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^aiimr-nca So/caaemu v/ ^ycience^' 


RECEIVED BY PURCHASE 
JULY 29, 1909 

FROM 

DR. GUSTAV HAMBACH 






/UoiUf'^' ^//^/ 









^^ 



THE 

GEOLOGICAL MAGAZINE 

-VOL. "V. 

JANUARY— DECEMBER. 1868. 



THE 



GEOLOGICAL MAGAZINE; 



P^ntlilg Journal of (S^clogj : 



WITH WHICH IS INCORPORATED 



''THE G-EOLOa^IST. ' 



NOS. XLIII. TO LIV. 



EDITED BY 

HENKY WOODWAED, F.G.S., F.Z.S. 

HONORARY MEMBER OF THE GEOLOGICAL SOCIETIES OF GLASGOW AND NORWICH ; CORRESPONDING 

MEMBER OF THE NATURAL HISTORY SOCIETY OF MONTREAL; AND OF THE LYCEUM 

OF NATURAL HISTORY, NEW TfORK. 



ASSISTED BY 

PROFESSOR JOHN MORRIS, F.G.S., &c., &c., 

AND 

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




-von.. -V. 

JANUARY— DECEMBER, 1868. 



LONDON: 
TRUBNER & Co., 60, PATERNOSTER ROW. 

CH. DELEGRAVE et Cie, 78, RUE DES ECOLES, PARIS. 

LEIPSIC: F. A. BROCKHAUS. 

TURIN & FLORENCE : H. LOESCHER. NEW YORK : LEYPOLDT & HOLT. 

1868. 



HERTFORD : 
PRINTED BY STEPHEN AUSTIN. 



LIST OF PLATES. 

PLATES , . PAGH 

I. New Limuloid Crustacean from the Upper Silurian ; 

Prosopon mammillatum, H. Woodward, Stonesfield . 1 
11. New Trilobites, etc., from the Upper Cambrian Eocks 

of North Wales ^ 5 

III. Amethyst-Quartz, with warped Faults in concretion . 12 

IV. StricJclandinia Davidsoni, S. Salteri, Pentamerus ohlongus 59 
V. British Graptolites 64 

VI. Cambrian Lower Beds, Eailwaj Cutting south-west 

side of Llyn Padarn, Llanberis 121 

VII. Banded Cambrian Slates, Glyn Quarries, Llanberis . 121 
VIII. ^c^i^iocemsJacca^wm, H.Wood w.jWoolhope Limestone 133 

IX. Fossil Pandanaceous Fruit 153 

X. Section and Map of a Concrete Agate 156 

XI. Saurosternon Bainii, Huxley ; a new Fossil Eeptile 

from South Africa 205 

XII. Pristerodon McKayi, Huxley ; a new Fossil Eeptile 

from South Africa 205 

XIII. Folded Agates and Mural Agates 208 

XIV. Cretaceous and Liassic Crustacea . 258 

■ XV. XVI. Earliest forms of British Brachiopoda 303 

XVII. Lower Lias Crustacea 353 

XVIII. XIX, New Species of Brachiopoda from the Lower Green- 
sand, at Upware 399 

XX. Trimerella, Billings, Upper Silurian, Island of Goth- 
land 441 

XXI. Pedunculated and Sessile-eyed Crustacea 489 

XXII. Skull of the Mammoth from Ilford (front view) . . 540 
XXIII. Ditto ditto ditto (side view) . .541 



LIST OF WOODCUTS. 

Brecciated Concretions 12, 13, 15, 17, 18 

Diagram to show the variable height of the base of an escarpment 

above the sea-level 41 

Section of the valleys of the Lea, the Eoding, and the Thames . . 43 

Section of the valley of the Ouse, near Buckingham 45 

Fossil from Studland Bay ; Kydia calycina, India ; Calycopteris (Getonia) 

fioribunda, India 74 

Contorted Eock, Basil Wood, Charnwood Forest 113 



vi List of Woodcuts. 



CAaB 



Ground-plan of Quarry near Buddon Wood, Charnwood Forest . . 113 

Swithland Old Pit, Charnwood Forest, etc 119 

Diagram of the Igneous Eocks of Charnwood Forest 120 

Section of New Tunnel, Glyn Quarries, Llanberis 122 

New Kail way Cutting, Llanberis 123 

Diagram to illustrate the origin of slaty cleavage 149 

Section of Albian or Gault at Copt Point, Folkestone 170 

Plan exhibiting the localities of Natural Pits near Kipon . . . .179 
Leskia mirahilis, Echinosphoerites aurantium^ Sphceronites pomum . .183 
Anterior aspect of head and mandible of Dinichthys Herzeri. . . .185 
Hills inside Estuary at the mouth of the Buffalo river, British Kaffraria 203 
Order of Superposition of Deposits, Buffalo Kiver, British Kaffraria 203 

Diagrams illustrating the origin of Faults 205, 206, 207 

Banded and Brecciated Concretions 209, 210, 211, 212 

Diagram of the Post-Glacial Cliff at Clacton, Essex 214 

Sections at Clacton 215 

Sections illustrating the Phosphatic Deposits of Nassau 263 

Section illustrative of the general geological structure of the Duchy 

of Nassau, Germany 263 

Loop of an old specimen of Waldheimia tamarindusj Sow 269 

Section of Strata at Upware on the Cam 273 

Diagram showing the distortion of an old brick wall 294 

Oholella desiderata 309 

Diagrams of Coal-plants, MegaphytoUj PalcEopteris, Calamites, Lepido- 

dendron, Sigillaria 331, 333, 335, 337 

Section of New Eed Marls, Mapperly Eoad, Nottingham .... 341 
Sketch-map^ of a portion of the district near Nottingham, showing the 

position of the Faults in the Eed Marls of the Keuper and Bunter 342 
Diagram-section of Columnar Basalt and White Chalk near Lisburn, 

Co. Antrim 346 

Section at Eoswell Hole, near Ely 348 

Diagram to explain the approximate dip of Strata at Eoswell Hole, 

near Ely 349 

Sketch-section exposed in the railway-cutting near Crofthead, Een- 

frewshire 394 

Diagrammatic section across the Cowdon valley, near Crofthead . . 395 

Microscopic structure of Terebratulidce 402 

Ground plan of Eoswell Hill Clay-pit, Ely 411 

Section of north bank of railway-cutting near Crofthead, Eenfrewshire 487 
Tooth of Clirnaxodus ovatus, sp. nov., Low Main Coal-shale, Northum- 
berland 496 

Section at the base of cliff at the first point west of Lower Sher- 

ringham 545 

Cliff- section on the Norfolk coast, showing contorted Strata. . . . 550 

Eailway-cutting west of Wells, Norfolk 551 

Diagram-section of side of Gravel-pit near Old, Northamptonshire . 563 



Roughly copied from the Geological Survey Map.— W.W. 



PREFACE 



In closing the Fiftli Volume of the Geological Magazine, we 
cannot omit to express our sincere thanks to our numerous friends, 
especially to those who have furnished the Original Articles, 
which, as a matter of course, are the very foundation of this volume. 
We welcome some as new Geological contributors, but the chief 
names are of old and valued supporters who have from the outset 
given us their aid. 

Our volume for 1868 contains articles by Messrs. T. P. Barkas ; 
Thos. Belt, C.E., F.G.S. ; E. Billings, F.G.S. ; W. Carruthers, 
F.L.S., F.G.S, ; Thos. Davidson, F.K.S., F.G.S. ; D. C. Davies ; 
T. Davies; W. Boyd Dawkins, M.A., F.E.S; C. E. De Eance ; 
J. Evans, F.E.S., Sec. G.S. ; K. Etheridge, F.R.S.E., F.G.S, ; 
Miss Eyton ; Eev. 0. Fisher, M.A., F.G.S. ; Messrs. David 
Forbes, F.E.S., F.G.S. ; Archibald Geikie, F.E.S.L. & E. ; James 
Geikie; J. E. Gregory; Prof. C. H. Hitchcock; T. McKenny 
Hughes, B.A., F.G.S. ; Dr. T. Sterry Hunt, F.E.S. ; Capt. F. W. 
Hutton, F.G,S. ; Prof. T.H. Huxley, LL.D., F.E.S., President Geol. 
Soc. ; Prof. T. Eupert Jones, F.G.S. ; Messrs. J. Beete Jukes, M.A., 
F.E.S., &c.; G. H. Kinahan, F.E.G.S.I. ; E. Eay Lankester, B.A. ; 
H. Leonard, F.G.S. ; J. Logan Lobley, F.G.S ; Dr. G. Lindstrom ; 
Dr. C. Lutken ; Messrs. D. Mackintosh, F.G.S. ; G. Maw, F.L. and 
G.S. ; C. J. A. Meyer ; Prof. J. Morris, F.G.S. ; Sir Eoderick I. 
Murchison, Bart., F.E.S. &c. ; Dr. H. A. Nicholson, M.B., F.G.S. ; 
Messrs. S. E. Pattison, F.G.S. ; C. W. Peach ; John Euskin, M.A., 
LL.D., F.G.S. ; G. Poulett Scrope, F.E.S., F.G.S. ; S. H. Scudder ; 
H. G. Seeley, F.G.S. ; S. Sharp, F.S.A., F.G.S. ; Eevs.W. S. Symonds, 
M.A., F.G.S. ; J. S. Tute, M.A. ; Messrs. J. F. Walker, B.A., F.G.S. ; 
J. M. Wilson, M.A., F.G.S. ; S. V. Wood, junr., F.G.S. ; B. H. 
Woodward, &c. 

Besides these, we are indebted for Notices and Eeviews to many 
gentlemen whose names we have not authority to publish, but to 
whom we sincerely tender our thanks. 



Vlll PREFACE. 

Nor have we failed to receive a goodly array of Letters, which, 
like the Original Articles, treat ' de omnibus rehus et quibusdam 
aliis ' in Geology and Palaeontology, and, as far as our space has 
permitted, we have given to each and all a place. We must, how- 
ever, again beg our Correspondents to make their letters as concise 
as possible, so as to allow of the insertion of as much variety both of 
matter and opinion as can be ; bearing in mind that a single letter 
by its length often shuts out several other communications equally 
deserving of a place. 

In the matter of Typography and Illustrations, the Artists, 
Printers, and Publishers have done their very best ; and if only 
more Subscribers will lend us their aid, we promise them a hundred- 
fold in return. 

Lastly — If they have not done so alreadj^ Annual Subscribers are 
earnestly requested to send in their names and subscriptions to 
Messrs. Trubner & Co., 60, Paternoster Eow, London, E.C. 

The Geological Magazine can be obtained through all Book- 
sellers in town or country; but if any difficulty or delay arises 
through this method of procuring it, the Publishers will always be 
happy to send it direct per post. 

The Editor. 



All Communications for the Geological Magazine should be 
addressed to the Editor, 142, St. Paul's Koad, Camden Square, 
N.W. 

Books for Eeview, and Parcels from abroad, sliould be sent 
addressed to the Editor, at 60, Paternoster Eow, E.C. 

Form for Subscribers to fill up and send to their Booksellers. 

To 

Be pleased to add my name to the List as a Subscriber 
for one copy of Volume VI. of the Geological Magazine, to be 
published monthly by Messrs. Trubner & Co., the First Part of 
which appeared on January 1, 1869, price Eighteenpence each 
number. 

Signature_^ 

Address 



:vl Man 1868 



Vol Y. FU. 



leu. 








luliu-h dA- kuxk 



J-'uj J j^ew Luniiioui Cnzstaxxcm. from, tke- IT. Sitanan. 
Fuj 2. Prosoj/oru -m-dnuruUaium., H. W. Stories fidd/. 



WWe,st 



vmp. 



THE 

GEOLOGICAL MAGAZINE. 



No. XLIII.— JANUARY, 1868. 

I. On a New Limuloid Crustacean [Neolimulus falcatus\ 

FROM THE Upper Silurian of Lesmahagow, Lanarkshire. 

By Henry Woodward, F.G.S., F.Z.S. 

(PLATE I., Fig. 1.) 

IN a paper which I communicated to the Geological Society of 
London, Nov. 21, 1866,^ (" On some points in the structure of 
the Xiphosura, having reference to their relationship with the Eu- 
rypterida'') I have recorded all the then known genera both of Xi- 
phosura and of Eurypterida, and in the tables which accompany the 
first part of my Monograph on the Merostomata,^ I have given both 
the genera and species with their range in time and space. 

Although it will be seen, by a reference to the last-named work, 
that none of the Xiphosura have hitherto been found in strata older 
than the Coal-measures, yet I have pointed out the existence of cer- 
tain Silurian forms (included by me in the sub-order Eurypterida), 
which indicate a passage — as it were — between the Eurypteridce and 
Pterygoti proper, and the Limulidce.^ 

It was with extreme interest therefore, that I obtained from Mr. 
Kobert Slimon, in September last, the first evidence of the existence 
of a true Limuloid form of Crustacean from the Uppermost Silurian 
shales of Lanarkshire. 

It is hardly possible to estimate too highly the persevering labours 
of Mr. Slimon and his sons in the investigation of these Lesmahagow 
deposits, and one is led to reflect what an enormous amount of ad- 
ditional knowledge would result, if other local geologists devoted 
themselves with the same energy to the investigation of the rocks 
of their own particular district. 

Unlike the majority of the Crustacea obtained from these deposits, 
our present acquisition cannot be classed among the giants of those 
days, the specimen only measuring five and a half lines in greatest 
length and six lines in greatest breadth. It is preserved upon the 
extreme edge of a piece of shale, so that, unfortunately, the ultimate 
segment, as I conceive, and the telson or tail-spine are wanting 
through being cut off by a cleavage-plane. I have allowed the artist 
to indicate their probable size in outline, in Plate I. Fig. 1 a ; the rest 
of the figure, actually preserved in the fossil, being shaded. 

1 See Quart. Journ. Geol. Soc. Feb. 1 867. Vol. xxiii. p. 28. PI. I. and II. 

2 Palseontographical Society, vol. xix. December 1866. 

3 Quart. Journ. Geol. Soc. vol. xxiii. p. 31. PI. I. figs. 3-6. 

VOL. v.— NO. XLIII. 1 



2 II. Woodward — On a new King -cr ah 

The head-shield is nearly two-thirds broader than long, the front 
margin is semicircular and smooth, and the latero-posterior angles 
are acute and directed backwards. The posterior border of the head 
is concave, curving slightly inwards near the centre, and backwards 
towards the latero-posterior angles. 

The glabella is semicircular and has a tolerably well-defined lateral 
border, separating it from the cheek, but it approaches to, and unites 
with the border of the head-shield in front. A line (which may cor- 
respond with the facial suture in Trilobites) passes from the latero- 
posterior horns of the head-shield, obliquely across the cheeks, and 
unites with the lateral border of the glabella just where the com- 
pound eyes are faintly indicated. (See PL I. Fig. \a.) A raised V- 
shaped lobe, having its apex directed backwards, marks the centre of 
the glabella : near its apex four minute dots are visible under the 
microscope, these are most probably the larval eye -spots or ocelli. 
From the sides of this V-shaped lobe two corresponding lines diverge 
and unite with the posterior border, whilst the lateral ridges marking 
the semicircular border of the glabella curve inwards on approaching 
the posterior border of the head-shield and unite with the median 
lines near the ocelli. The segments succeeding the head-shield are 
free, and are strongly trilobed, the ends of the pleurge are all distinct 
and falcate. The first six segments are thoracic ; the abdomen pro- 
bably consisted of three segments, followed by an ensiform telson, 
but only two of these segments are preserved. The breadth of the 
segments diminishes rapidly backwards, the first thoracic measuring 
five lines across, whilst the sixth is only three lines, but the depth 
of each segment is nearly uniform. The form which appears to 
possess the same number of segments is the genus Hemiaspis, from 
the Lower Ludlow of Leintwardine, in which we find six thoracic 
and three abdominal segments ; but, with this exception, our Lanark- 
shire fossil is a much more Limuloid form than Hemiaspis, reminding 
one strongly of Mr. Baily's Belinurus regince from the Irish Coal- 
measures ; from this latter, however, it is also easily separable, both 
in its general form, and also in the non-anchylosed condition of the 
abdomen. From the genus Prestwichia it is also separated by the 
free condition of all its segments. 

Another new form of Limulus (Belinurus Banm) from the Coal- 
measures of Illinois, U.S., has been described by Messrs. Meek and 
Worthen,^ for which Mr. Meek has since proposed the generic name 
of Euproops, in allusion to the anterior position of its eyes.^ This 
new form is considered by Mr. Meek to be more near Prestwichia 
anthrax, than to Belinurus, by reason of its anchylosed segments, but 
he considers that it differs from the former in the comparatively 
email and quadrangular form of the glabella.'' 

1 Geological Survey of Illinois, 1866, vol. ii. ; Palaeontology, p. 395, PL 32, fig. 2. 

2 Geol. Mag. 1867, Vol. IV. p. 320. 

3 Ilaving, through the kindness of Mr. Prestwich, F.R.S., the type-specimens of 
his Limulus {Prestwichia) anthrax in my possession, I am the more able to appreciate 
Mr. Meek's comparison of Euproops Dance with that species. It seems hardly possible 
to do more than separate them specifically : of their generic identity, I think there can 
be no doubt. 



In the Upper Silurian of Lanarkshire. 3 

Not being able to refer tbe Lanarkshire specimen to any previously 
described genus oiXiphosura, I propose to name it Neolimulusfalcatus.^ 

I shall not now venture to discuss the affinities of the Xiphosura with 
the Trilohita, a point on which I am deeply interested ; first, on account 
of want of information as to their appendages, and secondly, because 1 
believe that a better knowledge of the larval stages of the recent Limulns 
is essential to a true explanation of these earliest representatives of the 
group in past time. Dr. Anton Dohrn of Jena, and Prof. 0.0. Marsh 
of Yale College, Ot., and several other able naturalists have pro- 
mised me their aid in this interesting inquiry, which, to be carried 
out in a proper manner, necessitates a temporary residence on the 
N.E. Ooast of North America or the coast of China or Japan, where 
living King-crabs abound. 

EXPLANATION OF PLATE I., Fig. 1, la. 

Fig. 1. Neolimulus falcatus, H.Woodw. Natural size (the tail- spine and last segment 
restored) from the Uppermost Silurian shales of Lesraahagow, Lanarkshire. 
Fig. la. The same magnified four times. 

The original specimen is now in the British Museum. 



II. — On a new Brachyurous Ckustacean {Frosopon mammillatum), 
FROM THE Great Oolite, Stonesfield. 

By Henry Woodward, F.G.S., F.Z.S. 

[PLATE I., Fig. 2.] 

AMONG the new Oolitic Crustacea to which I drew attention at 
the meeting of the British Association, Dundee, was a species 
of Prosopon from the Stonesfield Slate. 

This genus was proposed by H. von Meyer, in 1835, for certain 
minute forms of Crustacea from the Upper White Jura of Oerlinger 
Thai, and other localities in Germany, from whence he has described 
twenty-nine species, and in addition to these, one from the Lower 
Oolite, three from the Coral Rag, and one from the Neocomian 
(see PalcBontographica, for December, 1860, vol. vii., p. 183, pi. xxiii.) 

In it, however, are included forms belonging to a very distinct 
family which cannot be placed with the Corystidce. A similar form 
to these, from our own Greensand, has been figured and described by 
Professor Bell in his Monograph on the Fossil Malacostracous 
Crustacea (Palseontographical Society, 1862, Part ii., p. 9, pi. ii.), 
and is correctly referred by him to the FinnotheridtB, under the 
generic name of PlagiopJithalmus. 

I would suggest that into this genus of Bell's should be removed, 
all those species at present included under the genus Prosopov, 
which have " an evenfy egg-shaped carapace with the front slightly 
produced and bent downwards, the surface nearly smooth, and 
marked by two shallow transverse furrows nearly parallel to each 
other, the orbits very small, elongate-oval, and placed obliquely 
within the margin, appearing as if pierced in the substance of the 
carapace" (Bell, op. cit. p. 9). 

^ j/eos, young, in allusion to its size, and also its early appearance in time (and 
limulus) ; axi^falcatus from the sickle-like form of the hody-segments. 



4 H. Woodivard — On Prosopon mammillatum^ 

Plagiophthalmus, Bell, would thus probably include within it the 
following species of H. von Meyer's genus Prosopon, namely : — 

P. hebes, P. simplex, P. rostratum, P. spinosum, P. elongatum, P. de- 
pressum^ P. ohtusum, P. Stotzingense, P. tuberosum, P. sublaeve, P. laeve, 
P. punctatum. The following are doubtful : P. insigne, P. cequilatum, 
P. marginatum, P. grande, P. excisum, P. lingulatum.. 

For the remainder, the generic name Prosopon should be retained, 
namely : P. aculeatum, P. ornatum, P. paradoxwn, P. torosum, P. Meg- 
dent, and P. (Bquum. 

Having only seen actual specimens of a few of these forms I do 
not wish, at present, to do more than indicate those species, which, 
I think, will need revision. They all occur merely as detached cara- 
paces, without appendages, and the under-side of the fossil usually 
adheres firmly to the matrix and is therefore seldom seen. 

The crab now to be described (Plate I. Fig. 2), although larger 
than the Wurtemburg specimens, is no doubt referable to the genus 
Prosopon in its restricted sense. 

It was first noticed by Professor Morris, F.G.S., who obtained an 
imperfect carapace many years since ; it was next observed by Mr. 
Samuel Stutterd, of Banbury," who found a portion of another spe- 
cimen, which he kindly brought to me for examination. Lastly, for 
the very perfect carapace, now figured, I am indebted to George 
Griffith, Esq., M.A., the Assistant- General Secretary of the British 
Association, who procured it at Stonesfield, from whence the two 
other examples, above referred to, were also obtained. 

The specimen measures fourteen lines in length, and eleven and a half lines in breath. 

The front of the carapace is four lines in breadth, and is marked by a semi-circular 
depression in the centre, and by two laterally diverging horns— similar to those which 
ornament the front of the carapace in many of the Triangular crabs. ^ Immediately 
behind these horns are placed the orbits which are bounded on their exterior angles 
by short blunt spines. Here the carapace measures six lines across ; the hepatic 
region then swells out into a tumid prominence, ornamented by a single spine, the 
breadth of the carapace being increased to nine and a half lines. Posterior to the 
hepatic region the cervical or nuchal furrow crosses the carapace, forming a deep in- 
dentation between the gastric and cardiac regions. A second transverse furrow, three 
lines behind the cervical furrow, indents the carapace and unites with the cardiac 
furrow on either side. 

The regions of the carapace are all well-marked and very tumid : the gastric region 
is the most prominent, and is marked by two mammillae (which have suggested the 
trivial name). When viewed in profile (see PL I. Fig. 2 a) these mammillae are 
elevated three and a half lines above the level of the slab on which the carapace 
rests. The posterior border of the carapace is nine lines in breadth, and but slightly 
curved. The branchial and cardiac regions of the carapace are covered with minute 
rounded tubercles. The gastric and hepatic regions are also tuberculated ; but the 
tubercles are fewer and of larger size. 

In a paper, communicated to the Geological Society, May 23rd, 
1866 (which was published in the Quarterly Journal, vol. xxii. 
p. 493, pi. xxiv. fig. 1), "On the oldest known British crab (^Palce- 
tnachus longipes) from the Forest Marble of Malmesbury, Wiltshire," 
I pointed out the synthetic characters which these early forms of 
Crustacea present. In Prosopon mammillatum we have another 
example of this blending of characters in the outset of the Bra- 
chyura in Oolitic times. 

^ The Macropodiada of Milne-Edwards. 



ccl.Mcug.2S68 



VolVn.E 










/3. 






16. 



15 





18. 



17 



^P 



1Z. 



19 






A T.KoUxckdeJ i- :U„ 



WWest imp 



New Trhiobites, ^ frorru the Upper Ccarhbruui. Rocks 
of North. Wales 



A new Crustacean from Stonesfield. 5 

Every systematic naturalist feels it incumbent on him to refer 
the form he is describing to its proper position in the family and 
class to which it belongs, but the palaeontologist knows well how 
difficult it is, from a portion only of an animal structure — whether 
vertebrate or invertebrate — to predicate with certainty its true 
affinities. In the present case the genus Prosopon has been referred 
to the Corystid(B, a group which nearly approaches to the Anomoura 
of Milne-Edwards. Even upon the imperfect knowledge which the 
present form gives us, we are led to perceive its affinities with the 
Anomoura, and probably when we are in possession of fuller 
information, we shall be able to refer it with confidence to the 
Honiolad(B, a true Anomourous family. In the meantime we must 
ask our readers to be contented with this brief description, in the 
hope that more perfect materials may shortly be discovered. 

EXPLANATION OF PLATE I., Fig. 2. 
Fig. 2. Prosopon mammillatum, H. "Woodw. Great Oolite, Stonesfield, twice the 

natural size. 
Fig. 2a. Side view of same. 

From the cabinet of G. Griflath, Esq., M.A., Harrow. 

III. — On the "Lingula Flags," or '* Festiniog Group" 

OF THE DOLGELLY DISTRICT. PaRT III. 
By Thomas Belt, F.G.S. 
[PLATE IL] 

HAYING- described in some detail, the rocks of the Maentwrog, 
Festiniog, and Dolgelly groups, and given a list of the fossils 
found in each,^ I shall now make some general remarks upon the fauna. 
In Part I. I have mentioned that out of all the numerous Trilobites 
from the Lower Cambrian^ rocks, only two genera, Agnostus and Co- 
nocoryphe, have been found in higher strata. Strictly speaking, this 
is only true of Agnostus, which passes unchanged in type from the 
Menevian to the Caradoc strata. On the contrary, the species of 
Conocoryphe from the Lower Cambrian rocks are of essentially 
different type from those that have been placed in that genus from 
higher beds. The latter have, I believe, been referred to the genus Co- 
nocoryphe rather from superficial resemblances than from true affinity. 

The possession of facetted or unfacetted pleurae has been con- 
sidered of sufficient importance to separate closely allied species into 
distinct families, and McCoy, in his Classification of the Trilohita, 
has even founded his two main divisions upon that feature. The 
facetting of the pleurae may be of generic, but it is not of higher 
value. The absence of facets to the pleurae of Paradoxides and Oienu^ 
does not prove, as some palaeontologists have supposed, that thej^ 
were incapable of rolling up. Trilobites with flat pleurae required 
no facets to facilitate that operation. It is only when the pleurae, 
are bent down near the middle that the facets are of use in allowing 
the ends of the pleurae to pack in underneath each other. 

It is through exaggerating the importance of this feature that some 

* See Geological Magazine, 1867, Vol. IV., pp. 493 and 536. 

* The Lower Cambrian period, according to the classification adopted in this paper 
is only part of the " Primordial Zone" of Barrande, as that illustrious palaeontologist 
has included in it Olenus and Feltura, which in reality helong to a second fauna. 



6 



Belt — On the Fauna of the *' Lingula Flagt 



species of Trilobites from the Dolgelly and Tremadoc strata have 
been separated from the Olenidce to which they naturally belong, 
and placed with the Conocephalidce with which they have no affinity. 
These pseudo-Conocoryphe have a thin and smooth crust and are flat 
or but little convex. The pleurge are falcate and pointed, and only 
slightly bent down at the fulcrum ; the axial furrows are shallow ; 
the facial suture ends below, some distance within the posterior 
angle. In all these points the pseudo-Conocoryphe approach the 
genus Olenus. The typical species of Conocoryphe from the Lower 
Cambrian rocks, on the contrary, are very convex and have a thick, 
granulated, or even sub-spinous crust. The pleurae are strongly 
bent down, so as often to be nearly vertical from the fulcrum ; the 
axial furrows are deep ; the facial suture ends below, close to the 
posterior angle, so that if the marginal furrow of the free cheek were 
produced downwards it would cut the suture. In all these points 
the typical Conocoryphe are distinct from Olenus and approach Caly- 
mene. All the species of Conocoryphe from the Lower Cambrian 
rocks belong to the typical group, and all the species that have been 
referred by various authors to that genus from the Upper Cambrian 
rocks belong to what I have called the pseudo- Conocoryphe ; I have 
only retained them provisionally in Conocoryphe, because it is im- 
possible without specimens of Angelin's species, or better figures of 
them than he has given us, to determine whether they belong to his 
genera Solenopleura, Centropleura, etc., or not. The whole of these 
pseudo- Conocoryphe show so many points of affinity with Olenus that 
in drawing up the following table of the Trilohita from the Maen- 
twrog, Festiniog, and Dolgelly strata, I have had no hesitation in 
including them amongst the Olenidce. 





Trilobites of the Maentwrog 


, Festiniog, and Dolgelly Groups. 


s 

1 

1 

1 


Species. 


Maentwrog 
Beds. 

Lower. Upper. 


Festiniog 
Beds. 

Lower. Upper. 


Dolgelly 
Beds. 

Lower. Upper. 


Dikelocephalus ? Cellicus, Sal. ... 

„ ? discoidalisj Sal. 
Conocoryphe ? abdita, Sal 














„ Hmita, Sal 


„ ? Williamsonu, n. sp. 

„ ? lonffispina, n . sp. . . . 

„ ?bucephala, n. sp. ... 

Olenus ffibbosus, Wahl 


„ truncatus, Ang 


,, cataractes, Sal 


Parabolina spinulosa, Wahl 

Peltura scarabceoides, Wahl 

Sphcerophthalmus ?iumilis, Phil.... 
„ bisulcatus, Phil. 

Agnostus nodosus, Belt 


,, pisiformisy Lin 


„ „ var. obesus. Belt. 
„ sp 


„ obiiisus, n. s^ 


„ princeps, Sal 


„ trisectus, Sal 



Belt - On the Fauna of the " Lingula Flags'^ 7 

The Lower Cambrian rocks, with their most abundant fauna/ are 
followed by strata, containing but two genera of trilobites — Aqnosius 
and Olenns. Of these, Agnostus comes from below and passes on 
upwards unchanged in type. Olenus, on the contrary, only remains 
true to its typical form through the Maentwrog beds, in which 
it has three British representatives. In the Upper Festiniog and 
Lower Dolgelly beds it branches off in two directions. In one, 
through Conocoryphef bucephala towards the pseudo- Conocoryphe and 
Dihelocephali of the Upper Dolgelly beds ; in the other, through 
ParaboUna spinidosa towards the Pelturce and SpJioerojjhtJialmi of the 
same strata. This relation is shown in the following diagram : — 

I — JDikelocephalm. 
— Conocoryphe ? — 
I ' — Conocoryphe ? 

Olenus — 

I I — Sphocrophthahnus. 

— Farabolina — 

' — Teltma. 

Many links in the chain are wanting, but this much is certain, 
that the typical Oleni of the lower strata are followed by two genera ; 
one of which — Conocoryphe ?, with entire pygidium and falcate 
facetted pleurae, is intermediate between the Oleni below and the 
Conocoryphe ? and Dihelocephali above ; the other, ParaboUna with 
serrated pygidium and spinous, unfacetted pleurae, intermediate 
between the Oleni below and the Sphcerophthalmi and Peltura above. 
This result is obtained, not by picking out from a number of species 
those that could be brought within such a generalization, but by 
using all the species, and placing them in the order, as to time, in 
which they occur in the strata. 

Some interesting relations between the fauna of the Maentwrog, 
Festiniog and Dolgelly beds, and that of the underlying Lower 
Cambrian rocks on the one hand, and of the overlying Tremadoc 
and Lower Silurian strata on the other, still remain to be pointed 
out. Between the deposition of the Upper Menevian and the Lower 
Maentwrog beds, the abundant fauna of the Lower Cambrian period 
disappears, and our next horizon shows only a few species of 
Agnostus and Olenus ; the latter, pigmy representatives of the giant 
Paradoxides of the preceding age. All on through the Maentwrog, 
Festiniog, and Dolgelly epochs, the various Trilobites that succes- 
sively appear either belong to or are closely allied to these two 
genera. The fauna is a compact and homogeneous one. We have no 
intrusions of new types of structure, but the more recent forms are, 
if I may use the phrase, the natural evolution of the older. When 
we pass on upwards into the Tremadoc and Arenig epochs, a great 
and apparently sudden change takes place. 

Large Trilobites belonging to the AsaphidcB now first appear, and 
then the Cheiruridce, Trinucleidce, and Calymenidce come upon the 
stage. Of these there has been no development in the area under 

1 See ante, Part I., "Table of the Cambrian Rocks showing the range of the 
Genera," Vol. IV. p. 495. 



8 Belt — On the Fauna of the " Lingula Flags." 

consideration. Tliey come in like an invading host, and the few 
species of Olenidce and AgnostidcB that struggle on upwards are out- 
numbered, and, as it were, crowded out, by the intruders. It is an 
interesting inquiry — from whence did the latter come? but our 
materials are too scanty to furnish a reply. It is, however, to be 
noted, that at least two of the Lower Cambrian genera which are 
entirely absent throughout the Maentwrog, Festiniog, and Dolgelly 
groups are represented in the Tremadoc and Arenig strata by two 
families, greatly modified it is true, but yet showing many points 
of structural affinity with the much more ancient genera. Micro- 
discus, so abundant in the Menevian beds, comes back to us after a 
long absence in the Trinucleidce of the Tremadoc and Arenig groups ; 
and the Menevian Conocoryphe are represented by the CalymenidcB of 
the Arenig and higher rocks, and are likewise absent from the inter- 
mediate strata. 

I think that it is not improbable that in the Tremadoc epoch we 
behold the return of a fauna driven from our area at the close of the 
Lower Cambrian period, and which has, in the meantime, been greatly 
developed, so far as the Trilobita are concerned, in some other area. 
This supposition would be a hazardous one to propound on the 
evidence of the Trilobites alone, but it is rendered more feasible by 
a study of the lower forms of life that accompany them. The sea. 
towards the close of the Lower Cambrian period must have teemed 
with life. Besides the various genera of Trilobites, Pteropodous 
Thecce must have swarmed, along with species of lAngulella, Obolella, 
Discina, and Protospongia. When the Trilobites disappear, these 
lower organisms disappear also. A few specimens of Lingulella 
have, it is true, been found in the Maentwrog beds, but they 
belong to a different type from the Lower Cambrian species, and 
Theca, OboleJla, Discina, and Protospongia are unknown. In the 
Festiniog beds, one, and perhaps two, species of Lingulella abound, 
but they are of the same type as the Maentwrog species, and 
the other genera are still absent. In the Dolgelly beds we have 
the rare occurrence of Obolella, and a single specimen of Proto- 
spongia has been found in a loose stone, believed to be from these 
strata. The Lingulella are still of a different type from the Lower 
Cambrian forms, and not a trace of Theca nor Discina have occurred. 
When, however, we pass into the Lower Tremadoc strata, all the 
lower types of life present in the Lower Cambrian rocks come back 
to our area, almost unchanged specifically. Thecce resembling the 
Lower Cambrian forms again abound, along with species of 
Obolella, Lingulella, Discina, and Protospongia, so like the Lower 
Cambrian species that I doubt whether they can be distinguished 
from them. When I first found this Lower Tremadoc fauna upon 
the flanks of Mynydd Gader, near Dolgelly, I doubted whether 
I had not come upon Menevian strata, brought in by some great 
fault, so similar were the lower forms of life ; and it was only the 
presence of Niobe Homfrayi, and Asaphus innotatus, that assured me 
that the rocks were really of Lower Tremadoc age. Lingulella ferru- 
ginea, Obolella maculata, Discina labiosa, Protospongia fenestrata, and 



Belt — On the Fauna of the ^' Lingula Flags.'" 9 

P. flahella, have almost their exact counterparts ia the Lower 
Tremadoc rocks of Dolgelly, although, as I have already shown, 
there are 5,000 feet of strata lying between, occupied by an entirely 
distinct fauna. 

When examining the nearly barren strata of the Maentwrog epoch, 
I have sometimes speculated on the cause of the poverty of its fauna. 
It was not on account of the nearness to the beginning of life on 
our globe, for in older rocks still, a varied fauna abounded. It could 
scarcely arise from conditions of sea bottom, for thick alternations 
of sand, with fine grained sediments, bespoke varied depths of water 
under which they had been deposited. The blue beds of the 
Maentwrog strata do not differ lithologically from the blue beds of 
the Menevian group. Might there not be in these ancient epochs 
great oscillations of climate, such as we have certain proofs of in 
more recent times ? Was it the advent of a cold period that drove 
southwards the Lower Cambrian fauna, excepting a few modified 
forms fitted to thrive in a more rigorous climate ? and was it the 
return of a warmer climate in the Tremadoc epoch that brought 
back the ancient types of life more or less changed ? 

NOTES ON THE SPECIES. 

Conocoryphe? Williamsomi, spec. nov. (PI. II. Figs. 7-11.) — Length 
lj-2^in., breadth |-l|^in. Ovate oblong. 

Head, broadly semi-circular, with short strong spines pointing downwards and out- 
wards. Glabella, a truncated cone, with two pairs of oblique furrows. Eyes small, 
joined to the glabella by short prominent ocular ridges, and distant from it about 
one-half its width. Frontal limb moderate, with a narrow margin. Fixed cheeks, 
curving out below the eye. Free cheeks, broad, with a scarcely impressed margin. 

Thorax of 14 rings. Axis tapering, depressed. Pleurae, flat, first two, pointed and 
strongly facetted, the remainder falcate and very slightly facetted, 

Pygidium of 4 axial rings, of which the last is pointed and ends in a narrow ridge, 
running out to the margin of the limb. Limb rounded and slightly retuse, with 
about four furrows. Margin depressed, broad next the pleurae and tapering to where 
it meets the ridge from the last axial ring. 

The head of this species somewhat resembles C. depressa, Salter, but is easily dis- 
tinguished from it by the deep glabella furrows, falcate pleurae and truncate, slightly 
retuse tail. I know of no other species with which to compare it. 

I have great pleasure in dedicating this fine species to my friend Mr. Ezekiel 
Williamson, in whose company it was first found by myself in 1865, in the black shales 
of the Upper Dolgelly beds, near Rhiw-felyn. 

Conocoryphe f longispina, spec. nov. (PI. II. Figs. 12-14. — Length 
Jin,, breadth Jin. Ovate. 

Head. — Head semi-circular, with long, slightly curved spines, reaching beyond the 
tail. Glabella oblong, truncate, about as broad as long, with two pairs of deep, 
oblique furrows, of which the lowest is most oblique, and reaches nearly to the neck 
furrow. Eyes large, connected to the glabella by prominent ocular ridges, and 
distant from it rather less than one-half its width. Frontal limb broad, with a 
lineated margin. Fixed cheeks, minute. Free cheeks broad, with a lineated margin. 

Thorax of 14 rings. Axis regularly tapering. Axial rings, with a small tubercle 
at each end, and traces of a central tubercle, which are more prominent on the 
lower rings. Upper pleurae pointed, strongly facetted; middle pleurae falcate, 
moderately facetted, lower pleurae truncate, slightly facetted : all bent down at less 
than one -half their length from the axis, 

Fygidium sub-rotund, of three axial rings. Limb, with three furrows. Margin 
narrow, linear. 

This species is easily distinguished by its long head spines ; short, broad glabella ; 
long eyes and broad frontal margin. It occurs sparingly along with the last in the 
. Upper Dolgelly beds, near Ehiw-felyn, where I discovered it in 1865. 



10 Belt — On the Fauna of the '^Lingula Flags.'" 

Conocoryphe? bucephala, spec. nov. (PL 11. Fig. 1-6). Length If in. 
Breadth 1 in. Ovate. 

Head broadly semi-circular with strong spines pointing downwards and a little out- 
wards. Glabella subconical. truncated, very prominent, and without furrows when 
perfect. Figs. 1 and 2 ; but when crushed Fig. 3, or divested of outer crust Figs. 4 
and 5, showing two pairs of internal ones of which the upper is short and the lower 
long and very oblique, reaching nearly to the neck furrow. Some specimens show a 
third short pair of furrows near the apex of the glabella. Eyes small and 
prominent, distant from the glabella about half its width and joined to it by 
ocular ridges that are nearly obsolete in perfect specimens of the head, but clearly 
shown in crushed ones. Frontal limb narrow, with a strong triangular margin 
marked off by a deep groove. Cheeks broad, prominently convex, with a wide margin. 

Thorax of 14 (?) rings. Axis convex, tapering. Pleurae falcate, pointed strongly, 
grooved, and facetted. Fulcrum of the pleurae prominent, less than half their length 
distant from the axis. (See PL II. Fig. 6.) 

Fyc/idium not preserved in any of the specimens, but it must have been small and 
of not more than one or two rings. 

The specimens of this species when perfect have all their parts prominent and convex. 
The head is large and resembles C. ? depressa, Sal., and that species also when un- 
crushed shows no glabella furrows, in which condition it is C. 2 verisimilis, Sal., and 
probably also C. ? vexata, of the same author. Specimens of C, ? bucephala, flattened 
by pressure, resemble Olenus micrurus, Salter, to which species I was at one time 
inclined to refer it, but an examination of the specimens of O. micrurus, from near 
Trawsfynydd, in the Museum of Practical Geology, has convinced me that it is a true 
Olenus and quite distinct from C, ? bucephala. C. ? hucephala is not uncommon at 
Gwern-y-barcud, near Penmaen-pool ; on Mynydd Gader, and near Craig-y-Dinas, 
along with Hymenocaris vermicauda, Bellerophon Camhriensis, and a small Lingula in 
Upper Festiniog beds, 

SpJi^ropJithalmus hisulcatus, Phil. ; syn., Olenus hisulcatus, Phil. Olenus 
(SpceropJithalmus) pecten, Salter. Olenus {Sphceropth.) jiagelUfer, Sal. 
Olenus alatus, Sal. 

I have examined the specimens in the Museum of Practical Geology, on which the 
above species were founded. They are fragments only, variously distorted. When 
they are studied in connection with the perfect specimens that we have now obtained 
from the Dolgelly district there can, I think, be no doubt of their being one and the 
same species. I think the species cannot be referred to Olenus fSphar.) alatus, Boeck, 
unless we assume a large amount of error in Angelin's figure of that species, as he 
shows the pygidium entire and with four axial rings, whereas Sph. hisulcatus has a 
minute serrated pygidium of two rings only, and is furnished with a long terminal 
spine. Some fragments of Sphcei^oph. alatus, Boeck, in the Museum of the Geological 
Society resemble Sphceroph. humilis, Phil., but that species also has a minute pygidium 
with a long terminal spine. At the same time I think it highly probable, that when 
we are able to compare our Cambrian trilobites with specimens of the Scandinavian 
species, many of our names will have to give place to those of Angelin, though we 
cannot at present identify them by the figures he has given us, 

Mr, E. Williamson discovered this species in the black shales at Rhiw-felyn in 
1865, More recently, Mr. J- C, Barlow found it in great profusion within a few 
yards of the first discovery. A band of about three inches thick of the shale, is 
almost entirely composed of the remains of S. hisulcatus, along with a few specimens 
of S. humilis. 

Agnostus ohtusus, spec. nov. (PI. II. Figs. 15, 16). Length Jin., 
breadth Jin. Oblong, obtuse. 

Head, a truncated semi-circle. Glabella five-eighths length of head, ovate, 
obtuse, with a nearly obsolete central tubercle, and traces of a nearly obsolete 
furrow, separating a terminal lobe. Two minute triangular lobes at base of glabella. 
Limb nearly of equal width all round. Margin narrow. 

Thorax, of two rings. Axis, broad. 

Fyyidium, shaped like head. Axis, short, pentangular, one-third the length of the 
pygidium, with a nearly obsolete tubercle, near the end. Limb narrow at the sides, 
and broad at the end of the axis. Margin marked ofi" by a deep groove, and 
widened near the lower angles, where it has a short spine on each side. 

This species belongs to the same group as A. tardus. Bar,, A. lentiformis, Ang., and 
A. trinodus, Sal., from all of which it differs in the much shorter and unlobed axis of 
the pygidium. In the Upper Dolgelly beds at Rhiw-felyn, I have found this species 



Belt — On the Fauna of the *^Lingula Flags'' 11 

very sparingly, along with A. trisectus, A. princeps, and the other fossils of the black 
shales. 

Agnostus trisectus, Salter. 

This species, described from, imperfect specimens of the pygidiura, occurs in 
great abundance in the black shales at Rhiw-felyn, where I have obtained numerous 
perfect specimens, a complete series of which is now deposited in the British 
Museum. These show that, like A. princeps, it was furnished with marginal spines 
Lo the pygidium ; and other close resemblances make it most difficult to dis- 
tinguish some of the specimens from that species, with which, however, I hesitate 
at present to join it, especially as the able author of the Monograph on the Trilo- 
bita has announced his intention of dealing with the AgnostidcB, in the next part of 
that valuable work, 

Agnostus Barlowii, spec. nov. (PL 11. Figs. 17, 18). — Length Jin., 
breadth ^in. Oblong, ovate. 

Head rounded, ovate, plain, rising from all sides to a point near the base, Margin 
very narrow. 

Thorax of two rings. Axis trilobate. 

Pygidium, shaped like head, rising to a central point near the base, with two slight 
indentations, marking the commencement of an obsolete axis. 

This species resembles Angelin's figures of his A. glandiformis and A. hituhercu- 
latus, but differs in the absence of tubercules, and in its trilobate thoracic axis. To A. 
nudus, Bar., it comes still nearer, but that species has neither the axial furrows of 
the pygidium, nor the trilobate thoracic axis of A. Barlowii. 

It is a striking example of the persistence of type amongst the Agnostidce, that 
the nearest known ally of A. Barlowii, which is a Tremadoc form, should be a 
species from the Lower Cambrian rocks of Bohemia. 

It occurs in the Lower Tremadoc beds near Rhiw-felyn, along with Asaphus inno- 
tatus, Niobe Hovifrayi, Conocoryphe? depressa, etc., where it was first found by Mr. J. C. 
Barlow, of Birmingham. This species comes from rocks a little beyond the limits of 
this paper, but I include it, as it is the first example of Agnostus from British Tremadoc 
strata, and for the purpose of commemmorating the services of Mr. J. C. Barlow, in 
elucidating the geology of the Dolgelly district. 

BelleropJion Cambriensis, spec. nov. (PL II. Figs. 19, 20.) 
Broadly involute with three or four distant, coarse ridges of growth, crossed by 
faint longitudinal striae ; keel narrow. 

The discovery of this species carries the range of the Heteropodous Mollusca much 
lower down in the Cambrian rocks than was before known. I first found it near 
Craig-y-dinas, but have since discovered that it is not uncommon along with Cono- 
coryphe? bucephala and Hymenocaris vermicauda, wherever the Upper Festiniog rocks 
are exposed as on Mynydd-gader, and at Gwern-y-barcud, near Penmaen-pool. 

EXPLA'NATION OF PLATE II. 

Figs. 1-6. Conocoryphe? bucephala, spec, nov., from specimens in British 

Museum and collection of Thos. Belt. 
„ 7-11. Conocoryphe? Williamsonii, spec, nov., from specimens in British 

Museum and collection of Thos. Belt. 
„ 12-14. Conocoryphe? longispina, spec, nov., from specimens in British 

Museum and Museum Practical Geology. 
„ 15, 16. Agnostus obtusus, spec, nov., fiom specimens in British Museum. 
„ 17, 18. Agnostus Barlowii, spec, nov., from specimens in British Museum 

and collection of Mr. J. C. Barlow, of Birmingham. 
„ 19, 20. Bellerophon Cambriensis, spec. nov. Both specimens figured are on 

one slab in British Museum. 

ERRATA. 

In Part I., page 495. Table of the Cambrian rocks. Obolella should have been 
marked present in the upper part of the Dolgelly group and lower part of the 
Tremadoc group, and Discina in the lower part of the Tremadoc group. 

In Part II., page 540, line 18 from the bottom, for Conocoryphe micrura, Sal., read 
Conocoryphe? bucephala, spec. nov. 



12 Ruskin — On Brccciated Concretions, 

TV. — On Brecciated Concretions. 
By John Ruskin, Esq., F.G.S. 
(Continued from the November Number, p. 483.) 
(PLATE III.) 

THE states of semi-crystalline silica are so various, and so con- 
nected in their variety, that the best recent authorities have 
been content to group them all with quartz, giving to each only a 
few words of special notice ; even the important chapters of Bischof 
describe rather their states of decomposition and transition than the 
minerals themselves. Nevertheless, as central types, five conditions 
of silica are definable, structurally, if not chemically, distinct ; and 
forming true species : and in entering on any detailed examination 
of agatescent arrangements, it is quite necessary to define with pre- 
cision these typical substances, and their relation to crystalline quartz. 
I. Jasper. — Opaque, with dull earthy fracture ; and hard enough 
to take a perfect polish. When the fracture is conchoidal the mineral 
is not jasper, but stained flint. The transitional states are confused 
in fracture ; but true jasper is absolutely separated from flint by two 
structural characters ; on a small scale it is capable of the most 
delicate pisolitic arrangement ; and on a larger scale is continually 
found in flame-like concretions, beautifully involved and contorted. 
But flint is never pisolitic, and, in any fine manner, never coiled ; nor 
do either of these structures take place in any transitional specimen, 
until the conchoidal fracture of the flint has given place to the dull 
earthy one of jasper; nor is even jasper itself pisolitic on the fracture, 
being too close-grained. The green base of heliotrope, with a per- 
fectly even fracture, may be often seen, where it is speckled with 
white, to be arranged in exquisitely sharp and minute spherical con- 
cretions, cemented by a white paste, of which portions sometimes 
take a completely brecciated aspect, each 
; fragment being outlined by concave seg- 
ments of circles (Fig. 1). Jasper is emi- 
nently retractile, like the clay in septaria, 
and in agates often breaks into warped 
fragments, dragging the rest of the stone 
into distortion. In general, the imbedded 




Fig. 1. fragments in any brecciated agate will be 

mainly of jasper ; the cement, clialcedonic, or quartzose. 

II. Flint. — Amorphous silica, translucent on the edges, with fine 
conchoidal fracture. Opaque only when altered, nascent, or stained. 
Never coiled, never pisolitic, never reniform ; these essentially ne- 
gative characters belonging to it as being usually formed by a slow 
accumulative secretion, and afterwards remaining unmodified (pre- 
serving therefore casts of organic forms with great precision). It is 
less retractile than jasper ; its brecciate conditions being not so much 
produced by contraction or secession, as by true secretion, even when 
most irregular in shape (as a row of flints in chalk differ from the 
limestone fragments represented in Vol. IV. Plate XX. Fig. 3, which 
might stand for a jasperine structure also). But there are innumer- 
able transitions between these two states, affected also by external 



GeoL:Maa/36S. 



VoLV. PL.ni. 




Fig.l 




Fig.,2. 




Ru-skirL.del^ Y\<S 3 


G. Allen, inc 


AMETHYST-QUARTZ . 




with warped Faults m concretion . 





Buskin — On Brecciated Concretions. ] 3 

violence, which we shall have to examine carefully. Within these 
nodular concretions, flint is capable of a subsequently banded, though 
not pisolitic arrangement. (See Dr. S. P. Woodward's paper on banded 
flints, in this Magazine, Vol. I. for October, 1864, p. 145.) 

III. Chalcedony. — Reniform silica, translucent when pure, opaque 
only when stained, nascent, or passing into quartz. The essential 
characteristic of chalcedony is its reniform structure, which in the 
pure mineral is as definite as in wavellite or haematite, though when 
it is rapidly cooled or congealed from its nascent state of fluent jelly 
it may remain as a mere amorphous coating of other substances ; very 
rarely, however, without some slight evidence of its own reniform 
crystallization. The study of its different degrees of congelation in 
agates is of extreme intricacy. As a free mineral in open cavities it 
is actively stalactitic, not merely pendant or accumulative, but ani- 
mated by a kind of crystalline spinal energy, which gives to its pro- 
cesses something of the arbitrary arrangement of real crystals, mo- 
dified always by cohesion, gravity, and (presumably) by fluid and 
gaseous currents. 

There is no transition between chalcedony and flint. They may 
be intimately mixed at their edges, but the limit is definite. Im- 
pure brown and amber-coloured chalcedonies, and those charged 
with great quantities of foreign matter, may closely resemble flint, 
but the two substances are entirely distinct. Between jasper and 
chalcedony the separation is still more definite in mass, jasper being 
never reniform, and differing greatly in fracture ; but the flame-like 
or spotted crin? ^on stains of chalcedony often approach conditions of 
jasper ; and there is, I suppose, no pisolitic formation of any sub- 
stance without jme inherent radiation, which associates it with 
reniform groups, so that pisolitic jasper must be considered as partly 
transitive to chalcedony. On the other hand chalcedony seems to 
pass into common crystalline quartz through milky stellate quartz, 
associated in Auvergne with guttate and hemispherical forms. 

IV. Opal. — Amorphous translucent silica, with resinous fracture, 
and essential water. Distinguished from chalcedony by three great 
structural characte >tics ; a, its resinous fracture ; 6, that it is never 
pisolitic or reniform; c, that when zoned, in cavities or veins, its 
zones are always rectilinear, and transverse to the vein, while those 
of chalcedony are usually undulating, and parallel to the sides of the 
vein ; level only in lakes at the bottom of cavities. 

V. Hyalite. — Amorphous transparent silica, 
with vitreous fracture, and essential water. 
Never reniform, nor pisolitic, nor banded ; but 
composed of irregularly grouped bosses, gene- 
rally elliptical or pear-shaped (only accidentally 
spherical), formed apparently by successive ac- 
cretion of coats, but not showing banded struc- 
ture internally (Fig. 2). Entirely transparent, 
with splendid smooth glassy fracture. Some- ^ ' 

times coating lava ; sometimes in irregularly isolated patches upon 
it : apparently connected in structure with the roseate clusters of 




14 Buskin — On Brecciated Concretions, 

milky chalcedony of Auvergne. I shall keep the term " guttate " 
for this particular structure, of which singular varieties also occur 
among the hornstones of Cornwall. 

These five main groups are thus definable without embarrassment : 
two other conditions of silica, perhaps, ought to be separately named ; 
namely, cacholony, which seems to take a place between chalcedony 
and opal, but which I have not yet been able satisfactorily to define ; 
the other, the calcareous-looking, usually whitish agate, which often 
surrounds true translucent agate, as if derived from it by decom- 
position. I am under the impression that this is chalcedony, more 
or less charged with carbonate of lime, and that it might be arranged 
separately as lime-jasper, differing from aluminous jasper by being 
capable of reniform structure ; but it is certainly in some cases 
an altered state of chalcedony, which seems in its more opaque zones 
to get whiter by exposure to light. I shall therefore call it white 
agate, when it harmoniously follows the translucent zones ; reserving 
the term jasper for granular aggregations. Perhaps ultimately it 
may be found that nascent chalcedony can take up either oxide 
of iron, or alumina, or lime, and might relatively be called iron- 
jasper, clay -jasper, and lime-jasper ; but for any present descriptive 
purpose the simpler arrangement will suffice. 

These, then, being the principal types of agatescent silica, it is of 
importance to define clearly the two structures I have severally 
called pisolitic and reniform. 

A pisolitic mineral is one which has a tendency to separate bj'' 
spherical fissures, or collect itself by spherical bands, round a 
central point. 

A reniform mineral is one which crystallizes in radiation from 
a central point, terminating all its crystals by an external spherical 
surface. It is, however, difficult to define this character mathe- 
matically. On the one hand, radiate crystals may be terminated by 
spherical curves, as in many zeolites, without being close set enough 
to constitute a reniform mass ; on the other, radiate crystals, set close, 
may be terminated so as to prevent smoothness of external spherical 
surface, and I am not sure whether this smoothness is a mere 
character of minute scale (so that chalcedony, seen delicately enough, 
might present pyramidal extremities of its fibres on the apparently 
smooth surface), or whether, in true reniform structure, the crystal- 
lization is actually arrested by a horizontal plane : I do not mean a 
cystalline plane, as in beryl, but one of imperfect crystallization, 
presenting itself only under a peculiar law of increase. Thus, in 
haematite, which is both reniform and pisolitic, the masses often 
divide in their interior by surfaces of jagged crystallization, while 
externally they are smooth and even lustrous ; but I put this point 
aside for future enquiry, because it will require us to go into the me- 
thods of possible increment in quartz-crystals, and for our present pur- 
pose, we need only a clear understanding of two plainly visible con- 
ditions of jasper and chalcedony, namely, that jasper will collect itself 
pisolitically, out of an amorphous mass, into concretion round central 
points, but not actively terminate its external surface by spherical 



Ruskin — On Brecciated Concretions. 



15 



curves ; while chalcedony will energetically so terminate itself ex- 
ternally, but will, in ordinary cases, only develope its pisolitic struc- 
ture subordinately, by forming parallel bands round any rough 
surface it has to cover, without collecting into spheres, unless either 
provoked to do so by the introduction of a foreign substance, or 
encouraged to do so by accidentally favourable conditions of repose. 
And here branch out for us two questions, both most intricate ; first, 
as to the introduction of foreign bodies ; secondly, as to the crystal- 
line disposition of chalcedony, under variable permission of repose. 

First — As to foreign substances. I assume that in true pisolitic 
concretion, such as that of the jasper, roughly sketched in Fig. 3. 




Fig. 3. Fig. 4. V'lg. 5. 

(it is not a coral — the radiant lines are merely conventional indica- 
tions of the grain of the jasper, so far as it is visible with a lens^), 
no foreign body has provoked the orbicular arrangement. The jasper is 
red ; the little dark circles are wells of pure chalcedony, each con- 
taining within it a white ball of crystallized quartz, forming a star 
on the section. The whole is magnified about three times in the 
drawing, being a portion of a horizontal layer, alternating with solid 
white jasper. It seems that the pisolitic structure is here truly 
native ; but we must nevertheless grant the possibility that the balls 
of quartz may have had some organic atom for their nucleus. On 
the other hand, in the ordinary conditions of dendritic agate, in 
which stalactites of chalcedony surround branches of clearly visible 
chlorite,^ or of oxide of iron or manganese, I assume that in the 
plurality of cases, such sustaining substances have been first de- 
veloped, and the chalcedonic stalactite afterwards superimposed, 
being, in the most literal sense of the word, *' superfluous " silica; 
but I, nevertheless, see great reason for thinking that, in many cases, 
the core of the group is only a determination to its centre of 
elements which had been dispersed through the mass. In the 
generality of Mocha-stones, the dendritic oxides, so far from being 
an original framework, are clearly of subsequent introduction, radi- 
cally following the course of fissures from which they float par- 
tially into the body of the imperfectly congealed gelatinous mass ; 
in other more rare, and singularly beautiful cases, the metallic 
oxides ramify in curves in the intervals of the pisolitic belts, and 

^ In my woodcut diagrams I shall employ no fine execution ; they will be merely 
illustrative, not imitative,— diagrams, not drawings. In the plates, on the contrary, 
with Mr. Allen's good help, I shall do the best I can. 

2 Or green earth ? I cannot find any good account of the green substance which 
plays so important a part in the exterior coats of agates, and Iceland chalcedonies. 



16 Buskin — On Brecciafed Concretions. 

then there is nearly always a dark rod in the stalactitic centre, 
which may or may not be solid. In the finest Mocha stones, 
I think it is a black film round a chalcedonic nucleus ; but in the 
associations of limonite Tvith chalcedony, it is usually of solid 
radiate iron-oxide, and doubtless of prior, though perhaps only of 
immediately prior, formation. A more complex state is presented 
by such stalactites, when enveloped in a chalcedonic solid paste, to 
which they do not communicate their own zoned structure. Ordi- 
narily, the surrounding mass throws itself into zones parallel mth 
those of the enclosed stalactite ; but, in some cases, it is of quite 
adverse structure, perhaps laid level across the stalactitic fall. 

The conditions admitting the interfusion of this solid paste,^ are 
strangely connected with those which cause chalcedony to form true 
vertical stalactites and straight rods, instead of arborescent and 
twisted stalactites. I have never seen the twisted stalactite unless en- 
veloping fibres of some foreign, perhaps organic, substance, enclosed 
in massive chalcedony ; but the straight stalactite is perhaps oftener 
so than free (unless connected with limonite), and it would appear, 
therefore, as if the apparently interposed mass were really of contem- 
porary formation, or else it would sometimes enclose the contorted 
stalactite. But this question respecting the causes of the vertical 
and twisted groups properly belongs to the second branch of our 
inquiry as to states of repose. 

Second : Conditions afiecting mode of crystallization. It is evident 
that fluent deposits of silica contained in a rock-cavity must be 
affected, in course of their solidification, not only by every addition 
to their own mass, but by every change in the temperature or grain 
of the surrounding rock, so thai we have innumerable modifications 
of state, dependent partly on accession and transmission of sub- 
stance, partly on changes in external temperature and pressure. 
And, under these influences, we perceive that the gelatinous silica 
occasionally obeys gravity,^ and occasionally resists it, becoming 
sometimes pendent from the roof, and forming level lakes on the 
floor of cavities ; at other times, throwing parallel bands on floor and 
roof alike, and in transitional periods, forming thick layers on the 
floor, and thin ones at the sides, the layers being liable, meantime, 
to different degrees of compression from their own modes of solidi- 
fication, which give them, locally, the appearance of an elastic 
compression and expansion : there seems no limit to the fineness of 
their lines at these compressed points, when their continuity is unin- 
terrupted. Figures 6 and 7 illustrate, in two small pieces of agate, 
each here magnified about three times, most of the appearances 
which must be severally studied. In Fig. 6 the lowest band, A. 
level at the bottom, broken irregularly towards the rough side of 
the stone, is yet of nearly even thickness everywhere ; above it, the 

1 I use this word gravity in some doubt ; not being quite sure that the straight 
beds are always horizontal, or always inferior to the rest deposited at the same time. 
I have one specimen in which, according to all analogies of structure, it wtmld appear 
that the vacant space is under the level floor, between it and reniform chalcedony ; 
and sometimes these floors cross pillars of stalactite like tiers of scaffolding. 



Rushin — On Brecc'iated Concretions, 



17 



one with a black central line encompasses the whole agate symmetri- 
cally. Then a white band, thin at the bottom., projects into concre- 
tions on the flanks. Then, a thick white deposit, B. does not ascend 
at the flank at all ; then a crystalline bed, with pisolitic concretions 
at the bottom of it, changes into dark chalcedony (drawn as black), 
which ascends at the flanks. Then another thin line at the bottom, 
in concretion at flanks ; then one thick at the bottom, thin at the 
flanks, and so upwards, In Fig. 7, a level mass, itself composed of 




Fig. 6. Fig. 7. 

silica in two difi*erent states, one separating into flakes, and the other 
even-laid, is surrounded by bands which melt into it with gradually 
diminishing thickness, these being evidently subordinate to an ex- 
ternal formation of crystalline quartz ; the whole terminated by a 
series of flne bands of graduated thickness, and by clear chalcedony 
(drawn as black). 

Now all these, and many more such variations, take place 
without any apparent disturbance of the general mass, each bed 
conforming itself perfectly to the caprice of its neighbour, and 
leaving no rents nor flaws. But an entirely diflerent series of phe- 
nomena arise out of the fracture or distortion of one deposit by 
another, after the first has attained consistence. Thus, in Fig. 4, a 
yellow orbicular jasper is split into segments, singularly stellate, or 
wheel-like, and then variously lifted and torn by superimposed chal- 
cedony ; and in Fig. 5, a white and opaque agatescent mass is rent, 
while still ductile, the rents being filled with pure chalcedony : and 
from this state, in which the pieces are hardly separate, and almost 
hang together by connecting threads, we may pass on through every 
phase of dislocation to perfect breccia ; but, all the while, we shall 
find the aspect of each formation modified by another kind of fault, 
which has no violent origin, and for the illustration of which I have 
prepared Plate III. This plate represents (all the figures being of 
the natural size) three sections of amethystine agate, in which the 
principal material is amethyst-quartz, and the white jasperine bands 
for the most part form between the points of the crystals. 

All the three examples are types of pure concrete agatescence in 
repose, showing no trace whatever of external disturbance. The 
fault in the inclined bed at the base of the uppermost figure, has 
some appearance of having been caused by a shock ; but for that 
reason is all the more remarkable, the bed beneath it being wholly 

VOL. V. — NO. XLIII. 2 



1 8 . Kinahan — Weathering of Rocks. 

undisturbed, and its own fracture quite structural, and connected 
with the crystalline elevation and starry concretion above. I have 
no idea at present why the central portions of these concretions of 
dark amethyst are partly terminated by right lines, or what deter- 
mines the greater number of bands on one side than on the other. 
The second figure is of a less varied, but of still more curious in- 
ter st. There is no trace of violence or fracture in the stone, and the 
line of the crj^stallized amethystine mass is undisturbed at the sum- 
mits, except by a partial dissolution in one part and mingling with 
the white bands above. But the white undulatory band at its base 
is cut into three parts, and the intermediate portion lifted (or the 
flanks removed downwards), a quarter of an inch, by pure calm crys- 
talline action, giving thus room for an interferent brown vein of less 
definite substance which proceeds without interruption, dividing 
the white band in a direction peculiarly difficult to explain, unless 
by supposing the interferent one to be the slow filling of a fissure 

originally opened in the direc- 
tion of the black line in Fig. 8, 
Fig. 8. and straightened in widening. 

But the third example is inexplicable, by any such supposition. 
It is the agatescent centre of a large amethyst nodule, in which a 
small portion, about the third of an inch long and a quarter of an 
inch thick, of its encompassing belt, is separated bodily from the rest, 
taken up into the surrounding concretion of quartz, and its place 
supplied by a confused segregation of chalcedony, with a sprinkled 
deposit of jasper spots on the surface exposed by this removal of its 
protecting coat; spots, which in the rest of the stone, form on 
the exterior of the coat itself, just under the quartz. There are many 
points in all these three examples which it is useless to take further 
note of at present, but to which I shall return, after collecting 
examples enough to form some basis of reasoning and comparison. 
I must apologize, as it is, for the length of this paper on a subject 
partly familiar, partly trivial, yet in which these definitions, not by 
skill of mine expressible in less room, were necessary before I could 
proceed intelligibly. 



-^^^^./W./'V/ 



V. — Notes of the Weathering of Eocks near the Sea. 
By G. Henry Ktnahan, F.R.G.S.I., Etc. 

THE following notes on the Weathering of Rocks near the Sea, 
culled from my note-books, appear to be facts unobserved by 
the various writers on subaerial denudation. Those agents would 
seem to act difierently near the sea than away from it, not only in 
the quantity of the work done but also on the colouring matter in the 
rocks. 

As to colour, I find — '' In the neighbourhood of Valencia, Co Keriy, 
the weather seems to have mostly affected the red colouring matter 
in the rocks for those of a purple colour, weather a whitish blue, 
while those of a green colour only become brighter ; inland, the 
purple rocks are weathered red, and the green yellow ; so that, there 



James Geikle — Denudation in Scotland, 19 

the weather seems to have the power of removing the bhie part of 
the colouring matter." In my notes on the rocks of the Co. Galway, 
I find : " The original colour of the Felsite associated with the granite 
on the north of Galway Bay seems to be a purplish green or grey, 
but at the coast they weather red, while inland they weather a 
yellowish or dirty white." 

On the disintegration of rocks has been noted — ''At the sea-shore 
south of Baltimore, Co. Cork, the slates immediately above the in- 
fluence of the waves have by the weathering out of their slaty 
cleavage become so rugged and sharp that they can be compared to 
nothing but knives placed side by side with their edges looking up- 
wards ; this appears to be remarkable, for if these rocks are followed 
only a little inland, they seem scarcely weathered as the ice striae are 
quite perfect on them." " The slates composing the Little Skellig, 
off the coast of Kerry, are weathered along the nearly vertical cleav- 
age planes, giving them a sharp serrated surface, while similar rocks 
on the main land only a little removed from the sea-coast are scarcely 
weathered." 

" On the Aran Islands, Galway Bay, the subaerial agencies seem 
to denude the limestones quicker than on the mainland, for on those 
islands the perched blocks having protected the portion immediately 
under them, now stand on pedestals from four to six inches high, 
while inland, the pedestals under the blocks rarely exceed four 
inches, and generally their average is about two inches and a-half." 

