
tions produced by pressure, as well as by variable conditions of
growth, make it difficult to find perfectly comparable specimens
among fossil Estherie. The characteristic feature is the presence
of numerous (about 20 or more) oblique stria radiating from the
middle region to the ventral and posterior borders. Posteriorly they
produce a series of undulating wrinkles, crenulating the edge; but
more forward they seem to have been little furrows formed by the
notches in the edge of each successive overlapping lamina of the
test, and giving a minute tile-like appearance to that part of the
surface. A pattern somewhat like this, but on a still smaller scale,
is visible in Estheria tegulata from the Scotch Coal-measures, to be
published in the Trans. Geol. Soc. Glasgow, vol. ix. pl. v. fig. 60.
In the Estheriella under notice the edge of each lamina is more or
less thickened at and between the notches, and was there sufficiently
produced as little hollow tubercles to leave the minute pits seen
in the inside of the test (figs. 10 a,b). Here, also, there are traces
of this structure reaching further up towards the umbo than on the
outside (Fig. 9).
The specimens of both this and the next species are very delicate
and scarcely ever perfect films of valves in bluish grey shale.
54 Prof. T. Rupert Jones—Fossil Estherie.
Some of the radials at their intersections of the lines of growth
retain thin brownish relics of the test ; but otherwise the valves are
represented by partial moulds and casts, much flattened.
Both come from the Lower Buntersandstein of Dirrenberg,
Saxony.
The specimens figured were courteously lent by the Director of
the Geological Survey ' at Berlin, at the instance of the late lamented
Prof. Dr. Ch. E. Weiss, who also gave me some other specimens,
collected by himself at Diirrenberg on the road to the Amtsberg,
May, 1875.
6. EstHerreLLa nopocostara (Giebel), 1857. Pl. II. Figs. 11, 18.
Posidonomya nodocostata, Giebel. Zeitsch. gesammt. Wissensch. Halle, 1857,
p. 309, pl. ii. fig. 7.
Eistheria ? nodocostata, Alberti. Ueberblick Trias, etc. 1864, p. 198, mote.
Listheria (Estheriella) lineata, Weiss. Zeitsch. D. g. Gesellsch. vol. xxvi. 1875,
p- 711, note.
Fig. 11.—Length 4-2 (hinge-line 2-7), height 2°5 mm.
Fig. 138. 59 3°5 ( 3 2°3), eens
Valves like those of the foregoing species, ovate-oblong in shape,
with long, straight dorsal border; umbo quite forward; postero-
dorsal angle usually pronounced; ends well rounded ; the posterior
curve larger than the anterior; ventral border gently .curved.
Concentric lines numerous and rather feeble. Radial riblets few
(about 9), but much stronger than in H. costata, being definitely
raised ridge-like wrinkles wide apart (Figs. 11 and 13). On the
inside of the valve (Figs. 13 a,b) there is a little pit wherever the
radial crosses a concentric stria, as if the edges of the successive
laminz of the test had been slightly raised just there, so as to leave
a little hollow below. The specific name applied by Giebel to this
form evidently has reference to this feature, as seen in Fig. 13 a.
Locality and collection the same as mentioned with the foregoing
species.
To make the history of the two foregoing species complete, the
following extracts are taken from the published memoirs concern-
ing them.
1857. Ch. G. Giebel, Paleeont. Untersuchungen; Zeitschrift fiir
die gesammten Naturwissenschaften, Halle, 1857, October u.
November, Nos. x. xi. pp. 801-318.
Posidonomye [ Estherie | in the Bunter Sandstone near Diirrenberg,
p- 308, pl. ii. figs. 6 and 7.
P. Wengensis, p. 308, pl. ii. fig. 6. Gr. Miinster, Beit. Petrefkd.
iv. p. 28, pl. 16, fiz. 12. Not far from P. minuta, but with fine
radial lines from umbo to border. Wissmann has not noted this [?];
but it is conspicuous as a characteristic [none given in fig. 6; nor
is the size mentioned]. [Some true Posidonomye are then compared. |
P. nodocostata, n. sp., p. 809 (fig. 7), as the other species may be
Konig. geol. Landesanstalt und Bergakademie, Invaliden Str. 44, Berlin.
Prof. T. Rupert Jones— Fossil Estherie. 5d
called, which occurs with P. minuta in two specimens from the
depth of 612 feet in the bore-hole No. 3, near Diirrenberg, is long-
oval in shape; 14” long, and not quite 1” high; convex; rather
smaller in front than behind; ventral border convex; the umbo
distinct and rounded. There are seven radials (three of them in
front, two in the middle, and one behind) reaching the border. An
eighth appears to follow the hinge-line backwards. About sixteen
regular, parallel, concentric lines cross the radials, and lose them-
selves in a series of roundish knots. The shell is very thin, of
a dark horn-colour, quite like that of the associated P. minuta.
The relative size shown by Fig. 6 (about 2 mm., instead of 13 mm.,
4 inch), and the recognition of its alliance to and occurrence with
#. minuta, make it probable that the P. Wengensis of Giebel is an
Listheria, and different from the P. Wengensis of Wissmann, as
intimated by von Alberti.
1864. Dr. F. von Alberti. Ueberblick iiber die Trias, etc., 1864.
(See also Grou. Mac. 1878, p. 102.)
p. 192, note.—Posidonomya Wengensis, Giebel (not P. Wengensis,
Wissmann, which is much larger), may be an Hstheria near
EF. minuta, distinguished by weak radial lines.
p. 193, note.—P. nodocostata, Giebel ; from 192 m. depth in bore-
hole No. 3, near Dirrenberg; long-oval 0-003 m. long, and
0-002 m. high. Probably a crustacean.
P. minuta is a crustacean ; so is probably Posidonia Alberti, Voltz,
probably the same as Posidonomya Germari, Beyrich [Zeitsch. D.
g. Ges. vol. ix. 1857, p. 377].
1875. HE. Weiss. Zeitsch. D. g. Gesellsch. vol. xxvii. 1875,-pp. 711,
C12:
From the Lower Buntersandstein of Diirrenberg on the Saale, in
Saxony, some small shells are described as being in size and condi-
tion like Zstheria Germari of Beyrich, and occurring with it, but
differing from it by having a certain number of riblets radiating
from the umbo, and thus constituting a new type. It is remarked
that Giebel had already described two species from Diirrenberg,
with the names of Posidonomya Wengensis and P. nodocostuta,
which may perhaps be identical with the above mentioned. ‘The
two latter came from a boring; but the foregoing were found in the
shales outcropping between the sandstone on the Saale, in the road
above the Salt-works of Herr Director Metzner, and the bore-hole.
When not well preserved, the valves lose their riblets near the umbo
and on the front and hind borders; but these remain strongest and
most distinct in the ventral region. In good specimens these two
kinds of ribbing are readily recognized ; one kind consisting of about
12 riblets, of which the middle 6-10, very sharply defined and wide
apart, occur on the convex face, and are hollow on the inside of the
valve, as furrows, proportionally distant with smooth spaces between,
broken only by concentric wrinklings. This form may answer to
P. nodocostata, Giebel, which, however, seems to have only 7 riblets.
06 Prof. T. Rupert Jones—Fossil Estherie.
The other species shows very numerous riblets, thickly set, more
particularly towards the front and ventral borders; these are less
sharp, and almost equal in breadth with the spaces between them.
In particularly well-preserved specimens about 30 were counted, in
others 20; but the number is difficult to determine; and we must
recognize the difference of the two forms in the above-mentioned
characters. This second species is evidently the Wengensis of Giebel.
Note at p. 711.—Dr. E. Weiss named the first of the two foregoing
species Hstheriella lineata, and the latter Z. costata; but he had a
doubt about the naming, and thought that these names should be
withdrawn until perfect proof of the difference between his and
Giebel’s species should be arrived at.
Dr. E. Weiss, though inclined to look on these two forms as
belonging to a new genus, thought that it might suffice, with their
great resemblance in general habit to Hstheria, to place the radially-
ribbed shells of Diirrenberg as a subgenus only, with the name
Estheriella.
For the form with about 12 ledge-like riblets (H. lineata, Weiss,
the nedocostata of Giebel), he gives—
mm. Proportion.
—=S>
The height to the breadth (length) = 28:43 = 1: 146
” 55 9p 322) 58423) 9 =) elie
1, ‘, ss 7: 8:6) =a leeice
For the form with over 20 riblets and furrows (£. costata, Weiss,
the Wengensis of Giebel),—
mm. Proportion.
mA
The height to the breadth (length) = 25:38 = 1:15
” ” ” AO 2 PO es is 4
” ” ” 2°33 33 = ie ee
) ” ” 22s ool) lee:
Near Diirrenberg there are other horizons of Estheria. In the
boring they are found at a depth of about 200 metres; near the
Royal Saltworks were found some very small Hstherie (without |
riblets'), also on the left bank of the Saale, some feet below the
first coarse white sandstones of the Middle Buntersandstein, at the
cliff between Graslau and Leina, near Corbeth.
Norr.—E. nodocostata (Giebel) retains its name, the form being
recognized as that which Giebel figured and described in 1857. His
Wengensis, however, is not the Posidonomya so named by Wissmann ;
nor is it from Wengen; and the name proposed by Weiss, namely,
costata (though too near to nodocostata for convenience), should take
its place.
In the “Mémoires du Comité Géologique,” 4to. St. Petersburg,
vol. vi. 1888, P. Kratow describes and figures two small bivalves
with radial striz as Estheriella trapezoidalis, pp. 469 and 507, pl. il.
fig. 27, and E. oblonga, pp. 470 and 557, pl. i. fig. 28 (reaching
1 Fig. 12 of Pl. 11. may be one of these small Zstherie, possibly H. Germari,
Beyrich.
C. Davison—British Earthquakes. 57
5mm. in length), from the Permian beds of Tscherdyn on the
Kolwa, on the western side of the Ural.
EXPLANATION OF PLATE II.
Fic. 1. Zstheria Andrewsti, sp. noy. Left valve of the short form; magn. 4 diam.
ee aD a § Right valve of the long form; magn. 4 diam.
1 Be a * Portion of surface; magn. 50 diam.
apres 3 a Another part of the surface, showing the inside of one
layer, the impression of its outside on the matrix
(dark) ; magn. 50 diam.
» 9. Estheria Hindet, sp. nov. Left valve; magn. 6 diam.
Pea) ap AF Portion of the beaded concentric strie ; magn. 60 diam.
op ae a 5 Portion of an interspace; magn. 50 diam.
op > 3 o Portion of two interspaces; magn. 50 diam.
» 9. Estheriella costata, Weiss. Right valve; magn. 10 diam.
aos AA x a, Part of the inside of a right valve; magn. 10 diam.
b, Portion of the same; magn. 40 diam.
», ll. Estheriella nodocostata (Giebel). Left valve; magn. 10 diam.
» 12. Estheria minuta (Alberti). Possibly 2. Germari (Beyrich) ; magn. 10 diam.
», 13. Estheriella nodocostata (Giebel). «a, Inside of left valve; magn. 10 diam.
6, Portion of the same; magn. 50 diam.
» 14. Estheria minuta, var. Brodieana, Jones. Left valve; magn. 5 diam.
IJ.—On tue British Harruquakes or 1889.1
By Cuartes Davison, M.A.,
Mathematical Master at King Edward’s High School, Birmingham.
| PROPOSE in this paper to write a short account of the earth-
_ quakes that have been felt in Great Britain during the year
1889, and to consider the relations of these earthquakes with the
geological structure of the districts in which they occurred. The
attempt seems to me worth making, for two reasons. The first is
that, though few in number and slight in intensity, the earthquakes
which visit this country are individually and in their connexion
with preceding shocks, of considerable interest. And, secondly, the
accounts, even when published, are widely dispersed, and, appearing
chiefly in local newspapers, become difficult of access in after years.
I believe, therefore, that an attempt to collect and discuss these
scattered observations cannot be without some value.
I will. in the first place, describe the nature of the evidence on
which these accounts are founded. For the two more important
earthquakes, the chief authorities are the newspapers published
within and near the disturbed areas. In a few cases, the notices
they contain are far from satisfactory, and bear obvious signs of
exaggeration.” But, in certain respects, their evidence seems to be
trustworthy ; and, as a general rule, I believe we may rely on them
for a knowledge of the places where a shock was or was not felt, of
the places where it was accompanied by the characteristic earthquake
sounds, and also for a record of the effects of the shock sufficient to
enable us to determine its intensity according to the Rossi-Forel
scale.
1 A paper read before the Royal Society, June 19, 1890, and published in abstract
in the Roy. Soc. Proc. vol. 48, pp. 275-277.
2 For example, the statement that, during the Edinburgh earthquake of Jan. 18,
a boy was thrown out of bed at Gogar, is evidently inaccurate.
58 C. Davison—British Earthquakes.
In many cases, however, this evidence has been supplemented by
inquiries made in the several districts or by letters addressed to the
local newspapers asking for further observations. The accounts
I have thus received, being generally replies to a few definite lead-
ine questions, are often of considerable value ; and I should like to
take this opportunity of again thanking the ladies and gentlemen
who have in this way rendered me such courteous and serviceable
assistance.
In the description of each earthquake, the heading contains its
name and date, the name being taken from that of the district
principally affected by the shock. The time of occurrence is given
in Greenwich mean time, the hours being numbered from 0 to 24.
The intensity is determined by means of the Rossi-Forel scale, a
translation of which is given below. ‘This scale is very generally
adopted by Italian and Swiss seismologists, and, though rough and
undoubtedly variable to a slight extent, is well suited to the nature
of the evidence at our disposal, the range of variability of any degree
of the scale being probably less than the limits of error of ordinary
observations.
Rossi-Forel Scale of Intensity."
I. Recorded by a single seismograph, or by some seismographs of the same model,
but not by several seismographs of different kinds; the shock felt by an experienced
observer.
II. Recorded by seismographs of different kinds; felt by a small number of
persons at rest
III. Felt by several persons at rest; strong enough for the duration or the
direction to be appreciable.
IV. Felt by persons in motion; disturbance of moveable objects, doors, windows,
cracking of ceilings.
V. Felt generally by every one; disturbance of furniture and beds, ringing of
some bells. :
VI. General awakening of those asleep; general ringing of bells, oscillation of
chandeliers, stopping of clocks; visible disturbance of trees and shrubs. Some
startled persons leave their dwellings.
VII. Overthrow of moveable objects, fall of plaster, ringing of church bells,
general panic, without damage to buildings.
VIII. Fall of chimneys, cracks in the walls of buildings.
IX. Partial or total destruction of some buildings.
X. Great disasters, ruins, disturbance of strata, fissures in the earth’s crust, rock-
falls from mountains.
The disturbed area is defined as that at every point of which the
earthquake-shock is felt. The form and position of its boundary
must therefore depend on the practice of observers and on their
power to detect a feeble shock; but, as a knowledge of this boundary
can possess but little value when it does not represent an isoseismal
line, I have endeavoured to draw it on the earthquake maps so as to
pass as nearly as possible through places where the intensity was
the same.
The epicentrum of an earthquake is the projection of the seismic
focus or centrum on the surface of the earth. To determine its
position, three methods have been proposed, depending respectively
1M. 8. de Rossi. Bull. Vulc. ital., anno. iv. (1873), pp. 39-40; F. A. Forel,
Arch. des Sc. phys. et nat., me pér. t. xi. pp. 148-149.
C. Davison—British Earthquakes. 59
on observations of the direction, intensity, and time of occurrence of
the shock in different parts of the disturbed area; but the second
method alone is applicable to the earthquakes here discussed. It
will be seen, on reference to the maps which accompany this paper,
that the isoseismal lines are approximately circles or ellipses of
small eccentricity ; and I have assumed that the epicentra coincide
nearly with the centres of these areas. The correctness of the
oe Dumferm line
Falkirk ‘erolmont
Finlith. /Qourr surly a
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sete
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turn... © + Horperri ,
Hartwood © alan? Goigts RENSES ae AD. Sygend,
Tem ple” NIG dleton
@].amancha sta.
+ Nether Fala Heriot sta.
~Fortmore Ho.
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ee eat ertadteston
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Dolphietow | Se cernetan :
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Fasterknofe.
Edinburgh Earthquake : January 13, 13839.
position so assigned to an epicentrum depends not only on the
accuracy with which the isoseismal lines are traced, but also on a
further assumption that their form is not greatly altered by variations
in the nature of the rocks within the disturbed area. Also, if the
seismic focus, as in the case of a fault, be inclined to the horizon,
the intensity must, ceteris paribus, be greater on the side towards
which the fault slopes; so that the epicentrum is probably nearer the
60 C. Davison—British Earthquakes.
intersection of the focus with the earth’s surface than would be
indicated by the above method. Nevertheless, for the majority of
British shocks, the assumption seems to me admissible, for the
isoseismal lines in all the cases here considered are of small dimen-
sions, and there is no evidence tending to prove any marked irregu-
larity in their form. I believe that the true positions of the epicentra
cannot differ by more than a mile (if by so much) from the positions
indicated for the four principal earthquakes considered in this paper.
In two cases I have attempted to assign the origin of the earth-
quake to the impulsive friction along well-known and prominent
faults. In each case, the evidence, being cumulative and far from
abundant, is by itself certainly not conclusive; and the deductions
made from it can only be regarded as at best but highly probable.
Taken as a whole, however, the reasons for connecting the majority
of non-voleanic earthquakes with such a cause are so weighty, and
the theory is so comprehensive of apparently disconnected phenomena,
that the inferences referred to are invested with a higher degree of
probability than that with which they would otherwise and separately
be endowed.*
The slow dying-out vibrations of very distant shocks are frequently
propagated to this country, and are registered by magnetic and other
recording instruments. More rarely are felt the perceptible vibrations
of earthquakes that are less distant, but still extra-British, in their
origin, e.g., the earthquake of May 30, 1889, which disturbed the
Channel Islands, the South of England, and the North of France.
To include either kind of shock would unduly extend the limits of
_ this paper, and I have therefore confined myself to the consideration
of earthquakes whose epicentra are situated within the area of the
British Islands.
Of these, there were at least five during the year 1889; namely,
on Jan. 18 in the neighbourhood of Edinburgh; on Feb. 10 in
Lancashire and parts of the adjoining counties; on May 22 on Ben
Nevis; on July 15 in Kintyre, Gigha Island, and Arran; and on
October 7 in the east of Cornwall. In addition to these, there were
three others, the seismic origin of which is at present doubtful, or
which rest on the evidence of one observer only.
1. EpinpurcH HarruquaKkes: Jan. 18, 1889.
At least two shocks were felt at, and in the neighbourhood of,
Edinburgh on this day, the first at about 4h. 10m., and the second
at 6h.538m. The time of occurrence of the former is variously given,
but, as a rule so approximately, that it is very doubtful whether the
existence of several separate shocks can be inferred. This may have
been the case, but I do not think that the evidence is sufficient to
prove that there was more than one shock preceding that which took
place at 6h. 53m.
1 It may be well to remark here, that, excepting the sections on the geological
relations of the earthquakes, the following accounts were almost entirely written,
the isoseismal lines were drawn upon the maps, and the positions of the epicentra
determined, before any reference whatever was made to the geological maps of the
disturbed areas.
C. Davison—British Earthquakes. 61
First Shock.
Time of occurrence, about 4h. 10m.; Intensity, about V.
Very few observations were made on this shock, and I have only
met with one detailed account, which I owe to the kindness of a
correspondent in Edinburgh. It is impossible, therefore, to deter-
mine the boundary and extent of its disturbed area or the position of
-its epicentrum.
The only records I possess of this shock are from Edinburgh,
Broomieknowe, Penicuik, and Bellsquarry ; and these are all within,
and several miles from, the boundary of the disturbed area of the
second shock.
The recorded times of occurrence are: Edinburgh, about 2h.,
about 4h., and at 4h. 10m.; Broomieknowe, about 2h.; Penicuik,
about 8h. and about 4h. 50m.; and Bellsquarry, at 5h. Most of
these seem to be mere guesses. I have selected 4h. 10m. as probably
the most correct time. It was obtained by reference to a clock
almost immediately after the event, and was given to me by the
correspondent mentioned above, who also estimated the time of the
second shock as about 6h. 50m.
The intensity was probably about V.; but this estimate must be
regarded as doubtful, as it is made from only one observation, and
this at a place which may have been some distance from the
epicentrum. At Hdinburgh, my correspondent informs me, it was
strong enough to make the bed rock: ‘‘ the bed-room door shook, its
handle rattled briskly and noisily and forcibly, and the glass above
shook also.”
A rumbling sound was heard at the time of the shock at Edinburgh ;
and at Broomieknowe a hollow noise was heard, but the shock itself
is not recorded as having been felt there.
Second Shock.
Time of occurrence, 6h. 58m. ; Intensity, VI.; Epicentrum, about
3 miles W. 42° 8. of Balerno.
Disturbed Area.—The evidence for the study of this earthquake
is much more abundant. I have altogether 93 independent observa-
tions, made at 55 different places. A large number, however, are
from Edinburgh, and the rest, unfortunately, are not very evenly
distributed over the disturbed area. On this account, the south-west
portion of its boundary can only be drawn approximately.
An excellent account of the earthquake was given in the
“Scotsman” for the following day, butin this attention was naturally
directed chiefly to the places where the more striking phenomena
were observed. With hardly an exception, the local newspapers
fail to supplement this evidence as regards the limits of the dis-
turbance; and I have therefore been obliged to rely principally on
the accounts given to me by correspondents, and these, though of
great value, are of course not numerous. With reference to the
southern part of the area, however, the case is very different. For
all the evidence from this part of the district, 1 am indebted to the
62 C. Davison—British Earthquakes.
kindness and courtesy of Dr. C. B. Gunn, of Peebles who, at the
cost of much time and trouble, sent me a report on the observations
of the earthquake made in and near the north of Peeblesshire. I
shall have occasion to refer again to this report, the value of which
it would be difficult to over-estimate.
The outline of the disturbed area as drawn upon the accompanying
map, is slightly elliptical in form. How far this outline may be
considered as accurate will be partly evident from an inspection of
the map, on which all places at which the shock was certainly felt are
marked with small black discs, and those where there is good reason
for believing that it was not felt with small crosses (+-)." There can
thus be little doubt about the form of the boundary from the neigh-
bourhood of Polmont, by Dumfermline, Burntisland, Musselburgh,
and Tynehead station, to Peebles; but, for the rest of the area, its
course is less certain. J have made several inquiries in this part of
the district, but entirely with negative results. From the intensity
of the shock at the nearest places at which it was felt, I do not think,
however, that the form of the boundary can differ very greatly from
that laid down on the map, unless, owing to peculiar local conditions,
the earth-vibrations were quenched more rapidly in the south-west
quarter than elsewhere.
The disturbed area as thus defined is about 30 miles from north
to south and 264 miles from east to west, and contains an area
(including the part occupied by the Firth of Forth) of about 830
square miles. Its boundary corresponds to an isoseismal line of
intensity less than V., but decidedly greater than TV. The centre
of the curve is about 3 miles W. 42° S. of Balerno.
It is worthy of notice that in Edinburgh, where the intensity was
V., the shock was not felt by any one on the Castle Hill, nor at
the Observatory on Calton Hill. The geological structure of the
district may also account for the shock not having been felt at
Inchkeith, and not having been recorded as felt within a large part
of the area occupied by the Pentland Hills.
Time of Occurrence.—Omitting all confessedly approximate deter-
minations of the time of occurrence, the following definite records
have been made: Hdinburgh, 6h. 50m., 6h. 52m., and 6h. 54m.
or 6h.55m.; Penicuik, 6h.52m.; Leith, 6h. 58m. 15s: + 10s. ;
Trinity (near Leith), 6h. 54m. + 4m.; Harperrigg and Peebles,
6h. 55m. These estimates, with one exception, are not exact
enough to be used for ascertaining the velocity of the earth-wave or
the position of the focus. Probably the most correct of these times
is that given for Leith; it was determined by Mr. G. Redpath. “TI
immediately turned round,” he says, ‘and noted the time, which I
found was 53 minutes 15 seconds past six by a clock in my sitting-
room. On going to verify it by an astronomical clock in another
room, I found to my regret that I would have to allow a margin of
about ten seconds—earlier or later.” This is sufficient, however,
1 To the south of Peebles, owing to the small scale of the map, I have been
obliged to omit the indication of a number of places where, as Dr. Gunn’s inquiries
show, the shock was not felt.
C. Davison—British Earthquakes. 63
to determine the epoch of the shock. I have given it as 6h. 53m.,
but, as Leith is about 12 miles from the epicentrum, it may have
been a few seconds earlier.
Nature of the Shock.—For descriptions of the nature of the shock,
I have to rely chiefly on newspaper accounts, and these, as a rule,
are far from being either exact or detailed.
In most parts of the disturbed area, it would seem that the shock
was noticed as a single oscillation, the observers in some cases feeling
as if the bed or chair on which they rested were slightly raised and
then lowered. A few compare the sensation to that of passing over
a wave in a small boat.
From at least five places, however, there come accounts of a
second oscillation immediately following the first; as if there were
two prominent vibrations, while the commencing and concluding
tremors were generally imperceptible. These places are Edinburgh,
Leith, Ratho, Balerno, and Peebles. But it should be noted that all
observers at these places did not detect the second oscillation; and
this was probably owing to the latter being, as one observer at
Edinburgh states, slighter than the first. At Balerno, again, it was
remarked that, though both movements were momentary, the second
was the more lasting of the two.
There is only one other noteworthy point that I can gather from
the somewhat scanty descriptions. In all the instances, but one, in
which the character of the movement is recorded, the oscillation is
described as arise of the ground, followed by a fall. This is the
case at Hdinburgh, Balerno, Trinity (near Leith), Davidson’s Mains,
Linlithgow, and Polmont. On the other hand, at Penicuik, a
“ workman, who happened at the moment to be seated, felt the brick
floor recede from his feet, and then, as it were, return to them.”
Now, the six places just mentioned are in the northern part of the
disturbed area; whilst Penicuik is a short distance to the east of
the epicentrum. I shall recur to this point in discussing the origin
of the earthquake.
Duration.—Records of the duration come from seven places, and
range from not greater than one second (at Davidson’s Mains), to
about two seconds (at Edinburgh, Trinity, Leith, and Penicuik),
and about three seconds (at Balerno and Kirknewton). Probably
some of the estimates of the duration also include that of the sound-
phenomena ; but, in either case, they seem to indicate a decrease in
duration as the disturbance radiated from the origin.
Intensity.—The following list gives the intensity of the shock at
places where the accounts were sufficiently detailed for its
determination.
VI. Balerno, Currie, Harperrigg.
Y. Bellsquarry, Corstorphine, Davidson’s Mains, Eddlestone,
Edinburgh, Gogar, Hartwood, Juniper Green, Kirknewton, Leith,
Linlithgow, Penicuik, Ratho.
IV. or V. Bathgate, Polmont.
IV. Burntisland, Causewayend, Cockburn, Dumfermline, Eskbank,
Peebles.
64 C. Davison— British Earthquakes.
These observations are not sufficiently numerous to enable isoseismal
lines to be drawn with any accuracy. But it is evident that the
isoseismal of intensity V. could not be very distant from the boundary
of the disturbed area, as drawn upon the map. We may therefore
conclude that this boundary corresponds to an isoseismal of intensity
between IV. and V., and probably nearer V. than IY.
Sound-phenomena.—All the places where the characteristic earth-
quake-sounds are known to have been heard are marked on the map
with a’small cross (+) through the spot indicating the position of
the place. They are unfortunately very few in number, only 19 out
of the 53 places from which records have been received. But, on
the other hand, there are several places where the shock was felt,
and where it is expressly stated that no sound was heard. These
are Leith, Trinity, Burntisland, and Polmont, and they are indicated
on the map by a stroke (—) drawn through the spot representing
the place. It is also important to note that, whilst records from
Edinburgh (where the intensity was V.) are numerous, 28 in number,
in only two cases is there any mention made of earthquake-sounds.
Again, at Peebles (where the intensity was IV.) out of four separate
accounts which Dr. Gunn sent me, two are records of the sound-
phenomena only, the shock being apparently not felt in these cases.
From these facts, two conclusions may be drawn:
(1.) The area throughout which the sounds were heard was not
coextensive with the disturbed area; a fact previously noticed in the
case of other earthquakes.
(2.) The centre of the sound-area was not coincident with that of
the disturbed area, but lay probably about 24 miles to the south or
south-east of the latter. It will be seen that a similar inference
may be made in the case of the Lancashire earthquake of Feb. 10.
I believe that this conclusion is new, and will be found to throw
light on the origin of earthquake-sounds.
In their character the sounds accompanying the Edinburgh
earthquake do not seem to have been in any way unusual. The
following are the only detailed descriptions I possess :
Balerno: like the falling of a heavy mattrass.
Bathgate: as if a heavy waggon had passed along the street.
Cockburn : as though a large tree had fallen near the house.
Edinburgh: (1) like the rumbling of a passing coach; (2) a
loud sharp crash, as if the door had been slammed in an extraordinary
manner.
Harperrigg: like the firing of a time-gun twice, accompanied
with an oscillation.
Kirknewton : a loud clanking noise.
Linlithgow : a suppressed rumbling sound.
Peebles: like the passing of a heavy cart.
Ratho: like the passing of a heavy traction-engine.
Tn every place the duration of the sound seems to have been very
short. This is evident from some of the above accounts, and
probably, as before remarked, the duration of the sound is included
in the estimates of the duration of the shock given above. ‘The
C. Davison—British Earthquakes. 65
sound is generally said to have accompanied the shock, but this is a
vague expression. Probably it overlapped the shock slightly at
either end; at different places in and near Peebles, Dr. Gunn informs
me that it was said in one case to precede the shock, in two to follow
it, and in one to both precede and follow it.
Position of the Seismic Focus and Geological Relations.—The faults
of the Edinburgh district ‘group themselves naturally into two
series, one more or less at right angles to the strike of the beds, that
is, east and west, or from south-east to north-west; the other usually
of greater magnitude, in long parallel north-east and south-west
lines.” The latter faults ‘lie almost wholly along the axis of the
Pentlands. In place of cutting across the strike of the country as
the other faults do, they run parallel to it. Flanking each side of
the anticline, their effect has been to depress the Carboniferous strata
against the older rocks of the hills, so that on the west side their
downthrow is to the west, and on the east side to the east.” Of
these main faults, which are four in number, three are shown on the
accompanying map of the Edinburgh earthquake. The first of these
(marked AA on the map) extends from the sea at Portobello to
beyond Carlops in Peeblesshire ; its downthrow is to the south-east,
and the amount of the throw in parts probably not less than 3000 feet.
The second fault (BB) reaches from the head of the Logan valley to
North Black Hill, where it seems to die out. The third fault (CC)
extends in a wavy line from Arthur’s Seat, near Edinburgh, to the
neighbourhood of Bevelaw ; but in certain parts its course is some-
what doubtful. The downthrow of the two latter faults is to the
north-west, but the amounts of their throw are unknown.!
Now, the centre of the disturbed area, as indicated on the map,
lies about 3 miles W. 42° 8S. of Balerno; and this, as before remarked,
may be regarded as the approximate position of the epicentrum,
which is therefore to the north-west of all three of the faults. The
earthquake cannot, then, have any connexion with the first of these
faults. From the line of the third fault (CC), the perpendicular
distance of the epicentrum is about 14 miles. The shock might ap-
parently have been caused by a slight extension of the fault towards
the south-west, or by a slip of the fault, supposing it to extend
underground far enough in this direction. But, unless we assume
that the earthquake originated at one fault, and the earthquake-
sounds at exactly the same moment at another, it does not seem
possible to connect the earthquake with this fault; for the centre of
the sound-area lies about two or three miles to the south or south-
east of the epicentrum, and therefore to the south or south-east of
the line of fault at the surface.
Turning next to the second fault (BB), we find the perpendicular
distance of the epicentrum from the line of fault at the surface is
about 24 miles; and this would admit of the sound-focus being on
the fault-plane, but probably close to the surface. It does not seem
1 H. H. Howell and A. Geikie, Geology of the Neighbourhood of Edinburgh,
pp. 118-119.
DECADE IfI.—VOL. VIII.—NO. Il. o)
66 C. Davison—British Earthquakes.
unreasonable to infer, then, that the Edinburgh earthquake was in
some way connected with this fault.
Tf the inclination of the fault were known in the neighbourhood
of the epicentrum, this would enable us to determine approximately
the depth of the seismic focus, assuming the inclination to be con-
stant to a depth of a few miles below the surface. The exact incli-
nation is, however, unknown; but Prof. J. Geikie informs me that
it ‘cannot be less than TU°—80° from the horizontal, say, about 15°
from the vertical.” If this be the case, then, the depth of the centre
of the seismic focus is not much less than 6 miles, nor much greater
than 123 miles, and perhaps does not differ considerably from 82
miles.
The bearing of the observations made on the first direction of
motion of the principal vibration will now be obvious. The six
places (Edinburgh, Balerno, Trinity, Davidson’s Mains, Linlithgow,
and Polmont) where the movement was first upward, lie on the
downthrow side of the fault. whilst Penicuik, where the movement
was downward first, is on the upthrow side. Now, if the mass of
rock on the downthrow side slipped slightly downwards, or if the
mass on the upthrow side slipped upwards, the particles on the
downthrow rock-face would be drawn upwards first, and those on
the upthrow rock-face would be drawn downwards. The earth-
wave or the rock-masses on either side of the fault would thus start
in opposite phases of vibration, and the resulting effects at the seven
places on the surface would be those described above.
I believe we may, then, with some probability, conclude: (1)
that the Edinburgh earthquake was caused by a slip of the fault
marked BB on the map, at a spot vertically below the position
indicated for the epicentrum, and therefore not far from the middle
of the fault, where, probably, the throw is a maximum and where
earthquake-action has been most frequent or most intense; (2) that,
on account of the simple character and short duration of the dis-
turbance, the horizontal length of the fault over which the slip took
place was very short, possibly less than a mile; (8) that the slip of
the downthrow side was downwards or that of the upthrow side
upwards, resulting, in either case, in an increase of the throw of the
fault in the neighbourhood of the seismic focus; and (4) that, while —
the region of maximum slip, the focus of the earthquake proper, was
probably at a depth of several (perhaps about 8) miles, the slip
extended upwards to within a short distance of the surface, this part
of the slip-area being the focus of the sound-vibrations. This latter
conclusion will be considered somewhat more fully in treating of
the Lancashire earthquake, and at greater length in a subsequent
paper.
‘When we reflect,” says Dr. A. Geikie, ‘upon the extent of
depression produced by these faults, we see at once that the Car-
boniferous rocks must formerly have stretched across the area of the
Pentland Hills, and that it is to the agency of these dislocations,
1 On the Existence of Undisturbed Spots in Earthquake-shaken Areas, GxoL.
Mae. (April, 1886), Vol. II]. pp. 157-159.
J. W. Evans—Apparatus for Isolating Minerals. 67
aided subsequently by an extensive denudation, that the older rocks
of that chain are visible.”! The Pentland faults have thus played
an important part in the past history of the district. But their
work is not yet finished, and the occurrence of the Edinburgh
earthquake shows that the process of geological change is still being
carried out on the same lines as before. It remains for future earth-
quakes to enable us to determine the laws which govern these
changes and the rate at which they are now taking place.
Authorities.—“ Dalkeith Advertiser,” Jan. 24; ‘* Dumfermline
Journal,” Jan. 26; “ Falkirk Herald,” Jan. 19; ‘Lanarkshire
Examiner,” Jan. 26; ‘ Peeblesshire Advertiser,” Jan. 26 ;
“Scotsman ” (Hdinburgh), Jan. 19, 21, 22, 23, 25, and Dec. 28;
“West Lothian Courier” (Bathgate), Jan. 19 and 26.”
For other information contained in the above account, I have
pleasure in thanking the following gentlemen: Mr. J. Aitken, F.R.S.,
Prof. R. Copeland, F.R.S.H., Dr. G. Craigie (Musselburgh), Mr. W.
Dick (Tynehead Station), Dr. John Doig (Bathgate), Prof. J. Geikie,
F.R.S., Dr. C. B. Gunn (Peebles), and the Rev. W. Ross (Polmont) .
(To be continued.)
IiL.—-Awn Inexprenstve APPARATUS FOR THE ISOLATION OF MINERALS
BY Means oF Heavy Lieuips.®
By J. W. Evans, LL.B., B.Sc., F.G.S. ;
Demonstrator in Geology, Royal College of Science, London.
AM aware that in describing a new apparatus for separation
by heavy liquids, 1 am adding another item to a list which is
already a very long one. My only excuse is that this particular
form has the advantage of being easily and cheaply constructed from
ordinary chemical apparatus, and yet has most of the advantages of
Thoulet’s* comparatively expensive form.
The construction and use will be best explained by means of the
accompanying drawings.
A is a cylindrical funnel. The conical portion connecting the
upper cylinder with the narrower cylinder or tube below, should be
as steep as possible, otherwise a little trouble is occasioned by par-
ticles adhering there.
The funnel is closed below by means of a piece of india-rubber
tubing and pinchcock. It may be supported on an ordinary wooden
filter stand.
1 Geol. of the Neighbourhood of Edinburgh, p. 120.
2 The following papers contain descriptions of the Edinburgh earthquake :—A. G.,
The Karthquake at Edinburgh, Nature (Jan. 31, 1889), vol. 39, pp. 324-325. R.
Richardson, On the Earthquake Shocks experienced in the Edinburgh District on
Friday, January 18, 1889 (read before the Edinburgh Geol. Soc. on Feb. 21, 1889),
** Scottish Geographical Magazine” for March, 1889.
3 A short notice of my apparatus in its simplest form will be found at p. 108 of
the interesting and valuable Manual by Professor Cole, of the Royal College of
Science, Dublin, entitled, “Aids to Practical Geology,’’ which has just been
published.
* Bull. Soc. Min. de France, t. ii. (1879) p. 17.
68 J. W. Evans—Apparatus for Isolating Minerals.
B represents a long glass tube (b,) passing through the centre of
a cork. At the lower end the tube is brought to a blunt point, in
which is a minute aperture. After being drawn out to a point, the
end must be carefully heated again so as to thicken the glass round
the hole without closing it entirely. Unless this is done, the point
of the tube is apt to break off. This tube can be closed above by
india-rubber tubing and a short piece of glass rod. The cork is also
perforated (as shown) by another tube (b,), which can be closed in
a similar manner.
mm,
Scale of Centi metres .
The liquid and the material to be operated on are placed in the
funnel. When the first separation has taken place, the apparatus B
is inserted, the point of 6, should reach down close to the pinchcock.
b, is left open at the top, and }, is connected with an air-pump,
which should be very cautiously worked and the pressure diminished
so that a gentle stream of bubbles passes from the opening at the
end of 6,. The particles are thus thoroughly shaken; the lighter
fragments that have been carried with the heavier, or vice versd, are
disengaged.
The upper end of 6, is now closed and the air is exhausted so as
to get rid of any air attached to the grains. The apparatus may
then be separated from the air-pump by compressing the india-
rubber tube attached to b, and at the same time disconnecting the
J. W. Evans—Apparatus for Isolating Minerals. 69
end and inserting the piece of glass rod. After the lapse of some
time air is re-admitted through 4,.
The above processes may be repeated several times, if thought
necessary ; to more thoroughly shake the lighter fragments, the
tube 6, may be raised till the end is only just below the liquid.
If an air-pump is not available, the air may be withdrawn by the
lungs, but the effort to overcome the weight of the column of liquid
is apt to render the passage of air rather violent. The tube 6, may
also be used (without the cork) to agitate the lighter layer by gently
blowing just below the surface; or to disturb any fragments resting
on the conical part of the apparatus, which may be best. done by
drawing up a portion of the liquid and then letting it descend from
the tube close to the fragments to be moved ; but it is safer to use a
pipette for this purpose.
A few lighter particles may adhere to the tube as it is removed ;
if it is desired not to neglect these, they may be washed back by
liquid of the same density.
In order to draw off the heavier particles, the apparatus C and D
is used. Cis a thistle-tube perforating a cork, and having at the
lower end a piece of india-rubber tube (c;) of less diameter when
unstretched than C. The india-rubber at the end of C fits tightly
into the top of the narrow portion of A. JD is a glass rod brought
to a conical point at the lower end. Insert it in C so that the end
projects some distance beyond the india-rubber ¢,, in which it should
fit tightly. The whole is then inserted in the funnel. If this is
done skilfully, few (if any) of the lighter particles are carried down
with it, as the conical end of the glass rod causes a centrifugal
movement at the surface as it passes down. To remove any that
may have descended, adjust the cork so that the india-rubber is a
little above the narrow portion of the funnel ; a little movement and
the lapse of a few minutes will be sufficient. If any particles are
caught by the lower end of the india-rubber ¢, they may be dis-
placed by an up-and-down movement of the rod D relatively to C.
Now depress C so as to fit tightly in the narrow portion of the
funnel, tighten the cork, withdraw the rod D, and open the pinch-
cock; the lower part of the liquid falls with the heavier fragments
into a beaker; the tube is then thoroughly washed clear of all
residuary particles by a stream of distilled water poured into the
cup of the thistle-tube C.
After letting the tube drain till nearly free from water, the pinch-
cock having been closed, and the tube C removed, the density may
be lowered for another separation; this is best done by gradually
adding the diluting fluid through 6, or a similar tube, the small
aperture being at the bottom of the narrow portion of the funnel.
The thin stream of lighter fluid easily mixes with the heavier as
it rises, especially if the tube is being gently agitated.’
1 J have not arranged for the calculation of density from the volumes used.
If required, the apparatus could be graduated (being heightened if necessary).
Practically it is better to dilute with a solution only slightly lighter till separation
takes place and then determine the density by one of the usual methods.
70 R. D. Oldham—Essays in Theoretical Geology.
The above form is adapted for use with Klein’s solution (Boro-
tungstate of Cadmium), which has been found the best for practical
use for densities below 38-28, as it has not the highly poisonous
character of the Sonstadt solution (potassium iodide and mercuric
iodide) and does not decompose and discolour so easily as methylene
iodide. Above 3-28, methylene iodide, with or without the addition
of iodoform (as proposed by Retgers),’ must be used. Here, as the
use of india-rubber is inadmissible, the pinchcock must be replaced
by a glass tap (but the bore need not be the same as that of the glass
tube, as is usually necessary in apparatus of this nature); and
instead of using the india-rubber ¢,, the end of the thistle-tube C
and the base of the conical part of the funnel must be ground so
as to fit one another, and the rod D must closely fit the tube. |
The tube C has some external similarity to the plug used in the
useful apparatus devised by Mr. Smeeth;* but there the plug is not
perforated, and there is no resemblance in the mode of action of the
two forms.
I ought to add that all my work with heavy liquids has been
carried on at the Royal College of Science, where Professor Judd
has kindly given me every facility in my endeavours to find the best
practical form of instrument neither too expensive nor too delicate
for students’ work.
1V.—LHEssays 1n THEORETICAL GEOLOGY.
By R. D. Otpuam, A.R.S.M., F.G.S.,
of the Geological Survey of India.
Tur AGE AnD Ornicin oF THE Himatayas. witH EsPEcIAL REFER-.
ENCE TO THE Rev. O. Fisuer’s Turory oF Mountain ForMATION.
The Facts (continued from p. 18).
HAVE already shown that the northern boundary of the Indo-
Gangetic alluvium is a structural one, and that the rock area
immediately to the north of it has been elevated, while the nature of
the boundary on the south, the deep imbayments of the alluvium,
the gentle manner in which the older rocks slip under it, and the
inliers, alike show that, on the south, the alluvium has gradually
encroached on the rock area by the subsidence of the latter.
I have also shown that at one period the present demarcation
of the Peninsular and Extrapeninsular areas did not exist, and that
the latter extended across the area now occupied by the Gangetic
alluvium into what is now Sikkim. From this we may conclude
that during the rise of the Himalayas the formation of the depression
now occupied by the alluvial deposits of the Indus and Ganges
has proceeded, and that, just as its northern boundary has been
encroached upon by the gradual southward extension of the Himalayan
region, so it has itself encroached on the rock area to the south,
and necessarily at a greater rate.
1 J. W. Retgers, Neues Jahrbuch, 1889 (2), p. 185.
* Scientific Proceedings of the Royal Dublin Society, vol. vi. (new series 1888),
p. 58. ;
R. D. Oldham—Essays in Theoretical Geology. (a!
If this hypothesis is true, the sections of deep borings near either
limit of the alluvium should show diverse results as to the relative
proportion of fine to coarse-grained deposits near the surface and
further down. On the north, the southward march of the edge
of the hills would lead to coarse-grained deposits extending over
finer, while near the southern margin the increasing distance from
the edge of the rock area should lead to fine-grained deposits being
laid down over coarser.
The deep borings, which have been put down in the Gangetic
alluvium, are few in number, and, except two, are not well situated
for testing the hypothesis.
The first of these is the boring made in Fort William, Calcutta,
in 1836-38. In discussing this and the other borings I shall adopt
the method of classifying the beds passed through as “sand” and
“clay.” A more perfect classification is impossible, owing to the
vagaries of nomenclature indulged in by the men, never trained
geologists, to whom the sinking of the borings must necessarily
be entrusted. By classifying “sand,” ‘coarse sand,” “clayey
sand,” etc., as sand; and “clay,” “silt,” “sandy silt,” ‘“limey
silt,” ete., as clays, we shall get a very fair general idea of the
relative coarseness of grain of the beds passed through in different
parts of the same boring.
Adopting this system of classification, we may make an abstract
of the Fort William boring?! thus :—
ft. ft. sand clay
OCO RO OF es eceetecis ) sao0anccoode 100
TOO. i) 200 eeeecasce's I Mier anesscecas 89
ZOO. G55 BOW Gahosusoocse OX) cosacnesoane 5
SOOM 400K tebe. bo. O18} inscd000d0n00 2
AQ iy ASI d -ces-ebsinase GIL odboaeocece 0
The increase in coarseness of grain of the beds passed through is
conspicuous enough in this abstract, but the reality is even more
striking, for, in the sand from 180 feet downwards, some beds of
gravel and pebbly sand are included, and the boring was finally
brought to a standstill in a bed of gravel which it was not found
possible to penetrate.
The second boring of importance is that made at Umballa.?
Adopting the same broad classification of clay and sand, we get the
following result :—
ft. ft. sand clay
OO MOO goddsaddoone SO tae A aa apps 37 soil 4
TOO Mice PAOM A aeacsaeseas INOS ta ahcaae cocen 42 kunkur 2
POON Ve) NE00N Tete ate BSU Wa es 42
BOO iy 00) aD, BE Nae .. 46
AQOM ES 2000) Pes aoe. AO BA nReSaReOOO 54
BOOM ML GOO Eunos Sy lianear seu one etc 63
GOO) OL 2s ee GOV RA A 95
Here we have, as the hypothesis requires, a very distinct increase
1 For detailed section see Rec. Geol. Sury, Ind. vol. xiv. p. 221 (1881); Cale.
Journ. Nat. Hist. vol. i. p. 324 (1841).
2 Rec. Geol. Surv. Ind. vol. xiv. p. 233,
72 R. D. Oldham—Essays in Theoretical Geology.
in coarseness of texture in the upper beds as compared with the
lower.?
Besides these two borings, one has been put down at Agra, the
evidence of which is slightly vitiated by the peculiar local conditions,
The abstract of the section is as follows ;?—
ft. ft. sand clay kunkur
Dw LOO sscocesse GH) so0c00000 GID) go0000000 0
MOO HOO Vsosoecn ie ew ates SO yee 0
HO 45 WO. csosssocn Oe Sees ss Qh
BOO 54 ROO! sssocsnnn 1 eee ay Touma 5d
ADO CART Tie ae Ee art Le 0
Here there would seem to be an increase of coarseness of texture,
both upwards and downwards, from 200 feet. The explanation of
this, I apprehend, is to be found in the fact that the surface deposits
round Agra are largely composed of blown sand; and it is probable
that the sand beds found in the uppermost 160 feet of the section are
of zeolian origin, while below that the beds are alluvial and exhibit
the gradual upward increase in fineness of texture required by the
hy pothesis.
A fourth boring has lately been sunk to a depth of 1336 feet
at Lucknow. As might be expected from its situation, “there is
no marked increase or decrease in the coarseness of the beds passed
through; but, near the bottom of the boring, some beds of coarse
sand were found, and these may indicate an approach to the base
of the alluvium and mark a time when its southern boundary was
not far from Lucknow.”
To sum up, of the four deep borings which have been made,
two are completely in accordance with the hypothesis; one is in
favour of it, though its evidence is vitiated by peculiar local condi-
tions ; while the fourth is so situated as to give no evidence one
way or the other till it is carried to a greater depth. Stronger
proof is at present impossible, and we may accept the hypothesis
as a true one.
To summarize the history of the Himalayas as revealed by their
geology, we find that at the commencement of the Secondary period
the Himalayan system of disturbance had not commenced; that,
some time towards the end of the Secondary period, it originated
near the middle of the range and gradually extended outwards,
reaching the country now accessible to observation in the North-
western portion of the Himalayas, about the commencement of the
Tertiary period; that the beds had, at this epoch, undergone but
* On a former occasion (Rec. Geol. Surv. Ind. vol. xviii. p. 118) I was misunderstood
when urging this argument; it was pointed out that Umballa is peculiarly situated
in an area which receives no coarse deposit ; that, at an equal distance from the foot
of the hills, large boulders were found in the foundations of the railway bridge over
the Jumna ; and it was urged that the section was consequently irrelevant. Owing
to this I must here point out that the argument is by no means affected by the
greater or less average coarseness of texture of the deposits on other sections, as it
only claims that on any individual section near the northern limit of the plains the
beds near the surface will, on the average, have a greater coarseness of texture than
those which underlie them.
* For detailed section see Rec. Geol. Sury. Ind. vol. xviii. p. 121.
R. D. Oldham—Essays in Theoretical Geology. 73
little disturbance and contortion, while such compression as they
had been subject to did not belong to the Himalayan system of
disturbance. From this time onwards the beds have been con-
tinuously subject to compression, contortion, disturbance and elevation,
and the Himalayas have been continuously an area of denudation.
As soon as the Himalayas were defined as a distinct hill range,
a series of subaerial deposits of great thickness began to be deposited
in a region of subsidence along their outer edge, and the demarcation
between the areas of subsidence and deposition on the one hand,
and of elevation and denudation on the other, was abrupt, exhibiting
itself at the present day as a gigantic fault. As the Himalayas rose, -
the boundary between the two areas advanced step by step to the
southwards; the beds which had been deposited along the foot of
the original hills were compressed, disturbed, elevated, and, con-
sequently, exposed to denudation; but the new limit between the
area of elevation and of depression was again an abrupt one, which,
on a subsequent further advance of the hill area, showed itself as a
fault with an upthrow towards the central range. Concurrently with
this southward march of the margin of the Himalayas, the depression
occupied by the Indo-Gangetic alluvium extended itself to the south-
wards by the gradual subsidence of the peninsular rock area.
Such are the main features of the history of the Himalaya. As
I have shown, there have probably been minor elevations of the
range unaccompanied by disturbance; but, in the main, its elevation
is the direct result of, and has been accompanied by, compression
and contortion of the beds of which it is composed.
I1.—The Theory.
It is now generally admitted that the elevation of what may be
called true mountain ranges is but a secondary effect of that com-
pression which their structure shows they have undergone. There
is also a general concensus of opinion in favour of the Herschel-
Babbage doctrine that denudation and elevation, deposition and
subsidence, are closely connected with each other, at least in so far
that denudation acts in intensifying the effect of the causes which
lead to elevation, and deposition of those that lead to subsidence.
The most recent and complete adaptation of this doctrine to the
theory of mountain formation is contained in the Rev. O. Fisher’s
work on the “ Physics of the Harth’s Crust.” Mr. Fisher’s hypo-
thesis demands a solid crust resting on a denser magma, whose
condition is actullay or virtually that of a fluid. The crust, on being
subjected to compression, yields along certain lines and as a result
is thickened, both upwards and downwards, from a zone somewhere
in the thickness of the crust “above which the material will on
the average be sheared upwards, and below it downwards ;” this
zone is called the “neutral zone,’ and, for reasons which it is
needless to enter into here, is placed at three-fifths of the thickness
of the crust from its upper surface."
As, for many reasons, it is highly improbable that the elevation
1 Physics of the Earth’s Crust, second edition, pp. 183-184.
74 R. D. Oldham—Essays in Theoretical Geology.
would be perfectly symmetrical, we may assume that the watershed
would be nearer one side than the other, and, consequently, a larger
amount of debris removed by denudation would be deposited on the
opposite side of the ridge, with the result that the centre of gravity
would be shifted towards that side on which the greater quantity of
sediment is deposited, that is, to the right of the diagram, Fig. 1.
In this state the centres of gravity and of flotation, are no longer
in the same vertical, and equilibrium is only restored by a rotation of
the disturbed tract accompanied by an extension of the depression
to the right and a diminution and ultimate extinction of that to the
left. Along with this rotation there would be a general shifting of
the tract to the right, which would expose the left-hand side to
tension, “‘which may possibly open fissures downwards on the
western side of the range.”
Fic. 1.—Fisher’s Physics of the Earth’s Crust. Diagram on p. 186. 2nd edition.
Fic. 2.—Diagram to illustrate the theory of the elevation of the Himalayas.
scale: hor. about 60 miles, vert. about 30 miles to 1 inch,
A.—Massif of the Himalayas.
B.—‘ Root ”’ of the same.
C.—Karlier marginal deposits, compressed and elevated.
e.—Continuation of the same, depressed and undisturbed.
D.—Subsequent deposits overlapping C.
b.—Sinking of lower surface of crust due to C and D.
The extinction of the Nummulitic sea of the central Himalayas
and the great volcanic outbursts which accompanied it may represent
the extinction of the depression on the left-hand side of the diagram,
but the greater part of the elevation of the Himalayas having taken
place since this, we are at once encountered by the difficulty that
the hypothesis requires a rotation of the whole of the Central Asian
plateau. We have no reason to suppose that so large a mass of the
earth’s crust would havea rigidity sufficient to allow of its rotation
as a whole; on the contrary, there is every reason to suppose that
it would yield infinitely to any long continued stress. In Mr.
Fisher’s investigation it is, however, assumed that all lateral pressure
is relieved before the action of denudation commences. Such a
simplification of the conditions is essential to a mathematical in-
vestigation; but as in the case of the Himalayas the compression
has lasted up to the recent period, while there are not wanting
indications that it is still in progress, we may take it that the
state of things which the latter part of Mr. Fisher’s investigation
deals with has not yet been reached, and we may consequently
neglect all considerations connected with the rotation of the Hima-
layan tract of elevation.
R. D. Oldham—Essays in Theoretical Geology. 75
We have now to consider what modifications are required to fit
the purely mathematical theory to the more complex conditions of
actuality. In the first place the elements of rigidity and rotation
being abandoned, we need not consider the left-hand side of the
diagram, and may redraw it in greater accordance with the conditions
of the Himalayan region. (See Fig. 2.) We have now an elevated
region A A subjected to denudation. and adjoining it an area
extending to R, on which deposition is taking place, the deposits
being contributed by the elevated ground A to the north, and the
waste of the rock area to the south. The tract being supposed to be
in equilibrium, as A is lightened by denudation, the surplus floating
power of B will cause it to rise, and the load thrown on D will cause
it to sink, especially in the neighbourhood of A, where the load is
greatest, till the magma displaced by the lower surface of the crust
is sufficient to float the load. The result will be, firstly an extension
of the depression in a direction away from the elevated tract A,
and secondly a strong tendency to either fracture or flexure of the
crust at the junction of A and D.
As we may take the crust to be infinitely yielding to long-continued
stresses, there is no reason why that produced by the lightening
of the one area and the loading of the other should not be relieved
simply by the sinking of the latter and the rising of the former
on either side of a separating plane. But denudation and deposition
are not the only forces at work ; for, to bring the case into connection
with that of the Himalayas, we must suppose compression to be
continually at work. This will be relieved partly by an additional
elevation of A, but also by the compression and consequent elevation
of the marginal deposits of D, which would not offer the same
resistance as the already consolidated beds of A. In this way the
deposits on the edge of the depression D would gradually come
to form part of the tract A, whose boundary would advance towards
R, but not to the same extent as the shifting of the outer boundary
of the depression towards Rf’.
This must not be regarded as a modification, but rather as an
amplification of Mr. Fisher’s theory; it is a more detailed investiga-
tion of a part of the process which does not lend itself to mathe-
matical treatment. The elevation of the marginal deposits of the
depression is of a different nature to that referred to by Mr. Fisher,
an elevation which belongs to the period of decadence of the range,
and is unaccompanied by disturbance. The Himalayas have only
just completed their growth, if they are not still growing, and the
elevated marginal deposits with which we have to deal owe their
elevation to compression, and belong to the period of growth of
the range.
Taking this amplification of the theory, we find that a mountain
range which has completed or nearly completed its growth, but not
entered on the period of its decadence, should show the following
features :—
I. There should be a region continuously exposed to denudation
and simultaneously to elevation.
76 R. D. Oldham—Essays in Theoretical Geology.
TI. Coterminous with this there should be an area where deposition
and subsidence are simultaneously taking place.
III. The area of deposition and subsidence should gradually spread
outwards from the mountain range.
IV. The region of denudation and elevation should gradually
encroach on that of deposition and subsidence.
V. The demarcation between the areas of elevation and of subsi-
dence should be abrupt.
VI. Near the limit the submontane deposits should, during
the elevation of the range, be raised with the accompaniment of
disturbance.
VIL. It is improbable that the system of disturbance would com-
mence simultaneously along its whole length, but rather it would
extend longitudinally as well as laterally.
It is only necessary to compare this statement of the deductions
arrived at theoretically with the results of observation as given in
the first part of the paper, to see how close and complete is their
accordance. And in this agreement we find very strong evidence
of the truth of the theory.
I have avoided overburdening the text with references; none of the facts are here
published for the first time, and but little of the deductions. The ideas and con-
clusions relative to the history of the Himalayas are well known to those who have
worked at it; in a more or less complete form they have been published at different
times, but have never before been collected together. The following papers have
been made use of, and should be consulted for further details :—
Sir P. T. Cautley. On the Structure of the Sewalik Hills and the Organic
Remains found in them. Geol. Trans. second series, vol. v. pp. 267-278 (1840).
H. B. Mediicott. On the Geological Structure and Relations of the Southern
Portions of the Himalayan Ranges between the Rivers Ganges and Ravee. Mem.
Geol. Surv. Ind. vol. ii. part 2 (1863).
F, Stoliczka. Summary of Geological Observations during a Visit to the Provinces.
of Rupshu, Karnag, South Ladak, Zanskar, Suroo, and Dras of Western Tibet, in
1865. Mem. Geol. Surv. Ind. vol. v. pp. 337-354 (1866).
A. B. Wynne, Observations on some Features in the Physical Geology of the
Outer Himalayan Region of the Upper Punjab. Quart. Journ. Geol. Soe. vol. xxx.
pp. 61-80 (1874).
H. B. Medlicott. Note on the Sub-Himalayan Series in the Jamu (Jummoo)
Hills. Rec. Geol. Surv. Ind. vol. ix. pp. 49-57 (1876).
A. B. Wynne. Note on the Tertiary Zone and Underlying Rocks in the North-
Western Punjab. Rec. Geol. Sury. Ind. vol. x. pp. 107-132 (1877).
Notes on the Physical Geology of the Punjab. Quart. Journ. Geol.
Soc. vol. xxxiv. pp. 347-3875 (1878).
H. B. Medlicott. Manual of the Geology of India. Cap. 22, 28, 25, 26, 27 (1879).
W. Theobald. The Siwalik Group in the Sub-Himalayan Region. Rec. Geol.
Surv. Ind. vol. xiv. pp. 66-175 (1881).
H. B. Medlicott. The Nahan-Siwalik Unconformity in the N. W. Himalayas.
Rec. Geol. Surv. Ind. vol. xiv. pp. 169-174 (1881).
R. Lydekker. Geology of the Kashmir and Chamba Territories, and the British
District of Khagan. Mem. Geol. Surv. Ind. vol. xxii. (1883).
R. D. Oldham. Note on the Geology of the Gangasulan Pargana of British
Garhwal. Rec. Geol. Surv. Ind. vol. xvii. pp. 161-167 (1884).
Memorandum on the Probability of Obtaining Water by Means of
Artesian Wells in the Plains of Upper India. Rec. Geol. Surv. Ind. vol. xviii.
pp. 110-112 (1885).
C. S. Middlemiss. Physical Geology of the Sub-Himalaya of Garhwal and
Kumaun. Mem. Geol. Surv. Ind. vol. xxiv. part 2 (1890).
Notices of Memoirs—W. W. Watts—On Long Mountain. 77
INT ORR AHS)» (OREL AM id at W@ aba stSy
I.—Pror. W. Dames on a SwepisH Creracrous Birp.
“Unser VoGELRESTE AUS DEM SALTHOLMSKALK VON LIMHAMN BEI
Maumo.” By W. Dames. Bihang till k. Svenska Vet.-Akad.
Handl., vol. xvi. pt. iv. No. 1, with plate (1890).
N this paper Professor Dames discusses associated right humerus,
coracoid, and scapula, apparently of a bird, obtained by
Professor Lundgren from the Upper Senonian of Southern Sweden.
In the course of his introductory remarks he alludes to the possible
occurrence of a gadoid fish in the same formation—the determina-
tion being apparently based upon the original example of Dercetis
limhamnensis of Davis. A detailed description of the bird-bones
follows, and the provisional name of Scaniornis Lundgreni is pro-
posed for the genus and species they represent. All known carinate
birds from the American and European Cretaceous and Tertiaries
are successively reviewed in comparison ; and a reference to recent
skeletons suggests that the new extinct Swedish type is a primitive
wader. JTS Ville
Il.—Tuer Gerontocy or tHe Lone Movunrain, oN THE WELSH
Borpers. By W. W. Warts, M.A., F.G.8.1
HE author described the Silurian succession in a part of West
Shropshire and Hast Montgomeryshire.
1. May Hill grit, sometimes conglomeratic, containing one richly
fossiliferous band of limestone at Cefn, Buttington, This is traced
from Cefn to the north end of the Breidden Hills, where it appears
to thin out. It rests unconformably on various members of the Bala
group, and at Cefn a small dyke of diabase is intruded along the
junction line.
2. Purple and green shales with very rare fossils, chiefly Ento-
mostraca and small Brachiopods.
3. Wenlock mudstones, earthy in the lower part, and more cal-
careous above, containing Cyrtograptus Linnarssoni, Monograptus
Flemingii, M. dubius, and M. serra. These beds appear to represent
the upper part of the Wenlock shale and the Wenlock limestone.
4, Thin muddy shales with rare flaggy ribs, containing Mono-
grapius colonus, M. Nilssoni, and Cardiola interrupta; these are the
equivalent of the Lower Ludlow beds.
5. Hard thick flags, with occasional shales. Monograptus Leint-
wardinensis, M. Salweyi, M. Roemeri, the equivalent of the Aymestry
limestone.
6. Thin fissile shales almost barren, but with Cardiola. These
occupy the place of the Upper Ludlow Rocks. Above these beds
comes an outlier of the Passage-beds with Zingula and Entomostraca.
The structure of the range is a large syncline with a steep dip on
the north-west side, but this is complicated by several dip- and
strike-faults and one or two small synclines.
The author acknowledged the great help rendered by Professor
Lapworth in determining the Graptolites.
} Abstract of a paper read at the British Association for the Advancement of
Science; Leeds, September, 1890; Section (C) Geology.
78 Reviews—S. A. Miller’s American Crinoids.
dee SEE 9 2 GEG WV VEiSe
—__—___—_.
I.—Nortra AMERICAN CRINOIDOLOGY.
S, A. Mituer.—Srrucrure, CLAssIFICATION, AND ARRANGEMENT OF
AmericAN Panmozoic Crinoips into Famitres. Amer. Geol.
Vol. vi. No. 5, pp. 275-286, and No. 6, pp. 340-357. Minnea-
polis, Nov. Dec. 1890.
HAT erudite and enthusiastic writer Mr. Samuel A. Miller of
T Cincinnati, already famous through his “ North American
Geology and Paleontology,” described by Prof. John Collett as
“the most valuable and learned work on Geology and Paleontology
ever published,” again compels the attention of the scientific world
by the elaborate article before us. .
“Mr. Miller has an extensive and peculiar acquaintance with
Crinoids, #.e. with those from the Paleeozoic rocks of N. America, and
has proposed a large number of generic and specific names, some of
which will probably stand. What more is needed? Indeed, Mr.
Miller himself ridicules P. Herbert Carpenter for supposing that a
knowledge of recent forms is of any advantage to the student of
fossils. Besides this, Mr. Miller’s specific names are never spelled
with a capital letter,! and they can all be translated by the aid of
Andrews’ Latin Lexicon. But, for all his learning, Mr. Miller
is not proud; he modestly writes as though he could read no language
except his own and English. Mr. Miller has too that rare merit in
‘a scientific man—consistency: he never (or hardly ever) changes
his opinion, and consequently has earned the right to abuse Wachs-
muth for changing his with the progress of knowledge. At the
same time it must not be supposed that the classification now put
forward by Mr. Miller is the same as that adopted in his “ North
American Geology.” He is careful to explain that it was not then
his object “to write an original treatise on any one branch.” We
are surprised, for that classification struck us as one of the most
original we had ever seen.
Discarding the puerile speculations of recent writers as wholly
unsupported by fact, Mr. Miller reverts to a classification according
to superficial similarities of structure, a method which, with the
advantage of simplicity, combines the sanction of antiquity. He, at
least, will not follow the vagaries of those who consider a certain
character of family value in one place and of barely specific import-
ance in another.
Mr. Miller cannot away with your Morphologist; hence he has
never accepted the view that the median circlet of plates in the cup
of a dicyclic Crinoid is homologous with the proximal circlet in a
monocyclic Crinoid. For him the “basal” plates are always those
next the stem; to these the animal was, he states, attached by
ligament: hence these plates are “the most important in classifica-
tion of any of the plates in the calyx.” The difficulties presented
by the numerous pseudo-monocyclic forms do not trouble Mr. Miller,
1 Except when a patriotic printer insists on a large A for ““ Americanus.””
Reviews—S. A. Miller’s American Crinoids. 79
for he does not undertake to deal with Crinoids other than Paleozoic,
and, as for these, he boldly asserts that ‘“ ‘rudimentary underbasals ’
could never have had an existence in any of them.” ‘The number
of basals and the shape of the basal disk are of the first importance ”
in classification ; for, as Mr. Miller points out, the number gradually
decreases in geological time, and of course no sound thinker could
imagine that later forms arise from earlier by descent with
modification.
“The only known function of the subradials is to increase the
capacity of the visceral cavity, . . . . in some genera they cover half
the calyx, .. .. in all cases they materially affect the form and
structure, .... where... . large they were supported by liga-
ments .... or by denticulated edges.... Therefore [how
subtle is this logic!]—no family should include genera having
subradials and those in which they do not exist.”
“The next family character will be found in the presence or
absence of regular interradial plates,’ while the last lies in the
structure of the posterior interradius.
“ The structure of the arms,” Mr. Miller thinks, ‘‘is never of
family importance, and above the brachials never of generic impor-
tance though always of specific value.” As we are not informed
what sense Mr. Miller chooses to apply to the term “ brachials,” we
can offer no opinion on this point.
We have not space to give a synopsis of Mr. Miller’s classification,
but afew of the most noteworthy changes may be quoted for the
delight of those who appreciate common-sense. Thus :—the
Symbathocrinide are ranged alongside the Calceocrinide: the
difficulty of separating species of Forbesocrinus from those of Ichthyo-
erinus can exist no longer now that the two genera are placed not
only in different families but in separate groups; while matters are
still more simplified by the approximation of Ampheristocrinus and
Closterocrinus to the ‘“ Ichthycrinoide.” Again, forms hitherto
foolishly placed so far apart as Hucalyptocrinus, Mariacrinus, and
Xenocrinus, are now to be found in the same group of families. In
the Cyathocrinide are gathered Bursacrinus, Carabocrinus, Graphio-
crimus and others, even including Cyathocrinus.
But for the rest of this exciting and amusing article we must refer
our readers to the Christmas number of the ‘ American Geologist”
for 1890. And we would especially recommend its perusal to our
younger readers; for there they will find exemplified a lucidity of
exposition, an accuracy of argument, and a courtesy in debate that
remind one of the Society upon the Stanislaus, though from the Report
of that body even Mr. Miller might profit. The journals in which
we publish may be “conduits of ignorance and conceit.” We are
“illiterate,” “reckless of symmetry,” “shallow pretenders” ‘venting
stupid hypotheses”; in our ‘unenlightened affectation’? we make
our “usually poor English more incomprehensible” by quoting
*“snatches from German authors,” we give full references, and we
never have more than 80 misprints in 18 pages (Mr. Miller rises to
40). Yes! we are all this; we do all this: and yet, “overgrown”
80 Reviews—J. W. Davis—Scandinavian Cretaceous Fish.
with “ignorance, assumption, and conceit” as we are, we humbly
confess that on this side the Atlantic we have never produced any-
thing that would, for sweet reasonableness and smoothness of
persuasion, stand a moment’s comparison with the gentlemanly
polemics of Mr. 8. A. Miller, Cincinnati, O.
I].—Mr. James W. Davis on ScanpINAvIAN OretAcreous FISHES.
“On tHE Fosstn Fish or tHE Cretacrous ForMATIONS OF
Scanpinavia.” By James W. Davis, F.G.S., F.L.S. Trans.
Roy. Dublin Soc. 712] vol. iv. pp. 863-484, pls. XXXVIi.—xl v1.
(November, 1890.)
F all extinct fish-faunas, that of the Cretaceous Dea is gradually
becoming the best known, on account of the abundance in
which remains are discovered in every part of the world. A large
proportion of these remains are too imperfect for precise determina-
tion; but they suffice, at least, to make known the geographical
distribution of the principal types, and the fossils of a few areas—
e.g. Britain, Westphalia, Syria, Brazil, and Western North America
—are so admirably preserved as to form definitely determined
standards for comparison. Mr. Davis’ new Memoir is the latest
contribution to the subject, and comprises a beautifully ilustrated
account of the Upper Cretaceous Fishes of Southern Sweden, with
its adjacent islands, and the neighbouring shore of Denmark.
Apart from incidental references, the Cretaceous fish-fauna of
this northern region has hitherto remained quite unknown, and
ichthyologists are much indebted to the Curators and Professors of
the Scandinavian Museums and Universities for entrusting all their
collections to a specialist for elucidation. Mr. Davis’ researches are
based upon materials from the Swedish State Museum, the Swedish
Geological Survey, and the Universities of Lund and Copenhagen.
On the whole, the specimens are of a very fragmentary character,
but most of them are at least generically determinable, and many
appear to be specifically identical with well-known forms from
Britain and other areas. The great interest of the collection consists
in the fact, that while it is in part derived from truly Senonian
horizons, the majority of the specimens were obtained from the
Danian series. Some of the species, therefore, are of a decidedly
Tertiary character. Prof. Bernard Lundgren supplies important
stratigraphical information which is tabulated at the end of the
memoir; and from this table may be perceived at a glance the geo-
graphical and geological range of the thirty-four species described.
Most of the fossils under discussion, as might naturally be
expected, are Hlasmobranch teeth; and the author’s introductory
remarks deal chiefly with the classification of the Cretaceous Lam-
nidee. While adopting to a large extent the arrangement formulated
in the British Museum Catalogue of Fossil Fishes, Mr. Davis prefers
to revert to the Agassizian conception of Otodus and Odontaspis,
and is uncertain whether any ichthyologist hitherto has philosophi-
cally determined the limits of Carcharodon. The principal difference
Reviews—J. W. Davis—Scandinavian Cretaceous Fish. 81
between the Catalogue just cited and the memoir now before us
consists in the fact that the former attempts to treat the fossils as
remains of genera and species of Hlasmobranchs, while the latter
deals with them as so many “ forms”’ of detached teeth, which can
be distinguished and thus variously named.
Among features of special interest relating to the Elasmobranchs,
may be noted the occurrence in the Danian of typical examples of
Ptychodus decurrens, P. mammillaris, Notidanus microdon, Oxyrhina
Mantelli, and the so-called Otodus appendiculatus—all well-known
Cretaceous forms. With these are found an undetermined species
of Myliobatis, and some apparently new forms of Scapanorhynchus,
Oxyrhina, Lamna, and Scyllium, besides a large imperfect tooth of
Notidanus indistinguishable from JV. dentatus of the New Zealand
Greensand. An Odontaspis, both from the Senonian and Danian, is
also identified with a New Zealand species (O. acuta); but we
venture to think that this is the well-known European Danian
species, 0. Bronni, to which the author makes no reference. The
so-called Odontaspis acutissima and O. faxensis are undoubtedly teeth
of Synechodus, as proved by the form of the root; and, as remarked
by the author himself, there is much doubt about the generic deter-
mination of the beautiful new teeth described as Oxyrhina Lundgreni.
Though often recorded from the Cretaceous, it is still very uncertain
whether the typically Tertiary species, Odontaspis elegans, ranges
so far downwards, and the smooth teeth assigned to this form by
Mr. Davis are far from conforming to Agassiz’ original definition ;
but the occurrence of a tooth indistinguishable from the so-called
Otodus obliquus in the Upper Senonian of Rugaard is a fact of great
interest. A portion of a tooth of Careharodon from the Danian
of Faxoe is even identical in character with the teeth of the existing
C. Rondeleti, but this:scarcely suffices for certain determination.
Some Chimeroid teeth from the Senonian appear to pertain to the
widely distributed species, first described from Switzerland as
Ischyodus Thurmanni and afterwards re-described in Britain under
the name of Ischyodus brevirostris. Hdaphodon, however, remains
unknown, and there are no traces of Hlasmodus.
Of Pyecnodonts, there occur only teeth which are referred with
much probability to Celodus subclavatus ; and of Teleosteans there is
only evidence of about six genera. Of the latter, the finest specimens
pertain to Hoplopteryx and to a new deep-bodied physoclystous fish,
which receives the name of Bathysoma Lutkeni. Berycopsis and
Dercetis also seem to be represented ; another fossil is provisionally
named Clupea Lundgreni; and some specifically indeterminable
teeth of Enchodus are recorded. With regard to Enchodus we would
remark that the author does not seem to have studied the most recent
discoveries, and thus assigns the genus still to the family Trichiuride.
Here is also placed Bathysoma, though a critic noting the fact will
perhaps be answered again in the words of the foot-note on p. 369,
that the arrangement is due to “the omission of a line.” Bathysoma,
indeed, is one of the most remarkable Cretaceous fishes hitherto
discovered, and we only regret that a more satisfactory determination
DECADE III.—vVOL. VIII.—NO. II. 6
82 Reviews—Dr. H. M. Hovelacque—On “ the Wooden Dinosaur.”
of its affinities has not been attained. So far as the terms of the
“generic definition” are concerned, the name will apply equally
well to a sole ora sun-fish ; but the fine figures and detailed descrip-
tion of the fossils help to compensate for the insufficiency of the
diagnosis.
The memoir as a whole makes an important advance in our know-
ledge of the Upper Cretaceous Fishes of Western Europe, and
ichthyologists are much indebted to the author for providing so
many new facts that will assist im future generalizations.
A. 8. W.
IJI.—Dr. EB. Fasrint on Macumrovnvs.
Macumropus (MrcanTHEREON) DEL VALDARNO SuPERIORE, Memorta
pEL Dorr. Eminio Fasrini. (Boll. R. Com. Geol. 1890,
Nos. 3-6, pp. 43, pls. 3.)
fl Pier present Memoir is another of the series intended to illustrate
the extinct Mammalian fauna of Italy, reference to which has
already been made in our issue of last month.
The author describes in full detail, with excellent illustrations,
all the more important remains of Sabre-toothed Tigers (Macherodus)
from the Pliocene of the Val d’Arno preserved in the Italian
Museums. He concludes that two species have hitherto been
confused together under the name of M. cultridens. In that species
the upper canine teeth of the male are long and narrow, and have
no serrations on their trenchant edges; and it is believed that the
smaller skulls and jaws which have been regarded as representing
a distinct species—M. meganthereon—are really referable to females
of M. cultridens. A second new species designated M. crenatidens
is distinguished by the shorter and wider canine teeth of the males,
in which both the front and hind edges are strongly serrated. In
accordance with the contour of the canine the hollow in the flange
of the lower jaw, against which they are applied, is likewise
unusual. It is considered that the lower jaw from the Norfolk
Forest-bed, described by the late Mr. Backhouse in the Geological
Society’s Journal, is referable to this form, whereby a new species
is added to the British Fauna.
A second new species, which it is proposed to designate M.
nestianus, is characterized by the upper canine teeth carrying
serrations only on their hinder edges; and likewise by the long
gap separating the third and fourth premolars in the lower jaws.
It is suggested that it may be advisable to regard this species as the
type of a new genus, in which case the name Homotherium might be
adopted. les Uy
IV.—Sur LA NATURE VEGETALE DE L’AACHENOSAURUS MULTIDENS,
G. Smers. Par Dr. Maurice Hovetacauz. (Mem. Soc. Belge
de Géol. iv. (1890) p. 59 et seq.)
fT\VHE “wooden Dinosaur” —as the so-called Aachenosaurus multidens
has not inaptly been termed on this side of the Channel—has at
length received its coup de grdce at the hands of the author of this
Reviews—M. Gourret— Tertiary Fauna of Basse-Provence. 83
memoir. The vegetable nature of the fossil could not possibly be
disputed by any one who examines the descriptions and figures in the
text with the accompanying plate; or who, like the writer of this
notice, has had the privilege of seeing sections of the ‘‘ bones” under
the microscope. The two fragments examined by Dr. Hovelacque,
viz. the so-called épine dermique and mdchoire, he shows to belong to
two different families of plants, and they now receive the names of
Aachenoxylon and Wicolia Moresneti respectively. Grate
V.—La Faune Tertiarrz Marine pe Carry, DE SAUSSET ET DE
Couronne (PRES Marsgitie). Facts DES BTAGES TERTIARE
DANS LA Basse-Provencre. Par M. Paun Gourret. (Mem. Soc.
Belge de Géol, iv. (1890) pp. 78-1438, with four plates.)
i hae author commences by giving a general outline of the Tertiary
beds of Basse-Provence, showing that the Eocene, Oligocene,
Miocene and Pliocene are each represented in that district. In this
memoir he gives a few paleontological details fixing the horizons of
the several beds and roughly correlating them with the Tertiary
strata of adjacent areas.
The second part enumerates the species found at the three places
mentioned in the title of the memoir, and under the heading of each
of these species are placed the names (where necessary) of what the
author considers to be synonyms, together with a brief account of its
geologic and geographic distribution. with occasional critical remarks.
This is the most important section of the paper, and it is put forward
as a revision of the whole fauna and as the result of much careful
research. In all, 301 species of fossils are recorded, which are
distributed as follows: — Pisces 8, Crustacea 5, Mollusca 247,
(Gasteropoda 157, Pelecypoda 90), Polyzoa 6, Brachiopoda 3,
Echinodermata 13, Coelenterata 19. The Fish belong to the genera
Lamna, Myliobates, Oxyrhina and Spherodus (sic); whilst the
Crustacea are mainly Balani. The Mollusca naturally claim a
large share of attention, and it may be remarked that in dealing
with them, the author does not adhere to certain well-known and
generally accepted rules of nomenclature, which is much to be
regretted. For example, when the generic appellation of a species
is changed, he inserts the name of the individual who made the
alteration after the specific, instead of that of the original describer
of the species. The science of Malacology has made great strides
during the past ten years, but this fact has not been sufficiently
recognized in the memoir now under review. It would be tedious
to point out all the shortcomings in this respect, but we may
mention Pyrula melongena, Bast., which should be Melongena
cornuta, Ag.; Pyrula bulbus, Desh. = Sycum bulbus, Sol.; Buccinum
baccatum, Bast. = Cyllenina baccata, Bast.; Buccinum reticulatum,
Linn.= Nassa reticulata, Linn.; Voluta rarispina, Lam. = Volu-
tilithes rarispinus, Lam.; Ancillaria=Ancilla; Chenopus=Aporrhais.
Again, no attempt is made to classify the larger groups — the
heterogeneous assemblage of forms which were included under such
84 Reports and Proceedings—
genera as Pleurotoma, Fusus, Buccinum, Bulla, Cerithium, Natica,
Venus, etc., during the first decades of the century, are still classified
as they then were, in the lists of the fossils from Marseilles before
us. The synonyms given are in many instances inaccurate also. It
may be said that the second section of the memoir is useful as
giving an idea of the richness and general character of the fauna of
the Upper Tertiary beds of the localities mentioned, and at any rate
it is something to have a complete list of the known species, even
although some may be wrongly determined ; but the whole requires
very careful revision before it can be of any material value to the
systematist.
The third section gives the distribution in detail of the fossils
found, showing their vertical and horizontal ranges, and this is
unquestionably the most useful portion of the work. The four
plates, which are beautifully executed, re-figure certain characteristic
Mollusca and depict five new species which are described in the text.
Go Here
VI.—Cararocun or Mryerars ror Saus. By Gwo. L. Enexrse
AND Co. 8yvo. Philadelphia and New York, 1890. Price 25 cents.
A Nae book is no mere dealer’s catalogue, but contains a large
amount of useful information, concisely arranged for ready
reference. A brief résumé of the more recently described minerals is
given, followed by a classification and list of all known minerals
arranged according to their chemical composition. In this list the
crystallographic system and the general formule are mentioned, and
the whole is rendered more complete by a good index at the end of
the volume. Several figures are given, including eight fine crystals
of Beryllonite from Stoneham, Maine.
RP ORLS AAND ROG Dm iG.S=
GEOLOGICAL Socrmuty or Lonpon.
I.—December 17, 1890.—W. H. Hudleston, Esq., F.R.S., Vice-
President, in the Chair.—The following communications were read :
1. “On Nepheline Rocks in Brazil.—II. The Tingua Mass.” By
O. A. Derby, Esq., F.G.S.
In a former paper the general distribution of the nepheline rocks,
so far as known, was given with a particular description of a single
one, the Serra de Pocos de Caldas. The present paper treats of a
second mass, the Serra de Tingua, a high peak of the Serra do Mar,
some forty miles from Rio de Janeiro.
The peak is essentially a mass of foyaite rising to an elevation of
1600 metres, on the crest and close to the extremity of a narrow
gneiss ridge of a very uniform elevation of about 800 metres. As
seen from a distance, the conical outline and a crater-like valley on
one side are very suggestive of volcanic topography. In the structure
of the mass both massive and fragmental eruptives are found, the
former greatly predominating.
Geological Society of London. 85
- The predominant rock is a coarse-grained foyaite which is found
everywhere in loose blocks about the margins of the mass, but not
extending beyond it. In the numerous cuttings in the immediate
vicinity, dykes of phonolite and basic eruptives (augitite) are ex-
ceedingly abundant, foyaite never appearing in a dyke form. There
is, however, abundant evidence that foyaite and phonolite are but
different phases of the same magma.
Aside from the dyke phonolites, true effusive phonolites associated
with fragmental eruptives (tuffa) were found high up in the crater-
like valley, proving that the mass was a volcanic centre in the most
restricted sense of the word.
This conclusion affords an explanation of some of the peculiarities
of the foyaite, which has many characteristics of effusive eruptives
mingled with those of the deep-seated ones (Teifengesteine). These
have, aside from the porphyritic structure, a schlieren structure
revealed by a peculiar fluted weathering (illustrated by a photograph)
and the presence of pseudo-crystals in the form of leucite.
Statigraphically the Tingua foyaites lie in sheet-like masses like
lava-flows, extending from the higher to the lower portions of the
mountain, the underlying gneiss being revealed at nearly all levels,
wherever the mass has been scored by streams. The general frag-
mentary character of the rock seems to be due to the undermining of
these sheets.
Specimens and photographs illustrating the peculiar pseudo-
crystals in the form of leucite that occur in both the foyaites and
phonolites of Tingua (although no leucite has been detected in the
rock) were exhibited and discussed.
2. “'The Variolitic Diabase of the Fichtelgebirge.” By J. Walter
Gregory, F.G.8., of the British Museum (Natural History).
The author has examined the variolitic diabases in the neighbour-
hood of Berneck, and adduces evidence of their having been intruded
into the Devonian rocks before the latter were affected by the great
earth-movements which have folded the Paleozoic rocks of the
district. He finds that the variolitic structure occurs in two different
arrangements: (a) on the surfaces of spheroidal masses of compact
diabase, which are comparable with those of Mt. Génévre; (0) as a
true contact-product on the selvage of the diabase, the latter being
comparatively rare, and the varioles less perfectly developed.
He gives proofs that the varioles are true spherulites, and not
fragments of Devonian rocks, as supposed by von Giimbel. He
argues that though they are the product of rapid cooling, too sudden
a solidification of the diabase may prevent their formation, and that
for a similar reason the amygdaloidal is less variolitic than the
compact diabase, the loss of the water that occupied the vesicles
having diminished the fluidity of the rock. Finally, he maintains
that the “ pseudo-crystallites”’ are rifts and fissures due to contrac-
tion, and that the remarkable optical properties described by Michel-
Lévy are due to the filling-up of cracks by felspathic matter deposited
in optical continuity with the crystalline fibres on each side.
86 Reports and Proceedings—
2
II.—January, 7, 1891.—A. Geikie, LL.D., F.R.S., President, in
the Chair.—The following communications were read :—
1. “On the North-west Region of Charnwood Forest, with other
Notes.” By the Rev. E. Hill, M.A., F.G.S., and Prof. T. G. Bonney,
Disc, ODS HIRES Ss VeRzGss:
The paper contains the results of a re-examination of the North-
west Region, when the authors had the advantage of using the
Six-inch Ordnance-map, published since the completion of their
former work. In this they had expressed the opinion that the rock
of Peldar Tor and that of High Sharpley were somewhat altered
pyroclastics, being: much influenced by the non-igneous origin asserted
for the “ porphyroids” of the Ardennes. But in 1882 one of them
had visited this region, and was then convinced that the porphyroids,
which closely resembled the rock at Sharpley, were felstones which
had been rendered schistose by subsequent pressure. The result of
their subsequent work in Charnwood has convinced the authors that
the rocks of Sharpley and of Peldar Tor are in the main of a like
origin and history. The mass of Bardon Hill, where the quarries
have been much enlarged, has also been studied, and some details in
the section formerly published have been corrected. The schistose
bands, on which the authors relied as marking horizons for strati-
graphical purposes, prove to be zones of exceptional crush. The
occurrence of a rock exactly resembling that of Peldar Tor is fully
established. It is extremely difficult to decide upon the true nature
of the rocks which are chiefly worked in the pit, but the authors
remain of opinion that for most of them a pyroclastic origin is the
more probable.
Some notes are added upon the relations of the holocrystalline
igneous and the sedimentary rocks of the Forest, upon the Black-
brook group, and upon the fragments and pebbles in certain of the
coarser ashy deposits. Some remarks are made upon the glacial
phenomena exhibited in the Forest-region ; these indicate that this
cannot have been overridden by a great northern ice-sheet and it
does not afford the usual signs of the action of local glaciers. At the
same time it has been a centre of dispersion for erratics, especially
towards the south and south-west, these being found sometimes more
than twenty miles away. Hence, in the opinion of the authors, the
erratics have been distributed by floating-ice during an epoch of
general submergence. Some minor ‘ Corrigenda” in the earlier
papers are noted, with certain changes in the names of localities,
bringing them into harmony with the Six-inch map.
2. ‘Note on a Contact-Structure in the Syenite of Bradgate
Park.” By Prof. T. G. Bonney, D.Sc., LL.D., F.RB.S., V.P.G.S.
The author described a specimen, obtained at Bradgate Park,
showing a junction of the syenite and slaty rock of Charnwood.
The latter rock is very slightly altered; the former exhibits a
number of grains of felspar’and quartz set in a matrix which has
now a “trachytic,’ now a devitrified structure. He traced the
former into the ‘micrographic” structure observed generally in
these syenites, and discussed its significance. His study of these
Geological Society of London. 87
structures in this and many other instances led him to infer
that they generally indicated that the rock, at a late stage, had
consisted of a mixture of previously formed crystalline grains
and a viscous magma, that the temperature of the mass has been
comparatively low, that it had cooled rather gradually, and that the
condition of the magma—i.e. one of very imperfect fluidity—had
not permitted of free molecular movements among its constituents.
Thus this structure, together with certain others mentioned, might
be regarded as indicative of “crystallization under constraint.”
3. “On the Unconformities between the Rock-Systems under-
lying the Cambrian Quartzite in Shropshire.” By Charles Callaway,
D.S8e., F.G.S.
I. Review of the Hvidence for the respective Ages of the Uriconian
and Malvernian Rocks.
The author criticizes the conclusions arrived at by Prof. Blake
(Q.J.G.S. 1890, p. 386), and adduces evidence to show :—
(1) That the felsites regarded by himself as Archean have not
been shown to be intrusive in Longmynd Rocks.
(2) That it has not been proved that the Longmynd Series is
divisible into two groups, separated by an unconformity; and that,
therefore, the evidence from included fragments remains unaffected.
(8) That the conglomerates and grits associated with the Uri-
conian are an integral part of that system, and are not of Cambrian
age; and that the granitic and metamorphic land-masses from
which so many of the fragments in the conglomerates are derived
are consequently of pre-Uriconian age.
(4) That the granitic rocks of Shropshire are not intrusive in the
Uriconian.
Il. The Relation between the Uriconian and the Longmyndian.
Pending the publication of Prof. Lapworth’s researches upon the
fauna of the Hollybush Sandstone, the author regards it as hardly
wise to assign positively a pre-Cambrian age to the Longmyndian
system.
In favour of an actual break between the Uriconian and Long-
myndian rocks, he gives details showing the general discordance of
strike between the two groups; the locally concordant strikes are
seen along a line of fault. Furthermore, as the junction between
the two groups is faulted, this, whilst of course not proving an
unconformity, renders incredible the hypothesis of conformity and
igneous intrusion along the line of junction. Again, the conditions
of deposit were different: the Uriconian is essentially a volcanic
formation, whilst the Longmyndian rocks are characterized by their
even sedimentation, and the author maintains that such a change of
conditions must indicate a break in time, though the unconformity
need not necessarily be very great.
Lastly, the occurrence of fragments of Malvernian granites and
schists (formed at great depths) in the Uriconian Conglomerates
indicates the existence of an unconformity between the holocrystal-
line and volcanic systems.
88 Correspondence—Dr. Gerhard Holm—MUr. H. W. Monckton.
CORRESPONDENCE.
“ STEM-OSSICLES ” OF CRINOIDEA, IN THE LEPT#NA-KALK
(UPPER ORDOVICIAN) DALECARLIA, SWEDEN.
Sir,—A reviewer (F.A.B.) of my notice “Om forekomsten af en
Caryocrinus i Sverige” has said in the GroztocicaL MaGazrne,
December, 1890, p. 570: “The rock is filled with stem-ossicles
which Dr. Holm, after the curious custom of collectors, thinks it
necessary to ascribe to Crinoidea.” What I regard as stems of at
least two species of Crinoids, the reviewer says are stems of Cystidea
without his having seen a single one of them. But the real fact is
that these stems in consequence of their structure must have
belonged to Crinoids. One of the supposed species has left frag-
ments of stems 45 mm. in length by 16 mm. in breadth. These
show the starting-points where strong cirrhi originated, and as
far as known cirrhi have not been found in the Cystidea. Thick
and expanded rootlets of Crinoids are also not rare. To this must
be added, that all known Cystidea from this same locality, with
the exception of Caryocrinus cfr ornatus, Say, are devoid of a stem.
According to Angelin the genera Spheronis, Hucystis and Caryocystis
are sessile, having the basis of the perisome itself directly affixed to
foreign bodies without the mediation of a stem, and several of the
specimens observed by me of Spheronis oblonga, Ang., and Hucystis
sp., either show the surface by which they were attached, or are
even yet affixed to Bryozoans or other marine Silurian fossils. Of
Caryocystis I have seen only a single specimen, and this does not
show the basis of the perisome clearly. —_
I.—On THE veRY Recent anp Rarip ELEevatTiIoN oF THE
Higuuanps oF Eastern ASIA.
By Henry H. Howorru, Esq., M.P., etc., etc.
MONG. the many interesting issues raised by the discovery of
Mammoth remains in large numbers along the Arctic borders
of Hastern Asia, one has, I think, ceased to be polemical. So far as
I know, there is no serious student who now contests the fact that
the Mammoth and his companions lived where their remains are
found. The rooted trees upon which they fed, and the southern
river-shells which were their contemporaries, both of which are
found with their remains (both being incapable of migration), prove
incontestably what a score of other arguments show, that the fauna
of North-Eastern Siberia in the Mammoth age, like its flora, must be
explained by some other theory than migration. This I have urged
in many ways in my work on the Mammoth.
If the arguments I have recently adduced in the GuonocicaL
Magazine to show that the two great rivers of Western Siberia
flowed southwards and not northwards in the Mammoth age be
sound, they give the finishing blow to what has virtually ceased
for many other reasons to be a tenable theory, namely, that the
Mammoth carcases and the vast débris of the animal world found
on the mainland and on the islands off the coast of Siberia are the
results of river portage. Against this last theory I have also tried
to converge a large number of arguments, old and new, in the work
just cited.
There remains only one possible conclusion, as I said at starting,
namely, that the great beasts whose remains abound so much in the
tundras east and west of the Lower Lena on the Bear Islands, etc.,
lived where their remains occur, as the Russian explorers and as our
most experienced writers agree.
This conclusion necessitates our postulating that the area in ques-
tion in the time when the Mammoth lived, instead of being as now
a bare tundra covered with snow for the greater part of the year,
and swept by icy winds, with a short summer of little more than
six weeks, was sufficiently temperate in climate to permit an abun-
dant and accessible vegetation to exist all the year round, not only up to
the present border of the Arctic Sea, but right across from Siberia
DECADE III.—VOL. VIII.—NO. III. 7
98 Henry H. Howorth—Elevation of Eastern Asia.
to Alaska. This deductive axiom is inductively proved by our
finding the remains of this same vegetation rooted in the very beds
where the Mammoths lie, and far beyond the present limit of forest
growth. The fact has to be explained in some way by those students
who do not emulate the conduct of the ostrich by hiding their heads
in the sand to baffle every pressing difficulty, and who recognize
that all hypotheses, however supported by authority, are in essence
tentative.
How, then, are we to explain a change of climate so important
and so considerable? What are the conditions which impose such a
hard climate upon North-Hastern Asia, and under what hypothetical
condftions could we reasonably postulate a fairly temperate climate
in the Bear Islands, the Chukchi peninsula and Alaska? It seems to
me that the severe climate of North-Eastern Asia is governed partially
by the fact that that area is in close contact with and bounded on the
north by the Arctic Sea, which is a reservoir of cold, and partially
and probably to a greater extent by the fact that it is in close con-
tact with and bounded on the south by the icy plateaux of Mongolia
and Tibet. It seems to me, further, that if we could remove these
two sources of cold, we should at once transform the climate of the
district we are discussing from one of extreme Arctic severity to one
of a moderate and perhaps even temperate character.
I will first say a few words about the Polar Sea. It is an
Opinion very generally held that a continental climate presents
much greater contrasts, and is in effect more severe than a maritime
or insular climate, which has its extremes tempered by the continued
presence of water, and the isothermal lines of the world are a singu-
lar proof of the general truth of the position. The position is never-
theless only partially true. It is only true when the water is in
the shape of water. When the water is frozen and remains frozen
all the year round, and is consequently never above the freezing-
point, but always below it, the proximity of a great mass of water,
instead of acting as a tempering instrument, acts as a perpetual
refrigerator, and every wind that blows across it and over the land
is an icy cold wind. Hence the Polar Sea, so long as it remains
frozen, has the effect of greatly intensifying the natural climate
due to a high latitude; and if it were removed, and replaced by
a mass of land, the effect would be much the same as if its waters
were unfrozen: the result would be in fact to greatly temper the
climate.
I have tried to show in a previous paper that when the Mammoth
lived, the polar area, or a considerable portion of it, was necessarily
dry land, otherwise that animal and its companions could not have
passed to and fro between Siberia and America, as we know they did,
and as we also know they did in very high latitudes. Hence, it follows
that when the Mammoth lived, either there was no Polar Sea, or its
area was greatly contracted, and thus this reservoir of cold did not
exist to continually sophisticate the north wind with its icy touch.
Pro tanto the effect of this must have inevitably been to modify the
climate in the direction of making it more temperate and genial.
Henry H. Howorth—Elevation of Eastern Asia. 99
This I have urged before in these pages. We must not, however,
exaggerate this cause, and attribute it to more than it can explain.
When we inquire why the climate of the valley of the Lower
Lena, and notably Yakutsk, should be so exceptionally severe, as
compared with almost every other place on the same parallel of
latitude, we shall find that it is due not so much to the prevalence
of excessively cold north winds, but to the prevalence of excessively
cold south winds: especially is this the case in summer, when in
many other areas on the same parallel the south wind brings a balmy
memory of the tropics with it. Here it always comes from the
sterile cold plateau of Tibet. It then flows across the Mongolian
highlands, and, after blowing over such a wide space of very elevated
land, it is not only drained of its moisture, but is also cooled down to
a low temperature. Hence at Yakutsk the south wind is often
nearly, if not quite, as terrible a visitor as the north wind.
If therefore we are to trace the present severity of the climate of
North-Eastern Asia to its most potent and efficient cause, we must
trace it to the existence of vast masses of mountain land and high
plateaux culminating in the Thian Shan, the Kuen Lun, and the
Himalayas and including the Altai range and the great upland steppes
of the Pamir of Tibet and of Mongolia proper.
So long as this vast refrigerator exists in Asia, so long does it seem
to me must the climate of North-Eastern Siberia remain a very cold
and severe climate, and one incompatible with vast herds of herbi-
vorous animals finding suitable food in the latitude of the Bear
Islands; and if we are to find the efficient and real cause of a once
temperate climate, where everything is now so palpably the reverse,
we must inevitably postulate the non-existence in the Mammoth age
of these great masses of high land. I have no hesitation in doing
so. The suggestion was made long ago as a suggestion merely, by a
much greater man than myself, whose sobriety of argument and ripe
judgment have been somewhat overshadowed lately by more imagina-
tive forms of scientific reasoning. I mean Alexander von Humboldt.
Humboldt argued that the rise of the Ural and Altai Mountains, and
with them of enormous masses of the continent of Asia, must have
so refrigerated Siberia, that its forests, which in the halcyon days of
Mammoths may have extended in certain promontories to near the
Icy Sea, had necessarily shrunk back to their present limits, and
left these coasts entirely to the Reindeer and its mosses (Russia and
the Ural Mountains, vol. ii. p. 497). Let us now see how this view
can be supported inductively.
The first remarkable fact to which I would call attention is one
that arrested notice long ago, namely, that in the Altai Mountains,
which are very lofty and otherwise well adapted to nurse large
glaciers, no traces of the so-called Glacial Age can be found. No
striated rocks, no ancient boulders. This is assuredly a remarkable
fact. It is attested by more than one reputable witness. One of the
first trained geologists who visited the Altai Mountains was Pierre de
Tchihatcheff, who published a very fine work on that chain in 1845.
He remarked in it on the absence from the Altai as from the Ural
100 Henry H. Howorth—Elevation of Eastern Asia.
chain of any erratic blocks so far as his observations went (op. cit.
pp. 896-7). In 1871 another special work on the geology of the
Altai was published at Leipzig by the famous geologist Bernhard
von Cotta. Inter alia, he remarks on the complete absence in the
Altai of any traces of a Glacial age, or of such evidences of an Ice
age as exist in Western Europe. He says that General von Helmersen
had failed to find any traces of erratic blocks of rounded rocks or of
polished surfaces; while he himself, in spite of an eager search, had
“not been able to find the slightest evidence of anything of the kind
either in the subordinate ranges and hills or the deeper valleys,
although the mountains there are from seven to eleven thousand feet
high, and at present a few small glaciers are to be found in the
south-eastern part of the range; and,” he adds, ‘those who would
explain the absence of old glacial action in the Urals from the fact
of their comparatively low altitude cannot use the same argument
here.” In another place Von Cotta remarks again on the fact that
the Altai range offers no traces of a former Glacial period or of an
Ice age (vide op. cit. pp. 65 and 107).
The two ranges of the Urals and the Altai therefore share in this
common absence of traces of a so-called Glacial age, an absence
which is also marked, as Humboldt long ago pointed out, in the
plains which separate the two ranges. All this is assuredly very
remarkable. That avast congeries of mountains should have existed
in the temperate zone of the northern hemisphere at the time when
the Alps and the Dovrefelds were shedding their great trains of
erratics far and wide and were covered with vast glaciers, and yet
that there should be no traces of old glacier action among them,
is explainable to myself by no other hypothesis than their non-
existence at the time. As in the case of the Urals, to which I
devoted the previous paper, the absence of traces of ice action
is the best evidence that the Altai range did not exist when ice
action was so developed on nearly every secondary mountain chain
in the north temperate zone.
Again, it is a remarkable fact that among the animal remains
found in the Altai caverns the Hyena should occur. The Hyena
is, I believe, very rarely if ever found in the caverns on the flanks
of the Alps or in those of the higher grounds of Germany, and was
a frequenter of the warmer plains. That it should occur in the
caverns of the Altai points again to that area having had a different
contour to the present one. Altogether, it seems to me that in
regard to the Altai Tange, such evidence as we have is completely
consistent with the @ priori view that these mountains did not exist
during the Mammoth age.
If we turn from the Altai range to the aang plateau which
forms the great mass of Central Asia, and is buttressed on the south
by the Himalayas, on the north by the Thian Shan range, on the
west by the Pamir and the Hindu Kush, and on the east by the
mountains of Corea, we have to deal with an area which has only
been visited and traversed at a few points. The testimony of
travellers, however, seems to be unanimous, whether they approach
Henry H. Howorth—Elevation of Eastern Asia. 101
this great upland from India, or Russia, or China, namely, in
vouching for the absence of those most easily distinguished and
most palpable proofs of wide glaciation which we meet with in
Western Europe and in Hastern America.
The Russian traveller Severtzoff has described the existing glaciers
of the Thian Shan, some of them still of enormous size, some
shrinking and recently shrunk, in consequence doubtless of the
gradual desiccation of the surrounding lowlands and consequent
diminution of moisture.
When he turns to a former development of glaciers, which ought
assuredly to have left enormous traces in this the very focus of
modern glacier action, at a time when Central Asia, instead of being
a dried-up waste, was occupied by a vast sheet of water, and when
the conditions for the growth of glaciers were so favourable, what
does Severtzoff say? I will copy his account, as communicated by
Krapotkin to Reclu’s great geographical work.
“‘Hvidently the Thian Shan,” he says, “has preserved its primi-
tive aspect better than the Alps. It has been less carved out by
rain, snow, and glaciers. While the névés and rivers of ice in the
Alps once covered the plains and lowlands surrounding that range
to a height of 200 metres, the glaciers of the Celestial mountains do
not appear to have descended into the lower valleys, and a vigorous
vegetation occupied the flanks of the mountains to a height of 750
metres above the level of the waters which bathed their feet. There
has, in consequence, resulted a very different law of vegetable distri-
bution. While the Alpine region has been itself colonized by species
of plants growing in the forest outside it during the intensity
of the ice, the zone of the Lower Thian Shan was the mother
country whence species spread in one direction towards the higher
summits, and in the other towards the dried-up plains.” —
(Severtzoff quoted by Reclus, Nouvelle Geographie Universelle,
vol. vi. pp. 859-860.)
It would not be easy to adduce stronger evidence than this that
on the great ramparts of mountains which form the northern frontier
of the great Asiatic plateau there is not only an absence of traces of
former great glacial development, but positive proof that no such
conditions could have then existed.
If we turn to the other extremity of this great plateau girdled
with mountains, namely, to Corea, we find the same story. Dr.
Gottsche, in his memoir entitled Geologische Skizze von Korea,
published in the 36th volume of the Proceedings of the Berlin
Academy, says emphatically, ‘Glacial phenomena do not exist in
Corea,” and he quotes Richthofen’s China, vol. ii. p. 111, as witnessing
to the absence of similar phenomena from Liautung. Both Corea and
Liautung are mountainous countries, and the former very much so.
If we now turn to the great southern buttresses of the Asiatic
plateau, namely, the Himalayas, we shall find a repetition of what
Severtzoff reports in regard to the Thian Shan range, namely, a
large number of glaciers showing signs of shrinkage, of which Mr.
Lydekker has given a very interesting conspectus. No doubt there
102 Henry H. Howorth—Elevation of Hastern Asia.
are traces BE their having been bigger and stretched further, but
these traces are nevertheless strangely limited in extent, considering
the huge reservoirs of ice which the Himalayas must have been, in
the so-called Glacial age, if the same conditions had prevailed there as
prevailed in corresponding times in the Alps. We must not forget
that not only was the southern monsoon there with its heavy rains,
but the Asiatic Mediterranean was also then existing, so that we
must not measure the amount of moisture then prevailing with what
prevails now; and what is the testimony of the best observers on
the subject? There has no doubt been a polemic in which many
writers, such as Theobald, Wynne, Lydekker, Drew, and others have
joined; but this has been rather about the extent to which the
modern glaciers have shrunk: all admit recent glaciation in the
higher valleys, but I know of no Indian geologist, except Mr.
Theobald, who has contended for signs of vast glaciation, such
as we find in the much smaller European ranges of the Alps and
Dovrefelds. I would add that Strachey has published in the
Encyclopedia Britannica a very useful diagram showing the com-
parative size of the Alps and the great Asiatic uplands, which is
a very useful measure of the kind of traces of a glacial age we
ought to meet in Hastern Asia. To revert, however: there is a
general concurrence among ovservers that the phenomena in the
Himalayas are on quite a small scale comparatively.
Thus, Mr. J. F. Campbell writes : “The Himalayan region is a slope
about 200 miles wide between the upper plateau of Asia and the
plains of India... . I looked at every stone and heap of stones
about the foot hills, expecting to find some glacial mark. I looked at
every hill top, expecting to find some remnant of a glacial record
between the river gorges. . . . I stayed at Simla for some time, and
found no sign of glacial action of any kind up to about 9000 feet.
All the ridges which divide streams are sharp and steep as the ridge
of a house. All the furrows are deep V-shaped, angular, steep
gutters, like the gutter between two steep roofs. I could not dis-
cover one rounded hill or hollow, one ‘saddle’ or ‘hogback,’ from
Simla, or from places near it to which I could travel... . The
highest ground visible is a jagged sierra of pyramidal angular points,
among which are the glaciers” (Quart. Journ. G. S. vol. xxxv.
pp. 109-110). ‘“Hirdswar is a sacred place where the Ganges
leaves the hills. At the sources of the Ganges are glaciers. If these
glaciers ever extended far during a Glacial period, some mark ought
to be found about the place where a river as big as the chief river
of Lombardy at its greatest size escapes from the great basin, whose
jagged edges and steep sides I had seen from Landour, where frosts
and deep snows occur frequently. In a like position in Italy, near
Turin, are ramparts of glacial débris. Hirdswar is 1124 feet above
the sea. The edge of the basin is nearly 20,000 feet higher, and
the area is large and comparable to the area of the Val d’Aosta or
the Lago Maggiore. ... . I stayed at Hirdswar for several days, and
could find no sign of glacial action whatsoever” (7d. pp. 113-114).
At Roorkee, in digging a huge canal, there was found only mud,
Henry H. Howorth—Elevation of Eastern Asia. 103
sand, pebbles, and abundance of large, smooth, egg-shaped, rolled
stones of considerable size. ‘I could not find,” says Mr. Campbell,
“one stone with scratches on it or with flat sides, or one angular
erratic near the canal. J could find nothing glacial about the end
of the Ganges basin. I could hear of nothing glacial from the
surveyors with whom I conversed at Dehra. I had photographs of
glaciers, and of glens near them, about the headwaters of the
Ganges and the Sutlej. In them I could see nothing to suggest the
former action of large glaciers like those which have left their spoor
in the Alps, in Scandinavia, in Scotland, and in Ireland. In some
few pictures only I could trace marks which seem to indicate a
former extension of glaciers which exist. Captain Senior, who made
the pictures, said that old glacier-marks eatend only a few miles from
ihe ice in this region. ‘The surveyors who mapped the ground con-
firmed what I saw and heard. The Ganges glaciers and others in
this region hang about the steep broken edges of great deep basins ;
and there is nothing to show that glaciers ever filled these basins, as
European hollows were filled of old. Opposite to the Ganges there
are no signs of that Glacial period to which Huropean ice-marks are
usually attributed.” Again, “I crossed the Jumna, the Sutlej, and
the Bias, about fifty miles from the hills. JI saw no glaciated
stones in the plains or near the banks of these three great rivers, all
three rising among glaciers. There is nothing at the foot of the
Himalayas “here comparable to the glacial débris of Lombardy or
the erratics of the American plains” (id.p. 114). ‘The Ravee (within
sight of the Kashmir hills) rises among glaciers; but there is
nothing like glacial work opposite to this great river-basin in the
plains. In the Kangra valley there was no sign of a great glacier
passing along the base of the Sutlej valley from east to west. Such
a glacier, if it ever existed, must have left a conspicuous mark. So
far as I have been able to learn from surveyors, geologists, travellers,
photographers, and photographs, there are no marks of a big glacier
in the Sutlej valley so far as it has been explored, but existing
glaciers are close at hand” (id. p. 115).
In regard to the famous deposit of rounded stones in this valley,
about which so much has been written and said, the same acute and
experienced observer writes that “at first sight these stones by their
great size suggested glacial action. They have been described as
erratics, and the deposits in which they occur as ‘moraines’ of the
Glacial period. I therefore sought carefully, but I could find none
of the known marks. The Kangra big stones are all smoothed,
dinted, and rounded; the biggest are next to the range. ‘The size
decreases as the distance increases, and the slopes grow less. They
are not arranged like moraines at Turin or elsewhere, but spread
like stuff of the same kind at the foot of the Pike’s Peak in America,
and at the end of the Dariel Pass in the Northern Caucasus. The
deltas to which these trains of big stones belong all spread like fans
from the jaws of deep, steep ravines near high, steep hills, and they
are all washed and rolled by floods of water... ..
At Dhada, a rest-house at the foot of the high range, “a gravel-
104 = A. S. Woodward—Belgian Neozoic Fish-teeth.
pit has been described by a very experienced geologist as one of the
Kangra moraines. The solid rock under the loose stuff was newly
laid bare. It is not glaciated. The whole of the stuff was sorted
by running water, and the big stones strewed on the top evidently
are the largest and heaviest in an old river deposit laid bare by
late rains which have washed away smaller stuff. There was no
moraine stuff in the section, no clay, and no scratched stones any-
where.”
Mr. Campbell is most emphatic in his conclusion that the
Himalayas present us with no evidence of a Glacial period. Glaciers
exist there, and may have been larger. ‘‘ While,” he says, ‘ Scandi-
navian and Alpine ice has shrunk by many meridian degrees, old
Himalayan glaciers have left no mark within a few miles. It seems
as reasonable to account for the length of an icicle by a Glacial
period, as to summon that cause to account for any extension of
Indian ice of which I was able to obtain proofs, from maps and
surveyors, geologists and papers, photography and photographers,
and travellers” (id. p. 118).
(To be continued in our next Number.)
II.—Nores on some FisH-REMAINS FROM THE LOWER TERTIARY AND
Uprrr Cretacrous or Bexierum, Contectep By Monsinur A.
Hovuzeav pre LeEnatz.
By Arruvur SmirH Woopwarp, F.G.8., F.Z.S.
(PLATE III. Fies. 1-17.)
OME time ago the writer was favoured by Monsieur A. Houzean
de Lehaie with the opportunity of studying his extensive col-
lection of teeth and other remains of fishes from the Bruxellian
HKocene, near Brussels, and the “Craie brune phosphatée de Ciply,”
near Mons. Monsieur Houzeau has generously presented a fine
series of these fossils to the British Museum, and the following
notes are based upon the collection.
I. Tue Fisn-rauna oF tHe Bruxetuian Eocene.
Like the contemporaneous Bracklesham Beds in England, the
Bruxellian Sands of Woluwe St. Lambert, near Brussels, yield only
very fragmentary remains of fishes. These have been studied more
especially by M. H. Le Hon! and Dr. T. C. Winkler;? and MM.
P. J. Van Beneden* and L. Dollo* have contributed additional notes.
1 H. Le Hon, ‘‘ Préliminaires d’un Mémoire sur les Poissons Tertiaires de
Belgique’’ (1871).
2 T. C. Winkler, ‘‘ Mémoire sur des Dents de Poissons du Terrain bruxellien,’’
Archiv. Mus. Teyler, vol. iii. (1874), pp. 295-804, pl. vii. ; also idid. vol. iv. (1876),
pp. 16-48, pl. u.
> P. J. Van Beneden, ‘‘ Recherches sur quelques Poissons fossiles de Belgique,””
Bull. Acad. Roy. Belg. [2], vol. xxxi. (1871), pp. 153-179. Also ‘‘ Notice sur un
nouveau Poisson du Terrain bruxellien,’’ idid. vol. xxxv. (1873), pp. 265-259, with
plate (Homorhynchus bruxelliensis).
4 L. Dollo, ‘‘ Premiére Note sur les Téléostéens du Bruxellien (Hocéne moyen) de
la Belgique,’’ Bull. Soc. Belg. Géol. etc. vol. iii. (1889), Proc.-Verb. pp. 218-226
(Arius Egertoni).
Geol. Mag 1891 . Deeade II, Vol. VIL, PL II.
Berjeau.& Highley del.eb lth .
1-17. BELGIAN EOCENE AND CRETACEOUS FISHES .
18.DENTAL CROWN OF BOTTOSAURUS BELGICUS, spmoy-
A. 8. Woodward—Belgian Neozoic Fish-teeth. 105
Several of the original determinations of the fossils were based upon
insufficient comparisons, and have subsequently proved erroneous ;
and the examination of M. Houzeau’s collection now enables the
present writer to confirm and extend the revision commenced by
recent authors.
ELASMOBRANCHIL.
Cestracion Duponti, Winkler. PI. III. Fig. 1.
1876. Cestracion Duponti, T. C. Winkler, Archiv. Mus. Teyler, vol. iv. p. 17,
pl. u. figs. 1-3.
Some anterior prehensile teeth of Cestracion have already been
described and named C. Duponti by Dr. Winkler ; and it is interesting
to find in M. Houzeau’s collection one of the crushing teeth so
characteristic of the middle portion of each ramus of the jaw in
this genus. The specimen measures 0:0095 in length and 0-008 in
maximum breadth, and is shown from the coronal aspect, of twice
the natural size, in PI]. III. Fig. 1. Having been discovered in the
same formation and locality as the prehensile teeth, and agreeing
with the latter in its comparatively small size, the new specimen
may also be named C. Duponti, and thus adds somewhat to the
scanty definition of the species. The tooth tapers gradually to its
extremities, which are obtusely angulated, almost rounded; and
there is a prominent median longitudinal keel, which rises to a blunt
apex at the point of maximum breadth. The coronal surface is also
coarsely rugose.
It is interesting to observe that the crushing tooth just described
corresponds more closely with those of the Cretaceous species than
with those of the existing forms; and it may be added that a similar
tooth has already been recorded from the London Clay of Highgate
Archway."
Odontaspis elegans (Agassiz).
1843. Lamna elegans, L. Agassiz, Poiss. Foss. vol. iii. p. 289, pl. xxxv. figs. 1-5
(non figs. 6, 7), pl. xxxviia. fig. 59 (non fig. 58).
1871. Lamna elegans, H. Le Hon, Prélim. Mém. Poiss. Tert. Belg. p. 12.
1875. Lamna elegans, A. Rutot, Aun. Soe. Géol. Belg. vol. i. p. "34.
1876. Otodus striatus, T. C. Winkler, Archiv. Mus. Teyler, vol. iv. pp. 8, 24, pl. i.
figs. 7-9.
1876. Lamna elegans, T. C. Winkler, ibid. p. 9.
1876. Lamna elegans, G. Vincent, Ann. Soc. Roy. Malacol. Belg. vol. xi. p. 123,
pl. vi. fig. 4.
1876. Otodus striatus, G. Vincent, ibid. p. 125, pl. vi. fig. 2.
1880. Zamna elegans, T. C. Winkler, Archiv. Mus. Teyler, vol. v. p. 74.
1885. Lamna elegans, F. Noetling, Abh. Geol. Specialk. Preussen u. Thtiring.
Staaten, vol. vi. pt. 4 Pp: 61, pl. iv.
1889. Odontaspis elegans, A. ~ Woodward, Catal. Foss. Fishes Brit. Mus. pt. i.
p- 361
Typical teeth of this species occur, and it seems most probable
that the teeth named Otodus striatus by Winkler are truly referable
to the sides of the upper jaw of the same fish. Noetling has
attempted to restore the dentition from the fossils of the Eocene
of Samland, placing relatively low-crowned and broad compressed
1 Catal. Foss. Fishes Brit. Mus. pt. i. p. 336.
106 A. 8. Woodward—Belyian Neozoic Fish-teeth.
teeth in the upper jaw,—an arrangement agreeing precisely with
that of the existing species of Odontaspis. Notwithstanding recent
criticisms,! we still venture to maintain that the form of the anterior
teeth proves the species to be referable to the last-mentioned genus,
and not to Lamna.
Oxyrhina nova, Winkler.
1876. Oxyrhina nova, T. C. Winkler, Archiv. Mus. Teyler, vol. iv. p. 22, pl. ii.
fig. 8.
This species may be accepted as well defined.
Oxyrhina Desori, Agassiz.
1843. Oxyrhina Desorii, L. Agassiz, Poiss. Foss. vol. iii. p. 282, pl. xxxvii.
figs. 8-13.
1885. Oxyrhina xiphodon, F. Noetling, Abh. Geol. Specialk. Preussen u. Thiring.
Staaten, vol. vi. pt. 3, p. 50, pl. iii. : ;
1889. Oxyrhina Desorii, A. 8. Woodward, Catal. Foss. Fishes Brit. Mus. pt. i.
p. 382.
Some broad upper lateral teeth of this species occur in M. Houzeaun’s
collection, and resemble those figured by Noetling (under the name
of Oxyrhina xiphodon) from the Samland Eocene.
Lamna vertiealis, Agassiz. PI. III. Fig. 2.
1843. Lamna (Odontaspis) verticalis, LL. Agassiz, Poiss. Foss. vol. iii. p. 294,
pl. xxxvii a, figs. 31, 32. ae
1874. Otodus minutissimus, T. C. Winkler, Archiv. Mus. Teyler, vol. iii. p. 297,
pl. vii. fig. 2.
1876. Otodus parvus, T. C. Winkler, doc. cit. vol. iv. p. 7, pl. i. figs. 5, 6.
1876. Otodus minutissimus, T. C. Winkler, ibid. p. 23.
1880. Odontaspis mourloni, T. C. Winkler, Joc. cit. vol. v. p. 77, figs. 1, 2. !
1883. Lamna (Odontaspis) verticalis, W. Dames, Sitzungsb. k. preuss. Akad. Wiss.
Berlin, pt. i. p. 145, pl. iii. figs. 8-10. ;
1886. Odontaspis minutissimus, F. Noetling, Sitzungsb. naturf. Freunde Berlin,
p. 16.
The large series of teeth of this species in M. Houzeau’s collection
seems to justify the above synonymy suggested by Prof. Dames.
The form and proportions of the anterior teeth are characteristic of
the true Lamna; and a typical lateral tooth is shown, of the natural
size, in Pl. III. Fig. 2.
The type specimens of L. verticalis are stated by Agassiz to have
been obtained from the London Clay of Sheppey, but the present
writer has not been able to identify teeth of this form from any
British Eocene deposit.
Lamna Vincenti (Winkler). —
1876. pes Vincenti, T. C. Winkler, Archiv. Mus. Teyler, vol. iv. p. 25, pl. ii.
gs. 9-10.
The teeth of this species exhibit no characters by which they can
be separated from those of the true Lamna. They are well character-
ized by Winkler, though a reference might have been made to the
supposed species, Lamna compressa of Agassiz. The latter comprises
teeth of very similar proportions but distinguished by the form of
1 J. W. Davis, Trans, Roy. Dublin Soc. [2], vol. iv. (1890), pp. 378, 398.
A. S. Woodward—Belgian Neozoic Fish-tecth. 107
the lateral denticles; and there cannot be much doubt that most of
these fossils are referable to the upper jaw of Lamna macrota.
Ginglymostoma thielense (Winkler).
1874-76. Plicodus thielensis, T. C. Winkler, Archiv. Mus. Teyler, vol. iii. p. 301,
pl. vu. fig. 5, and ibid. vol. iv. p. 20.
1886. Ginglymostoma thielense, F. Noetling, Sitzungsb. Ges. naturf. Freunde
Berlin, p. 14, figs. 2, 3.
The teeth described under this specific name exhibit all the
characters of Ginglymostoma, as already noted by Noetling.
Scymnus trituratus (Winkler).
1874. Corax tritwratus, T. C. Winkler, Archiv. Mus. Teyler, vol. iv. p. 27, pl. ii.
fig. 13.
1879. Seymnus trituratus, J. Probst, Wurtt. Jahresh. vol. xxxy. p. 176.
1886. Scymnus tritwratus, F. Noetling, Sitzugsb. Ges. naturf. Freunde Berlin,
p. 17.
Some very small Bruxellian teeth are indistinguishable in shape
from those of the existing Scymnus, and may thus be regarded as
pertaining either to this genus or to a closely allied form at present
undetermined.
Squatina, sp.
A tooth of Squatina oceurs in M. Houzeau’s collection, but cannot
be regarded as sufficient for specific determination. It is less robust
than the teeth of the same genus from the Heersian Beds,’ and
similarly differs from a Belgian Pliocene tooth described by Le Hon.’
Colorhynchus rectus, Agassiz.
1784. ‘‘ Pétrification inconnue,’’ Burtin, Oryctogr. Bruxelles, pl. vi. figs. a-E.
1844. Celorhynchus rectus, LL. Agassiz, Poiss. Foss. vol. v. pt. i. p. 92 (name only).
1850. Celorhynchus, F. Dixon, Foss. Sussex, p. 112, pl. x. figs. 14-17, pl. x.
fio. 26.
iS} 7/i- Coelorhynchus rectus and C. Burtini, H. Le Hon, Prélim. Mém. Poiss. Tert.
Belg. p. 14; also P. J. Van Beneden, Bull. Acad. Roy. Belg. [2],
vol. xxxi. p. 500.
No specific differences between C. Burtini and the typical C. rectus
have been pointed out, and they may be regarded as pertaining to
one and the same form.
TELEOSTOWMI.
Lepidosteus, sp.
1874. Trichiurides sagittidens, T. C. Winkler, Archiv. Mus. Teyler, vol. iv. p. 31,
pl. ii. figs. 22, 23.
1883. ‘‘ Lepidosteus-verwandter Ganoid,’’ Hilgendorf, Zeitschr. deutsch. geol. Ges.
vol. xxxv. p. 670.
As already recognized by Hilgendorf, the teeth described by
Winkler under the name of Trichiurides are indistinguishable from
those of Lepidosteus. Numerous teeth, head-bones, scales, and
1 Trigonodus primus, T. C. Winkler, Archiv. Mus. Teyler, vol. iv. (1876), p. 14,
pl. i. figs. 18-21.
2 Sculdia biforis, H. Le Hon, Prélim. Mém. Poiss. Tert. Belg. (1871), p. 7,
with figs.
108 A. 8. Woodward—Belgian Neozoic Fish-teeth.
vertebre closely resembling those of the latter genus are well
known from several European Lower Tertiary formations; and
a single vertebra has been recorded from the Bracklesham Beds.’
Pisodus Oweni, Owen. PI. III. Figs. 3-5.
1844. Pisodus Owenii, L. Agassiz, Poiss. Foss. vol. ii. pt. ii. p. 247 (name only).
1845. Pisodus Owenii, R. Owen, Odontography, p. 138, pl. xvii. fig. 3; also
Cat. Foss. Rept. and Pisces Mus. R. Coll. Surgeons (1854), p. 167.
Numerous detached teeth occurring in the Bruxellian of Woluwe
St. Lambert are identical with those of the peculiar dental armature
described by Owen from the London Clay of Sheppey under the
name of Pisodus. Two of these specimens are shown of the natural
size in Pl. III. Figs. 3, 4, and a portion of the typical dentition from
Sheppey is represented for comparison in Fig. 5. The teeth are
rounded or irregularly angulated, while the superficial gano-dentine
is thin and soon removed by wear. The greatest diameter of the
tooth is at the base of the crown, and the hollow root tapers below
to its point of attachment to the bottom of a socket in the support-
ing bone.
_ The affinities of Pisodus seem to have hitherto escaped recog-
nition, but a fine skull from Sheppey in the British Museum
(No. 39439) shows that in all essential cranial characters it is
identical with the existing Elopine Clupeoid, Albula. The peculiar
tritoral dentition occurs upon the parasphenoid bone, and is precisely
similar to that of the last-named genus.
Ancistrodon fissuratus (Winkler).
1852. Sargus? armatus, P. Gervais (errore), Zool. et Pal. Franc., Explic. p. 5,
pl. Ixix. figs. 9, 10.
1852. Sargust serratus, P. Gervais (errore), ibid. p. 2, pl. Ixvii. fig. 8.
1874. Corax fissuratus, T. C. Winkler, Archiv. Mus. Teyler, vol. iii. p. 299,
pl. vil. fig. 4.
1876. Corax fissuratus, T. C. Winkler, Joc. cit. vol. iv. p. 12, pl. ii. figs. 11, 12.
1883. Ancistrodon armatus, W. Dames, Zeitschr. deutsch. geol. Ges. vol. xxxv.
p- 664, pl. xix. fig. 2.
As pointed out by Dames the specimens named Coraaz fissuratus
by Winkler are truly pharyngeal teeth of a teleostean fish, and
may thus be assigned to the provisional “genus” O). It is evidently rutile, a mineral not
admitted in Riess’ monograph, but recorded by Méhl? in some of
the Norwegian eclogites. The crystals are simple tetragonal prisms,
either (110) or (100).
(iii.) Garnet-Amphibolite from Sutherland.
The locality is three miles south of Laxford Bay. The rock
shows abundant red garnets imbedded in a mass of greenish-black
hornblende. A curious feature is the well-marked series of parallel
cracks by which the garnets are traversed. These maintain a
constant direction throughout the specimen, but do not affect the
hornblende. They are evidently due to stress in the rock, and,
though better developed, are of the same kind as the cracks seen in
the garnets of various crystalline rocks, such as the Eddystone
gneiss and some of the Saxon granulites. These cracks are always
at right angles to the direction of ‘stretching’ in the rock, and so
perpendicular to any foliation or schistosity that may be present.
A slice [1254] shows the rock to be composed chiefly of garnet
and green hornblende. The garnet retains its red colour, and shows
well the series of parallel cracks preserving a common direction
throughout the slide. There is a less pronounced system of cracks
roughly perpendicular to the first. The crystals are of irregular
shape, but tolerably free from inclusions. They show no double-
refraction, nor does the rock as a whole present any trace of foliation
or other parallel structure.
The hornblende is in rude columnar crystals without terminal
1 Tsch. Min. u. petr. Mitth. 1878, vol. ii. pp. 165-172, 181-241.
* Nyt Mag. Naturvidensk. vol. xxiii. (1877), pp. 128-137.
172 Alfred Harker— Various Crystalline Rocks. ;
planes, and often so massed together as to prevent their free develop-
ment. It constitutes nearly half the bulk of the rock. The colour
is an intense grass-green, the absorption being, parallel to a yellow-
green, 8 and y deep grass-green, almost opaque. The extinction-
angle ¢ y is high, perhaps as mnch as 20°, but cannot be determined
precisely owing to the strong absorption.
The other constituents are little crystals of finely lamellated
plagioclase, irregular grains of an untwinned felspar, apparently
orthoclase, shapeless granules of opaque iron ore, and a little clear
quartz occurring interstitially among the hornblende and other
minerals.
(iv.) Quartz-Diorite from Viti Levu, Fiji.
This rock occurs in the cutting for a new road on the mountains
to the south of the Wainamala valley, below Narokorokoyawa in the
island of Viti Levu. It was collected by Mr. J. J. Lister during the
voyage of the “‘ Egeria” in 1889. It is a crystalline rock showing
lustrous black crystals of hornblende, about a quarter of an inch
long, and flakes of golden-brown mica, in a mass consisting mainly
of felspar. The specific gravity is 2-778.
Sections [1256, 1257] show that the felspar is exclusively plagio-
clase, in idiomorphic crystals, in which the usual albite-lamellation
is combined with Carlsbad and sometimes with pericline-twinning.
A strongly marked zonary structure is apparent in polarized light,
the extinctiun-angles being much wider in the interior than in
the border. There is clearly a transition in each crystal from a
thoroughly basic to an intermediate felspar. The hornblende, often
twinned, is of the green pleochroic variety found in the syenites
and most true diorites, aud the mica (biotite) is brown with intense
dichroism. These two minerals are often closely associated, and, for
the most part, mould the felspar. Quartz occurs interstitially as
the latest product of consolidation. The earliest-formed minerals
are apatite and magnetite, which are enclosed by all the other
constituents.
The specimens are quite fresh, and, as regards the mutual relations
of the minerals, the zoning of the felspars, ete, agree well with
some examples of the Banatite type of quartz-diorite, such as those
from Hodrics near Schemnitz [1085] and from Ben Nevis [397],
or some of the Banat rocks themselves. Wichmann,' in his account
of the Fiji rocks, has described a diorite from near the same locality ;
but it is clearly of a different type, and he makes no mention of
either quartz or mica.
(v.) Uralitized Gabbro from Eua, Tonga Islands.
This specimen, also from Mr. Lister’s collection, is from a boulder
on the east coast of Hua, but the position in which it occurs proves
that it must belong to the island itself. The point is one of some
interest, as Hua, like the rest of the group, appears at first sight to
be built entirely of volcanic and calcareous rocks. The rock is a
1 Tsch. Min. u. petr. Mitth. (n.s.) vol. v. p. 17; 1888.
R. N. Lucas—The Older Rocks of Finland. 173
moderately fine-grained cystalline aggregate, in which little patches
of black hornblende are seen moulding the dull whitish felspars.
In a slice [1258] the felspar is seen to be a lamellated plagioclase
in crystal-plates, idiomorphic towards the bisilicates, but interfering
with one another. Some crystals have their zones of growth indicated
by slight differences in optical properties. The wide extinction-
angles point to a basic composition. The hornblende has a pale
green-brown colour, with a fibrous structure. It is sometimes a
mass of matted fibres, though more usually there is a common
orientation throughout each plate. There is no doubt that the
mineral is pseudomorphic after augite, and there is frequently an
unaltered kernel of colourless augite in the centre of the uralitic
aggregate. In places, however, the usual amphibole cleavage is seen,
and this is accompanied by more pronounced colour and pleochroism.
The only other prominent mineral is magnetite, in irregular patches,
of later formation than the felspar, but moulded by the bisilicate.
The structure of the rock points to a plutonic origin, the general
characters being those of a gabbro rather than a diabase, though to
some extent transitional.
V.—Notes on THE OxtpeR Rocks or FINLAND.
By R. N. Lucas, B.A.
(Continued from page 299, Vol. VII. July, 1890.)
HE consideration of the Archzan rocks of Finland, as pointed
out in a previous article,’ naturally divides itself into two
parts: J. The treatment of the stratified or foliated members of
the series ; IJ. That of the igneous or eruptive rocks. In describing
the former, want of space compelled me to handle the subject in
what I fear must be regarded as a very fragmentary manner. In
addition I confined myself entirely to giving an account of the
older members of the formation, omitting all mention of the younger
schists, mica-clay slates, phyllites, etc., which go to make up what
is in Finland regarded as corresponding to the Huronian subdivision.
I did this from two reasons,—firstly, because I was personally better
acquainted with the rocks in question ; secondly, because it seemed
to me that it is the problem of the origin, sequence and composition
of the older members of the series which at the present day pos-
sesses most interest for the student'of the geology of the Archean,
and in consequence is the one with regard to which the greatest
divergence of opinion prevails. In the present article I propose
to give a short account of the more important eruptive rocks of
Finland ; but before proceeding to do so, it would not, I think, be
out of place to furnish a short résumé of the conclusions to which
the study of the foliated Archean rocks of the country has led
me, and which I believe to be thoroughly supported by the data
published in my former article. These are :—
1. The succession on which I especially insist, namely, commencing
from the base—(1) Granite-gneiss; (2) Grey micaceous gneiss;
1 Grou. Mac. July, 1890.
174 RR. N. Lucas—The Older Rocks of Finland.
(3) Hornblende-gneiss or eurite. This sequence corresponds with
that which has been established by Gtimbel in Saxony, by the official
survey in Sweden, by Groth in the Central Vosges (Geog. Unt. des
Reichslands), and recently by Prof. Bonney in Switzerland. A
similar sequence does not as yet appear to have been established
among the Archean rocks of the British Isles; but this may be due
to local causes or to its having hitherto escaped the notice of
geologists.
2. That the Archean rocks of Finland present a similarity—I
might I think almost say identity—of structure and composition
with those of all true Archean territories, whether situated in
Switzerland or Scandinavia, Canada or Saxony.
3. That though we meet with numerous instances of gneisses
which have been crushed and contorted, we also find plenty of
examples which show no evidence of excessive pressure, and are
nevertheless in all respects typical gneisses. This is particularly
the case with regard to granite-gneiss and hornblende-gneiss.
4, That many, if not all, of the crystalline limestones which occur
apparently interbedded with granite and gneiss, and in some of
which ‘“ Hozoon Canadense” was formerly asserted to occur, are not
deposits but veins, and are properly speaking to be classed with
pegmatites and metallic lodes.’
Such are, I think, the principal conclusions to which a careful
examination of the Finnish Archean rocks conducts. They may, I
trust, prove of interest not only because they summarize the results
of research in a distant country, but also because, owing to the
similarity of the Archean system at all points where it has been
observed, they may be regarded without hesitation as applicable
beyond the limits of the district from the study of which they have,
in the first instance, been derived.
Hrurtive Rooks.
In my former article I massed both foliated and eruptive rocks
together under the general heading of Archean. This procedure is
both convenient and customary, but it must be understood that its
adoption involves the making of assumptions only some of which
are in accordance with facts, others being actually controverted by
them. Thus to regard the crushed and foliated granites which are
interbedded with the older gneisses as of similar age with those
gneisses themselves is a view which, as far as I am aware, there is
nothing to disprove. But to consider all the eruptive rocks which
pierce the gneiss formation as of Laurentian or even Archean age,
is an opinion which it seems to me there is not only nothing to
support, but even the strongest presumptive evidence to disprove.
Examples of this are afforded by the rapakivi, which in Southern
and Western Finland occurs penetrating older strata, and might, if
it had only been observed in those two districts, be regarded as of
1 Instances in point are afforded by the limestones of Hoponsuo and Henriksnas,
in which the Russian geologist Pusirewski—one of the worshippers of ‘‘ Hozoon”’
—formerly believed himself to have discovered the object of his adoration !
R. N. Lucas—The Older Rocks of Finland. 175
Laurentian age. In the neighbourhood of Joensuu, however, a
rock corresponding in all respects to the rapakivi of the south and
west, was discovered by Prof. Wiik contorting and dislocating
Huronian slates and phyllites, and hence it has become customary
to consider the rapakivi as a ‘“‘ younger” eruptive rock. The case
of the diabases is very similar. No grounds could be advanced
which would lead to the conclusion that the dykes and bosses of
the north of Ladoga Lake (Wallamo) are much more recent than
the Huronian period. But in the extreme west of Finland a strip
of sandstone occurs which is usually regarded as Cambrian, and this
sandstone is pierced by diabase dykes. There is a strong family
resemblance between nearly all the Finnish diabases, and it would
certainly not be a very violent hypothesis to look upon them all as
approximately of the same age, 7.e. Cambrian or later—how much
later we cannot form even an approximate opinion, as in Finland
there is a “Gonungagap” from early Cambrian to Quaternary times.
I now pass to the consideration in detail of the more important
igneous rocks following the natural subdivisions of the subject, and
commencing with a description of—
1. Tue Actp Ervuptivt Rocks.
Gneiss-Granite.—The base of the crystalline series we found to
consist of the granite-gneiss—a rock in which coarseness of banding
and indistinctness of foliation cause it to present a superficial
resemblance to granite. In the gneiss-granite we have a granite
which, through the influence of pressure, shearing-stress, or other
causes, has assumed the appearance of a fissile gneiss, and which
might be very appropriately termed a foliated granite. In many
instances it appears to be the oldest member of the eruptive series ;
for in most cases where it is pierced by unaltered granite, the latter
is plainly a younger rock. I think, however, it would be incorrect
to assume that all gneiss-granites are of the same age, for I have
seen plenty of evidence to make me incline to the opinion that
gneiss-granite is in reality a facies assumed by granites which may
differ in age. Among other reasons for thinking this to be the
case, | may mention that I have most distinctly observed at least
one case in which a boss of granite which was mineralogically
homogeneous throughout, showed unmistakeable foliation near its
edges, which became less distinct and finally disappeared on
approaching the centre of the mass. This, I think, can only be
explained by assuming that pressure and. shearing-stress have made
their influence more felt upon the exterior portions than upon the
interior.
Statigraphically the gneiss-granite usually preserves relations of
more or less intimacy either with the granite-gneiss or with the
grey gneiss, running side by side with one or other of these rocks
over considerable tracts of country. Its foliation always appears
parallel to the strike of the gneisses—a fact which certainly favours
the view that it was the same pressure which tilted the gneiss strata
into their vertical position which produced the foliation of the granite.
176 R. N. Lucas—The Older Rocks of Finland.
That in spite of its foliation it is of eruptive origin is very well
shown by the fact that where it has gneiss for its next door neighbour,
the latter rock becomes impregnated with granite-magma, which, as
the gneiss-granite is the only granite near, cannot have been derived
from any other source. It is often said to pass into ordinary non-
foliated granite of a mineral composition identical with its own. I
feel very little doubt, however, that in many cases in which this is
stated to have been observed, and which I have not myself seen, the
facts are in reality similar to those in the instances I gave above,
namely, that the whole mass is one granite, foliated externally, and
losing its foliation inwards.
Cases occur in which the gneiss-granite is pierced to such an extent
by bosses and veins of massive (unsheared) granite, doubtless of later
age, that it becomes a matter of difficulty to decide which of the two
rocks in reality predominates. This state of things prevails in the
neighbourhood of the village of Nummis.
Petrographicaily the gneiss-granite consists, like ordinary granite,
of quartz, felspar, and mica. The quartz and felspar are as a rule
disposed quite irregularly throughout the mass of the rock, but the
mica occurs in laminz which show parallelism of arrangement, giving
rise to a semi-schistose, at times fissile appearance. Thus the
apparent foliation of the rock is due entirely to the mica, and if we
could dissolve it out or eliminate it by any other means, we should
as a rule obtain a structureless mass of felspar and quartz. It is
consequently the mica which enables us to distinguish gneiss-granite
both from ordinary massive granite and from granite-gneiss. In the
former no order of arrangement whatever is observable among the
minerals composing it. In the latter there prevails a certain
parallelism of arrangement among all the minerals of which it con-
sists, and this would still remain to be observed even if any one of
them such as the mica were to be removed. Jn addition true gneiss
nearly always displays more or less stratification which is entirely
absent in the case of gneiss-granite, for the latter quite resembles
typical massive granite in its petrological uniformity and sameness
of colour over wide areas.
Occasionally a certain subsidiary parallelism of mica cutting the
principal mica planes at an angle is observable. This appearance
we may, I think, correctly attribute to secondary stresses—it is in
fact the outward and visible sign of secondary cleavage.
There is also a curious variety of gneiss-granite in which the rdéle
ordinarily played by the mica is assumed by the quartz. In these
cases the quartz individuals are found as a species of laminze arranged
parallel to the general direction of cleavage and contributing to it
(Mantsila district). Where the quartz occurs in this manner, the
mica no longer shows parallelism—on the contrary, the mica and the
felspar are then disposed quite irregularly throughout the whole.
Rapakivi, Sheet No. 7.—The towns of Borga and Friedrikshamn
are situated in the Gulf of Finland, about 70 miles apart. A square
erected upon a line joining the two would, roughly speaking, com-
prise the celebrated Rapakivi district of the South of Finland. The
R. N. Lucas —The Older Rocks of Finland. 177
whole of this region is comparatively flat in character, consisting of
round dome-shaped protuberances covered with wood and alternating
with lakes and shallow valleys above the level of which they seldom
rise to a distance of more than about 50 or 100 feet. With the
exception of a few dykes and bosses of younger granite and syenite,
rapakivi forms the fundamental rock throughout the whole of this
district, and there is scarcely a hillock or elevation where it is not
to be seen emerging from beneath the Post-Tertiary formations which
frequently overlie it, and presenting to the view the large crumbling
boulders from which the rock has derived its name—rapakivi meaning
in Finnish rotten or crumbling stone. The aspect of these boulders
is very peculiar, at times picturesque; on the weather-side they
have not unfrequently crumbled away to what is obviously not more
than half their original size, and the base of the rock is in conse-
quence covered with a talus of weathered fragments of felspar
quartz-grains, hornblende crystals, etc., among which the large egg-
shaped balls of orthoclase, varying from about an inch in diameter to
the size of the fist, are still to be found comparatively intact.
Petrographically rapakivi consists of an aggregate of quartz,
orthoclase, biotite and hornblende—the last being always in evidence.
The orthoclase varies from pink to brick-red, occurring as a rule in
erystals of 1din. to 24in. long and lin. to 2in. thick, with glassy
principal cleavage often appearing as Carlsbad-twins, and forming
the principal constituent of the rock. Owing to radial accretion, it
often happens that the crystals assume the form of oblong spheres
which occur notably in the neighbourhood of Hlima. These large
erystals of orthoclase are surrounded by a mantle of oligoclase of a
yellowish-green colour turning white on weathering. The quartz
erystals, which are smoky grey or white, average about din. in
diameter. The mica, which is extremely black, is pretty equally
distributed throughout the whole in the form of brilliant lamine.
The hornblende, which is black, occasionally turning somewhat
green, occurs only in small quantities and in the form of short
monoclinic prisms. The rock does not display the slightest tendency
towards parallel arrangement of any of its constituents.
Rapakivi has been microscopically examined by H. Gylling, from
whose report the following facts are taken.
“In addition to orthoclase and oligoclase, microclinic felspar also
occurs, recognized by its peculiar structure and the fact that it
extinguishes polarized light 14° to 15° from the edge between the
clinopinacoid! and the basal plane. The microscopic.-examination
further shows that the quartz crystals are sometimes fully crystallized
out and contain water in minute cavities (fluid inclusions). Both
hornblende and oligoclase are much weathered, the former occa-
sionally being decomposed into calcite. As occasional constituents
occur yellow and yellowish-brown prisms of zircon, red laminz
and needles of hematite, and black opaque masses of magnetite
7 It will be seen that microcline is here regarded as really monoclinic—an opinion
with which I certainly agree.
DECADE III.—VOL. VIII.—wNO. Iv. 12
178 R. N. Lucas—The Older Rocks of Finland.
and titaniferous iron ore. Crystals of fluor-spar are also at times
visible even to the naked eye.”
Though as above pointed out the rapakivi is almost perfectly
uniform in its characteristics throughout the district in which it
occurs, a variety distinguished by comparative hardness and capacity
for resisting the weather is also found, as a rule on the confines of
the rapakivi region proper; for instance, in Morskom, Perno, and
Borga parish, where, as also in Helsingfors, it is largely used as a
building-stone. In this variety there is usually Jess oligoclase and
hornblende, and the orthoclase and quartz crystals are of larger size.
The remarkable tendency to fall to pieces under the action of the
weather, which, if we except the occurrence of microcline, is perhaps
the most characteristic peculiarity of rapakivi, has given rise to a
variety of attempted explanations. Some have inclined to the
opinion that the phenomenon in question is due to the presence of
iron. A strongly weathered rapakivi from Lapptrask, however,
was found to contain 7-62 per cent. of iron, while an unweathered
sample from Elima gave as much as 6°53 per cent.—a difference in
amount hardly sufficient to explain the observed variations in
behaviour towards the weather. Others again attribute the opposite
effects observed in the two varieties to the different proportions of
silica. Here are some analyses bearing upon the question :—
Silica.
A non-weathered rapakivi from Strémfors ... ... 00. 2. eee 67°44
A similar rapakivi from Elima ... ... sts | testes MODI
Rapakivi from Korsmalm, near Lapptrisk, ‘much weathered... ... 77°61
There seems, however, to be no reason why a high ‘porate of
silica should conduce to weathering, and it does not always appear
to be the case that the weathered specimens contain more silica than
the unweathered. Probably Moberg is right in attributing the
principal réle in the matter to the oligoclase which weathers easily
and occurs in greater amount in the weathered samples.
At a few places within the rapakivi territory it is pierced by
dykes of a younger granite consisting mainly of orthoclase and
quartz as at Norrby, near Lapptrisk.
Rapakivi is everywhere very much jointed and the jointing takes
place in certain regular directions.
This peculiar rock is, as is well known, confined exclusively to
Finland, with the exception of the boulders which were transported
thence to the North German Plains by the agency of ice during the
Glacial Period, where they are to be met with very frequently and
have been elaborately described by v. Ungern Sternberg (N. Jahrb. f.
Min. 1882).
There is another rapakivi district in the West of Finland, in
the neighbourhood, namely, of Nystad. Here the rock differs a
good deal from the southern and more characteristic type described
above. The structure there so common, according to which the
orthoclase balls are surrounded by a sort of mantle of oligoclase,
is here seldom observed. On the contrary, the orthoclase usually
occurs in separate crystals of considerable dimensions, and the
Notices of Memoirs—Three Papers on Graptolites. 179
general matrix of the rock surrounds the balls or nodules of orthoclase
without any intermediary concentric oligoclase layer.
Microscopically it differs also from the other variety in being
destitute of microcline. It occasionally shows micro-pegmatitic
structure ; and its quartz is peculiar, being very idiomorphically
developed and containing long needles (microliths) of a dark-coloured
mineral which the American geologist Hawes declares to be rutile.
In its stratigraphical relationships the western rapakivi is very
interesting, a great deal of evidence having been collected tending
to show that it has both exercised an enormous pressure on the rocks
through which it has been forced, and has itself in places been
modified by this pressure, which may perhaps justify the assumption
that it was in a very pasty condition when irrupted. The southern
rapakivi on the contrary does not appear to have modified the sur-
rounding rocks at all.
Great masses of granite, syenite, and eleolite-syenite occur
throughout the country; but as they do not on the whole differ from
similar rocks in other districts, I have not devoted any space to
a description of them.
The various questions relating to the origin, characteristics and
occurrence of pegmatites, I propose to reserve for future consideration.
INCRE OAS) — (Oar AMia aM OuesyS)
Turee Papers on GRAPTOLITES.
1. Usper pas ALTER DES SOGEN. GRAPTOLITHEN-GESTEINS MIT
BESONDERER BERUCHSICHTIGUNG DER IN DEMSELBEN ENTHALTENEN
GRAPTOLITHEN. Von Herren Orro JAEKEL, in Berlin. Zeitschr.
d. deutschen geolog. Gesellschaft, Jahrg. 1889, pp. 653-716,
Wafoxx vill, XX1x.
2. Gottanps Graprouiter. Af GrruarD Horm. Bihang till K.
Svenska Vet.-Akad. Handlingar, Bd. 16, Afd. iv. No. 7 (1890),
pp. 1-34, Taf. 1, 2.
3. UNDERSOKNINGAR OFVER SILJANSOMRADETS GraproLiter. Af Sv.
Leoyu. Tornaurst. Lunds Univ. Arsskrift. Tom. xxvi. pp. 1-33,
atest: 11.
1. On THE AGE OF THE SO-CALLED GRAPTOLITE STONE, WITH SPECIAL
REFERENCE TO THE GRAPTOLITES CONTAINED THEREIN. By Orto
JAEKEL.
2. Tue GRAPTOLITES OF THE IsLAND oF GoTLAND. By GerRHARD
Hom.
0. AN EXAMINATON OF THE GRAPTOLITES OF THE District or SILJAN,
Datarne, Swepen. By Sy. Leonu. Tornautst.
oe through the Drift of Northern Germany there are
numerous boulders of calcareous rock containing, with various
other fossils, several species of Graptolites, and for this reason they
were styled “ Graptolithen-gestein” by Ferd. Roemer. The parent-
rock of these boulders, situated somewhere in the Silurian basin of
180 Notices of Memoirs—Three Papers on Graptolites.
the Baltic, has not yet been discovered, and different opinions have
been expressed as to the particular divisions of the Silurian to which
the boulders belong. By the majority of German geologists they
have been referred to the highest series of the Silurian ; the Swedish
geologists on the other hand place them about the middle of the
Upper Silurian series. With the view of elucidating the question,
Dr. Jaekel has examined the Silurian outcrops in the West of
England, and he finds that there is a very close correspondence both
in the petrological characters and the fossils of these boulders with
the beds of Wenlock Shale age exposed at Burrington, near Ludlow,
and therefore he maintains that they really are of the age of the
Wenlock Shale.
In the present paper the characters and the geological distribution
of the fossils in the boulders are treated of, but the author more
particularly refers to the Graptolites, and brings forward some new
structural features which in his opinion will considerably modify
their present classification. Thus in the genus Monograptus, two
groups are proposed, based chiefly on the different position of the
thecal aperture and its appendages. In the first of these, Pristio-
gruptus, the aperture is free, and occupies the entire upper end of
the theca, and the only appendages are spines on the lower margin
of the aperture, and these are not always developed. In the second
group, Pomatograptus, the outer portion of the theca is contracted,
the aperture is small and situated beneath an extended roof-like
process which forms the upper end of the theca. Hitherto the
thecal aperture in these Graptolites has been supposed to be
at the extreme end of this arched process, but the well-preserved
examples figured by Dr. Jaekel show that this view is erroneous.
The author further maintains that Graptolites were not free-
swimming organisms, but probably lived at the bottom of deep seas
lightly anchored in the mud. He also considers that the simple
forms of Monograptus are not complete, but only branches of colonial
stocks; but, as pointed out by Dr. Holm, he seems to have over-
looked the fact of the presence of the sicula, which is never wanting
at the proximal end of the organism, and thus conclusively shows
the primary commencement of the growth of the polypary. A |
description of the structure of Retiolites is likewise given, but in this
no account is taken of the earlier works of Tornquist and Tullberg.
In the second paper above mentioned, Dr. G. Holm has revised
the list of Graptolites occurring in the Silurian strata of the Isle of
Gotland, and enumerates the following nine species and varieties ;
Dictyonema cervicorne, n. sp., D. abnorme, n. sp., Monograptus priodon,
Bronn, D. priodon, var. Flemingii, Salt., M. subconicus, Torng., M.
dubius, Suess, M. sp., Retiolites Geinitzianus, Barr., and R. nassa,
n.sp. A list is given of the names and distribution of the known
species of Dictyonema, and a very careful description of a new species,
D. cervicorne, based on specimens obtained free from matrix. Jn
these the upper portion of the theca is extended into a long, spined
process bifurcated at the extremity; and connected laterally with
each theca there is a cup-like or nest-shaped structure, possibly a
Reviews—Dr. A. Bigot—Archean and Cambrian of France. 181
gonangium. Dr. Holm further describes and figures some remarkably
well-preserved examples of Retiolites and Stomatograptus, in which
the structural details are clearly shown.
In the third paper, Professor Térnquist describes 22 species of
Graptolites occurring in the Ordovician and Silurian strata of the
district of Siljan; of these the following are regarded as new,
Clonograptus robustus, Tetragraptus curvatus, Didymograptus gracilis,
D. decens, Climacograptus internexus, and Diplograptus bellulus.
Many of the species in the area referred to are likewise common to
the Coniston Flags and to the Quebec Group of Canada,
RAV LHW SS.
eee.
L’ArcHi&en ET LE CAmMBRIEN DANS LE Norv pu Massir Breton
ET LEURS EQUIVALENTS DANS LE Pays pE Gauurs. Par A. Breor,
Docteur-és-Sciences. (Cherbourg, 1890.)
OCTOR BIGOT is a young French geologist who is rapidly
winning his spurs. Having done excellent work amongst the
older rocks of Northern France, he came over to Great Britain, and
compared the systems with which he was familiar with some of the
basal rock-groups of Wales and Shropshire. The results of this
comparison are given in the work before us, and will be found to be
in substantial agreement with the views maintained by those who
in this country have paid the fullest attention to the Archzan and
Cambrian rocks.
In the first part of his work Dr. Bigot describes the phyllads and
purple conglomerates in the district of Saint-L6 and in the west of
Calvados. From the typical area, he passes to the northern extension
of these formations, as studied in the district round Cherbourg. He
then takes up the same rock-groups south of Saint-L6, and describes
their occurrence in the south of Calvados, at Granville, and in the
island of Jersey, which lies about 50 miles to the north-west of
Granville. In Chapter IV. the author discusses the relation between
the Phyllads and the older Paleozoic groups. Chapter V. gives an
account of the eruptive rocks of Normandy and the Channel Isles ;
and Chapter VI. concludes the first part with a description of the
peneral stratigraphy of the Breton massif. In the succeeding chapters
the author discusses the correlations of the older rocks of north-
western France with their equivalents in Pembrokeshire, North
Wales, and Shropshire; and winds up with an excellent summary
of his conclusions. Then follows a valuable bibliographic index,
the authors being classed under the respective heads of ‘‘ The Breton
massif,” and “ Wales” (including Shropshire).
The schistose and slaty rocks named after the town of Saint-L6,
and usually referred to by French geologists as “schistes” or
“phyllades,” have been described by a long series of writers.
Dufrénoy in 1838 identified them with the Cambrian of Great
Britain, a very natural opinion at a time when the Longmynd
Series was accepted as typical Cambrian, and when the existence
of slaty rocks below the Cambrian was not recognized in Hurope.
182 Reviews —Dr. A. Bigot—Archean and Cambrian of France.
Dufrénoy’s identification was accepted by Dalimier, Bonissent, De
Lapparent, and finally by Barrois, though it should be remarked
that the last-named writer has been wont to quote Dufrénoy’s
opinion without positively endorsing it. Professor Hébert, however,
adopting a Cambrian age for the ‘“Conglomérats pourprés,” and
observing that these strata were unconformably superimposed upon
the ‘‘Schistes de Saint-L6,” concluded that the latter were of
Archean age. In this opinion, the late Professor of Geology at the
Sorbonne has been followed by his pupil, Dr. Bigot.
The evidence given in the volume before us would seem to be
decisive of the true relation of the Saint-L6 Series to the purple
conglomerates. The author confirms the existence of the strati-
graphical discordance alleged by Hébert, and he affirms that the
newer series contains pebbles of the sandstone which is intercalated
amongst the Phyllads. The unconformity would therefore seem to
be very marked.
The researches of Dr. Ch. Barrois and Dr. Bigot have brought to
light additional resemblances between the rocks of Saint-L6 and the
younger Archzans of Britain. According to the former writer, the
Saint-L6 Series sometimes presents a volcanic facies. In the north
of Brittany, acid rocks, such as “ quartz-porphyries and petrosilex,”
are said by him to be interstratified with the Phyllads, and to
furnish rounded fragments to the Conglomerates of Montfort, the
equivalents of the ‘“‘Conglomérats pourprés.” Dr. Bigot records
similar facts. He states that, at La Hogue and in the island of
Alderney, the “purple conglomerates” contain pebbles of ‘ petro-
siliceous porphyries,” evidently derived from an older formation.
According to Dr. Bigot, the district of La Hogue furnishes still
more emphatic proof of the gap between the Phyllads and the
purple conglomerate. A quarry displays a section of the Phyllads,
penetrated by numerous veins of “ granulite,’ and surmounted by
the purple series. The veins are described as modifying the
Phyllads, but producing no effect upon the purple beds; and it is
inferred by Dr. Bigot that the older group was invaded and meta-
morphosed by the granite previous to the deposition of the purple
conglomerates.
Weare gradually learning that the resemblances between the newer
Archean rocks in Northern France and Western Britain are very
close indeed. In the British area, the predominating types of rock
in the Pebidian (or Uriconian) are acidic volcanic eruptives, hypo-
metamorphic schists, grits more or less altered, and comparatively
unaltered slates; and these are precisely the lithological characters
most conspicuous in the Phyllads of Saint-Lo. The present writer
accompanied Dr. Barrois and Dr. Bigot in the year 1888 to Caer
Caradoc. Both of these geologists were struck with the lithological
similarities between our Uriconian and the volcanic rocks associated
with the Phyllads, and they have recorded their impressions in
subsequent publications.
But the parallelism between the older rock-groups of the French
and British areas has been shown to extend yet further. Dalimier,
Reports and Proceedings—Geological Society of London. 183
in 1861, and Bonissent, in 1870, recorded the occurrence of con-
glomerates intercalated in the Phyllads. Barrvis, in 1884, gave a
list of the contained pebbles, amongst which was a “ granite identical
with that of Chausey.” Hébert, subsequently (1886) described this
conglomerate, also identifying the Chausey granite amongst the
pebbles. and he concluded that the conglomerate proved the existence
of granites “older than the Archean,” the term “ Archean” by this
writer being limited to the group called by us “ Pebidian” or
“Uriconian.” Bigot supports Hébert’s contention, and carefully
distinguishes “the conglomerates of Granville, with pebbles of granite,
intercalated in the vertical Phyllads” from ‘the purple conglomerates,
almost horizontal, forming the base of a series which the Grés
Armoricain contormably overlies,” that is to say, he makes the former
conglomerate Archean, and the latter Cambrian.
The conglomerate of Granville strongly suggests the Archean
conglomerate, which, at Charlton Hill near the Wrekin, contains
pebbles of a granite which is undistinguishable from a granite
exposed in the Wrekin and at Malvern: and, if Hébert and Bigot
are right in their reading of the Granville section, a granite of
Pre-Uriconian age is proved in both the British and French areas.
Whether the Phyllads of Saint-L6 represent only the Pebidian
(Uriconian) of Britain, or also include the equivalent of the
Longmyndian, is at present an unsettled question. A small collection
of typical specimens from the Phyllads, sent some years ago by
Prof. Hébert to the present writer, would be considered thoroughly
typical of our Pebidian, and not at all like our Longmyndian.
The rocks which unconformably overlie the Phyllads are con-
sidered by Dr. Bigot to represent the several horizons of our British
Cambrian. In the following table he indicates the parallelism which
he believes to subsist between the members of the older systems in
the two areas.
WALES. NorMANDIE.
Arenig. Grés armoricain.
Olenidian. Grés feldspathiques.
Solva and Menevian. Schistes verts et grés verts.
Caerfai. Schistes rouges et marbres.
Conglomerate. Poudingues pourprés.
Pebidian. Schistes de Saint-L6.
IR IsHIS Oise) SAAN(D) 1Sss,O.Os Ia DamN lee
GEOLOGICAL Society or Lonpon.
I.—Feb. 20, 1891.—Annuat GeneraL Mererine.—Dr. A. Geikie,
F.R.S., President, in the Chair.
The Secretaries read the Reports of the Council and of the Library
and Museum Committee for the year 1890. In the former the
Council once more congratulated the Fellows upon the continued
prosperity of the Society, as evinced by its increasing number and
by the satisfactory condition of its finances.
184 ~ Reports and Proceedings—
The number of Fellows elected during the year was 76, of whom
56 qualified before the end of the year, together with 16 previously
elected Fellows, and these, with one Fellow readmitted, made a total
accession of 73 Fellows during 1890. As, however, from this
number a deduction of 43 was made for losses by death, resignation,
and removal, and for new Fellows compounding, the actual increase
in the number of Contributing Fellows was 30. The total number
of Fellows, Foreign Members, and Foreign Correspondents at the
close of the year 1890 was 1405.
The Balance-sheet for the year 1890 showed receipts to the
amount of £30384 8s. 1d., and an expenditure of £2429 16s. 2d.
Further, a sum of £420 10s. was expended in the purchase of stock,
and the balance in favour of the Society at December 31, 1890,
amounted to £433 17s. 6d.
The Council’s Report also referred to the publication of the late
Mr. Ormerod’s Third Supplement to his Index to the Publications
of the Society, to the editing of Nos. 183 and 184 of the Journal by
Prof. T. Rupert Jones, to the deaths of the late Foreign Secretary
and the late Assistant-Secretary, and in conclusion enumerated the
awards of the various Medals and Proceeds of Donation-Funds in
the gift of the Society. ;
The Report of the Library and Museum Committee included a list
of the additions made during the past year to the Society’s Library,
and announced the completion of the glazing of the Inner Museum.
In presenting the Wollaston Medal to Prof. J. W. Judd, F.BS.,
the President addressed him as follows :—
Professor Judd,—The Council have awarded to you the Wollaston Medal in recog-
nition of the important services rendered by you to Geological science, especially in
the department of Petrography. In recalling for a moment the value and extent
of these services, I am reminded that, after showing your powers by an excellent
paper on the strata of the Lincolnshire Wolds, you began your geological career in
the Geological Survey under Murchison, and that you had thus a fayourable oppor-
tunity of acquiring that practical acquaintance with the details of geological structure
which can in no way be so thoroughly mastered as by actual patient mapping. Your
volume on the ‘‘ Geology of Rutland’’ proved how well you had profited by the
advantages which your official duties afforded you. From the Jurassic rocks of
England, which you had studied in minute detail, you were led to undertake the
investigation of those of Scotland, which you succeeded in reducing to order, bringing
them into closer relationship with their equivalents in the southern part of the United
Kingdom.
It was in the course of those northern expeditions that you were drawn from the
field of stratigraphy into the study of volcanic rocks, to which you have since
devoted so large a part of your time and thought, and in the study of which you
have journeyed far and wide in this country, and have extended your travels to the
islands of the Mediterranean. The problems presented by these rocks in the field
led you to seek the aid of the microscope, and to enter upon a course of distinguished
petrographical research. I trust that the award of this Medal will be received by
you as a mark of the estimation in which your work is held by the Society in whose
Quarterly Journal most of it has been published.
Prof. Jupp, in reply, said :—Mr. President,—It is a source of legitimate gratifica-
tion to the student of science, when a favourable judgment on his efforts is pronounced
by his contemporaries and fellow-workers. In receiving this highly-prized mark of
your approval, I would fain forget for one moment, if that were possible, how far
the work—of which you have spoken in such graceful terms—falls in amount below
my hopeful anticipations of the past, how it fails to reach the standard of excellence
Geological Society of London. 185
of my cherished ideals. Any value which that work may be found to possess is
undoubtedly due, in great part, to the fostering care of the Society which to-day so
generously crowns my labours To the Geological Society, in its corporate capacity,
I am indebted for the reception and publication of the results of my studies ; to
individuals composing that Society 1 owe more than I can ever express, for kind
sympathy, warm encouragement, and friendly aid; and to both Council and Members
I shall always be deeply grateful alike for helpful suggestion and discriminating
criticism.
_ In handing the Murchison Medal awarded to Professor W. C.
Brégger, of Christiania, to J. J. H. Teall, Esq., M.A., F.R.S., for
transmission to the recipient, the President spoke as follows :—
Mr. Teall,—The Council has awarded the Murchison Medal to Professor W. C.
Brogger, of Christiania, and in asking you to transmit it to him I will request you
also to convey to him an expression of the high estimation in which we hold his
researches among the older rocks of Scandinavia. He is remarkable among the
geolugists of Europe for the great range of his acquirements. If we were to read
only his descriptions of the Silurian fauna of Southern Norway we should, doubtless,
believe him to be essentially a paleontologist. If we looked over his maps and
sections of the Christiania district, we should think of him rather as an admirable
stratigrapher and cartographer. If, again, we began with his account of the eruptive
rocks and their zone of contact-metamorphism, we should conclude that his chief
studies must have lain in microscopic and chemical petrography, of which he is so
accomplished a master. Or, lastly, if we knew him only by such essays as his late
paper on garnets, we should regard him as preeminently a mineralogist, gifted with
rare originality. He has swept a full chord on the geological lyre, and every note
sounds rich and true.
It gives me personally an especial pleasure to be the intermediary in conveying the
award of the Council, for I have had the advantage of being conducted by Professor
Brégger over some of his classic ground around Christiania, and I know from my
own experience how accurate and exhaustive is the work; how courteous, genial,
and helpful the man. He will, I trust, receive this Medal, bearing the likeness
and the name of one of the great masters of British Geology, who was also a pioneer
in the geology of Norway, as a pledge of our esteem and sympathy with him in the
great work he has already accomplished, and in the long and brillant career which
we hope is still in store for him.
Mr. Txatt, in reply, read the following communication received by him from
Professor Brégger :—‘‘I beg to express my hearty gratitude for the great and com-
pletely unexpected honour conferred upon me by the Council of the Geological Society
in the award of the Murchison Medal.
“‘The Founder of this Medal, almost half a century ago, classified the Silurian
rocks of the Christiania district, and pointed out their relations to the corresponding
strata of Great Britain; so that, if the subsequent investigations of Norwegian
geologists have furnished results of interest to the students of British Geology, this
is only a slight repayment of an old debt.
‘ Ory 90
Anterior part of skull of Zriceratops prorsus, Marsh; side view; one-
eighth natural size.
Front view of same.
The same; seen from below.
h'. nasal horn-core; . nasal; va. narial aperture; ym. premaxillary; 7.
rostral bone.
Pre-dentary of same individual ; side view; one-eighth natural size.
Bottom view.
a. anterior end; 6. upper border; d@. groove for dentary; s. symphysis.
Top view of same specimen.
PLATE VY.
Skull of Triceratops serratus, Marsh; diagram; seen from above. d.
epijugal bone; f. frontal; fp. postfrontal; 7. jugal; m. maxillary; x.
nasal; pf. prefrontal; pm. premaxillary; 2 pineal foramen (one-
twentieth natural size). :
Cast of brain-cavity of Triceratops serratus, Marsh ; side view; one-half
natural size.
c. cerebral hemispheres ; cd. cerebellum; m. medulla; o/. olfactory lobe;
on. optic nerve; p. pituitary body.
Maxillary tooth of Zriceratops serratus ; outer view; natural size.
The same tooth; side view.
The same tooth ; inner view.
The same tooth ; seen from below.
(To be continued in our next Number.)
II.—On Busatvs Barnir (SEEtry).
By Professor H. G. Snetzy, F.R.S., F.G.S., ete.
ERY little is known in England of the Tertiary deposits of
South Africa. Some marine beds are found, as at Bathurst,
where the limestone is full of teeth of Carchadon and Zamna, and
shells of Zurritella Ostrea, Donaxz, and Lucina. The shells are
200 Prof. H. G. Seeley—On Bubalus Bainia.
preserved in the Albany Museum. I was informed that these beds
are 300 to 400 feet above the sea. The teeth shown to me in their
worn, polished, yellowish tone rather recalled the condition of Red
Crag fossils.
All over the interior of the Colony freshwater Tertiary deposits
have filled up. ancient valleys, and sometimes existing rivers
have cut channels for short distances through these accumulations.
I noticed them sometimes to have been partially eroded and again
filled up, before modern river denudation laid the existing sections
bare. In these older muds and gravels are remains of a terrestrial
fauna which no longer lives in Africa. I had no opportunity of
determining its antiquity, or of making an approximate list of its
fossils; but my attention was called by M. Peringuey to some of
these remains in the South African Museum at Cape Town. Besides
these newer Tertiary fossils, there are one or two which would be of
exceptional interest if their African origin could be established.
Cranium of Bubalus Bainii, Seeley.
They are evidently very ancient acquisitions, and the circumstance
that they are not mentioned by the elder Bain, and have no mark
indicating presentation, refers them to a time too remote for tradition
to be helpful. One is the middle portion of a mammalian skull with
the teeth worn down to the alveolar margin, which seems to me to
be the Hippopotamus sivalensis and the trustees have generously
entrusted me with the specimen for determination. The skull is rather
smaller than the Indian specimens in the British Museum, and the
teeth are worn down to the alveolar border, so that characteristic
details of dental structure are obliterated. The other specimen is
the distal end of the femur and proximal end of the corresponding
tibia of an enormous proboscidian. The extremities of these bones
had a circumference of about 80 centim. They are as heavily
mineralized as Karoo fossils with which they had become associated,
and though free from matrix, are so like Siwalik specimens, that it
is possible that they may have been brought from India. In this
uncertainty I may mention that I once found in a newly unpacked
collection of Dicynodont bones from South Africa in the British
Museum, an undoubted Mammalian fragment, which was rejected as
being a Siwalik fossil, which had accidentally dropped among the
other bones. Still the possibility of such a fauna being represented
at the Cape is of sufficient interest to justify this reference to
specimens without a history.
Prof. H. G. Seeley—On Bubalus Baini. 201
Another mammalian fossil is better authenticated. In the Pro-
ceedings of the Geological Society of London, vol. ili. November
20th, 1839, the first evening communication was “Extract from
a letter addressed to Dr. Andrew Smith by A. G. Bain, Esq.,
dated Graham Town, Cape of Good Hope, February 21st, 1839,
and communicated by Charles Darwin, Esq. The object of this
extract is to announce the discovery by Mr. Martin Smith of
the piths and portions of the head of an ox in the alluvial banks
of the Moddar, one of the tributaries of the Orange River, and
40 feet below the surface of the ground. The piths with the breadth
across the os frontis measured 11 feet 7 inches, but it is calculated
that 5 inches had been broken off the end of each tip; and the
circumference of the piths at the root was 18 inches. The orbits
were situated immediately under the base of the horns. Part of
the upper jaw containing five molar teeth, and other fragments of
the head, as well as a cervical vertebra, were found at the same
time.” With time Mr. Bain’s estimate of the original size of the
horn cores extended. For in the Trans. Geol. Society, series 2, vol.
vii. p. 59, the specimen is again alluded to in a letter to Sir Henry
de la Beche from Fort Beaufort, April 29,1844. “From an alluvial
deposit on the banks of the Moddar River, before noticed, there was
obtained about five years ago the skull of a kind of Buffalo, retaining
the bony cores of a pair of horns which it is calculated must have
measured full fourteen feet from tip to tip when perfect. This fossil
is now in Cape Town.” In the same volume of the Geological
Transactions, p. 192, is a final reference to another and apparently
similar animal. Mr. A. G. Bain in a paper on the Geology of South
Africa, read Nov. 15th, 1852, says, “I ought perhaps to mention that
I have frequently heard of animal remains being discovered in the
alluvium, differing from those of existing animals; and I discovered
at Bloemhoff, in the Division of Graaf Reinet, about 10 feet below
the surface, in a marly alluvial soil, some remains of an extinct
ruminant, consisting of a skull, with the core of one horn attached,
the former being of extraordinary length in proportion to its breadth.
Its forms part of the collection of 1847 [sent to the Geological
Society ] and must speak for itseif. I have no doubt a diligent search
in the deep ruts or ravines which everywhere intersect the great
plains of the interior would produce a vast number of extinct
mammalian remains perfectly new to science.”
What became of the second specimen is not evident, but I make
no doubt that the former is the beautiful ornament which hangs
from the gallery in the South African Museum at Cape Town, partly
because Mr. Thomas Bain, who assisted in collecting specimens, has
always believed that specimen to be his father’s fossil, and partly
because it agrees with Mr. Bain’s description published in 1839. I
therefore propose to name it Bubalus Bainii.
This Buffalo has the largest pair of horn cores known in the
genus. They are remarkable not only for length, but for curvature ;
the horn bending first forward and then backward in a curve, which
lies in one plane, which otherwise rather suggests the form and
202 R. B. Newton—On the Genus Léveillia.
curvature of Mammoth tusks. The transverse measurement in a
straight line between the extremities of the horn cores, which are
nearly parallel to each other, is 8 feet 64 inches measured by M.
Peringuey. But on the right side the curve extends 14 inch further
outward from the middle line of the skull than on the left side. M.
Peringuey, of the South African Museum, had the kindness to verify
for me Mr. A. G. Bain’s measurement; and as now preserved the
length along the posterior or concave curvature is 11 feet 1 inch,
which corresponds sufficiently with 11 feet 7 inches obtained by Mr.
Bain probably by taking the outer curve. The horn cores are also
remarkably cylindrical, the flattening being moderate, a character of
some interest when compared with the flattened form of the horn
cores in the large Bubalus paleindicus of the Nerbudda. The face
is long and narrow, rounded above the orbits, flattened from side to
side and concave in length between the frontal and nasal region.
The length of the head as preserved is 224 inches, but with the
slight restoration at the back of the head and the lost premaxillary
prolongation in front it would be several inches longer. In general
character this fossil approaches nearest to the South African Buffalo,
so far as can be judged from its state of preservation ; and it probably
bears much the same relation to that type which the Bos primigenius
of our own gravels and superficial deposits has to existing British
cattle. It is not without interest to find that South Africa is no
exception to the general law, that some of the existing races of
animals have been preceded by allied species of larger size, as in
Europe, South America, and Australia.
I am indebted to a grant from the Government Grant Fund of
the Royal Society for the opportunity of identifying the specimen
described fifty-two years ago by Mr. Bain. The figure is from a
photograph taken for me by Mr. Allis, of Rosebank, Cape Town,
and is on the scale of about one millimetre to the inch.
TIl.—Ow tue Genus Lavercrra (Porceti14, LVEILLE), WITH A
Norice oF a New SrPEcIES FRoM THE CARBONIFEROUS LIMESTONE
oF IRELAND.
By R. Burzen Newron, F.G.S.,
of the British Museum (Natural History).
(PLATE VI.)
a. 1835 M. Charles Léveillé! described: a peculiar and extinct
univalve shell under the name Porcellia, which he had discovered
in the Carboniferous Limestone of Tournay in Belgium. Since that
time the right of this name to stand has never been questioned, not-
withstanding the fact of its pre-occupation by Latreille * in 1804,
for an Isopodous Crustacean genus, and which he rendered Porcellio,
As the retaining of two names so nearly alike, differing only in their
terminal letter, must constantly lead to confusion in Natural History
nomenclature, it becomes necessary to suggest an alteration, and
1 Mém. Soc. Géol. France, 1835, vol. ii. part 1, p. 39.
2 Hist. Nat. Crust. 1804, vol. vii. p. 48.
i Pi ae
Decade IIL Vol
Geol.Mag 1831.
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R. B. Newton—On the Genus Léveiliia. 203
Léveillia is therefore proposed to take the place of Léveillé’s genus
Porcellia.
I may state that my colleague Mr. EH. A. Smith, F.Z.S., the Con-
chologist of the British Museum, warmly supports my action in this
matter, and fully admits the justice and desirability of removing
Porcellia from the list of molluscan genera.
Genus Livernira, R. B. Newton, nom. mut.
Porcellia, C. Léveillé, 1835, non Latreille, 1804.
The chief characters of this genus may be briefly stated as :—Shell
nearly symmetrical, monothalamous, discoidal, biconcave; whorls
contiguous and on the same plane, except initial ones, which are
slightly raised, and all exposed within a wide umbilicus; the
dorsal area bears a narrow and centrally situated continuous band,
or groove, which opens on the external part of aperture in a slit;
aperture oval or quadrangular; surface structure beaded, ribbed, or
spirally striated; umbilical margin round or angular, with a series
of nodulations or quite plain; shell structure moderately thick.
The distinguished Belgian paleontologist, the late Prof. L. G.
de Koninck, published some extended observations on this genus
in 1843! and 1883,’ giving a full synonymy and an emended descrip-
tion of the original diagnosis.
Two species were described by Léveillé in illustration of his genus,
viz. Puzo and levigata. The latter of these being without a slit,
De Koninck removed to Euomphalus in 1843, and finally to the
genus Straparollus in 1883, trom which fact it is evident he con-
sidered the presence of the median band of the highest generic
importance, although Léveillé failed to include it among his original
characters, recognizing it as only of specific value in his description
of L. Puzo, the type of the genus. The central position of this band
divides the shell into two equal parts. With the growth of the
shell the band becomes successively filled up until it reaches the
aperture where it is still open to form the slit. The slit itself is
often difficult to trace in specimens, but it is usually well seen in
the weathered examples from Tournay. Its special function would
no doubt be as in other fissured genera for the purpose of ejecting
vitiated water from the branchial chambers of the animal.
Generic affinities.—In following the history of this genus we find
that much misconception has arisen as to its proper position in the
Mollusca. Many of its species have been ranked with the Cephalo-
poda under Ammonites, Nautilus, Goniatites, etc., though the total
absence of septa or chambers is strong evidence against such
determinations. Others have been described as Schizostoma,
Bellerophon, and Pleurotomaria. With regard to the first of these
genera, it may be stated that, possessing no slit, its other pecu-
liarities need not be discussed. On examining Bellerophon, or genera
known to be closely allied to it, we find it to be usually a heavy
globose and convolute shell, with a wide and semilunar mouth,
'1 Desc. Anim. Foss. Ter. Carbonif. Belgique, 1843, p. 357.
2 Faune Calc. Carbonif. Belgique, 1883, p. 112.
204 kh. B. Newton—On the Genus Léveillia.
which often bears strong callosities on its inner margins. The
continuous fissure is not, however, a persistent character, sometimes
consisting of a regular series of isolated perforations, as in Tremanotus
of Hall; in other species the central part of the dorsal area may be
keeled or form a mere depression without apparently any connexion
with the interior of the shell, until the lip is reached, when a deep
notch is usually present. Pleurotomaria, especially its more depressed
forms, i.e. P. mirabilis, Deslongchamps, presents more striking
resemblances to our genus. The whole of the Pleurotomariide
possess an uninterrupted slit, its position on the test varying
greatly in different species. The P. mirabilis differs from Léveillia in
being subdiscoidal and having a wide band excentrally situated, but
its surface ornament is very similar in structure and arrangement.
De Koninck,* in his latest review of this genus, ranked it with
the Haliotide, a family peculiar for shells bearing a regularly
arranged series of siphonal openings on the dorsum. With this
determination I am unable to agree, as the continuous slit or
groove is decidedly a feature of much importance in our genus.
The evidence would seem to justify us in uniting Léveillia with
the Pleurotomariide, thus following the views first adopted by Dr.
Ferd. Stoliczka? in 1868, afterwards by Mr. R. Etheridge, jun.,? in
1878, and Dr. Paul Fischer‘ in 1885. As Leéveillia and Bellerophon
have usually been considered to belong to the same family, viz.
the Bellerophontide, it may not be out of place to examine the
systematic position of the genus Bellerophon as now understood,
it having been, at all times, a question of much dispute among
Conchologists. This genus was first established by De Montfort °
in 1808, and classed under the Cephalopoda.
De Blainville® in 1825, followed by John Fleming” in 1828,
regarded it as a Tectibranchiate Gasteropod, and placed it in close
proximity to Bulla and Acton: but the peculiarities of these shells
were so very obvious that this grouping never received much
support. Deshayes,® in 1830, placed it with the Nucleobranchiata
(Heteropoda), and this view has been more generally received than
any other, though it seems somewhat anomalous when one con-
siders the delicately formed and small shells of this group, their
thin and transparent nature, and the invariable presence of an
operculum. It may be observed that no operculum has yet been
found in association with either Bellerophon or Léveillia. De Koninck’s
researches of 1843 led him to place both these genera among the
Prosobranchiates, between Capulus and Pleurotomaria. 'The Belle-
rophontidz were established by Professor M‘Coy,° in 1852, as a
family of Cephalopoda for the reception of Bellerophon only. Later,
in 1855, in a further fasciculus of the same work (p. 558), Léeveillia
1 Joc. cit. p. 10. 6 Man. Malacology, 1825, p. 477.
2 Gasteropoda, Mem. Geol. Sury. India, 7 Hist. British Animals, 1828, p. 338.
1868, p. 381. 8 Eneycl. Méthodique (vers), 1830, vol. 1.
3 Cat. Australian Fossils, 1878, p. 87. p. 133.
4 Man. Conchyliologie, 1885, p. 848. 9 Syst. Desc. British Pal. Foss. 1852,
5 Conchyl. Syst. 1808, vol. i. p. 51. p. 307.
ahs,
R. B. Newton—On the Genus Léveillia. 205
(Porcellia) was also included in the family. In 1864, Prof. James
Hall described Tremanotus, a new Bellerophontoid genus, from
the Niagara Limestone of Illinois, which possessed a regular series
of siphonal openings on the dorsal region of the shell instead of the
uninterrupted band. This discovery led to some valuable observations
by the late Mr. F. B. Meek,” in 1866, who, grasping the importance
of this unusual character in Prof. Hall’s genus, looked upon it as
the chief link of evidence required to prove the Prosobranchiate
affinities of Bellerophon, and the desirability of associating it with
the fissured shells of that group in close proximity to the Haliotide,
Fissurellide, and the Pleurotomariide. It is satisfactory to note
that Meek’s decision in this matter is at last being recognized with
favour, having been adopted by Prof. Karl Zittel* in 1882, Mr,
R. Etheridge, jun.,t in 1882, De Koninck® in 1888, Dr. Paul
Fischer ® in 1885, and lastly by Messrs. Nicholson and Lydekker 7
in 1889.
Distribution of Léveillia.—Devonian, Carboniferous, and Triassic
Rocks of various localities in England, Ireland, Scotland, Belgium,
France, Germany, Russia, America and Australia.
The Triassic species are peculiar to Hallstatt and St. Cassian.
Léveinita (Porcellia) Puzo,* C. Léveillé, 1835.
Mém. Soc. Géol. France, 1836, vol. ii. pl. x1. figs. 10, 11, p. 39.
Goniatites intercostalis, J. Phillips, 18386.
Illust. Geol. Yorkshire, Part 2, Mountain Limest. District, 1836, pl. 20,
figs. 61, 62, p. 237.
Porcellia Puzo, L. G. de Koninck, 1843.
Desc. Anim. Foss. Terr. Carb. Belgique, 1843, pl. 28, fig. 1, p. 359.
Faune Cale. Carb. Belgique, 1883, pl. 35, figs. 26-28, p. 116.
There is nothing to add to the characters of this type as originally
defined by Léveillé, and which have been further added to by
De Koninck. A notice of the species here is necessitated by the
introduction of Phillips’ Goniatites intercostalis into its synonymy
for the first time. The brief description, as given by Phillips of
this species stands thus: ‘“ Discoid, whorls costato-tuberculated on the
sides, round on the back, with spiral intercostal striz,” and this is
accompanied by two figures, one showing a side view with its nodu-
lated whorls, the other exhibiting the size and shape of the aperture,
both figures being taken from different specimens preserved in the
«Gilbertson Collection,” now arranged as one of the separate type
1 Highteenth Rept. Reg. Univ. New York, 1864, p. 347; Twentieth Rept. 1867,
pl. xv. figs. 23, 24.
* Note on the Affinities of the Bellerophontide, Proc. Chicago Acad. Sciences,
1866, vol. i. p. 9.
3 Handb. Paleontologie, 1882, p. 183.
* Proc. Roy. Phys. Soc. Edinburgh, 1882, vol. vii. parti. p. 73.
Piloc. cit. p. 119).
§ Man. Conchyliologie, 1885, p. 852.
7 Man. Paleontology, 1889, ed. 3, vol. i. p. 767.
8 For a fuller synonymy of this species the student is referred to De Koninck’s
works as here quoted.
206 R. B. Newton—On the Genus Léveilliia.
series in the Geological Department of the British Museum (Natural
History). The presence of the dorsal groove in these specimens,
evidently overlooked by Phillips, together with the well-developed
nodules bordering the umbilical margin, its highly ornamented
surface and quadrangular-shaped mouth, leave no doubt as to its
identification with this species.
Formation and Locality.—Carboniferous Limestone of Bolland.
[Gilbertson Collection, British Museum. |
LEVEILLIA LATIDORSATA (sp. nov.). PI. VI.
Specific characters.—Shell large, discoidal, biconcave, last whorl
massive and broad ; umbilicus wide, deep, with prominent angular-
shaped nodules, forming strong marginal serrations; nodules decrease
in size towards the younger volutions of the whorls; the ventral
surface of last whorl is deep, oblique and furnished with numerous
transverse and closely set lines minutely beaded in structure,
similar lines cross these concentrically on the younger whorls;
dorsal region moderately convex and very broad near the aperture,
but gradually diminishing in width towards the nucleus, ornamented
with strong and broad ribs, which are crossed transversely by fine
closely-set striz; ribs with a slightly wavy contour and widest near
the umbilical margins, decreasing in width and becoming straighter
and more numerous as they approach each side of the median
groove; aperture quadrangular; groove narrow and prominent ;
shell structure thick and robust.
DIMENSIONS.
Height = 40 millimetres.
Transverse diameter = 72 a
Height of mouth.. = 30 A
Width of mouth .. Re = 38 As
Diameter of umbilicus ... = 60 ms
Observations.—This species is Psinouthed from all others by its
large size, a lesser convexity, and greater width of the dorsal region,
together with the presence of the broad and prominent ribs over
the back instead of the spirally beaded surface. The important
angular-shaped nodules, with the deep cavity between each, gives
rise to a strongly serrated appearance, especially when the shell is
viewed dorsally. Another peculiarity, only shared by one other
species, viz. L. Duponti, De Koninck, is the fact that these nodules
follow the dorsal plane of convexity and extend down the ventral
surface only, without forming ridges by being produced over the
back as is general in the nodulated species of the genus. The
exception mentioned, though possessing this character, has a very
differently shaped aperture, and its surface ornament presents the
usual spirally beaded structure.
There are three specimens of our species in the British Mincenen
one of which has been sectioned to show the growth and contiguity
of the whorls as well as to prove the monothalamous nature of the
enus.
i Formation and Locality.—Carboniferous Limestone, Dublin and
Kildare. British Museum (Natural History).
R. B. Newton—On the Genus Léveillia. 207
REFERENCES TO THE DeEscriseD Species oF Léveillia; THOSE MARKED WITH AN
ASTERISK (*) BEING REPRESENTED IN THE British Mussum (Naturau
History) CouiEcrions.
TRIAS.
Léveillia (Schizostoma) Buchii,* \ Minster, 1841, Beit. Petrefactenkunde,
3 ss ) ee 1841, pl. xi. figs. 5, 6, pp. 105, 106.
Locality. St. Cassian.
Léveillia (Porcellia) Fischeri, Hérnes, 1855. Ueber die Gastropoden und
Acephalen der Hallstitter Schichten. Denksch. k. Ak. Wissen. Wien, 1855,
vol. 9, part 2, pl. i. fig. 7, p. 40.
Locality.—Hallstatt.
CARBONIFEROUS.
Liveri11a (Porcellia) AnmatA, Murchison, Verneuil, and Keyserling. Géol.
Russie Europe, 1845, vol. 2 (Paléontologie), pl. xxiv. fig. 3, p. 346.
Localities.—Orchard ; Craigenglen; Craigie (Western Scotland), vide Armstrong,
Young and Robertson’s ‘‘ Cat. Western Scottish Fossils,’’ 1876, p. 58.
Léveillia (Porcellia) carinata, L. G. de Koninck, 1888. Faune du Calcaire
Carbonifére de la Belgique, 1883, pl. xxxiii dis. figs. 27-31, p. 114.
Locality.—Tournay.
Léveillia (Porcellia) Duponti, L. G. de Koninck, 1883. oc. cit. pl. xxxv.
figs. 9-12, p. 118.
Localities.—Pauquys ; Ireland (var.).*
Léveillia (Porcellia) Le Honi, L. G. de Koninck, 1883. Loe. cit. pl. xxxiii bis.
figs. 32-36, p. 115.
Locality.—Tournay.
Léveillia (Porcellia) mosana, L. G. de Koninck, 1883. Joc. cit. pl. xxxy.
figs. 13-16, p. 117.
Locality.—Visé.
Léveillia (Porcellia) Puzo,* C. Léveillé, 1835. Apercu Géologique de quelques
localités trés riches en coquilles sur les frontiéres de France et de Belgique.—
Description des coquilles, Mém. Soc. Géol. France, 1835, vol. 2, part 1,
pl. u. figs. 10, 11, p. 39.
Localities.—Bolland ; Visé; Tournay.
Léveillia (Bellerophon) Vernewli,* D’Orbigny, 1838. Hist. Nat. Céph. acetab.
1838, pl. vi. figs. 12-14, p. 212.
Localities.—Bolland ; Visé.
Leveillia (Nautilites) Woodwardi,* W. Martin, 1809. Petrefacta Derbiensia,
1809, pl. xxxv. figs. 4, 5, p. 17.—Mineral Conchology, 1827, pl. 571, fig. 3.
—Rech. Foss. Pal. Nouy.—Galles Sud (Australie), 1876, pl. 23, fig. 8,
p- 319 (De Koninck).
Localities—Bolland ; Winster, Derbyshire; Visé. The original type of this
species was refigured by James de Carle Sowerby in the Mineral Conchology, 1827.
It now forms part of the ‘‘ Sowerby Collection,’’ arranged in the Type Gallery of
the British Museum. An interesting fact in its distribution is De Koninck’s record
of its occurrence in the Carboniferous rocks of Burragood, New South Wales.
Dervontan (European).
Léveillia (Porcellia) calceole, F. A. Reemer, 1866. Beitrage zur geologischen
Kenntniss des nordwestlichen Harzgebirges.—Paleontographica, 1866, vol.
13, pl. 33, fig. 6, p. 205.
Locahty.—Hartz. ,
Leveiilia (Porcellia ?) cincta, Minster, 1840. Loc. cit. 1840, p. 84 (not figured).
Locality.—¥lbersreuth.
Léveillia (Bellerophon) cultrata, D’Orbigny, 1838. Loc. cit. pl. 7, figs. 21-
23, p. 208.
Locality Bifel.
mene (Bellerophon) Edowardii, D’ Orbigny, 1838. Loe. cit. pl. 7, figs. 6, 7,
. 216.
See ity, Wiel.
Léveiilia (Porcellia) parvula, Minster, 1840, Loc. cit. 1840, p. 84 (not figured).
Locality.—Elbersreuth.
208 R. B. Newton—On the Genus Léveillia.
Léveillia (Ammonites) primordialis,* Schlotheim, 1820. Petrefactenkunde,
1820, p. 65.—Merkwiirdige Versteinerungen, 1832, pl. ix. fig. 2, p. 16.
(?) Schizostoma carinatum, F. A. Roemer, 1850. Beit. geol. Kenntniss nord.
Harz. 1850, pl. v. fig. 28, p. 38.
Locality.—Winterton, near Grund, Harz. Rémer’s species appears to be the
immature form of LZ. primordialis.
Léveillia (Bellerophon) radiata, D’Orbigny, 1838. Loc. cit. pl. 6, figs. 20-28,
p- 216.
Locality.—Eitel ; Russia.
Léveillia (Nautilites) Woodwardi, W. Martin, 1809, loc. cit.
55 (Bellerophon) Woodwardi, J. Phillips, 1841. Fig. Desc. Paleozoic
Foss. Cornwall, Devon, etc., 1841, pl. 40, fig. 201, p. 107.
Locality.—Newton, South Devon.
Drvonran (American).
Léveillia (Porcellia) crassinoda, C. A. White and R. P. Whitfield, 1862.
Observations upon the Rocks of the Mississippi Valley which have been
referred to the Chemung Group of New York, together with Descriptions of
New Species of Fossils from the same horizon at Burlington, lowa. Proc.
Boston Soc. Nat. Hist. 1862, vol. 8, p. 303 (not figured).
Locality.—Burlington, Iowa.
Léveillia (Porcellia) Hertzeri, J. Hall, 1876. Ilustr. Devonian Foss. 1876,
pl. xvi. fig. 24. Nat. Hist. New York (Paleontology), 1879, vol. vy. part 2,
pl. xvi. fig. 24, p. 126.
Locality.—Columbus, Ohio (Upper Helderberg).
Léveillia (Gyroceras and Porcellia) nais, J. Hall, 1862. Descriptions of New
Species of Fossils from the Upper Helderberg, Hamilton and Chemung
Groups. Fifteenth Ann. Rep. Regents New York, 1862, part D. pl. 6,
figs. 5, 6, p. 68.
Locality.—Chemung Co. (Chemung Group).
Leveillia (Porcellia) obliquinoda, C. A. White, 1862. Description of New
Species of Fossils from the Devonian and Carboniferous Rocks of the
Mississippi Valley. Proc. Boston Soc. Nat. Hist. 1862, vol. ix. p. 21 (not
figured).
Locahty.—Burlington, Iowa (Chemung Beds).
Léveillia (Porcellia) rectinoda, A. Winchell, 1868. Descriptions of Fossils
from the Yellow Sandstones lying beneath the ‘‘ Burlington Limestone”? at
Burlington, Iowa. Proc. Ac. Nat. Sci. Philadelphia, 1863, p. 18 (not figured).
Locality.—Burlington, Lowa.
EXPLANATION OF PLATE VI.
Fic. 1. Léveillia latidorsata (R. B. Newton), ventral view of specimen, showing
the nodulations and the wide umbilicus. The internal volutions are
much covered with matrix.
Fic. 2. Dorsal view of same specimen showing the prominent ribs, the median
groove, and the strong marginal serrations. The shell fracture a short
distance from the margin of the mouth opening exposes impressions of
the ribs and groove in the matrix.
Fie. 8. Internal section of another specimen of the same species showing the
thickness of the shell, the contiguity of the whorls and its globular
nucleus. The figure also illustrates the monothalamous nature of the
genus.
The figures are drawn of the natural size.
W. T. Blanford—Age of the Himalayas, ete. 209
TV.—NorteE on THE AGE AND ANCIENT GLACIERS OF THE HIMALAYAS.
By W. T. Buanrorp, LL.D., F.R.S., etc.
DO not think geologists who have studied the Himalayas will
be disposed to agree with Mr. Howorth (ante, pp. 97-104,
156-163) that those mountains have come into existence since the
time when the Mammoth flourished in Siberia. It is quite possible
that the Himalayas are higher now than they were in Pliocene or
even in Pleistocene times; but the geological evidence, so far as it
is known, is, I think, in favour of the view expressed by Mr. R. D.
Oldham in the Guotoeicat Magazine for February (anie, pp. 72-73).
This view is that the period of elevation has approximately coin-
cided with the Tertiary era. The Upper Pliocene beds along the
southern border of the range so closely resemble in material and
coarseness those forming in the same area at the present day as to
indicate very similar geographical conditions, and Mr. H. B, Medlicott
showed, many years ago, that where the great Himalayan rivers
flow now, great rivers have flowed since early Pliocene times at
least. The principal question in dispute amongst recent investiga-
tors of Himalayan Geology has been whether the range existed in
Pre-Tertiary times or not. Mr. Howorth’s contention that the
elevation of the Himalayas is Pleistocene (or, as some geologists
call it, Post-Tertiary) has the very great merit of novelty.
Mr. Howorth’s principal argument for the recent origin of the
Himalayas is founded on the absence of ice-markings on a large
scale. On this subject he has brought together a remarkable mass
of evidence. It is difficult, without writing a paper of considerable
length, to pick out the weak points in this evidence, and to show
how much may be said on the other side. I will give one example
of each form of reply.
One of Mr. Howorth’s principal witnesses, perhaps I should say
his principal witness, is the late Mr. J. F. Campbell. Now Mr.
Campbell’s main object in the paper quoted was to demolish certain
rather extravagant ideas, held only by a few extreme glacialists,
about polar ice-caps extending to the tropics and similar hypotheses.
As a matter of fact, Mr. Campbell never entered the main Himalayan
range; he only went to three or four hill-stations on the outer spurs.
On the other hand, Mr. Howorth has overlooked evidence by
geologists who really traversed the main range. The only part of
the higher Himalayas that I have been able to examine is to the
eastward in Sikkim. Here, more than forty years ago, Sir J.
Hooker described great moraines in every Himalayan valley that
he ascended, at or about 7000 or 8000 feet elevation (Himalayan
Journals, vol, i. p. 380). I found the same, and can entirely confirm
Sir J. Hooker’s observations. The Lachoong and Lachen valleys
(which unite to form the Teesta) have, above the lowest moraines,
the U-shape and other characteristics of glacier valleys. At the
present day, in this part of Sikkim, no glaciers descend below
14,000, and very few below 16,000 or 17,000 feet. Thus great
glaciers, in this part of the Himalayas, descended in Pleistocene
times from 6000 to 10,000 feet lower than they do now. In
DECADE III.—VOL. VIII.—NO. Y. 14
210 ©. Davison—Mountain Evolution.
Kashmir, according to Drew and Lydekker (Mem. Geol. Surv. Ind.
vol. xxii. p. 32), the case is very similar. In short, so far as I can
see, the extension of the glaciers in the Himalayas was very similar
to what it was in the Alps; but as the latter are from 15° to 20°
farther north, the glaciers came to the base of the mountains, and
flowed over some of the adjacent country, whilst in the Himalayas
all the ice melted within the range.
The only other fact cited by Mr. Howorth is the curious occur-
rence of remains of fossil Horses, Bovines, Rhinoceroses, etc., in
Hundes. Here, too, I think he has overlooked part of the evidence,
as he evidently is under the impression that none of the animals
mentioned, Horse, Ox, Deer, Rhinoceros, and Elephant, can live at
such elevations as 15,000 feet. The fact is, however, as Mr.
Lydekker has shown, that wild horses (Equus hemionus) and Oxen
(or rather Yaks, Bos grunniens) do inhabit Hundes at the present
day, that the supposed Deer are Antelopes belonging to the genus
Pantholops, peculiar to the Tibetan plateau, and that the only
difficulty is about the Rhinoceros (the occurrence of Hlephas is
doubtful, I believe). The beds containing the remains are now
regarded by Mr. Lydekker (Rec. Geol. Surv. Ind. 1887, p. 54) as
Pliocene, not Pleistocene. It is probable that these beds have under-
gone a certain amount of elevation; but if I were obliged to decide
which is more improbable, that a Rhinoceros in Pliocene times
lived 15,000 feet above the sea, or that the Tibetan plateau has
been raised to that elevation from near the sea-level since the
Pliocene period, I should feel very little difficulty in coming to
a conclusion.
Iam not prepared to accept all Mr. J. F. Campbell’s views as to
the Himalayas, but there is one remark in his paper with which
I thoroughly agree. He infers from the circumstance that what he
calls the “ waterfall zone” lies close to the sources of the rivers,
that the watercourses in the Himalayas are very old. I think if
Mr. Howorth had had an opportunity of seeing what is perhaps the
grandest example of subaérial denudation in the world, he would be
as little inclined as I am to believe that such gigantic furrows as
the Himalayan valleys can have been ploughed out by rain and
rivers since the frozen Mammoths were imbedded in the gravels of
the Siberian tundras.
V.—NorteE on THE Expansion Turory or Mountatn-EvoLurion.
By Cuarutzs Davison, M.A.;
Mathematical Master at King Edward’s High School, Birmingham.
Al following is the fundamental principle of the theory of
terrestrial evolution which has been sometimes called the
“expansion theory ” :—
Masses of sediment laid down in an area of subsidence are
gradually lowered to regions of the earth’s crust that are at a higher
temperature than that in which they were deposited. The sediment,
being heated, expands, is crumpled and folded internally, and,
A. 8S. Woodward—A Microsaurian from the Coal. 211
bulging up at the surface, is reduced by denudation to the form of
a mountain-chain.
This theory has at different times received attention from geologists,
and it has met with a considerable amount of adverse criticism.
Much of that criticism appears to me of a very forcible character,
but one of the strongest objections that can be brought against the
theory does not seem to have been generally noticed.’
It is obvious that the heat which passes into and expands the
sediment must be withdrawn from the immediately adjoining parts
of the earth’s crust, partly laterally, but chiefly from below ; and
that the amount of heat gained by the sediment must be equal to
that lost by the crust. The increase in volume of the sediment
must therefore be accompanied by an equal decrease in volume of
that part of the crust from which the heat has been derived. Thus,
the sediment in expanding must follow a crust that is retreating,
and this retreat must take place, partly laterally, but chiefly down-
wards. Instead, then, of the sediment bulging up at the surface,
and ultimately forming a mountain-chain, its uppermost layer must
remain practically stationary (so far as the effect of the transference
of heat alone is concerned), while most, if not nearly all, of the
sediment below must subside.
It may, in reply to this, be urged that the sediment will check
for a time the natural outward flow of heat from the earth’s interior,
while the heat will continue to pass as before through the other
parts of its surface which are not areas of sedimentation. This may
be the case, but the amount of heat so checked cannot be great.
Supposing no heat at all to escape for some time through the
sediment, then its effect in raising the surface of the mass relatively
to that of the earth, can at the very most be represented by the
diminution of the earth’s radius during that time; and this diminu-
tion will be small. The actual relative elevation of the surface of
the sediment, if there be any, will of course be very much less than
the change of radius.
It follows, then, that the expansion theory is a theory of sub-
sidence, rather than a theory of elevation.
VI.—On a Microsaurian (Hyzovomuus Wizpi, sp. nov.) FROM THE
LANCASHIRE COAL-FIELD.
By Artuur SmitH Woopwarp, F.G.S., F.Z.S.
URING a recent examination of a collection of fossils made by
Mr. George Wild in the Burnley Coal-field, Mr. John Ward,
F.G.S., recognized a novelty in the small Microsaurian which forms
the subject of the following notes. The specimen was forwarded
1 It has not, however, been overlooked by the Rev. 0. Fisher. “The heat
conducted into the new deposits,’? he remarks, ‘‘must be abstracted from the
couches beneath, so that there can be no absolute increase in the amount of heat
beneath the area in question except such as is supplied to it laterally, so that the
process must be excessively slow’’ (Physics of the Earth’s Crust, second edition,
p- 132). I am indebted to my friend Mr. Fisher for drawing my attention to this
paragraph, which, with the exception of the last few words, contains in a condensed
form the argument that follows.
212 A. 8. Woodward—A Microsaurian from the Coal.
to the British Museum for determination, and a detailed study of its
characters proves it to represent a Microsaurian family that has not
previously occurred in the Carboniferous of Europe.
The fossil was obtained from the roof of the “ Bullion Coal” at
Trawden, near Colne, and comprises the head, abdominal region,
and base of the tail of a small animal, occupying the whole of an
elongated split nodule 0:08 m. in length. The jaw cannot have
measured less than 0-017 in length, and the distance between the
two pairs of limbs must have been about 0-036. There are also
indications that the trunk was comparatively robust, and also some-
what laterally compressed.
Of the head, no recognizable portions remain beyond the
mandibular rami. The ramus of the left side, imperfect at both
extremities, is shown of twice the natural size from the inner aspect
in Fig. 1, md., and exhibits some of the conical teeth, which, though
robust, have a very large pulp cavity with the walls apparently
not folded even at the base. The axial skeleton of the trunk is also
unsatisfactorily preserved, the remains of vertebre@ merely indicating
that they were well ossified and not permitting the determination of
their characters. Portions of some of the anterior ribs (Fig. 1, r)
prove their stoutness, with an expansion both proximally and
distally ; but whether they possessed a distinct head and tubercle
cannot be determined. Traces of the posterior abdominal and caudal
ribs suggest that these were comparatively slender.
The interclavicle (Fig. 1, i. cl.) is relatively large, and seems to
have been rhomboidal in form, though the margins are not well
Fic. 1.—Hylonomus Wildi, sp. nov.: outlines of bones and dermal scutes.—Coal-
measures, Trawden, near Colne. d. dorsal scutes; f. femur; z. cd. interclavicle;
a. ilium; md. mandibular ramus; 7. anterior ribs (only partially exposed) ;
v, v'. ventral scutes. All the figures of twice the natural size, except v!., which is
enlarged four times.
shown. It must have been at least as long as broad, and the exposed
surface is distinctly ornamented with radiating rug and furrows.
Of the pectoral limb there are only obscure indications. In the
pelvic arch and limb, however, some of the bones are recognizable,
notably the left ilium and femur. The ilium (Fig. 1, il.) is vertically
elongated, with a short expansion below, a mesial constriction, and
a gradual widening towards the truncated upper extremity. At its
base, part of a thin laminar bone probably represents the ischium.
The ilium is almost as long as the femur (Fig. 1, f), which, though
fractured and perhaps in side view, seems to be comparatively
T. Stock—Keuper Conglomerate, Bristol. 213
slender, and must have been terminated at each extremity by unos-
sified cartilage. The tibia (? or fibula) also appears to have been
slender, equalling about one-half the length of the femur; but its
outline is not satisfactorily shown.
The dermal scutes cover the whole of the trunk so far as preserved,
all being oval in shape, deeply imbricating, and exhibiting promi-
nent concentric lines of growth. Those of the ventral armour (Fig.
1, v.) are much larger than those of the dorsal (d.); and the former,
when magnified (v'.), show feeble radiating lines either superficial or
structural.
The fossil thus described may be assigned without much doubt to
the Microsaurian family of Hylonomide as restricted by Fritsch.’
So far as known, indeed, it cannot be separated from the type genus
Hylonomus itself. The general proportions are similar, and there
are the same indications of the laterally compressed form of the
trunk; while the relative stoutness of the anterior ribs will also
doubtless be proved to characterize the typical species from Nova
Scotia when sufficiently well preserved examples are discovered.’
The closely allied genus Hyloplesion of Fritsch * is distinguished by its
short interclavicle with a long posterior process, by its more slender
anterior ribs, and by the relatively smaller size of the ilium; and
the remaining genera are excluded from comparison by equally
obvious characters. Upon present evidence it is thus proposed to
regard the Microsaurian from the Lancashire Coal-Measures as a
species of Hylonomus; and as this appears to be new, it may appro-
priately bear the name of H. Wildi, in honour of its discoverer, Mr.
George Wild, whose long-continued researches in the Burnley Coal-
field, especially in connection with the Carboniferous Flora, are well
known. Among distinctive specific characters may be enumerated
the form and proportions of the mandible and dermal armour ; while
the precise contour, size, and ornament of the interclavicle will not
improbably prove to be of diagnostic value when this element is dis-
covered in the several species from Nova Scotia.
VII.—OsseERvVATIONS on A KeuperR ConGLOMERATE AND ON A BRECOTA,
BOTH RECENTLY ExposeD IN THE NEIGHBOURHOOD OF BristTOL.
By T. Stock, Esq.
1. A conglomerate in the Keuper.—Whilst a drain was being cut in
Argyle Street, joining Upper and Lower Hastvilles, one of the upper
beds exposed consisted of a rather fine conglomerate, made up largely
of rolled quartz pebbles of small size, compacted with rounded
quartz sand and intermixed with coloured fragments (generally
very small flakes) of softer shale or clays. I did not measure the
thickness very carefully, but I should think that it did not exceed
1 A. Fritsch, Fauna der Gaskohle, vol. i. p. 159.
Sir J. W. Dawson, Grou. Maa. [3] Vol. VIII. p. 152.
3 A. Fritsch, tom. cit. p. 160. Hyloplesion is considered to be identical with
Hylonomus by Credner (Zeitschr. deutsch. geol. Ges. vol, xxxvii. p. 734) ; but this
identification is very doubtful, as lately remarked by Sir J. William Dawson (Grou.
Mae. [8] Vol. VIII. p. 153).
214 T. Stock—Keuper Conglomerate, Bristol.
six inches, and as the drain is now filled up, the means of more
accurate measurement are lost. The distance from the nearest
denuded edge of the Coal-measures is as nearly as possible half a
mile. Also, in making a drain-cutting in Heath Street, connecting
the two Eastvilles, and about a quarter of a mile nearer Stapleton
than the last, but about the same distance from the Coal-measures,
another conglomeratic bed was exposed, in which, however, the
quartz pebbles were smaller. As the Keuper beds lie horizontally,
or nearly so, in this district, the second bed may be a continuation
of the first, the altitudes being approximately similar. There is
nothing to show that this conglomerate differs much from most
others, in respect of derivation. being probably composed of the
worn-down materials of preexisting formations, of rocks perhaps for
the most part of Coal-measure age. The fineness of the conglome-
rate would naturally be attributed to its greater distance from the
shore. The traces of green clay or shale may be referred with some
probability to the Coal-measure shales, which are often variegated in
this vicinity and highly coloured, as may be seen in the section
at the Easton Brickworks and elsewhere. Apart from the question
of conglomerates, I think I have evidence, which requires however
to be carefully weighed and reexamined, of the using up of
contemporary materials, in the formation of certain Jurassic and
Coal-measure shales, in which there was, as is well known, frequent
subsidence and elevation. The evidence to which I refer is a few
instances in Somersetshire and Gloucestershire of well-preserved
fossils occurring upon natural casts of fossils, and the occurrence of
what I believe are pebbles of coal.
I may also mention that I have obtained or seen a good many
quartz pebbles in the Rheetic bone breccia at Aust; but as I have not
access to much of the literature of the Rheetic, I cannot say whether
the fact has been noted or not by others before.
2. A Dolomitic? Breccia in the parish of Alveston, Gloucestershire.
—My friend Mr. Olive, of Greenhill, lately drew my attention to an
interesting little section exposed whilst making a boundary-wall
on his property. It consists of a series of thin beds lying horizon-
tally, the upper ones being much brecciated, the thick basement bed
being homogeneous. The included fragments of the neighbouring
Carboniferous Limestone are distinctly angular, being in fact distinctly
a breccia, and not a conglomerate. One would naturally suppose
that this must be an outlier or continuation of the neighbouring
dolomitic conglomerate, which is marked on the Geological Survey
Map as running up triangularly to near this spot. If so, it is
interesting as an example of a conglomerate passing into a breccia,
on account of its closeness to neighbouring Carboniferous Limestone
cliffs. The bedding is also interesting, as also its (apparent)
horizontality. I do not feel sure whether it may not be a breccia
of later age. The matrix is apparently dolomitic, approaching,
however, in appearance, some of the Lower Liassic or even Oolitic
beds; but I must leave the matier in the hands of more experienced
geologists.
Notices of Memoirs—Natural History Transactions. 215
INO CS Oe) | IVE NE@ises S-
ae Ps
J.—SKURINGSMERKER OG MORHNEGRUS EFTERVIST I FINMARKEN FRA
_EN PERIODE MEGET HLDRE END “‘ISTIDEN.” Udgivet af Dr. Hans
Reuscu. (Med “An English Summary of the Contents.’’)
Norges geol. undersdgelses Aarbog for 1891, pp. 1-11.
GLACIAL-STRIZ AND BovuLpER-cLay IN FINMARK, BELONGING TO A
PERIOD MUCH OLDER THAN THE “Ick Acr.” By Dr. Hans
Revscu, Director of the Geological Survey of Norway.
HE northern shores of the interior of the Varangerfjord, at the
far north of the Scandinavian Peninsula, consist of a low range
of hills, mainly of sandstone and conglomerate, the beds of this
latter rock reaching a thickness of 50 metres. The conglomerate is
entirely unstratified; it is composed of stones and small boulders,
about the size of one’s head, of Archean gneiss, granite and diorite,
with a slight admixture of fragments of dolomite and quartz, which
are irregularly scattered in a ground-mass of reddish clayey sand-
stone. The general appearance of this rock so much resembled
Boulder-clay that Dr. Reusch was induced to search the stones in it
carefully, and he found definite well-marked scratches on some of
the fragments of dolomite, whilst the surfaces of some of the pieces
of harder rock were smooth and even, with traces of strize. These
markings were precisely similar in character to those produced
by ice-action on the same kinds of rock in comparatively recent
Boulder-clay, and could readily be distinguished from slickenside
markings which were found to be present in the conglomerate as
well. The evidence of ice-action was further shown by the presence
of striz and grooves on the surface of a hard sandstone immediately
beneath the conglomerate, which had been laid bare by the weathering
away of this latter. The striz appeared to belong to two systems,
and they could be traced up to and beneath the conglomerate.
_ The geological age of these ice-marked sandstones and con-
glomerates has not yet been satisfactorily determined; by Dr. Dahll
they are considered as Permian, but Dr. Reusch thinks that they
belong more probably to some portion of the Cambro-Silurian series,
which prevails so extensively in Scandinavia; hitherto no traces
of fossils have been found in them. If this view is correct, the
discovery of what appears to be satisfactory and conclusive evidence
of the presence of glacial action at this far distant period is a matter
of considerable geological interest. In the paper Dr. Reusch gives
figures of the scratched stones, with profiles and sketches of the
rocks in which they occur. G. J. H.
IJ.—Narourat History Transactions or NorTHUMBERLAND, DURHAM,
AND NewcastxLe-upon-Tyne. Vol. X. Part II. (1890.)
WO important contributions to the Geology of Northumberland
and Durham, by Mr. Richard Howse, are comprised in the
latest part of these Transactions. The first is a short paper on the
South Durham Salt Borings, with remarks on the fossils found in
the Magnesian-Limestone cores, and the geological position of the
216 Notices of Memoirs—Syénites, etc., de Pouzac.
salt. Mr. Howse attempts to prove the identity of the Upper Lime-
stone in the salt-borings in South Durham with the Brotherton
Beds in South Yorkshire, and the identity of both of these with the
Plattendolomit of Germany. He also regards the lowest deposit
of Rock Salt as of Permian age. The second contribution is a
“Catalogue of the Local Fossils in the Museum of the Natural
History Society of Newcastle-upon-Tyne,” which occupies sixty
pages, and was orginally issued as a separate publication at the time
of the British Association Meeting in 1889. This is interspersed
with numerous notes on stratigraphy, which are rendered invaluable
by Mr. Howse’s long experience in the detailed study of the district.
The localities from which the specimens were obtained are men-
tioned under each species, and a reference is given to the record of
its occurrence when already published.
II]. — Description pes Syfnires N&PHELINIQUES DE Povzac
Havures-Pyrénizs) et De Montrmat (CANADA) ET DE LEURS
PHENOMENES DE contact. By M. A. Lacrorx. (Bull. Soc.
géol. France (3), xiii. 1890, No. 7, pp. 511-58, pls. ix.—xii.)
HE many important contributions to our knowledge of the
nepheline syenites made during the past few years by Brogger
Tornebohm, Van Werwerke, Derby, and others, have received an
important accession in the above Memoir by M. Lacroix. He here
describes in detail the nepheline syenites of Pouzac and Montreal
and their contact phenomena. At the former the rock is intrusive
into a limestone, which is probably Cretaceous; the rock is of
especial interest in connection with the alteration products. Thus
the nepheline has given rise to (1) zeolites such as mesotype and
hydronephelinite ; (2) to white mica (gieseckite); (8) to garnets
(of the ouwarowite type), which either replace the whole of the
nepheline or are developed along the cleavage-planes; (4) to
cancrinite ; the amphibole (barkevicite) is altered to green mica,
and the pyroxene is often surrounded by a zone of aegyrine. On
the selvage the rock passes into a variety in which the magnetite,
apatite, sphene, etc., and the ferromagnesian minerals (that is to say,
those of the first two phases of the first stage of consolidation) are
absent, and the sodic minerals (nepheline and sodalite) are replaced
by a felspathic microlitic growth; the result is a rock comparable
to the tinguaites of Prof. Rosenbusch, which in Brazil and Portugal
are regarded as apophyses from nepheline syenite. Dipyre, actino-
lite, and pyrites occur in the limestone at the contact.
The nepheline syenite of Mont Royal, Montreal, pierces the
Trenton limestone, and is itself of Silurian age. It is the principal
member of a group of igneous rocks which includes some diabases,
teschenites, and porphyrites. The diabases and teschenites both
belong to a series resulting from the solidification of the same
magma; the teschenites differ from the diabases in the presence of
nepheline and sodalite; when olivine also occurs, the rock becomes
one of the true teschenites (of Fouqué and Michel-Lévy) or theralites
of Rosenbusch.
Notices of Memoirs—D. Bell—Glacial Epoch. 217
The normal porphyrites are probably microlitic forms of the diabase,
just as the nephelinites with which the former are associated (occur-
ring especially at the Mile End Quarries) are of the teschenites. At
St. Anne there is a melilite of the same age as the other rocks of
this group—a point of interest, as this variety has hitherto been
regarded as confined to the Cainozoic.
The dominant type of the nepheline syenite is a rock with granitic
structure and composed of grey or pink felspar, nepheline, sodalite,
amphibole, pyroxene, and mica. The complete list of minerals
numbers twenty-one, and these are all described in detail; the altera-
tion products are similar to those of Pouzac. There are also some
pegmatitic veins. Amongst the most important points in the memoir
are those connected with the contact alteration of the rock: at places
the normal structure is retained at the junction, but in other cases
the rock is profoundly altered for a distance of some metres; the
variations afford a complete transition from the granitic (grenu) to
the trachytic types of structure, i.e. from the normal syenite to the
“‘microsyenite””—a term he proposes owing to the analogy between
this rock and the microgranites. The large dyke gives off small
branches which traverse the limestone, and these are often composed
of many alternating zones of the granitic and trachytic rocks. These
dykes further lead to the mica porphyrites; the sodalite and nepheline
are absent either owing to original poverty in soda, or to the greater
influence of the endomorphic alterations on these thinner veins.
The extent of the alteration of the limestone at the contact varies
greatly; the minerals developed in the limestone are diopside,
wollastonite, garnet, perowskite, and more rarely biotite, sphene,
zircon, and felspars. The junction is sometimes marked by a band
of cancrinite; but when the felspar is abundant, a zone occurs which
may belong to either the eruptive or metamorphic rock.
The memoir is illustrated by twenty-six figures of rock-sections,
while the great range in the variations of the rocks is further well
brought out by the abundant use of M. Michel-Lévy’s formule.
M. Lacroix, it is interesting to note, rejects at the outset the use of
the term eleolite syenite, and he lays special stress in his concluding
paragraph on the identity in structure and mineralogical composition
of rocks of Silurian age in Canada with those intrusive in the
Cretaceous Limestone of the Pyrenees. J. W. G.
1V.—Puenomena or THE Guactat Epocu. Part IJ. Tue Great
Supmercence. By Ducatp Beuy. Trans. Geol. Soc. Glasgow,
Vol. IX. pp. 100-188.
Y this Memoir the author has added another name to the
2 growing list of papers written in opposition to the supposed
glacial submergence of England and Wales to the depth of over
1800 feet. He summarizes all the evidence in favour of this view,
and then subjects it to a careful examination, with the result of
dismissing it as absolutely valueless. A submergence of 500 feet
is admitted, but this the author attributes to the elevation of the sea-
level by the attraction of the polar ice-cap heaping up the water in
the northern latitudes. J. W. G.
218 Reviews—Stebbing’s Life of David Robertson.
See Hee VP Te SEs NV Ve SS
I.—Tue Narurarist or Cumprar. A True Story: Berne THE
Lire or Davip Rozertson. By the Rev. Thomas R. R. Stebbing,
M.A. 8vo. pp. 398. (Kegan Paul, Trench, Triibner & Co.,
London, 1891.)
\ R. ROBERTSON is well known to geologists through his
researches on the Ostracoda and Foraminifera of the later
Tertiary or Quaternary deposits; and in these studies he has been
associated with Dr. G. 8. Brady and the Rev. H. W. Crosskey.
The living forms of these minute organisms have likewise engaged
much of his attention, and in the course of dredging investigations
over a wide area around the British Isles, he has added largely to
our knowledge of Marine Zoology and Botany. A very pleasant
story of his life is given by Mr. Stebbing in the volume before us,
and although Mr. Robertson is still enjoying the fruits of a well-
spent life, yet being in his 85th year, his work is practically accom-
plished, and no apology is needed for the publication of the book.
Born in a humble sphere of life, and losing his father when quite
an infant, David Robertson was supported in early years by the —
Jabours of his mother, and under these circumstances he received
but a year’s regular schooling between the ages of 7 and 8. Then
he gained employment ona farm in Lanarkshire, and for some years,
under different masters, he was engaged chiefly in agricultural work,
obtaining an occasional change for short intervals in quarry-work
and in the weaving-trade. Thus was he occupied until he reached
the age of 24, without having made any position for himself, although
all along he was desirous of bettering his circumstances. He gained
what education he could by attending night-classes and by the loan
of books, whenever any were to be had; and it is noteworthy that
the Travels of Mungo Park and the Natural History books of Buffon
and Goldsmith thus came into his hands. ‘Two of Robertson’s old
playmates had now entered the College at Glasgow, as Divinity
students, and, remarkable as it seems, he was fired with the ambition
to become a Medical student. His friends naturally enough tried to
dissuade him; but he obtained an interview with the Anatomical
Professor, and received the encouraging assurance that by industry
he might accomplish his desires. He resolved to enter the College,
and gaining employment with a dyer, whereby he was enabled to
support himself in a frugal way, he pursued his studies with zeal.
During the next few years (1831-34) he duly attended the College
courses, and gained the needful certificates. He subsequently learned
Dispensing at a shop in Glasgow, and obtained some practical
experience in Medicine and Surgery at the Infirmary.
Now, however, at the age of 30, when ready to go up for
examination, circumstances entirely altered his career. He became
enamoured of the daughter of the dyer, a maiden who had charge of
a crockery-business that belonged to her father. There was the
opportunity for Robertson to take charge of a similar business, and
it set him meditating on his prospects. He wisely came to the con-
Reviews—Wachsmuth and Springer—On Crinoids. 219
clusion that business offered him better chances of making an income
than the work of a doctor. His friends, as well as the College
authorities, now urged him to proceed with his medical work; but
he had made up his mind. He married and set up in business, with
seven pounds in hand to furnish his house and stock his shop. Right
well he and his wife succeeded, so that the business steadily increased.
He made journeys to the Potteries and to Hamburgh so as to buy
direct from the manufacturers, and by dint of hard work succeeded
by the year 1860 in accumulating a sufficient fortune to retire in
comfort.
As early as 1837, however, Mr. Robertson began his natural
history studies. ‘Between the years 1850 and 1860 natural history
pursuits and business occupations overlapped one another, but the
true naturalist ‘has no time for money-making,’ and accordingly
the time came when science extinguished commerce.”
He then obtained a house known as Fern Bank, at Millport in
Great Cumbrae, an island in the Firth of Clyde. To this island he
had frequently gone for relaxation in previous years, and although
he continued to reside for some years principally at Glasgow, yet
since 1886 the little island has been the permanent home of the
Naturalist.
Rather more than half the volume is devoted to an account of
Mr. Robertson’s scientific labours, of his dredging explorations, and
of the Naturalists with whom he became associated ; amongst whom
Dr. Harvey, Dr. Baird, the Rev. A. M. Norman, Dr. Gwyn Jeffreys,
Dr. Dohrn, and others. There are reminiscences of Thomas Edward,
whose history, as Mr. Stebbing remarks, tends “to cast something
of a sombre gloom over scientific pursuits.” He adds, “It is well
that it should be seen that there is no necessary connexion between
an intense love of nature and a deplorable condition of a man’s
private affairs.” Mr. Robertson, however, was evidently too much
of a business man to neglect trade in the pursuit of his hobbies, and
after successfully fighting the battle of life, he has done excellent
service in the cause of science. H. B. W.
I].—Tue Pertsomic Puarses or tHE Crinoips. By Caartes WaAcuHs-
mutT and Frank Springer. Proc. Acad. Nat. Sci. Philadelphia,
1890, Part III. pp. 345-392, Pls. 1X. X. (February, 1891).
\HIS paper, although in the importance of the facts which it
makes known it can hardly rank with the same authors’ recent
paper on the ventral structure of Taxocrinus and Haplocrinus,’ will
nevertheless mark an important advance in the history of Crinoid
Morphology.
The authors divide the skeletal elements of a Crinoid into primary
and secondary. Primary elements include (a) the Abactinal plates,
developed on the right antimere and connected with the axial
nerve-cords, viz. stem-ossicles, infrabasals, basals, radials, and all
1 « Discovery of the ventral structure of Tarocrinus and Haplocrinus, and con-
sequent modifications in the classification of the Crinoidea,’’ Proc. Acad. Nat. Sci.
Philadelphia, 1888, part iii. pp. 337-368, pl. xviii. (February, 1889).
220 Reviews—Wachsmuth and Springer—On Crinotds.
brachials, and (b) the Actinal plates, developed on the left antimere
and connected with the mouth, viz. orals and all plates of the
ambulacra. The secondary or supplementary elements are all the
interradial, interbrachial and interambulacral plates, including the
anal plates and plates of the tube or sac. These apparently are what
they call “perisomic,” although the term would seem legitimately
applicable only to plates that, one way or another, form part of
the calyx.
The title, however, in no way does justice to the contents of the
paper. For the authors discuss the homologies first of the plates
of the ventral surface generally, secondly of the anal plates; and as
side-issues, but important ones, they treat of the interradial plates
and of the large plates, hitherto called interradials, seen in the
tegmen of the Cyathocrinide.
Those who have regarded the question in a purely morphological
aspect have long doubted the existence, at least in many cases, of
a “vault,” by which was meant that outer roof of plates supposed,
in the Camerata, to conceal another integument, often plated, homo-
logous with the so-called “disk” of an Antedon. Thus Dr. P. H.
Carpenter in his ‘Challenger’? Report on the Stalked Crinoids.
(1884), although he still allowed a “vault” to the Actinocrinide,
could not accept it for the Reteocrinide, Ichthyocrinide, and most
of the Platycrinide. The admission of Messrs. Wachsmuth and
Springer (Revision III.) that the calyx interradials were continuous
with those of the “vault” seemed inconsistent with the presence of
other interradials in a supposed “disk” beneath the “vault”; the
growth of plates outward and downward from the orals and upward
from the interradials, through regions where no connective tissue
previously existed, the two meeting in air like a eantilever bridge,
was incomprehensible; while the grave statement that the plates
of such a “vault”? corresponded one for one with the plates of
the underlying “disk” (Revision III. 60) showed the untenability
of the whole hypothesis. There were—as there are still—certain
difficulties in any other explanation; but the paper of Messrs.
Wachsmuth and Springer on Tarocrinus, etc., furnished so complete
a set of links between the “disk” and the “vault” that doubt was
no longer possible, and in April, 1890, the present writer denied
the existence of any structure covering the disk, and proposed in all
cases to use the word tegmen (Ann. Mag. Nat. Hist. [6] v. p. 318).
Messrs. Wachsmuth and Springer have now confirmed this con-
clusion by finding satisfactory homologies for the plates of the
tegmen in Actinocrinide. The simplest form of tegmen in Crinoids
consists of only five plates, interradially disposed, that meet over
the mouth and are called orals: this is now regarded as also the
earliest form. It is supposed that, to increase the calycal cavity,
interradial plates were developed between the radials, while similar
interambulacral plates, as well as extensions of the ambulacral plates,
gradually intervened between orals and radials. The orals might
disappear or remain. As the lower parts of the arms became in-
corporated in the dorsal cup, more and more ambulacral and inter-
Reviews—Wachsmuth and Springer—On Crinoids. 221
ambulacral plates naturally came into the tegmen. The plates of
the tegmen were at first small and yielding, as in the Ichthyocrinidz
and in most recent Crinoids; in this state when the arms are open
the ventral surface is depressed, when they are closed it bulges
upwards. To afford better protection to the viscera the tegminal
plates became more solid; the tegmen being thus less flexible was
fixed perforce in its protruded state. The covering-plates of the
ambulacra had perhaps been closed from the beginning, but as,
through the upswelling of the tegmen, they were now more exposed,
further protection was needed. Consequently they were lowered
beneath the surface and, starting from the solid orals, interambu-
lacral plates closed in over them. Certain of the covering-plates
however, especially, it would appear, the axillary pieces, which
perhaps could not so easily be covered by other plates, became
much stouter and were still exposed on the surface as solid radial
dome plates. In any form highly developed along these lines, e.g.
Batocrinus, the food-grooves, water-vessels and blood-vessels are
sunk right beneath the tegmen and are enclosed in a tube consisting
of alternating ambulacral or covering plates above and adambulacral
or side plates below. The interambulacral plates of the tegmen
send curious extensions into the interior of the calyx, and these
extensions, spreading out, form what was formerly supposed to be a
disk. We may, with Messrs. Wachsmuth and Springer, regard the
extensions as caused by the perforation of the plates for water-
canals; or we may regard them as simple processes for the purpose of
adding strength, without forgoing lightness, by a system of girders.
In the Inadunata Fistulata the dorsal cup never extended beyond
the radials, and the tegmen was not developed to the same extent as
in the Camerata. The orals did not, however, always persist in the
simple stage in which they occur in the Larviformia; in many cases
they were, in the opinion of the authors, entirely resorbed, while
their places were taken “by large covering plates, of which the
proximal ones joined in the center.” Ambulacral and sometimes a
small number of interambulacral plates occur in the tegmen of the
Cyathocrinide; besides there are four large plates, one in each
interradius except the posterior, which rest against the radials, meet
laterally beneath the ambulacra, and may be covered to a varying
extent by small interambulacral plates. In the posterior interradius
there lies, between the ventral sac and the mouth, a plate often very
similar in shape and position to these four. This plate is stated by
our authors to be ‘‘ profusely perforated” in various Lower Carbon-
iferous Cyathocrinide, and they state that on either side of it lies
a small narrow plate which meets the large plate of the adjacent
interradius beneath the ambulacrum. ‘These two narrow plates are
quite new discoveries. Once upon a time the five large plates were
considered to be orals, a view subsequently abandoned by Wachsmuth
and Springer and P. H. Carpenter owing to the passage of the
ambulaecra over and not between the edges of the plates. Wachsmuth
and Springer have since then regarded them as interradials; this
view they now drop because the plates “support the ambulacra and
222 «=Reviews—Wachsmuth and Springer—On Crinoids.
are covered by perisome,” and because in the posterior interradius
they do not rest on the special anal plate. They now believe that
“the perforated plate is a true anambulacral plate, analogous with
the perforated limestone particles at the disk of recent Crinoids,”
and that the two narrow plates and “possibly also the four larger
ones, wholly or in part, are subambulacral plates.”
This view is absolutely new and, if proved, of great importance ;
its adequate discussion is beyond the limits of a review, but we
cannot refrain from a few remarks. What do the authors mean by
““subambulacral plates”? The term was proposed by Joh. Miller
in 1854 for a series of median plates lying beneath the food-groove
of Pentacrinus asteria, and therefore radial in position like the
lancet-plates of the Blastoids. But the plates now under discussion
are interradial in position, and only their edges are immediately
beneath the food-groove. This difficulty must have been seen by
the authors themselves, for they say: “‘interradial plates, as the
term denotes, cannot be subambulaeral.” It is hard to see how
they better their position by the suggestion that these plates are
homologous with the deltoids of Blastoidea, and that they each
consist of a median interradial plate fused with two lateral plates
that underlie the ambulacra. Not only is this, as they admit,
unsubstantiated hypothesis, but if proven, while it would leave an
interradial portion still to be accounted for, would not make the
lateral portions one whit the more subambulacral, although they
might then be considered as adambulacral.
We do not here wish to maintain that the plates are orals, but
the authors hardly seem to have given good reasons for the rejection
of that view. How do they know that ambulacra cannot pass over
the edges of orals? The change may have taken place gradually,
and is no more impossible than the sinking of ambulacra. They
must show both orals and these interradial plates coexisting in some
particular specimen; and this they do appear to state on p. 307:
“That the plates are not orals is further proved by the fact that
there are in Cyathocrinus iowensis other large plates covering the
peristume, which naturally represent them.” But they do not say
how they distinguish the partly resorbed orals from the large
covering plates that, in the same specimen (pl. x. fig. 3), are stated
to join in the centre.
Then again the plates are stated not to be interradials, because
they are covered by perisome; but have the authors ever seen a
specimen in which these plates existed but were entirely hidden by
interambulacral plates? If so, it would have been well to have
definitely stated as much; and even then, why should not an
interradial plate sink below others until it is covered by them ?
Some argument, which we do not follow, is based on the “ per-
forated””’ plate or ‘‘madreporite.” Now this plate has been known
for some time, and presents all stages of folding, rugosity, and
pitting, but that the pits represent pores rests on the statement of
these authors. It is a pity that, with their abundant material,
they did not cut a single section so as to prove the point. This
Reviews—Wachsmuth and Springer—On Crinoids, 223
plate is present in Huspirocrinus spiralis, though they speak as if
it were absent; on the other hand they state that the ventral tube
of that species is “‘ profusely perforated.” Now in 1879 they said
of it, “Pores have not been observed” (Revision I, p. 148); their
present drawings show no pores; in the type-specimens pores are
not evident. On what grounds then are we to accept this assertion ?
Here we may also note an account of the anus in the Cyatho-
crinide differing from any previously given; and a repetition of
their former statement as to its position in the Poteriocrinidz; but
of proof or illustrations never a scrap. Messrs. Wachsmuth and
Springer should remember that, in scientific treatises at all events,
neither inspiration nor authority can supply the place of evidence
and argument.
The latter half of the paper deals with the anal plates. These
are not regarded as homologous with the interradials, but are more
supplementary still, being “ introduced as the case required.” They
are also distinguished from the plates of the ventral sac or anal tube,
a difference of terminology that occasionally seems to make the
authors think that there is also some difference in morphology.
However, since this idea materially simplifies all discussion as to
homology and at once puts some recent speculations out of court,
one cannot blame the authors for adopting it. It should, however,
be noted that to regard the special anal plate of the Fistulata as
a purely supplementary piece, and to suppose that the additional
anal plate in such forms as Poterioerinus is a fresh introduction, are
ideas wholly different to any previously advocated by these writers.
They have also considerably changed their views with regard to
. Baerocrinus. Much of this half of the paper is however unavoidably
controversial, and will be more fittingly discussed in another place.
The first half of the paper is also controversial in tone, although,
since their own errors were the greater, the authors might well have
left Dr. P. H. Carpenter alone. They have, we suppose, got so
accustomed to sparring with him that they like to keep it up if only
for exercise. This however hardly excuses the gloveless way in
which they handle him; while their occasional distortions of his
words are rather like hits below the belt. Thus on p. 350 they say :
“The ventral pavement of an Actinocrinus he calls ‘a structure sui
generis,’ 7.e. different from that of a Platyecrinus.” Dr. Carpenter’s
words (Chall. Rep. Stalked Crin. p. 157) are these: “The solid
vault of an Actinocrinus is a structure sui generis, unless, as I believe,
its proximal ring of interradial plates is represented by the orals of
a Neocrinoid,” 7.e. it is noé a structure sui generis; and Carpenter’s
homology of the proximal interradials is the very one now adopted
by his critics! Again (op. cit. p. 178) Dr. Carpenter says: “The
peripheral portion of the vault of Platycrinus, i.e. the zone between
the proximal dome plates in the centre and the calyx interradials,
is comparatively small; and its interradial spaces are ‘occupied by
three—rarely five—plates . . . resting upon the interradial of the
calyx.’ This series of four or six interradials, taken all together, ...
corresponds generally to the single large interradial of Cyathocrinus
224 Reviews—Dr. J. Lorié’s Pays-Bas.
. . + [2e.] all belong to the same system of interradial plates. . ..
Wachsmuth says that ‘the first interradial [of the Platycrinide| is
identical with the outer interradial plate of Coccocrinus,’ in which
I entirely agree.” Now see how these plain words are transmogri-
fied on p. 351 of the present paper:—‘“ He regards (p. 178) the
peripheral portion of the ‘vault,’ by which he means the zone
between the so-called summit plates and the radials, as generally
corresponding to the large interradial of Cyathocrinus, and to the
single interradial of Coccocrinus.” We draw particular attention to
these misrepresentations, not because we suppose for a moment that
they are intentional, but in order that readers of Messrs. Wachsmuth
and Springer may not trust too lightly either to their citations or to
the charges of misrepresentation that they bring against others.
We think indeed that what was correct in the writings of Dr.
Carpenter, not to mention others, might have been more graciously
acknowledged; and we would distinctly reprehend the omission of
all allusion to Dr. M. Neumayr’s explanation of the vault in the
Camerata, which appeared in Die Stamme des Thierreiches (1889),
and was substantially the same as that now put. forward by Messrs.
Wachsmuth and Springer. Much, however, may be pardoned in
consideration of the extreme interest of the present paper, which,
while it knocks the final nail into the coffin of the ‘‘ Paleeocrinoidea,”
gives promise of many a vigorous discussion in the near future.
The exquisite illustrations to this paper are by two well-known
Swedish artists. To the accuracy of the drawings by Mr. G.
Liljevall the present writer can bear witness; of their beauty there
can be no question. Those by Mr. A. M. Westergren are no doubt
equally accurate, but the touch is a little too delicate; plate x. .
should have been printed in darker ink. PI. ix. fig. 1, Cyathocrinus
alutaceus, Angelin, must be referred to C. ramosus; fig. 2, C. lvvis,
Ang., is also a C. ramosus; fig. 3, C. levis, Ang., belongs to an
undescribed species. It is important to note that the originals of
figs. 2 and 38 are abnormal in the cup. These changes make no
difference to the argument of Messrs. Wachsmuth and Springer ;
but the references to the figures (p. 8356) might be corrected with
advantage, the numbers 2 and 3 are interchanged, which is per-
plexing. Plate x. fig. 15, is not alluded to either in the text or in
the explanation of the plate. But our most serious criticism of the
drawings is, as said before—there are not enough. F. A. B.
IJI.—Conrripurions A LA GiotociE Des Pays-Bas—Y. Les Dunes
INTERIEURES, LES ‘OURBIERES BASSES’ ET LES OSCILLATIONS DU
Sot. Par Dr. J. Lorii, Archives Teyler, Sér. IJ. Tome III.
o& partie. (Haarlem.)
HE Memoir which forms the subject of this notice is the fifth
of a series which we owe to the industry of Dr. J. Loiré of
Utrecht. It brings the geological record of Holland down to the
period of authentic history, in fact, to the present day. In his
previously published works the author has brought together an
Reviews—Dr. J. Lorié’s Pays- Bas. 225
enormous amount of evidence bearing on the question of the later
Tertiary earth-movements in Holland. He has shown that there
has been extensive, though perhaps intermittent, subsidence in this
area during the Pliocene and Pleistocene period; he now attempts
to demonstrate that this movement has continued, intermittently and
irregularly, since the period of the Roman occupation, and probably
down to the present day.
The most interesting part of this Memoir to the English reader
probably will be that treating of the changes of the level which
have taken place since the Roman period; for though much of the
evidence has long been published, it has been so scattered that one
is now startled to find what a strong case can be made out for the
continuity of the movements of subsidence. Of course Dr. Lorié
takes into account the subsidence caused by the slow compression of
the peats and clays, as the organic matter decays and the water
is squeezed out. But making every allowance for this, there still
remains, according to Dr. Lorié, a considerable amount of subsidence
unaccounted for. It may be well, however, to point out that no one
case of Post-Roman subsidence in Holland appears to be conclusively
proved; for the absence of any solid foundations for either ancient
or modern buildings leaves it open for any one to suggest bad
foundations as the cause of the present low position of the remains.
It is the cumulative force of the evidence, all pointing in one
direction, that makes the case so strong, especially when the Pliocene
and Pleistocene subsidence to the extent of at least 1100 feet is
taken into account.
Among the Roman remains found in Holland below the sea-level,
the fortress of Brittenburg (‘Arx Brittani”) was perhaps the most
interesting. The ruins were visible at exceptionally low tides during
the sixteenth, seventeenth and eighteenth centuries, but have now
been entirely destroyed. They showed, according to Dr. Lorié, a
sinking of at least three metres since the third century. Another
ruin—the temple of Nehalennia in Zealand—was considered by
Laveleye to have subsided six or seven metres since it was built.
When last seen the floor was at the level of low water, and Laveleye
concluded that originally it must have been above the level of the
highest tides.
Oaken planks of prehistoric date have been found beneath the
peat at a depth of thirteen feet below mean tide, and traces of an
inhabited land surface with egg-shells and cut wood at sixteen feet
below the surface. By these one is reminded of the traces of a fire
found in a submerged forest at low-water level in some excavations
for docks at Hull. Belonging to a still older period we find
abundance of submerged forests and peat mosses at depths ranging
to fifty feet or more below the sea. Much of the remainder of the
Memoir is devoted to minute measurements of the amount of sub-
sidence which has taken place since the date of the first accurate
surveys. Other portions deal with the origin of the inland sand-
dunes, and with the peat mosses. C. R.
DECADE III.—VOL. VIII.—NO. V. 15
226 Reviews—G. H. Morton—Liverpool Geology.
IV.—Tue Gronocy or tHE Country Arounp LiIvEeRPOOL, INCLUDING
THE Nort or Furntsuiru. By G. H. Morton, F.G.8., ete.
Second Edition. Pp. 287. (George Philip and Son, London,
1891.)
EARLY eight-and-twenty years have elapsed since the former
edition of this work was published. During the interval Mr.
Morton has laboured with great enthusiasm and with much patience
at the rocks that lie within a distance of about twenty miles from
Liverpool. He now gives a particular account of the Carbon-
iferous rocks, to our knowledge of which, and especially of the
Carboniferous Limestone of Flintshire, he has largely added. This
Limestone is probably the most attractive formation within easy
reach of Liverpool, and the paleontology of its several subdivisions
has been carefully worked out by Mr. Morton. The Cefn-y-Fedw
Sandstone overlies the Carboniferous Limestone, and probably repre-
sents the Yoredale Series and Millstone Grit of other districts.
These beds and their subdivisions, together with the overlying Coal-
measures of North Wales and South-west Lancashire, are duly
described. Permian beds occur in some localities near Liverpool ;
but over much of the area to which reference is made, where the
strata are known only from the evidence obtained by shafts and
borings, there is a considerable difficulty in distinguishing between
Permian and Bunter.
The Bunter Beds, having a thickness of nearly 2000 feet, comprise
Lower and Upper Soft Sandstones, with intermediate Pebble-beds.
Mr. Morton in describing the Pebble-beds finds it convenient to
divide them locally into a lower division with numerous pebbles
and an upper division, with few or no pebbles. The Keuper Sand-
stone and Marl succeed. ‘The Sandstone is of especial interest on
account of the ‘“ Footprint bed” that occurs (about 124 feet from
the base of this division) in the Storeton quarries. Among the
tracks are those named Cheirotherium Storetonense by Mr. Morton, and
they are illustrated in a series of plates. The name of this familiar
genus is now unfortunately changed, and the animal is designated
Chirosaurus Storetonensis (Lydekker, Cat. Foss. Rept. and Amphib.
Brit. Mus. Part iv. 1890, p. 216). Footprints of Rhynchosaurus are
also described and figured.
Some space is devoted to the microscopic characters of the rocks,
and to Faults and Denudation; and a number of longitudinal
sections are described. Then follow accounts of the building-stones
and other economic products, a list of minerals, and remarks on
the subject of Water-supply. Some of these matters might better
have been treated at the end of the volume, for the author now
proceeds to describe the Pleistocene deposits. Among the more
interesting of these deposits are those found in the Caves of Ffynnon
Beuno and Cae-gwyn that contains relics of “ Pre-glacia]”” Mammalia, —
or more strictly speaking of forms older than the Boulder Clay of
the neighbourhood. Mr. Morton quite agrees with Dr. Hicks in
regarding the Mammalia as older than the Glacial Drift, and believes
that all the objections raised in opposition to this view have been
Reviews—W. A. E. Ussher’s Triassic Rocks. 227
answered. The Glacial deposits and the Glacial striz are fully
deseribed, as well as the Post-Glacial Peat and Forest-beds, and
other Recent deposits; and the author concludes with some brief
remarks on the Origin of the Mersey.
The labours of other geologists have received attention, references
being made more especially to the papers by Prof. Hull, Dr. Ricketts,
Mr. Mellard Reade, Mr. CO. E. De Rance, and Mr. A. Strahan. No
reference, however, is made to Mr. Mellard Reade’s paper on the
Physiography of the Lower Trias (Guot. Mac. 1889, p. 549) ;
possibly his views on this subject were considered too heterodox to
be mentioned. The author, moreover, has received special help in
some instances, Mr. R. Kidston having furnished a valuable list of
fossil plants from the Coal-measures of Ravenhead, near St. Helens ;
and Mr. J. G. Goodchild having contributed notes on some of the
rocks found in the Glacial Drifts. Combining as it does the results
of long-continued personal observation, Mr. Morton’s book furnishes
an authoritative guide to the student, and will be of essential service
to all geologists who seek acquaintance with the geology of the
country around Liverpool. EA Be We
V.—Tue Trrasstc Rocks or West SoMERSET, AND THE DEVONIAN
Rocks on THEIR Borpers. By W. A. EH. Ussuer. Proc.
Somerset Arch. and Nat. Hist. Soc. Vol. XX XV. for 1889. (1890.)
N this paper Mr. Ussher sums up the results of his observations
on the Devonian rocks of the Quantock and Brendon Hills,
and of the neighbourhood of Porlock and Minehead ; and he gives
his latest views on the Triassic rocks that border these old rocks
near Stogumber, Williton, and Porlock. The sandstones, breccias,
conglomerates and marls of the New Red Sandstone series, are all
grouped with the Trias; but some changes have been made by Mr.
Ussher in his grouping of beds at particular localities. Thus he
now recognizes no divisions older than the Keuper, among the New
Red rocks west of Williton, and believes that the coarser beds of
the Keuper were accumulated higher and higher in the series in
that region, progressive subsidence having led to the continuation
of marginal deposition.
With regard to the Devonian rocks, Mr. Ussher publishes a table
to show their general classification, and the correlation of the sub-
divisions in North and South Devon with those of Germany, France,
and Belgium. In West Somerset and North Devon there is a
much greater development of sandstones than in South Devon, for
the Cockington Sandstones of the Torquay district, at one time
regarded as Upper Devonian, are now placed (together with the
Lincombe and Warberry Grits) on the horizon of the Hangman
Grits of North Devon. It has been suggested that in North Devon
the Foreland Grits and Hangman Grits, which are of similar general
character, are the same. Mr. Ussher shows by diagram that this
may possibly be the case: but he gives various reasons, sufficient,
in his opinion, to negative the supposition that they are identical.
The Pickwell Down Sandstones, that were at one time grouped with
228 Reviews— W. Upham’s Lake Agassiz.
the Cockington Sandstones, are now placed alongside the Chudleigh
Limestone and the Frasnian Beds. The Morte Slates are left in
a doubtful position between Upper and Middle Devonian.
The facts brought forward have reference mainly to the dis-
tribution of the several divisions and to the faults and flexures to
which they have been subjected; and they are illustrated by an
excellent coloured geological map.
The author gives an interesting account of his discoveries of
fossils in the Lower Devonian rocks of South Devon, and hopes that
geologists will be stirred up to look for organic remains in the
great Grit-beds of North Devon. The Hangman Grits have yielded
Natica and Myalina: in the Foreland Grits no fossils have yet
been detected. The Morte Slates, regarded as unfossiliferous, have
since yielded a Lingula to Dr. Hicks, so that there is hope for
those who will have the patience to spend hours on rocks that
are apparently barren, instead of devoting their energies to more
tempting strata that are known to be fossiliferous. H. B.W.
VI.—Report or Exproration or THE GuactaL Lak AGaAssiz IN
Maniropa. By Warren Urnam. Ann. Rept. Geol. and Nat.
Hist. Surv. Canada, Vol. IV. Part E. Pp. 156, 2 Maps, and
Plate of Sections. (Montreal, 1890.)
HE suggestion by the late Prof. J. Carvill Lewis that the
Boulder-clay of our Hastern counties was formed in a great
glacier lake reminded English geologists of the wide extension of
such deposits in America. The theory was not a new one in
English geology, as it had been used by Agassiz in 1842 to explain
the origin of the Parallel Roads of Glen Roy, and has been applied
quite recently by Goodchild to the high-level drifts of the Thames
Hstuary. Mr. Warren Upham, in the above Memoir, has now
worked out in detail the evidence for the former existence of a
glacier lake in Minnesota and Manitoba compared with which our
own sink into insignificance. General Warren, in 1867, discovered
that Lake Winnipeg once had a southern outlet, due, he con-
sidered, to an alteration in the contour of the country; this view
was accepted by Dr. G. M. Dawson and Prof. Dana. Prof. Winchell,
however, in 1877, attributed it to the accumulation of water in front
of the northern ice-sheet, and two years later Mr. Warren Upham
advocated the same theory, and suggested the name of “Lake
Agassiz.” According to this view, by the recession of the ice-sheet,
a number of rivers were enabled to return to their original northerly
direction, but as their waters were dammed back by the ice, a series
of lakes were formed, the largest being Lake Agassiz. At first the
only outlet of this lake was down the Minnesota River to the south,
this being the lowest point on the watershed, but as the glacier
receded still further to the north, a series of outlets to Hudson Bay
were gradually opened. Five beaches were deposited during the
former period, and eleven during the latter. The deposits of the
lake now cover 110,000 square miles, so that it was larger than the
combined areas of the five Laurentian lakes; but it never reached
this size at any one time; when the highest beaches of the southern
Reviews—W. Upham’s Lake Agassiz. 229
part were being deposited, the northern part was still covered by
the ice, and before this district was submerged the opening of the
northern outlets had so lowered the water-level that the southern
shore had followed the ice to the north. With the final disappear-
ance of the ice-sheet, Lake Agassiz was reduced to a series of
scattered lakes, of which Lake Winnipeg is the largest.
The ordinary Glacial drifts of the district are attributed to the
action of land-ice, as there is no sign of any transport in or assort-
ment by water. The maximum thickness is 250 feet; the lower
part is very hard and tough, but the upper beds are fairly loose and
can be dug. The author attributes the difference to the former
having been subjected to the enormous pressure of the weight of
the ice-sheet, while the latter was merely dropped during the
melting of ice. There are many boulders mainly of the Archean
rocks from the N. and N.E.; the largest is 22 ft. by 8ft. by 14 ft.
Striz are well preserved and their directions are given in an
appendix. The more especially lacustrine deposits include a series
of sixteen beaches; these are from 25 to 30 rods in width, and rise
from 3 feet to 10 feet on the shore side, and from 10 feet to 20 feet
on the lake side. There are also a number of deltas and kames and
osars: the author uses the two last terms as defined by McGee and
Chamberlin; he applies ‘‘osars” to the drifts formed in the river-
courses, and ‘“‘kames” to the irregular deposits dropped where the
rivers have emerged from between their ice-walled channels and
spread out over the adjoining lowlands.
A few freshwater Mollusca of existing species have been found,
and some worked flints indicate that man lived on the shores of the
lake before the opening of the northern outlets. But the author,
quoting a long series of independent estimates, considers that this
was less than 10,000 years ago.
It is found that the beaches ascend as they are traced to the North,
the amount varying from one to sixteen inches to the mile: he con-
cludes—accepting Mr. R. 8. Woodward’s calculations—that a quarter
of this was due to the heaping-up of the water by the attraction of
the northern ice-sheet. After a careful consideration of Chamberlin’s
hypothesis of alterations of level being due to contraction of the earth’s
crust consequent on the lowering of the isogeotherms by a glacial
climate, it is rejected as inadequate, as its influence would be the
reverse of that which has taken place in the Lake Agassiz area.
The memoir closes with a chapter on the “Geologic and Agri-
cultural Resources” of the district. It is illustrated by a couple of
maps and a plate of sections; but further illustrations will no doubt
be given with the more detailed description to be given by the
author in one of the Monographs of the United States Geological
Survey. The exploration, it should be added, was undertaken, on
behalf of the Geological Surveys of the United States and Canada,
both of which may be congratulated upon an arrangement whereby,
in defiance of International Boundaries, the whole work was entrusted
to one man, and also upon having secured the services of a geologist
whom a long training in glacial geology had rendered especially
competent for the task. J. W. G.
230 Reviews—Prof. Cole's Practical Geology.
VII.—Aips in Pracrican Guonocy. By Prof. Grunvirun A. J.
Cots, F.G.S. 8vo. pp. 402. (London, Charles Griffin & Co., 1891.)
ROFESSOR Grenville Cole’s “‘ Aids” is a work occupying an
unique position in geological literature. Every one trained in
the modern school of Geology has a vivid recollection of the number-
less sources from which he was compelled to select the various
necessary items of information. Apart from ordinary geological
text-books, there were works on chemical analysis, qualitative and
quantitative, on blowpipe analysis, mineralogy, and general physics,
technical treatises and memoirs on the microscopical examination of
rocks, and various other less important references too numerous to
mention. He was continually dependent upon the Professor for
advice and help; and he was led most emphatically to realize the
extraordinary combination of scientific methods that is requisite for
the satisfactory study of a geological formation. The new volume
before us dispels all these difficulties, and now, for the first time,
renders it possible even for an ordinary amateur to gain an adequate
knowledge of the subject up to date. Not only is this the case, but
many of the open paths for further investigation are incidentally
pointed out, with sufficient references to original memoirs to enable
an enthusiastic student to proceed far in this direction.
Prof. Cole is throughout eminently practical. Several guides to
the beginner in Field Geology have already appeared, but we have
never met with so concise a series of useful hints as to small matters
that most geologists have to learn by experience, as can be found in’
the first part of the present work. Not only is the equipment dis-
cussed in a manner that betokens wide experience, but the most
precise information is afforded as to the best form of gymnastics for
various difficult circumstances, such as the crossing of streams and
the scaling of crags. In the remarks on packing specimens, again,
even such minutiz as the peculiar Parcel Post regulations of Italy
are briefly noticed ; and in this section of the book, as in the others,
scarcely an instrument is mentioned without some allusion to its
cost, its comparative efficiency, and the name of the maker from
‘whom it can be obtained. In many instances, directions are given
for the construction of simple apparatus from common materials,
such as gallipots, corks, and wire ; and the circumstances of travellers
in regions distant from ordinary civilization are always carefully
remembered.
‘The second part of the book is devoted to the examination of
minerals, forming not merely a concise statement of the ordinary
nethods of determinative mineralogy and an index to the characters
of the species of most common occurrence, but also comprising
numerous hints and cautions which the student will soon learn to
appreciate. Two conspicuous features are the elaborate treatment of
the determination of specific gravities, and an interesting chapter on
Szabo’s method of quantitative flame-reactions for the felspars and
their allies. After these preliminaries, the most important part of
the work, relating to the examination of rocks, immediately follows.
Rock-structures are first treated in a general way, the principal
Reviews —Prof. Cole’s Practical Geology. 231
characters and varieties of several groups—the coarsely fragmental,
ordinary stratified, cleaved, foliated, and igneous—being successively
pointed out. The determination of the specific gravity, fusibility,
and chemical composition of rocks, is next considered; and an
important chapter on the isolation of the constituents of rocks is
followed by a short and practical discussion of the petrological
microscope and the preparation of rock-sections. With the chapter
on the more prominent characters to be observed in minerals in
rock-sections, and the following synoptical remarks on the appearance
of thin sections of the chief rock-forming minerals, the student
enters upon a subject that requires long practice for its adequate
comprehension; but Prof. Cole’s ‘‘aids” are among the most valuable
that have hitherto appeared, including, indeed, some items that have
scarcely yet reached ordinary handbooks, and numerous notes in
special type when there is any possibility of doubt or misinterpreta-
tion. The sedimentary rocks, as usual, occupy a comparatively
small amount of space, but all the latest discoveries relating to them
seem to be duly incorporated in the synopsis. The igneous rocks
are treated with remarkable elaboration, and students will be grateful
to the author for presenting so concise a summary of the main facts
with a comparatively simple nomenclature. As Prof. Cole remarks,
“petrography has of late suffered from the introduction of an
abundance of new terms, and, what is far worse, of old terms defined
in new senses; but the majority of these can be avoided by the use
of familiar adjectives or mineral prefixes, to the great lightening of
the science.” The Holocrystalline Igneous Rocks are subdivided
into the six groups of Granite (with Eurite), Syenite, Quartz-
Diorite (with Quartz-Aphanite), Diorite (with Aphanite), Olivine-
Gabbro (with Olivine-Dolerite), and Peridotite. The Lithoidal
Igneous Rocks, with some glassy matter, are classified as Rhyolites,
Trachytes, Rhyolitic Andesites, Andesites, Olivine-Basalts, Lim-
burgites, and Hemicrystalline Nephelinites (with Leucitites). The
Highly Glassy Rocks comprise the Obsidian and Tachylyte Groups.
In the case of every term, a reference to its original definition is
given, with frequent notes upon subsequent changes in its meaning ;
and a table is added exhibiting the relationships of the various types,
so far as determined.
The chapter on Metamorphic Rocks is characterized by much
caution in alluding to theoretical matters, and the definition of the
limits within which the term “metamorphic” is applicable is well
stated to be a “matter of opinion.” Prof. Cole places in this
category all rocks in which new crystalline developments, or new
structures, or both, have arisen under the influence of subterranean
heat, or pressure, or actual earth-movement. He seems, moreover,
to show more sympathy with the original views of “regional
metamorphism,” than with the recent speculations of those who
regard the Archean rocks as unique among geological formations.
In referring to the so-called “true schists,” for example, he remarks
“that the alleged distinction between schist-like rocks and schists
of Pre-Cambrian age requires such great delicacy of definition that
232 Reriews—Harrison and Jukes-Browne’s Barbados.
the majority of observers must be content to use the word ‘schist’
in its wide practical signification, covering all well-foliated rocks,
of whatever age, which fall short of the coarser and more felspathic
type styled gneiss.”
The final section of the work is devoted to the examination of
those fossils which are of especial value for stratigraphical purposes.
The Invertebrata alone are treated, and an attempt is made to define
in scientific terms each of the more conspicuous genera, often with
an illustrative woodeut. This plan is a great improvement upon
the time-honoured custom of recording lists of names of fossils with
merely incidental allusions to their characters, of which occasional
figures are supposed to give an adequate conception. The subject,
however, is so vast that we doubt whether Prof. Cole’s brief outlines
will in many cases suffice for the requirements of an ordinary worker
in unknown regions, and we trust that some day the scheme may
be further elaborated.
It is difficult to criticize a work of this nature; every specialist
will hold his own opinion with regard to the particular section that
concerns his own line of research. We are inclined to think, how-
ever, that in some instances simple matters might have received
more attention. In certain strata, for example, a sufficiently accurate
determination of the true dip can readily be made by employing a
spirit level to ascertain the line of strike and fixing the clinometer
at right angles to this, without any of the geometrical constructions
such as Prof. Cole alone describes. But we have most serious fault
to find with the publishers. In a work so admirable both in
subject-matter and typography, the coarseness and inartistic character
of so large a proportion of the new figures is a blemish of which it
is impossible to speak too harshly. In this respect, it forms a
striking contrast to the scientific handbooks issued by publishers
abroad, and we trust that in the next edition the fault may be
entirely. remedied. That such an opportunity will soon present
itself we are fully assured, for the volume is one that will prove
invaluable and be welcomed by all students of Geology.
VIII.—Tue Gronocy oF Barpapos. By J. B. Harrison and A. J.
JuKkes-Browng. 8vo. pp. 64 and Map. (Published Barbadoes ?
1890.)
O long as it is argued that the Glacial period in England was
due to the diversion of the Gulf Stream will geologists feel
interested in all investigations upon the later Tertiary geology of
the West Indies. The island of Barbados moreover, possesses an
additional source of interest in the Radiolarian deposits so long noted
for the beauty of their fossils, and now of especial value from their
bearing on the question of the permanence of oceans and continents.
We must, therefore, feel much gratitude to the authors of this
memoir for the care with which they have worked out the geological
structure and past history of Barbados, and for the first time
definitely established the relations of the series of deposits of which
it is composed.
Reviews— Harrison and Jukes-Browne’s Barbados. 233
- Barbados is an island some 21 miles long by 11 broad and rising
at one point to a height of 1104 feet It is situated at a distance of
100 miles from the main chain of the Lesser Antilles, from which it
is separated by a sea 1500 fathoms deep. It is composed entirely of
sedimentary deposits, no volcanic rocks occurring on the island
except a little light dust and pumice which was probably ejected
from a vent within a radius of 300 miles; the authors, however,
suggest that the elevation may have been due to a laccolite. The
absence of volcanic rock is a point of importance, as we have been
taught on high authority “that all the Lesser Antilles almost with-
out exception are volcanic.”
The rocks are divided into four groups: the Scotland series, the
Oceanic series, the Coral limestones and the valley deposits and
blown sand. The first consists of an irregular series of sandstones,
grits, and shales, with some bituminous clays yielding petroleum,
resembling those of Trinidad and Venezuela; the whole series is
much contorted, faulted and even inverted; they are shown to be
more than 600 feet thick, while their base is not seen, and they are
unconformably overlain by the succeeding beds. Fossils are very
rare in this series, and they are so imperfectly preserved that all the
authors can conclude is that they have “ general resemblances to the
fossils in those deposits of Trinidad which are regarded as Miocene ”
(p. 15).
The Oceanic series overlie these unconformably; the basement
bed is a hard blue limestone, a fact of very considerable importance
on the question of the deep-sea origin of the succeeding 300 feet of
chalky earths, limestones, Radiolarian marls, and red clays. The
evidence of both lithology and paleontology is conclusive as to
the deep-sea nature of the deposits; thus the Foraminifera indicate
a depth of 1000 fathoms, the Echinoid of more than 1000, while
the Radiolaria point to still deeper conditions. The evidence as
to age is less satisfactory: the Microzoa are of little value in this
connexion ; while of the higher fossils the only one that has been
fully worked out is a specimen of Oystechinus crassus, Greg. The
authors, therefore, merely quote the opinion of the describer of this
fossil, that it was either of Pliocene or Pleistocene age.
The Coral Rocks form a sheet that covers 144 out of the 166 square
miles of the island; it is rarely more than 200 feet thick, but it is
in places as much as 260 feet. The coral rock is merely a rough
coarse-grained limestone; beds of freestone, a very porous building-
stone, locally known as dripstone, and some intensely hard compact
rock that forms good road-metal, also occur. Much of the coral
rock is formed of broken fragments of Corals, Mollusca, and
Nullipores. The base of the series is always of loose rubble or half-
consolidated coral or marl. In one of the caves opened by the
Water Supply Company, the coral rock is seen to rest on a mixture
of coral sand and material derived from the siliceous earth: none of
the deposits that one might expect to find on Dr. Murray’s hypothesis
seem to be present, as none such are referred to. The corals and
shells examined show that the whole series is of Pleistocene age.
234 Reviews—N. American Echinoidea.
Of the four concluding chapters, one gives an outline of the
physical history of the island from the continental conditions
indicated by the Scotland series till the recent elevations; a second
is devoted to the general configuration and drainage, a point of
much interest in connexion with the recent operations of the Water
Supply Company, under the able guidance of Mr. E. Easton, C.E.,
F.G.8., in intercepting the underground water-courses. The final
chapters are on the soils and surface deposits and contain an account
of the economic products of the island.
The memoir is certainly a most valuable contribution to our
knowledge of the geology of the Caribbean area; but it must be
judged not so much as a scientific monograph as a popular guide to
the authors’ geological map of the island. Its treatment of the
scientific problems involved is only preliminary to the series of
more detailed papers to be published elsewhere. But the work is
so simply and interestingly written, and the points upon which
further evidence is wanted so clearly indicated, that it ought to
stimulate the residents of Barbados to a more careful search of the
lower beds, and thus enable the authors to settle more definitely
the age of the Scotland series, which is the most important problem
that still awaits solution. J.W. G.
IX.—Norrn American Creracrous HcuinorpEa.
Nore sur quetquus Ecurnipes pu Terrain critackt pu Mex1qur.
Par G. Corrzav. Bull. Soc. géol. France [3] xviii. pp. 292-99.
Pl. I. II. (Paris, 1890.)
A Revision oF THE Orntacrous Ecutnoipga or NortaH AMERICA.
By W. B. Cuarx. Johns Hopkins University Circulars, No. 86.
1891. 8 pp.
die paucity of marine Mesozoic deposits in North America is in
striking contrast to the extensive development of those systems
in Western Europe; hence every addition to the fauna of those
‘‘ages”’ on the other side of the Atlantic is of great interest to
HKuropean geologists as supplying further material to assist in the
study of the evolution of the same group in the two provinces.
The Echinoidea have been especially neglected; hence both M.
Cotteau and Mr. Clark are able to make most valuable additions to
the North American fauna; the literature of the group moreover is
very scattered and most of the species have been described by men
who were not specialists, so that a revision of the genera was greatly
needed.
In M. Cotteau’s paper is given a careful description of six species
from Mexico; two of these, viz. Diplopodia malbosi (Ag.) and
Salenia prestensis (Gras), are characteristic of the European Aptien.
Three of the other species are of European genera, viz., Pseudocidaris
saussuret, Lor., Holectypus castillot, Cott., and Enallaster mexicanus,
Cott.; the last two are new species; the first was originally based
by M. de Loriol on spines, but the test has been described by M.
Cotteau. The sixth species is that described by D’Orbigny as
Hechinoconus (Galerites) lanieri, but for which Prof. Duncan in his
Reports and Proceedings— Geological Society of London. 235
“ Revision” established a new genus, Lanieria; with this course M.
Cotteau fully agrees. The last species may be of Tertiary age, but
the others are all Lower Cretaceous.
Mr. Clark’s “ Revision” contains a list of the species hitherto
described, with short notes on the synonymy. ‘The list includes 48
species, of which 19 are new; several old species are merged as
synonyms, and some are abandoned as indeterminable. As Mr. Clark
does not accept Roemer’s genus Macraster, not one genus in the list
is peculiar to America; while none of the species recorded are found
in Europe. Goniopygus and Botriopygus are now added to the
American fauna, and it is interesting to note that the author identifies
one species as a Psammechinus. The paper is preliminary toa detailed
monograph, and its issue was a very wise course, as in a group in
which the literature is so scattered, it was the only means of enabling
the work to be made fully complete. J. W. G.
Jav JENIP@pueabsS 2NaANMD) A151 Ol@ iss HDA (ews
——
GronogicaL Society oF Lonpon.
I.—Feb. 25, 1891.—A. Geikie, Esq., LL.D., F.R.S., President,
in the Chair.—The following communications were read :—
1. “A Contribution to the Geology of the Southern Transvaal.”
By W. H. Penning, Esq., F.G.S.
The following table shows the author’s classification of the
sedimentary rocks of this region, as compared with those of Messrs.
Dunn and Stow and Prof. Rupert Jones :—
Dunn. (Map, 1887.) Stow.| T. R. Jonzs. PENNING.
mR
Coal-measures: Upper Karoo| 3 .;| Upper e HighVeldt Beds )\ .;
(formerly Stormberg Beds, | # & | Karoo. o¢ =
above Upper Karoo). B Lower @ & 3
ZR Karoo. = 3 &
Kimberley Shales: Lower Karoo Bo Boon 4 5 | Kimberley Beds.
(formerly Upper Karoo). a6 Fa Z
S Klip River) >: 3
: Series. 3.8 4
a Ss:
Lydenburg Beds. E Sa
i} Witwaters- | [3A
2 rand Series. JSS.
wa 4
Namaqualand Schists. De Kaap - Valley =
Beds. a
a
The De Kaap-Valley Beds consist of schists, shales, cherts, and
quartzites, with some conglomerates, chloritic and steatitic beds of
great thickness, faulted, according to the author, against the granite.
They contain a few obscure Corals, and are provisionally referred to
the Silurian.
236 Reports and Proceedings—
The Witwatersrand Series consists chiefly of sandstones, shales,
cherts, and quartzites, having an estimated thickness of 18,000 feet,
possibly formed in a hollow of the granite, and perhaps of marine
formation.
The Klip-River Series is formed of shales, flagstones, cherts,
and quartzites, with numerous interstratified traps, and is at least
18,000 feet thick. Near its base is the ‘ Black Reef” and a
chalcedonite like that described by the author in connexion with
the Lydenberg district, which confirms his opinion that this area
is formed of part of the Megaliesberg formation. The base of the
series is generally conformable to the underlying rocks. The whole
of the lower half of the Megaliesberg formation is let down against
the north side of the granite south of Pretoria.
The author divides the formation which he described in 1884
under the heading of High-Level Coalfields of South Africa into the
Kimberley Beds and the High Veldt Beds. The former thin out
eastward, and are overlapped by the latter, the estimated thickness
of which is 2300 feet. A volcanic rock overlies the Coal-formation.
Near the base of the formation is a bed of loose, calcareous, sandy
clay inclosing many waterworn pebbles, some of large size, derived
from the quartzites and ‘‘bankets” of the underlying formation.
The author is convinced that the region was under glacial influences
at some time during the long period which intervened between the
deposition of the Megaliesberg formation and of the cval-bearing
rocks of the High Veldt, which latter, he maintains, are certainly
Oolitic; the latter contain Glossopteris (?) and Fishes, which he
considers to be nearly allied to Lepidotus valdensis, the latter being
from the Free State.
The High-Veldt rocks are of fluviatile origin, and there appears
to have been continuity of fluviatile denudation from the close of the
Oolitic period until now.
2. “On the Lower Limit of the Cambrian Series in N.W. Caer-
narvonshire.” By Miss Catherine A. Raisin, B.Sc. Communicated
by Prof. T. G. Bonney, LL.D., F.R.S., V.P.G.S.
In this paper the author examines the questions, whether the
Bangor beds should be included in the Cambrian series, and how the
strata associated with the southern felstone should be classed. The
lithological character of the rocks overlying the conglomerate at
Bangor is shown to be of little classificatory value, but the apparent
discordance between its strike and that of the beds beneath suggests
the inclusion of the latter in the pre-Cambrian series, as maintained
by Prof. Hughes and Prof. Bonney.
The age of the northern beds must depend, however, to a great
extent upon the classification adopted for the Llyn Padarn rocks.
It has recently been proposed to regard the felstone of this district
as a lava-flow of Mid-Cambrian age, and the beds to the north as
lower strata included in the same great series. The author points
out as objections to this view :—(1) the enormous thickness of beds,
which in that case must be cut out by the supposed Arenig uncon-
formity at Caernarvon; (2) the difficulty of assigning two telsite
Geological Society of London. 237
masses lithologically similar to two distinct periods; and (3) the
occurrence of conglomerates similar to those which are elsewhere
admitted to be basal Cambrian. But in addition to these minor
difficulties, the theory of a Mid-Cambrian age for the above-named
lava is shown to be without foundation. It was supposed that in
the Bryn Efail quarry the slaty rocks of the district immediately to
the north could be seen in contact with, and altered by, this lava.
The author shows that no slate occurs in the quarry, a diabase
having apparently been mistaken for it, and that there is no grit in
the section which would afford any support to the new theory. The
author concludes that the Llyn Padarn felsite is probably, as classed
by Dr. Hicks and Prof. Bonney, of pre-Cambrian age. As regards
the country to the north, the argument for the new arrangement
was based mainly on the interpretation of the Bryn Efail rocks;
but as this is seen to be erroneous, the section founded on it does not
appear preferable in any way to that published by the Geological
Survey.
3. “Ona Labyrinthodont Skull from the Kilkenny Coal-measures.”