" The veins of Eurite that traverse the Granites on the north of 
Galway Bay, are scarcely affected by the weather, and thereby give 
a record of the amount of waste the mass of the granite rocks have 
undergone since the ice disappeared from that country. From them 
it would also appear that the granites disintegrate more freely near 
the sea than away from it ; for inland these veins stand from half 
an inch to two inches above the mass of the rock, while near the 
sea they have been remarked as much as three and a-half inches, 
and rarely, if ever, are less than an inch and a-half ; moreover in. 
some places near the sea, even the Eurite veins are weathered." 



I. — On Denudation in Scotland since Glacial Times. 

By James Geikie, Esq., of the Geological Survey of Scotland. 

[Being the substance of a paper read before the Geological Society of Glasgow, 
28th November, 1867.J 

MR. JAMES GEIKIE began by remarking that, throughout the 
wide domain of Geological inquiry, there was perhaps no sub- 
ject of M^hich it was easier to gain some idea, and yet, at the same 
time, more difScult to acquire an adequate conception, than denudation. 
We all know how rains and frosts and chemical decomposition were 
employed unceasingly in modifying the aspect of hills and plains, — 
how rivers were ever deepening and widening the valleys in which 
they flowed — how the sea, by its constant wave-action, aided by 



20 Notices of Memoirs. 

frosts and other agencies, tended to reduce to its own level the solid 
lands, with all their infinite variety of outline. It was no less 
generally known how the Geological structure of a country must 
always influence its configuration — how the softer rocks would 
generally lie in the valleys, and those of a more durable nature oc- 
cupy the heights — how the contour of the heights would vary accord- 
ing as these were formed of schists of granite, of dolerite, of quartz- 
rock, or of any other well-marked species — and how this peculiar cha- 
racter was due to the unequal manner in which the different masses 
yielded to the touch of the atmospheric forces, so that a trained eye 
could oftentimes detect at a considerable distance the nature of the 
rocks by reference to the aspect of the hills alone. But while all 
were willing to admit that the subaerial agents might do something 
towards modifying the surface of a country, yet many would not 
allow that its straths and valleys had been mainly formed by these 
seemingly feeble forces. Nor when we reflected on the enormous 
time required by the hypothesis which they rejected, could it be 
wondered at that some geologists, whose chief stumbling-block was 
time, should have summoned up subterranean action to account for 
certain appearances connected with the superficial phenomena of our 
country, still less should we be surprised when the sea was appealed 
to as having been chiefly instrumental in moulding the land into hill 
and dale. 

There were probably few who began this study, that were not at first 
more deeply impressed with the energetic action of the waves along a 
sea-coast, than with the less obtrusive work carried on by the subaerial 
forces. Gaunt cliffs and long-retiring caves and inlets seemed to assure 
them, that rather in the restless activity of the breakers, than in the 
puny rains and rivers of the land, they had found the power which 
hollowed out the deep places of the earth. No one could heartily 
accept the theory which referred to atmospheric erosion the mould- 
ing of the land into hill and valley, who had not worked out his 
belief for himself in the field. This was the only way to learn 
what denudation, whether submarine or subaerial, really was. 
When we came impartially to consider the subject, we should find 
that a vast variety of agents had been at work, from the earliest 
geological times, in shaping out the contour of our country. Thus, 
it was not disputed that subterranean movements of elevation and 
depression, and the waves and currents of the sea, had, in many 
cases, determined the direction in which streams and rivers should 
flow ; but the cutting out of the valleys and the fashioning of the hills 
must be attributed principally to the action of the atmospheric forces. 

No one-sided theory, therefore, that should seek to explain all the 
phenomena by reference to one set of influences alone could be accepted. 

On the present occasion, Mr. J. Geikie could not pursue this subject 
further. The origin of our mountain and valley systems dated back 
to much more remote periods than the advent of the Glacial epoch ; 
and there was nothing more certain than this — that the direction 



James Geikle — Denudation in Scotland. 21 

followed by the Glacier ice of that age was influenced to a great 
degree by the pre-existing configuration of the country. In select- 
ing matter for illustration, he thought it better to confine himself to 
one small corner in this great field of inquiry, in the belief that by 
thus restricting the sphere of their investigations, they should be 
enabled to attain a better idea of the scope and bearing of the 
general question. The subject proposed to be considered was denu- 
dation in Scotland since Glacial times. Now it was very evident 
that before we could have any proper notion of the denudation of a 
country, we should first ascertain, as well as we could, the nature 
and geological origin of the rocks which appeared to have been 
denuded. For it was plain that until we knew how these rocks 
came to be amassed, we could never hope to gain any proper estimate 
of the degree of erosion to which they might have been subjected 
since the time of their formation. How could we expect to appre- 
ciate the amount of waste which strata had experienced, until we 
had first carefully examined these, and considered their geological 
relations, and gathered together all the evidence we could with 
regard to their former extension? Denudation was thus a much 
more complicated study than it might at first appear to be ; and he 
would repeat that it could only be thoroughly grasped by those who 
were content to work the matter out for themselves in the field. 
No doubt we might make up our minds on book evidence as to the 
probability of this or that theory of denudation ; but it was one 
thing to believe — it was a very different thing to feel that we believe. 

Before we could arrive at any conclusions regarding denudation 
in Scotland since the Glacial period, the deposits of that age must be 
critically examined. We must inquire into the mode of their accu- 
mulation so as to ascertain what degree of waste they had sustained 
since deposition, and how much of that erosion might be due to the 
action of the sea during the marine stage of the Glacial epoch — how 
much to that of the atmospheric forces in subsequent times. In 
short, our investigation should involve a study of the whole history 
of the Drift formation. In the remarks that were to follow, how- 
ever, he did not pretend to offer anything like a digest of that 
history. On the contrary, he would limit attention to those portions 
of the evidence that seemed best fitted to recall the general aspect 
which appeared to have been presented by the drift accumulations 
during the various stages of the Glacial period. 

The lecturer then described some of the more characteristic features 
of these deposits of clay and sand and gravel which are so abundantly 
scattered athwart the face of the country, and to which geologists 
had given the general title of the "■ Glacial or Drift Formation." 
These accumulations were found capable of being divided into more 
or less well-defined groups, relatively of different ages, but all be- 
longing to one great geological period. At the base we had the stony 
''Till," or Boulder-clay, and above that, in certain cases, came vast 
heaps of sand and gravel ; while in other districts the Till was over- 



22 Notices of Memoirs, 

lain by finely stratified fossiliferous clays, or sometimes by a very 
coarse Upper Boulder-clay. Mucli still remained to be done in the 
working out of the history of these deposits in detail, but the general 
succession of geological changes which they indicated were neverthe- 
less sufficiently ascertained. 

Geologists were agreed that the observed phenomena could only 
be explained by reference to what is now taking place in arctic and 
alpine regions. The rounded contour of our hills, the flutings and 
sculpturings of our vallej^s, the scratched and polished rock-surfaces 
that everywhere abounded, bore emphatic testimony to the former 
passage of a great sheet of ice, under which, at some distant period, 
these islands of ours, in common with the high latitudes of Europe, 
Asia, and America, lay buried — only the loftier mountain tops peer- 
ing above the desolate waste. And in like manner did the accumu- 
lations of sand and gravel and clay, and the pell-mell heaps of the 
Upper Boulder earth, testify to the subsequent presence of the sea 
over certain areas of the same regions. 

Mr. Geikie stated that during the early stages of the Glacial 
epoch the surface of our country, by the constant grinding action of 
the great ice-sheet, came to assume certain characters which are 
still very legible. He showed that the general trend of the ruts and 
scratches impressed upon the rocks by the passage of the glaciers 
was, in the northern hemisphere, from north to south, but that the 
form of the ground often had considerable influence in turning them 
from that general direction. Thus in our own country they were 
found to radiate downwards from the high grounds, following the 
lines of the principal valleys. 

During the continuance of this Arctic condition of our country, 
the waste of the underlying rocks must have been considerable. 
Mountains of schist had been in some measure deprived of the 
outlines which, under usual atmospheric action, they must have 
assumed. Hills of shattered and much jointed greywacke, which 
ought to rise up in broken, serrated, and peaky tors, showed instead 
a rounded and hummocky contour. Valleys which, from the nature 
of their strata, we should have expected to present steep or vertical 
walls, have been moulded into smooth and undulating hollows. 
Glens, at one time roughened with countless crags, and bristling 
with jagged points of rock, have had their sharp angles and rude 
corners cut away — the present ruinous and tumbled aspect of many 
of our Highland glens being due to subsequent atmospheric waste, 
which was gradually effacing the traces of Glacial action. The 
waste material that resulted from all this scooping and grooving 
and planing went to form the Boulder-clay. Some of it gathered 
underneath the great glacier as a moraine profonde — some of it was 
carried out to sea by icebergs. 

The character and mode of accumulation of the true Lower Boulder- 
clay were next described. As the " ground moraine" of the old ice- 
pheet, it gathered most abundantly over the surface of the lowlands, its 
occurrence at considerable elevations being the exception to the rule. 
It was remarked that in districts where the marine drift occurred, 



James Gelhie — Denudation in Scotland, 23 

the Boulder-clay had usually suffered much erosion, while in regions 
where the sand and gravel did not appear, it had commonly a much 
less denuded aspect, often forming well-marked terraces in upland 
valleys, and in straths frequently showing parallel mounds or broad 
ridges, which were probably, in the main, original inequalities 
acquired while the till was in course of formation as a moraine pro- 
fonde. 

The character and mode of accumulation of the upper or marine 
drifts were next considered. It was shown that these dej)osits con- 
sisted chiefly of sand and gravel, at other times of a coarse Boulder 
earth, and in some places fossiliferous clay also occurred. These 
beds had no doubt been derived chiefly from the waste of the Lower 
Boulder-clay, and also in some measure from the droppings of 
icebergs. In a district were the sands and gravels were typically 
developed it was often found that, as we left the central parts of the 
broad valleys and straths and approached the contiguous higher 
grounds, these drifts appeared to thin away from heaps of well- 
stratified materials to meagre, irregular sprinklings of earth and 
stony rubbish. The fine sands and gravels with diagonal bedding 
occupied chiefly the bottoms of the valleys, the kaims and mounds 
of coarse and angular debris lay for the most part along the hill-sides. 

These facts appeared to point to a passage from a deeper to a 
shallower sea-bed. The capricious distribution of the sand and 
gravel was then touched upon, and it was shown how this might 
give us an index to the probable maximum of depression attained 
during the marine period. The evidence furnished by the angular 
gravels, which seemed to mark out the upper limits reached by the 
Glacial sea, agreed with the independent testimony derived from the 
occurrence of the kaims in certain valleys and their absence from 
others. If we supposed the land to be submerged to the highest 
levels reached by the coarse angular gravels it would be observed 
that kaims only occurred in such valleys, as on a depression to this 
extent would form straits, channels, or comparatively open seas — that 
it was precisely in the same localities where the lower till was exces- 
sively eroded — while in those valleys which, under like conditions, 
must become long narrow fiords, marine drift did not appear, and 
the Boulder-clay had not been subjected to the same degree of denu- 
dation. In the straits marine currents would have free scope to 
plough up the deposits of the earlier period, while in the narrow 
firths no such action could be carried on, as we learned should be the 
case from a study of our own Highland sea lochs or the fiords of 
Norway. The later drifts, consisting of terminal moraines and that 
surface-wash which seems to have gathered under the snow or neve, 
showed us that, after the re-elevation of the land, glaciers continued 
to reach the sea for a time, and in their downward progress from 
the snowfields, scooped out the accumulations which had formed 
during the previous ages. 

Having thus given a resume of facts connected with the mode of 
occurrence of the drift deposits, and the kind oferosion to which they 
were subjected during the Glacier period itself, the lecturer then pro- 



24 Notices of Memoirs, 

ceeded to examine the nature and degree of subaerial waste experienced 
since the close of the great age of ice. Every geologist was familiar 
with the glaciated outline of the elevated regions of our country. The 
rounded crags, the smoothed and fluted hill sides, and the finely striated 
rock-surfaces were characters so well-known that he had only to 
mention them. When he said that these were to be met with every- 
where, of course he did not mean that every declivity would show 
its ice-mouldings, every crag exhibit roches moutonnees, or every ex- 
posed surface of rock exhibit a series of striations. Such must, no 
doubt, have been the case when the great ice-sheet first disappeared, 
but during the long ages that had since elapsed chemical decomposi- 
tion, frost, and rain had succeeded in obliterating many traces of the 
ancient glaciers. Notwithstanding all this, however, the memorials 
of the former presence of a vast body of ice were so abundant that 
we could not but conclude that the solid rocks of our mountains had 
suffered comparatively little waste since that covering of ice had 
vanished. A visitor from Alpine countries, where perennial snows 
and glaciers abounded, would see little in the outline of our Scottish 
mountains with which he was not familiar. The finer touches of tho 
great ice chisel would oftentimes indeed be wanting, but its broad 
effects would all be there, reminding one who wished to be fanciful, 
of those ancient sculptures from which the hand of time had effaced 
the delicate finish of the artist but had been powerless to destroy his 
design. 

Mr. Geikie next considered the present aspect of the Boulder- 
clay. He said that in our valleys and straths we could read the 
history of a Glacial period with as little difficulty as we deciphered 
its records at higher levels. It was admitted that the subaerial 
waste experienced by the Boulder-clay had been great, but when we 
came to estimate what effect this erosion had had in modifying the 
general aspect of that deposit it appeared to be scarcely appreciable. 
The greatest waste experienced by the Till took place during the 
growth of the marine drifts. Waves and currents in narrow straits 
and open seas had often made havoc of the Boulder-clay, while in 
the fiords and other sheltered regions the some degree of waste could 
not be effected. And the configuration thus given to the lower Till had 
not been obliterated by the atmospheric forces, although these had been 
so long employed in its reduction. If frosts and rains and rivers bad 
been unable to deprive the lower Till of the general aspect it assumed 
on the re-elevation of the land, they had been just as powerless to 
efface the external character of the upper or marine drifts. So per- 
fect were the forms of mounds and kaims of sand and gravel that 
these were capable of being classified and described by reference 
to the various kinds of bars and banks of analogous materials which 
were gathering on the bed of our own seas at the present day. But 
just as it was seen that the Boulder-clay had been extensively de- 
nuded by atmospheric agents, so we learned that the marine drifts 
had undergone no inconsiderable degree of erosion. From some 
valleys they had well nigh vanished ; in others the kaims had been 
obliterated and their materials re-assorted bv the streams and rivers. 



James Geikie — Denudation in Scotland. 25 

After referring to the proofs of this waste, Mr. Geikie went on to 
remark that a study of the valleys in which the kaims had been thus 
denuded would convince the geologists that in former ages our rivers 
must have greatly exceeded in size their present representatives. 
The position of some of the older alluvia, and the evidence of river 
action in places to which streams of the same size as now flowed in 
the valleys never could have attained, all led to this inference. He 
thought it extremely probable that it was during the age of forests, 
when Britain formed a part of the continent, that our rivers reached 
their greatest development. There were good grounds for believing 
that at this period glaciers filled some of our higher valleys. In 
some of the high level river gravels, also, we often met with large 
boulders, which appeared to have been ice-borne to their present 
position. And the testimony derived from the nature of the timber 
dug out of the peat-mosses was quite in harmony with such a sup- 
position. For the climate that nourished the large pine-trees of the 
English mosses must have covered our rivers with ice in winter. 
While this excessive climate prevailed, atmospheric waste, no doubt, 
went bravely on ; and even down to much later days, when the peat- 
mosses were increasing and the ancient forests decaying, the work of 
denudation must have proceeded more rapidly than now. 

Some examples of post-Glacial waste were then cited. He men- 
tioned the case of the gorge through which the Kiver Doon makes its 
way after escaping from its parent lake. In cutting out this ravine, a 
mass of rock, equal to at least 70,000,000 of cubic feet had been re- 
moved bodily by the stream ; and many similar cases might be adduced. 
But although, locally considered, the denudation thus experienced by 
drift deposits and subjacent rocks might be often great, it would re- 
quire a far longer lease of time than had elapsed since the close of 
the Glacial epoch ere the characteristic features impressed upon our 
hills and valleys during that period could be effaced. In conclusion, 
he said they could not fail to be impressed with one consideration, 
which, above all others, seemed to stand out prominently after a re- 
view of such matters as they had been that evening considering — 
and that was the enormous time required to produce the broader 
effects of denudation. How many long ages had rolled away since 
these islands rose above the level of the Arctic Sea in which our 
marine drifts were amassed, and yet, during all that time, how little 
change had come upon them at the instance of the atmospheric 
forces. And if the records of the old Arctic condition — the deli- 
cate ice-markings on the rocks, the loose incoherent deposits on the 
hill-slopes and plains — still remained so perfect, notwithstanding 
the ceaseless activity of the denuding agents — if the mere skin as it 
were, and surface -markings of the land were still so largely retained, 
what should we say to the time required for the growth of that 
covering itself, and for the production of these strange ice-mouldings 
and flutings, — and how, above all, could we apprehend (for compre- 
hend we could not) the truly tremendous lapse of time, during which 
the solid land was gradually sculptured into hills and valleys b}'- the 
rains and frosts and rivers of the past. — The Glasgow Herald, No- 
vember 30, 1867. 



26 Notices of Memoirs. 

II. — On the Internal Heat of the Earth. By Dr. Julius 

SCHVARCZ, F.G.S.^ 

THE author reviewed the evidence upon which is founded the 
doctrine of central heat as applied to the earth. It is based on 
three arguments. First, gathered from volcanic phenomena, — pheno- 
mena which may be explained by the chemical and electro-chemical 
schools of geologists, at least as satisfactorily as by the supporters 
of central fire ; the second argument is adduced from the nebular 
hypothesis, an hypothesis having now-a-days no other foundation 
than what is involved in it from the central fire hypothesis ; and 
the third is adduced from the supposed uniform increase of tem- 
perature down to the centre of our planet, in every part of the 
earth, — an argument which is again a mere hypothesis. 

Having carefully studied the literature of the subject, Dr. 
Schvarcz criticised the observations upon which the hypothesis 
of central fire is supported, and showed how imperfect and con- 
flicting is the evidence to prove that the increase of underground 
temperature is really general and uniform. 

Before generalising, we must accumulate a greater number of 
facts, precisely recorded, than are at present at command, and he 
therefore urged geologists to combine all their efforts in order to 
multiply geothermometrical observations, especially in countries now 
unexplored. 

He was of opinion that solar impressions of all the climates on 
our earth's surface, taken collectively, and local reservoirs of lava, 
not exceeding considerably the depth of thirty-five geographical 
miles, and manifesting themselves through volcanic cones from local 
processes of oxydation, must be taken for those secondary causes which 
remain indispensable elements of any astiology of underground tem- 
peratures, even for theories to come. Electricity, as connected with 
cosmical magnetism and planetary rotation, may have been an im- 
portant agent, besides the secondary causes just alluded to. 



III. — On a new Phosphatic Deposit, near Upware, Cambridge- 
shire. By J. F. Walker, B.A., F.G.S., &c. 

IT is unnecessary here to give a lengthened account of Mr. Walker's 
paper (read before the British Association, Dundee) as most of 
the facts have appeared in two previous numbers of the Geological 
Magazine.^ 

The author repeats his opinion that this Phosphatic deposit is of 
the age of the Lower Greens^nd — it contains fossils of that age as 
well as extraneous specimens. The bed contains sponges resembling 
those of Faringdon ; and during a recent visit to that locality he 
obtained several shells which he has also found at Upware. 

The phosphatised casts of shells found at Upware, and also at 

' Being an abstract of his paper read before Section C. of the British Association, 
Dundee, September, 1867. 
2 Geological Magazine, July, 1867, p. 309. Ibid.^ October, 1867, p. 454. 



Eeviews — Mortillet's History of Man. 27 

Sandy, he regards as derived from the denudation of older deposits ; 
because they are much water-worn, and often bored by Mollusca. 

Bryozoa and Serpulce occur attached to the surface of several of the 
phosphatic nodules at Upware. 



le^ZE'V^IEAATS- 



I. — Mortillet's ''Materials for the History of Man." 3rd 
Vol. Nos. 1-8 (in Five Nos.) [Materiaux pour l'histoire posi- 
tive ET Philosophique de l'Homme : Bulletin mensuel, etc., 
par Gabriel de Mortillet. Troisieme Annee, 1867. 8vo. Paris.] 

rilHIS useful monthly compendium of facts and notions, either 
_L published day by day, or communicated to the Editor, about 
Anthropology, Prehistoric Times, the Quaternary Epoch, the Origin 
of Species, and Spontaneous Generation, has now reached its third 
year, and steadily fulfils its mission in aiding the advance of a scien- 
tific knowledge of the history of early Man, and of collateral natural- 
history subjects bearing on the character of races and states of 
culture. The last two parts of this useful work M. Mortillet has 
j udiciously devoted to a succinct account of everything contributed to 
the Universal Exhibition at Paris that at all bears on primaeval Man 
and his habits and character. Every quarter of the globe contributed 
something, though not always arranged in the special galleries illus- 
trative of the History of Labour and Art. Every noticeable object, 
liowever, is classified by the Editor in these his ''Promenades Pre- 
historiques a I'Exposition Universelle ;" and, as far as possible, they 
are grouped under such subdivisions as " Caverns," " Quaternary 
Deposits," " Stone Epoch," " Ground and Polished Stone Imple- 
ments," "Bronze Age," " Iron Age," etc. After viewing all these 
very interesting objects, never to be again assembled under one roof, 
M. Mortillet draws the following conclusions (pages 366, etc.). 

It is impossible, he says, after having visited the Galleries of 
the History of Labour, supplied by Wurtemberg, Hungary, Switzer- 
land, Spain, Denmark, Sweden, Norway, Kussia, Italy, England, 
and especially France, to have any doubt of the existence of a great 
Law of Progress in Human Nature. We see Industry begin with 
instruments of Stone, mere flakes, so primitive and rudimentary 
that they are inferior even to such as are used by the least advanced 
of existing savages. Little by little the stone is better worked, and 
its use becomes more varied ; and there are numerous implements of 
bone and deer's horn. Then comes the art of grinding stone ; mark- 
ing an era of progress, and characterizing one of the great divisions 
of Pre-historic Time, — namely, the Era of Polished Stone. Still 
later it was that Metal appeared; at first Bronze alone and after- 
wards Iron. Stone chipped and flaked. Polished Stone, Bronze, and 
Iron, are so many successive characteristics of Human Progress 
before reaching our present civilization. Not only was it possible 
in the Exposition to follow step by step this onward inarch of pro- 



28 Remeivs — Mortillet's History of Man. 

gress, but even to recognize the chronological blank without which 
we cannot realize this progress. The chronology taught in all our 
schools is terribly distanced. Indeed it scarcely covers the historical 
period. In the Temple of Edfoa, erected by the Egyptian Govern- 
ment in the Park of the Exposition, we see the statue of Chephren, 
a veritable work of art, to which learned Egyptologists assign an 
age of 6000 years, — a date contemporary with '' the first man " of our 
school-teaching! How long a series of years, or rather of ages, 
must we not allow for man, once using stone flakes, not only to 
attain the art of grinding and polishing his implements of stone, but 
to develop the genius of the Sculptor and give life and sentiment 
to the hardest rock ! There has been an enormous lapse of time ! 
Indeed, Chephren was a cotemporary of a fauna altogether similar to 
that which exists ; whilst, on the other hand, the man who only 
used chipped stone was surrounded by animals now quite extinct ! 
It is fossil man, then, that lived with fossil animals ! 

In France, England, and Spain, and at Kome, stone implements of 
the first period are found associated with bones of the tichorhine 
Ehinoceros, the great Hippopotamus, various Hyaenas, the great 
Bear of the caves, the Megaceros of Ireland, the fossil Tigers or 
Lions, and Elephants, among which, especially, the hairy Mammoth 
is well known. Stone implements made by Man lie in place with 
these bones, in undisturbed deposits, and nowise rearranged; and 
hence they are decidedly contemporaneous, one being as much fossil 
as the other. For these conclusions the glass-cases on the left- 
hand side of the first saloon of the '' History of Labour" could leave 
no doubt. To this first period in the infancy of Mankind, charac- 
terized by a fauna comprising many now extinct species, succeeded a 
second period, during which there lived in our lowlands, and 
abundantly too, species that have emigrated, and are now found only 
in the north or on snowy mountain -heights. Such are the Keindeer, 
the Glutton, the vulpine Lagopede, the Musk-ox, the Chamois, the 
Ibex, the Marmot, the Heath-cock, etc. At that time there was 
progress ; for Man began to be an artist. He figured animals ; and 
he has left for us in France representations, not only of the animals 
that have retreated to cold regions, but also of some of those species 
which were dying out. The Man of that distant epoch has perfectly 
represented (together with the Eeindeer and the Ibex, which have 
emigrated) the great Bear, the cave Lion, and the Mammoth, all of 
which are extinct; and the figures were usually made on the 
Reindeer's antlers or on the ivory of the Elephant itself. Man was 
incontestably contemporaneous with these creatures, whose forms 
he represented so well, and whose bones, teeth, and horns he utilized 
in various ways. Of this we could not have more convincing 
evidences. 

The age of man goes back, then, to the later geological times, 
far away beyond the time of Chephren and of classical chronology ! 

The comparative study of objects of prehistoric antiquity and of 
objects now used by savages leads to the statement of another law, 
which completes, as it were, the law of Progress. It is the Law of 



Bevietvs — G. Lindstrom's Spitzbergen Fossils, 29 

Similarity of Development in Man. We find the greatest analogy 
— the most striking similarity — between the elementary civilization 
of savages and the primitive civilization of Prehistoric Times. We 
may say that throughout, in time as in space, Man has followed the 
same evolution, on the whole, in his industrial as in his moral deve- 
lopement. Thus (1) the Law of Human Progress, (2) the Law of 
Similarity in Development, and (3) the High Antiquity of Man are 
three facts, clear, precise, and irrefutable, which come out from this 
study we have made of the Great Exposition. — T. E. J. 



IL — G. Lindstrom's Triassic and Liassic Fossils from 
Spitzbergen. 
[Om Trias-soch Juraforsteningen fran Spetbergen af G. Lindstrom. 4to. 1866. From 
the Transactions of the Royal Swedish Academy of Sciences, vol. vi. no. 6.] 

IN 1837 Professor S. Loven collected in Spitzbergen some fossils 
different from the palasozoic specimens previously obtained there ; 
and he recognised that they were allied to, if not identical with, some 
Jurassic forms from Petschora Land, described by Keyserling, and 
even in part occurring in the Jurassic beds of Western Europe. 
Numbers of these Jurassic fossils of the high North were obtained by 
Professor A. E. Nordenskiold in Prof. Otto Terrell's first expedition to 
Spitzbergen in 18.58. In the second expedition (1861) Prof. Blom- 
strand brought home many new Jurassic things, besides other species 
belonging to a geological period not previously recognized in Spitz- 
bergen, and which, after careful comparison in several German 
Museums, Dr. Lindstrom has determined to be Triassic. To these is 
added the collection made by Prof. Nordenskiold in 1864 on the 
Isfjord and Storfjord. To describe these fossils is the object of 
Dr. Lindstrom's memoir. 

I. The Triassic Fossils. — These came for the most part from two 
points. Cape Thorsden and Sauriehuk, situated inside the Isfjord, on 
the tongue of land jutting out between the Nordfjord and Klaas- 
Billen Bay, and termed Midterhuk by Prof. Blomstrand in his geo- 
logical notes on the voyage to Spitzbergen in 1861 (Transact. Eoy. 
Acad. Stockholm, vol. iv. no. 6, p. 44). According to him this con- 
sists chiefly of a black and bituminous shale, here and there alter- 
nating with layers of harder rock, and overlain by a hard sand- 
stone. Most of the fossils are from strata at Sauriehuk, which, 
according to Prof. Nordenskiold's communication, rest on somewhat 
diff'erent shales at Cape Thorsden. These latter contain only two or 
three species, the leading form of which (Halobia) is distinct from 
H. Lommeli, characteristic of the upper beds. Navtilus Nordenskioldii, 
sp. nov. ; N. trocJileaformis, sp. nov. ; Ceratites Malmgreni, sp. nov. ; 
C. (?) Blomstrandi, sp. nov. ; C. laqueatus, sp. nov. ; Ammonites Gay- 
tani (Klipstein), var. (?) ; Fosidonia ; Halobia Lommeli, Wissmann ; 
H. Zitteli, sp. nov. ; Monotis, sp. indet. ; M. filigera, n. sp. ; Fecien, 
sp. indet. ; Lingula, sp. indet. ; Encrinus, sp. indet. (near E. granulosus, 
Miinster). Some obscure fragments of other fossils occur, comprising 
some small black seed-like bodies. 



30 Reviews — G. Lindstroms Spitzbergen Fossils, 

The relationship that some of these fossils have with Triassic 
species found in the Eastern Alps, in the Himalaya, in New Zealand, 
New Caledonia, and California, is noticed by the author, also the 
wide- spread occurrence of this formation of Secondary age. 

II. The Jurassic Fossils. — Most of these have been found in a 
usually grey sandstone and limestone, occurring at several points on 
the coast of the Isfjord. The greatest number were collected in 1861 
by Prof. Blomstrand at Advent Bay. The same kind of fossils in a 
similar sandstone and in shale were found at Green Harbour and 
Kyss-stugan, also on the east side of Advent Bay, by Loven, Nor- 
denskiold, and Blomstrand. Also in 1864 Nordenskiold got a har- 
vest from a thin black laminated limestone at Sassen Bay, and in 
a hard shal}'^ limestone, weathering reddish brown, at Cape Agardh in 
the Storfjord : Ichthyodorulites ; Serpula; Ammonites triplicatus/ Sow. ; 
Belemnites ; Dentalium ; Panojocea ; Tellina ; Cyiherea ; Cyprina incon- 
spicua, sp. nov. ; Cardium concinnum, Von Buch ; Solenomya Torelli, sp. 
nov. ; Nncula ; Leda nuda, Keyserling ; Inoceramus revelatus, Keyserl. ; 
Aucella mosquensis, Von Buch, var. ; Pecten demissus, Bean ; P. validus, 
sp. nov. ; Oplditra Gumaellii, sp. nov. 

The close alliance of the Triassic fossils of Spitzbergen with those 
of Petschora Land and of Eussia, and their correspondence with the 
Lower (Great) Oolite of Western Europe, is especially noted by the 
author. 

Some obscure plant-remains occur in the above mentioned Jurassic 
beds ; and besides these some Miocene Plants {Domheyojysis aceroides 
and Sequoia Langsdorfii) are found at the same places, apparently 
mixed with the Jurassic beds, but probably either really overlying 
the latter, or mingled with them by some disturbance. 

This interesting notice of the Secondary Fossils of Spitzbergen 
adds greatly to our knowledge of that interesting outlier of the Eu- 
ropean Continent. Carboniferous fossils are known to abound in 
that Island ; and one block, at least, of Permian limestone has been 
found on the coast, but it was either a drifted fragment, or was 
deriA^ed from the ballast of some wrecked whaler. 

The Carboniferous rocks lie on unfossiliferous schists and conglo- 
merates ; these on unfossiliferous slates, quartzites, and marble ; 
these on a lower series of slates, etc., and these on gneiss and granite. 
Thus, as Murchison has suggested, all the Palaeozoic formations, from 
the Laurentian upwards, may be present there. The coal of Spitz- 
bergen is of Tertiary age. 

See also Mr. Lament's paper on Spitzbergen in the Journ. Geol. 
Soc. vol. xvi; Nordenskiold's memoir in the Trans. Koy. Swedish 
Acad. 1866 ; Siluria, 4th. ed. p. 543.— T. E. J. 

1 A fragment of Ammonite was collected by Mr. Lamont at Bell Sound, see Journ. 
Geol. Soc. vol. xvi. p. xii. and 436. 



Geological Society of London. ol 



Geological Society of London. — November 20th, 1807. 
Warington W. Smyth, Esq., M.A., F.E.S., President, in the Chair. 
The following commimications were read : — 1. " On the Glacial 
and Post- Glacial Structure of Lincolnshire and South-east York- 
shire." By S. Y. Wood, Jun., Esq., F.G.S., and the Rev. J. L. 
Rome, F.G.S. The features of Yorkshire and North-east Lin- 
colnshire, having distinctive characters from those of Central and 
South Lincolnshire, the authors described the two areas separately. 
In the former, their coast sections exhibited the Glacial clay sepa- 
rated into two portions ; of these the lower, which they identified 
with the ordinary (or ujDper) Glacial clay of the south, contains 
abundant chalk debris ; but the upper or purple portion (which 
was in j^laces divided from the lower by sand or gravel beds) 
contains no Chalk in the upper, and but little in the lower part 
of it, the place of the Chalk being taken by swarms of Paleo- 
zoic fragments. The latter of these clays alone extends over tlie 
Wold-top at Speeton, and alone occupies the valley along the 
northern Wold-foot, and so away northwards to Scarborough, and 
the Tees' mouth, from which the authors infeiTcd that the north of 
England did not subside beneath the Glacial sea until after the 
south had been submerged. The so-called Bridlington " Crag " 
was shown to be an intercalated bed in this purple clay. Both 
these clays were shown to be denuded, and their denuded edges to 
be everywhere covered by a much thinner Boulder-clay, that of 
Hessle, which wraps Holderness like a cloth, extending to altitudes 
of 150 feet, and running down the east of Lincolnshire to the Fen- 
border. This Post-glacial Boulder-clay of Hessle is again cut 
through, and in those places covered by posterior beds of gravel, 
one of which (at Hornsea) contained fluviatile shells. At Hull this 
clay supports a forest, which is now submerged 33 feet below the 
Humber; the same submerged forest also occurring at Grimsby. 
The authors regarded the position of the sea during the Post-glacial 
period as having been principally on the west of the Yorkshire and 
North Lincolnshire Wold until the formation of the gravel-troughs, 
cutting through the Hessle clay, and that its present position was 
connected with a recent westerly elevation and easterly depression. 

The Glacial clay of central and South Lincolnshire belongs to the 
chalky portion, from which all the superior or purple part of the 
formation has been denuded ; and the valleys of Central Lincoln- 
shire were shown to be cut out of the Cretaceous series and Glacial 
clay as a common bed, the hills formed of the clay rising to eleva- 
tions equal to the Wold in that part. 

The Glacial clay of both areas was shown to be denuded west- 
wards ; and the denuded edges occupied with sands and gravels, 
termed by the authors denudation-beds. 

2. " On supposed Glacial markings in the Yalley of the Exe, 
North Devon." By N. Whitley, Esq. 



32 Geological Society of London. 

Mr. Jukes having, in a late paper, mentioned some glacial grooves 
observed by him in the valley of the Exe, the author stated his 
opinion that the *' Grooves " have been formed by the minor contor- 
tions of the strata, and not by glacial action. 

3. " On Disturbance of the Level of the Land near Youghal, in the 
South of Ireland." By A. B. Wynne, Esq., F.G.S. 

The object of this communication was to place upon record 
certain facts connected v^ith alterations of level in the shore of the 
South of Ireland, near the town of Youghal. The occurrence of 
submerged peat beneath the Youghal strand shows that considerable 
alterations of level have taken place along the coast of Youghal 
Bay subsequently to the formation of the peat which so commonly 
covers the Glacial Drift of Ireland. The author also inferred that 
toward the close of the Glacial period the sea was further from the 
present land than it is now ; that the land then sank to the depth of 
about 90 or 100 feet, and subsequently rose again, but not to its 
former level ; and, in conclusion, he pointed out the probability of 
its undergoing depression at the present time. 

II. December 4th, 1867.— Eobert Etheridge, Esq., F.G.S., in the 
Chair. The following communications were read : — I. "■ On the 
Graptolites of the Skiddaw Series." By Henry Alleyne Nicholson, 
D.Sc, M.B., E.G.S., etc. 

The author first described the geological relations and distribu- 
tion of the Skiddaw Slates, and noticed their correspondence with 
the Quebec Group of Canada, and then gave a description of the 
Graptolites found in these rocks. The genera and their distin- 
guishing characters are as follows : — 

1. Dichograpsus, Salter (3 species) : possesses a frond, repeatedly 
dichotomous from a basal stipe into 8, 16, or more branches, each 
with a single row of cells, the lower part of the stipe being enve- 
loped in a corneous cup. 

2. Tetragrapsus, Salter (3 species) : possesses a frond composed 
of four simple stipes, arising from a non-celluliferous funicle, which 
bifurcates at both ends. 

3. Phyllograpsus, Hall (2 species) : differs from the last in pos- 
sessing a frond composed of four simple stipes united back to back 
by their solid axes. 

4. Didymograpsus, M'Coy (7 species) : the frond consists of two 
simple stipes, springing from a mucronate radicle, which may be 
rudimentary or apparently absent. 

5. Diplografsus, M'Coy (4 species) : two simple stipes, united by 
their solid axes into a celluliferous frond furnished with a radicle at 
the base. 

6. Graptolites vel Graptolithus, Linn. (4 species) : simple stipe, 
with a single row of cells on one side, and a small, generally curved, 
radicle at the base. 

7. Pleurograpsus, Nicholson (1 species) : ceUuliferous branches 
derived from a main celluliferous rhachis. 

II. "On the Fossil Corals (Madreporaria) of the West Indian 



Geologists* Association. 33 

Islands.— Part IV. Conclusion." By P. Martin Duncan, M.B., 
Sec. G.S. 

In this communication the author concluded his series of memoirs 
on the Fossil Corals of the West Indies with a description of the 
Miocene corals from St. Croix, Trinidad, and with some supple- 
mentary remarks on the species described in his former papers from 
St. Domingo, Jamaica, and Antigua, including notices of new 
species from those islands. He also gave a complete and revised 
list of all the fossil corals he had described from the West Indies, 
including five species from the Cretaceous strata ; four species and 
one variety from Eocene deposits ; and one hundred and two species 
and twenty-six varieties from the Miocene formation, making a total 
of one hundred and eleven species and twenty-seven varieties. Of 
the Miocene species eleven still exist, namely, six in the Caribbean 
sea only, three common to that sea and the Pacific Ocean, and two 
in the Pacific Ocean and Ked Sea, but not in the Caribbean. 
Twelve other species are common to European deposits and the 
West Indian Miocene, ten being of the same age in both hemi- 
spheres, while two occur in the Lower Chalk in Europe. These 
twenty -three species being deducted from those of the West Indian 
Miocene, a large characteristic fauna still remains ; and Dr. Duncan 
showed that the recent representatives of the characteristic genera 
composing it are for the most part inhabitants of the Pacific and 
Indian Ocean, the Red Sea, and the Australian waters, and that 
their Tertiary congeners are found in Europe, Australia, Java, and 
Sinde. Of the fourteen genera thus enumerated, eight are not repre- 
sented in the recent coral-fauna of the Caribbean sea. 

Jamaica has yielded the only known Cretaceous and Eocene 
corals; and Dr. Duncan stated that the former are identical with 
European Lower Chalk species ; and that the latter are similar to 
species from the London Clay, the Bracklesham Beds, and the 
Paris Basin. 

Dr. Duncan then mentioned several curious facts in the distribu- 
tion of the West Indian corals, both fossil and recent, and especially 
the circumstance that whilst Jamaica, San Domingo, and Guada- 
loupe present solitary species, mixed with those indicating shallow 
water and a reef, Antigua and Trinidad offer for consideration only 
reef-species. In conclusion, the author drew attention to the con- 
firmation by subsequent discoveries of his theory of an Atlantic 
archipelago, which he had put forward in his earlier papers. 



Geologists' Association, University College, London. — On 
December 12th, 1867, Mr. Henry Woodward delivered a lecture to 
this association, *' On Eecent and Fossil Crustacea," in which he 
pointed out the great interest attaching to this group, not only on 
account of its wide geographical distribution, but also its early ap- 
pearance in geological time. He considered that the division Arti- 
culata was, probably, almost of as great zoological value as the 
sub-kingdom Vertehrata : that, in fact, in palaeozoic times, the repre- 
sentatives of the Articulata fulfilled the functions afterwards per- 

VOL. V. — NO. XLIII. 3 



34 Correspondence — Rev. 0. Fisher. 

formed by fishes and reptiles — that the Articulata alone, of all the 
Invertehrata, possessed the powers of aerial, terrestrial, and aquatic 
progression, and in as great perfection as the Vertehrata. 

Mr. Woodward called especial attention to those orders and 
families of Crustacea which are of greatest interest to the palaeonto- 
logists, because they are represented, in some instances, far back in 
time, their remains being found in oldest Palasozoic strata. 

He spoke of those world-wide forms — the bivalve Entomostraca, 
to which Messrs. Parker, Jones, and Brady, have devoted so much 
attention, which have lived on from Silurian times to our own : — 
of the Apus-Yike Crustacea, Ceratiocaris, Peltocaris, Dithyrocaris, &c., 
equally persistent : of the gigantic Eurypterida, and their modem 
relatives, the LimuUdce, (these latter appearing, by recent discoveries, 
to go back in time to the Upper Silurian)^: — of the extinct Trilo- 
bites and their relationship to Apus and Branchipus. Mr. Wood- 
ward noticed that aberrant group the Cirripedia, represented by the 
"Barnacle" and "Acorn-shell," and their relatives, who prefer 
whales and turtles backs to live on, rather than the sides of ships. 
He mentioned that one fossil Cirripede had been discovered as low 
down as the Wenlock limestone, and that the fossil shell, of a species 
parasitic on the whale, had been found in the Crag of Suffolk, where 
such vast quantities of the bones of fossil Cetacea are also met with 
in the Coprolite-diggings in the Crag. He then spoke of the higher 
forms, the Decapod Crustacea, represented by the Crab, Lobster, and 
Prawn, and showed that the short-tailed Crabs have, at present, only 
been found as far back in time as the great Oolite, but that the long- 
tailed type go back to the Coal-measures. 

In conclusion he strongly recommended this group to the attention 
of Town-members, as, from the London Clay, some of our finest 
Tertiary fossil Crustacea had been obtained ; whilst from the Chalk 
of Kent and Sussex and the Gault of Folkestone, an equally abun- 
dant harvest might be procured. 

Mr. Woodward's lecture was illustrated with a large series of 
Diagrams and Specimens of recent Crustacea, serving to show the 
wonderful diversity of form and modification of the appendages 
which are displayed in so remarkable degree by this interesting class. 



coI^I^ESI=OIs^l^E^:^^CE. 



DENUDATION, AND ITS AGENTS. 

Sir, — T am pleased to find that your contributors have of late re- 
turned to the attack upon the difficult subject of denudation. There 
is plenty of room for other workers to labour in other departments 
of our illimitable science, without this subject being lost sight of. We 
must be content to undergo a good deal more hard thinking and close 
reasoning upon it. Fine writing will not solve our difficulties. Even 
alliteration may fail to help us. 

Denudation has been going on for extended ages, and this pecu- 

* See the first article in the present number of the Geological Magazine, p. I. 



Correspondence — Rev. O. Fisher, 3o 

liarity attaches to it, that the last agency at work necessarily oblite- 
rates the marks of others which may have preceded it. When, 
therefore, we are discussing this subject, it is important to avoid 
misconception by stating clearly what stage of the whole process we 
are upon. One may say, we have marine action here ; another, we 
have glacial ; another, pluvial. Each may be right if he limits his 
assertion to the proper stage ; each will be in error if he carries it 
beyond. It is as, in describing the fashioning of a board, we might 
truly assert it to have been cut either by the axe, or by the saw, or 
by the plane. But if we were to attribute the formation of the 
smooth surface to one of the two former instruments, the assertion 
would be incorrect. 

The present phase of the discussion refers, I apprehend, to the 
final stage of denudation. To use the above illustration again, 
were I shown a board, and asked by what tool the surface had been 
brought to its present condition, I should look at two things — first 
at the form of the surface, and, secondly, at the condition of it. From 
the two together, I should be able to arrive at a sure judgment of 
the mode by which the surface had been produced. Now, I think 
that these tests have not been carefully enough applied to discover 
the true cause of the form of the ground. The acknowledged power 
of rain to carry some portions of the soil into the rivers, and the 
power of rivers to convey what the rain gives them into the sea, 
does not prove that the contour of our landscape was produced by 
those agents. The question to be decided is, whether rains can mould 
the surface to the particular form which it presents, and whether it 
can remove, not some material, but the particular material of which 
each locality has been denuded. This is a question concerning the 
mechanical power of water, in the quantities which rain yields, 
moving over surfaces having the minimum inclination of the denuded 
country. And when we call in the assistance of the weather to dis- 
integrate the harder rocks so as to fit them for removal by rain, we 
must recollect that, in cases of unequal solubility, the harder por- 
tions would be left, if only temporarily, to accumulate behind, and 
thus to point out the manner in which the waste of the surface was 
being effected. Neither must it be forgotten that such pluvial action 
must have been carried on when all the less elevated parts of the 
surface were covered with herbage, as they would have been if the 
climate was not glacial. If it was glacial to the extent of preventing 
the growth of herbage, then ice action would have taken place. 

The second index to the agency which has been in operation is to 
be found in the condition of the surface. It is inexcusable to neglect 
the study of this, which is to be seen in every shallow pit or ditch 
that is opened. Such sections always afford an interesting study. 
We must no longer be content to disguise our slothful ignorance of 
the true nature of the first few feet of every section under such terms 
as ''heading," "vegetable soil," "rain wash" (unless we can ^rove 
it such), "rubbish," or what not. There you have a veritable re- 
cord of the last touch of Nature's hand in fashioning the landscape. 
Say, what tool did She use ? Those contorted layers of gravel, those 



36 Correspondence — Mr. G. IL Kinahan. 

pebbles set on end, those larger stones suspended in what was once a 
plastic mud, that distinct line of demarcation between the moved 
and unmoved ground usually marked with slikenside if you look 
for it, those beds bent back and dragged down hill — nay, sometimes 
bent over on level ground : all these are indications of some universal 
agency, bringing the surface into the state in which we see it. What 
power was competent to produce, not one of, but all these effects ? 

The modern changes in the form of the ground, by the growth of 
peat, the silting up of valleys, the erosion of the banks of streams, 
the slipping of hill-sides under the action of springs, will help the 
close student of the subject to arrive at a satisfactory conclusion upon 
the older mode of denudation ; for they will show him that the pre- 
sent agency of rain, and rivers, and springs, is modifying, not 
continuing to produce, the original contour of the ground. Until all 
these indications of form and condition of the surface are patiently 
and honestly studied, this question will continue to vex the geolo- 
gical mind, and to occupy the valuable pages of your Magazine. 

0. Fisher. 

Harlton, Cambridge. 

P.S. — The above was written before the appearance of the 
December number of the Magazine, and has no reference to the 
papers therein contained. 

THE EARTH'S FEATURES. 

Sir, — " The true views of the operations of nature in sculpturing the 
surface of the earth can never he arrived at unless we take into con- 
sideration the effects of all possible agencies, and give them their due 
place in the great worTc.''^ 

Never were truer words spoken than the above, — Marinists may 
rave about what their special agent can do ; so may Suhaerialists pro- 
per, Glacialists, and every other ists, but unprejudiced observers will 
find that all the different agencies work hand in hand, and that if 
any of them had been absent, the present features of the earth could 
not have been formed as we now find them. 

Why is it necessary that any new theory should be invented or 
any special theory adopted to account for the present features of the 
Earth ? Why not rather allow the existing forces to do the work 
nature has assigned each ? Let the changes in the earth be con- 
sidered from " the beginning," and may not a solution for most, if 
not for all, the apparent difficulties be found ? To suit the special 
theories, various forms have been suggested as the first ; but is there 
one of them so simple or better than that given in The Book — " The 
earth was without form and void, and the spirit of God moved on the 
face of the water." From this, the oldest record, it would appear that 
at " the beginning," the earth was surrounded by an envelope of water. 
Moreover, this statement agrees with present conditions; for a 
similar phenomenon might again occur if all the land was sunk in 
the depths of the ocean. This sea, as proved by Mr. Campbell in 
*' Frost and Fire," must have been motionless, there being no light 
^ Hull, " Geol. Mag." Vol. IV. p. 569. 



Correspondence — CoL Greenwood. 37 

— when light was created, motion began, and after that, ^' the dry 
land appeared," — since then there has been perpetual motion, during 
which, parts of the land have been submerged, while other parts 
have been elevated ; and this process has been enacted over and over 
again. While the land was above the sea, " Frost and Fire," with 
"Rain and Rivers," have each in their appointed place done their 
work ; neither was the sea idle, as it must have acted on the land 
as it was appearing above, or disappearing under the waters, carving 
out the main features afterwards to be remodelled by the other 
existing forces. 

An observer who has seen the sea yearly carrying away a coast 
may be inclined to believe that it is the great destroyer ; while 
those who live among soft strata that are easily denuded, may pin 
their faith to " Rain and Rivers," and those accustomed to Alpine 
or Arctic regions to ice ; but an unprejudiced observer will find 
that " all are right and all are wrong." Moreover, if the advice of 
the Chameleon — 

*' When next you talk of what you view, 
Think others see as well as you," 

was generally adopted among geologists, it would not be so difficult 
a task as at present to find *' keys to fit all the locks." 

The Biblical record may be sneered at because human remains 
have not been found except among the most recent of the Tertiary 
deposits. However, in answer to this I may be allowed to put for- 
ward Col. Greenwood's suggestion ; that there is only negative evidence 
against the existence of Man and the other land animals from the earliest 
periods of the earth ; for to quote that author's words : ^ — ** Where are 
the fossil remains of land quadrupeds found ? In cavern deposits, in 
drift and alluvium ' deposited on dry land,' in filled up lakes, in 
bogs, or frozen up in polar regions. Now all these land museums 
are not only modern, but they are superficial and temporary. They 
are liable to be washed into the sea ; and their fossil contents must he 
destroyed before they can be re-deposited in marine strata." 

G. Henry Kinahan. 

CoNNEMARA, Bec. 1st, 1867. 

DENUDATION OF THE WEALD. 
SiE, — In your December number, page 572, Mr. Mackintosh 
names me as " Colonel Greenwood, the father of modem subaerial- 
ism." And thereupon he puts this question to me, *'If rain has 
washed away the soluble chalk, what has become of the insoluble 
flints?" In reply I would ask Mr. Mackintosh where do " surface 
flints " come from ? I have said " Everything on the surface of the 
earth which is not living is decaying. On this decay depends soil. 
On soil, vegetable life. On vegetable life, herbivorous animals. On 
herbivorous animals, carnivorous animals. So that all life depends 
on decay." At page 211, of " Rain and Rivers," is this passage, — 
" In chalk countries denudation leaves a residuum of flints on the 
surface, because though these flints disintegrate and though each is 
^ " Eain and Rivers," 2nd Edition, p. 199. 



38 Correspondence — Col. Greemvood. 

surrounded with a white soft surface of decay, they do not decay so 
fast as the chalk. Notwithstanding the most sedulous stone-piching, 
these flints still make their appearance. And it is the universal 
opinion among farmers that they grow, not in size but in numbers. 
But, however we may laugh at the idea of the growth of flints on 
land, for the fact that surface flints increase in number it is impos- 
sible to suppose more competent witnesses than farmers. And how 
is the fact to be accounted for unless they are the residuum of denu- 
dation ? When sheep in feeding off turnips have trodden the ground 
firm and the flints loose, I have seen them raked into rows and 
shovelled into carts. And were it not that the bulk of the layers of 
chalk which decay into soil, so infinitely exceeds the bulk of the 
layers of flint which decay into soil, the accumulation of surface 
flints would soon stop agriculture in chalk districts. But as rain 
gradually and annually washes away the soil, the plough brings up 
fresh flints. And this increase of surface flints in number proves 
a very universal denudation going on at this moment under our own 
eyes." With regard to "what has become of the insoluble flints," 
where large bodies of chalk have been removed, such as the ancient 
cap of the Weald Hill, have we no flint gravel iDcds ? Have we no 
beaches of flint? What of the flint-gravel of Kensington and Hyde 
Park ? What of the flints in the enormous beaches (Dungeness for 
instance) between Dover and the Weald at Hastings on the one 
hand, and between Beachy Head and Hastings on the other ? These 
witnesses once existed in the chalk which surmounted the Weald 
Hill above Hastings. Countless myriads of tons of them have 
travelled to and fro in all directions, and these travellers still exist 
on our coast at Hurst Castle, at the Portland beach, at Slapton sands, 
at Hellstone, and round the Lands-end and to the north of it. Count- 
less myriads of tons of them have been ground into sand. And as 
I have said in the chapter on the travelling of sea beach in " Eain 
and Eivers," '' as the wind blows the wave flows, as the wave flows 
the beach goes." But the wave flows up the shore obliquely and 
down the shore straight. The water then would heap to leeward 
unless there was an under- tow to windward. This under- tow 
carries sand which is fine enough to be held in suspension, and this 
is the cause of blown sand at the windward end of large beaches. 
And from Bridport, which is the windward end of Portland beach, 
millions of tons of sand are exported to every part of the world to 
make " Portland Cement." This is " what becomes of the insoluble 
flints." 

Mr. Mackintosh smashes what he calls " Colonel Greenwood's 
hard gorge and soft valley theory." I laid down the principle that 
'' as sure as there are alternations of hard and soft strata in the 
course of a river or valley so sure will there be alternations of gorge 
and alluvial flat." I first generated this theory in accounting for 
the valleys along the stretch of the soft Weald clay, behind the 
crorges across the comparatively hard chalk of the North and South 
Djwns. And I said that, owing to this principle, the original single 
Weald Hill had been cut by rain and rivers into three ridges, two 



Correspondence — A/r. R. H. Tiddeman. 39 

outside chalk ridges, and one inside Weald Hill. And that these 
three ridges of hills were as much formed by rain and rivers, as the 
statue is formed by the sculptor. 1 thought that this was quite 
simple. Mr. Mackintosh's receipt is more simple still. He first 
brings in fire to make " longitudinal cracks during axial elevation," 
then water in the form of currents " deflected and reflected so as to 
hollow out the curvilinear ' coves' by which the ' capes' are separated. 
But suppose it could be shown that powerful currents operating at a 
considerable, not ' too great' a depth, are incapable of scooping out 
the depressions bounded by escarpments, it would not be more in- 
consistent with uniformity to suppose a cyclically-recurring intensi- 
fication of the action of currents caused by sudden upheavals of 
strata (here we have fire and water together) than to admit occa- 
sional strides constituting breaks in the otherwise continuous series 
of (organic) changes." 

This seems so probable that if I remain of the same opinion still, 
it can only be from being convinced against my will. 

In the same number of your Magazine, page 568, Mr. Hull says, 
''I adopt, though with some hesitation the views of Professor Kam- 
say, Dr. Foster, and Mr. Topley, regarding the subaerial denudation 
of the Weald." If Mr. Hull will do me the honour to read the chapter 
on the Weald in " Rain and Rivers," I think that he will do me the 
justice to say that the above-named gentlemen have " adopted" my 
principles, first published in 1853, and again in 1857. 

George Greenwood, Colonel. 
Brookwood Park, Alresford, 
6 December, 1867. 

THE VALLEYS OF LANCASHIRE. 

Sir, — My friend and colleague Mr. Hull in the last number (page 
568) has again brought forward and endorsed his views as to the 
formation of the valleys of Lancashire. As I have now for some 
time been at work in North-East Lancashire and the adjoining parts 
of Yorkshire, my silence would imply that the country on which I 
am engaged bears evidence in favour of his views, whereas the facts, 
so far as my experience goes, tend towards an opposite conclusion. 

He says '' Most of the valleys are really double valleys, the smaller 
being alone due to river denudation, and the evidence of this lies in the 
fact that, the larger, or primary, valleys are filled with terraces of 
Marine Boulder-clay, and are really plains of marine denudation in 
their earlier stages." (The italics are mine.) The fact I can 
corroborate with pleasure, but I must difier from him in the in- 
ference. I find myself obliged to go further than my friend and 
state, that in the district, with which I am acquainted, the Boulder- 
clay lies also in the "secondary" valleys, and in water-courses of 
every size and at different levels (even in some of the narrow doughs 
down the hill-sides), in short, in many of those " channels and fur- 
rows," which Mr. Hull admits to have been formed " by the action 
of frost, rains, rivers, and glaciers." In fact many of the brooks of 
this part of Lancashire are simply re-excavating and enlarging fossil 



40 



Correspondence — Mr, A. H. Green, 



water-courses, and following in the footsteps of their pre-glacial 
pioneers. 

With these facts before me I see no escape from the inference, 
that, in this district at least, the Glacial Sea, so far from forming the 
" primary " valleys, in which it left the Boulder-clay, had not even 
the power to obliterate, in those valleys, many minor features formed 
by previous subaerial action. E. H. Tiddeman. 

Geological Survey of Great Britain, 
Clitheroe, December I2th, 1867. 



SEA-CLIFFS AND ESCARPMENTS. 
Sir, — In combating the notion that escarpments have been origin- 
ally sea-cliffs, Mr. Whitaker has stated so fully and forcibly the 
well-known fact that their bases are rarely or never at the same 
height above the sea-level for any distance, that there would at 
first sight seem to be little room for anything more on the subject. 
Mr. Whitaker's observations, however, having been confined to the 
Tertiary and Secondary rocks of the South-East of England, it may 
perhaps be well to shew that his remarks apply equally to the es- 
carpments of other districts. I also note that one of your corres- 
pondents still holds that depression would convert most of the prin- 
cipal escarpments of the Centre and North of England into sea-cliffs ; 
and another, while he admits that the bases of escarpments are not 
strictly horizontal, seems to think that their deviations from a level 
line are either so small, or so very gradual, that they might be con- 
verted into sea-cliffs by inequalities of depression by no means be- 
yond the limits of probabilit3\ Vague statements, like the latter, are 
easily made; but, before they can carry any weight with them, they 
must undergo the test of facts, and figures ; and for this end I have 
drawn up the following table shewing the details of two cases. 
Escarpment surrounding the Rivelin Valley near Sheffield. 



NORTH SIDE OF 


VAT.T.KY. 


SOUTH 


SIDE OF THE VALLEY. 1 


Height of 


Distance 


DiflFerence be- 


Height of 


Distance 


Difference be- 


from start- 


tween height 


from start- 


tween height 




ing point 


of base at each 


sea-level 
in feet. 


ing point 


of base at each 


in feet. 


in miles 


point and mean 


in miles 


point and mean 


and chains. 


height of base. 


and chains. 


height of base. 


1000 




+ 300 


1000 




+ 300 


1075 


0-40 


+ 375 


1075 


0-42 


+ 375 


1000 


0-60 


+ 300 


1000 


0-76 


+ 300 


900 


1- 


+ 200 


900 


1-35 


+ 200 


800 


M5 


+ 100 


800 


1-72 


+ 100 i. 
+ 100) ~ 


775 


2- 


. .}. 


800 


3-50 


700 


2-45 


700 


3-65 




600 


2-48 


— 100 


600 


4- 6 


— 100 


600 


3-40 


— 200 


500 


4-18 


— 200 


400 


3-60 


— 300 


400 


4-25 


— 300 


325 


4- 


— 375 


326 


435 


— 376 



Let us now see what will be required to make this line a sea-cliff, 
or, if it were once a sea-cliff, to convert it into the present escarpment. 

• Fault between these points. 

-t- Between these points the base|;is up and down between 800 and 850. 



Correspondence — Mr. A. H, Green. 



41 



S o §: 



: W 



The mean height of the base is about 700 feet above the sea, and 
it will give the minimum of oscillation if we suppose the land 
lowered to this amount. But even on this supposition we shall 
require the lowest point to be raised 375 j^ 

feet, a point only two chains off 300 
feet, a point seven chains further on 200 
feet, and so on ; while at the other end 
of the line additional depression will be 
necessary, and the heights of the first 
three points shew that this depression 
will not always increase uniformly in 
the same direction. I may add that I 
have neglected the gashes cut by small 
streams in the flank of the slope, and 
taken only the general line of the cliff : 
had all the lesser windings been followed 
the result would have been still more 
striking. This way of treating the mat- 
ter is, I think, fairer to my opponents, 
because, according to their view, these 
gullies were formed after the termina- 
tion of the process which gave rise to 
the escarpment itself. 

In order to shew more clearly to the 
eye the facts I am insisting on I have 
thrown the details of another case into 
the form of a diagram given in the 
woodcut annexed. The dotted horizontal 
line there represents the average level of 
the base of the escarpment, and the dis- 
tance between this dotted line and the 
hard black line at any point shews the 
difference in level between the actual 
base at that point and its mean height, 
and therefore the amount of additional 
elevation or depression required to turn 
the escarpment into a sea-cliff. The hori- 
zontal and vertical scales are each two 
inches to a mile. 

The cases just given have been taken 
at random, and, I believe, represent very 
fairly the general state of the escarp- 
ments of the Carboniferous rocks in Lan- 
cashire, Yorkshire, Staffordshire, and 
Derbyshire ; to turn these into sea-cliffs, 
sea- saw work like that described would 
be required for every one, alike in char- 
acter but varying in amount for each ; 
now, independently of the improbability 






42 Correspondence— Mr. S. V. Wood, Jun. 

of Mother Earth ever having been afflicted with St. Vitus' dance to 
this extent, I do not see how it is possible that such startling in- 
equalities in elevation or depression can have gone on in solid rocks 
at the surface without shattering them to pieces. 

Will you also allow me to tell Mr. Mackintosh that I have tried 
to explain how subaerial agency may begin the work of escarpment- 
making on p. 87, of the Geological Survey Memoir on the country 
round Stockport, Macclesfield, Congleton, and Leek. — A. H. Green. 

Monk Bretton, Barnsley, 
December 9ih, 1867. 



REPLY TO MR. W. BOYD DAWKINS, ON THE THAMES VALLEY 
DEPOSirS, &c.; AND TO MR. A. H. GREEN, ON THE OUSE 
VALLEY AT BUCKINGHAM. 

Sir, — Before replying to Mr. Dawkins' criticism, I must acquit my- 
self of any undue use of the letter to me to which he refers. I wrote 
him in reply to it, pointing out privately what I have now done 
publicly ; and asking him, as I valued his palaeontogical evidence, 
to correct what I considered to be a hasty error in his geology. 
All that I received was a letter, refusing in indignant terms to do 
this, and challenging me to make out my case. Not the faintest in- 
timation was given me of the mistake in places which Mr. Dawkins 
now says he made, notwithstanding that I had pointed out to him that 
Mountnessing and Ingatestone had nothing to do with the valley of 
the Blackwater, and the position of the Glacial clay near Witham 
had been shown by me a year previously, in sect, nine of my paper, 
at page 348 of your third volume.^ He must have been hurried 
indeed, if he ran his finger up the Wid to Ingatestone and Mount- 
nessing, instead of up the Blackwater to Witham, when the latter 
is not only fifteen miles distant from them, but is in another 
Ordnance Sheet. It was only upon this failure to get corrected, or 
even qualified, in an unobtrusive way, what I consider to be 
a fundamental error, that I sent in the note to my paper then 
awaiting its turn for reading at the Geological Society. 

With respect to the brick-earths of Grays and Crayford, I have 
given so many sections in illustration of their position in the 
memoir that accompanies my maps in the Geological Society's 
library, that it would only be unduly occupying your space to 
endeavour to illustrate the subject here. They must await the 
investigation of impartial observers, who will study and master, not 
one, but the whole of the highly complex features of the Eastern 
Thames valley. All that I would invite Mr. Dawkins, and it seems 
Professor Morris also, to do, is to show that the gravel of the lower 
terrace, which, with a thickness of fifteen feet, passes under the 
greater part of the Grays hrickearth, be not a part of the same sheet 
which occupies the valleys of the Darent and Cray, and to which 

I See Little Braxted, which is in the Blackwater valley, and only one mile from 
Witham Station. As the Glacial clay comes near to Witham, it may very probably 
ba at Witham station, but if so, is not visible, in the Railway section the only bed 
seen being the gravel. 



Correspondence^ Mr, S. V. Wood, 



the brickfield at Crayford forms 
a higher terrace, as shown in 
my section at page 409 of the 
twenty-third volume of the Quar- 
terly Journal Gcol. Soc. 

While Mr. Dawkins reserves 
a doubt whether the brick-earth 
of Dartford Heath and Hill- 
house be identical with that of 
Crayford, it is not worth while 
attempting to show that it is 
inferior to the Thames gravel ; 
otherwise, I think means could 
be found to satisfy even himself 
of that fact. 

Mr. Dawkins' position gene- 
rally is — first, That the chief 
part of the deposits of the 
Thames valley are older than 
the Glacial clay of the northern 
heights ; and the rest, viz., 
what he and Mr. Fisher term 
" Trail " (but whose existence 
as a formation I do not admit), 
is S3''nchronous with that clay ; 
and — secondly. That the main 
features of the country around 
the Thames area were sketched 
out before the Glacial clay pe- 
riod. With respect to the first 
of these propositions, I ask Mr. 
Dawkins either to show that 
section four at page 398,^ and 
section thirteen at page 409, of 
the twenty-third volume of the 
Quarterly Journal, and the sec- 
tion I now give are incorrect ; 
or else to explain by what con- 
dition of things such a structure 
as they display could on his hy- 
pothesis come to pass. Those 
who know the Thames valley 
are aware that a large arm of the 
chief deposit in it, the gravel, 
runs up the vallej^ of the Lea. 
Now the accompanying section 
shows the relation borne by 
this gravel to the Glacial clay, 
both in the Thames and Lea 
valleys; as well as the struc- 

1 By oversight the elevation of Upmin- 
ster Hall and Cranham Church is made too 
great in this section, but this has no bear- 
ing upon the structure displayed by it. 




Thames River at 
Crossness Well 
boring 



44 Correspondence — Mr, S. V. Wood, Jan, 

ture of these valleys, and that of the Boding, where the southern- 
most outliers of the Glacial clay occur, being those nearest to 
the common point of inosculation of the three valleys. Unless 
this section be wrong, I submit that if the posteriority of the 
Thames gravel (x4 and x5) to the Glacial clay be doubtful, then the 
posteriority of the implement graA^el at Bedford to the same clay 
must be doubtful also ; for, so far as this relative position goes, 
the two gravels are identical — what I contend being, that though 
both are posterior to the Glacial clay, the Thames gravel is much 
older than the Bedford, in the latter part only of which contention 
Mr. Dawkins agrees with me. Palaeontological evidence is a valuable 
auxiliary to Geological position, but cannot override it ; and if the two 
clash, the latter, I submit, should prevail. My own belief, however, 
is that they never really clash, and that the present case, where the 
Palaeontology, as deduced by Mr. Dawkins from the Mammalian re- 
mains and the physical Geology, as deduced by myself, so strictly agree 
is an instance of this. I also ask whether this section can be recon- 
ciled with the other of Mr. Dawkins' propositions, viz., that the main 
features of the country were sketched out before the Glacial period ? 
Is it not evident that the three valleys have been formed by a great 
denudation posterior to the Glacial clay ? So far from limiting my 
meaning of a valley to the stream itself, I contend that all the 
valleys of the East of England, with one or two exceptions, have 
been formed subsequently to the Glacial clay ; but I point out that 
this clay occupied depressions or erosions of greater or less extent, 
some of the smaller of which (as in the case of parts of the Eoding 
and Wid valleys), have been incorporated into existing valleys that 
chance to traverse them, quite irrespective of their original character ; 
and thus give in these parts an illusory impression of the valley having 
been formed before the Glacial period. I have been especially de- 
sirous to call to the attention of geologists the great contrast pre- 
sented, in this respect, by the valleys in strata newer than the Trias 
south of Flamborough Head, to those of the same strata north of 
that point. 