By R. Lydekker, Hsq., B.A., F.G.S.
The author describes a skull from Jarrow Colliery, which he
refers to Ichihyerpetum, and names I. hibernicum, giving reasons for
its specific distinctness from I. (Hrpetocephalus) rugosum, Huxley.
He compares it with allied forms, and believes that it is a member
of the group Brachyopina of Miall, and if so that we have a number
of forms belonging to a type which is unknown above the base of
the Permian in Hurope, but which survived to later times in the
Indian, Australian, and Ethiopian regions.
TJ.—March 11, 1891.—Dr. A. Geikie, F.R.S., President, in the
Chair.—The following communications were read :—
1. “ Manod and the Moelwyns.” By A. V. Jennings, Esq., F.L.S.,
F.G.8., and G. J. Williams, Esq., F.G.S.
The area described by the authors is on the N. side of the
Merionethshire anticlinal of Lower Cambrian rocks, and contains
Lingula flags, Tremadoc and Arenig rocks. The authors correct what
they think is an inaccuracy of some importance in the correlation
of beds in different parts of the range, as interpreted in the map
and memoir of the Geological Survey, and trace with greater com-
pleteness the position and constancy of the beds of slate in the
Arenig series—a point of considerable local and practical importance
to those engaged in slate-quarrying. They offer also what seems
to them to be conclusive evidence to show the intrusive nature
_ of the great crystalline mass known as the syenite of Tan-y-Grisiau,
and to its intrusion are due, in their opinion, the peculiar physical
characteristics of the surrounding country. Though in the immediate
neighbourhood of Festiniog there is no direct evidence of unconformity
between the Tremadoc and Arenig series, it seems probable that an
unconformity does exist; for when traced toward the west the
Tremadoc beds thin out and the Lingula flags are overlain by
Graptolite-bearing slates of Arenig age, while eastward, near Llyn
2038 Reports and Proceedings—
Serw, the grit comes close upon Upper-Lingula flags. The division
of the Arenig volcanic rocks into Lower Ashes, Felstone, and Upper
Ashes, while true of some districts and useful as a generalization,
conveys an idea of uniformity of strata all round the anticlinal which
more detailed examination of different districts does not support.
_ 2. “The Tudor Specimen of Hozoon.” By J. W. Gregory, Esq.
After careful examination of all the slides and figures, and after
consideration of Sir W. Dawson’s interpretation, the author is
absolutely unable to recognize in the specimen any trace of the
“proper wall,” “canals,” or ‘‘stolon passages” which are claimed
to occur in Hozoon, or any reasons for regarding the calcite bands as
the “intermediate skeleton” of a Foraminifer. There are points in
Sir W. Dawson’s figure which might pass as “ stolon passages,” but
they appear very different in a photograph, zine the specimen agrees
with the latter.
The author, however, gives reasons for donclacnt that the case
against the organic origin of the Tudor specimen does not rest on
negative evidence alone ; for though the rock is much contorted, the
twin lamelle and cleavage-planes of the calcite are not bent; and
the fact that the crystalline bands cut across the bedding-planes
further shows their secondary origin.
The rock in which the specimen was found is not “ Lower
Laurentian,” and is included by Messrs. Selwyn and Vennor in the
Huronian.
JII.—March 25, 1891.—Dr. A. Geikie, F.R.S., President in the
Chair.—The following communications were read :—
1. “ Notes on Nautili and Ammonites.” By 8. 8. Buckman, Esq.
1. The Position of the Last Septum.—Mr. Bather’s theory of shell-
growth in Cephalopoda (Ann.. and Mag. Nat. Hist. 1888, p. 300)
seems to depend upon the idea that the last septum in the young in
Nautilus and Ammonites was always formed at a proportionately
increased distance from the penultimate. This supposition is not
borne out by specimens of Nautilus, Witchellia, Lioceras, Ludwigia,
and Grammoceras examined by the author.
2. Shell-muscles of Nautili and Ammonites—Two specimens of
Ammonites in the author’s collection are marked by impressions
which seem to indicate the position of the shell-muscle.
2. ‘On the Drifts of Flamborough Head.” By W. G. Lamplugh,
Ksq., F.G.S. .
Yhe author describes in detail the characters and distribution of
the glacial deposits on Flamborough Head, and classifies them as
follows :—
Alluvial wash, freshwater marls, etc.... ... ... ... Recent.
Late glacial gravels o00 | 666" [660 an0 ) Bo" 066
Wyajoere Ixomnlklere ley? cae tne 2 Gon 00 cao. 00. One ||
Intermediate Series. Stratified beds with bands gh
Boulder Claircd qa isis costae sete eee ese
Basement Boulder Clay AOS OROMEDHE Mant BEEOr cho. |
Chalky rubble ie
“¢ Tnfra-glacial”’ beds of Sewerby and ‘Speeton. |
Glacial.
Geological Society of London. . 239
He discusses their relationship with other drifts, and arrives at
the following conclusions :—
1. The glacial deposits are divisible into Upper and Lower
Boulder Clay, with an Intermediate series.
2. The Lower Clay is a continuation of the Basement Clay of
Holderness, and is the product of the first general glaciation of the
area. The Intermediate series passes laterally into the Purple Clays
of Holderness, and has been deposited at the edge of the ice-sheet.
The Upper Clay includes the Hessle Clay of Holderness, and marks
the latest glaciation of this region.
&. The fossiliferous beds of Sewerby (‘ Buried-cliff Beds”) and
Speeton (‘‘ Hstuarine shell-bed”’) are older than the Basement Clay,
and therefore than the earliest glaciation.
4. The glaciation was effected by land-ice of extraneous origin,
which moved coastwise down the North Sea, and did not overflow
the greater part of the Yorkshire Wolds.
5. Neither the Boulder Clays nor the Intermediate gravels are of
marine origin, the shells which occur in them being derivative.
6. The ice-sheet seems to have filled the North Sea basin in this
latitude from the commencement of the glaciation until its close.
There is no clear evidence here for a mild interglacial period, but
only for extensive fluctuations of the margin of the ice.
3. “Ona Phosphatic Chalk with Belemnitella quadrata at Taplow.”
By A. Strahan, Hsq., M.A., F.G.S. (Communicated by permission
of the Director-General of the Geological Survey.)
Two beds of brown chalk in an old pit near Taplow Court owe
their colour to a multitude of brown grains. These grains are
almost entirely of organic origin, Foraminifera and shell-prisms
forming the bulk of them. Mr. Player has analyzed specimens of
the brown chalk. and finds that it contains from 16 to 35 per cent.
of phosphate of lime. The tests as well as the contents of the Fora-
minifera seem to have been phosphatized, the phosphate appearing
as a translucent film in the former case, and as an opaque mass in
the latter. In the case of the prisms of molluscan shells, the whole
of the phosphate appears to be in the opaque form. Minute
coprolites also occur, together with many small chips of fish-bone.
in which Dr. Hinde has recognized lacunz, while some have been
identified by Mr. EH. T. Newton as portions of fish-teeth.
Mr. Player observes that the phosphate occurs in such a condition
that it would not improbably serve as a valuable fertilizer, without
conversion into superphosphate. This condition is probably due to
the partial replacement of carbonate of lime by phosphate in the
organisms. The removal of the remaining carbonate leaves the
phosphate in a honeycombed state, peculiarly favourable for attack
by the acids in the soil.
The author comments upon the resemblance of the deposit to the
phosphatic chalk with Belemnitella quadrata which is largely worked
in Northern France, and upon a less striking resemblance with that
of Ciply, which is at a higher horizon.
240 Correspondence—Dr. A. Irving.—Miscellaneous.
CORRESPONDENCE.
——— >
DYNAMIC METAMORPHISM OF ROCKS.
S1r,—It is from no mere love of controversy that I should like
just to say, in reply to Mr. Hutchings’ query (Grou. Mag. for April,
1891, p. 168), that—while I am unable to appreciate unnecessarily
realistic play upon a metaphor which is no invention of mine, and
have no right to quarrel with him if he is still smitten with
the charms of the fallacy to which I referred—it seems to me that,
to apply the term ‘dynamic metamorphism” to a rock whose
internal structure shows no signs of differential movement (under
pressure) of its constituent particles, is only another instance, added
to those with which we are already too familiar in petrology, of the
abuse of technical language. Further, Mr. Hutchings seems to
me to surrender the point in the very next paragraph, if the Coal-
seams, by undergoing compression, have acted as buffers to relieve
the fire-clays of that portion of the mechanical force which otherwise
might be expended upon them to induce a cleavage-structure, in
those larger movements, to which the Coal-measures of Northumber-
land as a whole have been subjected. ‘There seems to be some
confusion between dynamic agencies of change in the internal
morphology of a rock and what Prof. Judd has described as static
(Grou. Mae. 1889, Dec. III. Vol. VI. pp. 248 et seq.), the potency of
of which I had previously recognized in my Thesis (see Chem. and
Phys. Studies, etc., pp. 538-55, 95) to the extent of inducing such
metamorphic alteration in chemical compounds previously formed as
might complete their individuality quad minerals.
This being so, I may be allowed to repeat my thanks to Mr.
Hutchings for his most valuable contributions of faets, the full
value and bearing of which will perhaps be better seen, when the
present acute stage shall have passed of that “‘ pressure on the
brain,” under which English petrology would seem at present to be
suffering.
WELLINGTON CouLeGE, BERKS, » A. Irvine.
4th April, 1891.
IMME SOs iby AVN eno Ss
—>—_
Discovery oF Lower Sriurtan Fisnrs.—At the meeting of the
Biological Society of Washington, on February 7th, 1891, Mr.
Chas. D. Walcott, of the United States Geological Survey, announced
the discovery of numerous dermal plates apparently of fishes in a
formation believed to be of Trenton age, near Canon City, Colorado.
Mr. Walcott contemplates presenting a full account of the subject to
the Geological Society of America at their forthcoming meeting in
Washington in August next.
Sh
GEOL. Mac. 1801. DeEcADE III. Vou. VIII. PLate VII.
eee “Ey
ose
Restoration of TriczRATops PRorsus, Marsh (one-fortieth natural size).
A Dinosaur of the Cretaceous period from the Ceratops beds of the Laramie formation; Wyoming Territory,
on the Eastern slope of the Rocky Mountains.
THE
GHOLOGICAL MAGAZINE.
NEW SERIES] DECADE III. VOL... VINE
No. VI.—JUNE, 1891.
QIRAEACINV AI), JR ASyAbIe Gm aHS-
I.—Tue Gigantic Creratorsip®, oR Hornep DINOSAURS, OF
Norto America.!
(PART II., continued from p. 199.)
By Prof. 0. C. Marsu, Ph.D., LL.D., F.G.S., etc.
Tse Scaputar Aron AND Fore Liuss.—The scapula is massive,
especially below. The shaft is long and narrow, with a thin edge
in front, anda thick posterior margin above the glenoid fossa. The
distal portion has a median external ridge, and a thick end (Wood-
cut, p. 242, Fig. 1, sc.).
The coracoid is rather small, and in old individuals may become
united to the scapula. It is sub-rhombic in outline, and is perforated
by a large and well-defined foramen. No indications of a sternum
have yet been found in this group (Woodcut, Fig. 1, er.).
The humerus (Fig. 2) is large and robust, and similar in form
to that of Stegosaurus. It is nearly as long as the femur in one
individual, proving that the animal walked on all four feet. The
radius and ulna (Fig. 3) are comparatively short and stout, and the
latter has a very large olecranon process.
There were five well-developed digits in the manus. The meta-
carpals are short and stout, with rugose extremities. The distal
phalanges are broad and hoof-like, showing that the fore-feet were
distinctly ungulate (Woodcut, Figs. 11-16, pp. 245-246).
Tue Petvis.—The pelvis in this group is very characteristic, and
the three bones, ilium, ischium, and pubis, all take a prominent part
in forming the acetabulum. ‘The relative size and position of these
are shown in the diagram (Woodcut, Fig. 4), which represents the
pelvic elements as nearly in the same plane as their form will
allow, while retaining essentially their relative position in life.
The ilium is much elongated, and differs widely from that in any
of the known groups of the Dinosauria. The portion in front of
1 Read before Section C, of the British Association for the Advancement of Science,
at the Leeds Meeting, September 4, 1890. See also American Journal of Science (3),
vol. xxxvi. p. 477, December, 1888 ; vol. xxxvil. p. 334, April, 1889; vol. xxxviii.
p. 1738, August, 1889, Dp: 501, December, 1889; and vol. xxxix. p. 81, January,
1890, p. 418, May, 1890.
DECADE III.—VOL. VIII.—NO. VI. 16
242 Prof. O. C. Marsh—Gigantic Ceratopside.
SS
Fic. 1.—Right scapula and coracoid of Triceratops prorsus,
Marsh ; side view.
Fic. 2.—Right humerus of same species ; front view.
Fic. 3.—Left ulna of same species; front view. cr. coracoid ;
g- glenoid fossa; h. head; o. olecranon; +. radial
crest; 7’. face for radius; s. suture ; se. scapula.
All the figures are one-eighth natural size.
Fie. 4.—Pelvis of Triceratops flabellatus, Marsh, side view, one-twelfth nat. size.
a. acetabulum ; id. ilium; is. ischium ; p. pubis.
Fie. 5.—Pubis of Triceratops prorsus, Marsh, side view, one-eighth nat. size.
Fic. 6.—the same pubis; top view. Fic. 7.—The same, side view.
@ proximal end; 4. face of ilium; ¢. pubic process; d, distal end.
244 Prof. O. C. Marsh—Gigantic Ceratopside.
the acetabulum forms a broad, horizontal plate, which is continued
backward over the acetabulum, and narrowed in the elongated,
posterior extension. Seen from above, the ilium, as a whole,
appears as a nearly horizontal, sigmoid, plate. From the outside,
as shown in the diagram, the edge of this broad plate is seen.
Fie. 8—Left femur of Zriceratops prorsus, Marsh (front view).
Fic. 9.—Left tibia of same species (front view).
Fig. 10.—The same tibia; distal end; (back view).
a, astragalus; ¢, inner condyle; c' cnemial crest; f, face for fibula ;
h, head; ¢, great trochanter. Figs. 8—10 all one-eighth nat. size.
Prof. O. OC. Marsh—Gigantie Ceratopside. 245
The protuberance for the support of the pubis is comparatively
small, and elongated. The face for the ischium is much larger, and
but little produced. The acetabular face of the ilium is quite
narrow.
The pubis is massive, much compressed transversely, with its
distal end widely expanded, as shown in the Figure (5). There is
no post-pubis. The pubis itself projects forward, outward, and
downward. Its union with the ilium is not a strong one, and is
similar to that seen in the pubis of Stegosaurus.
The ischium is smaller than the pubis, but more elongate. Its
shaft is much curved downward and inward, and in this respect it
resembles somewhat the corresponding part of the pubis of the
Ostrich. There is no indication that the two ischia met closely at
their distal ends, and they were probably united only by cartilage.
A comparison of this pelvis with that of Stegosaurus shows some
points of resemblance, but a wide difference in each of the elements.
The pubis corresponds in its essential features to the pre-pubis of
Stegosaurus, but the post-pubis is wanting.’
Tue Posterior Limps.—The femur (Woodcut, Fig. 8) is short,
with the great trochanter (é.) well developed. The shaft is com-
paratively slender, and the distal end much expanded. The third
trochanter is wanting, or represented only by a rugosity.
The tibia (Woodcut, Fig. 9) is of moderate length, and resembles
that of Stegosaurus. The shaft is slender, but the ends are much
expanded. The fibula is very slender, and the distal end was
closely applied to the front of the tibia (Woodcut, Figs. 9 and 10/.).
In adult individuals, the astragalus is firmly codssified with the
distal end of the tibia, as in Stegosaurus (Figs. 9 and 10 a, a).
The metatarsal bones which were functional are rather long, but
massive (Woodcut, Figs. 17-19). Their phalanges are stout, and
the distal ones broad and rugose, indicating that the digits were
terminated by very strong hoofs (Woodcut, Figs. 20, 21, 22).
All the limb bones and vertebre in Triceratops, and the nearly
allied genera, are solid.
CA ZO
Fie. 11.—Metacarpal of Triceratops prorsus, Marsh (front view), one-eighth
natural size. Fries. 12 and 13.—The same bone; side and back views.
Tue Dermat Armour.—Beside the armature of the skull, the
body also in the Ceratopside was protected. The nature and
position of the defensive parts in the different forms cannot yet be
1 The pubis recently discovered, and represented in Woodcuts Figs. 5, 6, 7, hasa
short, splint-like process, which may, perhaps, be a remnant of a post-pubic element,
although it has not the position of the post-pubic bone in other Dinosaurs.
246 Prof. O. 0. Marsh—Gigantic Ceratopside.
Fre. 14.—Terminal phalanx of manus of Triceratops flabellatus, Marsh; front
view ; one-fourth natural size. Fies. 15 and 16.—Side and back views of same.
Fic. 17.—Metatarsal of Triceratops prorsus, Marsh; side-view; one-eighth
natural size. Fries. 18 and 19.—Front and side view of same.
Fre. 20.—Ungual phalanx of Triceratops horridus, Marsh; front view; one-
fourth natural size. Fie. 21.—The same; side view. Fic. 22.—The same ;
posterior view.
Fic. 23.—Dermal spine of Triceratops ; side view ; one-eighth natural size.
Fies. 24 and 25.—Front and top views of same.
Erratum.—In Grot. Mac. May No. pp. 195, 196, 197, 199, for Triceratops
“porosus,’ read Triceratops prorsus, Marsh.—EKpit. Grou. Mae.
Prof. 0. C. Marsh—Gigantie Ceratopside. 247
determined with certainty, but various spines, bosses, and plates
have been found, that clearly pertain to the dermal covering of
Triceratops, or nearly allied genera. Several of these ossifications
were probably placed on the back, behind the crest of the skull
(Woodcut, Figs. 33-84), and some of the smaller ones may have
defended the throat, as in Stegosaurus.
(
\\\
Mii
AN
Fie. 26.—Dermal plate of Triceratops ; top view ; one-eighth natural size.
Fie. 27.—Bottom view of same. Fes. 28 and 29.—Side and end views of same.
Fics. 30-32.—Dermal plate of Triceratops; top, bottom and side views; one-
eighth natural size.
Fic. 33.—Dermal ossification of Triceratops; side view; one-half natural size.
Fie. 34.—Front view of same.
The remarkable extinct reptiles here briefly described present
many characters which separate them widely from all other known
Dinosaurs. Some of these characters are evidently the result of a
high degree of specialization, but there are others that cannot be
thus explained. The specialization evidently began in the skull,
and there reached its greatest development. The peculiar armature
of the skull has a partial parallel in the genus Phrynosoma among
the recent Lizards, and Meiolania among the extinct Turtles. A
suggestion of the parietal crest may be seen in the existing Chameleo,
248 Prof. O. C. Marsh—Restoration of Triceratops.
which offers other points of resemblance in its skull and skeleton.
These features, however, indicate only'a very remote affinity, and —
it is among the Dinosaurs alone that this group can be placed, as a
distinct family, in the order Ornithopoda.
The Ceratopside resemble, in various points, the Stegosauria of
the Jurassic, especially in the vertebre, limbs, and feet. The
greatest difference is seen in the skull, but the pelvic arch, also,
shows a wide divergence. In the Ceratopside, there is no marked
enlargement of the spinal cavity in the sacrum, and there is no
post-pubis.
The characters above given are based upon fossils which I have
personally investigated, including the type specimens of Ceratops
and Triceratops, on which, mainly, the family Ceratopside was
established. The material now at my command includes the
remains of many individuals, among which are portions of about
twenty different skulls, and some of these are nearly perfect. In
the memoir now in preparation, I shall fully describe and illustrate
all the more important of these specimens, and likewise discuss their
relations to allied forms.
The generic names, Agathaumas, Cratgomus, Monoclonius, and
one or two others, have been given to fragmentary fossils, which
may belong to this group, but these remains, so far as made known,
appear quite distinct from those here described.
In conclusion, let me say a word as to how the discoveries here
recorded have been accomplished. The main credit for the work
justly belongs to my able assistant, Mr. J. B. Hatcher, who has
done so much to bring to light the ancient life of the Rocky
Mountain region. I can only claim to have shared a few of the
dangers and hardships with him, but without his skill and energy,
little would have been accomplished. If it is borne in mind that
two of the skulls weighed nearly two tons each, when partially
freed from their matrix, and ready for shipment, in a deep, desert
canon, fifty miles from a railway, you will appreciate one of the
mechanical difficulties overcome. When I add that some of the
most interesting discoveries were made in the hunting grounds of
the hostile Sioux Indians, who regard such explorations with super-
stitious dread, you will understand another phase of the problem.
I might speak of even greater difficulties and dangers, but the
results attained repay all past efforts, and I hope at no distant day
to have something more of interest to lay before your readers.
II.—Aprenpix.—Resroration oF TRICERATOPS.
By Prof. 0. C. Marsu, Ph.D., LL.D., F.G.S., ete.
(PLATE VII.)
Le previous numbers of this Macazryu, the writer has given the
principal characters of the gigantic Ceratopside, or horned
Dinosaurs, from the Laramie, with figures of the more important
parts of the skull and skeleton.! The abundant material now
1 See Geox. Mac. 1890, January Number, pp. 1-6, and Plate I. Gzor. Mae.
1891, April Number, Pl. IV. May Number, Pl. V. pp. 193-199, ante, pp. 241-248.
Prof. O. O. Marsh—Restoration of Triceratops. 249
available for examination makes it possible to attempt a restoration
of one characteristic form, and the result is given in Plate VII.
This figure, about one-fortieth of natural size, is reduced from a
large outline plate of a memoir on this group, now in preparation by
the writer for the United States Geological Survey.
This restoration is mainly based on two specimens. One of these
is the type of Triceratops prorsus, Marsh, in which the skull, lower
jaw, and cervical vertebre are in remarkable preservation. The
other specimen, although somewhat larger, is referred to the same
species. It consists of parts of the skull, of vertebra, the pelvic
arch, and nearly all the important limb bones. The remaining
portions are mostly taken from other remains found in the same
horizon and localities, and at present are not to be distinguished
specifically from the two specimens above mentioned. The skull as
here represented corresponds in scale to the skeleton of the larger
individual.
In this restoration, the animal is represented as walking, and the
enormous head is in a position adapted to that motion. The massive
fore limbs, proportionally the largest in any known Dinosaur,
correspond to the head, and indicate slow locomotion on all four feet.
The skull is, of course, without its strong horny covering on
the beak, horn-cores, and posterior crest, and hence appears much
smaller than in life. The neck seems short, but the first six
cervical vertebrz are entirely concealed by the crest of the skull,
which in its complete armature would extend over one or two
vertebree more. The posterior dorsals with their double-headed ribs
continue back to the sacrum itself, there being no true lumbars,
although two vertebra, apparently once lumbars, are now sacrals, as
their transverse processes meet the ilia, and their centra are coossified
with the true sacrum. The four original sacral vertebrae have their
neural spines fused into a single plate, while the posterior sacrals,
once caudals, have separate spines directed backward.
No attempt is made, in this restoration, to represent the dermal
armour of the body, although in life the latter was more or less
protected. Various spines, bosses, and plates, indicating such dermal
armature, have been found with remains of this group, but the
exact position of these specimens can, at present, be only a matter
of conjecture.
This restoration gives a correct idea of the general proportions
of the entire skeleton in the genus Triceratops. The size, in life,
would be about twenty-five feet in length, and ten feet in height.
The genus Ceratops so far as at present known is represented by
individuals of smaller size, and in some instances, at least, of quite
different proportions. A third genus, which may be called Séer-
rholophus, can be readily distinguished from the other two by the
parietal crest, which had its entire posterior surface covered with
the ligaments and muscles supporting the head. In Ceratops and
Ticeratops, a wide margin of this surface was free, and protected by
a thick, horny covering. The type of the new genus is the specimen
described and figured by the writer, as Triceratops flabellatus, which
200 A. Harker—Rocks from the Tonga Islands.
in future may be known as Sterrholophus flabellatus, Marsh. There
is some evidence that other forms, quite distinct, left their remains
in essentially the same horizon of the Laramie, but their true
relation to the above genera cannot be settled without further
discoveries.
This group so far as at present investigated is very distinct from
all other known Dinosaurs, and whether it should be regarded as a
family, Ceratopside, as first described by the writer, or as a sub-
order, Ceratopsia, as later defined by him, will depend upon the
interpretation and value of the peculiar characters manifested in its
typical forms.
The main characters which separate the group from all other
known families of the Dinosauria are as follows :
(1) A rostral bone, forming a sharp, cutting beak.
(2) The skull surmounted by massive horn-cores.
(3) The expanded parietal crest, with its marginal armature.
(4) A pineal foramen.
(5) The teeth with two distinct roots.
(6) The anterior cervical vertebree codssified with each other.
(7) The dorsal vertebrae supporting, on the diapophysis, both
the head and tubercle of the rib.
(8) The lumbar vertebrze wanting.
The animals of this group were all herbivorous, and their food
was probably the soft succulent vegetation that flourished during
the Cretaceous period. The remains here figured are from the
Ceratops beds of the Laramie, and were found by Mr. J. B. Hatcher,
in Wyoming, on the eastern slope of the Rocky Mountains.
II].—Norrs on a Cotiection or Rocks rrom THE TonGA
IsLANDS.
By Atrrep Harker, M.A., F.G.S.,
Fellow of St. John’s College, Cambridge.
fliers Tonga or Friendly Islands in the South Pacific Ocean seem
to have received hitherto no attention from geologists, and
I can find no published information as to their geological constitu-
tion beyond the simple record of the existence of volcanoes and
coral-reefs. The material of these brief notes was mostly collected
by Mr. J. J. Lister, M.A., during the cruise of H.M.S. Egeria in
1889; and, through the courtesy of Captain Wharton, R.N., F.R.S.,
Hydrographer to the Admiralty, I have had the opportunity of
examining a few additional specimens collected by Captain C. F.
Oldham, R.N., Commander of the Egeria, in 1890. In view of the
general account of the islands which Mr. Lister is preparing, I notice
here only such points as arise directly from an examination of the
specimens.
It is well known that most of the Pacific Islands which have been
explored seem to be built largely of either volcanic or calcareous
formations, usually supposed to be of Recent origin. Indeed the
idea seems to have been entertained in some quarters that such was
A. Harker—Rocks from the Tonga Islands. 251
the universal construction of the islands. Drasche,' writing in 1879,
restricted this theory to those islands lying eastward of a certain
line, drawn from Kamschatka through Japan, the Philippines, New
Guinea, New Caledonia, New Zealand, Auckland and Macquarie
Islands to the Antarctic Victoria. Even at that time, however, such
rocks as clay-slates, greywackes, etc., had been recorded in the
Chatham Islands? and New Britain,® east of Drasche’s line, and
leptinites,* granite, and gneiss’ in the Marquesas, far to the east,
Later researches have proved the existence of numerous crystalline
rocks, igneous and metamorphic, in the larger islands of the Fiji®
and Solomon’ archipelagos, and suggested that in many other
islands such rocks may be only masked by a comparatively thin
covering of organic or volcanic accumulations.
It may be inquired, then, whether the Tonga Islands show any
indication of the existence of denuded crystalline rocks beneath the
newer deposits. No such rocks have been found in place, and the
evidence available is very slight. Eua, the most southerly of the
larger islands, differs to some extent from the rest in geological
structure, and from the eastern shore of this island Mr. Lister
collected a boulder, one of many there seen, which is neither a
volcanic nor an organic rock. I have described it (GroLoGICAL
Maeztine for April, p. 172) as a uralitised gabbro, and, though some
petrologists would prefer to name it diabase, it is unlike any super-
ficially erupted lava. Further, there is no doubt that it is derived
_from the island on which it was found. The only other suggestive
point is the rare presence of minute fragments of red garnet and
blue tourmaline in the calcareous andesitic sandstones largely
developed in the same island. These fragments, blown out from
a volcano, point to the existence of metamorphic rocks below,
though at what depth it would be idle to speculate.
With the exception of the dykes mentioned below, the volcanic
rocks of Hua seem to consist entirely of fragmental accumulations,
no lava-flows being seen. Mr. Lister’s collection, however, contains
a specimen of a boulder from the same locality as the one mentioned
above, which is a grey compact-looking andesite of specific gravity
2618. It shows under the microscope a kind of flow-brecciation
which causes us to compare the rock with extruded lavas rather
than with the dykes exposed near the locality in question. The
rock [1258] consists of very numerous little plagioclase crystals
imbedded, with marked parallel arrangement, in an isotropic ground.
The felspars are lath-shaped to acicular, and twinned or simple
according to their size. There is little or no augite, but an
occasional crystal of rhombic pyroxene transformed into pale green
1 Neu. Jahrb. 1879, p. 265.
® See Darwin’s ‘‘ Geological Observations:’’ cf. Haast, Trans. N.Z. Inst. vol. 1.
p. 180, 1869, and Hector, zd7d. vol. ii. p. 183, 1870.
5 Meinicke, ‘ Inseln des Stillen Oceans,’’ vol. i. p. 133, 1875.
* Jardin, Mém. Soc. Imp. Sci. Nat. Cherbourg, vol. iv. p. 55, 1856.
° Marcou, “‘ Explic. Carte Géol. de la Terre,’”’ p. 185, 1875; authority not cited.
6 Wichmann, Tsch. Min. Petr. Mitth. vol. v. p. i. 1882.
7 Guppy, ‘‘ The Solomon Islands, their Geology,’ etc., 1887.
252 A, Harker—Rocks from the Tonga Islands.
fibrous bastite. Magnetite grains and crystals occur sparingly.
The most plentiful secondary product is yellow-green pleochroic
epidote, which seems in part to replace some of the larger felspars.
The slide shows numerous irregularly shaped patches of andesite
differing from their matrix. They are sometimes of finer texture,
sometimes coarser, or again have a fine ground enclosing porphyriti¢
felspars. ‘These patches do not share in the general flow structure
of the rock, and seem to be relics of a solid crust formed on the
surface of a ecoulée, and broken up by subsequent movement of
the mass.
Mr. Lister notes three dykes exposed on the eastern shore of Hua.
These cut through the volcanic deposits, but are older than the
overlying limestones, which they do not penetrate. The specimens
are of a dull-grey andesite, sometimes showing porphyritic felspars
to about an eighth of an inch long, or little dark spots which
represent decomposing pyroxene.
Under the microscope these rocks show innumerable microlites of
felspar imbedded in an isotropic base. When porphyritic felspars
occur, they exhibit Carlsbad and albite twinning and strong zonary
banding in polarized light. Augite is not recognizable in the
ground-mass, but occurs in more or less idiomorphic crystals,
colourless or nearly so in section, among the earlier minerals. With
it is associated a pale yellow enstatite in good prisms terminated
by the dome (102) [slide 1261]. Magnetite is present either in
crystals of the earlier consolidation or in little granules in the
ground-mass. As secondary products we find calcite from the
felspars, delessite and calcite from the augite, and green dichroic
bastite from the rhombic pyroxene [1260]. A specimen [1259]
from the northerly dyke shows the usual microlitic ground traversed
by distinct branching veins which consist mainly of larger, though
still mostly untwinned, crystals of felspar, extinguishing nearly
parallel to their length, and perhaps referable to sanidine. These
veins are probably segregations marking the last phase in the
consolidation of the mass.
The fragmental volcanic rocks of Hua are well bedded in nearly
horizontal strata, and exhibit frequent alternations of types differing
in degree of coarseness, etc. Some are of the nature of volcanic
dust, forming bands of grey to red colour according to their fresher
or more decomposed condition. Among the finely divided material
of these bands may be recognized little rounded or irregular bits of
brown glassy matter, and broken crystals of clear felspar, green
augite, and occasionally pale enstatite. The extinction-angles
measured on cleavage-flakes of the felspar show that more than one
member of the soda-lime series is represented. The same materials
are recognized in various red-brown earthy rocks from the higher
ground of the island, apparently formed by atmospheric weathering,
and in the fine sand from the beds of the rain-channels in the
neighbourhood. The fragments in these fine ash-beds are fairly
uniform in size, though occasionally a few small lapilli occur.
These deposits are mostly free from carbonate of lime, but there
A. Harker—Rocks from the Tonga Islands. 203
are some which are highly calcareous. Specimens from the northern
part of Eua have a white chalky aspect, and effervesce freely with
acid, but they contain abundant felspar microlites and broken
felspar crystals, some giving nearly straight extinction (oligoclase-
andesine ?), besides occasional enstatite, etc.
A coarser type of rock, well represented in the collection, may
be termed a volcanic sandstone. It resembles an ordinary sandstone
of moderately coarse grain, though isolated fragments occur up to
about an eighth of an inch in diameter. On the generally yellowish
brown surface are seen little scattered broken crystals of black
augite and the lustrous cleavage-planes of felspar fragments. Some
of the felspar flakes give nearly straight extinction; others are
evidently more basic. As before, the bulk of the fragments com-
posing the rock are of brown-stained glassy lava. Good examples
come from the mouth of Ana-ahu.
At the last-named locality there is an alternation of harder and
softer beds. The softer are of the character just described; the
harder differ from them in possessing a cement of calcite, which
forms a large part of the rock. These calcareous beds, which occur
also in other parts of the volcanic series of Hua, present under the
microscope some points of interest. One of these features, the
occasional presence of minute chips of characteristic metamorphic
minerals, has already been alluded to. Slices [1268, 1273] show
that the fragments, some of which appear rolled, are of brown-
stained andesite, enclosing many felspar microlites and occasionally
a porphyritic crystal. The larger pieces have the spongy character
of pumice. Besides the andesitic fragments, are seen little chips
of minerals such as might be derived from the same source; clear
plagioclase, pseudomorphs of calcite after felspar, and brightly
polarising pyroxene; also rarely a grain or two of quartz, seemingly
clastic. The matrix of crystalline calcite encloses numerous fora-
miniferal tests which seem to belong for the most part to Globigerina.
More rarely occurs a small chip of shell or a fragment recalling
the characteristic structure of an echinoderm plate. The calcareous
matrix further exhibits in parts a beautiful oolitic structure, giving
the black cross well defined in polarised light. The structure is of
the spherulitic type, with radial but not concentric arrangement,
and is quite different from the rolled oolitic grains well known in
our Carboniferous and Jurassic limestones. It is produced in situ
by molecular action, as is sufficiently proved by the fact that one
of these spherulitic growths occupies each chamber of the forami-
niferal tests.
It seems clear that the whole of these volcanic rocks of Hua are
of submarine origin. This appears from their uniform and horizontal
stratification, the indications of the “sorting” action of water, and
the occurrence at various horizons of highly calcareous rocks, some
containing marine organisms. Probably some parts of the deposits
come from the destruction of volcanic, accumulations thrown up above
sea-level, such as Falcon Island at the present day, which is being
rapidly destroyed by the waves.
254 A. Harker—Rocks from the Tonga Islands.
The volcanic rocks of Eua are overlain, with evident unconformity,
by massive white limestones, and the earlier group must have suffered
considerable denudation before the newer was deposited. This
appears from the fact that while the horizontally bedded volcanics
crop out in the interior at a height of more than a thousand feet,
the limestones come down to sea-level on the coast within a distance
of half a mile. Further, the dykes which cut through the volcanic
deposits terminate without entering the overlying calcareous
strata.
The limestones occur in three terraces, and Mr. Lister was led to
regard them as elevated reefs. He observed reef-corals on the
edge of the lower terrace and on the top of the highest one. An
examination of a few thin sections of the rocks showed indeed a
comparative want of coral fragments, the rocks sliced, with their
abundant foraminifera, some of large size, recalling strongly the
Orbitoidal Limestones of Sumatra and Borneo as described by
Messrs. H. B. Brady? and A. V. Jennings? respectively. When
good coral remains occur, they are associated with similar foram1-
nifera, etc. [1329]. The specimens have, however, been submitted
to Dr. John Murray, whose large experience of calcareous deposits
is well known, and, pending the results of his examination, it will
be sufficient here to notice the more obvious petrological characters
of the rocks.
Some examples, eg. from Maui’s Oven, are rough-textured
yellowish limestones, in which abundant foraminifera can be seen
on a hand-specimen. In general, however, the deposition of
secondary calcite has converted the mass into a white or cream-
coloured limestone of very compact appearance, not unlike some
travertines, but containing sometimes little irregular vacuities which
the calcite cement has not filled.
The specimens sliced, whether from the lower, the middle, or
the upper terrace, show abundant foraminiferal tests and other
organic remains which will not be more closely described in this
place. Small oolitic growths are common in the secondary calcite
cement, but they are invariably of the spherulitic type. Concentric-
coated oolitic grains are conspicuously absent, nor is there any trace
of clastic material such as quartz- or shell-sand, volcanic detritus,
etc. The only large fossil observed is a cast of a Cerithium, not
perfect enough for specific determination.
I pass on to the specimens from other islands composed partly
or wholly of volcanic accumulations. The purely coral islands,
Tongatabu, Vavau, Nomuka, etc., will not be noticed.
Mango (Comango on the Chart) appears to be built entirely of
volcanic ejectamenta. Mr. Lister found no lavas except as frag-
ments in the tuffs. These, in the specimens examined, range up to
about six inches in length, and have a dull brown decomposed
aspect, with in many cases small vesicles filled with calcite. A slice |
of one [1267] shows a microlitic andesite with marked flow-
1 Grou. Mac. (2), Vol. II. p. 532, 1875,
2 Gzoz. Mag. (8), Vol. V. p. 529, 1888,
A. Harker—Rocks from the Tonga Islands. O55
structure and much ferruginous decomposition-product. The rock
is not porphyritic.
The fragmental accumulations from this island vary much in
character. Specimens from the eastern hill are white chalky-looking
rocks, in which nothing is to be seen beyond a rare crystal of augite.
They are very calcareous, and the residue after treatment with acid
is merely a mass of very fine scoriaceous and dusty material with
fragments of crystals of felspar, hypersthene (?), apatite, etc. From
other parts of the island come fine grey ashes with white spots of
decomposing felspar. These are non-calcareous, and consist of
minute fragments of brown-stained glass and various volcanic
minerals mingled with fine dust. Other rocks unmixed with cal-
careous matter are, rather, volcanic sandstones, enclosing numerous
fragments, usually rounded, of yellow or brown lava, etc. Specimens
of coarser texture—volcanic conglomerates—come from the western
or Observation Hill. These have a partly calcareous matrix and
include fragments of lava usually an inch or more in diameter and
of subangular form. In these coarse accumulations occur blocks of
coral, specimens of which are as much as six inches across, and have
portions of the conglomeratic rock adhering firmly to them.
Nomuka-iki is a small island lying to the south-west of Nomuka.
It is described as consisting in its northern part of a flat of coral
sand, while the southern and higher portion is of stratified volcanic
ashes, alternately fine and coarse, which are well exposed in a cliff
on the west, and contain marine fossils. The specimens from here
are mostly yellow-brown or greyish ashes of fine texture, only
occasionally showing fragments up to an eighth of an inch long, some
of which are of decomposing andesite. Little glistening felspars
are visible with a lens, besides countless little black dots which
seem to be partly altered pyroxene. Some specimens from the
upper layers are rather coarser, and show more conspicuous frag-
ments. In these, well-formed prisms of lustrous black augite may
be recognized as well as the felspars. The microscope shows that
these latter are, as usual, of a triclinic species; that a green,
pleochroic rhombic pyroxene occurs, in addition to the green
augite; and that yellowish volcanic glass and fine dust are also
represented. None of the Nomuka-iki specimens are calcareous
enough to effervesce with acid. The only fossil in the collection is
a well-preserved Pyrula. It rather resembles the Eocene P. nezilis,
but has more delicate markings, and is perbape to be matched
among later forms.
Tonumeia, a small island situated to the sath of Nomuka and
Mango, consists, according to Captain Oldham’s observations, of
stratified volcanic tuffs, which are exhibited in a cliff 80 feet high
on the west coast, showing a dip of 38° to the south. A specimen
(1.) of the finer tuff is a rather fine volcanic ash compacted by a
calcareous and ferruginous cement into a dirty yellow-brown rock.
In the residue insoluble in dilute acid are recognized chips of a
-monoclinic and a fibrous rhombic pyroxene with a basic felspar,
besides the usual brown-stained glassy and scoriaceous fragments.
256 A. Harker—Rocks from the Tonga Islands.
Other ae from this island are pebbles found on the beach.
One (II.) is a coarsely amygdaloidal lava, perhaps not a native rock.
Two others are black nodules of irregular but rounded form, the
larger being two inches in diameter (III.). They have externally
a sraphitic lustre, while the interior is duller and shows a certain
eccentric radial structure. Rough chemical tests indicate some oxide
of manganese, and the general characters are those of psilomelane ;
but the interior is softer, and the specific gravity of one nodule was
found to be only 8°54. This perhaps indicates a partial conversion
into wad or some other hydrated substance. These nodules are
evidently native to the island, and portions of the calcareous matrix
in which they have been imbedded are still adherent on their surfaces.
Captain Oldham also collected specimens from the small island
Tonua (not named on the Chart) situated north-east of Mango. Of
these, an “altered coral sand” (1V.) from the summit of the island
seems to be free from foreign admixture; the rest, from a cliff 20
feet high on the north side, are volcanic ashes usually with but little
calcareous matter, despite the fact that organic remains are visible
in several specimens. These stratified volcanic rocks, with an
easterly dip, build the mass of the island. Most of the specimens
are soft yellow-white rocks with a lumpy appearance, although the
enclosed fragments, up to about an inch in diameter, do not differ
essentially from the matrix in which they are imbedded (V. and Va.).
Minute glistening crystals of felspar and augite are visible here
and there in the dull mass, and the microscope shows only these
minerals with an occasional broken needle of apatite, and much fine
dusty matter. In other examples from the same cliff the fragments
are more distinct, and many of the smaller ones are rolled bits of
dark lava (VI. and VII.). These rocks contain numerous organic
remains, among which the most conspicuous seem to be the conical
tests of Pteropods: a rather indistinct cast of a Gasteropod also
occurs—possibly a Murex from the form of its canal, although the
varices are not very strongly marked. One specimen is traversed
by a half-inch seam of fine, non-calcareous character, with a dark
grey colour, clearly indicating the stratified nature of the deposits.
The microscope shows the usual triclinic felspars and green pyroxene,
the felspar crystals and fragments being especially abundant, together
with fine volcanic dust and glass fragments. There are also very
slender needles of a highly refracting yellow-brown mineral, which
has much of the appearance of rutile—a mineral scarcely to be
expected in such a connexion.
Falcon Island came into existence owing to a volcanic eruption
which occurred in the year 1885.1. The main mass of the island
consists of a fine grey ash, mostly quite incoherent, but containing
crumbling lumps. The microscope shows this to be a volcanic dust
similar to that so widely dispersed during the eruption of Krakatau.
It is composed largely of comminuted crystals, among which are
recognized felspars, some with twin-lamellation, green augite, and
1 A Visit to the newly emerged Falcon Island, Tonga Group, S. Pacific, by
J.J. Lister, Proceedings of the Royal Geographical Society, March, 1890.
Grou. Mac. 1891. Decwllie Vole Vill. Plt Viti
Remains or Hytonomus Lyenu, Dawson, 1859.
Coau-Mzasurss, Sourn Jocerns; Nova Scotia.
(1) Cranial bones and mandibles; (1a) Sternal and shoulder bones;
(2) Mandible ; (3) Humerus, ribs and vertebre ; (4) Hind limb;
(5) Pelvis; (6) Caudal vertebree.
A. Harker—Rocks from the Tonga Islands. 207
a rather fibrous rhombic pyroxene. Some of the felspars are
andesine, but they are not all of one variety. With these minerals
occur many fragments of yellowish glass, often with very irregular
shape and concave boundaries, such as would arise from the breaking
up of pumice.
The coarser accumulations would rather be termed agglomerates.
They have a rough and often porous texture, and are largely com-
posed of bomb-like ejectamenta, a quarter or half an inch in diameter,
besides pieces of vesicular and pumiceous lava. The interspaces are
often partly vacant, with a dusty lining. These ageglomeratic rocks
are grey or yellowish, but become red or brown by weathering.
Mr. Lister’s collection from Falcon Island includes a number of
specimens from the ejected blocks of lava scattered over the island.
These are more or less vesicular rocks, showing numerous little
glassy felspars, one-tenth to one-fifth of an inch long, imbedded in
a dark grey ground. Some, perhaps rather weathered, show a
lighter grey ; while others, more glassy, are black with a silky
lustre. The vesicles usually vary from mere pores to cavities an
inch or more in length; but in some examples they are drawn out
into narrow pipes more than six inches long. The more scoriaceous
and cellular varieties are free from porphyritic crystals, and the
perfectly glassy pumice is pure white.
These lavas appear to be basic augite-andesites, neither olivine
nor rhombic pyroxene being detected. One of the sliced specimens
gave a specific gravity 2-436, but this is evidently too low, and
indeed the specimen contains numerous microscopic vacuities ; a
more compact example gave 2°708, which seems to indicate a
decidedly basic composition.
In the slices [1264-1266] the porphyritic felspars seem, from
their extinction-angles, to be bytownite. They have Carlsbad and
albite-twinning, and some of the larger ones show pericline-lamellee
in addition. The crystals are well bounded, but often grouped in
clusters so as to interfere with their perfect development. The
crystals are clear, but contain glass-cavities, usually with zonal
disposition, and some entangled portions of the ground-mass. The
augite, pale yellow in section, is not very abundant. Some of the
larger crystals are so associated with the porphyritic felspars as to
prove that they belong to an early phase of consolidation, but the
bulk of the mineral occurs in ill-shaped idiomorphic crystals
scattered through the ground. The ground-mass consists of numerous
lath-shaped microlites of felspar imbedded with a more or less
fluxional arrangement in an isotropic glass. The proportion of
glassy base varies considerably, as might be inferred from the
appearance in hand-specimens. A very characteristic feature is
the occurrence in the mass of well-defined irregular, or usually
round, patches of lighter colour and containing less isotropic base
than the surrounding mass. These seem to be portions of lava
which while partly consolidated became involved in a more fluid
magma [1264].
With the exception of the Falcon Island rocks, all those examined
DECADE IfI,—VOL. VIII.—NO. VI. 17
258 Sir J. W. Dawson—On Hylonomus Lyelli.
from the Tonga Islands appear to be of submarine formation. The
absence or presence in different strata of any sensible proportion of
calcareous matter and organic remains is perhaps related to the
more or less rapid rate of accumulation at different epochs of
eruption. The volcanic material ejected seems to have been almost
exclusively of fragmental character, and in some cases there are
indications of violent explosive action. This is quite in accord with
the andesitic nature of the materials thrown out, which are of types
common in the Pacific region. As to the age of the rocks it would
be idle to speak until the evidence of their organic contents has
been duly set forth, but it would undoubtedly be very rash to refer
them all to a Recent age, and some of them may be found to go
back far into Tertiary times.
IV.—Nots on Hrzovouvus Lretx, wita PHotoGRAPHIC REPRODUC-
TION OF SKELETON.
By Sir J. Witt1am Dawson, F.R.S., etc.
(PLATE VIII.)
tN a sequel to my recent paper on new specimens of Den-
drerpeton, I have thought it desirable to reproduce by
photogravure, for comparison, the type specimen of Hylonomus
Lyelli now in the collection of the Geological Society of London.
The reproduction (Plate VIII.) is of the natural size, though less
distinct than in the original. Though the bones are scattered, this
specimen enabled me, by measuring the separate bones and adding
the cuticular scales found on other specimens, to restore the animal
in my “Airbreathers of the Coal Period.” ?
The specimen represented is one of the largest found. Most of
the others represent smaller (probably in some cases half-grown)
specimens, though not showing any structural differences. It will
be noticed that the caudal vertebree are seen in this example, a fact
which I had forgotten when the former paper was written. In the
species of Hylerpeton and Fritschia, though the teeth are different,
the development of the limb-bones seems to have been similar. In
Smilerpeton occidentatwm the limbs would seem to have been shorter
than in the case of other forms in the erect trees, and the skull long
and narrow.
The specimen here delineated, though the bones are scattered, has
the advantage of lying on a flat plane of lamination. Some of the
thinner bones have, however, scaled off, or have been removed by
aqueous infiltration. The cavities left by these have been touched
with white so as to bring them out. The difficulty in restoring
most of the specimens in the erect trees arises not from the absence
of the bones, but from these being scattered through non-laminated
material, sometimes soft and crumbling, in other cases hard and
arenaceous. In either case it is a work of time and care to uncover
the bones, and many of these cannot be reached without risking the
1 Also on a larger scale in ‘The Chain of Life in Geological Time.”
Major-General MacMahon—Rutile in Fireclays. 209
destruction of others. Some material of this kind representing
Fritschia, Hylerpeton, etc., is still only in process of development,
and may perhaps yet enable their skeletons to be reproduced more
perfectly than heretofore.
REFERENCE To Prats VIII.
(1) Skull and Maxille; (1a) Sternal and Scapular bones; (2) Mandible ;
(3) Humerus, Ribs and Vertebre ; (4) Hind Limb; (5) Pelvis;
(6) Caudal Vertebre.
V.—Nore on tar ALLEGED GENESIS OF RUTILE IN FIRECLAYS.
By Major-General C. A. MacManon, F.G.S.
\ R. W. M. HUTCHINGS’ “ Notes on the Fireclays of the Coal-
measures,” published in the April Number of the Gro. Mae.,
contains many interesting facts and suggestions on which I should
like to offer a few remarks. .
The conclusion at which the author appears to have arrived (see
para. 2, p. 168, read with the two bottom paras. of that page) is
that the formation of the “rutiliferous mica,” and its contained rutile,
is due to dynamo-metamorphism.
This is rather a startling conclusion and it is one which seems
to rest on slender evidence. Even if it could be proved that the
rutiliferous mica and the free rutile-needles are both of secondary
origin, no evidence has been adduced to show that their genesis
is due to dynamic and not to ordinary aqueous agencies. Evidence
on this point is the more desirable as one does not usually associate
beds of unindurated clay with the display of dynamic energy. Do
fossils of these Coal-measures exhibit pressure deformation ?
Even in cases where sedimentary rocks have evidently suffered
deformation from earth-movements, it would not be safe to assume,
without proof, that the secondary minerals found in them owe their
birth to dynamic causes.
With respect to the Seaton beds there are two distinct issues to
be proved. Are the rutile-needles and the yellow mica of secondary
or of clastic origin? And if secondary, to what process do they owe
their birth ?
_ Regarding the first issue I remark that some of the author’s facts
seem quite consistent with the view that the rutiliferous mica, and
the free rutile-nodules, were transported to the spot along with the
other constituents of the clay. The finest washings “A, B, ©,” con-
tain “far away the largest portion of the rutile-needles;” and
many of the quartz and felspar grains carry “more or less a skin
of rutiliferous ‘paste’ in spite of all the washing and agitation.
I think it is,’ Mr. Hutchings adds, “really corroded on to the
substance of the grains in many cases.” These facts do not give
much support to the theory that the mica and its endogenous rutile
‘is a new formation posterior to sedimentation.”
Another fact mentioned by the author seems to point to the same
conclusion: he tells us that the flakes of rutiliferous mica, with few
exceptions, are seen by their extinctions to be ‘‘aggregates of more
or less numerous smaller flakes overlapping one another, and with
260 Major-General MacMahon—Rutile in Fireclays.
different optical orientation.” If, as I understand, the orientation
is promiscuous, this fact seems to point to the deposition of the flakes
one above the other by water—ordinary sedimentation—rather than
to crystallization in siti. As the molecules of crystals possess
strong polarity, the molecules of mica would, at the moment of
crystallization, surely have followed the laws of crystallization and
have arranged themselves in definite order either as simple or as
twinned crystals. If, on the other hand, these “complex flakes ”
are the mere promiscuous agglomerations of numerous separate
individuals, and not single crystals, I fail to see how the fact of
this agglomeration supports the contention that the “rutiliferous
mica’ is a secondary mineral formed after the deposit of the clay.
Finely divided fragments of mica suspended in water would be very
likely to come together as mechanically mixed agglomerates even
before they sank to the bottom. This process, I suspect, is probably
responsible for Mr. Hutchings’ “globular aggregates in which the
mica lies in all azimuths.” The attraction which minute particles
suspended in water exercise on each other may be observed in a
chemist’s test-tube every day.
The author in his examination of the mud prepared in the Labor-
atory from the fireclay observed an upward and a downward limit
in the size of the flakes of rutiliferous mica, and he attaches con-
siderable importance to the fact. ‘Looking at the facts stated,”
he writes at p. 167, ‘the one that appears to have most bearing
on the main point concerned is the pretty strict upward limit of
size of the rutiliferous flakes.” Mr. Hutchings’ contention is that
the genesis of the rutiliferous mica, and the rutile contained in it,
is due to dynamo-metamorphism “posterior to sedimentation ”
(p. 168), and as the fact stated above seems to be “the main point
concerned,” it is worth while to consider it in some detail.
In the first place I would ask whether we can be quite sure that
the fact relied on is not in some way due to the process of
“fractional levigation”” employed. Mr. Hutchings’ process involved
the crushing of dried clay to powder and subsequent crushing in a
mortar with water, followed by repeated washings. After such
dynamic treatment, I doubt the value of any theory, as to the origin
of the rutile, based on the size of the mica flakes that were finally
found to contain rutile compared with the size of the flakes in which
this mineral was absent. Free rutile flakes appear to be more
abundant (p. 165, para. 2) than those included in mica; and the
author tells us, at p. 166, that ‘the rutile lies mainly in between
the minute component flakelets, and is set free when these are
detached.” And as Mr. Hutchings’ contention is that the rutili-
ferous mica is a secondary product formed subsequent to the
deposition of the clay, it follows logically that the free rutile-needles
were detached from the mica in Mr. Hutchings’ laboratory under
the gentle persuasion of his pestle and mortar.
Considering the rough treatment the mica received in the
laboratory or during its previous transport by river, and considering
the fact that the bulk of the rutile-needles (p. 165) were free and
Major-General MacMahon—Rutile in Fireclays. 261
detached from mica flakes, it does not seem remarkable to me that
the larger flakes should have been landed on the stage of the
author’s microscope minus their rutile-needles. The flakes of
rutiliferous mica appear to have been below z,jsoth of an inch
in diameter, and owing to their extreme microscopic size may have
been protected from abrasion by their superior powers of flotation.
If mica, as Mr. Hutchings seems to think, was the mother of
the rutile, we can hardly suppose that all the mica transported to
the Seaton beds was sufficiently rich in titanic acid to furnish the
titanium dioxide for the rutile. The titaniferous mica was probably
only one of several species of mica transported to Seaton; and if so,
each species may have been characterized by a size of flake peculiar
to itself. But apart from the question of habit, differences in the
size of the flakes may have resulted from another cause. Mr.
Hutchings found three species in his fireclay ; muscovite, biotite,
and a yellow to green species containing rutile-needles. No evidence
has been adduced to show that all three species came from the same
parent rock. They may, therefore, have come from different areas,
and the differences observed in the size of the flakes may be the
measure of the distances travelled by the different species.
The circumstance that rutile-needles were not found in the
muscovite or in the biotite may be owing to the fact that these
micas do not contain sufficient titanium dioxide; and [I fail to see
what bearing the absence of rutile from the muscovite and biotite
has on the points at issue, viz. whether the rutile and the yellow
mica are of clastic or secondary origin, and if secondary, whether
their genesis is due to ordinary aqueous or to dynamic agencies.
If, for sake of argument, we admit that the rutile is of secondary
origin, can we be sure that any of the species of mica found in the
fireclay was the mother of the rutile? Without disputing Roth’s
conclusion that the “separation of the titanic acid of weathered
micas as rutile is often enough observed,” it seems desirable to call
attention to the fact stated by Mr. Hutchings that “micaceous
ilmenite” is “rather abundant” in his fireclay. May not this
mineral have supplied the titanic acid for the rutile? The fact that
some of the needles of rutile are found between the mica “ flakelets”
does not negative this suggestion, because capillary action is a potent
factor in such cases. There is no evidence in Mr. Hutchings’ paper
to show that any of the mica of the fireclay contains titanic acid,
whereas we know that ilmenite contains a large amount—sometimes
as much as 59 per cent.—of titanium dioxide.
Lastly, I would suggest that if the yellow species of mica and the
rutile are really secondary minerals, they are products of ordinary
aqueous action. I think it will probably be admitted that the fire-
clay of the Coal-measures was laid down in water. If so, the soft
mud of which it was originally composed must have contained much
interstitial water. What has become of this water? May we not
assume that much of it was used up in chemical action on the finely
triturated minerals of which the solid portion of the mud was
composed? ‘The water, unless it differed from all other river and
262 Dr. J. W. Spencer—Subsidence versus Glacial Dams.
‘sea-water of which we have knowledge, must have contained
free oxygen, carbonic acid, and other potent chemical reagents.
Are we to believe that these active reagents sat still and did nothing
for thousands upon thousands of years until at the end of eons
dynamic metamorphism, like a muscular pedagogue with a long
birch, came to warm them into action ?
VI.—Post-Piiocens ContTINENTAL SUBSIDENCE (IN AMERICA) versus
Guacrat Dams.
By J. W. Spencer, M.A., Ph.D., F.G.S. L. and A.
HE growing interest in the evolution of the Continent now calls
for more accurate information than formerly regarding the
changes of level of land and sea in recent geological times. The
amount of these oscillations was one of the most important factors
in the investigation of the “ Building of the Great Lakes.” Hence
the study of the history of the lakes has contributed to our know-
ledge of the changing relations of the continent and the sea.
From a study of the submerged channels along the American
coast, it has been shown that the continent was greatly elevated
during some epoch or epochs intervening between the middle Mio-
cene and the early Pleistocene periods.1 The elevation of the land
was over three thousand feet higher than now, and probably reached
for a short time to over five thousand feet.
The elevated condition of the continent was followed by a depres-
sion of the land to far below the present altitude, before the upward
movement restored the now existing conditions. There may have
been more than one episode of elevation and depression; but the
problem that we seek to answer is: What was the maximum de-
pression of the later Pleistocene times, after the great beds of
boulder clay were formed? for the great elevation was shortly
before that epoch.
Most geologists are ready to accept the high continental elevation,
but there are differences of opinion respecting the amount of the
subsidence. Although many have their own views upon this
subject, few serious attempts have been made to solve the problem
unbiassed by theory.
We must seek for the evidence of the ine foie elevation in
the remains of old shore-lines, such as beaches, terraces and sea-
cliffs, which are more or less disturbed and obliterated. Isolated
remnants of beaches are not accepted by all as proof of a recent
elevation, although found at high altitudes, but the beaches often
contain the direct proof of their own elevation.
No better example is found than the Iroquois Beach of the
Ontario Basin. This elevated shore-line is one of the youngest and
best preserved in the Great Lake region. It rests upon the youngest
“till” deposits. Since its formation it has been warped towards the
north-east, and thus at Fine, north of the Adirondack Mountains, it
1 « Hich Continental Elevation preceding. the Pleistocene Period (in America),”
by J. W. “Spencer, Grou. Mac. Decade III. Vol. VII. 1890, p. 208.
Dr. J. W. Spencer—Subsidence versus Glacial Dams. 263
has been lifted over 600 feet above its own elevation at the head of
Lake Ontario.! By another series of deformed shore-lines,” it has been
found that the Iroquois Beach at the head of the lake has been lifted
its own height above the sea. Hence there is measured proof that
the northern side of the Adirondacks has been recently elevated a
thousand feet, or that it was recently a thousand feet lower than
now. The initial point of this movement was near the head of
Lake Michigan. Its maximum deformation occurs in the Adiron-
dacks, and amounts to six feet per mile. Whether this rise con-
tinues to the Atlantic, or is transformed into a depression, or is
faulted east of the mountains, remains a question to be determined.
Only fragments need be looked for east of the region already ex-
plored, for the deserted shore has been traced into a region of
broken mountains and wilderness.
Three hundred feet above the Iroquois plain the Algonquin Beach
of the Huron basins is located.* In it there is a similar deformation
to that recorded in the Iroquois shore, but the initial point of the
warping is beyond the head of Lake Michigan. With the deforma-
tion continuing to the north-east, it would appear that the Laurentian
Mountains north of the Great Lakes were very much depressed
during the Algonquin episode. The evidence of the formation of
the Algonquin Beach at sea-level has already been collected.*
Whilst there is great deformation recorded in the higher beaches,
the surveys of these more broken geological records do not enable
us to trace the shore-lines down to sea-level, as in the case of the
Troquois, and to nearly as perfect an extent, the Algonquin Beach.
Consequently, it is necessary to rely more fully upon the perfection
of the structure of the deserted shores, and upon their positions,
which would preclude their formation in confined lakes. Such
conditions exist in Ontario, Michigan, and Ohio, where extensive
surveys have been made.
The lower of these shores, as the Ridgeway Beach,° like those
before named, were formed about bodies of water which opened
only to the north or east. But ascending a little higher, the
Maumee Beach® occurs at altitudes which permitted its formation
in water having free communication with the Ohio and Mississippi
valleys by two depressions. Above this plain there are higher
gravel terraces and plains in Michigan, and elsewhere, notably
those between Kalamazoo and Marshall, with an elevation of a
little more than 900 feet above the sea. From them the country
falls away by steps towards the lakes; but the sheet of water which
they once bounded had at least five connexions with the drainage
1 <¢The Deformation of Iroquois Beach and Birth of Lake Ontario,’ by J. W.
Spencer, Amer. Journ. Sci. vol. xl. 1880, pp. 443-441.
2 Ibid. p. 447.
3 “Deformation of the Algonquin Beach and Birth of Lake Huron,” by J. W.
Spencer, Amer. Journ. Sci. vol. xli. 1891, pp. 12-21.
4 [bid. p. 21.
5 « Hich Level Shores in the Region of the Great Lakes and their Deformation,” '
by. W. Spencer, Amer. Journ. Sci. vol. xli. 1891.
Lbid.
264 Dr. J. W. Spencer-—Subsidence versus Glacial Dams.
of the Mississippi system. Other higher terraces about more
insular points are found in the same region, and farther north in
Michigan they are said to occur at the summit of the highest land
east of Grand Traverse Bay at 1682 feet above tide.
In Ontario there are well-marked sea-cliffs carved out of the
Niagara escarpment, as westward of Collingwood, especially at
elevations of from 1200 to 1425 feet above the sea. At various
intervals, between the plain of the Algonquin Beach and the highest
land of the peninsula—1709 feet—there are also terrace and beach
deposits moulded out of the drift. These remnants of shores are seen
to within 20 feet of the highest point of land. The shore-markings
of these elevated lands are rendered more certain by the perfectly
water-worn stones, and the extent of the beach and terrace structure.
The sea-cliffs are too deeply graven to represent evanescent coast-
lines. But all of these records are interrupted owing to the topo-
graphy of the country, erosion by atmospheric agencies, and the
recent Pleistocene deformation of the region.
Some of the positions of the surveyed coast-lines have been
mapped ; for a detailed list of localities reference should be made
to ‘“‘ High Level Shores in the Region of the Great Lakes, and their
Deformation.”
Again, at Dog Lake, north of Lake Superior, Professor H. Y.
Hind observed terraces at 1425 feet above the sea.”
After allowing for all the measurable Pleistocene and recent
deformation of the region, these elevated shores stand out so high
above every natural barrier, even far away to the south as well as
to the north, that their occurrence demands explanation by other
than local causes.
The highlands of the Ontario peninsula do not form Nilometers
reaching more than 1700 feet above the sea; but in Potter County,
Western Pennsylvania, 100 miles south of Lake Ontario, they develope
a watershed reaching to 2680 feet above tide, with the Genesee
river flowing north to Lake Ontario; the Alleghany to the Ohio
river; and Pine Creek to the Susquehanna. About the highest
flattened knob, of only a few acres in extent, and rising to within
twenty feet of its summit, there is a ridge of small, well water-
worn gravel, nearly free from sand. Mr. Carvell Lewis speaks of
it as kame-like,’ but its structure and form is not different from that
which may be true beach. This is emphasized by the occurrence
of a zone of boulders forming a pavement a few feet below the
' gravel ridge—a feature so commonly developed in front of the
deserted beaches of the Lake region. This gravel ridge rests upon
the highest point of land at the very front of the “terminal
moraine” of Mr. Lewis, with the land declining to the north, as
well as falling away to the south. These gravels form a superior
deposit resting upon “till” charged with angular shingle of local
1 Cited before.
2 * Assiniboine and Saskatchewan Expedition,”’ 1859, p. 120.
3 **A Terminal Moraine,” by H. C. Lewis, Geol. Survey Pennsylvania,
Rept. Z, p. 143.
Dr. J. W. Spencer—Subsidence versus Glacial Dams. 265
Carboniferous sandstones, and it is out of this material that the
pebbles were formed.
There are similar superficial gravels on other, but, of course,
inferior knobs along the very foremost portions of the “ terminal
moraine.” But the drainage from these ridges is to the north,
and Mr. Lewis emphasized the fact that there is no drift in the
small streams flowing to the south. The theoretical importance of
this observation will be noted later.
Besides these highest of all the superficial gravels, south of the
Great Lakes, which I have examined, I have also visited the high
terraces of the Genesee River flowing northward from the deposits
just described. Here several pauses in the receding waters are
recorded. These are notable from an elevation of 1900 feet down-
ward. At this named high altitude the valley is nearly a mile
wide, and now 250 feet below the terrace. Our knowledge of
these elevated and disconnected water deposits is yet very scanty,
but certainly very suggestive, when supplementing the surveys
of the lower coast-markings in the lake region.
A very interesting terrace remains in a valley three or four miles
to the east of Horseheads, New York. The altitude of the terrace is
1200 feet above tide, whilst the gravel-covered floor of the valley,
at Horseheads, is only 900 feet. This last valley is over a mile
wide, and is that connecting the trough of Seneca Lake with the
Susquehanna Valley.
Similar elevated terraces have been noted by Prof. I. C. White
along the higher Potomac Valley facing the Atlantic, and along the
adjacent tributaries of the Monagahela, which drains to the west-
ward. These deposits he notes up to an elevation of 1675 feet
above the sea, and 175 feet above the valley, along a tributary creek
above St. George, W. Va.
At Nachvak, in Labrador, Dr. Robert Bell found beaches of great
distinctness at 1500 feet above the sea. Gravel and shingle terraces
were also found to an estimated height of 2000 feet.?
It has already been noted that the differential rise of the Iroquois
Beach, north of the Adirondack Mountains, amounts to six feet per
mile, and that it has there been lifted to a thousand feet. If this
rise continue to the White Mountains, then the equivalent of the
Iroquois Beach may be found amongst the terraces of the high
valleys in that region. Its records may be preserved still further
north-east, on the drift-covered sides of Mount Katahdin, in Maine.
Mount Desert, on the coast of Maine, rises to 1500 feet,’ and shows
remnants of coast action to its summit (Shaler) ; consequently, it is
too low to bear records of the Iroquois shore, unless the warping at
the earth’s crust becomes one of depression east of the Adirondacks.
In Ontario, some of the high shores, referred to above, occur at
1 «*Rounded Boulders at High Altitudes,’’ by I. C. White, Amer. Journ. Sc.
vol. xxxvili. 1887.
* Rept. Geol. Sury. Canada, 1885, DD, p. 8, and Bull. Geol. Soc. Amer.
vol. i. p. 308.
® “Geol. Mount Desert,’’ by N. S. Shaler, Rept. United States Geol. Survey,
1888, p. 993.
266 Dr. J. W. Spencer—Subsidence versus Glacial Dams.
elevations of a thousand feet above the Iroquois plain; therefore
their equivalents in the northern Adirondacks should be looked for
at about 2000 feet above tide. The beaches reported in Vermont
by Prof. Hitchcock,’ at or below 2300 feet, doubtless correspond to
some high shore-lines of the Ontario peninsula. Upon the same
basis, these high beaches should be looked for at 8000 feet in the
White Mountains, and at greater elevation on Mount Katahdin, in
Maine.
If we regard the gravels of the highlands of Pennsylvania as
having been formed at sea-level, then it would be reasonable to look
for their counterpart at elevations of over 4000 feet on Mount
Washington, in New Hampshire, and to the summit of the drift
(4400 feet) on Mount Katahdin. These conjectural estimates, based
upon a possible uniformity, may aid in the correlation of the
topographic features of the mountain region of the east and of the
lake region.
As far as relates to the north-eastern portion of the continent,
our observations on Neptunian phenomena have now been epito-
mized. An explanation is necessary. That the pebbles of the
beaches and the shore-lines were the results of wave or current
action no one questions, but there are differences of opinion as to
the conditions under which the waters moulded their coast-lines.
Were these deserted shores constructed at sea-level, or were they
moulded in glacial lakes? These are the theoretical questions
before us.
The difficulties which the sea-level theory present to some minds
may be stated to be—(a) a great regional depression of the continent;
(6) the absence of absolute continuity of the beaches; (c) the
absence of marine organisms in the beaches; and (d) the personal
equation of theoretical views. On the other hand, the theory of
glacial dams presents such obstacles that their value will be con-
sidered at length.
The idea of the hydrostatic stability of the continent must not be
too strongly relied upon, for the evidence adduced, showing that the
continent lately stood three, or even temporarily at six thousand feet
higher than now, appears conclusive. Such mobility of the earth’s
crust being established, there appears no reason why the terrestrial
pendulum could not have moved equally in the opposite direction,
and carried down the highlands of Pennsylvania to nearly three
thousand feet, or those of New England to twice this depth. The
objections to such subsidence could only be based upon its magni-
tude, which observations must settle.
The absence of the continuity of the shore-markings is an
objection only to a limited extent. Part of the reported absence
arises from the imperfections in the explorations, owing to their
changing character; the local non-formation of beaches, as described
in a previous paper;? the failure of identification of separated
1 Geology of Vermont.
2 « Ancient Shores, Boulder Pavements, and High-level Gravel Deposits in the
Region of the Great Lakes,” by J. W. Spencer, Bull. Geol. Soc. Amer. vol. li. 1889,
pp. 77.
Dr. J. W. Spencer—Subsidence versus Glacial Dams. 267
points, owing to subsequent terrestrial deformation; and the inter-
ruptions occasioned by topographic features and subsequent obliter-
ation by erosion. All of these difficulties are greatest in the higher
regions, for there the beaches must be looked for amongst islands
and detached mountain knobs.
The absence of marine remains seems perhaps the greatest obstacle
to the acceptance of a sea-level formation of the beaches, as marine
organisms are found only up to 520 feet.’ But the Pleistocene
gravels occur in Georgia and Alabama, in positions facing the sea,
at altitudes of 700 or 800 feet, and higher up the greater valleys at
1500 feet,? without their containing any marine remains. Hven
where marine Pleistocene beaches occur on the coast of Norway,
there are very few localities where shells are found. How many of
the older geological formations are unfossiliferous? How many
of those ancient beach deposits now represented by conglomerates,
porous sandstones, and, indeed, many clays, are entirely barren ?
Under such conditions have we a right to pronounce judgment on
the freshness of waters based on the absence of aqueous organic
remains? This question will be referred to again in considering
the glacial dam theory.
As to the personal equation, it ought not to pass beyond the limit
of conservatism into the province of obstruction: but it is quite
proper that it should be considered; for, as Prof. Geikie has said,
when controversy ceases, the interest in the investigation declines.
Glacial lakes are of two kinds, those whose waters are retained
by morainic barriers, and others sustained by ice barriers alone.
The former class is represented in several valleys in the Alps,
where lateral glaciers enter and cross greater valleys; sometimes
the glacier carries its lateral moraine across the valley, and builds
a more or less permanent earth dam. Such lakes remain long after
the glacier has melted away, and, even when drained, show evidence
of their origin. A consideration of this class of glacial lakes does
not enter into the subject of this paper.
In Switzerland, Greenland, and Alaska, other glacial dams are
now well known. These are retained by the ice alone. When
glaciers, free from morainic materials, descend lateral valleys, and
cross other valleys, they do not obstruct the river, for it continues
to flow beneath the ice. However, there are many places where
elacial lakes occur between the ice and the sides of the valleys;
especially is this the case where two glaciers meet at the end of
a mountain spur, like Lac Tacul in Switzerland. Small glacial lakes
sometimes occur where lateral valleys unite with the glacial-filled
channel, like the Marjelen See. All modern glacial lakes are of
small size. One of the largest lakes described in Greenland is not
over three or four miles long, and a mile wide.’
Such lakes, when they exist above sea-level, are evanescent. Mr.
H. Topham described some glacial lakes of Alaska which discharge
by a tunnel eight miles long, under 500 feet of ice.t Mr. I. C.
1 At Montreal. 2 On the Upper Etowah River of Georgia.
3 Medellelser om Groenland. 4 Proc. Roy. Geogr. Soc. 1888, p. 424.
268 Dr. J. W. Spencer—Subsidence versus Glacial Dams.
. Russel makes similar reports. The out-flowing waters enlarge the
tunnels, thereby draining lakes; but the ice-roofs fall in, and by
the accumulation of ice blocks the tunnel becomes temporarily
obstructed, causing the water of the lakes to rise. In the very
nature of the case, large lakes could not be expected, for the
conditions which would permit their formation would cause the
glaciers to recede. Especially would this be the case if the glaciers
were hundreds of feet above the sea, with rivers draining beneath
or through them. It would be difficult to perceive how any water-
level could be maintained long enough to permit the waves to carve
out terraces and sea-cliffs. With glaciers coming down into the sea,
it is easy to understand how bays and inlets could be obstructed by
the ice so as to allow the water to be freshened. In such lakes the
water-level would be maintained long enough to leave inscriptions
in the form of terraces and beaches.
Such is a brief account of the natural history of glacial dams.
It has been said that the easiest explanation of the theory of our
great lakes is by regarding them as formerly great glacial dams.
So it was thought ten years ago, that the least troublesome hypothesis
of the origin of the great lake basins was by their excavation by
glaciers; but the writer, going into a field of investigation, almost
sealed by pre-judgment, has shown that glaciers did not scoop out
the basins, and has otherwise found satisfactory explanation of their
origin,’ without invoking the necessity of ice being converted into
rock diggers. So also the evidence of glacial dams has not been
found as far as my observations have been extended.
Let us examine how the glacial dam theory applies to the shore-
lines already described.
The physical features of the Ontario basin are the most favour-
able for the construction of a great lake retained by glacial dams.
As proved by its deformation, the Iroquois beach was formed at sea-
level. If this proof of the altitude of its birthplace did not exist,
the evidence of its elevation would be obtained from a consideration
of the ability of glaciers to close the St. Lawrence valley to the |
north-east. Such a barrier would have been from 80 to 100 miles
wide, and from 800 to 1800 feet deep (below surface of water)
according to location. Yet the drainage of the then expanded lake,
over 300 miles long (as far as surveyed) and 100 miles or more in
width, was against, into, or under the supposed glaciers, except to
a limited extent in its earliest stages, when a partial overflow was
by the Mohawk Valley. Had the lake been above sea-level, a river
as large as the St. Lawrence would soon have eaten its way through
the ice, and lowered the lake, for in that direction alone it had to
flow; consequently, the great cut terraces and beaches requiring
centuries or millenniums of time, could not have been formed
except at sea-level.
If the Algonquin Beach of the Upper Lakes were formed in a
glacial lake, then the ice barrier in the region of Lake Nipissing
1 “Origin of the Basin of the Great Lakes of America,” by J. W. Spencer,
Quart. Journ. Geol. Soc. Lond. vol. xlvi. p. 523.
Dr. J. W. Spencer—Subsidence versus Glacial Dams. 269
would have been 600 or 700 feet beneath the surface of the water.
The drainage must have been under the ice, and have amounted
to a discharge equal to that of the modern Detroit River, as the
drainage of Lake Superior, Lake Michigan, and Lake Huron basins
would have been thus borne seaward, descending 800 feet to the
level of the Iroquois water. Under such conditions, the question
may be asked, how could the lake surface be retained long enough
at any level to carve out the deeply-graven water-lines and terrace-
plains of the Algonquin Beach, in place of the discharging waters
melting away the icy barriers, which were supposed to have been
the means of retaining the lake 800 feet above the level of the
Iroquois waters ?
We now rise to the shores which bounded the Warren water.
These have been explored from Lake Michigan to New York, and
to north-east of Toronto, upon the Ontario peninsula. Upon the
glacial dam theory, this sheet of water would need a barrier to the
north as well as to the east. The drainage of the lake, at all stages
from the Ridgeway Beach downward, was to the north-east, and
beneath a greater mass of ice than in the case of the Algonquin or
the Iroquois water. But above the Ridgeway Beach,! at the
Maumee level,” there were outlets across Ohio and Illinois, if it were
alake. The difficulties are increasing.
The shore markings occurring near Kalamazoo, at about 900
feet above tide, represent a sheet of water having at least five
outlets across Ohio and Illinois.
Again, the sea-cliffs of the Ontario peninsula, at from 1200 to
1425 feet and more, and the beaches now found up to 1689 feet,
would demand great dams to the south as well as to the north. But
such dams could scarcely have existed, with open waters carving
out sea-cliffs and terraces on the high peninsula of Ontario, and
also leaving records, 200 miles to the south. It should be noted
that gravel deposits of the so-called kame and osar structures occur
at all high levels, but of these I do not take cognizance.
The drainage of this high country, such as the Genesee valley,
with terraces up to 1900 feet or more, and of the “terminal
moraine” up to 2680 feet, was toward the north without obstruction.
Ascending now to Potter County, we find the gravel ridge at
2660 feet, on the very edge of the highest knob of the “terminal
moraine.” This high point could not have stood out of the ice as
a Greenland Nunatak, with a lake around it, for it is at the margin
of the drift, and glaciers do not deposit their terminal detritus within
the ice, but at their very margins. It seems impossible to conceive
a glacial mass retaining a lake about this flattened knob, even if the
country were submerged to almost sea-level.
There are other similar deposits on adjacent summits. Again,
had a glacier existed on the top, or on the southern side of this
“moraine” ridge, its melting ice must have carried great quantities
of drift into the valleys to the south, which neither Mr. Lewis nor
t «High Level Shores in the Region of the Great Lakes and their Deformation,”
by J. W. Spencer, Amer. Journ. Sci, vol. xli. 1891, * Lbid,
270 =Dr. J. W. Spencer—Subsidence versus Glacial Dams.
I have seen. But the drainage was to the north, into the hypo-
thetical glacier, which, if it permitted subglacial drainage, could
scarcely have formed lakes.
Under these conditions fairly stated, I think, whether is it easier
to accept a great subsidence of the continent to nearly 2700 feet, in
Western Pennsylvania, or account for the phenomena by glacial
dams, formed on land, vastly lower to the north.
Indeed, the great deformation of the lake region had scarcely
begun, and consequently even the modern highlands, north of the
great lakes, were then very much lower than now, when compared
with the region to the south. I cannot hesitate in forming a con-
clusion that the evidence is in favour of a late continental subsidence,
rather than of hypothetical glacial lakes, hundreds of miles long
and broad, like nothing ever seen, which could not answer the
requirements.
The difficulty in accepting the subsidence without the occurrence
of marine shells has in part been pointed out. But their absence in
the lower beaches may be accounted for, in part, by the sheets of
water being more or less cut off from the sea, and receiving great
quantities of fresh water. This, however, will not explain their
absence on the higher beaches. The varying climatic conditions of
the water, and the changes of level, destroying the life, and too
rapid to allow of remigration, may in part account for the absence of
organisms in the shore-lines.
The record of subsidence deciphered in the high shore-lines of the
lake region is supported by the observations of Dr. G. M. Dawson,
Mr. R. G. McConnell, and others, on the mountains rising above the
great plains of North-Western Canada, and on the mountains be-
tween there and the Pacific Coast. Dr. Dawson!’ finds gravel
terraces upon high sides of the Rocky Mountains facing the east,
in position showing their origin not to have been river-terraces.
From extensive observations Dr. Dawson concludes that the
Pleistocene submergences amounted to 4000 or 5000 feet in the
region of the International Boundary (49th parallel), whilst in
Alaska it did not exceed 2500 or 3000 feet. He also hypothecates
two episodes of submergence, the latter being less extensive than
the former. Further, he regards the elevation and subsidence of the
great plains and western mountains as alternating, and that the drift
materials of the plains were deposited at sea-level.
Mr. R. G. McConnell informs us that on Cypress Hills, with an
altitude of 4800 feet, the drift does not rise above 4400 feet. A
hundred and fifty miles to the north-west the drift is not found
above 3400 feet on Hand Hills (Tyrrell). But south of the Cypress
Hills, near the 47th parallel, drift occurs up to 4660 feet on Three
Buttes (Dawson). From these figures Mr. McConnell shows a
differential level of 7-2 feet per mile, the elevation being greater
nearer the 49th parallel.’
1 «Tater Physiographical Geology of the Rocky Mountain Region in Canada,
with Special Reference to Changes in the Elevation and the History of the Glacial
Period,’’ Trans. Roy. Soc. Canada, 1890.
2 Geological Survey of Canada, Report for 1885.
Dr. J. W. Spencer—Subsidence versus Glacial Dams. 271
In the east, the history of the changes has not been fully de-
ciphered. Hrratics occur on the top of Mount Washington to
6300 feet, whilst on the top of Mount Katahdin, in Maine, they
occur to only 4400 feet (Upham). Conforming with Dr. Dawson’s
views, as applied to the west, we have a greater rise in the White
Mountains than eastward. The altitude of beach formation in the
highlands of Labrador (1500 to 2000 feet) shows the recent uplift
to have been less than in New England.
Combining the movements of the east and the west, it would
appear that the great Pleistocene uplift reached its maximum along
a line between the Gulf of the St. Lawrence and Vancouver Island,
rather than in higher latitudes. The youthfulness of the northern
topographic features shows that the elevation of the lands in the
higher latitudes, above the base-level of river-erosion, has taken
place in recent geological times; for there is a lack of such great
canons in the country to the north of the great lake zone, as occur
in the region to the south of it.
If the subsidence of the northern portion of the continent appears
to have been great, that of Barbadoes to the south-east appears to
have been greater, for Messrs. J. B. Harrington and A. J. Jukes-
Browne,' have pointed out that there are on the island oceanic
deposits resting upon beds of sandstones and shales of probable
Miocene age, and beneath coral formations of age not greater than
the Pleistocene. These deposits indicate an origin of not less than
a thousand fathoms, and, as Mr. Jukes-Browne points out, probably
of vastly greater depth. This geologically recent subsidence was
likely to have been synchronous with that of the north, but may
have been one of those alternating conditions hypothecated by
Dr. Dawson.
The fjords of the coast of Norway show that the Scandinavian
peninsula stood 4000 feet higher than now. ‘The silts and terrace
deposits at 3000” feet point to a subsidence of that region, the same
as similar deposits in the mountains of America.
The deep submerged channels south of Asia, like that of the
Ganges, which is 8570° feet deep, point to a recent submergence to
that amount. But such deep channels are not known in the north
of Asia, consequently the higher latitudes do not show a great
amount of recent depression. ‘The Pliocene deposits of Sicily, at
3000 feet, demonstrate a recent elevation.
Pliocene deposits in the south-east of England are now found at
600 feet above tide. Their counterparts at Utrecht have been shown
by Mr. Clement Reid to be now submerged more than 1143 feet.‘
The oft-quoted Moel Tryfaen deposits, in north-western Wales,
contain marine shells at 1400 feet, with similar but unfossiliferous
beds rising to nearly 2000 feet. These deposits, which I have
visited, I consider to have been formed where found. But they do
1 Geology of Barbadoes, 1890.
» « High-Level Terraces of Norway,’’ by J. R. Dakyns, Grou. Mac. 1877, p. 72.
5 Brit. Admiralty Chart, No. 70.
4 «« Nature,’’ August 12, 1886, p. 342.
272 T. Mellard Reade—Sedimentation and Temperature.
not represent so late a subsidence as our deposits in the lake region,
for they are not the superficial gravel, but are covered by a few feet
of more recent till.
These few foreign examples, just cited, show that the continental
movements, as set forth in this paper, are not peculiar to America,
but they were probably not synchronous, although they have taken
place in the most recent geological times.
This paper must of necessity be imperfect, as it is the first attempt
to work out the detailed evidence of recent terrestrial subsidence
from records in the ancient shore-lines, many of which have only
lately been reported. All of the phenomena cited show that in
modern geological times there have been gigantic movements causing
the earth’s crust to move to and fro, producing conditions which
have greatly modified the physical features, climatic conditions, and
distribution of life.
VIL—Tue Errect of SEDIMENTATION ON THE TEMPERATURE OF THE
Kartu’s Crust.
By T. Metuarp Reape, C.E., F.G.S., etc.
Y letter in the March Number of the Gronogican Macazine,
asking for a description of the “‘ Herschel-Babbage” theory
of Mountain formation, appears to have called forth Mr. Davison’s
“« Note on the Expansion Theory of Mountain Evolution,” in which
he favours us with his definition of the ‘‘fundamental principle of
the theory of terrestrial evolution which has sometimes been called
the ‘expansion theory.’ ”
Whether this fundamental conception is identical with the “ Her-
schel-Babbage” theory is not stated, but I am obliged to Mr.
Davison for putting his views on the subject into a form admitting
_ of examination and discussion. ‘To make my meaning plain, I shall
have to repeat Mr. Davison’s own words.
“Masses of sediment laid down in an area of subsidence are
gradually lowered to regions of the earth’s crust that are at a higher
temperature than that in which they were deposited. The sediment,
being heated, expands, is crumpled and folded internally, and,
bulging up at the surface, is reduced by denudation to the form of
a mountain-chain.”* On which the following observations are
made. “It is obvious that the heat which passes into and expands
the sediment must be withdrawn from the immediately adjoining
parts of the earth’s crust, partly laterally, but chiefly from below ;
and that the amount of heat gained by the sediment must be equal
to that lost by the crust.” :
So far from this being “obvious,” I consider it a fundamental
misconception. Jf a mass of strata at the surface having the sur-
face temperature could be placed in contact with another mass, say
ten miles deep, having the temperature due to that depth, the colder
1 Groztocican Macazine, May, 1891, p. 210.
2 It is unnecessary for me to criticize this “‘ fundamental ” definition further than
to disclaim it as an adequate statement of my own theory. For an outline of this
I must refer those interested to the forthcoming June number of the Philosophical
Magazine.
W. B. D. Edwards—On the Separation of Minerals. 273
rock would withdraw part of the heat from the hotter till an equality
of temperature was reached. But this is not what takes place; the
subsiding rock does not come into contact with strata at a higher
temperature.
So far from heat being withdrawn laterally and from below, the
general outflow of heat is checked in the areas where sediments are
being laid down. In these areas the sphere is losing less heat. than
where the surface continues in a normal condition. A portion of
the heat that would otherwise escape into space is being used up in
heating the sediment.
Mr. Davison seems to have had a glimmering of this truth before
completing his “ Note,” for the last paragraph but one is entirely
opposite and contradictory to the preceding which I have quoted.
Unfortunately the effect has not been to compel him to withdraw
the erroneous view, but to attempt to minimize the dynamical effect
of the true one. Having dealt pretty freely with the quantitative
problems in my “ Origin of Mountain Ranges,” I do not propose to
enter upon this phase here.
To say that the sediment piled up in an earth trough “ withdraws ”
heat from the underlying strata is about as correct as to maintain
that covering a steam-boiler with felt withdraws heat from it. To
give an illustration; if the valley of the Dead Sea were levelled up
with sediment, the underlying rocks would be raised to a tempera-
ture dependent upon the thickness of the sediment and its coefficient
of conductivity. The raising of the temperature of a body is not
usually considered to indicate a withdrawal of its heat.
VIIJ.—On tHe Preparation or A CHEAP Heavy Liquip, FoR THE
SEPARATION OF MINERALS.
By W. B. D. Epvwarps, A.R.C.S.,
of the Geological Survey of India.
HE high price of all heavy liquids, and the consequent care that
has to be taken in using them, the latter of course entailing
great expenditure of time, were the reasons which caused me to make
experiments, with regard to the manufacture of Klein’s solution
(borotungstate of cadmium) on asmall scale. The price quoted in
a well-known chemical manufacturer’s price-list is 3s. 6d. per oz.
My experiments have shown me that it can be made for about 7d. per
oz., plus the value of the time of the maker. The process is very
simple, and not much time is necessary in making it. A rough
outline of the method of preparation is given by Dr. Klein in the
Comptes Rendus, vol. xciii. August, 1881.
The apparatus required consists of two large porcelain evaporating
dishes 10’ diameter, two of 6’, and two of 3’, two glass beakers
10’ deep, and two 6’ deep, a glass funnel and a water bath. A
fume cupboard or some arrangement for carrying off acid fumes
is also necessary. The following weights given will make 160
grains of cadmium borotungstate (i.e. about 50 c.c.), and can be
conveniently manipulated in vessels of the size given above.
DECADE III.—VOL. VIII.—NO. VI. 18
274 W. B. D. Edwards—On the Separation of Minerals.
Dissolve 450 grams of crystallized sodium tungstate in as little
boiling water as possible. When quite dissolved, add 675 grams of
boric acid in small crystals, a little at a time, and with constant
stirring. This should be done in a large beaker.
When quite dissolved, the solution should be poured into a large
evaporating dish and put aside in a place where it will not be dis-
turbed or shaken. It should be covered up from dust. In about
twenty-four hours, or longer, the liquid, which is of a light purple
colour, should be poured off quickly into another evaporating basin
from the crystals. The latter should be in the form of a hard solid
deposit at the bottom of the basin. These crystals can be washed
with hot water three or four times, the washings being added to the
mother-liquor.
The latter will now probably be found to be in a thick pasty
condition, due to the formation of small crystals. These will be
found to dissolve up on heating the dish and its contents on a
water bath. About half of the water can now be driven off on
the water bath, care being taken not to drive off so much that a
crust begins to form on the surface of the hot liquid. The solution
is again set aside as before and left to cool and crystallize. The
liquid is poured off into one of the smaller dishes and the crystals
washed as before. This process of crystallization is gone through
again until a piece of orthoclase will float in the liquid. The
principal point being to always make the polyborates of soda crys-
tallize out either as single large crystals or as a hard crystalline
crust. It is impossible to separate and wash the crystals if they
are very small.
Owing to the high density of the liquid, in the later stages a
longer time is necessary for the sodium borates to crystallize out
than at first. A piece of glass or felspar will be found to float
when the liquid has been evaporated down to about 220 cc. The
next process is to heat the sodium borotungstate on the water bath
to 100° C.; pour into a large beaker, and add a boiling saturated
solution of barium chloride. This should be done carefully,
stirring the solution while pouring the BaCl, in, a little at a time.
The BaCl, solution should consist of 150 grams of crystallized
BaCl, in about 200 ec.c. of distilled water. A dense white
precipitate forms on pouring the barium chloride solution into
the sodium borotungstate, and this precipitate should be stirred
for some minutes so as to thoroughly mix the two liquids. After
a few minutes hot water should be added and the precipitate stirred
up thoroughly. In a short time the supernatant liquid can be
siphoned off from the precipitate. This washing process should
be repeated some 10 or 15 times. The white precipitate is next
transferred to a large evaporating dish, and about 300 c.c. of dilute
HCl added (1 HCl to 10 H,O); the mixture of precipitate and
solution is evaporated to dryness on a water bath, about 40 c.c. of
strong HCl being added towards the end.
The dried mass is then treated with about 300 e.c. of hot distilled
water, the former being thoroughly broken up into fine powder
with a glass rod flattened at one end.
W. B. D. Edwards—On the Separation of Minerals. 278
The green sediment of tungstic hydrate is filtered off and washed,
the washings being added to the solution of barium borotungstate.
The liquid is evaporated down and allowed to stand. Yellow
crystals are formed, and with a little care these can and should be
obtained as single large crystals. The latter crystallize in two
forms, one as modified tetragonal prisms with well-developed
basal planes, and the other as flattened forms much resembling
hexagonal forms in shape.
Nearly the whole of the barium borotungstate can be obtained,
the mother-liquid being evaporated down a little more after each
crop of crystals has been obtained. 'Towards the end of the process
transparent colourless platey crystals of barium borate may separate
out as well. The barium borotungstate crystals should be dissolved
up in water and recrystallized once again. They should then be
dissolved up in about 200 cc. of distilled water and a solution of
ClSo, added from a burette or a pipette, care being taken to add
it very slowly, drop by drop as long as a precipitate falls, and the
precipitate of BaSo, is then filtered off and the filtrate is evaporated
down in a porcelain dish on a water bath till a piece of olivine
floats on the surface. This liquid will be found to have a specific
gravity of 3-46 at 60° F., and it takes some hours before some of
the salt crystallizes out and the specific gravity falls to 3:28. It
might thus perhaps be used for the separation of some minerals
of specific gravity greater than 3:46, though care would have to be
taken not to allow crystals to form on the lighter minerals and
thus sink them.
It will be found that the cost of the chemicals used will come to
about three shillings, viz. :—
450 grams (nearly 11b.) sodium tungstate ...... Is.
675 ,, (nearly 14lb.) boric acid ............... 9d.
150 ,, (5 ounces) barium chloride ...... 45d.
25 ,, (0°87 ounces) cadmium sulphate ... 6d.
Pure hydrochloric acid, filter papers, etc. ......... 44d.
The quantity of cadmium borotungstate obtained is about 160
grams, or 50 c.c. The borotungstate crystals separate out from the
solution saturated when hot and are nearly colourless.
The crystals of barium borotungstate obtained earlier in the
process cannot be mistaken when once seen. They are light yellow,
transparent, and have asplendid lustre. The surface becomes yellow
and opaque on washing with water.
The principal difficulty in the manufactnre of this liquid is the
care that has to be taken in crystallizing the various salts out from
their solutions. There is no reason why any geologist with a little
knowledge of chemical manipulation should not make his own
heavy liquid, or why the manufacturer should charge such an
exorbitant price as at present, as the actual time spent in making
it is very small, though spread over several days.
In conclusion, I must express my, obligations to Prof. Judd, F.R.S.,
who has afforded me great facilities in carrying out these operations.
276 Reviews—Dr. F. H. Hatch’s Petrology.
RAV Lew Ss.
L—An IntrRopvuctTion To THE Stupy or PETROLOGY: THE IGNEOUS
Rocks. By Frepertck H. Harcn, Ph.D., F.G.8S. pp. 128.
(London, Swan Sonnenschein & Co. 1891.)
HE object of this little book (as stated in the preface) is to
describe the mineral constituents and structure of the Igneous
Rocks, their mode of occurrence and origin; and the author has
fulfilled his task in an accurate, clear, and concise manner.
Petrology is rapidly developing a language of its own, and
Dr. Hatch, who has already done good service in explaining the
meaning of its many terms in his Glossary (appended to Teall’s
British Petrography), gives also many useful definitions in his
present work. It will be of service, therefore, as a text-book for
students who are giving especial attention to Igneous rocks, while
to geologists in general it will be a handy book of reference on the
principal Igneous rocks, and their distribution in the British Islands.
These portions of the subject occupy about one-half of the volume,
the other half being mainly devoted to the constituent minerals.
We may observe, by the way, that a few diagrams showing the
mode of occurrence of the rocks would have been useful.
The title of the book is, perhaps, a little misleading (unless the
work be intended to form one of a series), for the author has
brought us into the presence of Petrology, without giving us any
real introduction. The student will find that he cannot make
acquaintance with the subject without a good preliminary know-
ledge of Optics and Crystallography, to say nothing of Chemistry.
Dr. Hatch, it is true, states that the scope of his work is too small
to admit the treatment of Optical phenomena, and he refers the
student to the lately published and excellent “Notes on a New
Form of Polarizing Microscope,” by Allan B. Dick. Mr. Dick’s
“beginner” is told how to measure angles of extinction, and how
to observe the “dispersion,” and the character of the pleochroism of
any mineral, but even he must start with some preliminary training,
and Mr. Dick recommends Spottiswoode on Polarized Light.
Thus the student who wishes to master the methods of research,
and be enabled to undertake investigations on his own account,
must seek help elsewhere. He will find much practical mformation
in Rutley’s ‘‘ Rock-Forming Minerals,” but that work is not altogether
free from technical terms, that may be familiar to the advanced
student, but which might discourage the beginner. Prof. Cole’s
« Aids in Practical Geology” introduce the subject in a far simpler
form, and thus provide more easy lessons on Petrology and its
methods of research. Dr. Hatch’s book contains only the main
facts concerning Igneous rocks, and it will not educate the student
to identify his specimens.
Although the identification of Jgneous rocks is a task that now-
a-days requires much special training, Petrologists unfortunately
appear to attach but little importance to rock names. They prefer
Reviews—Dr. H. Filthol—Mammals of Sansan. 2G
to treat the rocks as mineral aggregates and to describe their
structure and composition. The field-geologist is mainly concerned
with their mode of occurrence and origin; and to him rock-names
are a necessity. We are glad to find that the needs of the field-
geologist are not neglected by Dr. Hatch. Referring to the classifi-
cation of the rocks, he says ‘Chemical composition (as far as the
percentage of silica is concerned) and mode of origin or occurrence
occupy a chief place. Mineralogical composition is, on account of
its extreme variability, allowed to play only a subsidary role.” In
this difficult task of furnishing a classification of the Igneous rocks,
Dr. Hatch has achieved success.
IIl.—Dr. H. Fingot on tHe Fosstn MamMAts oF SANSAN.
Erupzs sur tes Mamuirires Fossites pe Sansan. Ann, Sci. Géol.
vol. xxi. Art. 1; pp. 320, 46 plates.
lies small village of Sansan, near Auch, in the department of
Gers, has long been celebrated for the number of remains of
Mammals found in beds belonging to the Miocéne Moyen of the
French geologists, and also for the beautiful state of preservation in
which many of these remains occur. The first in the field to under-
take the description of these specimens was the late M. Edouard
Lartet, but his investigations appear to have been hampered by the
lack of sufficient opportunities for illustrating his descriptions with
fivures. This want was to a certain extent remedied by the late.
M. Paul Gervais, Dr. Kowalevsky, and others; but only certain
Species or groups were fully treated, and we have never had any
attempt at a monograph of the Sansan Mammals since Lartet’s
preliminary catalogue.
In the work before us we now have the whole series of these
remains not only well described, but fully illustrated by excellent
plates ; and all who are interested in this branch of fossil zoology
owe a debt of gratitude to Dr. H. Filhol, of the Paris Museum, for
the execution of this laborious task. It appears that the Doctor has
been in the habit of paying periodical visits to the Sansan quarries
during the past three years, and has thus succeeded in obtaining
a number of specimens which far surpass most of those hitherto
described. Many of Lartet’s types have also been fully described
and figured for the first time.
The total number of species of Mammals which Dr. Filhol recog-
nizes from these deposits is 78; these being arranged under the
heads of 42 genera. In this notice we shall only refer to a few of
the species which appear to us of especial interest. Before doing
so, we venture, however, to call attention to some instances of
carelessness on the part of the author which are exceedingly em-
barrassing to those who, like the present writer, have to record
new genera and species. To begin with, Dr. Filhol never states
which of the genera and species to which his name is appended are
mentioned for the first time. In the absence of any back reference,
it would, however, be natural to assume that when we meet with
278 Reviews—Dr. H. Filhol— Mammals of Sansan.
names like Talpa primeva (Filh.), on p. 35, such specific names are
new ones. This, indeed, appears to hold good for that particular
instance, and also for Mustela leptorhyncha on p. 105. When, how-
-ever, we turn to Mustela larteti on p. 107, we find precisely the
same condition, although this specific name was applied by the
author in the “ Bull. Soc. Philom.” for 1888. A still worse instance
occurs on page 265, where we find the name Strogulognathus
sansaniensis, apparently as a new genus and species, without the
slightest reference to the fact that the specimens so named had
been described by the author in 1888 in the serial cited under the
name of Plutuprosopos sansaniensis. This change of the generic
name has been rightly made on account of the preoccupation of the
one first applied, but this ought to have been fully notified in the
text. Moreover, when he was changing the name, the author might
have given the correct Strongylognathus, instead of the incorrect
Sirogulognathus. It may also be mentioned that in 1888 Dr. Filhol
described a Mammal from Sansan under the name of Choilodon
elegans, although no such specific or generic name occurs in the
present work. Whether the omission of these names is due to
inadvertence, or whether they have been replaced by others, we are
quite unable to say.
Then, again, we notice some very embarrassing errors in regard
to references, as well as a large number of misprints. Thus, in
a footnote on page 133, the present writer is quoted as loc. cit.
without the slightest previous mention of any work to which the
loc. cit. could refer. As instances of carelessness in spelling, we
may refer to the generic name Lanthanotherium given on page 29,
but which appears as Lantanotherium on page 317; there being
here, again, not the slightest reference that this name first appeared
under the latter incorrect form (in which it has been quoted in
two Manuals) in 1888. Again, on page 73 et seq. we are some-
what surprised to find Pseudelurus or Pseudailurus modified into
Pseudelurus; but when we see the author’s own genus Proailurus
repeatedly appearing as Prailurus, our astonishment at the way
words are treated is still greater. In the index the appearance of
Myogale sansaniensis immediately after Mygale sansaniensis suggests
an inadvertent repetition of a name, till we turn to the text and
find that Myogale is a misprint for Myolagus.
We have alluded thus at length to these omissions and errors by
which the work is disfigured, as they are so embarrassing to those
who have to record and quote from it; but it is with pleasure that
we turn to notice some of the more important forms described by
the author.
Among the Insectivora, the author has found out that: the
commonly accepted name Parasorex is antedated by Galerix, which
is accordingly adopted.
is a nearly perfect skull of Macherodus ceed which is of
especial interest as showing the presence of an alisphenoid canal.
This canal being totally wanting in all existing Felide, its presence
Reviews—Dr. H. Fithol— Mammals of Sansan. 279
in the Sansan Macherodus seems to indicate that this genus,
although specialized as regards its dentition, is otherwise a
generalized type. The other most interesting Carnivore is the one
described by Lartet as Hemicyon, but referred by Gervais and
Gaudry to Hyenarctus. The only specimen of this species that
has hitherto been figured is part of an upper jaw with the hinder
molars; but Dr. Filhol tells us that the species was originally
founded upon the evidence of the mandible. An entire palate and
mandible are figured in pls. vii.—ix., which sufficiently show that this
animal does not belong to Hyenarctus, and as it is certainly not
referable to Cephalogale, and according to Dr. Filhol is different
from Dinocyon, it appears entitled to rank asa distinct genus. It
may be observed that although the premolars agree with those of
Hyenarctus, and differ from those of the Dogs, in the absence of
fore-and-aft cusps, yet that there are four of these teeth, in place
of the three of Zyenarctus ; the whole four in the lower jaw forming
a nearly continuous series. A further difference occurs in the
narrower and more trenchant form of the hinder half of the lower
carnassial tooth ; while Dr. Filhol states that the feet of this animal
were digitigrade, those of Amphicyon, and doubtless Hyenarcius,
being plantigrade.
Another equally large Carnivore described by Lartet as Pseudocyon,
but identified by Pomel with Amphicyon, appears likewise entitled to
represent a distinct genus. This animal is unfortunately known
only by the lower jaw, which agrees in general characters with the
half-bear-like half-dog-like animals so common in the Miocene and
Pliocene. It presents, however, the unique peculiarity that the first
lower premolar is implanted by two distinct roots; the position of
this tooth being far behind the canine, instead of close to it as in
Amphicyon.
In the Ungulates we have a good figure of the skull of Rhinoceros
sansaniensis, which is regarded as a good species; while a beautiful
plate (pl. xvi.) of the jaws of Anchitherium with the deciduous and
permanent teeth cannot fail to attract attention. Equally important
is the fine skull of Listriodon shown in pl. xviil., which, in spite of
its Tapir-like teeth, is clearly seen to be a true Pig. Space does
not admit of reference to the numerous Deer-like Ruminants which
are so abundant at Sansan ; but we wish that Dr. Filhol had had an
opportunity of comparing the jaw figured on pl. xxx. as Strogulo-
gnathus with that of the existing Hydropotes.
Passing by the Antelopes and Mastodons, our few remaining
observations must refer to the subject which forms the crowning
interest of the whole work—the identity of the limbs described as
Macrotherium with the skull and teeth of Chalicotherium. The
association of similar limb bones and teeth, not only at Sansan, but
likewise at Pikermi and Samos, as well as in the United States,
leaves no doubt that they belong to one and the same type of
animal, although it may, of course, prove that there is more than
a single genus. Dr. Filhol gives us not only figures of the bones
of the feet, but also attempts a restoration of the skeleton. In the
280 Reviews—A. Laville’s Paris Tertiaries.
hind-foot, in spite of the long Edentate claws, the general structure
is decidedly Perissodactyle; although this is much less marked in
the carpus. The teeth, as is well known, are practically indis-
tinguishable from those of some of the more generalized Perisso-
dactyles; and, whether it be eventually proved advisable to retain
Chalicotherium in that group, or to make it the representative of
a distinct suborder of Ungulates, we cannot agree with our author
im regarding it as in any way indicating an affinity between the
Ungulates and Hdentates, which, as has been recently pointed out
by Dr. Ameghino, probably have a totally different phylogeny.
In congratulating Dr. Filhol on the completion of this valuable
work, we cannot avoid expressing the hope that he may be induced
to treat the Mammals of other gisements of the typical French
Miocene in a similar manner. RK.
II.—Guipz pu GéotocuE pans LE TeRTIAIRE Paristen. Par
A. Lavinie. Pp. 24, Plates 1_—X. (Paris, 1890.)
HIS brochure will prove exceedingly useful to all students of
the Paris basin Tertiaries. There is no attempt at description
of the beds; it commences with a table giving the subdivisions
and groups of the divers formations within the area; followed by
lists of the principal fossils found in them; and concludes with
a series of ten maps of typical localities.
In the table the Meudon Conglomerate is classified with the
Montian, whilst the Pisolitic Limestone is omitted, presumably
because the author prefers to include it in the Cretaceous. The
Limnea strigosa marls form the superior limit of the Hocene, and
the highest bed of the Oligocene is the Beauce limestone. We
cannot agree with the author’s classification of the Champigny lime-
stone with the whole of the Gypsum beds; and we do not know
how the lacustrine limestone of Ducy can consistently be bracketed
with the upper, middle, and lower “sables moyens.” If it is to be
included in the last-mentioned division at all, it must be placed as
the equivalent of the Mortefontaine beds. In regard to the fossil
lists, which mostly deal with Mollusca, it is evident that the author
has paid much more attention to some genera than to others. He
is very ambiguous in his nomenclature, leaving it doubtful in the
mind of the reader whether he intends the brackets to include
genera, or subgenera, or merely discarded names. The maps form
the most valuable portion of the work. They are extracted from
the Government Surveys on the 80,000 scale, and clearly indicate
the position of the chief sections found within the limits of each
district defined. The ten plates of fossils illustrate many carefully-
selected characteristic forms.
IV.—Tue Tertiary Insects or North America. By Samurt H.
ScuppDER. Report or tHE Unirep SratTes GEOLOGICAL SURVEY
oF THE TERRITORIES. F. V. Haypen, U.S. Geologist-in-Charge.
Vol. xiii. 1890, 4to. pp. 734, pls. xxviil.
HIS massive volume contains the results of more than twelve
years’ labour devoted to the study of the fossil Tertiary Insects
Reviews—Scudder’s Tertiary Insects. 281
of North America, and even now only the lower orders of Insects
have been fully treated; the materials collected within the last
twenty years proving as abundant as all those hitherto known from
the entire European area. In the Introduction the author remarks,
“The pages and plates of the present volume bear testimony to the
fact that our Tertiary strata have preserved remnants of an ancient
host, so varied in structure, so closely also resembling their brethren
of to-day, that nearly or quite every prevalent family-group in the
entire range of the insect world has already been demonstrated ,to
have then existed. While often fragmentary and crushed, sometimes
beyond recognition, a not insignificant number are sufficiently pre-
served for us to repopulate the past; sometimes, too, they are
preserved in such a wonderful manner that in tiny creatures with a
spread of wings scarcely more than a couple of millimetres, one may
count under the microscope the hairs fringing the wings.”
There are several localities which have yielded the insects herein
described, but by far the most important is Florissant, in a narrow
valley high up in the mountains at the southern extremity of the
front Range of Colorado. The insects are here preserved in an old
lake basin, probably of Oligocene age, in shaly beds, now laid bare
by erosion, which are wholly composed of volcanic sand and ash,
and 15 métres in thickness. These beds yielded a greater number
of insects in a single summer than have been obtained at the cele-
brated Ciningen deposit in thirty years, and a very interesting
comparison is made of the percentage of representation of the
different groups at the two localities. At Florissant the most
numerously represented group is the Hymenoptera, which forms
40 per cent. of the total ; followed by the Diptera with 30 per cent.,
the Coleoptera with 13 per cent., the Hemiptera with 11 per cent.,
and the Neuroptera with 5 per cent., whilst the Lepidoptera,
Orthoptera, and Arachnida together only contribute ‘54 per cent.
Great numbers of plants are found associated with the insects
at Florissant, and both kinds of organisms indicate a climate con-
siderably warmer than that now prevalent in the locality.
Of probably the same age as the Florissant deposit are the
insect-bearing beds of the White River in Western Colorado and
Eastern Utah, and of two or three localities in Wyoming. From
fine clays of probably Miocene age, at and near Quesnel in British
Columbia, Dr. G. M. Dawson obtained numerous insects, mostly
Hymenoptera and Diptera; which Dr. Scudder has also described.
Of a more recent age are a considerable number of elytra and
other remains of beetles, obtained by Dr. G. J. Hinde in clay beds
near Toronto, Canada. Though only of interglacial age, the twenty-
nine species determined by Dr. Scudder are all extinct; some of
the forms are nearly allied to insects now inhabiting the same
district in Canada and the northern United States, whilst the
relatives of others now exist in the Lake Superior and Hudson
Bay Region.
The author notices some peculiar general features relating to
the occurrence of the fossil insects in North America; one, that in
282 Reports and Proceedings—
hardly a single instance has the same species been found in two
distinct localities, a fact which may perhaps be accounted for by
the beds not being exactly synchronous, and the author thinks that
the insect remains will prove of more value in the marking of
distinct horizons than the plants with which they are usually
associated. Another feature is the number and extraordinary pro-
portion of species each so far represented by a single specimen,
and, again, that no inconsiderable proportion of the species must
be referred to genera no longer existing.
The excellence of Dr. Scudder’s work is too well known to require
comment, and this present volume is an additional proof of the
immense labour and zeal which he brings to his herculean task.
Its importance will be fully recognized by all paleontologists on
this side of the Atlantic, and its promised further continuance will
be gladly welcomed.
seve @ evra SS | AND) ap @ C2 aD Ee Se
NS
GeronocicaL Sociuty or Lonpon.
I.—April 8, 1891.—Dr. W. T. Blanford, F.R.S., Vice-Presi-
dent, in the Chair.—The following communications were read :—
1. “The Cross Fell Inlier.” By Prof. H. A. Nicholson, M.D.,
D.Se., F.G.S., and J. E. Marr, Hsq., M.A., Sec.G.S.
The tract of lower-Paleozoic rocks lying between the Carboni-
ferous rocks of the Cross-Fell range and the New Red Sandstone
of the Eden Valley is about sixteen miles in length, and little more
than a mile in average breadth; the Inlier extends in a general
N.N.W. and S.S.E. direction, and the normal strike of the rocks is
about N.W. and §.E. The tract is divided along its entire length
by a fault, which separates the Skiddaw Slates (with the Hllergill
Beds of one of the authors and the Milburn Series of Mr. Goodchild)
from higher beds on the west. A detailed classification of the
Skiddaw Slates is not attempted, but the authors describe the suc-
cession of the rocks in the faulted blocks of the western portion.
Their classification is as follows :—
Coniston Grits = Ludlow.
Coniston Flags (lower portion) = Wenlock.
Stockdale Shales= Llandovery-Tarannon.
Ashgill Shales.
Staurocephalus Limestone.
Dufton Shales and Keisley Limestone. } = Bala.
Corona Beds.
Rhyolitic Group.
A brief comparison of these rocks with those of other regions is
made by the authors.
Two Appendices are added. One by Mr. Alfred Harker, M.A.,
F.G.8., contains petrographical notices of certain sedimentary and
volcanic rocks in the Skiddaw Slates, of the volcanic rocks of the
Eycott and Rhyolitic groups, and of the principal varieties of
intrusive rocks. The second, by Mr. A. H. Foord, F.G.S., contains
a description of some Cephalopods from the rocks of the Inlier.
Geological Society of London. 283
2. “On the Igneous Rocks of the South of the Isle of Man.” By
Bernard Hobson, Esq., M.Sc., F.G.S.
Omitting the Foxdale Granite, the oldest igneous rocks of the
island appear to be the diabase dykes of Langness, ete., intrusive in
Lower-Silurian slates. The Crosby microgranite dyke is also
‘intrusive in these beds, and though its age is difficult to fix,
it is probably newer than the Foxdale Granite, which appears to be
of post-Lower Silurian and pre-Carboniferous age.
Next come the volcanic rocks of lower-Carboniferous age—an
augite-porphyrite series consisting of tuff, breccia, agglomerate,
bedded lava, and intrusive masses exposed in a narrow strip
extending from Poolvash to Scarlet Point. A vent seems to have
been opened during or after the deposition of the Poolvash lime-
stone, from which fine volcanic ashes were ejected to form marine
tuff. At intervals between the eruptions the Poolvash marble was
deposited, and became interstratified with the tuff. The vent then
probably became plugged up, and a violent explosion following
supplied material for the agglomerate overlying the tuff. Lava then
welled forth, and finally the volcano became extinct, and the in-
trusive mass of the Stack, regarded by the author as a volcanic neck,
was exposed by denudation. It was probably at the close of volcanic
activity that a melaphyre dyke was formed resembling the porphy-
ritic olivine-basalt of the Lion’s Haunch, Edinburgh.
At Poortown an intrusive mass occurs, provisionally termed
augite-picrite-porphyrite, and considered by Mr. J. G. Cumming to
be of post-Carboniferous age.
Numerous dykes of ophitic olivine-dolerite occur between Bay-ny-
Carrickey and Castletown Bay, at Langness, etc. They are post-
Lower Carboniferous, and possibly of early Tertiary age.
Full details with regard to the development and the macroscopic
and microscopic characters of the various igneous rocks are supplied
by the author, who acknowledges his indebtedness to Prof. Boyd
Dawkins for the use of his geological map and notes.
I.—April 22, 1891.—Dr. A. Geikie, F.R.S., President, in the
Chair.—The following communications were read :-—
1. ‘‘ Results of an Hxamination of the Crystalline Rocks of the
Lizard District.” By Professor T. G. Bonney, D.Sc., LL.D., F.R.S.,
V.P.G.S., and Major-General C. A. McMahon, F.G.S.
The authors, in company with the Rev. H. Hill, spent a con-
siderable part of last August in examining anew those sections in
the Lizard district which had any bearing upon the questions raised
since the publication of Professor Bonney’s second paper in 1883.
They had also the advantage of occasional conference with Mr. Teall
and Mr. Fox, whose valuable contributions to the knowledge of the
crystalline rocks of the district are well known.
That the Lizard serpentines are altered peridotites may be regarded
as settled, but doubts have been expressed as to their relation to
other associated rocks, and as to the meaning of a streaky or banded
structure exhibited by certain varieties.
284 Reports and Proceedings—
The authors, after re-examination of a large number of sections,
feel no doubt of the accuracy of their original view that the peridotite
was intruded into the hornblende schists and banded “ granulitic”
rocks, after these had assumed their present condition. In it they
find no signs of any marked pressure-metamorphism, either prior or
posterior to serpentinization. They have failed to connect the
streaky or banded structure with any foliation or possible pressure-
structure in the schists, and they can only explain it as a kind of
fluxion-structure, viz. as due to an imperfect blending of two magmas
of slightly different chemical composition, anterior to the crystal-
lization of the mass.
The Porthalla sections have been examined with especial care, not
only because the serpentine is nowhere so conspicuously banded, but
also because its intrusive character has been denied, both it and the
hornblende schists being ascribed to the alteration of a series of
sedimentary rocks of suitable composition. For this view the
authors have failed to discover any evidence, and consider it
contrary to stratigraphical and petrographical facts.
In regard to the genesis of the crystalline schists, which for pur-
poses of reference were divided by Prof. Bonney into a “ granulitic,”
a ‘“‘hornblendic,” and a “ micaceous” group, the authors show that in
parts of the first the more acid rock breaks through the more basic,
as if intrusive, in others they appear to be perfectly interstratified,
the one passing backwards and forwards, though rapidly, into the
other. But between these extremes, intervals can be found where
the two rocks seem as if partially drawn out together. The authors
are agreed that certainly one, probably both, of these rocks are
igneous, that when the basic rock was solid enough to be ruptured,
the acid magma broke into it, and sometimes softened it sufficiently
to allow of the two flowing for some little distance together, after
which crystallization took place. In regard to the hornblende schists,
the authors are not yet satisfied that either fluxion or mechanical
crushing will account for every structure which they have examined,
and prefer to leave the question, in certain cases, an open one. The
most distinctive features of the micaceous group appear due to sub-
sequent earth-movements, so that, though it exhibits some special
characteristics, the authors are doubtful whether it is any longer
worth while separating it from the hornblende schists.
Of the igneous rocks newer than the serpentine, the gabbro has
received the closest attention. It exhibits in places (especially in
the great dyke-like mass as Carrick Luz) a very remarkable foliation
or even mineral banding, which has been claimed as a result of
dynamo-metamorphism. The authors bring forward a number of
instances to establish the following conclusions :—(a) That this
foliation occurs most markedly where the adjacent serpentine does
not show the slightest sign of mechanical disturbance ; (b) that it
must be a structure anterior to the consolidation of the rock ; (c) that
it sets in and out in a very irregular manner; (d) that when it was
produced the rock was probably not a perfect fluid. Hence they
explain it also as a kind of fluxion structure, produced by differential
Geological Society of London. 285
movements in a mass which consisted of crystals of felspar and
pyroxene, floating thickly in a more or less viscous magma.
The authors’ investigations tend to prove that (a) structures
curiously simulative of stratification may be produced in fairly
coarsely crystalline rocks by fluxional movements anterior to crys-
tallization ; and that (b) structures which of late years have been
claimed as the result of dynamo-metamorphism subsequent to con-
solidation must have, in many cases, a like explanation. This is
probably the true explanation of a large number of banded gneisses
which show no signs of crushing and holocrystalline, but in their
more minute structures differ from normal igneous rocks.
The authors have seen nothing which has been favourable to
the idea that pressure has raised the temperature of solid rocks
sufficiently to soften them.
2. “On a Spherulitic and Perlitic Obsidian from Pilas, Jalisco,
Mexico.” By Frank Rutley, Esq., F.G.S.
The specimen described is a leek-green rock with waxy lustre.
The sequence of the structures developed in it is made out to be as
follows :—First, the development of fluxion-banding; next, the
formation of spherulites; and then the setting up of a perlitic
structure, the fissures of which were finally sealed by the intro-
duction of chalcedonic matter.
A wavy transverse banding in the spherulites is apparently due
to a temporary check which the fluxion-bands have exerted on the
development of the crystalline bundles of the spherulites. In one
case a spherulite has been developed prior to the formation of a
similar but larger one which encloses it. Some of the spherulites
envelope small crystals of triclinic felspar.
The author considers it very probable that the obsidian has been
subjected to hydrothermal agency since its solidification, and sub-
sequent to the development of its perlitic structure, and gives
reasons for this view.
II.—May 6, 1891.—Dr. A. Geikie, F.R.S., President, in the
Chair.—The following communications were read :—
1. “On a Rhetic Section, at Pylle Hill or Totter Down, Bristol.”
By H. Wilson, Esq., F'.G.S.
In a deep railway-cutting at Pylle Hill, the Rheetic beds, having a
thickness of not more than seventeen feet, are exposed between the
Tea-Green Marls and the Lower Lias. There is no doubt as to the
division between the Rhetic and Keuper beds in this section, but
the line of demarcation between the Rheetic and the Lias has always
been a matter of uncertainty in the West of England. In con-
nection with this subject the term “ White Lias,” as applied to beds
some of which are Rheetic and others Liassic, is held to be unsatis-
factory. The author takes a limestone which is the equivalent of
the Cotham Marble as the highest Rhetic bed in the section
described. He divides the Rhetic beds of the cutting into an
Upper-Rhetic Series and Avicula-contorta Shales. The intimate
connexion betwixt the Tea-Green Maris and the Red Marls of the
286 Reports and Proceedings—Geological Society of London.
Upper Keuper is well displayed, whilst there is a sharp line of
demarcation between the former and the Avicula-contorta Shales.
Most of the characteristic fossils of the British Rheetic are met with
at Pylle Hill, together with a few forms which are new to England,
and some of these possibly new to science.
A detailed section of the subdivisions of the Rhetic and adjacent
beds, and a list of Rheetic fossils found in the section, are given by
the author.
2. ‘A Microscopic Study of the Inferior Oolite of the Cotteswold
Hills, including the Residues insoluble in Hydrochloric Acid.” By
Edward Wethered, Hsq., F.G.S., F.C.S., F.R.M.S.
The author gives the following main divisions of the Inferior
Oolite of the Cotteswold Hills in descending order:
Ragstones.
Upper Freestones.
Oolitic Marl.
Lower Freestones.
Pea Grit.
Transition beds resting on Upper Lias.
The strata are described, and the results of microscopic examination
of the different beds given. These latter confirm the author’s
views as to the important part which Girvanelle have taken in the
formation of oolitic granules; whilst an examination of the borings
referred to by Prof. Judd in the discussion of Mr. Strahan’s paper
“On a Phosphatic Chalk ” convinces the author that these have no
connexion with the genus Girvanella.
In the second part of the paper the insoluble residues left after
treating the various deposits with acid are considered. They contain
chiefly detrital quartz, felspars, zircons, tourmaline, chips of garnet,
and occasionally rutile. In the argillaceous beds silicate of alumina
was found to occur plentifully. The detrital material is considered
to be due to denudation of crystalline felspathic rocks, and not of
stratified ones. ‘This view seems to be supported by the quantity
of felspar and its good state of preservation.
The paper concludes with a consideration of the quantity of
residue and the size of the quartz-grains in the different deposits,
which are summarized in the following table :—
Percenta: Size of
of Residue, quartz grains,
Ragstones ..............+ 2°8 “17
Upper Freestones...... 11 "12
Oolitic Marl ............ 3°2 “09
Lower Freestones...... 1:8 13
Pea-Grit Series ...... 5:0 “14
Transition Beds ...... 38°3 13
This shows a great falling off in the percentage of residue above
the Transition Beds. That of the Freestones is remarkably low,
and it would appear that these rocks were formed under conditions
which allowed of very little sediment being deposited.
ERRATUM.—In the May Number, p. 240, last line but one of first paragraph,
for ‘* Metamorphic ”’ read ‘‘ Metatropic.”’
Correspondence—Mr. W. H. Dail. 287
CORR ESPON DENCE.
a ee
ELEVATION OF AMERICA IN THE TERTIARY PERIODS.
Srr,—I notice in recent numbers of the Grotogrcan MaGaziIne
that Mr. Upham has been discussing his views on the elevation of
the Gulf of Mexico, ete. It seems a pity that gentlemen, who
desire to launch such startling hypotheses, should not devote more
time to settling the facts upon which these hypotheses are based,
before promulgating their new views. As the statements made by
Mr. Upham may by many be taken as properly verified, and more
confusion be thereby occasioned, permit me to call attention to a few
facts which have been verified.
1. The late Dr. Maack when on the isthmus of Darien did not
collect any Pleistocene fossils from the summit of the Atrato divide
763 feet above the sea. 2. The Pleistocene fossils collected by Dr.
Maack were from an elevation of only 150 feet on the Panama side,
ten miles from Panama city. The fossils above this height collected
by Dr. Maack are Eocene or Miocene exclusively, and related to
the Miocene fauna of Santo Domingo, as indeed was pointed out by
Gabb nearly twenty years ago (Proc. Am. Phil. Soe. vol. xii. p. 572).
3. The summit or dividing ridge is not fossiliferous, and is probably
not later than the Mesozoic epoch.
I may add, from information to be shortly published, that the
supposed great elevation of Florida at any time since the later
Eocene is as improbable as any hypothesis which could well be
conceived. ‘The conclusions which the facts necessitate in the case
of Florida may be briefly outlined as follows :—During the later
Hocene, west central Florida was an island, like one of the Bahamas
at present, composed exclusively of organic marine sediments which
in the Vicksburg epoch attained an unbroken thickness of more than
1000 feet. The whole submarine plateau above which the present
Florida rises may turn out to be of this age and constitution. This
island had a land-shell fauna derived from the south. The strait
between the island and the main coast north of it was more than
fifty miles wide at the narrowest point, and was only closed at the
beginning of the Pliocene. There have been gentle changes of
level since the Hocene, but nothing violent, and the vertical range
has been small. The Hocene and the old Miocene faunas were of a
subtropical character like the Antillean fauna at present. A change
took place in Mid-Miocene by which a cool, temperate, or colder
water fauna invaded the Floridian region from the north, and about
200 feet of strata (Chesapeake Group) were deposited; equivalent
to the well-known Miocene beds of Virginia and Maryland. With
the elevation which connected the Floridian islands with the con-
tinent a warmer era was again inaugurated in the sea, and an
invasion of Pliocene Vertebrates began, on the Peninsula of Florida.
There were unquestionably great changes of level on the con-
tinent, increasing as one goes northward, both in Miocene and
Pleistocene times. In the Antilles it has been proved that great
changes have taken place. But the Floridian region, for some
unknown reason, escaped, and Yucatan, probably, also.
288 Correspondence—Dr. H. B. Medilicott.
I have been making a special study of Floridian Geology for
some years, and hope to publish a considerable amount of new
information on that subject during the coming summer.
Smirusonian Institution, U.S. Narionan Museum ;
Wasuineton, April 15, 1891. , Wu. H. Dat.
THE GEOLOGY OF THE SALT RANGE OF THE PANJAB.
Sir,—In the latest number (part i. vol. xxiv.) of the Records of
the Geological Survey of India there is an interesting paper by
Mr. C. S. Middlemiss on the Geology of the Salt Range of the
Panjab. Admirable sections are given illustrating two points until
recently in dispute, the positions of the Conularia Bed and of the
Obolus Shales; and a very bold beginning is made of a fresh
discussion, regarding the age and mode of origin of the Salt Marl
and its minerals, advocating peculiar eruptive conditions connected
with a primitive and hitherto undisturbed subterranean magma.
Until Mr. Middlemiss developes his position, it would be premature
to comment thereon; I will only ask leave to correct two personal
errors in the paper. On p. 25 a quotation is made from my paper
on the geology of the Panjab, published in the Provincial Gazetteer,
whereby I am made to appear as executing an erroneous reversal
of opinion upon a disputed unconformity in the Salt Range. Mr.
Middlemiss must have overlooked the note at the beginning of the
section on the Salt Range, stating that “this sketch is by Mr.
Wynne.” I did not alter a word of it. So the passage in question
is a repetition by Mr. Wynne of a view against which I had remon-
strated in vain. The other point is on p. 20, where I am represented
as “not entirely agreeing’ with the erroneous view of the Conularia
horizon. It refers to a short paper in which I had endeavoured to
soften a somewhat acrimonious dispute by an impartial summary of
the evidence; but there can be no doubt as to which side my
own opinion leaned. I even suggested the conclusion which Mr.
Middlemiss now presents as established: regarding the “ pebbles ”
with Conularia I asked—‘Is it not more plausible to suppose that
they were washed into the gravel bed from some contemporaneous
(Paleeozoic) pool deposit close by ?” (Records, vol. xix. p. 133).
Currton, 29th April, 1891. H. B. Mepuicorr.
OS sn EU PAS EIN.
We regret to record the death of Professor Joseph Leidy, the
distinguished American physiologist and paleontologist. The
deceased, who was in his sixty-eighth year, was Professor of
Anatomy in the University of Pennsylvania, and of Natural History
in Swarthmore College. He was also President of the Academy
of Natural Sciences of Philadelphia, Director of the Department of
Biology in the University, and a Foreign Member of the Geological
Society of London. His more important contributions to scientific
literature were, “The Extinct Mammalian Fauna of Dakota and
Nebraska,” and “Freshwater Rhizopods of North America.” He
also wrote an elementary treatise on human anatomy.—Standard,
Friday, Ist May, 1891.
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THE
GHOLOGICAL MAGAZINE.
NEW SERIES: DECADE Ili VOEs VIL.
No. VII.—JULY, 1891.
ORIGINAL ARTICLIEHS.
——_——>—_—__
I.—NotTeE oN A NEARLY PERFECT SKELETON OF JCHTHYOSAURUS
TENUIROSTRIS FROM THE Lower Litas oF STREET, SOMERSET.
By R. Lyprxxer, B.A., F.G.S8., F.Z.S8., ete.
(PLATE IX.)
le ten years ago Mr. Alfred Gillett observed in a quarry of
the Lower Lias near his residence at Overleigh, Street, Somer-
set, a number of broken slabs of shaly hmestone, containing por-
tions of the skeleton of an Ichthyosaur. These slabs, which had
been cast aside by the workmen, were fitted together by Mr. Gillett,
who finally succeeded, after the expenditure of great pains, in skil-
fully developing from them an almost entire example of the skeleton
of Ichthyosaurus tenuirostris, Conybeare.
With his usual liberality Mr. Gillett presented this remarkably
beautiful specimen to the Geological Department of the British
Museum (Natural History) in 1884, where it is now exhibited on
the east wall of Gallery No. XJ, forming one of the most striking
objects in the fine series of Reptilian remains from the English Lias.+
The gift of this specimen to the Museum was particularly oppor-
tune, since the collection, although rich in some of the other species
of the genus, was previously but poorly supplied with examples of
Ichthyosaurus tenuirostris ; and is even now widely distanced in this
respect hy the Dublin Museum of Science and Art. Mr. Gillett’s
specimen, of which we give a figure in Plate IX., although by no
means a large example of the species, is one of the best preserved
skeletons that have ever come under our notice. The animal lies
on its ventral surface, with the back exposed and the limbs sym-
metrically expanded on either side; and it is largely due to the
symmetrical position in which it has been preserved that the beauty
and apparently unusual perfection of the specimen are due. Almost
the only damage that the skeleton has sustained consists of some
crushing of the skull, and the loss of a few of the tail vertebra, and
of some of the small bones of the paddles.
The fortunate rescue of this interesting specimen by Mr. Gillett
affords a good instance of the value of local observers in preserving
rare fossils which would be otherwise totally lost.
We may remind our readers that the species before us is not a
typical representative of the genus Ichthyosaurus, of which the
1 The specimen is referred to in the Museum Catalogue of Fossil Reptiles, pt. 2,
p. 84, No. r. 498 (1889).
DECADE IIIl.—vVOL. VIII.—NO. VII. 19
290 R. Lydekker—Note on Ichthyosaurus tenutrostris.
normal forms are J. communis and I. intermedius. In those species
the front paddles are characterized by their great width, and the
large number of longitudinal rows of ossicles entering into their
composition. In the group represented by J. tenuirostris, on the
other hand, the paddles are much narrower and longer, and have
fewer rows of ossicles. Thus, as is well shown in our figure, the
third digit, or the one taking origin from the intermedium of the
carpus, consists of only a single row of ossicles; and there are
usually only four rows of these ossicles in the entire limb, against
seven or eight in the typical groups. Moreover, the radius—the
bone lying immediately below the humerus on the front side of the
limb—is a nearly square bone, with a notch on its front border;
whereas in the typical group it is much wider and longer, and has
no such notch.
All these characters indicate that the group represented by
I. tenuirosiris is much less specialized than the typical one, and
thereby less widely differentiated from more ordinary reptiles.
Indeed, so different is the structure of the paddles in I. tenwirostris
and I. communis, that if we had these alone to deal with there
could be but little hesitation in regarding the former as the repre-
sentative of a distinct genus. Unfortunately (or perhaps our purely
geological readers would prefer to say fortunately), however, there
are certain intermediate forms which render it much more difficult
to define such genera; so that for the present at least our species may
rest in the genus to which it was referred by its original describer.
The specific characters of the present species are to be found in
its long and slender rostrum, narrow fluted teeth, and the presence of
a notch on the hinder border of the coracoid. Specimens in the
British Museum with the rostrum still more elongated than ordinary
were separated by Sir R. Owen as I. longirostris, but these proved to
be identical with the earlier I. latifrons of Konig. The magnificent
series of specimens from the Lower Lias of Barrow-on-Soar in the
Dublin Museum indicates, however, that these variations are not of
specific value, so that all these forms should apparently be referred
to I. tenwirostris.
We may conclude this notice by calling attention to a point where
the British Museum Catalogue is in error. It appears from the
recent researches of Dr. HE. Fraas that the type of I. acutirostris,
Owen, has smooth carinated teeth, like those of I. platyodon, so
that this species should be transferred to the Platyodont group,
which it has been proposed to raise to generic rank as Temnodonto-
saurus. This leaves the name I. quadriscissus as the one best
applicable to the other specimens catalogued as JI. acutirostris.
Moreover, Dr. Fraas considers that I. zetlandicus, Seeley, is identical
with quadriscissus; and we are disposed to doubt the right of
separating I. longirostris, Jager (non Owen) from the same. Finally,
we observe with satisfaction that Dr. Fraas is disposed to consider
the American Baptanodon as inseparable from Ophthalmosaurus of the
English Oxford and Kimeridge Clays, of which such a fine series
has recently been acquired by the British Museum.
T. Mellard Reade—Perched Blocks near Austwick. 291
-TI.—Tue Percuep Brockxs or Norser Brow AND THEIR LEVELS
RELATIVE TO THEIR PLACE OF ORIGIN.
By T. Mztiarp Reape, C.E., F.G.S., F.R.I.B.A.
N a recent excursion the Liverpool. Geological Society visited
Norber Brow, near Austwick, to inspect the celebrated perched
blocks of Silurian rock lying upon the Carboniferous limestone
plateau. The visit was made in very appropriate weather during
a storm of hail which added a weird element to the scene and
heightened by contrast the blackness of the Silurian blocks. Since
returning home I have re-read Prof. McKenny Hughes’ interesting
paper on the subject,’ and find that generally speaking my notes
and measurements are in accord with his. The angularity of the
perched blocks, so different to the rounded and striated erratics
of the Boulder Clay Plains of Lancashire and Cheshire, and the
absence of Boulder Clay, is very striking, and inevitably suggests
their transportal by glacier ice probably at the last phase of the
glacial period.
It has, I believe, been generally taken for granted that these
blocks are higher than their origin, and have been, as stated by
Prof. Hughes, pushed up hill from the north.? Being specially
interested in this question, which was raised on the spot by our
excellent guide Dr. Ricketts, four of our party, after descending into
the valley, climbed up the western side and traversed it northwards
towards Crummack. The first object that attracted attention was
a magnificent glaciated surface or roche moutonnée of Silurian rock
on our left ascending the slope to the west transversely to the direc-
tion of the valley. On the right at about the level of the perched
block on Norber Brow figured in Prof. Hughes’s paper (p. 530),
which I shall refer to as Perched Block No. 1, and which we took
for our datum level, was what may be fitly described as a mason’s
yard of black angular Silurian blocks, as large or larger than those
on Norber Brow. The bed rock was Silurian also and further
northward up the valley appeared to be much glaciated. Continuing
our ascent we reached the junction of the Silurian with the Car-
boniferous Limestone, and following the contour northward came
upon a jutting crag of Silurian from which several huge blocks had
separated at the joint planes a distance of a foot or two. These
blocks had a slight cant down hill, and were just in a condition and
position for transportal had the valley been filled with glacier ice.