In reply to Mr. Green, I beg your readers to compare the section 
he has given in his letter to you with that which he gives in the 
Memoirs of the Geological Survey for sheet 45 (which is that 
objected to by me in my paper), and judge for themselves what 
similarity there is between them, for there appears to me to be 
scarce any. If the suppositious (or dotted) line be omitted, I see 
little in his section sent you to object to, beyond its incomplete- 
ness ; and I ask your readers to judge what ground it affords for the 
assertion, made in reference to the section given in Memoir 45, 
across the Ouse, *' that a valley existed in the stratified rocks, pre- 
vious to the deposition of the drift, which has been filled up with 
gravel, and then partly hollowed out again." ^ I subjoin a section 
shewing what I submit to be the true structure across the Ouse at 
Buckingham. In it I represent the Great Oolite and Cornbrash as 
presenting an eroded surface to the Glacial beds, which I submit 
^ Memoir for sheet 45, p. 34. 



Correspondence — Mr, S. V. Woody Jun. 45 

to be the cause of those features attaching to the Combrash upon 
which Mr. Green relies. The irregularity of the Pre-glacial surface 
is indicated by the outcrop at Lillingstone Dayrell of the older 
rocks, without the intervention of the bed No. 2, the gravel ; that 
bed coming in again in great force under Whittlebury, three miles 
beyond the northern end of my section. It is impossible that the 



1. The Great Oolite and Combrash concealed except where the valleys cut down to it. 2. Gravel 
and sand with boulder beds (the Middle Glacial), being bed No. 1, of Mr. Green's section. 
3. The Upper Glacial clay • — - Valley deposits, alluvium, etc. N.B. The Oxford clay may 
come in at the South end of the section under No. 2, but if so it is wholly concealed. 

The junction-line of 2 and 3 should be level instead of undulating as made by the engraver on one 
side of the Ouse. 

Base-line about 200 feet above the sea. Vertical scale about 500 feet to the inch. Length of section 
six miles. 

Post-glacial valley system should not frequently encounter these 
irregularities of Pre-glacial surface, which are thus made use of 
to found an argument for the Pre-glacial origin of our present 
valleys in the South. The main charge that I bring against this 
part of Sheet 45, and the Memoir accompanying it, is that both 
omit all reference to that which, having regard to its super- 
ficies and original thickness, is the greatest Tertiary formation 
of England, in point of magnitude — the Glacial clay. But few of 
your readers may be aware that, although the gravel given in Mr. 
Green's section is copiously illustrated, and this, as well as the 
valley beds, and even the alluvium, are described in the memoir, 
not the least allusion, either in map or memoir, is made to the 
Glacial clay. The result is that, not only this part of Sheet 45 E, 
but the greater part of Sheet 52, nearly half of Sheet 46 W, and part 
of Sheet 53, are delineated in a merely conjectural manner. Had 
this great formation not been thus ignored, I cannot conceive that 
the Geological surveyors would have failed to recognize that the 
valley of the Ouse, from the source of that river above Buckingham 
to its debouchure upon the Fen country, was, as Mr. Prestwich had 
shown it to be about Bedford, formed subsequently to the Glacial 
clay. S. V. Wood, Jun. 

P.S. — In his letter Mr. Dawkins says, in reference to the brick- 
earths in the Eailway cutting immediately to the North of Mile-end 
Terrace, and half-a-mile from Hill-house (which I have mapped as 
a part of the Dartford -heath brick-earth, and treated as identical 
with those of Crayford, Erith, and Ilford, which Mr. Dawkins 
regards as synchronous), that "the fact that they contain nearly 
all the testacea now living in our rivers, and none of those extinct 



46 Correspondence — Mr, Whitaker, 

in Britain, and no bones of mammals, proves them to be much 
newer than the neighbouring deposits containing older forms of 
life." Now, since writing you I have heard from Mr. Prestwich 
that he found the land and freshwater shells of the Erith beds 
in this cutting in the year 1850 or 1851, and among them, he 
thinks, the Cyrena fluminalis. Mr. Whitaker, also writes me, in 
reply to my enquiry, that he thinks he found the Cyrena in the 
cutting West of Dartford Station some years ago, but cannot speak 
with any certainty, not having his note books of that date with 
him. S. V. W., JuN. 



SUBAERIAL DENUDATION. 

Sm, — I did not intend to answer communications objecting to 
arguments and statements in my paper ; but one of the letters in 
your last number demands a few words. 

I am sorry that I should have misrepresented the views of my 
friend and colleague, Mr. Hull, and thereby given him any annoy- 
ance ; but, at the same time, I am glad that the name of another 
able and tried geologist may be added to the roll of those who allow 
that great things have been done by subaerial denudation, though he 
does not go so far as some of us, 

I read his letter on " Kiver-Denudation of Valleys," soon after it 
appeared (Geological Magazine, Vol. III., p. 474) but did not refer 
to it in my paper, as it seemed to me to uphold marine rather than 
subaerial denudation. My mistake arose from taking certain state- 
ments of Mr. Hull's, which had reference to some valleys of a certain 
sort, as applying to valleys generally. 

I have not seen his paper in the " Popular Science Eeview," and 
I do not hold myself bound to wade through journals of that kind, in 
search of original articles on geology.^ 

There is another geologist to whom justice was not done in my 
paper (p. 450) — the Eev. 0. Fisher, who, I believe, first published 
the second of those arguments against the marine formation of escarp- 
ments that Sir Charles Lyell admits to be unanswerable (p. 449). 

The remarks of your correspondents seem to me to divide them- 
selves, for the most part, as follows: — (1). Some show that, as 
might be expected (man being fallible), I have overlooked sundry 
small matters ; (2) some make statements of a kind that I have not 
denied or objected to at all ; (3) some have been already answered 
in my paper ; (4) some are simply exceptions to rules that I have 
stated to be general, not universal (and according to the old proverb 
" the exception proves the rule") ; (5) some are founded on a strange 
misunderstanding of the arguments of subaerialists ; (6) some are 
statements that I cannot agree to, and which I can only meet by 

1 Mr. Hull's criticism (Geol. Mag., Vol. IV., p. 567,) of a sentence in the first 
part of Mr, Whitaker's paper, "On Subaerial Denudation," (p. 453) should have 
been omitted, as the sentence objected to was corrected at the end of second part 
(p. 493), a month before Mr. Hull's letter appeared — by the insertion of the word 
"us," after "follow" (line 15, p. 453).— Edit. 



Correspondence — Mr. David Forbes. 47 

denial : none materially weaken tlie arguments in favour of sub- 
aerial denudation. 

That I do not take up the matter in detail is owing, not to inability 
to defend my position, but to a wish to steer clear of controversy. 

W. Whitaker. 

P.S. — (1.) Please insert the following corrections of the second 
part of my paper which appeared in your November number.' 
Page 485, fig. 1, the c should have been at the top of the cut. 
Page 489, fig. 2. The woodcut does not quite agree with the 
description. The broken lines, above what should have been a firm 
line on the right and a broken one on the left, but which is con- 
tinuous and somewhat shaky throughout, ought to have been dotted. 

(2.) In a notice of my '* list of Wells and Borings" (p. 510) the 
reviewer has mistaken the thickness of the surface-deposits, gravel, 
etc., given therein, for the depth of the wells. Instead of fifty feet 
being the greatest depth, some of the wells go down eight times that 
amount. 

I take this opportunity of asking all who have notes of wells and 
borings in the London district, to favour me with a copy of them, 
such information being very useful to the Geological Survey. — W.W. 



RESEARCHES IN BRITISH MINERALOGY. 

Sir, — Your last number (which my absence in Spain has pre- 
vented me receiving before now) contains a letter from Mr. T. 
Davies, dated from the British Museum, in which, after referring 
to some remarks contained in a late paper of mine (Kesearches in 
British Mineralogy, Phil. Mag. Nov. 1867), he states that true Silver- 
fahlerz, or Polytelite, is " found in quantity in this country and 
mined for the silver it contains." 

Being at present occupied in the preparation of a work on British 
Mineralogy, this information was very acceptable and at once in- 
duced me to visit the British Museum, in the full expectation of 
finding so valuable and interesting a British mineral species dis- 
played in case No. 11 ; unfortunately I could not perceive any such 
specimen labelled as Silver-fahlerz, or Polytelite, nor any notice of 
its occurrence in the official guide to the collection. 

In hopes, therefore, of eliciting further information I send you 
these remarks : — 

Tetrahedrite in general contains more or less silver, but can only 
be termed Silver-fahlerz, Weissgiltegerz, or Polytelite, when it con- 
tains a notably large amount of that metal, say a minimum of over 
5 per cent., for some specimens contain even more than 30 per cent, 
silver. The external appearance and physical character of this 
species, do not differ so considerably as to enable the argentiferous 
or non-argentiferous varieties of Tetrahedrite to be with certainty 
distinguished from one another. Although the former is generally 
found to be more brittle, lighter in colour and streak, and to possess 
a higher specific gravity, chemical examination can alone decide con- 
^ Unintentionally omitted from the December Number. — Edit. 



48 Correspondence — Mr. David Forbes, 

clusively as to whether a grey copper ore is entitled to the name of 
Polytelite, or not. 

The Foxdale mineral described and analysed by me is a true Poly- 
telite ; it contains nearly 14 per cent, of silver (or about 4500 ounces 
to the ton), and agrees in all its physical characters with the most 
characteristic specimens of this mineral. 

Quite prepared to admit that Polytelite may exist in quantity in 
the Silver Vein Mine near Lostwithiel, Cornwall, I must, however, 
confess that some of Mr. Davies' remarks rather tend to raise a 
doubt in my mind as to this being in reality the case. 

Mr. Davies states he knows of " no accurate analysis having been 
made of this ore," but informs us that " the last sample sold con- 
tained 36J ounces to the ton," and that some years back ''the 
average yield of silver was 68J ounces to the ton ;" and lastly, as 
something remarkable, states that in one instance it was " 214 
ounces ! " — Expressed in percentages these figures would merely be 
about 0'11-0'21 and 0-64 per cent, silver — amounts which, mineralo- 
gically considered, may be regarded as but traces of silver, not at all 
conclusive of the presence of Polytelite in the ore. 

Metallurgists would not regard such ores as silver ores, but only as 
argentiferous copper ores ; and many of the argentiferous copper ores 
imported from South America contain far more silver than even the 
richest of these, yet frequently do not contain a trace of Polytelite. 

"When, however, Mr. Davies adds that this " silver vein was 
formerly worked for \he rich deposits of silver it contained, I sup- 
pose in the state of sulphide" — does he not at once awaken a 
suspicion that the silver percentage of these ores may, in reality, 
be due to other sources than to the presence of Polytelite in quantity. 

When next in Cornwall, I shall be delighted to avail myself of 
any opportunity of visiting this mine ; and could I procure an 
authentic specimen of the mineral in question, should have much 
pleasure in analysing it. Previous experience has, however, taught 
me how little confidence can be placed in the genuineness of speci- 
mens purchased of Cornish minerals, and I have no doubt but that 
Mr. Davies' experience will have led him to the same conclusion. 
Accurate mineral analyses requires such an amount of time, skill, 
and expense, that before undertaking them it should be ascertained 
with the greatest care whether the mineral in question is an authentic 
specimen, or not David Forbes. 

11, York Place, Portman Square, "W., 
December 23rd, 1867. 



British Fossil Cycads. — Mr. W. Carruthers being engaged in 
investigating the structure of these fossils, would be obliged for 
information respecting specimens from any British locality which 
would enable him better to prosecute his enquiries. He reserves the 
examination of the foliage to a future period, confining himself for 
the present to the stems and fruits. Communications may be 
addressed to him at the British Museum. 



THE 

GEOLOGICAL MAGAZINE. 



No. XLIV.— FEBRUARY, 1868. 



I. — A Notice of the Chemical Geology of Mr. D. Forbes. 
By T. Sterry Hunt, F.R.S. 

THE Geological Magazine for October last contains a criticism 
by Mr. David Forbes of certain views put forward by me in a 
lecture delivered before the Eoyal Institution of Great Britain on 
the 31st of May, 1867. Of this lecture a short-hand report appears 
in this Magazine for August,^ besides which a condensed report, 
revised by myself, is published in the proceedings of the Institution, 
in the Chemical News for June 21st, and in three French translations 
in the Bevue des Cours Scientifiques, Les Mondes, and Cosmos. The 
Chemical News for October 4th contains a criticism of my lecture by 
Mr. Forbes, to which I have replied in a communication recently 
addressed to that Journal. 

In the lecture in question, I endeavoured to bring together the 
results of modem investigations in physics, chemistry, mathematics, 
and astronomy, and to construct from them a scheme which should 
explain the development of our globe from a supposed intensely 
heated vaporous condition down to the present order of things. I 
could not pretend to discuss, from their various stand-points, all the 
conclusions arrived at by different investigators, inasmuch as, even 
had my attainments permitted, the limits of an hour's lecture would 
have proved far too short. 

In regard to the structure of the earth I alluded to two views, 
one of which supposes a liquid globe covered with a thin crust of 
solidified rock, generally estimated at from twenty to thirty miles 
in thickness ; while the other regards the earth, if not solid to the 
centre, as having a crust at least several hundred miles in thickness, 
and of such solidity and rigidity as to be, so far as superficial 
phenomena are concerned, inert as if in a solid state. To this latter 
view I incline ; and I cited in support of it the conclusions of Hop- 
kins from the phenomena of precession and nutation, the inves- 
tigations of Archdeacon Pratt on the crushing effect of immense 
mountain masses like the Himalayah, and the deductions of Sir 
Wm. Thomson from the phenomena of the tides, showing the 
great rigidity of the earth, as so many concurrent evidences that our 

^ See the lists of Errata in tliis Magazine for September, p. 432, and October, 
p. 478. 

VOL. V. — NO. XLIV. 4 



50 Dr. T. Sterry Hunt — On Chemical Geology. 

planet, if not actually solid to the centre, has a crust far thicker than can be 
accounted for by the theory of a liquid globe covered only with a crust resulting 
from superficial cooling. This latter view, which was deduced from the increase 
of temperature observed in descending into the earth, is in conflict with the 
various mathematical and physical considerations above noticed, and it becomes 
necessary to revise the older notions of the conditions of a cooling globe. 

The investigations of Charles Deville, and of Delesse, as well as the earlier 
ones of Bischof, show that the density of fused rocks is very much less than that 
of the crystalline minerals of which they are composed. From this we may 
naturally conclude that the crystalline compounds which would separate by slow 
cooling from a bath of molten rock would gravitate towards the centre, as 
Saemann has already justly observed (Bull, Soc. Geol. de Fr., Feb. 4th, 1861). 
In opposition to this view, Mr. Forbes appeals to the results seen in a small 
scale in the cooling of melted metals, etc. — where a crust forms over the surface. 
It must, however, be considered that the conditions presented by a small vessel 
full of a hquid congealing in an atmosphere greatly below its own temperature, 
and having a crust growing out from and supported by the sides of the vessel, are 
widely different from those of a liquid globe slowly cooling beneath a very dense 
and intensely heated atmosphere. In such a case, with a bath of materials 
similar to those forming our present rock-crust, the crystalline minerals which 
have been shown by Deville to be from ^ to ^ heavier than the liquid mass ; 
these, as they separated, would sink as naturally as the crystals which form at 
the surface of an evaporating basin of brine. The analogy holds good, since 
the denser crystals formed at the surface, whether by evaporation or by cooling, 
obey the inevitable laws of gravity. 

Mr. Forbes next proceeds to some considerations drawn from the mean density 
of the earth, which, being about 5.3, is twice that of the average specific gravity 
of the solid materials known at the surface. Admitting that a solid crust of 
specific gravity 2.65 were to form at the surface of a liquid of density 2.3, and in 
obedience to natural laws, to sink therein, our critic conceives that, in its descent, 
it would meet with a denser liquid stratum. He supposes a liquid globe "be- 
coming rapidly denser in descending, as the pressure increased by the superin- 
cumbent column of liquid matter ; " and he tells us, in a note, that we may admit 
a density of "nearly 10.7 for the middle zone, and about 18.8 for the centre" 
(p. 435). Two pages further on he has completely changed his mind, for he tells 
us that " experimental research tends to show that a limit is soon reached beyond 
which the compression, or increase of density, becomes less and less in relation to 
the force employed ; " and concludes that there are strong reasons for believing 
that the central parts of the earth " must consist of much denser bodies, such as 
metals and their metallic compounds," — which he further on explains may mean 
"dense sulphids." 

To which of these two views does Mr. Forbes mean to hold, that of a rapidly 
and constantly increasing density from pressure, or that in which, limiting the 
condensing effect of pressure, he seeks to explain the density of the earth by a 
nucleus of heavy metallic compounds ? The latter is seemingly an after-thought 
of the critic, suggested by some notion of the principle involved in the augment- 
ation by pressure of the fusing point of bodies which expand in melting. As 
was shown by James Thomson, the effect of pressure upon ice (and naturally 
upon such metals and metallic alloys as, like it, contract in melting) would be to 
reduce its melting point, a fact which has been experimentally established for ice. 
Reasoning from the same principle, Sir Wm. Thomson deduced the conclusion 
that a reverse effect should result from pressure for all such solids as expand 
in melting ; that is to say, that their points of fusion would be raised, a conclusion 
verified by the experiments of Bunsen, and by those of Fairbairn and Hopkins. 
From some apparent irregularities in these results, and from the fact that certain 
of the substances submitted to experiment were bodies of the carbon series, 
which Mr. Forbes calls "organic," he argues against the conclusions which 
depend upon a well-defined physical law. In the case of the fusible alloys tried 
by Mr. Hopkins, it is to be remarked that most of these bodies, like ice, expand 
in cooling, and consequently should not have theirmeltmg points raised by pressure. 
For the memoirs of James and William Thomson, see Trans. Royal Soc. Edin., 
xvi. part 5, and L. E. D. Philos. Mag., [3] xxxvii. 125. A simple and popular 



Dr, T. Sterry Hunt — On Chemical Geology. 51 

exposition of the principle, and of Mr. Hopkin's argument therefrom, for the 
solidity of the globe, will be found in the fourth of Tyndal's lectures on Heat as a 
Mode of Motioti. See, also, Sorby's Bakerian lecture for 1863, cited farther on. 
Mr. Forbes must consider that just so far as he admits the condensing power of 
the pressure of the superincumbent mass, he increases the difficulty of maintaining 
that rocky mass in a liquid state. 

The condensing effect of pressure was by Dr. Young estimated to be sufficient 
to reduce a mass of granite at the earth's centre to one-eighth its bulk at the sur- 
face, which would give to the earth a mean density equal to twelve or thirteen 
times that of water. This consideration has led a recent writer in the London 
Athenmim to conclude with Herbert Spencer, that our earth and the other planets 
may be only shells of varying thicknesses, enclosing a central cavity filled with 
vaporous matter, by which hypothesis we may explain their apparently feeble den- 
sities. See Mr. Spencer's essay on the Nebular Hypothesis in the Westminster 
Review for July, 1858. It may be observed that his view, which supposes conden- 
sation to have resulted in the formation of a solid shell around a gaseous nucleus, 
is not incompatible with my scheme, which is simply opposed to a liquid interior. 
See also the note of Mr. Barkas, in this Magazine for September last, page 426. 
Leaving Mr. Forbes to settle these vexed questions, we may remark that in case 
we suppose condensation of the gaseous globe to have commenced either at the 
centre, or around a gaseous nucleus, it is probable that solidification from pressure 
must have taken place long before the liquefaction of earthy matters was complete. 
But if we adopt Mr. Forbes's second hypothesis, either that pressure would not 
materially augment the density nor raise the melting point of the fused mass, what 
grounds has he for assuming, as he does, that there occurred a separation of the 
liquid into zones of different densities ? That metallic sulphids could be formed at 
an elevated temperature, by condensation from an atmosphere containing an excess 
of oxygen, is contrary to all that we know of chemical affinities ; sulphurous acid 
and metallic oxyds would be the results so soon as the temperature fell below that 
of dissociation. As for the noble metals, whose compounds with oxygen are de- 
composed at elevated temperatures, their great volatility, as compared with earthy 
and metallic oxyds, would keep them in the gaseous form till the last stage of pre- 
cipitation of earthy oxydized matters, when by far the greater part of the globe 
was probably solidified. Hence we now find them in the earth's superficial crust, 
instead of being, as Mr. Forbes would suppose, carried to the centre of the planet. 
Judging from what we know of chemical affinities, and of the proportions of 
the elements now existing in the superficial parts of the globe, we cannot conceive 
anything else than the production of a homogeneous oxydized silicated mass, upon 
which, at a late period, would be precipitated the noble metals. From this mass, 
while yet liquid, there might take place a separation of various crystalline compounds, 
by a process analogous to that by which pure lead separates from the bath of the 
argentiferous alloy in Pattison's process, as Fournet has already suggested (Geo!. 
Lyonnaise, 1862, page 398). The last congealed and lighter portion of our globe, 
with which alone we have to do, was, probably, a sort of mother-liquor from 
which, during its slow cooling, compounds of various constitution and density may 
well have crystallized. In furnace operations, it is true, we may obtain, besides 
silicated slags, a dense stratum of reguline metals, sulphids or arsenids on the one 
hand, and a lighter one of saline sulphates or chlorids on the other. But neither 
of these classes of compounds was possible in the cooling globe, the reguline 
matters for reasons just given, and the saline compounds, for reasons yet to be ex- 
plained. 

I have in my lecture set forth that the earth's superficial crust must have been 
composed of silicates of the metallic, earthy and alkaline bases, surrounded by a 
dense acid atmosphere of hydrochloric, sulphurous and carbonic acids, besides 
watery vapor, nitrogen and oxygen. These chemical combinations are such as 
would naturally result from the affinities brought into play at the elevated tempera- 
tures then prevailing, in virtue of which all those elements capable of forming fixed 
and stable compounds with oxygen would be precipitated as oxyds. In these con- 
ditions, as already said, no metallic sulphids would be formed, and the whole of 
the sulphur would be found as sulphurous acid. In like manner the production of 
alkaline chlorids under such conditions, is inconceivable, since in the conjoined 
presence of oxygen, hydrogen, and silicon or silica, an alkaline silicate and hydro- 



52 Dr. T. Sterry Hunt — On Chemical Geology, 

chloric acid would result. Even if, as Mr. Forbes supposes, chlorid of sodium 
were to be formed in the heated atmpsphere, it would be precipitated into a bath 
of fused silicates, covered by an intensely heated atmosphere containing water, or 
mingled oxygen and hydrogen gases, and would immediately undergo the same de- 
composition that takes place when the vapors of common salt are diffused through 
a potter's kiln, or, as in Mr. Gossage's new soda-process, are passed with steam 
over red-hot flints. In both cases silicates of soda are formed with separation of 
hydrochloric acid. 

These considerations lead to the conclusion that after all the more fixed elements 
were precipitated, the whole of the chlorme would finally remain in the partially 
cooled atmosphere as hydrochloric acid, and the whole of the sulphur as sulphurous 
acid, together with a large proportion of oxygen, since we find this element in the 
form of sulphate and not as sulphite in the sea-waters. Mr. Forbes does not, it 
seems, believe that an excess of oxygen could exist in an atmosphere highly charged 
with sulphurous acid ; and elsewhere (in the Chemical News), he tells that it is, 
"if not impossible, at least highly improbable, that such a heated atmosphere con- 
taining sulphurous acid, hydrochloric acid, with oxygen and aqueous vapor, could 
exist," the elements being in his opinion incompatible. He is aware that at cer- 
tain temperatures sulphurous acid and oxygen unite, in the presence of water, to 
form oil of vitriol, but he forgets that at a higher temperature this compound is 
again resolved into water, sulphurous acid and oxygen ; and that one of the best 
processes for preparing the latter gas on a large scale is by this decomposition of 
sulphuric acid, and the subsequent removal of the sulphurous acid from the cooled 
gaseous mixture. Tn the opinion of Mr. Forbes, as set forth in the Chemical News, 
the sulphurous and hydrochloric acids would decompose each other in the presence 
of watery vapour (though every chemist's experience teaches him the contrary) ; 
another reason for holding that my supposed atmosphere was impossible. Un- 
fortunately for his opinion, however, it happens that large quantities of precisely 
such an atmosphere are disengaged from various volcanic vents. To cite one 
among many examples examined by Charles Deville and Leblanc (Ann. de Ch. et 
Phys [3] lii. pp. 5-63), a /?/w^r<?//^ of Vesuvius yielded in June, 1856, a mixture of 
highly heated steam, hydrochloric acid, sulphurous acid and air containing 18.7 
per cent, of oxygen. The sulphurous acid was equal to 2.6 per cent, of the air, 
and the amount of hydrochloric acid was about five times as great. Traces of 
sulphuric acid were found in the water condensed from this steam, doubtless 
formed by the slow combination of the sulphurous acid and oxygen ; and I may 
state for the information of Mr. Forbes, that it was doubtless by a similar reaction 
that the sulphurous acid became eliminated from the primeval atmosphere. We 
have here, I may remark, an illustration of the fact upon which I have elsewhere 
insisted, that volcanoes reproduce, on a limited scale, the conditions of the primeval 
earth, not only in their solid but in their gaseous products. 

Mr. Forbes next asserts that, according to my view, "the hydrochloric acid 
primeval atmosphere was derived from the mutual re-actions of sea-salt, silica, and 
in the water" (page 438), and then charges me with the folly of "supposing the 
pre-existence of compound bodies in a case where he had previously informed us 
that there were only dissociated elements engaged." Mr. Forbes knows better 
than this, or at least did know better when he wrote his criticism on my lecture in 
the Chemical News of Oct. 4, for he here quotes my own words, when, in describ- 
ing the cooling globe, the conditions through which it must have passed, and the 
affinities brought into play, I say the products must have been '•^ just what would 
now result if the solid land, sea, and air 7vere made to react upon each other tender 
the influence of intense heat.'''' It is so difiicult to characterise properly such a wilful 
perversion of an author's words that I must leave the task to my readers. What 
follows in Mr. Forbes's paper as to chlorids, etc., I have already discussed and 
disposed of. The theoiy of the constitution of the solid globe next put forward by 
Mr. Forbes, borrowed from Phillips, Durocher, and Von Waltershausen, is also, as 
I conceive, met by the argument in the previous pages. When, however, he comes 
to the atmosphere surrounding his primitive globe, Mr. Forbes puts forward a 
scheme which is strikingly original. He supposes around the "solidified crust," a 
dense vapour consisting chiefly of chlorid of sodium, "above this a stratum of 
carbonic acid gas, and then of water in the form of steam, whilst the oxygen and 
nitrogen would be elevated still higher" (p. 439), probably, also, separated in the 



Dr. T. Sterry Hunt — On Chemical Geology, 53 

order of their densities. In explanation of this order, he tells us in a note that the 
zone of carbonic acid gas would be heavier than that of steam, and should, there- 
fore, come below it. But he forgot that oxygen and nitrogen (or atmospheric air) 
are also both heavier than steam, and should, consequently, ho. placed below the 
zone of watery vapor. The specific gravities of carbonic acid and steam are re- 
spectively 1.525 and 0.624, air being i.ooo. But, apart from this absurd niistake, 
what shall be said to a man who ignores completely the laws of the diffusion 
of gases? Will Mr. Forbes kindly explain why, in our present atmosphere, the 
same elements, namely, oxygen, nitrogen, carbonic acid gas and watery vapour, are 
commingled, instead of being, as he would have them, arranged in separate zones? 

I have said in my lecture that the first ocean waters would hold in solution salts 
of alumina and the heavy metals, all of which would be precipitated before the 
separation of carbonate of lime commenced, in such events, says Mr. Forbes, 
''* geologists, though as yet unsuccessful in doing so, might still hope to find beds 0/ 
alumina or of the metallic oxyds or carbonates alluded tOj in the older strata. As 
no beds of such character are known to occur in nature^ he regards my view with 
distrust. Known to Mr. Forbes ! Has he never heard of beds of emery, which 
are chiefly crystalline alumina, and which occur in the crystalline limestones of 
Asia Minor, and in the old crystalline schists of New England? Is he ignorant 
that the beds of bauxite, so abundant in the Mediterranean basin, and used in the 
manufacture of aluminium, consist chiefly of hydrated alumina ? To console Mr. 
Forbes, however, I will say that I believe these beds of emery and of bauxite to 
have been formed by secondary and subsequent reactions, and that we have no- 
where exposed to view the first-deposited beds, which are everywhere destroyed or 
buried under more recent strata. When he remembers that the oldest known 
series of rocks, the Lauren tian, consists of quartzites, limestones, and gneiss, 
evidently of sedimentary origin, and derived from still older sedimentary rocks, he 
will understand why he cannot hope to discover the first deposits of alumina or 
metallic oxyds. These, however, in most cases, have doubtless, by mechanical 
sub-division, or by solution, been subsequently diffused, and enter into the com- 
position of later rocks. 

In a note to this paragraph, Mr. Forbes inquires what became of the sulphurous 
acid of the early atmosphere : as I have already told him, it doubtless became 
changed into sulphuric acid and passed into the sea. He then says, "it may 
safely be asserted that there is fully as much (if not more) sulphur than chlorine" 
in nature, and that according to my hypothesis the sea would become a solution 
of sulphate of soda. Very safely asserted indeed, since Mr, Forbes takes care to 
tell us that the sulphur in the form of dense metallic sulphids went to the centre of 
the earth, which I have shown, I think, good reasons for not believing. As it is, 
we have only to consider the quantities of sulphids and sulphates in the rocks and 
waters to see the absurdity of his remarks. 

He next proceeds to discuss the theory of the origin of carbonate of lime. I have 
said that with the exception that derived from the subaerial decomposition of 
primitive calcareous silicates, all the carbonate of lime of the earth's surface has 
been formed from the decomposition of the soluble lime-salts of the sea, by car- 
bonate of soda (and other soluble carbonates). I, moreover, lay down the propo- 
sition that "animals can only appropriate the carbonate of lime already formed." 
In the face of these quotations, cited by Mr. Forbes, he says, as if charging me 
with holding the view, that if limestones were "formed by precipitation, they 
would have, from the moment of their deposition, a decided crystalline structure," 
while " Sorby's microscopical researches prove satisfactorily that all limestones, 
from the most ancient up to the most recent, ^xe solely foi^med of the debris of organ- 
isms ;" this will probably be surprising news for Mr. Sorby, and a decisive blow for 
those who question the organic nature of Eozoon. I am prepared to go as far as any 
reasonable man in asserting the organic origin of limestones, and have, as every 
one must see, implied the intervention of organic life, when I say "animals appro- 
priate the carbonate of lime, etc." The question is, however, whence comes the 
carbonate of lime to supply the wants of these animals ? Mr. Forbes delares that 
"zoologists beheve that marine animals can utihze the other salts of lime existing 
in the ocean," evidently the sulphate or the chlorid of calcium once so abundant 
there. Will Mr. Forbes or the zoologists explain what has become of the acids 
once combined with the lime which has built up the thousands of feet of limestone 



54 Dr. T. Sterry Hunt — On Chemical Geology. 

chiefly fossilferous, which are found in the earth's crust ? The only plausible 
chemical explanation is that which I have given, namely — that the chlorid of cal- 
cium has been decomposed by carbonate of soda derived from decaying feld spathic 
rocks, giving rise thereby to common salt and to the carbonate of lime which has 
supplied the marine animals. 

As regards the question on the origin of dolomites, which Mr. Forbes next pro- 
ceeds to notice, he will do well to consult my paper on the subject in the American 
Journal of Science for July, 1866 ( [2] xlii. 49). In this, at §112, he will see that, 
apart from the formation of stratified sedimentary dolomites, I insist upon the fre- 
quent occurrence of dolomite as a mineral of secondary deposition, lining drusy 
cavities, filling veins, and even the moulds of fossil shells. To such cases the 
observations of Sorby may possibly refer. I can find no other account of his re- 
searches than the brief note in the Proc. of the Brit. Assoc, for 1856, cited by Mr. 
Forbes. Although I have a great respect for Mr. Sorby as an investigator, I have 
very little for the old theoiy of dolomitization of sedimentary limestones. No one 
who has carefully studied, as I have done for years, the distribution and association 
of the great beds of dolomite which occur in the Lower Silurian rocks of Canada 
and New England, can for a moment admit that these are the products of subse- 
quent alteration. Repeated alternation of pure blue limestones with reddish 
ferruginous dolomites, interrupted beds and patches of these enclosed in the 
former, the line of demarcation sharply drawn, and finally conglomerates in which 
pebbles of pure limestone are enclosed in beds of dolomite, are incontrovertible 
evidences against the theory of the dolomitization of limestones, and in favour of the 
deposition of dolomites as magnesian sediments. (Geol. of Canada, 1863, p. 612). 
Mr. Forbes, in a note, insinuates that I am unaware of the various speculations 
and theories which have been put forward to explain the supposed origm of dolo- 
mite by alteration. Although the stratigraphical relations of dolomite, as described 
above, completely contradict this hypothesis of its origin, at least in the great 
majority of cases, Mr. Forbes will find that the observations and speculations of 
Haidinger, Von Morlot, Marignac, and others, on this subject have been fully dis- 
cussed and made the subject of multiplied experiments by me in a memoir published 
in 1859 {Amer. Journ. Science, [2] xxviii. 170, 365), and later in the paper quoted 
above, and that I have shown by many experiments that the action of sulphate of 
magnesia on carbonate of lime, alluded to by Haidinger and Von Morlot before 
Harkness or Regnault, does not give rise to dolomite, but to carbonate of magnesia, 
which remains mechanically intermingled with sulphate of lime and any excess of 
carbonate of lime. 

Mr. Forbes says that some of the results of my prolonged study of certain of the 
salts of lime and magnesia, which are, for the most part, set forth in the papers 
just referred to, were considered by me to be worthy of being presented to the French 
Academy {Comptes Rendus, April 22, 1867) although he declares the reactions 
therein described, to have been for more than twenty years in general application, 
on a large scale in Great Britain for the manufacture of magnesia salts. Here it 
becomes difficult to admit the plea of ignorance which suggests itself for most of 
Mr. Forbes previous errors and mis-statements. I have, in the note to the French 
Academy, above referred to, pointed out the following facts, discovered by my in- 
vestigations of the salts of hme and magnesia : — 1st. That bi-carbonate of lime, at 
ordinary temperatures, decomposes solutions of sulphate of soda and sulphate of 
magnesia, with formation of sulphate of lime and bi-carbonates. 2nd. That from 
mingled solutions of sulphate of magnesia and bi-carbonate of lime, there separates 
by evaporation, crystalline gypsum, and, subsequently, a hydrous carbonate of 
magnesia ; the bi-carbonate of this base being, as is well known, very much more 
soluble than either the sulphate or the bi-carbonate of lime. 3rd. That this sepa- 
ration of gypsum is favoured and rendered more complete by an atmosphere 
impregnated with carbonic acid gas ; and 4th, that mixtures, in due proportions, 
of precipitated carbonate of lime and hydrous carbonate of magnesia, when gently 
heated under pressure, and in the presence of water, unite to form the anhydrous 
double carbonate, dolomite. These are the reactions which I described to the 
French Academy as new, and as forming the basis of a reasonable theory of the 
origin of gypsums and of dolomites. I now demand Mr. Forbes to make good 
his bold assertions to the contrary, or to show that any one of them has been 
employed for the last twenty years in the manufacture of magnesian salts. 



Dr. T. Sterry Hunt — On Chemical Geology. 55 

Mr. Forbes then proceeds to inform us that "the grand development of magne- 
sian limestones, dolomites, and gypseous beds, really took place in an epoch when 
numerous air-breathing animals, both vertebrates and invertebrates, lived upon the 
face of the globe." Is Mr. Forbes aware that a large proportion of the 4750 feet 
of limestone measured by Sir William Logan in Canada, and constituting the three 
great limestone formations of the old Laurentian system, is magnesian, and often, 
through great thicknesses, a pure dolomite ; that a large part of the Lower Silurian 
system, and nearly the whole of the Upper Silurian, from the St. Lawrence to the 
Mississippi, consists of dolomite, and embraces great gypsum beds ; and, finally, 
that immense gypsum deposits, found at intervals from Nova Scotia to the Ohio, 
lie at the base of the Carboniferous system, in which latter only are found \k\^ first 
remains of air-breathing vertebrates ? It is dangerous to generalize from the geology 
of the British Islands, or of a small part of Europe. Moreover, will Mr. Forbes 
attempt to demonstrate that at the time when Tertiary gypsums were deposited in 
the Paris basin, there did not yet remain sufficient carbonic acid in the air to modify 
its chemical action on solutions of bi- carbon ate of magnesia, and give rise to the 
associated dolomites, which I was the first to discover and to describe in that 
position ? 

We now, in the language of Mr. Forbes, approach the question of "the igneous 
origin of eruptive rocks and of granite in particular." I asserted in my lecture the 
non-igneous origin of granite, maintaining that "the composition of the fused crust 
would have excluded free silica," and "that granite is in every case a rock of 
sedimentary origin, as it includes in its composition quartz, which, so far as we 
know, can only be generated by aqueous agencies, and at comparatively low 
temperatures. " With regard to the first of these statements, it is to be observed 
that the primitive crust, holding, as we have seen, in the form of silicates, all the 
soda, lime, and magnesia which now appear in other combinations, must have 
been a highly basic rock ; moreover, even were it much richer in silica than we 
can suppose it to have been, there is no reason to believe that free silica, in the 
form of quartz, ever did or ever could crystallize from a fused slag, such as this 
primitive rock must have been. Quartz, in the shape of rock-crystal, or flint, when 
fused, or even when long exposed to a heat much below its meltmg point, is 
changed into an isomeric modification of silica, analogous to, if not identical with 
opal, and distinguished from quartz by a much less specific gravity (about 2*2 
instead of 2 "65), the absence of crystalline structure, and a much greater solubility 
in alkalies, and hydrofluoric acid. Silica crystallized in the form of quartz has, 
it is true, been repeatedly obtained by different reactions, but never hitherto 
except in the presence of heated water or of watery vapour. Heinrich Rose, to 
whom we are indebted for a careful study of this subject, records, that Gustaf 
Rose, having submitted to partial fusion a granite rich in quartz, obtained a glass, 
or obsidian, in which were enclosed unmelted portions of the quartz, converted, 
however, into the less dense and more soluble opal-like form. These facts in the 
history of silica were regarded by H. Rose as decisive against the notion of the 
igneous origin of granite, which he concludes to be incompatible with the actual 
state of our chemical knowledge. His paper on this subject, which should be read 
by every geologist, appeared in Poggendorf's Anitalen for September, 1859, and a 
careful abstract of it will be found in the L. E. and D. Philos. Mag. for January, 
i860 [4] xix. 32), The new view of the origin of granite, which is there cited, as 
maintained " particularly by Mr. Sterry Hunt," is, that all granite rocks are derived 
from the alteration of sediments, containing, besides feldspathic or argillaceous 
elements, quartz, derived, as I have explained, from the action of acid solutions 
at high temperatures on the primitive crust of silicates. 

The geological evidences are multiplied, that gneiss, which does not differ 
mineralogically from granite, and in its coarser varieties is constantly confounded 
with it, is the result of the alteration in sitit of sedimentary rocks consisting of 
quartz with feldspathic or argillaceous matters, the debris of pre-existing rocks. 
Moreover, it is demonstrable that these stratified sediments have been softened, 
and while in such a condition displaced or extravasated, and have thus taken the 
form of exotic or eruptive rocks. Having by this or other means lost the mechanical 
evidences of their former stratified condition, they are called granites. The same 
view is, according to me, applicable to dolerites, diorites, and trachytes. Modern 
lavas have no other origin, but take a different form, because they come to the sur- 



56 Dr. T. Sterry Hunt — On Chemical Geology, 

face, and are rapidly cooled, instead of being slowly solidified under the pressure 
of superincumbent strata. The fact that every eruptive or exotic rock (with the 
exception of certain rapidly cooled lavas) has its mineralogical equivalent among 
indigenous crystalline rocks, that is to say among sedimentary strata of chemical 
or mechanical origin, is a powerful argument in support of the view here put for- 
ward. In connection with this, I have shown that a combination of chemical and 
mechanical agencies naturally and inevitably leads to the division of aqueous sedi- 
ments into the two great types to which lithologists refer all eruptive rocks, namely, 
the acid, granitic or trachytic and the basic, doleritic groups, which are supposed 
to form the two zones of igneous rock imagined by Phillips, and since insisted upon 
by Durocher, Bunsen, and Forbes. As all of these crystalline rocks are, according 
to my hypothesis, ancient sediments, it follows that water has been present among 
them from their first deposition, and during all the subsequent processes of their 
heating, softening, crystallization, and ejection, — a view constantly insisted upon by 
me, and in accordance with the ideas maintained by Scheerer and subsequently by 
Sorby. This theory of igneous rocks, although suggested by Keferstein in 1834, 
and by Sir J. F. W. Herschel in 1837, has been elaborated by me in various papers 
for the past ten years. 

See Theory of Igneous Rocks and Volcanos, Canadian Journal^ March, 1858 ; 
Some Points in Chemical Geology, Quart. Journ. Geol. Soc.^ Nov. 1859 ; Chemistry 
of the Earth, Cojuptes Rendiis,]\xne gth, 1862; Chemistry of Metamorphic Rocks, 
Diiblm Quatt. Journ.^ July, 1863 ; Contributions to Lithology, Part i, American 
Journ. Science^ March, 1864. 

In view, then, of my theory of the derived and sedimentary origin of all eruptive 
rocks, what does Mr. Forbes mean when he inquires whether I am aware of the 
immense masses "of volcanic rocks (trachytes) scattered all over the face of the 
globe, which contain abundance of free quartz" ? If he will refer to my Contribu- 
tions to Lithology, just cited, he will find that I have insisted upon the presence 
of quartz in trachytes, and also upon the fact that such trachytes pass into granites, 
from which they differ only in structure {American yoiirn. Science [2] xxxvii. 260). 
The obvious conclusion to be drawn from the presence of quartz in granites and 
trachytes is, that neither during nor subsequent to crystallization have these rocks 
been subjected to a temperature sufficiently elevated to alter the quartz in the 
manner observed by Rose. In the paper last cited, I have devoted two pages to 
an analysis of the beautiful researches of Sorby on the microscopic structure of 
crystals, about which Mr. Forbes talks, though evidently without any conception 
of their geological bearing. Mr. Sorby, (who makes of the cavities partially filled 
with watery solutions, which occur in many crystals, thermometers which registered 
the temperature at which these crystals were formed,) concludes that the quartz, 
mica, feldspar, and tin-stone of the Cornish veins "were deposited from water 
holding various salts and acids, at temperatures varying from 200" centigrade to a 
low red heat," about 340° ; while, for some minerals from Vesuvius, which present, 
besides cavities holding liquids, others filled with stony and glassy matters, he 
deduces a temperature of from 360° to 380°, and concludes them to have been 
formed "at a dull red heat, under a pressure of several thousand feet of rock, 
when water, containing a large quantity of alkaline salts in solution, was present, 
along with melted rock and various gases and vapors. I therefore think," he says, 
" we must conclude provisionally, that at a great depth from the surface, at the foci 
of volcanic activity, liquid water is present along with the melted rocks, and that 
it produces results which would not otherwise occur." {Quart. Journ. Geol. Soc. 
xiv. 483). One of those results, as is evident from the above citation, is the reduc- 
ing of rocky matters to a melted condition at a dtdl red heat, a point to be borne in 
mind when Mr. Sorby speaks in his paper of igneous fusion in this connection. A 
true igneous fusion of such matters, zuitkout water, would, as every one knows, 
require a vastly higher temperature ; and I have elsewhere, after Scheerer, described 
this softening of mineral matters under the combined influences of water and heat, 
as an igneous fusion. 

Mr. Sorby has, moreover, calculated the temperature at which the quartz crystals 
in the trachyte of the Ponza Islands, cited by Forbes, were formed, and finds it to 
be 360°, they being, in fact, generated under like conditions with those of the 
quartz of granite veins, from which Mr. Sorby rightly concludes to a similarity of 
origin between trachytes and granites. That both have crystallized at temperatures 



Dr, T, Sterry Hunt — On Chemical Geology, 57 

not above dull redness, under great pressure, and in the presence of water, is pre- 
cisely what I have always maintained. When it is remembered that copper, gold, 
and silver require for fusion from 1000° to 1400", and quartz a temperature of 
2800°, it may not be thought incorrect for me to designate 360'', the highest 
assigned by Mr. Sorby for the crystaUization of quartz, as a "comparatively low 
temperature," to which expression, however, Mr. Forbes takes exception. Mr. 
Sorby further concludes from his investigations of crystalline metamorphic schists, 
that they must have crystallized at about the same temperature as the granites, 
affording, in his words, "a strong argument in favour of the supposition that the 
temperature concerned in the normal metamorphism of gneissoid rocks, was due to 
their having been at a sufficiently great depth under superincumbent strata." 

The reader may now judge how far the views of Mr. Sorby, whom Mr. Forbes 
invokes, differ from my own on the subject of metamorphic rocks, of which I say 
in my lecture, as quoted by Mr. Forbes, that they have been formed from ordinary 
sedimentary strata, " depressed so that they come within the action of the earth's 
central heat," a proposition which our critic thinks "may be disputed." What 
theory he substitutes, he does not deign to inform us, but proceeds to ask how I 
explain the depression of strata on the surface of a globe with a solid centre. 
Both in my lecture and in the papers already cited, I have taken pains to explain 
that the deeply buried layers of sediment, together with the superficial and water- 
impregnated portions of the solid nucleus, constitute a softened or plastic zone, 
from which all plutonic and volcanic rocks proceed, and which allows of the move- 
ments observed in the solid crust. Is Mr. Forbes aware that geology affords 
many examples of depression of the earth's surface over great areas, permitting 
accumulations of sediments, to the extent of 40,000 feet or more, followed by ele- 
vation of the yielding crust and denudation to as great an amount ? 

I here take occasion to call attention to an important consideration in connection 
with this, deducible from Mr. Sorby's admirable Bakerian lecture before the Royal 
Society, in 1863, on the Direct Correlation of Mechanical and Chemical Forces, 
in which he shows how chemical action is produced by mechanical force. Stating 
from a consideration of the results of Bunsen and Hopkins that those bodies which 
expand when fused have their point of fusion raised by mechanical pressure, and 
from the discovery of Sir Wm. Thompson tl^at water, which contracts in melting, 
has, on the contrary, its melting point lowered by pi-essure, we may say that as the 
solution of a solid in a liquid is a kind of fusion, the same general law will hold 
good, and that, for all those salts which contract in dissolving (to which rule there 
are very few exceptions), the solubility should be increased by pressure. This was 
abundantly established by the experiments of Mr. Sorby. If, now, we suppose 
that the mineral compounds of the crystalline rocks, like most salts, occupy a less 
bulk when dissolved that when in the solid state, we can understand the greatly in- 
creased solvent power of the water present in sediments submitted to a pressure 
equal to many thousand feet of rock. Moreover, as suggested to me by Sir Wm, 
Logan, the diminution of solvent power of the liquid as the pressure is removed, 
will help to explain the deposition of mineral matters from watery solutions, which 
in their upward flow through fissures in the earth's crust have given rise to mineral 
veins. 

But Mr. Forbes, after considering the conclusion of Sorby that water has played 
an essential part in the crystallization and softening of rocks, which have been 
effected at temperatures not above low redness, charges me with "sensation" 
writing in asserting that the plutonists claimed that igneous rocks were formed 
"entirely by fire," and accuses me of injustice to the memories of Hutton, Play- 
fair, Hall, Humboldt, and Von Buch, whose writings "show that they never 
overlooked the all-important influence of water." Now I mentioned none of these 
geologists in my lecture. As to Hutton, to whom belongs, I believe, the idea of 
the metamorphic origin of the crystalline schists, I have elsewhere written (Dublin 
Quart. Joiitn., July, 1 863), " I accept in the widest sense the view of Hutton and 
Boue that all the crystalline stratified rocks have been produced by the alteration 
of mechanical and chemical sediments." The question before us is, however, 
neither the views of Hutton nor yet the origin of metamorphic rocks, but what 
both he and modern plutonists hold with regard to the origin of granite, whose 
derivation from metamorphosed sediments neither he nor they admit. With regard 
to this point Mr. Forbes elegantly says, " the idea of dry fusion could only have 



58 Dr. T, Sterry Emit — On Chemical Geology, 

originated in the brains of their antagonists. " Farther, in a note to a paper on the 
Microscope in Geology, in the Popular Science Review for October, he says, with 
equal good taste and truth, *' the idea of a true dry fusion in nature exists only in 
the brains of the ultra-neptunists or the luke-warm hydrothermalist," and asserts 
that in igneous action the agency of water was always recognized. He alludes to 
Poulett Scrope, who in 1824 put forth his views on the intervention of water in 
giving liquidity to lavas ; but as Mr. Scrope himself tells us in his late paper 
{Quart. Journ. Geol. Soc. xii. 343), his views were declared to be unchemical, 
discredited, and ridiculed ; nor was it till in 1847, when Scheerer published his 
remarkable essay on the origin of granites, {BuL Geol. Soc. Fr. [2] iv. 468, ) that 
lithologists began to admit that water had intervened in the generation of granite 
and other eruptive rocks. But our readers shall judge what value is to be attached 
to Mr. Forbes's assertions in this matter. After Scheerer's view of aqueo-igneous 
liquidity had been made known to the Geological Society of France, Durocher, as 
the champion of the plutonists, maintained in opposition to it, the hypothesis 
already referred to of a separation of the liquid globe into two layers, the lower 
one heavier and basic, the upper lighter and acid, which by its solidification 
gave rise to granite. While he declared that ^^ Scheerer's new theory has for its 
principle the introduction of water in the solidification of granite rocks," Durocher 
conceived all the water found in eruptive rocks to have been subsequently 
absorbed by them {Bui. Soc. Geol. [2] iv, 1029, 1032). Riviere, following a second 
communication by Durocher on the same subject, declares, "I think with 
Durocher, that water has played no part (ji'a joue aucmi rSle) in the fo7mation of 
granite,'''' and as to the rocks considered by Scheerer (granites, etc.), he asserts " the 
geological position of these absolutely excludes the intervention^'' of water (Ibid. [2] 
vii. 287). I might further quote Fournet, who in his Geologic Lyonnaise, strongly 
maintains similar views to the above, and invokes in favour of his purely igneous 
theory the results and the statements of Hutton and Hall, Lest, however, there 
should be any mistake, and that the advocates of dry fusion, Durocher, Eiviere, 
and Fournet, be, after all, ultra-neptunists, I shall cite Elie de Beaumont, who in 
his classic essay on Volcanic Emanations, etc., (published in 1847,) Bid. Geol. 
Soc. Fr. [2] iv. 1249, has admirably discussed the question before us, giving the 
views of Fournet and Durocher, the former of whom explains the liquidity of granite 
by a surfusion of the quartz, which melts at 2800° centigrade, but remains viscid at 
much lower temperatures on cooling ; while Durocher, on the contrary, imagines 
"a sort of fusible alloy" of the various elements, from which the feldspar and mica 
crystallized. Eejecting these, which he designates 7i& '"'' purely igneous surfusion,'''' 
he declares in favour of Scheerer's '■''altogether novel idea" of a condition of quasi- 
fluidity at a low red heat, due to the intervention of water, and asserts that *' the 
hypothesis of a primitive state of simple igneous fusion of granite, notwithstanding 
the evidences brought forward in its favour, is no longer justified" {loc. cit. pp, 
1305, 1311)- It is in the face of records like these, and despite the energetic pro- 
test of plutonists against the possibility of the intervention of water, and in favour 
of a dry fusion or a simply igneous fusion of the elements of granite, that Mr. 
Forbes has the hardihood to assert that the intervention of water in igneous agency 
"was always recognized by the plutonist." 

But I have not done with Mr. Forbes until he shall have shown how, with his 
own theory of the earth, he explains the intervention of water in all igneous 
rocks, which, as he declares, are outbursts from the still fluid interior of our globe. 
How did the water find its way there, since, according to him, far above the 
already solidified crust, this element at first formed a vaporous layer, separated 
from the earth by a stratum of volatile chlorids and another of carbonic acid gas ? 
In virtue of what law did this water, after its precipitation, diffuse itself through- 
out the various layers of the liquid mass which still fills the centre of the earth, so 
as to be present in every eruptive rock coming up from that great reservoir ? For 
my part, I am inclined to say with Riviere, that the geological position of such 
matters must "absolutely exclude the intervention of water;" and until Mr, 
Forbes, or some other plutonist, shall have given a plausible hypothesis to explain 
the fact, which he admits, of the universal diffusion of water in igneous rocks, I 
prefer my own theory of their origin, namely, that the anhydrous and incandes- 
cent nucleus of the globe is solid, and, except in its outer portions, takes no part 
in volcanic or plutonic phenomena, which have their origin entirely in the stratified 



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E. Billings — New Species of Stricklandinia, 59 

sedimentary deposits, and in those superficial portions of the nucleus which were 
necessarily permeated, during their partial cooling and consequent contraction, by 
the superincumbent waters. 

One word in conclusion : Mr. Forbes, who prides himself on his great oppor- 
tunities of travel, and on his geological studies in various regions, discourteously 
taunts me with my own more limited field of investigation. Let me tell him in 
reply, that if the three papers which he published in October last show any one 
thing more clearly than his unfamiliarity with geological literature, it is his 
ignorance of the facts of geognosy, and that he involuntarily recalls to mind the 
wise saying of Thomas a Kempis, passed into a proverb among churchmen, — 
"those who make many pilgrimages rarely become saints." 
Montreal^ December, 1867. 



II. — Description of two new species of Stricklandinia. 
By E. Billings, F.G.S., PalsGontologist to the Geological Survey of Canada. 

(PLATE IV.) 

IN the " Canadian Naturalist and Geologist," vol. iv. p. 134, 
figs. 8-9 (1859), I figured a small specimen of a species of 
Stricklandinia under tlie name of S. lens ; but, at the same time, 
stated that I was not certain whether it was the true S. lens or a 
variety. It was more pointed in front than any of the English 
specimens I had seen. It had been collected in the Middle Silurian 
rocks on the Island of Anticosti, along with numerous other speci- 
mens, most of them in a fragmentary condition. Among these I 
thought that S. lirata could also be identified ; and thus both of the 
British species have been cited in several of the publications of our 
Survey. 

Through the kindness of the author I received, several months' 
ago, "Part 2" of Mr. Davidson's ''Monograph of the British 
Silurian Brachiopoda." The clear descriptions and beautiful illus- 
trations of this magnificent work at once enabled me to perceive 
that we have not (so far as is yet known) either of the two species 
above mentioned. What I supposed to be S. lirata, is the adult of 
the form figured by me as S. lens. The young and small individuals 
are smooth ; but with increasing size and age they become more and 
more strongly ribbed. 

While re-examining the whole collection, with a view to this 
paper, I broke up several pieces of limestone, which were almost 
entirely composed of the imperfect and detached valves of another 
species, and succeeded in getting out several specimens, sufficiently 
perfect to authorize a description. We have thus two new species ; 
and, as the error with regard to S. lirata and S. lens has been 
transferred from my publications into several important English 
works, it is thought advisable to describe them in the Geological 
Magazine at once, without waiting for my next report, which cannot 
be issued for several months. 

StricMandinia JDavidsonii, sp. n. — Plate IV. Figs. 1-ld. 

Spec. Char. — Shell longitudinally ovate ; sides and cardinal extremity rounded ; 
iront usually with a linguiform extension about one-third of the whole width, and of 
variable length, sometimes simply narrowed from the mid-length to a rounded point ; 
greatest width about the middle, or a little above. The valves are almost equally 



60 E. Billings — New Species of Stricklandinia, 

convex. The ventral valve has, in young individuals, an ohscure mesial sinus, which 
becomes obsolete with age ; towards the front this sinus often gives place to a well- 
developed fold. Some of the large individuals have neither fold nor sinus in this 
valve. The dorsal valve usually exhibits a fold, which becomes gradually broader 
from the beak to the front, where its width is equal to that of the tongue-like 
projection. The umbones and beaks are so slightly developed as to give only a very 
moderate angulation to the cardinal extremity. The hinge-line is about one-third 
or one-fourth of the whole width, and the areas are, in general, concealed by the 
close approximation of the beaks when the valves are in place; but in separated 
valves the ventral area is well seen : that of the dorsal valve is linear. In the 
interior of the ventral valve the mesial septum extends only four lines from the beak 
in a specimen thirty lines in length ; the triangular chamber is apparently two lines 
in length. In the dorsal valve the socket plates are very short, and not united : they 
have, as yet, only been seen by grinding down the beak. The small specimens are 
smooth, or only exhibit faint indications of ribs ; but as the shell increases in size 
the ribs become stronger, although in some of the larger (as in the one figured) they 
are not very distinct. In general there are three or four ribs running straight from 
the beak to the front ; but on each side of these they curve outwards to the sides. 
The ribs are rounded, and there are from tbree to five in the width of three lines at 
the margin. There are also fine concentric wrinkles, not, however, always visible. 

Length of large individuals, three inches ; width, varying from nearly equal to 
one-fifth less than the length. They occur of all sizes from a length of three- 
fourths of an inch to three inches. 

Ohs. — StricMandinia Davidsonii differs from S. lens, in being more 
narrowed in front, more strongly ribbed, and in having the area 
concealed when the two valves are in their natural position. Not- 
withstanding the variable form of the shell, there are none, in a 
collection of nearly a hundred specimens, that could be considered 
specifically identical with any of those figured by Mr. Davidson in 
the " Monograph," pi. xix. figs. 14:-21. But there is a dorsal valve 
from the Niagara limestone of Cabot's Head, Lake Huron, exceedingly 
like fig. 13. It is, however, quite distinct from S. Davidsonii, and I 
think from S. lens also. 

As before stated the large individuals often have the ribs strongly 
developed, and curved out to the sides. They thus closely resemble 
the figure of S. lirata in " Sil. Syst.," pi. xxii, fig. 6. Indeed, I 
could very nearly re-produce that figure from some of our broken 
specimens. It is these that I thought could be identified with 
S. lirata. The small smooth ones I supposed to be S. lens ; but, 
after seeing Mr. Davidson's figures, I re-examined the whole col- 
lection, and found that there is a gradual passage from the smooth 
to the strongly ribbed. The specimen figured (figs. 1-1 c) is about 
as perfect as a fossil can be, and is a good example of an intermediate 
form. 

Position and locality. — This species occurs at a number of localities 
around the coast of the Island of Anticosti, from Jupiter river to 
East Point. It is most abimdant at South-west Point, where the 
specimen figured was collected. It is associated with Strophomena 
rhomhoidalis, S. pecten, S. antiquata, Leptcena transversalis, Orthis 
Davidsoni, Pentamerus ohlongus, Spirifera plicatella, Leptocoelia 
{Airy pa) hemispherica, Atrypa reticularis, and many others, mostly 
new species. The rocks belong to the Anticosti group, division 3, 
a horizon which is very nearly, if not exactly, that of the Upper 
Llandovery rocks. It also abounds on the mainland at the Schick- 



E. Billings — New Species of Stricklandinia, 61 

schock mountains, on the south side of the St. Lawrence, about 250 
miles easterly from Quebec. I have never seen a specimen from 
any other part of America. 

Stricklandinia Salterii, sp. n. — Plate IV. Figs. 2-2a. 

Spec. Char. — Shell transversely ovcal ; width greater than the length ; sides and 
front usually rounded, but often with an obscure linguiform extension. Hinge-line 
nearly as wide as the shell, straight and a little sloping on each side of the beaks. 
Both valves are gently and uniformly convex. The ventral valve has often a barely 
perceptible mesial sinus ; the umbo small ; the beak not incurved ; the area very 
narrow, scarcely exceeding the thickness of the shell ; the foramen (as seen in 
detached fragments) triangular and open to the beak ; the small chamber at the beak 
almost exactly like that of S. loevis, and S. microcameriis, as figured by Sowerby, 
M'Coy, and Davidson. The dorsal valve sometimes gives indications of an obscure 
mesial fold ; but, in general, it is uniformly convex. I have not seen the area of 
this valve, but it must be linear ; there is no umbo. Surface with several concentric 
imbrications of growth, and with very narrow obscure ribs, three or four in twt) 
lines, curving outwards to the sides, and some of them upwards to the hinge-line. 
These are also crossed by fine concentric wrinkles. "When the specimens are 
slightly exfoliated all the surface-characters disappear. 

Length of the largest specimen seen, twenty-five lines ; greatest width of the 
same, at about the mid-length, thirty-three lines. Some of the specimens indicate a 
greater proportional length. 

Ohs. — There is no other known species with which this need be 
compared except S. Icevis, Sowerby, as described by M'Coy, under 
the name of Pentamerus microcamerus (Brit. Pal. Foss., p. 210). 
The width of that species, in proportion to the length, is stated to 
be as fifty-five is to one hundred, whereas in this it is, on an average, 
about eighty to one hundred. This great difi'erence in proportions 
rarely occurs in the same species. Messrs. Davidson and Salter are 
of opinion that McCoy's P. microcamerus is identical with S. lens. 
Be that as it may, the figure of S. Icevis, given by Sowerby in 
*' Sil. Syst.," pi. xxi. fig. 21, seems to be distinct from ^S. lens, and 
also from S. Salterii. He says {Op cit., p. 638), "Semicircular, 
compressed, smooth ; a slight elevation along the middle ; beaks 
rather prominent, the area between them narrow, with parallel 
edges. Length, eight lines ; width, twice as much." The words 
" elevation along the middle " could only apply to the dorsal valves 
of S. lens and S. Imvis, in neither of which can the dorsal foramen 
be seen, when viewed in the position in which Sowerby's specimen 
is drawn, as it is in the figure cited. This figure, however, always 
appears to me to exhibit a sinus rather than a fold, in which case it 
would be a ventral valve. Judging from Mr. Davidson's figures, I 
should say that the upper part of the ventral valve of S. lens must 
be of a very different form from that of the specimen represented 
by Sowerby. 

Position and locality. — Stricklandinia Salterii occurs at Heath 
Point and Cormorant Point, Anticosti, in the Anticosti group, 
division 3 = to the Upper Llandovery rocks. 

Besides these two species there is a form with the ribs straio-ht, 
which may possibly be a variety of S. Davidsonii. It occurs at 
Anticosti in the same beds with the others. 

In describing Stricklandinia 1 unfortunately stated that '' This 
genus includes three English species, which have been long known 



62 Dr. Peters — On the Geology of the Dobrudscha. 

under the names of Pentamerus lens, P. liratus, and P. Icevis.^^ I was 
aware that the P. Icevis of J. Sowerby was the young of P. ohlongus, 
and supposed that the name had become obsolete as to its first 
application. In that case Spirifera ? Icsvis, J. de G. Sowerby, which 
was a true Pentamerus, as the genus was then understood, became 
P. Icevis. That this is the one I had in view may be seen by the 
remark quoted from my Pal. Foss., p. 84, by Mr. Davidson in his 
*' Monograph," p. 158. The sentence is irregular ; but it was in- 
tended to read thus, " The hinge-line in some of the species, such as 
in S. Icevis and S. microcamerus, is straight and much extended."^ 
This could not possibly apply to the original P. Icevis, which has no 
hinge-line at all ; but it does apply to the figure of Spirifera ? Icevis 
above cited. There is not the slightest trace of any of the generic 
characters of StricMandinia in J. Sowerby's figure of P. Icevis, and 
it is impossible that I could have intended to include it in my genus. 
Several years before I proposed StricMandinia I was under the 
impression that P. Icsvis was the young of P. ohlongus from com- 
paring our own specimens, one of which I have figured (Fig. 3) ; 
and in 1858 I was informed, I think by Mr. Salter, that it was so 
regarded in England. 

EXPLANATION OF PLATE IV. 

Tig. l.'—Stricklandima Davidsonii, ventral valve; la, dorsal valve; lb, cardinal 
extremity ; Ic, side view ; Id, cardinal view of a small specimen, with 
beaks ground off to show the chamber and septa. 

Fig. 2. — Stricklandinia Salter ii, ventral valve, the right-hand cardinal angle re- 
stored. 2a, ventral valve, both cardinal angles restored. 

Fig. 3. — Young of Pentamerus ohlongus, from the Niagara limestone at Cockburn 
Island, Lake Huron. When I read the paper on Stricklandinia in 
March, 1859, I exhibited to the Natural History Society of Montreal 
a specimen just .like this, only a little larger, in order to show the 
difference between Fentamerus and Stricklandinia. — E. B. 



ni. — Notes on the Geology of the Dobeudscha, Bulgaria. 
By Dr. Charles F. Peters, of the University of Gratz, Austria. 

HAYING lately read some interesting remarks on the well-known 
green-coated flints of Kent in the Geological Magazine,^ I am 
induced to offer you the following notes. 

During the summer of 1864 I investigated many parts of Bulgaria, 
but more especially the Dobrudscha, where the sagacious observations 
of Capt. T. Spratt, E.N., F.K.S., frequently served me as guides. In 
the highly interesting Cretaceous strata at Kanara, near Kiistendsche, 
which had been correctly identified by Capt. Spratt as Chalk,^ and 
from which Professor Eeuss latety described many Foramtniferce,^ I 
discovered a pseudomoiphous substance, which replaces the flint at 
many points along the coast, and in the Kara- su valley. 

^ In the original it is " The hinge-line in some of the species, such as in S. Icevis 
and S. microcamerus, have the hinge-line straight and much extended." 

' See Mr. G, Dowker's article, Geological Magazine, 1866, Vol. III. p. 210, 
see also pp. 223 and 239 in same volume. 

3 Quart. Journ. Geol. Soc. Lond., vol. xiv. p. 207. 

* Sitzungsberichte, Wiener Akademie, lii. p. 445. 



Dr, Peters — On the Geology of the Dohrudscha, 63 

I should mention here, that the Chalk in this country is every- 
where overlain by calcareous or sandy beds of Miocene age. The 
metamorphosed masses consist of a green or greenish-grey soft 
mineral, which contains many crumbling remains of a flint-like 
silicious matter, the whole mixed with carbonate of lime. After 
extraction by acetic acid, the dry substance becomes of a yellowish 
colour. When analyzed by Dr. Richard Maly, it gave the following 
composition : — 

Silica 56-11 Magnesia 240 

Alumina 26-21 Water 12-00 

Peroxide of Iron 1.77 

It is, therefore, essentially a hydrosilicate of alumina. Although 
this mineral much more nearly resembles a chloropal poor in iron 
than an allophane, the relation of the latter to the Kentish green- 
coated flints is not so very distant but that we may suppose the 
process of replacement and the chemical causes were nearly the 
same in both instances, although occurring in such distantly removed 
countries. 

My paper on the geological and geographical description of the 
northern part of the Dobrudscha is published in the Transactions 
of the Academy of Vienna (vol. xxvii.). 

The district between the Danube and the Black Sea, known as 
the Dobrudscha, offers many interesting points in its geological 
constitution. 

The drift-deposits of Bulgaria and Bessarabia correspond v^ith 
the Hungarian " loess," forming vast undulating plains, which attain 
a height of from 400 to 500 feet above the sea. 

The freshwater deposits of Bessarabia, characterized by Dreissena 
polymorpha and many Cardium-like shells, intermixed with some 
species well-known in the Austrian loess and recent deposits, are 
not of Miocene age as Capt. Spratt has supposed, — they are rather 
truly intercalated in the land-shell marls or loess. This Dreissena- 
bed probably belongs to the oldest drift-series joining (in the Pontic 
regions) the upper marls with the true Miocene freshwater deposits, 
called the " Congeria-beds " by the Austrian geologists, and well 
characterized by many large species of Dreissena or Congeria, and 
Cardium. These beds have been observed in many parts of Bulgaria 
and Wallachia. A Miocene limestone, wholly formed by Tapes gre- 
garia, some species of Cardium, Buccinum, Troclius, and a multitude 
of Foraminifera, belongs to the " Sarmatic formation" of Mr. Suess, 
without a trace of the older Mediterranean or Indian shells. 

The Chalk corresponds, by the presence of Belemnitella mucronata, 
Ostrea vesicularis, and some Foraminifera, with the Chalk of Meudon. 
A Turonian division probably exists. A yellowish marl, from five 
to six hundred feet in thickness, occurring in the Babadagh moun- 
tains, and many banks along the coast, with remains of Ostrea and 
Inoceramus {Cripsii f) but not containing any Eudistes, appears to 
belong to it. Of the Upper Jurassic beds, a part, containing Diceras, 
Pteroceras oceani, and some species of Nerinea, resembles the Kimme- 
ridge Clay of Besan9on, and part containing numerous Terebratulce, 



64 TF. Carruthers — On the British GraptoliteSy 

Rhynclionella lacunosa, Ammonites hiplex, A. tortisulcatus, and many 
others, resembles the Carpathian Hmestone series. These Jurassic 
beds form a vast table-land, extending probably from the northern 
Dobnidscha mountains to the Chalk and Eocene hills near Shumla 
and Varna; and are elsewhere overlain by the before-mentioned 
Miocene and drift strata. 

The geological composition of the Dobrudscha mountains is much 
complicated. Except a reddish-brown Lias marble of true Alpine 
character, a well-marked Alpine Halobia shale, and a Triassic bed, 
resembling the Muschelkalk of Mikultschitz in Silesia, and the cal- 
careous Triassic strata at the Plattensee in Hungary, and containing 
gigantic specimens of Spiriferina Mentzeli, numerous remains of 
Terehratula vulgaris, etc., the older formations in the northern 
Dobrudscha repeat exactly the Transylvanian series, but without 
the rich coal measures of the Banatic countries. 

Igneous rocks, namely many granite-like masses, a quartziferous 
porphyry, and a great melaphyre dyke, penetrate this older forma- 
tion, as well as the Inferior and Middle Triassic strata. In addition 
to this, I will further state that I am of opinion that the Gneiss and 
Granite which the Danube touches near the town of Matschin, opposite 
Galatz, are identical with that through which the river passes at the 
perilous Iron-gate and in the high countries between Passau and 
Krems. It will be seen, therefore, that the Dobrudscha mountains, 
although not more than 1600 feet in altitude, embrace a rich series of 
deposits representing many types of formations widely removed from 
one another both in central and western Europe. 



ly. A Eevision of the Bkitish Graptolites, with Descriptions 

OF THE New Species, and Notes on their Affinities.^ 
By Wm. Carruthers, F.L.S., F.G.S., Botanical Department, British Museum. 

(PLATE V.) 

IT is of the first importance in Natural History to adopt a precise, 
and if possible a received terminology, and strictly to adhere 
to it. From the very different opinions that have been entertained 
regarding the nature of graptolites, a curiously mixed set of terms 
have been employed in their description, some being suggested by 
their supposed resemblance to plants, others being obtained from 
their affinities to animals. Discarding these I shall employ the 
terminology proposed by Allmann and Huxley for the Hydrozoa, 
now generally adopted', asking the reader to take here for granted 
what I hope presently to establish, that these fossils have their 
nearest allies in this class, and consequently that the terminology is 

1 As the chief purpose of this paper is to describe the new species noticed in the 
list I supplied to the recently puhhshed edition of "Siluria," along with others not 
referred to there, and to give the reasons for the changes introduced, i; shall freely 
use the communications I made to Sir Rod. I. Murchison, as well as two papers 
printed by me in the "Intellectual Observer," vol. ix. p. 283 and 365. I may be 
allowed to refer readers interested in these fossils to these papers and to the note in 
" Siluria," for observations which are here summarized or entirely omitted. 



VolV.PlV. 




W.Wlstxmp 



Sriytushy G-T-aptxiliXes 



their Structure and Affinities. Q6 

suited equally to both. As the terms, however, have not yet been 
generally introduced into text books, it is perhaps desirable to give 
definitions of those that I shall have to use in this paper. 

Every hydrozoon exists under two separate forms, the one the 
" trophosome" destined for nutrition and growth, the other the " gono- 
some " for re2)roduction. As nothing representing the gonosome of 
graptolites lias yet been or is likely to be observed, we omit the 
terms proposed in connection with it, and define only those applied 
to the trophosome. The " coenosarc " is the common connecting basis 
of the colony, organically uniting the various individuals or '^ poly- 
pites." The soft parts are more or less completely protected by a 
chitinous "polypary"; to that portion investing the coenosarc we 
confine the term "periderm," and the cup-like receptacle in which 
the individual polypite exists is called the " hydrotheca." The 
''hydrorhiza" is the root-like termination of the polypary by which 
the compound hydroid is attached to foreign bodies, and the " hydro- 
caulus " is the portion of the polypary that intervenes between the 
hydrorhiza and the first hydrotheca. In the Sertulariadcd the " gono- 
phores " or generative buds are produced from the sides of the '' gono- 
blastidium," or column which passes up the centre of the "gonotheca," 
or *' gonangium." ^ 

The general structure of the graptolite is very simple. The 
polypary only has been preserved, and that consists of a periderm 
sometimes forming a thread-like tube, from which the hydrothecae are 
given off at regular intervals (Bastrites), or a larger tube, the one face 
of which is formed of the conjoined bases of the uniserial hydro thecae 
(Graptolithus, etc.). The back of the polypary is strengthened by a 
slender solid axis, composed of the same substance as its walls, and 
capable of separation from the rest of the polypary. The graptolites 
with a double series of cells have a similar structure, being composed 
as if of two single-celled forms united along the back of the periderm, 
as is evident from the forms constituting the genus Dicranograptus, 
in which a double polypary at the proximal end is more or less 
speedily resolved by division into two branches, with a single series 
of cells on their outer aspect. 

From this definition I exclude several forms which have been 
referred to graptolites. First, two remarkable genera of double grap- 
tolites representing perhaps different sub-orders, — EetioUtes, Barr., 
which has no central axis, but the two series of cells rise on either 
side of a single internal canal which occupies the central portion of 
the polypary, and Phjllograptus, Hall, with a solid central axis, but 
destitute of a common canal, the plates of the different cells being 
continued to the solid axis. Also, the genera described by Hall and 
Emmons, in which no cells have been detected ; and lastly, the reti- 
culated fossils named Dictijonema, the affinities of which to grapto- 
lites seem to me very doubtful. 

The structure I have described is that of the normal members of 
the order. Before complicating our investigations regarding their 
modern representatives, by introducing the consideration of the ab- 
^ Allmann in Ann. and Mag. of Nat. Hist., May 1864, p. 350. 

VOL. V. — NO. iLlV. 5 



66 W. Carruthers — On the British Graptolites, 

normal genera, we must first determine the relations of these abnor- 
mal structures to the type structure of the order, which has not yet 
been done. 

I am induced to prefix to this revision of the British species a 
statement of the evidence which induces me to place the graptolites 
among the Hydrozoa at greater length, because of a paper recently 
published by Dr. Nicholson on this subject (Ann. and Mag. of Nat. 
Hist., Jan. 1868), which I will not characterise, leaving that to my 
readers after they have become acquainted with some extracts that 
I shall require to make from it. Every palseontological student will 
allow that it is wasting time to imagine the purpose of obscure and 
anomalous structures, or to discover for them by wild stretches of 
the imagination fancied analogies with structures in recent tribes to 
which the writer is anxious to ally them. There must be a cor- 
respondence of some kind between the organisms better than a 
" possibly," a " probably," or even an " apparently." If any trust- 
worthy determination is to be reached, it must not be built upon 
supposed resemblances about which there must always be a difference 
of opinion, but upon structural points existing in the fossils that 
are identical with, or at least similar to, what is found in recent 
organisms. 

All evidence from the coenosarc and its appendages is necessarily 
wanting in these palaeozoic fossils, and our comparison must be 
based entirely on the polypary. 

Accepting the opinion almost universally entertained, that the 
cells of the graptolite contained animals living in colonies, the 
investigation as to their modern allies is limited to the coelenterate 
and molluscoid zoophytes. The general form of the polypary is not 
of importance, as on the one hand it is one of the most variable 
characters in the same group, and on the other, it is one that repeats 
itself in very different groups. It would be impossible to distinguish 
between the Hydrozoa and the Polyzoa from general form ; besides, 
this is very variable amongst the graptolites themselves. Neither 
is the notion that the polyparies were free (granting that they were 
so) of much significance, inasmuch as there are free forms among 
both the Polyzoa and Hydrozoa. Nor can much stress be laid on 
the chitinoiis nature of the polypary, for though that of the Hydrozoa 
is always chitinous, in " many Polyzoa it is horny and flexible " 
(Busk), and all the species of the order of Polyzoa which most nearly 
resemble the graptolites have such a horny polypary. 

While the great systematic distinction between the Hydrozoa and 
the Polyzoa depends entirely upon the remarkable difference of the 
polypites, yet there has been found associated with each class so 
peculiar a structure of polypary that there is no difficulty in deter- 
mining to which group a particular polypary belongs. This struc- 
ture is connected with the presence or absence of a common canal, 
and with the relations of the cells which contain the polypites to it. 
The true affinity of the graptolite will be easily determined, when 
we ascertain to which of these two types of structure it most nearly 
approaches. 



their Structure and Affinities. 67 

The coralliim of the Anthozoa differs so widely from the polypary 
of the graptolite, that this great division of the Coelerderata may at 
once be excluded. And I do not except from this exclusion the 
Pennatulidce to which Beck in Murchison's ''Silurian System" re- 
ferred the graptolites. The apparent resemblance between Diplo- 
grapsus and Pennatula or Virgularia is very superficial. The three 
genera may agree in being free organisms, and they have a bilateral 
arrangement of parts and a prolonged solid axis, but in the fossil the 
axis is slender and corneous, and is produced at the distal end of the 
organism, while in the recent genera it is thick and calcareous, and 
proceeds from the proximal end. The cells containing the animals 
are dug out of the coenosarc in Pennatula and Virgularia, while in 
the graptolites the polypary is corneous and external. Our com- 
parison will therefore be confined among the Ccelenterata to the 
Hydrozoa. 

In the same way we may strike off those forms of the Polyzoa 
which have obviously no resemblance to the graptolites. In dealing 
with this class it is fortunate for the paleeontologist (although a matter 
of regret to the zoologist) that its classification is based almost entirely 
on the structure of the polyzoary. The freshwater forms and those 
without a hard cuticular layer may at once by set aside. In both the 
Cheilostomata and Cyclostomata the cells are budded from each 
other, and eventually all living connection between the polypites is 
cut off, so that in adult specimens no opening has been detected 
between neighbouring cells. The presence of a canal, common to 
and opening freely into all the cells, in the graptolite is sufficient 
to exclude these orders from our consideration. The flat double 
corneous disc of Dichograpsus has only an external resemblance to 
the discoid calcareous polyzoary of Defrancia, and in every other 
respect the structure of the two genera is totally different. The 
only order of Poly%oa with which the graptolite can be compared is 
that named by Busk Ctenostomata, and by Gray Polyzoa cornea from 
the composition of their polyzoary. The members of this order have 
a common basal tube on which the individual cells are placed. The 
base of the cell is cut off from the common tube by a septum, but 
through this there is a small opening by which the various poly- 
pites have a living connection with the circulation and the structures 
in the tube which are common to all the individuals of the colony.^ 
The correspondence in the arrangement of the cells on a common 
canal in Vesicidaria and Graptolithus, or in Farrella and Rastrites is 
very obvious, but the existence of the perforated septum at the base 
of the cell is an invariable and important character in all these 
Pohjzoa which at once distinguishes them from the graptolites. 

Professor Huxley in his Monograph of the Oceanic Hydro.oa, pub- 
lished by the Eay Society, has grouped the Hydrozoa into six orders 

^ Dr. Nicholson summarily dismisses the Tolyzoa by asserting that they *' have, as 
a rule, a more or less calcareous test, and the individuals forming the compound 
organism are not united by any organised connecting substance." Perhaps a common 
circulation in the basal tube is not, in Dr. Nicholson's opinion, an " organised 
connecting substance," and Gray and Busk may be ignorant of the true nature of the 
Polyzoan test. 



68 W. Carruthers — On the British Graptolites, 

from the leading modifications in their structure. It is important to 
us to find that these orders have marked distinctions in the protective 
coverings of the coenosarc, and it will enable us to establish a more 
satisfactory comparison if we give the characters of these orders, as 
far as they bear upon the parts in the graptolites with which we have 
to deal. 

I. HydridoB. — Hydrosoma consists of a single polypite. The ecto- 
derm developes no hard cuticular layer. Hydra is the only genus of 
this order. 

II. Coryntdcs. — Hydrosoma developed into a coenosarc of very 
various forms, supporting many polypites without thecse. The ecto- 
derm developes a strong cuticle. The hydrosoma is fixed by a hydro- 
rhiza. 

III. Sertulariadce. — Coenosarc with a strong, chitinous cuticular 
layer, which is usually branched, and supports polypites enveloped 
in thec93. The hydrosoma is fixed by a hydrorhiza. 

IV. Cahjcophoridce. — Coenosarc unbranched, flexible, and contractile, 
and has no hard, chitinous, cuticular layer. The hydrosoma is free, 
and the polypites have no thecas. 

V. Physophoridce. — Coenosarc unbranched or very slightly branched, 
flexible, and contractile, and has no hard chitinous outer layer. The 
hydrosoma is free, and the polypites have no thecae. 

VI. Lucernariadae. — The base of the hydrosoma is developed into 
an umbrella. The coenosarc has no chitinous layer. 

There are no parts in the first or in the last three orders which 
can be compared with graptolites. The members of these four orders 
are all devoid of any hard cuticular layer. They must therefore be 
at once set aside, and we are limited to the second and third orders. 
The Corynidce differ from the Sertulariadce in having no thecae for 
their polypites ; but the graptolites were certainly furnished with true 
thecal. In Bastrites the thecae rise at distant intervals from the com- 
mon canal, and in some species of Graptolithiis they are seen to be 
distinct structures from the epiderm of the canal. The most obvious 
indications of these that I have seen are in G. Hislngeri, in which 
there is a superficial line precisely agreeing with that which is seen 
at the junction of the theca and the epiderm of the canal in Cam- 
panular^a, etc. This is figured by M'Coy in his " British Palaeozoic 
Fossils" (Tab. LB. fig. 7a), and described by him as a septum ; but 
a specimen in my possession, preserved in the round, shows that the 
line truly belongs to the outer cuticular layer, and is not an internal 
structure. This excludes from our consideration the Corynidce, and 
confines us to the Sertulariadce. In this order there is a hard chi- 
tinous cuticular layer forming a periderm around the common canal, 
and distinct chitinous thecae for the individuals of the colony. In 
these respects no difference exists between the polyzoary of the 
Ctenostomata and the polypary of the SertuIariadcB ; but the separation 
between the cell and the common canal by a distinct structure, which 
is present in all the Polyzoa with a common tube, is absent in the 
Hydrozoa. In them the wall of the hydrotheca is continuous with 
the periderm of the common canal, and no septum exists separating 



their Structure and Affinities. 69 

the contents of the two. This, too, is, as we have seen, precisely the 
structure of the graptolite ; and if there were nothing more to be 
taken into account, the fossil could not be separated from the Sertu- 
lariad . But there is an important additional structure always present 
in the true graptolite — namely, the slender axis ; and there is no 
analogous structure in the Sertulariadce. We cannot well compare 
this axis with that of the FennatuHdce, even neglecting the nature 
of its composition, unless we make the whole so-called polypary of 
the Graptolitidid an endo-skeleton instead of an exo-skeleton : but this 
would introduce a yet more anomalous structure, for which it would 
not be possible to find any modern ally. 

The comparison, then, that we have instituted between the parts 
and composition of the polypary of the graptolite and similar poly- 
paries of living organisms, seems to me to establish beyond doubt 
that this interesting Silurian fossil has its nearest allies in the Sertu- 
lariadcc, from which it differs in having a solid axis to the polypary. 

The complete organism presents some characters that at first sight 
appear to differ from those of the Sertulariadce ; but these difi'erences 
are not so gi'eat as they are sometimes represented. The genus Den- 
drograptus has hitherto been found only in fragments in Britain, but 
the perfect specimens figured and described by Hall have dendroid 
polyparies with a strong hydrocaulus terminating in a hydrorhiza. 
This agrees exactly with the habit of Halecium. The other genera 
of graptolites are generally described as free, but it is remarkable 
that all of them are furnished with a longer or shorter non-celluli- 
ferous portion (radicle of Hall) at their proximal termination. The 
discovery of more perfect specimens shows that this is very generally 
present, and that in those specimens in which it had been observed, 
it is longer than has hitherto been supposed. I figure a beautiful 
specimen of Climacograptus scalaris, Hall (PI. V., Fig. 9), in which 
this is produced to a considerable length, and there is no indication 
that even here we have the termination. The relation of this process 
to the organism shows that whatever may have been its functions, it is 
homologous with the hydrorhiza ; there is, however, really no reason 
for supposing that it was functionally different. Hall thinks that the 
graptolites were free-floating organisms ; Nicholson, adopting this, 
as he does many other things, and, as his practice is, without acknow- 
ledgment, is not trammelled by the cautious language of Hall, but 
asserts that " there can he no doubt that the greater number were free- 
floating or free-8wimming organisms " (p. 59). And then he finds in 
the pneumatocyst of the Fhysophoridce the '' best homologue " {sic^ of 
the central corneous disc of Bichograpsus, and he furnishes the other 
genera with "possible" swimming bells, which, " o/ course, could 
never be preserved in a fossil condition " ! Finally, to complete the 
history, "it must suffice to state, that in the simpler genera the 
secondary cellules appear to be intercalated between the initial point 

or radicle and the primordial cellule or cellules This mode 

corresponds with that in the .... Physophoridcs''' (p. 58). Un- 
fortunately, however, it only exists in the author's imagination ; • it 

^ We suppose Dr. Nicholson will allow this, for in a sentence a little before that 



70 W, Carruthers — On the British Graptolites, 

is utterly impossible in several genera {Bichograpsus, Cladograpsus, 
JD'icranograptus^ etc), and extremely unlikely in all. As all the 
oceanic Hydrozoa of our present seas are entirely destitute of a hard 
outer layer, and have an excessively contractile coenosarc, it is '' very 
possible," indeed ''beyond doubt," that the Silurian seas were dif- 
ferently constituted to meet the requirements of Dr. Nicholson's hard, 
chitinous, and non-contractile free-swimming polypary. 

I will refer to only one other point in Dr. Nicholson's paper, — it 
would afford endless material for a persevering commentator, — and 
to that because it is one which the author has been diligently inves- 
tigating for some time, and in which consequently he has attained 
some proficiency. I refer to his '' Graptogonophores." In 1866 he 
published his great disco \^ery, first at the British Association and 
then in the Geological Magazine for November of that year. He 
found bell-shaped bodies organically attached by their broad ends to 
" GraptoUthus Sedgwickii.'' These were " gonophores or ovarian vesi- 
cles." (Geol. Mag. Vol. III. PL XVII. p. 489.) In the February 
Number of 1867, I suggested in a note on the systematic position of 
graptolites that if the bodies had anything to do with the graptolite, 
the specimen as figured by him was turned upside down {loc. cit. 
Vol. IV. p. 71). By the following June he had discovered that he 
was wrong ; but, without taking any notice of his error or my cor- 
rection of it, he gives drawings of the bodies attached by the slender 
pedicel to different parts of the polypary {he. cit. PL XI. p. 259). In 
the next Number I pointed out the error of supposing that the 
ovarian capsules could be borne in the same species on the common 
coenosarc, as well as developed from the individual polypites {loc. 
cit. p. 336). At the meeting of the British Association in September 
last he gave up the origin from the coenosarc, and in the paper just 
published in the '' Annals" he tries to let himself more quietly down 
by saying that such an origin " is perhaps accidental ; " but during 
the progress of his knowledge he nowhere acknowledges being in- 
debted for corrections. But now he has established his position 
" beyond doubt." And this is his last account of the bell-shaped 
bodies : — " They resemble the gonophores of the recent Hydrozoa 
in being external processes, in some cases permanently attached, in 
others ultimately detached; the likeness in form is also striking. 
They differ, however, in possessing a corneous envelope, so that, 
when detached, they were either simple free-floating organisms, or, 
if they possessed any independent locomotive power of their own, 
this must have been obtained by means of cilia or by some soft 
apparatus which would leave no traces of its existence. It is 
probable that the capsules did not contain the germs of grapto- 
lites as we now find them in a fossil condition, as thought by Hall, 
but that their contents were the ova in their earliest stages. The 
ova would probably be liberated, on the dehiscence of the capsule, as 

we have quoted from, he tells us that the minute corneous germ he describes is *' the 
primitive structure of the embryo," in imagination, that is, for he immediately adds 
" it must, in fact, be considered very probable that these germs, as we see them, 
are considerably advanced in growth, and that the earliest form of the embryo was 
devoid of any corneous test." 



\ 



their Structure and Affinities. 71 

minute ciliated free- swimming organisms, which subsequently, and 
as a later development, acquired a corneous envelope." I would be 
glad to have some light on this novel mode of reproduction. I con- 
fess my inability to understand it. My impression is — but I express 
it with diffidence — that Dr. Nicholson has somehow confounded the 
external bell -shaped gonothecae of the Sertulariadce and the gono- 
phores they contain, and that some clauses in the sentences quoted 
refer to the gonothec£e and some to the gonophores. 

The generic name Graptolithus was first employed by Linnaeus in 
the original folio edition of his famous " Systema Naturae" (1736), 
for certain natural objects which he describes as resembling, but not 
being, true petrifactions. Not a single form of the fossils to which 
the name is now confined had a place in the genus till the twelfth 
edition of the '^ Systema," in 1767, and of the eight species recorded 
there only one is a true graptolite. This he named G. scalaris, and 
quoted for it the illustration and description in his Scanian Travels 
(1751), p. 147, There can be no doubt that Hall is right in re- 
ferring this species to that which is generally known as Biplograpsus 
rectangular is, M'Coy. The " Systema" is always, though erroneously, 
quoted for another species, G. Sagittarius. Linn^us founded this 
species on the drawing of a fragment oid, Lepidodendron in Yolkmann's 
"Silesia subterranea" (1720), part iii., tab. 4, fig. 6, and accurately 
described it in his short diagnosis. Hisinger, in some unaccountable 
way, applied the name to a species of the restricted genus Grapto- 
lithus with which Linnaeus' s description has not one character in 
common. This error has passed through all the works on grapto- 
lites uncorrected, and has caused the Linnaean generic name to be 
applied to the species with one series of cells, whereas the only 
species described by Linn^us had a double series of cells. 

The difficulty of confining the original name to one of the various 
items included in the genus, and especially of applying a word to 
these organic remains, which its author employed to indicate that 
the species included under it were imitations of and not real fossils, 
presented itself to those who after Linnaeus studied this group. 
Nilsson proposed Priodon, but as Cuvier had used it for a genus of 
fish, he altered it into Prionotus. This was first published by 
Hisinger in 1837. Before this (1835), however, Bronn had pub- 
lished the name Lomatoceras, but this name had also been previously 
employed. The original name was restored by Murchison in his 
"Silurian System" (1839), in a slightly altered form {Graptolites) 
which has been adopted by British authors. A note by Beck on the 
family was printed in the same work, and he retains the original 
spelling, in which he is followed by writers abroad. Under this 
name all the forms described by Hisinger, Murchison, Portlock, 
Hall, Geinitz, and others, were included. 

Barrande first subdivided the genus (1850), by separating two 
marked forms under the names Rastrites and Retiolites, and by 
forming two sections of the limited genus Graptolithus, — Monoprion 
for those with a single series of cells, and Biprion for those with a 
double series. M'Coy in the same year gave these sections a 



72 W. Carrutliers — On the British GraptoliteSy 

generic value, retaining for the first the original name, and pro- 
posing Diplograpsus for the second. 

Barrande, accepting Hisinger's determination, considered the 
Friodon Sagittarius of that author the same as G. Sagittarius, Linn., 
and so held the species with a single series of cells to be the true 
Linnfean type of the original genus. He further endeavoured to 
show that Cr. scalaris, Linn., was a " scalariform " impression of a 
single-celled species, and, by an oversight which is remarkable in a 
work specially characterised by the careful and accurate observation 
that distinguishes all the labours of its illustrious author, he figures 
a double-celled Graptolite as the '' scalariform " impression of two 
single-celled species, viz. G. nuntius, Barr., and G. Kalli, Barr., as 
has been already pointed out by Hall. M'Coy, following Barrande 
and Hisinger, retained erroneously, as I have shown, the Linnasan 
name for the single-celled forms. Were it not that he has been 
invariably followed, I would have restored the name given by 
Linngeus to the only form with which he was acquainted ; but this 
would introduce into the accepted nomenclature so many changes 
without corresponding advantages, that the strict application here of 
the law of priority would scarcely be justifiable. To correct to 
some extent the error, and to make the extent of the acquaintance 
which Linnaeus had with these fossils more obvious, I have substi- 
tuted for G. Sagittarius, Linn, (a name which cannot be maintained), 
that of G. Kisingeri, after the distinguished palaeontologist who first 
described the species, but erroneously ascribed to it the Linnaean name. 

Suess, in 1851, added the name Petalolithus as a synonym to 
M'Coy's genus Diplograpsus. In the same year M'Coy gave the 
name of Bidymograpsus to a well-marked group, and in the following 
year Geinitz applied Cladograpsus to the same group. Unaware 
that this name had been employed, I proposed it in 1858 for a 
repeatedly branching form which I found at Moffat. While the 
paper in which I described this and other forms was passing 
through the press, I learned that Geinitz had used the name : but as 
I was unable to ascertain to what group he applied it, I permitted 
the name to stand, in the faint hope that we had independently 
selected it for the same form. In the same paper I described a new 
species of Didymograpsus, and recorded two other already described 
species, so that it is perfectly obvious that I applied the name to a 
different group from that which Geinitz had included under it. 
In 1867 Dr. Nicholson gave Pleurograpsus to be placed as a synonym 
to my genus Cladograpsus. 

Salter, in 1861, described a compound form Dichograpsus from the 
Skiddaw slates, similar to some that had already been observed in 
Canada by Sir Wm. Logan. 

Hall has more than any other palagontologist increased our ac- 
quaintance with species of graptolites, and added many very re- 
markable genera. His extensive acquaintance with the perfect and 
singular specimens that have been found in Canada and the United 
States have given him a high vantage-ground, which, independent of 
the care and ability with which he prosecutes his investigations, would 



their Structure and Affinities, 73 

demand for his opinions the most thoughtful consideration. An 
interchange of specimens between Europe and America would be a 
great advantage to observers in both countries ; for while the draw- 
ings of Barrande, Geinitz, M'Coy, and Salter, convey as accurate an 
impression of our European forms as can be given on paper, and 
those of Hall equally so of the American species, yet it is impossible 
for students fully to understand the nature of the organisms without 
their careful examination ; we must always on this side of the Atlantic 
have a defective knowledge of Bichograpsus, and the new genera of 
Hall, until we have an extensive series for examination ; and it is to 
be expected that on the other side erroneous ideas will be enter- 
tained regarding our old-world species, from the same cause. Had 
Hall examined perfect European specimens of the genus Graptolithus 
he would have seen that very few of these could be parts of the re- 
markable compound forms which he so admirably describes and illus- 
trates in the last Decade of the Canadian Survey. 

In 1857, Hall established the genus Phyllogr&ptus. In subse- 
quently published papers he proposed several additional genera, 
some of which are probably not true graptolites. In some he can 
detect no cell-openings, and hiocaulis, which is not rare in our 
British Silurians, has a solid homogeneous structure very different 
from that of any graptolite with which I am acquainted. Dendro- 
graptus is an interesting form represented in Britain, and his genera 
CUmacograptus and Dicranograptus, established for forms already 
known, are well characterised. 

This closes the history of the different genera of British graptolites. 
I shall now give an analytical key to the genera, and proceed to the 
enumeration of the species, having occupied much more space than 
I intended with this introduction. 

ANALYTICAL KEY TO THE GENERA. 

A. Polypary with a single series of cells. 

a. Polypary simple. 

a. Cells free throughout their whole length. Hastrites, Barr. 

b. Cells in contact throughout more or less of 

their length. Graptolithus (Linn.), M'Coy. 

b. Polypary compound. 

a. Polypary growing in one direction from the 

primary point, Cyrtograpsus, Can*. 

h. Polypary growing bilaterally and consisting 

of two simple or double branches, Bidymograpsus^W Coy 

c. Polypary growing bilaterally and branching 

regularly, and furnished with a central 

corneous disc. Bichograpsus, Salter. 

d. Polypary growing bilaterally, irregularly and 

repeatedly branching and rebranching, and 

without a central disc. Cladograpsus, Carr. 

e. Polypary with a thick common hydrocaulus, 

and branching irregularly. Bendrograptus, Hall. 

B. Polypary with two series of cells. 

a. Polypary with a slender solid axis, 

a. Cells which are true hydrothecse, Biplograpsus^ M'Coy, 

b. Cells hollowed out of the common periderm. CUmacograptus, Hall. 

b. Polypary without an axis. Retiolites, Barr. 

C. Polypary with single and double series of cells. Bicranograptus, Hall. 

D. Polypary with four series of cells. Fhyllograptus, Hall. 



74 Maw — On a Fossil Flower. 

EXPLANATION OF PLATE V. 
Fig. 1 a. Graptolithus convolutus, His., showing the free linear cells at the proximal 
end of the polypary. 1 b and 1 c. Cells with two spines rising from the 
mouth. 

2. Biplograpsus mucronatus, Hall. 

3. Viplograpsiis Whitfieldi, Hall. 

4. Biplograpsus comcta, Gein. 

5. Dendrograptus lentus. Carr. 

6. Dicranograptus Clingani, Carr. 6 c. Three cells magnified five times. 

7. Cladograpsus capillaris, C?ixv. lb. Four cells magnified five times. 

8. Bidymograpsus elegans, Carr. 8 Z» and 8 c. Two young specimens. 8 d. Four 

cells magnified five times. 

9. CUmatograptus scalaris, Hall., showing the axis produced at the proximal 

end to a great length. 

10. CUmatograptus minutus, Carr. 

11. Biplograpsus tricornis, Carr. 115. Young specimen. 

12. Biplograpsus minimus, Carr. 

13. Biplograpsus pristis, His., showing various forms of appendages at the 

proximal termination. 

14. Mastrites maximus, Carr. 

15. Rastrites Linncci, Barr. 

16. Eastrites capillaris, Carr. 

17. Cyrtograpsus Murchisonii, Carr. 17 b. Seven cells magnified five times. 

18. Graptolithus intermedius, Carr. 

19. Graptolithus Clingani, Carr. 

Figs. 1 a, 5, and 17 are from specimens in the Jermyn Street Museum; the others 
are from specimens in the British Museum. 

The systematic portion of the paper, and the description of the new species figured 
in this plate, will be given in next number. 



V. — On a Flower-like Form from the Leaf-bed of the Lower 

Bagshot Beds, Studland Bay, Dorsetshire. 

By George Maw, F.G.S., F.L.S. 

THE accompanying figure (1) represents a fossil in my possession 
obtained with some insect remains, by Mr. W. R. Brodie, of 
Swanage, from the Lower Leaf-bed of the Lower Bagshot beds, 
Studland Bay, Dorsetshire. It bears a general resemblance to the 




2 1 3 4 

Fig, 1.— Fossil from Studland Bay. Figs. 2, Z.—Kydia calycina, India. 

Fig. i.—Calycopteris (Getonia) Jloribunda, India. 

examples found by Mr. W. S. Mitchell, at Alum Bay and Bourne- 
mouth;^ and to those figured by Heer as Parana (Flora Tertiaria 
Helvetias, plate 103), from the Swiss deposits, except in its having 

^ See Mr. Mitchell's description of Parana (^ vectensis, etc., in Geological 
Magazine, 1865, Vol. IL p. 616, figs. 1-3.— Ed. 



Maw — 071 a Fossil Flower, 75 

but four instead of five lobes. It resembles somewhat in outline 
the recent Parana voluhilis, and, as the absence of the fifth lobe 
might be merely an abnormal condition of the individual example, 
it seemed, at first, scarcely sufficient to separate it from the genus 
with which all the other similar forms from the Tertiary beds had 
heretofore been identified. 

Mr. Kichard Kippist, of the Linnasan Society, has, however, within 
the last few days pointed out to me the much closer resemblance of 
the fossil to Kydia calcycina, an East Indian plant of the natural 
order Byttneriacece, and has furnished me with the recent examples 
of the enlarged involucre, represented in Figures 2 and 3 for com- 
parison with the fossil. A figure of the plant is also given in 
Wight's Icones plantarum Indm Orientalis (vol. iii. table 880, fig. 5). 
Mr. Kippist remarks that " the fossil agrees far better with Kydia 
than Parana in the number and blunt obovate form of the sepals, 
as well as in the numerous nearly parallel veins, the pointed sepals 
of Parana being penniveined with an intermarginal nerve ; in fact, 
that Wight's figure of the enlarged calyx of Kydia calycina is so 
completely identical with the fossil that the one might almost have 
been drawn from the other." In the fossil the inner or true calyx 
with the enclosed capsule appears to have become detached from the 
involucre (the part supposed to be represented in the fossil), though 
the broad scar in the centre shows clearly the point of attachment. 
A large proportion of the examples of Kydia have only four lobes 
to the outer calyx or involucre, but are occasionally found with five, 
as in Figure 2, or even with six lobes. The Hampshire and also the 
Swiss specimens figured by Heer vary in this way ; and, although 
the great majority have five lobes, it seems questionable whether the 
whole are not more properly referable to Kydia than Parana} Three 
examples of leaves in my possession from the Corfe leaf-bed, a con- 
tinuation of that exposed in Studland Bay, agree well with the form 
and venation of the leaves of Kydia calycina. 

1 submit these few particulars in the belief that the evidence in 
favour of the affinity of the Tertiary flower-like forms with Kydia 
is equal if not superior to the claims of Parana to include them, 
though the identification of fossil with recent Phanerogamous genera 
must always be uncertain and difficult. Fig. 4: represents the calyx 
of Calycopieris (Getonia) floribunda, for which I am indebted to 
Mr. Carruthers, and which is also more like the fossil than any of 
the recent species of Porana. 



itTOTiCiES OIF ^yc:E:M:oII^S- 

Classification of Meteorites. By M. Daubree.^ 

THE bodies which are comprised under the general name of 
meteorites have long since been arranged under two great 
divisions, the irans and the sianes ; it is, indeed, the division which 

^ See figures of Porana, op. cit., p. 516, 

2 Classification adoptee pour la collection de meteorites du Museum. Par M. 
Daubree; Comptes rendus des Seances de 1' Academie des Sciences, tome 65, July, 1867. 



76 Notices of Memoirs — Daubree, 

appears the most simple and natural, In examining a certain num- 
ber of these masses it has been thought convenient by some to 
establish a third, or intermediate division, to which the names of 
Mesosiderites, Lithosiderites, or of Siderolites, have been given. How- 
ever convenient may appear this latter division, it presents some 
difficulties when we examine the passages which connect the extreme 
terms of the series ; viz., from that of massive iron to that of the 
stone exempt from it. It is thus that certain specimens have been 
placed by some in the intermediate division, and by others in the 
third, or in the first division. In not admitting this division there 
are also difficulties, particularly for the meteorites, such as that of 
Pallas, where the stony grains are disseminated amongst the metallic 
mass, and which thus forms the first link between the irons and the 
stones. In placing the collection of meteorites in the new cabinet of 
the museum of the Jardin des Plantes, at Paris, M. Daubree has 
replaced the purely chronological arrangement formerly adopted, by 
a classification which enables one to perceive the relations of this 
series of planetary bodies. 

M. Daubree has adopted four great di^dsions, to each of which he 
has given particular names, which, although somewhat new and 
complicated, are intended to facilitate the study of these bodies. 

It is exclusively the solid, or coherent meteorites which are 
classified, leaving out of consideration the gaseous or liquid matters 
which may accompany the solid masses, and also the falls of powder 
which have sometimes been recognised. Metallic iron, which is ab- 
sent in all terrestrial rocks [?] , and is found in nearly all meteorites, 
has afforded the most natural basis for the great divisions, both as to 
its arrangement and mode of association with the stony matter, as 
by its relative proportion. The term Siderites is proposed for the 
meteorites containing metallic iron, and Asiderites for those without 
it. The Siderites may be deprived of all stony matter, or contain it 
in the most minute quantity ; these masses comprise the group 
Holosideres, coiTcsponding to the meteoric irons properly so-called ; 
as, for example, the masses of Caille and Charcas. When the 
Siderites contain silicates, the iron may exist as a continuous mass, 
similar to a sponge, the stony matter occupying the vacuities ; or 
the iron may occur in more or less large grains, disseminated in the 
stony matrix. In the first case the Siderites belong to the division 
Syssideres ; in the second to that of Sporadosideres. The Syssideres 
may contain the stony matter in two states, corresponding to those 
indicated for the iron ; either in distinct, disseminated grains, as is 
observed in the iron of Pallas, in that of Atacama, in that of Tuczon,^ 
etc. ; or in the form of a continuous mass, entangled as a network 
with the iron, similar to that of the iron of Eittersgriin. The 
division of Sporadosideres contains the greatest number of known 
meteorites. For the convenience of study, M. Daubree has divided 
them into three sub-groups, under the names of Polysideres, Oligo- 

^ The specimen from Tuczon, in the British Museum, presented by the town- 
authorities of San Francisco, 1863, shows that this meteorite should be classed with 
the Siderites.— J , M. 



Classification of Meteorites. 



77 



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78 Notices of Memoirs — Bauhrde^ Classification of Meteorites, 

sideres, and Cryptosideres, according as tlie iron is — in great quan- 
tity (Sierra del Chaco) ; in small quantity (Saint-Mesmin, Aumale, 
etc.); or in indiscernible proportion (Juvinas, Chassigny). These 
sub-divisions are far from having the same value; but they each 
correspond to sensible variations in the density. 

The fourth sub-division of coherent meteorites is that of Asideres, 
corresponding to the Asiderites, which is characterized by the ab- 
sence of metallic iron. The number of specimens of this latter 
group is very limited, and nearly restricted to the carbonaceous 
meteorites (Alais, Orgueil). Such is the principle on which the 
classification is based : the differences and relations which are found 
in the two types of meteorites are shown in the preceding table. 

Note. — The meteorite of Sierra del Chaco noticed above resembles, 
according to M. Gustav Eose, that of Hainholz, described by 
Keichenbach. Both are very different from other meteorites ; they 
present the remarkable peculiarity of containing Augite, which is 
not accompanied by anorthite, as in the meteorite of Juvenas, but 
which is, on the contrary, associated with iron containing nickel, 
with peridot, and magnetic pyrites. Besides, the nickel, iron, and 
pyrites, on the one hand, and the peridot and augite on the other, 
occur in nearly equal proportions. For these meteorites M. Rose 
has proposed a special name, that of mesosiderites} The arrange- 
ment of the meteorites in the museum of the Berlin University, by 
M. G. Rose, is based on their mineral character, and forms two 
divisions — the metallic and the stony meteorites, the first containing 
meteoric iron and the Pallasite, the second the Chondrites, Howardites, 
Chassignites, Chladnites, and lastly the Eukrites, which contain 
augite as well as anorthite. The meteorites of Alais and the Cape 
(and we may add that from Australia) contain carbon, and form 
with the mesosiderites two other groups. 

We may here refer to the collection of meteorites in the British 
Museum, which, under the able direction of the present keeper, has 
been so greatly augmented that it now stands unrivalled both for 
extent and value of the specimens, the number being about 260. 
They are arranged in two cases ; one contains the stony varieties or 
Aerolites, characterized by the presence of minute stony spherules. 
These are the Chondrites, Howardites, Chassignites, etc. They all 
contain meteoric iron in fine particles disseminated through them. 
In the other case are displayed the Siderolites and the Aero-siderites. 
The former are masses of meteoric iron, containing stony matter ; the 
latter consist of the metallic alloy of iron and nickel, with small 
amounts of other metals known as "meteoric iron." They also 
contain mechanical admixtures of compounds of these metals with 
phosphorus and with sulphur. — J. M. 

1 Vide Sorby on the microscopical structure of meteorites. Proc. Roy. Soc, June, 
1864. 



Reviews — Murchison's " SiluriaJ 



SiLURiA. By Sir Koderick I. Murchison, Bart., K.C.B., etc., 
etc. [Third Edition.] Fourth Edition, including the '' Silurian 
System." With a map, much new matter, and many illustra- 
tions. 8vo. 1867. 

AS its title-page explains, this work consists of " A History of the 
Oldest Eocks in the British Isles and other countries ; with 
sketches of the origin and distribution of native gold, the general 
succession of geological formations, and changes of the earth's sur- 
face," — subjects which, we all know, have long ranked high as 
favourites among Sir Eoderick's many scientific researches, and have 
had his earnest attention for many (some for nearly fifty) years. 
Again, then, has this veteran geologist, coming to the front with 
unabated energy and enlarged experience, applied his native acumen 
and clear judgment, his knowledge of details and power of gene- 
ralization, to describe and elucidate the older rock-formations — the 
foundation-stones of half the globe, and to give the history of the 
successive systems of primasval life, as shown by the Palgeozoic Eocks 
and Fossils of Great Britain and many other parts of the world. 

Like all historians. Sir Eoderick has had to apply to others for 
many data and for collateral information ; and this he has received 
abundantly, and with justice fully acknowledged ; indeed, he has 
taken pleasure in enumerating his helping friends and collaborateurs 
in his Preface (where upwards of twenty are mentioned), and his 
Index is rich with the names of authors and discoverers who have 
been quoted or referred to in furtherance of his work. 

Furnished wiih the latest information from all sides, and enriched 
with the results of his own labours during the last ten years, he has 
carefully considered the rapidly accumulated facts and opinions re- 
lating to palaeozoic geology, and has produced, as we might expect, 
a most valuable digest of all that is known of Laurentian, Cambrian, 
Silurian, Devonian, Carboniferous, and Permian Eocks and Fossils, — 
well written, well printed, and well illustrated ; and supplemented, 
moreover, with chapters on the geology of gold and the philosophy 
of geology. 

In the previous edition of " Siluria," Sir Eoderick was enabled to 
lead the geologist to a still lower stage in the rock-structure of the 
British Islands than had been previously recognized, namely, to what 
he then termed the "Fundamental Gneiss," which comes out at 
Cape Wrath and the Lewis, and underlies the great Cambrian masses 
of Eoss-shire (once thought to be '' Old Eed Conglomerate"), and the 
superposed Silurian quartzites and schists of Assynt, which, though 
disguised by metamorphism, were clearly recognised by the few 
fossils in their scanty seams of limestone. In the present edition Sir 
Eoderick gives us a still larger, and at the same time more intimate, 
view of these oldest and lowest rock-masses, which, once muds, 
sands, and reefs, have long since been changed into crystalline gneiss 
and marble, and now constitute wide lands in North America and 
elsewhere. Sir W. E. Logan and his associates in the Geological 



80 Reviews — MurcMson^s " Siluria." 

Survey of Canada have laboriously mapped and, as it were, unravelled 
(besides tlic many thousand feet of Lower Carboniferous, Devonian, 
and Silurian strata of that country) — a great lower series of quart- 
zites, chloritic schists, clay-slates, marble, and bedded diorites, alto- 
gether 18,000 feet thick, and called by them ''Huronian" (probably 
equivalent to our ''Cambrian" rocks) ; and inferior still to this, they 
recognised the great "Laurentian System," Upper and Lower. 
The upper portion consists of the wide and crumpled sheets of hyper- 
sthene and dark felspathic rock so characteristic of Labrador, with 
gneiss and imbedded marble, altogether 10,000 feet thick ; and this, 
as a really stratified though metamorphosed formation, "rests un- 
conformably on the worn edges of a still older group of gneiss, 
quartzites, conglomerate, and marble, 20,000 feet thick at least, 
crumpled and crystalline, converted here and there into granite, and 
traversed by intrusive syenites and greenstones." These Lower 
Laurentian rocks are not only the disguised sands, clays, shingle, 
and calcareous sea-beds of the primgeval earth, but bear witness to 
the life of the period ; for their seams of Graphite represent coal or 
other carbonaceous layers of animal or of vegetable origin, — their 
apatite, fluor, iron-oxide, and pyrites ''have reference probably to 
former animal organisms and their decompositions," — worm-tubes 
occur in the schists, — and, besides obscure fragments like those of 
crinoids, corals, and shells, the structure of a real Foraminifer has 
been detected by Logan and Dawson in these old Laurentian lime- 
stones. Similar in relative position and in structure to that of 
Canada, the gneiss of Cape Wrath and the Lewis belongs to Sir 
William Logan's well-established "Laurentian System;" and, grace- 
fully acknowledging his friend's hard-won discovery of this the 
earliest stage of the earth's terraqueous history. Sir Eoderick thus 
dedicates this new edition of his work — "To the geologist who has 
not only applied my (Silurian) classification to the vast regions of 
British North America, but has taught us by his recent important 
researches that the Laurentian Eocks constitute the foundation-stones 
of all Palgeozoic deposits in the crust of the globe, wherever their 
foundations are known." 

The condition of these old schists and gneiss in Bavaria and 
Bohemia are carefully treated of, and indications of their existence 
in Norway, Spitzbergen, Finland, and elsewhere are given in 
" Siluria." 

The nature, structure, and special features of the Cambrian rocks 
of the Longmynd, 26,000 feet thick, of Harlech and Llanberris, of 
Anglesea (where they are metamorphosed), of the North- Western 
Highlands, of Norway, Bohemia, and elsewhere, are next fully 
described and freely illustrated. These were once the Bottom-rocks, 
— these were once "Azoic;" but now the disentanglement of the 
so-called systems of mica-schist, slate, and gneiss, has opened out 
the above-mentioned 30,000 feet of still lower stratified formations 
(Laurentian) ; and the discovery of fucoids, worm-burrows, the 
Oldhamia, a Lingula, and a Trilobite, has partially, at least, educed 
the fauna and flora of these old Cambrian times. 



I 



Reviews — Murchison^s *' SiluriaJ^ 81 

The next overlying stage of deposits is represented by the succes- 
sion of flagstones, grits, and fossiliferous schists, 5,000 feet (?) thick, 
long known as the '' Lingula-flags;" but as their chief '' Lingulae " 
are Lingulellce, and as Lingidce abound also elsewhere, Murchison 
refers to them as '*' Primordial Silurian," after Barrande's name of 
" Primordial Zone." They flank both the Longmynd and the 
Malvern Hills on their western sides, comprising the " Holybush 
Sandstone" and Olenus-shale of the Malverns ; they enter into the 
constitution both of Snowdon and of Cader Idris, on either side of the 
Harlech anticline ; and they form the two great corresponding pro- 
montories of Caernarvon and Pembrokeshire. " This great series 
of Lingula-flags, so well developed in Wales, is the zone which, in 
Bohemia, through the enlightened researches of Mr. Barrande, has 
proved to be the basis of all Silurian life, and which therefore 
received from him the name of 'Primordial.' It is, indeed, clear 
that the fauna of this zone merits all the importance attached to it 
by its eminent founder, since we have now ascertained that, such as 
he has described it, the group exists in America, Scandinavia, 
Belgium, and Spain, as well as in the British Isles and Bohemia " 
(p. 47). This "Primordial Zone " is grouped by Sedgwick, Salter, 
and Lyell as the upper portion of the Cambrian system ; but with 
Murchison's " Cambrian " these Lingulella-flags have nothing in 
common, except that one small Lingula {L. ferruginea, var. ovalis), 
and one Trilobite (Palceopyge Kamsayi) have been found in the latter, 
showing that the life of the Lower Paleeozoic era had then already 
commenced. 

The Llandeilo formation, very rich in Graptolites, Trilobites, and 
other fossils, and upwards of 5,000 feet thick (including its inter- 
calated lavas and ash-beds of contemporaneous volcanic origin), next 
succeeds, forming a large part of Wales, and well represented 
abroad. The lower portion of this series has been divided off by 
other systematists as the " Tremadoc Slates," but Sir Eoderick re- 
gards the latter as real passage-beds between the Primordial Zone and 
the Llandeilo flags, and inseparable in classification. 

The Caradoc or Caradoc-Bala beds (4,000 feet in Shropshire, and 
thickened with upwards of 3,000 feet of contemporaneous volcanic 
rock in North Wales) are next described, with their many Brachio- 
pods, Trilobites, etc. Lying on the Llandeilo flags (and, indeed, 
formed in the shallowing sea, which at first, when deeper, origi- 
nated these latter shales and flagstones), the Caradoc beds cap 
Snowdon, and largely participate in forming the northern, central, 
and south-western districts of Wales and the border-counties in- 
cluded in Murchison's original " Siluria," or land of the old British 
Silures of Caractacus. This Silurian formation being shore-beds 
and sandy towards the east, its numerous shells have left only 
casts and moulds in the " Caradoc Sandstone ;" but the more muddy 
beds of the western and northern parts of the area have preserved 
the calcareous matter of the shells and corals more perfectly in the 
" Bala Limestone." Such a difference of character, further modified 
by the intercalation of volcanic ash-beds, was originally a hindrance 

VOL. V. — NO. XLIV. 6 



82 Reviews — MurckisorCs " Sihcria" 

in the recognition of the geological identity of the several parts of 
this important group. 

In the next set of deposits (the Llandovery), sandstones succeed 
schistose and slaty Caradoc beds in South Wales ; and are there 
divisible into Lower and Upper (at Noeth Griig) ; and the Upper 
Llandovery is again found in Radnorshire and the border counties, 
without the Lower member. Often full of the casts and moulds of 
fossils, as is the case also with the Caradoc Sandstone, the Llan- 
dovery beds have been mistaken for it, — especially the Upper 
Llandovery Sandstone of May Hill ; but the fossils are mostly 
distinct in species, and Pentameri abound so much that they form a 
coarse calcareous band (Hollies Limestone) on the western side of 
the AVorcestershire Beacon. The Llandovery beds are *' Middle 
Silurian," but not distinctly separate from the Caradoc below and the 
Wenlock formation above, — their fossils being not very often " pe- 
culiar," some being found above, some below, and some both in upper 
and lower formations ; but those of the upper part of the group 
more especially have alliances in the Upper Silurian formations 
which next come to be described. The "Tarannon Shales" are 
also mentioned as either occupying, in North Wales, the place of the 
Upper Llandovery Sandstone, or forming part of the next series 
(Wenlock formation), the local member of which, or the " Denbigh- 
shire Grits," there lies conformably upon them, passing upwards 
into ordinary Wenlock Shale. This last, with its two interbedded 
limestones, — the lower and thinner band being known as the "Wool- 
hope Limestone," whilst the upper calcareous la3''ers have the name 
of Wenlock or Dudley Limestone, — is the subject of an interesting 
chapter, which illustrates also the structure of the Wren's Nest and 
the curious Woolhope Valley of Elevation ; just as in the course of 
the earlier chapters the physical features of Snowdon, the Breidden 
Hills, Caer Caradoc, the Malverns, the Stiper Stones, and the Long- 
mynd are elucidated in connection with their geological structure. 

The Ludlow formation, including the Aymestry Limestone as its 
middle member, comes next. The information obtained of late 
years respecting its uppermost portion, whereby it passes upwards 
into the Devonian Sandstones of Herefordshire, is reduced to order 
in chap. vii. ; and the interesting discovery of the remains of a fish 
{Pteranpts Ludensis) in the Lower Ludlow beds at Leintwardine — 
the oldest vertebrate known — is alluded to. 

The Silurian rocks of other parts of Britain, beyond the typical 
region of " Siluria," namely, in Cornwall, the North-west of Eng- 
land, Scotland, and Ireland, are studied in chapter viii. Here we 
see how greatly our knowledge of Ayrshire and Edinburghshire 
has been advanced by the Geological Surveyors and others ; here 
also we have the history and relationships of the Lower Silurian 
schists, quartzites, and limestone of the Scottish Highlands clearly 
explained, as well as the Silurian series of Ireland, and its relation 
to the overlying Lower Devonian beds. 

The next two chapters are devoted to an illustrated systematic 
account of the characters and distribution of the organic remains 



Reviews — Murchison's " Siluria,^* 83 

found in the Lower, Middle, and Upper Silurian formations; but 
there are also notices and woodcuts of Graptolites, Starfishes, Eury- 
pterids, Corals, and many other fossils in the earlier chapters, 
where they come in as characteristic of the strata there treated of — 
there are others scattered through the after-portion of the work — and 
the Appendix contains not only supplemental palseontological notes, 
but a good synopsis of the Graptolites (by Mr. Carruthers), and 
an elaborate Table of British Silurian fossils, as now known, 
classified zoologically, and referred to their respective formations. 
This Table was greatly improved and augmented in the Second 
Edition by Mr. Salter ; and now, in the Third, it has received nearly 
300 additional species. At the same time, we may notice that 
several published species are omitted, because a careful examination 
has shown their identity with others previously described ; and the 
student will observe also " that many of the long-known names of 
Silurian fossils have been exchanged for more correct names, accord- 
ing to the recent determinations of their real alliances, often obscure 
before, and only established on the discovery of more perfect 
specimens, and by an extended knowledge of extinct forms of life." 
This revised Table has been prepared by Mr. Etheridge, assisted by 
Professors Morris and Jones, who have had the help of Davidson, 
H. Woodward, Carruthers, and Duncan, in their special subjects of 
Brachiopods, Crustacea, Graptolites, and Corals ; and they have had 
also the benefit of Mr. Salter's latest researches in Silurian Trilobites, 
Mollusca, etc., as well as the manifold labours of Barrande, James 
Hall, Billings, M'Coy, Baily, Edgell, Holl, and others, both at home 
and abroad. Not only in the Table, but in the body of the work, 
and in the Explanations of the Plates, the improved nomenclature 
has been adopted (a few exceptions are indicated in the list of 
Errata), many old names having been " exchanged for others more 
correct as to generic and specific affinities, or entitled to use by 
priority." 

The life -history of the Silurian age has thus been greatly eluci- 
dated, not only by the better zoological and geological classification 
of the known fossils, but by the many new forms (especially 
of Paradoxides, Conocoryphe, and other Trilobites) obtained from the 
Lingulella-flags ("Primordial Zone"), and from the Tremadoc 
Slates, by Messrs. Salter, Hicks, Homfray. and Ash (p. 202, etc.), 
indicating the succession of a deep sea, alive with Invertebrates, to 
the almost barren shoal waters that deposited the *' Cambrian " 
muds and sands, with no trace of former life in them in Canada and 
Scotland, with a minute LinguhUa at David's, and with little enough 
where the Longraynd has raised up the old schistose, rippled, sun- 
cracked, and burrowed mud-banks, as part of the '• Silurian " land. 

For both the earlier and the later formations of the Silurian 
system, their life-history is also made clearer by the increased number 
of Trilobites worked out by Salter, Eurypterids by H. Woodward, 
small En(omostraca by Jones and Holl, Brachiopods by Davidson, 
Graptolites by Carruthers and Nicholson, etc. There will be dif- 
ferences of opinion as to the exact allocation of some of the new 



84 Reviews — MurclmorCs " Siluria,^^ 

names, and of some of the accepted zoological views, in this Edition ; 
but evidently great care has been taken in the laborious task of col- 
lating books, figures, and fossils ; and Sir Roderick, as in former 
Editions, has been careful to secure the same painstaking and con- 
scientious work in the paLoeontology as he himself has bestowed in 
the history and physical geology of these the oldest rocks of the 
British Isles. 

We have space for but few remarks on points which are of interest to 
palaeontologists. The Table opens with '' Plantee," but we expect that 
the Sfongaria given under that head will prove to be casts of isolated 
septa of Orthoceras. Actinophyllum is like a radiating burrow-mark ; 
and occurs also in the Lower Greensand of the Isle of Wight (Mr. 
Beckles' Collection). There is some confusion in applying the term 
Salterella to the tube-like fossils at p. 166, if the latter be dae either 
to Annelids or Crustacea (as seems to be indicated) ; for Mr. Billings 
gave the name to a Pteropod. As for "Annelids," "Annelid-mark- 
ings," and "Fucoids," we are glad to see an inclination to refer 
some of them to the trails and burrows of Crustacea (p. 166 and p. 
201) ; and in this respect a reference to Dr. Dawson's llusophycus 
(allied to some forms of Bilohites), and his opinion as to its being the 
mark of a burrow-chamber of a Trilobite would have been interest- 
ing to Silurian students. 

The old fossil fish (the earliest Vertebrate) discovered by Mr. 
Lee at Leintwardine, in the Lower Ludlow formation, is alluded 
to at pages 126, 133, and 477, as a Pteraspis ; it was referred to 
in 1864 by Mr. E. E. Lankester (Brit. Assoc. Report) as Scaphaspis 
Zudensis, whilst Pteraspis truncatus (figured at p. 240) is also a 
Scaphaspis, and Pt. Banhsii is a Cyathaspis according to the same 
authority. Inadvertently this oldest species of Fish, and the refer- 
ence to Mr. Salter's original description of it as Pteraspis Ludensis, 
in the " Annals Nat. Hist." of July, 1859, have been omitted in the 
Table at p. 536 — an important but evidently accidental omission. 

Recurring to the body of the work, with chapter xi. we enter on 
the Devonian rocks and Old Red Sandstone. Mr. Geikie's clear 
explanation of the structure of the Lower and Upper Old Red be- 
tween the Cheviots and the Grampians is the first new point of 
interest in this chapter; a succinct re-written account of the Old 
Red Sandstone of Korth-eastern Scotland follows ; and the good 
palasontological reasons for excluding the Telerpeton, Staganolepis, and 
Ryperodapedon of Elgin from the Old Red category are fairly stated. 
Of so great importance is this matter to geologists in general that 
we here reprint the supplemental Notice (dated Oct. 30th, 1867) 
issued with the New Edition of " Siluria ": — 

" The reader of this edition will find that a very important change 
has been made in my views as given in former editions, respecting 
the age of the Upper Sandstones of Elgin and Ross-shire, which I 
have hitherto classed with the Devonian or Old Red Sandstone. My 
previous conclusion was founded entirely on the strong natural evi- 
dence presented to mo by the conformable superposition of those 
beds to the strata of the inferior and unequivocal Old Red Sandstone 



Reviews — Murchison^s *' Siluria.** 85 

replete with its well-known fossils. This opinion was confirmed by 
the examination of the rocks in question by Professor Kamsay, Pro- 
fessor Harkness, the Kev. George Gordon, the Eev. J. M. Joass, and 
others. 

" The existence, in strata of Devonian age, of reptiles of so high 
a class as the Telerpeton (see fig. 73 in my last edition, p. 289) and 
the Stagonolcpis was not, indeed, admitted by me without great 
reluctance, inasmuch as, if eventually substantiated, it would have 
weakened the main argument that runs through all my writings, 
which shows a regular progression from lower to higher grades of 
animals, in ascending from the older to the younger formations. 
Most joyfully, therefore, did I welcome the remarkable identification 
by Professor Huxley of the Hyperodapedon of the New Eed Sand- 
stone of Warwickshire with the Hyperodapedon of Elgin ; and 
bowing, as I have always done, to clear palasontological proof, I have 
now excluded all that portion of my former editions which placed 
these reptiles in the Old Eed Sandstone. 

" The importance of this rectification, due to my eminent associate, 
has very recently received a wide extension ; for among the fossil 
remains collected in India by the late Eev. S. Hislop, Professor 
Huxley has also found the Hyperodapedon. 

" The formation in India containing this reptile has been con- 
sidered by Professor Oldham, the Director of the Indian Geological 
Survey, to be either the Trias (New Eed Sandstone) or the repre- 
sentative of an intermede between the Palaeozoic and Mesozoic rocks. 
In all probability this correlation will have to be extended to South 
Africa, since one of the characteristic fossil reptiles of that country, 
the Dicynodon, has been found in the Eanigunj beds of this age in 
India." 

The Devonian rocks of Cornwall, Devon, and Ireland have evi- 
dently received the most careful attention in this revised chapter xi., 
Mr. Jukes's new views of the relations of these rocks having required 
special consideration. With a clear knowledge of all former re- 
searches, and supported by Messrs. Salter and Etheridge's late 
examinations of the strata and fossils. Sir Eoderick groups the upper 
portion of the Barnstaple band only with the Lower Carboniferous 
Limestone -shale, the Devonian formations ending with the Pilton 
and Marwood series, the latter of which may be the equivalent of 
the " Coomhola Grits" of the South of Ireland. In Dingle, South- 
eastern Ireland, the Lower Devonian schists, slates, grits, and sand- 
stones lie comformably on the Upper Silurian ; and on these " Glen- 
gariff Grits" (the Middle Devonian being absent) the Upper Old Eed 
rests unconformably, and passes upwards into the Carboniferous 
series, — a condition of things analogous to what is seen in the Pent- 
land Hills. 

Chapter xii. treats briefly but comprehensively of the Coal-fields 
of Great Britain and Ireland. Mr. Geikie has supplied a succinct 
account of the Carboniferous series in Scotland, as worked out by 
the Geological Survey. Of the Lower Carboniferous Eocks of Ire- 
land, it is remarked that it is their " strong lithological resemblance 



86 Reviews — MurchlwrC s " SiiuriaJ* 

which led Mr. Jukes to compare them with the lowest slaty rocks of 
Devonshire, which, containing very diifferent fossils, stand, in my 
opinion, precisely in the same position as that in which Sedgwick, 
De la Beche, and Phillips, as well as myself, have placed them" 
(p. 295). We observe the correction of the nomenclature of some 
Carboniferous fossils and a notice of the many new Reptiles (chiefly 
Labyrinthodonts) described of late years by Dawson, Owen, Marsh, 
and by Huxley in particular, who has added to the list eleven from 
the Scotch and Irish Coal-fields. A consideration of the origin of 
Bituminous shale and Petroleum forms part of this chapter, and also 
a portion of chapter xviii., in which the Palasozoic Rocks of North 
America are treated of. 

Chapter xiii. is in itself a concise monograph on the Permian 
Rocks of England, Scotland, Germany, and Russia, with reference 
to those of America and elsewhere. Carefully revised throughout, 
and augmented with Mr. Geikie's discoveries in Ayrshire, and those 
by the author and Professor Harkness in Westmoreland, it stands 
alone as a source of information to the student or general reader on 
Permian Geology and Palaeontology, and on the structure of some 
very interesting spots in Germany and elsewhere. 

The General Yiew of the Silurian, Devonian, and Carboniferous 
Rocks of Scandinavia and Russia, — of the Palaeozoic Succession in 
Germany, — of the Palaeozoic Rocks of the Harz, the Rhenish Pro- 
vinces of Prussia, and Belgium, — the Palaeozoic Rocks of France, 
Spain, Portugal, and Sardinia, — contained in chapters xiv.-xvii., 
already formed a well-known compendium of the geology of the 
Palaeozoic Formations on the Continent ; but now that it is fully 
revised and augmented by contributions from Kjerulf, Dahll, Hel- 
mersen, Schmidt, Tchihatcheff, Barrando, Geinitz, Giimbel, von 
Dechen, de Vemeuil, Collomb, de la Marmora, and other good 
geologists, we must value it still more highly. We particularly draw 
attention to the Bohemian portion of chapter xv. on account of the 
close relationship it has with the facts and arguments in the early 
chapters of the book, and on account of the many interesting points 
therein treated of, such as the so-called ''Colonies," and other fea- 
tures of this rich centre of Silurian life. The revised table (opposite 
p. 405) of the Upper Palaeozoic Rocks in Europe, from the summit 
of the Silurian to the Permian inclusive, will be found particularly 
valuable, as the chief localities both in the British Isles and Europe, 
as well as the typical fossils, are given as fully as space permits. 

'' The Succession of Primaeval Rocks in America," chapter xviii., 
is full of the latest information, much of which Sir W. E. Logan, 
Principal Dawson, and Dr. S. Hunt have directly contributed. The 
revised table of the Palseozoic Rocks of North America, compared with 
those of Britain, contains also lists of the characteristic fossils, and 
will be fully appreciated. 

' Chapter xix., giving us the author's views on the original intro- 
duction of gold into the earth's crust and its subsequent distribution 
in debris over various parts of the earth's surface, is rich with facts, 
new and old, illustrative of the subject. The researches of Selwyn 



Reviews — MiirchisorCs " Siluria." 87 

in Australia, Whitney in California, and David Forbes in South 
America, are especially referred to ; and the following are the con- 
clusions arrived at: — " 1. That looking to the world at large, the 
auriferous veinstones in the Lower Silurian Eocks contain the greatest 
quantity of gold. 2. That where certain igneous eruptions pene- 
trated the Secondary deposits, the latter have been rendered auriferous 
for a limited distance only beyond the junction of the two rocks. 
3. That the general axiom before insisted upon remains, that all 
Secondary and Tertiary deposits, except the auriferous detritus in the 
latter not so specially affected, never contain gold. 4. Tliat as no 
unaltered purely aqueous sediment ever contains gold, the argument 
in favour of the igneous origin of that metal is prodigiously strength- 
ened ; or, in other words, that the granites and diorites have been 
the chief gold-producers, and that the auriferous quartz -bands in the 
Palaeozoic Rocks are also the result of heat and chemical agency." 

In the last chapter of his work, Sir Roderick, taking a general 
view of ancient life from its earliest traces, points out the progress 
of creation after a long Invertebrate Period (represented by the 
Laurentian, Cambrian, Lower, Middle, and part of the Upper 
Silurian deposits) to the first period of Fishes (in the Lower 
Ludlow series), followed by the earliest epochs of Reptiles (Am- 
phibia in the Coal and Lacertilia in the Permian) and of Mammals 
(in the Rhaetic beds) ; thus indicating a succession of life from lower 
to higher classes, until Man crowns the scale of beings. Another 
subject which our author here keeps before his readers is, that in 
primaeval times there must have been a far greater intensity of 
action in the cracking, crushing, crumpling, and altering of the 
materials of the earth's crust, — that the concomitant earthquakes and 
volcanos were more energetic, and productive of greater special 
results, — that storms and floods, torrents and waves, were all more 
violent and more incessant in action, — that the degradation and re- 
arrangement of earthy and stony matters went on more ceaselessly 
and with greater results, both in the destruction and in the deposition 
of strata, — and that these last were more readily buried, more quickly 
changed, and more suddenly brought up by lateral squeeze and up- 
ward thrust than is now the case with sea-beds, volcanos, and moun- 
tain-chains. The great former changes of the surface, the enormous 
dislocations and wide and perfect denudations, the great fractures 
and reversals of strata, are brought forward as the results of great 
movements of the crust, and inexplicable by reference to modern 
causations, such as the faint shrinkings, the limited volcanos, the 
transient showers, the weak rivers of to-day. That the working 
giant, Ice, did not exist in those old days our author fully believes ; 
for the glaciers would require mountains, and those were not, if the 
uniformity of the old deposits, the world-wide distribution of 
similar animals, and the necessarily equable temperature, are fully 
allowed for. It is well now-a-days for thoughtful beginners to look 
on both sides of the many geological questions they meet with ; and 
here are the real " conservative " opinions of an old geologist, not 
lagging behind, but well up in the march of progress, — keeping in 



88 Geological Society of London. 

view the best of the old-fashioned thoughts and ripe opinions, whilst 
Ice-action is everything to some, — whilst Kain-action is the universal 
agent with these, and Sea- waves with those, — whilst Negative Evi- 
dence is the bug-bear of one party, Homotaxis a puzzle for another, — 
the gradual out-coming of new forms the belief of some, and the 
uniformity of nature, both physical and vital, the dogma of others. 

Once more, then, geologists have to welcome a revised edition of 
one of the most valuable of geological works, which, only by the 
use of much small type, has been made to contain within reasonable 
compass the great number of important additions to his Science that 
the author has had to notice. The many counties in England, Wales, 
Scotland, and Ireland that have their structure elucidated and their 
mineral wealth more or less treated of in this book, must all supply- 
many students and thankful readers. The traveller finds it of use, 
not only in Europe and North America, but in other parts of the 
world; indeed, an educated man anywhere can find something of 
interest in its less technical pages. The geologist proper well knows 
its value ; for, though he may here and there find more of the per- 
sonal history of Silurian research than he cares for, yet never, per- 
haps, will another such work be produced, in illustration of the sub- 
ject-matter it treats of, characterized by so full and perfect an associa- 
tion of the results arrived at by co-operating geologists, of all nations, 
clustered round a worthy centre — the author of this new edition of 
" Siluria," — a work rich in good facts, well arranged, and written 
by an earnest, mature, and philosophic mind. 