The upper surface of the crag appeared to be rounded. The rock
evidently breaks up naturally into cuboidal masses. Here then was
probably the origin of the blocks of Norber Brow, as according to
the aneroid observations made by me and checked by Mr. Ashton
Hill, C.E., this Crag is 265 feet above Perched Block No. 1 on
Norber Brow. The highest point of the Silurians we tried by
aneroid was 295 feet above the same datum. It is evident that the
movement of the blocks towards Norber Brow was in accordance
1 On some Perched Blocks and Associated Phenomena, Q.J.G.S. vol. xhi.
pp. 527-538 (1886). 2 Q.J.G.S. vol. xlii. pp. 531 and 438.
292 MM. Jukes-Browne and W. R. Dyer
with the laws of gravity and downhill. A glacier filling the Crum-
mack Valley would move southward and the blocks in question
clinging to the west side of the valley might be stranded where they
are found on Norber Brow. There is no doubt that the pedestals
and platforms on which most of them stand, and which vary from
one to two feet in height, are due to the wasting away of the sur-
rounding limestone rock as pointed out by Prof. Hughes and Mr.
Mackintosh, but I quite agree with Prof. Hughes that more data
than are at present available would he required before any reliable
estimate of the time that has elapsed since the close of the Glacial
Period could be worked out.
These remarks are not intended to apply to the Silurian blocks
above Settle, which Phillips states are 200 feet above any similar
rocks in the district in siéu.1 As we did not see them or test their
levels, any remarks of mine would be superfluous.
TJL.—Tur Lower Cretaceous SERIES OF THE VALE OF WARDOUR.
By A. J. Juxzs-Browne, F.G.S., and Rev. W. R. ANpREws, F.G.S.
J T has long been known that certain deposits of Lower Cretaceous
age lay between the Gault and the Purbeck group in the Vale
of Wardour, but the absence of any good open sections, along the
tracts where they reach the surface, has hitherto prevented geologists
from ascertaining the exact nature and succession of the beds.
Dr. Fitton, whose account of the Vale of Wardour is wonderfully
good and accurate, distinctly recognized the existence both of
Wealden and Vectian (Lower Greensand), stating that certain sands,
containing traces of marine shells, occurred beneath the Gault and
above the clays which he regarded as Wealden.
Mr. Bristow, however, when surveying the district in 1851 to
‘1858, does not seem to have obtained any evidence for the separa-
tion of the sands, and considered it safer to colour all the sands
and clays below the Gault as Wealden until clear evidence of their
marine origin could be obtained. Hence no Lower Greensand is
indicated on the Geological Survey Map.
During last year we jointly resurveyed a portion of the ground
on the six inch maps, and were able to obtain evidence that proved
Fitton’s view to be correct, and goes far towards completing our
knowledge of the succession in this district.
This preliminary notice is printed by permission of the Director-
General of the Geological Survey. Early in 1890 a well was sunk
at Dinton, which gave us important information regarding the beds
immediately beneath the Gault. The following is an abstract
account of the section thus obtained.
Feet.
cay Yellow, brown, and blue clay (with fossils) ... ... ... ... 215
ee { Sandy rock with a layer of small pebbles at the base (fossils) 143
Brown, grey, and yellow sands, with lumps and layers of
Tats ferrugimous Sandstone...) yes) =a. eae eee nee
““) Light grey sandy clay, becoming darker and passing down
into ‘staft’ black ‘clay © 02) (ee. oo ons) eee
692
1 Rivers and Mountains of Yorkshire, 1859, p. 111.
The Lower Cretaceous of the Vale of Wardour. 293
One of the ferruginous layers in the sands has yielded a fairly
good specimen of Exogyra sinuata, which is one of the most
characteristic fossils of the Vectian group.
In this well the base of the group is evidently not reached, but
most fortunately it is completed by a brook section at Teffont, which
begins in a black clay exactly like that found at the bottom of the
well. This black clay is about six feet thick, and passes down into
a nearly black sand which has a green streak when cut, and consists
mainly of dark-green grains of glauconite.
Underneath this sand are mottled clays, which were recognized
by Mr. Whitaker as similar to the “catsbrain” clays of the Weald,
—their tints are yellow and white, mottled here and there with
a rich claret-coloured stain, which imparts a special character to the
clay. Below are yellow loamy clays. We consider these to be of
Wealden age, and the dark sand to be the base of the Vectian; but
as the section is not clear, and this sand has not yet been found
elsewhere, we cannot say whether the sand is conformable to the
clays or not.
The maximum thickness of the Vectian appears to be about forty
feet, and the yellowish-green sands which underlie the pebbly base
of the Gault can be traced westward for several miles both along
the southern and the northern sides of the Vale, overlapping the
Wealden and the several divisions of the Purbeck beds, and
gradually thinning out.
The thickness of the Wealden clays is difficult to estimate, because
exposures are so few and the slopes are so gentle; but there can
hardly be more than 40 or 45 feet at the east end of the vale,
and they thin out rapidly towards the west, not extending far
beyond Teffont on the north side, nor far beyond Sutton Row on
the south side.
Eastward the Wealden occupies a certain width of flat ground
which merges into the alluvium east of Dinton Station. At the
cottages north of the station a well was sunk for about forty feet
through yellow-grey and brown clays. We were informed that
there was a perfect succession of clays without any sudden change
or any pebbly bed, but that at the bottom there was a floor of very
hard sandstone. The accuracy of this information we proved by
having the well emptied, and the bottom tested with a punch. A
piece of this sandstone was given to one of us by the well-sinker,
and is a hard grey calcareous grit with Cypridea punctata. The
material thrown out of the well also yielded Cyprides, Paludina
carinifera, and Unios. We believe these clays to be of Upper
Purbeck age, for the lower part of them, with a band of calcareous
grit, exactly like that in the well, can be seen in the first cutting
west of the station, and they are succeeded by a set of clays, marls,
and thin limestones, which have a much greater resemblance to the
Purbeck beds than to the Wealden.
When the railway was made there must have been an excellent
section of these beds and the upper part of the Middle Purbecks in
the two cuttings west of Dinton Station; now they are so over-
294 Hl. H. Howorth—Rapid Elevation of Himalayas.
grown that it is very difficult to make out the relations of the strata,
for they are certainly flexured and perhaps faulted. We feel sure,
however, that the beds in the first cutting are higher than those in .
the second, and we hope in a future paper to publish the evidence
on which we base our conclusions. If our reading is correct, there
is a well-developed Upper Purbeck series in the Vale of Wardour,
with a thickness of 70 or 80 feet; and this is succeeded by repre-
sentatives of the Wealden and Vectian series, which, however, are
poorly developed and taken together are less than 100 feet thick.
TV.—Tse Recent and Raprp Enevation or THE HIMaLaYas.
By Henry H. Howortu, Hsq., M.P., etc.
N the last Number of the Gzotocican Macazinz my friend Mr.
W. T. Blanford takes exception in very courteous terms to
the views I have maintained in regard to the recent elevation of the
Highlands of Hastern Asia. I cannot, however, quite grasp how
far he agrees or disagrees with me. He does not apparently question
the evidence which has so impressed experienced observers like
Humboldt, Murchison, Tschihatcheff, Cotta, and Senkofski in regard
to the absence of traces of widespread glacial phenomena in the
high mountains of the Ural, the Altai, and the Thian Shan ranges,
and which apart from all considerations seems to me inexplicable on
any other theory than that these mountains did not exist during the
so-called Glacial Period.
Mr. Blanford limits his criticism to the Indian evidence; but even
here I do not quite understand what is the exact position he main-
tains. In the Manual of Indian Geology, that splendid encyclopedia
of facts on whose title-page his name occurs with that of Mr.
Medlicott, it is stated over and over again that traces of glaciation
are nowhere present in peninsular India. In the same “ Manual”
it is argued that the so-called glacial phenomena which have been
said to occur in the Punjaub and other parts of the Plains are
to be otherwise explained, and I believe I am right in attributing
to Mr. Blanford the view that the old glaciers of the Himalayas
never protruded into the plains.
This limits the problem therefore to the Himalayas themselves.
Mr. Blanford objects to Mr. Campbell’s very emphatic evidence
because he had never penetrated into the inner valleys, and only
spoke of the outskirts where the valleys open out. ‘This is true;
nor does Mr. Campbell claim to have done more than deduce his
conclusions from what he saw. He was a very keen observer, he
had seen glacial phenomena in all parts of the world, he went
specially to study glacial phenomena on the spot, and his descriptions
of what he saw, which are very minute and graphic, seem to me to
be most conclusive that the lower parts of the Himalayan valleys
show no traces of glaciation.
But I did not quote Mr. Campbell only. General McMahon, who
has studied and written much on the Himalayas, and published his
observations in the Records of the Indian Geological Survey, is just
H. H. Howorth—Rapid Elevation of Himalayas. 295
as emphatic as Mr. Campbell. Lastly, it is true I have not myself
been there, but I have seen many photographs, and many drawings,
and notably the magnificent drawings of the Himalayan scenery by
Colonel Trotter, which show the contour and structure of the valleys
so admirably. These were exhibited only a few days ago at the
Geographical Society, and I was struck, as other people were, by
the angular, sharp, crisp outlines of the rocks and the absence of the
peculiar curves that denote glacier action, and this not merely on
the watersheds, but in the valleys themselves. The drawings, be it
remarked, represented nearly the whole length of the chain.
I must not be misunderstood. I did not say in my paper that
there are not traces of the glaciers having once extended further.
I said very plainly indeed that there are such traces. Sir J. Hooker
and Mr. Blanford proved this long ago. The Himalaya glaciers
seem to me like glaciers in other parts to have shrunk considerably.
What I do maintain is that these traces are only found when we have
mounted the valleys several thousand feet, and that they are quite
incommensurate in size and importance with the vast glacial débris
and phenomena which should be found on the flanks and in the
neighbourhood of these gigantic mountain buttresses if during the so-
called glacial age they had formed the feature in the landscape which
they do now. As gathering ground for ice at a time when Central
Asia was occupied by water instead of being an arid plain, they are
incomparably great, when contrasted with the Dovre Fjelds which shed
their débris as far as the Carpathians, Central Russia, and Norfolk ;
or the Alps whose débris occurs down the Rhone valley as far as
Lyons, and if they had existed in the so-called Glacial age we ought
to find the great Indian plain strewn widely with unmistakable
débris, instead of having to painfully search for it until we reach
a height of 7000 or 8000 feet. I must, therefore, claim Mr.
Blanford as supporting my conclusion rather than criticizing it.
In regard to the main question, an important witness is Mr. Blanford
himself. Let me quote testimony for which he was responsible
when he was in the very thick of his geological labours in India,
and long before he had largely forsaken the happy hunting grounds
of Geology for those of Zoology.
On page lvi of the introduction to the Manual of Indian Geology,
in discussing the origin of the Himalayas, we read, “The whole of
the gigantic forces, to which the contortion and folding of the
Himalayas and the other extra peninsular mountains are due, must
have been exercised in the interval which has elapsed since Eocene
times. . . . The direction of the Himalayan ranges is clearly due to
post-Kocene disturbance. It will be shown, in the chapters relating
to sub-Himalayan rocks, that the movement has been distributed
over the Tertiary and post-Tertiary period; and a great portion of
it is of post-Pliocene date.” Again, ‘As it is certain that a great
portion of the disturbances affecting the Himalayan strata are of
Pliocene or post-Pliocene date, it is reasonable to conclude that
at the close of the Miocene epoch no such mountain barrier as exists at
present separated the Indian peninsula from Central Asia. There is
296 Rev. Dr. Irving—On Dynamic Metamorphism.
independent evidence in favour of the view that the elevation of
the Thibetan plateau is of post-Siwalik date; for remains of
Rhinoceros and other large mammals occur at an elevation of 15,000
feet in Thibet, and it is not probable that these animals lived in so
elevated a region” (id. pp. 585 and 586).
Here is assuredly an important witness in support of the views
of Falconer and of Strachey, behind whose broad egis I claim to
stand.
In conclusion, there are two. statements in Mr. Blanford’s
communication which I wish to traverse. He says Mr. Lydekker
is of opinion that the Rhinoceros remains from the Hioondes
plateau are of Pliocene age. Mr. Lydekker was once of that opinion,
but he subsequently withdrew it, and has printed his opinion that
he now holds the beds in which they occur to be of post-Tertiary age.
In another venture Mr. Blanford says, “That if I had had an
opportunity of seeing what is perhaps the grandest example of
subaerial denudation in the world, I should be as little inclined as
he is to believe that such gigantic furrows as the Himalayan valleys
can have been ploughed out by rain and rivers since the frozen
Mammoths were imbedded in the Siberian tundras.”
My answer is that I do not for a moment believe that these
furrows were ploughed out by rain and rivers at all, and that it
seems to me as incredible to believe that the splintered precipitous
and sharp-edged precipices of the Himalayan valleys were carved
out by such agencies as that the Matterhorn or the pinnacles of
the Sierra Nevada or other similar objects were thus shaped. The
theory which attributes such forms to this kind of denuding agency
seems to me absolutely transcendental, and to involve a reductio ad
absurdum of Uniformitarian Geology.
V.—On Dynamic Meramorpuism.?
By the Rey. A. Irvine, B.A. and D.Sc. (Lond.), F.G.S.
N the originally epistolary form of my previous communication ”
on this subject brevity was aimed at as far as possible. It was
written at the time the letters therein referred to appeared, and my
object in throwing out such suggestions as I have ventured to make,
was to call the attention of writers on petrological subjects to the
desirability of avoiding a certain looseness of thought, which seemed
to attach itself not infrequently to the terms ‘chemical change’ and
‘chemical action.’
Mr. Fisher’s letter® in reply thereto is in reality an appeal from
the creed of the geologist, not to chemistry, but to the creed of the
chemist. JI am certain it will satisfy no one who has made a real
study of chemical physics.
The instances of the formation of CO and NO which have been
cited, along with a good many of the immense number of “ parallel
1 Written in January last.
2 See Grot. Mac. Dec. ITI. Vol. VII. pp. 562-564.
3 See the letters of Mr. Fisher and Mr. Harker in the GroLocicaL MaGazInE
for January, 1891.
Rev. Dr. Irving—On Dynamic Metamorphism. 297
instances” (loc. cit.), are very well known to students of
chemistry ; but they are not to the point. There is the error
which mistakes the algebraic sum of the results of a chemical
reaction (as expressed in thermal units) for pure chemical com-
bination, gud entry into atomic union. I thought that ‘chemical
combination’ was a phrase sufficiently guarded, if taken in its
technical and literal sense; and I still think so. All that Mr.
Fisher’s ‘authority’ has urged, and a good deal more, was before
my mind when I penned the sentence: “It is something much
more complex than that” (p. 563).1. Mr. Fisher’s authority thus
takes a different ground altogether from mine, when he enunciates
the doctrine that “many chemical changes are attended with the
disappearance of heat.” Of course they are. Why, every case of
dissociation (which is a ‘chemical change’) is attended with the
disappearance of heat or of an equivalent amount of electrical energy
(in electrolysis). But all such cases will at once be seen to be
rigidly excluded from the term “chemical combination.” The fact
is the term chemical change, as illustrated by the authority who
uses it, covers the whole process of the reaction in each case; it
includes the antecedent dissociation (or partial dissociation), bringing
on what I have elsewhere called the “‘quasi-nascent state,” * which
must precede the recombination of the atoms or radicles to form
new molecules. It is of the latter only that I speak in my December
letter ; and it must be quite obvious that pressure is antagonistic to
the former. We may put it thus:—If 6=the amount of kinetic
energy manifested (qud heat) as the result of a reaction of two
bodies on one another; further, if we take x = the amount of heat
used up in the preliminary dissociation (or partial dissociation) of
the antecedent molecules; and if y= the amount of heat evolved
in the recombination of the atoms thus rendered available; the very
simple equation
0=y—2
seems to me to cover the facts of the case, in the simplest form in
which the problem can be presented to us; as (e.g.) in the com-
bination of two volumes of hydrogen and one volume of oxygen to
produce steam. And if, as in a comparatively small number of
cases, there follows a secondary dissociation into proximate con-
stituents different from those which formed the antecedents of the
reaction, calling the heat expended in this a’, we get the equation
; 6=y-— (#+).
All that Mr. Fisher’s authority has contributed then to the
discussion is to inform us that in the cases he has cited (and there
are plenty of others) the value of « (or in some cases of «+4 2’)
exceeds the value of y, in which case @ is negative, and the phe-
nomenon is endothermic. On the other hand, if the value of y
1 Those who wish for real information on the subject may be referred to Pattison,
Muir’s ‘‘Thermal Chemistry’’ (1885), and the English edition of Ostwald’s
“* Outlines of General Chemistry ’’ (1890), both published by Macmillan.
2 See Chemical News, Nos. 1402 and 1505, ‘‘On Dissociation and Contact Action.”’
298 Rev. Dr. Irving—On Dynamic Metamorphism.
exceeds that of # (or « + 2’), @ is positive, and the phenomenon is
exothermic.: The subsequent, or even simultaneous absorption of
heat by a diluent (such as nitrogen, in all cases of bodies burning
in air) makes no difference, for this belongs to the distribution of the
heat, and makes no difference in the quantity of heat generated,
which is the same for the same weight of the same materials con-
cerned in the same reaction.”
We know, for instance, that heat is used up (endothermic) in the
reaction OC -+ CO, = 2CO, for the simple reason that more heat is
required to effect the dissociation CO, = CO + O, than is evolved
in the subsequent combination (molecule for molecule) expressed by
the equation C + O = CO; and we are pretty sure that this is the
true explanation of the observed phenomena, because we know from
independent evidence that the heat of combustion of C into CO is
less than one-half of that of the combustion of the same amount of
carbon in the reaction CO + O = CO,. These facts have found
their way for years past into such well-known text-books of chemis-
try as Williamson’s ‘‘ Chemistry for Students” (see § 60, 2nd ed.).
Again, in the case of NO we require the high temperature of the
electric spark-discharge to effect the antecedent dissociation of the
N, and O, molecules before we get NO formed; but in this case I
am not at all sure that the phenomenon is endothermic, though the
rapid distribution of the heat of combination may deceive us, if we
lose sight of the all-important distinction between quantity and
intensity of heat (absolute temperature).? The absence of explosive
phenomena proves nothing as to this point. All this and a good
deal more of like import has been discussed by myself and others in
published papers during recent years.
The question raised practically resolves itself into this: Does
pressure promote the dissociation of previously stable molecules, so
as to render the intra-molecular energy of their atoms available
for entry into new combinations? When this is answered in the
affirmative on the strength of cogent evidence, I will gladly admit
the ‘storage of energy’ (qud potential energy of chemical affinity)
in the crust of the Harth as the result of mere pressure. The latest
grand conception of Mendeléeff as to the nature of chemical affinity
points however exactly in the opposite direction.
In the cases of change of volume to which Mr. Fisher’s authority
refers, I suppose diminution of volume is meant. But I am not
sure that the very molecular strain involved in surface-tension may
not in these cases initiate chemical action ; and a suspicion remains
that the gases of the supernatant atmosphere may have something
to do with it. I am not, however, acquainted with the details of
the experiments referred to, nor do I think that for purposes of
dynamical geology they are much to the point.
1 For a clear exposition of these principles see a paper by Spencer U. Pickering,
F.R.S., on ‘Chemical Action and the Conservation of Energy,’’ Nature, vol.
xiii. pp. 165-167.
2 Very well illustrated in the case of ammonia, which will burn continuously in
pure oxygen, but not in common air.
3 See my ‘‘ Chem. and Phys. Studies, etc.’’ p. 54.
Rev. Dr. Irving —On Dynamic Metamorphism. 299
It is stated that, ‘“ Whether it be atomic energy or not, is not at
present known.” Does this mean that we cannot distinguish between
the energy of translation of the molecules of a gas or the energy of
cohesion of the molecules of a solid, and the intra-molecular energy
which the atoms possess per se? Is it meant to say that recent
advances in chemical physics have not led to the recognition of the
atom-temperature within the molecule as affecting for the time being
the stability of the molecule itself? Does it mean to tell us that
we cannot, in the light of a host of known facts, draw a distinction
between those molecular moods or states of matter which we call
magnetic and electric, and that interaction between the atoms which
is concerned in building up those molecules, and which we call
chemical affinity? Or, turning to his own chosen examples, can
My. Fisher’s authority bring forward any array of cogent facts to
shake or overthrow the doctrine that the avidity with which CO
takes up oxygen (whether free or combined) when the temperature
is raised, and that most characteristic avidity with which NO takes
up O, (at ordinary temperatures) is in both cases due, not to any force
resident in the molecule as such, but to the unsaturated valency of
the O-atom or the N-atom respectively? Intra-molecular energy
seems to me as clearly distinguishable from molecular energy, as the
. latter is from “ordinary mechanical or molar energy.” *
Reverting now to Mr. Fisher’s original paper in the GuoLocrcaL
Magazine (July, 1890), I think I can follow his reasoning pretty
clearly, until on p. 304 he says: ‘“‘We must now inquire into
what forms of energy the work has been converted.” Here there
seems to me some confusion of thought. ‘Energy’ is the capacity
for doing work; that is, for producing or retarding motion, or over-
coming resistance to motion. The amount of energy expended is
always proportionate to the work done. In the case before us the
energy is presented in the mechanical form of pressure, and if the
lateral pressure is the result of the original ‘energy of position’ of
another portion of the Earth’s crust, the actual source of the energy
is gravitation acting upon the mass favourably situated. This being
in part resolved into lateral thrust, the energy of that thrust is
expended in doing work which is distributed among the following
terms :?—
1. The lifting of the cover (potential energy of position) ;
2. The elevation of the centre of gravity of the deformed mass,
in so far as the extension of the mass takes place upwards (potential
energy of position) ;
3. The work of compression (molecular friction generating heat) ;
4. The work of shearing, bending, and fracture.
Where I am unable to follow Mr. Fisher’s reasoning is with
reference to the last term, which is surely outside the others altogether.
1 Since writing this paper I have noticed that the above cases with some others
are discussed in a very suggestive (though scarcely exhaustive) manner by Professor
Liveing in his little book “‘ Chemical Equilibrium, the Result of Dissipation of
Energy ’’ (1885).
* Referring to the geometrical construction used by Mr. Fisher ((oe. cit.).
300 Rev. Dr. Irving—On Dynamic Metamorphism.
All that he considers the result of shearing seems to me the direct
result of the lateral pressure; shearing, bending, and fracture being
simply concomitant items of expenditure of the energy of the lateral
pressure. Shearing, bending, and fracture are simply work done
in opposition to the force of cohesion; the force, that is to say, which
tends to maintain the molecules of a solid at fixed distances and in
fixed relative positions, to which the undeformed mass owed such
rigidity as it possessed; and this important factor Mr. Fisher seems
to have overlooked. In both shearing and bending we must also
have some molecular friction, with its thermal effect; but it is not
easy to see how even this applies in the case of fracture, which is
simply the work of overcoming cohesion. When Mr. Fisher says
‘this part of the energy is not convertible, etc.,” he seems to me to
be using the word ‘energy’ where he ought to use the term ‘ work.’ |
Herein appears to lie the fallacy of the whole argument; and
through this, as through a loop-hole, the idea of chemical action
seems to insinuate itself.
Turning now to Mr. Harker’s letter, the first thing that calls for
remark is the “direct correlation of mechanical work and chemical
energy.” This is very nicely put; so nicely that the unwary reader
is easily led off the scent. On this I simply ask for an explanation
of the word ‘correlation.’ What lies hid behind that rather big
word is the gist of the whole question we are trying to solve.
Sorby certainly suggested something of the sort; but we must have
something more solid than suggestions, as a basis upon which to
construct sound scientific theory. If Dr. Sorby or any one else will
show how we can step by step follow such a transformation in
harmony with what some of us know from years of thoughtful and
fairly extensive study at first-hand of the facts and phenomena
which form the groundwork of chemical theory, some real advance
will be made. Until this is done, we shall have to regard the cited
suggestion as no more than a gigantic guess. It may be useful in
pointing the way to further investigation; but to draw deductions
from it, as if it were a well-established induction, is altogether
unscientific.
Mr. Harker refers, however, to experiments of Cailletet, Pfaff,
and Spring, as affording practical verification of the suggestion of
Dr. Sorby. Unfortunately this rough massing together of experi-
mental evidence gives us a result of such a neutral character as
we are familiar with in ordinary laboratory-processes of alkalimetry.
I know some of Cailletet’s splendid work very well, but this has
hardly any bearing upon the question before us. If Mr. Harker
refers to his experiments on the effect of pressure upon the inter-
action of zine and sulphuric acid, or to those of Pfaff upon the
1 An illustration will perhaps make this clear. We may expend a definite amount
of energy furnished either by the muscles of a horse or the fuel consumed in the fire-
place of an engine in drawing a series of loaded trucks along a perfectly horizontal
line of rails. Work is done in overcoming the friction of the wheels against their
axles and against the rails, and in the displacement of a portion of the atmosphere
with the movement of the train; but would any one contend that energy was stored
up in the train P
Rev. Dr. Irving—On Dynamic Metamorphism. 301
interaction of hydrochloric acid and calespar, and upon the com-
bination of water with dehydrated calcium sulphate, they all tell
against the notion of pressure helping chemical action. Pfaff draws
this general conclusion from them: ‘It follows quite decisively
from these experiments, that high pressure intercepts chemical
affinity, when for its activity an increase of volume is necessary.” *
All this seems to have been clear enough to Mr. Harker some six
years ago, when he wrote:* ‘The effect of increased pressure is
to facilitate such physical and chemical changes as involve con-
traction of volume in the substances acted upon, and to retard
changes which are accompanied by expansion.” If he will furnish
references to later work of Pfaff in which his conclusion cited above
is superseded, he will confer a favour upon all who are interested
in this fundamental question of petrology.
As to the work of Dr. W. Spring, assuming that the alleged
crystalline copper sulphide was proved to be a definitely crystal-
lized chemical compound, we have to consider whether such alleged
combination is accompanied by increase of density. We may
attack the question I think fairly in this way :—
Assuming the following constants :—
At. Wt. Sp. Gr.
Meraliieycopper Wine.) were (CU) =) Ooo), weno tecnico
Hlementary sulphur .. S=32 Boo) obo | OEY
and dividing each at. wt. by the sp. gr., multiplied into the molecular
weight of water, we have for our present purpose,
63:5 + (8:9 x 18) = ‘389 (vol. ratio of Cu atom):
32 — (2:07 X 18) = ‘86 (vol. ratio of S atom).
If the combination were merely ‘additive,’ we should have :39+-86
(= 1-25) for the vol. ratio of the fundamental Cu S molecule.
But the sp. gr. of Cu S (crystalline) being 4:6, we get
(63°5 + 82) + (46 x 18) = 1:14
for the actual vol. ratio of the same molecule. This tells us plainly
enough that the union of atoms is accompanied by an increase of
density.
Mr. Harker is careful to point out the necessity for keeping the
apparatus cool in the experimental work of Dr. Spring, as cited by
him. Where, one may ask, would be the necessity for this, if
(i.) there were no heat generated by friction during compression ;
(ii.) the process of chemical combination (as alleged) were endo-
thermic? We have no right even here to say that any portion of
the mechanical energy is transformed into chemical energy. The
chemical energy was potentially already in the atoms of Cu and S
respectively, as a function of their atomic weights (according to
one of the latest generalizations of chemical science); all that the
pressure did in the experiment in question was to coerce them
1 See Allgem. und Ohem. Geol. pp. 308-810: ‘‘Es geht also aus diesen Ver-
suchen ganz entschieden hervor, dass starker Druck die chemische Verwandtschaft
dann aufhebt, wenn zu der Entfaltung ihrer Wirksamkeit eine Volumvermehrung
esforderlich ist.’’
» Brit. Assoc. Report, Aberdeen Meeting (1885), p. 846.
302 Rev. Dr. Irving—On Dynamic Metamorphism.
into such intimate contact as to bring them within the field of its
operation. 'This, too, seems to be Spring’s own interpretation of
the results obtained.’
A case, the exact reverse of that of CuS, has been established by
the more recent work of Dr. Spring in conjunction with Van’t Hoff.*
The substance acted upon was the double acetate of copper and lime.
The formula for this double acetate is Cu(C,H,;0,),.+Ca(C,H,0.),
+8H,O, and it occurs as 8-sided prisms of the quadratic system.
It is gradually built up with the aid of moderate external heat by
adding gradually free acetic acid to a warmed mixture of equivalent
proportions of neutral acetate of copper and slaked lime in water.*
The process is a complicated one ; but it is not reversible, for in the
experiment referred to the double acetate is resolved by a pressure
of 7000 atmospheres into the two separate acetates of copper and
lime with the separation-out of some of the water of constitution,
the same change in fact as is effected by heating the salt above
75° C. at ordinary atmospheric pressure. The effect of pressure
here is again to effect a transformation which is accompanied by
loss of volume; tending to give greater closeness to the atoms until
they obtain that configuration which belongs to their most stable
relation. We may compare it with the action of heat in breaking
up the molecules of ammonium nitrate to such an extent as to allow
the atoms to rearrange themselves (with evolution of heat) in the
more stable compounds N,O and H,O. ‘The fact is one which, taken
along with the.case of Cu §, is of far-reaching significance, but
cannot be followed up further here. So far as it goes, it lends
support to a ‘diagenetic’ rather than to an ‘epigenetic’ theory of
metamorphism.°
Mr. Harker misrepresents me, when he suggests that I have
assumed that “the whole of the work done in the compression,
deformation, and friction of rocks passes into heat.” I have never
assumed anything so nonsensical, as Mr. Harker may see, if he will
do me the favour of making a more intimate acquaintance with my
little work, to which he refers. Neither he nor I was dealing with
a case of ‘deformation,’ but with a hypothetical case of what Heim
calls ‘tiberlastet,’ the condition, that is to say, of ‘latent plasticity ’
antecedently to deformation, where the burden upon the deep-seated
rock-mass produces hydrostatic pressure greater than the internal
resistance to deformation which the cohesion can offer. All that
1 This was pointed out by me in App. ii. note D of my original thesis written in
1887 (see ‘‘ Chem. and Phys. Studies,”’ ete., p. 108).
2 See ‘Am. Journ. Sci.” vol. xxxv. (1888) p- 78, and vol. xxxvi. (1888) p. 288,
et seq. I am much obliged to General MacMahon for furnishing me with these
references.
3 See ‘‘ Zeitschrift fiir physik. Chemie,” i. 5, cited in ‘ Nature,’ vol. xxxvi. p. 160.
4 Wislicenus, ‘‘ Organische Chemie,”’ pp. 541, 542.
> From certain known facts, it does not seem at all improbable that such complex
syntheses may have taken place extensively in the early stages of the genesis of
rock-forming minerals. Among them I have suggested (“ Chem. and Phys. Studies,”
etc., App. i. note Q) the formation of minerals of the spinel type, in which Al,O,
plays the part of an acid, the alumina being set free with subsequent BARROS ot
physical conditions, to enter into new relations as a base.
Rev. Dr. Irving—On Dynamic Metamorphism. 308
I have maintained is that during the compression-stage you must
have molecular friction (or something equivalent thereto), just as,
while crushing is going on, you must have molar friction (if the
phrase may be allowed); and in both cases you must get some of
the energy expended manifested kinetically as heat. My real
contention was, that the intensity of such heat would be too low for
it to be of any practical importance.
To sum up, I must confess that in the light of what has been
adduced in this paper, I see no reason for unsaying or qualifying
anything in my previous letter’ (December, 1890), though I am
very sorry if any one’s susceptibilities have been wounded. It was
quite unnecessary for Mr. Harker to offer me any apology; but
Tam a little surprised that he should not have read what was put
into print as a criticism or stricture upon his own most valuable
essay, which was printed in the Report of the Brit. Assoc. in 1885.
The one great factor of mineral change at depths is superheated
water,” the existence of which is dependent on pressure. This both
Mr. Fisher and Mr. Harker seem to have overlooked. But the
experiments of Daubrée and others go to show that its action is in
- many cases in the direction of the resolution of higher and more
complex compounds into simpler and denser mineral forms, rather
than in the building-up of more complex out of simpler compounds.
[Since this paper was written I have received from M. Troutschoff
of St. Petersburg, a copy of his interesting paper in the ‘‘ Comptes
Rendus,” in which he gives an account of his method of preparing
erystalline quartz from a dialysed solution of silica in water by
prolonged heating in hermetically-sealed tubes ; and in ‘“ Nature,”
vol. xlii. p. 545, the somewhat startling announcement appears
of his successful achievement of the synthesis of hornblende, by a
similar method, out of the various oxides which generally enter
into the composition of that mineral. These were obtained partly
as dialysed solutions, partly as fresh-precipitated hydrates, and mixed
in right proportions as such. Hach tube before sealing up was
exhausted by a Sprengel pump, so that probably most of the un-
combined water was drawn away as vapour along with the air.
The sealed tubes were heated in a specially-constructed sand-bath
for three months to a temperature of 550°C. Under these con-
ditions the synthesis of hornblende crystals was effected, together
with some pyroxene, a zeolite, and a variety of orthoclase; and it
is not difficult to see that here synthesis of the denser minerals was
facilitated by the action under great hydrostatic pressure of the
superheated water which remained in the tubes, and separated out
from the hydrated materials as the digestion proceeded. M. Trout-
schoff applied in fact the conditions which may easily be conceived
as having obtained generally in the genesis of the heavier minerals
of the Archean schists. See my work (Ibid, pp. 68, footnote, and
91, 95, 96).]
1 With one exception, which no one has noticed. When I said ‘ shear-planes’
IT should have said ‘shear- and thrust-planes.’
* Compare pp. 10-15 of my ‘‘Chem. and Phys. Studies in the Metamorphism
of Rocks”’ ; also the quotation from Pfaff in App. ii. Note K. The work of Pfaff
is not as well known as it should be by English geologists.
304 W. Maynard Hutchings—Rutile in Fireclays.
VI.—Ruvuriue in FrrecLhays—Re=puiy to Masor-GeneraL MacManon.
By W. Maynarp Hourcuines, Esq.
igi the June Number of the Gronocican Magazine, p. 259, Major-
General MacMahon deals with my paper on fireclays, etc., and
raises, with much fairness, several objections to some of my inter-
pretations and inferences. Some of the criticisms are exactly what
I should expect to be made, and were more or less present in my
own mind, so that I can well see how they may arise in the minds
of others.
General MacMahon appears to have somewhat overstated my views
as to the “dynamic” part of the ‘‘Metamorphism” in question,
owing to taking all I say as equally applying to slates and clays,
which is not the case. Thus, the paragraphs he refers to on p. 168
will, I think, plainly show that I distinguish between what has
taken place in clays and allied shales, and what has taken place in
slates; and passages in my previous paper make this still more
evident. I fully hold that slates, such as I refer to, have undergone
metamorphism of very “dynamic” nature. And I hold that the
beginnings of the same thing went on in the clays and shales, but
in a so much less degree that I think General McMahon would fully
admit it.
All I claim for the clays is summed up in the sentence at bottom
of p. 316 (July Number of last year), where I speak of “the joint
action of pressure, warmth, and mineral solutions” as the probable
condition of the changes I believe to have taken place. It was only,
I think, in replying to Dr. Irving that I used the word “dynamic”
at all in connexion with the clays and shales of the Coal-measures.
It may be that it is a wrong expression in that combination.
“‘ Dynamic” and ‘‘ Metamorphic” are dangerous words, perhaps,
as they are used so variously by those we look to for light and
leading that we hardly know how to use them safely at all.
Such changes as I believe to have taken place in fireclays would
not, I assume, be brought about unless the chemical action had been
intensified by warmth and pressure. ‘That they have been under
conditions capable of producing the pressure and warmth is hardly
to be doubted.
What are we to call the effects of these things, as distinguished
from any ordinary surface-weathering due to simple chemical action ?
Would “ pressure-metamorphism” be allowed to include them ?
Where does simple chemical action end and ‘“ metamorphism ”
begin ?
I at once admit what General MacMahon says as to absence of
direct chemical evidence for my views. It is, very unfortunately, a
fact that lack of chemical work is felt throughout a great deal of
the petrological study that is going on. We have many workers
with the microscope, but very few workers with the balance.
In the present instance, however, the nature of the material is
such that I do not think the most devoted analyst could obtain very
much solid evidence.
The “pestle and mortar” business was not so violent as General
W. Maynard Hutchings—Rutile in Fireciays. 305
MacMahon seems to infer, the trituration of a clay (‘without
grinding”’) partly in water, being a gentle operation. But, violent
or gentle, I fail to see that it has any bearing on the fact, on which
stress is laid, that after separation none of the larger flakes of mica
contain any rutile at all; nor on the conclusion which this fact
enables us to draw, in view of what we know of the nature of the
materials forming these deposits, that the rutile was not brought into
the sediments in the mica, as such.
As regards the fact that the mica of these “complex flakes”’
containing rutile is orientated in all directions, I do not look upon
it as of much importance one way or other. General MacMahon
thinks that if the mica is secondary the “molecules of mica would,
at the moment of crystallization, surely have followed the laws of
crystallization and have arranged themselves in definite order.”
This is simply an @ priori supposition as to what ought to take place,
and can hardly count as an argument. As a matter of fact, obser-
vation of mica which is formed as a secondary product in altering
felspar, either in crystals of felspar or in fine felspathic ash-material,
seems to show that no such definite order is by any means the rule,
but rather in most cases quite the reverse. Such, at least, is my
experience with materials of this nature of which I am just now
making a special study.
It is suggested that the micaceous ilmenite may be the source of
the rutile. Ido not think examination of the materials could lead
anybody to this view. J regard this mineral as secondary, and
derived indirectly from the same source as the rutile. Ido not
know that the transparent and translucent micaceous ilmenite as it
occurs in these clays, etc., and abundantly in some slates, has ever
been regarded as anything but secondary, nor that any original rock
has been suggested whence it could be derived clastically.
Finally, while admitting the full force of some of General
MacMahon’s criticisms, I venture to think that the subject should
be looked at and judged a little more as a whole, taking in what I
might call outside matters as well as details of the laboratory and
the microscope.
Broadly, the matter stands as follows: We have these large
and extended deposits of the Coal-measures all apparently similar in
nature, derived from similar sources. All the evidence obtainable
goes to show that these sources were granites or gneisses. There is
not any evidence of any sort to show that any other class of rocks
was concerned in supplying the sediment, and I am not aware that
any student of them, in the field or in the laboratory, has ever sug-
gested another origin for these beds, either wholly or partially.
A portion of these deposits, the clays, contains these vast numbers
of rutile-needles, I suggest that these are of secondary origin,
formed in situ, and I think they result from the decomposition of
biotite-mica, which can be seen to have formed so large an item in
the original sediment; because biotite when tested has been found
to contain titanic acid, and because it has been observed, under some
conditions, to give rise to rutile during its decomposition.
DECADE III.—VOL, VIII.—NO. VII. 20
306 C. Davison—British EKarthquakes of 1889.
The needles of the fireclays may, however, be secondary and yet
not be derived wholly or even in part from the biotite. Some other
mineral, sphene for instance, may have been the parent, though, as
intimated in my paper, it does not seem s0 likely.
If the rutile is not secondary, it must have been brought in with
the original sediment. I consider it may be looked on as shown
that it was not contained as such in the original mica. Whence
did it come? Can anybody point to granites or gneisses containing
rutile-needles in the abundance required for these extensive deposits,
and containing them, moreover, not in the mica, the usual way in
which they do occur when seen at all? If, in spite of all the
evidence on this head, it is assumed that some other rock and not
granite or gneiss was the source of these deposits, then what rock
can be suggested which supplied the rutile and the mica? And if
it be supposed that this other rock supplied only a part of the total
materials, but all the rutile, then it would be still more interesting
to have that rock named. It is easy to say the needles came from
elsewhere ; but where did they come from ? ‘
The subject of the origin of the minerals in these special clays, etc.,
is of much interest, because it may throw light on the genesis of
slates and phyllites, a question which has given rise to much
speculation and discussion and received great attention from some
of the leaders in petrological work. It is a somewhat difficult
subject to deal with, and I would be the last to think that my own
suppositions and theories are in any way proved to be more than
attempts at an explanation. I only venture to hope that they are
not quite out of harmony with the other evidence, which seems
so strong, as to the original nature of the deposits; and to think
that if they are disputed, if the secondary nature of the rutile is
denied, some other definite source for it should be suggested, which
should at the same time harmonize with the other facts of the case.
NEwcastLe-on-Tynz, June, 1891.
VII.—On tue British HartaeuaKkss or 1889.1
By Cuartzs Davison, M.A.,
Mathematical Master at King Edward’s High School, Birmingham.
(Continued from page 67.)
2. Lancasuire Earruquake: Fes. 10, 1889.
Time of occurrence, 22h. 86m.: Intensity, VI. Hpicentrum about
two miles N.N.K. of Bolton, half a mile west of the village of
Bradshaw.
This interesting earthquake affected a district for the most part
thickly populated, and the accounts of it are consequently numerous.
In the newspapers mentioned below, records are given of observations
from 156 towns and villages, situated within a nearly circular area
about 55 miles in diameter. Considering the smallness of this area,
1 The Map will appear with Part III. in the August Number Gzon. Mac.
—Eprr. Gzou. Mac.
C. Davison—British Earthquakes of 1889. 307
I suppose that but few previous earthquakes have afforded materials
so abundant for the seismologist.
Accessory Shock.—It is probable that at least one slight accessory
shock occurred between ten and twenty minutes after the principal
shock. Near Blackburn, where the intensity was V., an observer
residing at Wilpshire “noticed a slight recurrence of the phenomenon
some time afterwards—about twenty minutes.” At Prestwich, the
intensity was about, or perhaps more than, IV., and there ‘“ another
but feebler shock took place—perhaps some ten minutes afterwards.”
The evidence is clearly incomplete, but it seems most probable that
both accounts refer to the same shock, which, owing to its very
slight intensity, escaped detection elsewhere.
Disturbed Area.—As in the previous earthquake, the places where
the principal shock was undoubtedly felt are indicated by small
discs, and those where there is good reason for believing that it was
not felt by small crosses (x). For the former, I have relied almost
entirely on the numerous accounts given in the local press; for the
latter, on inquiries made in the district with the view of determining
the exact form of the disturbed area. In the immediate neigh-
bourhood of the boundary, the evidence is somewhat scanty, and
especially is this the case near Glossop and in the Peak country.
Having, as will be seen, no positive evidence from the latter district,
the outline in this part cannot be regarded as very exact.
So far as we can judge from the materials collected, the outline of
the disturbed area seems to be approximately circular. It will be
seen, from the table of intensities given below, that the boundary
corresponds to an isoseismal line of intensity less than IV. and
greater than III. Outside this area, it is possible that the shock
may have been felt, and probable that it would have been detected
by any one accustomed to the observation of slight earthquakes. But
that it could have been felt as far as Birmingham, as one observer
states, is clearly impossible, first, on account of its distance from
the rest of the disturbed area, and, secondly, because it was not
registered by one of Prof. Hwing’s delicate seismographs erected
there in my cellar.
The disturbed area, thus defined, is 56 miles from north to south,
and 54 miles from east to west; and includes an area of about
2480 square miles.
Time of Occurrence.—The records of the time of occurrence can,
unfortunately, lay claim to no great accuracy. So far as I know,
the earthquake was registered by no instrument of precision. Hx-
cluding, however, all estimates that are admittedly approximate, we
have the following definite records. In the immediate neighbour-
hood of the epicentrum, where the intensity was not less than VLI.,
it was noticed at Bolton at 22h. 35m.; at Turton, at 22h. 364m.
by one account, and 22h. 37m. by another. Outside this range
and within the isoseismal of intensity V., we have the records of
22h. 35m. at Farnworth, of 22h. 387m. at Accrington, of 22h. 88m.
at Rochdale, Heywood, Bury, and Prestwich; of 22h. 40m. at
Tyldesley and Wigan; and, lastly, of 22h. 254m., clearly wrong if
308 C. Davison—British Earthquakes of 1889.
it refer to the same shock, at Radcliffe. Between this last isoseismal
and the boundary of the disturbed area, the following times are
given: 22h. 32m, at Rusholme, 22h. 87m. at Greenhalgh, Preston
and Meltham; 22h. 43m. at Marbury (near Northwich), and
22h. 45m. at Waterhead and Heaton Chapel.
From this evidence, I have indicated 22h. 36m. as the probable
time of occurrence at the epicentrum. If the average surface-
velocity of the earth-wave were 1200 feet per second, the shock
could be felt at the limits of the disturbed area about two minutes
later. But the records in all parts of the area are too discordant to
lead to results of any value.
Nature of the Shock.—The descriptions I possess of the nature of
the shock are, with one exception, derived entirely from newspapers,
and cannot always be closely trusted. Asa rule, they are too vague
and inexact to justify detailed quotation. There can be no doubt,
however, that the character of the shock, especially with regard to
the number of vibrations felt, was subject to considerable variation
throughout the disturbed area; but this we should be led to expect
from Prof. Milne’s seismic survey of an area of about nine acres in
Tokio.’ In the present case, it is possible that these variations may
in part be attributable to the form and position of the seismic focus.
From a very large number of accounts, I select the following as
fairly typical of the different effects observed :—
Bolton: a distinct heavy rumbling for a few seconds, and, mingled
with it, a sharp thud like an explosion.
Bury: a rumbling noise, lasting about four seconds, and then a
sort of heavy thud, as of some enormous weight dropping on the
floor, causing an alarming vibration and a rattling of window-
frames.
Prestwich: a shock as of a heavy falling body, which caused the
windows to rattle loudly ; two or three seconds later, a second thud-
like shock of somewhat greater intensity than the first; followed
by gentle, but distinct tremors, lasting, perhaps, twenty or thirty
seconds more.
Chorley : a noise like the rumbling of heavy waggons on a stone
pavement was suddenly heard, and, along with it, a few sharp thuds
were felt, accompanied by a vibratory motion of the earth.
Bowdon: a sudden jar was felt, like that produced by a heavy
body falling, or by the slamming of a heavy door; then the floor
vibrated three times distinctly ; and this was followed after a few
seconds by another slight vibration, a double one.
Bolton and Bury, it will be seen, are close to the epicentrum of
the earthquake, and, at both these places, a single thud, or prominent
vibration, was felt. It follows, then, that the double or multiple
vibrations observed in other parts of the district cannot have been
due to a recurrence of the shock near the same spot as the first; and
it seems almost impossible to suppose that they were produced by
repetitions of the initial disturbance in different parts of the area.
We must conclude, therefore, that the nature of the shock varied
1 Japan Seism. Soc. Trans. vol. x. pp. 1-36.
O. Davison—British Earthquakes of 1889. 309
with the position of the piace of observation relatively to that of
the seismic focus, or with the geological structure of the surrounding
country.
Now, a single vibration was felt at: (a) Blackburn, Bury,
Meltham ; (b) Bolton, Heywood, Ramsbottom, Wigan; a double
vibration at: (a) Longridge, Prestwich, Rhodes; (b) Burnley,
Leigh, Marbury, Nelson ; three or more vibrations at: (a) Chorley,
Failsworth, Hollinwood, Middleton, Stretford, Whitefield; and, lastly,
a tremulous or continuous vibration at: (a) Bowdon, Crompton,
Darwen, Manchester, Preston; (b) Leftwich, St. Helens, Tottington.
The direction of the Irwell fault in the neighbourhood of the
epicentrum is approximately N.W. and 8.E., and, if lines be drawn
through the epicentrum from north to south and east to west, they
will divide the disturbed area into four quarters, so that places on
the N.W. and S.E. quarters are more nearly in a line with the
Trwell fault than places in the N.E. and §.W. quarters. Places in
the former pair of quarters are preceded by the letter (a) in the
above list, and places in the latter pair by the letter (b). The results
may thus be summarized :—
a. d. Total.
ime Obyibrablomyelst) mcs) | seat sce cds) (ON mess) Art een © at
Double or multiple vibrations ... ... 14 ... 7 ... 21
In the majority of cases, then, double or multiple vibrations were
felt at places nearly in a line with the Irwell fault at Bolton; and
a single vibration at places whose directions relatively to the
epicentrum are nearly at right angles to this direction.
On the vertical component of the motion, very few observations
‘seem to have been made. The movement is described as an up-
heaval simply, at Chorley, Eccles, Farnworth, Nelson, Oldham,
and Wigan; but it is not stated whether the upheaval was followed
or preceded by a lowering, or even whether it was accompanied
by any such movement in a contrary direction at all. These places
are not confined to any particular part of the disturbed area. On
the other hand, at the following places, there was first a rise,
followed by a lowering of the ground.
Ramsbottom: persons felt as though they had been bodily lifted
up and dropped quickly.
Heywood: the sensation was that of a sudden lifting of the
dwelling and of as sudden a sinking.
Bury : persons in bed felt as if their beds were raised for a brief
time and then allowed to fall.
Prestwich: a jerk up and down, followed by a trembling
movement.
These four places, it is important to notice, lie on the north-east
side of the Irwell fault, and at only a few miles distance from its
intersection with the surface.
Duration.—If, as I believe, the earthquake was due to a slip of
the Irwell fault in the neighbourhood of Bolton, and if that slip
was confined, not to a point, but to a definite area, we should expect
the duration of the shock, as well as its nature, to vary throughout
the disturbed area. The duration should of course be greatest at
310 C. Davivon—British Earthquakes of 1889.
places in the line of direction of the fault, and shortest at that
place situated so that a line joining it to the centre of the seismic
focus is perpendicular to the fault-plane. On the other hand, the
apparent duration depends on the distance of the place of obser-
vation from the focus, and, what is far more important, it depends
on the power of the observer to detect the faint initial and final
tremors. On this account, chiefly, I think it is not possible to
discover any certain law in the distribution of places according to
the duration of the shock felt there. In this respect, more may
be learnt from the duration of the sounds.
The following are the recorded durations of the shock :—
About 15 seconds. Farnworth.
53 6 i Blackburn, Bolton.
90 5 35 Crosby, Heaton Chapel, Melling.
3 4 53 Chorley.
a 3 As Prestwich.
2
5 Bacup, Cheetham Hill, Crumpsall, Darwen, Meltham,
Preston, Waterhead, Whalley.
"a 1 Leftwich, Oldham, Tyldesley.
Intensity.—In the following lists are given the names of the places
where it was possible to determine the intensity according to the
Rossi-Forel scale.
VI. Bolton, Ramsbottom, Tottington.
VY. or VI. Bury, Chesham, Farnworth.
V. Besses, Blackburn, Chorley, Darwen, Golborne, Heywood,
Horwich, Hulton Park, Ince, Rochdale, Turton, Whitefield, Wigan.
IV. or V. Blackley, Castleton, Cheetham Hill, Crumpsall, Har-
purhey, Littleborough, Middleton, Prestwich.
TV. Accrington, Altrincham, Bolton-by-Bowland, Bowdon, Breight-
met, Cheetham, Eccles, Facit, Heaton Park, Lees, Leigh, Leyland,
Little Hulton, Manchester, Milnrow, Newhey, Northwich, Whit-
worth, Withington.
III. or IV. Crosby, Melling, Preston, Whalley.
III. Meltham, Stockport, Wardleworth.
The observations are not sufficiently numerous to enable the
isoseismal of intensity VI. to be drawn. All the places where the
intensity was V. lie, however, within a well-defined curve which is
shown upon the map. This curve is approximately circular. Its
dimensions are 22 miles from north to south, and 23 miles from east
to west. It includes an area of about 396 square miles. Its centre
is half a mile west of the village of Bradshaw and two miles N.N.E.
of Bolton.
It will be noticed that, at several places within this curve, the
intensity is given as only IV. This may be due to one of two
causes. (1) The intensity may really have been more than IV.,
but the rattling of windows, etc., may have been recorded as the
most noticeable effect of the shock; or (2) the intensity may have
been different at two neighbouring places within this isoseismal,
this being only what we should be led to infer from Prof. Milne’s
seismic survey of Tokio.
Outside this isoseismal, the places where the intensity is known,
though numerous, are scattered over a much greater area, and it is
”
CO. Davison—British Earthquakes of 1889. dll
not possible to draw with any accuracy the isoseismal of intensity
IV. As some of these places are not very distant from the line
which I have indicated on the map as the boundary of the disturbed
area, we may conclude that that boundary represents an isoseismal
of intensity less than IV., but yet greater than III. This area, as
before remarked, is nearly circular, and it is almost exactly
concentric with the isoseismal of intensity V.
Sound-Phenomena.—Records of sound-phenomena come from 49
out of the 156 places where the shock is known to have been felt.
These places are indicated as before by small crosses (+) drawn
through the spots representing them. .
Referring to the map, it will be seen that, with four exceptions,
all the places where sounds are said to have been heard lie within
an area which is approximately circular. It is of course possible
that, outside this area, the sounds might have been heard by
observers who were listening attentively or who happened to be
more sensitive to such vibrations. This may have been the case
in the four exceptions just referred to, but it should be noted that,
at each of these places, we have only one record of sound-phe-
nomena, while at all the other places there are either several
independent accounts, or else the description is so clear as to be
quite free from doubt. ‘The following are the accounts from these
four places :—
Bolton-by-Bowland: a rumbling noise.
Longridge: a noise as of a sough of wind.
Greenhalgh: an underneath rushing rumbling noise.
Marbury: a dull rumbling noise.
Whilst, then, the characteristic earthquake-sounds may have been
heard outside the curve marked (by a dotted line) upon the map,
I believe that that curve includes all the places where the sounds
were distinctly and certainly heard.
Assuming this to be the case, two facts are at once evident from
an inspection of the map. .
(1) The sounds were not heard so far as the vibrations of longer
period were felt. They were confined to a nearly circular district,
29 miles in diameter, and about 686 square miles in area.
(2) The sound-curve is not concentric with the two isoseismal
curves drawn upon the map. At its northern limit, it nearly
touches the isoseismal of intensity V.; but, at the other end, it
passes about six miles to the south-west of this line. Its centre is
about 34+ miles $.S.H. of the epicentrum; but this determination
cannot be regarded as so accurate as in the case of the Edinburgh
earthquake, for it is not checked by a knowledge of places where
the sound was certainly not heard.
This second conclusion—the excentricity of the sound-area—is
also borne out by the following table. The earthquake-sounds are
recorded as having been heard :—
Within the isoseismal of intensity V. at 33 out of 72 places, or in 46 p.c. of the whole.
Between this isoseismal and the sound-
@URVE Bb cot! eco 'b90' G00" 806 WE 2G)
Between the sound-curve and the
boundary of the disturbed areaat 4 ,, 41 5 10 ”
” 48 »
312 C. Davison—British Earthquakes of 1889.
Throughout the area in which they were heard, the sounds varied
greatly both in nature and duration; and, in most cases, the variation
seemed to have depended on the position of the place of observation.
The exact duration is not often explicitly stated. It is given at about
four seconds at Bury, four or five seconds at Chorley, about two
seconds at Bacup, several seconds at Altrincham, and a few seconds
at Bolton and Middleton. Something may, however, be inferred
from the numerous accounts that have been given of the phenomena.
The following descriptions seem to indicate that the sound was
more or less sudden and transitory :
(a) Cheetham: as of a heavy body falling in the street.
Darwen: (1) closely resembling that made by a door being
violently shut; (2) like the fall of a signal-post.
(b) Accrington: like the thud caused when snow falls from the roof.
St. Helens: a rumble as of a heavy thud on the gable end of
the house.
Tyldesley : as if some heavy weight had fallen in the room
below.
In the next group, the sounds were apparently more prolonged :
(a) Chorley: like the rumbling of heavy waggons on stone
pavement.
Eccles: there was a noise as of very heavy snow sliding
down the roof, and as it passed the 8.8.W. corner there was
a sound as if many tons of snow had fallen on the ground.
Heaton Chapel: resembling a vehicle in the street.
Leyland: such that a cabman thought his horse had run away.
Lower Broughton: like the suppressed roaring of wind
entering a gorge.
Manchester : a rustling noise as of wind playing among loose
paper.
Moston: a noise attributed to a colliery explosion.
Prestwich : like a heavy but distinct roll of thunder.
Sough: resembling that of a horse which had got loose in
its stall.
(b) Bacup: like that of a road-engine.
Hulton Park: as if a carriage were driving up to the door.
Leigh: as of heavy waggons rolling rapidly along the street.
Orrell Post: like that of a heavy conveyance passing in the
heavy snow which had fallen during the day. .
Now, in both lists, all places preceded by the letter (a) are situated —
in the N.W. and S.E. quarters formed by drawing lines from north
to south and east to west through the epicentrum; and those
preceded by the letter (6) are in the N.H. and S.W. quarters.
These results are summarized in the following table :
a. 6. Total.
Sounds of short duration at ... 2 ... 3 ... 45 places.
Sounds of long durationat ... 9 ... 4 ... 13 ,,
We may conclude, then, that, on the whole, the duration of the
sound was greater at places near the line of the Irwell fault than
at places more remote from it.
C. Davison—British Earthquakes of 1889. 313
Miscellaneous phenomena.—As it is somewhat unusual for earth-
quakes to be felt strongly, if at all, in pits and excavations, it is
worth mentioning that the Lancashire earthquake was noticed in
mines in several instances. In one of the collieries in the Ince
district, near Wigan, the shock was felt so distinctly by a party of
men, that a careful inspection was made by them to see if any
accident had happened. In the Pendlebury Colliery, “at about
10.30 p.m. the colliers on No. 9, Hast side, Rams Mine, came out of
their working places to the engine-house and reported to the fireman
that they had heard a rumbling noise in the roof of the working
places.” At Agecroft Colliery, “only one man noticed anything.
He was in No. 2 pit, and when he heard the sound he went out to
the pony road to see if it had been caused by a fall of dirt.” *
Stonyhurst Observatory is about 19 miles north of Bolton, out-
side the isoseismal of intensity V., but still some miles within the
boundary of the disturbed area. As it seemed possible that the
magnetic instruments might have been affected by the earthquake,
I wrote to the late Father Perry on the subject. The letter arrived
during his last absence from England; and, after his death, Mr.
W. C. Cameron was good enough to inform me that no trace of the
earthquake was shown by the magnetic curve of February 10. This
result is curious, considering that, shortly after several recent earth-
quakes, magnetic instruments in distant observatories, far beyond the
range of the sensible shock, have been perceptibly affected. The
cause of these disturbances is not certainly known, but is probably
due to the mechanical action of the shock, the masses of the two arms
of the instrument being made unequal, in order that it may rest
horizontally.? If this be the case, the absence of any noticeable
disturbance at Stonyhurst may have been due to the fact that the
line joining it to the epicentrum of the earthquake is so nearly in
the direction of the magnetic meridian.
Position of the Seismic Focus and Geological Relations.—The
faults of the Bolton district are, with a few ‘small exceptions,
arranged in two systems, one running N.N.W. and §.8.H., and the
other nearly E. and W. Prominent among the former series is
the great Irwell Valley fault. This important dislocation, which is
shown upon the map of the earthquake, has been traced for a
distance of more than twenty miles, from near Poynton in Cheshire
to about three miles north-west of Bolton. Throughout its whole
course the downthrow is towards the north-east. The amount of its
throw is considerable, being 1050 yards at Farnworth, about three
miles south-east of Bolton.’
Now, as we have seen, both isoseismal lines are approximately
circular and almost exactly concentric. The centre of the smaller
curve (intensity V.), which is the more accurately drawn, is about
two miles N.N.H. of Bolton, or half a mile west of Bradshaw; and
1 The last two accounts are quoted from a note read by Mr. J. Knowles before the
Manchester Geological Society on March 12, 1889.
2 Gzou. Mae. Dec. III. Vol. II. pp. 210-211.
3 EH. Hull, Geology of the Country round Bolton, Lancashire (Geol. Surv. Mem.).
co)
314 C. Davison—British Earthquakes of 1889.
we may take this point as indicating very nearly the position of the
epicentrum, which is therefore close to the intersection of the Irwell
fault with the surface, and on the downthrow side of it.
The centre of the sound-area, as drawn upon the map, lies, how-
ever, about 31 miles 8.S.W. of the epicentrum, and therefore to the
south-west of the line of the Irwell fault. But since, as before
remarked, there may be a slight error in this determination, and since
the minor faults of the district are excluded, by their position with
respect to the epicentrum, from any relation with the earthquake, I
think we may with some probability connect the origin of the earth-
quake with the Irwell fault.
There is, however, other evidence bearing on the point. -(1) It
has been shown that, as a general rule, in the neighbourhood of
the continuation of the Irwell fault near Bolton, the number of
vibrations was greater than elsewhere, and the sound-phenomena
were also more lasting; and this is what we should expect if the
seismic focus were a plane whose strike is N.W. and S.E. (2) The
maximum intensity was recorded at Tottington, about two miles
east of the epicentrum, and this, it will be seen, is not far from the
point where the perpendicular to the fault-plane through the centre
of the seismic focus meets the surface of the earth. Other conditions
being the same, it is evident that the intensity should be greatest
in the neighbourhood of this point.
The inclination of the Irwell fault near Bolton is 28° from the
vertical, according to the horizontal section (sheet 67) of the
Geological Survey, which is drawn across the fault. If this in-
clination be approximately constant to within a few miles from the
surface, it follows that the centre of the seismic focus must be at a
depth of about 3% miles.
Again, as in the case of the Edinburgh earthquake, the movement
at four places (Bury, Heywood, Prestwich, and Ramsbottom) on
the downthrow side of the fault, was upwards first and then down-
wards. There are no records of a contrary movement on the
upthrow side of the fault; but the evidence, so far as it goes, in-
dicates that the earthquake was probably caused by a slip which
slightly increased the throw of the fault.
Lastly, that the distance in a horizontal direction over which the
slip extended was very short, may be inferred: (1) from the
approximate circularity of the isoseismal lines, and (2) from the
short duration of the earthquake-shock and the accompanying sound-
phenomena. Since the duration is rarely mentioned as being more
than a few seconds, it is possible that this distance was not much
greater than a mile.
The whole evidence being taken together, the following conclu-
sions seem to me probable: (1) the Lancashire earthquake was
caused by a slip of the Irwell fault, a few miles from its north-
western extremity as traced upon the map: (2) the horizontal
length of the slip-area was short, possibly less than a mile: (3) the
slip resulted in an increase of the throw of the fault: and (4) the
slip must have extended upwards to within a short distance from, if
C. Davison— British Earthquakes of 1889. old
not quite up to, the surface, the amount of the slip near the surface
being of course extremely small.
Origin of the Sound-phenomena.—The observations on the sounds
that accompanied the Edinburgh and Lancashire earthquakes lead
to an important result, throwing light on the origin of these vibra-
tions and the part of the focus from which they proceed. I will.
now point out briefly what I believe to be the origin of these sounds,
reserving a more complete discussion of the question for a subsequent
paper in which other facts bearing on the problem may be con-
veniently brought together.
In both earthquakes, the shock and sound, we have reason to
believe, were caused by slipping along well-known faults, the foci
of the sounds being nearer the surface than the foci of the corre-
sponding shocks. In both, also, the area over which the slip took
place must have been very limited in extent: and, while the amount
of the slip may have been greatest near the centre of this area, it
must certainly have died away towards its upper and lateral margins.
Now, the seismographic records recently obtained by Prof. Milne
and others in Japan show that earthquakes usually begin with a
series of tremors very small in amplitude and very rapid in period,
from six to eight occurring every second, but becoming slower
before the shock takes place. These may last for many seconds or
even several minutes. Following, and continuous with, them come
the sensible vibrations, of larger amplitude and longer period, about
three to five occurring in every second. One or more of these,
attaining a still greater amplitude and longer period, of one or two
seconds each, constitute what are generally known as the principal
shock or shocks. The earthquake closes with vibrations of smaller
amplitude, but which have a period so long that no record of them
‘can be obtained. The earliest tremors, on the other hand, are not
registered on account of the smallness of their amplitude, and, in
all probability, as Prof. Milne suggests, the “minute movements
which have been recorded are the continuation of still smaller and
more rapid movements which .. . . have never yet been rendered
visible.” It is to these supposed rapid vibrations which form the
front portion of an advancing earthquake, that Prof. Milne attributes
the origin of the earthquake-sounds.._ We may conclude from these
observations that, initially at any rate, the period of the vibrations
increases and decreases with their amplitude.
Now, from different parts of the area over which a fault-slip takes
place, there must proceed vibrations differing greatly in amplitude,
and therefore also in period. From the central portions of the
slip-area will come, as a rule, the vibrations of largest amplitude
and longest period; while, from the margins there will proceed
minute vibrations of a period so short that they may be perceptible
onlyas sound. The position of the line separating the marginal and
central parts of the slip-area will depend only on the amplitude of
the vibrations corresponding to the period of the lowest sound that
1 Prof. J. Milne, Japan Seismol. Soc. Trans. vol. xii. (1888), pp. 53-62 and 107-8.
316 Notices of Memoirs—A. P. Brown—Young Baculites.
can be heard ; it will not at all depend on the amount of the slip at
the centre of the area, 7.e. it will be independent of the intensity of
the shock.
I shall endeavour to show, in a later paper, that this theory of
the origin of earthquake-sounds accounts satisfactorily for all their
phenomena, so far as they are known to us. For the present, it will
be sufficient to point out that it explains (1) the fact that the sound-
area is not concentric with the disturbed area, and the sound-focus
is nearer the surface than the rest of the seismic focus; and (2) the
fact that, in great earthquakes, the sounds are only heard within a
comparatively small area immediately surrounding the epicentrum.
Authorities. —“ Accrington Gazette,” Feb. 16; ‘Accrington Times,”
Feb. 16; “Altrincham Division Advertiser,” Feb. 15; “ Blackpool
Times,” Feb. 18; ‘‘ Bolton Chronicle,” Feb. 16; ‘‘ Bradford Observer
Budget,” Feb. 16; “Burnley Express,” Feb. 16; ‘‘Bury Guardian,”
Feb. 16; “Chorley Standard,” Feb. 16; “Craven Herald” (Skipton),
Feb. 16; “ Darwen Post,” Feb. 16; ‘Halifax Courier,” Feb. 16;
“« Heywood Advertiser,” Feb. 15; ‘ Huddersfield Chronicle,”
Feb. 16; ‘Lancaster Guardian,” Feb. 16; “Leeds Mercury,”
Feb. 12; ‘Leigh Chronicle,” Feb. 15; “Liverpool Mercury,”
Feb. 12; “Macclesfield Chronicle,” Feb. 15; “Macclesfield Courier,”
Feb. 16; ‘Manchester Hxaminer,” Feb. 12; ‘‘ Manchester Guar-
dian,” Feb. 12, 18; ‘Middleton Guardian,” Feb. 16; “ Northwich
and Knutsford Chronicle,” Feb. 16; ‘Oldham Standard,” Feb. 16 ;
«“ Preston Guardian,” Feb. 16; ‘Rochdale Observer,” Feb. 13, 16;
“¢ Wigan Observer,” Feb. 13.
Nature, vol. 39, p. 376; T. R. H. Clunn, The earthquake in Lan-
cashire, Nature, vol. 39, p. 390; J. Knowles, The earthquake shock
of February 10th, 1889, Manchester Geol. Soc. Trams., vol. xx.
pp. 165-157.
For other information I am indebted to the kindness of the fol-
lowing gentlemen: the Secretaries of the Geological Societies of
Liverpool and Manchester, Mr. W. C. Carlisle (Stonyhurst Obser-
vatory), Mr. B. Hainsworth (Rossall), Mr. G. Hartnup (Liverpool
Observatory, Bidstow) Prof. E. Hull, F.R.S., and Mr. Isaac Roberts,
F.R.S. (Maghull).
(Zo be continued.)
NOTCH S (Ox) Wer rVE@iak Se
On tHE Youne or Bacuzires coupressus, Say. By Amos P. Brown.
(Proc. Acad. Nat. Sci. Philadelphia.)
T the meeting of the Academy of Natural Sciences of Phila-
delphia on March 10th, Mr. Amos P. Brown described the
young of Baculites compressus, Say, recently discovered by him in
some Cretaceous marl from the vicinity of Deadwood, South Dakota.
Associated with them in the same material were several species of
Baculites, Scaphites, and Inoceramus. The young Baculites varied
in length from 1 to 3 cm., with a diameter of 0-4 to 2 mm.
Reviews—Prof. H. F. Osborn—WMolars of Perissodactyla. 317
The shell originates in a spiral consisting of from two to two and
one-half slightly overlapping whorls, and ranging in diameter from
0-8 to 1 mm.; thence it extends in a straight line, tangent to the
spiral, or sometimes slightly reflexed. The straight portion of the
shell rapidly increases in diameter from 0:38 to 0°40 mm. at the
spiral, to about 1:5 to 2 mm. at 2 cm. length. Some of the
specimens were entire, and showed that the body-chamber occupied
about one-half the length of the shell. The siphuncle is eccentric,
and was found to lie near the outer margin of the spiral.
The species was determined from an examination of the suture-
line which was traced from the simple form of the very young shell,
through forms of gradually increasing complexity, up to the typical
suture of the adult of Baculites compressus, Say.
That this spiral portion should have hitherto escaped observation
can be easily accounted for by its small size and fragile character.
Tn all probability it was broken off long before the shell had attained
adult size, and is therefore to be met with only in shells which were
preserved in their immature condition.
The description is given in the Proceedings of the Academy, 1891,
part i. pp. 159-160, and is accompanied by figures of the young
Baculites, and of a series of their suture-lines showing the gradual
development from a comparatively simple form to the typical suture
of the adult of Baculites compressus, Say.
SEW oe Wh 25 dH Wwe tSe
——>__—__
J.—Proressor Osporn on THE Monars OF THE PERISSODACTYLA.
ANY of our readers are probably acquainted more or less fully
with Professor H. F. Osborn’s elaborate and interesting
researches into the nature of the primitive plan on which the
molar teeth of mammals are constructed, summaries of which have
appeared from time to time in several English scientific journals.
The result of these researches was to show that this primitive type
of tooth was of the so-called ‘tritubercular’ form. It may not be
out of place to remind our readers that such a tritubercular tooth in
the upper jaw is composed of an inner tubercle, or protocone, and
of two outer tubercles respectively designated paracone and metacone.
By the addition of a second inner tubercle—the hypocone—and of
‘two intermediate ones, known as the protoconule and metaconule,
such a tritubercular molar becomes converted into the sextubercular
one occurring in many Ungulates.
Professor Osborn has recently been engaged in investigating how
the more complex molars of the specialized Perissodactyles have
been evolved from this sextubercular type; the results of this
investigation being published in a memoir issued under the auspices
of the Museum of Harvard College.’ Since these results are of con-
siderable morphological importance, and are especially interesting
to paleontologists, a short resumé of them may be acceptable to our
1 Bull. Mus. Comp. Zool. Harvard Coll. vol. xx. pp. 87, e¢ seg. (1890).
318 Reviews—Prof. H. F. Osborn—Wolars of Perissodactyla.
readers. For this purpose Prof. Osborn has been good enough to
place at our disposal clichés of some of the figures illustrating his
memoir; which figures, with some of our own, we reproduce.
It may be well to premise our observations by stating that the
upper molars of the Perissodactyles are constructed on what is
known as the lophodonét type; this modification consisting of an
outer wall, connected with two more or less nearly complete trans-
verse crests inclining backwards. The simplest modification of this
type of molar is to be found in the little Hyracotherium of the
Fig. 1.—Left upper premolar and molar teeth of Anchitheriwm (Mesohippus) bairdi.
pr. protocone; pp. posterior prominence.
London Clay ; but those of the generalized Horse-like animal known
as Anchitherium (including Mesohippus) are but little more advanced.
Of this genus we reproduce two of Prof. Osborn’s figures; one
(Fig. 1) showing the whole series of cheek-teeth, and the other
(Fig. 2) a single molar. One species (Fig. 1) is a smaller and simpler
form, in which the tubercle marked pp is less developed than in
the larger species (Fig. 2). In these teeth there is no difficulty in
recognizing the six elements of the sex-
PW mE tubercular tooth, all of which are indicated
ae by letters in Fig. 2, with the exception of
the metaconule, which is the unlettered
\ ridge occupying the middle of the tooth,
pl-% immediately below the m. ‘The four
DSi pfo remaining elements, lettered a. m. p. and
pr We pp-, have been developed from the basal
Si, iy hy cingulum surrounding the molar of Hyra-
. cotherium; and, accordingly, have nothing
whatever to do with the primitive foldings
of the crown. ‘This origin is very im-
portant with regard to the tubercle marked.
pp. Thus in Fig. 2 this is so strongly
marked as to suggest an origin like the
other main tubercles; but its commence-
ment as a slight swelling of the cingulum
outer aspects of a lett upper isyiclearly Saar in ie ee
molar of Anchitherium longi. @lements respectively marked a. m. and
criste. pr. protocone; pa. pp., Professor Osborn applies the terms
paracone ; me. metacone; dy. anterior pillar, median pillar, and posterior
Bec CN pillar ; stating that the latter term is taken
ridge; p. posterior ridge; from the writer of this notice, by whom it
pp. posterior prominence. is said to have been proposed for the teeth
Fie. 2.— Grinding and
Reviews—Prof. H. F. Osborn—Wolars of Perissodactyla, 319
of the Horses. ‘T'o this statement we must take the present oppor-
tunity of objecting. The term posterior pillar (although it has been
' t . H
hy. ml. pr. pl.
Fic. 3.—Three right upper cheek-teeth of Hipparion. ml. metaconule ;
letters as in Fig. 2.
subsequently employed by the writer) was first proposed by Prof.
Huxley (‘Anatomy of Vertebrates,” p. 854, 1871), and was applied
to the tubercle in the molars of the Horses marked hy. in Figs. 3 and 4
(these figures are unfortunately from the opposite side of the jaw to
those figured by Prof. Osborn). This tubercle corresponds with the
one similarly lettered in Fig. 2 (the hypocone) ;
and has, therefore, nothing whatever to do
with the one marked pp. Under these circum-
stances we propose to substitute the term
posterior prominence for the tubercle pp. Again,
the term anterior pillar was proposed by Prof.
Huxley, and adopted by the writer for the
tubercle marked pr. (the protocone) in Figs.
2,3; and it is, therefore, quite inadmissible
to apply it to a. in Fig. 2. Under these
ERE Wich tapes circumstances we would suggest that the
molar of Equus stenonis; Vertical ridges marked a. m. and _p. in Fig. 2
letters as in Fig. 3. (which become still more prominent in the
teeth of the Horses), should respectively be
designated the anterior ridge, middle ridge, and posterior ridge.
The figures sufficiently indicate how the equine molar has been
evolved from that of Anchitherium by the development of one pro-
jection from the protoconule to join the metaconule, and of another
from the latter connecting it with the posterior prominence, and
thus with the metacone; the lengthening of the crown and the
filling of the valleys with cement being a concomitant process.
The result of this evolution has been to form complete crescents
in the equine molar, of which the hinder one is always connected
with the hypocone (hy.); while the anterior one may either be
connected with the protocone (pr.), as in Equus, or completely
isolated, as in Hipparion. This has also entailed the division of
the median and posterior valleys of the Anchitherium molar into an
inner and an outer moiety.
The remaining type of Perissodactyle molar we have to notice
is that of the Rhinoceroses (Fig. 5). Here Prof. Osborn has intro-
820 Reviews—Prof. H. F. Osborn—WMolars of Perissodactyla.
duced three convenient new descriptive terms, which will be equally
applicable to the molars of other Perissiodactyles. It appears that
the outer wall of the Rhinoceros molar is formed by the union of
the primitive paracone (pa.) with the metacone (me.), to which is
added the anterior ridge (a.); and for this outer wall the term
ectoloph is suggested. ‘The anterior transverse crest, formed by the
union of the paracone (pa.), protoconule (pl.), and protocone (pr.)
is termed the protoloph; while for the posterior transverse crest, _
compounded of the metacone (me.), metaconule, and hypocone (hy.)
we have the name metaloph.
pl.
rem
fs
. h
i A
pr. hy
Fic. 5.—Left upper molar of Rhinoceros paleindicus. Letters as in Fig. 2.
a. to me. is the ectoloph; a. to pr. the protoloph; and me. to hy. the
metaloph. The process projecting from the metaloph into the median
valley is the crotchet.
In the primitive Rhinoceros molar the three elements—anterior
ridge, paracone, and metacone—of the ectoloph are represented by
distinct vertical ridges; but some or all of these tend to disappear
with the increasing flatness of the outer surface of this part of the
tooth as specialization increases. And it is somewhat noteworthy
that while in the most specialized types of teeth, like those of the
Indian Rhinoceros, of the two African species, and of the extinct
Woolly Rhinoceros, the development of the paracone is less marked
than in the more generalized Sumatran and Javan species; yet the
ridge marking the metacone is decidedly more pronounced. Although
there is no distinct representative in the Rhinoceros molar of the
Reviews— Geological Survey of Iilinois. O21
median ridge (Fig. 2, m.) of the equine tooth, yet we think that
this is foreshadowed in the former by the flexure which often
occurs in the ectoloph between the para- and meta-cones.
In referring to the secondary enamel-folds which grow from the
three compound elements of the Rhinoceros molar into the median
valley (the large fissure penetrating Fig. 5 from the inner side), it
is to be regretted that Prof. Osborn has. again displayed some care-
lessness in quoting previous work. Thus he states, ‘‘These secondary
elements consist, first, of three folds projecting into the median
valley, one from the ectoloph, the crista; one from the protoloph,
the crochet; one from the metaloph, the anticrochet;” his figures
being lettered accordingly. Now the fact really is that it is the
crotchet (as we prefer to spell the word) which projects from the
metaloph, as shown in Fig. 5, while the anticrotchet, when present,
is carried by the protoloph. The crotchet corresponds, in fact, pre-
cisely in position with the projection arising from the protoconule
of the protoloph of the equine molar (Figs. 3, 4) ; and when reaching
across to the metaloph divides the median valley into an inner and
outer moiety precisely after the equine manner; the only difference
being that while in the Rhinoceros the two divisions of the valley
remain open, in the Horse they are completely filled with cement.
(In Fig. 3 the cement filling the ‘island’ formed by the outer part
of the median valley is drawn white, while that in the outer part
of the same—between pr. and ml.—is made dark and crossed by
vertical lines; this difference is owing to the staining of the fossil,
but in a recent Horse’s both would be pale buff.)
In conclusion, it may be observed that, while it may be convenient
in monographs to retain for the description of the molars of the
various families of the Perissodactyla the terms commonly in use,
yet the importance and interest of being able to trace the precise
morphological equivalents of the elements of all these teeth, not
only to one another, but also to the primitive type of mammalian
tooth-structure, can scarcely be overrated. To a certain degree as
regards the former part of this task, and altogether as regards the
latter part, zoologists and paleontologists are indebted to the labours
of Prof. Osborn. R. LyprekKer.
I].—Geotocican Survey oF Inuinois, A. H. Worrnen, Director.
Volume VIII. Grotocy anp Panmwontotoey. Edited by Josua
Linpaut, Ph.D., State Geologist. Geology, by A. H. WorTuEn.
Palgontology, by A. H. Wortuen, Coartes WacusmutH, FRANK
Sprincer, HE. O. Utricu and Oxtver Everirr. With an Ap-
pendix (Biography, Bibliography and General Index to Volumes
I-VIII.). Text. Published by authority of the Legislature of
Iilinois, July, 1890. 8vo. pp. xiii. 758 and 151, 1 Portrait,
1 Map. Plates .—LXXVIII. and Explanations, bound in a
separate volume.
ITH this massive volume and the Plates accompanying it,
the series of Reports on the Geology and Palecontolozy of
Illinois, which have appeared at various intervals since 1866, is
DECADE III,—VOL. VIIIL—NO. VII. 21
322 Reviews— Geological Survey of Illinois.
finally closed. These Reports, second only in importance to those
of the State of New York, have very materially contributed to the
advancement of Geological Science on the North American Continent,
and they serve as a permanent memorial in honour of Prof. A. H.
Worthen, the State Geologist, by whom they have all, with the
exception of the closing volume, been edited. To a great extent
the present volume was also prepared under his superintendence,
but death removed him from his labours, whilst the work was going
through the press. The final editing was completed by Dr. J.
Lindahl, the successor of Prof. Worthen on the State Survey, and it
is very appropriate that a sketch of the life and scientific work of
the late Director should have been included in the contents of the
final volume. Dr. Lindahl has further contributed a General Index
to the entire series, which will prove of considerable assistance to
all paleontologists and others who may require to refer to it.
The present volume commences with a chapter on the Drift
Deposits of Illinois by Prof. Worthen. From this it appears that
they vary in thickness from 10 to 350 feet, and they often extend
below the present drainage level of the streams and rivers. The
Drift materials are thickest in the central portions of Illinois, they
thin out to the south of the State, and, with the exception of the
Loess, they all disappear before reaching the Ohio River. The
lowest beds consist of stratified sands and clays filling up pre-
glacial valleys, over these a layer, 2 to 18 feet thick, of peaty soil
filled with plant remains, is usually present. This old soil is covered
by Boulder-clays, from 20 to 100 feet in thickness, and these again
are partially covered by modified drift and loess containing the
bones of Mastodon, Mammoth, Bos, Castoroides, etc. In some
places there appears to be a deposit of Boulder-clay material beneath
the peaty soil as well as overlying it. The preservation of this
soft peaty soil leads Prof. Worthen to the conclusion that the
Boulder-clay must have been produced by floating ice rather than
by glaciers.
In a second chapter the same author gives the results of numerous
borings for coal and in search of natural gas and oil, but though
some of the borings have been carried to a depth of over 2500 feet,
penetrating nearly to the base of the stratified rocks in the region,
no economical results as regards gas and oil have been obtained.
The second part of the volume is devoted to Palzontology, and
the first section contains descriptions of fossil Invertebrates by
A. H. Worthen. Numerous species of Corals, Crinoids, Molluscs, ete.,
for the most part from different divisions of the sub-Carboniferous,
are treated, but they do not seem of special importance. The
discovery of a new species of Ascoceras, A. Southwelli, from the
Niagara Limestone, is of interest.
In section ii. Messrs. Wachsmuth and Springer describe new
species of Crinoids and Blastoids from the Lower Carboniferous of
Le Grand, Iowa, and from the Niagara Group of West Tennessee.
Not infrequently the stems of these Crinoids are preserved intact,
and in almost all cases they taper distally to a fine point and give
Reviews— Geological Survey of Illinois. 020
off rootlets or cirrhi in all directions, from which the authors
conclude that these and other Paleeocrinoids probably lived a semi-
free existence, like recent forms of Pentacrinus, either anchored by
the cirrhi to the soft oozy sea-bottom, or at intervals attached to
foreign bodies. The new species belong to the following genera:
Actinocrinus, Megistocrinus, Dorycrinus, Rhodocrinus, Platycrinus,
Dichocrinus, Graphiocrinus, Scaphiocrinus, and Taxocrinus. A speci-
men of a new Blastoid, Orophocrinus fusiformis, retains a portion of
the stem and also the pinnules.
In sections iii. iv. and v. Mr. E. O. Ulrich (in part nominally
associated with Mr. O. Everett) treats of American Palaeozoic Sponges.
The author’s study of this group of fossils is evidently limited and
imperfect, shown more particularly when he ventures to express
Opinions of his own as distinct from those procured from the
writings of and correspondence with experienced authorities. Thus,
for example, he believes that there are homological affinities between
some of the new Silurian lithistid sponges described and the
Stromatoporoid genus Actinostroma! It is generally acknowledged
that the correct determination of fossil sponges is beset with special
difficulties owing to mineral changes which they have undergone,
and those which Mr. Ulrich has attempted to describe are no
exceptions to the rule. This fact will, perhaps, account for the
extraordinary type of spicule which is figured as characteristic of
a proposed new family, the Aspidellide (p. 224, fig. 6), in which
four smooth simple rays are thrown off in pairs from the ends of
what is styled a profoundly elongated node or horizontal central bar!
Of Devonian and Carboniferous forms, the author describes four
new genera: Hystriospongia, a tetractinellid; Batospongia, either a
lithistid or a calcisponge ; Belemnospongia, a monactinellid, but which,
if correctly delineated as having acerate spicules connected by short
transverse processes, must be quite distinct from this sub-order, and
Syringelasma, a lithistid. At the lower horizon of the Trenton
limestone, at a single locality in Illinois, a considerable number of
fossil sponges have been obtained, which retain their outer forms
and canal structure, but their original siliceous skeletons have been
replaced by calcite. These sponges have been arranged in several
new genera, and placed as a distinct lithistid family of the Aspidellidz
on the ground that the form of their spicules differs from that of
any previously described sponge. From an examination of some
of these forms, we believe their spicular structure is closely similar
to that of Astylospongia and that they can be included in the
Anomocladina family. The two principal genera are Zittelella and
Anthaspidella, which apparently differ only in the fact that the
former is simple and the latter compound. The former genus,
moreover, seems to be synonymous with the previously described
Steliella,t Hinde, which has been overlooked by the author. Another
new genus, Hdriospongia, seems to be based on a portion of a
specimen of Aspidella. Strotospongia and Dystactospongia are
included with Calcisponges; but the former of these is almost
1 Canadian Record of Science, July, 1859, p. 395.
024 Reviews—A. H. Foord’s Catalogue of the Cephalopoda.
certainly siliceous ; the character of another new genus, Camarocladia,
is very indefinite.
A single Stromatoporoid is placed under Actinostroma ? Trentonense,
and its minute structure is stated to resemble that of the Aspidellid
sponges !
Section vi. treats of Paleozoic Bryozoa, by HE. O. Ulrich, and
forms by far the most important subject in the volume, occupying
403 pages of text and 49 quarto plates. On this group we can
readily recognize that the author is on safer ground than when
treating of fossil sponges, for he has thoroughly investigated the
microscopic structure of nearly all the American species, and
prepared nearly 4000 thin sections for this end. His descriptions
and figures furnish an immense addition to our knowledge of the
minute structural details of the various forms, and they afford
a very striking instance of the advantage to be gained by the
systematic microscopic study of all the forms in a single group of
organisms. A chapter is devoted to the general and comparative
structure of Paleozoic Bryozoa, and the views stated will be
generally accepted; some exceptions, however, might be taken to
the assertion that the acanthopores were all originally hollow,
though it is acknowledged that their summits generally appear
solid at the surface. Allied to the acanthopores are the so-called
median-tubules, and the hollow structure of these is equally doubtful.
As regards the classification of the Palaeozoic Bryozoa, Mr. Ulrich
adopts the plan of extreme division, and a great number of new
families and genera are introduced on grounds which appear quite
insufficient. It is very doubtful if either of the proposed suborders,
Trepostomata, Ulrich, and Cryptostomata, Vine, can be logically
established ; and numerous objections could be taken to many of the
family and generic divisions which have been made. That many of
the new genera appear to conflict seriously with those already
established is only what may be looked for in a work hailing from
the United States, and much of this apparent synonymy could
probably be avoided by a franker recognition of the characters of
the older types and a less hostile attitude towards the authors of
these. In spite of these drawbacks the work of Mr. Ulrich on the
American fossil Bryozoa merits the warm appreciation of all paleon-
tologists, and affords a safe basis for future students and systematists
to build upon. G. J. H.
I.—Caratocur or tHe Fosstn CrepHaLopopA IN THE BritisH
Mussum (Naturat History), Part II. conTaInInG THE RE-
MAINDER OF THE NavrinoipEA. By Arraur H. Foorp, F.G.S.
(London, 1891.) Printed by order of the Trustees, and sold by
Kegan Paul, Trench, Triibner & Co. 8vo. pp. xxviii. and 408,
with a large folding Table and 86 Woodcuts.
E gladly welcome Part II. of Mr. Foord’s Catalogue of the ©
Fossil Cephalopoda in the British Museum (Natural History).
Two years have elapsed since the completion of- Part I., containing
part of the suborder Nautiloidea, consisting of the families Ortho-
Reviews—A. H. Foord’s Catalogue of the Cephalopoda. 325
ceratide, Endoceratide, Actinoceratide, Gomphoceratide, Ascoceratide,
Poterioceratide, and Cyrtoceratide. The present volume contains
the remainder of the Nautiloidea, consisting of the families Lituitide,
Trochoceratide, and Nautilide. The family Bactritide was inserted
by the author in the Table of the Nautiloidea which he gave in his
Introduction to Part I., but in the Introduction to Part II. he states,
“On reconsidering the question of the affinities of Bactrites (the
sole representative of the family Bactritide), in. the light of the
investigations of Branco and Hyatt, I am now prepared to accept
the systematic position assigned to it by those authors—that is, at
the commencement of the Ammonoidea. Bactrites will therefore be
dealt with in Part III. instead of in this volume.”
From a Table appended to the Introduction giving the “ Distri-
bution of Genera and Subgenera of Nautiloidea described in Parts
I. and II. of the present Catalogue, with the number of species
assigned to each,” it is seen that there are in the Museum 575
species included in the Nautiloidea, 459 of which are Paleozoic,
93 Mesozoic, and 21 Cainozoic. The Paleozoic species are dis-
tributed in 29 genera and 6 subgenera, the Mesozoic in 4 genera
and 2 subgenera, and the Cainozoic in 2 genera and 1 subgenus.
The author commences the present volume with the Lituitide,
which family includes the genera Lituites, Ophidioceras, and Ancis-
troceras; the last-named genus does not appear to be represented
in the National Collection. The first is represented by the well-
known JL. lituus from the Orthoceras limestone of Sweden, and
possibly by one British species. To the genus Lituites, J. de Carle
Sowerby referred several British species which he described in
Murchison’s ‘Silurian System.’ Prof. Blake, in his Monograph of
the British Fossil Cephalopoda, Part I., retained in this genus only
one of these species, viz. ibex, and associated with it in the sanie
genus, though with a query, some specimens which he identified
with Trochoceras arietinum of Barrande. Mr. Foord replaces this
latter species in Trochoceras, and refers the ibex of J. de OC. Sowerby
to Lituwites with a query, remarking that “the presence of Litwtes in
the British rocks must, for the present, be considered as very far
from satisfactorily determined.”
Ophidioceras, which is known only in the Silurian of England
and Bohemia, was regarded by its founder Barrande as a subgenus
of Intuites, but Prof. Blake regards it as a distinct genus only
“remotely related” to Lituites, while Hyatt places it near to
Ascoceras. Mr. Foord considers it to be a distinct genus “ whose
alliance seems to be clearly with Lituites.”
In Trochoceras, the genus representing the Trochoceratide, and
ranging from the Cambrian to the Devonian, the author describes
two new Silurian species, each founded upon a single specimen.
The one, Trochoceras boreale, collected by Captain Inglefield in the
Silurian rocks at Wellington Channel, Arctic America, is a smooth
species, and is stated to be “much larger than any of those of the
Niagara rocks of North America that come at all near to it.” The
other, from the Woolkope Limestone, at Hay-Head, Hast of Walsall,
826 Reviews—A. H. Foord’s Catalogue of the Cephalopoda.
Staffordshire, is a distinctly ribbed species most nearly allied to
Trochoceras mirandum, Barrande.
In Vol. I. of the Paleontology of New York, Hall described and
figured under the name Litwites undatus specimens which, according
to Mr. Foord, belong to two distinct genera. Prof. Hyatt referred
them to the genus Trocholites, but Mr. Foord considers that some
belong to the genus Trochoceras, and to these he has given the name
Trochoceras Halli.
By far the greater part of the volume is occupied by the Nautilide,
the following genera and subgenera being treated of :—
Trocholites, Conrad.
Gy oceras, de Koninck.
' Subgenus Aipoceras, Hyatt.
Subgenus Trigonoceras, M‘Coy.
Hercoceras, Barrande.
Barrandeoceras, Wyatt.
Discites, M‘Coy.
Subgenus Phacoceras, Hyatt.
Ephippioceras, Hyatt.
Celonautilus, Foord.
Pleuronautilus, Mojsisovics.
Temnocheilus, M‘Coy.
Subgenus Centroceras, Hyatt.
Solenocherlus, Meek and Worthen, emend. Hyatt.
Nautilus, Breyn.
Subgenus Hercoglossa, Conrad, emend. Meek.
Subgenus Clydonautilus, Mojsisovies.
Aturia, Broun.
No new species is added to the genus Trocholites, but a new
species of Gyroceras, “closely allied to Gyroceras ornatissimum, de
Koninck, sp.,” is described from the Carboniferous Limestone of
Treland under the name Gyroceras hibernicum, and upon a single
specimen from the same horizon and locality is founded a new
species of the subgenus Aipoceras, viz. A. compressum.
Prof. Hyatt included in Barrande’s genus Hercoceras such forms
as Gyroceras alatum, Barr., and Trochoceras flecum, Barr., in which
the apertures are not contracted, but Mr. Foord restricts the genus
to species which have the aperture peculiarly contracted, as in
Hercoceras mirum, Barr., thereby retaining H. mirum (with its variety
irregulare) as the only known species of the genus.
In addition to the two well-known British species, which fall into
the genus Ephippioceras, viz. Nautilus clitellarius, J. de C. Sowerby,
from the Coal Measures of Shropshire and Worcestershire, and
Nautilus bilobatus, J. Sowerby, from the Calciferous Sandstone of
Closeburn, Dumfriesshire, the author describes under the name
costatum a new species, which occurs in association with N.
clitellarius.
The name Celonautilus is comparatively new. The first mention
of it seems to be in an exceedingly interesting paper which appeared
in the GronocrcaL Macazine for November, 1889 (p. 494), by
A. H. Foord and G. C. Crick, “On the Shell-muscles of Colonautilus
cariniferus, J. de C. Sowerby, sp.,” in a footnote to which paper it
is stated that “this name from xo?dov, hollow (referring to the
Reviews—A. H. Foord’s Catalogue of the Cephalopoda. 327
umbilicus), and Nautilus, is proposed by one of us in substitution
for Trematodiscus, Meek and Worthen, which was used by Hackel
for a genus of Radiolarians. The name T’rematoceras proposed by
Hyatt (Proc. Boston Soc. Nat. Hist. 1883, vol. xxii. footnote, p. 291)
in lieu of Trematodiscus is equally ineligible, because preoccupied,
for although the species described by Hichwald (Leth. Rossica, 1860,
vol. i. p. 1259)— Trematoceras discors—was a Bactrites, a generic
name once published cannot be again employed, even for a different
group, without risk of confusion.” Prof. Hyatt retains for the
shells comprised in the present group the name Vestinautilus proposed
by Ryckholt; but de Koninck pointed out that this name was
evidently founded upon an error of observation, and since it
“cannot be used in the sense intended by its author,’ Mr. Foord
agrees with de Koninck in treating Ryckholt’s name as a synonym.
Mr. Foord reproduces the figures of the impression of the shell-
muscles of Coelonautilus, which appeared in the GEoLoercaL Magazine
for November, 1889, and it is to be hoped that his examination of
the large number of specimens of Ammonoidea contained in the
National Collection will enable him to demonstrate also the form of
the muscular impression in some of the Ammonites. Several new
species of Oclonautilus are described, as well as of the genera
Temnocheilus and Solenocheilus.
Then follows the genus Nautilus, of which, according to a table
given by the author in his Introduction, the Museum contains 88
species, viz. 5 Triassic, 30 Jurassic, 40 Cretaceous, and 13 Tertiary.
Mr. Foord remarks: “It might perhaps have been supposed that
a genus so rich in species as Nautilus is would have supplied many
subdivisions or groups of species; but after carefully considering
the matter, I have come to the conclusion that such groups are in
the present case unnecessary, first, because the relationship in which
the species stand to each other is fully set forth in the remarks
appended to the descriptions of the species, and, secondly, because
such groups are apt to become very artificial, owing to the necessity
for frequent change in the selection of the characters upon which
they rest. It is true that there are often met with in the genus
Nautilus assemblages of species having many characters in common,
which are, however, too variable to found genera upon.”
Many of the species of Nuutilus are comparatively new, having
been described by the author and Mr. G. U. Crick in the Annals
and Magazine of Natural History for April and May, 1890; some
are quite new, but the excellent figures which accompany the descrip-
tions of these species will greatly facilitate their identification.
It is to be regretted that the whereabouts of some of Sowerby’s
type-specimens is unknown. This is the case with Nautilus simplea.
On comparing the characters given by Sowerby with Mr. Foord’s
description of his new species semiundatus, we think the author has
good grounds for suggesting the possibility of Sowerby’s specimen
being a badly-preserved example of ‘this new species. He adds
(p. 285), “ Unfortunately, the siphuncle has not been seen in N.
semiundatus, and therefore it cannot be invoked in aid of this com-
028 Reviews—A. H, Foord’s Catalogue of the Cephalopoda.
parison.” Doubtless he meant to have said that the siphuncle has
not been seen in the adult stage, for in his description of semiundatus
(p. 280) he observes, “The siphuncle in a young individual (No.
36603), 1$ inches in length, is very near the inner (dorsal) margin
of the septa.” The position of the siphuncle then, so far as it is
known, constitutes another point of agreement with Sowerby’s
N. simplex.
As the author has not been able with abundant material before
him to determine to what maturer form Sowerby’s small specimen
of N. inequalis belongs, we quite agree with him that it is much
better to drop the name altogether. The specific determination of
very young Nautili is often absolutely impossible.
Passing on to the genus Aturia we notice, that while Edwards in
his Monograph of the Eocene Mollusca (Pal. Soc. 1849) described
and figured two varieties of the well-known Aturia ziczac, Mr.
Foord reserves this name for the form figured by J. Sowerby in
plate i. of his Mineral Conchology, and gives a new name, A. Charles-
worthi, to the more compressed shell which Edwards distinguished
as var. 8. The latter comes very near to the Dax shells Aturia
Aturi, Basterot, but the differences in the suture-line and the amount
of compression are considered sufficient to justify the separation of
the species. As to the Nautilus lingulatus, v. Buch, from the Eocene
of Kressenberg, Bavaria, Mr. Foord concurs with Dr. Geinitz in
referring it to Aturia ziczac, J. Sowerby, sp.
The concluding section on the Nautilide deals with the Rhyn-
cholites or the mandibles of fossil Nautiloids. Various names
have been given to these fossils, and various opinions have been
entertained as to the advisability of referring them to genera and
species. Although it has been suggested that Rhyncholites may be
of more importance for the purpose of classification than the guards
of Belemnites, Mr. Foord refrains from referring them to genera and
species, (1) owing “to the want of stable characters upon which
to found genera and species,” and (2) because the material is not
“sufficiently abundant to enable one to trace the variations that may
arise in different stages of growth, and thus to afford data for the
limitation of such species as may be constituted,” and he adds,
‘‘Under these circumstances I have merely figured some of the
principal types of the fossil beaks met with in the Jurassic and
Cretaceous rocks of England which, so far as I am aware, have
not been illustrated.” The figures are exceedingly good, and in
addition to the fossil beaks the author gives some admirable
figures of the upper and lower mandibles of the recent Nautilus
(Nautilus pompilius).
Dr. K. A. von Zittel, writing in 1884 (Handb. d. Paleont. Band II.
p- 386), states that hitherto lower mandibles have been found only
in the Muschelkalk. Mr. Foord’s examination of the National
Collection has, however, enabled him to record and figure specimens
from the Lias of Lyme Regis and the Lower Chalk of Dover.
The Rhyncholites are so rarely associated with the Cephalopod
to which they belong, that the specimens of Nautilus Libanoticus
Reports and Proceedings—Geological Society of London. 329
in the Museum that the author states have one or other of the
mandibles in sitd must be regarded as treasures indeed. A figure of
one of these specimens is given, showing the mandible upon the
surface of the cast of the ventral aspect of the body-cbamber.
The figures in the book are both numerous and excellent, and we
feel quite sure that the volume will prove a most valuable addition
to our knowledge of the Cephalopoda.
REPORTS AND PROCHHDINGS.
——————
GroLocicaL Society or Lonpon.
T.—May 27, 1891.—Sir A. Geikie, F.R.S., President, in the
Chair.—The following communications were read :—
The Secretary announced the presentation by Sir John W. Dawson,
LL.D., F.R.S., of a series of photographs of Nova-Scotian Coal-
Measure Amphibia and Reptilia, and read an explanatory note
written by the donor.
Dr. G. J. Hinpr remarked that additional interest attached to the
genus Hylonomus from the fact that a representative of it had lately
been discovered in the Burnley Coalfield, and described by Mr. A.
Smith Woodward, F.G.S., in the May Number of the GroLoGicaL
Magazine under the name of Hylonomus Wildi.
1. “On the Lower Jaws of Procoptodon.” By R. Lydekker, Esq.,
B.A., F.G.S.
After reviewing Sir R. Owen’s writings upon the large extinct
Kangaroos for which he established the genus Procoptodon in 1874,
the author describes two mandibular rami from the clay beds of
Miall Creek in the neighbourhood of Bingera, N.S.W., which belong
to this genus, and from their characters and a comparison of them
with the lower jaws in the British Museum, he maintains that this
part of the skull indicates two very distinct species of the genus, for
which he retains the names P. rapha, Ow., and P. goliah, Ow.,
though it is possible that the types of those two species are really
specifically identical, in which case the name P. pusio, Ow., might
have to be adopted for one of the species described.
2. “On some recently exposed Sections in the Glacial Deposits
at Hendon.” By Henry Hicks, M.D., F.R.S., Sec. Geol. Soe.
In this paper the author brings forward evidence obtained from
sections exposed in gravel-pits and deep cuttings made for the pur-
pose of laying down the main sewers, to show that Glacial Deposits
had been spread out to a much wider extent over the Hendon
plateau than had hitherto been supposed, and that they had reached
down the slopes to below the ordnance-datum line of 2000 feet. He
further mentions that there is evidence to show that these deposits
have extended in a S. and §.W. direction across the Brent and Silk
Valleys, and now occur on most of the heights in the parishes of
Kingsbury and Willesden. As the sands, gravels, and Boulder-clay
which cover the Hendon plateau and the neighbouring heights are
found to rest on an undulating floor of London Clay, and to follow
830 Correspondence—Mr. Warren Upham.
the contours of the hills and valleys, the author considers that it
is clear that the main physical features of this portion of N.W.
Middlesex were moulded at a very early stage in the Glacial
period, and before the so-called Middle sands and gravels and over-
lying Upper Boulder-clay with Northern erratics, were deposited.
He believes that at this time there could have been no barrier of
any importance to prevent these deposits from extending into the
Thames Valley, and that the evidence clearly points to the conclusion
that the implement-bearing deposits on the higher horizons in the
Thames Valley should be classed as of contemporaneous age with
the undoubted glacial deposits at Hendon, Finchley, and on the
slopes of the Brent Valley, which they so closely resemble. The
author is therefore satisfied that man lived in the neighbourhood
of the Thames Valley in the early part of the Glacial period;
probably, he thinks, in pre-Glacial times.
CORRESPONDENCE.
ea get
CORRELATION OF QUATERNARY CHANGES OF LEVELS IN NORTH
AMERICA AND THE CARIBBEAN REGION.
Srr,—Referring to Mr. Jukes-Browne’s letter in this Macazine
for March (p. 143), and to his and my preceding articles and corre-
spondence therein cited, I have to reply that the questions which he
asks are manifestly very difficult; but certain points may be noted
which partially answer them. If the end of the Tertiary era and
beginning of the Quaternary were characterized by elevation of the
greater part of the North American continent to such altitude as to
give a much cooler climate, and by a contemporaneous depression of
the West Indies and the Isthmus of Panama, allowing a large part
of the equatorial Atlantic current to pass into the Pacific Ocean, the
result of these combined conditions being the accumulation of the
ice-sheets of North America and Europe, we should expect to find
west of the Gulf of Mexico, as Mr. Jukes-Browne suggests, evidences
of recent changes of levels. The subsequent depression of the con-
tinent north of the Gulf and the uplift of the West Indies and the
Panama region, bringing the present relative heights of land and
sea, may have produced the east to west line of fissuring and faulting
which crosses Mexico near 19° north latitude, shown by the very
remarkable series of volcanoes of Tuxtla, Orizaba, Popocatepetl,
Ixtaccihuatl, Toluca, Jorullo, and Colima. Farther west, this line
of disturbance in the earth’s crust probably extends to the volcanic
Revillagigedo Islands. Hastward, after crossing the base of Yucatan,
it appears to be represented by the Great and Little Cayman Islands,
and by the Sierra Maestra on the south shore of eastern Cuba, with
the contiguous “ Bartlett Deep,” a very profound narrow trough of
the Caribbean Sea, reaching from Honduras Bay to the Windward
Passage; and thence the same orographic belt is continued by Santo
Domingo, Porto Rico, and the Windward Islands, with the very
deep oceanic troughs north, south, and south-east of Porto Rico
(bathymetric map of the Caribbean region, A. Agassiz, Three
Cruises of the “ Blake,” vol. i. fig. 57).
Correspondence—Ir. Warren Upham. aol
The disturbances along this belt, however, have been of a different
order from the uplifts and subsidences which have affected the
whole continental area northward from the Gulf of Mexico, as
known by the Pleistocene submergence of river valleys and fjords
on the Atlantic, Pacific, and Arctic shores of North America. No
less than twenty submerged valleys, some of them extending to
depths of 2000 to 3000 feet, have been found by soundings on the
coast of California by Prof. George Davidson, of the U.S. Coast
Survey; and Prof. Joseph Le Conte has shown that the time of
elevation during which they were eroded was the Pliocene and early
Quaternary, which also included the plication of the Coast Range,
the outpouring of the lavas forming the Cascade Range, and the fault-
ing and tilting that elevated the Sierra Nevada, Wahsatch, and Basin
‘Ranges to their present height (Elements of Geology, new ed. 1891 ;
Bulletin G.S.A. vol. ii. 1891, pp. 323-330). On the Atlantic coast,
too, the submerged valleys mentioned in previous articles were
doubtless eroded during the same time. Excellent evidence of this
is given by the submarine channel of the Hudson, partly a profound
fjord, extending about 100 miles beneath the sea, and descending to
the depth of 2844 feet; for samples of its bottom and banks,
brought up by the sounding-lead, appear to belong to a continuation
of the Tertiary sandy clays of New Jersey (Am. Jour. Sci. III.
vol. xxix. pp. 475-480, June, 1885; vol. xl. pp. 425-487, Dec. 1890,
with map). These deeply submerged, narrow river channels, and
the similar Arctic fjords, together bear testimony of a late Tertiary
and early Quaternary elevation of nearly all of North America to
such altitude that the resulting colder climate would induce glaciation.
So widely extended continental uplifting, and the later Pleistocene
depression of the same area, belong to a class of the earth’s crustal
movements which Gilbert and White have called epirogenie, that is,
continent-making, in contrast with orogenic or mountain-making
upheaval and subsidence.
In the Caribbean region depressions succeeded by elevation during
the Quaternary era, which are known from the raised coral reefs
studied by Mr. Jukes-Browne and others, belong to orogenic move-
ments, chiefly by faulting, uplifting, and tilting, which have taken
place on a most grand scale in this era throughout the chain of the
West Indies and Windward Islands, and along the entire Cordilleran
belt from Cape Horn to Panama, to the Sierra Nevada and Great
Basin, and to Mount St. Elias and the Aleutian Islands. These
mountain-making disturbances have been closely related with the
great epirogenic uplift and depression of North America, and with
their duplication in two distinct Glacial epochs, divided by a very
long interglacial epoch on this continent; but to attempt discussion
of details of their correlation, or to speculate upon the condition
of the earth’s crust and interior permitting such changes of levels,
would require too much space for a letter. Some notice of these
matters will be found, respectively, in my article in the American
Journal of Science for January, 1891, and in my appendix of
Wright’s “Ice Age in North America.”
SomERVILLE, Mass., April 6th, 1891. Warren UPnam.
302 Obituary—Prof. P. Martin Duncan.
A VARIETY OF PICRITE (SCYELITE) IN SARK.
Srr,—Rather more than two years since (Dee. III. Vol. VI. p. 109)
I wrote a description of a variety of Picrite which I had found in
boulders at Port du Moulin, Sark, stating that I published it, as
there was “no probability of my returning to Sark for years, if
ever,” in the hope some one would trace this interesting rock to its
home. But the unexpected often happens: last summer’s work
among the hornblende schists of the Jizard determined Mr. Hill
and myself to re-examine those of Sark, and in the process of this
the picrite was not forgotten. After a careful search along the
rocks at low water we found a dyke of this rock at the foot of the
cliffs between Port du Moulin and Saignie Bay, nearly opposite to
(perhaps rather to the south of) the Grand Autelet. It is at the base
of a little spur from the cliff of banded gneiss, into which it is
intrusive, but it only shows for a foot or so above the shingle, in two
or three humps, running seawards. In this direction, about fifteen
yards off among the boulders, is another boss. .I have examined the
rock under the microscope. The olivine is not so well preserved,
there is rather less mica and more hornblende than in the specimen
described in 1889; it is not quite so obviously connected with the
serpentines, but I have no doubt that the boulder came from some
part of this dyke. We searched the cliffs very carefully up to the
further side of Saignie Bay on the north, and for some distance to the
south of Port du Moulin without finding any other dyke. We
now think it very improbable that Ansted, in speaking of a dyke
of serpentine as crossing the island, referred to this rock. We
reserve further particulars for a paper in which we hope to com-
municate to the Geological Society the result of our work in Sark.
T. G. Bonney.
aS Tee ASao ya
SN cE
PETER MARTIN DUNCAN,
M.B. (LOND.), F.R.S., F.G.S., F.LS., ETC.
Born, 20TH Aprin, 1824. Dizmp, 28TH May, 1891.
Peter Martin Duncan was born at Twickenham in 1824, and
received most of his early education in the Grammar School there.
After leaving this he lived for a short time in a school in Switzerland,
and on his return to England entered the Medical Department of
King’s College, in September, 1842. He there received the whole
of his formal scientific training; he passed the preliminary M.B.
examination with honours in Anatomy and Physiology in 1844, and
obtained the full degree in 1846; he was elected an Associate of
his College in 1849.. Upon the conclusion of his medical studies,
he acted for a time as assistant to a doctor at Rochester, whence he
removed to Colchester, where a practice had been purchased for him,
Here he remained for many years, and it was during this period that
he published his first scientific essay, which consisted of “‘Observations
on the Pollen tube, its growth, histology and physiology” (1856).
But he did not at Colchester secure much time for original research,
for most of that which was left him by his profession was occupied
Obituary—Prof. P. Martin Duncan. 339
by work in connexion with the municipal politics of the borough,
in which he seems to have played a prominent part. The fact that
he served as Mayor shows that he had won the confidence of his
fellow-townsmen, while the admirable arrangement of the local
Museum, which under his direction was reorganized upon lines far
in advance of the time, is a sign of his interest in the educational
institutions of the town. After his return to London to a practice
at Blackheath, he was able to spare more time for scientific work,
specializing upon the Corals; and as his interest deepened in the
problems which these presented him, he was led to abandon lucrative
prospects in his profession and devote himself entirely to original
research. In this he was no doubt encouraged by the reception
accorded to his first paleontological papers, which were read in
1863; they at once gained him recognition as one of the ablest of
British paleontologists; he was in the following year appointed one
of the Honorary Secretaries of the Geological Society, and two years
later he was elected F'.R.S.
After leaving Blackheath he settled near Regent’s Park, but he
was not long allowed to remain in retirement, as in 1870 he was
called to the chair of Geology at King’s College, and a Fellowship
followed in the next year. Shortly afterwards he accepted also the
Professorship of Geology at Cooper’s Hill, and he held both appoint-
ments till his death. He resigned the Secretaryship of the Geological
Society in 1870 after a seven years’ tenure of office through a period
in which the change of apartments had made the duties more than
usually onerous. In 1872 he was elected one of the Vice-Presidents,
an office which he held till his promotion to the Presidency in 1876
and 1877. In 1881 he was awarded the Wollaston Medal, the highest
honour which the Geological Society can bestow. Though it was
the Geological Society with which he was most closely connected, he
was an influential member of other scientific bodies; he served on
the Council of the Royal Society from 1876 to 1878, was President
of the Geological Section of the British Association in 1879, and of
the Microscopical Society from 1881 till 1883. By his resignation
of this post he terminated an official career of no ordinary useful-
ness, and retired to Gunnersbury, where he passed the remaining
years of his life.
On turning to Prof. Duncan’s scientific work, one is impressed by
the enormous amount he accomplished and the wide range of his
interests and influence. As has been previously remarked, his first
paper (1856) was botanical, and he long retained his interest in
the subject, his last paper on vegetable physiology being published
in 1874; while still later he worked out the parasitic alge
which he discovered in some of his Silurian Corals. His first
important work was the series of five memoirs on the Fossil Corals
of the West Indies, a subject which he took up, as at that time he
failed to get the necessary facilities for the study of the recent forms.
The subject was full of difficulty ; the living Corals of the area were
but little known, so that the materials for the comparison of the
recent and fossil faunas were quite insufficient. But Prof. Duncan
attacked the subject with characteristic energy, and his sound
$34 Obituary—Prof. P. Martin Duncan.
common sense enabled him to avoid many a pitfall; his memoir
was certainly a most valuable addition to the knowledge of the
later Tertiary Corals. This work was followed by a long list of
papers and monographs in which he described the Coral faunas
(especially the Cainozoic) of England, Australia, Tasmania, India,
Java, Arabia, and Malta. His “ British Fossil Corals ” is probably one
of the finest contributions to English Paleontology ever published by
the Paleontographical Society ; it was so much more modern in its
methods and more thorough in its treatment than the less painstaking
work to which it was issued as a Supplement.
But though Prof. Duncan’s interests were probably at first rather
zoological than geological, he soon became absorbed in the line of
work which he had been led by circumstances to select. He early
realized that the devcription of the anatomical structure and the
determination of the systematic position of a fossil did not constitute
the sole duties of a paleontologist. With him these were but pre-
liminary to the consideration of the affinities of faunas and their
bearing on the physical geography of the past. He was a paleon-
tologist in the truest sense of the word,—not a morphologist who
happened to study extinct forms, but a geologist who used fossils
as a petrologist uses minerals. Hence his early work on the West
Indian Corals commenced by a detailed study of their conditions
of fossilization and closed by a discussion of their evidence as to
the Cainozoic physiography of the Caribbean region ; similarly his
later studies of the European Corals led to his striking paper on
“The Physical Geography of Western Europe during the Mesozoic
and Cainozoic periods elucidated by their Coral Faunas.”
It was probably his desire to check the conclusions yielded by
the Corals that led him to take up also the study of the Kchinoidea,
and as work with these is more definite than with the former, it
yielded him some of his most interesting conclusions. He com-
menced with the Hchinoids of beds, the Corals of which he had
already studied; among the most remarkable were the collections
from South Australia, which he described in a series of papers dating
from 1864 to 1887. It was apparently his interest in the origin
of this fauna, with its mixture of Cretaceous and Cainozoic genera,
that led him to turn with such zest to the Indian Hchinoids, which,
in conjunction with Mr. Sladen, he monographed with great detail
and care.
Of the Mesozoic Hchinoidea he studied with especial interest those
of the Cenomanian, and by the aid of the small collections of the
Rev. W. F. Holland, in Sinai, and Dr. Carter, in South Arabia, he
gradually built up the connexion of the Huropean fauna with that
of Northern India. And then, by his comparison of those of the
Peninsular and Extra-Peninsular areas, he demonstrated the existence
of the land barrier that stretched across India and away to the south-
west, of which such important use has been made in recent con-
troversy. His views on geographical distribution were original and
had been carefully matured ; his lecture on “The Formation of the
Main Land Masses” showed that he did not accept the view of the
Obituary —Prof. P. Martin Duncan. 000
permanence of oceans and continents, a subject upon which his
Opinion was of especial value. Another of his contributions to
chorology was his paper on the fauna of the Alpine Lakes, perhaps
the most serious blow ever struck at the theory of the Glacial origin
of the Swiss lake-basins.
But though Professor Duncan did not regard morphology as the ~
highest end, he did not by any means neglect it; thus our know-
ledge of the perignathic girdle of the Hchinoids and its value in
classification we owe mainly to him; while his remarkably sug-
gestive and original essay on the structure of the ambulacra of the
regular Hchinoidea, perhaps his most masterly piece of work, has
gained the highest praise from men prejudiced against him.
But in addition to his contributions to paleontology he has done
much in zoology: he wrote a series of papers on the anatomy of the
Temnopleuride, Saleniide, and other groups of the Echinoidea, and
described, amongst others, the Madreporaria of the Porcupine
Expedition, the Ophiuroids and Corals of Mergui, and in conjunction
with his constant collaborator, Mr. Sladen, the Echinodermata from
Greenland. It was probably his close study of the recent forms that
made his judgment usually so sound, while the knowledge gained
was indispensable for the preparation of his two invaluable works
“The Revision of the Madreporaria”’ and his “ Revision of the
Genera and Great Groups of the Echinoidea.” The former was issued
in 1885, and consisted of diagnoses of every genus of Corals (ex-
cluding Rugosa) and of a classification which has not yet been
supplanted. His Revision of the Hchinoidea was perhaps still finer,
and made a great advance in our knowledge of every order. The
application of his own discoveries on the ambulacral structure
enabled him to bring the Palechinoidea from chaos into order, and
to replace the artificial arrangement of the Diadematidz by a natural
classification ; his previous detection of the fundamental differences
between the pits of Temnopleurus and the fossettes of Temnechinus
gave him the clue to the arrangement of that group; and his sub-
stitution of positive for comparative diagnoses in many recent genera
has greatly aided the comparison of the fossil and deep-sea types.
But his use of the perignathic girdles in another order was less
successful, while his acceptance of Lovén’s results brought him into
conflict with some continental paleontologists regarding the classifi-
cation of the Spatangoidea. By these two Revisions alone Prof.
Duncan has earned the gratitude of every paleontologist. and
zoologist; they precisely formulated the best current thought of
their time, and have given a firm basis for future work. They
must be indispensable works of reference to every student of these
groups, till in years to come the progress which they have so
largely aided has rendered necessary a new revision, and until some
one is then ready and able to undertake the enormous labour such
a task involves.
But in addition to the Corals and Echinodermata, Prof. Duncan
made some contributions to the study of the Protozoa and Sponges,
while his clearness as a teacher led him to undertake a good deal
336 _ Obituary—Prof. P. Martin Duncan.
of lecturing and popular literary work; thus he edited the six
volumes of “Cassell’s Natural History,” and amongst others wrote
a primer of physical geography, a volume of biographies of the
‘Heroes of Science,” a paper on Voltaire’s attitude to geology, and
edited recent issues of Lyell’s “‘Students’ Hlements.”
In the course of so much, and such widely different work, it was
but natural that Professor Duncan should at times have come into
conflict with his fellow-workers, however much he himself detested
controversy. On the one hand, his passionate love of justice led:
him to accept the names of the pioneers of systematic zoology, and
thus his nomenclature has been in places rejected by the younger
school. On the other hand, his work has been severely criticized
by men who, caring for none of the physiographical problems
Prof. Duncan set himself to solve, expected him always to unite the
detailed precision of an histologist with the grasp of a paleeontologist.
But at the time of his work on the West Indian Corals, for example,
such investigations would not have aided him in his comparison of
the recent and fossil faunas; and later opinion seems far more in
agreement with his work than with that of the elaborate monographs
of Michelotti and Duchaissang that immediately followed his. But
it is to be regretted that he did not adopt some modern methods
quite as early as he might have done, especially as his work on the
Temnopleuride shows how well he knew how to use them. Another
source of trouble was that he had a somewhat aggravating way
of giving wrong references, which brought down upon him the
censures of those who seem to think that it is a mere matter of
detail whether the species be rightly identified so long as the
reference be correctly cited. But, loathing controversy as he did,
he ignored criticism as far as possible, and perhaps the only time
when he was really roused to wrath was by the neglect by some
recent Echinologists of the results of the work of his great Swedish
friend; the vigour of his onslaught on this occasion puzzled those
who did not understand his devotion to the man to whom he often
referred with modest reverence as ‘‘my master Loven.”
To his first love, the Corals, he proposed to return on the con-
clusion of his revision of the Echinoidea; he commenced work upon
a large Indian collection, and planned a supplement to his Revision
of the Madreporaria in which he intended to discuss recent criticism
and incorporate subsequent progress. But it was not to be: he was
smitten with disease, and after a long and painful illness quietly
passed away on the early morning of the 28th of May.
The fine keen sense of humour which remained unblunted almost
to the last, the genial kindness with which he was ever ready with
help especially to younger men, united with the recognition of his
sterling worth and sound judgment, gained for him wide popularity
and esteem. And now that Prof. Duncan has passed to his well-
earned rest not only is the world the poorer by the loss of a great
paleontologist and of a strong and original intellect, but a wide
circle of his fellow-workers have to mourn the departure of a
trusted friend. J. W. G.
THE
GEOLOGICAL MAGAZINE.
NEW SERIES. DECADE III. VOL. VIII.
No. VIII.—AUGUST, 1891.
Om EG-EIN ASE, Auk Ee ras.
I.—On tHe Sanps anp GRAVELS INTERCALATED IN THE
BovuLDER-CLAY.
By G. W. Buiman, M.A., B.Sc., Corbridge-on-Tyne.
HE interpretation of the sands and gravels intercalated in the
glacial drift is one of the most interesting problems in glacial
geology. Do they, on the one hand, represent the deposits of one
or more mild intervals alternating with periods of intense cold; or
were they, on the other, laid down during one continuous cold
period marked by such slight oscillations as can be shown to occur
in connection with existing glaciers and ice-sheets ?
The former view has been ably advocated by geologists of repute
—notably by Prof. J. Geikie—and implies the belief in one or more
intervals of mild climate, each comparable in duration to the cold
period which it followed and preceded. It is founded partly on
the idea that the sands and gravels are due to such aqueous action
as would indicate a permanent retreat of the ice; and partly on
some few mammalian and other remains found in them.
Prof. Geikie expresses his opinion as follows :—
1. “The till itself is a truly glacial deposit, due to the grinding
action over the surface of the country of immense masses of glacier
ice. But no one will doubt that its intercalated and subjacent beds of
silt, sand, and gravel have had a very different origin. .They occur
in such layers as could only have been spread out by the action of
running water.” 4
2. “We have found that there is abundant proof to show that the
accumulation of a moraine profonde by one great ice-sheet was inter-
rupted several times; that the ice-sheet vanished from the low
grounds, and even from many of the upland valleys, and that
rivers and lakes then appeared where before all had been ice and
snow. We have also learned that during such mild interglacial
periods, Oxen, Deer, Horses, Mammoths, Reindeer, and no doubt
other animals besides these occupied the land.’’?
But, admitting such evidence, it is obvious that there must have
been not one but several such mild interglacial periods. And so
we find Prof. Geikie stating, in his address to the Geological Section
of the British Association at Newcastle in 1889, that, “In some
places three or more such boulder-clays have been observed over-
1 “Great Ice Age,’’ p. 165. 2 Ditto, p. 204.
DECADE III.—VOL. VIII.—NO. YIII. 22
338 G. W. Bulman—Glacial Geology.
lying one another throughout considerable areas, and these clays
are described as being distinctly separate and distinguishable the
one from the other.” And further :—‘‘ Penck, Bohn, and Brtickner
find evidence of two interglacial epochs, and maintain that there
have been three distinct and separate epochs of glaciation in the
Alps.” ?
iad according to Dr. Croll’s views, there must have been a greater
number. For his calculations indicate that the glacial epoch lasted
160,000 years, and dividing this into periods of 10,000—the time
allowed for a warm interval—we get eight such mild interglacial
periods.
Prof. Geikie himself divides the ice age into periods as follows : *—
1) Pre-glacial mild period... .... ... First bed.
2) First glacial period ... ... ... Cromer Clay and contorted beds.
( Sand and rolled gravel above
Cromer clay.
Great chalky boulder-clay, etc.
Beds between great chalky boulder-
clay and purple clay.
Purple clay, lower boulder-clay of
Lancashire.
mild ) Hessle gravel, middle sands, ete.,
uy of Lancashire.
Hessle clay, upper boulder-clay
ne { of Lancashire.
3) First interglacial mild period .
4) Second glacial period ...
6) Third glacial period ... ..
eo \
5) Second interglacial mild period ... {
7) Third and last interglacial
JOOMEL, “355, (G65) Loca hos) 4, dco
8) Last glacial period
With regard to the first point in the evidence, two suggestions
occur :
(1) Beds of sand intercalated in the till may be in part the result
of the action of the ice itself. In fact, if we do not so regard them,
the composition of the till and boulder clay is a difficulty on the
usual hypothesis of its origin. The products of glaciation are
supposed to be these clays, and morainic debris: that is to say, very
finely ground rock matter, forming the clay, with large and small
stones making up the rest of the till and the morainic matter. But
in the process of grinding down there must have been an inter-
mediate product, viz. coarse and fine sand; and if these are not
represented by the intercalated sand beds, where are they? And
even if all the rock matter excepting the boulders and pebbles had
been ground down to the fineness of the sediment forming the clay,
it is difficult to understand how a purely siliceous sand could ever
become plastic, and form a clay. For although the glacial clay is
at times sandy, its general composition does not permit the suppo-
sition that it contains all the sand produced by the grinding down
of the rocks by the ice. In fact, it seems almost certain that sand
must necessarily be one of the results of ice action; and that it
should occur interstratified with the till is as natural as that in a
river deposit sand should be intercalated with gravel.
And in his “Ice Age in North America,” Dr. Wright speaks of
“the sands and gravels of the terminal moraine” of the Muir
glacier (p. 47).
1 See Brit. Assoc. Reports, 1889, pp. 55€—558.
2 Great Ice Age, p. 393.
G. W. Bulman—Glacial Geology. 339
_ (2) The products of stream and ice action would necessarily be
mingled during the continuance of the cold period. For, during
summer, ice action would give place to that of water near the
termination of the ice-sheet or glacier; and thus truly aqueous
deposits would be formed over the glacial, to be in turn overlaid
by the latter.
A succession of exceptionally warm summers, too, might cause
the temporary retreat of the ice—just as in recent years a succes-
sion of exceptionally severe winters caused the formation of a
veritable glacier in one of the Scotch valleys—and permit of the
formation of a thicker series of sands and gravels.
And as near the extremity of a glacier or ice-sheet stream action
takes the place of that of ice every summer, and to a more marked
extent during a succession of warmer seasons, so we should expect
to find the retreating ice, as the glacial epoch passed away, followed
by a series of mixed fluviatile and glacial deposits.
And as oscillations in the extent of existing glaciers are well
known, so we naturally infer it was in the past.
As regards the present day, Prof. Prestwich quotes the case of
a glacier which has advanced a mile in a century, and that in a
region where there is a general retreat of the ice.
And Mr. Lydekker, in his account of the Geology of Baltistan,
Kashmir, describes one glacier which is retreating, and another
which is advancing. Thus of the Tapsa glacier he writes:
“A comparatively modern terminal moraine, forming a dome-
shaped hill covered with cypress, bounds the cultivated ground
superiorly ; above this old moraine is the present terminal moraine
of the glacier. The above appearances seem to indicate that the
Tapsa glacier has receded by small gradations, pausing here and
there, until it finally attained its present shrunken dimensions.”
But of the Palma glacier:
“The present Palma glacier shows pretty evident signs of being
on the increase, since it terminates inferiorly in an abrupt and
precipitous wall of ice, with but comparatively little debris and no
distinct terminal moraine, which seems to have been overflowed and,
so to speak, swallowed up by the glacier.” !
The possibility of lacustrine action in glacial times is also sug-
gested by the usually received interpretation of the parallel roads
of Glen Roy. These are held to have been formed by a lake caused
by the blocking up of the lower part of the valley by ice. While
the lake stood at different levels, the action of the water formed a
series of shelves on the mountain side along the margin of the lake.
But it is difficult to resist the conviction, that if the lake was fed by
streams, more or less lacustrine deposits would be formed in it : in
other words that gravel, sand, and silt would be laid down, and
afterwards overlaid by typical glacial deposits.
And stream action also, it is well known, occurs beneath the ice-
sheet and glacier. Springs, for example, issuing from the ground
beneath the ice, will cut for themselves channels through it. The
1 Records Geol. Surv. India, vol. xiv. pp. 44-45.
340 G. W. Bulman—Glacial Geology.
great thickness of the ice itself prevents the intense external cold
reaching such springs, and they may continue to flow during the
cold period. We may even speculate on the probability that in
those ancient days, so much nearer the period of Tertiary volcanic
activity, warm springs were more numerous and powerful than they.
are to-day. At first sight the suggestion doubtless arises, that the
springs would lack their usual source of supply, and early in the
glacial period become dried up. But, in the first place, the surface
ice is constantly melting, and the water at times sinking down
through cracks to the bottom; and, in the second place, ice melts
through pressure and friction such as occur beneath an ice-sheet or
glacier. These two sources of supply might still feed the springs,
and serve to increase the streams formed by them.
The possibility of stream action beneath a great continental ice- _
sheet is indicated by a study of that of Greenland. Explorers
describe surface rivers cutting for themselves channels between
banks of ice, and all finally disappearing by plunging down through
openings in the ice to the bottom.! These rivers then probably
flow along sub-glacial channels to the extremity of the ice-sheet,
eroding the rocks, and forming fluviatile deposits as they go.
In connection with this, it may be noted, that it is held by many
that more heat was received from the sun during the summer of the
glacial epoch than at present, and that consequently this surface-
_ melting, and formation of rivers would be on a larger scale.
And in “The Ice Age in North America,” Dr. Wright notes the
occurrence of water-worn débris on the ice of the existing Muir
glacier: ‘Here a vast amount of water-worn débris covers the ice,
extending up the glacier in the line of motion for a long distance.” *
The streams issuing from the: extremity of the ice, indeed, whether
glaciers or ice-sheets, are frequently not formed merely by the
melting of the ice at the extremity, but are actually rivers which
have run for considerable distances beneath the ice.
Thus, writing of the glaciers of the Alps, M. Rendu describes
streams running beneath the whole of that portion of the ice-river
which descends below the line of perpetual snow :
«When we traverse the Glacier des Bois, at the bottom of each
crevasse we admire a little stream of fresh and limpid water, which
appears to flow over a surface of emerald. These streams reach
the edges of the glacier, lose themselves among the stones of the
moraine, and unite again beneath the ice at the bottom of the hollow
which contains it. Other streams reach the same destination by the
Openings which penetrate to the bottom of the glacier ; and, lastly,
springs and waterfalls fall also upon the banks of the icy river, and
take the same direction; so that we are sure that there is a
subterraneous river which flows beneath the whole extent of the
glacier, and which comes to light only at its lower extremity.”’® :
- And what we must, I think, regard as an example of the mingling
of aqueous deposits with glacial occurs in the drift, near London.
1 Nordenskiold, Guox. Mac. Vol. IX. p. 393. 2 p. 62.
5 «« Glaciers of Savoy,’’ Translation. Edited by Prof. George Forbes, pp. 156-7.
G. W. Bulman— Glacial Geology. 341
In describing the middle glacial beds, Mr. Whitaker writes:
“‘ Besides these, however, there is sometimes a layer of true Boulder
Clay in the gravel, that is, a clay that contains irregularly rounded
fragments or boulders of various rocks, the surfaces of which are
furrowed and scratched in the way that is peculiar to stones that
have been dragged along by masses of ice over a floor of rock.
This clay being like that which occurs in force above the gravel,
serves to link the two deposits together, and to show that the
glacial conditions which seemed to have reigned supreme during
the great mass of Boulder Clay existed also during the deposition
of the lower bed, though to a less extent.” *
This layer of Boulder clay in the gravel can hardly be considered
as the product of a glacial epoch, followed and preceded by a mild
epoch when gravel was laid down.
And there is another way in which true river sands and gravels
may be intercalated in glacial beds without the intervention of a
warm interglacial period. They may be preglacial river deposits
pushed on by the advancing ice over boulder clay already laid down.
Such preglacial river sands and gravels must have been abundant,
and it is usually believed that a part of the work of the ice was to
sweep these down the valley. What more likely than that some
of these deposits, thus pushed on, would be stranded in some quieter
spot and at times left on the surface of already deposited till ?
In writing of the glaciation of South Lancashire, Mr. A.
Strahan speaks of the Boulder clay as “‘sometimes rudely strati-
fied,” although “usually devoid of such lamination as is shown by
clays deposited freely in water.” ?
He thus further describes the alternation of sheets of Boulder clay
with sand and gravel in certain districts :
“In every case where the drift attains any thickness, as in a
preglacial river-valley, or the maritime plain of North Flintshire
and Denbighshire, it is found to consist of alternations of sheets of
Boulder-clay with sand and gravel, the beds running sometimes for
a mile or two without interruption.” °
Here, again, we cannot suppose each sheet of Boulder clay to
represent a glacial epoch, and each separating gravel a mild period ;
we are rather bound to conclude that the glacial conditions which
‘produce Boulder clay are able also to produce sand and gravel;
that the alternations here seen are due to merely temporary alterations
of conditions, as between summer and winter or small oscillations in
the extent of the ice.
The section at Blackpool is, perhaps, one of the most favourable
to the hypothesis of a mild interglacial epoch. There it is said there
are two Boulder clays, separated by a series of sands and gravels.
This series of beds is described in detail with a section by Mr. T-.
Mellard Reade.!
But although it is true there is in this coast section a lower bed
* Geology of London, Geol. Surv. Mem. pp. 52, 53.
2 Q.J.G.S. vol. xlii. pp. 373-4. 3 Op. cit. p. 383.
4 Q.J.G.S. vol. xxxix. p. 83.
342 G. W. Bulman—Glacial Geology.
of Boulder clay, succeeded by a series of sands and gravels, which
are in turn overlaid by Boulder clay, the general relations of the
beds point rather to a partial sorting of materials produced under
one set of conditions than to such a great change as that implied by
a passage from a glacial to a mild climate.
There is, in the first place, no sign of the denudation of the lower
bed of clay before the deposition of the sands and gravels, or of the
latter before the deposition of the upper clay.
Secondly, the series of sands and gravels is neither so extensive
nor continuous as might be expected on the hypothesis of their inter-
glacial origin.
At one end of the Blackpool section, for example, the only
separation between the upper and lower clay is a bed of sand a few
inches thick.
Further, the separation into upper and lower Boulder-clay seems
merely local. In the first place, Mr. Reade points out, that in a
description of the Blackpool section some years previously by Mr.
Binny, no separation of the clay by sand and gravel is given in one
particular part of the section where there is such a separation now.
He explains this on the supposition, that, as the section is now
several yards further inland, the separating beds now visible had
thinned out seawards. And he suggests the probability that if the
beds could be followed inland, the upper and lower clays would be
found to coalesce in a similar way. The probability of this is further
indicated by the sections in the neighbourhood.
_ Thus Mr. Reade describes one where “the Boulder-clay was
divided by very persistent seams of sand, though in places these
thinned out and the upper and lower beds coalesced and became
one without observable division.” In other cases, “the shingle is
divided by patches of Boulder-clay ;” while “irregular sporadic
patches of sand occur in the clay.”
An artificial section at Sankey Bridge is thus described :—“ The
Boulder-clay was here penetrated to 100 feet below the surface,
the last 20 feet showed 5 feet of sand mixed with coal-dust and
15 feet of clay with bands of gravel. A sand and gravel seam
2 feet thick was passed through about 53 feet from the surface.