Geological Society of London. — December 18th, 1867. — 
Warington W. Smyth, M.A., F.E.S., President, in the Chair. The 
following communications were read : — 1. " On the Parallel Roads 
of Glen Eoy." By Sir J. Lubbock, Bart., F.R.S., Pres. Ent. Soc. 

The author did not enter into the question as to the manner in 
which the valleys were filled with water, but assuming that the 
'* roads " or " shelves " represent ancient water margins, he at- 
tempted to point out the manner in which they were produced. 

The theory of Macculloch, which has been adopted by Darwin, 
Lyell, and Jamieson, is, that the matter brought down by frost, 
rain, etc., from above, was arrested by the water, and heaped up by 
the action of the waves. If this was the true explanation, however, 
Sir John argued that the roads would form an excrescence on the 
slope of the hill, which they do not ; that their breadth must vary- 
considerably ; that the slope of the roads would be towards the hill ; 
and that the roads would be widest where the inclination of the hill 
is less than usual, and where streams bring down matter from above; 
whereas, on the contrary, in these places the roads disappear. 

In opposition to this theory. Sir John then argued that the action 
of the waves, under such circumstances, would be to throw matter 
down, and not up. Given a slope of angular debris standing at the 
angle of repose, partly in air and partly in water, the angle will be 



Geological Society of London. 89 

about the same throughout, because the angle at which matter will 
•stand depends partly on gravity and partly on friction. Now, as 
long as the water is at rest, the equilibrium in water remains as in 
air ; but as soon as the water is agitated, the friction is diminished, 
and the angle of repose becomes less. In other words, the pebbles 
are set iii motion, and roll down the hill. 

This explains the equal width of the roads, because the new angle 
of repose being equal througliout, and the depth to which the agita- 
tion extends being also equal, the width of the road must be equal 
also ; and when once the new slope of repose was acquired, the 
hill-side would again be in a condition of equilibrium, and the road 
would receive no further enlargement, however long the water might 
stand at the same level. This explains why there are no roads 
when the natural rock appears, or when the hill-side is less steep 
than usual ; whereas, if the roads were due to a heaping-up action, 
of course in places where the sides were more shelving the roads 
would be better marked. We can also thus understand why there 
are no rolled pebbles on the roads ; and lastly, as the lower line of 
the roads marks the depth to which the water was disturbed, we can 
see why the roads become narrower wherever they are steeper than 
usual. 

Finally, the vertical height of the roads — that is to say, the 
vertical difference between their upper and lower lines — gives the 
measure of the depth to which the water filling the valleys was 
agitated, and affords thus an additional argument in favour of its 
having been that of a lake, as in a tidal sea the width of the roads 
must have been much greater than it is. 

2. " Remarks on the Geological Features of the Northern part of 
Formosa and the adjacent Islands." By Cuthbert CoUingwood, 
M.B., F.L.S. Communicated by the Assistant-Secretary. 

The west coast of Formosa is flat, consisting of low alluvial 
plains, with a few hills, some of which approach the coast ; a range 
of mountains runs nearly through the island. Near Tamsuy, on the 
right bank of the river, is a thick deposit of clay, containing boulders 
on which the author could detect no traces of glacial strise. Higher 
up the river, on the north side, hills containing sulphur-springs rise 
from the plain. On the north-east side of the island sandstone 
extends from Masou peninsula, north of Kelung, to Petou Point on 
the south-east. The harbour of Kelung is a spacious excavation in 
the sandstone, which is hollowed out into numerous caves ; and Dr. 
CoUingwood states that the land is slowly rising, blocks of water- 
worn coral being found above high-water mark. Sano Bay, the 
only harbour on the east coast, is protected by a reef composed of 
trap-rock. The Pescadores are of volcanic origin, and are composed 
of basalt. The author then describes Hai-tan, and the islands of 
Craig and Agincourt, which lie to the north of Formosa, as well as 
the Pinnacle Islands, lying still further north. 

3. "On some Sources of Coal in the Eastern Hemisphere." By 
Cuthbert CoUingwood, M.B., F.L.S. 

1. Kelung, Formosa. —The coal is found in depressions in Eed Sand- 



90 Geological Sockty of Glasgow. 

stone, and is of comparatively recent origin. It is light, bums very 
rapidly, gives out great heat, produces fifty per cent, of ash, and 
forms considerable quantities of clinker. 

2. Labuan, Borneo. — Several seams of coal crop out conspicuously 
near the coast, the lowest being eleven feet four inches in thickness. 
It is heavy, close-grained, fast-burning, and gives out considerable 
heat ; it is of very recent date, dammara resin, and leaves of recent 
trees being found associated with it. 

3. Diu, Saghalien. — Coal excellent, burns quickly, with little ash. 
Presents a fracture similar to Welsh Coal. 

4. Japan. — The author describes coal from several localities in 
Japan as bright, clean, and resembling Sydney coal, but having a 
tendency to form clinker. He concludes with a description of some 
coal from Ivanai, Niphon, which is very clean, highly bituminous, 
burns with a flame in the flame of a candle, and would probably be 
valuable as a gas -producing material. 

Geological Society of Glasgow. — Notes on the Geology of 
Norway. By Eev. Henry W. Crosskey, Vice-President. Eead 19th 
December, 1867. — The paper described investigations carried on in 
Norway by Mr. Crosskey, in company with Mr. David Eobertson — 
especially in the Post-tertiary formations of that country. The 
districts visited were the fijord of Christiania, the rivers and lakes 
leading into the heart of the Thelmaken, Gousta mountain, and. the 
Ejukan Foss. The study of the Norwegian beds greatly facilitates the 
due arrangement of the clays, sands, and gravels of Scotland ; and 
indubitable evidence exists as to the action of the same great physi- 
cal agents in both countries, during the glacial epoch and continuing 
to the present day. The rounded bosses, and general contour of the 
scenery, remarkably evident in the Christiania fijord; the scratched 
rocks and grooved and polished surfaces ; the development of a 
Boulder-clay precisely analogous to that seen over Scotland; the 
terraces of sand and gravel stretching along the valleys (as, for 
example, from Tingeset to Semb) were described at length as indi- 
cating the same series of physical changes. A Laminated clay, cor- 
responding to that well known at Paisley, and probably caused by 
muddy water issuing from beneath ice, was described as resting 
upon the Boulder clay, in the neighbourhood of Christiania. The 
oldest Norwegian shell-beds examined at Moss and Upper Foss 
prove the former degree of cold to have been much intenser than 
the present, and very analogous to that which formerly prevailed in 
Scotland. The characteristic shell at Moss is Leda arctica, a highly 
arctic species ; and this is equally characteristic in the clay-bed at 
Errol, in the Carse of Gowrie. A well-defined, arctic group of 
shells is common to the older Scotch and Norwegian clays, and 
proves in both cases a considerable intensity of cold. The Post- 
glacial shell-beds examined near Skien, and other places, prove the 
gradual character of the change of climate. Arctic forms are mixed 
with species more southern in character. At the Bisoet tile-works, 
e.g., Isocardia cor is associated with Tellina proxima. The island of 



Royal Microscopical Society, 91 

Barholmen, off Drobak, was described at length as one of the most 
interesting and important localities. Masses of the Finmark coral, 
Oculina proUfera, are there found, rising to a height of 1 20 feet, and 
attached to the rock at the bottom of the fijord, at a depth of 10 to 
15 fathoms. This coral never lives at a less depth than from 150 to 
300 fathoms ; and its occurrence as a fossil at Barholmen thus proves 
an elevation of the land (since the extreme glacial epoch of the pre- 
ceding group of beds) to an extent of about 135 fathoms. Asso- 
ciated with this coral, are the shells belonging to a similar depth of 
water, such as Lima excavata; Pecten aratus. In fact, the isle of 
Barholmen was formerly a sea-bottom, 135 fathoms deep, inhabited 
by a fauna similar to that now native to the deeper waters of Fin- 
mark. Shells, indeed, are common in this fossil bed which are now 
dying out in Finmark itself. As indicative of similar elevation, the 
occurrence of Balani attached to the rock, in Aremark, at 450 feet 
above the sea, was also noted. The general conclusions submitted 
from the details given in the paper were (1) tbat the same physical 
causes were at work in Norway as in Scotland during the Glacial 
epoch. (2) The subsequent changes in climate took place by degrees, 
each alteration leaving its mark on some point in the series of shell- 
clays. (3) The classification of the shell-beds, which can be made out 
in Norway, is applicable to Scotland, and their order of succession is 
the same in both countries. (4) The south and south-west districts 
of Norway were much colder than at present ; and the climate in 
Scotland shared a kindred intensity of cold. (5) The elevation of 
the land since the close of the period of extremest cold has been not 
less than 800 feet. In conclusion, Mr. Crosskey described the ascent 
of Gousta, 6,000 feet in height, and the peculiar level character of 
the surfaces of the ranges of mountains commanded by it ; and the 
waterfall of the Kjukan Foss, where a considerable river plunges 
over a precipice 900 feet in height. — J. A. 

EoYAL Microscopical Society. — At the meeting on the 8th inst., 
James Glaisher, Esq., F.E.S., President, in the chair, a paper was 
read by Professor T. Rupert Jones *' On Recent and Fossil Bivalve 
Entomostraca." The Professor said that the word Entomodraca 
(shelled-insects) applied to them was a misnomer, for that although 
they were originally believed to be water-insects, and from their 
jumping motion some of them were called water-fleas, they are not 
insects at all, but hold a place amongst the Crustacea. He described 
the structure of different kinds of these small Crustacea, especially 
referring to the various uses of the limbs. Nature always makes 
one part or organ useful, if possible, for more than one purpose, and 
thus one of these limbs may be made to serve as a jaw, or as a foot 
or organ of motion, as a branchia or organ of respiration, or as an 
instrument for holding the eggs beneath or above the body. He 
alluded to the wide-spread distribution of Entomostraca over the earth, 
not only at the present day, but in ages long gone by. From an early 
period of the existence of life on our globe, these little creatures have 
filled the seas and rivers in immense numbers. They are found in 



92 Correspondence — Mr. David Forbes, 

the lowest rocks of tlie Silurian ; in the strata of the Old Eed Sand- 
stone the schists are marked with the little microscopic spots where 
they have been. In many limestones they are well preserved; in 
the Coal-series they are so abundant that they make up massive 
layers, and so through all the groups, as plentifully in the marine as 
in the fresh-water beds. Existing as they did in such vast numbers 
in the waters and muds of the ancient seas and rivers, it necessarily 
follows that the accumulated shells of the dead specimens should far 
outnumber the living ; and when we examine our ponds, etc., at the 
present day, and find them teeming with this form of animal life, we 
may understand how largely these minute Crustacea have contributed 
to form the carbonate of lime in the various rocks above mentioned. 
The speaker explained how new forms had been discovered in the 
mud of foreign countries, and requested his hearers to induce any of 
their friends who might be going abroad to bring or send home pill- 
boxes filled with the dried mud of any of the rivers or lakes they 
might pass in their travels. By keeping these carefully separated, 
and putting them in distilled water on their arrival in this country, 
he said that many new and interesting species might be developed. 
Land and Water ^ January 18, 1868. 



coI^I^:Es:poIs^x)EI5^CE. 

DE. T. STEEEY HUNT'S GEOLOGICAL CHEMISTEY. 

Sir, — In the last number of the " Chemical News" ' (Jan. 17), Dr 
Sterry Hunt has inserted a reply to some remarks of mine contained 
in No. 409 of that Journal, but which, in reality, is in great part a 
criticism on the contents of my communication to the Geological 
Magazine for October last, the substance of which Dr. Hunt accuses 
me of having, " for some unknown reason, witheld from the readers 
of the ' Chemical News.' " The absurdity of this accusation is self- 
evident, as in the '' Chemical News " the reader is distinctly given to 
understand that the communication was but a supplement to the 
previous one in the Geological Magazine of October 1st ; and, as you 
are aware, in the Geological Magazine of that date, special attention 
is directed to this forthcoming supplement. I would, therefore, ask 
the favour of your inserting in your forthcoming number the enclosed 
communication, which, by also appearing in the next number of the 
"Chemical News," will, I hope, satisfy Dr. Hunt that it is not my 
wish to withold any of the points of this controversy either from the 
readers of the *' Chemical News " or of the Geological Magazine. 

20^A Decetnber, 1868. DaVID FoRBES. 

^ If the reader will compare the article by Dr. T. Sterry Hunt, in the Chemical 
News, here referred to, with that contained in our present Number, p. 49, he will 
perceive, that, to a great extent, they are the same ; this letter is therefore capable 
of being treated as a reply, in part, to both of Dr. Sterry Hunt's communications ; 
but there are several points discussed by Dr. Hunt in this Magazine which are not 
entered upon in the Chemical News. To these Mr. Forbes will no doubt reply after 
he has seen and compared the two articles.— Ed. 



Correspondence — Mr, David Forbes. 93 



ON SOME POINTS IN CHEMICAL GEOLOGY. 
By David Forbes, F.R.S., etc. 

In the '' Chemical News " of October 4th, 1867, I commenced 
some remarks under this title, for the express purpose of exciting 
more interest in the application of Chemistry to Geology, and with 
the hope of starting a discussion which might at the same time en- 
liven as well as elucidate the subject. Accepting Dr. Hunt's invi- 
tation, — his views, being the most recent, were first selected for 
consideration, and although that gentleman now appears greatly 
astounded at my presuming to differ from his opinions, it is still 
highly gratifying to find that he has at last condescended to reply. 

As this reply, however, contains absolutely nothing which can in' 
any way affect or modify the opinions which I have already expressed 
on the views of Dr. Hunt, or even require a reconsideration of the 
arguments upon which those opinions were based, I am enabled to 
reply tout de suite. 

Dr. Hunt adopts a line of argument which is an elaborate attempt 
to convince his readers of the utter incompetency and ignorance of 
his reviewer ; yet, at the same time, it is amusing to observe that the 
character and tone of his remarks, in conjunction with his studious 
avoidance of some of the knotty points and more important argu- 
ments brought forward in opposition to his views, are strikingly 
suggestive of his being afilicted with a presentiment that there may 
after all be rickety points in his theoretical views. 

Men who live in glass houses should not throw stones : Dr. Hunt's 
accusations of ignorance will appear strange to those who have paid 
attention to some of his sweeping assertions : amongst others, for 
example, when he emphatically declares that quartz '^ can only be 
generated by aqueous agencies," geologists will infer that Dr. Hunt 
must be ignorant of the most important fact, that quartz is found in 
abundance in volcanic lavas in many parts of the world, although 
not in Canada. 

Had Dr. Hunt remained content with his Canadian laurels, he 
would probably have enjoyed them in peace without having his 
opinions disputed ; but when he now aspires to be recognised in 
Europe, he cannot complain if his views be criticised by any or all 
of those interested in the subject — an ordeal which must be under- 
gone before he can expect them to receive general acceptance, for 
surely he does not issue them as axioms or oracles. Europe differs 
greatly from Canada, and amongst other things, in close competition 
being the order of the day. No man in Europe can expect to retain 
any portion of the field of science exclusively for himself, or to travel 
alone on any of the many different roads which lead to one and 
the same scientific truth. 

If real progress is to be made in science, the student must reason 
for himself, and not be content with accepting, merely on authority, 
opinions which are inconsistent with his own deductions or experi- 
ments ; nor should he be deterred by the opposition to be expected 



94' Correspondence — Mr, David Forbes. 

from those already in office or authority, who are sure to be jealous of intruders on 
what they imagine to be their own domain, and, doubtless, dislike having their 
peace of mind disturbed by innovations. 

A discussion of this nature may be carried on in two ways, either by considering 
the main points of the argument first, before engaging in the minor details, or the 
reverse ; Dr. Hunt prefers the latter course, which, no doubt, is best suited to the 
defence of a weak cause, but which his rather rambling remarks in last week's 
Chemical News^ will show is not calculated to convey to his reader any very clear 
idea of the exact points at issue, and is likely to confuse by then umber of minor 
details, having little or no bearing upon the main questions. 

It is, therefore, most important for me that no misunderstanding should arise as 
to the exact points on which I have presumed to differ from the principles of 
chemical geology which Dr. Hunt has recently brought before the scientific public 
in Europe. 

Expressed in as few words as possible, I object to the following of Dr. Hunt's 
assumptions or assertions : — 

1. That the earth is solid to the core. 

2. That the surface of the earth, immediately previous to its entire solidifica- 

tion, was "a liquid bath of no great depth surrounding the solid nucleus," 

3. That the original atmosphere contained " the whole of the chlorine in the 

form of hydrochloric acid, the sulphur as sulphurous acid. " 

4. That the saltness of the sea is due to a rain of hydrochloric acid ''flooding 

the half-cooled crust" with a highly heated acid deluge. 

5. That the whole of " the calcareous strata, the marbles, and various limestones 

which we find on the earth's surface" have been precipitated from the sea 
by carbonate of soda. 

6. That all the magnesian limestones and gypseous beds were formed in a dense 

atmosphere of carbonic acid. 

7. That quartz "can only be generated by aqueous agencies." 

8. " That granite is in every case a rock of sedimentary origin." 

9. That volcanic rocks are merely ordinary sedimentary beds, melted by being 

"depressed, so that they come within the action of the earth's central 
heat." 

Any minor differences fall naturally under these heads, and I may add that the 
perusal of Dr. Hunt's defence has confirmed me more than ever in the belief that 
the above premises are unsound, and I shall now endeavour, as concisely as possible, 
to examine the arguments pro et contra. 

I. — The earth solid to the core. 

Dr. Hunt seems to imagine that if the earth is not solid to the core, it can only 
consist of an immense central sphere of molten matter covered by a thin external 
crust or shell, for he wastes all his arguments in attempting to upset this theory, to 
which I had never given my adhesion. 

I have preferred adopting in the main the hypothesis of Bunsen, no mean 
authority, and when opposing Dr. Hunt's views simply asserted my opinion that 
the earth still encloses "a vast reservoir or reservoirs of still fluid igneous matter 
in its interior ;" and the main argument with winch I support this opinion is, that 
I consider that the molten lava ejected from volcanos must be derived from some 
such source. This is a veiy simple but common-sense view of the case, which I 
imagine Dr. Hunt will find some difficulty in refuting. 

II. — That the earth's surface immediately previous to its entire solidification was 
"a liquid bath of no great depth surrounding the solid nucleus." 

Hopkins has taken into favourable consideration the supposition that the earth 
actually was solid both in its centre and crust, and yet might retain fluid igneous 
matter in the intermediate space ; and taking a somewhat similar view of the case, 
I believe that, even allowing that the solidification actually did commence at the 

1 It is necessary to explain here that many of Dr. Hunt's observations refer to a previous 
communication in the October Number of the Geological Magazine, and not to the subsequent 
one in the Chemical News of Oct. 4, which, as is distinctly stated therein, i.«, only supplementary 
to the former and to be read in conjunction with the same ; yet Dr. Hunt indulges in the absurd 
accusation, that the contents of that communication have, "for some unknown reason, been 
withheld from the readers of the Chemical News" 



Correspondence — Mr, David Forbes, 95 

centre, it still could not have reached the exterior before, on the other hand, 
the surface itself had also solidified and formed a crust commencing from the 
exterior, due to the external cooling action. 

In opposition to this. Dr. Hunt states that silicates, when cold, are from one- 
seventh to one-sixteenth part more dense than when molten, and would at once sink 
down into the fluid mass below, and further adds that no crust could be formed 
unless the laws of gravity were suspended. I do not know what Dr. Hunt's idea 
of the laws of gravity may be, but I would merely again ask how far he imagines 
a crust of sp. gr. 2 "6 could sink down into a molten sphere of a mean sp. gr. 5 •3. 
I will not, however, repeat the other arguments which I have used in the 
Geological Magazine, but content myself by bringing forward one not before 
employed by me in support of my opinion. 

Some experiments which I am now engaged in, on the effect of heat on bodies 
which contract in cooling, i.e. which are more dense when cold than when molten, 
show in the cases tried that a body upon the first application of heat expands and 
continues to do so up to near its melting point, when it contracts at the instant of 
fusion ; in other words, although the substance when cold was heavier than 
when molten, yet the same substance expanded by heat was lighter than when 
molten. Thus, some metals were found to float about (like ice upon water) upon 
the surface of a molten bath of the same metal into which they were placed in a 
heated condition,^ It appears probable that the same phenomena would account 
for such a crust as Dr. Hunt disputes, not sinking but floating on the molten bath 
below. 

That the earth may possibly have solidified at the centre first, is not disputed by 
me, nor does its so doing in any way affect my theoretical views. The object of 
my observations on this head was to show that we are altogether too ignorant of 
the character of the central mass of the earth, and of the effects likely to be 
produced by such enormous pressures, to be enabled to reason upon such insuffi- 
cient data with any confidence in the result. 

III. -That the original atmosphere contained "the whole of the chlorine in the 
form of hydrochloric acid, the sulphur as sulphurous acid." 

The perusal of Dr. Hunt's remarks does not in any way tend to modify the 
conclusions I had previously arrived at on this head. I still believe that chemists 
will not be disposed to regard an atmosphere containing enormous volumes of 
sulphurous acid, steam, and oxygen in excess, or in other words, which resembles a 
great sulphuric acid chamber, as probable; and as Dr. Hunt does admit that they 
would slowly unite to form sulphuric acid, it merely becomes a question of time 
as to whether they united slowly or quickly. 

The arguments which I advance against supposing that such an atmosphere 
ever did exist are, that I consider that the sulphur would unite mainly with the 
heavier metals, and the chlorine mainly with the alkaline metals, and I conse- 
quently infer that these elements never went into the atmosphere in any such 
quantity as Dr. Hunt imagines. 

Dr. Hunt, in opposition, states that sulphides could not be formed, since 
oxygen was in excess. Metallurgists know that sulphides are far less easily 
oxidizable than is generally imagined, and that they are produced in both blast and 
air-furnaces when the waste gases still contain unconsumed oxygen, and that time 
is an important element in this consideration. 

But we have no proof whatever of any great excess of oxygen in the primeval 
atmosphere ; on the contrary, we know^ that a vast amount of the oxygen now 
present in the air must have been derived from the decomposition of the carbonic 
acid, when the immense supplies of carbon afterwards buried in the various sedi- 
mentary formations were extracted from the atmosphere by the action of vegetable 
life. The slight excess of oxygen which, no doubt, was present would, further, 
be so diffused through the enormous volume of carbonic acid, nitrogen, and 
aqueous vapour, that it cannot be imagined to have exercised other than a most 
feeble oxidising action. 

» As a metallurgist I have frequently observed such cases, but for a long time did not under- 
stand the explanation ; I have to thank my friend Mr. Hackney for directing my attention to 
the behaviour of Bessemer steel under these circumstances, as it gives great trouble to the work- 
men by persistently floating high on the surface of the melted steel (even when in pieces of 
40 lbs. or more) as long as its temperature is below its fusing point. 



96 Correspondence — Mr, David Forbes, 

The carbonic acid, also, being so infinitely more dense, and present in so over- 
whelming a quantify, would further act as a powerful shield against the very 
oxidising action which Dr. Hunt lays such stress upon. 

That the chlorine did not go into the atmosphere, as Dr. Hunt imagines (com- 
bined with hydrogen as hydrochloric acid), I infer from the well-known far 
greater affinity which it has for sodium than for hydrogen, and the volatility of the 
sodium would be far more likely to bring it in contact with the chlorine than with 
the silica. 

The idea that the action of the feeble excess of oxygen above alluded to, in con- 
nection with silica and steam, would prevent the formation of chloride of sodium, 
is not of much weight, since the chloride of sodium would be formed as a vapour 
in the atmosphere, while the silica remained below in the earthy mass in a solid 
form. 

But Dr. Hunt next writes : "Even if, as Mr. Forbes supposes, the chloride of 
sodium were to be formed in the heated atmosphere, it would be precipitated into 
the intensely heated bath," etc. Precipitated ! when it would be in the state of 
vapour at this temperature. 

Metallurgists know how indifferent chloride of sodium is when fused with silicates, 
and to this property is due the employment of what is termed a salt-cover in assays ; 
however well the salt may be intermixed, once the mass is fused it rises and 
swims on the top, and (if the heat be not too elevated or protracted as to vola- 
tilise it entirely) presents, upon cooling, a well-defined crystalline crust of salt, 
below which is found the unaltered silicate slag, and below this again the button 
of metal, pure or more or less in combination with sulphur, arsenic, antimony, 
etc., as the case may be; thus presenting, on the small scale, an illustration of 
what I have supposed may have occurred in nature, m which case also the cover 
or crust of salt would act as a shield against oxidation. 

In a potter's kiln, the vapour of salt under confinement merely glazes the sur- 
face of the ware to a minute depth, which very glaze protects the silicates 
from further action ; but both the potter's kiln and Gossage's soda-process are 
worked under forced circumstances, not applicable in this argument ; and when Dr. 
Hunt explains that in his illustration of this subject he merely used the words, 
'"'■ if the elements were made to react upon one aitotker,^^ is it not rather he who 
is trifling with the subject, when he supposes conditions which never could occur 
in nature in the case referred to. 

IV. — That the saltness of the sea is due to a rain of hydrochloric acid "flooding 
the half cooled crust " with a highly heated acid deluge. 

This assumption requires no further comments than those included under the pre- 
ceding head, where I have endeavoured to show that the whole of the chlorine did 
not ascend into the atmosphere as hydrochloric acid, and, consequently, could not 
flood the earth with the hot acid deluge insisted on by Dr. Hunt. 

V. — That the whole of "the calcareous strata, the marbles and various lime- 
stones which we find on the earth's surface," have been precipitated from the 
sea by carbonate of soda. 

Geologists have long agreed, that sedimentary limestones are the products of 
the action of organic life; and microscopists, in confirming this, have further 
proved that they do not possess the character of precipitates. Dr. Hunt evades 
any reply to these objections, but asks a question in return, requesting to know 
what becomes of the acid in case, as I contend, animals can utilize the salts of 
lime contained in the sea. As is well known, sulphur plays a very importan 
part in vital economy, entering both into the composition of organisms, and being 
also given off as sulphuretted hydrogen in the gaseous form. I see, therefore, 
many reasons for believing that animals do assimilate the sulphate of lime, which 
we know is contained in such an enormous quantity in the ocean. 

VI. — That all the magnesian limestones and gypseous strata were formed in a 
dense atmosphere of carbonic rxid. 

In 1H46, when in Birmingham, I was informed that for some years the manu- 
facture of magnesian preparations was based upon the reactions of the compounds 
of magnesia with carbonic acid, in a compressed atmosphere of carbonic acid. In 
1849, Mr. Osborne, a gentleman connected with a si4»ilar manufactory in Ireland, 
fully confirmed these statements, and shortly after the publication of Dr. Hunt's 
paper in the Comptes Rendus, Dr. Lawson, in the course of conversation, ex- 



I 



ll 



1 



Correspondence — Mr, David Forbes. 97 

pressed his surprise at Dr. Hunt being unaware of this, since he knew that the 
principle had been long in use in a manufactory at Cork. 

Dr. Hunt has further applied this principle,^ and obtained very interesting results, 
which he considered to be the counterparts of nature's operations ; and, remember- 
ing that there are dolomite beds in the lower Silurian strata of Canada, at once asks 
geologists to believe the rather hasty generalization that all the magnesian lime- 
stones and gypseous beds were formed in a dense atmosphere of carbonic acid. 

Geologists, however, well knowing that the grand development of magnesian 
limestones and gypseous strata occurred in periods when air-breathing animals 
existed on the surface of the globe, could not believe that these animals actually 
lived in a dense atmosphere of carbonic acid ; and had some of the more modern 
great gypseous formations occurred in Canada, Dr. Hunt would probably not 
have brought forward this theory. 

Vn. That quartz "can only be generated by aqueous agencies." 

Dr. Hunt, wisely no doubt, does not take any notice of my arguments against 
this assertion, since they are facts, not opinions, and consist merely in pointing 
out that volcanic lavas of Italy, Hungary, Peru, Bolivia, Chili, etc., contain 
abundance of quartz often in well-defined crystals. In connection with this I may 
here extract a passage from a letter received from Mr. Sorby, who writes, " I have 
splendid cases of recent lavas with quartz, both in the shape of small crystals and 
as rounded masses, like those seen in some older rocks ; and this quartz in both 
cases (crystals and rounded masses) contains splendid glass cavities, just like those 
in the felspars, the Arran pitchstone, and the various lavas ; thus we have complete 
proof, according to my views, that quartz both can and has crystallized out from 
a melted mass of rock." Now, in face of such facts, what importance, may I ask, 
can be attached to such of Dr. Hunt's dogmatic assertions as, "that the composi- 
tion of the primitive crust would have excluded free silica?" that quartz " is only 
the result of a secondary process ? " etc. 

Vni. — " That granite is in every case a rock of sedimentary origin," 

Dr. Hunt makes this assertion in opposition to the opinion of many able men who 
have well studied the subject. If he, however, only founds this opinion on the 
presence of quartz in granite, the value to be attached to it may be inferred from 
the remarks contained in the preceding paragraph. If he speaks as a geologist, 
it may fairly be inquired whether he considers his Canadian experience sufficient 
to enable him to arrive at such sweeping generalization. 

Sir Charles Lyell has stated that three things were essential to a geologist, 
namely, "to travel, to travel, and to travel;" and such advice may be recom- 
mended to Dr. Sterry Hunt before he ventures again to generalize for the world 
on the strength of a local knowledge of a very minute part of the same. 

IX. — That volcanic rocks are merely ordinary sedimentary beds, melted by being 
" depressed, so that they come within the action of the earth's central heat." 

In the Geological Magazine I ventured to inquire of " the author of this 
ingenious theory by what mechanical arrangement he supposes strata, on the 
surface of the earth, to be lowered down into a globe solid to the core ; " and 
again, "how are we, according to this theory, to account for the fact that volcanic 
rocks, taken from any quarter of the world, no matter how far distant from one 
another — from Iceland or Terra del Fuego, from the Islands of the West Indies 
or from those of Polynesia — that in all cases such rocks possess an absolute identity 
in chemical and mineralogical composition, in physical and optical properties : 
can any geologist be expected to believe that such rocks have been formecl by the 
melting up of a mere mechanical aggregate of rock debris, possessing no analogy 
whatsoever, and whose chemical composition, etc., is known to vary to the widest 
imaginable extremes?" — questions as yet unanswered. 

Before concluding these remarks, I would here acknowledge that Dr. Hunt has 
discovered an inaccuracy which occurs in my communication to the Geological 
Magazine, where the position of steam in the imaginary original atmosphere is 
by accident placed below that of air, although steam is in reality lighter — as a 
moment's reflection would have shown. This error has not the most minute influ- 
ence on any of my generalizations, as it is perfectly immaterial whether this 
stratum be above or below that of air. 

I shall always be ready to admit at once any error which may be found in my 
^ Vide Chemical NewSy Sept. 13, 1867, p. 148. 
VOL. V. NO. XLIV. 7 



98 Correspondence — Rev. 0, Fisher, 

communications, and Dr. Hunt is quite entitled to make the most of such a 
bhmder, if he considers it will support his views ; at the same time I trust that he 
will also be equally candid in cases where he may be found tripping. 

Dr. Hunt alludes to a rough sketch of some of my views contained in the 
Geological Magazine ; but as I have already accepted the invitation of the 
Council of the Chemical Society to give a lecture on Chemical Geology (20th 
February next), Dr. Hunt will thus be enabled to take my views into full con- 
sideration, and after comparing them with his own 1 trust he will give us the 
benefit of his scrutiny ; for as I regard the ultimate object of all my labours as 
being the attainment of scientific truth, I am as fully prepared to be corrected in 
points where I may be proved to be wrong as to defend those which I hold to be 
right. 

THE BOULDER-CLAY AT WITHAM AND THE THAMES VALLEY. 

Sir, — Mr. Dawkins has spoken of the occurrence of a Boulder-clay 
at Witham as affording a presumption that the valley there is older 
than the glacial drift. I am able to give a rough section of the 
boring for the well in v^hich it occurred, where I saw it in 1865. 
I obtained the depths from the men at work, in answer to questions 
regarding the stuff which I saw to have been brought up. 

SECTION OF ARTESIAN WELL AT WITHAM STATION, ESSEX. Feet. 

Coarse gravel 20 

Greyish Glacial clay, with large flints and chalk pebbles 150 

Fine clayey sand, brown and green, with green-coated flints at the bottom, 

(Thames sand) 10 

Chalk, in which the water was obtained. 

The spot is more than 20 feet above the stream, so that the gravel 
is a terrace gravel ; and, in what is probably the same bed, I found 
a short time previously a good specimen of an oval flint implement : 
I picked it off a heap in the gravel-pit, at the entrance of the lane 
which leads to the Goods' Depot. 

Now, as regards the glacial clay in this section, there is a pecu- 
liarity which at the time surprised me much. I allude to the entire 
absence of anything like the " middle drift" beneath it. This drift 
occurs in full force along the high ground to the south, by Danbury 
and Wickham Bishops ; and Mr. S. V. Wood, jun., has shown it in 
section 9 of his paper on the Essex valleys,^ as underlying the Boulder- 
clay at Little Braxted close by. A glance at that section will show 
that the position of the Boulder-clay at Little Braxted has no analogy 
with that at Witham Station, where it extends many feet below the 
bottom of the valley. These circumstances, to my mind, throw a 
considerable doubt upon the clay at the station being the true 
Boulder-drift ; and if it be not, we cannot argue from it that the 
valley is older than the Boulder-drift. 

We are told of the existence of several Boulder-clays — and I can 
myself speak to a Boulder-clay occupying a valley in Essex which is 
clearly newer than the true Boulder-drift. It is to be seen on the 
shore, beneath the terrace, at Walton-on-the-Naze. It contains 
Chalk pebbles, large flints, London clay septaria, and Crag sand, 
and is full of mammalian bones. In hard specimens it could not be 
distinguished from the older Boulder-clay. 

I have not a sufficiently minute acquaintance with the neighbour- 
^ Geol. Mag., Vol. III. p. 348, map. 



Corre!ipondence — Rev. 0. Fisher. ^-99 

hood to be able to contribute many observations to the elucidation of 
the question at issue regarding the age of the Thames valley. But, 
as I have already stated in your pages, I cannot admit the presence 
of the re-arranged material, which I call " trail," to be any proof of 
geological antiquity ; regarding it, as I do, as an accompaniment of 
the last general denudation of the surface. When Mr. Wood says 
that he does not admit the existence of this deposit (though it is not 
strictly a deposit) as ''a formation,"^ I understand liim to mean that 
he thinks that peculiar condition of the sub- soil to be of various 
geological ages, from the glacial drift upwards, instead of referring 
it to our period, as I do. Thus, although we disagree upon the age 
of the trail, we are in accord as to its existence, and also as to its 
having no bearing on the question in hand, viz., the antiquity of the 
mammaliferous deposits of the Thames valley. 

It was asked during the discussion on Mr. Dawkins' paper, why 
the Boulder-clay did not cross the valley of the Thames. I then 
offered the suggestion that the cause might be found in the elevation 
of the Weald. Denudation is a function of altitude. In a given dis- 
trict it requires a certain amount of coherence in the constitution 
of a deposit to enable it to resist destructive influences of altitude. 
Hence, if the Boulder-clay was once spread over the North Downs — 
and they have been raised higher since — we need seek no other rea- 
son for its disappearance in that area. There is, I believe, a parallel 
case in Hants and Dorset. The elevation of the southern part of the 
Isles of Wight and Purbeck, and of the Weymouth district, south of 
the uplifted chalk, is probably of the same date as that of the Weald. 
Now, in the south-western counties, the Boulder-clay, as I believe, 
is represented by the thick bed of coarse flint gravel which forms 
the capping of most of the tabular hills of the New Forest and of the 
Tertiary country of South-east Dorset. But this bed of gravel does 
not cross the Chalk Downs. It appears to have been lifted up and 
carried away together with all the other deposits which once lay 
upon the Chalk ; and, in passing, I may mention that the Tertiary 
strata which cap Eidgway Hill near Weymouth are vertical, being 
just as much affected by the disturbance as those of Alum Bay. 

Now the Thames valley is so near the northern boundary of the 
Weald that we may well conceive the local disturbance to have been 
felt in it. And, indeed, the occurrence of a fault bringing up the Chalk 
against the London clay near Purfleet is probably part of the same 
movement. Again, the altitude attained by the Middle Drift along 
the hills south of Chelmsford and Witham is almost in itself suffi- 
cient proof that the disappearance of the Boulder-clay in that direc- 
tion is due to denudation. 

My impression is, that the mammaliferous bed of Grays Thurrock 
is of the same age as that of Clacton. It is possible that species may 
be present in the Clacton deposit which have not been collected, for 
it is most difficult to obtain specimens there. The late Mr. John 
Brown, by a combination of assidiiity and good fortune, obtained a 
good many ; but although I watched the place for nine years I never 
1 Geol. Mag., Vol. V. p. 43. 



100 Correspondence — Mr. C. Carter Blake. 

got a single bone, and am persuaded that the bed during that time 
was not once laid open by the tides. On the other hand, the excava- 
tions in the Thames valley are very extensive, and continually 
worked, so that, probably, most of the species have turned up which 
are there buried. There is certain proof of the depression of the 
Clacton area subsequently to the period when the mammalia were 
entombed, for the bed in which they lie is purely freshwater, and it 
is covered with several feet of brackish water beds, with small 
Scrohicularice ; and at the top of the section occurs a seam in which 
I found Cyrena fluminalis, associated with dwarfed Cardium eduUy 
and a Paludina undistinguishable from lenta. Now a similar de- 
pression of the area seems to be shown at Grays, by the false 
bedded sand. No. 5 of Mr. Dawkins' section/ overlying the mam- 
maliferous gravel. 

The Clacton deposit is a true valley deposit, cut out of the London 
clay, and an overlying gravel which Mr. Wood calls the " East 
Essex Gravel." This gravel, as I understand him, he supposes 
much newer than the Boulder-clay ; but at any rate it cannot be 
older than the Middle Drift, and in either case it throws the Clacton 
deposit into Post-glacial times. 

0. Fisher. 



BOS LONGIFEONS. 



Sir, — Owing to my absence from England, I have only just 
enjoyed the pleasure of reading the memoir which my friend Mr. 
Boyd Dawkins has contributed to the " Quarterly Journal of the 
Geological Society," and which appears in their 91st No., p. 176. 
There are some passages in this to which I may reasonably be 
allowed to demur, and I therefore, while giving Mr. Boyd Dawkins 
the utmost credit for the ability with which the case for the plaintiff 
has been stated, will at once proceed to open the defence. 

The characters of Bos longifrons are clearly described by Mr. Daw- 
kins, with such lucidity, in fact, that he is '' unable to assign any 
characters of specific value to the animal." But I cannot allow that 
he shows sufficient cause why two out of the three other species of 
fossil English Bo vines should be abandoned. In a memoir of eight 
pages, exactly twenty-one lines are devoted to the examination of 
the claims of Bos frontosus to specific distinction ; whilst Bos trocho- 
ceros is utterly ignored. Both these species were found associated 
with Bos longffroYts in a refuse heap in London Wall, by my friend 
Lieut. -Colonel A. Lane Fox, F.S.A., and the circumstances of their 
gisement have been accurately described by him in the " Journal 
Anthrop Soc. Lond.," Dec. 1866. Of their identification there can 
be no doubt, and the specimens will be gladly placed in Mr. Daw- 
kins' hands for description. 

Mr. Dawkins' argument is as follows, — " A very large number of 
skulls from the Irish turbaries in the Museum of the Eoyal Dublin 
Society show a marked gradation in size and form, and constitute 
^ Quart. Journ. Geol. Soc. vol. xxiii. p. 94. 



Corlrespondence — Mr. C. Carter Blake » lOl 

an unbroken series with the Bos frontosus of Nilsson at one end, and 
the more common variety of Bos longifrons at the other. *•'' ** ** 
In consequence of this, I am unable to assign any characters of 
specific value to the animal. *** **'* The Bos frontosus of Nilsson is 
proved by the series in Dublin, as stated above, to be a mere variety." 
Such, and such only, are the grounds on which Mr. Dawkins dis- 
poses of this species. He gives two measurements of skulls of indi- 
viduals who confessedly appertain to Bos longifrons, and have no 
" Frontosine" characters, and eight measurements of horn-cores. No 
further are vouchsafed to us ; none are even promised, though we 
learn that some detailed measurements of teeth and long bones are 
to be appended at the end of his third paper. The facts are not 
forthcoming, or at least are not shown, on which Bos frontosus can 
be eradicated from the catalogue. It is quite possible that the large 
series of longifrons remains in the Dublin and Oxford Museums may 
corroborate Mr. Dawkins' conclusion ; those in the British Museum 
and Eoyal College of Surgeons Collections, to which Mr. Dawkins 
appeals, have not led me, after most careful examination, to arrive 
at the same result. Science imperatively requires, not a mere 
sweeping assertion ihdX Bos frontosus ''cannot be made out" as a 
species, but a careful series of measurements of at least fifty speci- 
mens, so that the " unbroken series" which Mr. Dawkins imagines 
to exist may be distinctly shown. Till evidence is really put in, 
Nilsson's species must be allowed to stand. 

Mr. Dawkins' arguments in favour of the "affinity" of the old 
Aquitanian cave-dwellers " with the Esquimaux" do not appear to 
be of the strongest value. " The habit of sculpturing animals on 
their implements" is common in all savage races; ''the carelessness 
about the remains of their dead relatives" is also predicable of many ; 
" the fact that the food consisted chiefly of reindeer" only proves that 
reindeer was an accessible and plentiful food, and by no means 
denotes community of origin. Mr. Dawkins' argument is : — All 
who eat reindeer meat are " closely allied : " Esquimaux eat rein- 
deer meat, and Aquitanian cave-dwellers ate reindeer meat: 
Esquimaux and Aquitanian cave-dwellers are "closely allied." 
At the present moment, English, Americans, Negroes, and Eed 
Indians are feeding here on beef (when they can get it) : yet 
there is no community of race. Mr. Dawkins' last statement 
regarding the small stature being " proved in the people of the 
Dordogne Caverns by the small-handed dagger figured by Messrs. 
Lartet and Christy in the Revue Archeologique" I must doubt. All 
who are acquainted with the small-griped swords of the exist- 
ing Hindoos, and of many of the so-called Phoenician sepultures, 
will know that they are held in the hand in a very different way to 
that of our own swords, and that the smallness of the grip by no 
means connotes the size of the individual. I must not, however, 
discuss this matter further in a periodical devoted to geology. 

Mr. Dawkins accuses Professor Owen of holding "contradictory 
opinions." In opposition to the first, that " the Eomans imported 
into Britain their ' already domesticated cattle,' and our breeds are 



102 Correspondence — Mr. T. Davies. 

their descendants," he brings the statement that " Bos longifrons is 
the only ox found in the refuse heaps, in not one or two but all the 
camps, cities, villas, and cemeteries that bear the impress of Eoman 
civilisation in Britain." In the first place, in one, at least, of the 
Eoman camps (London Wall) Bos longifrons is not the only ox found, 
as B. frontosus and trochoceros are associated with it. ^Whatever Mr. 
Dawkins may say of Bos frontosus, I presume he will not slump B. 
trochoceros in gurgite vasto of his longifrons. In the second place, I fail 
to see how he can point out any difference between the characters of 
the Eoman cattle, which he nowhere describes, and those of Bos 
longifrons, to which he is '' unable to assign any characters of specific 
value," Where one factor is unknown, and the other undefined, it is 
difficult to perceive how any conclusion can be arrived at. Probably 
if Mr. Dawkins examines carefully a series of the bovine remains 
from Italian sepultures, he may consider these also to be longifrons. 
This fact remains to be proved. 

Mr. Dawkins' first conclusion, that B. longifrons " has not yet been 
proved to have existed before the Pre-historic age, in the bone-caves 
and alluvia of which it is found abundantly," I must leave him to 
discuss with Professor Owen. His second conclusion, that " it is the 
ancestor of the small Highland and Welsh breeds," is self-evident, 
and unnecessary to be proved. I fail to see that Professor Owen's 
original opinion to this effect needed such a repetition, nor do I see 
any new arguments in favour adduced by Mr. Dawkins. When, 
however, he employs the expression that ''it is essentially the animal 
with which the archseologists have to deal," I must humbly put in a 
plea in favour of the animal nature of man, and express my belief 
that up to the present time I thought that arch geologists had to deal 
with human works, and human remains, as well as those of horses, 
goats, and sheep, when found with human relics. For the present, 
I must close this letter. 

" La plaza al punto el buey desembaraza 
Quedando stros mas bueyes en la plaza." 
Arriaza. 



C. Carter Blake. 



JavalI Mine, Chontalf.s, Nicaragua, 
ith December, 1867. 



SILVER-FAHLERZ IN CORNWALL. 

Sir, — Will you allow me space for a short reply to the letter of 
Mr. David Forbes contained in your last number ? That gentleman 
seems to have quite misunderstood the object of my communication 
to the Geological Magazine of December last (p. 575), upon which 
he comments. The explanation I have to give is as follows : — 

Mr. Forbes having stated that ''the cupriferous tetrahedrite (oc- 
casionally containing traces of silver) has been found in small 
quantities at various localities in both England, Ireland, Scotland, 
and Wales," I believed he would be interested to know of the fact, 
that a cupriferous tetrahedrite, containing sufficient silver to render 
it of considerable commercial value, had been already worked in large 
quantity for some time past, at the Silver- vein mine in Cornwall. 



Correspondence — Br. A. von Koenen. 103 

Mr. Forbes has treated the results of various assays (made for com- 
mercial purposes) which I quoted, as if intended by me as evidence of 
this mineral being identical in composition with that from the Fox-dale 
mine, which would have been absurd. The figures were given 
solely for the purpose of showing that this ore contains certain 
quantities of silver ; and I specially stated that I knew of no 
analysis having been made of it. Mr. Forbes will notice, if he 
refers to my letter, that I did not use the term polytelite at all, 
Glocker having proposed this name in 1847,^ for a mineral analysed 
by Eammelsberg in 1846,^ which not only contained between 6 and 
6 per cent, of silver, but also from 36 to 38 per cent, of lead, with 
only 0-32 per cent, of copper (and which has been regarded by some 
mineralogists as an argentiferous hournonite). I do not believe the 
Cornish ore contains any lead. 

The difference of opinion appears to arise from the question, as to 
what constitutes a silver-fahlerz ; but I had not, nor have T now, the 
least intention to enter upon a discussion respecting tetrahedrite, and 
its many varieties, considerable difference of opinion existing as to 
the precise limits of the latter. It is quite possible that this ore 
(which is worked and sold in Cornwall as a silver and copper ore) 
may be an argentiferous tetrahedrite only ; and that is precisely the 
point I hoped to induce Mr. Forbes to determine by analysis, and 
hence my letter. Thos. Davies. 

P.S. — Since writing the above I have been favoured with a letter 
from Prof. A. H, Church, of the Eoyal Agricultural College, Cirencester^ 
in which he says : — " I have found in one of my laboratory books the 
determinations of silver in Cornish fahlerz to which I alluded in 
conversation with you some time ago. They were made in August, 
1865, for the purpose of ascertaining the value of the ore raised from 
the Silver-vein mine near Lostwithiel. The following were the 
results : *73^|o Silver in a mixed sample of ore in coarse powder. 
7-23^|o Silver in a crystallized fragment of fahlerz, having the density 
4-85. 10-45^|o Silver in another crystalline mass." — T.D. 

THE BELGIAN TERTIAMES. 
Sir, — In the December number (p. 565), Mr. Godwin-Austen 
protests against the observations which I made on his paper on the 
Belgian Tertiaries, in my article in the Geological Magazine for 
November last (p. 501). With regard to my objections, I can only 
assure him that I wrote them down in order to remove mistakes, 
and without the slightest intention of personally offending him. 
Mr. Godwin-Austen gives a list of fossils from the Cassel-beds 
(Upper Oligocene) in order to corroborate his opinion on their 
relative age. I am not aware now where this list is taken from, 
but that is of no consequence : but I must assure him that nearly all 
the names there cited are erroneous, according to the works of 
Sandberger (on the Mayence Basin), of Beyrich (Norddeutsche 

^ " Generum et Specierum Mineralium Synopsis," by E. F. Glocker, Halle, Saxony, 
1847, 8vo., p. 31. 
2 " PoggendorfTs Annalen," vol. Ixviii. 1846, p. 516. 



104 Correspondence — Mr. A. H. Green. 

Tertiaer-conchylien), of Semper (Palseontologische Untersucliungen), 
and of Speyer (who has described and figured a large number of 
fossils exactly, from these beds in Palaeontographica), — that is to say, 
according to all the important works published on that subject in 
the last ten or fifteen years. The opinion of Mr. Nyst, who of 
course is the best judge about Belgian Tertiaries, has been cited 
against me, but this was his former opinion ; it is now quite in 
conformity with mine after the discoveries of the last few years. 
Lastly, I must repeat that it is possible, and therefore necessary, to 
divide the Tertiary deposits into far more than two, four, or six 
periods. It is of no consequence which names are adopted for them, 
whether the names Eocene, Oligocene, Miocene, and Pliocene are 
associated with Lower, Middle, and Upper, or whether we use the 
names given by Prof. Ch. Mayer at Ziirich to all the different 
** Etages." A. von Koenen. 

Makburg, Prussia, 20^7i Dec.^ 1867. 



THE OUSE VALLEY. 
Sir, — I am sorry that the mistake into which Mr. Searles Wood 
has fallen respecting the quarter-sheet 45 N.E., of the map of the 
Geological Survey of England and the Memoir thereon obliges me 
to request space for self-defence. Mr. Wood's charge is that I have 
omitted " all reference to the Glacial Clay." It is true that I have 
not sub-divided the Drift of that country into an upper clay and a 
lower gravel, because, as far as I could judge, I did not find evidence 
to support such a classification ; but I have very distinctly stated 
that Boulder-clay is one of the forms which the Glacial deposits take 
(p. 53 of the Memoir), and have described sections where the clay 
is to be seen (p. 57). The Glacial Beds are not laid down on the pub- 
lished map because, as I have mentioned in the Memoir (p. 59), 
" additional surface maps are in course of preparation, on which the 
areas covered by superficial deposits will be marked out ;" adding, 
what every one who has tried the experiment knows very well, 
that " it would be impossible, on the one-inch scale, to show these 
beds and the stratified rocks on the same map." 

With respect to the sections on p. 34 of the Memoir, and p. 564 of 
your last volume, which Mr. Wood finds so different, I have only to 
state that the first has one scale for heights and another for distances, 
so that the former are exaggerated ; the other is drawn to something 
like a true scale. In the one case too the outline of the supposed 
ancient valley is rashly drawn hard, and in the other indicated by a 
dotted line. The facts represented are exactly the same in each case, 
and I take it rather hard that I should be blamed because four years ; 
experience has made me cautious and, may-be, rather a betterd raughts- 
man. I have no wish to set up my own limited experience, which 
I have urged in the Memoir (p. 58) as a reason for refraining from 
theorising, against the widespread and long-continued researches of 
Mr. Wood ; but I do expect him, before he criticises, to do me the 
justice to read my memoir more carefully. A. H. Green. 

Monk Bretton, Barnsley, January lUh, 1868. 



THE 

GEOLOGICAL MAGAZINE. 



No. XLV.— MARCH, 1868. 



<D:ElX<3rXlSTJ^Xj .^I^TIOXJES. 



I. — On Dr. Sterry Hunt's Geological Chemistry. 
By David Forbes, F.E.S. 

IN considering the mutual relations of the sciences of Geology and 
Chemistry, the student must always bear in mind which of 
these two sciences is to form the basis or starting point for his 
inquiry, for this cannot fail to exercise an important influence on his 
reasonings and deductions. 

In what Dr. Sterry Hunt calls my Chemical Geology,^ I have taken 
Geology as my starting point, and then endeavoured to apply che- 
mistry, especially experimental chemistry, to the explanation of 
known geological phenomena. On the other hand. Dr. Hunt, in 
what may be termed his Geological Chemistry, starts from data purely 
chemical, and then looks around for geological instances to which 
they may be applied. 

Thus, for example, starting from the chemical fact, that a 
solution of carbonate of soda will throw down carbonate of lime 
from a solution of the chloride of calcium, he at once asserts 
that the whole of " the calcareous strata, the marbles and various 
limestones which we find on the earth's surface," have been precipi- 
tated from the sea by a solution of carbonate of soda. 

And again, Dr. Hunt observing in the laboratory that the reaction 
of the compounds of magnesia with carbonic acid in a dense atmo- 
sphere of that acid could be turned to account in facilitating the 
separation of Dolomites and Gypsums, at once jumps at the conclu- 
sion " that all magnesian limestones and gypseous strata from the 
most ancient up to the Tertiary periods were formed in a dense atmo- 
sphere of carbonic acid." Now in face of these assumptions, I con- 
tend and I feel confident the Geological world will bear me out, that 

^ Here it should be explained that Dr. Hunt, from having some time back published 
both in England and France an outline of his principles of Chemical Geology, has 
thereby fairly laid himself open to having his views both criticised and disputed ; 
whilst, on the contrary, Dr. Hunt's knowledge of my views on this subject could be 
only derived from the allusions to my opinions scattered through the two papers re- 
lating to this controversy in the Geological Magazine of October 1 and the Chemical 
News of October 4 of last year. Although his virulent criticism might therefore be 
considered as hardly fair; still, so far from objecting to it, I feel truly thankful to Dr. 
Hunt for thus enabling me to strengthen the weak points, and inspiring me with more 
confidence than before in the resume of the views on Chemical Geology put forth in a 
lecture to the Chemical Society, now in the press. 

VOL. V. — NO. XLV. 8 



106 David Forbes — Reply to Dr. T. Sterry Hunt. 

no Geologist whosoever could in applying the study of Chemistry to 
the explanation of the phenomena of his science ever by any possi- 
bility have arrived at such sweeping generalizations. 

When the safety of Kome was endangered by the victories of Han- 
nibal, the advice of Scipio to the Romans was to save Eome by 
attacking Carthage ; and the papers of Dr. Hunt in the Chemical News 
of Jan. 17, and the Geological Magazine of Feb. 1st, evidently 
prove that he is determined to pursue a similar course ; yet I confi- 
dently trust with a different result, since in this case I believe the 
forces at command are fully adequate, both for offence as well as for 
defence. 

In this discussion, however, much more trouble is likely to be 
caused to me by the method in which Dr. Hunt carries on his scientific 
warfare, and which seems to partake of the character of the country 
in which he resides, where the Indian system used to be, to worry 
out the enemy by skirmishing, but never to attack strong points ; 
and the history both of scientific discussion as well as of nations has 
shown how very effective such a plan of operations may prove, even 
in the defence of a very weak cause. 

For this reason, therefore, I have considered it wise to keep the 
main points under consideration as prominently in view as possible, 
and if possible not to allow the discussion to become so diffuse as to 
risk losing sight of them, which I fear the readers of Dr. Hunt's long 
communication may be likely to do. Acting upon this determina- 
tion, therefore, I have in my reply to Dr. Hunt's paper in the Chemical 
News of Jan. 17, which also appeared in the Geological Magazine 
of Feb. 1, given a plain and concise statement of the points, num- 
bered 1 to 9, in which I have presumed to differ from Dr. Hunt's 
views ; and as I now find nothing in his subsequent communication 
to the Geological Magazine of February 1 which could in any way 
tend to shake my conviction of the unsoundness of these points, I 
must be content to wait until Dr. Hunt may condescend to bring 
forward new evidence in their defence. 

If now, however, after a perusal of Dr. Hunt's paper in the 
February number of the Geological Magazine, it is compared 
with his preceding communication in the Chemical News, it will be 
perceived, as the Editor of the Geological Magazine has already 
observed, to be to a great extent the same, and in many parts even 
verbatim ; and remembering Dr. Hunt's puerile accusation, that I, 
"for some unknown reason, withheld from the readers of the 
Chemical Neios'" matter which I published in the pages of the 
Geological Magazine, it is amusing to observe that Dr. Hunt 
has in like manner reserved for the readers of the Geological 
Magazine several interesting observations which probably he may 
have considered (and with some reason) as beyond the capacity of 
the chemists who patronize the Chemical News, — among others, 
for example, the following : ''As for the noble metals, whose com- 
pounds with oxygen are decomposed at elevated temperatures, their 
great volatility, as compared with earthy and metallic oxides, would 
keep them in the gaseous form till the last stage of precipitation of 



David Forbes — Beply to Dr. T. Sterry Hunt, 107 

earthy oxidised matters, when by far the greater part of the globe 
was probably solidified. Hence we now find them in the earth's 
superficial crust." And a little further, "We cannot conceive any- 
thing else than the production of a homogeneous oxydized silicated 
mass, upon which, at a late period, would be precipitated the noble 
metals." 

Chemists will not require any comments upon the above, for they 
are accustomed to regard Platinum, for example, as one of the most 
refractory bodies known, which, of course, cannot be the case now 
that Dr. Hunt has made this interesting discovery of its great vola- 
tility at a point at which silicates solidify ; and further, they were not 
aware that the extreme refractory nature of the other metallic oxides 
had been so completely demonstrated, since some of them, at least, 
as Lead, Bismuth, Antimony, Molybdenum, etc., are not remarkable 
for that property ; whilst geologists will not feel convinced from Dr. 
Hunt's mere assertion that the noble metals have from the beginning 
been in the earth's superficial crust, precipitated on to it from the 
skies like Jupiter's golden rain, but may also be inclined to believe 
that they may have been carried up from below. 

The only important point which Dr. Hunt now advances is 
the courteous request for Mr. Forbes to explain "the intervention 
of water in all igneous rocks, which, as he declares, are outbursts 
from the still fluid interior of our globe." The above words do not 
exactly express my views, since I advance that igneous rocks have 
their sources in some ^'reservoir or reservoirs'" of still fluid matter in 
the interior of the earth ; and I would add that, by the actions of 
capillarity and heat, I see no difficulty in explaining the infiltration 
of the requisite amount of water for the supply of such a source. 
As, however, I could not even think of accusing Dr. Hunt of " un- 
familiarity with geological literature," to use his own words, I 
could not suppose him ignorant of the writings of Daubree, who, 
in Europe, at least, is regarded as somewhat of an authority on 
these subjects ; Dr. Hunt will find this question fully answered 
by that gentleman, whose words are : " En resume, sans exclure 
I'eau originaire, et en quelque sorte de constitution initiale, que Ton 
suppose generalement incorporee aux masses interieures et fondues, 
M. Daubree est porte a conclure de I'experience ci-dessus relatee, que 
I'eau de la surface pourrait, sous Taction combinee de la capillarite 
et de la chaleur, descendre j usque dans les parties profondes du 
globe." 

Always preferring, when possible, a reference to fact or experi- 
ment than to authority, 1 would advise Dr. Hunt, in order to form a 
conception of such strange action, to examine a common Gifford or 
other injector used to supply feed- water to a high pressure boiler, 
and he will soon perceive that the very forces which otherwise would 
prevent the entrance of the water into the boiler are the very means 
of forcing it in. 

Dr. Hunt also asks me to remember " that the oldest known series 
of rocks, the Laurentian, consists of quartzites, limestones, and gneiss 
evidently of sedimentary origin and derived from still older sedimen- 



108 David Forbes — Reply to Dr, T. Sterry Hunt. 

tary rocks." When I was in Canada, what little I saw of the Lau- 
rentian rocks did not at all prove to me that they had been derived 
from still older sedimentary rochs, but, on the contrary, whilst believ- 
ing that the Laurentian gneiss, quartzites, &c., were of metamorphic 
sedimentary origin, I inclined to the conclusion that the materials of 
which they had been reconstructed had most probably been the debris 
of eruptive igneous rocks, and this view I have maintained since 
1854 with regard to some of the analagous Norwegian rocks which 
Dr. Hunt claims to be Laurentian. To refresh my memory, how- 
ever, I have read over the description of the mineral characters of the 
Laurentian rocks in the Report of the Geological Survey of Canada, 
pp. 22-49, but can find no evidence whatsoever to the contrary — and, 
therefore, without disputing the correctness of Dr. Hunt's assertions 
on points where he ought at least to be confident, I would ask whether 
this statement is founded on facts or on hypothesis. 

Dr. Hunt devotes a whole page to what appears to be an inquiry, 
as to who first showed that water played a part in igneous action, 
a subject which may be of personal or historical interest, but which 
is quite irrelevant to the questions under consideration ; for all 
geologists will persist, notwithstanding whatever Dr. Hunt opines 
to the contrary, in regarding igneous action as volcanic action and 
volcanic action as igneous action, nor can they suppose for a moment 
that any person, except one who never had seen a volcano in eruption, 
could be blind to the evidence of his senses and deny the co-associa- 
tion of vapours and gases with volcanic action ; — that the results of 
Mr. Scropes' admirable researches should have been discredited 
and ridiculed and declared unchemical, should be a warning in future 
to chemists not to hazard such opinions without having studied the 
subject in the field as well as in the laboratory. 

As Dr. Hunt brings forward the question of the density of quartz, 
I may here state, what I omitted in my paper in the Chemical Neivs, 
that all arguments based on this fact are completely invalidated by the 
fact that the specific gravity of crystallised quartz out of true volcanic 
lavas is 2-6, or the same as that of the quartz in granite ; and, further, 
that Mr. Sorby's examination of the quartz out of these lavas com- 
pletely proves that it was crystallized out of the melted rock, and not, 
as Dr. Hunt would have us infer, merely entangled from the debris of 
originally sedimentary strata. 

Having long occupied myself with the application of the micro- 
scope in geology, and repeated most of Mr. Sorby's experiments 
relating to this subject, I consider it superfluous to contradict 
Dr. Hunt when he accuses me of not understanding Mr. Sorby's 
views, being quite content with that gentleman having expressed 
himself decidedly to the contrary. I would recommend Dr. Hunt 
also to commence with the study of microscopic geology, and 
can well imagine his being disconcerted when, on opening the last 
number of the Geological Magazine, he found a few lines from Mr. 
Sorby, quite sufficient to annihilate all the deductions he had so 
elaborately arrived at from the study of that gentleman's memoirs, 
with the object of making them serve his own purposes. 



David Forbes — Mepli/ to Dr. T, Sterry Hunt. 109 

All the other points have been noticed in my recent communication 
to the Chemical News, and I would merely state here that as regards 
Dr. Hunt's criticisms upon my views it is probable that many of 
them would not even have been advanced by Dr. Hunt had he 
waited until the outline of my views on Chemical Geology,, now in 
the press, had appeared, instead of selecting scattered and disjointed 
sentences for attack, without giving the context. Thus, for example, 
when he accuses me of being ignorant of the laws of diffusion, he 
would have found my opinions expressed as follows : — 

" Whilst, on the one hand, the zones formed in the earth are con- 
sidered to have possessed a somewhat stable or permanent character, 
those formed in the atmosphere would, on the contrary, be the reverse, 
for no sooner had the gasiform products forming them, by in the first 
instance obeying the impulse of gravity so overcome the counter- 
acting tendency of the laws of diffusion of gases, than these latter 
would assert themselves, and, in process of time, entirely obliterate 
this arrangement." 

And again, " as before stated, this arrangement would be gradually 
obliterated by diffusion, but, as the element of time is of vital im- 
portance in considering the effects of diffusion, it is imagined that, 
before being obliterated, this arrangement may have had considerable 
influence in modifying the chemical re -actions which took place at 
this period in the earth's history." 

Dr. Hunt, whose knowledge of the laws of diffusion does not seem 
to include any appreciation of the importance of the element of time 
in their consideration, might just as well tell us that a lump of sugar 
could not reach the bottom of a tumbler of water because sugar 
will dissolve in water. As Dr. Hunt seems to have such respect 
for authorities on the subject, I will, with the greatest pleasure, 
submit the question, whether the above proposition is invalidated by 
the action of the laws of diffusion, to the decision of Mr. Graham, 
the great expounder of these laws, and abide by his verdict.' 

In the discussion of new views, more is required than mere quota- 
tions from old authorities. What is specially wanted are facts and 
experimental evidence. It must also be remembered that much de- 
pends upon the mode in which authorities are made use of in such 
discussions, since it is often an easy matter to select passages, or 
disjointed fragments, from the published works of authorities, which 
may appear to support almost any view which may be taken of a 
subject under consideration. 

Dr. Hunt, whose paper consists, in greater part, of references to 
numerous authorities, from the time of Thomas a Kempis down to 
that of Sterry Hunt, seems to be quite aware of this fact, as an in- 
stance or two will testify. 

Thus, when Dr. Hunt quotes Hopkins in support of his views as 
to the consolidation of the molten sphere, he takes care not to inform 
his readers that Hopkins distinctly declares his opinion that the ex- 
terior was not the last to solidify, but would have consolidated be- 

^ It must be remembered that these gases are supposed to be formed at an instant 
of general combination in situ, and not gradually gathered from the realms of space. 



110 David Forbes — Reply to Dr. T. Sterry Hunt. 

fore the interior had became entirely solid, a view which I have 
adopted on his authority, and which is diametrically opposed to Dr. 
Hunt's opinion that the surface of the earth immediately previous 
to its entire solidification was " a liquid bath of no great depth, sur- 
rounding the solid nucleus." 

Again, although he finds it convenient to quote Forchammer in 
reference to some minor points quite beyond the limits of the present 
discussion, he seems to be quite unaware of the fact that the idea of 
the saline crust of chlorides, &c., which he ridicules my having 
adopted, was long before propounded by Forchammer, who made the 
calculation that the chloride of sodium in such a crust would have 
been fully sufficient to have clothed the entire sphere with a coating 
of salt some 10 feet in thickness. 

And yet again when he refers to Sorby's experiments as proving 
many points in favour of his views, amongst others that quartz can- 
not be volcanic, i.e., a product of igneous fusion in nature, his deduc- 
tions are at once entirely put to rout by the few lines from Sorby 
himself, produced in my last communication to the Chemical News. 

On the other hand, after a careful consideration of the various 
memoirs of Hopkins, Forchammer, and Sorby, along with a careful 
repetition of many of their experiments, I cannot discover any one 
single point inconsistent with the views I have advanced. I am 
also able to bring much evidence in their favour from the writings 
of Daubree, Bunsen, Durocher, Phillips, and other men of eminence, 
whose opinions Dr. Hunt evidently considers of no importance. 

To prove that it is better to stay at home in one's laboratory than 
to travel wide and far in order to study Nature's operations in the 
field (as recommended by Sir Charles Lyell and other eminent men). 
Dr. Hunt quotes Thomas a Kempis, to the effect that " those who 
make long pilgrimages rarely become saints." What we require, 
however, is geologists, not saints ; and it is well known that a know- 
ledge of the world acquired by travel is the best antidote to bigotry 
or one-sided opinions. 

As I have previously explained, I was induced to enter into this 
controversy (which I am quite confident will do good to science, 
by ventilating some obscure points) by the special invitation, 
conveyed in writing, from Dr. Hunt "to have a friendly fight;" 
but 1 now find, if I may judge from the style of that gentleman's 
communications, both to the Geological Magazine and Chemical 
News, that his idea of scientific discussion consists in an attempt to 
overwhelm his opponent with sneers and countless accusations of 
incompetency and ignorance,^ — ignorance of chemistry, of geology, 

* Dr. Hunt does not merely content himself with mere accusations of ignorance, 
for when disputing my assertion that " reactions of the compounds of magnesia with 
carbonic acid in an artificially compressed atmosphere of that acid," had long been 
employed on a large scale, he uses the words " here it becomes difficult to admit 
the plea of ignorance, which suggests itself for most of Mr. Forbes's previous errors 
and mis-statements." I may merely add that, since the appearance of Dr. Hunt's 
communication in tbe Chemical INews of January 17, I have received various com- 
munications from Chemists and others, connected, or acquainted, with this manufac- 
ture, not only offering to supply more facts in corroboration of the truth of my 



Baden Powell — Igneous Rocks of Charnwood Forest. 1 1 1 

of petrology, mineralogy, microscopy, literature of the subject, etc., 
etc. ; whilst at the same time he has not omitted to herald in his own 
views as what might be termed the quintessence of the combined 
" results of modern investigations in physics, chemistry, mathematics, 
and astronomy." 

Would it not have been more wise, as well as more becoming, to 
have left to our readers the task of forming their own judgment upon 
these points after having weighed the evidence brought before 
them on both sides, in the course of this discussion. 

Having no pretensions, like Dr. Hunt, either to being a saint, or 
even to be versed in saintly lore, I cannot cite Thomas a Kempis, 
yet I can, nevertheless, follow his example, and even at the risk of 
appearing still more uncourteous, I really cannot resist the tempta- 
tion to remind him of the old saying, — passed into a proverb among 
laymen — that " Curses, like chickens, come home to roost." 

II. — On the Igneous Kocks of Chaenwood Forest and its 
Neighbourhood. 

By the late Rev. Baden Powell, F.R.S., F.G.S., formerly Savilian Professor of 
Geometry in the University of Oxford. 

[This paper, written in 1859, has been obligingly communicated to the Editor by 
Warington W. Smyth, Esq., JF.R.S., President of the Geological Society of London."] 

THE geology of Charnwood Forest appears to have been first 
systematically investigated by Professors Sedgwick, Whewell, 
and Airy in 1833. A very brief notice of their labours by C. AUsop, 
Esq., is appended to the history of Charnwood Forest by J. K. 
Potter, 1842, as is also a valuable and detailed memoir on the 
geology of the district, by J. B. Jukes, Esq. 

More recently the labours of the Government Survey have fur- 
nished us with the geological colouring of the Ordnance Map, and 
with several sections ; accompanied by a few notes by H. Howell, 
Esq. 

Since these researches I am unable to learn that anything has been 
published on this interesting region, which is admitted by Mr. Jukes 
to present many problems for investigation. In the very elaborate 
classified index of Mr. C. W. Ormerod, F.G.S. (1858), not a single 
instance occurs of any paper illustrative of the geology of this 
district, having been published in the Quarterly Journal of the 
Geological Society of London. 

Having enjoyed an opportunity of residing upwards of two months 
in this region, during the summer of 1859, I examined and collected 
specimens from nearly every locality of igneous action. The brief 
notices here given have no pretensions beyond that of being faithful 
records of a few facts which fell under my notice, which do not seem 
to have been previously attended to, but which appear to bear on 
the questions still open to discussion, as to some of the geological 
features of this remarkable district. 

assertion, but also directing my attention to an expired patent, taken out many 
years ago (No. 9102, a.d. 1841) by the late Mr. Pattison, of Newcastle, in which 
these identical reactions are embodied. 



112 Baden Powell — Igneous Rocks of Ckarnwood Forest, 

Nomenclature. — The map of the Geological Survey marks granite 
at Mount Sorrel; syenite at Bradgate, Markfield, and other places. 
In the margin of the map they are both classed as igneous rocks. 
But in the Museum of Economic Geology, specimens from all 
(except Mount Sorrel, from which there is no specimen) are arranged 
under the name of altered rocks. Mr. Jukes describes them all as 
syenite. In the Museum there is a specimen described greenstone from 
Quorndon. This, I presume, is from the quarry in Buddon Wood, 
which is part of the Mount Sorrel mass. I have found specimens 
closely resembling greenstone in the Mount Sorrel quarries. In 
fact, among specimens collected from all these quarries, many are 
found exactly alike from the most distant localities, while, in the 
very same rock, varieties so distinct may be found that it might be 
described by the most different designations. Even in the same 
specimen, there is often a transition from the most coarse-grained 
mottled white or pink syenite to the most compact mass resembling 
greenstone. 

The nomenclature of igneous rocks has confessedly been ill-de- 
fined. But, perhaps, recent remarks rather lead to a general disre- 
gard of such distinctions, and to giving more prominence to the idea. 
so strongly supported by the researches of Mr. Marshall and others 
(British Association, 1858, and Prof. Phillips' address to Geol. 
Society, 1859), that they are all simply varieties of a very few 
primary types under different conditions of fusion. 

Still there is the material question involved, how far any given 
rock is properly a deposit or sedimentary formation, remaining as 
such even though much dislocated and disturbed, but which has been 
altered in its constitution perhaps totally by the action of heat from 
below, — and how far it is an original fused or hypogene mass carried 
up, in a fused state, by eruptive action into its existing position 
among, and breaking through, other rocks. In the phenomena pre- 
sented by the rocks of Charnwood and its neighbourhood there are, 
confessedly, many problems of this kind still open for investigation. 

Localities of Igneous Action. — Commencing with the admitted 
purely eruptive masses of Mount Sorrel,^ including the hills of 
Buddon Wood, adjoining to Quorndon, and several minor outbursts 
of the same syenitic or granitic rock, upon and adjacent to Mount 
Sorrel Common, indicating the general substratum, — we trace a 
remarkable continuous development of the same rock in a S.W. 
direction, at the top of Kirksley hill, along its side, at the farm, 
at its base, and lastly, at Brazil or Basil Wood, in the valley ; 
within half-a-mile of the village of Swithland, and at about the 
same distance from the commencement of the slate district to the N. W. 

Brazil, or Basil, Wood. — This locality is one of peculiar interest. 
The Geological Survey accurately marks three patches at this spot, 
as igneous. 

^ The syenite of Mount Sorrel has yielded several minerals, amongst which may 
be mentioned Molybdenite [sulphur et of Molybdena), by no means of common occur- 
rence in England. Associated with it, in the same quarry, occur copper and iron 
pyrites, the latter but sparingly distributed. These minerals appear to occupy de- 
finite planss, or points, in the syenite.— R. E. Geol. Mag., Vol. III., p. 525. 



Baden Powell — Igneous Rocks of Charmvood Forest. 113 



The first of these consists of what might to a casual observer 
seem merely a small heap of transported blocks in the New Eed marl, 
but the larger blocks are deeply inbedded ; the ground falls on every 
side from the mass : and it has the appearance of a true outbreak. 
These masses consist entirely of a dark syenite, coarse-grained, with 
large black crystals of hornblende. 

The other two masses occur in the adjacent wood. They are both 
small knolls or hills, covered to the summit with the red marl, 
sufficiently thick at all parts to bear not only wood, but trees of 
considerable size. 

In the most northernly of these knolls, small portions of 
rock everywhere project, consisting of a deep syenite, more closely 
grained than the former. Some blocks also occur of a pink hue ; 
like that of Mount Sorrel. 

Of the third mass, perhaps one half has been quarried away. 
The section shows the red marl, covering it to the top. The nature 
of this rock is peculiar ; at some parts the pink syenite occurs, but 
only in thin beds, between the other portions, in variously inclined 
positions. In some parts, but very rarely, this syenite is full of 
glittering scales of mica, which it has been suggested to me indicate 
the action of heat by their peculiar appearance. This is the only 
locality in which I have found any mica ; excepting minute specks 
of it which may be detected in some specimens from Mount Sorrel. 

The great mass of the quarry consists of a very dark, compact, 
hard rock, largely used for road making, and esteemed by the work- 
men the hardest in the district. Throughout many portions minute, 
hard, and brilliant crystals are diffused. In some specimens they lie 
in bands or veins, while the rest is destitute of them. 

At one part, in a kind of corner between two upheaved masses, a 
portion of the same rock is seen contorted, as in the annexed sketch. 
(Fig.l.) This dark rock, which seems unique in the district, has not, as 





Fig. 1. Contorted Rock, 
Basil Wood. 



Fig. 2. Ground-plan of Quarry n< 
Buddon Wood. 
a, b, c, portions of Basaltic Dyke. 



far as I can find, been noticed. From an examination of my specimens 
it has been described to me as, probably, a micaceous slate, altered 



114 Baden Powell — Igneous Rocks of Charnwood Forest. 

by contact with the igneous rock. If so, this locality exhibits a true 
junction of the slate and igneous rock, not hitherto detected. 

Basaltic Dylces. — Mr. Jukes, in his Memoir (1842), has circum- 
stantially described two basaltic dykes in the neighbourhood of 
Mount Sorrel. Neither of these can now be traced as described. 

The first is mentioned in the quarry near the Buddon Wood, on the 
opposite side of the road. The ground plan of this pit is annexed (Fig.2). 
It is situated in the slope of a hill, and opens level with the ground 
at the south end. The rock is everywhere syenite, like Mount Sorrel, 
except at the points marked a, h, c, where there rise up, from the 
floor of the pit, two small projections (a, 6), of a dark brown, but 
not very hard, rock, much split and shattered, perhaps two or three 
feet in height and breadth, and extending six or eight feet in length ; 
and at c a small buttress of the same rock projects from the wall, 
but no termination of it can be traced on the other side. The mass 
of the dyke has, doubtless, been quarried away since Mr. Jukes 
wrote. 

The second dyke is described as existing in Simpson's pit, near 
the S.W. corner of Mount Sorrel Common. This small pit is not 
now worked. I found it (1859) filled up partly with rubble, partly 
with syenite, broken, and worked for paving. In this I could find no 
specimen of basalt. And, in carefully examining all the rock which 
appears round the margin, could detect no appearance of the termi- 
nations of any dyke. It must, probably, have been all quarried 
away like the first. Lest any mistake as to the locality should have 
been committed, I carefully examined every pit, or appearance of 
rock, in the neighbourhood, but could detect nothing like a basaltic 
dyke. 

At quite the opposite side of the forest, near Markfield, in a pit at 
the cross roads, another dyke has been pointed out by Mr. Jukes, 
which is remarkable from the conformable manner in which the 
altered slate is superimposed on it. I found it to consist of an 
intensely hard, compact, dark grey mass, presenting, when exposed, 
a rounded surface, to which the slate conforms.^ 

Anticlinal Axis. — The anticlinal axis of the slate district was 
originally traced by Professors Sedgwick, Whewell, and Airy in 
1833, in a line extending from near Whitehorse Wood at the N.W., 
to somewhere near Swithland Wood at the S.E. The more detailed 
examinations of the Government Survey have confirmed this general 
direction, but show the necessity for some modifications in its details. 
But the general resulting character of the elevation has not been 
clearly described. 

In its northern portion the anticlinal axis is clearly defined running 
in nearly a straight line, for the most part in a continuous valley, 
the hills on each side having opposing dips from the neighbourhoo. 
of Whitehorse Wood, in a S.E. direction as far as to near Bandon 

1 In the extensive syenite quarry at Markfield, a vein of compact calcite occurs of 
considerable extent ; it has a red or pink tinge, and possesses throughout the well- 
defined rhombic cleavage. It has been proposed to use this for economical pur- 
poses, owing to the extent of the vein and its pure character. 



Baden Powell — Igneous Rocks of Charnwood Forest. 1 ] 5 

Castle. From this point, continuing still in the same direction, a 
boundary line is clearly marked, on the N.E. side of which the dip is 
still, as before, towards the N.E. as far as to the neighbourhood of 
Swithland Wood. But on the S.W. side of this line a different 
arrangement occurs. Throughout a considerable space of a triangular 
form, whose points are Bandon Castle, Hammercliff, and Greenhill, 
the direction of the dip has not been ascertained, probably from the 
few, if any, indications of rock, except those of igneous character, at 
the top of the hills just named, all the lower district being covered 
with the new red. 

Continuing towards the S.E., commencing from Greenhill, we 
enter a district extending thence to Groby on one side, and to 
Holgate on the other, within which a new direction of the dip prevails, 
being, on an average, almost uniformly at the jS.E., or at right angles 
to the former directions. This region includes the hills of Bencliff, 
Old John, and others. On the outside of this region, both (as 
already shown) to the N.E. and also to the S.W., the original op- 
posing directions of the dip prevail, and extend, with few trifling 
irregularities, to the boundaries of the slate district on either side. 

It would be important that the intermediate region just mentioned 
should be more closely examined, to discover, if possible, precisely 
where the change in the dip commences. 

Relation of the dip to Igneous Action. — This remarkable disposition 
of the directions of the dip, and interruption of the regularity of the 
axis of elevation, seem to bear a relation to the localities of igneous 
action. 

Along the whole N.E. side of the Forest generally, there are few 
or no indications of igneous, or porphyritic, rock, even among the 
most remarkably elevated and dislocated slate rocks. As we ap- 
proach the axis towards its northern part, such indications occur, 
though sparingly ; but, when we come to the intermediate region, the 
instances of igneous action become more frequent and remarkable, 
especially within that region, and, in some degree, outside of it. 
More precisely near the northern termination of the axis, in the 
valley under the S.W. side of Buck-hill, and further on, nearly in the 
same direction, at Long Cliff and New Cliff, developments of green- 
stone occur, but they do not rise to any elevation above the surround- 
ing district. 

In the same region, further to the S., in the valley under the S.W. 
bore of Beacon-hill, it is stated, in Mr. Allsop's notice, that Prof. 
Sedgwick detected a small manifestation of syenite ; but it is not 
recognized in the Survey. I examined the locality described, 
answering to which there are two pits : one close above the farm 
called Alderman's Haw, which shows a close grained, dark grey 
rock, presenting little of the ordinary appearance of syenite, and 
more resembling porphyry ; at another point, a little higher and 
more to the W., there is a larger mass of the altered slate rock. Of 
this another instance is marked in the Survey, on the top of Block's- 
hill, still more to the S. 

Black-hill. — In the same region of N.E. dip, but somewhat S. of 



116 Baden Powell— Igneous Rocks of Charnwood Forest. 

the point of commencement of the intermediate region, we have a 
locality marked in the Survey as one of feldspathic porphyry, at the 
summit of Black-hill, which offers a peculiar appearance, different 
from others similarly designated. 

These all retain externally, at least at their upper parts, the usual 
jagged and split character of the slate, however altered and fused 
below. But Black-hill presents a very different appearance. To a 
casual observer the top of this hill (covered by a plantation) might 
seem merely over-spread with a collection of blocks ; they are mostly 
of that comparatively smooth appearance, with partially rounded 
edges, which is totally different from the jagged structure of the 
slate. When more carefully examined most of these blocks are found 
to be deeply imbedded, and, in some instances, closely aggregated 
together. This seems allowed to constitute the evidence of their 
being a true porphyritic rock in situ. 

Intermediate region. — Eecurring now to the region before men- 
tioned, intermediate between the opposing dips, the first igneous 
locality which claims our notice is the hill on which is situated the 
farm called Bawdon, or Baldwin, Castle, which is marked in the 
Survey as syenite at the top, surrounded by slate, and on one side by 
the New Eed marl. 

On the body of the hill no rock whatever is visible ; the whole 
surface being under cultivation, and covered apparently with the New 
Ked marl, as most of the lower hills are. 

In two fields, just below the summit, a few corners of rock project 
through the turf, and there are many scattered blocks. 

Bawdon Castle. — At the summit, in the midst of that one of the 
two plantations nearest the farm, thickly overgrowTi with under- 
wood, which renders it not easy to find, is a small knoll or mass of 
rock, consisting mainly of large pieces irregularly piled up. The 
specimens are so closely grained and compact as to resemble green- 
stone much more than syenite ; as is the case also with some of the 
portions just below, before mentioned. Among these, however, and 
among the blocks, I found several specimens of the usual type of 
pink syenite, as well as others less marked, and approaching more 
nearly to the former character. In the museum of the Survey there 
is a specimen marked, '^ Greenstone from Bawden-hill," which, I 
presume, is from this locality. But, throughout the district, the 
names are most variously spelt and pronounced. 

Line of Igneous action. — The most marked feature in the inter- 
mediate region, is the occurrence of several points of igneous action 
on the tops of the hills called Green-hill, Bencliff, and Old John, all 
lying in a straight line with each other, and with Black-hill, and 
parallel to the axis. 

Out of this line, at a point near the S.W. base of Bencliff-hill, I 
have noticed another locality, not marked in the Survey, where there 
appears a mass of porphyritic rock, which seems to approach closely 
towards syenite in character, in a plantation by the side of the road, 
near the foot of the hill leading up from the Ulverscroft valley. 

Old John-hill— On the hill called Old John, one part is marked 



Baden Powell — Igneous Rocks of Charnwood Forest, 117 

in the Survey as altered slate or feldspathic porphyry, of which there 
are specimens in the Museum, justly described as exhibiting great 
action of heat. But these characters are by no means confined to 
one spot, but are exhibited by various rocks about different parts of 
the hill, especially in a large mass of rock on that part immediately 
above Holgate, marked picturesquely by a gnarled oak growing out 
of the crevices. 

These appearances of igneous action become more numerous as we 
approach the syenite of Bradgate. 

Syenite of Old John-hill. — Besides a remarkable isolated mass of 
syenite, near the base of Old John-hill, close to one of the plantations 
of Bradgate Park, which, I believe, has not been described, there is, 
on the shoulder of the same hill, just over the village of Newtown, 
under a clump of trees, a remarkable collection of blocks of syenite. 
Some of these seem deeply imbedded. Are these merely transported 
and heaped on that one spot ? or, is it not an analogous case to that 
of Black-hill — a true manifestation of syenite in situ ? 

Igneous action. — It is, theoretically, quite conceivable that a true 
igneous eruption might have vented itself with so little force as 
merely to break off, as the erupted matter cooled, in detached lumps, 
especially when under the sea, and be scattered over a small sur- 
face immediately adjacent, as in these instances ; while it might 
have been only the same kind of action, in higher intensity, which 
protruded the heaps and knolls of rock at several other localities, and 
the larger and loftier hills in other places. 

Following the indications of igneous action in this central region, 
as we approach its S.E. boundary, towards the syenite of Bradgate, 
we are naturally led to connect them, and to imagine that the igneous 
force, after expending itself while pent up, in elevating the slate by 
a regular fracture, producing the axial valley, with opposing dips 
along its sides, — in some cases altering the slate into porphyry when 
it came into closer contact, and even in one or two places itself find- 
ing a vent, — at the commencement of this intermediate region began 
to force up new matter, filling up the fracture with elevations, through 
which in some places the fused matter protruded, and at length ter- 
minated in exuding through a wider space about Bradgate and its 
neighbourhood. 

It has been argued by some that rocks adjacent to igneous erupted 
matter, not altered or upheaved by it, must have been subsequently 
deposited. I do not see the force of this conclusion ; for if we sup- 
pose the elevating, dislocating, and altering force to be that of the 
igneous action, so long as it was pent up beneath the superincumbent 
mass, then as soon as it found a vent the fused matter- would be 
ejected quietly without injury to the adjacent rocks, like steam when 
the valve is opened. 

Extension of axis. — The line of the axis has been traced to extend 
to the limestone region at Breedon, beyond the N.W. end of the 
slate region, and is nearly parallel to the great fault which abruptly 
bounds the coal-field of Ashby on the W. side towards Charnwood, 
as well as to other faults which traverse it. 



118 Baden Powell — Igneous Rocks of Charnwood Forest, 

These facts seem to show that through a considerable distance to 
the N.W. the same subterranean force operated, perhaps in still 
greater intensity, as is indicated by the violent disturbance and 
almost vertical position of the limestone at Breedon, and the enor- 
mous fault of 500 feet near Whitwick ; and would accord with the 
fact of the absence of any indication of igneous eruption, or vent to 
the hypogene matter, in these regions. 

Localities of igneous action S. W. side. — It is along the S. W. side of 
the Forest hills that the marks of igneous action are by far the most 
frequent and remarkable. There is, in fact, in this part one main 
line running nearly parallel to the anticlinal axis, along which they 
seem to follow a continuous series. 

On the south side of the road leading from Newtown to Mark- 
field I noticed a small pit displaying a porphyritic rock, approaching 
to Syenite. This I believe to be the most southernly point in this 
series or range as yet detected. 

Continuing to the N.W. I have also noticed a small mass of a 
similar porphyritic rock, at the end of the same range of hill which 
at about half-a-mile further in the same line to the N.W. brings us 
to the remarkable ridge bearing the inviting name of Hammerclifif, 
marked in the Survey as porphyritic or altered slate along its sides 
and ends, while the summit is an outburst of Syenite. There is a 
specimen of Greenstone in the Museum of the Survey from Copt Oak 
Farm, which lies just below the summit of this hill. 

Pursuing the line of this range still to the N.W., we have the 
rocks of Birchwood plantation marked Greenstone in the Survey, 
but in the Museum named porphyritic Cambrian, which agrees much 
better with what I have noticed of its character. Further in the 
same direction occurs the similar rock (by whichever name de- 
signated), of Greenhill.^ These ridges at length terminate further 
still in the same general line, in the extensive tract or elevated 
plateau bounded by the porphyritic or altered Cambrian rocks of 
High Towers and Tin Meadow, etc., on the south, and of High 
Sharpley and High Cadman, etc., on the north, including among the 
former those of Pedlar's Tor, which furnished the specimen of Crys- 
taline Cambrian in the Museum of the Survey. In the midst of this 
elevated plain, with its horizon everywhere bounded by these jagged 
and fantastic forms of rock, amid partial attempts at enclosure and 
cultivation, stands the monastery of S. Bernard. 

Character of altered rocks. — The extensive ranges of rock on the 
monastery hills are graphically described by Mr. Jukes as presenting 
all varieties and degrees of igneous action mixed in inextricable con- 
fusion. The specimens, however, which I have collected from various 
parts of this region all agree in exhibiting the same more or less grey 
porphyritic appearance and manifestly faded character. 

Deposition of the New Red. — That the New Eed marl throughout 
this district has been deposited unconformaUy upon the slate, and 
therefore since its dislocation, is palpable from the mere fact of the 
universally high inclination of the strata of the slate and the com- 
paratively level position of the New Red. 

1 A different hill from that before mentioned, bearing the same name. 



Baden Powell — Igneous Rocks of Charnwood Forest, 119 

But there are several localities where the New Red has clearly 
undergone some disturbance since its deposition. In the cases which 
I have observed, the inclination of the strata of the New Red, marked 
by distinct bands, does not amount to more than 12° or 15° measured 
on the surface of the section exposed. But the real dip may, of course, 
amount to any quantity greater than this. Sketches of a few cases 
are annexed. These are all instances of deposition over slate. Some 
cases where the New Red is deposited over igneous rocks have been 
before noticed. 




Fig. 3. Swithland Old Pit, reopened in 1859. 



Fig. 4. Mr. Ellis's Pit, inner part, facing South. 




Fig. 5, Mr. Ellis's Pit, near the entrance. South-west side. 
[a. o. New Eed Sandstone, h. h. Slate, e. Cave, The letters a and 6 have the same reference 

in Figs. 3, 4, and 5.]^ 

Other cases are those, for example, at Groby, mentioned by Mr. 
Jukes, and where I have seen a good instance of the horizontal de- 
position of the New Red, immediately over the syenite. Again, at 
New Cliff the New Red is undisturbed by the greenstone. The 
syenite hills of Buddon Wood are densely covered with trees, even 
at their summits, growing apparently out of no inconsiderable thick- 
ness of the New Red marl. This is more remarkably the case in the 
abrupt knoll, or ridge, which forms the top of Kinlesley-hill, the 
upper end of which is cut away by a quarry, and the whole bears 
large trees, the thickness of soil being exposed by the face of the 
quarry, though no distinct marks of stratification enable us to judge 
of its conformability. At the lower end of the knoll (which slopes 
towards Swithland) there is a small quarry, where the superposition 
of the New Red is still more apparent. 

Connexio7i of Igneous Rocks. — The syenite or granite of Broadgate 
and Groby has been ejected over a considerable space, mostly with- 
out being forced up to any elevation above the surrounding region ; 
but at Markfield, and in a less degree at Cliff-hill, it has risen in 
higher and isolated hills ; while, on the same side of this district, 
standing apart to the westward, the greenstone of Bardon-hill attains 



120 Baden Powell — Igneous Rocks of Charnwood Forest, 



the greatest elevation of them all, rising to 800 feet above the sea 
in an isolated peak, covered entirely with dense wood, except a rocky 
knoll, or ridge, at the top. These outbursts, which at a little distance 
flank the S. and W. of the slate district, seem to be not improbably 
connected with the similar developments at Mount Sorrel, to the N. 
and E. Such a junction may, possibly, be indicated by a remarkable 
ridge in the New Ked sandstone, which reaches, nearly in a straight 
line, from Bradgate Park to Rotherby Plain, near Mount Sorrel; 
along which, and in the valley below, blocks of Syenite constantly occur. 
The yet more probable extension of a similar rock, in a continued 
southerly direction, has been inferred by Mr. Jukes, from the occur- 
rence of small manifestations of it in the New Eed, all lying nearly 
in a line to a distance of about 15 miles or more, at Kirby, Muxloe, 
Enderby, Marborough, Croft, Sapcote, and Potter's Marston. I only 
add, that a further distance, of nearly the same extent, in the same 
direction, brings us to Arbury-hill, near Daventry, at which place, 
in the operations of the Trigonometrical Survey, Capt. Kater found 
that remarkable deviation of the plumb-line of nearly 5^^ in extent, 
which he attributes to an increase of gravitation at that locality, 
owing to the presence of a dense rock below the surface, and remarks 
its probable connexion with "Mount Sorrel and other primary 
rocks" of this district. 



QOOBJUDON 




MARKEllEiJD 




CilOBi' 



Fig. 6. Diagram of the Igneous Rocks of Charnwood Forest. 
Altered Rock. 



Igneous Rock 

Dykes. 

Average direction of dip. 

The line running from S.E. to N. W. indicates the direction of the great Anticlinal Axis. 



&u>h Ma<f. 1868. 



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Maw — Cambrian Rocks of Llanberis. 121 

III. — On a New Section of the Cambrian Rocks in a cutting 
OP the Llanberis and Carnarvon Railway, and the Banded 
Slates of Llanberis. 

By George Maw, F.G.S., etc. 
(PLATES VI. AND VII.) 

THE importance of the question of conformity in the classification 
of the earliest stratified rocks induces me to give a short 
description of a new section of a part of the Cambrian rocks of 
Llanberis, exhibiting an apparent case of unconformity towards their 
base. 

The section has only been exposed within the last few months, 
and at the time the district was mapped by Professor Ramsay, this 
complicated part of the series was hidden under a roughly weathered 
and glaciated surface, from which few of the details of structure 
could be determined. The railway in course of formation, along 
the southern side of Llyn Padam, has exposed for nearly a quarter 
of a mile the lowest and most intricate part of the Cambrian rocks, 
a representation of which is given in Plate VI. A new tunnel in the 
neighbouring Glyn quarries has also opened up another section of 
the beds given in the engraving (see Woodcut, Fig. 1). 

The upper part of the Cambrian series, not included in these 
sections, consists of three or four alternations of blue and purple 
slates interstratified with conglomerates and beds of a greenish rock. 
From the Lingula flags downwards they appear to be perfectly 
conformable ; but the conformity of the lowest workable slates in 
the Grlyn quarries, with the underlying beds, appears to me to be 
less certain. 

These lower grits and conglomerates, which are visible on both 
banks of Llyn Padarn, graduate into the great mass of porphyry 
crossing its western end. The gradation and metamorphism 
of the beds is well seen beyond the north-western end of the 
cutting; but whilst the change of the conglomerates to crystalline 
porphyry, from east to west, is evident, the overlying workable 
slates of the Glyn quarries resting directly upon them are entirely 
unaltered at the point of junction. In the south-east end of the 
section (Plate VI.) two masses (a a) of the blue slates are faulted 
down between the underlying altered grits and conglomerates h and c, 
and the same thing is observable in the tunnel. Fig. 1. Irregular 
bosses of these underlying rocks, termed "Hards" by the quarry- 
men, rise up in several places among the purple slates, but whether 
this was solely due to faulting, or to the deposition of the slate on a 
pre-existing irregular surface of the metamorphic rock, is not easily 
determinable : the contortions in the latter do not, however, appear 
to be repeated in the overlying slate, and the irregular line of 
junction as seen in parts of the tunnel cannot, I think, be altogether 
accounted for by the faults that have thrown the porphyry and 
slates together. 

Between 150 and 470 feet from the south-east end of the cutting, 

VOL. V. — NO. XLV. 9 



122 



Maw — Cambrian Rocks of Llanheris. 





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the beds have a general inclination of about 45° 
to the south-east, and are much broken and 
contorted ; they are of a dark greenish grey- 
colour, faintly banded with dull buff, the strati- 
fication becoming less apparent towards the 
north-west ; and at 475 feet from the south-east 
end of the cutting the dark green rock suddenly 
terminates, resting on the upturned edges of an 
older slate (e Plate VT.), dipping north-west, and 
of a different character to the workable slates 
of the Glyn and Dinorwic quarries. 

The line of junction, given in Fig. 2, is clearly 
defined, the irregular outline of the slate (b) 
being bleached along the line of contact. The 
remainder of the cutting exposes a broken 
synclinal of this '' bastard slate " interstratified 
with conglomerates (c), which at the north-west 
end graduate into the porphyry^ (/). The 
synclinal trough of slate can be traced on the 
opposite side of the lake and appears identical 
with that marked 2*2 in Professor Eamsay's 
section (Fig. 53, page 144, Geology of N. Wales.) 
The slate marked 2^ is, however, I believe, not 
a repetition of 2-2, but corresponds with the 
higher bed of workable blue slates in the Glyn 
quarries, in which case the point corresponding 
with the unconformity on the south side of the 
lake would be somewhere between the figures 
2 and W in Professor Eamsay's section. The 
details of structure are, however, not so fully 
exposed here as on the south side. 

The dark green rock (a Fig. 2, and d Plate 
VI.) resting unconformably on the "bastard" 
slate (b) in the railway cutting closely resembles, 
in physical character, the thin green bands in- 
terstratified with the blue slates (Plate VII., 
Figs. 1 and 2) of the Glyn quarries, and also 
the green beds separating the blue from the 
overlying purple slates. As some difference of 
opinion was expressed at the late meeting of 
the British Association regarding the character 
of these green layers, it may be well to notice 
one or two points in connection with their com- 
position and mode of occurrence. 

With reference to their chemical constitu- 
tion, the following analyses made for me at 
the laboratory of the Museum of Practical 

^ This gradation of the stratified heds into the porphyry 
is fully described in Professor Ramsay's work on the " Geo- 
logy of North Wales." — G.M. 



Maw — Cambrian Rocks of Llanheris, 



123 



Geology indicate that it is very different to that of the blue 

slates : — 

Analysis of the Dark Green Layers (the darkest portion reprbsented 

IN Plate VII.) interstratified with the Blue Slates, Glyn Qua,rries, 

Llanberis. 

Silica 66-45 Potash 



Soda 

Carbonic Acid .. 
Combined Water 



Titanic Acid , 0-63 

Alumina , ... 13-38 

Protoxide of Iron 1-71 

Peroxide of Iron 1*41 

Protosesquioxide of Manganese 0*91 

Lime 2-86 

Magnesia 6-28 

With traces of Phosphoric and Sulphuric Acid. 



0-05 
0-90 
1-30 
3-90 



Hygroscopic Water 0-13 



99-91 





--*' . 



: , V-:^ :^^ I 






J B 



I 



is 5«t\W 




Fig. 2.— New Railway Cutting, Llanberis ; corresponding with, letters d e, on Plats VI. 

The green rock {d Plate VI., a Fig. 2) resting unconformably on 
the " bastard " slate e contained i-,89 per cent, of magnesia and traces 
of titanic acid. 

Analysis op Blue Slate (the middle tint in Plate VII.) interstratified 
with the Green Layers. 

Silica 60-68 Soda 2-09 

Alumina 21-20 Titanic Acid 0-59 

Peroxide of Iron 568 Carbon 0-07 

Protoxide of Iron 0-46 Combined Water 2-70 

Protoxide of Manganese 0-16 

Lime 1-71 

Magnesia 0-88 

Potash 3-64 

With traces of Sulphuric Acid. 
Mr. David Forbes, v^'^hq h^s obligingly made sections for me of the 
green beds and slates and examiiit^cL'them: iui|ier the microscope, in- 
forms me that " the slate appeared to be composed of a pretty uniform 
mixture of grains of quartz sand with ferruginous clay, both in fine 
division, and that the green bed vras made up of quartz fragments 
with decomposed felspar and particles of red oxide of iron, and 
occasionally a greenish mineral in small quantity, probably chlorite." 
It is evident from the analysis, that the slate and interstratified 



Hygroscopic Water ............ 0-18 

100-04 



124 Maw — Cambrian Rocks of Llanberis. 

layers not only differ as to the state of mechanical subdivision of 
their constituents, but, notwithstanding the sudden and numerous 
alternations which often occur within a few inches, have a very 
different composition, and must have been derived from distinct 
sources of material. The most striking difference is in the pro- 
portion of the magnesia, of which the green layers contain seven 
times the amount of that in the slate, and the slate contains more 
than six times the amount of alkalies found in the green beds. 
Again, lime, magnesia, and protoxide of iron are much more largely 
present in the green beds than the slate, and a comparison of the 
two analyses, as well as the microscopic structure, conclusively show 
that the green bands could not have been derived by chemical 
segregation from the slate. ^ Moreover, the thicker bands contain 
mechanical fragments of a pale green slate. In the Glyn quarries 
(Plate VII.) they invariably range with the stratification, and appear 
to have been subject to all the movements and alterations the slate 
has undergone since its deposition ; the adjacent slate, generally 
on the under side only, but sometimes on both the upper and under 
side of the band, has been changed to a pale green (the lightest 
portions of Plate VII.), and the isolated spherical blotches are of the 
same character, surrounding a small nucleus of the green matter. 

As I have referred to the character of this pale discolouration in 
another paper recently communicated to the Geological Society,^ I 
would here only observe that analyses of the bleached bands fail 
to support the view expressed by Mr. Sorby^ that ''they are con- 
cretions of a peculiar kind formed round bodies lying in the plane 
of bedding." Their general composition is identical with that of 
the blue slate in which they occur, differing only in the reduced 
amount of peroxide, with no increase of protoxide of iron present. 
Mr. Sorby has pointed out that these discoloured blotches have been 
much elongated and distorted in harmony with the lines of cleavage 
(Plate VII., Fig. 2), indicating that the discolouration was antecedent 
to the cleavage. The banding and bleaching has also been inter- 
rupted (as in Plate VII., Fig. 1) by the dislocations of the slate. 

A strong proof of the contemporaneous interstratification of the 
dark green layers is that their upper surface, which is comparatively 
level, graduates into the overlying slate, as though in the deposition 
of the succeeding layers of mud, some of the green matter had been 
washed up and intermixed with it. The junction with the slate on 
the under side is, however, defined with remarkable precision, and 
instead of being nearly level it has a curiously undulating outline, 
pockets of the green rock here and there running down into the 
slate below. It seems difficult to explain vihj the green beds should 
thus graduate upwards into the slate, whilst the slate beds shew no 
gradation on their upper surface into the overlying green layer. 

Another remarkable feature is that they are not horizontally con- 

^ The view suggested by Trofessor Phillips at the late meeting of the British 
Association. rf. 

^ "On the Disposition of Iron in Variegated Strata." 
3 " On Origin of Slaty Cleavage," Edinboro' New Philosophical Journal, July, 1853 



Carruthers — On British Graptolites, 125 

tinuous ; the limits of many cannot be traced, but tbey also occur as 
isolated patches environed on all sides by the slate. The nuclei of 
the bleached spheres represent their smallest development, between 
which and the continuous layers patches of every intermediate size 
occur. 

The ultimate composition of the green beds would be consistent 
with their containing a large proportion of hornblende. Bischof^ 
refers to beds of similar character interstratified with clay slates in 
the Thuringian Forest, and discusses the question whether they may 
not be a metamorphic product from the slates ; but in the case of the 
Welsh slates, whatever be the source of the materials composing the 
green layers, whether simply detrital accumulations from eruptive 
rocks, or otherwise, their sedimentary interstratification is scarcely 
open to question. 

The bleaching of the blue slate adjacent to the dykes of intrusive 
Greenstone seems to be of a different character to that adjacent to 
the interstratified layers. Instead of being defined by a distinct out- 
line as in Plate VII., the pale colour graduates into the normal 
colour of the slate, and analyses of examples from the Penrhyn and 
Llanberis quarries indicated that the change of colour was due to 
the reduction of most of the iron from sesquioxide to protoxide, 
probably by the agency of a moderate degree of heat on the in- 
trusion of the Greenstone. As I believe there is no published 
analysis of the composition of these Welsh Greenstones, it may not 
be out of place to give the result of a determination made for me by 
Dr. Voelcker for comparison with the composition of the green 
layers interbedded with the slate. 

Analysis op Greenstone Dyke, Penrhyn Quarries. 

"Water of Combination 1*99 * Carbonate of Lime 14-85 

Bisulphide of Iron 0'23 *Carbonate of Magnesia 14-59 

Protoxide of Iron 10-22 Potash 0-43 

Peroxide of Iron 1-97 Soda 0*70 

Titanic Acid 2-51 Silica 47-47 



Alumina 5-80 



Sulphate of Lime 008 100-633 

* The carbonate of lime (and magnesia ?) occurs for the greater part in the shape 
of separate crystals, which are visible in a fresh fracture to the naked eye, and 
eflfervesce in isolated spots on the application of hydrochloric acid. 



IV. — A Kevision of the British Graptolites, with Descriptions 

OF THE New Species, and Notes on their Affinities.'^ 

By Wm. Carruthers, F.L.S., F.G.S., Botanical Department, British Museum. 

(PLATE V. p. 64.) 

Class, Hydrozoa. Order, Graptolitidce. 

Gen. I. Rastrites, Barr. (Grapt. deBoh. p. 64). Polypary simple, 
consisting of a slender capillary common tube, supporting a single 
series of isolated hydrothecae, which are free throughout their whole 
length. 

^ " Chemical and Physical Geology." English edition, vol. iii., p. 315. 

' Concluded from the February Number of the Geological Magazine, p. 74. 



126 Carruthers — On British Graptolites, 

Sp. 1. R. peregrinus, Barr. (Grapt. de Boh. p. 67, pi. 4, fig. 6), Loc. Moffat. 

2. R. LinnaU Barr. (loc. cit. p. 65, pi. 4, fig. 2-4). Common tube, very 
slender, supporting largish hydrothecse, broad at the base and narrowing gradually 
upwards. From 10 to 15 in an inch, uniform in the same specimen. Plate V. 
Fig. 15. Loc. Moffat. 

3. R. maximus, sp. nov. (PI. V. Fig. 14). Common tube slender, supporting 
very large hydrothecoe at wide intervals. Hydrothecae nearly half an inch long, 
somewhat enlarged towards the apex, and furnished at the base with a triangular 
corneous membrane extending a short distance up the margin of the cells. About 6 
cells in an inch. Loc. Moffat. 

4. R. capillaris, sp. nov. (PI, V. Fig. 16). Common tube very slender, with 
short isolated triangular hydrothecae, their base of attachment to the common 
canal as long or longer than their depth. About 16 cells to an inch. Loc. Moffat. 
Richter figures this specimen in Zeitschr. Deutsch. Geol. Gesellsch. V. 1853, Tab. 
xii. fig. 34 a., referring it io R. gemmatus,^Qxx.^ which is very different, and of 
which his fig. 34 b. is a good representation. 

R. triangulatus, Harkn. (Geol. Journ. vol. vii. p. 58), was founded on portions 
of the proximal end of G. convohitus^ His., as has been stated by several observers. 
It is remarkable, however, that this species of Graptolithus really terminates proxi- 
mally in a polypary that cannot be distinguished from Rastrites. This was pointed 
out to me by Prof. Wyville Thompson in a specimen figured on PL V. Fig. i, which 
Prof McDonald found one day he joined me in the search for the fossils at Bell 
Craig, near Moffat. The specimen is now in Jermyn Street Museum. I have in 
my own collection a smaller specimen, which exhibits also both structures on the 
same organism. How far this may affect the stability of the genus Rastrites I cannot 
at present say. All the species are founded on comparatively small fragments, and 
it is possible that they may all be the proximal terminations of different species of 
Graptolithus > 

R. Barrajidi, Harkn. (Geol. Journ. xi,, 475)? was founded upon specimens of 
Cladograpsus gracilis^ Carr., according to Prof. Harkness himself (Geol. Mag. IV. 
p. 258). 

Besides the forms enumerated, I have obtained several fragments agreeing with 
the figures of Richter's Graptolithtcs urceolus (Zeitschr. Deutsch. Geol. Gesell. V. 
1853, p. 462, Tab. xii., fig. 29, 30), and with the specimens drawn on Tab. v. fig. 
3 and 4 of Geinitz's "Graptolithen," which he refers to the lower portion of the 
stem oi R. triangulatus, Harkn., but which are certainly the same as the forms 
figured by Richter. These fragments differ from R. peregrinus^ Barr. , in having a 
small portion of the free end of the hydrotheca bent at a right angle, the mouth 
being turned round so as to open in the direction of the proximal end of the poly- 
pary. This character is so marked that I would not hesitate to include it in Ras- 
trites, as a true species of that genus as it is at present understood, were it not 
that I have hitherto met with it only in very short fragments ; and these will be 
found, I believe, when more perfect specimens are obtained, to be the proximal 
terminations of a Graptolithus^ agreeing in this respect with what I have described 
in G. coftvohitus, His. 

Gen. II. Graptolithus. Linn. (Syst. Nat., Ed. I.). Polypary 
simple, with a single series of hydrothecas in contact tkroughout 
more or less of their length. 

Sp. I. Mlssoni, Barr. (Grapt. de Boh. p. 51, pi. 2, figs. 16, 17). Loc. Moffat. 

2. G.ifttefjnediiis, sp. nov. (PI. V. Fig. 18). Polypary slender ; proximal end 
composed of a slender canal with distant, isolated, and very small hydrothecae ; 
adult hydrothecae, short, triangular, the upper margin of the cell forming an acute 
angle with the common canal. About 26 cells to an inch. This species differs 
from G. Nilssoni, G. temeis, and G. Hisingeri in the form of the cells, and from 
the last also in the slender common canal. Perhaps Portlock's figure 6a. pi. 19 of his 
Report belongs to this species. Loc. Moffat. 

3. G. teituisy Portl. (Report of Geol. of Londonderry, p. 319, pi. 19, fig. 7). 
Loc. Moffat. 

4. G. Salteri, Gein. (Die Grapt. p. 36), G. tenuis, Salter (Quart. Journ. vol. vii . 
p. 173, pi. 10, fig. i). Loc. Girvan. 

5. G. Hisingeri, Carr., G. Sagittarius, His. et auct., non Linn. I have, in a 



Carruthers — On British Graptolites. 127 

previous page, given the reasons for changing this name. Although so well marked 
a^species, it has perhaps been more frequently figured and described as new than 
any other graptolite. To it I refer the following : G. scalaris, Gein. (Leon, and 
Br. Jahrb., 1842), G. incisus, Salter (Quart. Journ.), G. tcenia^ Sow. and Salt. 
(Geol.Journ. vol. v.), G. Ba7'ra7idei ^c\idiXtn. (Grapt. p. 15), G. virgulatus, Scharen. 
(Grapt. p. 14), G. lattts, Roem. (L. and Br. Jahrb., 1855), G. polyodo7tta Roem. 
{idid), G. obliqiit-iriincattis^ Roem. {ibid), G. Jungsti, Roem. {ibid), G. serratus, 
Gein. (L. and Br. Jahrb, 1842), G. nuntius, Richt. (Zeitschr. Deutsch. Geol. Ges., 
1853), G. laxus Nic. (Quart. Journ. vi. ). G. rectus, Emm. (American Geol. i.) 
is the same species, but it is erroneously drawn with the cells directed towards the 
proximal end. G. Conybeari, Portl. (Report, p. 320), — I cannot distinguish the 
authentic specimens in the Geological Museum, Jermyn Street, from G. Hisingeri. 
Loc. Moffat, etc. 

6. G. Flemingii, Salter (Quart. Journ. viii. p. 390, pi. ai, figs. 5-7). Loc. 
Wigton. 

7. G. convolutus. His. (Leth. Suec. p. 114, pi. 35, fig. 7). The following 
synonyms belong to this species G. spiralis, Gein. (L. and Br. Jahrb. 1842). G. 
Sedgwickii, M'Coy, not Portl. (Pal. Foss, p. 6, pi. iB, fig. 2). G. Sagittarius, 
Giebel (Die Silur. Fauna, pi. 6, fig. 11). G. pectinatus, Richt. (Zeitsch. Deut. 
Geol. Ges. 1853). G.elegans, Emmons (Am. Geol. i. p. 106). Rastrites triangu- 
latus, Harkn. (Quart. Journ. vol. vii.). I have figured on PI. V. Fig. i the most 
perfect specimen of this species I have yet seen. The importance of the specimen 
was pointed out to me by Prof W. Thompson. The older portion of the poly- 
pary has the structure of Rastrites. The cells are linear and isolated. Each cell 
is furnished with two spinous processes from the sides of the mouth. Indications 
of these are to be seen in the specimen figured, but I have numerous other speci- 
mens in which they are more obvious, appearing as in Figs, lb, and \c. The first 
cells are long and slender, they gradually become shorter and thicker, and then 
they assume the triangular form characteristic of the full-grown polypary, with the 
bases extended so far along the common canal as to meet. Loc. Moffat, etc. 

8. G. Sedgwickii, Portl. (Report, p. 318, pi. 19, figs. 1-3, 6). M'Coy having 
mistaken this species, has caused it to be confounded with G. convolutus. Hark- 
ness gives a very good representation of the species from Dumfriesshire specimens 
(Quart. Journ. vol. vii. p. 58). In the original description Portlock clearly dis- 
tinguishes it from G. convolutus. He says : " The serratures are strong projecting 
hooks having a wide base." 

9. G. priodon. Bronn. (Leth. Geogn. p. 56, pi. I, fig. 13). G. ludensis, 
Murch. (Sil. Syst. p. 694). Loc. Ludlow, etc. 

10. G. Halli, Barr. (Grapt. p. 48, pi. 2, fig. 12, 13, excl. fig. 14, 15). Loc. 
Moffat. 

11. G. Becki, Barr. (Grapt. p. 50, pi. 3, figs. 14-18). G. lobiferus, M'Coy (Pal. 
Foss. p. 4, pi. IB. fig. 3). G. Nicoli, Harkn, (Quart. Journ. vol. vii., p. 61 ). G. 
millepeda, M'Coy (Pal. Foss. p. 5, pi. IB, fig. 6). Diplograpsus nodosus, Harkn. 
(Quart. Journ. vol. vii., p. 63). Loc. Moffat. 

12. G. Clingani, sp. nov. (PL V., Figs. 19^., 191^). Polypary, small and 
arcuate, with a broad common canal, and slender somewhat recurved hydrothecae. 
This beautiful little graptolite I long supposed to be only the proximal portion of 
some other species, but the large number I have met with, all equally perfect, 
none larger than fig. 19^, and many showing the prolongation of the axis beyond 
the distal end, together with the great breadth of the common canal (forming two- 
thirds of the breadth of the whole polypary), unlike the early portion or proximal 
fragment of any graptolite with which I am acquainted, have induced me to con- 
sider it a good species. I have associated with it the name of my earliest friend, 
the late J. Morison Clingan, M.A., my school-mate and fellow-student, my 
companion in rambles over the green hills and among the picturesque valleys of 
our native district, in exploring its geology or enjoying its beauty, and my friend 
and counsellor until death early cut him off, but not until he had shown promise 
of great excellence in the literary pursuits to which he had devoted himself, and 
had endeared himself by his virtues to a large circle of friends. 

13. G. Griestonensis, Nic. (Quart. Journ. vol. vi. p. 53). Loc. Peebleshire. 

Gen. III. Cybtogkapsus, CaiT. (Murch. Sil., Ed. IV., p. 540). 



128 Carruthers — On British GraptoUtes. 

Polypary growing in one direction from the proximal end, and 
giving off simple or compound branches at irregular intervals. 

Sp. I. C. Mn7rhisonii, s^. nov. (Table V. Y\g.\']a, \'jb). Hydrothecae triangular 
apiculate, furnished with a spine. The upper margin of the cell at right angles to 
the axis, about twenty-eight cells to the inch. The polypary is considerably 
incurved at its proximal end, and as it grows it gradually opens into a larger curve. 
The branches spring from celluliferous surface of the polypary, but as there is no 
break in the continuity of the hydrothecse, they must rise from the periderm 
covering the common canal. The branches also curve in the same direction as 
the main portion of the polypary. Loc. Pencerrig, Builth. I have associated 
the name of the author of "Siluria" with this remarkable species. The only British 
specimens I have seen are in the Geological Museum, Jermyn Street, but among 
the specimens obtained by the British Museum from M. Barrande there is a 
specimen from Listice, labelled G. priodon., which belongs to this species, 

2. C. hamatus {G. hamatus, Bail. I. Quart. Journ. Geol. Soc. Dubl., i86i, pi. 4, 
fig. 6). This remarkable form, of which I believe only a single specimen has been 
found, now in the Museum, Jermyn Street, where I have examined it, probably 
belongs to this genus. 

Gen. IV. DiDYMOGEAPSUs, M'Coy (Brit. Pal. Fossils, p. 9). Poly- 
pary growing bilaterally from the initial point, consisting of two 
simple or bifurcate branches and without a central disc. The initial 
portion of the proximal end forming a non-celluliferous process always 
proceeding from the common canal or axis ; the opposite or celluli- 
ferous side of the polypary frequently ornamented with one or more 
teeth or spines. The branches of the polypary sometimes extend at 
right angles to the initial process (D. hirundo), sometimes they are 
bent backwards upon it (2). Moffatensis), and less frequently they 
are turned inwards from it {D. Murchisonii). 

The forms with bifurcating branches for which Salter proposed the genus Teira- 
grapsus do not differ in any essential character from the type of Didyjnograpsus. 
The precise number of branches is not taken into account in his genus Dichograpsus, 
in which there are species with eight, eighteen, etc, , branches ; and if of no value 
there, it can scarcely be employed here. It is not easy indeed to discover any 
character whereby to separate Dichograpsus from this genus, except it be the cor- 
neous disc that envelopes the non-celluliferous proximal portions of the polypary, 
which has never been found associated with specimens of Didymograpsus, and 
only with certain forms of TeU-agrapsus and Dichograpsus. But this disc is not 
always present even in those graptolites in which it is known to occur ; it may have 
been more perishable than the polypary itself; perhaps, however, the species which 
originally possessed it may be distinguished by other characters, as by the posses- 
sion of an obvious branching hydrocaulus. There are, unfortunately, no materials 
in this country to enable one to determine this ; but if this character should prove 
a good one, it would enable us to class the various forms into two well marked 
genera ; some species of Tetragrapsus, such as G. (T.) Headi and G. crucifer, 
belonging to Dichograpsus^ while G. (T.) bryonoides^ etc., would be placed in 
Didymog rapsus. 

Sp. I. D. hirundo^ Salt. (Quart, Journ. xix. p. T37, fig, 13/"), D. constrictus^ 
Hall (Grapt. Quebec Gr. p. 76). Polypary of two branches, diverging at right 
angles from the initial points, and having its full size from the beginning. From 
22 to 26 cells in an inch. Loc. Skiddaw Slates. 

2. D. Murchisonii, M'Coy, Graptolithus Murchisonii, Beck (Sil. Syst. p, 694, 
pi, 26, fig. 4). Prionotus geminus. His, (Leth, Suec. Suppl, 2, p. 5, pi. 38, fig. 3). 
Loc, Llandrindod, etc. 

3. Z>. V-fractus, Salt. (Quart. Journ, xix. p. 137, fig. I3<f). Polypary of two 
branches bent inwards, forming an acute angle but speedily opening, and widely 
diverging from each other. From 20 to 24 cells in an inch. Loc. Skiddaw 
Slates, 

The amount and direction of divergence of the branches are so variable in 
some well-marked species of this genus, as might be expected in polyparies com- 



Carruthers — On British Graptolites, 129 

posed of a flexible substance, that I doubt if specific characters of value can be 
deduced from them. 

4. n. sextans, M'Coy (Pal. Foss. p. 9). G. sextans^ Hall (Pal. of N. York, 
vol. i., p. 273, pi. Ixxiv., fig. 3). Loc. Moffat. 

5. D. Forchhanwiei'i, Baily (Grapt. of Meath, etc., p. 6, fig. 7). Cladograpsits 
Forchhammeri, Gein. (Die Grapt., p. 31, pi. v. figs. 28-31). Branches of poly- 
pary slender, divaricating in straight lines, and at a vv^ide angle, bent backwards 
towards the initial point. Ilydrothecce not very marked, in contact throughout 
almost their whole length ; about 28 in an inch. Initial process permanent : 
the two first cells developed at a right angle to it, their mouths furnished each with 
a very fine short spine ; a third similar spine proceeds from between the bases of 
the two primary cells opposite to the initial process. Loc. Moffat, and Kilnacreagh, 
Co. Clare. 

6. D. elegans^s^. nov. (PI. V., Fig. ^,abc). Branches of the polypary divarica- 
ting at various angles, and with a slight curve within a short distance of the 
proximal origin of the polypary. The hydrothecoe are rounded at the apex, and 
free throughout a considerable portion of their length, and the intervening spaces 
are rounded at the base ; about 22 cells in an inch. The initial process is obvious 
in young specimens, but I have not been able to detect it in old individuals ; the 
outer apex of the angle ornamented with 3 short strong spines. Loc. Moffat. 

Dr. Nicholson has enabled me to refer his D. flaccidns (Geol. Mag., Vol. IV., 
p. no, PI. VII., Figs. 1-3) to this species. His fig. i has a general resemblance to 
Hall's G. flaccidns, but the form and number of the cells and the breadth of the 
polypary are very different. In Hall's species there are "from 28 to 30 and near 
the base sometimes 31 " cells in the space of an inch. In Dr. Nicholson's drawing, 
" nat. size," there are 14 ! The figs. 2 and 3 made me fancy that he might mean 
the species I have just described, but it would have been impossible, except on his 
own authority, to have settled the matter. Loc. Moffat. 

7. D. Moffatensis, Carr. (Trans. R. Phys. Soc. Edin., 1858, p. 469, fig. 3). 
G. divaricatus. Hall (Pal. N. York, vol. iii. pt. i, p. 514, 1859). D. anceps^ 
Nicholson (Geol. Mag., Vol. IV., p. no, PI. VIL, Figs. 18-20). The last 
paragraph in Dr. Nicholson's description of this species shows that he had over- 
looked D. Moffatensis when he wrote it, and his comparison of his fossil with 
Hall's figure puts it beyond a doubt that I have rightly placed D. anceps here as 
a synonym. Loc. Moffat. 

8. D. caduceiis. Salt. (Quart. Journ. vol. xix., p. 137, fig. 13). G. Bigsbyi^ HaU 
(Grapt. Quebec Gr. p. 86). Hall has to my mind clearly shown this to have four 
branches. Loc. Skiddaw Slates. 

9. D. bryonoides. — Tetragrapsns bryonoides, Salt. (Quart. Journ., vol. xix., 
P- 137* fig- ^^)- <^- bryonoides, Hall (Grapt. Quebec Gr. p. 84). Loc. Skiddaw 
Slates. 

10. D. quadribrac hiatus — G. quadribrachiatus^ Hall (Geol. Surv. of Canada, 
Rep. 1857, p. 125). 'x etragrapsus crucialisy Salt. (Quart. Journ., vol. xix., p. 137, 
fig. %b). Loc. Skiddaw Slates. 

Gen. V. — DicHOGRAPSus, Salt. (The Geologist, iv., p. 74). Poly- 
pary compound, growing bilaterally, and branching more or less 
frequently in a dichotomous manner, the hydrocaulus, or non-celluli- 
ferous bases of the branches invested with a corneous disc. 

Sp. I. D. octobrachiatus, — G. octobrachiatus. Hall (Canada Rep. 1857, p. 122 ; 
Grapt. Queb. Gr. p. 96, pi. 7, 8), D. aranea^ Salt. (Quart. Journ. xix., p. 137, 
fig. 9). Loc. Skiddaw Slates. 

2. Z). Sedgwickii, Salt. (Quart. Journ. xix. p. 137, fig. ii). Loc. Skiddaw Slates. 

Gen. VI. — Cladograpsus, Carr. (Trans. E. Phys. Soc. Edin., 1858, 
p. 467). Polypary compound, growing bilaterally from the primary- 
point irregularly, and repeatedly branching and rebranching, and 
without a central disc. Pleurograpsus, Nicholson (Geol. Mag., Vol. 
IV., p. 256). 

Sp. I. C. linearis, Carr. (Trans. R. Phys. Soc. Edin., 1858, p. 467, fig. i). 
Plmrograpsus linearis^ Nich. (1. c. ) This species has a slender polypary, and cells 



130 Carruthers — On British Graptolites, 

so slightly elevated as not to be clearly seen without the aid of a lens ; there are 
about i8 to the inch. Dr. Nicholson's figure, " nat. size," represents a strong 
polypary with well-marked cells, and from 6 to 9 in an inch ! I have no doubt 
that it was drawn as Dr, Nicholson says for this species, but it is greatly to be re- 
gretted that such drawings are published ; they can serve only to increase the dif- 
ficulties that under the most favourable circumstances beset every scientific investi- 
gation. Loc. Moffat. 

2. C. capillaris, sp. nov. (PI. V., Fig. 7 a, b) Extremely slender polypary, 
with remote branches, and very minute hydvothecse ; about 24 in an inch. It is 
not so abundant as C. linearis, and is very easily distinguished by its capillary ap- 
pearance. It is probably the same species as that figured and described by 
Emmons in his American Geology, vol. i., p. 109, pi. I, fig. 7, under the name of 
N'emagrapsus capillar is. Loc. Moffat. 

3. C. gracilis, — G. gracilis, Hall (Pal. N. York, i. p. 274, pi. Ixxiv, fig. 9); 
Rastrites Barjandei, Harkn. Loc. Moffat, and Bellewston Hill, Meath. 

Gen. VII. — Dendeograptus, Hall (Grapt. Quebec Gr. p. 126). 
Polypary compound, with a thick common hydrocaulus giving off 
branches irregularly, which repeatedly subdivide in a dichotomous 
manner. 

Sp. I. D.furcatulus, Salt. (Mem. Geol. Surv. iii., pi. il. a, fig. 5). 

2. D. lenfus, Carr. (Murch. Sil., Ed. iv., p. 541, fig. 5). Branches of the poly- 
pary repeatedly dichotomising ; hydrothecse acute-angular, about 18 in the inch. 
This is a much more robust species than that described by Salter. I have seen no 
more of it than the well-marked specimen figured (PI. V., Fig. 5). Loc. Fer- 
managh. 

Gen. VIII. Diplograpsus, M'Coy (Pal. Toss., p. 7). Polypary 
with a double series of cells on either side of a slender axis. Hydro- 
thecee distinct from the periderm of the common canal. 

Sp. I. D. pristis, His. (Leth. Suec. p. 114, pi. xxxv. fig. 5), D. foliaceus, Murch. 
(Sil. Syst.) Fucoides deniatus, Brongn. (Hist. Veg. Foss. I. p. 70). D.physophora 
Nich. (Ann. Mag. Nat. Hist., January, 1868, p. 56). Z>. vesiciilos7is, Nich. (ibid 
P- 57)- This is the best known and most abundant species of JDiplograpsus. 
Although it has been frequently figured I have had four specimens drawn on PI. 
v., with the view of illustrating the different forms of the appendages at the 
proximal end. The species generally appears as if it terminated in an acute point, 
formed by the approximation of the two primal cells ; occasionally a spine con- 
tinuing the line of the axis, and two lateral ones, are found (13 b, c, d), and in one 
specimen (13 «) I have observed two long slender processes rising together from 
the proximal points of the polypary, and produced apparently by the abnormal 
division of the medial spine. The axis is generally prolonged at the distal end, 
and is sometimes twisted and enlarged as described by Barrande (Grapt. deBoh. p. 
4), and figured in different species of Diplograpsus by Barrande, Geinitz, Baily, 
etc. Dr. Nicholson has founded his D. vesiadosus on a specimen with the axis in this 
condition, and Z>. physophora is evidently another specimen of the same species 
in accidental contact with a " grapto-gonophore, " or some other body. Loc. 
Moffat, etc. 

2. D. minntiis, sp. nov. (PI. V., Fig. 12, a, b). This agrees with Z>. pristis in 
general appearance, and in the form and arrangement of the cells, except that the 
whole polypary and all its parts are so very small. Had I met with only a few 
specimens, I would have considered it as merely an accidental variety, but I have 
seen so many, all agreeing in size, that I cannot doubt that it is a good species, 
especially as young specimens of D. pristis early attain their full breadth, and the 
increase of the polypary is by additions to its distal end, and not to the size of the 
already formed hydrothecDS, just as in the living Sertidariadce. About 38 cells to 
one inch. Loc. Moffat. 

3. D. ajigustifolitcs, Hall (Pal. N. York HI., p. 515, figs, i and 2). D. acumi- 
natus, Nich. (Geol. Mag., IV., p. 109, PI. VII., Figs. 16 and 17). Loc. Moflfat. 

4. D. persculptus (Cat. Foss. Mus. Pract. Geol. p. 25). Beautiful specimens of 
this species, which I recently saw in the Woodwardian Museum, Cambridge, 
convinced me of its distinctness. It is nearly allied to D, pristis and D. folium. 



Carruthers — On British Graptolites, 131 

A satisfactory description and drawing of it would be of value. Loc. Gogofau, 
Carmaerthenshire. 

5. D. Whitfieldi, Hall (Pal. N, York, iii. p. 516, fig. i,). D. quadri-mucro- 
natus, Nich, (Geol. Mag. IV. PI. VII. Fig. 6). This species I had long considered 
to be a mucronate form of D. pristis, with which species it for the most part agrees, 
except in the possession of the spines proceeding from the cell mouths. In the 
drawings, PI. V. Fig. 7,b and 3^, the spines are represented by somewhat too 
strong lines ; their direction, which seems in life to have been at right angles to the 
direction of the polypary, depends in the fossil upon the way in which they have 
been pressed before or during fossilization. The direction is different on the two 
sides of Fig. 3 r. 

6. D.mucronatus, Hall (Pal. N. York i. p. 268, pi. 73, fig. i.), PI. V. Fig. 2. 
Loc. Moffat. 

It is not easy to determine how far the processes from the mouths of the 
hydrothecas are to be depended upon for specific characters. Mr. Baily, from 
Irish specimens, has figured under the name of D. mucronaius (Grapt. of Meath, 
etc., fig. 4 a, by f), a remarkable form, with the general aspect of D. pristis and D 
Whitfieldi, but with several branching and apparently anastomosing processes from, 
the cell mouth. I have met with the same form at Moffat, and figured them in the 
Intellectual Observer, May, 1867, pi. i, fig. 6 ; and Hall, also, in his Graptolites of 
the Quebec group, pi. B. fig. 10, gives a drawing of a somewhat similar structure. 
He considers the processes to be the marginal fibres of the reproductive sacs, the 
sacs themselves having been removed (by maceration). The discovery of additional 
specimens may show that it is really a new species ; and should it turn out to be 
so, I would suggest that it be called D. Bailyi^ after the palaeontologist who is 
doing so much towards the illustration of the paleozoic fauna of Ireland. The 
polypary has been very flexible, as bent and twisted specimens have occurred both 
to Mr. Baily and myself. 

7. D. tricornis, Carr. (Trans. R. Phys. Soc. Edin. 1858, p. 468, fig. 2). G. 
majcidiis, Hall (Pal. N. York iii. p. 515, figs. 1-3). When I described this species 
I had not detected the mouths of the cells in those specimens in which they should 
have been shown on the upper surface. In more perfectly preserved specimens 
since obtained these have been beautifully shov/n (PL V. Fig. iia). I have given 
a drawing (Fig. 11^) of the early state of this graptoHte. I drew attention to this 
early form and figured it in the Physical Society's Transactions for 1858, and in the 
Annals and Magazine of Natural History for January, 1859. In the third volume 
of the Palaeontology of New York, published in 1 859, with the dedication dated 
September, 1859, Prof. Hall figured the early state of the same species, p. 508. 

8. D. cojneta, Gein. (Grapt. p. 26, pi. i, fig. 28), D. tubidariformis, Nich, 
(Geol. Mag. Vol. IV., p. 109, PI. VII. Figs. 12-15). This is a remarkable species, 
which should, perhaps, be made the type of a new genus. Geinitz's figure is very im- 
perfect and fragmentary ; an excellent figure is given by Richter in the German 
Geol. Society's Zeitschrift (1853, pi. xii. figs. 16, 17). I have given (PI. V. Figs. 
4<a:, (5, and c) drawings of three different forms. These faithful drawings by Mr. 
Hollick may be compared with Dr. Nicholson's figures quoted, and some idea may 
be formed of the value of his illustrations ; but his own drawings supply materials 
for their condemnation, for in his enlarged drawing of Fig. 14 he has made the 
8 cells of the "nat. size" into 10, and in fig. 15 the 4 cells in the "nat. 
size" become 6 in the enlargement, so increasing not only their size but their 
number also. 

Gen. IX. Climacograptus, Hall (Grapt. Quebec Gr. p. 111). 
Polypary with a double series of cells hollowed out of the common 
epiderm. 

Sp. I. C. scalaris. Hall (Grapt. Quebec Gr. p. ill), Graptolithus scalaris, Linn. 
(Skanska Resa, p. 147), Prionotus scalaris,YL\s. (Leth. Suec. p. 113). G. palmeus, 
Barr. in part (Grapt. Boh. pi. 3, figs. 5 and 6). G. mcntitcs, Barr. in part {ibid. 
pi. 2, figs, 7 and 8). G. Halli, Barr. in part {ibid, pi, 2, figs. 14 and 15). G. 
personattis, Scharen, (Grapt, p. 15, pi. i, fig. 12). G. teretiiiscuhcs. Salt. (Quart. 
Journ. viii. pi. 20, figs. 3 and4). Diplograpsics rectangiilaris, M'Coy (Pal. Foss. p. 8, 
pi, IB, fig. 8). D. pristis, var, scalar iformis, Baily (Grapt. fig, 2 a, b, c). 

From the time of Hisinger until Hall restored the name, this species was greatly 



132 Carruthers — On British Graptolites, 

misunderstood. It is a misfortune that cannot now be corrected, that this, the 
only species which Linnaeus describes, finds a resting place in one of the most 
recently established genera, instead of being the type of the genus Graptolithns. 
Loc. Moffat, etc. 

2. C. mimitus, sp. nov. (PI. V. Fig. loa, b). This is a very minute but well- 
marked species, never attaining a greater size than represented on the Plate. 
There are at the rate of from 32 to 40 cells in the space of an inch. Loc. Moffat. 

3. C. bicornis. Hall (Grapt. Quebec, Gr. p. in). Loc. Moffat. 

4. C. biillatiis, — Diplograpsics bullatus^z\.\.. (Quart. Journ. vii., p. 174, pi. x., 
fig. 2). Loc. Piedmont Glen. 

I have never seen a specimen oi D. pennatus^ Harkn. ; it probably belongs to 
this genus, if it be not founded upon two mono-prionidian forms accidentally 
placed back to back. 

Gen. X. DiCRANOGRAPTUs, Hall (Grapt. Quebec Gr. p. 57). Poly- 
pary in the proximal portion, with a double series of cells, but di- 
viding distally into two branches, with a single series of cells in their 
outer aspect. Hall describes this genus as having the structure of 
Climacograjptus, as regards the cells in which the polypites were 
lodged, but in the two British species the polypites are certainly lodged 
in true hydrothecas. The form of the polypary, however, supplies 
sufficient characters for the separation of the group as a distinct 
genus. 

Sp. I. D. ramosus. Hall (Grapt. Quebec, Gr., p. 57), Loc. Moffat. 

2. Z>. Clingani, sp. nov. (PI, V., Fig. 7 a, ^, c). Polypary with a short 
diprionidian portion, the proximal end furnished with three very delicate spines ; 
hydrothecae forming a slight serration along the margin ; 21 cells in the inch. 
Loc. Moffat. 