It is obvious, I think, that sands and gravel and boulder-clay
mixed up in this way cannot be referred to distinct glacial and inter-
glacial epochs. And if we admit a glacial origin for such patches
and layers of sand and gravel, we are bound to admit the possibility,
if not the probability, of a similar origin for the greater development
in the Blackpool section.
The evidence of the fossils of these Lancashire Drift beds is also
against the hypothesis of a mild interglacial epoch.
_ Thus Mr. Mellard Reade after an extensive examination of the
Mollusca found in them, concludes that the intercalated sands and
_ gravels are not separable from the boulder clays by their organic
remains, as they clearly ought to be on the hypothesis of a mild inter-
glacial period. ‘‘My object,” he writes, “in these preliminary
investigations was to ascertain if there were any organic remains
-G. W. Bulman—Glacial Geology. 343
by which the drift-beds might be separated into geological horizons
—pbecause, if, as some maintain, two glacial and one inter-glacial
period are represented in these beds, there ought to exist, a priori,
some decided distinction in the Molluscan fauna. I have utterly
failed to detect any.”!
That the limited mass and area of these sands and gravels, and
the absence of signs of denudation between them and the Boulder-
clay, is decisive evidence against their being the deposits of a mild
interglacial epoch, comparable in duration to the glacial period
itself, is indicated by a consideration of what would probably take
place during such an interval, and by a study of post-glacial sands
and gravels.
For, on the melting of the ice, river action would be intensified ;
vast quantities of morainic matter would be carried down by the
swollen streams, and spread out over the boulder-clay of the plains
in the form of sand and gravel. At the same time there would be
denudation of the boulder-clay in places, and some of these denu-
dation hollows would be filled again with gravel. In places this
sand and gravel might reach the sea, and form marine deposits.
But this would not continue for very long: the streams would
lose their carrying power; the gravel would no longer be carried to
the lower grounds, and they would commence to cué their channels
through the gravel, and then through the underlying boulder-clay.
This gives a clear idea of the unconformable, denuded junctions
we should expect to find between the sands and gravels of an inter-
glacial epoch, and the boulder-clays of preceding and succeeding
glacial epochs. And such a course of events is indicated for the
close of the glacial epoch, and the incoming of the present mild
climate by a study of post-glacial sands and gravels.
In Northumberland, for example, a considerable thickness of such
deposits, known as the “ Upper Drift Sands and Gravels,” are found
overlying the boulder-clay. At the junction the latter shows signs
of denudation in places, while the overlying beds show at times
clear indications of being in part composed of the re-assorted
boulder-clay. And since the formation of the upper beds the
streams have, in many cases, cut down through sand and gravel
and boulder-clay to the rock below.
Ought we not, then, to look for some evidence of a similar course
of events in the relations and characters of the beds of the supposed
interglacial epoch ?
The glacial phenomena of the Vale of Eden, as described by
Mr. Goodchild (Q.J.G.S. 1875), point rather to the intermingling
and overlapping of the action of ice and water taking place more
or less contemporaneously, than to distinct glacial and interglacial
periods.
A few sections at the foot of Stainmoor, Mr. Goodchild points out,
“show that locally a threefold division of the drift obtains.” Yet
he adds a little further on, “It is nearly impossible to make out any
definite order of succession in the drifts in the lower parts of the
, 1 Q.J.G.S. 1874, p. 124, ,
3844 G. W. Bulman—Glacial Geology.
valley ; the few sections seen show plainly enough that masses of
sand and gravel pass into, and are interwoven with clay drifts in
such a way as to defy any attempt at separation over large areas,
although single sections may be indicated which do show a definite
sequence.”
An inspection of the remarkable series of sections from the
cuttings of the Settle and Carlisle Railway given in Mr. Goodchild’s
paper, showing the intimate interweaving of stratified sands and
gravels and laminated clays with till and boulder clay, indicate the
utter impossibility of referring the former to a distinct period.
And it is interesting to note that, “towards the mouths of the
rivers, the total quantity of clay in the whole accumulation of drift
steadily decreases, until very little else than clean sand and gravel
is to be found, except in the maritime districts, where the true
boulder-clay comes on.” For, as the ice descended the valley, the
greater would be the amount of aqueous action, and the less that
of ice proper.
The glacial deposits of Lincolnshire, and the neighbouring parts,
may be cited as apparently favouring the view of interglacial epochs.
Mr. Searles Wood (Q.J.G.S. vol. xxiv. p. 146) divided the series
as follows :—
Hessle clay.
Hessle sand and gravel.
Purple clay.
Sands and gravel.
Basement clay (Chalky boulder clay).
He maintained that there was a great break below the Hessle
beds, and separated these from the glacial series altogether.
Supporters of the hypothesis of warm interglacial epochs will
find evidence for these in the intercalated gravels, and in the
supposed breaks in the series.
For, the result of the survey of the district by Mr. Jukes-Browne,
leads him to place another break between the chalky boulder clay,
and the purple clay, although he repudiates the break higher up
established by Mr. Wood.
A consideration of the facts brought forward by Mr. Jukes-
Browne (Q.J.G.S. vol. xli. p. 114), in his paper on the Boulder clay
of Lincolnshire, shows that the series of deposits—even if the
above division can be shown to be chronological—does not
necessarily indicate climatic changes.
In the first place the chalky clay and the purple clay are not
found together in one district; the former occurs on the west of the
Wolds, and the latter on the east.
‘“‘In East Lincolnshire,” says Mr. Jukes-Browne, ‘there are only
three localities where the Brown Boulder-clay comes into contact
with the White Boulder-clay.” And after describing these junctions,
he concludes that the appearances at these places are not against the
supposition that the brown clays pass into chalky clay.
Other considerations, however—which do not appear to me con-
clusive—incline him to conclude that the-two clays are separable
chrono ogically. But, whether this is so or not, the fact remains
G. W. Bulman—Glacial Geology. 345
that, in the absence of sections, there is here no evidence of an
interglacial epoch between the periods of the chalky and purple clays.
Again, glancing at Mr. Jukes- Browne’s map, one is inclined to ask,
why, on the hypothesis that the formation of the purple clay was
subsequent to that of the Chalky, none of the former was laid down
on the latter over all that region west of the chalk Wolds where it
occurs; while at the same time it does occur further west and north
away from the chalky boulder clay? And why, on the other hand,
the chalky clay is not found beneath the purple on the east of the
Wolds ?
As regards the division between the purple and Hessle clays,
Mr. Jukes-Browne shows that the sands and gravels separating
them graduate into both lower and upper clays; the sand beds
containing patches of boulder-clay, and the latter beds of sand in
the usual way. He concludes finally that there is no break between
the clays.
The presence of Cyrena fluminalis, noted by Mr. Wood in the
Hessle beds, may be taken as an indication that the climate was
ameliorating as the ice gradually disappeared.
Prof. Geikie points to the Interglacial beds of other countries as
additional evidence of mild interglacial periods in our Northern
hemisphere—he claims it, in fact, from every country yet examined :
“Tn every country where the glacial deposits have been studied, we
have clear proof of a mild interglacial period having supervened.” '
The intercalated beds of Switzerland are of special interest, con-
sisting as they do of seams of lignite from two to five and some-
times even twelve feet thick, and which have been worked for fuel.
They are made up of the remains of peat-forming plants, and rest on
sand and clay, beneath which is the grund-morane. Remains of
Pines, Oaks, Birches, Larches, etc., occur in these lignites, from
which Prof. Heer, has inferred that the climate, at the time of its
formation, was the same as that of Switzerland at the present day.
The inference drawn by Prof. Geikie is, “that the great mer de
glace eventually vanished from the low grounds, and the glaciers
shrunk back again into the deep mountain-valleys. The climate
grew as mild as it is at present. Oaks, Pines, and other trees
overspread the ground, and many large animals became denizens of
Switzerland. That this condition of things must have endured for
‘a long time no one can doubt. Nor could the change from the
intense glacial climate of the great mer de glace have been other
than gradual. The glaciers would slowly retire, and many ages
would elapse before the condition became such as to induce the
growth of Oak-trees. After the genial climate that nourished these
trees had lasted for untold centuries, the cold again increased.
Slowly the glaciers crept down the valleys. Little by little, year
by year, they continued to advance, until at last, escaping from the
mountain-valleys, they deployed upon the low grounds. And now,
encroaching upon, and eventually occupying the basins of the
1 Great Ice Age, p. 491.
346 G. W. Bulman— Glacial Geology.
Alpine lakes, they crept out from these and piled up great end-
moraines upon the lower grounds beyond.”’!
Prof. Heer’s inference as to climate is, however, somewhat incon-
clusive. Pine, Oak, Birch, and Larch are doubtless native trees in
Switzerland at the present day, but do they not occur up to such
heights that they might easily be mingled with the deposits of the
present glaciers, especially during some of those minor oscillations
to which these are subject? And if those in the lignites are proved
to be intercalated with glacial deposits, it may not mean any more
than that these temperate forms of vegetation approached the ice
of the glacial period as nearly as the same trees approach the ice
of to-day. But the evidence that the growth of these trees was
succeeded by a glacial period is less satisfactory than that it was
preceded by the same.
The lignite is surmounted by sand and gravel upon which are
several large alpine erratics. This is certainly suggestive, but
hardly sufficient; for, to quote the authors of the Manual of the
Geology of India, such “ presumed erratics” are the “least certain
form” of evidence of glacial action. And in considering such the
enormous carrying power of Alpine torrents is perhaps too much
lost sight of.
“But,” says Prof. Geikie, “the erratic blocks that overlie the
lignite are not the only evidence of this second advance of the
glaciers. That the ice after retiring from the Jura to the mountain-
valleys did again invade the low country had been inferred before
the interglacial character of the lignite beds was discovered. It had
been known for years that the first ground-moraine and ancient
alluvium were overlaid by newer ground-moraines, terminal
moraines, and alluvium; the meaning of this having been pointed
out by Morlot as far back as 1854.” ?
The facts adduced by M. Morlot, however, can scarcely be con-
sidered conclusive evidence of two glacial epochs separated by a
prolonged warm interval.
In his paper he speaks of two glacial periods, a general mighty
glaciation, and a more limited local glaciation. The evidence adduced
is the presence of “diluvial drift” on boulder-clay.
‘‘ During the diluvial period,” he writes, ‘the glaciers had entirely
disappeared, as has been shown, whilst after the diluvial period the
glaciers returned, leaving on the diluvial terraces abundant deposits.’’?
M. Morlot mentions examples of this “ diluvial drift” overlaid by
erratics, and others of the same drift lying upon till; but he brings
forward no case where it lies between glacial beds.
The formation of the loess is attributed to the glacial period.
The evidence of the glacial origin of the loess, however, is far from
certain, nor is the opinion that it thus originated by any means
universal among geologists; so that any argument drawn from its
presence on supposed interglacial beds is inconclusive.
1 Great Ice Age, pp. 405-6.
* Edinburgh New Philosophical Journal, 1855, p. 14.
3 Edin. New Phil. Journ. 1855, p. 18.
G. W. Bulman—Glacial Geology. 347
Prof. Geikie agrees with M. Morlot as to the relative severity of
the two glacial epochs:
‘The glaciers of the second period, although of very much larger
dimensions than their puny descendants of to-day, yet were them-
selves but pigmies as compared to the gigantic ice-flows of the first
eriod.”
: But surely it would be difficult, or even impossible, to distinguish
between glacial deposits formed at two distinct epochs of such
character separated by a mild interval, but with no distinct memorials
of the latter, and a series of deposits formed by ice-sheets and
glaciers continuously or intermittently retiring. If the ice, after
gradually retiring to a certain point, made a prolonged pause before
finally shrinking to its present limits, we might expect to find two
apparently distinct sets of deposits such as those described, and one
of which indicated a much more limited extent of ice. In fact, all
the phenomena of these Swiss beds here mentioned are not only
possible on the hypothesis of an oscillating and intermittently
retiring body of ice, but are exactly such as we should expect on
this view.
And Prof. Prestwich does not consider the evidence of these beds
—nor indeed the evidence for interglacial periods generally—as
conclusive.
“It is asserted,” he writes, ‘“‘ that in Europe there were interglacial
periods during which the ice disappeared from the surface for great
lengths of time. But either the evidence is insufficient or it points
to slight temporary effects, except in one case, which is of more
importance, and on which the greatest stress is laid, namely, that of
Diirnten in Switzerland. There beds of lignite with mammalian
remains are intercalated between two glacial deposits. Admitting
the fact that the lignite rests on beds of undoubted glacial (ground-
moraine) origin, and that the trees grew on the spot where their
stumps and remains are found, it by no means follows, as contended,
that because these trees are all of species now living in Switzerland,
the temperature was that of Switzerland of the present day. Pinus
sylvestris, Abies excelsa, the Yew, the Birch, and the Oak flourish
equally in Sweden and far north in Siberia. On the other hand,
there is one species of Pinus (P. montana) which is spread over the
mountain country up to heights of 7000 feet, and is rare in the low
lands; while one of the Mosses is closely allied to a species now
growing on the hills of Lapland. The few species of Mammalia
have a distinctly northern facies. Hlephas primigenius, H. antiquus,
Ursus speleus, as also Cervus elaphus, and Bos primigenius, are
commonly associated with the Reindeer, Musk, etc., and other
Arctic animals of the cold post-glacial times.
Is the return, therefore, of the retreating glacier, supposing the
boulder-gravel above the lignites of Diirnten to be due to direct
ice-action, to be ascribed to anything more than a comparatively
slight temporary change of climate, like those that now for a
succession of seasons cause, from time to time, a temporary advance
of the glaciers, only more marked? _ We must allow, of course,
348 J. H. Cooke—Geological Notes on Gozo.
for greater differences and longer intervals of time than now
DOTS Sues ale But the beds of stratified sand, gravel, and boulders
overlying the lignite are more likely to have been the result of
glacial torrents than of the direct super-position of the ice which
may have again approached, but is not proved to have ever covered
the spot.” }
(To be concluded in our September Number.)
II.—Norers on THE “ Pietstocens Beps” oF Gozo.
By J. H. Cooxs, F.G.S.
N the year 1874 a letter signed by Messrs. Feilden and Maxwell
appeared in the Maltese Journal “I1 Barth,” in which attention
was drawn to a Post-pliocene deposit, said to have been found in the
vicinity of Cala Dueira and I Kala, in Gozo.
A specimen of the deposit, together with a number of shells, that
were found in the bed, were forwarded to Prof. Seguenza, who,
after having examined them, expressed an opinion that the discovery
was one of much importance. From that time to this no further
attention appears to have been paid to the matter.
During the latter portion of the summer of 1890 I was engaged
in investigating the geology of the Dueira district, and, it was in the
course of one of my expeditions that I first discovered evidences of
the bed to which Messrs. Maxwell and Feilden had alluded seven-
teen years ago.
Cala Dueira is a small bay, which is situated at the western
extremity of Gozo. Its southern and eastern shores are bounded
by mural cliffs of Lower Coralline Limestone,’ that tower above the
level of the sea to a height varying from 150 to 200 feet.
In consequence of a fault, that extends from Monsciar at the head
of Wied-el-Arab to Dueira, the eastern boundary of the bay has been
let down, and the cliffs are, therefore, no more than 20 feet high in
some parts, while towards the west the strata shelve gradually off,
and finally disappear in the sea.
At the mouth of the bay there is an outlier of the Lower Coralline
Limestone, which is known as the ‘‘ Fungus” or ‘“‘ General’s ” rock.
It once was apparently a continuation of the now depressed northern
boundary. The bay, itself, forms the embouchure of the Dueira
valley, the catchment area of which is bounded on either side by
a fault of considerable magnitude. That on the northern side
extends from the “ General’s” rock to the northern base of the hill
known as Ghar-Ilma. The down-throw that has resulted from this
1 Q.J.G.S. 1888, pp. 402-3.
2 The following table shows the order in which the Maltese formations occur :—
Dr. Murray’s Capt. Spratt and Dr. Adam’s
Classification. Classification.
I. Upper Coralline Limestone. I. Upper Coralline Limestone.
II. Green Sands. II. Sand bed.
III. Clay beds. III. Marl beds.
IV. Globigerina Limestone. IV. Freestone.
Y. Lower Coralline Limestone. . Y. Lower Limestone.
J. H. Cooke— Geological Notes on Gozo. 349
fracture, has depressed the area to the south of it to about 40 feet
below the top surface of the Lower Limestone escarpment, that lies
exposed along the line of fault.
The fault on the southern side of the bay extends from Dueira via
Monsciar to Miggiar Scini, and the result of its fracture has been to
depress the area to the north of its line.
The accompanying map will show the relative positions of these
two faults, and the effect that they have had on the area that lies
between them.
Map oF A Part OF THE IsLAND OF Gozo, NEAR Matta.
EXPLANATION.
a. Upper Coralline Limestone; 4. Green Sands; ¢. Marl;
d. Globigerina Limestone ; ¢. Lower Limestone ;
J. line of fault which has disappeared North of Ghar-I]ma ;
J’. line of fault extending to Monsaar, and thence to Miggiar Scini ;
A. Pleistocene.
The strata that have thus been let down are much broken and
displaced ; and, on the southern slope especially, there are several
minor faults, all of which wend in a direction that is at right angles
to the main fracture.
The beds on both sides of the valley slope at varying angles, in
many cases the inclination being as much as 45° and even 60° out
of the horizontal. The beds dip inwards, and the result of the
synclinal depression, which has thus been formed, is the Dueira
valley, the bed of which is represented by the trough of the syncline.
an
350 J. H. Cooke—Geological Notes on Gozo.
The southern slopes are very uniform in outline; but those on the
northern side are divided into a series of smaller valleys or gullies,
down which miniature torrents pour their waters for a few occasional
hours in the winter time.
The deposits of which the valley is composed do not consist of
the Lower Coralline Limestone as is represented in the Geological
Map of the Island, which was published by Ducie, Spratt, Adams,
and Murray. On the contrary, the Lower Limestone is entirely
absent save where it is exposed along the lines of faults that bound
the valley ; and the deposits consist of all of the beds that are found
interstratified between the uppermost and the lowermost of the series.
The Globigerina Limestone is the predominant rock; but the blue
and yellow clays,’ and the Greensands,’ are also to be found in situ
along the southern slopes.
Fringing the upper portion of the sides of the valley the Lower
Limestone may be seen marking the line of fault, with the Globi-
gerina beds of the undisturbed district above it, and those of the
depressed area beneath it. The. former relation that existed
between the depressed area and its surroundings is therefore
distinctly apparent.
I have entered thus into detail because some misapprehension
appears to have formerly existed with reference to the geology of
this part of the island. Instead of being a valley of erosion similar
to the Kaura, the Scini Sclendi, Asel and the Yebbug gorges, it is
simply a depressed area, which has been let down by the dislocation
of the strata on either side of it. It is also important that these
details should be carefully considered; as on their correct repre-
sentation depends the evidence that must be adduced for proving the
the relationship which formerly existed between the Pleistocene
deposits found in the valley below the line of fault, and those found
on the summit of the slopes above it.
It was while engaged in noting the points of difference between
the geology of the district, as it is represented on Ducie’s. map, and
that which actually exists, that I first came across the Pleistocene
bed which I am about to describe.
Starting at the head of the valley and proceeding towards its
mouth, the Globigerina strata will be observed sloping down the
valley side at angles of varying magnitude; and breaking off
abruptly towards the lower part, thus forming cliffs of from 10 feet
to 15 feet in height. Fringing the slopes that lie beneath these
escarpments, there is a bed of white limestone, overlying a bed of
yellowish grey loam.
The deposit may be traced for some distance down the valley ;
but in some places owing to the denuding action of several small
streams, that have cut their way, it will be found to occur in
patches only.
It is elevated at a height of from 20 to 30 feet above the present
bed of the valley; and it extends, East and West for a distance of
about thirty yards, and North and South for about fifteen yards.
1 Bed III. * Bed II.
¢
J. H. Cooke—Geological Notes on Gozo. dol
It is lenticnlar in shape, but breaks off abruptly at the lower
side, and an escarpment is thus formed, which shows the maximum
thickness of the bed to be about 7 feet, while at the extremities it
thins out to 18 inches and a foot.
Its upper surface is extremely hard; and like the surfaces of
the surrounding strata, it has been considerably honeycombed and
otherwise weather-worn.
The materials of which it is composed are very uniform, both in
general appearance and in arrangement. They consist for the most
part of fine detrital matter, the product, apparently of the erosive
action of the atmosphere on the Upper Coralline, the Greensands
and the Globigerina beds.
The deposit is divisible into two well-marked zones, the most
persistent features of each of which are the irregularity of its
divisional planes and its non-crystalline character.
The top zone consists of an impure, perfectly formed limestone
of a whitish colour, and it is usually overlain by a thin, stalagmitic
layer of about one inch or less in thickness.
A chemical analysis showed a sample of this bed to consist of
about 80 per cent. of carbonate of lime.
In many parts of the bed, minute perforations are noticeable
traversing the rock in all directions. They vary considerably both
in length and in the diameter of the bore. None of them exceed
sth of an inch in diameter, while many of them are much less.
These capillary tubes often play an important part in determining
the direction in which the rock cleaves. They are, however, not
persistent throughout the formation, and are more numerous in some
parts than in others.
This upper division of the deposit is very fossiliferous; but,
owing to the imperfect character of the rock, the Mammalian
remains are seldom found in a perfect condition, and even when
found entire, they are often so rotten that they fall to pieces under
the slightest pressure.
Besides large quantities of land-shells, and mammalian remains,
the teeth and vertebrate of Sharks, Echinoderms, several species
of Corals, and other representatives of a marine fauna occur. All
of these latter have, however, been derived from the Globigerina
Limestone.
The following is a list of the organic remains that I have found
in this bed.
Marine.
Two teeth. (Oxyrhina hastilis).
One tooth. Oxyrhina xiphodon.
(Both of these species are characteristic of beds 2, 3, and 4.)
Flabellum, Zoantharia, and Corallines. One Echinoderm (Schiz-
aster, sp.).
LAND SHELLS.*
Helix vermiculata (Mull.) (common). Helix virgata ? Mont.
Helix pisana (Miull.) (common). Helix caperata ? Mont.
Helia striata (Drap.). Pomatias melitensis (Sow.).
* Kindly identified by Mr. E. A. Smith.
302 J. H. Cooke—Geological Notes on Gozo.
FoRAMINIFERA.
In the washings of about two pounds of the material, the following
Species were observed :
Orbulina universa, ad’ Orb. Truncatulina ungeriana, d’ Orb.
Globigerina bulloides. Nodosaria sp.? (broken).
Cristellaria sp. ? Nodosaria obliquestriata, Reuss. (broken).
Clavulina cylindrica, Hantken. Many fragments of others.
Of the land shells the most numerous are those belonging to the
Helicide.
The specimens are always found in an excellent state of preserva-
tion, and in some cases even the original colour of the bands being
preserved. Minute specimens of Helix virgata? appear present in
the greatest abundance; and by washing a portion of the deposit in
a sieve, considerable quantities of them may be obtained.
Next in descending order occurs a layer of yellowish grey loamy
earth, but the transition between it and the overlying limestone is
so gradual, as to render it a matter of considerable difficulty to
determine where the one ends and the other begins.
Being of a loose texture the bed easily disintegrates, and thus, by
undermining the superincumbent strata, it causes portions of them
to break away from the main mass and roll down the slopes.
This loam, like the overlying limestone, abounds in fossil land-
shells; but no Mammalian remains appear to be present. Water-
worn pebbles of all shapes and sizes are to be found interspersed
throughout every part of the bed; but in the loam, though they
are more numerous than in the indurated rock above; they are, in
the aggregate, much smaller. An examination of a number of these
pebbles shows that they have been derived from the three great
limestone formations of the islands (Beds I. LV. and VY.) in, approxi-
mately, the following proportions :—
Bed I. Upper Limestone ... ... ... ... ... 100 15 per cent.
Bed IV. Globigerina Limestone ... ... ... ... 50t070 ,,
Bed YV. Lower Limestone ... ... ... ... ... 201030 ,,
Black Limestone ... . 10 to 15
All of these pebbles are much harder than the rock from which
they were derived; and, when broken, they usually present the
appearance of a hard external ring of rock of a semi-crystalline
character, within which is encased a nucleus of limestone, that is
similar in every respect to the rock of the bed from whence the
pebble bed had been derived.
This change in the external part of the pebble is apparently due
to the infiltration of the limewater, which, after depositing its burden
of lime in the interstices of the stone, slowly evaporated, and thus
leaves the stone more compact and of a closer texture that when the
water was first absorbed in it. The same phenomenon is observable
wherever the Limestone beds of the Maltese Series crop out as a
surtace deposit.
Another remarkable feature of this Pleistocene bed is the extra-
ordinary quantity of Black Limestone pebbles that occur in it.
Notwithstanding a diligent search in the district around, I was
J. H. Cooke—Geological Notes on Gozo. 353
unable to discover any traces of a formation partaking of the
lithological characteristics of these pebbles, to which they might
have been referred.
Proceeding down the valley in a westerly direction, four mounds
of blue and yellow clay (the marl beds of Spratt and Adams), are
to be seen resting conformably on the southern slope, at an elevation
of about 20 feet above the bottom of the valley; and in two cases,
the black and yellow sands, that are invariably found to overlie the
stratum, are also present.
On the summits of these clay-beds, there occur cther patches of
the Pleistocene deposit; but unlike those portions that have just
been described, these are not in siti, but have been formed, ap-
parently, by the degradation of beds, that were originally deposited
higher up the slopes. The materials of which these cappings are
compused appear to differ but little from these of the other portions
of the bed, save in the total absence of perfect shells, and the
comminuted condition in which the fossil bones are found. Such
are the principal characteristics of the Pleistocene deposits that are
found along the southern slope of the Dueira valley.
The following sketch shows the relative positions of the subdivisions.
A. Greyish, non-crystalline, slightly indurated limestone. Helices and other land-
shells occur in abundance ; but no Mammalian remains appear to be present.
B. Limestone of a similar character to A, but interstratified with irregular layers of
stalagmite. These layers vary from } to 4 of an inch in thickness.
C. A layer of boulders and pebbles, all of which have apparently been derived from
beds IV. and V. Some of the boulders measure eighteen inches, and two feet
in length ; and all of them are rounded, and otherwise much water-worn.
D. Loam intermixed with quantities of smaller pebbles. Black limestone pebbles
occur in this layer in abundance.
E. A yellowish grey loam, similar in every respect to that which occurs at the base
of the other deposits. It abounds with Helices and other land-shells, but no
Mammalian remains were found in it.
If, now, the road which winds up the hill-side towards Gebel-ta-
Ben-Giorgio, be traversed, the observer will pass from the Globi-
DECADE I1I.— VOL. VIII.—NO. VIII. DR
354 J. H. Cooke—Geological Notes on Gozo.
gerina Limestone of the depressed district, across the line of fault
marked by the Lower Limestone, to the Globigerina above it.
On the right-hand side of the pathway, that runs through this
elevated region, and at a distance of about a quarter of a mile from
St. Georgio, another remnant of the deposit may be seen.
Passing down the hill again, and crossing to the northern slopes
of the valley, another development of similar accumulations, of even
greater extent, will be met with.
These beds, however, present many striking points of dissimilarity
to those on the opposite side of the valley. Like the deposits on the
southern slope, they extend in an east and west direction, and lie
unconformably on the Globigerina Limestone. They occupy a kind
of platform on the hill-side, and towards the lower boundary they
break off and form an escarpment of from 6 to 8 feet in height.
Approaching the valley from the Kaura Gorge, an excellent section
of the bed is to be met with about 150 yards down the slope. Its
‘ace forms the northern boundary of a field, a large portion of the
oil of which has, apparently, been derived from the deposit. This
section shows the bed to be made up of a number of layers, each
of which differs in a most marked manner from those above and
below it.
It will be seen, therefore, that, though agreeing in some respects
with the formation on the opposite side of the valley, there are also
many important points of dissimilarity.
The most striking of these may be seen in the following table of
comparison.
Deposit oN THE SoUTHERN SIDE. Deposir on THE NortHern SIDE.
a. Boulders are comparatively small, a. Boulders are large, and are dis-
and are interspersed throughout the tributed in well-defined layers.
bed. b. The loam is overlain by alternating
b. The loam is overlain by a single layers of pebbles, boulders, lime-
layer of limestone. stone and stalagmite.
c. Mammalian remains. c. No Mammalian remains.
The distinct evidences of stratification that are apparent in every
part of the beds offer unequivocal proofs of their aqueous origin ;
and that is a conclusion that is still further borne out by the rounded
and otherwise water-worn state of the pebbles that occur so plenti-
fully in them. The finer materials, the pebbles, the shells, and
the Mammalian remains have all apparently been collected from the
surface of the surrounding country by the agencies of freshets, and
inundations of a similar character.
From the evidences afforded by the nature and position of the
various portions of the deposits, it would seem as though the surface
configuration of the district has undergone changes of a marked
description since these beds were formed. Thus the occurrence of
patches of the bed both above and below the line of fault would
seem to indicate that their deposition must have taken place ante-
cedent to the downthrow to which the now-existing valley owes
its origin.
What the immediate causes were that gave rise to the flood- waters,
A. H. Foord—Orthoceras vaginatus. 355
it is not my purpose here to attempt to determine. That no ordinary
floods such as now occasionally occur in the winter months, effected
the work of erosion in the Kaura and Dueira districts is a fact that
no one would feel inclined to dispute, after seeing the precipitous
and. rugged sides of the Kaura Gorge, a valley of erosion that lies
a few hundred yards to the north of the Dueira valley. The
denuded condition of the surface in these localities points to the action
of torrential volumes of water; and it was, probably, to the occasional
overflow of these from their ordinary channels, combined with the
transporting action of the rain on the slopes, that the deposits that
form the subject of this article owe their origin.
TIL.—On OrraocerATITES VAGINATUS, SCHLOTHEIM.
By Arnruur H. Foorp, F.G.S.
Royal Dublin Society.
HAVE lately been favoured by Dr. W. Dames with a separat:
copy of a communication made by him to the Neues Jahrbuc
fiir Mineralogie, etc.,! dated Berlin, 18th December, 1890, in whic.
he points out that in my Catalogue of Fossil Cephalopoda, British
Museum (Nat. Hist.) part i. (1888) I have (following Hichwald*)
wrongly referred a certain ‘“‘smooth” species of Endoceras from
Reval in Esthonia, to the Orthoceratites vaginatus of v. Schlotheim,
—a ribbed species. Dr. Dames states, in the above communication,
that he was asked by Dr. Lindstrém of Stockholm (at the time
when the latter was occupied with his edition of the “ Fragmenta
Silurica”) if he could inform him to what species v. Schlotheim
had given the name Orthoceratites vaginatus. Dr. Dames’ reply to
this question was inserted by Dr. Lindstrom in the midst of a very
full table of synonymy of Orthoceras [ Endoceras| vaginatum,* and in
that rather obscure situation it escaped my notice. The reply in
question was to the effect that the examples of v. Schlotheim’s type,
sent by Dr. Dames from the Berlin University Museum to Dr. Lind-
strom, were without doubt v. Schlotheim’s species.* The latter
(widely distributed in Esthonia, Sweden, and Oeland®) has more or
1 1891, Band i. Zweites Heft. Breifl. Mittheil. ii. p. 210.
* Leth. Rossica, 1860, vol. i. p. 1248.
3 Fragmenta Silurica, Angelin and Lindstrém, 1880, p. 2.
4 The following is a translation of y. Schlotheim’s description of ‘‘ Orthoceratites
vaginatus’’ (Petrefactenkunde, 1820, p. 53):—‘‘ Very beautiful and instructive
examples from Reval, in Ueberg. Kalkst., some part still in the matrix, some free,
and only about five inches long to a diameter of one inch ; besides separate pieces of
its remarkable siphuncle. Cf. Knorr, pt. iii. suppl. t. ivd. and Breynii opuscula,
t. v. f. 26., where this Orthoceratite, together with its elegant, somewhat cylindrical
siphuncle is tolerably well portrayed. The length and thickness attained is, it
appears, very considerable, whilst the siphuncle belonging to it is found of consider-
able stoutness. Its relation to the other part of the OUrthoceratite is so important
that it almost appears as a part of the shell-wall of the latter. It runs, moreover,
close to one side of the shell, which in most of the representations of it is not
properly indicated, and its protuberances have somewhat of a screw shape; very
ornamental, as if elaborately designed. The shell itself is very distinctly oblique,
with sharp, somewhat forwardly projecting lines, striated in the direction of the
chambers, which latter are bent inwards somewhat stronger towards the siphuncle.”’
° An island in the Baltic, off the east coast of Sweden,
396 A. H. Foord—Orthoceras vaginatus.
less distinct transverse coste, and is also covered with conspicuous
transverse striz. On the other hand, the species described by
Hichwald under the name Orthoceras vaginatum (and by the present
writer under that of Endoceras vaginatum) has a “smooth” test,
numerous chambers, and a remarkably large siphuncle, larger in:
fact than that of v. Schlotheim’s species. Doubtless, continues Dr.
Dames, Hichwald was led into this error by v. Schlotheim’s citation
of a figure in Breyn (Dissertatio physica de Polythalamiis, etc.,:
1732, p. 36, t. v. ff 1-4), which apparently represents a smooth
Orthoceras. Dr. Dames then goes on to say that the specimens
called Orthoceratites vaginatus by v. Schlotheim himself in the
paleontological collection of the Royal Museum of Natural History
in Berlin are all typical, well-preserved specimens of Orthoceras
vaginatum, with ring-like swellings [coste], and distinct striz.
When, observes Dr. Dames, v. Schlotheim published his “ Petre-
factenkunde” [1820], he possessed only Esthonian specimens; but
Jater on he received several from Oeland, and as they were identical
with the others, he placed them in the same species, and labelled
them accordingly. In the Catalogue of Schlotheim’s collection,
printed in 18832 (p. 82), Oeland is mentioned as the locality, and
the quotation from the “Petrefactenkunde” has been added. It
therefore appears, says Dr. Dames, that in his reference to Breyn
v. Schlotheim has compared a species with Orthoceras vaginatum
that has no connexion with it. Concluding his remarks, Dr. Dames
says that all the specimens in v. Schlotheim’s Collection, which he
[v. Schlotheim] has named Orthoceras vaginatum, belong to the
species (recognized as such by all authors except Hichwald and
Foord) which is distinguished by its transverse ribs and strie.
In strict equity v. Schlotheim’s name vaginatus ought long ago to
have been superseded in favour of Hisinger’s trochleare, because the
former was admittedly inadequately described, while the latter was
not only described, but figured,’ in an intelligible manner. It is true
that Hisinger had an inkling of the form to which v. Schlotheim
had applied the name Orthoceras vaginatum, for he inserts that name
(though with a note of interrogation after it) under his description
of Orthoceras trochleare. That v. Schlotheim’s description of Ortho-
ceras vaginatum was unintelligible even to those who had abundant
specimens of it at their command, is clearly proved by the fact that
Dr. Lindstrém was obliged to appeal to the type-specimens in Berlin
to ascertain what was the species to which v. Schlotheim had applied
that name.
However, in deference to Dr. Lindstrém’s authority, added to the
testimony afforded by the specimens at Berlin under the care of
Dr. Dames, I cannot but assent to the adoption of Schlotheim’s
name for the species in question, and I take this opportunity also
of tendering my thanks to Dr. Dames for pointing out the error into
which I fell with reference to Hichwald’s species. On comparing
1 Lethea Suecica, 1837, p. 28, Tab. ix. fig. 7. The name Orthoceras [ Endoceras|
trochleare appears to have been originally bestowed by Dalman. See Hisinger’s
Anteckningar i Physik och Geognosie, femte haftet, 1831, p. 12, Tab. iv. fig. 3.
Rev. Dr. Irving—An Ancient Estuary. 307
a specimen of the latter in the British Museum with the Endoceras
zaddachi of Schréder,! I can see no reason for changing the opinion
I formed about it when writing part i. of the Catalogue of Fossil
Cephalopoda, viz. that the two species are identical. The vayinatus
of Hichwald (non Schlotheim) becomes therefore a synonym of
zaddachi, Schroder, and not vice versa, as in my Catalogue.
TV.—Puysicat Srupies oF an Ancient Estuary.’
By the Rev. A. Irvine, D.8c., F.G.S.
T is needless to recapitulate, for the information of the readers
of the GronogicaL Magazine, all the incidents which are
known to accompany the formation of new land by rivers, or to
repeat the descriptions which have been given of the more remark-
able instances of them, such as those of the Nile, the Mississippi,
the Ganges, the Rhone, the Po, and the Danube. These have been
scientifically discussed long ago, by Lyell in his Principles. The
object of this paper is rather to suggest how a eareful collation
of such facts as may be learned in connexion with the formation
of modern deposits at the mouths of great rivers, or in great
estuarine areas (such as the Wash), which receive a number of
streams from widely-extended inland catchment-basins, may throw
light upon the history of older formations of the same kind, and
more especially of those of Tertiary times, during which many
important changes were wrought in the physiography of the
continent of Europe.
As instances of the work done by rivers in making new land,
especially when aided by tidal action, within historic times, one
might cite the case of the Po, co-operating with the Alpine rivers
which come down from the Venetian Alps, forming a _ great
series of lagoons around the head of the Adriatic Sea, or the
advance of the land upon the sea, which has placed the town of
Ravenna (a sea-port under Augustus) several miles from the shore ;
or again, the proved advance of the delta of the Rhone upon the
Mediterranean, which has been found to place the Tower of St.
Louis a league or so further from the shore in the short space of
a single century. But these, and such cases as these, are hardly
necessary, when we have here in our own Humber the formation
of Sunk Island within the course of a few centuries. This island
(so-called) is probably well known to Yorkshiremen, but perbaps
a comparatively small number of them are aware of its importance,
from a geological point of view, as a testimony to the work done by
rivers in compensating to some extent the work of degradation and
denudation of the higher parts of the country, which is ever in
progress, year in year out. This island has been formed by the
deposition of sedimentary materials by the rivers Ouse, Trent, and
Hull, as their onward flow has been checked, and their transporting
1 Schrift. der physikal-ékonom. Gesell. zu Kénigsberg, Jahrg. xxii. Abth. i. p. 93,
Taf. iv. ff. 5, a—d.
2 Paper read before the British Association, Section C, at the Leeds Meeting, 1890.
308 Rev. Dr. Irving—An Ancient Estuary.
power proportionately lessened, by the counter-force of the tides,
rushing up the estuary of the Humber; a process, to the reality of
which every ‘dredge’ employed bears testimony. This process,
which the French geologists aptly term ‘atterrissement,’ is well
exemplified in the fact that Sunk Island (a genuine island under
Charles II., then just raising its head above the water-line) presented
140 years ago an area of 1500 acres, and was, even then, being
brought under cultivation. About the beginning of the present
century its acreage was doubled to 3000 actually under cultivation ;
and in 1854 the survey returns gave between 6 and 7 thousand
acres, showing that in the present century the rate of alluvial deposit
taking place has greatly increased. The saying of the first Napoleon
that, Holland naturally belonged to France, because it was made up
of the mud of a French river (as he considered the Rhine), is, I
dare say, well known.
Prof. Green in his valuable and deservedly popular text-book of
«« Physical Geology ” has discussed the geological principles involved
in the formation of a great series of estuarine deposits, with their
constant alternation of fresh-water, brackish, chemical and terrestrial
formations, their current-bedding, and the wedge-shaped interlacing
or interdigitation of beds of different mineral composition. This
interdigitation arises for the most part when a series of rivers
draining tracts of country of different lithological character, con-
verge to a common estuary ; but in cases where the deposits have
been laid down, and the process of atterrissement has gone on, in the
neighbourhood of the mouth of one great river (with perhaps minor
affluents) this characteristic is less marked, and we then find that
the vertical variation of the rock-character of the series constitutes
its principal feature, the successive deposits being traceable over
miles of country.
My own studies of the Bagshot Beds of the London Basin have
led me to regard them as in the main a mixed series of fluviatile,
terrestrial and truly estuarine deposits, laid down under some such
conditions in later Eocene time. There is a general vertical
sequence traceable through the area, as Prestwich recognized long
ago, with variations laterally of percentage of lithological con-
stituents and homogeneity of structure, of the several beds. By
the term ‘estuarine’ I mean to indicate those deposits which
are laid down in the open area into which the river flows, and
to which the ocean-tides have access; a connotation supported
both by etymology and the usage of earlier writers on geology.
Such deposits are thus distinguished in a real sense from those
which are deltaic or fluviatile. A parallel case might be cited
in the still older Eocene series known as the Lignitiferous Series
of the Soisonnais; a series of numerous alternations of sands,
clays, and beds of lignite, while the fossils met with indicate
a special régime; shells of mollusca essentially marine (as Ostrea
and Pectunculus) occurring along with others (such as Melama,
Melanopsis, Neritina, Cerithium) which are known to prefer the
mouths of great rivers for their habitat, while such strictly fresh-
Rev. Dr. Irving—An Ancient Estuary. 309,
water shells as Paludina are also found.1 Now the Bagshot Series
do not present us with quite such a complex of alternating conditions
as is recorded in the Lignitiferous Series of the Soisonnais: they
rather mark a progressive series of changes from strictly fluviatile
conditions to those which prevail in a marine estuary. The physical,
the stratigraphical, and the paleontological lines of evidence all
agree in testifying to this fact; a fact that can only be satisfactorily
explained by the phenomenon of a slow subsidence with inter-
mittent pauses of long duration, during which the relative levels
of sea and land remained pretty stationary.”
The starting point in the investigation of the physical history of
the London Bagshots was the discovery of the organic origin of the
green colouring matter which is so commonly found in these sands at
certain horizons. Various salts of iron are formed in this way,
which uitimately break up by exposure to atmospheric oxygen ;
their non-metallic constituents are resolved into carbonic acid and
water, while the iron is precipitated as limonitic mud. So com-
pletely was this proved to be a true process of nature, that I was
able to make it the basis of a process for the purification of water
contaminated by dissolved vegetable matter, for which a patent was
granted me in the year 1885. Not only limonite but iron pyrites
is formed, the latter by the sulphur, furnished by the decay of
vegetable albuminous matter, attacking iron. Both these minerals
are of very common occurrence in the Lower and Middle Bagshot
strata; and both serve as cementing material for nodules which we
frequently meet with both in the sands and in the more sandy
varieties of clay. Even lignite in a fragmentary state is not un-
common, reminding us of the great brown-coal deposits of the
Continent of about the same age.
The limonite is deposited in large and small concretionary masses,
and sometimes in continuous layers, resembling in every way that
which is dredged up from the Swedish and Canadian lakes, to be
utilized as iron-ore; the excellent quality of Swedish iron being
largely due to the fact that a pure chemical precipitate of iron oxide
is thus made the basis of its manufacture. As there the conditions
of primeval forest prevail over a large proportion of that Archean
region, and the decay of forest litter furnishes the acid solvents for .
the leaching-out of iron from the rocks, the iron being precipitated
as the water undergoes oxygenation in the shallow lakes; so here
in this ancient Eocene delta vegetation has by its decay furnished
the solvents; the same cycle of change, and the same laws of nature
have been in operation. As solvents, too, of silica in the presence
of strong bases, these organic acids may have played their part in
1 See Prof. Stanislas Meunier, ‘‘Les Causes Actuelles en Géologie,” pp. 269, 270.
2 I may be allowed to refer to a sketch in a popular form, of what I conceive
to have been the outline of the history of the Thames Basin, as I put it forward in
a lecture last winter, a summary of which appeared in ‘‘ Science Gossip’’ for May
and June, 1891. I should like to draw particular attention to the many points of
similarity between the conclusions I have arrived at as to the Tertiary history of this
part of England, and those arrived at by Prof. Sacco of Turin, as to the Po Basin.
(See ‘‘ Bull. de la Soc. Belge de Géologie, etc., tome iv. 1890.)
360 Rev. Dr. Irving—An Ancient Estuary.
the formation of the glauconite (essentially a mixture of hydrous
silicates of potash and the oxides of iron'), which gives such a
marked character to the green earthy sands of the Middle Group,
and helps to testify to their lagoon-origin. [The minute flakes of
glassy silica described in previous papers, as well as the secondary
crystals on the quartz grains, are, I believe, authigenous products ;
while the abraded scales of mica, so common in the sands associated
with the clays of the formation, are in all probability allothigenous
material, testifying to the erosion and denudation in later Hocene
time of the crystalline rocks of the mountain-system to the west,
which furnished the head-waters of the great Hocene river. |
“‘ False-bedding,” both on the larger scale and on that smaller scale
known as “current-bedding ” or “oblique lamination” is a pheno-
menon of extremely common occurrence in the sandy beds of both
the Lower and Middle Group, testifying to the variations in strength
and direction of the currents which laid the deposits down in their
present position. Between the sand-beds (often current-bedded)
there frequently occur, both in the Middle and Lower Group, thin
seams, sometimes mere films, of pure pipe-clay, telling us of alterna-
tion of quiet conditions and the settling-down in still waters of the
fine argillaceous materials, which, as every geologist knows, are
capable of suspension in water for a considerable length of time.
This alternation of conditions is so frequently and so strongly
marked in the interlaminated arrangement of clay and sand in certain
beds of the Middle Group, that, as a physical fact, it was one of the
first among those, with which my earlier observations of these beds
made me familiar, to suggest to my mind a deltaic origin for them.
Some of the older geologists were startled three or four years ago,
at my suggestion that the pipe-clay might be, in part at least,
derived from the Chalk strata, which must have been exposed to
subaérial erosion over considerable areas within the catchment-
basin from which the waters were concentrated to the area in
question. I was able to establish the probability of this by a very
simple piece of laboratory work. A small quantity of the marly
material of the Lower Chalk was pulverized and treated with very
dilute acetic acid. The material was washed and re-washed with
this, until no further escape of carbonic acid could be detected. The
insoluble argillaceous residue settled down after suspension in
water, to form a thin film of pure clay, similar in every way to the
filmy deposits of pipe-clay which we meet with in the Bagshot
Sands. What a feeble organic acid could do in that case might
easily be done in the ordinary processes of nature, with sufficient
time and the conditions prevailing in a deltaic area, by the action
of the humus acids, which decaying vegetation furnishes. The
facts here stated seem, I think, to: justify my refusal to accept the
presence of either current-bedding, or pipe-clay films, or of both
together, as infallible tests of horizons, as has been persistently
urged by one or two workers in the Bagshot Series. The fact
1 See Naumann-Zirkel: ‘‘ Elemente der Mineralogie;’’ Leipzig (Engelmann),
1885. Also, Justus Roth’s ‘‘ Chem. und Allgem. Geol.”’ p. 559.
Rev. Dr. Irving—An Ancient Estuary. 361
established by more extended observations is that a pure massive
clay deposit is found only in the Middle beds, and that the conditions
favourable to its deposit were feebly anticipated in the upper
horizons of the older fluviatile sands, and were feebly repeated in
places in the earlier stages of deposition of the younger Upper Sands.
In the Quart. Journ. of the Geol. Soc. for August, 1887, I have
given many of the results of my studies in the Bagshots, not the
least interesting being the discovery of Freshwater Diatoms in some
of these beds. In a later number of the same Journal (May, 1888)
I have pointed out that the prevalent rounded form of the grains
of sand in the greenest beds points to their having suffered a vast
amount of eolian attrition, in the shifting of sand-dunes by the
wind, before they were deposited in the lagoons, in the same manner
as is now going on on some parts of the shores of the Baltic. To
this kind of evidence we may now add the frequent occurrence of
thin beds and lamine of very pure clay in the very heart of these
green-earth beds, where they are most fully developed, telling us
of the still waters of the deeper portions of these lagoons, never
ruffled by the wildest storms, too deep as yet to allow of the growth
of the vegetation which lined their margins and covered the inter-
vening swamps. We can even in some cases, with the data now
to hand, measure the rate of the thinning out of the green-sand series
as well as of the Lower quartz-sands, and thus at the same time
approximately map the original outlines of some of the lagoons, as
well as measure roughly the amount of local and contemporaneous
subsidence which the underlying clays suffered.!
In the former paper referred to (1887) I ventured to suggest a
natural classification of the beds of the Bagshot Series of the London
Basin into—
a). An Upper Marine-estuarine Series ;
b). A Lower Fresh-water Series of riverine, delta, and lagoon origin ;
in the place of the more empirical division into Upper, Middle and
Lower, which is of no importance except for cartography, and
even there is often as misleading as not.
The fact that occasional fossiliferous bands or zones are met with,
and that some of the forms bespeak a marine habitat, no more proves
the marine origin of this complex of sands, green-earths, and clays
than the marine shells found driven some miles inland by a great
south-westerly gale in the Rhone Delta® prove the marine origin of
its beds; it might as well be argued that the Coal-measures were
a “marine series” because of the occurrence at certain horizons of
the well-known “ mussel-band,” or even of occasional lines of real
marine shells. Colonies of creatures of a more or less marine
character doubtless established themselves here and there in the
more saline parts of the lagoons, and in the Bagshot beds these are
preserved usually as casts in the cemented sand; but in the rare cases
in which actual shell-structures have been preserved, it is certainly
1 Perhaps the Norfolk Broads present some analogy to the conditions which
prevailed in this old Tamisian estuary in later Eocene time.
» Described by Lyell in the ‘‘ Principles.’’
362 Rev. Dr. Irving—An Ancient Estuary.
true, as far as my observations have gone, that, they are much
‘broken, worn, and even comminuted:” for one even tolerably
perfect shell there are hundreds of fragments of shelly débris,
speaking to us eloquently enough of their drifting inland from time
to time from the outer marine area. Some of the little Oysters
O. flabellula) found for example at Yateley, were so much abraded
that it was only after comparing them with many forms in the
Jermyn Street Museum (with Mr. Newton’s kind help) that I could
convince myself of their specific identity.
Toe Upper SAnps.
Messrs. Gardner, Keeping, and Monckton, in a recent paper,'
state that ‘the beds [of the Upper Bagshot], and what can still be
recognized of their fauna, are such as might have been formed in
an open sea of considerable depth.” But this statement amounts to
very little, because, so far as the fauna is concerned, there is nothing
inconsistent with the view that the molluscan forms which they
have tabulated might just as well have been left by creatures which
inhabited a shallow salt-water estuary. This will, I think, be clear
to any one who will take the trouble to work through their list with
the aid of such a reliable work as Woodward’s ‘‘ Manual of the
Mollusca.” That they are right in correlating the Upper Sands of
the London Basin with the Barton of the Hampshire Basin is very
probable; indeed, my own studies, which have proceeded rather on
physical and stratigraphical lines, have led me to the same con-
clusion as that at which they have arrived; namely, that the break
postulated at the base of the Upper Sands is in reality very
inconsiderable. So far from requiring any great length of time to
convert this Eocene delta with its swamps and lagoons into a tidal
arm of the sea, we know that such changes may take place without
any great draft on the bank of geologic time, seeing that within
a 1000 or 1500 years the swamps and lagoons of the Yssel,
through which, Tacitus tells us, Germanicus led his forces against
the immortal Hermann, have all disappeared beneath the waters of
the Zuyder Zee; while several hundreds of square miles of Holland
at the present day are only preserved from permanent submergence
by artificial barriers. Of the comparative rapidity of this later
subsidence of this Hocene area we have evidence in the strata
themselves. It is only by such an encroachment of the sea that
Wwe can give a rational account of the Bagshot pebble-beds, which
recent researches have established as an important fact of Bagshot
stratigraphy. ‘These beds vary in thickness from a few inches to
five feet or more. They are composed of well-rolled flint-pebbles
derived entirely from the Chalk strata, which must have enclosed
this Hocene area of deposition on the south and the north-west. It
may be assumed that no rivers, that could have drained this Chalk
area in Eocene times, even when all allowance is made for its
quondam extension, could have manufactured such vast quantities
of rounded pebbles out of angular flint fragments as we find sealed
1 See Q.J.G.S. vol. xliv. p. 616, 1888.
Rev. Dr. Irving—An Ancient Estuary. 363
up in the Bagshot Beds over a large extent of country in the Basin
of the Thames. We must look, therefore, to the action of a tidal
surf as the only efficient agency. We know by direct observation
how the hardest rock-fragments are converted into smooth pebbles
by grinding along a shore-line under the influence of tides and
storms; and we have plenty of instances of the way in which such
pebbies are piled up into ‘Chesil-banks’ along the seaward margins
of deltas. Even the form of the pebbles themselves testifies to
this as their true history; the discoid form which they frequently
acquire (as may be seen on the coast of South Devon, at Weybourn
on the Norfolk coast, or on the ‘Chesil-bank’ at Portland), being
reproduced in the flint-pebbles of our Bagshot Beds. In one of the
most massive pebble-beds the pebbles are so commonly of a smooth
discoidal shape that I have seen numerous heaps of these picked
out from the pebbles that have been used in making a new road.*
Now when we recollect that the facts cited tell us of shore-action
upon a Chalk shore-line, there is no difficulty in conceiving how
the waters of the Eocene sea may have pursued their destructive
work upon the Chalk of the east of England, as it extended in all
probability at that time much further to the north and east.
When the last great stage of subsidence of the area set in, the
pebbly shingle accumulated in the way here indicated would be
driven inland, strewn over the original delta, and swept in places
along its margin into such shelves or banks of shingle as we actually
find along the northern margin, as far as we have been able to trace
it. Nor do we suppose that there was anything of a cataclysmic
nature in this; for, though the most general distribution of pebbles
is at the base of the Upper Sands, this change did not come on all
at once, as we know from the fact that other and less widely dis-
tributed pebbly deposits occur mixed up with the green earthy sands
of an earlier stage at their uppermost horizon. Again, of the 52
species of Mollusca given by the authors quoted above as found in the
Upper Sands some deduction must be made on account of the very
imperfect way in which they have been preserved (merely casts for
the most part in sand cemented together with peroxide of iron) ;
and of the residuum, as many as ten are represented by their genera,
and two at least by their species in the preceding Middle Group.
These facts seem to warn us against postulating any very con-
siderable temporal break between the two series. That the most
massive banks of pebbles are found towards the western portion of
the area would seem to follow as a natural result of the narrowing
of the area towards the west, and consequently greater driving
power of the tides, as their velocity increased with the narrowing
of the area over which they were driven.
It was this subsidence of the area into a marine estuary which no
doubt furnished the sandy and muddy bottom on which most of its
fauna passed their existence; nor do I think that there is any real
1 Pebbles of this form are frequently used for rough paving-work, in this part of
the country, just as the great market-place of Nottingham is paved with Bunter
pebbles collected from the drift of the Trent valley. The whole of the streets of
Norwich were thus formerly paved with pebbles from the Boulder-clay and Drift.
364 C. Davison—British Earthquakes of 1889.
scientific basis for the hypothesis that the Upper Sands were once
as rich in fossils as the more clayey Barton beds of Hampshire.
The hypothesis of ‘decalcification’ may be run too hard. We must
be allowed to insist upon proof of the fact being given in any case
before admitting it as an explanation. In the case before us we can
understand perfectly well how atmospheric waters, charged with
the humus acids furnished by the decay of forest-litter in this area
of ancient forest-land have first taken up iron in the sands to form
salts of the protoxide, and then, on coming into contact with the
shells embedded in the sands, have by a simple chemical reaction or
interchange of acids and bases substituted for the carbonate of lime
carbonate of iron, to be subsequently broken up by the oxidation
of the iron into the peroxide, which gives the pseudomorphic casts
of the original shells.' I have not, after much study of the question,
the slightest doubt that this is the true history of these ‘irony casts’ ;
and I think that the direct action of merely carbonated atmospheric
waters has had very little to do with their production.
In connexion with these Upper Sands space prevents me from
adding more than to draw attention to the fact that there are I
believe signs in places of their beds having been formed by the
planing down of the sand-dunes of the earlier deltaic stage; the
materials having been stored up to a large extent during the long
period occupied by that stage, and only needing redistribution by
tidal action to give us in part the present beds of the Upper Sands.
The time represented by these few hundred feet of strata, as
measured by the maximum development of their continental equiva-
lents, is seen to be very great; and the study of their physical
history tells us that such a lengthened period of time was required
for their formation. The two series of deltaic clay deposits (entirely
unfossiliferous), with their intervening and intimately associated
green earths, probably occupied by far the greater portion of it.
Compared with the necessarily slow accumulation of materials which
the physical study of these reveals to us, the deposition of the fluvia-
tile sands which preceded them and of the marine-estuarine sands
which succeeded them was probably what might almost be called
a rapid process.
V.—On tHE British Eartuquakes oF 1889.!
By Cuarues Davison, M.A.,
Mathematical Master at King Edward’s High School, Birmingham.
(Continued from page 316.)
(PLATE X.?)
3. Ben Nevis Hartuquake: May 22, 1889.
Time of occurrence, 13h. 58m.; Intensity, about lV. Hpicentrum,
probably not far from Ben Nevis.
1 There is nothing new in this. Dr. Alexis A. Julien explained in this way the
formation of the irony casts in the ‘“‘ Northampton Sands,’’ which are well known.
See ‘‘ Amer. Assoc. Adv. Sci.’’ for 1879.
2 Plate X. illustrates the area disturbed by the Lancashire Karthquake of February
10th, 1889, described in the Grotocican Macazine for July, 1891, pp. 306-316,
forming part 2 of this communication.
‘duit MEMS ISAA,
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C. Davison—British Earthquakes of 1889. 365
I am indebted to Mr. R. T. Omond, Director of the Ben Nevis
Observatory, for the only information I have been able to obtain
with reference to this earthquake. ‘It was,” he says, “sufficiently
strong to make part of the wooden roof creak, but was, as far as
I know, not noticed in any other part of the country.” The few
inquiries that I have been able to make confirm this remark, and I
think we may therefore conclude that the epicentrum cannot have
been very distant from Ben Nevis. The great fault, which crosses
Scotland from Inverness in a south-westerly direction, passes at the
surface within a short distance from Ben Nevis; and being, in
other parts of its course, closely associated with recent earthquakes,
may possibly, by a slip, have given rise to the Ben Nevis shock.
In connexion with this earthquake may be mentioned a slight
shock felt on June 19, 1889, at Th. 40m., at Invergarry, a place
26 miles N.E. of Ben Nevis, and also close to the same great line
of fault. Mr. John Grant, of Invergarry, was kind enough to
send me a note of this shock, and also a list of several others
felt between Jan. 1, 1888, and Jan. 19, 1890. I have followed the
rule laid down by the Swiss Seismological Commission, of not
treating as undoubted earthquakes those which rest on the authority
of one observer only; but, at the same time, I think it is evident,
from the opportunities which Mr. Grant has had for these obser-
vations, that this is a somewhat exceptional case. I add here his
list of the earthquakes felt at Invergarry during the year 1888, as it
has an obvious bearing on the seismic history of the district:
1888.
Jan. 5, dh. 30m., four vibrations, strong enough to shake lamps,
dishes, etc. (Intensity IV.)
Feb. 2, 5h. 5m., one vibration, like the passing of a heavy
carriage.!
Feb. 29, 20h. 10m., one vibration, like a carriage passing.
March 1, 9h. 15m., the same.
April 4, 9h. and 11h., like a light carriage passing.
May 20, 18h. 10m., the same.
July 5, 14h. 30m., the same.
Oct. 22, 13h. 25m., the same.
4. Kintyre HartHquakeE: Jury 15, 1889.
Time of occurrence, about 18h.; Intensity, V. Epicentrum, about
34 miles S.H. of Clachan.
Disturbed area.—I have only succeeded in obtaining records of this
shock from eight places; but the information received from these
and other places is sufficient to enable the boundary to be drawn
with a fair approach to accuracy. Thus, the shock was not felt at
Campbeltown or Southend, nor on the west side of the ridge of
Gigha Island. In Arran, the Rev. J. Johnstone informs me, it
“was felt from Pionmill right by the Crawhill and Lochranza,
passing through the glen that enters Lochranza from Sannox.”
1 This earthquake was felt over the greater part of northern Scotland.
Geol. Mag.182l
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366 C. Davison—British Earthquakes of 1889.
The disturbed area is thus roughly elliptical ; its longer axis, in
a direction about N. 380° E. and S. 30° W., being about 25 miles
long, and the shorter axis about 18 miles. The whole area disturbed,
including that covered by the sea, is about 350 square miles. The
boundary of the disturbed area corresponds to an isoseismal line of
intensity IV.
Nature of the Shock.—From the few records I possess on this
point, it would seem that the shock consisted of only one vibration ;
no tremulous motion, either before or after the shock, being noticed
at any place.
Duration.—The estimates of the duration are fairly concordant.
It is stated to have been not more than two to three seconds at
Glen Saddell; several seconds at Kilberry; two seconds, or perhaps
more, at Lochranza; and not more than four or five seconds at
Gigha. But, as there was only one vibration noticed, it is probable
that these estimates include also the duration of the sound that
accompanied the shock.
Kintyre Earthquake: Jaly 16.1889.
Intensity. At Lochranza, the intensity must have been V. or
nearly so. It was probably greater than IV. at Killean; and IV.
at Glen Saddell, Kilberry, Clachan, and Gigha.
Sound-Phenomena.—So far as I can learn, the sound-area was
approximately co-extensive with the disturbed area considered as
bounded, as above stated, by an isoseismal of intensity IV. From
Ardpatrick and Tarbert I have no particulars beyond the fact that
C. Davison—British Earthquakes of 1889. 367
the shock was felt at those places. But, at the other six places
marked on the map, the characteristic earthquake-sounds were
heard. They were compared to the movement of heavy articles
of furniture overhead (Glen Saddell and Killean), the passage of
heavy vehicles (Kilberry and Lochranza), a strong blast of wind up
the chimney (Gigha), and a cartload of stones being suddenly emptied
(Gigha). The sound is said to have accompanied the shock at
Kilberry, and to have preceded it at Glen Saddell and Lochranza.
Position of the Epicentrum and Geological Relations.—The centre
of the disturbed area is about 33 miles 8.E. of Clachan. That the
earthquake can have had no connexion with the great southern
boundary fault of the Highlands is evident from the distance of
the epicentrum from the continuation of the line of this fault.
Prof. C. Lapworth, F.R.S., has, however, been good enough to give
me the following note on the possible geological relations of this
earthquake.
“The geological structure of this district shows that between
Loch Fyne and its prolongation, Loch Killisport, there is a band of
slaty material more or less unaltered, A corresponding band occurs
on the fringe of the Highland district, running from Stonehaven to
Dunoon and Rothesay. Between these two well-marked lines of
slate, lies a great area of gneiss. The relation of the gneissic rocks
to the slaty rocks is disputed; by some it is suggested that the
gneisses rise in an anticlinal form from below the schists; by
others, that the gneisses lie on a synclinal formed of the slates.
The apparent dips of the metamorphic strata make the latter
interpretation the simpler and more probable one to geologists
accustomed to lowland areas. If we recollect, however, that the
Highlands are actually a denuded mountain complex, it becomes far
more probable that this apparent synclinal is actually a fan-structure
or inverted anticlinal, as suggested in my paper on “The Secret of
the Highlands.”! If this is the case, the slipping and movements
caused by lateral pressure will take most effect along the two planes
of contrary motion running midway between the crest of the main
fold and its bounding synclines. Curiously enough, the line of
direction of the axis of the disturbed area coincides precisely with
the theoretical position of the southern zone of contrary movement,
on the assumption that the gneisses form an inverted anticlinal.”
Authorities.—The only published account of the earthquake that
I have met with is contained in the ‘Oban Times” for July 20;
and I am indebted to the courtesy of the Editor of this paper for
searching his files and sending me the extract referred to. For
the greater part of the information on which the above account is
founded, I have to thank the following gentlemen: the Revs. J.
Johnstone (Lochranza, Arran), D. N. Macdonald (Killean), J. F.
McKenzie (Gigha), and H. W. Strang (Campbeltown); Mr. R. A.
Cavana (Gigha) ; and especially Mr. J. N. Macleod of Kintarbert and
Saddell, without whose aid the account of this earthquake would
have been much more imperfect than it is.
1 Grou. Mag. Dec. II. Vol. X. pp. 120-8, 198-7, 337-44 (1883).
368 C. Davison—British Earthquakes of 1889.
5. East Cornwatt Hartraquake: Oct. 7, 1889.
Time of occurrence, about 13h. 45m.; Intensity, 1V. Epicentrum,
about 22 miles §.W. of Altarnon.
Disturbed Area.—All the places, 24 in number, at which the
earthquake is recorded as having been felt, are included within an
area which is roughly elliptical in form. The larger axis, which
runs nearly east and west, is about 25 miles in length, the shorter
axis about 20 miles, and the whole area disturbed about 400 square
miles. The curve bounding this area is an isoseismal of intensity LV.
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LE. Corravall Ecrthquake : Océ/7 1689.
Nature of the Shock.—The accounts of the shock, though few in
number, are sufficient to indicate roughly the way in which the
nature of the shock varied throughout the disturbed area. We may
divide the observations into two groups. In the first we have:
Altarnon : a distinct rumbling was heard, as if the chimney were
on fire or a heavy waggon passing up the road; very little if any
perceptible vibration.
North Hill: a sound heard as though something had struck the
wall of the house, and “then the sound seemed to vibrate at the
back.”
C. Davison—British Earthquakes of 1889. 369
St. Clether: like a distant peal of thunder or the passing of a very
heavy loaded waggon ; no tremors perceived.
Temple: like the rumbling of thunder for a few moments, fol-
lowed by a tremulous motion.
Trenegloss: a loud rumbling noise like thunder; no tremulous
motion perceis 2d.
With the exception of Laneast, from which I have no detailed
account, these five places are nearer to the spot indicated as the
epicentrum than any of the others from which records have been
received. From this point, Altarnon is distant 24 miles, North Hill
5, St. Clether 4, Temple 4, and Trenegloss 6} miles.
The second group includes places in the neighbourhood of the
boundary of the disturbed area:
Bodmin: as if some person were walking with a heavy tread
three or four steps overhead.
Boscastle: two distinct shocks are said to have been felt.
Liskeard: (1) as if a heavy substance were thrown violently on
the floor of the adjoining room and also against the partition dividing
the two rooms, tremulous movements before the shock; (2) one
sudden crash like an explosion, no tremulous motion perceived.
North Petherwin: a slight vibration like that produced in a house
by the passage of a heavy waggon.
St. Breward: like that produced by a cart passing along the road
at the back of the house.
Warleggan: as if something very heavy had fallen in the house
with great violence, followed by a tremulous motion.
From these accounts, we may conclude that, in the neighbourhood
of the epicentrum, the sound-vibrations were most noticeable, but
that these died out more rapidly towards the boundary of the
disturbed area than the vibrations of longer period, and near the
boundary the shock was felt as one or several thuds, or vibrations
of much larger amplitude than those which preceded and followed
them.
Duration.—The duration of the shock is variously estimated at
from two to about twenty seconds. Thus, at Liskeard, according
to one account, it is said to have been more than two seconds,
according to another about fifteen seconds; a tremulous movement
before the principal vibration being included in the latter estimate.
Other observations give about 2 seconds at North Petherwin, about
3 at St. Clether, 3 or 4 at Temple, 4 or 5 at Warleggan, 10 to 20 at
Trenegloss, and 12 to 20 at St. Breward.
Intensity.—Throughout the disturbed area, the intensity seems
to have been remarkably uniform, indicating probably a great depth
of the seismic focus. According to the Rossi-Forel scale, the
intensity was IV. at the following places: Bodmin, Camelford,
Liskeard, Newport (near Launceston), St. Breward, Temple,
Trenegloss, Tresmere, and Trevalga. It may have been slightly
greater than IV., though probably not as great as V., at Altarnon,
St. Clether, and Warleggan: and perhaps slightly less than IV.
at North Hill.
DECADE III,—VOL. VIII.—NO. VIII. 24
70 C. Davison—British Earthquakes of 1889.
Sound-Phenomena.—'The sounds accompanying the earthquake
have been already alluded to: they form perhaps its most note-
worthy features. They seem to have been of the usual description,
being compared to thunder, to heavy waggons passing rapidly along
adjoining roads, and to the roaring of a chimney on fire. At the
following places the sound is said to have accompanied the shock :
Camelford, St. Breward, St. Clether, Temple and Trenegloss. It
preceded the shock at North Petherwin, and perhaps also at North
Hill and Tresmere. At Warleggan, the rumbling sound was heard
just after the shock, “as if a waggon had run away down the hill
outside our house: it increased in sound and then appeared to me
like an express train going through a station. .... The rumbling
ended quite abruptly.” At Liskeard, it preceded the shock; but
another correspondent at the same place informs me that it was
heard both before and after the shock, both times very low, but
rather louder after than before.
The earthquake-sounds were heard at all places from which I
have detailed accounts. The sound area and the disturbed area may
therefore have been coextensive, or nearly so. Further, since the
sounds were the most notable part of the phenomenon near the
epicentrum, and at a place like Liskeard near the boundary of the
disturbed area were only heard by a few persons, we may conclude
that the intensity of the sound diminished more rapidly than that of
the shock as the distance from the epicentrum increases ; and, con-
sequently, that the sound-focus was nearer to the surface than the
rest of the seismic focus.
Position of the Epicentrum and Geological Relations.—The epicen-
trum of the earthquake is about 23 miles S.W. of Altarnon, 7.e. not
far from the centre of the great granite boss which occupies so large
a part of Hast Cornwall. It is also noteworthy that the duration of
the shock was in some parts considerable, as much as 10 or 12 seconds,
arguing probably a larger seismic focus than in any of the previous
cases ; further, that the longer axis of the disturbed area runs east
and west, i.e. parallel to the direction of folding of the district.
Though we may not at present be in a position to assign a definite
origin to this earthquake, it seems at least probable that it had
some connexion with the geological structure of the district, and
that the forces which have combined in producing that structure
have not yet ceased to act.
Authorities.—“ St. Austell Weekly News,” Oct. 12; “ West Briton
and Cornwall Advertiser” (Truro), Oct. 10; ‘Western Morning
News” (Plymouth), Oct. 8.
The earthquake was but slightly noticed in the local press, and
nearly all that is of value in the preceding account I owe to the
kindness of the following ladies and gentlemen: the Revs. R. H.
Boles (St. Breward), C. Bridgewater (St. Tudy), J. R. Browne
(Bodmin and Temple), W. Jago (Bodmin), A. H. Malan (Altarnon),
C. Olive (Warleggan), J. Partridge (St. Clether), T. B. Trentham
(North Petherwin), Canon Vautier (St. Mabyn), T. Walters (Boyton),
and T. Willing (North Hill); Mr. J. C. Chapman (Trenegloss),
C. Davison—British Earthquakes of 1889. av
Mrs. L. Davy (Tresmere), Miss F. E. Jenkin (Liskeard), Mr. W. E.
Parsons (St. Breward), and Miss L. Thorne (Liskeard).
DovstruL HartHQuakEs.
1. Invergarry, June 19, 1889, Th. 40m. (see p. 365).
2. Little Rhondda Valley (South Wales), June 22, 1889, about
22h. 30m. ; intensity, V.
A shock, supposed to be that of an earthquake, was felt at this
date in and near the Little Rhondda Valley. The area disturbed by
it was very small, probably not more than a few miles in its greatest
diameter. It was felt at Llwynypia, Pontygwaith, Tylorstown,
Watts Town, Ynishir and Ystrad.
The disturbance, which lasted a second or two, consisted of one
vibration, and at Ynishir is described as having been like the shock
of a blasting explosion, but much stronger. It was accompanied
by a deep rumbling noise, like distant thunder, at Llwynypia,
Pontygwaith, and Watts Town. The intensity was IV. at Ponty-
gwaith, but cannot have been less than V. at Llwynypia and
Ynishir. The shock was felt by workmen underground in the
Ynishir Steam Colliery, and in one or two other collieries in the
adjoining district.
This is all the evidence I have been able to obtain, and I do not
think it is sufficient to put beyond doubt the seismic origin of the
shock. For so small a disturbed area, the intensity is unusually
great, arguing a very small depth for the centre of disturbance ; and,
besides this, the mining operations of the district are being carried
on so rapidly and extensively that, from time to time, considerable
masses subside, occasionally, it is said, causing tremors very like
those of an earthquake.
Authorities.—‘ Nature,” vol. 40, p. 208; ‘South Wales Daily
News” (Cardiff), June 24, 1889. For other information contained
in the above account, I beg to thank Mr. W. Galloway, Mr. J. J.
Thomas, of Ynishir, and Mr. R. R. Hood, of Gilfach.
3. Lyme Regis, July 5, 1889, between 23h. and 28h. 15m.
Noises were heard at intervals between the times stated. They
“consisted of a distant rumble which grew nearer till at last the
windows of the houses rattled and in some cases distinct vibrations
of the houses were felt.” They were probably not caused by the
firing of guns at sea: and they may have been due to earthquakes,
though the evidence is clearly incomplete.
This note is taken from a letter by Mr. A. R. Sharpe, in Nature,
vol. 40, p. 294.
ConcLusion.
With one possible exception (that of Ben Nevis), the earthquakes
of 1889 are typical examples of British shocks—they occurred in
districts where earthquakes are rarely felt, and their disturbed areas
are circular or only slightly elliptical in form. Turning to a more
distinctly seismic area, Switzerland for example, we find that the
disturbed areas are often extremely elongated, the longer axes
being parallel to those of the neighbouring Alpine chain; earth-
372 Dr. W. T. Blanford—Age of the Himatayas.
quakes are more frequent, their intensity, as a rule, is greater, and
much larger areas are disturbed. Different stages in the geological
history of a district are characterized by different kinds of earth-
quakes. The Alpine system is not yet old, fault-formation is still
in progress, and the fault-slips are long and frequently recurring.
In. Great Britain, we meet with a later stage. Fault-formation in
our seismic area is more advanced, and slipping takes place so
slowly and over distances so short, that our earthquakes are rare
and the areas disturbed by them more or less circular in form.
Every stage in the process, however, requires investigation, and
that of which our British earthquakes are witness is certainly
deserving of attentive study. Unattractive though it may be at
first sight, the epoch immediately preceding the death of a mountain-
chain, is at least as interesting to the geologist as the more vigorous
periods of origin and growth.
Errata in THe Maps.
Edinburgh earthquake: or Costorphine, read Corstorphine.
», Georgie, », Gorgie.
», Curriehall, », Curriehill.
Lancashire earthquake: ,, Tongridge, », Longridge.
», Mihnrow, », Milnrow.
», Harwich, », Horwich.
Kintyre earthquake : », Larber, >, Larbert.
», Glachan, », Clachan.
In the map of the Lancashire earthquake, the outermost of the two smaller circles
should have been a dotted line. In the map of the HE. Cornwall earthquake, the
spot between Nerth Hill and Callington should be erased.
ViI.—Tue Acer or THe Himanayas.
By W. T. Buanrorp, LL.D., F.R.S., ete.
REGRET that I cannot accept as unquestionable the evidence
brought forward by my friend Mr. Howorth in favour of the
recent elevation of other mountain ranges in Asia besides the
Himalayas. I dealt with the latter alone, because I have a slight
acquaintance with parts of them, and some knowledge of the
observers whose opinions are quoted. But I argue from the known
to the unknown, and if I find reason to reject the evidence on
which Mr. Howorth relies to prove the absence of extensive glacial
markings in the Himalayas, I am disposed to be sceptical as to that
on which he founds his argument in the case of other ranges. I
decline to be drawn into a discussion about the latter.
I quite agree in the improbability of the Himalayan ice having
ever reached the Indo-Gangetic plain, but I think I have shown that
this is not the question at issue. I cannot, however, help remarking
that if I depended chiefly, as Tchihatcheff and Cotta appear to have
done in the case of the Altai, on the presence or absence of erratics,
I might come to a different conclusion, for there are unmistakable
“‘erratics”—huge blocks believed to have come from the higher
Himalayas—in the Northern Punjab.
I hope I do no injustice to Mr. Howorth’s argument in placing
Dr. W. T. Blanford—Age of the Himalayas. O70
it in this form: because the glaciers of the Alps in Pleistocene
times extended some distance beyond the base of the mountains,
those of the Himalayas, if they existed, should have done the same.
Surely no one can contend that the glaciers of the Alps must descend
to the sea-level at the present day because those of Greenland do so.
But the difference in latitude between the Himalayas and the Alps
is practically the same as that between the Alps and Greenland. .
But, Mr. Howorth urges, there was a great sea in Central Asia
in Pleistocene times, and consequently Himalayan ice would have
transported glacial débris beyond the mountains. I dispute both the
fact and the inference. Even if there was a greater ice-accumu-
lation (and I think I have shown that there was), it does not at all
follow that this would have reached plains, but little above the sea,
within from 26 to 34 degrees of the Equator. With regard to the
Central Asiatic sea, of course there was a considerable tract covered
with water in late Tertiary and probably in Pleistocene times in the
Caspian and Aral area. But this area was I believe then, as it is
now, cut off from Tibet and the Himalayas by the great ranges
extending from the Pamir through the Thian-Sban to the Altai, and
surrounding Eastern Turkestan on the West and North. As to
great lakes having occupied the depressions of Hastern Turkestan,
the Gobi, etc., I can only say that I once mistook similar plains in
Persia for lake-basins, and have seen reason to believe I was in
error. The occurrence of salt lakes and salt plains merely indicates
the absence of drainage, and is by itself no proof of the former
occupation of any area by the sea. The horizontal or nearly
horizontal beds supposed by many observers to be marine or
lacustrine are probably similar to those found throughout the drier
regions of Central Asia, and due purely to the wash of detritus from
the hills into the plains by rain and melting snow, where the whole
rainfall is insufficient to form rivers and to wash away the accumu-
lations, all the water evaporating within the plains themselves.
With the coarser beds fine Holian deposits are associated. I do not
wish to appear dogmatic, but after having had better opportunities
than fall to the lot of most European geologists of studying the
subject, I am unable to attach any value to the evidence brought
forward, although I fully acknowledge how strong that evidence
appears at first sight by admitting that I was at one time led away
by it. .
Of the two quotations from my contributions to the Manual of
Indian Geology that are adduced as supporting Mr. Howorth’s
views, the first, and the first part of the second, do not appear to
me at all favourable to his theory. Surely, to say that ‘a move-
ment has been distributed over the Tertiary and _ post-Tertiary
period, and a great portion is of post-Pliocene date,” is not the same
as to say that the whole movement, or even the greater part of the
movement, is post-Pliocene ; nor is the argument that “at the close
of the Miocene period no such mountain barrier as exists at present
separated the Indian Peninsula from Central Asia” equivalent to
saying that the barrier was wanting at the close of the Pliocene.
374 Dr. W. T. Blanford—Age of the Himalayas.
The citation of my remarks as to the post-Siwalik elevation of the
Tibetan plateau, however, is a fair hit, and shows how thoroughly
Mr. Howorth has collected the testimony in favour of his views,
though he appears to have overlooked the footnote (on p. 586)
appended to the words quoted, and, to some extent, qualifying the
Opinion recorded, as it called attention to the greater area once
occupied by Himalayan ice. The explanation, however, of my
having published what I now think was probably an incorrect view
in 1879, is that at that time I had only the evidence concerning the
fossil fauna of Hundes that was obtained by Falconer and Strachey.
When Lydekker, in 1881, found that one of the best-preserved
Tiundes fossils was a skull of Pantholops, an Antelope confined to
the Tibetan plateau, and only living at high elevations, the whole
evidence was materially changed. The question now is, whether it
is more likely that Pantholops inhabited a low level or an unknown
Rhinoceros a high one. Of course, where Yaks can find food, there
is no reason why a Rhinoceros should not obtain subsistence.
I must again call attention to the fact that far from attempting to
go into the whole evidence as to the elevation of the Himalayas, I
merely selected two items, one to prove the insufficiency of the
evidence brought forward by Mr. Howorth, the other to show the
facts which he had overlooked, both items belonging to one, and, in
my opinion, by no means the most important part of the geological
evidence. Merely to show how wide the question is, I should like
for once to “forsake the happy hunting grounds of Geology for those
of Zoology,” and to call attention to a fact which to my mind is
sufficient by itself to disprove a subrecent origin of the Tibetan
highlands.
Throughout the great region generally known as Palearctic, there
is no tract of country of the same extent that contains as many
peculiar forms of animal life as Tibet. Amongst Mammals alone
there are the genera Pantholops, Nectogale and Hupetaurus, and pro-
bably Zluropus and Budorcas, together with the Yak, two kinds of
wild Sheep, a Gazelle, two Hares, several Lagomys, at least three
Marmots, and several Voles. I must say that it is to me incredible
that this peculiarly specialized fauna can have been differentiated
since Pleistocene times, and very improbable that it can have
entirely developed since the Pliocene period. So high a degree of
specialization points to a long continuance of the peculiar conditions
that still prevail.
Of the two, statements of mine that are traversed by Mr. Howorth,
one is of course a matter of opinion; upon the other it will I think
be found that my information was correct. Mr. Howorth says that
Mr. Lydekker formerly classed the Hundes fossils as Pliocene, but
subsequently adopted the opinion, which he still holds, that the beds
are post-Tertiary. Mr. Lydekker’s assignment of a Pleistocene age
to the beds in question dates from 1881 (Rec. G.S.I. vol. xiv. p. 158) ;
but in 1886 (Cat. Foss. Mam. Brit. Mus. vol. iii. p. 158) and in 1887
(Rec. G.S.I. vol. xx. p. 54) he has stated that he is now inclined to
regard the beds as Newer Pliocene.
Reviews—Dr. A. Fritsch—Paleozoic Fishes. 375
Tt is useless, I fear, to discuss the other statement traversed,
whether the contours of the Himalayas are due to freshwater
denudation; and we must continue to differ. But I must say
that I still think a personal acquaintance with the Himalayas
would give a very different idea from photographs and drawings
of picturesque bits. The splintered precipices referred to by Mr.
Howorth are probably due to the effects of frost; and however
common in the higher Himalayas, especially where glaciers exist
now, or existed formerly, are not, I think, prevalent in the lower
valleys. If it be transcendentalism to refer to the denuding action
of rain and streams, valleys and ridges which, however gigantic, are
the exact counterparts in form of those seen in a bank of clay after
exposure to a season’s rain, how should the reference of such
contours to an unknown agency be fitly designated ?
Sa a=l} VG ABE VES
J.—Dr. Anton Fritscu on Patmozoic ELAsmMoBRANCH FIsHus.
‘¢HauUNA DER GASKOHLE UND DER KALKSTEINE DER PERMFORMATION
Boumens.” By Dr. Anron Frirscu. Band II. Heft IV. (pp. 93-
114, Pls. 80b.-90); Band III. Heft I. (pp. 1-48, Pls. 91-102).
Ato. (Prague, 1889-90.)
HE two latest parts of Dr. Fritsch’s well-known work on the
Permian Vertebrata of Bohemia form one of the most im-
portant contributions to our knowledge of the Paleozoic Hlasmo-
branchs that have hitherto appeared. A fine Dipnoan skeleton is
first described and figured under the name of Ctenodus tardus, as a
supplement to the preceding part; but with the exception of the
two pages and one plate devoted to this, the whole of the instalment
is occupied with what the author terms the ‘Ordnung Selachii.”
Following ancient custom, the Holocephali are included in the group
thus designated in the preliminary remarks; and, for the purposes
of the memoir, the Plagiostomi are subdivided into the four “ tribes ”
of Squalides, Xenacanthides, Acanthodides, and Rajides.
Of the “Squalides,” or ordinary Sharks, only a single tooth has
yet been found in the Bohemian Gas-coal. This tooth is hybodont
in form, and receives the name of Hybodus vestitus. The determin-
ation, however, falls under the same category as the author’s now-
abandoned statement concerning the occurrence of a Permian species
of Ceratodus; and it by no means proves the downward range of
the Mesozoic genus Hybodus into the Paleozoic formations. As in
the case of the Dipnoi and the Pleuracanths, detached teeth of the
hybodont Sharks are worthless for generic determination.
Of the “ Xenacanthides ” only the single family of ‘‘ Xenacanthidee”’
is recognized; but why the author should depart from the ordinary
system of nomenclature, and not derive the title of this family from
its type-genus Pleuracanthus, it is difficult to understand. The three
genera Orthacanthus, Pleuracanthus, and Xenacanthus are regarded as
quite distinct, and re-defined upon the basis of the new Bohemian
SA
\ ANY
Reviews—Dr. A. Fritsch—Paleozoic Fishes.
376
Reviews—Dr. A. Fritsch—Paleozoic Fishes. Byard
specimens. The characters of the teeth, dorsal spine, of the denticles
upon the branchial arches, and of the pectoral fins, are quoted as
diagnostic; while of Pleuracanthus and Xenacanthus the materials
suffice to justify the two restorations reproduced through the courtesy
of Dr. Fritsch, on the opposite page.
As in Britain, Orthocanthus is only known in Bohemia from com-
paratively fragmentary remains. To it are referred (i.) rounded
spines having posteriorly placed denticles; (ii.) large teeth with a
relatively small median denticle; (iii.) clustered branchial tubercles ;
and (iv.) long pointed pectoral fins without horny fin-rays. Four
Bohemian Permian species are determined, and a fifth (O. senken-
bergianus) is briefly described from the corresponding horizon of
Lebach. Even yet, however, the genus is far from being satisfactorily
diagnosed ; and with reference to the dentition, we venture to think
that it would not be difficult to cite more than one British specimen
proving the occurrence in one and the same mouth of the two forms
of teeth which Dr. Fritsch regards as characteristic of Orthacanthus
and Pleuracanthus respectively.
Some brief remarks on three undetermined Ichthyodorulites follow
the account of Orthacanthus, and bear the newly-applied generic
names of Tubulacanthus, Brachiacanthus, and Platyacanthus. These
names may be only provisional, but we would remark that the first
is an inadmissible hybrid, while the two latter are pre-occupied.
The sections devoted to Pleuracanthus and Xenacanthus, with the
general conclusions resulting from the study of these types, make
a most important advance in our knowledge of the group to which
they belong. As will be observed in the author’s restored figures
of the two genera (Figs. 1, 2), Pleuracanthus is a somewhat more
slender fish than Xenacanthus, and differs considerably in the
character of the fins; in the former genus there are no dermal
skeletal parts and the pectoral fin is much elongated, whereas in
the latter genus dermal fin-rays are conspicuous and the pectoral
is comparatively short and broad. The cavity in the dorsal spine
is also described as relatively smaller in Pleuracanthus than in
Xenacanthus. Four Bohemian species of the former genus are
determined, and short notes follow on the German P. sessilis and
the French P. Gaudryi; while of Xenacanthus the type-species
‘X. Decheni is regarded as the sole known representative. Numerous
detailed descriptions with beautiful figures of various parts of the
skeleton appear in connection with the several species; and the
systematic work concludes with a chapter of general observations
on the organization of the Pleuracanth fishes as now known.
The results are briefly summarized in the following statement :
The skin in these fishes was destitute of scales; the cartilaginous
skeleton exhibits everywhere a granular calcification; the skull
consists of a continuous piece of cartilage, without investing
membrane bones; the nuchal spine is fixed upon a papilla of the
cranial roof, and is not connected with a fin; the axial skeleton of
the trunk is notochordal, with a calcification of the central fibres;
the neural arches are strongly developed, and. in two genera there
378 Reviews—k. Lydekker’s Catalogue of Fossil Birds.
are intercalary cartilages; there are seven branchial arches; the
shoulder-girdle is comparable to a branchial arch; the paired fins
must have developed from a series of parallel rays, and the joints of
the axial rod have arisen partly by thickening, partly by the fusion
of several adjoining rays ; there are no pelvic elements, the so-called
“velvis” being the basipterygium ; the claspers of old males are
similar to those of existing Sharks, and there are also the same
developments in aged females; the oval eggs have a strong capsule.
In conclusion, Dr. Fritsch finds the nearest living allies of the
Pleuracanth fishes in the remarkable family of Notidanide, and
adds the inevitable ‘‘Stammbaum ” to show the ancestral position in
which he would place them. Few who closely study the evidence
will fail to be convinced of the reasonableness of this arrangement ;
and the majority will doubtless be disposed to follow the Professor
in his most interesting theoretical excursus on the origin and
development of the paired fins. Recent discoveries compel us to
add only one word of caution, namely, that it is rash to assume
there were no groups higher than the so-called “‘Urfische”’ retaining
the primitive parallel disposition of the cartilaginous rays in the
paired fins. The fishes with a Cladodont dentition lately made
known by Dr. Newberry from the Lower Carboniferous of Ohio
under the names of Cladodus Kepleri and C. Fyleri, seem to have
been true Elasmobranchs; but their pectoral fins are not “archi-
pterygial” in the sense of Gegenbaur’s terminology, and appear to
consist merely of segmented parallel bars. However this may be,
the recent rapid advances in our knowledge of the paleontology of
the Paleeozoic Elasmobranchs must be a source of much gratification
to all who are interested in the evolution of the vertebrata; and to
no one are we indebted more than to Dr. Anton Fritsch for enduring
contributions to the subject. A. S. W.
IJ.—Caratocut or tHe Fossin Brrps In THE British Museum
(NaruraL History), Cromwetn Roap, 8.W. By RicHarp
LypEkKer, B.A., F.Z.8., F.G.8. (London, 1891.) Printed by
order of the Trustees, and sold by Kegan Paul, Trench,
Triibner & Co. 8vo. pp. i-xxvili, and 368, with 75 Woodcuts.
R. LYDEKKER has earned the hearty thanks of all those
who are interested in the paleontological history of the
higher Vertebrates, by the valuable series of Catalogues of the Fossil
Mammalia, Aves, Reptilia, and Amphibia which he has prepared,
under the auspices of the Trustees of the British Museum (Natural
History), which form ten separate parts or volumes, containing 3119
pages of text illustrated by 537 woodeuts. The earlier published
volumes have already been noticed in this Magazinn, and we now
have much pleasure in drawing attention to the final volume on the
Fossil Birds, which has just been completed. If we except the
Amphibia, the class Aves forms the smallest group of Vertebrates
known in a fossil state; yet the number of living species exceeds
8000. Thirty-five years ago, it appeared as if the hope of
Reviews—R. Lydekker’s Catalogue of Fossil Birds. 379
attaining a knowledge of the ancestry of Fossil Birds was destined
never to be gratified. But in 1861 a split slab of Lithographic
Limestone was discovered at Hichstidt near Solenhofen, in Bavaria,
in the Lower Kimeridgian formation, showing a nearly entire
skeleton and impressions of the feathers of what was at first supposed
to be a Reptile, but afterwards proved to be a remarkable long-tailed
Bird, with twenty slender caudal vertebra, each joint having a pair
of feathers, one feather on each side. Twenty years later, a second
specimen was discovered, identical with that described by Prof.
Owen in 1862, but in some respects more complete, from which we
learn that the jaws were armed with from ten to twelve teeth in the
pre-maxillary border on each side, and three or more teeth in the
lower jaw also; the teeth were conical and apparently planted in
distinct alveoli. The three metacarpals and the phalanges of the
fingers were free and were armed with strong recurved claws like
those of a Lizard’s fore-limb. This singular creature is at present
the earliest, as it is also the most generalized bird with which we
are acquainted ; the sternum was well developed, and probably
provided with a carina: indeed, from the characters of both the fore-
and hind-limbs, we are justified in concluding that Archeopteryx was
a perching, flying, Carinate type of Bird; it is the only representative
of a distinct order, the Saururz&.
After another interval of ten years, two other types of toothed
Birds were discovered by Professor Marsh in North America: one,
the Ichthyornis, being a bird of powerful flight, with biconcave
vertebrz ; the other, Hesperornis, had a perfectly flat sternum, and
was a large flightless aquatic Bird, probably resembling the Loons
and Grebes in structure. These American birds, however, are from
the Upper Cretaceous of Kansas, and, although of Secondary age, are
much younger, and more specialized types than the Archgopteryzx,
which is of Upper Jurassic age.
Previous to these discoveries it had been supposed that the great
group of running Birds, such as the Ostrich, Rhea, Emu, Cassowary,
and Apteryx, represented the earliest types known; and seeing
also that these Ratite, or raft-breasted flightless birds, have been
found in a fossil state in England, France, India, Madagascar, New
Zealand, Australia, and America, it was only natural to connect
them with the still earlier discovery of Bird-like, bipedal impressions
met with so abundantly upon the slabs of Triassic sandstone in the
Connecticut Valley. ‘These are now, however, commonly attributed
to the huge Dinosaurian reptiles, whose remains have of late years
been met with, both in N. America and in Europe, many of which
evidently progressed upon their hind-legs only, and, having the same
number of toe-bones as a bird, might have left similar foot-prints.
Of the other early remains of Birds known in a fossil state, by far
the greater part are in an extremely fragmentary condition. ‘hus
the Enaliornis Barretti, from the Cambridge Greensand, is founded
upon an isolated fragmentary bone, the tarso-metatarsus. The
Odontopteryx toliapica is founded on an imperfect skull from the
London Clay of Sheppey, was considerably larger than that of
380 Reviews—R. Lydekker’s Catalogue of Fossil Birds.
a Solan Goose, which had the margins of the bones of both the
upper and lower jaws coarsely serrated, and was no doubt also a
large fish-eating Bird. Numerous remains of carinate Birds are
represented in the Collection by detached bones from various localities
and deposits, all of Tertiary age, and many of them referred to
existing genera. The Great Auk (Alca impennis) is recorded
from a guano deposit on Funk Island off the coast of Newfound-
land; nearly all the bones with the exception of the phalanges
are preserved; this is one of a dozen or more individuals found by
Professor John Milne, F.R.S.
By far the most important part of the Collection, if we except
the Archgzopteryx, consists of the remains of the Ratite Birds, the
LEpyornis of Madagascar being represented by two species, namely,
Af. maximus, casts of the femur, the tibio-tarsus, and the tarso-
metatarsal bones, reproduced from types in the Paris Museum ; the
shaft of an actual bone, and an entire egg, 36 inches in longest
circumference by 30:3 inches in girth; and Af. medius, an egg, 30: 2
inches in longest circumference, and 26:3 inches in girth.
The Indian Ostrich (Struthio Asiaticus), from the Pliocene of
the Siwalik Hills, is represented by a conjoined mass of bones,
colprising nine cervical vertebrz in natural juxtaposition, some
imperfect bones of the wing, and the distal portion of the right
tarso-metatarsus, together with the greater portion of the proximal
phalangeal of the third digit in apposition with the latter. The
Dasornis Londiniensis is only known by the cranium from the
London Clay of Sheppey ; but taken in connexion with the discovery
of the limb-bones of another Struthious Bird, the Gastornis Klaasseni,
in the Lower Kocene of Croydon, Surrey, we may conclude that
Ostrich-like Birds lived in this country, and also in France and
Belgium, in Eocene times. Of the great flightless birds of New
Zealand, no fewer than six skeletons have been set up in the
Gallery, representing at least five species; there is also a very large
collection of detached bones referred to some twenty different
species, all described by Prof. Owen. Some of these remains are
so recent as to be still covered with dried skin and traces of feathers,
showing that their extermination in those islands must have been
of very modern date, and no doubt due to the hand of man.
Owen’s genus Dinornis, we observe, has been subdivided by
laydekker into five genera ; but we venture to question the desirability
of this course, seeing how great is the individual diversity presented
by the skeletons of these large running Birds; we incline rather to
the view that they are the result of local variation produced by
scarcity or abundance of food and the nature of their habitat; even
difference of sex may account for size and robustness in individuals.
Whilst on the subject of nomenclature, we would also question
the right to substitute H. von Meyer’s specific name lithographica
for Archeopteryx macrura, the latter name having been given to
the original skeleton of the long-tailed Bird from Solenhofen by
Owen, whereas Meyer’s name was only applied to a detached
feather of some Bird. found in the same.deposit a year or two
previously. The only justification which we can conceive for this
Reviews—G. A. Boulenger’s Extinet Reptilia. oel
act, is that of the old proverb, that “‘ Birds of a feather flock together.”
But the evidence of identity is by no means conclusive, and it seems
hard, therefore, on Sir Richard Owen to wipe out his specific name
with a feather, he having been the original describer of the almost
entire skeleton.
Too much praise cannot be accorded to the Trustees of the British
Museum, Natural History, for authorizing the publication of the
long series of Catalogues of Recent and Fossil forms, in the Collec-
tions under their control, and we earnestly trust that the work may
be continued until all the groups, both of Vertebrate and Invertebrate
life, have been similarly recorded and illustrated.
II].—Mr. G. A. Boutencer on Extinct Reprizia.!
R. BOULENGER contributes three papers of much palzonto-
logical interest to the June number of the Proceedings of the
Zoological Society. The first deals with some fragmentary Eocene
Chelonian remains; the second and third relate to taxonomic questions
of wide importance.
During an examination of the reptilian fossils in the Museum of
the Royal College of Surgeons, Mr. Boulenger met with a skull of
Trionyx, apparently from the well-known Upper Eocene formation
of Hordwell Cliff, and, if so, proving that the species represented
is a typical member of the genus. The skull much resembles
that of the existing T. hurum, and it is provisionally referred to
T. planus (Owen), of which the shell is also closely paralleled by
that of the recent species just mentioned. A Sheppey fossil in the
same collection, described by Owen as ‘‘the lower or distal end of
the tympanic bone of the Crocodilus toliapicus,” is shown to be the
proximal end of the left humerus of an Athecan Turtle, evidently
Eosphargis gigas; while of two other fossils referred by Owen to
the same “‘ Crocodile” the so-called ‘ portion of the left ramus of the
lower jaw” is stated to be part of a scapula of Kosphargis, and
«another portion of the right ramus of the lower jaw” truly belongs
‘to a Liassic Plesiosaurian. Incidentally it is pointed out, that no
species of the genus Crocodilus occurs in the Hocene, the so-called
C. Spenceri being referable to Diplocynodon.
A study of the osteology of Heloderma and an attempt to determine
its systematic position, lead Mr. Boulenger to express his views upon
the classification of the order Squamata. Referring only to the
structure of the vertebral column and limbs the following table of
diagnoses is given :—
Order SquaMara.
‘A. Pectoral arch or its rudiments present. Caudal hypapophyses forming chevrons.
Suborder I. Dolichosauria. 15-17 cervical vertebre. Extremities archaic, 7.e.
approaching the Batrachian type.
2 «Qn Some Chelonian Remains preserved in the Museum of the Royal College
of Surgeons,’’ Proc. Zool. Soc. 1891, pp. 4-8, figs. 1-6.
Notes on the Osteology of Heloderma horridwm and H. suspectum, with Remarks
on the Systematic Position of the Helodermatide and on the Vertebre of the
Lacertilia,’’ idcd. pp. 109-118, figs. 1-6.
‘On British Remains of Homeosaurus, with Remarks on the Classification of
the Rhynchocephalia,’’ idcd. pp. 167-172, figs. 1, 2, ~
O82 Reviews—G. A. Boulenger’s Extinct Reptilia.
Suborder II. Pythonomorpha. 9 or 10 cervical vertebre. Extremities paddle-
shaped, with hyperphalangy.
Suborder III. Lacertilia. 8 or 9 cervical vertebre. Fibula reduced proximally ;
fifth metatarsal reduced in length and strongly modified.
Suborder IV. Rhiptoglossa. 5 cervical vertebre. Hxtremities pincer-shaped ;
all the metatarsals reduced in length and strongly modified.
B. No trace of a pectoral arch. Caudal hypapophyses disconnected distally.
Suborder V. Ophidia.
Figures of the hind limb are added, the so-called Hydrosaurus
lesinensis of the Cretaceous being selected as a typical representative
of Dolichosaurus.
The left mandibular ramus of a small Rhynchocephalian reptile,
also in the Museum of the Royal College of Surgeons, forms the text
of Mr. Boulenger’s third contribution. An examination of the matrix
suggests that the specimen was probably obtained from the Lower
Oolites of Wiltshire ; and the left maxilla of a nearly similar reptile,
from the Purbeck Beds of Swanage, is recorded as having been
recently acquired by the British Museum. These fossils are believed
to be referable to Homeosaurus, and the first is described and figured
as the type of a new species, H. major. 'To the same species is also
assigned a mandible from the Kimmeridgian of Hanover described
by Struckmann in the Zeitschr. deutsch. geol. Ges. vol. xxv. p. 249,
pl. vii. Some remarks on the systematic position of Homeosaurus
follow; and after several critical observations in regard to the
non-diagnostic character of most of the existing definitions of the
Rhynchocephalia and the component families of the order, the
following revised table is appended :—
Order RuYNCHOCEPHALIA.
Suborder I. Prorrrosauria. Each transverse segment of the plastron composed
of numerous pieces. Pubis and ischium plate-like. Fifth metatarsal not
modified.
Vertebre conically excavated at either end, with persistent notochord, all
with intervertebral hypapophyses; limb-bones without condyles ; humerus
with entepicondylar foramen. .... 1. Paleohatteriude.
Vertebre fully ossified, cervicals opisthoccelous, dorsals biconcave ; no hypa-
pophyses between the dorsal vertebr ; limb-bones with condyles ; humerus
with entepicondylar foramen or groove. .... 2. Proterosauride.
Suborder II. RuyncnocePHatia veRA. Each transverse segment of the plastron
composed of three pieces, a median angulate and a pair of lateral. Pubis and
ischium elongate, and fifth metatarsal modified, as in the Lacertilia.
A. Nasal openings distinct. Mandible with coronoid process, the rami not united
by suture. Vertebrz deeply biconcave.
Humerus with ectepicondylar and entepicondylar foramen ; ribs with uncinate
processes; all the vertebre with intercentral hypapophyses. 38. Hatieride.
Humerus with entepicondylar foramen; ribs without uncinate processes ; no
hypapophyses between the dorsal vertebre. .... 4. Homeosauride.
B. Nasal opening single. Mandible without coronoid process, the rami united
in a solid symphysis. Vertebre fully ossified, feebly biconcave; no hypa-
pophyses between the dorsal vertebrae. Humerus with ectepicondylar foramen
or groove.
Snout short, ending ina beak. .... 5. Rhynchosauride.
Snout crocodilian in shape, with toothed premaxillaries. . . . .
6. Champsosauride.
Reports and Proceedings—Geological Society of London. 383
ae Ones SAN Si © G7 BED PNG S-
——
GeroLocicaL Society or Lonpon.
June 10, 1891.—Sir Archibald Geikie, LL.D., F.R.S., President,
in the Chair.
A Special General Meeting was held at 7:45 p.m., before the
Ordinary General Meeting, at which the following resolution was
proposed by Dr. Evans, seconded by Mr. Bavrerman, and carried
unanimously :—That the Society approve of the recommendation of
Council that Mr. Isaac Charlton, the House Steward, on his retire-
ment, after fifty years’ service, be granted a pension of £70 per
annum for life.
Before the commencement of the general business, Prof. BLAKE
rose, on behalf of those present at the meeting, to congratulate the
President on the honour that it had pleased Her Majesty to confer
upon him. No one who knew him could fail to appreciate how
thoroughly it was deserved; and the Geological Society would
doubtless feel also the honour conferred on their science in the
person of their President and the Head of the Geological Survey of
the United Kingdom.
_ The PrestpEnt referred to the services of the late Dr. Duncan,
and suggested that in the name of the Society a message of cordial
sympathy should be sent to Mrs. Duncan on the great loss which
had befallen her. This proposal was approved of by the Fellows
present; and the Smcrerary was requested to communicate with
Mrs. Duncan.
The following communications were read :—
1. “ Note on some Recent Excavations in the Wellington College
district.” By the Rev. A. Irving, B.A., D.Sc., F.G.S.
This paper furnishes new facts of Bagshot stratigraphy obtained
from open sections since the author’s last paper was read on Nov.
12th, 1890. The whole sequence of the beds, as given in the
published section of the College Well, has now been verified at their
respective outcrops; percentages of clay in the beds laid open in
excavations in March last along the critical portion of the ground
are given as results of mechanical analyses of samples of them; and
the northerly attenuation of the green-earth series and of the quartz-
sand series is reduced to a question of mere measurement, for which
the requisite data are now to hand.
The author claims to have demonstrated that the mapping of the
Geological Survey contradicts itself; that later workers in adopting
this as the basis of their work along the §.E. Railway have fallen
into serious error ; and that a complete contradiction is given by the
facts to the adverse criticisms offered on his corrected section along
the railway, which was exhibited in November last, and is repro-
duced for the present paper.
2. “Notes on some Post-Tertiary Marine Deposits on the South
Coast of England.” By Alfred Bell, Esq. Communicated by R.
Ktheridge, Esq., F.R.S., F.G.S.
384 Oorrespondence—Rev. A. Irving—Mr. R. Lydekker. ¥
The author’s object in this paper is to trace the successive stages
in the development of the present coast of the north side of the
English Channel, and to ascertain the sources of the diversified
faunas.
The first traces of marine action on the South Coast in Pace
Tertiary times are found on the foreshore in Bracklesham Bay. The
author’s reading of the section is somewhat different from that of
the late Mr. Godwin-Austen; and he divides the marine series into
(1) an estuarine clay with Mollusca common to estuarine flats ;
(2) a compact hard mud; and (3) a bed of fine sandy silt with many
organisms. ‘These beds indicate a change from estuarine to deep-
water conditions. A full list of the Selsey fossils is given, including,
amongst other animals, upwards of 200 Mollusca. Of 35 species of
Mollusca not now living in Britain, the majority exist in Lusitanian,
Mediterranean, or African waters; furthermore, nearly 45 per cent.
of the Mollusca are common to the older Crags of the Hastern
counties. The author considers the fauna of the Portland Bill shell-
beds to indicate the further opening of the Channel subsequent to
the formation of the Severn Straits, and believes that this fauna
represents the deposits wanting between the Selsey mud-deposits
and the erratic blocks which, according to him, overlie the mud;
these Portland shells indicate an intermediate temperature ‘“ rather
southern than northern ” according to Dr. Gwyn Jeffreys.
In conclusion, details concerning still newer beds are given, ead
lists of fossils found therein; and rae author observes that there is
no evidence to show when the English Channel finally opened up,
beyond the suggestion of Mr. Godwin-Austen that, if the Sangatte
beds and the Coombe Rock are of the same period, it must have
taken place after their formation. —™
CORRESPONDENCE.
SS
PFAFF’S “ALLGEMEINE GEOLOGIE.”
Srr,—By an inadvertence I have, in quoting Dr. Pfaff’s work on
p- 301 of the July Number of the Grox. Mac. confused the title
with that of a well-known work by Justus Roth. The true title of
Pfaff’s work referred to is Allgemeine Geologie als exacte Wissen-
schaft. I shall be greatly obliged if you can afford space for this’
correction in the forthcoming Number.
A. Irvine.
MOLARS OF PERISSODACTYLA ;—A CORRECTION.
Str,—In my notice on this subject on page 321, line 15 from top,
I have inadvertently written crotchet instead of anti-crotchet.
R. LypDEKKER.
Stegosaurus ungulatus, M
from the Jurassic forme
Jnited States, North An
DECADE III. Vou. VIII. PLATE XI.
arsh. (s'5 nat. size. )
ition of Wyoming Territory,
rerica.
THE
GHOLOGICAL MAGAZINE.
NEW SERIES. DECADE Ill. VOL. VIII.
No. IX.—SEPTEMBER, 1891.
OR eae Avie, VASE a Cees
————
J.—RestoraTIOn oF STEGOSAURUS.
By Prof. 0. C. Marsu, Ph.D., LL.D., F.G.S., ete.
(PLATE XI.)
; if the American Journal of Science in 1877, the writer described
a remarkable extinct reptile from Colorado, under the name
Stegosaurus armatus,' and later a much more perfect specimen of
another species, Stegosaurus ungulatus, from essentially the same
horizon, in the Jurassic of Wyoming.” The latter specimen was
in fine preservation, and the more important parts of the skull and
skeleton, and especially of the remarkable dermal armour, were
secured, Subsequently, more than twenty other specimens of these
and other species were obtained, so that nearly every part of the
osseous structure thus became known, and only portions of the
dermal armour were in doubt. A fortunate discovery cleared away
most of the doubt in regard to one species, Stegosaurus stenops, as
the type specimen had the skull, skeleton, and dermal armour
together when entombed, and almost in the position they were when
the animal died.
With this rich material at hand, an attempt has been made to
give a restoration of one of the group, and the type specimen of
Stegosaurus ungulatus has been selected as the basis. This has been
supplemented by a few portions of the skeleton of Stegosaurus duplea,
apparently a closely allied species from nearly the same locality,
while some other parts, especially of the dermal armour, have been
placed in accordance with their known position in Stegosaurus
stenops.
The result is given in Plate XI., which is believed to represent
faithfully the main features of this remarkable reptile, as far as the
skeleton and principal parts of the dermal armour are concerned.
This figure, one thirtieth natural size, is reduced from a larger
restoration, one-tenth natural size, made for a lithographic plate
to accompany the monograph of the Stegosauria, prepared by the
writer for the U.S. Geological Survey. When alive, the animal
was about twenty feet in length, and nearly or quite twelve feet
in height.
1 American Journal of Science, III. vol. xiv. p. 513, December, 1877.
2 Ibid. vol. xviii. p. 504, December, 1879. See, also, vol. xix. p. 253, March,
1880 ; vol. xxi. p. 167, February, 1881; and vol. xxxiy. p. 413, November, 1887.
DECADE III.—VOL. VIII.—NO. IX. 25
DeEcaDE III. Vou. VIII, Pilate XI,
Grou. MAG. 1891.
Restoration of Stegosaurus ungulatus, Marsh. (s!p nat. size. )
A Dinosaurian Reptile from the Jurassic formation of Wyoming Territory,
United States, North America.
ee hg
oe
086 Prof. O. C. Marsh—Restoration of Stegosaurus.
In this restoration, the animal is represented as walking, and the
position is adapted to that motion. The head and neck, the massive
fore limbs, and, in fact, the whole skeleton, indicate slow locomotion
on all four feet. The longer hind limbs and the powerful tail show,
however, that the animal could thus support itself, as on a tripod,
and this position must have been easily assumed in consequence of
the massive hind quarters.
-In the restoration as here presented, the dermal armour is the
most striking feature, but the skeleton is almost as remarkable, and
its high specialization was evidently acquired gradually as the
armour itself was developed. Without the latter, many points in
the skeleton would be inexplicable, and there are still a number
that need explanation.
The small, elongated skull was covered in front by a horny beak.
The teeth are confined to the maxillary and dentary bones, and are
not visible in the figure here given. They are quite small, with
compressed, fluted crowns, and indicate that the food of this animal
was soft, succulent vegetation. The vertebre are solid, and the
articular faces of the centra are bi-concave or nearly flat. ‘The ribs
of the trunk are massive, and placed high above the centra, the
tubercle alone being supported on the elevated diapophysis. The
neural spines, especially those of the sacrum and anterior caudals,
have their summits expanded to aid in supporting the massive
dermal armour above them. The limb bones are solid, and this is
true of every other part of the skeleton. The feet were short and
massive, and the terminal phalanges of the functional toes were
covered by strong hoofs. There were five well-developed digits
in the fore foot, and only three in the hind foot, the first toe being
rudimentary, and the fifth entirely wanting.
In life, the animal was protected by a powerful dermal armour,
which served both for defence and offence. The throat was covered
by a thick skin in which were imbedded a large number of rounded
ossicles, as shown in the figure. The gular portion represented was
found beneath the skull, so that its position in life may be regarded
as definitely settled. The series of vertical plates which extended
above the neck, along the back, and over two-thirds of the tail, is
a most remarkable feature, which could not have been anticipated,
and would hardly have been credited had not the plates themselves
been found in position. The four pairs of massive spines charac-
teristic of the present species, which were situated above the lower
third of the tail, are apparently the only part of this peculiar
armour used for offence. In addition to the portions of armour
above mentioned, there was a pair of small plates just behind the
skull, which served to protect this part of the neck. There were
also, in the present species, four flat spines, which were probably
in place below the tail, but as their position is somewhat in doubt,
they are not represented in the present restoration.
All these plates and spines, massive and powerful as they now are,
were in life protected by a thick, horny covering, which must have
greatly increased their size and weight. This covering is clearly
Tr. F. Jamieson—the Scandinavian Gtlacier. 387
indicated by the vascular grooves and impressions which mark the
surface of both plates and spines, except their bases, which were
evidently implanted in the thick skin.
The peculiar group of extinct reptiles named by the writer the
Stegosauria, of which a typical example is represented in the present
restoration, are now so well known, that a more accurate estimate of
their relations to other Dinosaurs can be formed than has hitherto
been possible. They are evidently a highly specialized sub-order
of the great group which has the typical Ornithopoda as its most
characteristic members, and all doubtless had a common ancestry.
Another highly specialized branch of the same great order is seen
in the gigantic Ceratopsia, of the Cretaceous, which the writer has
recently investigated and made known. The skeleton of the latter
group presents many interesting points of resemblance to that of
the Stegosauria, which can hardly be the result of adaptation alone,
but the wide difference in the skull and in some other parts indicates
that their affinities are remote. A comparison of the present restor-
ation with that of Triceratops, recently published by the writer,’
will make the contrast between the two forms clearly evident.
All the typical members of the Stegosauria are from the Jurassic
formation, and the type specimen used in the present restoration
was found in Wyoming, in the Atlantosaurus beds of the Upper
Jurassic. Diracodon, a genus nearly allied to Stegosaurus, occurs
in the same horizon. Omosaurus of Owen, from the Jurassic of
England, is the nearest European ally now known, but whether it
possessed a crest of dermal plates like that of Stegosaurus is doubtful,
although caudal spines were evidently present.
I].—Tue. ScanDINAVIAN GLACIER, AND SOME INFERENCES
DERIVED FROM IT.
By T. F. Jamison, F.G.S.
T is now fifty years since Charpentier” told us that the heaps of
Northern boulders which stretch across the plains of Prussia
and Saxony mark the ancient limits of the great glacier of Scandi-
navia, and that the smaller debris met with farther south represents
the stuff carried on by the torrents that escaped from the margin of
the ice. All this he explained to his incredulous contemporaries,
and now after half a century of debate, in which every other con-
ceivable mode of accounting for the phenomena has been tried, it
seems to he agreed on all hands that he was right—right in every
particular—but, strange to say, it appears to be now generally for-
gotten that he was the man to whom we owe the first sketch of this
explanation.
Agassiz,* in 1846, alluding to the previous observations of Char-
pentier, candidly said, ‘‘I was unable to believe in his conclusions
when he first imparted them to me, and I made observations in order
1 See Grou. Mae. Dec. IIT. Vol. VII. 1890, Pl. I. pp. 1-5, and Vol. VIII.
1891, pp. 193-199, Pls. IV. and V., and pp. 241- 260, Pl. VIL; ‘and Amer. Journ.
of Science, vol. xli. p. 339, April, 1891.
2 Essai sur les Glaciers, note to p. 319.
3 Bull. Geol. Soc. France, 2 ser. iii. p. 420, 6 April, 1846.
’
388 T. F. Jamieson—the Scandinavian Glacier.
to combat them, but I have been converted to his mode of view.”
Charpentier, however, tells us that it was his friend Venetz who
was the first to perceive (as he tersely puts it) that “tout le phé-
noméne du terrain erratique trouvait son explication dans lexistence
ancienne d’immenses glaciers.”
When the Scandinavian Glacier reached its maximum, it extended
over most of Northern Europe and stretched eastward beyond
Moscow. ‘To the south-east it went as far as the 50th parallel of
lat. on the banks of the Dnieper, and from that its southern border
ran westward along the northern base of the Carpathian Mountains
and the hills of Central Germany to the mouth of the Rhine. If
the starting-point lay in the mountain-chain of Scandinavia, the ice
must have travelled to the south-east, a distance of fully 1000 miles.
Nitikin’ tells us that the northern erratics extend over the whole
Government of T'schernigow and the east part of that of Kiew, but
the unstratified brown Boulder-clay which accompanies them does
not go beyond the eastern border of the Tschernigow Government.
General Helmersen’ says that heaps of northern boulders, generally
of small size, but some of them four feet in Jength, occur as far as
Moscow, while further south they rapidly diminish in size to mere
pebbles. The large angular blocks mentioned as occurring in the
Governments of Kursk and Woronesh are not erratics, but consist of
sandstone the same as that of the district in which they are found.
The size of the erratics diminishes gradually with the distance from
_ their source. In Finland they are often as big as cottages, and in
the Government of St. Petersburg blocks of large dimensions may
also be seen. Most of them are of granite and gneiss, such as occur
in Finland and Northern Norway.
Judging from the accounts of Torell, De Geer, and other Swedish
geologists, the stream of ice that came down the Baltic must have had
a length equal to fifteen degrees of latitude, or more, and the whole
tenor of the evidence leads me to think that I am not overstating,
when I say that the Scandinavian glacier travelled in some directions
at least 1000 miles. The reason why it went so far to the south-east
no doubt was because there were neither hills nor opposing glaciers
to obstruct its march, and the plains of Russia gave ample room
for it to spread freely onwards. ‘The Canadian ice seems to have
travelled nearly as far in a south-westerly direction, and for similar
reasons.
Now what would be the inclination or slope of the surface in a
glacier of such dimensions? ‘The nearest thing of the kind that we
have any knowledge about is the ice-sheet of Greenland. What the
average slope of its surface amounts to has not yet been properly
determined, but from all we have hitherto learned it does not seem
to be less than half a degree, or 46 feet per mile. In the glaciers of
1 §. Nitikin, Die grenze der Gletscher spuren in Russland und dem Ural Gebirge,
Peterm. Geog. Mit. 1886; also Geol. Bau der Hisenbahn linie, Gomel Briansk,
Russia, 1887.
2 G. V. Helmersen, Studien iiber die Wanderblocke und die Diluvial Gebilde
Russlands, Mem. de l’Acad. Imp. des Sci. St. Petersburg, 1869.
T. F. Jamieson—the Scandinavian Glacier. 389
the Swiss Alps the smallest mean inclination is 3° or six times
greater.
Nordenskiold’s Expedition, in 1883, in lat. 68°, was alleged to
have penetrated 160 miles into the interior of Greenland, at which
distance an altitude of 6000 feet was said to have been attained.
This would give an average rise of 374 feet per mile over the whole
distance ; but I suspect these figures cannot be relied upon, because
we are told the last 115 miles were done by the Laplanders of the
party, whose estimate of the distance seems to have depended on
mere conjecture. Nordenskiold himself attained a distance of only
62 miles from the outer edge, at which point he made the altitude to
be 4500 feet or 724 feet per mile. The positions of his camp were
determined by solar observations, the other distances by pedometers,
while the heights seem to have been fixed by the barometer. How
the Lapps estimated the height they reached I have been unable to
ascertain.
Dr. Hayes, who believed that he penetrated 70 miles into the
interior of Greenland, found that the surface of the ice had a slope
at first of about 6°, and then diminished gradually to 2° at the end
of the first 30 miles. At 70 miles from the coast he calculated that
he had attained an altitude of 5000 feet, which would give about
71 feet per mile, and this is almost the same result as that obtained
by Nordenskiold himself. Dr. Nansen states that, in 1886, an
American, R. H. Peary, travelled 100 miles from the edge of the
iceblink, his highest elevation being 7525 feet. This was further
north than Nordenskiold’s route in 1885, and gives 75 feet per mile.
Nansen and his party, in 1888, landed on the east coast of
Greenland at lat. 61° 50’, and then travelled along the coast north-
ward to Umiavik, lat. 64° 30’. From this, after penetrating ten
miles into the interior, they reached a height of 3000 feet. In lat.
64° 50’, at 40 miles from the coast, they were at a height of about
7000 feet on the 27th of August. By the beginning of September
they got to a flat extensive plateau, whose height was 8000 or 9000
feet, and which seemed to rise considerably higher to the north.
Over this plateau they travelled for more than two weeks, reaching
the west coast in lat. 64° 12’ on the 26th September. The breadth
of Greenland where Nansen crossed it in lat. 644° does not seem
to exceed 340 English miles, which would make the central point
170 miles from the coast, and taking the altitude at the centre to be
8500 feet, this would give an average slope of just 50 feet per
mile. Nansen’s results probably afford the best approximation we
have yet got, as the fact of his crossing the whole breadth of the
land in an ascertained latitude enables us to gauge the extreme
distance he penetrated into the interior with some confidence, if
our maps are at all correct. Further north the greatest width of
Greenland seems to be about 700 miles, which would make the
middle point 850 from the coast. A rise of 50 feet per mile on this
distance would give 17,500 feet for the altitude of the surface at
the centre.
From all we know of the Greenland ice it would seem that the
390 T. F. Jamieson—the Scandinavian Glacier.
gradient of its surface increases always towards the outer edge, and
that for the first hundred miles from the border we would not be
justified in assuming an average slope of less than 60 feet per mile,
and probably 70 would be nearer the truth. Then for the remainder
of the distance suppose we put the slope as low as even 12 feet per
mile, we still get the following result for a distance of 1000 miles,
100 miles at 60 feet per mile 6,000 feet.
00m! ooh Od2D Neh WU i GSpot es
1000 miles. 16,800 feet.
which gives an average of nearly 17 feet per mile over the whole
length, and I see no reason for thinking a less slope at all probable.
Now the present culminating point of Scandinavia is 8544 feet, and
only a very few of the mountain tops exceed 6000 feet; we have
therefore a very strong presumption that the former height of that
land must have been vastly greater than it is now, and the same
conclusion will apply to the centres of glaciation in Canada and
Scotland. Supposing that in Scandinavia we place the centre of
radiation for the ice not in the Norwegian hills, but in the lower
ground to the eastward, still it will not materially affect the result,
for although we thereby shorten the length of the glacier, we lower
the present altitude of the point from which it had to start. The
probability, therefore, seems to be very great that at the commence-
ment of the Glacial period the altitude of Scandinavia was higher—
very much higher—than at present, and this conclusion is strongly
supported by other considerations of scarcely less weight.
1. In the first place the whole sea-board of Norway is inter-
sected by long deep fjords, which have all the appearance of
being the sunken valleys of a submerged mountain-land that had
been deeply cut by rivers at a time when the country stood at a
far greater height above the sea. Christiania Fjord reaches a depth
of 1580 feet, Hardanger 2624, and Sogne Fjord no less than
4080 feet. Their sides are often very precipitous, and Sexe’ tells
us that in the Hardanger Fjord, in fine calm weather, when the
water is very transparent, the head turns quite giddy on looking
over the side of a boat down these submarine cliffs. Probably few
will believe that glaciers could have eroded the hard crystalline rocks
of Norway to a depth of thousands of feet beneath the sea-level, or
could have cut them into such precipitous forms, for the action of a
glacier on its bed has a tendency to produce flowing or bowl-shaped
outlines. Moreover, the heaviest current of ice seems to have been
that which came down the Baltic, which is a shallow sea, the general
depth being only 40 to 60 fathoms. The probability, therefore,
seems to be that these fjords of Norway, like the canon of Colorado,
were cut by mountain-streams in pre-Glacial times when the land
stood at a much greater height, for how otherwise can we suppose
them to have been excavated? The same observation will apply to
the sea-lochs which indent the west coast of Scotland and also to
the fjord latitudes of America, as Dana long ago pointed out.
1§. A. Sexe, Moerker, efter en Iistid i omegnen af Hardangerfjorden.
Christiania, 1866.
T. F. Jamieson—the Scandinavian Glacier. 391
2. Again, Dr. Tyndall reminds us that what we most want in
order to produce the glaciers of the Ice-time is improved condensers.
Now there is no better condenser that a lofty mountain. Heave it
high enough and you will get snow at the Equator, as we see on the
Andes, and at Kilima-Njaro in Africa. Here then we have another
good argument for a much greater height of the Scandinavian
plateau, and the same observation will hold good for other glaciated
regions. I therefore think that at the commencement of the Ice-
time these countries had a far greater altitude than at present—an
opinion which I expressed quite as distinctly thirty years ago.’ It
is difficult, indeed, to see how otherwise a sufficient permanent
condensing power could have been sustained in these latitudes; for
even in Greenland, at the present day, the line of perpetual snow
is 2000 feet above the sea-level, and it is on the high mountain range
of the interior that the ice is generated. Dr. Croll,’ in his paper on
the Antarctic ice, asserted that ‘‘the Greenland ice-sheet, like the
Antarctic, must be thickest at the centre of dispersion and thinnest
at the edge.” If the ice lay upon a perfectly flat horizontal plane,
no doubt it would require to be thickest at the centre, but if the
ground supporting it is 10,000 or 15,000 feet higher at the centre
than at the edge, as seems not unlikely, then the thickness at the
centre of dispersion need not be so very great. If Croll had said
that the surface of the ice-sheet must be highest at the centre and
lowest at the edge, it would have been all very well; but the thickness
of the ice at the centre of dispersion must depend much upon the
altitude of the surface on which the ice rests.
As the ice accumulated upon these lofty regions they appear to
. have gradually undergone a movement of depression, and the opinion
seems to be gaining ground that this depression may have been
caused by the weight of ice which was laid upon them.’ It is at
any rate quite clear that after the period of maximum glaciation
Scandinavia underwent a partial submergence, during which the
great glacier seems to have broken up and disappeared from much
of the ground it once covered, and this same order of events seems
to have occurred in the other great centres of glaciation in Britain
and North America.
Dr. Penck’s* theory that the submergence was caused by attraction
of the ice drawing the sea up on to the land, has not been sustained
by an appeal to mathematical investigation ; for Woodward in
America, Drygalski, and Hergesell in Germany, and Faye in France,
who have in elaborate papers discussed the subject from a mathe-
matical point of view, seem all to agree that the cause in question
would be quite insufficient to account for the facts, even on the most
liberal estimate of the possible volume of ice. Indeed, it would
1 Quart. Journ. Geol. Soc. vol. xviii. p. 180-1, Feb. 1862.
2 Quart. Journ. of Science, Jan. 1879.
4 Schwankungen des Meeresspiegels, Jahrb. der Geog. Ges. zu Munchen,
bd. vii. 1882.
392 Prof. H. Sjogren—Valleys of the Caucasus.
appear that, owing to the abstraction of water required to form the
ice, the surface of the sea would on the whole be lowered, and this
effect would surpass the other, however great the thickness of ice,
so that the combined effect of the European and North American
glaciations, if simultaneous, would be to cause a general sinking of
the sea-level during the period of maximum ice. The general
result, however, would depend much upon the relative extent of the
Arctic and Antarctic glaciers at the time, a subject regarding which
we know little or nothing. Penck seems to have been under the
impression that the attraction would have caused the sea to rise
towards the border of the ice in a comparatively rapid swell, but
such would not have been the case. Any rise in the level of the
sea induced by such a cause would be nearly parallel to the present
surface, and would extend much further horizontally outwards than
Penck seems to have contemplated, while its vertical extent would
be far less than he supposed.
If at the commencement of the Glacial period, Scandinavia (or
at least a large part of it) stood several thousand feet higher than
it does now, then it follows that the subsequent depression must
have been very considerable indeed, and the subsidence of such
a large area to the extent required would no doubt occasion much
squeezing, disturbance, and probably some upheaval in neighbouring
regions. Jam inclined to think that the ice was gathering on the
mountains of Norway at a much earlier period than is generally
believed, and that the coming on of the glaciation took place in
early Pliocene times, or even sooner. Many of the disturbances
that have taken place in the strata near the Straits of Dover and
elsewhere may have been occasioned by strains induced by the load
of ice, and the bursting out of volcanoes in Germany, Auvergne,
and other places may have arisen from pressure on the subterranean
lava due to the same cause.
IJJ.—Transverse VALLEYS IN THE HastERN CAUCASUS.
By Professor HsauMar Ss6GREN,
Professor of Mineralogy and Geology in the University of Upsala, Sweden.
1. The Sulak gorge below Gimri in Daghestan.
ee the many valleys of Daghestan that are interesting to
the geologist there are none more remarkable than the channel
by which the river Sulak passes through the chain of Cretaceous
and Jurassic mountains which borders Inner Daghestan. Just above
the entrance of this defile the four rivers Koissu unite in one stream,
which in a series of cataracts tears through a stupendous chasm
some fifteen miles in length, cutting the huge ridge almost at right
angles to its axis.
The gorge traverses the main chalk ridge in the direction N. 40°
E., then changes its line to N.W., which it still follows at the
widening of the valley below Tjirkei, and finally comes back to due
N. as it passes through the Tertiary hills below Subut. The mean
height of the ridge thus cut asunder is some 2000 métres or more
Prof. H. Sjégren— Valleys of the Caucasus. 393
than 6500 feet ; in the summit of Salatau, which lies about three miles
from the gorge, it reaches nearly 8000 feet; the bed of the river
Sulak at its entrance below Gimri is about 1000 feet and at its exit
near Tjirkei about 600 feet above the sea. The huge cutting has
therefore a vertical depth of from 5000 to 6000 feet, while its
breadth is so small that the river leaves no room for a proper road,
and scarcely enough for a narrow horse-path, which is itself im-
passable at certain seasons of the year. The walls of the defile,
which mainly consist of a compact dolomitic limestone and show
the lines of stratification with unusual distinctness, rise almost per-
pendicularly into the air and are altogether unscalable. For this
reason the valley of the Sulak, which forms a hydrographic link
between Inner and Outer Daghestan, is as a means of communication
between the two divisions of the province of no significance what-
ever. The road between Temir Chan Schura and Gimri is carried
over the 6000 feet to which the intervening range of mountains here
rises instead of being taken through the river gorge. This cireum-
stance is sufficiently indicative of the wildness and inaccessibility
of this transverse valley.
Before going farther, I had perhaps better give a short sketch of
the orographical structure and hydrography of Daghestan.
nef UMS
Chiu Wie
POs}
Sketch-map of Daghestan, N. Caucasus.
Daghestan lies entirely on the N. slope of the main chain of the
Caucasus, though for administrative purposes it is included in Trans-
caucasia. A reason for this arrangement may be found in the fact
that the province is bounded on the N. also by a continuous range
394 Prof. H. Sjégren—Valleys of the Caucasus.
of mountains, the peaks of which rise to a height of 8000 or 9000
feet. The main chain of the Caucasus, where it forms the southern
boundary of Daghestan, runs in a straight line W. 28° §., while the
northern ridge I have just spoken of forms a regular curve, branch-
ing off from the other at Barbalo-Dagh and joining it again at Dulty-
Dagh. (See Sketch-Map, p. 393.)
The tract of country included between these two ridges is Inner
Daghestan. Outer Daghestan is the tract which lies on the outer
slope of the more northerly of the two ridges, and which therefore
looks towards the Terak Steppe on the N. and the Caspian Sea on
the N.E. Inner Daghestan may also be described as the basin of
the four rivers Koissu. Surrounded as it is on every side by lofty
mountains, this region would be altogether without an outlet for its
waters, had not the combined streams of Koissu, which after their
junction bear the name of Sulak, found a way to the Caspian Sea
through the defile which we are now considering. This narrow
gorge is the only channel for the drainage of an area of nearly
5000 square miles.
The physiographical character of these two regions, Inner and
Outer Daghestan, is very different. Outer Daghestan consists almost
entirely of Tertiary formations, Paleogene (probably Eocene) clay-
slates and sandstones, Sarmatian limestones, etc. It is only in the
crests of the anticlinal folds that the Cretaceous rocks here and there
appear. The strata of this region lie in gentle gradients as a rule,
and there are no dips exceeding 45°. The slope towards the Terek
Steppe and the Caspian Sea consists of terrace-like plateaux or
undulating highlands of a mean height of some 1800 feet, only the
branches and outgrowths of the mountain-chain behind reaching a
greater elevation.
The character of Inner Daghestan is altogether different. Here,
as Abich pointed out years ago, Tertiary formations are entirely
wanting. The fundamental rock is exclusively Cretaceous or Jurassic
with the exception of certain of the earliest Caucasian schists, the
age of which is as yet unknown.
Inner Daghestan again may be divided into two sections, as I
have already suggested in my paper ‘“‘ Uebersicht der Geologie
Daghestans und des Terek-Gebietes.”! 'The lower section consists
mainly of limestones and dolomites belonging to the youngest
Jurassic and oldest Cretaceous periods, 7.e. Malm and Neocomian.
These formations form extensive and high-lying basin-like plateaux,
which often end in precipitous, almost perpendicular, cliffs. It is
only in the deep and narrow river-gorges that the schists of the
middle Jurassic period come into view. Among these plateaux are
that of Keher, lying between the Kara-Koissu and the Kumuch-
Koissu, and reaching its highest point in Turtji-Dagh (7950 feet) ;
that of Gunib between the Kara-Koissu and the Avarian Koissu, the
highest point of which reaches some 7770 feet; and that of Kunsach
between the Avarian and the Andian Koissus, of which the Talokol
range (8980 feet) may be looked upon as the southern edge. The
1 Jahrbuch der k. k. geolog. Reichsanstalt,’”’ vol. 39, p. 417 (1889).
Prof. H. Sjogren— Valleys of the Caucasus. 395
southern faces of these huge plateaux, all of which look towards
the main Caucasian chain, lie almost in a straight line with a
W. 25° N. direction, a line which marks the boundary, so important
in physiographical respects, between the upper and lower sections
of Inner Daghestan. While the average height of these plateaux is
about 6250 feet, the average height of the river beds which traverse
them is not more than some 2000 feet. ‘To this great difference
of elevation is due the great difference between the climate and
products of the deep valleys and those of the high plateaux in this
region.
The physiographical nature of the upper section of Inner
Daghestan shows a striking contrast to this. Here there are no
solid strata of limestone and dolomite, but only loose schists with
subordinate beds of sandstone belonging to the Lias formation or the
fundamental Caucasian schists. The high-lying plateaux, with their
precipitous cliffs, are no longer to be seen; the river-valleys are
broader and more practicable; the mountains slope less abruptly,
and their sides are modelled more softly by the ramifications of the
lines of erosion.
We will now proceed to examine the structure of the chain of
mountains which encloses Inner Daghestan to the N. and N.E., and
give our special attention to that section through which the Sulak
has found a passage.
On the whole the structure of the dividing ridge is very simple,
and for the greater part of its length it may be considered as an
oblique anticlinal fold or a system of several such folds. This at
least is its nature for a length of some 70 miles, from Bozrach in
the W. to Suluch-Dagh in the E. Throughout this stretch the ridge,
which consists entirely of Cretaceous rocks, forms a boundary as
well as a watershed between Inner and Outer Daghestan, and has
a mean elevation of nearly 6000 feet. The steeper side of the fold
lies throughout inside, 7.e. it faces S. and 8.W., while the strata of
the outer slopes show a gentler angle. A marked feature of this
particular section of the whole ridge is that the compression of the
fold has been more violent than in the adjacent sections, where there
has been less disturbance of the stratification.
I may here repeat a passage from another paper of mine which
refers to the same region. ‘I have already shown, when treating
of the Cretaceous region of Daghestan, that the boundary between
the Outer and Inner divisions of the province is formed by a huge
ridge which belongs chiefly to the Senonian, though towards the
west the Neocomian also comes in. This watershed throughout a
great part of its length consists of an oblique fold. On the outer
Slope the strata fall gently in angles of from 10° to 20°, on the
inner slope steeply, reaching from 60° to 90°.”
On the eastern slope of Salatau, immediately above the transverse
valley of the Sulak, the mountain is seen to be composed of three
of these oblique folds, lying one above the other.
1 “ Uebersicht der Geologie Daghestans und des Terek-Gebietes.’’ Jahrb. d. k. k.
geol. Reichsanst. vol. 39, p. 484 (1889).
396 Prof. H. Sjogren—Valleys of the Caucasus.
From the above short sketch of the main orographical features of
Daghestan, we will proceed to trace the course of the four rivers
Koissu, a survey of which will help to give the reader a clear
notion of the conditions under which the transverse valley we are
now considering was formed.
The most westerly, and at the same time the largest, of these four
streams, the Andian Koissu, passes first through the deep valleys in
the fundamental schists which divide the Katju range of mountains
from the main chain, and so far its course is entirely longitudinal.
The channel then bends to the N.E., and soon assumes a transversal
character, the valley traversing a plicated region of fundamental
schists and Lias, and at Konada passing into a tract of folded Jurassic
and Cretaceous rocks. In its lower section the channel is alternately
longitudinal and transversal; in some places it cuts obliquely
through huge folds of Jurassic and Cretaceous strata (Malm to
Senonian), while at others it runs parallel with them.
The two middle streams of the four, the Avarian Koissu and the
Kara-Koissu, have both eminently transversal courses, as is shown
indeed by their general N.N.E. direction, which is at right angles
to the prevailing strike-line of the stratification. In their upper
and intermediate sections these rivers flow over the fundamental
schists and form wide open valleys thickly set with hamlets. But
as soon as they enter the Jurassic and Cretaceous formations these
valleys become so constricted that they are scarcely habitable. This
is especially the case with the Kara-Koissu, the lower portion of
which, from Gunib, which is the centre of the government of the
district, forms a barren gorge eut in the plateaux of Malm-dolomite
and Neocomian limestone. Its only inhabited points are the military
stations at the bridges of Gunib and Salti. After this there is no
change of direction, as the river continues to cut at right angles
through the huge Malm and Neocomian formations, its channel
separating the plateaux of Gunib and Salti, which would otherwise
form an unbroken whole, and the mountains of Sochtala from those
of Koppa.
Much the same state of things is to be seen in the course of the
Avarian Koissu, though its valley is not so narrow and impracticable
as that of its fellow river. It enters the flat Cretaceous and Jurassic
folds at a small angle, and then below Kara-Dagh traverses them
perpendicularly.
The most easterly of the four branches, the Kumuch-Koissu, in
its upper course from Chosrek to Kasi-Kumuch, the centre of the
local government, has a N. 25° W. direction, which corresponds with
the general strike of the schists and sandstones over which it passes.
On both sides of the valley the strata fall to the H.S.E., the character
thus being that of an isoclinal valley. Lower down, near Kumuch,
where the river-channel enters the Jurassic and Cretaceous strata, it
partly cuts through the huge folds at a sharp angle and partly runs
parallel with them.
If we now shortly summarize what I have just said, we shall
see that the four rivers Koissu have on the whole a course which
Prof. H. Sjogren— Valleys of the Caucasus. 397
Z 3
traverses the prevailing strike of the stratification, and in their
upper valleys flow over soft and unresisting schists of Lias and
earlier formations. They then enter a region of folded Jurassic
and Cretaceous strata, where they cut through a plateau of synclinal
character, the mean height of which is 6250 feet, while the river
beds reach no more than some 2000 feet. Still further down, below
Gimri, the four streams unite at a height of about 1100 feet, and
then, as the Sulak, pass through a range of mountains which reach
more than 6500 feet in mean elevation.
For these phenomena I can find no explanation so well supported
by the data at hand as the hypothesis that the bed of the Koissu
rivers and the Sulak originally lay at so high a level that the water
flowed over the great range of mountains without cutting it, and
that the transverse valley which now exists was subsequently eroded
to its present depth, its erosion keeping pace with the general
denudation of the valleys which lay behind. I came to this con-
clusion when I was travelling in Daghestan in 1888, though I had
then given no special attention to the general question of transverse
valleys. After my return I was induced to study the subject more
closely, and I then discovered that the same or similar hypotheses
had been advanced long before.
If we apply this theory to the special case which we are con-
sidering, we shall soon see how these rivers in their upper channels,
where they flow over soft and easily destructible beds of schist,
have managed to hollow out the wide open valleys which there
occur, while in the solid and compact limestones and dolomites of
the lower part of Inner Daghestan, they have only been able to
produce deep narrow cuttings with precipitous walls. General
denudation has reduced the level of the upper schist region, till
its elevation has become less than that of the limestone and dolomite
plateaux and that of the great mountain ridge, all of which once
lay below it. The same explanation which serves for the Sulak
gorge below Gimri will apply to the narrow defiles at Gunib and
Salti in the lower course of the Kara-Koissu, and they may also
be regarded as true transverse valleys.
But the whole of the valley system will be still clearer to us if we
consider its original history and gradual development.
It was probably at the beginning of the Tertiary period that Inner
Daghestan rose above the sea and became dry land. I have already
drawn attention to the important fact that there are no Tertiary
formations in Inner Daghestan, for which reason we must suppose
that this region already lay above the sea, whereas Outer Daghestan
consists mainly of formations of this period. On the other hand
we find in the lower part of Inner Daghestan among the Jurassic
folds remains of Gault and Aptian (Middle and Lower Greensands)
which show that the sea of the Cretaceous period covered at least
a part of this region. This is also proved by the enormous Senonian
deposits which form the dividing ridge between Outer and Inner
Daghestan and show a thickness of more than 3000 feet. At the
beginning of the Tertiary period, however, it was probably this
398 Prof. H. Sjogren—Valleys of the Caucasus.
ridge that formed the limit of the land, and its outer slopes, which
look to the N. and N.E., would in that case have been washed by
the Tertiary sea.
As soon as Inner Daghestan rose above the sea the work of erosion
must have begun. At that time there would have been no river
valleys or lines of erosion in the comparatively smooth surface of
the country, and the drainage would have followed the general
slope to the N. and N.E. To this period we must assign the origin
of the valley-system which the Koissu rivers now follow, and it is
easy to see how, on the then smooth and featureless surface, the
channels could show such independence of the geological structure of
the subjacent rocks as we have seen is actually the case.
During the long geological periods that have since elapsed, this
region has been exposed to many and great changes. Subterranean
forces have raised the whole mountain system of the Caucasus;
the forces of denudation have at the same time from prominent
points stripped off whole masses of strata and displayed the older
formations which lay beneath. ‘Throughout all these changes, how-
ever, the Koissu rivers have retained their original course, owing to
the fact that the erosion of their channels has kept pace with opera-
tions which have threatened to divert them. Just as general
denudation has lowered the level of the country which formed their
upper basin, so and in a corresponding degree has erosion deepened
the narrow defile in which they pass through the barriers of Jurassic
and Cretaceous folds, and has produced the present state of things
which at first sight strikes us as so abnormal.
This explanation is the same that Penck, in his review of theories
to account for transverse valleys, has characterized by the term
“‘Geologische Gefallsthaler,”' or valleys which are due to intense
denudation in their upper sections. The first to apply the explana-
tion was Giimbel, in the special case of Altmiihl in Bavaria. At
about the same time and quite independently similar hypotheses were
advanced by Jukes and other English geologists to explain similar
phenomena in England and Ireland.
These transverse valleys have the important and characteristic
feature that their rivers pass from the older formations which lie at
their sources on to strata of newer and newer date. The later strata
upon which such a river enters in the lower portion of its course
were no doubt once present in the region about its source. This
region lay, when the river began to run, higher than those tracts
through which it now passes further down, but now, owing to
excessive denudation of the upper basin, the conditions are just the
opposite.
2. The Gerdiman-tschaj gorge below Lagitsch.
A precisely similar origin must be assigned to the fine transverse
valleys in which the Gerdiman-tschaj, after flowing through the
cauldron-like valley of Lagitsch on the southern side of the main
1 «Tie bildung der Durchbruchthaler,’’ Schriften des Vereines zur Verbreitung
naturwissenschaftlicher Kenntnisse in Wien, vol. 28, p. 483 (1888).
Prof. H. Sjogren— Valleys of the Caucasus. 399
Caucasian chain, passes the Lagitsch range, which on the eastern
side of the gorge has the name of Nial-Dagh, on the western that
of Elgja-Duk. In point of volume the Gerdiman-tschaj river is
insignificant compared with the Sulak, but the natural cutting made
by it to the south of Lagitsch is little inferior in grandeur to that
through which the larger river passes near Gimri.
In order to make clear the topography and geological structure
of the Lagitsch valley and the surrounding mountains, I reproduce
the following from an earlier paper of mine: “Bericht tiber einen
Ausflug in den siiddstlichen Theil des Kaukasus in Oktober und
November, 1889.” 3
The Lagitsch valley-system consists of two separate branches, of
which the larger and more easterly is the channel of the main
river Gerdiman-tschaj, while the smaller, which lies to the west,
carries a tributary stream. ‘The two are separated by a mountain
ridge running N. and §. and reaching a mean elevation of some
6000 feet. The minor valley forms an almost circular cauldron
about six miles across, at the bottom of which lie the villages of
Dachar and Wascha. The main valley on the other hand is long
and narrow, and may be divided into two sections, of which the
upper, running from N.W. to §.E., begins on the slope of Baba-
Dagh, while the lower, which runs nearly N. and 8., may be said to
end with the beginning of the Gerdiman-tschaj defile. Both valleys
are separated by high ridges of about 7200 feet from the Pyrsagat
valley-system on the H., and from that of Gok-tschaj on the W.
On the N. the Lagitsch valleys are bounded by the main range of
the Caucasus, which just here rises with excessive abruptness, and
reaches its highest point in Baba-Dagh, a peak of 11,940 feet.
The only opening in the mountains enclosing the Lagitsch valleys
lies to the S. Here, through the transverse cutting with which we
are now concerned, the Gerdiman-tschaj passes a mass of mountain
composed of basalts, tuffs, and limestones raised to an almost vertical
position. Owing to the comparative impracticability of the gorge,
where the encroachments of high-water prevent the construction
of a good road, it is only at intervals that a regular communication
between the country above and below can be kept up. The most
convenient link of connexion is the road which goes to the E. over
the pass of Machtokjan-gjadu (7090 feet) to the Pyrsagat valley.
At the entrance of the gorge, a mile or so below the village of
Lagitsch, the bed of the Gerdiman-tschaj has an elevation of about
3430 feet. As the ranges of Nial-Dagh and Elgja-Duk, which lie
on either side, reach heights of 6900 feet and 7600 feet respectively,
it follows that this transverse valley has a vertical depth of more
than 8800 feet.
In respect to their geological structure the Lagitsch valleys con-
sist of a huge stratified series of clay-slates, which are to a great »
extent ferruginous, and thinly laminated limestones, which are
impure, compact and often half crystalline. As there are no fossils
in these beds,—I have only found in some of the clay-slates doubtful
1 Mittheilungen d. k. k. geographischen Gesellschaft in Wien, 1890, p. 153,
400 Prof. H. Sjogren— Valleys of the Caucasus.
fucoid impressions—the geological position of the whole complex
can only be determined indirectly. The petrographic features remind
one strongly of the Eocene formations in the Eastern Caucasus, and
the superposition upon limestone in the case of Nial-Dagh is
analogous to the superposition on Senonian white chalk in the other
instance. Moreover, the occurrence of strongly ferruginous clay-
slates both to the N. and §. of the eastern Caucasus is especially
characteristic of the Hocene period. At the northernmost end of
the two valleys, on the side of Baba-Dagh itself, there are thinly
laminated limestones raised at considerable angles.
We will now turn to the structure of the ridge of mountains which
the channel of the Gerdiman-tschaj enters as it leaves the Lagitsch
valley. This ridge I have myself crossed on the way from Mudschi,
a village on the 8.E. side, over to Lagitsch, as well as by the route
through the Gerdiman-tschaj gorge, in which the stratification is
very finely displayed. Regarded as a whole, the Nial-Dagh ridge
consists of a colossal fold leaning over towards the S. and is mainly
composed of limestones and stratified eruptive tuffs. If we look
to the details we see that massive eruptive rocks, with the character
of basalt and andesite, also enter into the composition of the ridge.
It must still be left an open question whether these eruptives
occur as dykes in the stratification or formed beds originally.
As one ascends the slopes of Nial-Dagh from Mudschi, one passes
across a series of zones, which in petrographical respects differ
from each other distinctly. The series is as follows, beginning from
below :—
1. Compact grey thin-bedded limestones, together with light grey crystalline
thick-bedded limestones, both of these alternating with soft stratified tuffs,
which are often much weathered.
2. Eruptives varying from dark grey to a greyish-green together with the accom-
panying tutis, the first forming compact rocks of andesitic and basaltic
ee which often split spheroidally, the latter being foliated or thinly
bedded.
3. Dark grey shaly tuffs together with conglomerates and pudding-stones; the
pebbles of eruptive material or limestone ; the matrix calcareous or tuff-like.
4. Light grey crystalline limestones in thick beds, with greyish green shaly and
much weathered tufts. :
5. Dark clay-slates, sometimes with green calcareous layers intervening ; in some
of the conglomerate beds green grains are abundantly distributed and probably
come from disintegrated eruptive material.
6. Light grey limestones and greyish green tufts, as in 4. : : ‘
7. Thinly-laminated clay-slates, sometimes strongly ferruginous, in thin, reddish
brown, sandstone-like beds, and with numerous veins of cale-spar.
The whole of this complex of strata reaches a thickness of some
8250 feet. In 1 the dip was 65°-70° N.N.H., and the strike
N. 60° W.; in 4 the dip was 62°-65° N.E., while the strike lay
N. 45° EK. At the pass (6600 feet) the strata of 7 stood vertically.
I will now shortly state the observations I made during the
passage of the Gerdiman-tschaj gorge. The direction is N.E. to
S.W., the length about five miles, and to the 8.W. the defile
increases in width, while the mountains decrease in height.
At the entrance of the gorge, a little 8. of Lagitsch, come first
the same clay-slates which occupy the greater part of the Lagitsch
Prof. H. Sjogren—Valleys of the Caucasus. 401
valley; here the strata dip sharply towards the N. Then come two
thick systems of strata, standing almost vertically, and consisting
of light half-crystalline limestones, which correspond to the two
sections 4 and 6 in the above Nial-Dagh profile, and are separated
by a series of clay-slates (section 5 in the preceding profile). One
then passes some dark, shaly, and often tuff-like strata, corresponding
to section 3, and enters a zone of massive basalts and andesites,
answering to section 2 in Nial-Dagh. So far there is complete
correspondence with the Nial-Dagh profile, though there the
eruptives appear only once, while in the 8. portion of the river
gorge they form three several divisions of the profile. Between the
first and second masses of basalt, reckoned from the N., is a narrow,
closely compressed fold of limestone, which has both its limbs
dipping isoclinally to the N., and is encased in a mantle of slate.
The second and third masses of basalt are separated by thick
compound folds of slate, which have a general dip to the N.
If we now summarise the facts that I have adduced as to the
geological structure of the various parts of the Gerdiman-tschaj
valley, we see that the upper basin of the river on the S. slope of
Baba-Dagh consists of hard and compact rocks, but that shortly
afterwards the channel passes into the looser-slate of the Lagitsch
region, where an open cauldron-like valley has been formed by
erosion. On entering the hard limestones and eruptive rocks of
the mountain ridge now barring its way, the river has had its
channel again constricted to a narrow cleft, as erosion has here
been unable to do more than maintain a narrow furrow, at a level
which has kept pace with the continual sinking of its upper basin
by ordinary denudation.
Our consideration of this valley will thus lead us to the same
conclusion that we arrived at in the case of the Sulak. Originally
the river bed lay at a much higher level and passed over the ridge
of Nial-Dagh instead of cutting through it. Subsequently the wide
Lagitsch valley has been hollowed out by the denudation of the
loose, soft slates in which it lies. With this denudation and con-
sequent sinking of level the river-erosion which went on below, on
the Nial-Dagh section, has been able to keep pace, and the stream,
working, so to say, after the manner of a saw, has cut a deep groove
through the mountain ridge of hard and compact rocks.
It is well worthy of notice that the river has chosen a point in the
ridge where for the sake of a channel it had to cut through three
huge columns of basalt and where the work of erosion must have
been considerably more difficult than farther east. This fact is in
full agreement with the circumstance that transverse valleys of this
kind, as is shown by observations elsewhere, often cut their way
through some mass or column of hard rock which could easily have
been circumvented. This should be a proof that such channels
have originally passed at a far higher level, when the obstacle in
question was absent, and that they have since contrived in spite of
it to pursue the course they had once adopted.
The Gerdiman-tschaj shows us well that the rule of permanence of
DECADE III.—VOL. VIII.—NO. IX. 26
402 G. W. Bulman—Glacial Geology.
channel holds good, not only in the case of large and deep rivers,
but also in the case of so comparatively insignificant a stream as
this, which at certain seasons of the year runs almost dry and has
so trifling a volume of water that it disappears completely in the
Kura Steppe without reaching either river or lake of any kind.
And yet this small volume of water has been able to execute so
grand a piece of erosive work.
IV.—On tHE Sanps AND Graves INTERCALATED IN THE
BovuLDER-CLAY.
By G. W. Butman, M.A., B.Sc., Corbridge-on-Tyne.
(Concluded from the August Number, p. 348.)
On the Italian side of the Alps a similar set of lignite beds occurs
as on the Swiss side. But these Italian lignites, although occurring
beneath, are not underlaid by glacial deposits.
Evidently, then, they afford even less evidence of an interglacial
period than those on the Swiss side; and this Prof. Geikie himself
seems to confess; for he writes of them: .
“They are clearly of older date than any recognizable morainic
or diluvial deposits in Northern Italy; and if it were simply a
question of local geology, one could have no good reason for
doubting their pre-glacial age.” '
And yet, taking them along with the Swiss beds, he finds in them
similar witness to an interglacial period.
With regard to the ‘marine sands” with which the lignites seem
to be contemporaneous, Prof. Geikie considers the evidence of their
fossil shells insufficient to establish their pre-glacial age.
The number of extinct species in the sands is said to be from
15 to 20 per cent.; and if we compare this with the 18 per cent.
extinct species of the Norwich Crag, the inference seems obvious
that the beds are pre-glacial.
Prof. Geikie points out, however, that such comparisons are only
conclusive when confined to the same geographical area; and when
we substitute the Italian Pliocene for the English, a very different
conclusion is suggested. For in the lowest beds of the former the
per-centage of extinct shells is 83, and in the Upper 68. If, then,
these Italian Pliocene are rightly classed, the lignites must be at any
rate Post-Pliocene. But even then, it is still possible they may
have been formed before the ice reached the district where they
occur. A local geologist, however, the Italian Prof. Gastaldi, does
not consider the Italian lignites to be interglacial. At the same
time he believes them to be of the same age as the Swiss beds. But
if the Swiss lignites lie upon glacial beds, and the Italian below
glacial beds, and if they are of the same age, it follows that the
lignites must be interglacial.
The argument seems to hinge on the question whether the organic
remains indicate a similar age for the lignites on the two sides of
1 Great Ice Age, p. 527.
G. W. Bulman—Glacial Geology. 403
the Alps. Mammalian remains are found in Swiss lignites, and are
of distinctly recent aspect: they are,—
(1) Asiatic Elephant (Elephas Indicus) (B. antiquus >),
Urus (Bos primigenius).
(2) Stag (Cervus elaphus).
(8) Cave Bear (Ursus speleus).
Rhinoceros sp. (R. Merkiz?).
(1) It is somewhat difficult to decide how old a deposit may be
which contains this living species, as it is so seldom found fossil.
Writing in 1868, Dr. Hugh Falconer states that, ‘There is no
good evidence of the existing Indian Elephant having as yet any-
where in India or in Europe been met with in the fossil state.” *
And according to Woodward and Sherborn (British Fossil Verte-
brata) it has not been found fossil in Britain.
(2) This species is found in the ossiferous caves of Wales and
Gibraltar, in the Norfolk Forest-bed, in Pleistocene, Prehistoric, and
Historic deposits. This leaves a wide margin for the age of the beds
in which it occurs.
(3) This occurs in the Forest-bed, in the Pleistocene, and in the
caves. Again no evidence as to age.
On the whole such an assemblage might have occurred at any
period from late Pliocene to Postglacial times. And yet the general
aspect of such a fauna suggests a later period than one in which
15 or 20 per cent. of the Mollusca are extinct.
And finally, even if the lignites are interglacial as to position, this
does not, as we have seen, necessarily indicate a warm interglacial
climate.
In America, again, Professor Geikie finds evidence of warm inter-
glacial conditions :
“Another interesting feature in the American glacial deposits is
the occurrence of intercalated fossiliferous beds.” *
According to Prof. Newberry the succession of changes indicated
are as follows:
Ist. A period of a great continental glacier or ice-sheet.
2nd. The retreat of the ice, and the appearance of a vast fresh-
water lake (covering a large part of Ohio), in which were deposited
the Erie clays, etc.
drd. The silting-up of the lake, and the advent of a luxuriant .
forest-growth.
4th. The submergence of the land and the deposition from floating
ice of blocks and boulders.
And the resulting succession of beds was as follows in descending
order :
1. Iceberg drift.
2. Forest bed.
3. Erie clays.
4, Glacial drift.
The “Iceberg Drift” above the Forest Bed, however, does not
necessarily imply a return of Arctic conditions after a mild interval ;
it may simply represent a phase in the gradual retreat of the ice
when its southern extent was still greater than it is to-day.
1 Pal. Mems. vol. ii. p. 157. 2 Great Ice Age, p. 416.
404 G. W. Bulman—Gtlacial Geology.
It may have retreated far enough to allow of the deposition of
the Hrie clay in Ohio (between lat. 88° and 42°) near its extreme
southern limit, the silting up of the lake, and the growth of forest
upon it.
If the land then sank, it need not be supposed that the southern
fringe of the retreating ice was too far off to allow it to send ice-
bergs floating over the submerged land, and depositing the “ Ice-berg
Drift” on the “ Forest-bed.”
The phenomena of the American “inter-glacial beds,” in fact,
seem to mark the retreat—perhaps intermittent and with prolonged
pauses—of the ice, rather than the occurrence of a warm climate
between two periods of cold.
And this is the opinion to which Dr. Wright inclines after pro-
longed and careful study of the glacial deposits and actual glaciers
of North America, although it is in opposition to that expressed by
other American geologists. In his “ Ice Age in North America,” he
expresses himself thus:
“‘A thorough study of the condition and distribution of the buried
forest beds bears strongly, as I cannot but think, against the com-
plete separation of glacial epochs in North America. In addition to
the facts about to be enumerated, it is a significant circumstance that
the buried vegetable deposits under consideration do not mark
a warm climate, but a climate much colder than the present—such
a vegetation, in fact, as would naturally flourish near the ice margin.
The buried forests of Southern Ohio have a striking resemblance
to those we described in Glacier Bay, Alaska. Peat and hardy
coniferous trees are predominant.”’!
And again,
‘Usually, as has been remarked, these buried deposits of peat and
wood have been assumed to imply the existence of two distinct
glacial periods. But, from what has been said above, it would
appear that the facts point rather to shorter periods of advance and
recession of the ice-front, analogous to those which are now in
progress in the Alpine glaciers, as heretofore noted.”?
At the same time Dr. Wright admits difficulties in the case of
some of the more northern deposits :
“Tt must be confessed, however, that some of the facts concerning
vegetal deposits still further north, especially in the valley of Lake
Agassiz, are more difficult to explain upon the theory of a single
glacial epoch.”
And finally summing up the matter he writes,
“Such are, in brief, the considerations which seem to make it
proper to hesitate before recognizing the theory of two distinct
glacial epochs in America as an established doctrine to be taught.
Most of the facts adduced to support the theory of distinct epochs
are capable of explanation on the theory of but one epoch with the
natural oscillations accompanying the retreat of so vast an ice-front.” *
_ The intercalated beds on the Norfolk coast are instructive. They
1 Tb. p. 482. 2 Tb. p. 490. 8 Ib. p. 495. 4 Ib. p. 500.
G. W. Bulman—Glacial Geology. 405
are described by Mr. Clement Reid! as “ well-laminated ripple-
marked clays and marls with seams of fine false-bedded sand,
deposited on the hummocky surface of the First Till,” and are in
turn overlaid by the Second Till. They have not yielded any
fossils except shell fragments derived from the Boulder Clay, and
Mr. Reid is led to the following conclusions as to their origin :
“The absence of all signs of life appears to point to a freshwater
origin for these beds, and for the similar unfossiliferous laminated
clays which are so common in glacial deposits in other parts of
England. Modern glacial lakes show a similar barren character ”
(p- 88).
Finally, Mr. Reid does not consider that they afford evidence of
an inter-glacial warm climate :
‘«‘After the deposition of the First Till, the ice appears to have
retreated, perhaps only for a few miles, leaving the Boulder Clay
with a curious hummocky surface, over which was deposited ripple-
marked clay and marl in thin beds. This deposit seems to be
glacial mud, such as would flow from beneath the ice, and be spread
over the surface lately abandoned. Such an evenly-bedded loam
cannot be taken as sufficient evidence of an inter-glacial warm
climate, though it is traceable nearly continuously for at least four
miles; for at the present day glaciers of the Alps and the ice of
Greenland advance and retreat short distances without any very
marked cause.” ”
Nor do the sands which come between the second Till and the
Boulder clay or Stony loam afford any stronger evidence. They are
described as “fine false-bedded loamy sands, always chalky and
carboniferous, and of a peculiar pale tint, easily recognizable ;”
and they rest on the eroded surface of the Till. Like the beds
between the first and second Tills they have yielded no fossils.
And this so-called Boulder-clay is a deposit of rather a curious
character. In general composition according to Mr. Reid it is much
like the underlying till, but it contains bedded masses of sand of
which the bedding is often vertical. It perhaps marks an advance
of the ice less pronounced than that which produced the second Till,
and which permitted more freely the action of streams.
The inconclusive nature of the evidence derived from the inter-
calated sands and gravels is further illustrated by a study of those
of South Lancashire as described by Mr. A. Strahan (Q.J.G.S. vol.
42, p. 362).
According to Mr. Strahan these sands and gravels “usually
underlie Boulder-clay.” Yet there is no evidence of glacial action
beneath them: “Lastly, it is almost invariably under Boulder-clay
that the rock has been found to be striated. Though the sands and
gravels are included among the glacial deposits, the Boulder-clays
alone show direct evidence of the action of ice.” On the Welsh
coast, on the other hand, Boulder-clay is described lying beneath
marine drift:—‘‘The occurrence of a tough blue basement clay
1 Geology of the Country around Cromer, Mem. Geol. Surv.
2 Ditto, p. 91.
406 G. W. Bulman—Glacial Geology.
packed with stones, most of which are scratched, underneath the
undoubted marine drift of the Welsh coast, has been previously noted.”
The view that these sands and gravels are interglacial rests on
the assumption, that the beds thus lying above the Boulder-clay in
one place are of the same age as those lying beneath it in another.
The mammalian and other remains found in the intercalated beds
are taken by Professor Geikie as evidence of the mild climate he
supposes to have prevailed. Yet similar remains are noted as
occurring in the Till itself:
“In the mass of the Till itself fossils sometimes, but very rarely,
occur. Tusks of the Mammoth, Reindeer antlers, and fragments of
wood have from time to time been discovered in this position.” *
And there are so many ways in which such remains as are found
in the intercalated beds might come to be imbedded in them that a
mild interglacial climate should not be assumed without very strong
evidence.
It seems to be generally inferred, that the glacial conditions drove
such Mammalia, and other temperate forms, out of the country, and
that a mild interval, and a union of England with the continent,
was required to allow of their return.
But is it not possible they may have lingered in the southern
unglaciated districts, migrating northwards during the summer,
and occasionally leaving their remains where glacial deposits were
being laid down? And a succession of warm summers might
induce them to travel to higher latitudes than usual. And it is
worthy of note that these mammalian remains are found in the
lower districts, where there would be less ice and milder conditions,
and where the ice was likely to melt most completely during the
summer. Prof. Geikie accounts for their absence on the higher
grounds by the greater intensity of the glaciation which he thinks
removed them; but the alternative explanation that they never
existed there is worthy of consideration. And a hint of how
mammalian remains may come to be imbedded in deposits far
beyond the usual habitat of the species is afforded by Dr. Meyer,
in his account of his recent exploration of the glaciers of Kilimanjaro
in Hastern Equatorial Africa:
“We were about half way through this terrific bit of work,” he
writes, “when we came upon what was perhaps as wonderful a
discovery as any we made in Kilimanjaro. It almost savours of
the fabulous, but here in this stern frost-bound region, at the very
summit of a mountain 20,000 feet high, we lighted on the dead
body of an Antelope—one of the small species we had noticed on
the pasture-lands below. How the animal came there it is impossible
to say. In all probability it had made its way upward by the same
path as ourselves, at a time when the ice was covered by its winter
coating of snow, and overtaken in these lofty solitudes by the
fury of a mountain-storm, had paid with its life the penalty of its
adventurous curiosity.” ?
1 Great Ice Age, p. 164.
* Across East African Glaciers, by Dr. Hans Meyer, pp. 183-4.
G. W. Bulman—Glacial Geology. 407
~ And Colonel Tanner, in his description of a Himalayan glacier,
shows how vegetation and ice-action may overlap. The following
passage occurs in a paper read before the Geographical Society
(see Nature, April 30th, 1891, p. 622) :—
“Speaking of the Himalayan glaciers, Colonel Tanner stated that
the most extensive and picturesque he has ever seen are in the Sat
valley, which drains the southern face of the Rakaposhi mountain in
Gilgit. Three great glaciers come down into this valley, and
dispute with the hardy mountaineers for the possession of the scanty
area of the soil. Here may be seen forests, fields, orchards, and
inhabited houses all scattered about near the ice heaps. The only
passable route to the upper villages in this valley crosses the nose
of the greatest of the three glaciers, and threads its way over its
frozen surface. This glacier is cut up into fantastic needles of pure
green ice, some of which bear on their summits immense boulders.
About half a mile from its lower end or nose, Colonel Tanner found
an island bearing trees and bushes, and at one place above this
a very considerable tarn of deep blue-green water. The glacier had
two moraines parallel to it and with each other, and both bearing
pine trees.”
Dr. Wright also describes the close proximity of glaciers and an
abundant flora and fauna in North America at the present day:
“The mountains on each side of Muir Inlet rise immediately from
the water from three thousand to five thousand feet. These we
often ascended, and were thus permitted repeatedly to behold one of
the most marvellous views anywhere to be found in the world.
At that season the level places around our feet upon these summits
were carpeted with soft green grass, interspersed with large areas of
flowers in full bloom. Here were extensive, gorgeously-coloured
flower-beds, where bluebells, daisies, buttercups, violets, the yellow
arnica-flower, and the purple epilobium, were striving for mastery
or for recognition. On the northern slopes of slight elevations great
masses of snow were preserved in the very midst of these brilliant
flower-gardens, and from their melting, clear little pools of water
were on every hand inviting us to drink. The tracks of the
mountain goat, the mountain lion, and of various smaller animals,
and the songs of birds witnessed to the abundance of animal life... .
In such a setting of grandeur and beauty we gazed upon the full
face of the great glacier itself lying at our feet. Below us its
diminishing outlet disappeared in the waters of the bay. Distance
made the rough places plain, and lent enchantment to the view.
Down from the mountains in every direction from the north came
the frozen torrents ;—
Glaciers to the right of us,
Glaciers to the lett of us,
Glaciers in front of us,
Volleyed and thundered—
pouring into a vast amphitheatre, and then uniting their volumes,
preparatory to their exit through the entrance into Muir Inlet.” ?!
1 Ditto, pp. 37-89.
408 G. W. Bulman—Glacial Geology.
The same writer further describes some of the islands in Glacier
Bay—at the head of which is Muir Inlet—as covered with vegeta-
tion :—“‘ Near the mouth of Glacier Bay is a cluster of low islands
named after Commander Beardslee, of the United States Navy.
There are twenty-five or thirty of these, and they are composed of
loose material—evidently glacial débris—and are in striking con-
trast with most of the islands and shores in south-eastern Alaska.
These, also, like all the other land to the south, are covered with
evergreen forests, though the trees are of moderate size.”
It is obvious that a very slight advance of the ice—such as are
known to be of common occurrence—might cover this vegetation
with glacial deposits and present all the phenomena of “interglacial
beds.”
Another indication of the possible close association of a Mammalian
fauna, and the action of ice is furnished by the phenomena of the
region of Hundes in India.
No glaciers descend there below 14,000, and very few below
16,000 or 17,000; and it has been shown by Mr. Lydekker that
Wild Horses (Equus hemionus) and Yaks (Bos grunniens) live there
at elevations of 15,000 feet. That remains of these could very easily
be imbedded in glacial deposits is obvious.’
And that vegetation may occur on the higher ground, while
intervening valleys are filled with ice, is indicated by Tayelel en's
account of the glaciers of Baltistan.
Of the Tapsa glacier he writes :
‘Cypress trees extend to a height of 1000 or 1500 feet above the
level of the glacier.” ”
A further illustration of the overlapping of an even temperate
vegetation with the ice is given in Rendu’s “Glaciers of Savoy.”
He speaks of the ice advancing between banks covered with
flowers, and adds, “‘I stopped near a field of rye which was by the
side of the Glacier des Bossons. An ear, almost ripe, and swayed
by the wind, each instant touched the ice, and drew back as if
frightened by this strange guest come from a climate which has no
power save for death.” °
It is obvious, in fact, that while the higher part of a glaciated
region may be removed from all animal or vegetable life, the lower
or melting portion must in some way invade the zone of living
creatures, and thus tend to mingle their remains with the tokens of
ice action.
But do the facts of the case admit the supposition that any
considerable portion of our fauna and flora were actually able to
exist in the southern unglaciated portion of Britain during the period
of intense cold ?
On the hypothesis that the ice-sheet extended as far south as the
latitude of London, there seems but a small area left—and that in
close proximity to a great ice-sheet—for its conservation. But in
1 See Grou. Mac. May, 1891, pp. 209-210.
2 Records Geol. Surv. India, vol. xiv. p. 44.
3 Translation, p. 68, Edited by Prof. George Forbes.
G. W. Bulman—Glacial Geology. 409
connexion with this point some remarks of Sir Charles Lyell in
relation to existing conditions in Greenland should be borne in mind.
“The perpetual snow,” he writes, “usually begins at the height
of 2000 feet, below which level the land is for the most part free
from snow between June and August, and supports a vegetation of
several hundred species of flowering plants, which ripen their seeds
before winter. There are even some places where phenogamous
plants have been found at an elevation of 4500 feet, a fact which,
when we reflect on the immediate vicinity of so large and lofty
a region of continental ice in the same latitude, well deserves the
attention of the geologist, who should also bear in mind that while
the Danes are settled to the west in the ‘outskirts,’ there exists due
east of the most southern portion of this ice-covered continent, at
the distance of about 1200 miles, the home of the Laplanders with
their Reindeer, Bears, Wolves, Seals, Walruses, and Cetacea. If,
therefore, there are geological grounds for suspecting that Scanda-
navia or Scotland or Wales was ever in the same glacial condition
as Greenland now is, we must not imagine that the contemporaneous
fauna and flora were everywhere poor and stunted, or that they may
not, especially at the distance of a few hundred miles in a southward
direction, have been very luxuriant.” !
Nor must we lose sight of the possibility that the land extended
further south in glacial times than now; or was even perhaps joined
to the continent. For it is still a moot point whether glacial Britain
was a cluster of low, ice-covered islands, or a highly elevated
glaciated region surrounded and united to continental Europe by
a great plain inhabited by an abundant flora and fauna.
We must further remember that the supposition that the ice-sheet
extended thus far south is founded on the hypothesis that the Till
was formed beneath the ice-sheet, and this view of its formation is
by no means certain or universally received.
Prof. Boyd Dawkins, for example, points out that the evidence
from “causes now in operation” is against this view. For, as he
remarks, no similar deposit is found where glaciers or ice-sheets have
retreated ; whereas in Davis Strait an analogous formation is being
laid down by the water from the melting ice entering the sea.
If this view of the formation of the Boulder-clay be adopted, the
ice-sheet may be supposed to have terminated much further to the
north, and the difficulty of supposing a part of the pre-glacial fauna
and flora to have found an asylum much lessened.
The peculiar flora of the south-west of Ireland seems to me to
afford a hint that a portion, at least, of our plants and animals were
not entirely driven out of the country. For there are difficulties in
the way of the supposition that this peculiar flora—not now found
further north than Spain and Portugal—migrated there after the
glacial epoch ; and Prof. Forbes, in his essay on the fauna and flora
of the British Isles, inclines to the view that the migration took
place before.
If this is true, these plants must have survived the Glacial epoch ;
and if these, why not many others of our plants and animals ?
1 Antiquity of Man, p. 278.
410 A. B. Wynne—The Salt Range.
A similar hint is offered by the fact that the glacial drift of the
west of England, and of parts of Ireland, contains mollusca of a more
southern aspect than that of the east side of the former. For it
allows us to suppose a milder climate existing on the west all
through the period of cold, and thus affording a retreat for forms
which might otherwise have perished.
Thus, although the question of the probability of mammalian and
other remains in the glacial drift of Britain without the intervention
of warm intervals, cannot be definitely settled until the preliminary
one of the extent of the land of the Glacial period is disposed of,
enough has been brought forward to show how easily it might
happen under certain conditions.
Finally, it may be affirmed that the evidence that the intercalated
sands and gravels were formed during a mild interglacial period is
in no single case conclusive; that while they are not the sort of
deposits to be, a priori, expected as the result of a mild interval,
they are just such as would naturally result from the action of sub-
glacial streams, the oscillations in the extent of the ice causing the
overlapping of glacial and aqueous deposits, and the work of the
ice itself; and that a gradually, but intermittently, advancing ice-
sheet, or glacier, could not avoid overwhelming and burying in its
own debris masses of vegetation, while the latter, closely following
the retreating ice, and growing on its accumulations, could not fail
now and again to be buried beneath the deposits of some temporary
advance of the same.
And since, looking to the present, the work actually done beneath
an ice-sheet or glacier—especially in those parts remote from its
lower margin—is still shrouded in mystery, it seems rash to assign
every bed which does not conform to our usual idea of the work of
the ice to an interglacial epoch.
V.—Recent GroLocicaL INVESTIGATIONS IN THE SALT RANGE.
By A. B. Wxnnz, F.G.S.
See Geological Survey of India Records, vol. xxiv. part 1, 1890,
only came to hand to-day, enabling me to see Mr. Middlemiss’s
late paper on the Salt Range.
It appears to be one of the many charms and mysteries of Salt
Range geology that it affords fresh discoveries to each successive
explorer; hence, possibly, something yet remains to reward the
next pilgrim who may have the chance to criticize Mr. Middlemiss’s
conclusions,—let us hope instructively.
The paper at present referred to possesses a great deal of interest,
and has much importance with regard to structural geology. I trust
it may receive worthy notice under light more modern than that in
which my Salt Range work was carried out more than twenty years
ago, without the advantage or disadvantage of a tendency to form
foregone opinions about the views of others before I reached the
ground. Perhaps I may also remind readers that when I was
thus engaged, the doctrines of inversion, earth-thrusts of several
A. B. Wynne—The Salt Range. 411
miles, and shearing, so largely affecting Mr. Middlemiss’s views,
and which arm his criticisms, were in their early infancy or still
unborn, and had not been developed by the exhaustive researches
in complicated districts of the Scottish geologists, whilst complex
superficial displacements from landslip abounded in degree and
magnitude sufficient to render conclusions as to inversions, etc., such
as the paper advances, very doubtful.
One conclusion (not the author’s alone), namely, that the Boulder
beds form a single continuous horizon, seems incontrovertible upon
the accepted evidence advanced for unconformity. This relation is
easier to understand when it is assumed that the Salt Marl is an
accidental associate, and not integral as an original basal part of the
series. Regarded as of the latter nature, in intimate connexion
with the lowest succeeding members, whether boulder conglomerates
or sandstone, it was of course impossible to hold such boulder
rocks to be contemporaneous with others, at a higher stratigraphical
level, in an apparently perfectly conformable sequence. The inter-
pretation depended upon the existence of either conformity or
discordance within beds lying in a general way more or less
horizontally, and the question formed one of those problems more
likely to be solved by the application of broad considerations than
of local details.
The paper itself suggests an illustration of this where reference
is made to derived pebbles as proofs of discordance; for it is an
uncontested fact that sandstone beds in the Eocene group trans-
Indus enclose rounded pebbles of fossiliferous Nummulitic limestone,
and are overlaid by conformable beds of similarly fossiliferous
Eocene limestone with little or no disturbance (Mem. G.S. I. vol. xi.
p- 3d, eé.s.). In other cases formations containing rolled fragments
of their own rocks have also been recorded. The inference from
these cases is quite as strongly in favour of conformity as of dis-
cordance: in fact, as strict evidence of the latter, the occurrence of
these pebbles has little or no weight. If this be true of trans-
Indus Nummulitic pebbles, why should it be otherwise as to
dolomite pebbles from the Salt Marl in an overlying conglomerate ?
or as to Hocene limestone pebbles in the next Tertiary layers above ?
In each case the separation as to time is reduced, and the likelihood
of a break diminished, leaving to wider general considerations rather
than to dogmatic rules the position of the safest guides. At the
same time the contention of Mr. Middlemiss may be correct, but
the case affords an instance in which each observer is at liberty to
form, or even to alter, his own conclusions according to his lights.
_ The most important part of the paper is the author’s suggestion
that the sub-Cambrian Salt Marl has no ordinary stratigraphic
relations with the rest of the series, but is of plutonic, igneous or
deep-seated origin, introduced in Tertiary times, accompanied by
lateral and vertical disturbance, thrusting, and shearing. The idea
of an igneous or deep-seated origin for rock-salt formations is not
new; it was considered and discussed so far as possible before
my Salt Range Memoir was written, but there did not then seem
412 Prof. T. G. Bonney and Miss Raisin—
sufficient evidence to found a case adverse to the generally received
theory of production of saline deposits. I gather that, notwith--
standing what is now advanced, the case is still incomplete, yet
I trust Mr. Middlemiss will follow up the subject to conclusions
that cannot be called hypothetical, and may effectively reconcile
several obscurities on both sides of the Indus.
When I was at the Salt Range, the facts of internal lateral thrust
displacements not having been demonstrated, it was plain the series
must have been laid down upon something, and the marl occupied
the place of the visible floor to the rest. Supposing the part above
to have been unconformably deposited, what conditions would have
preserved a soft saline marly mass to have received later accumu-
lations? But if it was found immediately succeeded by earthy
layers passing up into sandstones, the main conditions for tranquil
sequence would seem to have been present as I saw the sections.
I have not seen the brecciated junctions of the Purple sandstone
with the underlying marl as described in the paper, nor do I quite
grasp how such a condition—not merely superficial, but the result
of deep friction—might be established between substances like
soft ‘scum’ and hard sandstone. This, of course, is said with
reserve, and subject to correction by students of earth-movements,
thrusting, and so forth, which I have not had the advantage of
working out in natural éxposures.
While greatly interested in Mr. Middlemiss’s frank, able, and
lucid contribution to the literature of the Salt Range, I am yet
fain to hope that—aside from subsequent revelations in structural
geology—other readers of my memoir will find most of its con-
clusions reasonable at the time it was written. Our knowledge
is happily progressive, and considering the extent of the region
itself, with the circumstances governing its exploration, I can scarcely
feel vain regret that something did, or may still, remain to be dis-
covered. On the contrary, few will learn with greater satisfaction of
solid additions or improvements to what has been already ascertained,
notwithstanding that the results, such as they were, which attended
my labours for rather more than two working seasons, cost me a
good deal of thought and exertion, with serious loss of health, and
consequently of my employment—considerations, however, already
amply recognized as having nothing whatever to do with the geology
of the Salt Range or other regions. Nevertheless, the retrospective
pleasure of appreciating the observations of later investigators made
upon the spot, must still remain possible to an old field-geologist
like myself.
Kinestown, 287d July, 1891.
VI.—Report on some Rock-Specimens From THE KIMBERLEY
Diamonp-M1nzs.
By Prof. T. G. Bonney, D.Sc., LL.D., F.R.S., F.G.S.,
and Miss C. A. Ratsn, B.Sc. .
[From a collection of stones obtained from the refuse-heaps of
the Kimberley Mines by Mr. Louis Atkinson, a selection was made
Rocks from the Kimberley Diamond-Mines. 413
by Prof. T. Rupert Jones and, by kind permission of Prof. Bonney,
was submitted to him for examination, in packets marked I.—VIII.
and X. Specimen No. IX. was sent many years ago, as a trap-
rock with garnets from the Vaal River, by Mr. Robert Crofts
Jones.—T. R. J. ]
For the most part the specimens were too small to permit of
slices being made; the results therefore were in such cases obtained
by examining the powder got by crushing the fragments.
I. a. The green mineral is Enstatite, and is associated with a
colourless transparent mineral, appearing cracked and fractured,
which seems to be probably Topaz.
B. A clear bright-green crystal of Enstatite.
y- The green mineral is a Pyroxene, and is intercrystallized with
red Garnets.
6. A slide was prepared of this specimen, which showed that it
consisted of Garnets enclosed in a green Pyroxene, probably Ompha-
cite, with small rifts or tubuli traversing the crystal transverse to
the prism-zone. A colourless transparent mineral is associated with
the Pyroxene; it has straight, or nearly straight, extinction, and
might be Zoisite or possibly Kyanite.
II. a. A transparent, pale, resin-coloured specimen of Topaz.
B. A bright green Pyroxene, with a yellowish or greenish-grey
mineral, which has one good cleavage and straight extinction, and
may be Zoisite. Very dull purplish Garnets are included, and flakes
of brown Mica.
q. A Pyroxene of rather foliated habit, having a clear, deep, rich
green colour and a sub-metallic lustre, apparently like the Omphacite
described by von Drasche. To this is attached a white fibrous
mineral evidently a carbonate, probably Calcite.
6. A pale sea-green mineral with silky or pearly lustre, which
shows well-marked cleavages, breaks into rhomboidal forms, and
appears to be a variety of Diallage.
III. Many specimens of Iron-pyrites; also others of a rock
composed of Pyroxene, Garnet, and (?) Zoisite.
1V.a. Matrix seems to consist of minutely granular Serpentine
and Olivine with some brown Mica—a ground-mass apparently
similar to that in the slide cut from specimen VI. Green crystals of
Augite are enclosed.
B. Garnets enclosed in a clear greenish mineral, very pale in tint
when seen in thin flakes under the microscope, and somewhat
foliated ; it is probably a pyroxene of the nature of Omphacite.
y- Three specimens of Garnet-pyroxene-mica-rock, as described, II. p.
6. Three specimens of Garnet-pyroxene-(?)zoisite-rock, as pre-
viously described, III.
V. Specimens of Ilmenite (called ‘‘ carbon ” by the miners).
VI. A slide prepared from this rock shows a ground-mass, the
constituents of which are difficult to distinguish ; it appears to be an
irregular mixture of brown Mica, brownish-green Serpentine, and
a dirty-looking mineral, which is seen with polarized light as an
aggregate of fine granules, and in parts seems to be associated with
414 Prof. Bonney and Miss Raisin—Rocks from Kimberley.
the serpentine in a sub-ophitic way. Within the ground-mass are
well-formed crystals of green Augite, also red Garnet and brown
Mica. Some Olivine is in good preservation, and Serpentine occurs,
dark- to light-green, the result of the alteration of a ferro-magnesian
silicate, most probably an Olivine rather rich in iron. The rock
thus would seem to be a Granatiferous Picrite.
VII. These irregularly cylindrical bodies consist apparently of
small fragments of the minerals of the rocks, Garnet, Pyroxene, etc.,
and also of well-rounded Quartz grains, all the constituents being
cemented together, apparently by Calcite. The structures may very
possibly be concretionary and have formed within a sandy rock.
VIII. From examination of the powder obtained by crushing a
fragment, this specimen appears to be Pyroxenic,—a pale-greenish
minutely crystalline Augite.
IX. This rock consists of red Garnets, with rather perfect crystal
faces, imbedded in a brown ground-mass. A slide has been prepared
which shows that the matrix consists of an ill-defined crystalline
mass, including either incipient or partially-decomposed forms of
a mineral which has an appearance suggesting crystal outlines
of a Felspar-like character. Some Quartz may also be present. A
brown Mica occurs, rather iron-stained, and somewhat confusedly
crystallized. There are also crystals, which are short stout prisms,
rather rounded, terminating in basal and dome planes, transparent
and colourless, highly refractive, and with straight extinction ; these
may possibly be Topaz. The somewhat decomposed and iron-
stained condition of the rock makes it difficult to speak with
precision, but on the whole the probability is that it is a somewhat
altered fine-grained Granatiferous Mica-Diorite.
X. Quartz pebbles.
Note by Prof. T. Rupert Jones, F.R.S.
The following specimens were previously supplied by Mr. L.
Atkinson, and returned to Kimberley labelled for the use of the
miners and others.
1. Slag of “Blue Ground” (local matrix of the diamond) arti-
ficially burnt.
2. Tufaceous coneretions, roughly cylindrical and branched,
formed locally near the surface, from the decomposition of the
felspar of igneous rocks yielding carbonate of lime, and the calci-
ferous water percolating sandy strata.
3. Pebbles and fragments of chalcedony from the agates of
amygdaloids, either local or drifted from the upper country. 4.
Quartz crystal, probably from an agate. 5. Calcite, probably from
the local tufa or from an agate. 6-10. Iron-pyrites in irregular,
knobbly, concretionary forms; Hematite; Ilmenite; Garnet; Epidote;
probably from the “ Blue Ground.”
11. Shale veined with calcie carbonate. From the ‘“ Kimberley
Shale” of the “‘ Lower Karoo” formation, traversed by the diamond-
stuff. 12. Porcellanite; possibly burnt shale. 13. Silicified wood ;
coniferous, from the “Upper Karoo” formation. 14. Soft ferru-
Dugald Bell—Glacial Mound in Glen Fruin. 415
ginous grit-stone; probably from the Karoo Beds. 15. Sandstone;
from the Karoo Beds. Nos. 13 to 15 have been drifted from the
Stormberg and neighbourhood higher up the country. 16. Pebble
of brown quartzite; possibly from the Karoo Beds.
17. Mundic in slate. 18. Siliceous schist, or brown banded
lydite. 19. Jasper. 20. Vein-quartz. Nos. 17—20 have been
derived from the old rocks; probably having been brought up from
below, but possibly drifted on the surface.
The mineral contents of the diamond-matrix or “ Blue Ground ”
of Kimberley (De Beer’s, etc.) were described by the late Professor
H. Carvill Lewis in the Gzou. Mag. 1887, pp. 22-24.
The diamond-yielding gravel of the Vaal River, partly drifted
from the igneous and the old rocks of the higher country on the
Hast, and partly derived from diamantiferous necks and patches, has
much analogy to that of the refuse-heaps or washed stuff of the
diamond-mines. The constituents of the Vaal gravel, and of that
of Dutoit’s Pan, are enumerated in the Gron. Mac. 1871, pp. 55,
56; and Quart. Journ. Geol. Soc. vol. xxviii. 1871, pp. 17-21.
VIJ.—On a Guactat Mounp 1n Guen Frurn, DumBARTONSHIRE.
By Dueatp Bett,
Geological Society of Glasgow.
LEN FRUIN’ is a quiet secluded glen, about six miles in length,
extending in a north-westerly direction between Lochlomond
and the Gareloch, and opening off the neck of land which divides
those lochs at between 200 and 300 feet above the sea. To the
south-east, it slopes towards Lochlomond, of which the Fruin water
is one of the principal affluents. On the west it is divided from the
Gareloch by a range of hills 1000 or 1200 feet in height, which at
its upper extremity subside into a col or pass of 600 or 700 feet.
This upper part of the glen is composed of the mica and clay slates
common to the Western Highlands. The lower part is formed of
beds of the Calciferous Sandstone series, which have here been
faulted down against the older formations.
The upper part of the glen bears every indication of having been
at one time occupied by a lake.
A huge boulder of mica-schist, resting on the sandstone, occurs
near the foot of the glen, and there are many smaller ones in the
same neighbourhood. The respected Convener of the Edinburgh
Boulder Committee, the late Dr. Milne-Home, thought this large
boulder had been brought by an iceberg (which was his favourite
means of transport) either coming down Lochlomond and drifting
aside into Glen Fruin, or more probably finding its way over the
head of the glen during a period of ‘“ great submergence.”
The iceberg hypothesis seems to be attended with insuperable
difficulties, when we consider (1) where such large icebergs could
be formed in the event of so great a submergence as the theory
1 The ‘‘ Glen of Sorrow,” scene of a sanguinary conflict between the Colquhouns
and Macgregors in 1608. (See Introduction to ‘‘ Rob Roy.”’)
416 Dugald Beli—Glacial Mound in Glen Fruin.
requires; and (2) by what possible main currents of the ocean,
which alone could move them, they could be brought to these
localities and positions. For these and other reasons, it seems more
probable that such boulders owe their transport to a great sheet of
land-ice which once filled the glen from side to side, proceeding
from the Argyleshire mountains on the north-west, and overflowing
the neck or col at the bend of the glen as also that at the head of
the Gareloch, between it and Lochlong.’
This view is strongly corroporated by the phenomenon we have
now to describe, viz. a remarkable mound of detritus which occurs
about half a mile farther up the glen than the large boulder referred
to, and extends for a considerable distance in a winding line across the
hill-side in a direction from 8.W. to N.H., i.e. transverse to the glen. »
- It is most conspicuous on the eastern side of the glen, where it runs
from 300 to about 500 feet above the sea, “tailing out” on the
hill-side towards Lochlomond at a still greater elevation; but it can
be traced on the western side also, in the same general direction,
though there the ground is lower, and not so favourable for its
preservation. It is composed of typical moraine matter—large and
small stones, sand and gravel, confusedly mixed together; many of
the stones being distinctly striated. Some are sandstones from the
immediate neighbourhood ; others, schists and quartzes, from greater
distances.
The mound varies from 10 to 20 or 25 feet in height, and from
20 to 30 feet in breadth. In some parts it resembles a row of
hummocks of varying height; in others it rises from the surrounding
moor, distinct and continuous as a railway embankment. A number
of boulders, some of considerable size, are perched on its sides or
summit, and strewn along its base.
There can be little doubt this is a “terminal moraine ” of the great
ice-sheet which once occupied the glen; and we may add it is one
of the most notable and characteristic which we have seen in the
West of Scotland.
A number of detached mounds of considerable size occur at lower
levels, beyond the opening of the glen towards Lochlomond, and
may be relics of still older moraines.
Meantime the one we have described suggests the following
inferences :
1. There has been no submergence to this point since the mound
was deposited. Its rough, undressed, unstratified condition—its very
existence as a distinct mound—proves this. Had there been a sub-
mergence of as much as 500 feet since it was deposited, such a loose
earthwork would soon have been demolished and effaced by the
currents sweeping across this low neck of land between Lochlomond
and the Clyde.
2. For the same reason, there could be no submergence to that
extent while the mound was being deposited. Some geologists hold
that the ice-sheet reached the sea as the land rose (assuming a sub-
mergence) and laid down such mounds along the sea-margin. In
1 As noticed many years ago by C. Maclaren; Edin. New Phil. Journ. vol. xi.
Dugald Bell—Glacial Mound in Glen Fruin. 417
that case they would surely have borne distinct marks of assortment
and stratification, especially in localities where strong currents must
have been in operation.
3. Nor, finally, is there any proof of a “great submergence ”
prior to these latest works of the ice. This is where the advocates
of such a submergence join issue. They maintain that there was a
first or general glaciation, then a deep submergence, then a partial
or local glaciation, by which all distinct traces of the submergence
were removed. But a little reflection will show (a) that it is very
improbable any subsequent local glaciation could remove all traces
of the sea’s presence at high levels, supposing it had been there.
The sea marks a horizontal line and goes into every nook and cranny
of the land along the line; whereas the glacier marks a descending
line, and keeps to one main channel, not branching off in every
direction as the waters do. The area of the glacier, therefore, could
not coincide with that of the submergence so as to remove all traces
of the latter. Then (6) if such traces had been entirely removed
Fic. 2.—General Aspect of the Mound.
from every glen like this Glen Fruin, they should at least be
discernible in the heaps of débris which the ice has left near the
mouths of such glens. All over the country there are innumerable
glacial mounds and heaps—the “‘sweepings”’ of glens which, in the
case of the alleged submergence, must have been sheltered inlets of
the sea, favourable to almost every form of marine life. ‘These
heaps, as well as the Boulder-clay of the country generally, should
abound in fragments of marine fossils, if there had been such a
1 See Trans. Geol. Soc. of Glasgow, vol. ix. p. 109.
DECADE IIl.—VOL. VIII.—NO. IX. 27
418 Reviews—Flower and Lydekker’s
submergence, instead of being, as they are on the whole, quite
destitute of organic remains.
This argument is not founded on a supposition, but on a fact.
Wherever the ice can be shown (by the strize on the rocks, ©
the stones in the “drift,” etc.) to have passed over what is still
a sea-bed, or what there is no doubt was formerly such, during a
very moderate submergence, there also numerous fragments of sea-
shells are found in the drift or Boulder-clay ; as in the instances of
Caithness, Arran, Drymen, South Ayrshire, Holderness, Cromer,
Lancashire, ete.
The advocates of the “great submergence” have therefore these
two facts to account for: (1) the absence of all proofs of such sub-
mergence in situ at the high levels to which it is supposed the sea
attained; and (2) the absence of all evidence of it in the debris
derived from these high levels.
Dey dal VE aE Jen Ws (Se
J.—Awn Inrropuction to tHE Srupy of Mammats Lrvine snp
Extinot. By Wittram Henry Frower, C.B., F.R.S., D.C.L.,
etc., etc., and Ricnarp Lyprexxer, B.A., F.G.S., etc., etc. S8vo.
pp. xvi. and 763, Illustrated with 357 Woodcuts. (London,
Adam and Charles Black, 1891.)
HE authors of this important Manual have rendered a most
valuable service to Biological Science by furnishing us with
a book, long wanted, but heretofore not to be met with in any
country or language, and one which will be eagerly sought after by
zoologists and paleontologists engaged in the study of the higher
Vertebrates all over the world.
The few manuals approaching somewhat to this in size, in other
countries, are of too popular a character to be compared with the
present work. We have some bulky recent works, and smaller
manuals too, on systematic zoology, on paleontology, on comparative
anatomy, and on the habits of mammals. In the present volume
these different details are so happily amalgamated together that we
are enabled to gain a good general knowledge of our subject, which
a laborious journey through many volumes by various authors would
have failed to procure for us.
Originally initiated as a series of articles running through the
twenty-four volumes of the ninth edition of the “ Encyclopedia
Britannica,” from 1875 to 1888, by one of the authors (Prof. Flower),
the present work has the additional advantage not only of bringing
all this information on the Mammalia together, but by the codperation
of Mr. Lydekker, as joint author with Prof. Flower, much new
matter relative to fossil forms has been added, and the whole brought
up to date, both as to the living and extinct forms.
After a brief introduction of six pages, chapter ii. (pp. 7 to 81) is.
devoted to the general anatomical characters of the Mammalia; these
are written in terse yet clear language, and by the aid of some
Living and Extinct Mammalia. 419
twenty-four figures in the text are brought within the comprehension
of the youngest student of comparative anatomy.
Chapters iii. and iv. (pp. 82 to 116) are devoted to the Origin and
Classification, and to the geographical and geological distribution
of the class, and will be read with deep interest by all who seek to
trace the beginnings of Mammalian life on our earth.
So long ago as 1879 Prof. Huxley came to the conclusion, that in
looking among the Vertebrates for the progenitors of the Mammalia
we must pass over all known forms of Birds and Reptiles and go
straight down to the Amphibia, “they are the only air-breathing
Vertebrates which, like Mammals, have a dicondylian skull. It is
only in them that the articular element of the mandibular arch
remains cartilaginous, while the quadrate ossification is small, and
the squamosal extends down over it to the osseous elements of the
mandible, thus affording an easy transition to the mammalian con-
dition of those parts. The pectoral girdle of the Monotremes is as
much amphibian as it is sauropsidian ; the carpus and the tarsus of
all Sauropsida, except the Chelonia, are modified away from the
Urodele type, while those of the Mammal are directly reducible
to it.” In 1885 Prof. Cope called attention to the remarkable re-
semblance to the Monotremes presented by the skeleton of that
group of early Secondary reptiles which he then designated the
Theromorpha, but which may be included in the Anomodontia of Sir
Richard Owen, and came to the conclusion that in that group we
have the true ancestors of the Mammalia.
“Since that date observations made on the structure of the South
African Anomodontia have shown such an intimate connexion between
this group and the Labyrinthodont Amphibians, that there can be no
hesitation in regarding the one as the direct descendant of the other ;
and we may probably regard the Mammalia as having originated
from the same ancestral stock at the time the Amphibian type was
passing into the Reptilian. From this point of view, some of the
mammalian features found in the more specialized Anomodonts may
probably be regarded as having been acquired during a parallel line
of development.”
In dealing with existing forms of Mammals we find that they have
become so broken up into distinct groups by the extinction of inter-
mediate forms, that a systematic classification is perfectly practicable.
When, however, we pass to the extinct world, all is changed. In
many cases the boundaries of our groups become enlarged until they
touch those of others. New forms are discovered which cannot be
placed within any of the existing divisions, and they are no longer
sufficient for the purpose, and some other method will have to be
invented to show the complex relationships existing between dif-
ferent animal forms when viewed as a whole.
We quite agree with the authors that a linear classification cannot
be made to express the many inter-relationships existing between
the different families and orders; indeed, as regards many of the
fossil forms, it is almost impossible to decide where to place them
in relation to living families.
420 Reviews—Flower and Lydekker’s
On pp. 107-115 is given a summary of what is known of the
Mesozoic Mammals, and on pp. 115-116, a few remarks on Tertiary
Mammals; but these are dealt with in greater detail in the sub-
sequent chapters under the heads of the groups to which they are
severally allied. ‘The comparatively scanty evidence of mammalian.
life hitherto yielded by the Cretaceous (formation), coupled with the
number and variety of forms approximating to the existing groups
found even in the lowest Tertiary, indicates a great imperfection of
the geological record. At present, indeed, we have no decisive
evidence of the existence of any members of the Hutherian sub-
class previously to the Tertiary; but it can hardly be doubted
that in some part of the world they had made their appearance
before that epoch. The Eutherian mammals of the lowest Hocene,
both in Europe and the United States, are of an extremely gene-
ralized type; and although many of them approximate to existing
groups, they show such a combination of characters, now restricted
to individual groups, as to indicate that several of the various orders
into which the subclass is now divided were at the period very
intimately connected. A marked feature of these early Hutherians
is the prevalency of trituberculism in the dentition, not less note-
worthy being the frequent occurrence of pentadactylism in the feet,
while many of the individual bones were devoid of the grooves and
ridges found in those of later types. By the time that we reach the
upper division of the Eocene period, such as the horizon of the
well-known gypsum of the Paris basin, nearly all the chief groups
of mammals had become clearly differentiated from one another,
although their representatives were usually more generalized than
their existing allies. From this date to the later geological periods
there is a gradual approximation to the type of mammalian life
existing at the present day.”
Turning to the table (pp. 88-92), we find the class Mammalia
subdivided into sub-classes, orders and sub-orders, and lastly into
families. One hundred and thirty-one families are recorded, of
which eighty-six are living and forty-six are extinct. Many of the
so-called families of extinct forms are represented by a single genus
founded on a fragmentary individual remain, so that, although of
extreme interest, they can hardly claim equal taxonomic importance
with known families represented by many genera all composed of
complete individuals.
_ We notice a trivial slip (pp. 88-89), Tritylodontides being given
twice over in the Prototheria and in the Metatheria. The reference
to it under Multituberculata is doubtless correct, and the second
(under Marsupialia) may be cancelled.
Owing to the diligence of recent explorers the extinct families
known are now fully half as numerous as the living, nevertheless of
many of these our information is of the scantiest; nor do they help
us to trace the derivation of, or the inter-relationship which we
know must have existed in the past between many of the great
groups which stand out to-day in strongly-marked distinctiveness
from the rest of the class. What, for instance, do we know of the
Living and Extinct Mammata. 421
derivation of the Proboscidea? the Sirenia? the Cetacea? or of the
Edentata? These are some of the most difficult questions which
have to be answered by the modern comparative anatomist and
biologist.
Under geographical distribution the authors have adopted the
Zoological regions proposed by Mr. Sclater in 1867, but although
there are a few instances recorded of change of distribution due to
geological causes in late Tertiary times, we may take it that in this
part the fossil evidence is omitted. Thus under the Nearctic region,
it is stated, “there are, however, no Perissodactyla,” whereas
Rhinoceros megalodus has been described by Cope, as well as numerous
other Tertiary forms by Leidy and by Marsh.
We should very much like to see an attempt made to show the
geographical distribution of the Mammalia in past times, as well
as at the present day. For instance, Dr. Sclater’s Palearctic and
Nearctic regions were certainly one, in late Pleistocene times, as the
evidence of the Mammalia clearly shows. Thus we have Rangifer
tarandus, Alces machlis, Cervus elaphus, and its varieties, Ovibos
moschatus, Bison priscus, with the Lemming, Marmot, tailless Hare,
Beaver, Fox, Wolf, Otter, White Bear and Brown Bear, the Mammoth
and the Horse spread over all these Northern regions alike in the old
and the new world, so that these modern geographical regions only
represent the torn-up portions of far wider areas formerly connected.
The same holds good of the Ethiopian and Oriental (or Indian)
regions, the faunz of which even now show such strong marks of
affinity the one with the other.
Professor Flower is one of those who has advocated more strongly
than any other Zoologist the importance of incorporating fossil and
recent forms together; but there are not wanting signs in this
volume of the difficulties which the authors have felt in attempting
this course. In each family the extinct species are carefully kept
apart from their recent congeners, a plan which certainly bespeaks
the doubts which the authors must have often felt, owing to the
imperfect nature of the fossil evidence, of incorporating them in
the same series.
_ For a Second Edition, which will certainly not be long delayed,
we venture to offer the following corrections. Among the Rodentia,
to the family Lagomyide, are given + or 2 premolars (p. 491), whilst,
according to Forsyth-Major, the number of premolars in this family
is the same as in the Leporide, viz. 2, this being the number of the
deciduous molars, as observed in Myolagus Meyeri, and M. sardus ;
moreover the statement, “molars rootless,” does not apply to all the
members of the family, as in Lagodus (Titanomys), which for this,
and other reasons, deserves to rank as a genus distinct from Lagomys,
as well as Myolagus, the premolars and molars are both rooted.
In the small space at our disposal it is impossible to give more
than a bare idea of the volume before us. Of its usefulness there
can be no question, and we may speedily expect to see French and
German editions appearing on the Continent.
We heartily congratulate the authors upon the successful issue
422 Reviews—Dr. O. Jaekel—Armoured Paleozoic Sharks.
of their labours; they have produced a book which will greatly
advance our knowledge of the higher Vertebrata, and must prove
most helpful to the student of Mammalogy; nor can any Library of
reference be complete without this most excellent vade mecum.
Il.—Armovurrep Patmozorc SHarks.
1. Usser FLOSSENSTACHELN ODER IcHTHYODORULITHEN IM ALLGE-
MEINEN. By Dr. Orro Janxen. Sitzungsb. Ges. naturf.
Freunde, Berlin, 1890, pp. 119-1381.
2. Unser Mevasris, NEBST ALLGEMEINEN BEMERKUNGEN UEBER DIE
SYSTEMATISCHE STELLUNG DER Exasmoprancut. By Dr. Orto
JarKuL. Ibid. 1891, pp. 115-131, with Plate.
3. ORACANTHUS BOCHUMENSIS, n.Sp., EIN TRACHYACANTHIDE DES
DEUTSCHEN Konnencesirces. By Dr. Orro JauKen. Zeitschr.
deutsch. geol. Ges. 1890, pp. 753-755, Pl. xxxvii.
a month we had the pleasure of recording important progress
in our knowledge of some Paleozoic Elasmobranch skeletons,
due especially to the researches of Dr. Anton Fritsch among the
Pleuracanth fishes of the Bohemian Permian formation. On the
present occasion we are able to chronicle another interesting advance
in the study of allied forms, resulting from the renewed examination
of a fossil from the German Kupferschiefer described many years
ago by Giebel. It has long been known that certain representatives
either of the Elasmobranchii or of the Holocephali, in Palzozoic
times, possessed a remarkably developed dermal armour. Hitherto,
however, the portions of this armour have almost invariably been
found isolated, only few discoveries suggesting that they were fixed
upon the head and anterior part of the trunk of the fishes to which
they originally pertained. Quite recently Dr. Otto Jaekel has made
an interesting contribution to the subject by further extricating from
the matrix the supposed Elasmobranch fossil described and figured
by Giebel without name in the Zeitschr. gesammt. Naturw. Halle,
1856, p. 367, pls. iii. iv.; and this is identified with a problematical
fish very inadequately described by Ewald in the Monatsber. k.
preuss. Akad. Wiss. 1848, p. 33, under the name of Menaspis armata.
The fossil in question is clearly and concisely described in the
second memoir quoted at the head of this notice, and Dr. Jaekel is
to be congratulated upon the success with which he has removed the
obscuring film of matrix which caused the vagueness in Giebel’s
original figure. The specimen is but small—perhaps not more than
0-15 in length—and is interpreted as displaying the dorsal aspect
to the hinder border of the pelvic fins. The head and anterior part
of the trunk seem to have been comparatively broad and depressed ;
and the pectoral fins were evidently larger than the pelvic pair.
There are three lateral pairs of much elongated dermal spines, with
recurved tips, fixed upon the head ; and a single pair of Oracanthus-
shaped spines also occurs postero-laterally. Between the pectoral
fins there is placed another pair of smaller broad triangular spines ;
and in the skin of the back there are symmetrically disposed longi-
Reviews—Dr. O. Jaekel—Armoured Paleozoic Sharks. 428
tudinal series of spinous tubercles. Of the cartilages of the head
and trunk nothing is visible; and in the paired fins there are only
feeble traces of nearly parallel rays. No median fins can be seen ;
and the dentition is doubtfully inferred from fragments to have
consisted of Cochliodont plates.
Dr. Jaekel was led to the investigation of Menaspis by his studies
of Ichthyodorulites, detailed in the first and third of the memoirs
quoted above. The result is most gratifying to those who recognize
in this fossil, as now elucidated, the dawn of our knowledge of the
Paleeozoic armoured Sharks. At the same time, however, it is much
to be regretted that before launching into broad speculations, the
author did not further take advantage of the kind offices of Prof.
K. von Fritsch, and borrow for study another of Giebel’s Kupfer-
schiefer fishes—Dichelodus acutus. If this be correctly interpreted
in the original memoir (Zeitschr. gesammt. Naturw. Halle, 1857,
p- 121, pl. iv.), it affects very materially some of Dr. Jaekel’s gene-
ralizations concerning “'Trachyacanthide ”; and we venture to think
that an examination of it would have considerably modified many
matters which we regard as baseless imagination.
Whether, indeed, from an imperfect acquaintance with English, or
from defective memory, or hasty work, Dr. Jaekel’s theoretical
remarks are full of misconceptions, which it may be of advantage in
some respects to point out. In the first place, he arranges dorsal
fin-spines in three divisions—the ‘“ Cestraciont,” the “ Acrodont,”
and the “Chimeroid’”’—according to the form of their transverse
section. -We would remark that Nemacanthus (termed ‘“ Cestraciont ”’)
and Ctenacanthus (termed “ Acrodont”’) have in fact the transverse
section and lateral denticles described by Dr. Jaekel as exclusively
“‘Chimeroid”’; whereas the dorsal fin-spines of the Myriacanthide,
which are certainly Chimeroid, present differences again. In the
first memoir, too, a whole page is devoted to a fundamental miscon-
ception of Gyracanthus ; but this is cancelled (as the result of an
interview with Dr. Traquair) by a footnote in the second memoir.
Finally, Dr. Jaekel places all the paired Ichthyodorulites, e.g.,
Oracanthus, Erismacanthus, Physonemus, Gampsacanthus, etc., in a
new “group” termed “Trachyacanthide’ and in the original
memoir this is regarded as including both the Cochliodontide
and the Chimeroid genera, Myriacanthus (‘ Prognathodus”) and
Chimeeropsis.
The latest researches on the Myriacanthide, however, of which
Dr. Jaekel overlooked the preliminary results in his first contribution,
have caused a considerable modification of the “ group Trachyacan-
thide”’ in his second memoir. Menaspis is still retained as a member
of the new group, and made, in fact, its type: but the Myriacanthide
are now declared to be “ entirely different.” So far all will doubtless
be in accord with Dr. Jaekel; but when he raises this group to rank
as a distinct division equivalent to—and intermediate between—
the “‘Selachier” and ‘“‘Chimaeriden,” few will be satisfied with the
available evidence.
Here, again, several fundamental statements require correction
424 Reviews—Dr. O. Jaekel—Armoured Paleozoic Sharks.
before it is possible to proceed. When the author remarks that
unsymmetrical spines never occur in the Selachii, we would inquire
in what essential characters the cephalic spines of Hybodus, Acrodus,
and Asteracanthus differ from Hrismacanthus, Gampsacanthus, and the
slender paired spines of Menaspis. Furthermore, the spine named
Myriacanthus yranulatus has never been regarded as a head-spine
(“‘ Kopfstachel ”), as Dr. Jaekel states: and it is another error to
assert that the type-species of the so-called Prognathodus has been
in part claimed as pertaining to the same fish as Myriacanthus granu-
latus. To suppose that the typical Cochliodont dentition is of an
essentially different character (‘‘wesentlich anderes Gebiss” ) from
that of all true Selachii, displays a very superficial acquaintance
with existing knowledge of the subject; and when the author sug-
gests that this dentition may have been firmly anchylosed with the
supporting cartilages of the jaw (‘‘mit den Kieferknorpeln fest
verwuchsen”’), we become alarmed by his apparent disbelief in
some of the accepted fundamental principles of vertebrate anatomy.
A mere reference to literature will suffice to correct the extra-
ordinary mis-statement contained in the expression, ‘“ Placoidei, Ag.
= Elasmobranchiit, Bonap. = Chondropterygii, Cuv. emend. Giinth.” ;
and the idea that the calcification of the Elasmobranch endoskeleton
always consists merely in a superficial “ incrustation,” will soon be
removed when the author proceeds further in his studies especially
of the Paleozoic genera.
Legitimate inference from an array of facts is always a welcome
incitement towards new research; but when so many premises are
false, theoretical disquisitions are a burden to literature. As long
ago recognized by Owen, when he founded the family of Cochlio-
dontide, the peculiar dentition of this group of Sharks results only
from the fusion of one or more transverse series of teeth into con-
tinuous plates, which proceed to grow at the inner border in normal
fashion, and curve downwards outside instead of breaking away.
Every stage in this process of specialization is known, from the
slightly modified Pleuroplax to the extremely specialized Deltopty-
chius; and the only remains of the trunk of these fishes hitherto
discovered (Pleuroplax and Dichelodus) conform to the Cestraciont
type—not to that of Menaspis. As Egerton himself observed in
the original memoir, the teeth of the Myriacanthide bear much
superficial resemblance to the dental plates of the Cochliodonts ;
and it is thus easy to conceive how they may have been developed
at first in a similar manner from a dental armature such as was
possessed by the earlier Hlasmobranchs. But the teeth even of the
Myriacanthidz are already typically Chimeroid in structure and
mode of growth; and to infer from the possession by these fishes of
triangular dermal plates, that the Palaeozoic Cochliodonts must be
somehow related and armed with the ichthyodorulites named
Oracanthus, etc., seems to us an entirely unscientific procedure.
We still remain of opinion that the Cochliodonts are a specialized
offshoot of the Cestracionts, and that the Menaspide (as the family
typified by Menaspis ought to be termed) represent some unknown
X
Reviews—Memorials of John Gunn. 425
group that yet requires elucidation. Dr. Jaekel has done good
service in dispelling a remarkable illusion’ and in adding some
important facts to our knowledge of the armoured Sharks of
Paleozoic times ; but we will conclude with the hope that in future
the author’s contributions of this kind may bear signs of maturer
study and be less overburdened with reckless speculation.
A.S. W.
IJI.—Memortats or Jonn Gunn, M.A., F.G.S.: Berne some Ac-
COUNT OF THE CromeR Forest Bep anv rts Fosstn MamMatta,
AND OF THE ASSOCIATED STRATA IN THE CuiFFs oF NoRFOLK
AND SUFFOLK, FRoM THE MS. Notes oF THE LATE JOHN GUNN.
With a Memorr or tHe Avtuor. LHdited by Horace B.
Woopwarp, F.G.S., with the assistance of EK. T. Newton, F.G.S.,
F.Z.S. (Norwich: W.A. Nudd, 1891.)
OR the last half century Mr. John Gunn hag been a central
figure among the geologists of Norfolk, and the present volume
is a welcome addition to the records of work accomplished by local
observers, to whom British Geology is so much indebted. At the
time of his death Mr. Gunn was occupied with a second edition of
his ‘Sketch of the Geology of Norfolk” (contributed in 1883 to
White’s History and Gazetteer) ; and a series of plates illustrating
the larger Mammalian remains of the Cromer Forest Bed had already
been prepared and printed. The MS. was well advanced towards
completion, and, by the expressed wish of the author, it was
entrusted to Mr. Horace B. Woodward for publication in whatever
form might seem most desirable. Mr. Woodward wisely decided
not to reprint the earlier “Sketch,” which is already accessible, and
would have required much alteration in the bringing up to date ;
but, with the assistance of Mr. E. T. Newton, he only selected such
portions of the Supplementary Notes as contained Mr. Gunn’s
original observations and opinions. A short Memoir of the Author,
with a Portrait, and a summary of his work, have been added to
these notes; and the series of plates, with the explanatory remarks,
form an interesting guide to the Gunn Collection of Forest Bed
Mammals now preserved in the Norwich Museum.
The principal items in the biography of Mr. John Gunn were
given in the obituary notice in the GroLocroan Macazine of July,
1890 (pp. 331-833). Mr. Woodward’s additional notes on some of
his papers, however, are worthy of enumeration. Though chiefly
concerned with the later formations, Mr. Gunn paid some attention
to the Chalk and underlying rocks; and his opinions concerning the
Red Chalk and the possibility of discovering Coal-measures beneath
the Secondary strata of Norfolk are worthy of respect. The age
and relations of the stony bed at the base of the Norwich Crag
received much attention from the author, who was especially
interested in the Mammalian remains it yielded; and two important
sections (one at Bramerton, the other at Coltishall) are reproduced
1 0. M. Reis, Geognost. Jahrb. 1890, p. 30.
426 Reviews —Brockbank and De Rance—Geological Section.
from his unpublished MS. Long-continued researches in connexion
with the Forest Bed series and Boulder-clay eventually led Mr. Gunn
into wide speculations as to the cause of the Glacial Period; and in
his published “ Sketch” he treated of still more recent phenomena,
making interesting observations on the growth and accumulation
of plants in the Norfolk Broads. .
Mr. Gunn’s own chapters in the volume before us, as might be
expected, relate almost entirely to the Forest Bed series. Even to
the last his views as to this formation and some of its fossil
Mammalia were not altogether in accordance with those of the
latest authors; and a table is added to show Mr. Gunn’s classification
‘of the deposits as compared with the schemes of Prof. Prestwich
and Mr. Clement Reid. It is of great value to have a permanent
record of the observations and conclusions of one who made so
prolonged and detailed a study of this much-discussed series; and
some new woodcuts help to explain the text. The notes on the
Mammalia were evidently only just begun, and are thus confined
to a discussion of the so-called Elephas (Leptodon) giganteus, Cervus
bovides, and Cervus Cromptoni. None of these names are adopted by
Mr. E. T. Newton, who supplies the latest lists of the Forest Bed
and Norwich Crag Vertebrate Faune; but it is very satisfactory
to have a definite statement by the author of the grounds upon
which he founded his determinations.
The little volume of “ Memorials” is, indeed, a work of far more
than local interest ; and we commend it to the notice of all who are
occupied in studying the latest phase in the geology of the western
border of Hurope.
IV.—Norts on THE GroLocicaL SECTION EXPOSED IN THE RAILWAY
Currine From LrvensHutME To Fattowrienp. PartI. By
Wm. Brockpank and C. E. pz Rance. Mem. and Proc. Lit. and
Pui. Soc. Mancunstsr, ser. 4, vol. iv. pages unknown, with
plate v. in 3 sections: date uncertain, 1891.1
ie this section the Upper Measures of the Lancashire Coal-field,
possibly the highest Coal-Measures known in England, are
seen to underly “‘ Lower Red Sandstone” of Permian age. In the
present paper the authors describe the eight groups of limestones
with associated marls that form the Upper Coal Measures in this
locality. The sixth group from the top is considered to correspond
with the Ardwick Limestone of Phillips containing Megalichthys
Hibberti. Most of these Limestones consist largely of Hntomostracan
and Annelide remains, and contain numerous coprolites, but not
many other fossils. The presence of Hematite produces “beautiful
gradations of colour” in both limestones and marls, and we are
assured that, in the long coloured section given with the paper, the
actual tints are reproduced ; to dispel doubts excited by the brilliancy
of the plates, this assurance is subsequently repeated. The authors
‘ As the Authors’ copy, which alone has been sent to us, has been repaged, we
are unable to give our readers the correct reference to the original place of publi-
cation.
Reviews—Dr. Vigliarolo—Fossil Species of Pristis. 427
reserve for a future paper the description of the junction of the
*‘Levenshulme Limestones” with the Permian “Collyhurst Sand-
stone.”
V.—Britisu Fossit Brirps.
R. R. LYDEKKER contributes a valuable article on British
Fossil Birds to the July Number of “The Ibis,” containing
a critical summary of present knowledge of the subject. The article
occupies pp. 381-410 of the current volume, and treats in succession
the birds of the Superficial Deposits, those of the Pliocene Crags,
those of the Upper Eocene (Oligocene), those of the Lower Kocene,
and the few fragments from the Cretaceous. The researches
undertaken by the author for the recently published “Catalogue
of Fossil Birds in the British Museum” form the basis of the
Memoir; and it constitutes an important readable addendum to the
work just cited (see Review of Catalogue in August No. p. 378):
VI.—‘“ Pantoprsiion: An InteRNATIONAL BIBLIOGRAPHICAL ReviEW
oF THE Wortp’s Sorentiric Lirerarurn.” Hdited by A.
Kersua, C.H. (St. Petersburg and London: Swan Sonnen-
schein & Co., 1891.)
Ei have received the first number of this new monthly, edited
and printed in St. Petersburg, and to be obtained in England
from Messrs. Swan Sonnenschein & Co. Nearly 300 pages are
occupied with classified lists of new scientific works and periodicals,
some of which are briefly reviewed. Under the heading “Geology
and Mineralogy ” we find recorded several Inaugural Dissertations
and small separate publications such as are often overlooked by
workers. The new periodical will prove most valuable to all
engaged in scientific pursuits, and especially to those dealing with
applied science.
VII.—Monoerarn or.tHEe Fossin Spectres or Pristis. [ MonoGRaFra
DEI Pristis FOSSILI CON LA DESCRIZIONE DI UNA NOVA SPECIE DEL
CatcarE miocenico pi Leccr.|] By Dr. Grovannt VicrtaRoLo.
Mem. R. Accad. Sci. Napoli, [2] vol. iv. append. No. 8, pp. 1-28,
with plate. (1890.)
‘A FTER a definition of the genus Pristis and a partially critical
synopsis of all known species determined upon the evidence
of fossils, Dr. Vigliarolo proceeds to a detailed description of three
fragments of a rostrum, from the Miocene of Lecce, preserved in the
Geological Museum of the Naples University. The description is
illustrated by a large folding plate, and justifies the recognition of
a new species, Pristis lyceensis. Sclerorhynchus and Propristis are
regarded as extinct genera of Pristide, but Amblypristis is considered
to be merely a synonym of Pristis. The known fossils are so frag-
mentary that they seem to be scarcely worthy the extended treat-
ment they have received at the hands of the author; but the result
of his investigations is a useful epitome of our present knowledge of
the subject.
428 Reports and Proceedings—
ie @ eS PASS) ay @ Cana ae
—
GrEoLoGicaL Soorrty or Lonpon.
June 24, 1891.—Sir Archibald Geikie, D.Sc., LL.D., F.B.S.,
President, in the Chair.—The following communications were read :
1. “On Wells in West-Suffolk Boulder-clay.” By the Rev. Edwin
Hill, M.A., F.G:S.
It might be supposed that in a Boulder-clay district water could
only be obtained from above or from below the clay. But in the
writer’s neighbourhood the depths of the wells are extremely
different, even within very short distances; and since the clay itself
is impervious to water, he concludes that it must include within its
mass pervious beds or seams of some different material which com-
municate with the surface. It would follow that this Boulder-clay
is not a uniform or a homogeneous mass.
The visible sections are only those given, at hand by ditches, and
at a considerable distance north and south by pits at Bury St.
Edmunds and Sudbury. The appearances in these harmonize with
that conclusion. Conclusion and appearances differ from what we
should expect on the theory that this Boulder-clay was the product
of the attrition between an ice-sheet and its bed.
2. ‘On the Melaphyres of Caradoc, with Notes on the Associated
Felsites.” By Frank Rutley, Esq., F.G.S.
Within very limited areas the melaphyres of Caradoc differ con-
siderably in texture and in structure, some having once been basalt-
glass or andesite-glass (such being the superficial portions of a
lava-stream); others have possessed a certain amount of interstitial
glass, which has subsequently been rendered more or less opaque by
the development of magnetite, while at times it appears to have.
been converted into a palagonitic substance. In some of the rocks
the crystalline texture is very fine, in others comparatively coarse.
Near the summit of Caradoc is a basalt-tuff or andesite-tuff.
The melaphyre or dolerite of Little Caradoc differs from the lavas
in that the augite remains fresh and the felspars are altered, while
in the lavas of Caradoc proper the pyroxenic constituent is decom-
posed and the felspars remain as a rule unaltered.
Whether the melaphyre of Little Caradoc may be regarded as
a neck from which the lavas lying to the south-west of it emanated,
is a point which can only be demonstrated by further field-work.
The author considers that further investigation may prove beyond
dispute that the associated felsites are rhyolites of which the original
structures have as a rule been almost entirely obliterated. In an
appendix further evidence is adduced in favour of the original rhyo-
litic nature of these felsites, and a fragmental rock from Bowdler’s
Chair is described as unquestionably a rhyolite-tuff.
3. “Notes on the Geology of the Tonga Islands.” By J. J.
Lister, Esq., M.A. (Communicated by J. E. Marr, Esq., M.A.,
F.R.S., Sec.G.8.)
The islands of the Tonga group are situated on a long ridge
Geological Society of London. 429
which rises from deep water on either side to within a thousand
fathoms of the surface of the sea. The general direction of the ridge
is N.N.E. and 8.8.W.
(1) A line of volcanoes, some active, some extinct, traverses the
group. Continued southward, the direction of the line passes through
the volcanoes of the Kermadec group, and those of the Taupo zone
of New Zealand; while to the north it cuts the line of the Samoan
volcanoes at right angles.
(2) Besides the purely volcanic islands there are some formed by
submarine eruptions, whose layers have been laid out under water
and since elevated, with or without a covering of limestone.
(3) The remaining islands are formed entirely of limestone.
Hua is an example of the second group. The volcanic basis con-
sists for the most part of beds laid out beneath the sea, and some of
the upper ones contain pelagic shells. Dykes of augite and hyper-
sthene-andesite project on the shore, and a representative of the
plutonic series occurs. There is evidence that the island has been
elevated and again submerged prior to the elevation which has raised
it to the present height. The volcanic basis is largely invested with
limestone, and this rock forms the summit 1078 feet above sea-level.
Sections show that it is a shallow-water deposit.
_ Of the purely limestone structures, Tongatabu, Nomuka, and the
long reef on which the larger islands of the Hapaii group are
situated, form more or less complete atolls, all of which have been
elevated to a greater or lesser extent.
The Vavau group is remarkable for its very indented contour,
suggesting the idea that it rests on a much denuded basis. Both
here and at Kua there are raised limestone formations with atoll or
barrier-like contours; and there is some direct evidence to show
that these have been formed without the aid of subsidence.
The presence of islands formed of volcanic materials laid out in
layers beneath the sea, and the manner in which the recently formed
Falcon Islaud is now being reduced to the condition of a submarine
bank, suggests that the atolls of the group may rest on similarly
formed foundations.
4. “On the Inverness Harthquakes of November 15th to De-
cember 14th, 1890.” By C. Davison, Esq., M.A. (Communicated
by Prof. Charles Lapworth, LL.D., F.R.S., F.G.S.)
In this paper the author gives reasons for supposing that the
Inverness earthquakes of last year were due to the subsidence of a
great wedge of rock included between a main fault and a branch
one; and he considers that there is little doubt that these recent
earthquakes were the transitory records of changes that, by almost
indefinite repetition in long past times, have resulted in the great
Highland faults.
The next meeting of the Society will be held on Wednesday,
November 11th, 1891.
430 Correspondence—MUr. G. Roper—Rev. O. Fisher.
CORRES PON DENCH.
THE SUPPOSED DICYNODONT FROM THE ELGIN TRIAS.
Srr,—At the meeting of the British Association at Aberdeen in
1885, much interest was excited by the alleged discovery of Dicynodon
in the Triassic sandstones of Elgin. Prefessor Judd stated his
belief in the specimen at the time (“ Nature,” Oct. 15, 1885, p. 578),
and said that the specimen was in the hands of Dr. Traquair. In
Woodward and Sherborn’s “Catalogue” (1890) I notice these
authorities place a (?) before the reference, thus indicating the
doubtful nature of the find, while Lydekker in vol. ii. “‘ Manual
of Paleontology” does not even refer to it. Are we to interpret
Dr. Traquair’s six years’ silence as a withdrawal of the original
determination? When an important discovery has been announced,
it seems only just that the geological public should hear more about
it, and this practice of throwing out vague and unsatisfactory state-
ments is very annoying to those who prefer exact information and
rather disparaging to the discoverer, who naturally expects so
great a find to be worthy of notice. G. Ropzr.
ON DYNAMO-METAMORPHISM.
Srr,—I think Dr. Irving has not quite understood the reasoning
in my short article on Dynamo-metamorphism of a year ago. I
wrote, that the part of the work of compression expressed by the
product (P— W) w, where P is the compressing force upon a cubic
element of the disturbed mass, W the weight of the cover, and w
the height through which the cover has been lifted, was employed
in bending and breaking the rock and overcoming friction, and that,
since this part of the energy is not reconvertible into mechanical
work, it must take the forms of heat and chemical action. He thinks
this ‘‘last term is surely outside the others altogether”; that is, I
suppose, is employed upon the rock external to the portion of it
under consideration. But the expression is not very clear, though
his illustration in the note (p. 3800) seems to show that such is his
meaning. He says there that, if a horse or engine draws a series of
loaded trucks along a perfectly horizontal line of rails, ‘‘ work is done
in overcoming the friction of the wheels against their axles and against
the rails, and in the displacement of a portion of the atmosphere
with the movement of the train; but would any one contend that
energy was stored up in the train ?”
Energy of motion is so obviously stored up in the train that Dr.
Irving cannot refer to that. He must refer to the energy imparted
to the atmosphere, and to the energy absorbed by friction, which
last is distributed between the trucks and the rails. The energy
communicated to the air is “ outside” the other effects, and so is the
energy absorbed by the rails. But the energy absorbed by the
friction of the wheels against their axles is partly converted into
heat, and is partly employed in producing a molecular change in the
iron, rendering it more granular and liable to fracture. I should
consider this a case of dynamo-metamorphism. Still it appears to
Oorrespondence—Mr. Alfred Harker. 431
me that the illustration is not apt. The amount of work to which
I refer must be expended on bending and breaking the particular
mass of rock under consideration, and in shearing the parts of it —
past one another, and not on the rock outside of it. Hence the
energy which is its equivalent has been introduced into the mass;
and, energy being indestructible, none of it is lost, and there is
now more energy in the mass than there was before. The question
which I proposed was simply, what form does that energy take?
Is it heat? or is it, as I (perhaps rashly) enquired, chemical energy ?
Dr. Irving says that both Mr. Harker and myself have overlooked
the one great factor of metamorphism, viz. superheated water. I do
not think we either of us proposed to discuss all the causes of meta-
morphism, but only the mechanical. O. FisHER.
Harton, CAMBRIDGE, 11 July, 1891.
DYNAMO-METAMORPHISM AGAIN.
Str,—A short space will suffice for what I have to say in reply
to Dr. Irving (p. 296). I am sorry to have misunderstood, or, as
he phrases it ‘misrepresented,’ him as assuming that the whole of
the work passes into heat. J am not sure that even now his position
is clear to me. His dictum “chemical combination must generate
heat” is intelligible, though, as Mr. Fisher has pointed out, by no
means universally accepted by chemists; but simple combination
does not cover any of the chemical changes that characterize the
metamorphism of rocks. These are “much more complex,” and if
Dr. Irving believes that in these cases there is always, on the
balance, a positive amount of heat generated, he believes that for
which no proof whatever is offered.
It is possible that some of the differences between Dr. Irving and
myself would resolve into a question of words, if his language were
more intelligible to me; but unfortunately his usage of physical
terms often bears no relation to the definitions in use among physicists.
“Intensity of heat”? seems to mean temperature, but what are we
to make of the expression (used in taxing another correspondent with
confusion of thought) “the energy is presented in the mechanical
form of pressure”? The simple word ‘ deformation’ also appears
to be employed in some occult sense.
The experiments of Cailletet and Pfaff which I cited are the
same as those referred to in the “ Report on Slaty Cleavage’ mentioned
by Dr. Irving. They seem to establish that increased pressure
retards chemical changes involving a diminution of density, while
Spring’s researches tend to show that pressure assists changes in-
volving an increase of density. The two conclusions appear to me
not contradictory, but complementary parts of one law. As regards
Spring’s experiments, Dr. Irving has ludicrously misunderstood me
when he implies that I deny the generation of heat by friction
during the compression. What I said was that the heat so generated
was carefully removed (by conduction). As Major-General McMahon
points out (at p. 90 of this volume), M. Spring himself seems to
have changed his views as regards the significance of his work, but
432 Obituary—Mr. Daniel Mackintosh.
the published details of his experiments leave others free to draw
their own conclusions from them. Kroustchoff’s interesting syn-
thetic production of hornblende and other minerals do not seem to
throw any new light on the problems in hand.
ALFRED HaRkKER.
@73 LEEW) AvEe
—p>—
DANIEL MACKINTOSH, F.G.S.
- Born 1815. Diep 19 Jury, 1891.
WE regret to announce the death of Mr. Daniel Mackintosh, F.G.S.,
who was born in the memorable year 1815, at Blairgowrie, in Perth-
shire, where his father had a mill worked by water-power. Imbued
with an early love of Natural Science, he left Scotland when about
30 years of age. For many years he was a lecturer on Scientific
subjects and well known in the south of England, where he lectured
at various public institutions and schools on Astronomy, Geology,
Physical Geology and Ethnology with considerable success. His
manner as a lecturer was clear and spirited, and aroused an interest
in the subjects of which he treated.
Mr. Mackintosh was elected a Fellow of the Geological Society in
1861, and contributed his first paper on “Terminal Curvature ” in
1867, and afterwards numerous papers to the Society on Surface
Sculpture, Denudation, Drift Deposits and the Dispersion of Erratic
Blocks. Many of his papers are in the ‘‘ Reports of the British
Association,” and the “ Proceedings” of Societies of which he was
a member. He was a frequent contributor to the GroLocroaL
Magazinz, and other scientific publications.
In 1869 Mr. Mackintosh produced his work on “The Scenery of
England and Wales,” in which he favoured the action of the sea as
the greatest denuding agent, and it is illustrated by 86 sketches of
geological interest. He received four successive grants in aid of
Original Scientific Research, from the Government Grant of the
Royal Society. In 1881, he was presented with the Kingsley
Memorial Medal of the Chester Society of Natural Science, and in |
1886 was awarded the proceeds of the balance of the Lyell Fund by
the Geological Society, in recognition of his studies of the Glacial
and other Superficial Deposits of the north-west of England.
About 20 years ago Mr. Mackintosh went to reside at Chester,
but a few years after he settled in Birkenhead, and was president of
the Liverpool Geological Society during 1881-8. In recent years
he devoted much time to the examination of the Drift Deposits and
Boulders of North Wales, and during his last exploration ascended
Cader Idris when nearly 70 years of age. Soon after he began to
fail in both mind and body, and died on the 19th of July last, and
his remains now rest in Flaybrick Cemetery, Birkenhead, close to
the glaciated areas he so frequently visited and described. His
papers on the Glacial Deposits will hold a permanent place in geo-
logical literature, and he will be remembered for his kind and gentle
disposition by all who came in contact with him.—G. H. M.
Grou. Maa. 1891. Dec. III. Vol. VIII. Pl. XII.
CONCRETIONS
FROM THE
MAGNESIAN LIMESTONE OF DURHAM.
GEOL? MAG, TS9F. WC omeieteaysOl, =) fit, fl eo Tell
LIMESTO SHOWING CONTINUITY OF BEDDING PLANES.
THE
GHOLOGICAL MAGAZINE.
NEW SERIES. DECADE Uli, VORA: Viti.
No. X.—OCTOBER, 1891.
rv rGINPASr: PAS reese
I.—On tHE Ortcin anp Mops or ForMaTIon OF THE CONCRETIONS
In THE Magcnesian Limestones or DurHam.
By E. J. Garwoop, B.A.,. F.G.S.
(PLATES XII. anp XIII.)
N 1826, 27, and 28, Prof. Sedgwick contributed to the Geological
Society of London his classical papers on the Magnesian
Limestone of the East of England,’ in which he describes in detail
the concretionary structures which occur in many of the beds of this
formation in Durham. ;
Although he describes these concretions in minute detail, he says
but little as to their probable origin, but it is clear that he regarded
them as composed of carbonate of lime derived from the beds in
which they occur, when he says—‘“The particles (of lime), after
deposition, appear to have run into lumps and masses more or less
crystalline, rejecting great portions of the earthy residuum.” ? Since
Prof. Sedgwick’s papers little seems to have been contributed to the
subject of the mode of formation of these concretions.
Two opposite opinions are held with regard to the pronimcte
source of the carbonate of lime :—One to the effect that the lime
was introduced into the concretionary bed subsequent to its forma-
tion, in solution from without; the other that it was deposited
contemporaneously and subsequently segregated out zn situ.
The latter opinion is, we believe, that generally held,’ though
there are some who advocate the former, which may be called “the
Stalactitic”* theory.
Looking at the Magnesian Limestone series as a whole, many of
the concretionary structures appear as if they might have been formed
in the stalactitic manner supposed; but when the individual beds
containing the concretions are studied in detail, they are found to
present many points which appear irreconcilable with the theory of
their stalactitic origin.
The locality where these beds can be most satisfactorily examined
1 Prof. Sedgwick, ‘On the Geological Relations and Internal Structure of the
Magnesian Limestone,” Trans. Geol, Soc. London, 2nd series, yol. iii. 1835.
2 Op. cit. p. 89.
3 Prof. Green, Physical Geology, p. 279; Geikie, Textbook of Geology, 1835,
p. 472.
4 R. Howse, ‘‘On the Stalactitic Origin of Conglobated Structures in the
Magnesian Limestone, ” ‘Tyneside N aturalists’ Field- club, October, 1889.
DECADE III.—VOL. VIII.—NO. X. 28
434 E. J. Garwood—Origin of the Concretions
is at Marsden quarries on the coast of Durham, between Sunderland
and South Shields, where masses of stratified limestone are inter-
bedded with marls containing concretions in every stage of de-
velopment. Where fully developed, the concretions assume a
spherical form, and are sometimes as much.as 1 to 2 feet in
diameter, the average size being from 38 to 6 inches. They are
composed of fibrous crystals of calcite radiating symmetrically
from the centre, which frequently consists of a valve of Ascinus
dubius or Myalina Hausmanni. (See Plate XII. Fig. 1.) Very
often, however, the centre is composed merely of a small cavity.
These concretions occur in irregular masses 20 to 80 feet thick,
showing here and there rough stratification, and often passing
laterally into well-bedded limestone. Many of the larger specimens
show well-marked concentric bands developed at regular intervals.
The concretions are piled on one another with but scant matrix
between ; chemically they consist of 91 to 95 per cent. of carbonate
of lime and 1:5 to 4 per cent. of magnesia.
It is difficult to see how such masses of limestone could have been
formed by infiltration from beds above. Where are the beds into
which the carbonate of lime dripped during the formation of the
concretions? If we suppose these concretions to have been formed
from carbonate of lime introduced in solution from an overlying
bed subsequent to the consolidation of the deposit in which they
occur, then the original bed, now replaced by concretions, must
have disappeared. But this bed would originally contain 20 to 30
per cent. of magnesia, which must have been subsequently dissolved
out; yet it is hardly likely that water which was saturated with
carbonate of lime would dissolve out carbonate of magnesia the less
soluble salt of the two,'and we cannot suppose that the magnesia bed
was dissolved out first, leaving an enormous cavity into which the
carbonate of lime afterwards dripped, forming around shells sus-
pended in some mysterious manner; the symmetrical development
of the concretions also, which is as perfect vertically upwards from
the nucleus as it is laterally and vertically downwards, seems to
preclude the possibility of their having been formed in a previously-
solidified rock-mass.
Again, the shells forming the nucleus of the concretions are often
in beautiful preservation, which is hardly likely to have been the
case if they had lain in a porous bed exposed to the action of
infiltrating waters, while in those cases where the centres are hollow
it is impossible for the carbonate of lime trickling through the
beds in solution to have crystallized out round a cavity, whereas we
can easily imagine the centre to have originally consisted of an
organic body in the sediment which, serving as the nucleus round
which concretionary action was set up, afterwards decomposed.
But it is in the beds containing immature concretions in various
stages of growth that the strongest arguments against the formation
of the concretions by stalactitic action are supplied.
1 Hardman, Carbonif. Dol. of Ireland, Proc. Roy. Irish Acad. vol. ii, ser. 2, 1877.
in the Magnesian Limestone. 435
These beds consist of friable yellow marl, in which are imbedded
hard spheroidal concretions often much flattened. The concretions
consist of 85-95 per cent. of carbonate of lime, and 6 to 12 per cent.
of magnesia, while the matrix often contains as much as 50 parts of
magnesia on 100 of carbonate of lime.
The beds are markedly stratified, the lines of bedding passing
uninterruptedly through matrix and concretions alike. (See Pl. XLII.)
This fact was first noticed by Prof. Sedgwick, and it is perhaps
the strongest argument in favour of what we may call the ‘Segre-
gation’ theory. The advocates of the ‘Stalactitic’ theory refer
these lines of stratification in the concretions to lines along which
the carbonate of lime spread out when dripping from above in
solution; but this does not account for the individual lines of
bedding passing uninterruptedly from matrix to concretion, nor
does it account (if the formation is still supposed to be taking
place) for the fact that where the heds dip at a considerable angle,
the lines in the concretions are still parallel to the general bedding
of the rock, not parallel to the horizon, as would be the case if
they were being formed up to the present day by infiltration.
These flattened concretions contain numerous small shells dis-
seminated through them, notably Pleuropterus costatus and Turbo
helicinus, whereas these appear to be altogether absent from the
matrix. This we should expect according to the ‘Segregation’
theory, the shells being the nucleus round which the carbonate of
lime segregated, and any fossils remaining in the matrix, which
is extremely porous, would, after the solidification of the bed, be
readily dissolved out by subsequent infiltration, whilst those em-
bedded in the concretions would be protected by their impervious
covering of hard limestone.
These fossils are frequently found projecting from the sides of the
concretion along lines of bedding, in the same way that one-half of
a sponge spicule, or other organic body, is found embedded in a
flint, while the other half projects into the surrounding chalk.
It is difficult to account for the presence of fossils in these
flattened concretions if we assume their stalactitic origin, as we
cannot suppose them to have been introduced in solution, and to
have reformed as fossils on the solidification of the concretion.
Turning now to the chemical side of the question. It had been
hoped that a detailed chemical investigation of these beds would
have conclusively proved by which of the two processes under con-
sideration these concretions had been formed. For supposing the
average analysis of the beds containing concretions to have agreed
with the analysis of beds containing no concretions, we should have
been justified in concluding that the carbonate of lime, of which
the concretions are mainly composed, had not been introduced from
overlying beds in solution, but had been originally deposited as part
of the bed in which they are now found; but the complicated nature
and variable chemical composition of the different beds of the series
cause the evidence so afforded to be less certain than had been hoped,
although the results are by no means valueless in this connexion.
436 E. J. Garwood— Origin of the Concretions
The great drawback to the evidence is the very variable com-
position of those beds in which no concretions are developed, and
the difficulty of selecting a bed or beds representing the original
composition of the deposit, as regards the relative quantities of
carbonate of magnesia and carbonate of lime present. In the annexed
table are given average analyses of concretionary, stratified, and
compact magnesian beds :—
I. Il. IIl. IV. V.
Matrix. | Coneretious. [Tend I1.| Bel © | 100 feoh,
| Carb. Lime ...| 46°07 100-00} 86-14 100-00 | 59-43 100 | 85-78 100 59°81 100
Silicate ......... 2°03 26 1-50 “09 —
Carb. Magn....) 30°68 66°74 9-5 11:0 | 23°62 40] 6:5 7:5 26°06 48
Peroxide Iron 1°52 1-8 12°60 2-0
Alumina ...... 16°58 3°15 14°13
Insol. in HCl. | 3-00 1:98 2°5 2-10
99°88 99-68 99°65 99-62 100-00
Column I. gives an average of 12 analyses of the matrix which
are each tested from 15 samples, the composition shown being thus
the average of 180 samples. In the same way Column II. shows
the average composition of 180 samples of the concretions.
The bed selected for examination is that shown in the photograph,
(Plate XIII.), which extends for some 12 to 15 feet in a downward
direction. It will be seen that whereas the matrix contains 66, the
concretions only contain 11 parts of magnesia to 100 parts of lime.
The overlying bed (No. IV. of the Table) is a well-bedded lime-
stone, which forms the surface beds in this district, and if the con-
cretions had been formed stalactitically, it is from this bed that the
lime must have been derived; but the bed shows no honeycombed
appearance, and is one of the most compact members of the series.
This overlying bed, which is 20 to 50 feet thick, is itself thoroughly
concretionary in its structure, although on a minute scale, on the
type of the globular concretions which overlie and pass into it, and
if the lime forming the concretions is to be regarded as derived
from infiltration, the whole of this upper bed must then have been
formed in like manner, for we cannot fix an arbitrary size of con-
cretion and declare that all those larger than this size were formed.
by infiltration and all those smaller, although of exactly similar
structure, represent the bed as originally deposited. Since then the
beds immediately overlying our concretionary bed are also con-
cretionary, we cannot consider them as representing (according to
the stalactitic theory), the original deposit, and we cannot use them
therefore for instituting a chemical comparison with the typical
concretionary beds. If, however, we go to higher beds, omitting
those which have concretionary limestone interbedded with them, we
find at Roker a massive bed nearly 100 feet thick ; its composition,
as given by Messrs. Browell and Kirkby,’ is shown in Column Y.
of our Table.
in the Magnesian Limestone. 437
In order to compare the composition of this bed with that of our
bed of concretions, we must obtain the average composition of the
latter, and to do this we must determine the relative proportions of
concretions and matrix present. Numerous estimates along the
exposure give roughly 2 of matrix to 1 of concretions as the approxi-
mate proportions, and working this out (Column III. of the Table),
it gives us 40 parts of magnesia to every 100 parts of carbonate of
lime, which will be found to agree very closely with the analysis
of the Roker bed, which gives 43 parts of magnesia to 100 of
carbonate of lime.
This entirely confirms the theory that the lime composing the
concretions was derived from the beds in which they occur, and was
not introduced subsequent to their deposition. We must, however,
frankly acknowledge that there are two uncertain factors in this
comparison, namely, the difficulty of arriving at an exact estimate
of the relative proportions of matrix and concretions, and the some-
what arbitrary selection of the bed with which they are compared ;
as, however, great importance has been attached to a detailed
chemical investigation of these beds, we give the results of our
work in this direction, which confirm, as far as they go, what we
have before alluded to as the ‘Segregation’ theory.
There is, however, other evidence in this direction derived from
a study of the chemical composition of the concretions, namely, the
presence in them of magnesia and insoluble matter.
The amount of magnesia, which is sometimes as much as 12 per
cent., varies considerably in different concretions in the same bed,
analyses of two concretions lying a few feet apart yielding in one
case 2:3, and in the other 6-3 per cent. If the concretions had
been deposited from percolating water, it is difficult to see why the
water should vary at the distance of a few feet in the amount of
magnesia it contained, whereas on the segregation theory we should
expect the amount of impurities imprisoned during the process to
vary from point to point, and it is still more difficult to account for
the presence of insoluble matter, which is usually about 2 per cent.,
and in one specimen amounts to as much as 8°d per cent. of the
concretion.
The last argument against the stalactitic origin of this deposit
that we have to bring forward is the fact that large quantities of
calcite occur in these beds which have undoubtedly been formed by
stalactitic action. They consist of pure white fibrous calcite,* and
contain no magnesia or insoluble matter, they line cavities and
cracks, and fill in the interstices between the concretions, often
coating their surfaces to the thickness of an inch, and roughly
modelling themselves on their external shape. These deposits, which
here and there attain a thickness of 5 to 6 inches, can be traced to
joints in the overlying beds through which the carbonate of lime
has undoubtedly obtained access in solution, the walls of the joints
1 Browell and Kirkby, on ‘‘The Magnesian Limestone of Durham,”’ Nat. Hist.
Trans. of Northumberland and Durham, vol. i. pt. 2.
* Not aragonite, as often described locally.
438 E. J. Garwood—Origin of the Concretions
being lined with a similar deposit. Figs. 3 and 4, on Plate XII., show
concretions coated with it. In many cases (Fig. 4) the calcite has begua
to replace the original concretion, or perhaps add to its original mass,
but this replacement is limited to about a quarter of an inch on the
surface, and it never penetrates far, except when it fills cracks in
the concretion. It is obvious, then, that it is either replacing the
concretion from without inwards, or is forming on the surface of
previously existing concretions, and its secondary nature is quite
unmistakeable.
Summary.—We can then sum up the evidence against the stalactitic
origin of these concretions under the following heads :—
I. Stratigraphical.—(a) The marked stratified condition of these
beds as a whole, which would to a large extent have been obliterated
by the copious infiltration necessary for the formation of the conere-
tionary structures.
(6) The uninterrupted passage of the lines of bedding through
matrix and concretions alike. .
(c) The enormous thickness of some of the concretionary limestones.
(d) The fact that the concretions occur only in the Upper Magnesian
Limestone, which is overlaid by the Triassic Marls and Sandstones,
a deposit containing originally probably but little carbonate of lime.
(e) The fact that the concretions are confined to the Magnesian
Limestone series.
II. Evidence from fossils.—(a) The occurrence of shells in the
centre of the radial concretions.
(6) The occurrence of cavities at the centre, probably originally
occupied by organic matter.
(c) The wonderful state of preservation of shells occurring in these
concretions and the almost total absence of fossils from the earthy
matrix.
III. Chemical.—(a) The great similarity in composition between
the concretionary bed as a whole, and the massive beds higher in the
series which contain no concretions, with reference to the relative
amounts of carbonate of magnesia and carbonate of lime that they
contain. Showing that it is unnecessary to assume the introduction
of extra carbonate of lime from beds above. .
(b) The variable amount of magnesia in contiguous concretions.
(c) The presence in the concretions of a considerable quantity of
insoluble material.
(d) The presence of calcite in these beds which has undoubtedly
been deposited by stalactitic action and which in appearance, com-
position, and behaviour is so dissimilar to these concretions.
Having shown that the carbonate of lime of the concretions has
in all probability been derived from the beds in which the concre-
tions occur, we should like to add a few words as to the manner in
which they appear to have been produced.
That some of the carbonate of lime disseminated through the
deposit was abstracted from the general mass, and segregated round
definite centres of attraction, is doubtless true, and, as Prof. Green
remarks, we may give to this process a name of its own and call it
im the Magnesian Limestone. 439
“Concretionary Action,” but it does not enable us any better to
realize the immediate cause of the process, or to understand the
manner in which it was brought about. With regard to the first part
of the problem, namely, the cause of the segregation, the following
considerations may throw a little light on the subject.
The concretionary beds are usually crowded with fossils, and it is
round these fossils that the carbonate of lime has segregated out ;
they, together with other foreign bodies (probably for the most part
organic particles, and now represented by cavities), were the, so
to speak, chemical magnets which attracted to themselves the
available carbonate of lime.
The Roker beds, on the other hand, which are quite unfossiliferous
but are, as shown above, approximately identical in composition,
contain no concretions.
It might be urged against this that the Middle Limestone, which
contains the most numerous assemblage of fossils in the whole
system, has developed no concretions; but those beds contain a
relatively large proportion of carbonate of magnesia to carbonate
of lime, which, as we are about to point out, seems also to have
influenced the decision as to whether a certain bed should or should
not develope concretions.
The presence of carbonate of magnesia in the unconsolidated
deposit appears up to a certain point to have assisted the segregation
of carbonate of lime; but when the quantity of magnesia present
reached over 30 per cent., it has prevented this segregation from
taking place, except in small local patches. On the other hand, in
those beds which are composed of almost pure carbonate of lime,
the concretionary structure is only developed in a minute form
throughout the mass.
It would appear, then, from this that where the deposit was fairly
free from magnesia, the “concretionary action” started from so
many centres, that no centre had time to aggregate more than a
small quantity of lime to itself, before it came in contact with the
growing peripheries of neighbouring concretions, and its further
growth necessarily ceased. When, however, the deposit contained
more magnesia, the particles of lime were consequently more
widely separated, there was less inducement for individual effort
on the part of would-be centres, and only the larger and stronger
ones succeeded in attracting particles from the surrounding mass,
and grew in size in proportion to their numerical scarcity; the
distance from which they were able to draw particles increasing —
in proportion with the increase of their mass. When, however, the
proportion of magnesia present exceeded a certain amount, the
distance between the particles of lime became so great, and their
mutual affinity was so weakened by this increased separation, that
no foreign body was sufficiently powerful to start the migration of
particles in its own direction, and the deposit solidified as an
ordinary compact bed.
We have then in concretionary action a very analogous process to
crystallization. When the solution of a salt is concentrated and
440 LE. J. Garwood—Concretions in the Magnesian Limestone.
allowed to stand, it rapidly crystallizes, forming a mass of small
crystals. If, however, the solution had been previously diluted,
fewer and larger crystals would have been formed, and this dilution
might have been carried to a point, after which further dilution
would have prevented crystallization from taking place altogether.
That the presence of magnesia is the primary cause of the forma-
tion of the concretions is borne out by the fact that they are confined
to this formation, although there are plenty of other limestones in
the geological sequence in which they should otherwise have occurred.
We may remark in passing that no argument in favour of the
‘Stalactitic’ theory can limit the application of that theory to these
particular beds, for the character of the deposit into which the lime
is supposed to have been introduced could have no influence what-
ever in causing that lime to be dissolved from the beds above.
The second part of the question, namely, the process by which
the particles of lime were conveyed: from their original positions in
the deposit, and were aggregated round their respective nuclei, is
a very difficult one to answer, and we do not appear to have
advanced much towards the right understanding of this process
since the days when Prof. Sedgwick wrote. Broadly, the process is
comparable to the solution of sponge spicules in the chalk, and their
redeposition round nuclei in the form of flints.! Carbonate of lime,
and silica are, however, different material. What do we know
about the pectous and colloid forms of carbonate of lime? It is
true that the aragonite forming the shells of mollusca is an animal
product, and may perhaps be analogous to the form of silica known
as organic; and we know that it is frequently converted into calcite
in fossil shells, showing that a rearrangement of the molecules of
carbonate of lime does take place after the entombment of the shell.
The carbonic acid and other gases given off from the decomposing
organic matter in the deposit, and existing under considerable
pressure, have probably played an important part in maintaining
the particles of carbonate of lime in a state of molecular suspension,
in which condition they were able to migrate to the nucleus which
was irresistibly attracting them. Whether this state was one of
true solution as usually understood, or whether it was one analogous
to the colloid condition of silica, it is impossible to say. Recent
experiments on the combination of solids under pressure, and the
movement of the individual molecules of a dry mixture, show that
more rearrangement probably takes place amongst the particles of
an unconsolidated deposit than we are accustomed ‘to imagine.
1 W. J. Sollas, Ann. and Mag. of Nat. Hist. dth series, vol. vi,
H. H. Howorth—Elevation of American Cordillera. 441
T1.—Tur Recent anp Rapip ELEVATION oF THE AMERICAN
CoRDILLERA.
By Henry H. Howortu, Esq., M.P., etc., etc.
N some papers which have lately appeared in the GronocicaL
MacGazinge, I have endeavoured to show that the Ural
Mountains, and also the great masses of high land in Hastern
Asia from the Altai to the Himalayas, are of very recent geological
origin, and that it was probably their rapid elevation which caused
the great diluvial movement of which traces are to be found all over
the Siberian plains. I now wish to call attention to some of the
evidence which points to the American Cordillera being also a very
recent geological feature, and dating from the same period of cata-
clysmic revolution which closed the Mammoth age.
It is a curious fact that one name, America, connotes both of the
great continents hung together by the isthmus of Panama. The
cause of this is of course purely historical, and yet it coincides with
a great physical fact, namely, their essential unity in more than one
respect. The generic unity of the old inhabitants of both continents
is a peculiar fact in ethnography ; but the unity is even more remark-
able in this, that the vertebral column which runs north and south
through the two Americas is essentially one backbone.
On this subject Humboldt writes with his usual lucidity and
force. Speaking of the great chain of mountains that runs through
both continents, he says: “This is the most continued, the longest,
the most constant in its direction from south to north, and north-
north-west, of any chain of the globe. It approaches the north and
south poles at unequal distances of from 22° to 838°. Its develop-
ment is from 2800 to 3000 leagues (20 to a degree), a length equal
to the distance from Cape Finisterre in Galicia to the North-Hast
Cape (Chukchoi-Noss) of Asia. Somewhat less than the half of
this chain belongs to South America, and runs along its western
coast. On the north of the isthmus of Capica and of Panama, after
an immense lowering, it assumes the appearance of a nearly central
ridge, forming a rocky dyke that joins the great continent of North
America to that of the South. ... As the continent beyond the
parallel of Florida again widens towards the east, the Cordilleras,
of Durango and New Mexico as well as the Rocky Mountains, which
are a continuation of those Cordilleras, appear to be thrown anew
towards the West, that is, towards the coast of. the Pacific Ocean ;
but they still remain eight or ten times more remote from it than in
the southern hemisphere. We may consider as the two extremities
of the Andes, the rock or granitic isle of Diego Ramirez, south of
Cape Horn, and the mountains that reach the mouth of the Mackenzie
River (lat. 69°, long. 1804°), more than twelve degrees west of the
Green Stone Mountains, and known by the denomination of the
Copper Mountains” (Humboldt’s Narrative, vol. vi. pp. 409-411).
It is to this chain chiefly that I wish to direct your readers.
The first and most remarkable fact to which I would draw atten-
tion is that throughout its vast length (in places towering to an
442 H. H. Howorth—Elevation of American Cordillera.
enormous height) there are only slight traces to be found of ancient
glacial action, except in the length which separates Chili and Patagonia.
Excluding this length, there are hardly any scratched boulders,
roches moutonnées, or polished or striated surfaces which we can
assign to that vast ploughshare of ice which has left its mark so
plainly written on the flanks of the Alps and the Dovrefelds, the
granite wastes of Labrador and the North-Hastern parts of America.
Upon this point the best observers are unanimous.
We will first turn to South America.
It was Darwin who first drew attention to the distribution of
boulders in South America. Humboldt had argued that, inasmuch
as they are never found in the great intertropical plains of the
Hastern side of America, they are entirely absent from the whole
continent. Referring to this conclusion, Darwin says: “ As far as I
am able to discover from the works of travellers, and from what I
have myself seen, the remark holds good in the countries on both
sides of the Cordillera as far south as Central Chile. Azara has
particularly stated such to be the case in Chaco. With respect to
the tributaries of the Amazons, nothing can more strongly prove it
than La Condamine’s story ” (Darwin’s Narrative, p. 289). He says:
“Below Borja even for 400 or 500 leagues, a stone, even a single
flint, is as great a rarity as a diamond would be. The savages of
those countries do not know what a stone is, and have not even a
notion of it. It is diversion enough to see some of them when
they come to Borja, and first meet with stones, express their
admiration at them with signs, and be eager to pick them up, load-
ing themselves therewith as with a valuable merchandize. . . .
Neither in the southern nor in the northern hemisphere do the frag-
ments, coming from the Polar regions, or from other mountain
groups, arrive within a considerable distance of the lines of the
tropics” (Darwin’s Narrative, pp. 288-9). In the Appendix he
says: “The lowest latitude in South America, in which I found
large angular fragments, which must have been transported by ice
there formed, or by some unknown means, was in latitude 41°.
But as I did not examine the country immediately north of it, ] am
not prepared to say that this is their extreme limit, but between
latitude 27° and 83° I found no appearance, on either side of the
Cordillera, which indicated a power of transportation of the kind
required to remove boulders from a distance. Thus we find that
the limit of their dispersion in the two Americas is nearly the
same” (id. p. 615).
Darwin curiously compares the Andes with the Himalayas in
this respect. Thus he says: ‘‘We must couple the absence of erratic
blocks along that part of the Andes which is situated under a
warmer climate, with the similar non-occurrence, as | am informed
by Prof. Royle, in Northern India round the flanks of the Himalaya,
those loftiest pinnacles on the face of the globe” (id. p. 289).
What is true of South America is true of North America also. I
must not be misunderstood. I am only speaking of the Rocky
Mountains proper, which also are treated by Humboldt as in
H. H. Howorth—Elevation of American Cordillera. 448
essence identical with the Andes. I do not include the so-called
Coast Range or the Cascade Mountains, or the Selkirk Range, or the
Sierra Nevada. + On all these there are traces of glacial action on
a considerable scale; but in the case of the dominant range this is
not so, and, except on some of the higher peaks, where the phenomena
may have a very recent origin, there is a very singular absence of
such phenomena.
In such a matter I cannot quote any one better than Mr. Clarence
King. He writes:
ie the field of the United States Cordilleras, we have so far
failed to find any evidence whatever of a southward-moving con-
tinental ice-mass. As far north as the Upper Columbia, and
southward to the Mexican boundary, there is neither any boulder
clay nor scorings indicative of a southward-moving ice-mass. On
the contrary, the great areas of Quaternary material are evidently
subaerial, not subglacial. The rocks outside the limit of local
mountain glaciers show no traces either of the rounding, scoring,
or polishing which are so conspicuously preserved in the regions
overridden by the northern glacier. Hverything confirms: the
generalization of Whitney as to the absence of general glacia-
GON: fey ieait Not more than a thirtieth part of the entire surface
of the fortieth parallel area was ever covered by glacial ice.....
Whatever the greater causes may have been, the Cordilleran surface
south of Washington Territory was free from an ice-sheet, and the
only ice-masses were small areas of local glaciers which did not
cover two per cent. of the mountain country.”
Whitney also tells us that in the interior parts of the Cordillera
the ancient glaciers usually extended down to about 70U0 or 8000
feet above the sea (United States Geol. Expl. of the 40th Parallel,
pp. 459-461 and 464).
In Dr. Wright’s recently published “Ice Age in North America,”
we read :
“ According to Whitney there are no signs of ancient glaciers
in Western Nevada, though some of the mountains rise to a
height of 10,000 feet..... In Colorado there are evidences of
ancient glaciers only above the 10,000 foot linen... . The most
southern point at which signs of local glaciers in the Rocky
Mountains have been noted is near the summits of the San Juan
Range, in South-Western Colorado. Here a surface of about
25 square miles, extending from an elevation of 12,000 feet down
to 8000 feet, shows every sign of the former presence of moving
ice. Northward of Utah and Colorado the signs of former glaciation
are of the same local character; that is, glaciers everywhere radiated
from the higher mountain masses, and extended a short distance
down the canons and valleys..... The glaciers of the Sierra
Nevada and Cascade Range in California, Oregon and Washington
Territory were on a much grander scale than those in the Rocky
Mountains” (op. cit. pp. 148, 149).
Professor George Dawson, in criticizing some of Prof. Whitney’s
views, says:
“The general result arrived at in the areas of Whitney’s and
444 H. H. Howorth—Elevation of American Cordillera.
King’s surveys is that comparatively only a very small portion of
the highest ranges of mountains has ever been covered with glaciers,
and that there has never been in this region anything like a northern
drift period or a transportation of material in any given direction
independent of the present topographical features of the country”
(“ Nature,” 1881, p. 290).
Again, Mr. G. K. Gilbert, in his report on the geology of Nevada,
Utah and Arizona, says:
“About White’s Peak in the Schell Range, Nevada, are the
terminal moraines of five or six glaciers that descended to 8000 feet
altitude in lat. 89° 15’. At about the same altitude and in lat. 39°
are moraines and an Alpine lake upon the flanks of Wheeler’s Peak,
of the Snake Range of Nevada. Old Baldy Peak (N. lat. 38° 18’),
near Beaver, Utah, overlooks two terminal moraines, one of which
contains a lakelet at an altitude of about 9000 feet. No traces were
seen of a general glaciation such as the Northern States experienced,
and the cumulative negative evidence is of such weight that Mr.
Gilbert is of opinion that the glaciers of the region referred to were
confined to the higher mountain ridges” (“ Nature,” vol. xii. p. 299).
I will quote one more witness, and he the most important,
because his remarks refer to the northern prolongation of the
Rocky Mountains in latitudes where we should expect to see glacial
phenomena on a very wide scale.
Professor George Dawson, the distinguished son of a distinguished
father, has recently mapped out in detail the district threaded by
the more northern parts of the Rocky Mountains, and what do we
find on his map? Why, that while on the west of the chain the
erratics, which were once shed by.the Cascade Range, come almost
up to the Rocky Mountains on the one hand, and on the east the
drift, which has everywhere spread so far from Labrador and its
neighbourhood, has similarly travelled right up to the flanks of the
Cordillera, not an arrow or a mark is found on the map to show
that the Rockies themselves threw off any erratics of their own, or
that the great masses of ice which (one must suppose) covered them
in the Glacial age, if they were then existing, formed any barrier to
the spread of drift on either side of them. Assuredly the fact is
a very extraordinary one.
North America presents to us the most gigantic traces of ice-
action to be found anywhere. Nowhere else are the polished and
striated surfaces so widespread, and the boulders and wreckage of
ice-action so conspicuous. Hast and west of the Rocky Mountains
the evidence is the same. How comes it, then, that the highest
ground of all, which would naturally be looked upon as the main
reservoir of the ice, should be so free from its marks, and should be
so sharply contrasted with the mountains of Scandinavia, with the
Alps, with the Cascade Range, and with the gathering ground of
the Laurentian glacier? ‘To my mind there is only one possible
explanation of the facts here mentioned, namely, that the great
American Cordillera, both in North and South America, is not only,
as Hlie de Beaumont affirmed, one of the newest mountain ranges
_ A. H. Howorth—Elevation of American Cordillera. 445
in the world, but that it only dates in its main features from that
period of cataclysmic revolution in physical geography which closed
the Mammoth age, and that it was not existing at the time of the
so-called Glacial period.
This position may be supported, as similar evidence can be
supported in the case of the Urals and other ranges. In the first
place, it is a curious proof that the Rocky Mountains are very recent,
that they do not constitute a real zoological boundary. On this
subject I cannot quote a better authority than Mr. Murray, who, in
his Geographical Distribution of Mammals, p. 318, says, “ We
should expect the Rocky Mountain range to form the chief longi-
tudinal line of separation, but, as already said, it only separates
species in a minor degree. The actual mountain barrier appears to
be the Cascade Range on the west side of the Rocky Mountains,
separating Oregon and California from the rest of North America;
and the dividing limit between the two other regions seems to be
the Nebraska country, on which lie the Mauvaises Terres and
Nebraska, and Niobrara beds on this side of the Rocky Mountains—
the line of separation, in fact, being marked by the site of the
ancient Tertiary sea in which these beds had been deposited.”
In the first place, it is a remarkable fact that the remains of the
South American Mastodon of precisely the same species should have
been found on both sides of the Cordillera of the Andes. It ig
incredible that an animal of the type of the Mastodon, which, as we
know, fed on trees, should have traversed the high range over which
the Alpaca and Vicuna can hardly pass. In North America the
same fact presents itself, and we have remains of the Mastodon
occurring in California and in Oregon, on the western side of the
Rocky Mountains, as on the plains east of that range. This seems
to me to be very strong evidence that the Cordillera was not
existing in the Mammoth age to act as a zoological frontier.
Again, it was long ago observed by Humboldt that remains of the
same animal occur on the high plateau of Quito and elsewhere at
a tremendous elevation in South America, while the Mammoth left
its bones on the high plateau of Mexico, thus offering a parallel
to the remains from Hiundes in Tibet.
I will quote one or two instances in support of this contention.
Inier alia, Humboldt discovered a large number of Mastodon remains
in the so-called Giants’ Camp at Santa Fé de Bogota, in Peru, at a
height of 1300 toises (é.e. 2600 métres) above the sea (id. p. 264).
He found similar remains near the volcano of Imbaburra in the
kingdom of Quito, also in Peru, at a height of 1200 toises
(i.e. 2400 métres) (id. p. 266). Others again at Chiquitos, near
Santa Cruz de la Sierra, in 18° S. lat. and almost in the centre of
South America. On the west of the Cordillera J. de Jussieu reports
a great deposit of these bones in the valley of Tarifa at a
distance of more than 130 leagues from the sea, and 200 from
Potosi, while Humboldt sent one to Cuvier from Conception de
Chili in 87° S. lat. (¢d. p. 267). Darwin also found remains of the
Mastodon at Santa Fé, and speaks of their occurring up to the
snow-line.
446 HH. H. Howorth—Elevation of American Cordillera.
These facts are assuredly remarkable, and it is not strange, there-
fore, to find that Humboldt, after remarking how the bones of the
great pachyderms scattered in the auriferous gravels on the flanks
of the Urals prove the very recent origin of that chain, should go on
to say: ‘Cette méme conclusion de soulevement s’applique aux
Andes, ou, dans les deux hemisphéres sur les plateaux du Mexique,
de Cundinamaska (near Bogota), de Quito et du Chili, on decouvre
des ossemens fossiles de mastodontes 4 1200 et 1500 toises de hauteur ”
(Geol. et Clim. Asiatique, pp. 3881, 382, note).
See also his Relat. Hist. vol. i. pp. 886, 414, 429; vol. iii. p. 579.
Turning to another part, one curious feature of the Rocky
Mountains pointing to their cataclysmic origin is the sudden and
abrupt way in which they rise out of the adjoining plains. Thus
Mr. Ball says: “The Rocky Mountain rises up from the midst as
it were of a horizontal sea of red sandstone; as if some tremendous
force had driven it upwards, like an island forced up from the depths
of the ocean” (Silliman’s Journal, vol. xxv. p. 35).
Reclus says: “a chaine des Montagnes Rocheuses ne projette
pas de rameaux proprement dit dans les plaines orientales. Des
terrains onduleux viennent se heurter au pied des Monts comme des
ragues qui frappent les rocs d’un promontoire: la transition est
brusque entre les escarpements et les plaines” (Nouvelle Geog.
Univ. vol. xv.).
This is assuredly only consistent with this chain having been
elevated by a local paroxysmic movement, and not by a slow general
alteration of the level of the continent.
Another feature in which America and Asia resemble one another,
and which points to a recent elevation of the land, is the fact of the
existence of a number of small salt lakes which attest to wide areas
of water having been recently drained. Thus, Mr. J. K. Gilbert, in
his Geological Report, says that the level of what is now “ Great
Salt Lake must at one time have been much higher, and its area
must have been much greater than it is at present. Former levels
are marked by a series of conspicuous shore-lines carved on the
adjacent mountain slopes to a height of more than 900 feet. When
the waters rose to the uppermost beach, they must have covered an
area of about 18,000 square miles, eleven times that of the present
lake, and a trifle less than that of Lake Huron. The average depth
was 450 feet, and the volume of water nearly 400 times greater than
now.” Mr. Gilbert believes “that the flooding of the Great Salt
Lake Valley was contemporary with the general glaciation of the
northern portion of North America, and with the formation of the
numerous local glaciers of the western mountain systems, he considers
it a phenomenon of the Glacial Epoch” (‘“ Nature,” vol. xii. p. 299).
Reclus describes the American salt wastes in his usual graphic
manner. Thus, speaking of the desert of Utah, he says, “It is an
immense surface of clay, dotted over with thin tufts of Artemisia ;
in certain places, however, it exhibits no trace of vegetation, and
resembles a causeway of concrete, intersected by innummerable
clefts, forming nearly regular polygons. In the midst of these
H. H. Howorth—Elevation of American Cordillera. 447
solitudes no rivulet flows, and no water spring gushes forth; only
after journeying for many a long hour the traveller sometimes
comes upon some field of crystallized salt, a white expanse on
which the clouds and blue sky are reflected as on the surface of
a lake..... The solitudes of the Andes most resembling the desert
regions of the old world and of the United States are the elongated
plateaux, which rise one above another between the sea and the
principal chain of the Andes, in southern Peru, and on the frontiers
of Bolivia and Chili; such as the Pampas of Islay and Tamarugal,
and the desert of Atacama. The Pampa of Tamarugal has a mean
altitude of from 2960 to 3900 feet. It is a plain nearly covered
with beds of salt, or salares, which are worked like rock-quarries.
The strata of salt are so thick, and rain is so rare upon the plateau,
that the houses of the village of Noria, which are inhabited by the
workmen, are entirely constructed of blocks of salt. Some deserts
situated to the east of the Tamarugal, on more elevated plateaux,
contain a still larger quantity of salt.
The Pampa of Sal, which is overlooked by the volcano of Isluga,
has a mean altitude of not less than 18,800 feet, and its whole
extent, which is 125 miles long, and from 9 to 24 miles wide, is
perfectly white. The depth of salt deposited upon this plateau
varies from 5 to 16 inches, according to the undulations of the
ground.”
** Whence do these enormous masses of salt proceed? Doubtless
from the sea or ancient lakes which formerly covered these countries,
and have been gradually emptied by the rising of the soil” (Reclus,
«The Harth,” pp. 107-108, and 110-111).
We can hardly separate the drainage of these seas from the
upheaval which uplifted great collections of bones of the Mastodon
to a level close to the snow-line, and quite outside the range of the
soft-wooded trees on which they fed. The Salt-licks of Ohio actually
contain great masses of Mastodon and other bones.
If we cross the Cordillera, both in North and South America, from
west to east, we have another and equally difficult problem to solve,
namely, to account for the vast and continuous beds of unstratified
loam which, whether we call it Loess or Pampas mud, has the same
structure, and which no ingenuity can mistake for a deposit which
has been thrown down by water in a gradual way, or been accumu-
lated at all in a gradual way, since it not only has no signs of
stratification, except in very local circumstances, but overspreads
whole continents with its mantle, irrespective of the drainage or the
contour of the country, and which seems unmistakeably to prove the
operation of some rapid and cataclysmic cause.
In regard to South America some of the most distinguished
geologists, such as D’Orbigny, Brongniart, Elie de Beaumont, etc.,
have not scrupled to explain it as a consequence of the sudden or
very rapid upheaval of the Andes. D’Orbigny, who is much the
most distinguished geologist who has written on South America,
which he explored so diligently, and upon which he published a
most magnificent work, is very emphatic on the subject, and I must
quote some passages from his too little consulted masterpiece.