Gen. XI. — Eetiolites, Barr. (Grapt. Boh., p. 68). Polypary 
without a solid axis, cells arising from a central common canal in a 
double series, and in contact throughout their whole length. Poly- 
pary reticulated on the outer surface. 

In Dicranograptus the double septum and axis become separated in the branches 
into their elements, forming a closed back and axis to the two mono-prionidian 
polyparies. The structure of Diplograpsus is exactly that of the proximal portion of 
Dicranograptus, being theoretically, if not actually, composed of two mono-prioni- 
dian polyparies, united back to back. In Climacograptus the filiform axis alone re- 
mains, and the divisions between the polypites is carried down to the axis, leaving, 
however, a continuous free space on either side of the axis for the common coeno- 
sarc. In Retiolites this union is still more complete, the ccenosarc of the colony 
being common to the two series of polypites by the total disappearance of the 
axis and dorsal portion of the epiderm in Graptolithus, or axis and septum in 
Diplog7'apsus. 

Sp. I, R. Geinitzianus, Barr. (Grapt. Boh., p, 69). (Murch. Sil., Ed. IV., p. 
541, fig. 2,) Loc, Cumberland. 

2. R. venosus. Hall (Pal. N. York ii., p. 40, pi. 17 A., fig. 2). Loc. Cum- 
berland. 

Gen. Xn. — Phyllograptus, Hall (Canada Geol. Keport, 1857, 
p. 135). Polypary consisting of four laminse of cells united rectan- 
gularly by their longitudinal axes. 

The British specimens of this genus which I have seen exhibit only thin films 
on the surfaces of highly indurated or somewhat metamorphosed rocks, sufficient 
to determine their relation to Hall's genus, but utterly insufficient to exhibit any 
details of the remarkable structure of the genus. If I rightly understand Hall's 
descriptions and figures, the individual polypites in this genus are entirely separated 
from each other, the septa between the hydrothecae being united [to the periderm 
and continued to the axis. This structure is so anomalous among the GraptolitidcB 
that I am inclined to think that I misunderstand it, especially as Hall does not 



Cre.ol.Mc^. {^6^. 



Voi.v: pi.vni 




ACTINOCERAS BACCATUM. Sjs.Hov. 

WocLh dJth _Z/ um e.dL orvt, - L iXZLe^ ~J1 u/\. o Q z4>CLrry, /faol/Jvoh^c . 



Woodward — On Actinoceras. 133 

distinctly describe it, although it seems to me to be necessarily implied in his 
figures and descriptions. 

Sp. I. P. angiistifolms. Hall (Canada Rep., p. i39 J Quart. Journ., vol. xix , 
P- '^?)1'> 6g' 7)- Loc. Skiddaw Slates. 



V. — On Actinoceras baccatum, a New Species of Orthoceratite 

FROM THE WOOLHOPE LiMESTONE. 

By Henry Woodward, F.G.S., F.Z.S. 
[PLATE VIII.] 

THE fossil about to be described was obligingly sent to me by 
Dr. Bull, of Hereford, having been happily rescued from the 
remorseless hammer of the road-mender, by Kichard Johnson, Esq., 
the Town Clerk of that city. It exhibits the shell in section, fractured 
longitudinally, and embedded in a hard compact mass of dark blue 
Woolhope Limestone, which may be seen well exposed in situ in 
the Little Hope quarries, near Woolhope, from whence the block 
which contains the fossil was derived. Dr. Bull informs me that 
the Woolhope Limestone from these quarries is always used for 
road-metal in the surrounding district. 

It is most faithfully delineated (of the natural size) in the ac- 
companjring lithograph (Plate VIII. ), by the able pencil of Dr. Bull. 

The fossil has been fractured so as to remove the upper surface, 
exposing seven perfect and two fractured beads of the siphuncle, 
and giving evidence of ten septa ; the chambers formed by w^hich 
remain partially hollow and are partly filled by calcareous spar. 
None of the exterior wall is visible from which the nature of the 
ornamentation of the shell, if any, might have been ascertained, 
but the interior portion is so characteristic of the genus that I have 
no hesitation in referring it to Actinoceras. 

That genus is characterized as follows : — '' Siphuncle very large, 
inflated between the chambers, and connected with a slender central 
tube by radiating plates."^ 

Of the species referred to this genus five are British, namely, 

Actinoceras Brongniartii, Portl. Lr. Silurian, Tyrone. 

„ Brightii, Sowerby, U. „ Malverns. 

„ nummularium, Sowerby, „ Tortworth. 

„ giganteum, Sowerby, Carb. L. Yorkshire, etc. 

,, pyramidatum, M'Coy, ,, Ireland. 

The Woolhope fossil most closely resembles A. pyramidatum, of 
M'Coy, both in the beaded form of the siphuncle and the general pro- 
portions of the chambers, but the beads of the siphuncle are much 
less spherical in A. pyramidatum, and the sides of the chambers form 
a less acute angle at their junction with the outer wall of the shell 
than in the fossil before us.^ 

1 See'" Woodward's Manual of the Mollusca," p. 58. 

"^ Compare figure on Plate VIII. with M'Coy's figure in Carbonif. Foss. of Ireland, 
table ^, fig. 5 ; see also Barrande's " Syst. Silur. de Boheme (Cephalopoda) " vol. ii., 
pi. 232, fig. 11. 



134 'Woodward — On Actinoceras. 

The following are the proportions of the Woolhope specimen : — 

Extreme length of siphuncle composed of 9 beads, 4 j inches : transverse diameter 
of largest bead of same, 9 lines ; vertical thickness of same, 7 lines ; transverse diameter 
of smallest bead, 6 lines ; vertical thickness of same, 4 lines ; greatest diameter of 
shell, 2 inches; least diameter of shell, 1 inch 4 lines; interspace between one septum 
and another in largest chamber, 6 lines ; in smallest, 3 lines. 
Neither the apex or body-chamber of the shell being present, 
we can only surmise its length. A section of Actinoceras giganteum(f) 
from Derbyshire, preserved in the British Museum, measures 2 
feet in greatest length and 3 J inches in greatest breadth, and exhibits 
thirty-eight body-chambers. An Orihoceras from Ireland, in same 
collection, measures 2ft. lOJ inches in length and 16in. in circum- 
ference. Many have been discovered even far larger than these. 

To this group, undoubtedly, belong the most gigantic forms 
of the straight Nautilidce. 

The interest attaching to this most ancient group of chambered 
shells is such, that I have gladly availed myself of Dr. Bull's kind 
proposal to notice it in the pages of this Journal, accompanying the 
notice with his excellent figure. I have not only carefully examined 
the specimen myself, but have been favoured with the opinion of 
Professor Morris thereon, and I am confirmed in the conclusion that 
the Woolhope specimen is specifically distinct from any other 
heretofore described. I have therefore (at the suggestion of Dr. 
Bull) named it Actinoceras haccatum (in reference to the beautiful 
bead-like structure of the siphuncle). 

The characteristic fossils obtained from the Little Hope quarries 
in the Woolhope Limestone from whence A. haccatum was derived 
are : Trilobites — Illoenus Barriensis, Homalonotus delphinocephalus, 
and Phacops caudatus. Mollusks — Orthoceras annulatum, Strophomena 
depressa, S. euglypha, S. pecten, BhyncTionella Wilsoni, and B. 
Stricldandi, Cirrus — sp. ; and also Cormdites serpularius and PtycJio- 
phjllum patellatum. 

The Little Hope or Scutterdine quarries (which are quite beneath 
the Wenlock shale) are intersected by the Geological Survey, section 
No. 2 on sheet 13, and their precise position is laid down on the 
Ordnance Map No. xliii., N.W. 

It is to be hoped that the Woolhope Naturalists' Field-club, 
which numbers some excellent geologists among its members, will 
detect further specimens of this interesting fossil, and that we may 
be able, at a future day, to add a more full description to the 
present very brief notice. 

Mammalian Eemains at Ilford. — Mr. Antonio Brady, F.G.S., of 
Maryland Point, Stratford, has again, at great expense, endeavoured 
to save from destruction some fine remains laid bare a few days 
since by the workmen in Hill's Pit, at Ilford. The remains included 
two fine pairs of horn-cores of Bos primigenius, a fine antler of Cervus 
Elaphus (with eight prongs), and a grand tusk of Elephas primigenius, 
measuring 9 feet 6 inches in length. Large numbers of loose limb- 
bones and vertebra} of Bos, and bones of Ursus and Equus, were also 
obtained. 



Geology of the South- West of England, 135 

3^0a?ICES OIF nyCEIMIOII^S 

GEOLOGY OF THE SOUTH-WEST OF ENGLAND. 

1. — ''On the Middle and Upper Lias of the South-west of 

England." By Charles Moore, F.G.S. 

Reprinted from the Proceedings of the Somersetshire Archaeological and Natural 
History Society. Vol. xiii. 1865-66. 

2. — " On Abnormal Conditions of Secondary Deposits when con- 
nected with the Somersetshire and South Wales Coal- 
Basin; AND ON THE AgE OF THE SuTTON AND SOUTHERNDOWN 

Series." By Charles Moore, F.G.S. 

Quarterly Journal of the Geological Society, December 1, 1867. Supplementary No. 

IN the first of these papers, Mr. Moore describes the beds between 
the so-called Upper Lias Sands and the zone of Ammonites rari- 
costatus, the highest member of the Lower Lias, in their passage 
through Somersetshire into Gloucestershire. He gives numerous 
sections, and lists of fossils, with descriptions and illustrations of 
the Mollusca, — some of which are new species. A typical section at 
Ilminster, showing 158 feet of Middle Lias, and 10 feet of Upper 
Lias, is first explained, and then compared with other sections in the 
South-west of England. The beds of the Middle Lias consist of 
irregular thickly-bedded marlstones, marls, and sands, with much 
ironstone. The Upper Lias comprises thin beds of clay and lime- 
stone, crowded with organic remains. Though iron is plentifully 
distributed in the Middle Lias of the district under consideration, 
the beds are not quite thick enough to be worked with profit. 

In noticing the Ichthyosauri of the Upper Lias, Mr. Moore re- 
marks that whilst these reptiles appear in Liassic times to have fed 
on the naked cephalopoda, others of this family in their turn retali- 
ated. In several instances their bodies have been found covered by 
colonies of Ammonites, which were evidently preying upon the 
Ichthyosauri before they were finally entombed. 

Mr. Moore discusses the recent classification with the Upper Lias, 
of the Yellow Sands beneath the Inferior Oolite, and states that he 
has never been able to recognize this arrangement. Not only is 
there in each horizon as distinct a fauna in its general facie s as 
can be found in any other formation, but wherever the junction 
of the sands with the Upper Lias is observed, there is a most marked 
and permanent lithological distinction in argillaceous beds crowded 
with Ammonites, etc., capped by yellow sands, with but few 
evidences in their lower beds of organic life. Moreover, he adds, 
that wherever the junction of the Upper Lias with the Sands is ex- 
posed, the former presents an eroded surface. 

Mr. H. B. Brady contributes a synopsis of the Foraminifera ; and 
Mr. Henry Woodward furnishes a communication on the Crustacea, 
wherein he points out the interesting fact that many forms, common 
to the Lias, agree in identity with species found only in the Litho- 
graphic stone of Solenhofen, showing that they must have migrated 



136 Reviews — Meyer^s Catalogue of Tertiary Fossils. 

before the close of the Liassic period in this country, and thus have 
been enabled to live on during the deposition of the long series of 
sedimentary deposits which occur between our Lias and the Upper 
Oolite in Bavaria. 

2. — In the second paper, Mr. Moore shows that south of Bath 
there is a very remarkable thinning- out of the Secondary beds 
as compared with their equivalents beyond the Mendips, and that 
whilst in the latter case they attain an aggregate thickness of 3320 
feet, in the neighbourhood of Eadstock, Paulton, and Camerton 
they are reduced to 169 feet, which he considers to arise from the 
Mendip Hills having been a land-area during a great part of this 
lengthened period, and so serving to prevent the incursion of the 
Secondary seas within its borders. 

The mineral veins of the district show most conclusively that the 
Carboniferous Limestone must for a very long-extended period have 
been within the influence of the Liassic seas, and that from the 
latter have been derived most, if not all, of their mineral treasures, 
whether iron, lead, or calamine. 

Mr. Moore's observations lead him to the conclusion that the eleva- 
tion of the Mendips and their South Wales continuation may be 
assigned to a time not far removed from the deposition of the Upper 
Beds of the Trias or New Eed Sandstone. His discovery of a 
basaltic dyke in the Mendips clearly explains to him the origin of 
the up-heaval and disturbance of the beds forming this range of hills. 
A section across the Nettlebridge valley shows that by the protru- 
sion of the dyke rocks of enormous thickness have been carried 
bodily forward in a northerly direction for a great distance, and are 
not only left standing vertically, but are in some instances folded 
over upon themselves. In consequence of this, Coal has been able 
to be worked beneath a reversed band of Carboniferous Limestone. 

In regard to the Sutton Stone, Mr. Moore is of opinion that its 
peculiar lithology is only local, and he shows that these beds are truly 
Liassic — a view corroborated by Mr. Bristow's detailed observations 
in the field. Mr. Moore notices many points of palgeontological 
interest, especially the wonderfully rich fauna of Brocastle, from 
which he has obtained nearly 200 species, including many Corals 
which have been examined and described by Dr. Duncan. — H.B.W. 



I^EVI:B"ws. 



Catalogue Systematique et Descriptif des Fossiles des Ter- 
rains Tertiares, au Musee Federal de Zurich. Cahiers 
1 AND 2. Par Charles Meyer. 

THIS work appears in the Quarterly Journal of the Nat. Hist. 
Society of Zurich, but its value as a contribution to Palaeonto- 
logy is far greater than its unpretending and somewhat fragmentary 
mode of publication would imply. It is the result of critical study 
of species by an experienced and accomplished conchologist, and 



Reviews — Meyer's Catalogue of Tertiary Fossils. 137 

promises in the sequel to supply materials by which the Faunas 
of the various Tertiary basins may be compared : under which, that 
of the Swiss valley will be as interesting as any. 

M. Meyer still adheres to the old Geological term ''Tertiary," 
and includes the great Nummulitic series, in all its equivalents ; but 
he shows in the sequel where and why a line should be drawn, 
which would detach the Nummulitic from the true Kainozoic series, 
or that of which every part contains some proportion of living forms. 

In his Catalogue of species of fossil shells M. Meyer does not 
proceed according to any systematic arrangement. His first part 
comprised the Chenopides, the Strombides, and the Ficulides. In 
Part 2 are the Mactrides, and the Pholadomyides. Numerous 
species are reviewed, as to their range vertically, and their geogra- 
phical distribution. Other columns, such as that of the money value 
of a specimen, or, again, that of its relative abundance or scarcity, 
might have been dispensed with. 

To each Part of the Catalogue a Geological Introduction is prefixed. 
In his last M. Meyer proposes to make two additions to his previous 
scale (Tableau synchronistique des Terrains Tertiares, 1865), — the 
one quite at the base of the series, between the " Danien " and the 
" Suessonien ; " the other, now the 12th, between the " Tortonien " 
and " Astien." The first of these is to include a fauna which haa 
recently been discovered below any former subdivisions of the 
Belgic Nummulitic group ; the other for certain beds which he 
had formerly considered as forming the lower portion of the 
" Astien " stage, but which he has now separated, in accordance 
with the views of M. Seguenza. Few geologists will agree with M. 
Meyer that this addition to the already long series of his " Tertiary '* 
stages makes that period of more importance than either the Jurassic 
or the Cretaceous ; but most will go with him in this — that they 
render more desirable than ever that the " Tertiary " period should 
be formed into two symmetrical and natural groups. 

M. Meyer disposes summarily of older Geological arrangements. 
What, he asks, is the Pliocene ? A simple stage, like any other ; 
based, in Italy, on the preceding stage, and connected with neigh- 
bouring stages by so large a portion of its fauna, as hardly to retain 
a characteristic species. What is the Miocene? A jumble of four 
distinct stages, stratigraphically considered, of which the first 
(Aquitanien) has in common with the uppermost (Tortonien) but 
certain living species, and a few which make their appearance from 
the Tongrien period. Wliat is the Oligocene ? Three stages which 
occur in the little North German Tertiary basin, and which are 
joined together, because there accidentally is a break both above and 
below them, but the which are more completely distinct from one 
another than the lower and the higher are from those which precede 
or follow. 

" But since it would be well to establish one or two great 
sections in the over-long Tertiary Series, it seems to me that 
there is a method of separation which above every other has 
the advantage of being convenient and perfectly symmetrical. 

VOL. V. — NO. XLV. 10 



138 Reviews — Meyer's Catalogue of Tertiary Fossils. 

It is the method proposed by M. Hoernes, which places the 
boundary line between the Eocene and the older Miocene, or be- 
tween the Tongrien and Aquitanien stages. Let the Prussian 
geologists say what they may, it is precisely then — at the close of 
the Tongrien period — that in Europe the most important changes 
took place, either with respect to the displacement of seas, or the 
change of fauna. At that time, in the north of Europe, the sea 
retired from the whole of the English, French, and Belgic portions 
of the Tertiary basin, and there was a contraction of one-third of the 
North German basin. In central Europe there was a general and 
important elevation, or at least a first marking of the boundaries, 
of the whole Alpine chain ; evidenced by the presence of Tongrien 
depositions on the mountains of Faudon and St. Bonnet, of the 
Dent-du-Midi, the Diablerets, the Titlis, &c., and by the position of 
the earliest marine deposits, of the Aquitanien period, at the base of 
the great Alpine wall. In the S.W. of France there was a con- 
traction and emptying of that basin, as shown by depositions either 
wholly fresh-water or brackish. Palseontologically considered, there 
was nearly a complete disappearance, in the Aquitanien stage, of all 
the Eocene species, that is of those which still in considerable 
numbers connect the Tongrien with the subjacent stages ; there was 
a complete extinction of Nummulites, which are still accumulated in 
great numbers in the upper beds of the Alpine and southern zones 
of the Tongrien stage ; — (St. Jacques near Eennes, Gaas, le Tuc-du- 
Saumon near Dax, Faudon, Argentines in the French Alps, the 
Dent-du-Midi, the Diablerets, Acqui, Cassinelle, Pietra-Bissara, etc., 
in the Piedmontese Apennines ; Verona, Castel-Gomberto ;) — lastly 
the first appearance of the great Pachyderms, and swarms of still- 
living species of MoUusca." 

It is true that M. Meyer suggests certain Palseontological conside- 
rations which may detract from the value of this proposed line of 
demai'cation, such as an admixture of fossil in certain localities, just 
as was supposed to be the case at the Bolderberg ; of such difficulties 
as these the physical geologist sees an obvious explanation. The 
Nummulitic group must be wholly separated from the Kainozoic, 
and be made to constitute the uppermost member of the Mesozoic 
series of Periods. 

The changes which M. Meyer now proposes are these : — ^I. For 
" Mayencien " he substitutes the designation " Langhien," from a 
chain of hills between Acqui and the upper course of the Tenaro ; 
the change is made in deference to the dislike of the Germans to the 
word Mayencien, — a very insufficient reason. II. Mr. Toumouer's 
recent discovery, on the boundary of the Department of the Gers 
and the Landes, of beds identical with the Faluns of Touraine, 
proves that these last are not merely a facies of the Saucats beds, 
but belong to a higher level, strati graphically distinct ; as also by 
a fauna less rich in tropical species, richer in Mediterranean forms. 
This level being intimately connected, in the S.W. and central 
France as in the Swiss-German Jura, with that which follows 
(the beds of Serravalle), it becomes necessary to unite it to the 



Reviews — Meyer's Catalogue of Tertiary Fossils, 139 

"Helvetien" stage. Mayencien ii. b. becomes Helvetian i. ; Helv6- 
tien ii. and iii., H. i and ii., for all the localities quoted, except those 
of the hill of Turin, which remain at the level of the Manthelan 
beds (Kio della Batteria, Villa Eoassenda, lower Baldissero), or at 
that of the Serravalle beds (Termo-Foura, Pino, upper Baldissero). 
The beds with large Lucinae, of Pino, Stazzano, of Monte-Baranzone 
near Modena, are the Italian representatives of the Leitha lime- 
stone. 

"The new stage which, in agreement with M. Seguenza, I propose 
to intercalate is in every respect most interesting. First it fulfils 
exactly, both by position and fauna, the middle place betwixt the 
Miocene and Pliocene which was wanted, to demonstrate the useless- 
ness of such distinction. It presents at the same levels extended 
salt, brackish, and fresh-water deposits. Lastly, it connects together 
a number of deposits whose places had not been determined, such 
as the brackish water beds of the Danube basin, and the upper fresh- 
water Mollasse of Switzerland. It is to the middle stage that M. 
Heer gave the name of that of '' CEningien ; " it is to its lower level 
that the Sarmathian stage of M. Suess is to be referred ; and it ii 
for its thick marine beds of the neighbourhood of Messina that M, 
Seguenza would propose the name of the Zankleen stage. Sepa- 
rated from the Astien stage, such as I had at first proposed it, the 
Missinien stage comprises 3 levels. 

" 3. The Epplesheim beds, including the pebble beds of the 
Tortonias and of the Plaisantin. The sands and pebbles 
with Dinotherium of the valleys of the Danube, the Jura, 
and the Ehine, and the corresponding beds in the S.W. of 
France. 
" 2. The Dreissena (Congeria) beds of the Danube valley, and of 
Kertch, the region of the upper gypsum beds of the N. Apen- 
nines, the upper fresh- water Mollasse of Switzerland. 
" 1. And lowest, the Billowitz beds, those with Cerithia and 
Mactra Podolica of the Danube valley and Eussia. The 
marls with Cerith. of Stazzano and St. Agate near Tortona. 
The white, sandy and micaceous Mollasse of the North of 
Switzerland. 
" The Marine marls of Messina, their great thickness considered, 
are the probable equivalents of the whole of these three levels." 



Geological Society of London. — I. — January 8, 1868. — 1. 
" Notes on the Lower Lias of Bristol." By W. W. Stoddart, Esq., 
F.G.S. 

Three sections in the suburbs of Bristol were described by the 
author, as exhibiting the following strata in descending order, 
namely, at Ashley Down, (1) Ammonites-costatus bed, (2) Saurian 
bed, (3) Ammonites- Conyleari bed (commencement of the zone of 
A, Bucldandi), and (4) Lima-beds; the succeeding beds are covered 
up for a short distance, and then, in Montpelier quarry, are exposed. 



140 Reports and Proceedings. 

(5) Ammonites-taurus bed, (6) Echinoderm-beds, (7) Ammonites-John- 
stoni beds, and (8) Avicula-bed; in Gotham quarry are seen (9) 
Rubble-bed, containing Ammonites planorbis, Lima gigantea, and Z. 
Dunravenensis, (10) Ammonites-tortilis bed, (11) Sutton-beds, (12) 
Pholidophorus bed, (13) Ammonites-Johmtoni beds, (14:) White Lias, 
and (15) Gotham marble resting upon the Keuper marls, the Avic- 
ula-contorta beds being absent. Mr. Stoddart considered that the 
Gotham section afforded very decided evidence of the Bridgend 
series being above the Rhaetic beds, and in the Planorbis-zone. He 
also described an horizontal section of the deposits between Ashley 
Down and Gotham, and remarked on the physical conditions which 
had combined to produce the phenomena observed in the district. 

2. " On the Lower Lias Beds occurring at Gotham, Bedminster, 
and Keynsham, near Bristol." By G. 0. Groom-Napier, Esq., F.G-.S. 

The author described in detail sections exposed in two quarries at 
Gotham, and noticed others seen at Bedminster and Keynsham. He 
had made an extensive collection of fossils from the several beds, 
and he now exhibited a table showing the names and ranges of the 
several species. The conclusions at which he had arrived were that 
the Sutton-stone is a Liassic rather than a Rhaetic bed, and belongs 
to the Planorbis-zone ; and that the Planorbis-zone and the Sutton 
series are subdivisions of the White Lias. Mr. Groom-Napier also 
described two new species from the Planorbis-zone of Gotham, 
namely, Avicula Sandersi and Anatina Cothamiensis ; and one — 
Hinnites minutus — found in a stratum at Gotham associated with 
Monotis decussata. 

3. "On the Dentition of Rhinoceros Etruscus," Falc. By W. Boyd 
Dawkins, Esq., M.A., F.R.S. 

The number of teeth possessed by B. Etruscus is the same as that 
of the species already described by the author. 

The first premolar, if present at all, disappeared very early in 
life, leaving no trace of its existence. This character separates it 
from all other known Miocene species. Of the milk-molars the 
author has not yet sufficient materials to attempt a description. 

The upper true molars differ from those of other British species 
in the lowness of their crowns, the abruptly tapering form of the 
coUes, d and e, and the stoutness of the guard o on the anterior 
aspect. The grinding surface of the crown is deeply excavated, not 
worn flat as in B. tichorhinus. The horizontality of the guard o, and 
the height above the cingulum, characterize the whole of the pre- 
molars, and distinguish this species from all others found in Britain. 

The lower true molars differ from those of B. ynegarhinus in being 
smaller, having the crowns lower, and the guard o more strongly 
marked. They differ from those of B. leptorhmus and tichorhinus in 
the position of the guard, the lowness of the crown, the thickness of 
the enamel, and the absence of costse from the rounded anterior 
area. 

B. Etruscus, together with all Miocene species (except those of the 
Sewalik Hills), belong to the brachydont section, while all the living 
Pliocene and Pleistocene species (except Etruscus) belong to the hypo- 



Geological Society of London, 141 

dont section. We have, therefore, to compare B. Etruscus with Miocene 
rather than with Pliocene and Pleistocene species. It differs from the 
Khinoceros of Auvergne principally in the greater complexity of its 
anterior valley and the larger development of the posterior comhing- 
plate. Its nearest ally is the hornless Rhinoceros of Darmstadt, the 
Aceroiherium incisivum of Kaup. 

B. Etruscus has been found associated with B. megarJiinus, but not 
with B. tichorhinus nor B. leptorhinus. 

It has not been found with any animal (except the Mammoth) fitted 
for living in a severe climate, nor in any deposit of post-glacial age. 

11. January 22nd, 1868.— 1. ''On the Speeton Clay." By John 
W. Judd, Esq., F.G.S. 

In tracing the history of discovery in connexion with this forma- 
tion, the following epochs were pointed out by the author : — (1) 
the separation of the Cretaceous from the Kimmeridge beds, by Prof. 
Phillips, 1829 ; (2) the reference of the former to the Neocomian 
formation, by MM. Agassiz, Godwin -Austen, Romer, and others, 
1838, etc. ; and (3) the recognition of Portlandian beds in the series, 
by Mr. Leckenby, 1864. 

Mr. Judd then proceeded to give a description of the unique cliff- 
section exposed at Speeton, which is unfortunately greatly complicated 
by faults and contortions, and much obscured by drift, landslips, and 
mining workings. 

After adducing evidence, both stratigraphical and palseontological, 
to prove that no portion of the Speeton clay is of Gault age, the 
author showed that this great series of clays (probably over 1,000 
feet thick) belongs to no less than seven formations, viz., Upper, 
Middle, and Lower Neocomian, Portlandian, and Upper, Middle, and 
Lower Kimmeridge. These formations, as displayed in Filey Bay, 
were described in detail; lists of the fossils from each (drawn 
up with the assistance of Mr. Etheridge) were given, and their 
equivalents, both in this country and on the continent, pointed out; 
and the author concluded his paper with appendices on the fossils 
and the economic products of the Speeton clay. 

2. "Notice of the Hessle Drift as it appeared in Sections more 
than forty years since." By Professor John Phillips, D.C.L., E.R.S., 
F.G.S. 

Referring first to the difficulties formerly experienced in attempt- 
ing to explain the origin of the Boulder-clays and Northern drifts 
more than forty years ago, without the aid of glaciers and icebergs, 
the author expressed his belief that the lowest gravels, resting on 
the Chalk at Hessle, are of pre-glacial date. He stated his opinion 
that there is no evidence of the beds in question being marine; while 
the abundance of mammalian remains offers a strong presumption 
against this interpretation. Beds of this order, composed of chalk 
and flint fragments, are not only unknown in the midst of the 
Boulder- clay, but can hardly be imagined to exist there. Further, 
the Boulder-clay rests on them without conformity. Professor 
Phillips also observed that if the Hessle clay be the upper part 



142 Reports and Proceedings. 

of the great Holdemess deposit, and not met with beyond the out- 
crop of the Chalk, it must be designated a third Boulder-clay ; and 
he concluded his paper by a detailed description of his original 
observations of the Hessle cliff more than forty years ago. 

Geological Society of Glasgow. — At the usual monthly meeting 
on Thursday evening, Dec. 12, — Dr. Young, president, in the chair,^ 

Mr. J. Thomson exhibited specimens of Carboniferous corals of 
the genera CUsiophyllum, Cyclophyllum Duncan and Thomson, and 
AulopJiyllum Edwardsi, sp. nov., D. and T. ; and entered into ex- 
planations of the structural characters upon which these forms 
were established 

Mr. John Young made some remarks upon this so-called new 
genus of corals, Oyclophyllum fungites, and stated that since the time 
of David Ure (who was the original discover of the genus in 
question) this coral had been changed from one genus to another 
by Palaeontologists, no less than two new genera having been 
established to receive it, and he doubted very much if it had yet 
found its final resting-place. He deprecated very much the estab- 
lishing of generic distinctions upon small and unimportant points in 
any organism, as tending to burden science with useless synonyms. 
He further pointed out that Professor M'Coy had clearly delineated 
the various parts constituting the internal organization of this coral. 

And in his remarks upon the genus Aulophyllum of Milne Edwards 
(of which lire's coral was the type), M'Coy showed that the 
characters which he relied upon as points of generic distinction 
only serve to characterise a well-marked species. Dr. Duncan's 
figures reveal no new points in the structure of this coral which 
were not already known, and however much Dr. Duncan may differ 
from Professor M'Coy and other Palseontologists who have worked 
upon this genus, in his interpretation of the various points of 
structure therein displayed, yet he (Mr. Young) thought that these 
points were so small and unimportant as hardly to warrant it being 
again placed in a new genus. 

Mr. Thomson, in replying to Mr. Young's remarks, drew attention 
to two errors of Ure's ; first, that he described the corallum referred 
to by Mr. Young as being broad at the base, a feature presented 
by Amplexus only; second, that he gives Kilbride as the locality, 
whereas Mr. Thomson had not found in any of the Kilbride localities 
any other turbinated Coral than Zaplirentis. Mr. Thomson repeated 
the structural characters of Clisiopliyllum, Aulophyllum, and Cyclo- 
phyllum, and insisted on the* essential difference of the latter from 
the two former in this, that the endothecal structure of its columella 
is formed by a system of down-curved sub-convolute plates passing 
from the inner margin of the minute lamella of the essential colu- 
mella ; and that a groove was thus formed round the inner ends of 
the primary septa and the columella by the curvatures of those 
plates, and that the minute septa coalesced and formed a system of 

^ The report of this meeting was unavoidably delayed. 



Geological Society of Glasgow, 143 

plates which passed inwards and downwards, conforming to the 
central concavity of the top of the columella. 

n. — January the 9th, Prof. Young, President, in the chair, the 
Secretary read a letter from Mr. Eobert Craig, of Beith, on the 
Glacial Drift in that district. He stated that it consisted of two 
easily distinguished beds, the lower composed of dark-blue clay, full 
of polished stones of great size ; the upper of a light reddish friable 
clay, full of small stones, rounded and smoothed, but the polish had 
a weather-worn appearance. 

The Eev. Mr. Crosskey read some "Notes on the Discovery of 
Leda arctica at Stevenston, Ayrshire." This shell is so remarkable, 
on account of its high northern habitat, that its discovery in any bed 
is of peculiar importance. Living, it dwells only within the Arctic 
circle and on the North-east Coast of America. It was identified by 
Dr. Torell among the shells found at Elie by the Eev. T. Brown, 
and occurs in the clays at Errol and Montrose, on the east of Scot- 
land, but hitherto has not been found in any of the clay beds of the 
West. The specimen exhibited (kindly given to him by Mr. 
Armstrong) was found at Stevenston, Ayrshire, and is in a fine state 
of preservation. Its occurrence in the West proves that the 
character of our fauna has been as severely Arctic as the ancient 
fauna of the Eastern beds. ' Leda arctica is the characteristic shell 
of the clay at Mess in the Christiana fjord, although not now found 
living even in that locality. It is also a characteristic fossil in the 
Saxicava-sand of Canada. The occurrence of Leda arctica in the old 
clays of Canada, Christiana fjord, Errol, and Stevenston, affords a 
curious illustration of the wide distribution of very highly Arctic 
moUusca during the glacial epoch. Mr. Crosskey also read a paper 
" On the Characteristics of Boulder Clay." There are various 
boulder clays, instead of one single deposit, which it is imperatively 
necessary to distinguish from each other. The attention of geo- 
logical students was called to the necessity of discriminating between 
the different kinds of materials which have been loosely united under 
the general name " boulder-clay." 

III. — Thursday evening, 16th January, E. A. Wiinch, Esq., V.P., 
in the chair. 

Edward Hull, Esq., E.E.S., of the Geological Survey of Scotland, 
delivered a lecture " On the physical causes which seem to have 
regulated the distribution of the calcareous and sedimentary strata of 
Great Britain, with special reference to the carboniferous formation." 

While admitting that calcareous matter was sometimes precipitated 
on the sea-bed from chemical solution, the lecturer maintained that 
all great masses of limestone are the result, either directly or indi- 
rectly (by subsequent triturition and stratification) of vital agencies, 
while the sedimentary strata were of mechanical origin. Hence the 
essential distinction of the two classes in their origin. It was shown 
that the limestones of geologic periods were the work of a few 
groups of animals of an organization inferior to that of the molluscs, 



144 Reports amd Proceedings, 

which only took a secondary position as the builders of these rocks. 
These animals included corals {Anthozoa), crinoids {Echinodermata), 
bryozoa, sponges (AmorpJiozoa), Foramimfera, and amongst these the 
Biatomacece also took an important position in eliminating the sili- 
ceous matter held in solution ; but these were all animals which re- 
quired clear water, free from sedimentary matter, in order to fulfil 
their functions. 

Sedimentary strata on the other hand, being the detritus of land 
surfaces carried down and deposited by currents over the floor of the 
sea, could not co-exist in any quantity with the calcareous formations, 
but must have had a source at some region opposite to the centre of 
distribution of the limestones. Hence the conclusion was drawn — 
(1). That in any natural group of rocks the calcareous and sedi- 
mentary members must have had their sources in opposite centres 
of dispersion; and (2). That the maximum development of these 
two classes of strata must be at opposite points of a special region. 

The ''passage beds" and alternations of limestones with shales 
and grits, similar to those of the lower carboniferous series in the 
north of England, were accounted for on the ground of the alternate 
predominance of the vital and mechanical conditions of marine 
depositions over intermediate areas or border lands. 

The tendency of geological groups to arrange themselves in a 
threefold order — the lowest and highest members being of sedi- 
mentary materials, and the central one calcareous — was then alluded 
to ; and the lecturer proposed a classification of this kind for the 
whole of the geologic series, from the Lower Silurian to the Tertiary 
inclusive, and believing this to be a truly natural grouping, he 
accounted for it on the ground that each natural group was composed 
of the representatives of three periods — the 1st, one of movement, 
accompanied by change of land and sea and much denudation ; 2nd, 
a period of comparative repose, and a minimum of denudation ; and, 
3rd, of change, gradually increasing in intensity to the close of 
the epoch. 

The following is a brief outline of the classification as proposed by 
the lecturer : — 
Tertiarv ( ^* ^^^i^^ntary — Miocene beds. 

p '-? \ 2. Calcareous — Nummulite Limestone. 
' 1. Sedimentary — Lower Eocene beds. 
3. Sed. — Uncertain. 

2. Cal.— Chalk. 
1. Sed. — Greensand and Gault. 

3. Sed. — Marine equivalents of the Purbeck and Wealden. 
Portland. \ 2. Cal. — Limestone. 

1. Sed. — Sands. 
Coralline ( l' ^^f-^^^^' 9^^* ^^^ Kimmeridge Clay. 
Oolite. I Cal.-Corallme Oolite. 
{ 1. Sed.— Calc. Grit. 
Lower \l' Sed.-Oxford Clay. 
Jurassic ) ^^^* — ^^^^^ Oolite Limestones. 

V 1. Sed. — Lower, Middle, Upper Lias. 



Creta- 
ceous. 



Geological Society of Glasgow, 145 

3. Sed.— Bed Marl. 
Trias. \ 2. Cal. — Muschelkalk (Germany). 
1. Sed. — New Ked Sandstone. 

!3. Sed. — Marls and Lr. Bunter Sandstone (Saxony). 
2. Cal. — Magnesian Limestone. 
1. Sed. — Conglomerates, Marls, and Sandstones (Rothe- 
todte-liegende). 
Carboni- ( 3. Sed. — Yoredale beds, Millstone Grit, Coal Measures, 
ferous. I 2. Cal. — Limestone. 
England. ( 1. Sed. — Lower Shales, Yellow Sandstone (Ireland). 

3. Sed. ^. /- Sandstones, / Schists, Sandstones, 

Schists, etc. . ( etc. 

Tk ^^ ' ; 2. Cal. "m ) Ilfracombe § 1 Eifel Limestone. 

JJevonian < ^ \ t ■ i. i.*a^ 

o j Limestone, etc. '^ i 



^ f a^i,,'^j.^ a J W 



1. Sed. ^ f Schists, Sand- [ Spirifer Sandstone 

^ V stones, etc. V Group. 

Tj ( 3. Sed. — Tilestones and Upper Ludlow beds. 

a,-i -^ \ 2. Cal. — Aymestry and Wenlock series. 
Silurian. | j_ s,a.-my Hill Group. 

For the purposes of determining the directions in which the two 
classes of sedimentary and calcareous strata augmented and decreased 
in thickness, leading to a knowledge of the position on the globe of 
the continents and open seas of former geologic times, Iso-metric lines 
were proposed. These lines, drawn over the areas occupied by the 
formations, and each line representing a certain thickness of its 
special class (calcareous or sedimentary) of strata, would be found 
to lead to very interesting results. Mr. Hull had already drawn 
these lines for the Carboniferous group of Great Britain, and they 
are shown in the map published by the Geological Society of London 
(Quart. Journ., vol. xviii., p. 127) ; and he had no doubt that if 
similar lines were drawn for all formations in different countries, an 
amount of light would be thrown on the physical condition of the 
respective groups that would considerably advance this branch of 
science. The tracing of these lines had thrown much light on the 
physical geology of the Carboniferous group, showing that the cal- 
careous member (mountain limestone) attained its maximum de- 
velopment in central England, and the sedimentary member in the 
North, leading to the inference that an old North Atlantic continent 
was the original source of the sedimentary materials. 

The reason of the comparative thinness of the sedimentary strata 
of the Carboniferous series in Scotland, as compared with those in 
North Lancashire, was then explained, on the ground of the shallow- 
ness of the sea bed ; the impediment to the transportation of materials 
presented by the Highlands (only partially submerged) and the in- 
completeness of the series. It had also been found that the sedi- 
mentary beds of the Triassic group, and of the succeeding Jurassic 
group of England, swell out towards the north ; and the lecturer 
expressed his belief that originally all the limestones of this series 
tailed out or passed into sedimentary strata northwards, while the 
clays, shales, and sandstones of the same group attained the highest 



146 Correspondence — Mr. Mackintosh, 

development in the same direction. This would lead to the conclu- 
sion that there had, throughout a long lapse of geologic time, been 
a general transportation of materials southward from old lands which 
once occupied the region of the North Atlantic. 



BEACHLESS SEA-COASTS. 

Dear Sir, — Though the true form of the ground can be best 
judged of by those who are in the habit of viewing it from greater 
or less distances, such minute observations as those stated by Mr. 
Green, in January last, are very important. It is, however, to 
be regretted that so accomplished a surveyor should not be em- 
powered, by a committee of the British Association, to examine 
those sea-shores where level beaches are exceptional, and where the 
slope, above and below mean water-mark, is characterized by every 
form of escarpmental phenomena. On such shores, rising and falling 
lines of cliff may not only be observed at certain heights above the 
sea (where, in some instances, they might be called indirect sea- 
cliffs, being the effect of coast-slips), but likewise passing under, 
and from under, the water. Beachless shores are the general rule 
on the west and north coasts of Ireland, among the Shetland and 
Feroe Islands, etc. But, though on a smaller scale, they are very 
characteristic of the coasts of Devon and Cornwall, where, in many 
places, the base of a line of cliffs consists of a succession of heights 
and hollows. The minor deviations from a plane presented by many 
upland lines of cliff may thus be satisfactorily accounted for. To 
deny that the general inclination of an escarpment can be the effect of 
elevation is to ignore the established principle that the rise of the 
land must be in excess of the rise of the bottom of the sea. In bring- 
ing forward instances of escarpments, it is desirable that the meaning 
attached to the word should be clearly stated. If an escarpment 
runs along the strike it must maintain one level throughout, or a 
succession of different levels. If an escarpment follows the dip of 
the strata, it cannot run along the strike, and, unless the dip of the 
table-land above corresponds, no downwardly-operating agent could 
ever have commenced the work of escarpment-making. If an escarp- 
ment crosses the dip of the strata it must have been denuded irre- 
spectively of structure. Wherever the dip of the strata (local or 
general) is as great as the dip of the escarpment, it is certain that 
the former must have been unequally upheaved or depressed, or 
thrown out of their originally horizontal position at some period, and 
why not after the formation of the escarpment, unless in instances 
where reasons to the contrary can be assigned ? These considera- 
tions would seem to bo overlooked by subaerialists, who thus render 
themselves liable to be misunderstood. 

The Kev. 0. Fisher's letter (p. 34, written before the appear- 
ance of my letter in the December Number) contains observations 
wonderfully agreeing with the views I have been advocating in your 



i 



Correspondence — Rev, 0, Fisher, 147 

pages. Col. Greenwood (whose description of the transportation of 
flints by the sea is very graphic) has misunderstood me on the sub- 
ject of residual flints. What I meant was simply that in many 
chalk districts (not arable-fields) the denudation has been as clean, 
and as irrespective of flints, as if the groimd had been shaved down 
with a gigantic scythe. D. Mackintosh. 

POLYTELITE IN CORNWALL. 

Sir, — The substance of Mr. Davies's letter in your last number 
does not, I imagine, require any reply; but in the postscript he 
mentions that Professor Church had found 7'23^|o Silver in a crystal- 
lized fragment of fahlerz, having the density of 4*85, from which I 
infer that true polytelite is found at that locality. This per centage 
of silver in, and the specific gravity of, this specimen, might be ac- 
counted for by supposing the silver in other state of combination, as, 
for example, argentiferous sulphide of silver (Stromeyerite), which 
in fracture closely resembles some fahlerz ; and therefore it would be 
interesting to know from Professor Church whether the other con- 
stituents of polytelite (antimony, for example) were found, which 
would at once decide the question. 

Mr. Davies does good service to British mineralogy by directing 
attention to any cases of unrecorded mineral localities ; and I believe 
such inquiries will prove that we possess many more mineral species 
in Great Britain than are at present recorded. Amongst others, I 
may mention that polytelite from N. Wales, and Gersdorffite from 
Argyleshire, are described in the second part of my '' Eesearches in 
British Mineralogy," now in the press. David Forbes. 



THE BOULDER CLAY AT WITHAM STATION, AND THE THAMES 

VALLEY. 

Sir, — My last letter was accidentally printed without my correc- 
tion, and contains errors, two of which are of some importance. 

In the section, the sand with green-coated flints should be 
"Thanet" instead of ''Thames" sand. 

My views regarding the age of the " Trail " are singularly mis- 
represented, where I am made to say it is of " our " age. I wrote 
" one " age ; which I believe to have been upwards of 110,000 years 
ago, as I have shown in the fourth volume of your Magazine, p. 197. 

Harlton, Cambridge. 0. FlSHER. 

THE OUSE VALLEY, THE THAMES VALLEY, etc., etc. 
Sir, — I find that at pages 53-57 of the memoir for sheet 45, 
reference is made to the Glacial clay, but so slightly that it escaped 
me. Moreover the Glacial clay tract north of Buckingham, partly 
traversed by the section in my last letter, is aUuded to (p. 57) as that 
of the " Oxford or Kimmeridge, as the case may be " ; but as neither of 
those clays are shown in this part of the map, some slip of the pen 
may have occurred. Therefore, to this extent, I must qualify the 
remark in my letter and tender Mr. Green my apology for it. 



148 Correspondence— Mr, S. V. Wood, Jun. 

The accuracy and bearing of our respective sections I leave to the 
judgment of others. 

From Mr. Green's view, that the Glacial and Post-glacial beds 
cannot be represented on the inch scale without detriment to the 
delineation of the older geology, I strongly dissent, so far as concerns 
the secondary and tertiary area, south of Flamborough Head; and 
I have done my best, in sheets 1 and 2, to show that all beds 
may be represented together without detriment to any; and I 
contend that it is beyond human ability to represent, with any 
approach to accuracy, the geological features of such part of that 
area as is occupied by the Glacial beds in force, except those beds 
be mapped in with the older formations. North of Flamborough 
Head it is otherwise. I have examined railways in course of 
formation in Northamptonshire and Huntingdonshire, through 
districts in which the hills and valleys appear from the survey 
maps to be cut out of the secondaries, and in one instance out of 
a succession of secondary strata ; but the cuttings have disclosed that 
the hills traversed by them are wholly formed of the Glacial beds, 
nothing of the map delineation being visible. 

Mr. Fisher has correctly represented my views as to the cappings 
termed Trail; and I quite agree with him that the Clacton and 
Grays deposits are of similar age, having so expressed myself at 
page 350 of your third volume. The other points in his letter 
would take up too much of your space to discuss ; but, if the in- 
formation he obtained from the Witham boring be truly reliable, 
it seems to point to a great local disturbance and denudation of the 
four or five miles from Kelvedon to Witham, either between the 
Middle and Upper Glacial formations, or during the earlier part of 
the Upper; and I suspect that in such case my sections, No. 9 of 
page 348 of your third volume, and No. 9 of page 402 of the twenty- 
third volume of the Quart. Journ. of the Geol. Soc, may prove to 
contain an error in so far as they show the Middle Glacial dipping 
with a fold under the Upper, where they cross the Blackwater. 
There is, I think, evidence, from clear sections, of such an inter- 
mediate disturbance and denudation near Ipswich, the effect of 
which has been to bring the Glacial clay into the bottom of the 
Gipping valley for three or four miles without any Middle Glacial 
under it ; while the Middle and Upper Glacial beds form the whole 
country around, the valleys being entirely cut out of them. The 
Gipping valley, except where this anomalous structure occurs, forms 
no exception to the general features presented by these valleys, and 
the case of the Blackwater seems much the same. I am very glad, 
although I dissent from the gravels over the Hampshire Tertiaries 
being the equivalent of the Glacial clay, to see Mr. Fisher dis]30sed 
to regard the Glacial sea as having extended over the South of 
England prior to the great upheavals and denudation of that part, 
and to connect the dislocations in the Thames valley with those 
movements ; these being the most important links in the chain of 
events which I contend have followed the Glacial period. 

S. V. Wood, Jun. 



I 



II 



Correspondence — Mr. George Maw, 



149 



GRAVITATION, COMPKESSION, AND SLATY CLEAVAGE. 

Sir, — Dr. Sterry Hunt, in his paper in the February Number 
of the Magazine, referring to the alleged condensing power of the 
superincumbent mass on the central parts of the earth, remarks : 
" The condensing effect of pressure was by Dr. Young estimated to 
be sufficient to reduce a mass of granite at the earth's centre to the 
eighth of its bulk at the surface, which would give the earth a mean 
density equal to twelve or thirteen times that of water : this con- 
sideration has led a recent writer in the London Athenoeum to 
conclude with Herbert Spencer that our earth and the other planets 
may be only shells of varying thickness, enclosing a central cavity 
filled with vaporous matter, by which hypothesis we may explain 
their comparatively feeble densities." Mr. David Forbes has also 
noticed that the average density of the earth falls short of what it 
would be, supposing it grew denser in descending, in proportion to 
the superincumbent pressure ; and " That experimental research 
tends to show that a limit is soon reached beyond which the com- 
pression or increase of density becomes less and less in proportion 
to the force employed." 

Do not the estimates of hypothetical increased central density fail 
to consider the influence which the spherical form of the earth would 
have in counteracting accumulating pressure, and diverting the fore© 
of gravitation to a direction parallel with the circumference ? 

The case seems strictly ana- 
logous to that of an arch, in 
which the resulting force of gra- 
vitation is diverted along the arch 
to the abutments. If the earth 
is hypothetically assumed to be 
made up of a series of concentric 
hollow spheres (see Woodcut) 
A, B, C, D, it will be at once 
evident that each of such spheres 
would be self-supporting, just as 
in the case of a bridge, the addi- 
tion of each successive course of 
brickwork composing the arch 
adds no pressure to, but rather 
increases, the resisting power of 
the single course first laid; the 
direction of the resistance of the gravitation of the mass being 
accumulated on the spring of the arch. Again, if we go on filling 
up this arch internally with successive courses of brickwork, we do 
not interfere with the stability of the external arch, neither is the 
weight of the first structure borne by the inner courses ; in fact 
every zone of the arch or sphere is individually self-supporting. 
The vertical pressure of gravitation, which in successive superimposed 
layers of a plane would accumulate, is vertically neutralized in a 
sphere, and instead of getting the sum of the weight of the con- 




150 Correspondence — Dr. Nicholson, 

centric layers, the independent pressure of each successive course 
is diverted in a line parallel with the circumference. To carry out 
the analogy we have merely to suppose two such semicircular arches, 
E F E and E D E, placed base to base in contact ; the balance of 
resistance is completed, and we get a perfect epitome of the 
equilibrium of gravitation in the crust of the earth. Will not this 
satisfactorily explain the point noticed by Mr. Forbes, that the actual 
density of the earth falls short of its calculated density, on the 
estimate of the accumulation of superincumbent pressure ? and will 
not the lateral pressure, analogous to that existing between the 
voussoirs of an arch, account for the horizontal force which seems 
to have operated in the production of Slaty Cleavage ? 

George Maw. 
Benthall Hall, Broseley, 

Feb. 10th, 1868. 

I.— THE GRAPTOLITES OF THE SKIDDAW SERIES, ETC. 
II.— ON THE CLASSIFICATION OF GRAPTOLITES. 

Sir, — 1. In the Geological Magazine for January (p. 32), an 
abstract is given of my paper on the Graptolites of the Skiddaw 
Series, read before the Geological Society, December 4th, 1867. 

As the generic characters of Dichograpsus are therein mis-stated, 
I should be glad if you will allow me to correct the error, ^ since I 
observe that it has been reproduced in a recent paper on Graptolites. 

The presence of a corneous cup does not form a character of the 
genus Dichograpsus, since it is present in some species of the genus, 
and is uniformly absent in others. It likewise occurs in some 
Tetragrapsi, whilst it is never found in others, as T. hryonoides, Hall, 
and T. quadri-hrachiatus, Hall. Lastly, it is occasionally found in 
some Diplograpsi, as D. bicornis, Hall. As the remainder of the 
definition of the genus is also incorrectly stated, I may be permitted 
to add that Dichograpsus is sufficiently defined by "the possession 
of a frond composed of a variable number (always more than four) 
of simple stipes, arising from a central non-celluliferous stem or 
funicle. The stipes are monoprionidian, and are given ofi" from the 
funicle in a radiating manner." 

n. — As a recent paper of mine on Graptolites (Ann. and Mag. 
Nat. Hist. Jan. 1868) has formed the subject of a somewhat lengthy 
criticism by Mr. W. Carruthers, in the Geological Magazine for 
February, (p. 64), I trust you will afford me space for a reply. For the 
sake of brevity as well as clearness, I will notice such points as I 
may think necessary, in the order in which they occur in Mr. 
Carruthers' paper, premising that I have no intention of criticising, 
and shall simply touch upon such points as concern me personally. 

1. Mr. Carruthers finds fault with me for " summarily " dis- 
missing the Polyzoa, and for asserting that they " have, as a rule, a 
more or less calcareous test, and the individuals forming the compound 
organism are not united by any organized connecting substance." 

1 The abstract here referred to, is furnished by the Assistant Secretary of the 
Geological Society, and is merely reproduced in the Geological Magazine. — Edit. 



Correspondence — Dr. Nicholson. 151 

In answer I have simply to state, that my paper was intended to be 
simply an abstract, and " summary " of a more detailed one, which I 
trust may one day see the light, and that it was, therefore, impossible 
for me to enter into minutiae. Secondly, though perfectly aware of 
this existence of free and corneous Polyzoa (the Ctenostomata of 
Busk), the above statement nevertheless remains true of the 
Polyzoa, '^ as a rule,"" and I see no reason for altering it. 

2. Mr. Carruthers charges me with adopting a statement of Hall's, 
as to the free mode of existence of Graptolites, without acknow- 
legement. To this it is quite enough to reply, that the statement in 
question was not made as an original observation on my part, and 
that it is impossible in a general paper to quote references for all 
the facts which have been previously noticed. As to my making a 
" practice " of so doing, no denial on my part can be needed. My 
published papers on the subject bear ample witness how much I am 
indebted for real solid information to the writings of Hall, Salter, 
Harkness, Barrande, and Geinitz. The changes in my views, to 
which Mr. Carruthers refers, have been the result of the progress of 
my own researches, and I could not, with honesty, attribute them to 
any " corrections " from Mr. Carruthers. 

3. As for my use of the word "gonophore," instead of '^gono- 
theca," to signify the external bell-shaped ovarian capsule of the 
SertularidaB, it will suffice to make the following quotation from 
Prof. Greene, whom, I suppose, Mr. Carruthers will allow to be some- 
what of an authority upon the Hydrozoa. ''In the Sertularidse .... 
the reproductive bodies appear externally as distinct buds or sacs, 
for which Prof. Allman has proposed the name of ' gonophores ' " 
(see Coelenterata, p. 40) . This is but one of many similar statements 
in the same work, but it will, I imagine, be sufficient to justify my 
employment of the term. 

4. With relation to the genus Pleurograpsus, the facts of the case 
are simply these. In 1852 Geinitz proposed the name Cladograpsus 
to include certain Graptolites (species Gemell^, Bronn.), comprising 
Diplograpsus ramosus, Hall, and several species of Didymograpsus. 
In 1859, seven years afterwards, Mr. Carruthers applied the same 
name to a very peculiar branching Graptolite from Dumfriesshire, 
without giving any generic characters of any kind, an omission which 
he failed subsequently to rectify. The same Graptolite was described 
by me in March, 1867, in a paper read before the Geological Society of 
Edinburgh, in which I described it as the type of a new genus, 
giving a full diagnosis, and terming it Pleurograpsus. (See also 
Geol. Mag. Vol. IV. No. 6, June, 1867.) In June of the same year, 
Mr. Carruthers re-described the species as a Cladograpsus, this time 
assigning characters to it as a new genus. As, however, these 
characters are totally different from those of the original genus of 
Geinitz, and as I was the first to give any generic description, the 
name Pleurograpsus must obviously be retained. 

Finally, to the personalities with which Mr. Carruthers has seen 
fit to adorn his paper I shall return no reply, considering them 
unworthy of any genuine scientific controversy. I shall content 



152 Correspondence — Dr, Anton Fritsch. 

myself with quoting the following passage, from a letter by Mr. D. 
Forbes in the last number of your Magazine, the sentiments of which 
I heartily endorse. 

" No man in Europe can expect to retain any portion of the field of science exclu- 
sively for himself, or to travel alone on any of the many diflferent roads which lead 
to one and the same scientific truth. If real progress is to be made in science, the 
student must reason for himself, and not be content with accepting, merely on authority, 
opinions which are inconsistent with his own deductions and experiments ; nor 
should he be deterred by the opposition to be expected from those already in office 
or authority, who are sure to be jealous of intruders on what they imagine to be their 
own domain, and, doubtless, dislike having their peace of mind disturbed by innovations." 

Henry Alleyne Nicholson. 

Queen Street, Keighley, Febnmry lO^A, 1868. 



GEOLOGICAL SURVEY OF BOHEMIA. 

Sir, — I send you a short extract from the Eeport of our Geologi- 
cal Surveyors in Bohemia. A reference to the map shows that these 
labours have been very little disturbed by the late war. 

The Orograpliical section (Prof. Koristka) completed, in the year 
1865-6, 5,000 trigonometrical measures over a surface of 123 
German square miles. 

The Geological section (Prof. Krejci) have continued the exami- 
nation of the Chalk formation, which will be very valuable when 
the large collection of fossils made by me shall be determined. 

During the past three years I have placed 3,536 chalk fossils 
from 65 different localities in the Museum. One locality alone, 
called Korycan, has supplied 70 species. 

The most important discoveries consist in (1) the finding of fresh- 
water shells in the Upper Greensand, and (2) of a large deposit of 
Eadiolites, near the city of Kuttenberg, where a celebrated Gothic 
Church is entirely built of these curious shells. 

In 1867, 1,500 chalk fossils have been added to the Museum from 
17 localities. 

A new locality for Eozoon has been met with in the Gneiss, near 
Skuc, in S.E. Bohemia. 

And, lastly, we have discovered reindeers' horns in the diluvial 
Loess, near Prague. Med. Dr. Anton Fritsch. 

EoYAL Bohemian Museum, Prague, 26tb Dec., 1867. 



IMlISCELIL^n^riEJOTJS. 
Award of the Wollaston Gold Medal and Donation-fund. — 

At the Anniversary meeting of the Geological Society held Feb. 21, 
1868, the President announced the Award of the Wollaston Gold 
Medal to Dr. Carl Friedrich Naumann, Foreign Member of the 
Geological Society, Professor of Geology and Mineralogy in the 
University of Leipzig, etc., in recognition of his labours, extend- 
ing over nearly half a century, in the departments of Geology, 
Mineralogy, Crystallography, etc. The President also stated that 
the Balance of the Proceeds of the Wollaston Donation-fund had 
been awarded to Mons. J. Bosquet, of Maestricht, in aid of the 
valuable researches on the Tertiary and Cretaceous Mollusca, Ento- 
mostraca, and other fossils, of Holland and Belgium, on which he sah 
been so long and successfully engaged. 



G-eolMciglS6d. 



Vol.VFlU 




A TIfoUick,' del ejb lizh. 



Wyhst If rip 



J'ossil/ PcLfLdjuwbceozbS Jn-wUy 



THE 

GEOLOGICAL MAGAZINE 



No. XLVI.— APRIL, 1868. 

I. — British Fossil Pandane^. 
By Wm. Carruthers, F.L.S., F.G.S., Botanical Department, British Museum. 

(PLATE IX.) 

THEEE is room for considerable difference of opinion as to the limit 
of the order Pandanece or " Screw-pines." However extended it 
is made there can be no doubt that Nipa has closer affinities with the 
palms than with the screw-pines. I shall therefore exclude the 
remarkable fruits from the Lower Eocene of Sheppy to which 
Brongniart applied the name Pandanocarpum, altered afterwards by 
Bowerbank m accordance with the more precise determination of 
the affinities of the fruits to Nipadites, a change in which Brongniart 
acquiesced. 

More nearly allied to Pandanem are the CijclanthecB with their 
scaly flowers, polyspermous, many-celled fruits, and fan-shaped 
leaves, and the Freycinetiece agreeing with Cyclanthece in the struc- 
ture of their fruit, but with Pandanece proper in their flowers and 
foliage. Whether these three closely allied groups form only a 
single natural order is not of much importance in connection with 
an enquiry into the fossil Pandanece of the British rocks, inasmuch 
as these all, as far as known, belong to the restricted group Pan- 
daneis, represented by the genus Pandanus of the younger Linnaeus, 
now split up by Gaudichaud, De Yriese, and Hasskarl, into several 
divisions considered by them of generic value. 

The recent Pandanece, thus restricted, are arborescent plants, the 
stem generally branching dichotomously and sending down aerial 
roots, with long, linear-lanceolate leaves, their margins almost 
always spiny, and their bases amplexicaul, leaving after decay 
annular scars, which have suggested the name screw-pine, the latter 
half of the term referring to the external resemblance of the plants 
to Bromeliace'ce or pine-apples. The flowers are dioecious and naked, 
and the fruits are composed of numerous one-celled and one-seeded 
fibrous drupes congregated singly or in compact parcels into large 
spheroidal or oblong heads. The plants of this group live in the 
marshy forests of the moist tropical and sub-tropical regions of the old 
world, their head-quarters being in the Malayan Archipelago* and in 
Madagascar ; some extend as far north as Japan and the Himalayas. 

Specimens of foliage referred by Ettingshausen to this order, 

VOL. V. — NO. XLVI. 11 



154 Carruthers — British Fossil Pandanece. 

although described originally by him under the name Palceohromelia 
have been found in the Tertiary deposits of Austria (Sitzungsber. 
d. Math.-Nat. classe der K. Akad. der Wissen. Vienna, vol. viii. 
p. 492). He considers that he has fragments representing five 
species, which he refers to the genus Pandanus. 

In England the discovery of fruits has supplied more satisfactory 
evidence of the former existence of the PandanecB} The first known 
specimens of a Pandanaceous fruit were figured and described by 
Prof. Lindley in the second volume of his Fossil Flora (1835), plate 
129, under the name of Strohilites Bucklandi. Lindley, with great 
success, educes from his imperfect materials characters which would 
have led him to place the fossils in Pandaneos, had he been obliged 
to give them a positive position, but he preferred referring them to 
the provisional genus Strohilites, until additional specimens should 
supply the materials for a more satisfactory determination. Lindley 
mentions neither the locality nor the age of these fossils, but only 
that they belonged to Miss Bennet, whose collections, I believe, 
are now in America. Professor Morris, in his Catalogue of British 
Fossils, says they were found in the Upper Greensand of Wiltshire. 

In 1836 Buckland figured and described a fruit to which, at K. 
Brown's suggestion, he gave the name Podocarya. The fossil was 
found in the inferior Oolite, at Charmouth, Dorsetshire. It is the 
size of a large orange, and composed of an indefinite number of cells, 
each containing, near the surface, a single longish seed, about the 
size of a grain of rice. The cells were separated from the spadix by 
long fibrous footstalks, and were surmounted by hexagonal tubercles, 
in the centre of which could be seen the remains of a stigma. It is 
to be regretted that Brown did not communicate to Buckland a 
written description of this hitherto unique fossil fruit, for a loose- 
ness of language and defects in knowledge are to be found in the 
account of the fossil which cannot be charged to him. It is said that 
" the collection of the seeds into drupes, surrounded by a hard nut, in 
the fruit of Pandanus, forms the essential difference between this 
genus and Podocarya^ But the fruits of a large number of species 
of Pandanus consist of separate one-seeded drupes, and if each seed 
in Podocarya be considered as contained in a distinct drupe, there is 
no essential difference between these species and the fossil. I am in- 
clined, however, to consider it rather as a more complete condition 
of the union of the ovaries into groups than any form among recent 
fruits — a condition in which all the drupes were as thoroughly 
united as they are in each of the phalanges of the fruit of Eydouxia 
macrocarpa, Gaud. In the species with such compound fruits, the 
fibrous pedicles are much longer than in the other species, forming 
another point of correspondence with the fossil. • 

1 The external markings of the stems found hy Mr. W. H. Bensted in the 
Iguanodon quarry, and named by Konig Braccena Benstedii, are more like those of 
a Pandanus than a Braccena^ but the remains of wood in the interior of these stems 
suggest doubts as to whether they belong to either the one or the other. I hope to 
obtain a section of one of the stems and to examine the minute structure of the wood, 
and I may then be able to determine, with more certainty, their systematic position. 



1 



Carruthers — British Fossil Pandanem, 155 

This singular fruit has been lost. Buckland says it was in 1836 
in the Oxford Museum, but Professor Philipps has never seen it. 
Its re-discovery would be a real benefit to science. 

Through the kindness of S. Sharp, Esq., F.G.S., I have been 
able to examine a remarkably perfect specimen of a fruit belonging 
to the same genus as those described by Lindley, and supplying the 
material which he desiderated in order to refer his fossils to their 
positive position. This specimen was found in the Moulton Park 
Quarries, at Kingsthorpe, near Northampton, in the White Limestone 
of the Great Oolite. It was presented by A. Markham, Esq., to the 
Northampton Museum, where it is now deposited. The matrix in 
which it is preserved is an amorphous cream-coloured limestone 
which has abounded in molluscan remains, but the shells have been 
removed, and the spaces they occupied, as well as the other larger 
cavities in the rock, are lined with or entirely filled up by crystallized 
calcite. The fruit also is only a cast, in the same material, of the 
cavity which originally contained it. The fine white mud had in- 
sinuated itself into every crack and opening of the fruit, and filled 
the decayed interior of the upper portion of the drupes. The walls 
of the seed cavity and the seeds themselves, as well as the outer 
membrane of the drupes, resisted decay until the matrix was some- 
what compacted. These hard portions at length decayed, but the 
insoluble carbon remained as a black amorphous substance, giving 
an external coloured coating to the crystallized carbonate of lime, 
which in the end filled the cavity, preserving in the most perfect 
manner the form of the fruit, and even some of the minute details 
as to the relation of the different parts. The hammer of the quarry- 
man that accidentally laid open the fruit has fractured it through the 
middle of the cells, the portion broken off containing the upper por- 
tions of the cells and the apices of the drupes buried in the rock. 

The fruit consists of a thick spadix, — not so thick, however, in 
proportion to the drupes as in Bryantia hutyrophora, Webb. The 
drupes leave the spadix at a right angle about one-third from the 
apex, those above have an ascending and those below a descending 
direction, increasing as it reaches the fruit stalk, which is seen in 
the fossil, and shown in the drawing. This arrangement is precisely 
that of Sussea conoidea, Gaud. (PL IX. Fig. 7). The drupes are 
rhomboidal at the base, spreading out laterally towards the apex, 
where their form is a broad compressed rhomb (Fig. 4) two or three 
times longer than it is broad. The cell containing the seed is near 
the base of the fruit (Fig. 3) leaving only a short pedicle or being 
really sessile, as in the recent species with single-seeded drupes 
(Fig. 7). Each drupe contains a single seed ; and although, as I 
have said, the whole structure is replaced by calcite, yet the details 
are so beautifully shown that the connection of the seed by an in- 
ternal unilateral placenta adnate to the whole length of the cell is in 
many cases obvious (Fig. 6). The seed is ovoid and compressed 
(Figs. 5 and 6), and the cicatrix at its base, by which it was attached 
to the placenta, can be detected. 

The comparison of the drawings of Sussea conoidea, Gaud., taken 



156 Buskin — On Banded and Brecciated Concretions. 

from Gaudichaud's Voyage sur la Bonite, plate 24, given on Plate 
XX. Figs. 7-11, with the figures of the fossil and the description I 
have given, must place it beyond doubt that this is a true Pandana- 
ceous fruit. I propose to designate the genus by the name of 
Kaidacarpum, Kaida being the Malabar name which Kheede em- 
ployed in his Hortus Malabaricus, from which book the younger 
Linnasus chiefly obtained the materials for his genus, although he 
adopted the later name, Pandanus, from Eumphius. 

Besides the species which I have described, I have seen another 
in the Woodwardian Museum, Cambridge, from the Potton Sands, 
which, from its imperfect condition, it would have been impossible 
to have made anything of, but there is sufficient to establish that 
it belongs to this genus, and is a distinct species. 

SYNOPSIS OF THE BRITISH PANDANE^. 

Gen. I. — Kaidacarpum, gen. nov. Fruit composed of pyramidal rhomboidal 
single-seeded drupes, sessile, or sub-sessile on a thickened spadix. 

Sp. I. K. ooUticum, sp. nov. From the Great Oolite at Kingsthorpe. Plate IX. 
Figs. 1—6. 

Sp. 2. K. Bucklandi, Carr. Strobilites Bucklandi, Lindl. and Hutt. Fossil 
Flora, Plate 129. From the Upper Greensand, Wiltshire. 

Sp. 3. K. minus, sp. nov. From the Potton Sands, Cambridgeshire. 