448 HH. H. Howorth—Elevation of American Cordillera.
The Pampas deposit, he tells us, covers an area of 23,750 square
leagues, and rises gradually from the sea-level to a hundred metres
or more. It also fills small elevated valleys as at Tarija, at Cocha-
bamba, 2575 métres above the sea, and all the Bolivian plateau at
the mean height of 4000 métres; so that it occurs at all heights
from the sea to the summit of the Cordilleras. It consists of a
homogeneous reddish unstratified loam. It is the same at Chiquitos
and Moxos, while on the Rio Piray it is somewhat mixed with clay,
and is the same on the high plateaux as it is on the Pampas, and
only contains Mammals’ bones. It covers, in fact, the surface of
nearly all South America, and is the result of one general cause
(D’Orbigny, vol. iii. pt. 8, pp. 250, 251). It covers deposits of all
ages—Silurian, Devonian, Carboniferous, Triassic and Trachytie
(id. p. 253). If, as Darwin argued, this deposit was of fluvatile or
estuarine origin, how, says I)’Orbigny, can we explain its presence
both on the plains and the high plateaux? This makes it clear that
its cause was not a local but a general one (id. p. 255).
Another fact which points the same moral is the absence of
stratification in these loamy beds. In certain places it is harder
or more or less sandy; but these parts, far from being separated
from the rest by horizontal lines, which always show themselves in
beds deposited slowly from water, form one mass with indistinct
zones which are very transient. In one word, it may be said that
the Pampas mud was deposited in a very short time and was the
result of a great terrestrial commotion (d’Orbigny, vol. iii. pt. 3,
. 73).
; Elsewhere he explains what, in his view, was the nature of this
commotion. He tells us how great dislocations took place in the
bed of the ocean to the west of the American continent. This dis-
location was coincident with the sudden or rapid upheaval of the
Andes over a length of 50 degrees or 1250 leagues. This upheaval
caused the sudden movement of the sea, which invaded all at once
the continent, carried off and overwhelmed the Mastodons which
inhabited the eastern flanks of the Bolivian Cordillera, the
Megatheriums, Megalonyxes, and the multitude of animals daily
being discovered in the caverns and the fissures of the mountains
of Brazil—all the species, in fact, which are extinct. It was then,
perhaps, that, mixed with the earth, the animals were tumultuously
deposited in the lower parts of the Tertiary basin of the Pampas,
and thus formed the immense deposit of Pampas mud (op. e7é. vol. ili.
pt. 8, p. 82).
Again he says: “ My final conclusion from the geological facts
I observed in America is, that there was a perfect coincidence
between the upheaval of the Cordilleras, the destruction of the
great race of animals, and the great deposit of Pampas mud. Thus
these three questions of immense importance for American geology
and for the chronological history of faunee, may be explained by one
cause, namely, the upheaval of the Cordilleras, to which we may,
perhaps, attribute the analogous phenomena of which Hurope has
been the theatre ” (id. vol. iii. pt. 3, pp. 85, 86).
HI. H. Howorth—Elevation of American Cordillera. 449
Elsewhere again he points to other facts which prove more
directly the coincidence in time of the rise of the Cordilleras and the
deposit of the Pampas mud by the waters as the result of this
elevation are without doubt the numerous depressions and denuda-
tions which cut into the soil from east to west, and the dispersion of
porphyry boulders over all the Tertiary deposits of Patagonia. If
these denudations had been subsequent to the deposit of the Pampas
mud, it is evident that the porphyritic boulders with which the
ground is covered over round the circumference of the Pampas
would also have covered the Pampas deposit, whereas they cease
just where the Pampas mud begins, as Darwin showed when he
says they are found from the Straits of Magellan to the Rio Colorado.
We may thus look upon the elevation of the Cordilleras as the cause
which at the same time drove the water from West to Hast with
sufficient violence to denude the Tertiary soil in the direction of the
slope, and to sweep from the Andes the porphyry boulders which
cover all Patagonia, and we may see in the same fact the reason
why the vegetable soil, etc., was swept from all the Tertiary strata
of Patagonia to be deposited in the great reservoir of Pampas mud.
I hold that the waters which deposited the Pampas mud were
salt, because all the clay deposits of the Upper Andes containing
bones are saline. It is so also with the Pampas mud, which shows
efflorescence at different points. But the best proof is the existence
of salt lakes dating from this period at the summit of the Cordilleras,
and in all the depressions caused by water in the plains of Patagonia,
and this perhaps accounts for the salt springs occurring in various
places” (D’Orbigny, vol. iii. part 8, p. 82, etc.).
These views were shared by other inquirers. Thus in a report to
the French Academy on the discoveries made by Lund in Brazil,
we find the reporters, Brongniart, Dufrenoy, and Elie de Beaumont,
saying, ‘The deposit in Brazil only differs from that of the Pampas
by the presence of quartz pebbles, probably derived from subjacent
beds; there it is from 3 to 16 métres thick, and extends up the
flanks of the mountains to a height of 2000 métres.” Mr. Lund
attributes the red loam of Brazil to a great irruption of waters
which covered all this part of the earth, and put an end to the
existence of living animals. “Whatever modifications this hypothesis
is destined eventually to suffer, it seems to us evident,” say the
learned reporters, ‘‘that the extension of the Pampas mud over the
mountains of Brazil upsets the theory that this mud was deposited
tranquilly in the estuary of a great river, and this extension seems
very probable, since the Brazilian mountains are not the only ones
where it occurs.” .... The area covered by the Pampas mud is
equal to that of France, and the deposit which contains Megatherium,
Megalonyx, Hoplophorus, and Mastodon, on the Parana, is 200 myria-
metres from Minas Geraes, where Lund found the same animals,
proving that the cause of their deposition operated on a great scale
over the continent of America, and that we must invoke, if we are
to explain it, some general and widespread cause.
I have not pretended in this short paper to do more than collect
DECADE III,—VOL. VIII.—NO. X. 29
450 C. Davison—British Earthquakes of 1890.
a few salient facts, which might be greatly multiplied. They seem
to establish that the American Cordillera, like the Highlands of
HKastern Asia, form a very new feature in the physical history of the
world. They show that their upheaval dates very largely from
post-Tertiary times, that it was very rapid, if not sudden, and that
it caused a widespread diluvian movement, to which we must
attribute the destruction of a large part of the Pleistocene fauna,
and the spreading of the great mantles of unstratified loam in the
Pampas of South America, and the Loess districts of the North.
III.—Own tHe British HartraquaKkes or 1890, witH THE EXCEPTION
OF THOSE FELT IN THE NEIGHBOURHOOD OF INVERNESS.
By Cuaruzs Davison, M.A.,
Mathematical Master at King Edward’s High School, Birmingham.
HE most remarkable earthquakes of the year 1890 were those
felt in the district round Inverness between November 15 and
December 14. These have been described in a separate paper.’
The remaining earthquakes were of comparatively slight intensity.
Two or three were felt during the night of June 25-26 within
a very small area to the north-east of Leeds, and one at least in
Kintyre on July 24. Several slight shocks at Invergarry and
Feddan, in Inverness-shire, complete the list so far as known to me,
with the exception of a doubtful shock at Tulliallan in Perthshire
on January 6.
It is hardly necessary to do more than refer here to the two
supposed earthquakes felt on January 7 at and near Chelmsford.
Tn a letter to “‘ Nature,”? I have given the evidence in full; and it
appears to me sufficient to show that they were merely the reports
of one of the great Woolwich guns. The reasons of this conclusion
are, briefly: (1) exactly at the times given (12h. 30m. and oh.
25m.), a 110-ton gun, the heaviest in the service, was fired at
Woolwich ; (2) the wind was §.W. over nearly the whole of
_ England on the day mentioned, and all the places from which I
have received records are: --ose to a line passing in a north-easterl y
direction from Woolwich, and (8) the descriptions of the shocks
show that they were due to impulses transmitted through the air
rather than through the earth.
YORKSHIRE HARTHQUAKES: JUNE 25-26.
a. June 25, about 22h. 30m.; Intensity, IV.; Epicentrum, about
half a mile N.E. of Walton.
b. June 26, about Lh.
First Shock: June 25, about 22h. 30m.—I have received records
of this shock from 19 places, which, with two exceptions, lie within
an area about 114 miles long and 7 miles broad; the direction of
its longer axis being about W. 17° N. and H. 17° 8. The boundary-
1 Read before the Geol. Soc. on June 24.
2 “‘Nature’’ (Feb. 20, 1890), vol. 41, p. 369.
C. Davison—British Earthquakes of 1890. 451
line of this area corresponds to an isoseismal of intensity IV. or
nearly so; it contains a little more than 60 square miles.
Throughout the disturbed area, the shock seems to have consisted
of a single vibration; no tremulous motion being noticed either
before or after. At Boston Spa, it is said to have resembled “an
explosion, or the sudden and loud banging of a subterranean door.”
At Walton, a village close to the epicentrum, the movement was
lateral only, no vertical motion being perceptible.
4+ Hunsingore
Cotrthorpe To, a tle
Eke Re erton:
irk DeGielore
o Lpicentrum
Wetherby + Walton
° Lertore
x
e
SON Sere oe Thorpe Arche
Neer + ae Spor
“Ns.
~.
Bolton Percy
Lorkshire Larthquake, Sine 23, 1890, (2h.30m.)
Estimates of the duration are variable, sud probably include that
of the accompanying sound in one or two cases. At Collingham,
the shock seemed to be instantaneous. It is stated to have lasted
a second or two at Boston Spa, two sx; mds at Hunsingore, about
three seconds at Walton, and about ten s. conds at Tockwith.
The intensity was IV. at Askham Richard, Bilbrough, Boston Spa,
Cowthorpe, Spofforth, Tockwith, and Walton; and III. at Bolton
Percy.
Sounds were heard accompanying the shock at eight places at
least ; from eight others no record is given on this point; at three
places, Askham Richard, Bolton Percy, and Spofforth, it is expressly
stated that no sound was heard. The sound-area was, therefore,
somewhat less extensive than the disturbed area.
The epicentrum is about half a mile N.H. of the village of Walton,
and 15 miles N.E. of Leeds.
Second Shock: June 25, about 1h.—This shock was felt by several
persons at Boston Spa, but I have not been able to obtain any
detailed observations.
452 O. Davison—British Earthquakes of 1890.
On the same day, at about 4h., a third shock is said to have been
felt, at Wetherby; but, in the absence of any further information,
its occurrence must be regarded as doubtful.
Origin of the Shocks.—In the immediate neighbourhood of the.
epicentrum, there appears to be no fault with which these earth-
quakes may be connected: at any rate, none is marked upon the
Survey map. The evidence given above, slight as it is, seems to me
also rather to oppose than to favour the view that they were fault-
formed shocks.
Somewhat similar shocks, though disturbing smaller areas, are of
frequent occurrence at, and in the neighbourhood of, Sunderland.
These have been studied and discussed by Prof. G. A. Lebour in an
admirable paper “On the Breccia-gashes of the Durham Coast, ete.” !
The magnesian limestone at Sunderland is about 400 feet thick.
It contains numerous caverns, many of them naturally formed, some
probably artificial owing to the withdrawal of water by the local
water company. Fragments of rock must frequently fall from the
roofs of these caverns, and it is to the concussions produced by them
that Prof. Lebour, with very good reason I believe, attributes the
Sunderland shocks. That such falls have frequently taken place
in former times is obvious from the constitution of the numerous
“ breccia-gashes”’ which may be seen along the coast of Durham.
That they are probably continuing at the present time is shown by
evidence which has been obtained since the publication of Prof.
Lebour’s papers. The Sunderland shocks are especially numerous
at certain parts along the banks of the Hendon Burn, a small
stream about a mile south of the River Wear. The Sunderland
and Ryhope Road crosses the stream nearly at right angles, and,
for a distance of about 400 yards on the north side, and about
150 yards on the south side of the stream, it has been found that
the road has recently subsided. The Ordnance Survey levelling of
the road was carried out in 1857, and in 1887 the levelling was
repeated by a well-qualified surveyor at the instance of Mr. T. W.
Backhouse, of Sunderland. The average subsidence of the road
‘over the distance mentioned was found to be 1 foot 10 inches in the
thirty years; at the stream itself the subsidence was 2 feet 4 inches.
A large part of this subsidence seems to have taken place towards
the end of this period; for, in four years, 1883-87, Mr. Backhouse
found by observations of a distant chimney, that his observatory,
which is close to the Ryhope road, had been lowered by 1 foot 4 inches,
and it is worthy of notice that just about this time the slight shocks
became especially frequent.
The part of the disturbed area surrounding the epicentrum of the
first of the Yorkshire shocks consists also of magnesian limestone,
though its thickness is less than at Sunderland.* The depth of the
1 Trans. of the N. of Engl. Inst. of Mining Eng. (Newcastle-upon-Tyne),
vol. 33, 1884, pp. 165-174. See also a paper by the same author, ‘¢On Some Recent
Earthquakes on the Durham Coast and their probable cause,’ ’ Gzor. Mae. (1885),
Dee. 3, Vol. II. pp. 513-515.
2 In the neighbourhood of Tadcaster, the thickness of the Permian formation
(Upper Marls to Lower Magnesian Limestone, inclusive) is 300 feet (Mem. Geol.
Sury., Explanation of Quarter- sheet 93 8.W.).
C. Davison—British Earthquakes of 1890. 453
seismic focus must have been very slight. This is shown by—
(1) the smallness of the disturbed area considering the intensity of
the shock; and (2) the horizontal direction of the motion at Walton,
a village only about half a mile from the epicentrum. Bearing in
mind also the nature of the disturbances, it seems to me therefore
very probable that the Yorkshire earthquakes were due to the falling
of masses of rock in caverns of the magnesian limestone.
Authorities.—A short account of the shock is given in the “ Leeds
Mercury” for June 27. But for most of the observations on which
the above description is founded, I am indebted to the kindness of
the following correspondents: Askham Richard, Mr. T. B. N. Miles ;
Bilbrough, Miss Metcalfe; Bolton Percy, the Right Rev. the Lord
Bishop of Beverley ; Collingham, Rev. G. L. Beckwith ; Cowthorpe,
Rey. 8. H. Gaisford; Hunsingore, Rev. J. J. D. Dent; Spofforth,
Mr. R. T. Vyner; Tockwith, Mr. F. M. Clarkson; Walton, Mr. E.
B. Waite, F.L.S. The details with reference to the subsidence of
the Sunderland and Ryhope Road are taken from a letter by Mr.
Backhouse in the “‘Sunderland Daily Echo” for Dec. 6, 1887.
Kintyre WartTHQuake: Juty 24.
Time of occurrence, 11h. 37m. ; Intensity, V.
I did not hear of this earthquake until some months after its
occurrence. Partly on this account and partly from the difficulty of
obtaining information in a district so thinly peopled, I can give but
little beyond a slight description. I regret this the more, as it
would have been interesting to have traced its relations with the
earthquake felt in the same district on July 15, 1889.
Most of the places from which I have received records are in-
dicated on the map of the earthquake of 1889.‘ These places are
Clachan, Glen Saddell, Gigha, Kilberry, Tayinloan and Whitehouse.
At Clachan and Tarbert the shock was accompanied by a rumbling
noise. Throughout the island of Gigha, to the west of Kintyre,
a rumbling noise was heard, but the shock itself was not perceived.
Neither shock nor sound was noticed at Bellochantuy, nor at
Lochranza in the island of Arran.
With evidence so slight, it is not possible to determine the outline
of the disturbed area. It cannot have differed much from that of
the year before; towards the north and south its limits may have
been about the same; but it did not extend so far towards the east.
Its epicentrum, though probably not very distant from the village of
Clachan, must therefore lie somewhat to the west of that of the
earthquake of 1889.
With regard to the nature of the shock, I know very little. At
Clachan, it began with a series of tremors “so sharp, short and
quick as not to be easily counted.” These increased in intensity
until, at the end of twenty seconds, “a vibration was felt like what
would be caused by a heavy stone falling from a very great height.”
1 See page 366 of this volume. Tayinloan is about one mile N. of Killean;
Whitehouse, 7 miles E. 15° S. of Kilberry; Bellochantuy, 7 miles S. 10° W. of
Killean,
454 C. Davison—British Earthquakes of 1890.
After this prominent vibration, or “blow,” the tremulous motion
was again felt, and lasted for five seconds. During the whole time
that the tremors lasted, a sound was heard “‘ resembling the noise of
stones falling down a chimney,” loudest at the moment when the
“blow” was felt, a dull “thud” being then heard ‘‘as of a sup-
pressed explosion.”
The intensity was V. at Clachan, and at Tarbert not less than IV.
About noon on the same day, a second shock was felt at Clachan ;
but, so far as I know, by one observer only.
Authorities.—For the information on which the above short
account is furnished I have pleasure in thanking: Bellochantuy,
Miss M. Currie; Clachan, Rev. J. Cameron, Mr. A. McLellan;
Glen Saddell, Mr. J. Mcleod, of Saddell; Gigha, Mr. R. A. Cavana,
Rev. J. F. McKenzie; Lochranza, Rev. J. Johnstone; Tarbert,
Mr. J. Brown.
EARTHQUAKES AT INVERGARRY AND FEDDAN.
The earthquakes at these two places! are interesting owing to
their possible connexion with the great fault which follows approxi-
mately the course of the Caledonian Canal. Invergarry lies about
a mile N.W. of the centre of Loch Oich, and Feddan about three
miles N.W. of the centre of Loch Lochy. For the following lists
1am indebted to the kindness of Mr. John Grant, of Invergarry,,
and Mr. Murdoch Matheson, of Feddan, both of whom are doing
most valuable work in recording the occurrence of earthquake-shocks.
Invergarry.
Jan. 5. 2h. 30m., a shock of intensity IV.
i) 16h. 385m.
fe 16h. 40m.
im 16h. 47m., like a heavy carriage passing.
Jan. 19. 16h. 55m., the same.
Mar. 15. 8h. 45m., resembled the noise of a heavy train.
May 29. 16h. 45m., like a heavy carriage passing.
Aug. 8. 15h. 85m., the same.
Nov. 16. 20h. 30m., like a passing train. Though occurring at
the same time as the fourth shock of the Inverness
series, this must have been a distinct shock.
Dec. 1. 10h. 10m., a slight shock.
Feddan.
Noy. 19. 1h. 33m., a very slight shock, preceded by a low
rumbling noise.
Dec. 26. 18h. 10m., a loud noise resembling thunder heard,
followed by a trembling motion, lasting fully two
minutes. Almost immediately afterwards, another
and louder sound was heard, without any accompany-
ing tremor.
1 At both places, che shocks are recorded by only one observer, and should there-
fore, strictly, be regarded as doubtful shocks; but I have placed them under a
separate heading, as both observers have for several years diligently recorded the
occurrence of every shock felt by them. ;
Rev, P. B. Brodie—Lower Greensand and Purbeck Beds. 4655
Dovstrunt HarrHquake.
Jan. 6, between Lh. and 2h., Tulliallan (south of Perthshire).
The following account is taken from a paragraph in the “ Perth-
shire Advertiser” for Jan. 8. ‘‘ Between one and two o’clock....
what-is believed to have been an earthquake shock was distinctly
felt in the parish of Tulliallan. The night was extremely stormy,
with thunder and heavy sleet showers. But readily distinguishable
from the sound either of the wind or of the thunder there arose
a roaring noise like that of an express train passing at full speed,
accompanied by a trembling sensation of the ground, such as
Londoners who dwell near the Underground Railway are accustomed
to. The noise seemed to increase in intensity as it approached, and
then died away again in the distance, just as that of a passing train
would have done. There is no railway within several miles.”
This is the only account I have been able to obtain. From the
description, it is obvious that the shock closely resembled that of an
earthquake, but, considering the circumstances of its occurrence, the
evidence is not sufficient in itself to establish its seismic origin.
ITV.—Lower GREENSAND AND PuRBECKS IN THE VALE OF
Warpour, WILTs.
By the Rev. P. B. Bropviz, M.A., F.G.S.
N the Grotoaicat Magazine for July last the Rev. W. Andrews
and Mr. Jukes-Browne gave an account of Lower Cretaceous
strata in the Vale of Wardour. I can bear testimony to the correct-
ness of this statement. Many years ago, when geologizing in the
vale chiefly among the Purbecks, I found many portions of iron-
stone and hard ferruginous sandstone, in the fields and by the road-
side both at Dinton, Teffont and especially at Chilmark, containing
casts of Cyrena, Turritella, and a part of a dermal scute of a Saurian,
which I believe belong to the Lower Greensand, but I never saw it
im situ, and it seems to have been greatly denuded. A few years
ago, after an absence of nearly fifty years, I paid another visit to
some of my old haunts in this beautiful district, in company with
Mr. Andrews, who was anxious to find out the exact spot where I
obtained insects, fish and Archgoniscus ; but after a careful search no
trace of the old quarry could be seen, and the place was filled up
and overgrown with bushes. In no other locality in the Vale has
a similar limestone been found, though Archgoniscus and a few
remains of insects occur lower down in the Middle Purbecks at the °
lime quarry above Teffont Rectory, where Mr. Andrews has obtained
several new and interesting fish,' plants, and other organisms. At
Dinton the insects were fairly abundant, and Archgoniscus especially
1 Among these fish is Coccolepis Andrewsii, A. S. Woodw., which is allied to~
Paleoniscus, and is now in the Jermyn Street Museum. Mr. Smith Woodward
lately showed me another remarkable small fish sent to him by Mr. Andrews from
Teftont, which the former will shortly figure and describe. ‘These, added to the
others long ago figured and described from Dinton, make a most interesting list of
new forms from the Wiltshire Purbecks. The other genera from Teffont include
Pleuropholis, Microdon, showing the teeth in siti, and Lepidotus minor.
456 A. J. Jukes-Browne—Lower Greensand in Dorset.
so. It seems probable that the insect limestone below the Archzo-
niscus bed there is of limited extent, though if pits were opened at
the same spot more of the limestone would be found.
The cutting in the railway close by exposed the Isopod limestone,
but no trace of the Insect bed was seen, as the excavation at this
spot was not deep enough to reach it. At Chicksgrove, in the large
quarry then opened near Tisbury, at the base of the Purbecks, I
only obtained one elytron of a beetle, but some Archewoniscus very
much larger than those at Dinton and Teffont. This may be a
new species, but has not been figured or described. It is twice as
large as the specimen figured in Fossil Insects, pl. i. fig. 7. Owing
to the rough ‘nature of the matrix, probably ‘the cap’ of the Isle
of Portland, these are not so well preserved as those from Dinton
and Teffont. This Isopod Crustacean evidently ranged from the
base of the Lower Purbecks at Chicksgrove, through the lower part
of the Middle Purbecks at Teffont to the upper division at Dinton.
In one specimen of Archeoniscus from Durlstone Bay, Dorset, the
Tsopod is lying on its back, showing all the legs folded together under
the abdomen,—the only example I ever obtained in this position.
The recent discovery by Messrs. Andrews and Browne of Upper
Purbecks in the Vale of Wardour, hitherto supposed to be absent,
is of much interest to geologists, especially to those who, like myself,
have long studied these beds.
V.—NorteE on AN Unprscrisep ArrA oF LowER GREENSAND
oR VECTIAN IN Dorset.
By A. J. Juxzs-Browne, B.A., F.G.S.
Communicated by permission of the Director General of the Geological Survey.
NTIL recently no outcrop of the Vectian or Lower Greensand
was known to occur between Lulworth on the coast of Dorset
and the neighbourhood of Devizes in Wiltshire. It was supposed
that, with the exception of a small area of Wealden in the Vale of
Wardour, the whole of the Lower Cretaceous Series in Dorset and
South Wilts was concealed and buried beneath the overlapping
Upper Cretaceous strata. A recent examination of this district
however has revealed two areas where the Vectian sands emerge
from beneath the Gault. One of these has already been indicated
in the pages of the Grotocrcan MaGazine;? the other is the subject
of the present communication.
Reference to the Geological Survey Map, Sheet 15 will show that
the Gault was supposed to thin out and disappear near Shaftesbury
so as to allow the Upper Greensand to rest directly on the Kimeridge
Clay. This proves to be a mistake; the Gault is continuous below
‘the Upper Greensand into and beyond the valley of the Stour.
Moreover, two miles south of Shaftesbury and a little east of the
hamlet of Twyford a tract of sand emerges from beneath the Gault
and forms a terrace which for a little distance has an escarpment of
1 The Lower Cretaceous Series in the Vale of Wardour, by A. J. J ukes- Browne
and W. R. Andrews, Grou, Mae. for July, 1891, p. 292.
A. J. Jukes-Browne—Lower Greensand in Dorset. 457
its own. Near Bedchester this terrace, or dip-slope, is nearly half
a mile wide; thence it can be traced southward to Farrington, where
it bends westward, still making a prominent feature, and passing
above Fontmell Parva it runs into a hollow by Child Okeford on the
eastern side of the Stour valley.
The length of this tract is between four and five miles, but only
two good exposures have yet been found along it. These are, how-
ever, sufficient to give some interesting details of the beds which
constitute it. One of them is a road-cutting by Piper’s Mill, between
Bedchester and Fontmell Magna, and to expose this more clearly
two narrow trenches were cut down the bank. By this means the
following beds were observed :—
Feet.
Brown loamy soil__.. 1 to 2
Mottled brown and grey clay containing in the lower part
pebbles of vein quartz and lydianite as large as beans
(? base of Gault). UP cesnitese
Greenish-brown sand with ‘clay ‘mottlings: @
Soft purple brown clay (1 foot) passing into dark ¢ ereen
sandy clay, with laminz of purple clay and patches of
greenish-brown sand, and finally into mottled sand,
brown, yellow, and green : S60, amo eGo vere 1
Purple black laminated clay and sand doo" 0a0° oon
Greenish-black clay full of glauconite grains... ... ... 2
0
1
2
bo bo
Hard brown sandstone cemented with oxide of iron
Rather coarse yellowish-brown sand...
Fine soft greenish-grey sand, seen for
about ... ... 18
The other exposure in a sand-pit east of Bedchester seems to
begin where this leaves off. It shows remnants of the ferruginous
sandstone underlain by greenish-brown sand with two layers of
coarse yellowish sand and then 6 feet of fine greenish brown
sand, below which is some 5 or 6 feet of dark-green glauconitic
sand. This last is well exposed along the gully of the watercourse
that runs by this spot toward Piper’s Mill.
From these particulars it appears that the total thickness of the
sands near Bedchester is at least 30 feet, and probably between
30 and 40 feet. There are some thin layers of coarse quartz sand
in the upper part, but the greater part is fine sand consisting of
small even-sized grains of quartz (not much rounded), and grains
of dark-green glauconite, many of which are smaller than the
quartz-grains.
_ The occurrence of the dark glauconitic mud or clay is particularly
interesting, both as showing that we are not here dealing with a
littoral or very shallow water deposit, and also because a similar
bed, consisting of black clay in the upper part and dark greensand
below, was found in the Vectian of the Vale of Wardour. The bed
at Piper’s Mill appears to consist of an intimate mixture of dark
purple-grey clay and very fine glauconitic sand, chiefly glauconite,
with some minute grains of quartz and mica.
It may be mentioned that a boring made at Fontmell Brewery
a few years ago has been carried through the Gault into sand
458 E. Wilson—Colour-bands in Waldheimia.
similar to that above described, and a good supply of water was’
obtained which rises above the surface of the ground.
It is also worthy of note that this emergent tract of Vectian sand
is the most westerly exposure yet known, with the exception of
that near Lulworth Cove, which, however, is of much smaller size,.
compared with the tract above mentioned. It happens too that this
tract, and that near Lulworth, are almost exactly on the same line
of longitude.
Considering its position, the amount of glauconite present, the
fineness of the sand, and the existence of interstratified clay are
remarkable facts, suggesting that the deposit was formed at some
_ distance from a shore- line. Comparison with the exposures near
Devizes and Seend certainly suggests that the latter were formed in
much shallower water and much nearer a coast-line.
VI.—On 4 Specimen or WaLDurIMia PERFORATA (PIETTE), SHOWING
ORIGINAL CoLOUR-MARKINGS.
By Epwarp Witson, F.G.S.,
Curator of the Bristol Museum.
HE retention of the original colour-markings amongst fossil
Brachiopoda is a somewhat rare occurrence: the following
str iking instance therefore seems worthy of record.
It is true that Deslongchamps in the Paléontologie Frangaise
mentions the colours of a number of Jurassic Brachiopods, but in
nearly all these cases the colours are spoken of as if uniformly dis-
tributed and not patterned over the shells,’ and therefore we cannot
be sure that they are original and not subsequently produced.
Of British fossil Brachiopods which show the colour-markings,
Terebratula hastata and Discina nitida respectively from the Carboni-
ferous Limestone of Longnor, Derbyshire and Hamilton, Scotland,
Terebratula intermedia from the Cornbrash of Wollaston, and Tere-
bratula biplicata from the Upper Greensand of Cambridgeshire, are
examples.’ In these cases the colour-marks are generally in the
form of radial, z7.e. vertical bands or striz.
The specimen to which I now call attention is one belonging to
the species Waldheimia perforata, Piette, and comes from the Lower
Lias of Bitton, Gloucestershire.
The colour indications on this shell are in the form of clearly
defined concentric bands of black and white of varying breadth,
conforming approximately but not rigidly with the lines of growth.
The bands of colour are bilaterally symmetrical, and, what is still
more important as indicating that they are original, correspond in
the two valves, except that as we should expect they are broader in
the larger and more rapidly growing ventral valve, and show a
tendency in that valve to split up into smaller rings. Commencing
at the beaks we have in each valve a white circular area crossed by
1 The colour of Waldheimia perforata for example is given by this author as
‘ inch.
They are mostly pretty evenly dispersed and occur indifferently in
the spots and in the surrounding mosaic, but at some parts of the
slides they are aggregated into large clusters and packs.
This mineral, again, seems to be very local in its occurrence,
appearing and disappearing within a distance of a few yards along
the slide, and of a few feet across it.
One of my objects in taking a new series of specimens was to
endeavour, if possible, to obtain more evidence as to what is the
real nature of the substance, or substances, in course of formation in
W. WM. Hutchings—Coniston Flags at Shap. 461
the comparatively clear “spots” which are so prominent a result of
the alteration of these rocks. In this I have not been successful.
All the spots, however, are not of the same nature. In some cases
they appear to consist almost wholly of white mica. In others, after
much observation and comparison with other contact-specimens, I
am of opinion that, as suggested by Harker and Marr, andalusite is
the mineral being formed. But that mineral, in definite recognizable
form, does not occur in any of my sections. In other slides, again,
the material of the spots is quite different from either of the pre-
ceding and quite beyond any attempt at identification.
Messrs. Harker and Marr are of opinion that probably a good deal
of felspar is formed in these altered flags, together with the mosaic
of regenerated quartz. There are few questions of greater interest
than that of the formation of new felspar in sedimentary rocks,
whether by contact or by regional metamorphism, and any instance
brought forward is important. Such instances are not very numerous,
and some of them do not appear to be by any means fully accepted.
In the case of these rocks in Wasdale Beck I have made every effort
to obtain proof of the occurrence of felspar, but without any success.
All the grains of the mosaic are perfectly limpid. Many suggest
felspar by their outlines, as stated by Harker and Marr, and there is
decidedly an impression produced that the mineral is there. But of
scores of tests in convergent light, made on promising-looking
grains, not a single one has given proof of a biaxial mineral, which
would in this case be sufficient confirmation. The sections for
studying this class of rock are necessarily very thin; but with
equally thin slices of some of the neighbouring altered volcanic
rocks with quartz-felspar mosaic, it is quite easy to pick out and
identify the felspar grains. Although it is by no means unlikely
that felspar is present, I prefer to consider it as not proved, so far
as any of my own specimens are concerned.
Although on a minuter scale, great interest attaches to the changes
which are undergone, during the alteration of rocks in this class,
by the minerals consisting wholly or largely of titanic acid; and
these flags of Wasdale Beck are specially suited for observing these
changes, as we may here see several of them together which have been
noticed elsewhere singly by different observers at different places.
At the falls near the hotel, where alteration is already well
advanced as regards formation of brown mica and is distinctly com-
mencing as regards regeneration of quartz, we still see the original
“clay-slate needles” in considerable numbers. They are of very
small size. The only change seems to be that they are not as equally
diffused as in the original rocks, having apparently commenced to
disappear at some parts of each slide examined. A few yards higher
up, with much increased development of brown mica and regenerated
quartz, these minute rutiles have disappeared ; and in due course,
as the new limpid mosaic is developed, we note the appearance of
rounded and ovoid grains of rutile and of crystals of that mineral,
which are much larger and relatively thicker and blunter than the
original needles. These things, together with other indeterminable
462 W. M. Hutchings—Coniston Flags at Shap.
granular and microlithic bodies, appear in the grains of regenerated
quartz and assist in distinguishing it from the still remaining
clastic fragments.
At another stage still larger rutile crystals are seen in eroups
and interlacing clusters, mustering strongly at some parts and
wholly absent from others.
In some of the sections where “spots” are strongly developed,
clusters of beautiful little crystals of anatase are seen, as recorded
by Harker and Marr.
At the time when they introduced the note on this mineral into
their paper it had been only seen by me in one section. I now have
several, from different points along the beck, in which it is plentifully
represented, not only as clusters in the spots, but also scattered
about in the mosaic.
This appears to be a rare case, as Mr. Harker tells me that
anatase is only once previously recorded (by Lossen) as a contact-
mineral. It is a very interesting fact that titanic acid as original
slate-needles is reabsorbed in some manner, and then reappears,
in one and the same rock, either as rutile or as anatase, and that the
latter clusters thickly in special spots.
Another form in which the titanic acid reappears is in combination
with lime and silica as sphene, granules of which are abundant in
some of the sections, though none is seen till after the disappearance
of the original rutile-needles.
_Again, at some parts of these rocks we have abundant minute
transparent plates of ilmenite, largely as perfect hexagonal crystals,
thickly grouped together in the spots in just the same manner as
we have the anatase. ‘his appearance of ilmenite in contact-rocks,
with the corresponding disappearance of original rutile, is pointed
out by Rosenbusch (‘ Massige Gesteine”).
Finally, where veins of white mica are formed, we may see, in
and along the edges of these little veins, large crystals and grains
of rutile, many times larger than any so far mentioned, resembling
in size and form those which are seen so abundantly in some schists.
The occurrence of anatase in this manner being apparently so
rare, it may be of interest to mention that I have recently observed
another instance of it. A specimen of “ash,” or fine-grained tuff,
which I collected this summer at Falcon Crag, Derwentwater, is
made up in about equal parts of volcanic lapilli and small fragments
of sedimentary rocks. Some of these fragments are of altered rocks,
1 These crystals, when best developed, are about gouo inch longer The form is
that of a tetragonal pyramid, either simple or showing also prism-faces in narrow
bands. In some of the later specimens there are large clusters consisting almost
wholly of perfect, or nearly perfect crystals.
2 These fragments of sedimentary rock are of various slates and grits. Some are
very micaceous and chloritic, not very quartzy, full of ‘‘clay-slate needles,’’ and not
altered in any way. ‘They are like many common types of slates. Others are very
quartzy, more like the flags at Wasdale Beck, but even richer in quartz. The alteration
of part of these is shown by formation of some of the “regenerated”’ quartz, and in
some'cases brown mica is formed, though this is not much developed, a white mica
in good-sized flakes being more usual. It is in these altered, more quartzy, grits
or flags, or whatever they may be best called, that the anatase crystals are seen.
Notices of Memoirs—British Association. 463
the nature of the original material and of the alteration being some-
what like what we have in Wasdale Beck; and in these altered
fragments several crystals of anatase occur, similar in all respects
to those described. ‘They are not clustered together, but scattered
about ;—the alteration of the rocks has not proceeded so far as the
development of any spots.
NOR he aS) Oe" Paver IVE Oreeycss
I.—Britiso AssocraTIoN FOR THE ADVANCEMENT OF SCIENCE.
CarpirFr Mretine, Aueust 207TH to 257u, 1891.
List oF TitnEs oF Papers READ In Section C, GrEonoey.
Professor T. Rupert Jones, F'.R.S., F.G.S., President.
The President’s Address.
Sir A. Geikie.—Discovery of the Olenellus-zone in the North-west
~ Highlands.
Sir A. Geikie—On some Recent Work of the Geological Survey on
the Archean Gneiss of the North-west Highlands.
A. Smith Woodward.—Report of the Committee on the Registration
of Type Specimens.
A. Smith Woodward.—Remarks on the Lower Tertiary Fish Fauna
of Sardinia (see infra, p. 465).
A. Smith Woodward.—Evidence of the Occurrence of Pterosaurian
and Plesiosaurian Reptiles in the Cretaceous of Brazil.
A. J. Jukes-Browne.—The Cause of Monoclinal Flexure.
A. J. Jukes- Browne.—Note on an undescribed area of Lower Green-
sand or Vectian in Dorset (see supra, p. 456).
A. C. G. Cameron.—On the Continuity of the Kellaways Beds over
extended areas near Bedford, and on the extension of the Fuller’s
Earth Works at Woburn, Bedfordshire.
Prof. W. Boyd Dawkins.—On the Discovery of the South-Eastern
Coalfield.
W. Topley.—The Geology of Petroleum and Natural Gas.
O. C. Dalhousie Ross.—The Origin of Petroleum.
Dr. H. Hicks.—A Comparison between the Rocks of South Pembroke-
shire and those of North Devon.
W. A. E. Ussher.—Vulcanicity in the Lower Devonian Rocks. The
Prawle Problem.
A. R. Hunt.—On the Occurrence of Detrital Tourmaline in a Quartz-
Schist west of Start Point, South Devon (see infra, p. 465).
C. EH. De Rance.—Report of the Committee on the Circulation of
Underground Waters.
C. EH. De Rance.—Notes on the Discovery of Estheria minuta (var.
Brodieana) in the New Red Sandstone.
O. W. Jeffs.—Report of the Committee on Geological Photographs.
Montagu Browne.—On Colobodus, a Genus of Mesozoic Fossil Fishes.
C. Davison.—Report of the Committee on Harth Tremors.
464 Notices of Memoirs—British Association.
Dr. H. J. Johnston-Lavis.—Report of the Committee on the Voleanie
Phenomena of Vesuvius.
Sir R. S. Ball.—The cause of an Ice Age.
Dr. H. W. Crosskey.— Report of the Committee on Erratic Blocks.
Dr. H. W. Crosskey.—Notes on the Glacial Geology of Norway.
Prof. G. Frederick Wright.—Recent Discoveries bearing on the
Relation of the Glacial Period in North America to the Antiquity
of Man.
Dr. H. Hicks.—On the Evidences of Glacial Action in Pembroke-
shire, and the Direction of Ice-flow.
H. Bolton.—On some Boulders at Darley Dale.
P. F. Kendall.—On a Glacial Section at Levenshulme, Manchester.
Prof. G. Frederick Wright.—Recent Discoveries in the Pleistocene
Lava Beds of California and Idaho.
B. Harrison.—Report of the Committee on Excavations at Oldbury
Hill.
Prof. J. Prestwich. —Bahianneny Note on Excavations at —
Hill.
Rev. EH. Jones.—Report of the Committee on Hlbolton Cave, near
Skipton.
J. Storrie.—On the Occurrence of Pachytheca spherica, Hooker, and
Nematophycus, n.sp., in the Wenlock Beds at Ty Mawr Quarry,
Rumney.
Beeby Thompson.—Report of the Committee on the Lias of North-
amptonshire.
Prof. J. Hoyes Panton.—The Mastodon and Mammoth in Ontario,
Canada.
E. T. Newton.—On the Occurrence of Ammonites jurensis in the
Tronstone of the Northampton Sand Series near Northampton.
S. S. Buckman.—The Ammonite Zones of Dorset and Somerset.
G. R. Vine.—Notes on the Polyzoa (Bryozoa) of the Zones of the
Upper Chalk.
Papers read in other Sections bearing on Geology :—
Section A.—Mathematical and Physical Science.
Prof. J. Milne, F.R.S. —Report of the Committee on the Volcanic
and Seismological Phenomena of Japan.
Prof. J. Milne, F.R.S.—On Phenomena which might be observable,
if the Hypothesis that Harthquakes are connected with Hlectrical
Phenomena be entertained.
Section B.—Chemical Science.
Prof. W. C. Roberts-Austen, C.B., F.R.S., and Prof. A. W. Ricker,
F.R.S.—The Specific Heat of Basalt.
Section E.—Geography.
Dr. Phené.—Changes in Coast Lines.
Section H.—Anthropology.
E. Seward.—On the formation of a Record of the Prehistoric and
Ancient Remains of Glamorganshire.
Notices of Memoirs—A. R. Hunt—Start Point. 465
IJ.—Remarxks on THe Miocene Fisn-Fauna or Sarpinia. By A. ©
SmirH WoopwarD, F.G.S.!
HE author referred to a series of fragmentary fish-remains from
the Miocene in the neighbourhood of Cagliari, Sardinia, collected
and submitted for examination by Prof. D. Lovisato. A memoir
on the subject by Prof. F. Bassani (see infra, p. 476) had lately
appeared, and the present communication contained only brief sup-
plementary observations. In addition to the Selachian genera and
species recognized by Bassani, the author identified teeth of Scymnus,
Oxyrhina Desori, Galeus, Aprionodon, and probably Physodon, besides
dermal scutes of Trygon. The collection comprises no evidence of
ganoid fishes, and most of the remains of teleosteans are too imperfect
even for generic determination. Traces of Scomberoids and Labroids
occur, and there is evidence of a new species of the Berycoid
Holocentrum. Teeth of Chrysophrys, Sargus, and other common
Mediterranean genera are abundant; and a few detached yellow
teeth represent an indeterminable species of Balistes.
IJJ.—On tue Discovery or a New Species or Fossin Frise
(Srrepsopus Brockpavk1) 1x THE Uerrr Coan Measures
Livestonre or Levensuutme, No. 6 Group, From THE RAtLway
Currinc at LrvensHuLME, Near Manouester. By James W.
Davis, F.G.S. Mem. and Proc. Manchester Lit. and Phil. Soc.
[4], Vol. IV. 1891 (reprint paged 1-3).
ERY fragmentary remains of Strepsodus in the collection of
Mr. W. Brockbank, F.G.S., form the subject of this note.
“The teeth differ from those of Strepsodus sauroides, Young, in the
greater breadth in proportion to the length; the surface striation is
similar in the two, with the exceptions that in S. Brockbanki the
strize are larger, and there is no evidence of bifurcation, and whereas
in S. sauroides the base of the crown is ovoid and laterally com-
pressed, and the apex twice bent nearly at right angles, in this
species the base of the crown is circular, and the point is not twisted
to the same extent.”
IV.—On tHe Occurrenor or Derriran TourRMALINE IN A QUARTZ
ScuHist west or Start Point, Sourn Devon. By A. R. Hunt,
M.A., F.G.S8.1
HILE examining the Devonian cliffs near Street Gate at the
north-east end of Slapton Sands, South Devon, in company
with Mr. W. A. E. Ussher, F.G.S., the author selected a hard mica-
ceous sandstone of fine grain, occurring as a band between softer
rocks, for comparison with a micaceous quartzite or quartz-schist,
previously noticed by Mr. Ussher at a point on the coast south of
Start Farm and west of Start Lighthouse. The quartz-schist occurs
as an impersistent band among the mica-schists west of Start Point.
1 Abstract of paper read before Section C (Geology), Brit. Assoc., Cardiff, 1891.
DECADE III.—VOL. VIII.—NO. X. 30
466 Notices of Memoirs—A. R. Hunt—Start Point.
Mr. A. Harker, F.G.S., on examining the sandstone, at once
pointed out the presence of tourmaline and white. mica, of detrital
origin; and considered that the rock had the appearance of having
been derived from a tourmaline-bearing granite.
On a careful examination of two slides of the quartz-schist,’ the
author detected a single grain of tourmaline. Six additional slides
were forthwith prepared, and detrital tourmaline was found in them
all. One of these slides contains a pellucid grain of quartz with
fluid inclusions and active bubbles; another contains a grain crowded
with hair-like inclusions and with one fluid inclusion whose bubble
is easily moved by the heat of a wax match. Both these grains
could be easily matched in the quartzes of different granites.
The derivation of the quartz-schist from granites of more than
one character, but one of which must have been schorlaceous, seems
clearly indicated.
The above facts have two distinct bearings, viz. as to the age of
the metamorphic schists of South Devon, and as to the derivation
of the tourmaline. |
The two rocks under consideration, viz. the quartz-schist and the
Devonian sandstone, are related to each other in four particulars,
insomuch as they contain four constituents common to both, viz.
detrital tourmaline, detrital mica, quartz of fine grain, and iron.
It seems difficult to avoid the conclusion that such similar rocks
must be of like age and derivation; and that as the sandstone is
undoubtedly Devonian, the quartz-schist, one of the metamorphic
schists of South Devon, must be of Devonian age also, and not
Archean, as has been supposed by some geologists.
The derivation of the tourmaline is a more difficult question.
Whatever may be the age of the mass of the Dartmoor granites,
those of a schorlaceous character seem to be post-Carboniferous.
Moreover, no tourmaline has been noticed in the granites trawled
in the English Channel. There is thus no recognized source of
pre-Devonian tourmaline in the neighbourhood of South Devon, yet
the source of derivation of the rocks under discussion could not
seemingly be remote, or the tourmaline, quartz, and mica could
scarcely have kept together. The tourmaline granites of Cornwall
would meet the case, if any of these are of pre-Devonian age; but
on this point the author has no information.
Besides the tourmaline observed in the rocks at Street Gate and
Start Point, the author has noticed the same mineral, occurring in
the same way, in a sandstone from near Tinsey Head in Start Bay,
and in a sandstone from near Charleton on the Kingsbridge estuary,
both of Devonian age.
1 The hand-specimen selected for slicing was kindly placed at the author’s diposal
by Mr. A. Somervail, of Torquay.
Reviews—Dr. Munro’s Lake-Duwellings. 467
Tee aE Vi Ee EVV Se
I.—Tue Laxe-Dwe.iines or Hurore, BEING THE RuainD LeotuREsS
In ArcHmOLoGY For 1888. By Rosert Munro, M.A., M.D.
Royal 8vo. pp. xl. and 600, with 199 composite Illustrations,
containing 2172 separate Figures, and 14 Maps and Plans.
(London: Cassell & Company.)
VHE study of Prehistoric Man, or the attempt to discover
evidences of the early races who first occupied Hurope in
Prehistoric times, and to interpret these relics by a knowledge of
the habits and customs of existing aboriginal races, may certainly
be said to have been initiated near the end of the first half of the
present century. But the most important discoveries were actually
made within the second half; discoveries so vast in importance
in connexion with the history of the human race as to excite the
attention of the whole scientific world and to result in the develop-
ment of a literature devoted entirely to Prehistoric Archzology.
In Denmark, England, Belgium, France, Switzerland and else-
where, the stream of new light seemed never ending. Yet many of
these novelties had really been discovered long, long, before, but
no one seemed disposed to notice them, nor was any curiosity
expressed when their discovery was announced. Then why this
sudden enthusiasm ? Simply because the public mind had become
educated and was beginning to take an interest in natural science,
and men like Falconer, Prestwich, Lyell, John Evans, Lubbock,
Pitt-Rivers, Franks, Boyd-Dawkins and Pengelly in England ;
Lartet and Christy in France; Keller in Switzerland, and very
many others, were able, not only to discover, but to correctly
interpret and describe, what they found or saw. It is to the labours
and publications of these men that we owe the great advance in
Anthropological knowledge to which we have attained, and to the
general intelligent interest taken by the public at large in the
history of early man in Europe.
Following the sequence of these discoveries, we find primitive
man wandering and homeless, save for some cave, or rock-shelter ;
here as a bold paleolithic hunter of the Mammoth and the Woolly
Rhinoceros, or disputing his right to some cave with the Bear, the
Lion, or the Hyzna. There, as the humble shore-dweller, feasting
upon the oyster or the whelk, the limpet, or the mussel. Or,
again, engaged in making excellent harpoons out of Reindeer-antlers,
and manufacturing needles out of the leg-bone of the Horse;
leaving behind him abundant evidence of his prowess in the chase
in the form of well-carved or incised figures of these and other
animals, on their antlers or pieces of their bones; unrivalled as
a skilful worker in flint and other stone, from the rough to the
polished implement of perfect beanty. Nor is this all,—for in those
districts of Europe where rivers and lakes abound, we learn that
certain Neolithic peoples—probably at a somewhat later period—
occupied their shores and banks as mixed fishers, hunters, and even
as early agriculturists—if their garden-patches may have deserved
468 . Reviews—Dr. Munro's Lake-Dwellings.
that name; and being possessed of more worldly gear than the
earlier Cave-Dwellers, and, though living in communities, were yet
a peaceful and less warlike race; they had invented a system of
fortified habitations, raised above the level of the water, by means
of piles driven into the bed of the river or lake, bearing a platform
of horizontal timbers upon their tops, on which the dwellings were
placed. These lacustrine habitations were sufficiently far from the
shore to protect them from enemies, and yet near enough to be
approached by a narrow bridge which could easily be removed or
destroyed in case of a hostile attack from the land.
The relics of these dwellings first attracted attention at Ober-
Meilen, on the east shore of Lake Zurich, during the winter of
1853-654, when, owing to the extreme lowness of the water of the
lake, the heads of numerous wooden piles were exposed, around
which were portions of Stag’s antlers, stone hatchets and other
implements which excited some curiosity. Other finds followed
and led to the subject being taken up by Dr. Ferdinand Keller,
President of the Antiquarian Association at Zurich, to whom the
world is indebted for making known one of the most remarkable
archeological discoveries of this century,—a discovery which in its
consequential results is unique for the variety and wealth of mate-
rials with which it has. illustrated that singular but long unknown
and forgotten phase of prehistoric civilization in Europe, which
found its outcome in the habit of constructing dwellings in lakes,
marshes, ete.
Dr. Keller’s researches were most extensive and were made known
in a series of exhaustive reports sufficient to fill many volumes.
They were first translated and the plates redrawn and published in
English by Mr. John Edward Lee, F.S.A., in 1866; but, in ten years,
Keller’s continued researches in Switzerland had so grown, that, to
keep pace with them, a second edition was required extending to
two large volumes.
«Since then, however (1878), the results of lacustrine researches
have been greater and more important than during any previous
corresponding period. The ‘Correction des Haux du Jura,’ together
with various harbour alterations in the lakes of Zitirich, Geneva,
etce., have been the means of enormously increasing the lacustrine
collections of Switzerland. In North Italy not only have new
and remarkably interesting lacustrine stations been discovered and
exhaustively investigated, as Lagozza and Polada, but the researches
in the terremare have been such as to entirely alter the previous
opinions held in regard to them. Nor has the progress in this field
of research in many other countries in Europe been scarcely less
important: in proof of which I have only to mention the additions
made to the Scottish and Ivish crannogs; the curious fascine-struc-
tures brought to light. in Holderness, Yorkshire, the novel revela-
tions extracted from the é¢erp-mounds in Holland, and other low-
lying districts on the coast of the German Ocean; the greatly
extended and more accurate details of lacustrine structures in North
Germany ; the discovery in Hungary of prehistoric mounds analogous
Reviews—Dr. Munro’s Lake- Dwellings. 469
to the terramara deposits of Italy, ete. In short there is hardly any
corner of the lake-dwelling area in Europe which has not yielded
new materials, throwing more or less light on this strange phase of
Prehistoric life.”
The present volume, Dr. Munro tells us, originated with the
Society of Antiquaries of Scotland, who offered him the Rhind
lectureship in Archeology for 1888, and suggested that the course
of six lectures should be on the “ Lake-dwellings of Europe.”
These lectures are here printed in extenso, and are very copiously
illustrated by drawings of all the most typical antiquities discovered,
prepared as far as possible from the actual objects by Dr. and Mrs.
Munro, who perambulated the whole of Central Europe with note-
and sketch-books in hand visiting, as far as practicable, the sites of
lake-dwellings, and searching museums and libraries wherever they
thought such relics or records were to be found.
“The eastern limit,” we are told, “of the region thus visited may
be represented by a line drawn from Konigsberg to Trieste, passing
through the intermediate towns of Krakow, Buda-Pesth, and Agram.
The materials brought together from this area are, to a very con-
siderable extent, absolutely new to British archeologists.” Care
has also been taken, as far as possible, not to repeat illustrations
given by Keller’s translator, except where the objects are the best
or the only representatives of their kind. To show how well
Dr. Munro has carried out his task, and how great is the area over
which he has travelled, we must consult the work itself; indeed, it
is one which every student of prehistoric archeology must possess
in order to be posted up to date in all the researches which have
been carried on since the date of the last English edition of Keller’s
work.
The first lecture gives an account of the earliest discovery of Lake-
dwellings; the settlements of the shores of Lake Ziirich; those of
Western Switzerland and France (pp. 1-109). Some idea may be
formed of the vast number of objects of ornament, weapons, and
articles of domestic use, in stone, bronze, earthenware, iron, bone
or wood, delineated in this work, when we find that in the 23 page-
illustrations to the first lecture alone, there are 517 separate figures
engraved.
The second lecture (pp. 110-185) deals with the settlements in
Eastern Switzerland, the Danubian Valley, and Carniola. Here is
given an account of some curious traps made of wood which have
been found in settlements as widely separated as Ireland, North
Germany, Styria, and Italy, which it is suggested may have been
used as Beaver or Otter traps. As many as 52 individual remains
of the Beaver were obtained at Laibach alone, where these supposed
beaver-traps were also met with. Four hundred and fifteen objects
are figured in the text to illustrate this lecture.
The third lecture (pp. 186-276) treats of the Lake-dwellings and
pile-structures in Italy, including the Terramara Settlements in the
Po Valley, which are illustrated by 527 figures in the text.
The fourth lecture (pp. 277-348) describes the remains found at
470 Reviews—Dr. Munro’s Lake- Dwellings.
La Téne and in the Lake of Paladru; also the Lacustrine and
Marine dwellings in. the Lower Rhine District and in North
Germany; two hundred and eighty-five of the antiquities from
which are illustrated in the text.
The fifth lecture (pp. 349-494) treats of the Lake-dwellings of
Great Britain and Ireland, describing the Scotch and Irish Crannogs,
ete., with two hundred and seventy-four illustrations.
The sixth and last lecture (pp. 495-554) deals with the liaise
dwellers of Europe, their Culture and Civilization ; and is illustrated
by 154 figures; making a total of 2172 objects figured, besides
fourteen maps and plans.
The protracted period of time represented by these pile-dwellings
is attested both by their wide geographical distribution, and by the
fact that some flourished at a time when the use of metals was
entirely unknown to their inhabitants, as all the tools and weapons
recovered from the débris were made of such materials as stone,
bone, or antlers of deer, etc. The substitution of bronze for these,
marks a decided change in the culture and civilization of the
Lake-dwellers—a change which becomes further modified by the
introduction of iron.
‘““We have thus a great variety of lake-dwellings, distinguishable ~
from each other generally by the character of their industrial
remains, according to the particular civilization which prevailed at
the period of their habitation, some dating back from the pure Stone
age, others from the Bronze age, while others again bear the imprint
of various later civilizations, as Roman, Celtic, Carlovingian, Slavish,
etc., clearly proving their continuance in various parts of Hurope
for a very long period extending from the Neolithic age to the dawn
of written history.”
“In hazarding an opinion as to the original founders of the lake-
dwellings of Central Hurope (writes Dr. Munro), I would say that
they were part of the first Neolithic immigrants who entered the
country by the regions surrounding the Black Sea and the shore of
the Mediterranean, and spread'westwards along the Danube and its
tributaries till they reached the great central lakes. Here they
founded that remarkable system of lake-villages whose ruins and
relics are now being disinterred as it were from another or forgotten
world.
Those following the Drave and the Save entered Styria, where
they established their settlements on what was then a great lake at
Laibach. From this they crossed the mountains to the Po valley,
where they founded not only the pile-villages, but subsequently the
terremare. The Danubian wanderers having reached the upper
sources of the Danube, crossed the uplands by way of Schussenried,
and arrived on the shores of Lake Constance, from which they
quickly spread over the low-lying districts of Switzerland. From
Lake Neuchatel, still continuing a westward course, they reached
the Rhone Valley by way of Morges, where they erected one of their
earliest and largest settlements. From the Lake of Geneva they
had easy access to the lakes of Annecy and Bourget.”
Reviews—J. F. Whiteares’ Fossils of Manitoba. ATI
“ After the collapse of the great Lake-villages it is not singular to
find that a knowledge of the system remained among the surround-
ing nationalities, which subsequently germinated into activity in
various sporadic corners, and produced not only the Scottish and
Irish crannogs, but the analogous remains in Friesland, North
Germany, Paladru, etc. As the great extinct mammals are known
to have lingered in the recesses of mountain-ranges and other
secluded localities, so the artificial islands or crannogs and other
lake-habitations of the Iron Age are but the deteriorated remnants
of a doomed system which, like every dying art before final ex-
tinction, passed through a stage of decay and degeneration.” Dr.
Munro’s book has afforded us no small pleasure and profit in its
perusal, and we congratulate both Dr. and Mrs. Munro on the
excellence and abundance of the illustrations, which bespeak a real
love of the graphic art.
A descriptive catalogue of all the objects illustrated in the text,
also a copious index, and an exhaustive bibliography of lake-dwelling
researches in Hurope, give to Dr. Munro’s volume a completeness
which is, alas! too often wanting in scientific works.
IJ.—Descriptions oF somE New or Previousty UNRECORDED
Spectres oF Fossins From THE Deyontan Rocks or MANITOBA.
By J. F. Wuirzaves. From Trans. Roy. Soc. Canada, Section
IV. 1890, pp. 98-110, Plates IV. to X. (Montreal, Dawson
Brothers.)
ITH the exception of Stringocephalus Burtini, the species de-
scribed in the present paper are new. They are as follows :—
PELECYPODA. CEPHALOPODA—continued.
Modiomorpha attenuata. Actinoceras Hindi.
Megalodon subovatus. Gomphoceras Manitobense.
Orthonota corrugata. Cyrtoceras occidentale.
Cienenonant Homaloceras (gen. nov.) planatum.
Tetragonoceras (gen. noy.) gracile.
Gyroceras Canadense.
Jilicinetum.
submammillatum.
Pleurotomaria goniostoma.
Huomphalus Manitobensis.
”
CEPHALOPODA.
Orthoceras (Thoracoceras) Tyrrellit.
In the Report of Progress of the Geological Survey of Canada for
1874-75 (p. 68), “a Brachiopod resembling Stringocephalus” was
recorded from ‘the western shore of Dawson Bay,” Lake Winne-
pegosis, ‘from slabs apparently derived from the neighbouring cliffs.”
Collections made during 1888 and 1889 by the author and Messrs.
Tyrrell and Dowling in the neighbourhood of Lakes Manitoba and
Winnepegosis, included a remarkably fine series of specimens which
the author considers to be specifically identical with the Stringo-
cephalus Burtini of British and Huropean areas. ‘They present
nearly all the variations in external form which that protean species
assumes,” and some exhibit the internal characters. ‘The only
appreciable characters in which the Manitoba specimens seem to
differ from British or European ones are, that in the former the
loop in the dorsal valve is much broader proportionately, and the
bP)
472 Reviews— J. F. Whiteaves’ Fossils of Manitoba.
muscular impressions, which, however, are very indistinctly defined,
were probably longer.”
At Lakes Manitoba and Winnepegosis, all the species described in
the paper, with the exception perhaps of Gomphoceras Manitobense,
and Gyroceras submammillatum, were associated with this Brachiopod,
a shell which, in Europe, occupies a definite horizon in the Middle
Devonian.
Although based upon very meagre material, the species referred
to the genus Modiomorpha can, it is believed, “be recognized at a
glance by its unusually large size and narrowly attenuated form,
although it is by no means certain that it is correctly referred to
this genus.” Since the hinge is not well preserved in any of the
specimens collected, the species assigned to the genus Megalodon
is provisionally referred to that genus on account of its “strong
resemblance in external structure to the M. truncatus and M. rhom-
boidalis of Goldfuss from the Devonian rocks of the Hifel.”
Of the two new Gasteropods which are described, viz. Plewroto-
maria goniostoma and Huomphalus Manitobensis, the latter is stated
to be one of the most abundant and characteristic fossils of the
Devonian rocks at Lakes Manitoba and Winnepegosis. In addition
to detached opercula, oné specimen has been found in which “the
shell is so broken as to show its operculum in situ, though a little
displaced from its normal position.”
A remarkable species of Orthoceras is described under the name
O. (Thoracoceras) Tyrrellii. It has a marginal siphuncle and is
ornamented with transverse plications and longitudinal ridges, each
point of intersection of a transverse plication with one of the longi-
tudinal ridges being marked by a short, slightly curved spine. The
author observes that it “seems to belong to that group of the
Orthocerata for which Fischer de Waldheim proposed the generic
name Melia in 1829, though, finding this preoccupied, he changed
it to Thoracoceras in 1844.” Fischer gave as the type of the genus
Thoracoceras, Th. vestitum—a species with a rather small, sub-
marginal siphuncle, and ornamented with spinose, longitudinal
ridges. Although adopted by some subsequent writers, the genus
has been variously interpreted. According to Prof. Hyatt, who
regards the genus as valid, it includes “all those longicone species
in which the ridges become spiny or are roughened by the promi-
nence of the transverse striz or ridges,” and also such forms as
Cyrtoceras corbulatum, Barrande, Cyrt. canaliculatum, de Koninck and
Cyrt. Puzosianum, de Koninck. The author adopts Thoracoceras,
but regards it only as a subgenus of Orthoceras.
The figure given of Gomphoceras Manitobense certainly bears atte
the author’s statement that the anterior end of its body-chamber
appears to be more like that of Poterioceras. ‘The species, however,
is rather donbtfully referred to the genus Gomphoceras on account
of its general resemblance to the G. eximium of Hall.
Two new genera of Cephalopoda are described, viz. Homaloceras
and Tetragonoceras. The former is thus characterized—“ Shell con-
sisting of, a slender tube which is broadly and strongly arcuate,
curved in the same plane and much flattened laterally, its venter or
Reviews—Hugh Miller’s Landscape Geology. 473,
outer border being very narrow, truncated and depressed in the
centre. Sutural line consisting of two very narrow saddles with
an equally narrow sinus between them on the venter, a broadly
concave sinus or lobe on each of the sides, and a rather narrow
saddle on the dorsum; siphuncle in the only species known, cylin-
drical, exogastric, and placed near the venter or outer and convex
margin. Body-chamber long, occupying about one-third of the
entire length.”
The author is doubtful as to which of Prof. Hyatt’s families the
genus should be referred, but he is “inclined to regard it as an
extremely aberrant member of the Hercoceratidee.”
The other new genus—Tetragonoceras—is proposed for a loosely
coiled shell with a quadrangular transverse section. ‘Cyrthoceratites”
tetragonus, d’Archiac and de Verneuil, from the Middle Devonian of
the Hifel, also has a quadrangular transverse section, but according
to Prof. Hyatt’s statement, this species, which he places in his genus
Centroceras, appears to have been a true close-coiled Nautiloid.
Of the three new species of Gyroceras, G. Canadense and G.
filicinctum are very like the G. Hifelense from the Middle Devonian
of the Hifel, while G. submammillatum bears a most striking resem-
blance to an internal cast of the well-known G. ornatum from the
same horizon and locality. Gare:
I]I.—Lanpscare Grotocy: a Pua For THE Stupy oF GEOLOGY BY
LanpscaPe Painters. By Hueu Miuimr, of H. M. Geological
Survey. 8vo. pp. 63. (Edinburgh and London, William Black-
wood and Sons.)
| eae pictures exhibited in the Royal Academy have at times been
subjected to criticism in the pages of “ Nature.” The repre-
sentation of clouds, waves, the apparent size of the Moon, and the
delineation of rock-structure, have in turn undergone praise or
stricture ; and it would seem that the unhappy Landscape Artist need
make acquaintance with Astronomy and Meteorology, with Geology.
and Physical Geography, and with Botany and Zoology, if he or she
wishes to escape the scientific critic. But the plea of the Artist is
that he essays to represent things, not necessarily as they are, but
as they appear to him; and Mr. Briton Riviere (quoted in the work
before us) says, “It is the personality of the artist, the impress on
the work of the artist’s own mind and intention, adequately ex-
pressed, which gives the art.” Hence, “It is possible for a picture
to be scientifically true and have no art at all in it; and, on the
other hand, to contain several scientific blunders, and yet to be a
great work of art.”
No one will find fault with the Artist for representing things as
they appear to him; but in pictures that aim to be topographical, it
is desirable that the outlines of hill and mountain, of crag or scarp,
should bear some relation to the anatomy of the earth. Mr. Miller
disclaims any desire to go geologizing through the picture galleries,
though he agrees with the critic who says, “Is it too much to ask
that the artist shall not give us slate where there is only gneiss, or
granite boulders where there are none ? ”
474 Reviews—Hugh Miller’s Landscape Geology.
The author remarks that Geology, like all the teachings of Nature,
will be found to be fraught with Poetry, and he urges that it is
possible to convey some poetic expression of past time as well as of
modern agents in the delineation of both mountains and rocks. He
points out the position of blocks in a torrential stream, with their
plane sides sloped gently towards the current; and to the shapes
and altitudes of boulders on a hill slope. Artists, he says, as a rule
look upon rocks as in themselves rather expressionless objects, but
he urges that much expression may be given to them when attention
is paid to their texture, structure, and colour. He would ‘make
the varying aspects and colouring of rocks the object of special
studies—not forgetting that it is possible to find varying expression,
and, so to speak, a different handwriting, or perhaps hidden ciphers,
in the same rock from day to day.” In these and other remarks he
endeavours to show that Geology taken in connexion with the
physical aspect of the country may be studied as an exercise for the
imagination. |
He would wish the artist to ‘open his mind to ideas of strange
vicissitude and awful age in connexion with rocks and mountains,”
though the mountains be depicted “not as rent and’ torn by dis-
rupting forces from within, but as wasted and sculptured by the
forces of ‘denudation’ at work without.”
In this way Mr. Miller maintains that some acquaintance with
Geology would be to the Landscape-painter what a knowledge of
History is to the painter of historical subjects. It would help and
inspire him in giving expression to his subject.
It is often urged that Geology, dealing for the most part with
pre-human periods, can yield little material for poetic minds. The
author himself observes, ‘Ruins are pregnant with human asso-
ciations ; rocks have none.” But Geology blends its History with
that of Man and many associations may be called up, directly or
indirectly, in the imprints of the past upon the present.
Referring to the Scenery of Scotland Sir Archibald Geikie has
remarked that if the Geologist ‘‘can only present his results in
simple and intelligible guise, they will be found in no degree to
lessen the charm of the sceuery. He cannot diminish the romance
that hangs like a golden mist over the country; on the contrary,
he reveals another kind of romance, different indeed in kind but
hardly less attractive, wherein firth and fell, mountain and glen,
glow with all the fervour of a poet's dream.” The same writer
adds, ‘‘ Let me, however, assure him [the reader] at the outset that
if the human associations of the land are uppermost in his mind
as he wanders through it, my sympathies are wholly with him.”
A Geology made easy for Landscape Artists is still a desideratum.
There is need of a work that would simply describe types of rock-
structure and the relations between various rocks and the form of
the ground. Mr. Miller has in the little book before us discussed
his subject in such choice language and in so poetic a spirit, that
we are led to hope that he may supplement his plea by some more
practical guide for the use of the Landscape-painter.
Reviews—Tertiary Fishes. 475
IV.—Trrtiary Fisues.
1. Neve UnrersucHunGEN aN TERTIAREN FiscH-OTOLITHEN. By
Prof. Dr. Ernst Koken. Zeitschr. deutsch. geol. Ges. 1891,
pp. 77-170, Pls. I—X. Woodcuts 1-27.
2. PALAEOICHTHYOLOZEI PRriLozi(CoLLECTAE PALAEOICHTHYOLOGICAE).
Part Il. By Dr. D. Goreanovié Krampercer. Rad jugoslav.
Akad. 1891, pp. 78, Pls. VIII.
3. ContRIBuTO ALLA PaLzonroLociA DELLA SarpeGNna. ITTIoLIT1
Miocenicrt. By Prof. Francesco Bassani. Atti R. Accad. Sci.
Napoli, Ser. 2, Vol. IV. Mem. No. 3, 1891, pp. viii.+60, Pls. II.
4, UEBER EINEN MIT HYPEROSTOTISCHEN BILDUNGEN VERSEHENEN
ScHADEL EINES SUBFossILEN Pagrus von Muxgourne. By Prof.
Dr. W. Dames. Sitzungsb. Ges. naturf. Freunde Berlin, 1890,
pp. 162-167, Woodcut 1.
5. ScIAME DI PxEScr FOSSILI RICOPRENTE UNA LasTRA DiI CALCARE
mARNosO. By Dr. Carto Pouuint. 8vo. pp. 1-8, Pl. I. (Milan,
1891.)
R. ERNST KOKEN, now Professor at Konigsberg, is con-
tinuing his well-known researches in the determination of
fish-otolites; and his latest contribution to the subject, mentioned
above, concludes with some general remarks of much interest. It
is a surprising fact that a large number of groups of fishes that
must have existed from early Tertiary times are scarcely, if at all,
represented by tolerably complete fossil skeletons, or by readily
recognizable fragments. If, however, Dr. Koken’s determinations
of the fossil otolites are well founded, this circumstance is proved to
be merely another example of the imperfection of the ‘“ geological
record”; and whole groups of which the paleontologist has hitherto
known almost nothing are shown to occur in comparative abundance
at certain horizons in several classical localities. Of the Gadidee
much evidence of the genera Gadus, Morrhua, Merlangus, Raniceps,
and Merluccius is recorded, especially from the Oligocene of Germany.
Many otolites of Ophidiide are also discovered in the same horizon,
but the genus Fierasfer alone can be more precisely determined.
Macruridz seem to be recorded among fossil fish-faunas for the first
time ; otolites of Macrurus itself being recognized in the Pliocene of
Tuscany, and some generically indeterminable specimens occurring
both in the Lower Oligocene of Lattdorf and in the Senonian of
Siegsdorf. With reference to the latter, Dr. Koken remarks that he
does not consider either of them abyssal forms, but more nearly
approaching the typical Gadide. Of the Anacanth Flat-fishes even
otolites are scarce and very difficult to determine. Platessa and
Solea are recorded from the German Oligocene, and the former also
occurs in the Phosphates of Alabama. The remarkable Berycoid
genera Hoplostethus and Monocentris are believed to be indicated by
otolites from the Eocene of Copenhagen, the Oligocene of Germany,
and the Pliocene of Tuscany ; and undetermined genera of the same
family are also recorded from the German Oligocene. Scizenidz are
well represented in the Upper Oligocene and Miocene. Most of the
Percidz are as yet generically indeterminable, from want of recent
476 Reviews—Tertiary Fishes.
material for comparison; and the same remark applies to the
Gobiide. Sparide, as might be expected, are widely distributed ;
and the Cataphracti seem to be represented in the German Middle
Oligocene by the genera Trigla, Peristedion, and Agonus. ‘These
determinations, as Dr. Koken points out, add considerably to the
material available for a discussion of the distribution of the Tertiary
Teleostean Faunas in Hurope; and the author is finally tempted to
devote no less than seventeen pages to a treatise on otolites in
reference to their bearing on the classification of Fishes.
Dr. Kramberger’s new work is of a different character from that
of Dr. Koken, being based upon a series of remains of skeletons,
which are beautifully figured in the accompanying plates. It is
unfortunately written in a language that few can read; but the
scientific diagnoses and principal headings are also given in Latin
and thus made accessible to all. There are seven short chapters
relating to as many fish-faunas, chiefly Tertiary ; and several new
Species are determined. The first chapter deals with Cretaceous
species from Lesina, already described under the names of Clupea
lesinensis, Scombroclupea macrophthalma, Thrissops microdon, Hemielo-
popsis Suessi, and H. gibbus. ‘The second chapter is more extensive
and relates to the marine fishes of the Aquitanian Formation of
Styria. Here several new species are determined and named re-
spectively Labraw latus, L. Mojsisovicsi, L. sagorensis, Sparnodus
inflatus, Lichia alia, Zeus Hoernesi, and Z. robustus. A supposed
Leuciscus (L. eibiswaldensis, sp.n.) is also represented by an im-
perfect skeleton from the freshwater beds of Hibiswald in Styria,
associated with Leuciscus macrurus, Ag., and Gobius brevis, Ag. sp.
Teeth from the Miocene of the neighbourhood of Agram are dis-
cussed in chapter iii. and referred to Chrysophrys, Aetobatis,
Hemipristis serra, and Sphyrna cf. prisca. The fish-remains of the
well-known Sarmatian beds of Croatia form the subject of chapter iv.
and include some new forms, notably Syngnathus affinis, Apostasis
(gen. nov. Acronuridarum) Sturi, A. croatica, Scomber (Ausis)
sarmaticus, Blennius fossilis, Atherina sarmatica, and Labrus (Crent-
labrus) Woodwardi. The generic name Metoponichthys is relegated
to the synonymy of Proantigonis among the Carangide. Chapters
v. to vil. are brief notes on fragments, of which the most striking
are the remains from the late Tertiary beds near Sofia, Bulgaria,
described under the new specific name of Lucioperca Skorpili.
Thanks to the explorations of Prof. Dr. D. Lovisato, of Cagliari,
some information concerning the Miocene fish-fauna of Sardinia is
now forthcoming. In the memoir quoted above Prof. Bassani has —
employed the new material not only for detailed descriptions but
also as the basis of an elaborate treatise on the distribution of some
of the commonest Tertiary Selachian teeth. Carcharodon megalodon,
C. auriculatus, Galeocerdo aduncus, G. minor, Hemipristis serra,
Lamna salentina (including “ Otodus Lawleyi”), Notidanus primi-
genius, Odontaspis contortidens, O. cuspidata, Oxyrhina hastalis, Sphyrna
prisca, and a species of Squatina are recognized among the Selachian
teeth ; and unsatisfactory fragments of dentition of Teleostean fishes
Reviews—Permian Fishes. ATT
are assigned to Ohrysophrys cincta, Dentex, and Thyrsites Lovisatot
(sp. nov.).
Finally, two smaller papers may be mentioned among recent
interesting contributions to knowledge of Tertiary fishes. Dr. Dames
has described the skull of a sub-fossil Pagrus from the neighbour-
hood of Melbourne, Australia, giving a good figure and discussing
the remarkable hyperostoses by which the cranial roof is character-
ized. Dr. C. Pollini publishes a photograph of a slab of marl,
probably from Aix-en-Provence, in the Genoa City Museum, dis-
playing a shoal of Lebias cephalotes, Ag. A detailed description of
this fish is given, and some remarks are added as to a possible
explanation of the occurrence of so large a number of individuals in
so small an area. Dr. Pollini has omitted to observe that Dr. Sauvage
some years ago (Bull. Soc. Géol. France [3] vol. viii. p. 445) pro-
posed to place L. cephalotes in a new genus, Prolebias—a subject
that might have been appropriately discussed after the detailed
description. A. 8. W.
V.—Tue Lower Permian Fisues oF FRANCE.
Erupes pes Gites Minféravx pr LA FrANcE: Basstn Hovurnuer Et
PERMIEN D’AUTUN ET D’Erinac. Fasc. III. Poissons Fossiles.
By Dr. H. E. Sauvacs. 4to. pp. 31, Pl. V. (Paris, Imprimérie
Nationale, 1890.)
HOUGH dated 1890, this interesting work on the Permian fishes
of the neighbourhood of Autun has only just been brought to
our notice. It is a well-illustrated, detailed account of a fish-fauna,
of which much has long been known; and it forms an appropriate
supplement to the memoirs of Prof. Gaudry, who has devoted
special attention to the associated Amphibian and Reptilian fossils.
After a brief historical and bibliographical sketch (in which the
only omission we detect is that of Egerton’s well-known memoir in
the sixth volume of the Geological Society’s Quarterly Journal), Dr.
Sauvage proceeds at once to a detailed description of the species,
The majority of the forms are Paleoniscid fishes related to the
Lower Permian genera, Paleoniscus and Amblypterus; three only
being referable to the lower orders, namely, an undetermined species
of Acanthodes, a Pleuracanth Elasmobranch, and a Dipnoan fish. The
generic name Amblypterus is employed in almost as extended a sense
as is adopted by Traquair, and five species are determined, including
two novelties. The so-called new genera Adua and Archeoniscus
(this name preoccupied by a well-known Isopod) are based on
characters which we venture to regard as of very doubtful value;
and we are inclined (with Traquair) to disbelieve that the fin-rays in
any of these fishes are invested with scales, as Agassiz originally
maintained, and as is now re-asserted by Dr. Sauvage. Moreover,
we cannot perceive much difference between the type-specimen of
fidua Gaudryi and Kgerton’s Paleoniscus Beaumonti, which Dr.
Sauvage appears to have overlooked. One small new species is
assigned to Paleoniscus, and another may possibly represent Rhadin-
ichthys. Finally, among the Palzoniscide is placed the fish originally
478 Reviews—J. W. Evans—N.E. Caithness.
named Pygopterus Bonnardi by Agassiz, not hitherto described. It
is gratifying at last to have a good figure and description of the
fossil to which this name refers; but we fail to recognize the
slightest resemblance to Pygopterus, and until Dr. Sauvage is able to
bring forward further evidence on the subject, we shall continue to
believe that P. Bonnardi is founded on part of the caudal region of
a Pleuracanth Elasmobranch.
Of the Dipnoan fish described by Gaudry as Megapleuron Rochet,
and of the Pleuracanth spine named by the same author Pleuracanthus
Frossardi, Dr. Sauvage merely reproduces the original descriptions
and figures. No allusion is made to Dr. Anton Fritsch’s observations
on Megapleuron, in which the rhomboidal scales are correctly,
as we consider, assigned to a fragmentary Paleoniscid mingled
with the skeleton. This correction is of importance, for it enables
“« Megapleuron” to be recognized as a typical Sirenoid Dipnoan.
There is now hope that Dr. Sauvage’s long-promised memoir on
the Paloniscid fishes of the Coal-measures of Commentry will not
much longer be delayed; and we await with interest the further
contribution to our knowledge of this intricate group of fishes.
A. 8. W.
VI.—Tue Gronoey or tae Nortu-Hast or Catruness, AnD A Dis-
CUSSION AS To THE AGE OF THE OLD Rep SANDSTONE OF THE
Norra or Scornanp. By Joun Wituiams Evans, LL.B., B.Sc.,
F.G.S. Pp. 48, with Sketch-Map. (London: Green, McAllan
and Feilden, 1891.)
N this pamphlet the author gives us the result of six weeks’
field-work in Caithness. The county is occupied almost entirely
by the Old Red Sandstone with coverings of Glacial Drift; it is to
the older formation that attention is now directed.
Murchison divided the Old Red Sandstone of Scotland into three
portions: the Lower, including the Arbroath flags, with Cephalaspis,
Pteraspis, and Pterygotus ; the Middle, including the Caithness flags,
with Osteolepis, Asterolepis, Pterichthys, etc.; and the Upper, in-
cluding the Dura Den beds, with Pterichthys, Holoptychius, etc.
Sir Archibald Geikie afterwards referred the Caithness flagstones
to the Lower Old Red Sandstone, and maintained there was no
evidence of any Middle division.
The observations of the author lead him to maintain that the
Old Red Sandstone of Caithness belongs entirely to the Upper
division; and he thus represents the succession of the Scottish
Upper Ob Red Sandstone :—
Sub-zone of Bothriolepis hydrophila, \
Holoptychius Flemingi, and Glypto- { Dura Den, etc.
pomus minor.
Zone of
Orcadian. Bothriolepis.
Sub-zone of Holoptychius nobilissimus
and Cricodus favosus.
Sif
S)
|
| Scat Craig, Clashbennie, etc.
\
Le of Microbrachius Dicki and Tristichopterus alatus.
SANDSTONE.
Caithness Flags, Orkney and Shetland beds, and the Old Red Sand-
stone of Cromarty, Gamrie, etc.
Basement Conglomeratic series.
Uprrr OLrp Rep
Correspondence—Mr. R. Lydekker—Rev. Dr. Irving. 479
CORRESPONDENCE.
THE STUDY OF MAMMALS.
Srr,—I am indebted to the reviewer of this work in your last
number for pointing out that the family Tritylodontide occurs twice
in the systematic table. Its second occurrence is not, however, as
he supposes, an inadvertent repetition, but a ‘‘ misprint” for Tricono-
dontide. Another slip occurs on p. 99, where in giving the range
of Oryx Persia stands instead of Syria. R. LypexxKer.
DYNAMIC METAMORPHISM ‘“AGAIN.”’
Str,—Personally I am sorry to be called upon to point out briefly
that Mr. Fisher (Guot. Mac. Sept. 1891, p. 480) has made the
mistake of substituting exclusion (or “outness”’) in space for logical
exclusion of one term from a series of other terms used in a train of
reasoning, and that this misconception seems to run through the
whole of his letter except the last paragraph. It is not Mr. Fisher’s
(P-—W) w, but the “last term” of the four which I had just
enumerated (p. 299), which is logically outside the other three. To
say that it is outside the cubic unit (not “element” of the mass,
on which the work is done, is something to which I am unable to
attach any meaning at all. The energy, to which the motion of the
train (in my illustration) is due, is dissipated (not annihilated or
necessarily ‘‘ converted” into some other form of energy) according
to the ordinary laws of thermodynamics, having been obtained as
heat from the potential energy of the fuel and atmospheric oxygen,
and utilized, while in‘a condition of high intensity (the H,O being
the carrier of the energy), to move the piston of the engine with the
load attached. In running down from a state of high intensity
(in which work can be got out of it) to a state of low intensity (in
which it is either absorbed by surrounding bodies, or passes off by
radiation into the general entropy’ of the universe), there is no
destruction, there is only dissipation, of energy; and when it is
thus dissipated, you cannot get any more work out of it. If energy
were (under the conditions specified) “stored up in the train,” after
it had come to a’standstill (the idea which was before my mind,
though, I fear, not explicitly stated), the train would be, after
translation, in a position of advantage with respect to motion, as
compared with its position before translation, which is absurd.
Certainly during the accelerating stage of translation energy is
being stored in the train, just as you store energy in the weight of
a clock in winding it up; but the same amount of energy is taken
out of the train in bringing it to a standstill, just as it is taken out
of the clock-weight, when it runs down. There is therefore no
more energy stored in the train, after it has come to rest, than there
is in the weight and works of a clock after it has run down. So in
the case of the rock-mass under consideration, the source of the
energy is gravitation. The work done on the rock is only a case of
1 «« Entropy”? in the sense in which the word was first used by Clausius.
480 Correspondence—Rev. Dr. Irving.
potential energy of position becoming kinetic, without taking aught
from the force, with which gravitation continues to act upon the
portion of the earth’s lithosphere, to whose descent towards the
earth’s centre of gravity the lateral thrust is due. The clock has
merely run down, asit appears to me. Work has been done, and that
work is the equivalent of the potential energy. In the infinitesimal
amount of molecular change in the iron (where bad material is
used), which I had overlooked, and Mr. Fisher recognizes as a case
of ‘‘dynamo-metamorphism,” we have indeed an excellent example
(so far as it goes) of metatropy resulting from the action of forces
purely mechanical, as I have contended for the last three years;
but as this is quite a different thing from what we understand by
chemical change, there is no “storage of chemical energy,” which is
the crux of the whole business.
Turning now to Mr. Harker’s rather donnish letter (p. 481), in
which he persists in regarding the phrases ‘“‘ chemical combination ”
and “chemical change or action” as convertible terms, I can only
say that there is nothing to be gained by discussing that point
further. The remainder of the paragraph is, I] think, answered by
anticipation in what I have already written. I certainly have main-
tained that ever since this globe began to cool down in space through -
dissipation of its energy by radiation, that cooling has been (and is
still) retarded by a considerable exothermic balance of heat, as
mineral changes in the lithosphere have upon the whole advanced
from less stable to more stable states of combination; and in doing
so 1 take my stand upon the broad teaching of thermal chemistry
in its recent development. It is there that Mr. Harker must look
for the “proof” that he wants. Perhaps Prof. Roberts-Austen’s
recent address to the Chemical Section of the British Association at
Cardiff may help him. To his appeal to an imaginary consensus of
“physicists” it is, I think, a fair reply that there are physicists and
physicists ; and that, although a good deal of what I have written
(in the GEonocican Macazine and elsewhere) may seem to some
of them to be written in an “unknown tongue,” I am happy to
know that there are others to whom it is all perfectly intelligible.
The term ‘intensity of heat,” for example, is used to emphasize
the inverse variation of absolute temperature in relation to dis-
tribution in time and mass (allowance being made for what Sir
William Thomson calls “diffusity”) for a given quantity of heat,
as velocity and mass are related in the momentum of a body in
motion. The term must stand on its own merits.
The importance of the indirect action of pressure in promoting
chemical change, by making the existence of superheated water
possible (the action of which is exceedingly well illustrated by the
recent work of Kroutschoff) is not, I think, lessened by the failure
of our two friends to appreciate it. There is surely in this a storage
of potential chemical energy. Why do they refuse to use the weapon
placed in their hands ? A Ulmvince
WeELuLiInGTon CoLLEGE, Berks, 8th September.
THE
GHOLOGICAL MAGAZINE.
NEW ceRIES. DECADE: Tl. VORA Till:
No. XI.—NOVEMBER, 1891.
Qe ese Acden | Asses lean @ abe
—_<—_@—___
I.—On Prevrovavrizus [ Navrinzus] Novoso-caRINATUS, ROMER, SP.
By Artuur H. Foorp, F.G.S.
HROUGH the kindness of Mr. A. OC. Seward, M.A., F.G.S., the
British Museum has been put in possession of a fine specimen
of this interesting species, collected by him in the Millstone Grit of
Caton, Lancashire. The species is there found associated with
Nautilus [ Pleuronautilus| armatus, J. de C. Sowerby,’ Solenocheilus
[ Nautilus | latiseptatus, de Koninck,? Actinoceras [ Orthoceras] sulca-
tulum, M‘Coy,* etc. These I have identified in a small collection
submitted to me by Mr. Seward.
Plewronautilus nodoso-carinatus.——a, lateral view, showing the ornamentation of the
test ; b, peripheral view, showing the deep median furrow, and the septa in the
lower half of the figure, where the test is absent. a, drawn from the original
specimen in the Woodwardian Museum, Cambridge; 6, from a specimen
presented to the British Museum (Nat. Hist) by A. C. Seward, Esq., M.A.,
F.G.S. Both figures are about two-fifths the natural size.
From the Carboniferous Limestone, Caton, Lancashire,
1 Tn Prestwich, Geology of Coalbrookdale, Trans. Geol. Soe. ser. ii, vol. v. pt. iii.
p- 492, pl. xl. fig. 8, 1840.
2 Faune du Calcaire Carbonifére de la Belgique (Ann. du Mus. Roy. d’ Hist.
Nat. de Belgique, tom. ii.), p. 110, pl. xxii. figs. 1-3 ? 1878.
3 Synop. Carb. Foss. Ireland, p. 8, pl. i. fig. 4, 1844.
DECADE III.—VOL. VIII.—NO. XI. 31
482 Rev. J. F. Blake—Precambrian Geology.
Actinoceras sulcatulum and Solenocheilus latiseptatus are common
in the Cement-stone (Upper division of the Carboniferous Limestone)
of the West of Scotland. I have myself collected them in the
Arden Quarry, at Nitshill, near Glasgow (see Cat. Foss. Ceph. Brit.
Mus. (Nat. Hist.), pt. i. 1888, Suppl. p. 319).
The present species has been well described, but poorly figured
by Armstrong (Trans. Geol. Soc. Glasgow, vol. ii. pt. i. sp. 74, pl. i.
figs. 6-7) under the name of Nautilus (Discites) nodiferus. Its
identity with Rémer’s species is, however, beyond question.
The following is Armstrong’s description :—‘ Shell discoidal,
composed of about three gradually enlarging, contiguous, nearly
subquadrate whorls, completely exposed in a moderately shallow
umbilicus; back broad, rounded at the edges, and traversed in the
middle by a wide and deep channel, on the sloping sides of which
are two fine thread-like ridges. The remainder of the space on
the back and sides of the shell is occupied by six rows of closely
set, prominent, obtuse tubercles, elongated in the direction of the
aperture, one row of tubercles of large size bounding the back, a
double row of equal size between it and the channel, and three on
the sides, which decrease in size towards the umbilicus. Surface
marked with coarse, squamose, wavy lines of growth, which are
arched backwards in the dorsal [=ventral, or peripheral] channel.
Septa numerous, their edges arched considerably backwards on the
periphery, and slightly so at the sides. Siphuncle -*; inch diameter,
central. Dimensions—width of greatest diameter 3} inches, width
of outer whorl near the aperture, 1 inch.”
The specimen presented by Mr. Seward is a valuable accession to
the British Museum collection, which hitherto possessed only some
small fragments of this beautiful species. ‘These are described in
part il. of the Catalogue of Fossil Cephalopoda (1891), p. 139, where
also Armstrong’s description of the species is quoted.
IJ].—On some Recent Contriputions To PrEcAMBRIAN GEOLOGY.
By J. F. Buaxe, M.A., F.G.S. |
HE last two numbers of the Quarterly Journal of the Geological
Society contain three communications concerning rocks which
are, or are thought to be, Precambrian. ‘Two of them are in direct
attack on work of mine, and the third incidentally opposes some
portion of it. The materials of any reply I may have to make are,
for the most part, already published in my papers, but the bearing
of these facts seems to require to be pointed out.
Taking the communications in order, the first is the Anniversary
Address of the President. In this he deals, so far as my work is
concerned, first with Anglesey. Sir A. Geikie states that he was
not prepared by previous writings for certain results he obtained.
He was much astonished to find in central Anglesey so striking a
counterpart to portions of the old gneiss of the north-west of Suther-
land and Ross. Speaking of the rocks which he here refers to, I
wrote, “he question is suggested whether we may not touch here a
Rev. J. F. Blake—Precambrian Geology. 483
piece of genuine Archean.”! This question Sir A. Geikie answers
offhand—by the guidance of petrographical characters—aided by the
hummocky surface of the ground, which latter, however, is not
confined to Archean gneisses. These petrographical characters I
have described,” and state that the rocks have “much the aspect of
a Highland gneiss”; but I do not think these characters may safely
“be taken as a guide” to age. There is certainly at this moment a
controversy whether they can be or not.
Sir Archibald then speaks as if no order of succession has been
made out in the Anglesey rocks, and as if their metamorphism was
the only argument for their Precambrian age in the strictest sense.
I would point out that near Beaumaris the Lowest Cambrian has
been shown to overlie them.
But the most important matter is the decision of the age of the
rocks of the Northern District which the Director-General now
considers to be Silurian. He states in the first place that “the
necessity for inserting” the bounding “fault apart from any actual
visible trace of its occurrence arose when the conclusion was arrived
at that the rocks at the extreme north of Anglesey were essentially
altered Cambrian rocks.” That is to say, it is a theoretical fault.
Dr. Callaway has given evidence for this fault, and my own state-
ment is: “In this Northern District a very definite sequence of
rocks may be demonstrated, . . . . We can follow the strike with
considerable accuracy. Now, whatever part of the series we may
be on from the lowest to the highest, and therefore whatever class
of rock is on the northern side of the fault, as soon as we overstep
that boundary we are immediately landed in black shales, which
have a pretty uniform character throughout. This leaves no alterna-
tive but a fault or an unconformity ; if it were an unconformity, the
upper group would run parallel to the boundary, which it does not.”
Whoever denies this fault, let him answer this argument, and also
explain how masses of Cemmaes Limestone come to be found in the
basal Silurian conglomerates.
In fact, however, this line is not in modern language a fault, but
a “thrust.” The Director adds: “Where the supposed elliptical
fault reaches the shore at Carmel’s Point, the two groups of rock
seem to me to follow each other in unbroken sequence.” So they
do to me, but things are not always what they seem. At Craig-an
Knockan, Ross-shire, and elsewhere, there is an apparent ‘* conform-
able upward succession” between Silurian rocks and the overlying
gneisses. The little bands of black slate caught up in the motion
in Anglesey are just what we might expect in a similar case.
Dealing next with the nature of the upper part of the rocks, some
of which have yielded fossils, he states that they include “ courses of
black shale containing Lower Silurian Graptolites”; also ‘it has been
supposed that-the higher bands of black shale may also have been
brought into their present position by faults” ... “but this suggestion
is completely disproved by the coast sections, which exhibit many
thin leaves of black shale, sometimes less than an inch thick.”
1 Q.J.G.S. vol. xliv. p. 497. 2 Rep. Brit. Assoc. for 1888, p. 32.
484 Rev. J. F. Blake—Precambrian Geology.
I am not aware that there are any courses (in beds parallel to the
rest) of black shale; the faults which let down the masses which
are said to have yielded Graptolites may be seen on both sides. If
there are thinner black shale bands which I have not observed, that
is, no doubt, a point to be considered; but it could only be decisive
if they contained Graptolites of known Silurian species.
The Director sums up by saying that this area “is proved by the
evidence of fossils at its base, towards its centre, and at its top to
belong to the Lower Silurian series.” This sounds like a settled
matter. But may I ask (or rather can I get an answer to the
questions ?) What is the lowest bed of the series above the Black
Shales? What are the names of the supposed Silurian fossils it
contains ? and where inay they be seen? All Sir A. Ramsay says
is, “ On the north by the shore a few poor fossils in irregular bands
of limestone clearly indicate the Caradoc or Rala age of some of
the beds.” What are the names of the Graptolites which occur
towards the centre? and what is the proof that Orthis Bayleana is
a Bala fossil ?
The arguments generally for the Monian age of these northern
rocks are these: The volcanic group is more or less repeated in
various parts of the island. It must be admitted, however, that those
that most resemble these northern rocks do not clearly show their
stratigraphical relations. The quartz knobs and limestone masses
which are found amongst them also characterize parts which are
admittedly Precambrian. It may be said against this that these
may be of several ages; but it is strange that they occur only in
Anglesey and amongst these rocks. Bala rocks are known in the
island as black shales proved to be Bala by their named fossils (see
Mem. Geol. Survey, vol. iii. p. 225), including Orthides ; but none of
these are O. Bayleana, and it would be strange that, the volcanic —
rocks of different ages should be so similar north and south, and
rocks of the same age so different in the centre. If all these
arguments could be met and the volcanic group were accepted as
Bala, the next alternative would be that of Sir A. Ramsay, to
consider part Silurian and part Cambrian, the line of separation
being obliterated by the squeezing. Otherwise, if all were Bala,
we should have identical chloritic schists at Llanflewin and Abersant,
the former Bala, the latter overlaid unconformably by Arenig grit,
to say nothing of similar rock overlaid by the same at Carmel’s Point
and Treiorwerth.
I have next to notice the reasons given for rejecting the term
“Monian” for a series of rocks in Scotland, of which it can be
written, “No one familiar with the Dalradian rocks of Scotland and
Treland can fail to be struck with the close resemblance which these
younger Anglesey schists bear to them, down even to the minutest
details,” and ‘‘if we are justified in grouping these Anglesey rocks
with the Dalradian schists.” I will not say that, if by ‘‘ Dalradian ”
is meant the whole of the seventeen groups enumerated, these reasons
as a whole are not well founded, since in that case it may include
more than one system, of which, to judge from the statements made
Rev. J. F. Blake—Precambrian Geology. 485
and if petrography can be shown in this case to be a safe guide, the
Monian is certainly one. But on the next page (75) it is stated that
Dalradian is proposed for the “crystalline schists” alone. In a
note he says that the Monian includes Archean gneiss. This it
does not do, for if the rocks which I suggested might be Archean
gnéiss were proved to be so, that fact would exclude them from the
Monian; and if they are not Archean gneiss they are foliated
granite, and as such form no part of the system. Also that it
includes “strata, volcanic and fossiliferous, of undoubtedly Bala age.”
But even if this could be proved, these strata could be eliminated
from the Monian without destroying its existence or making it
much smaller.
I now pass to the next paper by Dr. Callaway “ On the Uncon-
formities between the Rock Systems underlying the Cambrian
Quartzite in Shropshire.”
The first question dealt with is the age of the ‘“ Volcanic series ”
or Uriconian. This I concluded to be younger than the Longmynd
shales. The evidence I brought forward for this was entirely
original, for Dr. Callaway never discussed the question at all, to my
knowledge, and even now he does not bring forward a shred of
positive evidence that it is older. He says they are faulted together,
in which case either might be the younger. The fact is he proved
the Uriconian to be older than the Cambrian Quartzite, and assuming
the Longmynd shales to be Cambrian also, that carried the point.
Even now, I can scarcely regard its younger age as definitely proved ;
it may be that they are more or less contemporaneous in spite of
any difference of strike. All I can say is that all the evidence
available is most in favour of the voleanic series being younger ; and
actually Dr. Callaway’s own statements are primd facie to the same
effect. Thus he refers to a locality on the S. E. of Ragleth (which
after careful searching I failed to find) where shale like the Long-
mynd shale is overlaid by red felsite. Again, he states that near
Hazler cottages the Longmynd slate near its junction with the
Uriconian “has a burnt appearance and the cracks are injected with
red felspar.”
He next refers to the Pontesford Hill area, and says that the rocks
next the rhyolite are not altered. Assuming that they are not,
though ‘to my mind they certainly are, the section is still proved by
stratigraphy to lie above the whole of the Longmynd series. It is
difficult to understand the gist of the concluding sentence: ‘‘ As
this crucial case breaks down on examination, I thought it needless
to re-examine the other masses of Uriconian which appear on the
line of the great Pontesford Linley fault.” If it means that because
in his opinion I am in error about the alteration (in common with
Sir R. I. Murchison, who seems to have examined this district more
thoroughly than any one else), therefore I am unworthy of credence,
his paper might have conveniently stopped there.
Turning next to the unconformity in the middle of the Longmynd,
he selects for sole examination the section at Narnells rock. I give
the junction as it is actually seen, and this is what I say about it.
486 Rev. J. F. Blake—Precambrian Geology.
“The grit is here seen to be unconformable, but the evidence is
scarcely satisfactory or conclusive. If it had been conformable, the
motion which is indicated by the slickensides might easily have
produced the amount of unconformity apparent.” Dr. Callaway
says just the same, “‘The grit appears to have been a little squeezed
into the slate, so that here and there a trivial unconformity is
apparent.” According to his section, which, by the way, is not
what is seen at any one spot, but is made up from several exposures,
all the rocks have the same dip, so there is an apparent conformity.
Tt is not easy to see how an apparent conformity combined with
an apparent unconformity can “absolutely disprove” the reality of
either one or the other. My deduction is that the evidence here is
not conclusive. But other evidence is, or at least is put forward as
such, but it is not tackled by the critic.
With regard to the conglomerates and grits found on the “ Volcanic
Hills” being superficial or otherwise, it will be well to state what
I regard as evidence of a rock being superficial. When the boundary
of a rock is of an irregular kind, like the outline of a map, and is
surrounded on all sides by other rocks which have a more definite
strike, particularly if its boundary is nearly horizontal and follows
approximately the contours of the present valleys, I take it to be
superficial. In proportion, of course, as these features are wanting,
the evidence is less satisfactory. They are all fulfilled by the grit
on Caidington Hill. I am not at all sure that Dr. Callaway has seen
this patch, for the rock which composes it is not like the Woodgate
quarry rock. As to Charlton Hill, Dr. Callaway gives a section,
but this section is not seen, but inferred. The map I give is what
is actually seen, and this proves the inference to he wrong. I am
sorry to say that this map, on p. 410, is so small that it requires
a lens to examine it. Small circles on it indicate exposures, and
the boundary lines are drawn to include exposures of similar rock.
Let Dr. Callaway show that this is wrong. It is drawn carefully to
scale on the One-inch Ordnance Map, and there cannot be the slightest
difficulty in knowing the exact spots intended. The same remark
will apply to the two patches of igneous rock “near the south-
eastern end of the Wrekin,” as to which he says he is in the dark;
a lens will show him exuctly where they are on the One-inch Map.
On the crystalline rock of the Ercal, it will be sufficient to compare
the two following passages: “ Prof. Bonney said the rhyolite was
clearly intrusive in the granitoid series” (Q.J.G.S. 1879, p. 669).
“He” (Prof. Bonney) “cannot find any distinct proof of the intrusion
of the felsite in the granite” (Q.J.G.S. 1891, p. 118).
Finally, with regard to the difference in strike of the rocks of the
Volcanic Hills and the Longmynd rocks, it does not appear to me
to be of any great consequence, and in any case does not prove the
former to be older. Many of the rocks in the former have no strike
at all, and the strikes noticed are very variable. Volcanic rocks, even
when clastic, are apt originally to have a quaquiversal dip, and more
than all, the rocks on the east side of the great fault have had to
bear the brunt of all the earth-movements, and they have yielded to
them in no simple way.
T. Mellard Reade—Normal Faulting. 487
The third paper I wish to speak of is by Miss Raisin, “On the
Lower Limit of the Cambrian Series in N.W. Carnarvonshire.”
This I have only here to refer to as it deals with supposed Pre-
cambrian rocks. One general observation is necessary. The
authoress continually speaks of my conclusions as ‘“‘new.” They
are in fact essentially the conclusions of Sir A. Ramsay, and the
only novelty about them is the reconciliation of these with some
portion of the more recent conclusions of other writers.
The proofs which [ gave of the general correctness of Sir A.
Ramsay’s conclusion Miss Raisin has sought to invalidate, and in
one case I have now to acknowledge she has done so with success.
On re-visiting Bryn-Efail I find that her reading of the section is
the true one, and my own is erroneous. I would make this acknow-
ledgment in any case, but I do it now with all the more readiness,
that I find that the mistake is an entirely gratuitous one. If my
reading had been correct, it would have constituted a difficulty, rather
than an aid in the true reading of the district.
The fact is, that when I wrote my paper I was studying Pre-
cambrian rocks, and as soon as I found that there were none in the
district—for the proof of which the other observations are amply
sufficient, and had led me to this conclusion before ever I saw
Bryn-Hfail—I grudged any more time for the subject, and was glad
of a short cut, which has proved to be disastrous. I saw that to
understand the real history of these volcanic masses involved a
survey of the whole of the Cambrian rocks of the district—a task
from which I shrank. That survey I have, however, now made,
and hope shortly to present the results. By this I have learnt, that
a great number of previous supposed results, some of my own among
them, are entirely wide of the mark. The only thing that becomes
clearer than ever is that there are no stratified Precambrian rocks in
the ordinary sense in North-West Carnarvonshire. These results will
render it useless to reply to any other points in Miss Raisin’s paper.
II.—A Miyrarvure Intusrrarion or Norman Favuttina.
By T. Metuarp Reanpg, C.E., F.G.S.
HEN examining the Glacial drift at Nevin, Carnarvonshire, I
observed in a banded silty clay occupying the top of the cliff
of drift at a point between Porth Nevin and Porth Bodeilias, an
excellent illustration of my theory of Normal Faulting.!
The bed in question consisted of an extremely finely laminated
silty clay, sometimes called book-leaf clay, the laminations being
grouped in ribands about half an inch wide and six inches apart,
of lighter and darker colours, presenting a striped appearance very
conspicuous from the shore. In thé upper part of the bed the bands
were continuous, though a little wavy: the lower part of the bed,
as far as it was visible above the talus of sand, was faulted as
shown in the accompanying diagram (Fig. 1). These faults simu-
lated in a remarkable manner sections of faulted coal-fields which
1 Chap. viii. Origin of Mountain Ranges.
488 T. Mellard Reade—Normal Faulting.
have been drawn from actual mining exploration and measurement. —
The greatest throw was 3+ inches measured on the hade of the fault.
Almost every feature of Normai Faulting was reproduced in miniature
by this natural diagram, among which are the dropping of the
wedge-shaped blocks (as at e, Fig. 1); the universal hade to the
downthrow ; the occasional curve of the beds (bands) downwards
on one side and upwards on the other as at fff, the result of slipping
and the tight fitting together of all the parts or wedges into which
the strata have been divided by shearing.
— SSS
Bas SELF FILE SF
TTT
ST;
Fie. 1.—Section of faulted laminated silty clay as exposed in the Cliffs of Glacial
Drift at Nevin, Carnarvonshire. Scale 4 inch to a foot (a portion only.)
a. Banded laminated silty clay (unfaulted).
b. Cavity, the underside at x studded with hardened guttz of sand, —the cavity
in part being filled with sand.
e. Similar banded clay to a, but faulted as shown.
d. Talus of sand below this.
It is evident that the faulting of these banded beds is due to their
contraction and loss of volume, either by actual drying or by the
draining away of their water. Between the overlying unfaulted
bed (a) and the faulted bed (c) there was a cavity at (b) six inches
wide at the widest part. On the bottom or underside of the un-
faulted bed at x were ‘“‘ guttz” or drops of hardened sand, the under-
side looking as if studded with petrified raindrops. Probably this
cavity was formerly a thin bed of sand which allowed the surface
water percolating through the upper bed to drain away without
affecting the lower bed. It is not easy to trace the exact modus
operandi of Nature in this case, as observation was difficult from
the insecure foothold on the sand talus at d.
An examination of the constitution of this laminated silt by
breaking up six ounces of it in water and riddling it showed that
a few grains of sand only were caught in a mesh of 335 of an inch,
and 10 grains by weight of sand in a mesh > of an inch. All
the rest passed through the ;35 inch mesh and #? oz. and 10 grs.
were caught by precipitation.
The portion that flowed away without precipitation must have
consisted largely of very small granules, probably of quartz, for the
Charles Davison—VW ork done by Lobworms. 489
silty clay when dry rubs on to the fingers like flour. This peculiar
constitution, together with the fine sandy laminations at which the
clay readily separated, rendered the material very “‘short”’ on drying,
facilitating its rupture by shearing and the keying up of its divided
portion by wedging, on the principle known to mechanics as “ fox
wedging.” If the bands were replaced in their original position,
they would not fill up the gap. The material must shrink a good
deal in drying.
If we substitute volumetrical-contraction by change of temperature
for contraction by loss of moisture, and increase the size, weight,
and rigidity of the beds, we have at once my theory of Normal
Faulting, as explained in chapter viii. of the Origin of Mountain
Ranges. It is certainly remarkable how the material gets repacked
by shearing and wedging up, even in such miniature faultings as are
here described. There are absolutely no cavities, the faults being
mere lines, so close do the constituent parts fit each other. No doubt
_ Nature reproduces great faulting in this miniature manner through
the small shearing strength of the beds. Had there been more clay
in the material, it would have proved too plastic for the purpose.
In the actual faulting of the earth’s crust the weight of the rock is
much greater in proportion to the shearing stress brought into play
by contraction.
In conclusion J ask, as a suggestion for the consideration of those
who have studied the subject, whether the minute faults sometimes
found in banded slates have not been produced in somewhat the
same manner.’ It certainly seems clear to me that the faulting in
such cases has preceded the cleavage.
ITV.—On toe Amount or Sanp BROUGHT Ue BY LOBWORMS TO THE
SURFACE.
By Cuartes Davison, M.A.,
Mathematical Master at King Edward’s High School, Birmingham.
EN years ago Charles Darwin published his last work,? the
result. of more than forty years’ observations on the habits of
earthworms and the rate at which they bring up soil to the surface.
To ascertain this rate, he made use of two methods. In the first
place he measured the rate at which layers of lime or cinders were
covered over by the spread-out castings of worms; and, later, he
collected and weighed all the castings thrown up over a definite
area within a given time. As is well known, the general result
of his investigation was greatly to exalt our ideas of the importance
of earthworms and of the work they do upon the surface of the land.
The work performed by lobworms on the surface of tidal sands
seeming not less worthy of study, I made some observations on the
subject during a short stay in Holy Island last August. Between
this island and the opposite coast of Northumberland is an expanse
l See ‘‘ A Faulted Slate’’ by J. J. Harris Teall, Geox. Mac. 1884, pp. 1, 2.
2 “—_
Wirs deep regret we record the following deaths :—
Cuaries Suire WiiKrnson, F.G.S., F.L.S., V.P.L.8., N.S.W., the
Government Geologist for New South Wales, who died at Sydney
on 25rd August, 1891, aged 47 years.
Puiie Hersert Carpenter, D.Sc. (Camb.), F.R.S., FLS.,
Science-Master of Eton College, who died on 21st October, 1891,
aged 39 years.
We hope to publish a fuller notice of these eminent geologists
and paleontologists next month.
eke Sy
lee
i
GroL. Mac. 1891. Dec. III. Vol. VIII. Pl. XIV.
LE. C. Woodward, del. Mezsenbach Co. st._
Olenellus Callavei, Lapworth,
from the Comley, or Hollybush Sandstone, of Shropshire.
GEOL. Mac, 1891. Dec. III. Vou. VIII. Pl. XV.
Olenellus Callavez, Lapworth,
Comley, or Hollybush Sandstone of Shropshire.
Theoretical restoration, natural size.
THE
GEOLOGICAL MAGAZINE.
NEW SERIES. DECADE Ill. VOL. VIII.
No. XII.—DECEMBER, 1891.
Oi GAIA, --Azkve EC ease
——
I.—On Ozewnet~tus CALLAVEI AND ITS GEOLOGICAL RELATIONSHIPS,
By Pror, Cuartes Lapworru, F.R.S.
(PLATES XIY. anp XY.)
N the year 1888 I published a short paper in the pages of the
GuotocicaL Macazine' and in “ Nature,”? in which I gave
a brief account of the discovery of the fauna of the Olenellus (or
Lower Cambrian) zone in the Comley or Hollybush Sandstone of
Shropshire. Since that date great advances have been made in our
knowledge of the Olenellus fauna of other areas, and the Olenellus
zone has now generally attained an established rank and systematic
position in the Geological Record as the basal zone of the Cambrian
system.
At the time my paper was written sufficient material had been
obtained to enable me to recognize the existence of a well-marked
species (Ol. Callavei) of the genus Olenellus in the Comley Sand-
stone series. But the form appeared to be so closely allied to the
Olenellus Bréggerit, which had been discovered by Mr. Walcott,—
the distinguished paleontologist of the United States Geological
Survey—in the basement beds of the Cambrian of Newfoundland,
and exhibited and named by him at the meeting of the Geological
Congress in London in 1888, that, as I explained in the paper
referred to, I felt that it was but just that I should await the
appearance of the formal description of his species before publishing
. my own.
Thanks to the kindness of Mr. Walcott, his brilliant and long-
expected Monograph “On the Fauna of the Olenellus Zone”? now
lies before me, in which Olenellus Bréggeri is admirably figured
and described; and although it includes a comparative diagnosis of
Olenellus Callavei, sufficient for registration and identification, I take
this my first possible opportunity of figuring and describing in full
our Shropshire form, that the want of acquaintance with its minor
specific characters may not delay those who may be desirous of
publishing new species from the Olenellus zone elsewhere.
1 Lapworth, ‘‘ On the Discovery of the Olenellus Fauna in the Lower Cambrian
Rocks of Britain,’? Grotocicat Macazinz, 1888, Dec. III. Vol. V. p. 485.
2 “ Nature,’’ vol. xxix. p. 213.
3 See next page.
DECADE III,—VOL. VIII.—NO. XII. 34
530 Prof. C. Lapworth—On Olenellus Callavei.
The fragments figured on Plate XIV. are those which were
exhibited by myself at the meeting of the Geological Congress at
London in 1888, supplemented by a few others which were at the
time in my possession. The majority were collected by Mr. H.
Keeping (acting under my instructions with the kindly consent of
Prof. T. McKenny Hughes, F.R.S.) during the previous years, and
are the property of the Woodwardian Museum, Cambridge.
The restoration attempted on Plate XV. is founded essentially
upon these fragments; so that paleontologists will be able to
judge for themselves in what respects that restoration is justified
or defective.
OLENELLUS (Hormta) Cantavet, Lapw.
Plate XIV. Figs. 1-25. Plate XV. Fig. 26.
1888. Olenellus Callavei, Lapworth, Grotocican Magazine, Dec. III. Vol. Y.
. 4865.
1888. Jbid. Lapworth, ‘‘ Nature,’’ vol. xxix. p. 213. :
1889. Olenelius Callavei, Walcott, American Journal of Science, vol. xxxvii. p. 391.
1891. Olenellus (Holmia) Callavei (Lapw.), Walcott, “Fauna of the Olenedlus
Zone,’’ 10th Report Geol. Survey, U.S.A., pp. 640-641, p. 581, ete.
Description.— General form ovate-elliptical, about one and a half
times longer than broad. Head broad, semi-circular to semi-elliptical
in outline and moderately convex. Margin edged exteriorly by a
broad conspicuous rounded rim or flange, and limited interiorly by
a faint parallel angular ridge. Posteriorly the margin is broadened
and prolonged in a strong rounded spine. The under side of the
proximal margin forms a broad rounded doublure. The posterior
margin of the head bears two short, stiff, spur-like ‘“‘interocular ”
spines, which are directed backward and outward, and are continued
interiorly by a faint ridge which appears to be prolonged almost to
the crest of the glabella in advance of the occipital furrow.
Glabella broadly convex in elevation, and sub-clavate in outline ;
attaining its greatest width near the anterior extremity of the eye-
lobe, and having a sharply rounded to sub-triangular frontal edge.
It is furnished with three pairs of glabellar furrows (with traces of
a fourth anterior pair). They occur as shallow and broad double
depressions, deepest midway between the axis and the lateral
margins, and almost disappearing as they cross the central parts
of the glabella. Occipital furrow of the same type as the rest; but
broader and deeper, and limited in part anteriorly by a slight but
conspicuous ridge (the proximal extension of the ‘“interocular”
process?). Occipital ring flat and narrow laterally; rising posteriorly
to a strong marginal rim, and rapidly increasing in width and height
to its centre, where it insensibly graduates into a stout claw-like
spine, which arches backward over the first two (?) segments of
the thorax.
Hye-lobes prominent, elongate, narrow, lunate to semi-circular,
situated sub-centrally with respect to the height of the glabella;
arching outward from the base of the anterior lobe to a distance
equal to half the width of the glabella, and backwards almost te
a line with the occipital furrow. Visual surface unknown. Area
Prof. C. Lapworth—On Olenellus Callavet. 531
between glabella and eye-lobe flat, and separated from the glabella
by an irregular undulating groove. Frontal limb narrow. Surface
of free cheek slightly convex, sloping inwards to the eye-lobe, and
outwards to the groove bounding the lateral margin. Thorax with
18 (?) segments. Axial lobe elevated; prominently rounded and
narrowing throughout. Each axial segment is well defined. It is
thickened posteriorly and laterally grooved; and it bears centrally
a short and stout recurved claw-like spine, with a spreading base,
and a sharp ridge-like upper surface. The terminal segments bear
in addition two lateral rudimentary spurs, while the central spine is
much reduced in size. Pleural lobes, flattened for the first half to
two-thirds of their length; and then gracefully curving and con-
tracting to the recurved falcate extremity. The proximal surface of
each is relieved by an oblique pleural groove.
The associated pygidium is small, simple, almost semi-circular
in form; with slightly converging lateral margins, straight and
shortened posterior edge, distinct central elevation, and anterior
groove.
The test or body-covering of both head and thorax is marked
throughout by a raised fretwork of inosculating lines or ridges,
the pattern of which varies in different parts.
Dimensions.—The larger fragments collected indicate a length of
about six inches and a breadth of about four inches. With the
exception of Olenellus (Holmia) Bréggeri, Walcott, this form is the
largest species of the genus yet discovered.
Comparisons.—Olenellus Callavet, as I have already more than
once pointed out,! is most intimately allied to Olenellus Kjerulfi,
Linnarsson, from the Lower Cambrian of Norway, and Olenellus
Bréggeri, Walcott, from the basal beds of the Cambrian of Newfound-
land. ‘These three species appear to me to constitute a special sub-
generic (?) group, intermediate between Olenellus, Hall (including
Mesonacis, Walcott, and Olenoides, Meek). They all possess the
remarkable “interocular” processes and conspicuous dorsal spines
of the latter, but differ in the absence of the facial suture. They
agree with Olenellus (including Mesonacis) in the general form of
the head and of the glabella, and in the peculiar ornamentation of the
test; but differ in the absence of the great median or terminal spine.
From both groups’ they are strikingly distinguished by the great
development of the occipital process. In allusion to this common
characteristic feature, I suggested for the group the title of Cephala-
canthus ;2 but, as Mr. Walcott has pointed out, this term must give
way to Holmia, the subgeneric title published by Mr. Matthew’
in June, 1890, for Olenellus (Holmia) Kjerulfi, Linnrs., the first
discovered species of the group.
Olenellus Oallavei not only agrees with Ol. Kjerulfi in its general
characters, but in the conspicuous development of the interocular
spines, in the existence of a faint ridge sweeping back from the
1 Grou. Mac. etc., Joc. cit. supra. Fauna Olenellus Zone, pp. 640-641.
2 Gzou. Mac. 18838, p. 641.
3 Matthew, Trans. Roy. Soc. Canada, 1890, p. 160.
532 Prof. C. Lapworth—On Olenellus Callavei.
spine almost to the axis of the glabella just in advance of the neck
furrow; in the double character of the lobes and furrows of the
clabella itself, and in the form and position of the eyes. It differs
from O. Kjerulfi in its larger size, and more compact habit; in the
rapid contraction of the glabella towards the front, in the much
greater development of the occipital spine, and in the falcate charac-
ter of the terminal parts of the pleura.
O. Callavet agrees, on the other hand, with Ol. Bréggeri in all
those features which distinguish the former from O. Kjerulfi; and
differs from it in all those characters which are common to the
English and Norwegian forms. In addition, a minor distinction is
constituted by the much greater extension of the genal and inter-
ocular processes in O. Callavei than in O. Bréggeri, and a much lesser
extension of the great occipital spine.
The form is dedicated to my friend Mr. Charles Callaway, D. Se.,
F.G.8., who was the first to detect organic remains in the Comley
Sandstone, and the first to demonstrate the presence of true Cambrian
fossils in Shropshire generally; and whose original and sagacious
inference as to the probable pre-Cambrian age of the unconformably
underlying rocks the discovery of Olenellus places beyond much
dispute.
In addition to the fragments upon which the foregoing description
has been mainly drawn up, a few figures (Figs. 24 and 25) are given
on Plate XIV. of younger examples of the species, in which the same
characteristic features will be recognized.
Olenellus Callavei occurs in a highly caleareous bed of bright
purplish-red calcareous sandstone, or sandy limestone, near the base
of the Comley Sandstone (Hollybush) series of Central Shropshire.
The figured specimens were all procured from a single locality—the
Comley Quarry—at the foot of the hill of Little Caradoc, near Church
Stretton. In this district the Olenellus-bearing sandstone passes
down into olive-green felspathic flags, grits, and concretionary shales,
and the base of the entire Comley Sandstone series is formed of the
well-known Caradoc or Wrekin Quartzite, which reposes unconform-
ably upon the Volcanic Uriconian Group of Callaway. The Olenellus-
bearing beds are overlain at once by conglomerates, and gritty and
quartzose strata, containing abundant fragments of igneous rocks,
concretions of carbonate of copper, calcareous bands, and limy
nodules; and these in turn pass up into flaggy shales and quartzose
grits, forming the highest visible parts of the Comley series.
Olenellus Callavei appears to be strictly confined to that part of
the Comley series which lies below the conglomerate bands mentioned
above; and its associates include Kutorgina cingulata, Linnarssonia
sagittalis, Hyolithellus (compare H. micans, Walcott) and Hillipio-
cephalus, sp.
The overlying conglomerates and limestones are distinguished by
the presence of a large species of Paradowides (P. Groomii' sp. nov.),
together with forms of Ptychoparia, Obolella, Protospongia, etc.
1 Paradoxides Groomii, sp. nov. In general form and size intermediate between
Prof. C. Lapworth—On Olenellus Callavet. 533
The generic position of the two characteristic forms of the Lower
and Upper Divisions of the Comley Series being thus settled, the
descriptions of the less important associated forms may conveniently
be deferred to a more favourable occasion.
We possess in the foregoing facts sufficient paleontological
evidence to establish the Lower Cambrian age of that part of the
Comley series which contains the genus Olenellus; and we have
now obtained stratigraphical and paleontological proof that it is
succeeded at once by the so-called Middle Cambrian or Paradowidian.
Further, as Dr. Callaway’ originally pointed out some years ago,
the Hollybush (or Comley Sandstone) series is followed in turn
by the Shineton Shales, which contain locally a fauna of highest
Cambrian age. In these Central Shropshire rocks, therefore, the
Comley and Shineton Groups, which constitute an integral part in
this district of Murchison’s original Lower Silurian, and have a
collective thickness of perhaps less than 38000 feet, we have apparently
a condensed epitome of the entire Cambrian system as at present
generally defined.
Here, as elsewhere, we find the Cambrian divisible into three
sections —an Upper Cambrian above, marked by the presence
of the genus Olenus (Olenidian) ; a Middle Cambrian group with
Paradowzides (Menevian or Paradoxidian); and finally a Lower
Cambrian (Olenellus zone) or basal group (possibly of somewhat
different systematic importance), distinguished by the presence
of Olenellus. No one has yet, so far as I know, suggested any
general title for the basal division of the Cambrian. Recollectiny,
however, that the very first discovered species of the genus Olenellus
was named and figured? by the American geologist, Dr. Emmons, as
early as 1846 from the rocks of his Taconic or Taconian system ; and
was claimed by him as early as 1853° as coming from strata older
than any of the fossil-bearing Silurian (including the Primordial
zone) then discovered ; while even at the present day the genus holds
its own as marking a distinct and identifiable life-zone in the strata
of Emmons’ typical Taconic area; it would be very convenient if
geologists and paleontologists generally would agree in calling it
the Taconian.
In my short paper already referred to, ‘“‘On the Discovery of the
Olenellus Zone in Britain,” I drew a few provisional inferences,
novel at that time, but thrown out then as “constituting a pro-
visional working hypothesis, of service mainly as a guide and
Pur. Harlani (Green) and Par. Davidis (Salter). Length 8 to 9 inches, breadth 53.
Head semi-circular, with pointed genal spines from two to three inches in length.
Glabella prominent, clavate, more than half its length being occupied by the broadly
rounded and smooth frontal lobe. Hypostoma of the type of that of Par. Bohemicus
(Boeck). Plewre (no ?) falcate, and sharply pointed. Pygidium a raised dise with
central tubercle; embraced laterally by long. sabre-like, distally-diverging spines.
Localities. Neves Castle (Lapw., 1889) and Comley (Groom, 1890). Named after
T. Theo. Groom, Esq., B.Sc., who first collected fragments sufficient for description.
ae Ney ‘Upper Cambrian Rocks in South Shropshire,” Q.J.G.S. 1877,
; , ete. :
. 2 As Elliptocephala asaphoides, Emmons, Taconic System, 1846, p. 213, figs. 1, 2, 3.
3 Emmons’ American Geology, 1855, pt. 1, pp. 6 and 7, etc, -
534 Prof. C. Lapworth—On Olenellus Callavet.
stimulus to future discussion, investigation, discovery and correc-
tion.” It is somewhat instructive to note how—taking the publica-
tion of these provisional inferences as our starting point—geological
knowledge and opinion in this department has advanced in the
interval. These theoretical conclusions were three in number, and
for the sake of comparison—the contrasts between them (as para-
phrased from their original crude form), and their present aspect
(in so far as can be deduced from the actual state of geological
opinion),—may very briefly be summarized as follows :—
(a) The presence of Olenellus in these Shropshire strata appears to fix the pre-
Cambrian age of the Uriconian Series of Dr. Callaway, and to render the pre-Cambrian
age of his Longmyndian a matter of fair probability.
Since 1888, Professor Blake, who has of late years added very
much of great value to our knowledge of the Cambrian and pre-
Cambrian rocks, unhesitatingly assigns the lower zones of the
Longmynd Series of Callaway to his own Monian, or pre-Cambrian.!
Sir A. Geikie, after studying the Olenellus-zone and the overlying
and underlying rocks in the field, has frankly expressed his view
that the Uriconian may be of pre-Cambrian age.’ » Finally, the fact
brought forward in the present. paper—namely that representatives
of all three divisions of the true Cambrian, as at present acknow-
ledged, are actually known to occur in Central Shropshire, being
mapped as constituting an integral part of Murchison’s original
Lower Silurian,—renders it very unlikely that the Longmyndian
(the original pre-Silurian or Cambrian of Murchison and the other
great stratigraphists who immediately followed him) can be any-
thing else than pre-Cambrian.
(6) The so-called Upper Cambrian of the Malverns, Central England and N.W.
Scotland may be in reality a greatly attenuated representative of the entire Cambrian
system; part of an originally fairly continuous Cambrian once extending from
Lapland through Britam and Europe to Sardinia—and the Sardinian and Durness
formations may both range down to the base of the Cambrian.
The recent brilliant discovery of Olenellus by the officers of the
Geological Survey of Scotland,’ in the Fucoid and Salterella zone, in
the lower parts of the Durness-Hriboll Series, establishes the correct-
ness of this suggestion for the N.W. Highlands. The detection of
Paradoxides Groomii in the supra Olenellus—infra Olenidian —zones
of Central Shropshire, as described in the preceding pages of the
present paper,* appears to settle the matter equally satisfactorily as
regards Southern Britain :—
(c) If so the Torridon Sandstone of North West Scotland would possibly go with
the Longmyndian into the pre-Cambrian, the Schists of St. Lo in France, and the
rocks of corresponding antiquity elsewhere.
Here, again, this provisional conclusion has been extended and left
far behind by later research and opinion. As already pointed out by
Sir A. Geikie,’ the discovery of Olenellus in the Durness-Eriboll
1 J. F. Blake, On the Monian and Basal-Cambrian Rocks of Shropshire, Q.J.G.S.
1890, p. 386, ef. seq.
2 Sir A. Geikie, Anniversary Address, Q.J.G.S. 1891, pp. 86-90.
3 Sir A. Geikie, Grou. Mac. 1891, p 449.
4 See ante p. 532. 5 [bid. p. 449.
Prof. C. Lapworth—On Olenellus Callavet. 539
Series fixes the pre-Cambrian age of the Torridon Sandstone.
Again, Dr. Katzer’ has shown that the strata of the Bohemian
Urgeberge (the Cambrian* of Barrande and Murchison—Etages A.
and 1.) lie (at least locally), unconformably below the rocks of the
true Cambrian or Primordial zone (a conclusion recently confirmed
by Dr. Wentzel*) and must, therefore, be now classed as pre-Cam-
brian or Archean. In precisely the same way in two recent and
most valuable memoirs by M. Bergeron and M. Bigot we are
presented in one area (N.W. France) with clear physical proofs,*
and in another (Languedoc) with actual paleontological evidence,°
that the condensed Cambrian of Central Britain is apparently pro-
longed through France from the Channel Isles to the Montagne
Noire; and as a consequence the underlying (often unconformable)
schists of St. Lo, etc.—i.e. the Cambrian of Dalimier, Dufrenoy
and Murchison—may now be regarded as of Archean or pre-Cam-
brian age.
Thus while we have still very much to learn respecting the fossils,
the component members, and the local development of the ancient
Paleozoic strata, and while we must admit that many of our present
inferences and conclusions lie open to improvement and correction
by future investigation and discovery—the students of these old
rocks (however much they may conscientiously differ in the pro-
visional nomenclature in which they clothe their facts) have now
all more or less attained to the conviction that we are at last
reaching a satisfactory homotaxial base to the Paleeozoic rock-series.
We now see that the Lower Paleozoic cycle of formations (the
Protozoic or Protogean) or the Silurian of Murchison’s ‘ Siluria’ and
Barrande’s ‘ Systéme’ has proved itself to be a geological cycle of
the first order. We agree, in principle, that it is made up (like
each of the succeeding great cycles), of three sub-equal groups® or
systems—an Upper system (the Silurian proper, or Salopian) a
Middle system (the Ordovician) and a Lower system (the Cambrian).
This lower system, like each of the two systems above it, has now
shown itself divisible in its turn into three sections—an Upper
Cambrian (Olenidian), a Middle Cambrian (Paradozidian) and a
Lower Cambrian (Tuconian).
Underneath this Cambrian lie sometimes conformably, sometimes
unconformably, the strata of the mysterious cycles of the Pre-
Cambrian (or Archean). Of these, certainly the rocks of the
unaltered divisions (the Eozoic or Hogean cycle) are now so well
circumscrived geographically that there appears little to hinder their
detailed study and investigation by an extension and development
1 Dr. Fr. Katzer, Das dltere Paleeozoicum in Mittel Bohmen, Prague, 1888, pp. 5, 7.
2 Siluria, 4th edition, p. 2738.
3 Dr. Josef Wentzel, Die Beziehungen der Barrandischen Etagen C, D, E zum
Britischen Silur., Jahrbuch d. k. k. Reichsanstalt, Wien, 1891, p. 119.
4 A. Bigot, L’Archéen et le Cambrien du Massif Breton, Cherbourg, 1890,
pp. 28, 73, etc.
Dds Perecrely Etude géologique du Massif ancien du Plateau Central, Paris, 1889,
. 78, pl. il.
Pg Tie Silurien supérieur, Silurien moyen, and Silurien inférieur respectively, of
the younger French geologists.
«
536 W. M. Hutchings—On some Lake-District Rocks.
of the same rules which have been employed in satisfactorily deter-
mining the order and the characteristic organic remains of the more
recent systems. Surely it is not too much to hope that the day is fast
approaching when these Eozoic formations will be reduced to their
natural order as fossil-bearing systems, comparable in all respects
(except in the greater paucity of their organic remains) with the
Post-Archzan systems which at present form the accepted members
of our great geological scale.
EXPLANATION OF PLATE XIV.
Fie. 1. Olenelius Callavei. Glabella in relief, showing the characteristic shape,
the lobes and furrows, and the broken base of the
occipital spine.
Fie. 2. ———— ——— Do. Side elevations.
Fie. 3. ———— Occipital lobe with base of central process. Posterior
aspect.
Fig. Fragment of hinder part of glabella, etc., from above,
showing size and length of a broken occipital spine.
Fie. _ Do. Side elevation.
Fic. Fragment of part of head, showing marginal and
interior ridges.
Terminal part “of free cheek with marginal ridge, and
genal and ‘‘interocular”’ spines.
Do. Another and smaller example.
Kye lobe.
Do. Smaller example.
Fic.
Fic.
4
5
6
Fie. 7.
8
9
Fic. 10
Fie, 11. One of the anterior segments of the axis, showing the
form and position of the median spine.
Fie. 12, ———— Do. From central parts of axis.
Fie. 13, 14. —-— Do. Profile views.
Fig, 16. Segment of axis near posterior end.
Fic. 16. Sub-terminal (?) segment of axis, showing central and
lateral tubercles,
Fic. 17. Pygidium.
Fig. 18. One of the proximal pleure, showing general form,
pleural groove, and falcate extremity.
Pleuree from near posterior end of thorax.
Superficial ornamentation of test. (Magnified. )
Fie. 22. Ditto. (Magnified.)
Fie. 23. ————— Doublure for attachment of hypostoma.
Fie. 24. Young form of O. Callavei, showing general form and characters of the
glabella, eyes. frontal margin, etc.
Fic, 25. Do. Another example.
(All the fragments figured, except Figs. 21 and 22, are of the natural size.)
Figs. 18, 19, 20, 24, are from my own Collection, the remainder are in the
Collection of the Woodwardian Museum, Cambridge.
PLATE XY.
Fic. 26. Olenellus Callavet, Lapw. Theoretical restoration, natural size.
Fie. 19, 20.
Fig. 21.
| Il I | U : |
IJ.—Perrronocicaa Notres on some Lake District Rocks.
By W. Maynarp Hurcurnes, Hsq.
Dae the last three years I have at various times collected
and studied rocks from the Lake District. Some of them are,
I think, of sufficient interest to render them worth describing. It is
my opinion that a great deal of very interesting petrological work
still remains to be done among these rocks, and that when they are
W. M. Hutchings—On some Lake-District Rocks. 537
more studied in detail they will be found to present more diversity
of type than is usually supposed.
I will first note the occurrence of a variety of rock not previously
recorded in this district. It is a quartz-andesite, or dacite. It is
exposed on the ridge between Greenburn and Wytheburn, not very
far from Dunmail Raise, and near to a new wire-fence which bounds,
I believe, the property of the Manchester Waterworks. It is a
dark-coloured rock, on a newly-fractured surface of which are seen
numerous light spots of porphyritic felspars, and some of calcite,
with many grains of quartz, some of good size. It was the grains
of quartz which instantly attracted my attention to this rock when
a bit was chipped off it in passing the exposed crag.
Under the microscope these grains of quartz are seen to be
corroded and eaten out into “bays and gulfs,” and their nature as
true constituents of the rock, and not extraneous fragments, is
vouched for by their enclosures of ground-mass. None of them
show definite crystalline form. In addition to the larger porphyritic
grains, some very small ones are seen among the ground-mass, but
not abundantly.
The many porphyritic felspars are fairly well preserved. They are
plagioclase, mostly well twinned, sometimes on both albite and
pericline systems. So far as may be inferred from the extiction-
angles of symmetrica]ly-extinguishing twins, the chief felspar present
appears to be oligoclase.
The porphyritic ferro-magnesian constituent appears to have been
mainly, if not wholly, biotite, which was abundant. The outlines
and cleavages of the numerous large individuals are still quite
preserved, but great alteration has taken place into chlorite, epidote,
and indeterminable matter, probably partly carbonates and ferric
oxides.
I have not met with any other andesite in the district in which
biotite can be recognized as present, or formerly present, nor am
I aware of any such rock having been recorded. My impression
is that biotite-andesite was very sparingly represented, though of
course it is possible that the chlorite, so abundant in some cases,
may partly represent former biotite; but in that case we should
expect to sometimes see recognizable pseudomorphs, as one so
frequently does in these rocks after augite.
The ground-mass of this quartz-andesite consists of a network of
small felspar-laths, intermixed with, and at places more or less
obscured by, grains of chlorite, epidote, sphene, calcite, and other
matter, as is usual in all these rocks. In the greater portion of
it the felspars are very distinct and fresh, and allow of optical
measurements. They are largely untwinned, the rest being binary
twins. Extinctions are either quite parallel or at very low angles.
We may conclude that there is oligoclase, and most likely some
orthoclase present. So far as can now be made out, very little,
if any, glass was present in the original rock. There are many
good-sized crystals of apatite, and zircons are much more numerous
than in the usual local andesites. The sp. g. of the hand-specimen
538 W. WM. Hutchings—On some Lake- District Rocks.
brought away is 2°74, and the silica-percentage is 60:45. Roth
gives as the outside figures for silica recorded for dacites, 68-18
per cent., and 55-91 per cent. respectively, the latter being from an
altered rock. It is not likely that the figure obtained by me for
this Lake District dacite quite represents the original percentage,
which, judging by the alterations, was probably a little higher,
though certainly not nearly high enough to place the rock among
the rhyolitic andesites. We have here, then, a well-characterized
biotite-dacite, and it is likely that this or a similar rock will be
found exposed at other points besides the one indicated.
Another rock occurring above Hasedale Tarn, Grasmere, on the
side towards Langdale, is a conspicuous representative of the other
extreme of the series of Lake District rocks. It is a dolerite, a guod
deal more basic than any described by Mr. Ward, and differing in
other ways from any hitherto recorded in the district. It is a very
dark-coloured rock, easily recognized with a pocket-lens as a rather
coarse-grained dolerite, without any porphyritic structure. Micro-
scopic examination shows it to be made up of augite and plagioclase-
felspar, with usual alteration-products. Augite is abundant, and
much of it is still quite fresh. It existed originally, apparently,
wholly as irregular grains, mostly of good size. The rock has
undergone considerable crushing and shearing, and many augite-
grains are cracked in several places, the cracks being cemented with
chlorite. In some cases large grains have been completely shattered
into small fragments, now lying among chlorite and calcite, due
to subsequent infiltration. Here and there augite is fringed with
secondary hornblende, but chlorite is the more usual alteration-
product.
The felspar is in the form of relatively broad laths, tabular
sections, and many irregular grains; it has been a good deal affected
mechanically, like the augite, but is very fresh otherwise. There is
no ophitic structure and no trace of ground-mass of any description.
The rock is distinctly a holocrystalline, non-porphyritie dolerite,
verging towards granitoid structure. The sp. g. is 2°95, and the
percentage of silica is 45°65.
Another totally different type of basic rock examined is from near
the summit of Scarf Gap Pass. Mr. Ward mentions a bed of basic
lava on the east side of the pass, and gives description and figure of
it. Ido not know whether this is the same rock, and his figure is
of very little use in deciding, while some points in his description
do not agree with the occurrence here noticed.
It is a vesicular rock, the vesicles being now infilled with
chlorite and other alteration-products. It has comparatively few
porphyritic felspars, all very much altered. There is abundant
porphyritic augite in good-sized crystals and grains, much of which
is still perfectly fresh, though much fractured in some cases. ‘The
ground-mass consists of very small felspar-laths, perfectly fresh,
nearly all binary twins. They are mainly if not wholly labradorite.
There is the usual abundance of alteration-products throughout the
ground-mass, but a good deal of augite in small grains is still dis-
W. M. Hutchings—On some Lake- District Rocks. 539
tinguishable. There appears to have been a good deal of interstitial
glass originally, but it is now devitrified, and obscured by alteration.
The sp. g. is 2°82 and the silica-percentage 51:35. This rock,
then, corresponds to a porphyritic augite-dolerite, or probably, more
correctly, basalt.
Turning to the andesites, there is a type of them abundantly repre-
sented at one part of the district, and apparently recurring at several
other points, which is very interesting and differs in several ways
from the usual varieties as described by Mr. Ward, or as summarized
by Sir A. Geikie (Presidential Address to Geol. Soc. 1891). It
consists of rocks of mostly a grey-green or grey-blue colour,—a
colour not easy to exactly describe,—with resinous lustre and
extremely splintery fracture. On a newly-broken surface small
dark spots are seen, but hardly ever any sign of a felspar, and
when seen these are very small. These particular rocks are exposed
largely at Harter Fell, Mardale, making the main part of the cliff
facing towards Haweswater ; on the ascent from Nan Bield Pass on
to High Street ; and in cliffs on the right side of Kentmere Valley,
some distance below the reservoir.
A series of sections prepared from specimens taken at all three of
the above localities shows that the rock is essentially the same in
nature at all of them. There are numerous felspar-crystals, sharp
in outline, though inwardly much altered, porphyritic in a ground-
mass which originally varied from a wholly glassy base to an
intimate mixture of glass and exceedingly minute felspar-microlites.
There are chlorite-pseudomorphs after augite, distinct in form, as
well as indefinite patches and streaks of chlorite. The entire ground-
mass is permeated by chlorite in minute flakelets, with small granules
of epidote, calcite, and other matter.
Sections from the summit of Harter Fell, close to the double cairn,
show a good deal of pertectly fresh augite as well as many pseudo-
morphs. The ground-mass here consists nearly wholly of devitrified
glass; a dimly-polarizing, speckly, felsitic mass with scarcely any
felspar microlites at all. Sections from Kentmere, again, have a
ground-mass of the most typical “hyalopilitic ” nature, wherein the
same devitrified glass is quite full of tiny laths and needles of felspar,
showing well-developed flow-structure round the porphyritic felspar-
crystals. The largest and most clearly-developed of these felspar-
needles are close around z;s5>th inch in length and extinguish quite
parallel. The average size is very much less.
There is no doubt that, though varying more or less in detail from
place to place, and even within very short distances, we have here
an altered augite-andesite of a much more vitreous nature than the
dominant type of lavas of the Lake District. A characteristic
specimen from above Nan Bield has the sp. g. 2:65 and a silica-
percentage of 57°55.)
1 Mr. Ward refers to rocks of a grey-blue colour, very compact, which are
outwardly not unlike those above described. ‘The closest resemblance is in a lava
from near Lodore Hotel, which is singled out by him on account of its non-
porphyritic nature aud the smallness of its felspar-needles. He gives the average
540 W. WM. Hutchings—On some Lake- District Rocks.
Rocks closely similar to the above, macroscopically and micro-
scopically, are exposed on both sides of Easedale Tarn, Grasmere.
One specimen, from the right side of the Tarn, is very much altered
and impregnated with calcite and other secondary matter, reducing
its silica-percentage to 52°45. Its ground-mass appears to have been
wholly vitreous, and porphyritic felspars, etc., are very scarce.
Specimens from the opposite side of the Tarn are again full of
minute felspar-needles, are less altered (free from calcite), and have
a silica-percentage of 60°75; but here also the porphyritic con-
stituents are much less abundant than at Harter Fell, etc.
From these vitreous and minutely ‘“hyalopilitic” varieties, we
may see all gradations of development of crystals in the ground-
mass, up to the more usual, much coarser-grained andesites, as we
mainly have them in Mr. Ward’s descriptions.
An interesting example is exposed in a small disused quarry by
the side of the road from Seatoller to Seathwaite. The rock is grey
tinged with green, showing dark spots of chlorite, but no felspars
to eye or lens. It is very fissile, splitting into tolerably thin plates,
and approaches more nearly to a slaty cleavage than any other lava
known to me in the district ; though I am told there are cases of
lavas which are sufficiently eleaved to be worked for roofing-slates.
The ground-mass-felspars in sections from this quarry are still
small, but larger than in the rocks just described, ranging up to
zoo Of an inch as maximum. Porphyritic felspars are greatly
altered, being almost wholly replaced by calcite, and deformed by
pressure and shearing; but the pseudomorphs after augite are mostly
but little damaged, and show more numerous recognizable forms
than in any other slides I have. The ground-mass is completely
permeated by infiltrated calcite, of which there is so much present
altogether that the silica-percentage of the rock now only reaches
01-6, though originally it must have been fully as high as in the
average local andesites, if not higher.
The numerous lavas on Dale Head, High Scawdell, and Seatoller
Fell, present an interesting variety, as we find here not only the
more normal Lake District andesites, but also types which seem to
lie between these and the basic rocks, and to require such terms
as doleritic (better basaltic) andesite, or andesitic dolerite (better
basalt), to describe them ;—that is, if we adhere to the more usual
custom of distinguishing between andesites, and dolerites or basalts,
as extremes of a series. Of course they all pass imperceptibly into
one another, and there are petrologists who cail the whole series
andesites, as does Professor Cole in his system of classification
(‘Aids in Practical Geology’), simply distinguishing them at the
ends of the line as “‘trachytic andesites” and “ basaltic andesites.”
Rock-classification, in the present state of the subject, is very much
length of these as 775th of an inch. They are, therefore, very much larger than
in the rocks referred to by me, and from his description the Lodore lava was evidently
very much less vitreous than these. It resembles, as Mr. Teall points out, the
ground-mass of the average andesites of the district; a ground-mass in which the
felspars are above the average sizes of typical andesites elsewhere.
W. M. Hutchings—On some Lake-District Rocks. 541
a matter of individual taste, so many are the systems offered to us.
For my own part I think a very much clearer idea of the rocks is
conveyed by the more usual method of separate grouping of andesites
and basalts (using the name dolerite exclusively for non-vitreous
rocks) ; as is exemplified in the classification given by Dr. Hatch
(“Introduction to the Study of Petrology”). Various stages of the
passage from one to the other extreme may then be clearly indicated
by the use of the adjectives basaltic and andesitic respectively,
according to whether we wish to specify an andesite which is
tending towards a basalt, or a basalt which is tending towards an
andesite.’
While on this subject, it is difficult to see why we should retain
in use the word “ porphyrite” for altered andesites like those of the
Lake District. The supposed differences between rocks of different
geological age being no longer admitted among English petrologists,
and bound to vanish also in Germany sooner. or later, why retain
any of the names which are connected with the obsolete system of
classification, and which appear wholly superfluous when once this
is discarded? As some writer has said, I think, in effect, why
should we have a separate name for an old and altered rock, any
more than we have a separate name for a man because his hair is
grey and his teeth no longer well preserved? Such names only
burden the memory, obscure ideas, and open the way for confusion,
because they are so liable to be used in different senses by different
writers. It is better, and specially so for younger students, to use
two words (or a whole sentence if necessary!), and to convey a
clear and unmistakeable idea by their means, than to use one word
which itself needs a definition attached to it, and very likely has
several different ones. Why should not such words as porphyrite,
melaphyre, propylite, and very many more, disappear into the
lumber-heap ? They are only a stumbling-block to beginners, and
an unnecessary addition to a nomenclature too much burdened with
dreadful names in any case.
The regular types of andesites of the district have in their ground-
mass a felspar which shows very small angles of extinction, and
sometimes extinguishes parallel.
It seems tolerably safe to assume that oligoclase largely prevails,
and it is very probable that orthoclase is also frequently present.
But there are also rocks in which these optical tests show a felspar
allied to labradorite to be present in the ground-mass. Labradorite
does not appear to be usually recorded as existing in the ground-
mass of normally acid andesites. In some of the lavas on Dale
Head, etc., examples of it may be seen, lavas which are very full of
porphyritic felspars and are unquestionably andesites.
1 Mr. Teall uses the term ‘‘andesitic dolerite’’ on several occasions, pointing out
that some authors would simply call such rocks augite-andesites ; and he adds the
very sensible reminder that ‘‘it is a matter of indifference what we call them,
provided we recognize their true characters and relations’’ (British Petrography,
pp. 194, 195).
542 W. M. Hutchings—On some Lake-District Rocks.
A rock from Seatoller Fell is of some interest. It is a very com-
pact, dark rock, quite free from vesicles. Its numerous porphyritiec
felspars are all much altered, though still perfect in outline and
relationship to the ground-mass. There are no definitely recognizable
larger pseudomorphs of chlorite after augite, though good large
patches of chlorite are present. The ground-mass consists of perfectly
fresh felspar-laths of a rather larger size than usual, all twinned,
and showing by many extinction measurements that labradorite is
dominant. These felspars lie in among a yellow-brown, dimly-
polarizing, partially devitrified glassy ‘base, full of minute dark
dusty matter. The amount of this base is considerable. In among
the felspars and glass are a large number of good-sized irregular
grains of very pale-green hornblende, which is clearly secondary
after former augite. In many cases the felspars penetrate the horn-
blende in a manner showing that a certain amount of ophitic
structure was present, but more usually the grains lie wedged in
the angles formed by the felspars. There are also numerous bits
of chlorite occurring in exactly the same manner as the hornblende.
Originally the rock must have contained a considerable amount of
augite in this form, but none of it is now seen unaltered. ‘There is
abundance of finely disseminated chlorite and grains of epidote,
some of which appears to represent a smaller generation of augite in
the ground-mass. The sp. g. is 2°88, and the silica-percentage
03'05. This rock would have to be classed as “‘ andesitic basalt.”
Hornblende secondary after augite is not at all frequently observed
in these rocks. There is another lava on Seatoller Fell, a normal
andesite, in which it occurs as prismatic grains of deep green colour,
this being the only case in which I have observed hornblende in
one of the regular local andesites. Original hornblende is never
seen nor any sign that it ever was present. It seems probable that
hornblende-andesites were never represented in the district.
Enstatite has been shown by Prof. Bonney (Gon. Mae. 1885,
p. 77) to have been a constituent of some of the Eycott Hill lavas ;
and Mr. Teall supposes it probable that the andesites of the district
contained it. I have sought carefully for it in many rocks from
various localities, but have not found it, nor any secondary product
which suggests it, in any undoubted lava. In a rock from Dale
Head, of which I am uncertain whether it was a flow or an ash,
there are good-sized serpentine-pseudomorphs after some mineral,
which I think was very probably enstatite. The secondary mineral
is not bastite. Again, in an ash or tuff from the summit of Sargeant
Man a good deal of serpentine appears, some of it in the form of
small prismatic pseudomorphs, contained in andesitie lapilli, strongly
suggestive of original crystals of enstatite; and in a tuff from
Glaramara one good-sized serpentine- -pseudomorph is also seen, the
form being quite that of the enstatites of andesites, etc.
It would seem likely that enstatite was a rare constituent of
these rocks.
A rock occurs at Thornthwaite Crag, a little below the tall Cairn,
which differs sufficiently from the usual andesites to be worthy of
W. M. Hutchings—On some Lake-District Rocks. 543
mention. It is a grey-green, highly vesicular rock, the vesicles
now filled with chlorite and chalcedony. In thin sections the
difference alluded to is apparent in the felspars of the ground-mass.
These to a very large extent consist of untwinned laths, many very
elongated in proportion to breadth, and extinguish mainly quite
parallel to their length. Such of them as are twinned are almost
without exception binary twins, and of these a large proportion
extinguish simultaneously and again quite parallel, or at very low
angles. There are a good many square tabular sections also seen,
more than in any other local andesites examined, The laths are
of various sizes, and pass down to very small ones with mainly
forked and ragged ends. So far as optic discrimination in thin
sections is a guide, the felspar in this ground-mass seems to be
mainly, if not almost wholly, orthoclase. There is a good deal of
devitrified interstitial glass and the usual amount of diffused
alteration-products. The porphyritic felspars are still fairly fresh,
and several of them in some of the slides examined appear to be
orthoclase, while in others they are wholly plagioclase, the ground-
mass remaining as above described. In one hand-specimen there
are large groups of felspar crystals clustered together in the manner
described by Mr. Teall in the case of the Tynemouth Dyke; that is,
they are idiomorphic towards the outside of the group, and allotrio-
morphic inside it. Some of these groups are so large that they give
the effect, on fractured surfaces of the rock, of being infillings of
good large vesicles with felspar, but the microscope shows their
true nature.
Some of this rock was prepared for analysis by crushing moderately
small and picking out sufficient bits quite free from vesicles or their
contents. The analysis was kindly made for me by Dr. J. B. Cohen,
of Owens College, and is calculated on dehydrated rock :—
Silica = 58-69 per cent.
Alumina ... = 15°84 3
Ferric Oxide = 17 $i (Ferrous Oxide not
Lime = 3°43 o determined. )
Magnesia ... a = 2-91 3
Manganous Oxide = (5K 5
Potash = srieté 53
Soda = 5:06 ns
98-99
These figures would stand equally well for a trachyte or an
andesite, the proportions of the alkalies being much the same as in
many analyses given of trachytes; agreeing for instance almost
completely with one of the “typical analyses” given by Professor
Cole in his ‘‘ Aids in Practical Geology.” It appears that whether
a magma of certain composition will consolidate as trachyte or as
andesite, depends largely on conditions other than purely chemical.
The rock in question is not a trachyte, but it would become one by
a very moderate degree of further differentiation from the accom-
panying andesites. Rocks with a closely similar orthoclase ground-
544 W.M. Hutchings—On some Lake-District Rocks.
mass, and some apparently orthoclase porphyritic crystals, occur also
near Keswick.
It is not at all unlikely that undoubted trachytes may be found in
the Lake District. Sir A. Geikie, in his address above referred to,
alludes to the general resemblance of these lavas to the “porphy-
rites” of the Old Red Sandstone in Scotland, and Dr. Hatch quotes
the authority of Professor Judd for the fact that ‘‘excellent sanidine-
trachytes ” exist among these rocks at Haddington (“ Introduction
to the Study of Petrology,” p. 100). Some lapilli seen in certain
tuffs also suggest that good trachytes exist somewhere among the
Lake rocks.!
Sir A. Geikie states that from the observations of himself and
Dr. Hatch on the rocks of the Lake District, he concludes that
lavas are much more abundant among them, relatively to “ashes,”
than was allowed by Mr. Ward in his Survey Memoir and other
writings. In this conclusion it is probable that most workers in
the district would now agree. But there are, of course, many cases
in which it does not seem possible to decide whether they are flows
or ashes, either in the field or with the microscope,—certainly not
with the latter. The difficulties of this kind of examination are
very fully (not to say a little gloomily!) put forth in a paper by
Mr. Rutley (“On Community of Structure in Rocks of Dissimilar
Origin,” Q.J.G.S. vol. xxxv. 1879), and anybody who may be in
danger of underrating these difficulties, or of getting too much
confidence in his power to solve them, or indeed to solve any sort
of questions whatever in microscopic petrology, would do well to
read that paper.
The chemical and mineralogical changes which have taken place
in these rocks are of very great interest in some cases. ‘They are,
however, most fully seen in the detrital rocks,—the ashes and
tuffs,—and I hope to return to some of them in connexion with
a study of the ash-slates, etc., of the district. :
1 Prof. Cole points out (‘‘ Aids in Practical Geology ”’) that the older trachytes
(or quartzless porphyries, orthophyres, etc.) may often be difficult to mark off from
the rhyolites, and suggests that the marked absence of porphyrite quartz in some of
the ‘‘altered rhyolites”’? may give rise to a suspicion that they were trachytes.
There is a ‘‘ rhyolite” exposed in the plantation in front of Shap Wells Hotel, which
differs notably Low the other rhyolites near to it. Macroscopically it shows erystals
of felspar more prominently than any of the others do. Microscopically it shows
an abundance of felspar-laths and microlites, all orthoclase, lying in a rather plenti-
ful eryptocrystalline base, ‘‘speckly ” in polarized light, apparently devitrified glass.
Such laths and microlites are absent from the other local rhyolites, There is none
of the spherulitic structure so abundantly developed in these rhyolites, and there is
no sign of free quartz or of ‘‘granophyre.’’ The silica-percentage of a specimen
collected by me is 61:15, as contrasted with over 75 per cent, found in rhyolites of
Wasdale Head and Stockdale by Mr. Garwood. The microscope shows nothing
whatever to lead to the supposition that the silica-percentage has been lowered by
decomposition or infiltration, the rock being very free from chlorite, etc. This was
apparently never a rhyolite, but was most probably a trachyte with a large amount
of glassy base.
A. Smith Woodward—Pholidophorus in U. Lias, Whitby. 545
Il].—PaoLipoPHORUS GERMANICUS: AN ADDITION TO THE FisuH Fauna
oF THE Urrrr Lias or WHITBY.
By A. Smita Woopwarp, F.G.S., F.Z.S.
EVERAL species of Vertebrata are now known to be common to
the Upper Lias of the neighbourhood of Whitby, Yorkshire,
and the corresponding formation so widely developed in parts of
Wiirtemberg and Bavaria. The recent discovery of another link
between the two faunas in question thus seems to be worthy of
placing on record. Moreover, the latest comparisons render it
possible to assign to the fossil under consideration a more precise
specific diagnosis than has hitherto been published; and the an-
nouncement of the discovery may lead to the recognition of other
specimens besides those in the British Museum, with which alone
.as yet the present writer is acquainted.
The fossil in question is a Lepidosteoid fish, long ago observed by
Quenstedt in the Lias of Wiirtemberg, and briefly described under
the name of Pholidophorus germanicus.' A figure of the head and
anterior portion of the trunk accompanies the original description ;
and it is satisfactorily proved that the fish is a typical species of the
well-known early Mesozoic genus to which it is referred. It is the
largest known Liassic species of Pholidophorus, attaining a length
of nearly 0-3 m.
Two almost complete examples of the species, and four more
fragmentary specimens were obtained from the neighbourhood of
Whitby by the late Sir Philip Egerton and the Earl of Enniskillen.
These at present form the series in the British Museum. They
agree precisely in all their characters with several typical specimens
of Pholidophorus germanicus from Ohmden, Wirtemberg, in the same
collection; and the chief points of specific importance are noted in
the following paragraph.
As usual in Pholidophorus, the body is gracefully fusiform in
shape. The length of the head with the opercular apparatus some-
what exceeds the maximum depth of the trunk, which equals about
one-fifth of the total length of the fish. The rugose ornament of the
head and opercular bones—especially that of the cranial roof—is
very fine and conspicuous; and the ruge on the maxilla and dentary
bone tend towards a longitudinal striation. The pelvic fins arise
slightly in advance of the middle point of the trunk, and are provided
with small fulcra (as especially well shown by B. M. No. P. 1058).
The dorsal and anal fins are of the ordinary small proportions, and
the former is directly opposed to the pelvic pair. The scales are
large and nearly smooth, but with a faint, coarse rugosity, most
conspicuous in the caudal region; their hinder margin is very
slightly convex, and not serrated; and there are at least six longi-
tudinal series of flank-scales much deeper than broad.
Of the characters just mentioned, the peculiar ornament of the
scales seems to be especially distinctive, and renders possible the
1 F, A. Quenstedt, ‘‘ Der Jura’’ (1858), p. 234, pl. xxx, figs. 9-11.
DECADE III.—VOL. VIII.—NO. XII. 35
546 J. H. Cooke—On Stereodon Melitensis.
determination even of fragments. The feebly marked ruge are
broad and rounded, and towards the superior margin of the scales,
more particularly on the caudal pedicle, they exhibit a tendency
towards arrangement in a series of short, parallel, vertical folds.
TV.—PszuvorrionvYx FROM THE BRACKLESHAM Bens.
By A. SmitH Woopwarp, F.G.8., F.Z.S.
HE extinct genus of Chelydroid Chelonians to which M. Louis
Dollo gave the name of Pseudotrionyx,' has already been re-
corded from the London Clay of Sheppey, by Messrs. Lydekker and
Boulenger.? It is somewhat remarkable, however, that until the
recent acquisition by the British Museum of the collection of Mr.
J. B. Ogle, no certain evidence had been observed of the occurrence
of the genus in the Bracklesham Beds—the English equivalent of
the Bruxellian Series which yielded the Belgian Pseudotrionyx%
Delheidi.
This evidence is still very small, but appears ‘nevertNelees conclu-
sive. It consists of one of the middle marginal bones, well preserved
and showing the pit for the reception of “the extremity of the rib.
The bone measures 0-05 m. in length, 0-042 in the maximum width
of the upper face, 0-03 in that of the lower face, and 0-018 in the
maximum thickness of the angulation. Both the upper and lower
faces of the bone are covered with the characteristic coarse, but
faintly-marked pitted ornament; and the angulation of one extremity
measures about 90°, while that of the other is slightly greater.
The fossil thus described agrees so closely in its proportions and
sculpturing with the type-species P. Delheidi that, in the absence of
further material, it may be assigned to this form.
V.—Notes on Srerzopon Metirensis, Owen.
By Joun H. Cooxz, F.G.S., ete.
N the year 1865 portions of the upper and lower jaws of a
large extinct fish that had been found imbedded in the Globi-
gerina Limestone® of Malta were submitted by Dr. Leith Adams to
- Professor Owen for identification. Adams had considered them as
being the remains of a crocodilian; but in a paper that appeared
in the Grontocicat Magazine for April, 1865, Owen pronounced
them to be the remains of a large extinct fish that belonged to “the
cycloid order, and having sauroid dentition,” and he proposed that
“this fine addition to Miocene Tertiary fishes”? should be known by
the name of Stereodon Melitensis.
1 L. Dollo, ‘‘Premiére Note sur les Chéloniens du Bruxellien (Hocéne Moyen)
de la Belgique,” Bull. Mus. Roy. d’Hist. Nat. Belg. vol. iv. (1886), pp. 75-96,
pls. i. 1°
2 R. Lydekker and G. A. Boulenger, Grou. Mac. [3] Vol. IV. (1887) p. 274.
3 Bed LY. The ‘‘freestone’’ of Spratt and Adams.
4 +¢Stereodon Melitensis,’? Owen, Geot. Mae. April, 1865.
J. H. Cooke—On Stereodon Melitensis. 547
A portion of the bony skeleton of a fish of the same species was
also discovered in the same locality; but as it was not sent with the
other specimens, it has been neither figured nor described.
In the course of his paper Owen repeatedly refers to it, and
finally concludes by saying, “It is much to be desired that the rest
of the skeleton of this extinct fish should be figured.” No attempt
has, hitherto, been made to carry out this suggestion, and as no
record of this interesting specimen exists, I have therefore visited
the Malta Museum, wherein the fossil is now deposited, and have
obtained the following particulars relating to it.
The specimen is oblong in shape, and measures 223 inches from
the snout to the 10th dorsal vertebra. It consists of a fragment of
the head, and a portion of the vertebral column, the latter of which
extends as far as the 10th dorsal.
The vertebre are circular in shape, and they form a continuous
chain which curves slightly in a downward direction. They are
well ossified, but, unfortunately, most of them have been badly
developed from the matrix, and their characteristic features have
thereby been obliterated. The Ist, 2nd, 3rd, and dth are, however,
in an excellent state of preservation; and the 10th vertebra
distinctly shows deep lateral pits longitudinally extended. Hach
vertebra is bi-concave, and its body is somewhat depressed towards
the middle. Compared with the posterior diameter, the antero-
posterior diameter is much the shorter of the two.
Posterior diameter of the 6th dorsal vertebra 13 inches.
Antero-posterior of the 6th dorsal vertebra 2 of an inch,
Posterior diameter of the 10th dorsal vertebra ... 2 3
Antero-posterior of the 10th dorsal vertebra 3 mH
The average diameter of the posterior extremities is 12 inches.
Above and below each of the vertebra exhibits a broad protuber-
ance, which forms the base of a long, sword-shaped spine, the
flattened sides of which lie in a plane with the vertebral column,
while the thin edges lie in the direction of the articular facets.
These spines are anchylosed with the neural and hemal arches of
the vertebrae. They average three inches in length, and half an
inch in width. The neural spines spring obliquely upwards and
backwards from the centrum, while those on the hemal side spring
obliquely downwards and backwards, and gradually become shorter
and more slender as the caudal extremity is approached.
There are no traces of scales.
' Considerable. portions of the bones of the head have been pre-
served in the limestone matrix, but most of them are so crushed as
to be quite unrecognizable.
A fragment of the left branch of the lower jaw, containing a tooth
which is similar in every respect to those that formed the subject of
Professor Owen’s paper, is intact, and thus affords an opportunity
for the comparison of the two fossils.
Hicuianp Hovsz, Sr. Junran’s, Maura.
048 Notices of Memoirs— Geological Survey Memoirs.
IN OTEtCaS Ol Vlei n@imE se
UUs Cai
I.—GerotocicaL Survey PUBLICATIONS.
1. Tue Grotocy or THE CouNnTRY AROUND MALLERSTANG, WITH
' parts oF WENSLEYDALE, SWALEDALE, AND ARKENDALE. By
J. R. Daxyns, R. H. Trppeman, R. Russexz, C. T. Croven,
and A. Srranan. (Parts by J. G. Goopcuizp, C. EH. De Rance,
G. Barrow, and F. H. Haron.) 1891. pp. 213. Price 3s. 6d.
HE area described by the numerous authors in this Memoir is,
for the most part, an elevated tract rising 2000 feet and more
above the sea-level, and including the sources of the rivers Ure (or
Yore), Swale, Lune, and Eden. The oldest rocks exposed belong
to the Coniston Limestone Series, and of this series the Ashgill
shales form the upper part, and the top of the Lower Silurian (or
Ordovician). The lowest division in the overlying Upper Silurian
system is that known as the Stockdale shales, and it is remarked
that its base is determined principally on paleontological considera-
tions, for there is an abrupt change from the fauna of the beds
below, without any stratigraphical unconformity. Succeeding the
Stockdale Shales are the Coniston Flags and Grits, and the Bannis-
dale Slates. Resting unconformably on the Silurian rocks comes
the great Carboniferous series, including representatives of the
Basement red conglomerate and sandstone (which may be of the
age of the Upper Old Red Sandstone), Lower Limestone Shales,
Great Scar Limestone Series, Yoredale Rocks, and Millstone Grit.
The description of these rocks occupies the greater part of the
Memoir, which indeed deals with the district of Uredale (Yoredale)
or Wensleydale, from which the Yoredale rocks take their name.
Some Permian and Triassic rocks, as well as Glacial Drifts and
Recent deposits, are described. There are also notes on the Lead-
mining, on the Coal-beds which occur in the Yoredale Series and
Millstone Grit, and on the Building-stones. ;
Dr. Hatch contributes notes on the Hruptive rocks; and there is
a list of Carboniferous fossils by Mr. Etheridge.
2 Tue Grotocy or Parts oF CAMBRIDGESHIRE AND OF SUFFOLK
(Ely, Mildenhall, Thetford). By W. Wurraker, H. B. Woop-
warp, F. J. Bennett, 8S. B. J. Sxerrcuty, and A. J. Juxus-
Browne. 8vo. pp. 127. Price 2s.
a this Memoir we have the accounts of the Oxford Clay,
Corallian Beds, and Kimeridge Clay of the neighbourhood of
Willingham, Upware, and Ely. Mr. T. Roberts has contributed
a revised list of the Upware Fossils (from his, as yet unpublished,
Sedgwick Essay of 1885); and Mr. EH. T. Newton has some notes
on the Vertebrata from the Kimeridge Clay, in the collection of
Mr. Marshall Fisher of Ely. Then follow notes on the Lower
Greensand and its Coprolite Beds, on the Gault, and on the several
Notices of Memoirs—Hyatt’s Carboniferous Cephalopods. 549
divisions of the Chalk which includes the Coprolite Bed of the
“ Cambridge Greensand.”
About half the work is devoted to Glacial and Post-Glacial
Drifts, and this includes notes by Mr. Skertchly on beds at Culford,
Mildenhall, and other places, where he obtained worked flints,
believed by him to have come from strata older than the Chalky
Boulder Clay; as Mr. Whitaker remarks, the question is whether
the implements were really obtained from the beds in which they
were reported to have been found.
A number of records of well-sections are given, and there are
ae geological bibliographies of Cambridgeshire and
uffolk.
3. EXPLANATIONS OF HoriIzoNTAL SECTIONS.
Nos. 180 to 139 have been prepared by Mr. C. Fox-Srraneways,
with the assistance of Mr. H. H. Howenn, Mr. Cruement Rem,
and Mr. Grorcr Barrow. They give concise descriptions of the
Jurassic, Oretaceous and other strata in various parts of Hast
Yorkshire. Explanation of Horizontal Section, Sheet 140, by Mr.
Horace B. Woodward, describes the Jurassic and other strata along
a line from Bishopstone, near Hartwell, to near “the Centre of
Hngland” at Wibtoft in Warwickshire. These explanations are.
issued to the public at the modest price of 2d. each.
IJ.—Carpontrerous CrepHatopops. By Aupneus Hyatr. From
Second Annual Report of the Geological Survey of Texas, 1890.
pp. 829-856. (Austin, State Printing Office, 1891.)
HE descriptions given in this paper were taken partly from a
collection forwarded to the author by Mr. HE. T. Dumble, State
Geologist of Texas, partly from specimens belonging to the United
States National Museum, Washington, D.C., and partly from speci-
mens belonging to private individuals whose names are given in
connexion with the specific descriptions. As stated in an intro-
ductory note, the forms here described comprise a larger number
of Carboniferous species than has hitherto been got together in a
single publication. The genera represented are divided between the
Nautiloidea and the Goniatitine. ‘Vo the former belong Temnocheilus
with five species (Forbesianus, latus, conchiferus, depressus, and
crassus, the last three being new) ; Metacoceras with five new species
(cavatiformis, dubium, Walcotti, Hayi and inconspicuum) ; Tainoceras
with one new species (cavatum); Domatoceras, a new genus
allied to Centroceras, represented by the new species wmbilicatum ;
Asymptoceras with one new species (Newtoni) ; Phacoceras with one
new species (Dumbli) ; Ephippioceras with one new species (divisum) ;
and Endolobus with one new species (gibbosus). ‘The Goniatitine are
represented by the genus Gastrioceras with the new species G. com-
pressum. The descriptions are accompanied by outline figures.
900 =. Reviews—Newton’s Eocene and Oligocene Mollusca.
Il].—Procerpines or tHE Cotrreswotp Naturauists’ Frrtp CLus
For 1890-91, Vol. X. Part 2, 1591.
HREE of the four papers in this Number of the Proceedings
are devoted to Geology; even the address of the President,
Mr. W. C. Lucy, is largely concerned with the same science, giving
as it does accounts of excursions to Lydbrook and Symond’s Yat,
May Hill, Hastnor, Swindon, and Avebury.
The first paper is by Mr. H. D. Hoskold, and entitled ‘Geological
Notice upon the Forest of Dean.” In it the author gives a very full
account of the formations, referring to the early work of Buckland
and Conybeare, David Mushet, De la Beche, and others, and adding
a number of new records of the strata passed through at various
collieries. He estimates that the Forest of Dean contains nearly
250 millions of tons of coal available for use—the amount raised
during 1888 was a little over 800,000 tons.
Professor Allen Harker contributes a paper “ On the Geology of
Cirencester Town, and a recent discovery of the Oxford Clay ina
deep well-boring at the Water Works.” He gives accounts of
various wells in the neighbourhood, and announces the discovery
of a small faulted tract of Oxford Clay that was proved by a boring
at Lewis Lane, Cirencester. Important details of the Forest Marble
and Great Oolite are given.
Dr. Frederick Smithe and Mr. W. C. Lucy furnish “ Some
Remarks on the Geology of Alderton, Gretton, and Ashton-under-
Hill.” Their descriptions refer to the Middle and Upper Lias, and
they give lists of fossils from these formations at Alderton Hill.
Among the records are Ammonites radians from the Upper Lias
(lower part), and 4. aalensts from the Middle Lias; identifications
which we anticipate will be doubted by those who believe in the
rigidity of zones.
RV Lew Ss.
I.—Systematic List or THE Freprerick EH. Epwarps CotLnotion
or Bririss Oxicocenr anp Eocene Mouiusca in THE British
Museum (Natural History), with references to the type-specimens
from similar horizons contained in other collections belonging to
the Geological Department of the Museum, by Ricuarp BULLEN
Newton, F.G.S. [With Appendix by G. F. Harris.] London,
printed by order of the Trustees and sold by Longmans & Co. ;
B. Quaritch; Dulau & Co.; and Kegan Paul, Trench, Tribner
& Co., Paternoster House, Charing Cross Road, W.C. 8vo. pp.
Xxvili. and 365, 1891.
HIRTY-SEVEN years have elapsed since the historic “Catalogue
of British Fossils,” by Professor John Morris, saw its second
edition published ; a modest work of 372 pages, 8vo., embracing all
classes of fossil-remains.
Since that date, a long array of British Fossils have been figured
and described, many groups of the Invertebrata being fully Mono-
Reviews—Newton’s Eocene and Oligocene Mollusca. 551
graphed, as for example, the Brachiopoda, by Dr. Davidson; the
Sponges, by Dr. Hinde; the Blastoidea, by R. Etheridge and P. H.
Carpenter; the Merostomata, by Dr. Woodward. In others great
progress has been made as in the Foraminifera by Carpenter, Parker,
Jones, and Brady; the Hydroida by Nicholson; the Polyzoa, by
Busk and Vine; the Trilobites by Salter and Woodward; the Ento-
mostraca and Phyllopoda, by Prof. Rupert Jones; the Corals, by
Prof. Duncan; the Echinoidea, by Wright; the Decapod Crustacea,
by Bell and Woodward; the Cephalopoda, by A. H. Foord; and the
Tertiary Mollusca, by F. E. Edwards and Searles V. Wood.
In CaraLoGurs, serving as supplements to Morris, we have (1),
a complete “Catalogue of British Fossil Vertebrata,” by Arthur
Smith Woodward and C. Davies Sherborn, 1890, 8vo. pp. xxxv. and
896; larger by 51 pages than the space occupied by Morris for the
whole of the classes of Planta and Vertebrata in 1854. (2), Fossils
of the British Islands Stratigraphically and Zoologically Arranged,
Vol. I. Patzozoro, by R. Etheridge, F.R.S., 4to. 1888, pp. 475, giving
6022 species from the Cambrian to the Permian.
Mr. Etheridge tells us that Vol. II. Mesozoic, and Vol. IIL.
Cainozoie, are sitll in MS., and, adding their contents to the Paleozoic
volume already published, we have 18,000 species of British Fossils,
both Fauna and Flora, up to 1888.
Morris’s Catalogue, up to 1854, records a total of 8359 species ;
so that, according to Etheridge, there had been an increase of at
least 10,000 species in thirty-four years from 1854 to 1888.
The only other catalogues which supplement Morris’s Catalogue
are British Fossil Crustacea, by H. Woodward, F.R.S. (1877); Fossil
Foraminifera, by Prof. T. Rupert Jones, F.R.S. (1882) ; Palaeozoic
Plants, by Robert Kidston, F.G.S8. (1886) ; and lastly that of the
Edwards Eocene Mollusca, by Mr. R. B. Newton, now before us
(dated 25 July, 1891).
This important work gives us a carefully prepared record of 1229
described species of British Hocene and Oligocene Mollusca, dis-
tributed in 255 genera; 428 being Lamellibranchiata, 786 Gastero-
poda, and 15 Cephalopoda.
In addition to the whole of the Edwards Collection, this volume
also contains a record of all the “types” of Eocene Mollusca con-
tained in the Bowerbank, Brander, Brown, Dixon, Gardner, Mantell,
Prestwich, Shrubsole, William Smith, Sowerby, Wetherell, and Wise
Collections, all preserved in the British Museum of Natural History.
Every species bears after it its author’s name, the date when given,
and references to the principal works where it has been figured and
described, with its synonyms, and lastly the horizon and locality in
which it occurs.
570 MS. names of species, proposed by F. EH. Edwards, are also
given; but as these have never been described, they cannot be
considered as of value, save as indicating that Mr. Edwards
believed they marked new and undescribed species. Many of
these names have been printed in various lists previous to the
publication of Mr. Newton’s Catalogue; and the author states (in
502 Reviews—Newton’s Eocene and Oligocene Mollusca.
his Introduction, page v) his intention to describe and figure all
those specimens bearing MS. names in due course; we hope he will
keep his resolution strong, and get them all as speedily as possible
stamped with the imprimatur of authority.
Apart from this, the work is a step in the right direction. which
all who are interested in Malacology will be delighted to welcome.
For many years past the nomenclature adopted for the fossil Mollusca
in England has been much behind the times, many quite dissimilar
forms being frequently included in the same genus. In the work
before us, as the result of recent researches, many of these old
genera have been split up into two or more genera, and although
the older workers may denounce this as fiercely as in Joshua’s days
they cursed the man who removed his neighbour’s landmark, never-
theless, in a more calm and philosophical state of mind, we are
compelled to admit that these adjustments, if honestly and judiciously
made, must be of material assistance to the student in the future,
especially if he is attempting to correlate (as he ought) the recent
with the fossil forms.
This revision has not been carried out always with equal rigour
by the author. The old genus Cerithium, for example, has been
very properly split up into several genera; but Pleurotoma, which
also needed revision, is retained in full force, although numerous
Malacologists have shown that it comprises many genera well
known to the student of living mollusca.
Again, the genus Chrysodomus, in the work before us, includes
a number of diverse forms which might have been dealt with more
analytically by the author.
In a first attempt at completing such a task as was left behind
unfinished by F. E. Edwards and Searles V. Wood, it must necessarily
follow that much more is needed before the work can be said to be
thoroughly accomplished.
Tn carefully following the original authors in their varied spelling
of species, and terminations of the names, Mr. Newton has laid
himself open to criticism from the more exact writers on recent
and fossil shells, who would, in their earnest desire for uniformity,
alter the terminations of such names so as to bring them all into
one regular line, like a regiment under inspection ; but, unless
absolutely a misspelling, many writers consider such alterations of
names actually wrong.
Thus Deshayes’ name is used specifically in eight different
genera, and by as many different authors, four species being spelt
Deshayesii, and four Deshayesi. Similarly. we have Bowerbanki on
page 22, and Bowerbanki on page 219; Wetherellii on page 26, and
Wetherelli on page 215. In each case the names are by different
authors, and given according to their own notions.
Some few specific names vary to the extent of two final letters.
Thus we have Cardium Etheridgii, p. 51, and Helix Etheridgei, p. 270;
Aporrhais Sowerbii (p. 97) Bullinella Sowerbyi (p. 266), and Planor-
bis Sowerbyi (p. 283); but different authors have each adopted their
own termination, and these Mr. Newton has retained and respected.
In the matter of generic names, and the changes which they have
Reviews— Harris and Burrows—Paris Basin Mollusca. 5538
undergone, it would be no exaggeration to say that numbers of these
genera have now as many aliases as a notorious pickpocket or a
crack burglar.
If opinion as to the lines upon which alterations of names should
be made was only unanimous, much labour would be spared. Some
Naturalists hold that a name used for a genus of Vertebrates, as
Palgoniscus, Blainville, 1818, for a genus of fossil fishes ; and
Palgoniscus, Milne-Hdw., 1848, for a genus of fossil Isopods, need
never disturb our peace of mind or our nomenclature; but it seems
to be considered desirable that such repetitions should as far as
possible be eradicated from the Index Zoologicus.
Names, once familiar as household words, are now constantly being
swept away, and all our ancient landmarks cast down. But we are
told it is for our good, and, like the “nasty doctor’s stuff,” we are
bound to swallow it. We would like, however, to see these changes
effected with more reverent and careful hands, and without that
indecent haste which too often marks the action, as if the alteration
of a name were a noble achievement in science, whereas it too often
simulates, but in a more humble sphere, those barbarian conquerors
of Egypt or of Nineveh, who erased every preceding monarch’s
name on temple and on palace and substituted their own. There is
something more in science than a name, and those who would earn
the gratitude of posterity may do so by adding to the walls of her
ever-rising temple some well-worked stones: let whoever will, after-
wards, cut or scratch his name thereon, he will at least have the
nobler satisfaction of having done a piece of solid work.
The Introduction deals with the alterations in nomenclature made
by the author; there is a good Bibliography (pp. 299-825), followed
by a very useful Appendix prepared by Mr. George F. Harris,
F.G.S., “On the Correlation of British with Continental Tertiary
Strata,” illustrated by a series of small tables and a large folding-
table. which gives the equivalents for each horizon, as far as possible,
for English and Foreign localities where Tertiary fossils have been
obtained. This cannot fail to prove most useful to all students and
workers in these deposits. and is an excellent piece of work.
We congratulate Mr. Newton on the completion of his Catalogue,
and hope he will follow it up with figures and descriptions of the
new or little known species of Hocene shells in the Edwards
Collection in the British Museum.
II.—Tue Eocene anp Oxrcocens Bens or True Parts Basin. By
Grorce F. Harris, F.G.S., and Henry W. Burrows, A.R.1.B.A.
(A Paper read before the Geologists’ Association April 3, 1891).
Published by Edward Stanford (Price 3s.). 8vo. pp. vill. and
130. September 28rd, 1891. Illustrated by a Geological Map
and numerous Sections.
JHE Geologists’ Association can no longer be spoken of as a young
Society, and hardly deserves the title of a Society of Amateur
Geologists. It was established in 1859, and is consequently in its
thirty-third year, and numbers amongst its 550 members a large
proportion of the most eminent and accomplished geologists and
554 Reviews—Harris and Burrows—Paris Basin Mollusca.
paleontologists in England. Its Proceedings have become the
depository of a most valuable series of Memoirs; the records and
illustrations of its excursions, which extend to Belgium, France,
and Italy, form a volume by themselves; and having, if we may
assume, exhausted the geology and paleontology of their own
country, they are attacking and peacefully re-conquering the
arcient country of France, by publishing, in a separate form, a
Memoir on the Eocene and Oligocene Beds of the Paris Basin.
The authors of this work have qualified themselves for the task by
repeated careful examinations of the French Tertiary area, and one
of them by an extended traverse over other parts of the Tertiary
formations of Europe. They justify the special study of the
French Tertiaries on the ground “that no adequate conception can
be formed as to the meaning and value of our own Tertiary beds and
their organic remains without conjointly studying those on the other
side of the Channel—especially in regard to the paleontological
aspect of the subject.” They point out that the Mollusca have
always afforded the best basis for correlating the several horizons
in France, Belgium, and England, by reason of their abundance,
their wide distribution, and the very perfect state of preservation in
which they occur, especially in the Paris basin; so that the French
area supplies, as it were, the key by which to open up and interpret
correctly the sequence and life-history of other Hocene and Oligocene
strata in neighbouring areas.
The authors deal especially with the Mollusca, and in order to
equip themselves thoroughly for the task, they have worked very
carefully and critically over the great French collection acquired
from G. P. Deshayes some forty years since, and preserved in the
Geological Department of the British Museum (Natural History).
These specimens bear, in almost every case, Deshayes’ original labels,
and therefore form a valuable basis for fixing their nomenclature
even where, as in so very many instances, these names have now to
be exchanged for more modern and presumably more correct deter-
minations. They have also visited and examined the chief collections
in Continental Museums.
Pages 1—44 of this Memoir are occupied with a carefully prepared
description of the Eocene and Oligocene Beds of the Paris Basin,
well illustrated with sections at Issy ; at Cuise-la-Motte; at Arcueil ;
at Auvers; near Ver, on the road to Ermenonville; at La Chapelle-
en-Serval ; at Butte d’Orgement ; and Quarry of Vintué, near Ktrechy.
In each, the lithological characters of the several beds are clearly
given, as well as the typical Mollusca which mark each horizon.
This is followed (pp. 44-56) by an Outline Guide to the principal
sections and fossiliferous localities. Here is useful practical advice
to collectors (p. 45). ‘A word or two as to the collection of fossil
may be useful. Strong calico bags of various sizes, but mostly large,
say 12in. by Tin. to Tin. by 4in. are the best receptacles for fossils,
and they should be so made that the mouth can be drawn together
and tied by tape. A brass ring sewn on enables several bags to be
threaded on a strap and carried with ease, without fear of breaking.”
“ Sift! is the watchward in the Paris area, as the smaller species of
Reviews— Harris and Burrows—Paris Basin Mollusca. 555
mollusca are always missed if this be neglected. Two wire sieves,
one sixteen meshes and the other eight meshes to the linear inch,
are suitable. A hammer is not often required; a pointed trowel,
with a blade 5 in. or 6 in. long, is exceedingly useful for taking
up the loose material. Some chip boxes, to hold the rarer or more
delicate species, should be provided. A written label, tied to the
ring of each bag, shows at a glance the locality and formation of
the contents. For the fossils of the Sables Inférieurs, some preserva-
tive, such as potassic silicate, is required; or they may be brought
away wrapped in cotton-wool, and subsequently treated. But by
far the greater number of the fossils are in a magnificent state of
preservation, and are easily collected and carried without the least
risk of fracturing them.” Thus equipped, and with Messrs. Harris
and Burrows for travelling companions, we visit more than eighty
localities, and have a really good time. Those who cannot arrange
to be “ personally-conducted” by the authors, must spend “three
shillings nett,”’ and have the benefit of their printed directions, with-
out which it will be next to impossible to make a successful tour to
the many widely-separated rural French districts. And here the
excellent Map, which accompanies this book, proves most useful.
The last section (pp. 57-129) is occupied with a description of the
Palzontology of the Eocene and Oligocene Beds of the Paris Basin.
The authors have received the assistance of Mr. Arthur Smith
Woodward with the Vertebrata (a careful list of which is given,
including Mammalia, 19 species; Aves, 12; Reptilia, 10 species ;
Pisces, 38 species). The Arthropoda are credited with 5 genera;
the Hchinoidea with 14 species; the Brachiopoda with 20 species ;
the Bryozoa with 4 species; the Actinozoa with 11 species; the
Foraminifera are too numerous to catalozue. The Plante are briefly
referred to. References are given to authors for the several groups ;
so that the student may go to the original works in every case.
The Mollusca occupy from pp. 63-124. Tables are given of all
the species, arranged with columns showing the range of each from
the Lowest Eocene; the Lower Eocene; the Middle and Upper
Eocene. The Oligocene Mollusca form a separate table. These
Tables of Genera and Species, which occupy 48 pages of the work,
produce the following summary.
For the Eocene Beds of the Paris Basin :—
Pelecypoda or Lamellibranchiata (including additional species
on page 114 supplied by Cossmann) ... ... ... ... ... 1083
Oligocene Lamellibranchiata 112
—- 1195
Eocene Gasteropoda (including additional species supplied by
Cossmann, pp. 114-118) ee een ee ees D002
OleorenelGasteropodar? \We.. Pick c..kens sl Gant asel ticcateseen LMT
GasteropodaPulmonata | 25-0 @ C2 > ENG
ADDRESS TO THE GEOLOGICAL SEOTION oF THE Britisa Assocra-
TION, BY Proressor T. Rupert Jonus, F.R.S., F.G.S., President
of the Section, Cardiff, August 19th, 1891.
(Concluded from the November Number, p. 524.)
Looking at these Coal-measures alone, and considering that slow de-
pression accompanied their formation, the mind is strained in estimating
the time required for the gradual subsidence to 10,000 feet, with shallow
water always in place, and jungle growing steadily after jungle, inundation
following inundation at intervals,—and is somewhat confused in reasoning
on the possible causes and the exact processes by which not only the
sinking of this region of the earth’s crust was brought about, but how, in
turn, the 10,000 feet of new accumulations and deposits were raised into
the great undulations, which Professor Ramsay has described and depicted
in his Memoir before mentioned, and how and when they were slowly worn
down day by day into the present beautifully varied surface of South
Wales and adjacent country.
I may here remark that the analogous coal-field of Nova Scotia, investi-
gated by Sir W. E. Logan, Sir J. W. Dawson, and others has a thickness
of 14,570 feet, including seventy-six seams of coal and ninety distinct
Stigmarian underclays.
Mr. W. Galloway communicated, in 1885, to the Cardiff Naturalists’
Society 1 some valuable observations on both the vertical and the horizontal
occurrence of different coals in South Wales; and showed by a map (pl. iii.)
where the ‘seam-coal’ mainly exists in the large eastern third; the
‘intermediate coal’ in the narrow middle third ; and ‘anthracite’ in the
western third of the Glamorgan-Monmouthshire area. He refers to the
gradual transition from bituminous to anthracitic coal along a hypothetical
plane passing through the coal-field, with its major axis lymg E.N.E.—
W.S.W., and its minor axis dipping at a very low angle towards 8.8.E. He
accepts Professor Geikie’s tabular scheme of the strata at p. 24. Mr. W.
Galloway has favoured me with the following remarks on the vertical place
of the several kinds of coal in the series :—“ The long-flaming bituminous
seams are about 700 yards higher in the ground than the semi-bituminous
seams ; the semi-bituminous, or good steam-coal seams are 200 or 300
yards above the dry steam-coal seams; the last are perhaps 300 yards
above the bastard anthracites ; and these inferior anthracites may be 400
yards or more above the perfect anthracites. You have thus somewhere
about, say, 1500 or 1600 yards from the long-flaming coals to the
anthracites. It may be a good deal more in some parts of the coal-field ;
but, as the deepest shaft is only about 800 yards, we cannot get a direct
measurement,”
Of these three sorts of coal—the long-flaming dry coals above have some
seams suitable for gas-making ; the middle are caking coal, good for making
coke ; the others produce dry steam-coal and anthracites.
6. Output of Coal in South Wales.—The following is the official account
of the quantity of coal raised in South Wales last year as compared with
that got ten years ago :—
1 Trans. vol. xvil. 1886, pp. 20-34.
Prof. T. Rupert Jones— Address. 561
Table showing the Output of Coal in the South Wales District in the Years
1880 and 1890.
Increase or
Decrease in the
County. 1880. 1890.
ten years.
; Tons. " ‘Tons. Tons.
Breconshire ... ... ... 100,616 259,260 +158,644
Caemarthenshire ... ... 625,933 762,032 +136,099
Glamorganshire .,. ...| 15,320,096 91,426,415 +6,106,319
Monmouthshire a Sse 5,039,549 6,895,410 +1,855,861
Pembrokeshire ... ... 79,386 71,908 —7,478
Totals: South Wales.) 21,165,580 29,415,025 +8,249,445
Total Output for the United Kingdom.
Total Increase in
nee 1820; the ten years.
: Tons. Tons. Tons.
England, Wales, Scot-)| 146 969,409 | 181,614,288 34,644,879
land and Ireland ...
Dr. E. Hull refers to the increased production in the South-Welsh Coal-field,
together with remarks on other fields and the future supply and working of coal,
in the ‘‘ Transactions of the Edinburgh Geological Society,’’ vol. vi. part 2, 1890,
where also Mr. H. M. Cadell follows with valuable notes on the probable future of
the coal-trade.
7. Varieties of Coal.—The coal of the British Coal-fields exhibits every variety
of composition between anthracite, which is nearly pure carbon, and the so-called
bituminous coals, such as ordinary coal and cannel coal (hydrocarbons), rich in
hydrogen. Anthracitic beds are rarely seen except in districts where the strata have
been much disturbed, or peculiarly affected by other circumstances. Heat, whether
direct or induced by pressure, vertical or lateral, has probably been the important
agent in depriving coal of its hydrogen with some of its carbon, and thus changing
it into anthracite. Neither in this latter nor in the compact cannel coal are the
laminar structure and symmetrical jointing so distinct as in the ordinary coals. The
last lose their volatile hydrocarbons also by exposure to the air, at outcrops and in
open faults; hence they are not nearly so good for burning as those got at a greater
depth. As it is well to have definite notions as to the appearance and structure of
the different kinds of coal, some notes on the several sorts will now be offered.?
Anthracite is glossy or semi-lustrous, sometimes iridescent ; it ignites with
difficulty, and burns without smoke, and with little flame, on account of no volatile
hydrocarbons being formed during combustion. This purely carbonaceous material
differs from ordinary coal by its brilliant, semi-metallic lustre, its greater density,
hardness, and brittleness, and by its massive and conchoidal fracture with sharp
edges. Some of it can be cut or turned on the lathe into fancy articles.
Called anthracite (from av@pat, coal) by Karsten and the older mineralogists,
it is also known as mineral carbon, blind-coal, stone-coal, culm, glance-coal, and
non-bituminous coal. It is mentioned by mineralogists and geologists as having
been found at many places in the Alps, Pyrenees, France, Germany, the United
States, and the British Isles, under various geological conditions; but in regular
and extensive beds it occurs chiefly in Pennsylvania, and largely also in South
Wales. It is reported to have been found in China and elsewhere.
In the Franco-Belgian coal-field the coals become more and more anthracitic as
they pass down to greater depths ; both kinds, therefore were of the same age in
1 Much information as to the constitution’ of coal and its varieties is given in
Roland and Richardson’s Chemical Technology.
DECADE III.— VOL. VIII.—NO. XII. 36
562 Reports and Proceedings—
formation; in South Wales also, as already stated, the anthracite and the other
coals are all of one age. The squeezing, faulting, and inversions in the former field
are accompanied by an alteration of the highly bituminous coals into dry coals and
anthracite. ,
An interesting historical sketch of the use of anthracite, and some systematic
remarks on its distribution in South Wales, were given by J. P. Bevan, F.G.S., in
the ‘‘ Geologist,’’ vol. 11. 1859, pp. 75-80.
The anthracite of Pennsylvania is traceable from the inner folds of the mountain
chain, where the strata have become more and more crystalline, and contain
graphite as well as this non-bituminous coal, westward into Ohio, where the same
beds consist of ordinary coal. In the eastern part of the Allechanies the coal has
only 6 to 14 per cent. of volatile matter, further west 16 to 22 per cent., 30 to 36
per cent., and in Ohio 40 to 50 per cent. (Prestwich). This coal-field before compres-
sion was probably 900 miles long by more than 200 broad in some places (Lyell).
The depression of strata by accumulated sediment above them may raise their
temperature by the rise of the isogeotherms (surfaces of equal subterranean tempera-
ture), and they may reach a relatively high temperature. ‘‘ Mere descent to a
great depth, however, will not necessarily result in any marked lithological change,
as has been shown in the cases of the Nova-Scotian and South- Welsh coal-fields,
where sandstones, shales, clays, and coal-seams can be proved to have been once
depressed 14,000 to 17,000 feet below the sea-level, under an overlying mass of
rock, and yet to have sustained no more serious alteration than the partial conversion
of the coal into anthracite. They must have been kept for a long period exposed
to a temperature of at least 212° Fahr. Such a temperature would have been
sufficient to set some degree of internal change in progress had any appreciable
quantity of water been present, whence the absence of alteration may perhaps be
explicable on the supposition that those rocks were comparatively dry.’ +
Coal in contact with granite is changed into anthracite or graphite; when in
contact with voleanic and trappean rocks,-it may become coke (columnar or other-
Wise) or mere soot.
Steam coal is very compact, burns with little smoke, and contains so little
bituminous matter that it is not liable to spontaneous combustion, whether pyrites
be present or not. It is an intermediate kind of coal, having more hydrocarbon
than any anthracite has.
Ordinary coal, common coal, household coal, pit coal, black coal, coal proper,
bituminous stone coal; of this there are several sorts :—
1. Oaking coal, coking coal, bitwminous coal (not really bituminous, but containing
the constituents of bitumen—7 to 9 per cent. of hydrogen, with carbon and oxygen,
or 4 to 6 per cent. of hydrogen and 6 to 8 per cent. of oxygen). When heated, it
undergoes a kind of fusion and ‘cakes’ together, one piece adhering to another by
the soft bituminous matter into which it is mainly changed. Such coals are used
for coking, coke being more or less impure carbon left after the hydrocarbons have
been driven off.
2. Cherry coal, or soft coal, is thinly laminated, soft, velvety, short-fractured,
friable.
3. Splint coal (breaking off in long ‘boards,’ and into fragments with angular
ends called ‘splints’—Mushet), bone coal, hard coal, free-burning coal, dry coal
(passing into shaly, slaty, and stony coal). This is less bituminous than some of the
foregoing ; burns free and open (that is, without swelling and caking), with a long
smoky flame; with less than 6 to 8 per cent. oxygen and 4 to 6 per cent. hydrogen ;
it is also called dry coal. The hard coal comes out in long blocks; the cherry coal
in short pieces.
Reedy coal has alternate layers of splint coal and bright coal (Mushet).
Cannel coal, or parrot coal, is compact, and varies from lustrous to a dull earthy
aspect; breaks irregularly, but with a conchoidal (shell-like) fracture; can be
polished and cut into ornaments in a lathe. Yields mineral oil by distillation.
Much used in gas-making ; not fit for coking.
Torbanite, Torbanehill mineral, Boghead cannel-coal, or Boghead coal, is a kind of
dark brown cannel-coal, good for making gas and oil (parrafin, etc.), and gives a
light, spongy coke. It consists of minute light brown granules of hydrocarbon, with
some earthy matter and portions of the tissues of coal-plants.
1 Geikie, “‘ Textbook,’’ etc., 2nd edit., 1885, p. 273.
Prof. T. Rupert Jones—Address. 568
As a scheme for the general classification of coals the following table may be
useful :—
Torbanite, cannel-coal, aa matter
parrot-coal much altered.
Gasicoalsimeae
minous. . Tasmanite, Better-bed
coal, etc. a } Spore-coals.
Common Bitu Household coals ..
cherry coal, splint coal, (mother-coal) &
Highly a
minous ...4
Caking and coking coal, | Laminee of charcoal
- (
} and other coals hydrocarbon.
Semi - bitumi-) Free-burning { 1. Charcoal deposited abundantly at first.
WOUS:; :
Anthracitic .
| steam coals... | 2. Hydrocarbon partially lost by change.
Pee pos eee Hydrocarbon nearly all lost by change. '
All the hydrocarbon lost by heat under pres-
sure.
Anthracite ... Smokeless coal
Coke ... 240) Sees ny \ Hydrocarbon lost by heat without pressure.
8. Constituents of the Coal-measures and of Coal.—Sandstone, shale, coal and
clay, in successive repetition, constitute (as we all know) the main materials of the
‘Coal-measures’ (‘ measures’ being an old mining term for strata). Each of these
substances well deserves the close investigation they have received from numerous
observers. We need not take the sandstone in hand now; it will be enough to
say that the quartz-grains have been derived from the quartz of the same granite
rocks which gave the little mica-flakes to mix with much of the sandstone, and the
kaolin to form the basis of the shales and clays in the same great Carboniferous
formation.
Shales and Ironstone.—The shales are varied ; some are almost purely argillaceous ;
others contain carbonaceous matter in different proportions, even becoming quite
black and bituminous. The lighter-coloured shales often have plant-remains,
especially ferns, scattered through them, and even whole stems and branches of
Lepidodendron and Sigiliaria, squeezed flat, and reaching long distances. The
darker shales also have plant-remains, but less perfect, and very often shells and
other fossils, including relics of fish and numbers of small bivalved crustaceans ;
with regard to the last, the fishes, when alive, fed on the Cypride and other
organisms, and in turn these little Ostracoda ate the dead fishes when they could.
Here and there are more or less continuous layers of cronstone, or more frequently
groups of nodules parallel with the planes of bedding, and containing either parts
ot plants, more rarely small limuloids or other crustaceans, or even spiders, scor-
pions, insects, or relics of fishes and amphibia. In some cases the shales are of
marine origin, judging from the character of the shells imbedded in them; but
usually the evidence from the fossils is of a negative character. The shells that
were tormerly thought to be mussel-shells, like freshwater Unios, are now known
to belong to a different family ; and, not being quite the same as any known sea-
shell, they may have been estuarine.
The nodular and the flat masses of clay-ironstones in the shales have been due
to the formation of carbonic acid in the water and mud by the decomposition of
vegetable matter and the removal of some oxygen from the peroxide of iron present
there, and by the carbonic acid thereupon forming carbonate of iron. This then
segregated around some organic object in the mud, and, mingled with clay, gave rise
to nodules or larger masses of argillaceous ironstone.! In consolidating the nodules
frequently split internally, and the fissures of retreat, filled with calcite, blende,
pyrites, or other mineral, constitute septa, or divisions, in the septarium or septarian
nodule. The so-called ‘ beetle-stones’ are septarian nodules broken across, showing
central and diverging lines.
The iron-ores of South Wales are fully treated of in the ‘ Memoirs Geol. Survey,’
Tron-Ores, part iii. 1861, by E. Rodgers, and their fossils by J. W. Salter. From
official sources we learn that the details of Production of Ironstone, chiefly Argilla-
ceous Carbonate, from mines under the Coal-mines Regulation Act, for the year
1859 were —
1 De la Beche, ‘“‘ Memoirs Geol. Survey,’’ vol. i. pp. 185, 186.
564 - Reports and Proceedings—
Total | Average |Total value | Amount
: : price |of ironstone} of metal
pouty CHES ean per ton. jat the mine.|obtainable
Tons all ee Dons. wiles. a: £ Tons.
-_, (Hastern part of 50 ll 6 29 \
Breconshire \ Western part o 462} 512 { 9 0 208 |
Caermarthenshire Bee Peal ot, coe 118 oo 53 +
Glamorgan- {Eastern part of — E 12,548
shire... {Western part of 93,764} Fenlo- 2 ee
Monmouthshire ... ... 0 ...) — 17,485 | 11 6 10,025 )
24,276 | 41,829 pe 21,009 =
In Mr. J. P. Lesley’s “ Manual of Coal,” etc. 8vo. Philadelphia, 1856, at pp.
22, etc., the variations in shales, and their passage even into coal, as the proportion
of carbonaceous (vegetable) matter increases by local conditions, are carefully
detailed.
Coal, Mother-coal, Coal-balls, etc.—The coal itself, to which the shales (‘ batts,’
‘binds,’ etc., as they are variously termed) usually serve as a roof, or in which they
form ‘ partings,’ or thin intermediate layers, comes next to be considered. Some
remarks on the different kinds of coal have already been made. Common black coal
is easily seen to be composed of thin alternate lamin of dull and bright material,
and usually the blocks or pieces have flat sides nearly at right angles with those
delicate layers of deposition. These faces are due to shrinkage-joints ; one is termed
the ‘ face’ (as it is presented on the long edge of the seam exposed in working), or
the ‘bord,’ and the other or cross joint is the end; the former is also called the
‘cleat,’ and this term is sometimes applied to both sets of joint-divisions. The
block of coal usually breaks also along the flat lamine, exposing a somewhat dull,
charcoaly surface, more or less interfered with by the next-lying bright lamina. The
dull parts are real charcoal, or decomposed wood, and soil the fingers when touched ;
whilst the bright, or hydrocarbon, portion keeps clean when dry. On the fire the
coal breaks more easily along the lamin, because the bright portion softens and
swells up with its bituminous change, and the ‘ mineral charcoal,’ or ‘ mother-coal,’
keeps the portions distinct for a time; so also the jointings open then, or give way
easily to the poker.
The mineral charcoal may readily be seen to be flat fragments of woody tissue in a
carbonised state ; it is more or less impregnated with bituminous or mineral matter
from the associated beds, and retains the mineral matter of the original wood. It is
due to ‘‘ the chemical changes experienced by woody matter in decay in the presence
of air,’’ when ‘‘ wood parts with its hydrogen and oxygen and a portion of its
carbon, in the forms of water and carbonic acid. . . . Under water, or imbedded
in aqueous deposits, the principal loss consists of carbon and oxygen; and the result-
ing coaly product contains proportionally more hydrogen than the original wood.
This is the condition of the compact bituminous coal.” !
The ‘ mother-coal’ necessarily indicates a periodical change (maybe that of the
rainy season) in the formation of a coal-seam, for it lay exposed, as decaying wood,
whilst that which was accumulated just before must have been sufticiently covered
up by water (a few inches may have been enough) to undergo the advanced chemical
changes causing a proportional increase of hydrogen. The dead sticks and stems
projecting out of and above the water-covered peaty mass below would naturally
supply the decaying touchwood and charcoal now lying as described above.
Doubtless a progressive change in the elaboration of hydrocarbon soon took place
to some extent, even as it does in peat; but probably it was not completed in the
compact coal until many layers ot both vegetable and earthy matters had been
accumulated (the former in place, and the latter from inundation), and caused some
amount of pressure and consequent heat.
As, under favourable circumstances, the bright coal can be seen to have been
made up of spores, leaves, branches, and stems of special trees, and other plants,
the place of growth must have been a swampy forest or jungle, of enormous extent,
1 Dawson, Quart. Journ. Geol. Soc., yol. xv. 1859, pp. 627, ete.
Prof. T, Rupert Jones—Address. 565
probably in a warm (perhaps sub-tropical ') climate, to account for the hundreds of
square miles of continuous coal-seams.
Much has been learnt from the broken and rotting ruins of a forest, standing on
an area of the coal-growth, having been here and there sealed up and preserved in
that original state, before hydrocarbonisation had proceeded far; whilst the rest of
the fallen timber and accumulated relics passed into the state of bright coal, and
became almost undistinguishable as to its structure except under the microscope after
special manipulation. ‘The ‘coal-balls’ of Oldham, in Lancashire, and the ‘ bullions’
at South Owram, in Yorkshire, are calcareo-carbonaceous nodules, having been
formed by the infiltration of water carrying carbonate of lime from the shells in
an overlying shale down into the bed of woody fragments and other bits of dead
plants. The carbonate of lime there segregated from the mass to certain centres,
and preserved, in round nodules, the vegetable structures, before they were quite
decomposed, more or less distinct as they had fallen on the forest floor. Hooker,
Binney, Williamson, and others have elucidated much of the botany of the coal
from this source.
In the Lower Carboniferous series at Pettycur Bay, Burntisland, in the Firth of
Forth, are some well-preserved relics of the materials which would otherwise have
been used to form a coal-seam (referred to by Williamson and Binney). In this
ease volcanic material has been ejected into or through a peaty mass, and, having
removed by force some of the soft wet material, has been mixed up with it and
settled down as a hard stratum, with well-preserved fragments of wood and other
tissues, into which carbonate of lime was subsequently infiltered (Carruthers).
A third instance was discovered by Mr. Wiinsch, in 1865, in the Lower Car-
boniferous series on the north-eastern shore of the Isle of Arran, where numerous
plant-remains are well preserved in and under volcanic ashes. ‘The strata are
alternate sandy shales, thin coal-seams, and peperino-like tuff. Numerous truncated
trees remain upright, rooted in the shale. Sigillaria, Lepidodendron, Lepidophloios,
and Halonia, besides Sphenopteris and other ferns, are present.”
Cannel, etc.—Under the name of ‘cannel’ are known some important varieties
of coal, useful for distillation and gas-making; and certainly they differed in their
method of deposition both from ordinary coal and in some particulars among them -
selves. They all appear to have been formed of vegetable matter that, having
been soaked and macerated to a black pulp, like the most rotten and semi-fluid
peat, in lakes, lagoons, or other limited water-areas, became homogeneous masses
of hydrocarbon, with much still discernible vegetable tissue, and occasionally with
bones, teeth, and scales of fishes, and remains of Amphibia. Earthy matter was
sometimes mixed with the cannel; and occasionally so much accumulated that
the black mud graduated into carbonaceous shale. Light substances would also
have been blown into the water by wind. According to the relative abundance of
yellow-reddish hydrocarbons and macrospores, or of amorphous black substance
(carbon) and microspores, is the difference between black and brown canunel
(Carpenter).
Elsewhere the condition and place of the cannel are such as to suggest that, like
a burst peat-bog of the present day (Buckland), the fluid carbonaceous pulp escaped
from its birthplace, and found local hollows at lower levels that could receive and
keep it. It is also suggested that such black, decomposed, fluid refuse of a swampy
jungle, bordering a lagoon, might drain into the water, and settle as carbonaceous
mud, or as coal itself, among the water-plants there (Grand’Eury). If poured in
suddenly, it probably overwhelmed and poisoned many fishes. ‘The cannel coals,
being wholly subaqueous, have not formed and do not possess mineral charcoal ”’
(Dawson)
Torbanite consists almost entirely of minute sub-globular accretions of hydro-
carbon (amber-coloured by transmitted light), derived either from chemical change
of plant-remains, or more probably, directly from lycopodiaceous spores.
Spore-coal.—Very much of the substance of some coal-beds consists of hycopo-
diaceous spores that have been traced to the great lycopods, Lepidudendron and
Sivillaria, allied to the club-mosses and Selaginelle, and were probably shed
periodically in enormous quantities (Prestwich and Morris, Hooker, Binney,
1 A great predominance of ferns and lycopods indicates moisture, equability of
temperature, and freedom from frost, rather than intense heat (Lyell).
2 Grou. Maa. 1865, and Trans. Geol. Soc. Glasgow, 1882.
066 Reports and Proceedings—
Williamson, Carruthers, Balfour, Huxley, E. T. Newton, Orton, Dawson, Rheinsch,
Wethered, Bennie, Kidston, and others). Mr. E. Wethered has suggested that the
chief material in common coal was derived from the spores of a water-plant nearly
allied to Zsoétes, and that woody material has supplied but little of the hydrocarbon.
He objects to the theory of “submerged forests’’ because of the difficulty that
Professor Dana has described, resulting in the calculation that for a four-foot seam
of coal there would be required a thickness of 32 feet of accumulated forest
vegetation and 48 feet for four feet of anthracite.| The macrospores of Isoétes
lacustris have been found in the mud dredged in Loch Coulter, Stirlingshire, by
Mr. Thomas Scott.?
‘Dawson is disposed to think that the tuberin of cork, of epidermis in general,
and of spore-cases in particular, is a substance so rich in carbon that it is very near
to coal, and so indestructible and impermeable to water that it has contributed more
largely than anything else to the mineral.’’ Prestwich refers to these, and especi-
ally to gums and resins, as main constituents of the coal; and argues that the climate
was warm and moist, with a larger percentage of carbonic acid than exists at the
present day, and a more rapid plant-growth.4
Messrs. Bennie and Kidston® have not only carefully given the botanical history
of Lepidodendron and Sigillaria, and of their fructification, but have described the
spores met with in their examination of the Scotch Carboniferous strata, and have
given their conclusions as to the nature and condition of the beds from which the
spores were collected. The splint and parrot coals yielded most ; the cherry or soft
coals are too far bituminised to show them clearly, though present. Some fireclays
yield them in the upper two or three inches. Some thin shales (plant-beds and
takes) yield spores, and some have plant-remains as well. ‘‘Carbonised wood was
common in all the poor or shale-like coals... . Some of the thin coals were
almost entirely composed of such carbonised vegetable matter.’? Fragments of
scorpions and eurypterids occur plentifully in some of the ‘old soils’ (fireclays).
The former, being land-animals, and probably adapted to a hot (or, at least, warni)
climate, are among the most interesting of the coal-fossils.
Drift-coal.— Formerly, more so than now, it was thought by some that the coal
had been formed by the accumulation of drifted timber and floating masses of
vegetation in rivers and estuaries. There are several difficulties in the way of
this hypothesis. There would have been more ash in the coal, because the water
would shift and deposit sand and clay, together with rafts and grass islands; and
the ash of pure coals agrees in relative quantity and composition with the earthy
matter naturally contained in plants (Green and others). How far a calculation
could be made as to a given quantity of ash in coal, and the amount of mineral
matter belonging to plants, as a basis for proving the original quantity of woody
matter concerned in a given quantity of coal, would be difficult to determine, for
some of the original mineral constituents have been probably removed by per-
colating water.
Professor Lesley ® has calculated that the Mississippi could not supply by driftage
from the forests of its valley in 100,000 years wood enough for one of the Schuylkill
authracite beds; mineral sediments would also interfere with the results. Under
favourable conditions, he adds, tropical forests (Central Africa) and coast-swamps
(Florida, Guiana, India) would supply good and sufficient material. So also the
swamps of the ‘ Sunk country’ of Arkansas and Louisiana, as well as the ‘ Great
Dismal Swamp’ in Virginia, for one set of conditions (Lyell) ; and the mangrove
jungles in the West Indies and elsewhere for another.
Fireclay, underclay, undercliff, underbed, seat-earth, seat stone, bottom-stone,
spavin, clunch, fake, pouncin. ‘This is usually a dense clay,7 but sometimes sandy,
1 Journ. Roy. Microse. Soc. ser. 2, vol. v. 1885, pp. 406-420.
2 Report of the Fishery Board, 1890.
3 Baltour, “ Paleontological Botany,’’ 1872, p. 67.
* Geology, vol. 11. 1888, pp. 117-120.
5 Proceed. Royal Phys. Soc., Edinburgh, vol. ix. 1886, pp. 82-117.
6 ‘Manual of Coal,’ etc., 1856.
7 In examining microscopically the ultimate particles of some shales and under-
clays, Mr. W. M. Hutchings has discovered that these are composed of a ‘micaceous
deposit,’ in which there is some fragmental mica, but that the mass appears to con-
Prof. T. Rupert Jones—Address. 567
and even altogether a hard sandstone (‘ganister’). It varies in colour from black to
white ; and is from six inches to ten feet or more in: thickness. A characteristic
feature is its being penetrated in all directions by the stigmarian roots and rootlets
of the trees (Sigillaria, Lepidodendron) that grew on it when it was the soil of the
coal forest, having been slowly deposited by the quiet, shallow, muddy waters that
succeeded the deposition of shale or sandstone by waters with stronger currents,
these last terminating one of the periodical disturbances to which the many stages
of gradual subsidence gave rise. Every coal-bed (or coal-seam, according to the
application of those words to either a simple or compound layer of coal) lies on
a more or less distinguishable ‘underclay’; but this is often omitted to be recorded
in coal-mining sections and documents.! Sometimes an underclay forms a root of
a coal; but it is the seat-earth of a coal lying on it.
Deundation.—Among the many examples of denudation in the Coal-measures,
coal-beds have been washed away from their underclays; but these latter are so
greatly toughened by their contained network of roots that they have more effectually
resisted denudation. Both coals and underelays, however, were not unfrequently
destroyed, or, at least, deeply and widely channelled by contemporaneous floods and
rivers ; for not only are the ‘horses,’ ‘lows,’ and ‘ washes’ such watercourses, but
the occurrence of pebbles of coal and small detrital particles scattered through some
of the sandstones are due to similar denudation.”
Sir J. W. Dawson, in ‘ Acadian Geology,’ 1868, p. 139, states :—‘‘ The occasional
inequalities of the floors of the coal-beds, the sand and gravel ridges which traverse
them, the channels cut through the coal, the occurrence of patches of sand, and the
insertion of wedges of such material splitting the beds,..... are constantly
represented in modern swamps and marshes, more especially near their margins,
or, where they are exposed to the effects of ocean storms or river inundations.”’
The great thickness of coal and carbonaceous shale in the Albion Coal-measures at
Picton, Nova Scotia, were formed in a depression separated by a shingle bar
(conglomerate) from the more exposed flats outside.*
9. Fossils of the Coal-measures of South Wales.—An examination, or even an
enumeration, of the fossils would be much more than we have time for now,
whether we took in hand the plants or the animals.
I. Of the characters of the former+ we have indicated some particulars, such as
facts about the spores and roots of the gigantic trees of which the humble Se/aginelia,
Isoétes, Sphagnum, and Egquisetum are the living representatives. Descriptions of
their roots, trunks, leaves, woody and other structures have been given to the world
by both Foreign and British palobotanists in numerous goodly memoirs and
volumes, illustrated with excellent plates; and the many ferns, tree-ferns, and
eycadaceous plants (the last known by their fruits chiefly) have been well described
and figured. Kidston’s ‘Catalogue of the Carboniferous Plants in the British
Museum’ gives full references to many of the above, and the others are well known.
With increased knowledge, the supposed dome-like, long-armed, stigmarian plants,
with subaqueous leaves or processes, either floating on or in the water, or growing
on the mud, have become the depressed stools, dichotomous roots, and innumerable
long, narrow, leaf-shaped rootlets of Sigillaria and Lepidodendron (Binney and
others). C. Grand’Eury, however, still distinguishes some perfectly aquatic and
peculiar plants, which floated in the water with their roots trailing on the bottom ;
and of Stigmaria he holds the opinion that it indicates a formation in deep water,
contrary (as he says) to what is generally stated.> ‘The supposed palms have disap-
peared in the explanation that the supposed fruits are only the marks of compressed
gas bubbles fixed during their escape from the foetid black, decomposing mud.®
sist mainly of minute, rutiliferous, mica-like flakes, regarded by him as of secondary
origin, made from the original components of the stratum (Ggou. Mac. 1890 and
1891). Mr. Hutchings kindly informs me that, of the numerous fireclays which he
has examined, several are being used for brick-making (Letter, May 20, 1891).
1 De la Beche, Mem, Geol. Survey, vol. i. pp. 173 and 177.
2 Logan, De la Beche, Buddle, and others.
3 Dawson, Q.J.G.S. vol. x. p. 46.
4 A useful compendium of our knowledge of coal-plants in 1863, by Professor
John Morris, was published in the Proceedings Geol. Assoc, of that date.
5 Mém. présentés, etc., Acad. Sciences, etc., France, vol. xxiv. No. 1, 1877; and
Annales des Mines, sér. 8, Mémoires, vol. i. 1882, p. 161.
§ Carruthers, Gzou. Mac. 1870, p. 215.
568 Reports and Proceedings—
Great advances have been made by Prof. Dr. W. C. Williamson in the knowledge
of the lycopodiaceous trees of the coal, which he shows to have partaken of the
exogenous structure of modern trees.
Various more or less artistic representations of ideal coal-forests are to be met
with, both in special books treating of the subject and in treatises on geology in
general. Eloquent deseriptions of such a forest by Ansted and Hugh Miller are
quoted by Balfour.!
Of the flora of the Uplands, which were bordered by the peaty coal-swamps,
very little is known; only that the fern fronds and some other plants in the roof
shales, and the occasional either prostrate or snag-like trunks of conifers in the
sandstones, were probably brought to lower levels by streams or river-floods (Dawson,
Lyell, and others).
II. The fossil animals of the coal are necessarily of very great interest, but we
can now refer to only a few.
1. Of the invertebrates a fair number occur in South Wales, but none of the
insects, myriopods, spiders, scorpions, eurypterids, land shells, and other rare forms
known elsewhere have yet been met with.
In the “ Memoirs of the Geological Survey of Great Britain,” ete., Iron-Ores,
etc., Part III., the late Mr. J. W. Salter very carefully classified and tabulated the
fossils found in the ‘ironstone bands’ of South Wales, describing and figuring the
most characteristic species. He hoped to have taken up the fossils of the coal bands
im like manner, but unfortunately the time never came. His observations at p. 220,
on the importance of managers of collieries and others making very careful collections
of fossils, with notes on their exact beds, should even now command attention. He
notes as follows :—
Black Band; Anthracomya, Fish remains ... ... ...: ... +. Brackish.
Soap Vein; Worm-burrows, Anthracomya, Ferns ... ... ... Brackish.
Black Pins; Anthracosia, Dadoxylon, Knorria, and Halonia ... Brackish.
Ell Balls, above Elled Coal; Asterophyllites, Lepidodendron, and
Ulodendron, Ferns degy Liou.) aha ges Ge cules ARS ee San DAC kel
Under Big-vein Coal ; Anthracosia <0. 0... 2-5 es, =e) ese Pe tdelsishe
Over Three-quarter Coal; Anthracomya ... ... ... ..- «.. Brackish.
Will Shone, or Pin Will Shone, over the Bydyllog Coal; Athyris Marine.
Darran Pins; Anthracosia, Anthracomya, Myalina -»» oo» Brackish.
Over Engine Coal; Spirifer‘and Productus, Fen ... .. ... Marine.
Black band, over Old Coal; Anthracosia, Fish ... ... ... ... Brackish.
Spotted Vein; Spirorbis; track of Limulus (?) 6 feet below the
VEU | ak plbaaeidevsies Phcey le seis fats ah ainge egies limes Yeni aE eee ee Sea
Red Vein; Anthracosia, Modiola, Edmondia (?) ... ... ... ... Marine?
Blue or Big Vein; Myalina, Anthracosia, Spirorbis ... ... ... Marine? ~
Bottom Veins; Fish (8 genera) Brackish.
Rosser Veins ; (under the Farewell Rock and above the Millstone
Grit); Brachiopoda (7 genera), Conchifera (8 genera), Gaste-
ropoda, Heteropoda, and Cephalopoda (9 genera), Encrinite
Stems; ‘Mish remams es pee a ee) bee) see) | liege net eeun een ee
Anthracosia® was originally regarded as a Unio by Sowerby, then referred to
Cardinia by Agassiz, and to Pachyodon by Stutchbury ; but it was ultimately detined
by W. King as related to Unio, but, being distinct from that genus, it was named
by him Anthracosia. Mr. Salter noticed that it has a wrinkled epidermis, and
considered that it was related to the Mfyade, and of brackish, if not marine, habitat.
This is the shell composing the so-called ‘ mussel bands’ and ‘ Unio bands’ of the
Coal-measures.
Anthracomya, ‘ Tron-ores,’ ete., page 229. Mr. Salter indicates that the shells
which he describes under this name have oscillated in catalogues between Avicula,
Modiola, and Unio, and that it has a wrinkled epidermis, like the foregoing.
Anthracopiera® is a triangular shell, with wrinkled epidermis, and belonging to
the same group as the above.
All the forms of this characteristic group of Coal-measure shells are called
Naiadites by Dawson,‘ and regarded by him as allied to D’Orbigny’s Byssoanodouta.
1 «« Paleont. Botany,’’ pp. 70, 71. 2 Tron-Ores South Wales, pp. 226, 227.
3 Salter, Q.J.G.S. vol. xix. 1863, p. 80. 4 Acadian Geol., 1868, pp. 201-203,
Prof. T. Rupert Jones—Address. 569
Giimbel and Geinitz have described them as belonging to Unio and Anodon ; and
Ludwig refers Anthracoptera to Dreissena. At all events there is a great probability
of their not being truly marine. They may have lived in the brackish water of
lagoons and creeks in the black, muddy swamps, having some communication with
the sea, and often or occasionally inundated with salt water (Dawson, Salter, etc.).
Spirorbis carbonarius is frequent in the Coal-measures of South Wales and else-
where. This little annelid, though belonging to a marine genus, is often found
attached to plant fragments in the coal-shales. These plants may have hung down
into the water and been infested by the annelid; or it may have attached itself to
floating plants which were ultimately drifted back to the littoral mud-swamp. This
Spirorbis is an important constituent in the Ardwick limestone of Manchester and
Shropshire, but is associated with Ostracoda (Curbonia), which are probably of
brackish-water habitat.
The Brachiopoda are necessarily marine. The fish are not good witnesses, for
they might have migrated to and fro, as some now inhabit both fresh and salt
waters ; and some might have been essentially estuarine.
Thus there are few decidedly marine beds in this series, and these, of course,
correspond with the occasional domination of the sea during its inroads and during
extreme depressions of the district.
In addition to the occurrences of fossils in Salter’s list above quoted we may
notice that in the Grou. Mac. 1870, pp. 214-220, is an account of some fossils
discovered by the late Mr. W. Adams, of Cardiff, in 1869, in a ‘ Black Band’ in
the Rhymney Valley, about 800 feet higher in the Coal-measures of South Wales
thau any hitherto found. The band is calculated to have been rightly 81 feet above
the Mynyddysllwyn coal, from which it is divided by a fault; it is in five layers and
about 8 feet thick, with its associated shales. One of these in its midst and the
lowest shale carry the fossils. With some plant remains there is Anthracomya, with
Estheria (?) Adamsii, E. tenella, and Leaia Leidyi, all probably of brackish
habitats ; also Carbonia Eveline and C. Agnes, Ostracodes typical of a genus which
is found in the black shales, presumably of either fresh or brackish-water origin.
Mr. Adams also found a shale full of Anthracomya at Aberbeeg, Ebbw Vale, over-
lying the Troed-rhiw-Clawdd coal, and 226 yards below the Mynyddysllwyn coal
(p. 215).
Dy oi the Vertebrata the fishes enumerated in Mr. Salter’s list are important.
The following are the genera named:—Megaliclithys, Rhizodus, Pleuracanthus,
Byssacanthus (?), Palseoniscus, Amblypterus, Helodus, and Peecilodus.
Although reptilian remains are rare in South Wales, yet they are not altogether
wanting. In 1865! Professor (now Sir Richard) Owen described some remains of a
smali amphibian (between newt and lizard), found by the late J. K. Lee in the lower
part of the Middle (or upper part of the Lower) Coal-meaures at Llantrissant,
Glamorganshire. The animal was rather larger than the allied Dendverpeton
Acadianum, and Professor Owen named it Anthrakerpeton crassosteum, ‘‘ the thick-
boned coal-reptile.” This paper and its illustrations were reproduced in the ‘‘ Trans.
Cardiff Nat. Soc.”’
10. Extent of the Coal-measures under the South of England.—Sir H. De la
Beche in 1846? noted that a great sheet of Paleozoic rocks, including the Coal-
measures, extending from Belgium to Central England, had been rolled about,
undulated, crumbled, and then partially worn away before the New Red Sandstone
and other Mesozoic strata were laid down upon them; and that these, in their turn,
had been denuded so as to expose here and there portions of the underlying Coal-
measures, though near by a ridge of profitless Mountain-limestone or other older
rock might come to the surface.
In 1856 Mr. Godwin-Austen, following up his reasoning about the areas of coal-
growth (see above, page 521), explained that the movements of disturbance which
they had undergone had tended to preserve the great Franco- Belgian coal-band, and
had rendered it available; and he proceeded to state that the course of that band of
Coal-measures may be traceable westward, and probably coincided with, and may
some day be reached along the line of, the Valley of the Thames.
Protessor Prestwich in 1871 extended this inquiry ;* and, having carefully com-
1 Grou. Mae. Vol. II. pp. 6, 8, Plates I. and II.
2 Mem. Geol. Surv., vol. 1. pp. 2138-214.
3 Leport Royal Commission Coal-Supply, 1871; Anniv. Address Geol. Soc.,
070 Reports and Proceedings—Prof. T. Rupert Jones—Address.
pared the coal-beds of Somerset and Belgium, described the characters and relations
of the strata in detail, and showed that the coal might be met with at a workable
distance from the surface along a narrow but interrupted curved area from West-
phalia, through Belgium and France, to England; then along the north-eastern
part of Kent (Isle of Thanet, etc.), and through Herts, Bucks, Oxfordshire,
Gloucestershire, to the Bristol coal-field, and on to South Wales. ‘The coincident
axis of disturbance is south of the river ‘'hames, in his opinion throwing off the
coal-beds on its northern flank.
Mr. W. Galloway has given in the ‘‘ Cardiff Nat. Soc. Report,’’ vol. xvii. 1856,
p- 23, a sketch of the views here alluded to. A full account of the history and
literature of the question of the underground range of the older rocks in the South-
east of England, especially as to the possible occurrence of the Coal-measures, is
published in the ‘‘ Memoirs of the Geological Survey: The Geology of London and
of Part of the Thames Valley,’’ vol. i. 1889, pp. 13-28, by Mr. Whitaker, F.R.S.,
who, having given close attention to this subject, has suggested the followimg
localities as likely sites in the search for coal in the South-east of England: St.
Margaret’s, Chartham, Chatham, and Shoreham, all in Kent; Bushey (Herts),
Loughton (Essex), and Coombs, near Stowmarket (Sutfolk).2
An interesting fact relating to this matter is that in February, 1890, the engineer
of a boring at the foot of Shakespear’s Cliff, Dover, announced that at 1204 feet
below the surface there a thin seam of coal was met with, and at several yards
lower down coal eight feet thick was pierced, associated with clays, grits, and
blackish shales (Newspapers). In Dr. Blanford’s ‘‘ Anniversary Address to the
Geological Society ’’ on February 21, 1890, he stated that Professor Boyd Dawkins,
in a letter received the day before, had informed him that a coal-seam had really
‘“been reached at a depth of 1180 feet, and that this seam is proved to be of Car-
boniferous age by the plant-fossils in the associated clays. . .. The discovery is solely
the result of scientific induction, and arrived at by following the line of research first
indicated, I believe, by the late Mr. Godwin-Austen, and subsequently by Professor
Prestwich.’’ The boring was undertaken with the advice of Professor W. Boyd
Dawkins ;? and we learn, from his latest Report,? that the Coal-measures were
reached at 1118 feet below high-water mark, and were penetrated to 1500 feet;
also that in the 387 teet of Coal-measures six seams were met with, giving an
aggregate of 10 feet of coal. The distance of the Coal-measures below high-water
mark is a near approximation to Professor Prestwich’s computation of the probable
depth at which coal might be found in that part of Kent, namely, 1000 to 1100
feet * The account of the coal-plants or other fossils from these beds has not yet
been published.
11. Conclusion.—The formation and subsequent arrangement of coal and the
Coal-measures have been so ordered that the blessings of civilization have been
largely enjoyed wherever the fossil fuel at man’s feet has been industriously worked
by his hands, and carefully applied to the improvement of his social being. These
labours of careful perseverance, and arts of skilful manipulation, have given special
characters to those whose energies have been directed to coal-mining and various
manufacturing enterprises ; and all conditions of society have been influenced thereby.
So also the geologist, chemist, and botanist, seeking out the composition of the
various coals, their local position and extent, their special natural history, the mode
of passage from dead plants to first-rate fuel—in fact, aiming at a complete mastery
over all the mazy events and complicated results of the coal-formation—not only
find a useful exercise of their cultivated intelligence and accumulated knowledge,
benefiting all by the practical results, but they widen the mental culture of others,
and show how the study of nature is an indispensable element in good education,
and necessarily productive of lasting benefit to society at large.
1872; Popular Science Review, July, 1872; and Proceed. Instit. Ciwil Engineers,
vol. xxxvii. 1874, p. 110, ete., plates viii. and ix.
1 Grout. Mac. November, 1890.
? See also ‘‘ Contemporary Review,’’ April, 1890; and his ‘‘ Lecture to the Royal
Institution,’’ June 6, 1890.
3 “« Report of Proceed. General Meeting of the South Eastern Railway Company,”
July 28, 1891, p. 10; and ‘‘ Financial News,’ July 24, 1891.
4 “« Proceed. Instit. Civil Engineers,’’ vol. xxxvii. 1874, pp. 16 and 26 of the
Separate paper.
Obituary—C. S. Wilkinson. 571
Light, heat, motion, fragrance, and colour are all now obtainable from coal.
What more could the sun himself do for us? It is as if the sunshine that cherished
the luxuriant jungles of the past had been preserved in the coaly mass of the buried
trees. Indeed, the light and heat of former days, expended in thus converting
carbonic acid and water into coal, are here stored up for man. By converting coal
into carbonic acid and water he can again evolve that heat and light, and use them
in a thousand ways beneficial to his race—nay, essential to his very existence as
a civilised being (J. W. Salter and others).
Nevertheless, a great deal has yet to be learnt about the natural history of the
Coal-measures, the order and extent of the special kinds of their animals and plants,
the time occupied in formation, and the geographical and hydrographical conditions.
At all events, we know that all their strata have been arranged im order, have been
buried under circumstances favourable to production of the various coaly fuels, and
then turned up in orderly disorder, ready to the hand of man, and well adapted for
his use in this passage-stage of his civilization and development, helping him, when
intelligent, active, careful, and persevering, to higher ends. For we cannot doubt
that all things here are arranged for his better being, his progress towards more and
more useful arts, wider ranges of science, and fitter aptitudes of life, of which as yet
we have but little conception. We are still the early settlers in a beautiful world,
whose capabilities, imperfectly known as yet, wait until higher developments of man
can understand them fully, and apply the results to the general good.
OSs EASevae
a
GHAREES SMITH WILKINSON, F:G.S:; F:L.S.,)V:P. es:
NEW SOUTH WALES.
Born 18438, pirp 23rp Avaust, 1891.
Mr. Witgtnson was born in Northamptonshire. His father, Mr.
David Wilkinson, was associated with George Stephenson in design-
ing the first locomotive engines. His family settled in Melbourne
in 1852, where he received his education. In 1859 he was ap-
pointed to the Geological Survey of Victoria under A. R. C. Selwyn,
F.R.S., and in 1861 was employed in the Survey of the country from
Bass’s Straits northward to near Ballarat. Cape Otway mountains
were surveyed by Mr. Wilkinson in 1863; and three years later,
when engaged upon the Geological Survey of the Leigh’s River
District, some important investigations were made as to the mode of
deposition of gold and the formation of gold-nuggets. Subsequently,
Mr. Wilkinson’s health gave way, and he spent three years in the
Wagga district. In 1872 he passed the examination for licensed
Surveyors in New South Wales, and was afterwards sent by the
Surveyor-General to the then newly-discovered tin-mining district
of New England, upon which he reported. He was appointed
Geological Surveyor in the Department of Lands in 1874, and when,
the following year, the Geological Survey was transferred to the
Department of Mines, he was appointed Government Geologist
for New South Wales, which office he filled until his death, with
great ability and much advantage to the Colony.
Mr. Wilkinson was a member of the Board appointed to disburse
the Parliamentary Vote for Goyernment aid to mineral pro-
spectors in his Colony. He has also served as President of the
Royal Society of New South Wales and President of the Linnean
572 Obituary—C. S. Wilkinson.
ty
Society of the Colony. His lengthened experience in practical
geology and mining, and his scholarly attainments, united to a
modest demeanour, gained for him a wide circle of friends both at
home and in the Colonies. For seventeen years Mr. Wilkinson was
a member of all Commissions for the Colony, in connexion with
International and Inter-colonial Exhibitions, and he took a prominent
part in preparing the collections showing the mineral resources of
the Colony. He was also mainly responsible for the excellent
collection of minerals in the Mining Museum at Sydney.
Mr. Wilkinson represented his Government as Geological Director
of the New South Wales Royal Commission at the Mining Exhibition
held at the Crystal Palace in the autumn of last year.
He was elected a Fellow of the Geological Society of London in
1876, and a Fellow of the Linnean Society in 1881.
Notz.—This Notice and the accompanying portrait of Mr. C. 8S. Wilkinson are
reproduced, by the kind permission of the Editor, from the ‘‘ Mining Journal”’
October 17, 1891.—Enir. Grou. Maa.
Obituary—Dr. P. H. Carpenter. 573
There may be many geologists in New South Wales ready to
succeed Mr. Wilkinson in his post, but it will be difficult to find one
possessing the same extensive geological and mineralogical know-
ledge, combined with so amiable a disposition and a readiness to
impart information to those seeking it, which will cause his memory
to be long held in esteem by all who had the pleasure to come in
contact with him, whether officially or socially; and especially will
his loss be deeply felt by a very wide circle of personal friends.
PREP AERBERD CARPENTER.
M.A., D.SC. (CAMB.). F.R.S., F.L.S.
Born Frsruary 6TH, 1852. Diep Ocroprer 22np, 1891.
Puitie Herpert CarPENnter, whose sad death we recorded in
our last Number, was the fourth son of Dr. W. B. Carpenter, C.B.,
F.R.S. Born in Westminster, he was taught at University College
School, and in 1871 went to Cambridge as a scholar of Trinity. In
1874 he graduated as B.A. in the first class of the Natural Science
Tripos, and proceeded to the further degrees of M.A. in 1878 and
D.Sc. in 1884. Between 1875 and 1877 he studied at Wurzburg
under Prof. Semper, and in the latter year was appointed assistant
master at Eton College, being especially charged with the teaching
of biology. This post he held until his death. In 1884, when his
father received the Lyell Medal from the Geological Society of
London, to Herbert Carpenter was awarded a moiety of the Fund.
In 1885 he was elected a Fellow of the Royal Society, and he served
on the Library Committee and Council of the Linnzan Society from
1887 onward.
By the death of Dr. Carpenter, at the early age of thirty-nine,
we lose one of the chief authorities on Echinoderm morphology
and the acknowledged leader in the study of the Crinoidea. For
this position he was by his early training eminently fitted. As a
boy his interest was excited by the researches which his father
was prosecuting into the embryology and morphology of Antedon.
When only sixteen he joined his father and Wyville Thomson on
the deep-sea exploring expedition of H.M.S. Lightning, ‘‘ manfully
bearing no little hardship and helping to lighten the evil times to
his seniors.” It is interesting to remember that the chief incentive
to that exploration was the discovery by Sars of new Crinoids in
the North Sea two years before. In 1869 he was on the second and
third cruises of the Porcupine, making analyses of sea-water, but no
doubt keeping an eye on the many rare animals, especially Echino-
derms, dredged by that vessel. The summer of 1870 was again
spent on the Porcupine, this time in the Mediterranean. In 187d
he accompanied Sir G. Nares’ Arctic Expedition as far as Disco
Island, for the purpose of assisting in the dredging operations that
were carried out there and in the North Atlantic by H.M.S. Valorous.
It was not, however, till September, 1875, that he turned his
attention seriously to the Crinoidea, and then as it were by chance.
His first studies at Wiirzburg were on ‘the minute anatomy of the
genital glands in the Crayfish.” It happened, however, that Semper
and Ludwig had criticized certain statements of W. B. Carpenter
O74 Obituary— Dr. P. H. Carpenter.
with regard to the arms of Antedon, and P. H. Carpenter naturally
wished to examine Semper’s material. Thus his first paper (Journ.
Anat. and Physiol.) reconciled the views of his father and of his
father’s critics. The interest once aroused led him on to the investi-
gation of the Phillipine Actinometre, placed in his hands by Semper,
and after two years’ work he presented to the Linnean Society the
important paper on that genus which is published in their Transac-
tions. Meanwhile the Challenger expedition had returned, and in
January, 1878, the description of the free-swimming Crinoids
collected on it was entrusted to Carpenter by Sir Wyville Thomson.
Thus his scientific career was determined, and from that time to his
death, a constant stream of papers from his pen, on Hchinoderm
and especially Crinoid morphology, found their way to the Royal,
Linnean, Geological, and Zoological Societies of London; to the
Quarterly Journal of Microscopical Science, the Annals and Maga-
zine of Natural History, Zoologischer Anzeiger, and many other
publications.
The report on the Challenger collection of Stalked Crinoids was to
have been written by Wyville Thomson, but on his death in March,
1882, the work naturally fell to Carpenter. This report, published
in 1884, and that on the unstalked forms, which appeared four years
later, embody the main work of Carpenter’s life: their accuracy and
exhaustiveness are known to all who have to deal with Crinoids.
This led to much other systematic work, such as that on the Comatule
of the Leyden Museum, of the Hamburg Museum, of the Barent’s
and Kara seas, and of the Mergui Archipelago; besides much left
unfinished on the Blake collections from the Carribbean sea, the
Crinoids from the Port Philip Survey, from Torres Straits and
elsewhere.
What must strike any one who reads these reports is the constant
allusion to fossil forms. The refusal to separate for a moment the
animals preserved to us in the rocks from those living in modern
seas, which distinguished Carpenter’s work from that of most
zoologists, constitutes his chief claim on the attention of the readers
of this Magazine. “I have,” he said “the strongest conviction
(and many mistakes would be avoided were it a universal one) that
the only way to understand fossils properly is to gain a thorough
knowledge of the morphology of their living representatives. These,
on the other hand, seem to me incompletely known if no account
is taken of the life-forms which have preceded them.” And this
conviction was acted up to: thus, even a new Antedon from the
Mergui Archipelago was shown by him to throw light on the position
of Jurassic species. No stronger argument than the extreme value
of all Carpenter’s palzeontological papers can be needed to show the
utter fatuity of ever expecting really good work to be done upon
fossils by those who are prohibited from acquiring a practical know-
ledge of their living relations. For those, however, less fortunate
than himself his help was always ready, and none will feel his loss
sooner or more bitterly than they who have so often availed them-
selves of it in solving the many problems presented by the Crinoids
Obituary—Prof. H. N. Moseley. 575
of the past. Besides many papers contributed to the Geological
Society, Carpenter was joint author with Mr. R. Etheridge, jun., of
the Catalogue of the Blastoidea in the British Museum; and the
last number of the Journal of the Linnzan Society, published on the
day of his funeral, contains a contribution to the Morphology of the
Cystidea of the very highest importance (see antea, p. 135).
Carpenter’s enthusiasm made him a keen controversialist, but his
love of truth kept him open to every argument. He may have
sacrificed brevity to exhaustiveness, but his conscientiousness has
given to all his work the highest reputation for accuracy. These
are the virtues of the man of science, but to them he added a
kindness of heart and a bright joyousness of nature that leave us
doubtful whether we have lost more in the teacher or in the friend.
Lists of Dr. P. H. Carpenter’s papers, some written in conjunction
with Mr. kh. Etheridge, jun., are given in his two Challenger
Reports, and in the Catalogue of the Blastoidea in the British
Museum. To these the following list is supplementary.
' 1882. On the Relations of Hybocrinus, Baerocrinus, and Hybocystites, Quart. Journ.
Geol. Soc. vol. xxxvi. (No. 151), pp. 298-312, pl. xi.
1886. Note on the Structure of Crotalocrinus, Ann. Mag. Nat. Hist. ser. 5,
vol. xvii. pp. 397-406.
1887. Notes on Echinoderm Morphology, No. 11; on the Development of the
Apical Plates in Amphiwra squamata, Quart. Journ. Micr. Sci. vol. xxviii.
pp. 303-317.
1889. Report on the Comatule of the Mergui Archipelago, etc., Journ. Linn.
Soc. London (Zool.), vol. xxi. pp. 304-316, pls. xxvi. and xxvii.
1890. Preliminary Report on the Crinoidea obtained in the Port Phillip Biological
Survey, Proc. Roy. Soc. Victoria, new series, vol. ii, pp. 185-136.
1890. On certain points in the Anatomical Nomenclature of Echinoderms, Ann.
Mag. Nat. Hist. ser. 6, vol. vi. pp. 1-23.
1891. Some publications on American Carboniferous Echinoderms, Ann. Mag,
Nat. Hist. ser. 6, vol. vill. pp. 94-100.
1891. On certain points in the Morphology of the Cystidea, Journ. Linn. Soe.
London (Zool.), vol. xxiv. pp. 1-52, pl. i. Abstract in Rep. Brit. Assoc.
for 1890, p. 821; and in Gzon. Mac. Dec. III. Vol. VIII. p. 135,
March, 1891.
1891. Notes on some Arctic Comatule, Journ. Linn. Soc. London (Zool.), vol.
XXlvy. pp. 58-63, pl. i.
1891. Notes on some Crinoids from the Neighbourhood of Madeira, op. et tom. cit.
pp- 64-69.
Dr. Carpenter also contributed an admirable popular account of
the Hchinoderms to Cassell’s Natural History (1883), and was
largely responsible for the section on the same group in Nicholson
and Lydekker’s Paleontology (1889). IDs Ys 1B
Henry Norrie Mosetey, LL.D., F.R.S., who, after a protracted
illness, died on the 10th of November last, at the age of 46, was well
known asa “Challenger” Naturalist, and as Linacre Professor of Com-
parative Anatomy at Oxford. That part of his published work of
most interest to the paleontologist related to the Hydrocoralline,
Alcyonaria and Madreporaria. But throughout his work, especially
in his capacity as teacher, he was always alive to the value of fossils,
and lost no opportunity of impressing on his pupils the importance
O76 Correspondence—Prof. T. Rupert Jones.
of their study. His enthusiasm, his energy, his genial humour and
his far-travelled experience would often keep the attention of his
youthful hearers for a full hour beyond the appointed lecture-time ;
and, though his voice has for some years been silent, his memory
will not yet cease to be dear to all who had the privilege of
knowing him.
Tomas Pauiister Barxas, F.G.S., was stricken with paralysis
about a month prior to his death, which we regret to record occurred
on the 13th of July last. He was born in Newcastle on the dth of
March, 1819, and in his early days was a well-known lecturer in
his native city on scientific and literary subjects. To geologists he
is best known by his “Coal-measure Paleontology ” (1873), illus-
trative of the fauna of the Northumberland Coal Field. In this
book he figured numerous specimens preserved in his own collection,
and others which he had given to the local: museums. Mr. Barkas
was a great populariser of his favourite science, and took a warm
interest in the Newcastle-on-Tyne Natural History Museum.
CORRESPONDENCE.
CONCERNING NOMENCLATURE.
Sir,—In reading Mr. J. W. Gregory’s Revision of the British
Tertiary Echinoidea in the “‘ Proceedings of the Geologists’ Associa-
tion,” vol. i. parts 1 and 2, 1891, I was, of course, impressed with
the industry and acumen of the author, but I was much grieved at
finding that ten of the original specific names given by Professor
Edward Forbes in 1852 are maltreated by arbitrary and unnecessary
alteration, after the latest fashion of pseudo-classical nomenclaturists,
who propose to bring specific names to one artificial form and standard.
They forget that the original ‘“ Woodii,” for instance, is preferable
to Woodi, being more euphonious,—and that a name may be as
lawfully latinized after the plan of Junius as of Iulus; and that
there are as many Roman names ending in dus as in us. Further it
seems to be forgotten, or not known, that the genitive in a specific
proper name indicates the author’s intention of honouring the dis-
coverer of the specimen, whereas the adjectival form, as Branderianus,
has reference to one otherwise connected with the species. ‘Thus,
to change “ Hemiaster Branderianus” to H. Branderi is to falsity, not
only the fact in nomenclature, but the author’s intention to indicate
the method and degree in which he meant to honour the person
named. ‘The reduction of capitals in specific names, as in branderi,
is unworthy of real literateurs, convenient to printers, if any of
them wish to save a little arm-stretching in composing the type,—
and depriving both beginners and experts of seeing at a glance some
indication of the scientific history of the species. Linné’s method of
giving initial capital to any noun used as a specific name is far
preferable to the new fashion, which is probably based on the
unimportant circumstance that in ancient inscriptions only uncial
and uniform letters were used. T, Rupert JoNEs.
INDEX.
ABN
BNORMAL Cretaceous
noids, 116.
Address to Geological
Cardiff, 517, 560.
Age of the Himalayas, 209, 372.
Old Red Sandstone of the
North of Scotland, 178.
Asrosaurus Macgillivrayt, Seeley, 138.
Altered Coniston Flags at Shap, 459.
America, North, Cretaceous Echinoidea
of, 234.
Ammonites juressis in Ironstone, 493.
Ammonite Zones of Dorset and Somer-
set, 502.
Anarosaurus pumilio, Dames, 35.
Ancient Estuary, Physical Studies of
an, 357-
Ancestral Horse, 517.
Annual General Meeting of the Geo-
logical Society, 183.
Apes, Fossil Italian, 36.
Apparatus for Isolating Minerals, 67.
Archean and Cambrian Rocks of
France, 181.
Armoured Paleeozoic Sharks, 422.
Atkyris leviuscula, Sow., sp., 495-
Autobiography of the Earth, 131.
Australia, South, Cherty Siliceous Rock
from, I15.
Echi-
Section at
PAGSHOT Beds of the London
Basin, 42.
Bassani, F,, Tertiary Fishes of Sardinia,
475-
Bather, F. A., Crinoidal Stems in the
Ordovician of Sweden, 141.
Barbados, Geology of, 232.
Barkas, J. P., Obituary of, 576.
Bayswater, Greywether at, 119.
Belgian Neozoic Fish-teeth, 104.
Bell, A., Post-Tertiary Deposits of the
South Coast, 383.
Dugal, The Great Submergence,
217; on a Glacial Mound in Glen
Fruin, 415.
Bibliography of Paleeozoic Crustacea,
mise)
Bigot, A., Archean and Cambrian of
France, 189.
Blake, J. F., on Precambrian Geology,
482.
DECADE Tiere VIII.—NO. XII,
CAR
Blanford, W. T., on the Age of the
Himalayas, 209, 372.
Bolton, H., Note on Boulders at Darley,
512.
Bonney and Hill,
Forest, 86.
on Charnwood
McMahon,
Rocks of the Lizard, 283.
Raisin, on Rocks from
Kimberley, 412.
. G., Contact-Structure in
Syenite, 86; Reply to Mr. Somervail,
89; Picrite in Sark, 332
Bottosaurus Belgicus, A. S. Woodw.,
sp. nov., U4.
Boulder-clay in Finmark, 215.
Boulenger, G. A., on Extinct Reptilia,
81
Crystalline
381.
Brady, H. B., Obituary of, 95.
Bracklesham, Pseudotrionyx, from, 546.
Breccia, Recently Exposed near Bristol,
213.
British Association at Cardiff, 463, 498.
Earthquakes, 59, 306, 364, 450.
Fossil Bird, 427.
Brockbank and De Rance, Geological
Section at Levenshulme, 426.
Brodie, P. B., Lower Greensand and
Purbeck Beds, 455.
Brown, A. P., on the Young of Baculites
compressus, 316.
Browne, M., on Colobodis, 501.
Bubalus Baini, Seeley, sp. nov-, 199.
Buckmann, S. S., Notes on WVauteli
and Ammonites, 238.
Ammonite Zones of
Somerset and Dorset, 502.
Bulman, G. W., Sands and Gravels in
Boulder-clay, 337, 402.
ALLAWAY, C., Unconformities
between Rock- Systems, 87.
Cambrian Quartzite in Shropshire, $7.
Cameron, A. C., Continuity of the
Kellaway Beds, 504.
Capellini, Prof., on Italian Gharials, 34.
Carboniferous "Amphibians, Remarks
on, 146.
Caussnieons Cephalopods, 549.
Cardiff Meeting of the British Asso-
ciation, 463, 498, 560.
37
018
CAR
Carpenter, H. P., Morphology of the
Cystidea, 135 ; Obituary of, 528, 573.
Catalogue of British Fossil Vertebrata,
ae
— — Eocene Mollusca in the
British Museum, 550.
Fossil Fishes in the British
Museum, 123.
Minerals, 84.
Caucasus, Transverse Valleys in the,
392.
Cause of Monoclinal Flexure, 505.
Causes of Volcanic Action, 121.
Century Ago, A Geologist of a, 1.
Cephalopoda, Catalogue of Fossil, 324.
Ciply, Tooth of Extinct Alligator
from, 114.
Changes of Levels in North America,
330.
Charnwood Forest,
Region of, 86.
Classification of American Palzeozoic
Crinoids, 78.
Clark, W. B., Revision of American
Echinoidea, 234.
Cole, G. A. J., Aids to Practical
Geology, 230.
Colour-markings on Waldheimia per-
Jorata, 458.
Concerning Nomenclature, 576.
Concretions in Magnesian Limestone,
528.
Coniston Flags, 528.
Contact-Structure in Syenite of Brad-
gate Park, 86.
Contributions to Precambrian Geology,
482.
Cooke, J. H., on the Pleistocene Beds
of Gozo, 348.; Notes on Stercodon
Melitensis, 546.
Cordillera, Recent Elevation of the
American, 441.
Cotteau, G., Cretaceous Echinodea of
Mexico, 234.
Cotteswold Field Club, 554.
Cretaceous Echinoids, Abnormal, 116.
Fishes from Mexico, 514.
—_. Scandinavia, 80.
Crick and Foord on Nautilus Neocomz-
ensis, 25. :
Crinoidal Stems in the Ordovician of
Sweden, 141.
Cross-Fell Inlier, 282.
the North-west
DA. W. H., Tertiary Flora of
Florida, 130.
— Elevation of America
in the Tertiary Period, 287.
Dames, W., on JVothosauria, 353; ona
Swedish Cretaceous Bird, 77; a
Tertiary Fish from Melbourne, 475.
Index.
EXT
Davies, W., Obituary of, 144, 190.
Davis, J. W., on Scandinavian Cre-
taceous Fishes, 80; a new species of
Fossil Fish from Levenshulme, 465.
Davison, C., on British Earthquakes,
57, 306, 364, 450; on the Expansion
Theory of Mountain Evolution, 210 ;
Sand brought up by Lobworms, 498.
Dawson, Sir J. W., on Carboniferous
Amphibians, 146; Note on Aylono-
mus Lyell, 258.
Day, A. E., on Funnel-holes on
Lebanon, 91.
Dean, B., Pineal Foramen in Fishes,
513.
Dendrerpeton Acadianum, Owen, 146.
rca and Elevation of the Weald,
8.
Dewy, O. A., on Nepheline Rocks,
4.
Detrital Tourmaline in a Quartz Schist,
465.
Dicynodont from the Elgin Trias, 430.
Dorset, Lower Greensand in, 456.
Drift Stages of the Darent Valley, 136.
Duncan, P. M., Obituary of, 332.
Dynamo-metamorphism, 47, 48, 89,
94, 240, 296, 430, 431, 479.
PARTHQUAKES,
306, 364, 450.
Edwards, W. B. D., on the Separation
of Minerals, 273.
Effect of Sedimentation on Temper-
ature, 262. ;
Elbolton Cave, Exploration of, 525.
Elevation and Subsidence during the ,
Glacial Period, 92, 143, 287.
of the American Cordillera,
British, 57,
441.
of the Highlands of Eastern
Asia, 98, 156.
English, G. L., Catalogue of Minerals,
8
4.
Eocene and Oligocene Beds of the
Paris Basin, 553.
Essays on Theoretical Geology, 8, 70.
Lstheria Andrews, Jones, sp. Nov.,
50.
Hindei, Jones, sp. nov., 51.
Estheri@, on some more Fossil, 49.
Evans, J. W., Apparatus for Isolating
Minerals, 67; Geology of N.E. of
Caithness, 478.
Evolution of Animals, 515.
Excavations at Oldbury Hill, 524.
Expansion Theory of Mountain Evolu-
tion, 210.
Exploration of the Glacial Lake Agassiz,
228. ‘
Extinct Reptilia, 381.
Index. 579
FAB
F ABRINI, E., on Macherodus, 82.
Filhol, H., on the Fossil Mam-
mals of Sansan, 277. ;
Finland, Notes on the Older Rocks of,
13.
Fireclays, alleged Genesis of Rutile in,
259.
a ae Further Notes on, 164.
Fish Fauna of Whitby, 545.
Fish-remains from Tertiary and Creta-
ceous of Belgium, 47, 430.
Fisher, O., Dynamo-metamorphism,
47, 430.
— Mr. Oldham on the Hima-
layas, 140.
Flamborough Head, Drifts of, 238.
Fletcher, L., on the Mexican Meteorites,
36.
Flower and Lydekker, Living and Ex-
tinct Mammals, 418.
Fossil Birds, Catalogue of, 378.
Lstheri@, 49.
— Fishes, Catalogue of, 123.
-— Sponge from the Utica Shale, 22.
Fossils from the Devonian Rocks of
Manitoba, 471.
Foord, A. H., Catalogue of Fossil
Cephalopoda, 324.
on Orthoceratites vagi-
natus, Schloth., 355.
on Pleuronautilus nodoso-
carinatus, 481.
Foord and Crick, on Wautilus Neoco-
miensis, 25.
Fritsch, A., on Palzeozoic Elasmobranch
Fishes, 374.
Fullers-earth Works at Woburn, 504.
Funnel-holes on Lebanon, 91.
({48woon, E. J., Concretions in
Magnesian Limestone, 433.
Geikie, Sir A., Olenellus-zone in the
Highlands, 498.
Geological Investigations in the Salt
Range, 410.
Notes, 514.
Relationship of Olenellus Cal-
lavet, 529.
Section, 426.
—— Society of London, 41, 84,
136, 183, 235, 282, 329, 383.
——— Structure of the Maltese
Islands, 134.
Survey of Illinois, 321.
of New South Wales,
40.
Survey Publications, 548.
Geologist of a Century ago, I.
Geologists’ Association, Proceedings of
the, 39.
HIN
Geology, a Study for
Painters, 4.73.
of Ayrshire, 130.
of Barbados, 139.
Cambridgeshire, etc., 548.
of the Lizard District, 46.
of the Long Mountains, 77.
of the Paris Tertiaries, 280,
Landscape
553:
of the Salt-Range of India,
288.
——— Wensleydale, etc., 548.
Gigantic Ceratopside, 193, 242.
Glacial Action in Pembrokeshire, 500.
Dams, 262.
Deposits at Hendon, 329.
Geology, 337, 402.
Mountain in Dumbartonshire,
Als.
Glass, Norman, on the loop of Athyris
leviuscula, 495.
Glen Fruin, Glacial Mound in, 415.
Goodchild, J. G., the Motion of Land-
Ice, 19.
Gourret, P., the Tertiary Fauna of
Basse-Provence, 83.
Gozo, the Pleistocene Beds of, 348.
Graptolites, Papers on, 179.
Gregory, J. W., Variolitic Diabase, 85.
Greywether at Bayswater, 119.
Gunn, John, Memorials of, 425.
ARKER, A., on Dynamo-meta-
morphism, 48, 31; on various
Crystalline Rocks, 169; Rocks from
the Tonga Islands, 250.
and Marr, on the Shap
Granite, 139.
Harris, G. F., and Burrows, H. W.,
Eocene Beds of the Paris Basin, 553.
Harrison and Jukes-Browne, Geology
of Barbados, 232.
Hart, T., Notes on Volcanic Explo-
sions, I2T.
Hatch, F. H., Study of Petrology, 276.
Herschel-Babbage Theory of Mountain
Building, 140.
Hicks, H., on the Rocks of North
Devon, 43; Glacial Deposits at
Hendon, 329; Comparison between
the Rocks of Pembrokeshire and
Devon, 500; Glacial Action in
Pembrokeshire, 500.
Hill and Bonney on Charnwood Forest,
86.
Himalayas, Ancient Glaciers of the, 209.
Rapid Elevation of the, 294.
Hinde, G. J., on a New Fossil Sponge,
23; on Specimens of Cherty Rock
from South Australia, 115.
580
’ HOB
Hobson, B., Igneous Rocks of the Isle
of Man, 283.
Holland, T. H., Specimens from the
Korea, 41.
Holm, G., on ‘‘Stem-ossicles” of
Crinoidea, 88; on Graptolites of
Gotland, 179.
Horned Dinosaurs of North-America,
193, 242.
Hovelacque, M. M., on the Wooden
Dinosaur, 82.
Howorth, H. H., on Recent and Rapid
Elevation, 98, 156; Rapid Eleva-
of the Himalayas, 294; Recent and
Rapid Elevation of the Cordillera,
441.
Hutchings, W. M., Further Notes on
Fireclays, 164; Rutile in Fireclays,
304; Note on Altered Coniston Flags
at Shap, 459, 528; Petrological
Notes, 536.
Hutchinson, H. M., the Autobiography
of the Earth, 131
Hull, E., on the Physical Geology of
Tennessee, 45 ; Physical Geology of
Treland, 556.
Hunt, A. R., on Detrital Tourmaline,
467.
Hyatt, A., Carboniferous Cepalopods,
549-
Hylonomus Lyelli, Note on, 258.
Wildi, A. S. Woodw., sp.
nov. 211, 320.
CHTHVOSAURUS tenuzrostris,
from Street, 289.
Identity of Mautilus Neocomiensis, and
NM. Deslongchampsianus, 25.
Igneous Rocks of the South of the Isle
of Man, 283.
Illinois, Geological Survey of, 321.
Inferences derived from the Scandi-
navian Glacier, 387.
International Geological Congress, 47,
192.
Investigation of the Cave at Elbolton,
525.
Treland, Physical Geology of, 556.
Irving, A., on the Bagshot Beds, 42;
Dynamic-Metamorphism, 94, 240,
296, 479; Motion of Land-Ice, 141 ;
Physical Studies of an Ancient
Estuary, 359; Recent Excavations
near Wellington College, 383.
Isolation of Minerals, Apparatus for, 67.
AEKEL, O., on Perforating Fungi,
35 ; on Fossil Remains of Prestzo-
phorus, 39; Age of the so-called
Index.
LOO-
Graptolite-stone, 179 ; on Palzeozoic
Sharks, 422.
Jamieson, T. F.,
Glacier, 387.
Jones, T. R., on some more Fossil
Estheri@, 49 ; Address to Geological
Section at Cardiff, 517, 560; Cam-
bro-Silurian Ostracoda from Ame-
rica, 559; Concerning Nomencla-
ture, 576.
Jukes-Browne, A. J., Elevation and
Subsidence, 143 ; Lower Greensand
in Dorset, 456.
the Scandinavian
Cause of Monoclinal
Flexure, 505 ; Concretions in Magne-
sian Limestone, 528.
— and Harrison, Geology
of Barbados, 139.
EUPER Conglomerate
Bristol, 213.
Kimberley Diamond-Mines, 412.
Koken, E., Tertiary Fishes, 475.
Korea, Notes on Specimens from the,
near
4l.
Kramberger, G., Tertiary Fishes, 475.
Krause, A., Silurian Ostracoda of
North Germany, 559.
ACROIX, M. A., Description of
Nepheline Syenite, 216.
Lake-District Rocks, 536.
Lake-dwellings of Europe, 467.
Lamplugh, G. W., on the Drifts of
Flamborough Head, 238.
Land-Ice, the Motion of, 19, 141.
Lapparent, A., on the Porphyritic
Rocks of Jersey, 41.
Lapworth, C., on Olenellus Callave,
20.
Laville, A., on the Paris Tertiaries, 280.
Law that Limits the Action of Flowing
Streams, 43.
Leeds Geological Association, 516.
Leidy, J., Obituary of, 288.
Leveillia latidorsata, Newton, sp. nov.,
206.
on the Genus, 202.
Life of David Robertson, 218. ~
Lindsay, J., Notes on the Geology of
Ayrshire, 130.
Linnzean Society, 135.
Liverpool, Geology of the Country
round, 226. b
Lizard District, Crystalline Rocks of
the, 283.
Lobworms, Sand brought up by, 489.
Loop of Athyris leviuscula, 495.
Index.
LOR
Lorie, J., Geology of the Pays-Bas,
224.
Lower Silurian Fishes, 240.
Lucas, R. N., Notes on the Older
Rocks of Finland, 173.
Lydekker, R., on a new species of
Trionyx, 41 ; on Ornithosaurian and
Dinosaurian Remains, 46 ; on /h-
thyosaurus tenutrostris, 289; on the
Lower J aw of Procoptodon, 329 ; Cata-
logue of Fossil Birds, 378; the Study
of Mammals Living and Extinct, 479.
ACH ZRODUS, from the Val
d’Arno, 82.
Mackintosh, D., Obituary of, 432.
Magnesian Limestone, Concretions in,
in, 433-
McMahon, C. A., on Dynamo-meta-
morphism, 89.
Mammals Living and Extinct, 418.
Marr, J. E., On the Shap Granite, 139.
Marsh, O. C., on Horned Dinosaurs,
193, 242.
Restoration of Stegosaurzs,
Martin, H. J., on Water-worn Stones,
44-
Mastodon and Mammoth, in Ontario,
04.
eee Boulders at Darley, 512.
Medlicott, H. B., Salt-Range of India,
288.
Memorials of John Gunn, 425.
Mesozoic Fossil Fishes, 501.
Mexican Meteorites, 36.
Mexico, Cretaceous Fishes from, 514.
Microscopic Study of Inferior Oolite
from the Cotteswold, 286.
Microsauria from the Lancashire Coal,
Die
Middlemiss, C. S., Physical Geology of
the Sub- Himalaya, 93.
Miller, H., Landscape Geology, 473.
S. A., Structure and Classifi-
cation of American Crinoids, 78.
Minerals, on the Separation of, 273.
Miniature Illustration of Normal Fault-
ing, 465.
Miocene Fish-Fauna of Sardinia, 465.
- Silex-Beds of Tampa, 130.
Monckton, H. W., Denudation of the
Weald, 88.
Morphology of the Cystzdea, 135.
Morton, G. H., Geology of the Country
round Liverpool, 226.
Moseley, H. N., Obituary of, 575.
Motion of Land-ice, 19, 141.
Mountain-Evolution, Expansion Theory
of, 210.
581
OST
Munro, R., the Lake-Dwellings of
Europe, 467.
Murray, J., the Maltese Islands, 134.
N ATURAL History, Transactions
of Northumberland and Durham, .
215.
Nautili and Ammonites, 238.
Nautilus neocomiensis, Sharpe, 25.
Nepheline Rocks in Brazil, 84.
—— Syenite of Pouzac and Mon-
treal, 216.
New Species of Zevezl/ca from Ireland,
202.
New South Wales, Geological Survey
of, 40.
Newton, E. T., on Ammonites jurensis,
493-
R. B., on the genus Levezllia,
493; Catalogue of Eocene Mollusca,
550:
Nicholson and Marr, on the Cross-
Fell Inlier, 282.
Norber Brow, the Perched Blocks of,
201.
Normal Faulting, 487.
North America, ‘Tertiary Insects of,
280.
Northampton Sands, Ammonites juren-
sis in the, 493.
(_) BITUARY of Antonio Stoppani,
94; H. B. Brady, 95; G, W.
Ormerod, 144; William Davies, 144,
190; Joseph Leidy, 288; P. M.
Duncan, 332; D. Mackintosh, 432 ;
C. S. Wilkinson, 528, 571; P. H.
Carpenter, 528, 573; H. N. Mose-
ley, 575; I. P. Barkas, 576.
Obsidian from Pilas, Mexico, 285.
Odontaspis Houzeaut, A. S. Woodw.,
sp. nov., III.
Older Rocks of Finland, 173.
Oldham, R. D., on Theoretical Geology,
8, 70; Action of Flowing Streams,
43.
Ol is Callavei, Lapworth, 529.
Olenellus-zone in the N.W. Highlands,
498.
Ordovician, Fossil Sponge from the, 22.
Origin of Concretions in Magnesian
Limestone, 433.
Ormerod, G. W., Obituary of, 144.
Ornithosaurian and Dinosaurian Re-
mains, 46.
Orthoceratites vaginatus, Schlot., 355.
Osborn, H. F., Molars of the Peris-
sodactyla, 317, 384.
Ostracoda, Recent Memoirs on Palos
ozoic, 558.
582
PAL
PALZONTOLOGY, Handbook of,
37:
Paleozoic Fishes, 374.
Pantobiblion, 427.
Panton, J. H., Mastodon and Mam-
moth in Ontario, 504.
Pavlow, M., Note on Aipparion, 517.
Pays-Bas, Geology of the, 224.
Penning, W. H., Geology of the
Southern Transvaal, 235.
Perched Blocks near Austwick, 291.
Perforating Fungi, in Fossil Elasmo-
branch Teeth, 35.
Permian Fishes of France, 477.
Perissodactyla, on the Molars of the,
317, 384.
Petroleum, Geology, 508.
=== Ong Oi, Sos.
Petrological Notes, 536.
Petrology, Introduction to the Study of,
276.
Pfaff’s Allgemeine Geologie, 384.
Phenomena of the Glacial Epoch, 217.
Pholidophorus Germanicus, 545.
Physical Geology of the Sub-Himalaya,
93-
— Tennessee, 45.
Physical Study of an Ancient Estuary,
357-
Picrite in Sark, 332.
Pineal Foramen in Fishes, 531.
Pleistocene Beds of Gozo, 348.
Pleuronautilus nodoso-carinatus, Romer,
sp., 481.
Pollini, C., Tertiary Fishes of Aix-en-
Provence, 476.
Porphyritic Rocks of Jersey, 41.
Post-Pliocene Continental Subsidences,
262.
Post-Tertiary Marine Deposits, 383.
Potonié, H., Erect Tree-stump with
. Roots, 133.
Practical Geology, Aids to, 230.
Precambrian Geology, 482.
Prestwich, J., Drift in the Darent Valley,
136; Saiga Antelope in Britain, 190.
Priem, F., Evolution of Ammonites,
515.
Pristis, Monograph of Fossil Species
of, 427.
Pristiphorus, Fossil Remains of, 39.
Proceedings of the Cotteswold Field-
Club, 550.
Pseudotrionyx Delheidi, 546.
Purbecks in the Vale of Wardour, 455.
Pylle Hill, Rheetic Section at, 285.
READE, T. M., Theory of Moun-
tain Building, 140; Sedimentation
and Temperature, 262; Perched
Index.
STE
Blocks of Norber Brow, 291 ; Normal
Faulting, 487.
Recent and Rapid Elevation, 98, 156,
204.
Reply to Mr. Somervail, 89.
Restoration of Stegosaurius, 385.
Reusch, H., on Glacial-strie and
Boulder-clay, 215.
Ristori, Dr., on the Italian Alps, 36.
Roberts, T., on two Abnormal Creta-
ceous Echinoids, 116,
Rock-shelters, 524.
Specimens from Kimberley, 412.
Rocks from the Tonga Islands, 250,
North Devon, 43.
of Pembrokeshire and Devon,
500.
Roper, G., Dicynodont from the Trias,
439-
Ross, O. C. D., The Origin of Petro-
leum, 506.
Rutley, F., on a Spherulitic and Perlitic
Obsidian, 285.
Rutile in Fireclays, 259, 304.
G AIGA Antelope in Britain, 94,
190.
Salt Range, Recent Investigations in
the, 410.
Sand brought up by Lobworms, 489. .
Sands and Gravels in Boulder-clay,
337, 402.
Sansan, Fossil Mammals of, 277.
Sauvage, H. E., Lower Permian Fishes
of France, 477.
Scandinavian Glacier, the, 387.
Scudder, S. H., Tertiary Insects of
North America, 280.
Seeley, H. G., on a Saurischian Reptile
from Australia, 138; on Audalus
Bainit, sp. nov., 199.
Shap, Altered Coniston Flags at, 459.
Granite, 139.
Sherborn and Smith Woodward, Cata-
logue of Vertebrata, 25.
Siliceous Rocks from South Australia,
115.
Sjogren, H., on Valleys in the Caucasus,
92.
Sona a nearly perfect J/chihyo-
Saurus from, 289.
Somervail, A., Geology of the Lizard,
6.
Ga J. W., Continental Subsidence
in America, 262.
Stebbing, T. R. R., the Naturalist of
Cumbrae, 218,
Stegosaurus, Restoration of, 385.
“* Stem-ossicles ” of Crinoidea, 88.
Index
STE
Stephanella sancta, Hinde, gen. et sp.
nov., 23.
Stereodon Melitensis, Owen, 546.
Stock, T., on a Keuper Conglomerate
near Bristol, 213.
Stoppani, Cav.
Obituary of, 94.
Strahan, A., on the Phosphatic Chalk
at Taplow, 239.
Strepsodus Brockbanki, Davis, sp. nov.,
405.
Study of Mammals, 479.
Smyth, Sir Warington, successor to, 94.
Swedish Cretaceous Birds, 77.
Abate Antonio,
*T APLOw, Phosphatic Chalk at,
239.
Temperature, Effect of Sedimentation
on, 262.
Tertiary Fauna of Basse-Provence, 83.
Fishes, 475.
Theoretical Geology, 8, 70.
Titles of Papers read at the British
Association, 463.
Tomistoma, Fossil Italian species of, 34.
Tonga Islands, Rocks from the, 250.
Topley, W., Geology of Petroleum, 508.
Tooth of Extinct Alligator from Ciply,
114.
Toérnquist, S. L., Graptolites of Siljan,
Sweden, 179.
Transactions of the Leeds Geological
Society, 516.
Transyaal, Geology of the Southern,
235.
Transverse Valleys in the Eastern
Caucasus, 392.
Tree-stump with Roots in the Coal, 133.
Triassic and Devonian Rocks, 227.
Trionyx melitensis, Lydekker, 41.
LRICH, E. O., on American
Palaeozoic Ostracoda, 558.
Upham, Warren, Elevation and Sub-
sidence, 92; Exploration of the
Glacial Lake Agassiz, 228; Changes
of level in North America, 330.
Ussher, W. A. E., Triassic Rocks of
West Somerset, 227; the Prawle
Problem, 511.
ARIOLITIC Diabase of the
Fichtelgebirge, 85.
Various Crystalline Rocks, 169.
Vectian in Dorset, 456.
583
ZA:
Vertebrates, Catalogue of British Fossil,
25.
Vigliarolo, G., Monograph of Species
of Pristis, 427.
Vogdes, W. A., Palseozoic Crustacea,
132.
Volcanic Paroxysmal Explosions, 121.
Vulcanicity in Lower Devonian Rocks,
Sil.
ACHSMUTH and_ Springer,
Perisomic Plates of Crinoids,
219.
Waldhemia perforata, showing Colour-
markings, 455.
Wardour, Lower Greensand and Pur-
becks in the Vale of, 455.
Water-worn and Pebble-wor stones, 44,
Watts, W. W., Geology of the Long
Mountain, 77.
Wellington College, recent Excavations
near, 393.
Wethered, E., Inferior Oolite of the
Cotteswold Hills, 286.
Whiteaves, J. F., New Species of
Devonian Fossils, 471.
Wilkinson, C. S., Obituary of, 528,
571-
Wilson, E., on a Rhetic Section at
Pylle Hill, 285; Waldeheimia per-
forata, with Colour-markings, 458.
Winchester College Natural History
Society, 514.
Wooden Dinosaur, the, 82.
Woodward, A. S., on Fish-remains
from Belgium, 104 ; on Tooth of an
Extinct Alligator from Ciply, 104 ;
Catalogue of Fossil Fishes in the
British Museum, pt. ii., 123; on
Lylonomus Wild, sp. nov., 211 ;
Miocene Fish-Fauna of Sardinia,
465 ; Philidophorus germanicus, 545 ;
Pseudotrionyx Delheidi, 546.
————— Ish 1, Iie Gn a (Ces
wether at Bayswater, I19.
Samuel, of Norwich, 1.
and Sherborn, British Fossil
Vertebrata, 25.
Woodwardian Museum Notes, 116, 169.
Wynne, A. B., Investigations in the
Salt Range, 410.
VRENG of Baculites compressus,
A. P. Brown, on the, 316.
ITTEL’S Handbook of Palzon-
tology, 37.
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