Gen. II. PoDOCARYA, Buckl. Fruit composed of an indefinite number of single- 
seeded cells united into one large compact spheroidal head, and attached to the 
spadix by long fibrous pedicles. 

Sp. 1. Fodocarya JBucIclandi, Ung., Gen. et Species Plant. Fossillium, p. 327. 
Buckland, Geology and Mineralogy, PI. 63. From the Inferior Oolite of Char- 
mouth, Dorsetshire. 

EXPLANATION OF PLATE IX. 

Fig. 1. Kaidacarpum oolitimm. Nat. size, showing the bases of the cells from which 
the seeds have fallen out. The upper portions of the drupes are seen imbedded in the 
rock around the fruit. — Fig. 2. A portion from the side of the fruit, showing the rela- 
tion of the seeds to the drupe. — Fig. 3. Ideal section of a drupe aud seed. — Fig. 4. 
The form of the apex of a single drupe. — Fig. o. Front view of seed. — Fig. 6. Side 
view, showing where the placenta touched the seed. Fig. 7. Sussea conotdea, Gaud. 
Half of a fruit. — Fig. 8. Longitudinal section of a single drupe. — Fig. 9. Transverse 
section of ditto. — Fig. 10. Seed, front view. — Fig. 11. Ditto, side view. 



II. — On Banded and Brecciated Concretions. 
TA^y John Euskin, Esq., F.G.S. 

(CoNTINb^D FROM THE JANUARY NuMBER, P. 18). 
(PLATE X.) 

PROPOSE now to pursue my subject by describing in some detail 
a series of typical examples of the j)rincipal groups of agatescent 
minerals ; noting, as we proceed, tlie circumstances in each which 
ai^pear to afford proper ground for future general classification. 

The upper figure in Plate X. represents, of its real size, the surface 
of a piece of- jasperine agate in my own collection, belonging to the 
same general group as the specimen, a, h, d, 5, in the British Museum. 
This group consists, broadly, of irregular concretions of jasper affected 
by faults caused by contraction, having their interstices filled with 



I 



Iri'ol:. M,ni. ir>(>3. 



Vn/..V I'LX 




J, Tbiskln, del 



J C Aimytage, 




G- Ailen, del et Inc. 



SECTION AND IVlAP OF A CONCRETE AGATE 



Ruskin — On Banded and Brecciated Concretions, 157 

chalcedony, and the whole enclosed by a quartzose crystalline mantle 
or crust. 

The British Museum specimen {a, h, d, 5) is said to be Icelandic. 
Two others of the group are labelled " Oberstein ; " one, of parallel 
construction, but slightly varied in character, is from Zweibrucken, 
in Bavaria. I do not know the locality of my own, but there is a 
community of feature in all the specimens, which assuredly indicates 
similarity of circumstance in their localities ; and the more various 
the localities, the more interesting it will be eventually to determine 
their points of resemblance. I have not yet obtained an example 
of this group in the gangue, but the crust of the stones themselves 
is in every case composed of quartz-crystals rudely formed, some- 
times so minute as to look like a crumbling sandstone : in my own 
specimen they can only be seen with a lens, associated in filiform 
concretions like moss ; within this crust two distinct formations have 
first taken place, and then a change of state is traceable affecting 
both in new directions. The map-diagram, PL X. Fig. 2, is lettered, 
so as to permit accurate indication of the parts. ^ 

The outer formation, next the crust, is composed of very pale 
whitish brown jasper. It is expressed by a shade of grey in the 
map, and is limited towards the interior of the stone by the strong 
line (with occasional projecting knots) thrown into curves, convex 
outwards. 

The inner formation is of a finer jasper, with dark chalcedony in 
segregation. The vertical lines in the map indicate the chalcedony, 
and the pure white space, the inner jasper, terminated outwardly by 
convex curves. We are thus led at once to note the distinction 
between the two families of agates, formed from within outwards in 
knots, and from without inwards in nests. The first group, to which 
our present example belongs, is usually agatescent in the interior, 
and crystallized on the surface; the second is agatescent in the 
coating, and crystallized in the interior. 

Supposing the silica deposited under the same circumstances of 
solution, and the same time granted for solidification, the difference 
between these two structures would depend (and often does de- 
pend) only on the chance of the silica finding a hollow prepared 
for its reception, or a solid nucleus round which it can congeal; 
the ordinary deposits on the inner surface of a nest often become 
nodular or stalactitio as they project into its open space, and the 
greater part of the apparently independent concretions are probably 
mere fragments out of the hollows of larger ones. Bat there is, 
nevertheless, frequently a true distinction between the two modes of 
deposit. The agates formed on a central nucleus appear usually to 
have had a longer time for their construction than those which fill 
hollows, or, at least, they are the portion of the mass, in the hollow 
itself, which has crystallized most slowly ; they are distinctly reni- 
form in their chalcedony, and distinctly symmetrical in their crystals ; 

^ 1 have carelessly worded the title of Plate X. as if the two figures were a vertical , 
section and surface map ; but the lower one is, of couise, only explanatory of the 
upper. 



158 Buskin — O71 Banded and Brecciated Concretions, 

while the nested agates rim into level or irregularly continuous 
bands, and choke their cavities with confused net- work of quartz. I 
have difficulty in finding convenient names for these two families of 
agate ; but merely for reference to them in these papers, I shall call 
those formed in knots, which are often conspicuously radiant in the 
lines of their ciystals, '• stellar" agates; and those evidently formed 
in cavities, '' nested " agates. 

I believe that the stellar forms, when independent, will be found 
most frequently under circumstances admitting the possibility of 
slow concretion at comparative!}^ low temperatures, while the nested 
or bomb-like structure belongs characteristically to volcanic forma- 
tions, in which the cavities might be filled by comparatively violent 
infusion, and their contents in many cases quickly cooled. Both condi- 
tions, of course, sometimes agree in all their processes ; and we shall 
be able finally to classify these processes of deposit under description 
which will apply equally to the stellar and nested forms, marking 
afterwards the points of exceptional difference. Thus, for instance, 
the most frequent of all the forms of tranquil deposit, uninterrupted 
by flowing additions of material, is that in which a clear band of 
chalcedony, perfectly equal in breadth throughout, is first formed 
round the point (or branch) of nucleus, in stellar, or on the outer 
wall of the cavity in nested, agate. But after this has been formed 
in stellar agate, the succeeding belts will not usually show a minor 
pisolitic structure, whereas, in nested agates, marvellous groups of 
pisolitic hemispherical arches often rise from the inner surface of the 
clear external chalcedony, in section, like long bridges crossing a flat, 
and modify the whole series of bands above them ; but, again, with 
this most important distinction between these and the bands of stellar 
agate, — that stellar bands, the farther they retire from the nucleus, 
usually throw themselves with increasing precision into circular 
curves, till they sometimes terminate in perfect and exquisitely 
drawn segments of spheres; while in nested agate, the bands, if 
parallel, efface more and more the original minor curves as they 
approach the centre of the nest, and sweep over them in broad in- 
determinate lines, as successive coats of paint of equal thickness 
efface the projections and roughnesses of the surface they cover, or 
as successive falls of snow, undrifted, efface irregularities of ground. 
And now, observe, we shall want a word expressive of an inter- 
mediate condition between the states above defined as pisolitic and 
reniform. A pisolitic mineral we define to be one which separates 
into more or less spherical layers by contraction ; and this kind of 
division takes place sometimes quite irrespectively of the crystalline 
structure, and on the grandest, as well as the most minute scale. 
In one of my specimens of Indian Sard, there are multitudinous 
pisolitic flaws, exquisitely perfect in spherical curvature, dividing 
the parallel bands of the agate transversely in every direction, look- 
ing like little palea^ of chaff in its clear substance ; on a large scale, 
the aiguilles of Chamouni are pisolitic, rending themselves into 
curved layers five or six hundred feet in the sweep of their arcs, 
variously crossing their cleavage (which is rectilinear), and often 



Ruskin — On Banded and Brecciated Concretions, 159 

diametrically crossing their beds. On the other hand, true reniform 
structure is perfectly compact, and dependent on minute radiating 
crystallization of substance. But between the two there is the fine 
agatescent structure, in which bands of different materials, jasperine 
and chalcedonic, are separated from each other under a radiating 
law ; and yet not divided by a mechanical contraction ; for though 
they are often so distinct as to separate under the hammer stroke, 
they never leave spaces between, as true pisolitic beds do in ultimate 
separation. For this intermediate action, the most frequent of all, 
I shall keep the term " spheric ;" and I was forced to admit only a 
guarded use of the word '' gravity" in last paper, because this spheric 
action is constant, as far as I know, in all agatescent matter, so that 
I have never yet seen an instance in level-laid agate of the transition 
from the lake in the (lowest ?) part of the cavity to the beds at the 
sides being made under any subjection to the mechanical law of 
gravity on fluent substance ; but (as in the petrifaction of the banks 
of Dante's Phlegethon lo fondo suo, e amho le pendici, fatt 'eran pietra, 
e i margini dal lato, '' its bottom, and both the slopes of its sides, and 
the margins at the sides, were petrified"), the flinty bands form in 
parallelism on the slopes as well as the bottom, and retain this parallel- 
ism undisturbed round the walls and vault of the agate. On the other 
hand, I cannot but admit the idea that these rectilinear tracts are 
formed under a modified influence of gravity, because, first, I have 
never seen them laid in difi'erent directions in different parts of the 
same stone ; and, secondly, whenever they are associated with pendent 
stalactites, they are at right angles to them. So that the aspect of 
one of these levelled agates in cavities may be approximately de- 
scribed as that of a polygonal crystal in which the position of one of 
its sides is determined by gravity ; and the other sides modified into 
curves by radiating crystallization (of course the changes of form 
caused by gradual entrance or exit of material being at present with- 
drawn from consideration). In the example before us, which, 
though showing but feeble crystalline energy, belongs to the stellate 
group, the outer formation of rudely spheric white jasper withdraws 
itself confusedly from the sandy crust of quartz and becomes finer 
and finer towards the inner jasper, on the surface of which it throws 
down a coating of superb crimson (oxide of iron ?) which is itself 
arranged every here and there in minute spherical concretions. The 
same formation exists in the same position under the quartzose outer 
bed and on the surface of the chalcedonic interior one, in the speci- 
men figured in Plate III. Pig. 3 ; and when we find it, as we often 
shall in future, under similar circumstances, I shall speak of it 
simply as the " medial oxide." In the map, this crimson deposit is 
throughout represented as black. 

Proceeding next to examine the inner formation on the surface of 
which this medial oxide is deposited, we find it composed of two 
parts, sharply divided ; a white jasper, and dark grey translucent 
chalcedony. The white jasper has a spheric structure much more 
perfect than that of the outer coat, and so delicate as to be hardly 
visible without a lens (not that the spheres are small, — they are on 



160 Buskin — On Banded and Brecciated Concretions » 

the average the third of an inch in diameter, — but the lines of division 
are so subtle that the mass appears compact) . In this character the 
inner deposit seems only a finer condition of the external one : but it 
differs specifically in being affected by sharp displacements apparently 
owing to contraction. To these faults, though minute, I would 
direct the reader's special attention. They are by no means small 
in proportion to the extent of material affected by them ; and they 
differ wholly from ordinary displacements, in this, that there is no 
trace whatever of movement at the limiting convex curves, but only 
at the edge of the chalcedony — so that the fault at a seems owing to 
contraction within the space a b, and at c, to contraction within little 
more than the space c d ; and farther, the fissures ah, c d are not 
rugged or broken, as if caused by the displacement, but sinuously 
current, passing on through the chalcedony from c to e,f, and g ; and 
in fact, I am very certain that these veins are not caused by the con- 
traction in question ; but that the contraction takes place unequally 
on each side of the primarily formed vein. This kind of faiilt, of 
which we shall find frequent instances, the unequal contraction, 
namely, of beds on opposite sides of a vein or dyke, I shall call fault 
" by partition," and the violent fracture of beds at a point where no 
vein or dyke previously existed, I shall call fault '' by divulsion.'* 
Deposits which fill compartments in fossil shells may often 
be seen, in a correspondent series of beds, to vary their pro- 
portionate thickness at each partition : the rectilinear bands of 
Labradorite may be found varying in thickness and position while 
they correspond in direction, in contiguous crystals ; and I do not 
doubt but that even on a great scale, displacements of beds which at 
first sight might be supposed to have given rise to the fissures which 
divide them, will be found on examination to be the result of an 
unequal contractile action in the masses released by the fissure, pro- 
tracted for long periods after it had given them their independence. 
Lastly. The separation of the chalcedony from the jasper does not 
take place only in the inner formation. It is an operation evidently 
subsequent to the deposition of both layers, and even in the outer 
one, makes the entire dotted space, as far as the curved limit x y , 
chalcedonic, and flushes it with a diffusion of the medial oxide from 
its edges ; this medial oxide here drawing itself into bands, which 
being parallel with those of the grey chalcedony, are manifestly pro- 
duced by a segregation which has taken place simultaneously in the 
two layers. This being clearly ascertained, the intensely sharp line, 
which separates the chalcedony from the while jasper, considered as 
a result of segregation, becomes highly remarkable, and a standard 
of possibility in sharpness of limit so produced. 

The spots surrounded by dark lines in the lower part of the figure 
are portions of the inner formation cut off by the surface section. 
It is often difficult on a single plane to distinguish such spaces, the 
truncated summits of an inferior, or, as here, remnants of a superior, 
bed, from isolated concretions : and it is always necessary in examin- 
ing agates to guard against mistaking variation of widths of belt 
caused by obliquity of section from true variations in vertical depth. 



Pattison— Formation of Vallies, 161 

All the difficulties of a geological survey sometimes meet in the 
space of a single flint. The gradated softness of edge in belts 
widened by oblique section is however usually an instant means of 
recognising them ; but in this stone the material is so fine that the 
oblique edges are as sharp as the vertical ones. 

I could not without tediousness proceed farther in the description 
of this stone ; it presents other phenomena peculiar to itself; but, 
resuming the points hitherto stated, we may define the family of 
agates, which it represents, as consisting of at least two formations 
enclosed by quartz ; the inner formation being affected by disloca- 
tions which do not pass into the outer one. Generally their colour 
is brownish red and white, and their main material opaque and j asperine ; 
their chalcedony developing itself subsequently and subordinately. 
The crimson veins and stria3, which in some examples traverse the 
inner formation, will furnish us with a study of separate interest 
after we have obtained determinate types of other large and typical 
groups : the minor details in each may then be examined with a 
better field for comparison. For convenience sake I shall in future 
refer to the group described in this paper as " Bipartite jaspers." 
Their division may, indeed, be into more than two coats or forma- 
tions, but the operation of a contractile force in one, which does not 
affect another, sufficiently justifies the term for general purposes. 



III. — Formation of Vallies. A Description of Heudeshope. 

By S. E. Pattison, F.G.S. 

THE Heudeshope beck is a small feeder of the Tees, running 
swiftly down a steep valley into the main stream, at Middleton 
Teesdale. It is wholly in the lead-measures (Carboniferous lime- 
stone), which are here nearly horizontal, undisturbed by trap, and 
shew only a few faults, so small as not to affect the surface. The 
great Teesdale fault operates on the other side of the main valley. 
The Heude beck flows north and south. Its source is in the table- 
land, forming the water-shed, between Weardale and Teesdale, 
whence four or five streams issue in different courses. It is un- 
obscured by the drift beds, which characterize the opposite lower 
slopes of the Tees valley. It is excavated down to the solid rock, 
the banks have been quite undisturbed by cultivation. It passes 
through forty-three distinct alternations of grit, shale, and limestone, 
to each of which the miners have given a distinct name ; it falls 
about 1,000 feet in the six miles of its course. In the hope that 
a tramp down by the side of its brawling rivulet, during the short 
hours of a winter day, might illustrate some theory of valley - 
formation, I devoted one of the last days of the year to the task. 

The summit of the table-land is formed by grit beds, called 
Firestone, stratigraphically just below the Millstone grit. The 
gorge begins by two scoop-like hollows, springing from the level. 
These are covered with sharp blocks of unrolled, unscratched stone. 
There is no nick in the table-land, no change of strata, no fault. 



162 Pattison— Formation of Tallies. 

The plateau bears no mark which offers the slightest reason why 
the four or five tiny streams should have originally flowed in one 
direction rather than another. But the crust of the plateau has 
been broken up in the direction of the valleys, and the uppermost 
reaches are incumbered by untravelled blocks of the grit which 
have been somehow broken in situ and then left. What effected 
this operation? Certainly not denudation, not rain or rivers, not 
atmospheric agency. These are minor polishing agencies, but they 
could never originate the basis of their operations. Not ice, for 
there is no trace of glacial grinding action. Looking from this 
summit level at the diverging lines of ruin, one would say, here we 
are at the spot where force has come to its vanishing point. Some 
great poimding and crushing and disturbing operation has radiated 
from the line of the river vallies below, and spent itself in the 
everlasting hills ; the maximum of the force was displayed at the 
base, in the main valley below, and its minimum up here at the 
summit ; the intervening wedge of material was shattered and 
loosened, leaving to rain and rivers the operation of its removal. 
The latter have done the barrow-work, but the powder- work was 
first done. After descending through about 100 feet of grits we 
come to the shales (Plate and grey beds), in which the stream 
becomes more peaceful, we then re-enter a sandstone sill, down a 
succession of steps, in which the perpendicular is formed of shales 
and the steps of grit, the former constantly yielding and the latter 
breaking, so as to deepen the gorge, now in one place and then in 
another. Crossing the thin fell-top limestone, we came into a well- 
marked succession of slate sills and grits. On looking around we 
see that the tiny rivulet has, and has always had, a definite course. 
True, it skips about, now here and now there, within limits of a 
dozen yards, now coursing down one channel and then another, as 
its broken ledges, or as floods determine, but its course is at the 
bottom of the gorge, and is quite distinct from the gorge itself, 
which has sloping sides ; it is a water staircase, like the celebrated 
Cascade at Chatsworth, but with smooth inclined side walls. The 
whole dip of the strata is eastward, and therefore if the valley had been 
excavated by water or by rain it would have gone in the direction 
of the first shale bed, and been marked by an overhanging cliff of 
grit in its down eastward course. On reaching the limestone, which 
is here called the Great Limestone (the cliffs of which gives name 
to the middle of the little valley, the Skears, but which is not the 
Scar limestone of other districts) we find a beautiful development 
of the cutting-back power of the water. The beds of the limestone 
have first been worn quite smooth, leaving the corals and Brachiopods 
in exellent relief, the spray has hollowed out the shales beneath, the 
limestone has given way, the rivulet has suddenly acquired a new 
level, the old bed with its lips and pot-holes and curved lines is left 
dry, like a broken well-dish. This action is confined to the staircase ; 
it does not extend back into the side slopes, The amount of river 
bed thus acted on is very considerable. Judging from rough 
calculation, it must have been going on for ages before the Boulder- 



De Ranee — On the Albian or Gault of Folkestone. 163 

clay. This trituration, with its step-like results, is quite distinguish- 
able in its effects from the phenomena of the slopes extending 
upwards on either side of the actual present and past channel. The 
limestone forms, as usual, a terrace in the side of the fells, and shews 
picturesque cliffs. Below this we get pale flaggy beds with shale, 
the former exhibiting fine markings of two species of Crossopodia. 
Through these the burn descends past the village of Middleton 
down to its junction with the river, in the four fathom limestone. 

I closed a pleasant day's ramble in the conviction that we had not 
made much progress in the valley question since the days of Hutton, 
simply because a physical fact once ascertained becomes an axiom. 
What more can be said than the following : — " The original in- 
equalities of the surface, and the disposition of the strata, must, no 
doubt, have determined the water-course at first ; but this does not 
hinder us from considering the rivers as having modified and changed 
those inequalities, and as the proximate causes of the shape and 
configuration which the surface has now assumed." — Flay fair, Illus- 
trations of the ffnttonian Theory, p. 357. 



IV. — On the Albian, or Gault, of Folkestone. 
By C. E. De Eance, of the Geological Survey of England and "Wales. 

FROM the proposition of Professor Forbes, that a species once 
extinct never reappears, it follows that when a species recurs, 
it must have existed elsewhere during the whole of the time occupied 
by the deposition of the strata between the deposits containing it. 
In viewing the distribution of species through the chief stages of the 
Lower Cretaceous system, it appears that the same species reappear 
when there is a recurrence of the same or similar physical conditions, — 
the Neocomian and Albian clays having more species in common than 
the intervening Aptian ; and the Aptian and Cenomanian sands, being- 
more closely allied than the intervening Albian clay. An examination 
of the latter, at Folkestone, appears to allow of its being divided into 
eleven lithological stages or beds which have been more or less re- 
cognized by all geologists and fossil collectors who have visited 
the district. To these beds provisional names have been assigned 
expressive either of their colour, position, or characteristic fossils. 
But in tracing all the recurring species from their genesis in one 
stratum to their extinction in another, these beds are found to have 
no great palseontological value, but to resolve themselves into two 
groups divided by a junction bed, in the same way as the *' junction 
bed" separates the Albian from the Upper Aptian. Beds i, to iii. 
forming an Upper, beds v. to x. a Lower Albian, beds iv. and xi. 
being the two phosphate junction beds. 

As Mr. Judd,^ in his admirable paper on the " Speeton Clay," has 
adopted D'Orbigny's term, "Neocomian," for that formation, the 

1 Geol. Mag. Vol. V. p. 141. 



164 De Ranee — On the Albian, or Gault of Folkestone. 

following terms have been used by the writer of this paper as being 
more uniform with it : — 

Danian Stage =: Upper Chalk. 

Zone of =: Chalk rock. 

Upper Turonian sub-stage =Lower Chalk. 

Zone of Belemnitella mucronata disjunction led. 

Lower Turonian sub-stage =Grey Chalk. 

Zone of Scaphites oiqualis = Chloritic Marl. 

Cenomanian stage =Upper Greensand. 

Upper Albian sub-stage =:Upper Gault. 

Zone of Am. Beudantii z=. Nodule hed. 

Lower Albian sub-stage =Lower Gault. 

Zone of Am, interruptus -zziJunction led. 

Upper Aptian := Folkestone beds. 

Zone of Rhynchonella sulcata ■ztl Junction hed. 

Middle Aptian =Sandgate beds. 

Zone of Terelratula ohlonga =iJunction led. 

Lower Aptian sub-stage =Hythe beds. 

Lower Neocomian sub-stage r=Atherfield Clay. 
A •' true 'junction bed' represents in a tangible form the actual break 
in organic life between two stages, and either introduces a new 
fauna altogether, as Bed xi., separating the Aptian from the Albian 
stages ; or contains a ' limit fauna,' as Bed iv., dividing the Upper 
from the Lower Albian sub-stages. Some species have an extremely 
limited vertical range in a stage or sub-stage, and yet reappear in 
other stages, producing the phenomenon of recurrent forms and 
horizons." Thus there are two distinct horizons of Peden asper in 
the Albian of Kent, and another in the first foot of Greensand below 
the Chloritic Marl or Zone of Scaphites ^qualis at Beaminster and 
Chardstock. As an assemblage of horizons of similar range constitute 
a zone, a recurrence of several horizons defines or marks a recurrent 
zone, which, as above stated, appears to occur at every return of similar 
physical conditions. The junction beds between all the stages and 
sub-stages of the Cretaceous are examples of this, for they contain in 
addition to the " initiative " or " limit" fauna, as the case may be, a 
large percentage of forms peculiar to themselves, thus the reptile 
Icthyosaurus campylodon is found in every junction zone, from the 
zone of Bhjnchonella sulcata, between the Upper and Middle Aptian 
(Folkestone and Sandgate beds), to the zone oi Belemnitella mucronata, 
between the Upper and Lower Turonian (Lower and Grey Chalks). 
Many other species occur in a similar manner ; Solarium conoideum, 
which is limited to the upper three feet of the zone of Ammonites 
Beudantii (between the Upper and Lower Albian), even reappearing 
in the zone of Scaphites cequalis and Am. varians (Chloritic Marl) at 
Cambridge. Associated with these recurrent species, in every junction 
bed, are found phosphatic nodules, those from the Albian beds iv, 
and XI. are rich in phosphates and contain sulphuret of iron, silica, 
and lime, the phosphatic matter appears to have been deposited in a 
decomposed or gelatinous state, for it often entirely surrounds shells, 
bones, bored wood, and Crustacea, sometimes entangled with and 



Be Ranee — On the Albian, or Gault of Folkestone. 165 

around fragments of broken ammonites, sometimes filling up empty 
cavities, and in few cases enclosing small quartz pebbles. Taking 
all these facts into consideration, it appears probable that these 
phosphatic nodules are the molluskite and other animal remains of 
the recurrent forms which existed in another area during the time 
occupied by the deposition of the intervening strata. 

The Lower Neocomian is exposed at low water on the beach 
between Sandgate and Hythe, and is reached in well-borings at 
both towns ; the zone of BhjncJionella sulcata is to be seen near 
the turnpike between Folkestone and Sandgate, on the Lower 
Sandgate Koad; the Middle Aptian beds at this point are over- 
laid by a recent deposit, two to three feet thick, which con- 
tains the empty shells of the recent species Cyclostoma elegans, 
a shell, peculiar to chalk districts, only now met with living, 
two miles further east, on the chalk of the undercliff at Eastweir 
Bay. The Upper Aptian sands, with its seams of rag and sandy 
ironstone, form the cliff above. The junction bed xi, is first seen 
in the cliff, at a point immediately over the before-named turnpike. 
Under the junction bed, at the top of the Upper Aptian, there is a 
highly fossiliferous bed (the zone of Ammonites mammillaris, Am. 
Beudantii, and Inoceramus Salomoni). This zone, which contains 
many Aptian forms, is succeeeded hj a seam of sulphuret of iron 
nodules, with crystals of selenite, and occasionally wood, bored by 
GastrochcBna pyriformis ; this seam is a portion of the junction 
bed XI., and is the real base of the Gault Clay, or Albian stage. ^ 

LOWEK ALBIAN. 

Zone of Am7nonites interruptus. Bed xi. — This zone consists of 
three portions, the iron seam, before alluded to; a seam of dark 
green sand, containing two lines of phosphatic nodules ; and a band 
of dark marly gault, with one line of nodules ; the nodules in each 
case being mixed with fragments of A7n. interruptus and Am. dentatus. 
The first portion is generally about a foot in thickness, the second 
from eighteen inches to four feet thick, the third from one to three 
feet. This zone is well shown in the cliff section, from its first 
appearance above the turnpike, before-mentioned, to the point in 
which it sinks below the beach, a little east of Copt Point. At the 
eastern corner of the west cliff, at the Battery, it is cut into and 
redeposited with the local '* Elephant " bed existing at that point, of 
which the following is a section taken by the writer of this paper 
in 1866 :— 

1. Vegetable mould 3 feet 3 inches. 

2. Eag flagstones of Old Monastery „ 3 „ 

3. Clay, with oysters, bones of Ox, etc 2 „ 6 „ 

4. Small shingle „ 4 „ 

5. "White loam, with Helix concinna, Succinea ohlonga. Lower ] 

Chalk. Terebratula, and " junction bed." Ammonites and > 6 „ 4 „ 
nodules ) 

6. Angular flints, with bones of mammalia, and fragments of | , 



Am. interruptus 
7. Upper Aptian 95 ,, „ 

1 For the particulars of the distribution of the Aptian beds, see Mr. Drew in Geol. 
Survey, Memoir on sheet iv. 



166 De Ranee — On the Albian, or Gault of Folkestone, 

The last set of bones found were exhumed in the presence of 
Captain Sweeney, R.A., who told me they were found in bed 6 of 
this section, two or three large tusks of Elephas pri^nigenius being 
left at the bottom of the excavation, where they remain to this day. 
A similar deposit to that of bed 4 of the above section, was found 
in an excavation for some cottages, between the New Gas Works 
and Railway Embankment ; this deposit, capped by brick earth and 
resting on Upper Aptian, contains Lower Chalk fossils and nodules 
of iron from the Chalk. 

The junction bed xi, may be well seen on the Canterbury Road, 
in a sand pit, a little south of the brickfield above the Red Cow Inn ; 
the zone of Am. interruptus resting here on the zone of Am. mam- 
millaris, at a height of forty feet above the road. At the gate leading 
to the brickfield it dips under the road, and is never met with at the 
surface further north. It was, however reached in a well-sinking 
at Canterbury Terrace, Dover Road, at a depth of eighty feet. The 
two upper bands of bed xi. were three feet six inches, and the 
sulphuret of iron seam eighteen inches in thickness ; water was 
touched the moment the latter seam was pierced, and welled up in 
abundance after passing through five feet of dark greensand, re- 
sembling in lithological character the beds of the Middle Aptian. 

Zone of Ammonites Benettianus {?) Bed x. — The "bottom bed " of 
the Albian contains one seam of phosphatic nodules, with few 
organic remains. 

Zone of Am. auritus, var. Bed ix. — The variety of Am. aicritus 
found in this zone has long and slender spines. The zone is well 
shown in the Copt Point section, in the patch of Albian exposed on 
the beach in the Eastwear Bay, between Copt Point and the Pre- 
ventive Station, and in the Brickfield before mentioned. 

Zone of Crustacea. Bed viii. (" Crab-bed ") is composed of a light 
fawn-coloured clay ; a striking contrast to the deep black of zone ix., 
and is poor in fossils in proportion to its thickness, but contains 
seven species peculiar to itself. 

Zone of Nautilus Clematinus. Bed vii. — The clays of this zone are 
strongly spotted with light markings of fawn colour on a dark 
ground ; this kind of mottling is invariably found in the clays of the 
Lower Albian ; on the contrarj'-, in the Upper Albian, the clay 
deposits are streaked (not spotted), with dark marks on a light 
ground. Many characteristic Albian shells make their first appear- 
ance in this zone, and seven are peculiar to it. 

Zone of Am. denarius. Bed. vi. though of small vertical thick- 
ness and lithologically similar to the last, is palseontologically 
distinguished from it, from the fact that many of the most marked 
forms of zone vii. do not pass into it, while on the other hand it 
contains at least six species peculiar to itself. This zone is well seen 
in plan, in the patch of Albian on the beach ; it is there distinguished 
from the last by the darker colour of the ground between the 
mottlings, and is physically separated from the following zone by a 
Beam of hard rag about six inches thick. 

Zone of Am. auritus. Bed. v. is very dark in colour, though 



Be Ranee — On the Albian, or Gault of Folkestone. 167 

not so dark as the zone of Jm. auritus var., and is highly 
fossiliferous. Two distinct forms of Ammonites Deshayesii occur 
in the lower Cretaceous series, one with a square flat back, the 
other with a rounded back. The former occurs in the zone of 
MhynchoneUa sulcata, and the sand seam in the zone of Am. in- 
terruptus ; the latter form in the Lower Neocomian clay of the Isle 
of Wight, and the clay of the Lower Albian, zone v., at Folkestone. 
Zones v., vi., and vii. constitute the horizon of Ammonites elegans, 
whilst that of Am. lautus probably corresponds with the entire space 
occupied by the Lower Albian. 

Zone of Am. Beudantii. Bed. iv. being the ''passage" be- 
tween the Upper and Lower Albian, cannot be strictly said to 
belong to the one more than to the other. It marks the total extinc- 
tion of many Lower Albian forms, no less than the introduction of 
others, which took their place. But this replacement is marked rather 
by a greater number of individuals, than of species, for of the 88 
species which became extinct in the Lower Albian, only 45 new 
forms occur as peculiar species to the Upper Albian. Zone iv., in 
addition to being the "limit fauna" of the two Albians, contains 13 
species peculiar to itself, and also the other 13 species which are com- 
mon to the Upper and Lower Albians. We thus see how well the 
Upper Albian is specialized by the group Cristati, not a single speci- 
men of which is found in the Lower Albian ; whilst with the excep- 
tion of Am. splendens, the Lower Albian is equally characterized by the 
Dentati and Tuber culati — bed xi. being especially the zone of the 
former, and beds vii., vi.,.and v. of the latter. This zone, as seen in 
the patch on the beach, consists of four portions. The lower, five 
inches at the outcrop, contain phosphatic nodules with Am. prohos- 
eideus ; the second, 18 inches thick, nodules with variety of Am. 
denarius [Am. crenatus of the Brit. Mus. coll.) ; the third, four feet 
four inches, with few nodules and Am. Bouchardi ; the fourth, two 
feet, with nodules and Am. Beudantii, constituting four well defined 
Ammonitic horizons. 

UPPER ALBIAN. 

Zone of Nautilus Deslongchampsianus. Bed in. is at once 
distinguishable from any other by the occurrence of Inoceramus 
sulcatus, in casts, in great abundance, the surface of the bed being 
everywhere marked by their silvery impressions. This shell first 
occurs in the Lower Neocomian clay of Hythe, is not again found in 
the Aptian series, but re-appears in the zone of ^m. interruptus\ a 
single specimen only, however, has been found by Mr. Etheridge.^ 
It next appears sparingly in bed iv., and reaches its maximum of 
development in bed in., the zone under consideration. A few speci- 
mens occur in bed ii., and also in the Blackdown beds, a portion 
of which, at least, represents the Upper Albian. Near the base of 
zone III. there is a seam of phosphate containing Nucula hivirgata and 
Cardita tenuicosta, Inoceramus sulcatus^ and a quartz pebble. A little 

^ Memoir of the Geol. Survey, sheet iv. 

2 A distinct variety of In. sulcatus, figured in "Mollusques Fossiles," by Pictet 



168 De Ranee — On the Alhian, or Gault of Folkestone. 

above is a seam of hard rag containing stems of Pentacrinus Fittoni. 
Another bed of rag, physically dividing this zone from zone ii. ; im- 
mediately under the rag is a seam of very large specimens of Am. 
cristatus. 

Zone of Am. circularis and Kingcena lima. Bed ii. In colour a 
pale cold grey, poor in organic remains, but containing several 
seams of phosphatic nodules mixed with fossils ; these nodules 
appear to be the principal cause of the preservation of as many as 
fifteen peculiar species of fossils. Before describing the position of 
these, the following is a key to the beds before named, exposed 
on the beach ; the measurements give the width of outcrop of each 
zone, along a line at right angles to the coast from the cliff to a large 
chalk rock marked by the writer with a broad arrow. 





FT. 


IN. 


I... 


.. 56 


10 


II.... 


.. 81 


7 


III.... 


.. 11 


5 


IV... 


.. 8 


4 


v.... 


.. 23 





VI.... 


.. 3 





VIL... 


.. 10 


10 1 



Zone 1 56 10 Fault. 

Zone TI 87 

Ill 8 6 

Fault. 

Zone V 8 1 

Fault. 
Zone VII 2 



Fault. 
Zone V. 20 

Fault, 

Zone VIII 35 

Sand, covering 
Albian 90 



The first seam of phosphate in zone iv, occurs at 5 ft. 6 in. above 
zone III. in the patch on the beach ; it is there 4 in. thick, and contains 
Inc. concentricus and vertebrae ; the second, a foot thick, occurs at 
4ft. 9 in. above the last, and contains Terelratula liplicata^ Nucula 
ovata, Am. cristatus, Hylodus, Lamna suhulata, vertebrse. Samites at- 
tenuatus, Pentacrinus Fittoni, Nucula livirgata, and Pecten asper. About 
the middle of this zone there is a very dark band, well seen at the 
foot of the cliff section, a little west of the Preventive Station and 
east of the great patch on the beach, which contains no less than 
five seams of phosphate nodules in about as many feet ; these consti- 
tute the horizon of Belemnites {minimus) ultimus and Samites armatus, 
they also contain Am. cristatus and Am. varicosus. 

Zone of Am. GoodhalUi, and Am. rosiratus. Bed. i. — This zone is 
traversed by a system of joints, with smooth surfaces which are 
coated with a film of oxide of iron, or " dark partings." These 
smooth surfaces slipping against each other, partl}^ contribute to the 
faulted and folded state of the beds beneath ; the whole base of the 
cliff, a little west of the Preventive Station, sometimes moving a foot 
in a week, the upper bed folding over, and reaching more seaward 
than the lower beds. In connection with the unstable state of the 
undercliff in the bay, it may be mentioned that the whole surface of 
the land between Martello Tower 3 and the Tramroad, is slowly 
sinking, and in the line of greatest depression, according to the 
Coastguard men, at the rate of a foot in a year. Zone i. is divided into 
two ]oortions by the occurrence of a bed of dark green sand, contain- 
ing four seams of shining phosphatic nodules. It contains Am, 
GoodhalUi, Icthyosaurus campylodon, Pecten orbicularis, Belemnites ulti- 

and Roux, pi. 42, fid, exists in this scam, two specimens being found, half of the 
shell resembling mkatus and half like concentricus. — C. E. E. 



De Ranee — On the Albian, or Gault of Folkestone. 169 

mus, and a Choanite ; the latter three species were obtained by Mr. 
Topley.^ AH the species enumerated from zone i., occur in that por- 
tion of it, under the horizon of Am. Goodhallii. A fragment of a 
Pecten from the upper portion, appears to be a Lower Turonian 
species. 

CENOMANIAN. 

This formation is 28 feet thick at Copt Point, the first 22 feet 
being green sand and the remaining six brown sand. It runs from 
this point to the air shaft of the tunnel, and from thence along the 
underoliff capping the cliff section west of the Coastguard Station, 
and occurs all along the beach a little east of the same, between the 
cliff and the little patch of Albian beds i. and ii., locally called 
''Pelter Gault." 

The following fossils were collected by Mr. Topley and myself 
from the Cenomanian of Folkestone : — Brachiolites {?), Solarium 
ornatum, hioceramus Crispn{?), Ventriculites impressa, Exogyra conica, 
JEJx. columha, Pecten orhicularis, and Lima parallela. 

Zone of Scaphites aqualis. — The " Chalk with green grains" or 
''Chloritic Marl," is seen at Folkestone, in the inlier at Copt, 
where it occupies a small circle around the Martello Tower. It 
is apparently unfossiliferous, and is five feet in thickness. 

The Lower Turonian sets in near Martello Tower 2, and is well 
exposed on the beach at Abbots' Cliff. The Upper Turonian forms the 
escarpment overlooking the Aptian plateau ; and the Danian first 
appears at the top of the cliff a little west of the Preventive Station 
at Abbots' Cliff. 

In conclusion, I would wish to thank Mr. Etheridge for his kind- 
ness in determining the species of the majority of the fossils, and for 
his assistance in various ways. 

List of the most Characteristic Species peculiar to each Zone. 

Zone XI. — (7 Species pecuHar.) Am. Beshayesii, Am. dentatus, Am. Gervillianus, 
Trochosmilia sulcata. 

Zone IX. — (5 sp, p.) Mytilus Galliensis, Fusus Iterianus, Scalaria Dupiniana. 

Zone VIII. — (9 sp. p.) Pinna tetragona, Turbo decussatus, AmpuUaria Icevigata^ 
Etyus Martini^ Falceocorystes Broderipii, Hoploparia longimana, Otodus appendiculatus. 

Zone VII. — (7 sp. p.) Hamites tuberculatus, Ham. Sablieri, Gervillia solenoides, 
Rostellaria varicosa, Bellerophina minuta. 

Zone VI. — (6 sp. p.) Trochocyathus conulus, T. Harvey anus. 

Zone V. — (17 sp. p.) Ham. simplex^ Fecten quinquecostatus, ActcBon offinis, Avel- 
lana injlata, Eostellaria Robinaldina, R. carinella, F. cingulata, Acmcea tenuicosta, 
Turbo allied to Yonninus. 

Zone IV. — (13 sp. p.) Am. verstcosiatus, Rost. allied to pyrenaica, Fleurotomaria 
Gibbsii^ Cyathina BoiverbanJcii, Fdaphodon brevirostris (?), Fycnodus. 

Zone III. — (2 sp. p.) Falceocorystes Stokesii. 

Zone II. — (15 sp. p.) Hamites elegans, H. armattts, Kingcsna lima, Adelia Beehei. 
Species Characteristic of Lower Albian. — Belemnites attenuatus, Rostellaria 
carinatd, R. Farkinsoni, Turritella granulata, Fhasianella Gaultina, Fterocera 
retusa, Cyclocyathus Fittoni. 

1 Who also obtained Trochocyathus conulus{}) from it.— C. E. R. 

vol. v. — NO. XLVI. 12 



170 Be Ranee — On the Albian, or Gault of Folkestone, 

Species Characteristic of Upper Division. — Am. Bouchardii, Inoceramus sul- 

catus, Peclen asper. 
Species Chahacteristic of Lower and Upper Albian. — Samites rotundutf^ 

Terebratiila biplicata, Inoceramus concentricus, Nucula pectinata^ N. ovatay iV\ 

bivirgata, Perdacrinus Fittoni. 
SECTION OF ALBIAN OR GAULT AT COPT POINT, FOLKESTONE. 



I. Zone of Am. Ooodhallii 
and 
Am. rostratus. 




II. Zone oi Am. circulnris 
and 
Kingoena lima. 



III. Zone of Nautilus Deslong- 

champsianus. 

IV. Zone of Jm. Beudantii. 



V. Zone of Am. auritus. 



VI. Zone of -4m. denarius. 

VII. Zone of Nautilus Clemen- 
tinus. 

VIII. Zone of Crustacea.] 



IX. Zone of ^m. auritus, Var. O 
X. Zone of Am. Benettianiis 1 
XI. Zone of Am. interruptus. 
Zone ol Am. mammillaris. 

C.E.R. 



CENOMANIAN. 



Clay with dark partings. 



n. I Greensand. Am. Ooodhalii. 
n. ) 

Clay with dark partings. 
Ammonites rostratus. 

Nodules. 

Am. Bouchardianus. 
Am. circularis. 
Am. varicosus. 
Inoceramus sulcatus. 

Nodules. Am. cristatus. 

Nodules. 

Hard seam. 

Am. cristatus. 

Am. varicosu 

In. sulcatus. 

Hard seam. Pentacrinus Fittoni. 



W/M 

//j/mw/Bi Nodules 

'^^ Am. Bouchardi. 
Am. denarius. 
Am. lautus. 
Am. tuhereulatus. 
Dark Clay. 
Am. splendens. 
Am. elegans. 
Hard seam. 



Am. splendens. 
Am. elegans. 
Am. tuberculatum. 




Am. splendens. 



G?e^en2nd ! ^^- »'»'«'*''«1'*»»- 
S. Iron Nodules. 
pcaaaj-iSS?^ APTIAN. hi. Salomoni. 
Am. Beudantii. 



De Ranee — On the Albian, or Gault of Folkestone. 171 



The following Table exhibits a summary of the species common 
to the Upper and Lower divisions of the Albian or Gault, of those 
peculiar to each, and of those also which mark the zone of Ammonites 
Beudantii, or the " passage-bed " between the Upper and Lower 
Albian. A list of all the species, with their ranges, will, I believe, 
be printed in the Survey Memoir on Sheet III. 



Plants : 

Fucoids and wood 

FORAMINIFERA , 

EADIA.TA : 

Zoophyta 

Echinodermata , 

Annelida , 

Crustacea : 

Cirripedia 

T> J ( Macrura 

iJecapoda { -n 7 

^ { Brachyura 

MOLLUSCA : 

Brachiopoda 

a. Monomyaria 

b. Dy my aria 

Gasteropoda 

Cephalopoda : 

a. Ammonitid(B 

b. Nautilidce 

c. Belemnitidce 

Pisces 

Reptilia 






20 






'oS 



oS 



82 



13 



P.S. — The species found in the true Gault or Albian of Black Yen, Dorset, are those 
of the Lower Division. 



Coal in New Zealand. — On the suggestion of Dr. Hector, 
Captain Hutton, F.G.S., has been making a survey of the Lower 
Waikato district of the North Island. He reports that there is no 
probability of finding a payable alluvial gold-field of any extent, 
but that the district has other deposits of value. The Tertiary 
formation contains '' brown coal," having the appearance of cannel 
coal, lustrous and pitch black in colour, with brown film in places. 
It is a hydrous coal, still containing a certain per-centage of water, 
but it is found to answer well in the steamers on the Waikato. It 
burns with a bright, clear flame, throwing out an intense heat. 
Captain Hutton estimates the coal bed to contain 140,000,000 tons 
of coal. The whole can be worked without pumping or any 
mechanical means for raising it to the surface, and therefore it can 
be supplied at a light cost. 



172 Scudder — Fossil Insects of North America. 

V. — The Fossil Insects of North America. 

By Samuel II. Scudder, Curator of the Museum of the Boston Society of Natural 

History, U.S. 

THE discovery of fossil insects in North America is of very recent 
date; even now, scarcely a hundred specimens have been 
brought to light, and they have occurred, with few exceptions, as 
solitary individuals. The Reports of State and provincial geologists, 
which have added so richly to our knowledge of the palaeontology of 
North America, have hardly mentioned these fossils. As descriptions 
of them are scattered through many publications — doubtless difficult 
of access to English 'geologists — and as most of the specimens 
referred to have passed under my eye, I have prepared this general 
resume of what is known and have accompanied it with critical re- 
marks.' 

The oldest fossil insects yet discovered in America — and, indeed, 
in the world — consist of a few broken wings of Neuroptera, imbedded 
in the Devonian rocks of Lancaster, New Brunswick. The locality 
— '' Fern Ledges " — so called by Mr. C. F. Hartt, the discoverer of 
the remains, is about a mile west of the town of Carleton, not far 
from St. John. The rocks form a series of ledges, exposed on the 
sea shore between high and low water marks. The beds of sand- 
stone and shale, of which they are composed, have a seaward dip of 
about 45° and a strike of about W. 10° N., corresponding very nearly 
to the trend of the shore. The fossiliferous shales between the en- 
closing sandstones are worn away by the action of the water, leaving 
the fossils accessible in but few places. The whole deposit is of very 
limited extent; it reaches along the shore for about three hundred 
and twenty-five paces, exposing a thickness of strata of one hundred 
and forty-five feet, with a width of some three hundred feet. 

Mr. Hartt has given a detailed description of these strata, from 
which the following section, showing the position of the fossil insects, 
is derived : — ' 



Sandstones and shales 


Calamites and obscure markings 


23 ft. 


Fine-grained, light-greenish shales 


Obscure markings 


1ft. 


Sandstones and coarse shales 


Cordaites (two sp.) and Fecopteris 


26 ft. 


" Plant Bed No. 8." 3 Fine -grained, 
tough but fissile sandstones, rather 
coarse shales, often of a greenish 
cast, and, at the top, a thin layer 
of very black shale, very rich in 
plants— the lower portion filled 
with remains of plants like the 
leaves of an herbarium 


€ordaites (three sp.), AsterophyU 
lites, Annularia, Pinnularia, Ly- 
copodites, Cyclopteris (two sp.), 
]S europteris^ Hymenophyllites, Fe- 
copteris (two sp.), Cardiocarpon 
(three sp), and several other un- 
determined plants. Insects : Ho- 
mothetus fossilis, Dyscritus vetus- 
tus, and Lithentomum Earttii 


1ft. 10 in. 



" A short account of these discoveries of Insect remains in North America was 
given by Principal Dawson, LL.D., F.R.S., with some figures of the same in Vol. IV. 
of the Geological Magazine, September, 1867, p. 385. 

2 See Bailey's Observations on the Geology of Southern New Brunswick. Appendix 
A, pp. 131-141, 8vo., Frederickton, 1865. 

3 The highest in the series. I have reversed the order followed by Mr. Hartt. 



Scudder — Fossil Insects of North America. 



173 



Compact sandstone and coarse shales 


No fossils 1 3 ft. 


♦• Plant Bed No. 7." Shales, variable 
in character, generally grey and 
compact, but sometimes light- 
brownish or even black, fissile, 
and soft 


Very rich in plants : Cordaitts, Ca- 
lamites (two sp.), Asterophi/llites, 
Annularia, Tinnularia, Psilophy- 
ton, Neuropteris, Cyclopteris, Sphe- 
nopteris, Hymenophyllites, Cardio- 
carpon (three sp.), Aletkopteris, 
and Pecopteris (three sp.). In- 
sects : Platephemera antiqua 


2 ft. 


Sandstone and coarse shales 


Abundance of plant-remains, prin- 
cipally Cordaites and Calamites 


5 ft. 


"Plant Bed No. 6." {a) Coarse 
shale of a greenish -grey colour; 
[b) soft, very friable shale ; (J) 
coarse shale ; (d) fine-grained and 
light- coloured shale 


{a) Pecopteris (two sp.), CordaiteSy 
Calamites^ Neuropteris, Cardiocar- 

pon (two sp.) ; {b) few fossils ; 
(c) Cordaites, and stems of plants ; 
{d) Cordaites and Calamites 


2 ft. 


Compact flaggy sandstones and 
coarse shales 


Few plants 


8 ft. 


"Plant Bed No. 5." Soft, fine- 
grained, light-greenish shale 


Cordaites, Calamites, Psilophyton, 
Asterophyllites, Pecopteris (two 
sp.), Sphenopteris, Hymenophyl- 
lites and Neuropteris — also Spi- 
rorbis 


6 in. 


Sandstone 


Obscure markings 


gift. 


" Plant Bed No. 4." Coarse shales 


Cordaites, Calamites, Neuropteris 
(two sp.), Psilophyton, Pinnu- 
laria, Cardiocarpon, and other 
undetermined forms 


1ft. 


Sandstone and coarse shales 


Badly preserved remains 


ISf ft. 


Light-greenish, coarse shales 


Fern-stems, Cordaites, and obscure 
markings. {Carpolithes ?) 


7 in. 


Sandstone and coarse shales 


Obscure markings 


5 ft. 10 in. 


Sandstone and shales 


Calamites and Cordaitet 


9 in. 


Sandstones 


No fossils 


4 ft. 10 in. 


Shales 


Obscure remains of plants 


2^ in. 


Sandstones 




2ift. 


Soft shale and fissile sandstone 


Calamites 


3^ in. 


Coarse sandstone 


Sternbergice and Calamites 

Calamites (two sp.),Asterophyllifes, 
Annularia, Pinnularia, Psilophy- 
ton (two sp.), Cordaites, Cyclop- 
teris, Neuropteris, Sphenopteris 
(two sp.), Pecopteris, and Cardio- 
carpon (two sp.) 


6ift. 


"Plant Bed No. 3." Black and 
lead - coloured shales, compact 
above, crumbling below, traversed 
by thin quartz veins 


10 in. 



174 



Scudder — Fossil Insects of North America. 



Compact, flaggy sandstone 


No fossils 


6 ft. 10 in. 


" Plant Bed No. 2." Shales, variable 
in character, sometimes very com- 
pact and hard, light-lead coloured, 
slate-like and arenaceous; at other 
times very soft and fissile and of 
a very black colour 


Calamites (two sp.), Asterophyllites 
(four sp.), Annularia, Finnularia, 
Fsilophyton (two sp.), Cordaites^ 
Cyclopteris (three sp.), Neurop- 
teris (three sp.), Splienopteris (five 
sp.), Eymenophyllites (three sp.), 
Fecopteris (two sp.), Trichoma- 
nites, Cardiocarpon (two sp.), and 
Trtgonocarpon ; also Eurypterus, 
Amphipeltis, Trilobita, and Spi- 
rorbis. Insects : Gerephemera 
simplex and Xenoneur a antiquorum 


1ft. 


Very soft, dark, lead-coloured shales 


Fragments of plants 

Remains of T^lants— Calamites, etc. 


4 ft. 


Compact, flaggy, grey sandstone 


2 ft. 


Black, arenaceous shales 


No fossils 


11 in. 


Grey sandstones and flags 


Calamites, Cordaites, Asterophyl- 
lites, and SternbergicB 


21 ft. 


"Plant Bed No. 1." Black, arena- 
ceous shales, varying from a fissile 
sandstone to a semi-papyraceous 
shale, very fine-grained and very 
fissile 


Rich in plants. Calamites, Astero- 
phyllites, (four sp.), Sphenophyl- 
lum, Fecopteris, Sphenopteris, Car- 
diocarpon, and Fsilophyton. 


1ft. 



These sandstones and shales rest immediately upon another series 
of rocks consisting of heavy beds of grey Sandstones and flags, esti- 
mated to be 300 feet thick. 

This latter series of rocks has been termed ''Dadoxylon Sandstone," 
while the former series — represented by the section — belongs to the 
" Cordaite Shales" of the provincial geologists. Together, they form 
the little river group of Matthew^ or Nos. 2 and 3 of the Series given 
by Dr. Dawson in his paper on Devonian plants.^ In other parts of 
New Brunswick, these rocks are of much greater importance, the 
Dado xy Ion Sandstones attaining a thickness of 2,800 feet, and the 
Cordaite shales of 2,400 feet, together with the Mispeck group, 
which overlies them, and the Bloomsbury group, upon which they 
rest, they constitute the upper portion of the Devonian formation. 
The appearance of insects on our globe is thus carried back a whole 
geological epoch, and is made synchronous with that of land plants. 

Fortunately no substantial doubt rests upon the declared age of 
these rocks. Dr. Geinitz, indeed, believes them to be Carboniferous,^ 
but he has based his opinion upon an examination of a single speci- 
men of one of the insects which I showed him ; this was accompanied 
by a fern which he considered CyatMtes plumosus Artis, and which is 
characteristic of the Carboniferous formation. 

If, however, Dr. Geinitz's determination of this species were cer- 
tainly correct, it would not invalidate the statements of geologists 

^ Can. Nat. vol. viii., p. 244. 2 Quart. Journ. Geol. Soc. Lond., vol. xviii., p. 303. 
3 Sitzungsb. der Naturh. Gesellsch. Isis. Dresden, 1866 : 22. 



Scudder — Fossil Insects of North America. 175 

who refer this deposit to the Devonian, for several species of plants 
are stated to be common to this formation and to the Carboniferous. 

In evidence of the Devonian age of the fossils, we have Dr. 
Dawson's admirable papers upon the plant remains of these beds, 
given in the Quarterly Journal of the Geological Society of Lon- 
don for November, 1862, and November, 1863. The rocks are 
referred by that distinguished authority to the Chemung and 
Portage group of the New York geologists. Furthermore, the 
group of rocks to which this plant-bearing series of shales belongs, 
underlies unconformably beds whose Lower Carboniferous age is 
unquestionable. The Cordaite shales of Lancaster rest directly and 
conformably upon the Dadoxylon Sandstone,^ but as the shales are the 
highest members of the series of rocks lying on the westerly side of 
Courtney Bay, we must cross to the eastward to discover the super- 
incumbent formations. 

The Dadoxylon Sandstone is composed of rocks, easily traceable 
throughout the province by their uniformity.^ The overlying 
Cordaite shales are usually rich in metalliferous deposits, and have 
been very carefully explored : upon them rest conformably, more 
than 1800 feet of rocks, described by Dr. Dawson^ as •' dark red 
and greenish shales ; flaggy sandstone sand grits ; coarse angular 
conglomerate." They are called the Mispeck group, and considered 
the uppermost member of the Devonian series. Now these latter 
rocks are covered unconformably by conglomerates, which form the 
very base of the Carboniferous formation.^ Special instances may 
be cited in the neighbourhood of Eed Head^ and at Martin's Head® 

Great interest attaches to the insects themselves : six specimens 
in all,'' each differing from the others, were discovered by Mr. Hartt. 
They are all Neuroptera. 

Gerephemera simplex is represented by a slight fragment on the 
tip of a wing ; the wing must have been large and broad ; the veins, 
distant, weak, and simple. It is apparently a member of the family 
of Ephemerina. 

Platephemera antiqua belongs to the same family, although its 
neuration is quite peculiar, and I have never seen in a Ephemerid 
so much reticulation in the anal area; the intercalary nervules, 
which, in Ephemerina, generally originate independently, arise here 
from a bent cross-vein, much as in Odonata. It is a gigantic species, 

1 Hartt, in Bailey's Geology of Southern New Brunswick, p. 134. 

3 Bailey. Geology of Southern New Brunswick, p. 55. 

3 Quart. Journ. Geol. Soc. Lond., 1862, p. 302. 

* Bailey. Geology of Southern New Brunswick, pp. 77 and 80. Dawson. Quart. 
Journ. Geol. Soc, Lond., 1865, p. 98. 

5 Quart. Journ. Geol. Soc, Lond., 1862, p. 302. 

« Bailey. Geology of Southern New Brunswick, p. 96. I have been particular 
in my references to authorities, because if the determination of these rocks prove 
correct, a whole class of animals, hitherto known as early as the Carboniferous, are 
referred at once to a previous epoch. 

' A brief notice of these remains was given in Professor Bailey's Geology of 
Southern New Brunswick, published in 1865, and short descriptions and figures have 
been furnished to Dr. Dawson for the new edition of his Acadian Geology. See also 
Sill. Amer. Journ. Sc. and Arts [2] xliv., p. 116: and Geol. Mag., 1867, Vol. IV., 
p. 385, PL XVII. 



176 Scudder — Fossil Insects of North America, 

which must have measured five inches in expanse of wings ; the 
fragment belongs to an upper wing, embracing all but the base and 
a slight portion of the tip. 

Dyscritus vetustus is represented by a very small fragment, 
broken probably from the middle of a wing, near the base, or 
not far from the division of the middle and anal areas ; but, while 
its characters are clear enough to distinguish it with certainty from 
the other specimens, it is impossible to determine either the ap- 
proximate size of the insect or the family to which it belongs. 

LiTHENTOMUM Harttii was the first specimen discovered by Mr. 
Hartt. It is a fragment from the central portion of the wing, giving 
the extension of the principal veins towards the base and along the 
costal border. Apparently, it does not belong to any family of 
Neuroptera represented among living forms, but agrees more closely 
with Hemeristina, a family which I founded upon a fossil insect 
discovered in Illinois, and of which I shall shortly speak. It differs 
from Hemeristina both in the mode of division of the nervures and 
in the peculiar cross-veining of the wing, and probably comes 
between that family and the Sialina. 1 think that the fragment is 
a piece of the lower wing, and that the insect, when expanded, 
probably measured about three and a half inches. 

HoMOTHETUS FOSSiLis is represented by the greater portion of the 
upper wing ; although it is in a mutilated condition we can determine 
the extent and character of every principal nervure. At first sight, 
it seems to be an abnoimal member of the Sialina, but, in reality, 
it is the representative of another new family, synthetic in nature, 
combining features of the Odonata and Sialina. These latter families 
are members each of different groups, and are thought by some 
naturalists to belong to different orders. The feature which bears 
the strongest resemblance to the Odonata, and which, in fact, has 
never been noticed in any other family, is a heavy cross-vein near 
the base of the wing, between the two principal middle nervures, 
from which cross-vein new prominent veins take their rise. 

Xenoneura antiquorum is the last, and perhaps the most interest- 
ing, of all these fossils. It is the basal fragment of a wing, smaller 
than those which we have mentioned, expanding probably about two 
inches ; the neuration is peculiar throughout, so that, like the two 
preceding specimens, it must represent a new family of Neuroptera. 
The most striking peculiarity is the development of apparently inde- 
pendent veinlets, forming portions of concentric rings at the base of 
the wings. There is nothing analogous to it among living Neuroptera, 
and I can only compare it to the stridulating organ of some male 
saltatorial Orthopteron. Is it possible that this insect was a member 
of a group forming a synthetic type between OrthopterasmdNeuropteraf 
The Carboniferous formation has yielded several localities of fossil 
insects in America. 

One of these insects was described and figured by Professor Leo 
Lesquereux^ under the name of Blattina venusta. It is the upper 

1 Owen's Second Report of a Geological Reconnoissance of the Middle and Southern 
Counties of Arkansas, p. 314, pi. v., fig. 11., 8vo. Philadelphia, 1860. 



Scudder — Fossil Insects of North America. 



177 



wing of a cockroach, and was found in the Coal Measures of Frog 
Bayou, Arkansas, The fo lowing section, which I owe to the favour 
of M. Lesquereux, will give an idea of its stratigraphical position : — 



Millstone Grit 


200-300 ft. 


Shale with Cordaites and wing of insect 


2 ft. 


Frog Bayou Coal 


2 ft. 


Sandstone with Sigillaria Siigmaria, etc. 


12 ft. 


1st Archimedes Limestone 


30 ft. 


Sub-Carhoniferous Sandstone 


30 ft. . 


2nd Archimedes Limestone 

1 


20 ft. 



An upper wing, quite similar to the foregoing in general appear- 
ance, was recently discovered by Mr. James Barnes in the coal 
measures of Pictou, Nova Scotia. It differs from Blattina venusta in 
the curve of the costal border — affecting the direction of nearly every 
vein in the wing — as well as in the extent and direction of the 
mediastinal vein and in the distribution of the veins in the anal area. 
Nor does it agree even generically, so far as I can determine, with 
any of the fossil cockroaches enumerated by Giebel in his Fauna der 
Vorwelt, so that I have considered it the type of a new genus. 
Through the favour of Dr. Dawson, I have been permitted to examine 
this fossil. It will be described and figured under the name of 
Archimulacris aoadicus in the forthcoming edition of his Arcadian 
Geology. 

Several years ago, a wing — possibly of the same species — was 
found at the Joggins, Nova Scotia, by Professor Marsh, of New 
Haven. According to his recollection, it was similar in appearance 
to Lesquereux's Blattina, but it was packed away at the time of its 
collection, and has never since been examined. 

Mr. Barnes has discovered another wing of very great interest ; it 
was obtained in the Coal-measures at Schooner Pond, Cape Breton, 
on Boss's Lease, two feet above a seam of coal. Dr. Dawson kindly 
sent me a photograph of the wing; it will be described in his 
Arcadian Geology under the name of Haplophlebium Barnesii. 
The wing is quite well preserved, although the base is not present 
and a portion of the apex is concealed by a fern leaf ; it is very long 
and narrow, giving an expansion to the insect of fully seven inches. 
The extreme simplicity of the neuration probably places this insect 
among the EpJiemerina, although the form of the wing, and the reti- 
culation which appears vaguely on the photograph, recall the 
Odonata ; other features of the wing resemble the Odonata, and it is 
not impossible that Haplophlebium forms a synthetic type, combining 
essential characters of Odonata and EpTiemerina. 

3 See also Sill. Amer. Journ. Sc. and Arts. [2], xliv., p. 116. 

(To he concluded in our next.) 



178 



Tute — Natural Pits near Ripon. 



VI. — On certain Natural Pits in the Neighbourhood of Kipon. 
By the Rev. J. S. Tute. 

NEAE the city of Eipon, on both sides the river Ure, but more 
jDarticularly on the eastern side, there are a great number of 
natural pits, probably fifty or sixty, the origin of which appears 
to be very obscure. 

They chiefly occur in groups of two, three, or four, in the lowest 
beds of the New Ked Sandstone, and the overlying drift-gravel ; 
but there are some also in the Magnesian Limestone. Their general 
form is crater-like, with a diameter of 40 to 100 feet, the sides 
having a slope of about 30°. But, in one instance (marked c on 
the plan), the pit consists of a perpendicular shaft about 30 feet 
in width and 60 in depth, cut through the New Ked Sandstone. 
Here the gravel bed is very thin. In another, close to this one, the 
crater-like hollow terminates in a sandstone shaft, which is nearly 
filled with water. In a third, a, the sides of the pit, which occurs 
in the Magnesian Limestone, are perpendicular on one side, but 
slope gradually down to the bottom on the other. The limestone 
is thinly-bedded, and in small slabs, dipping evenly to the east, 
about 5^. 

Plan Exhibiting the Localities of the Principal Pits. 

The crater-like form of these 
pits is evidently due to the fall- 
ing in of the sides when a pit 
has occurred beneath the gravel ; 
though in what manner the pits 
themselves have been formed 
is very difficult to understand. 
That they are due in some way 
to the action of water is pro- 
bable, as they seldom, if ever, 
occur more than half a mile 
from the river ; and several of 
them now contain water. The 
Magnesian Limestone in the 
neighbourhood is full of cracks, 
and swallow-holes, and subter- 
ranean passages. If any of the 
overlying rock gave way, this 
would produce rather irregular 
subsidences, than such regu- 
The structure of the New Ked 



N. E. Ry. 



R. Ure 




Sharrow 



RIPON 



N. E. Ry. R. Ure. 
Scale— \ inch to a miie. 

larly formed pits as these are. 



Sandstone will be understood best from the following copy of a 
well-sinker's report of a well sunk 28J yards deep, very near to 
the pit marked d : — 

" After cutting through the soil, which is not very thick, a soft 
sandy red rock, 10 feet thick, was penetrated, and then a layer of 
soft marly clay, about 10 inches thick. These clay layers occur 



Tute — Natural Pits near Ripon, 179 

about every 10 feet of rock. The rock was much harder as the 
shaft descended, and alternated red and white. The rock is not 
laid in horizontal layers, but is what well-sinkers call Eddy-Bock ; 
and not all inclining one way, but crossing one another with great 
irregularity, and at various angles of descent." 

Three of these pits have been formed in the memory of persons 
now living. The one marked a fell in about six or seven years ago. 
A clergyman, who happened to be near at the time, told me that he 
was standing by the river side with some boys watching two men, 
who were fishing, when they heard a noise like thunder ; and looking 
round in the direction of the noise, they saw a mass of earth and 
stones rising into the air, and then falling down again. One of the 
men went near, and found that the rock had fallen in, and a pit had 
been formed about 30 feet in depth, at the bottom of which there 
was a quantity of water in a state of ebullition. The water con- 
tinued in this agitated state during the following day, and afterwards 
gradually sunk. At present the pit is dry, and partially filled up 
by the falling in of one side. 

Another pit, 6, fell in about twenty-two years ago with a con- 
siderable noise, alarming the inmates of a neighbouring house, 
from which it is only separated by a road, but otherwise doing no 
harm. It is crater-like, having occurred beneath the gravel, and is 
now planted as an orchard. The pit marked c, mentioned above, 
fell in about forty years ago. It contains water, but in dry seasons 
this is nearly all drained away, and the rock is laid bare at the 
bottom. 

These pits are also of frequent occurrence in the parish of Hutton 
Conyers ; there are several in Sharrow, and one in Bishop Monkton, 
three miles south of Eipon, which was formed between thirty and 
forty years ago, near the Old HaU. Some men had been engaged 
in making a stack, and had left it for some purpose, when suddenly 
the ground gave way beneath the stack, and it disappeared. The 
place still exists, a receptacle for rubbish. 

Perhaps some of the readers of the Geological Magazine will 
be able throw a little light upon the manner in which these singular 
pits have been probably formed. 



JiTOTZCES oip :IyE:E3^0Iz^s. 



On Leskia Mibabilis (Gray). By Prof. S. Loven. 

Comnmnicated by Dr. Christian Liitken, Assistant Zoologist in the Museum of 
the University, Copenhagen. 

THIS little paper, inserted in the "Proceedings of the Eoyal 
Swedish Academy" for 1867, well deserves the attention of 
palseontologists, though its principal aim is to re-describe a little- 
known recent Sea-Urchin from the Eastern Seas, because this animal 
throws a peculiar light on certain important points in the morphology 
of Cystidea. It is, moreover, distinguished by all the ingenuity. 



180 Notices of Memoirs — By Dr, C. Lutken. 

accuracy, and profound knowledge which is peculiar to the works of 
the celebrated Scandinavian zoologist. 

The genus Leslcia is described, in 1851, by Dr. J. E. Gray, in the 
''Annals," and subsequently, in 1855, in the "Catalogue of Recent 
Echinida," from specimens from Lugard, in Mr. Cummings' collec- 
tion. It is most intimately allied to the Spatangidce, of which it has the 
general stamp, but is distinguished from them, and therefore the type 
of a peculiar family (Lesldadce Gray) or tribe {Falceostomata Loven) 
by the peristome and periproct being closed up with a few "trian- 
gular converging valves," those of the vent with some small "spicula" 
in the centre. Dr. Gray has already remarked that " in the form of the 
mouth and vent it has considerable affinity with the fossil Cystidea, 
especially the genus Echinosphcerites.'^ The detailed description given 
by Prof. Loven quite confirms this remarkable combination of fea- 
tures ; the characters assigned to the " Palceostomata'' are as follows : 
testa oviformis, peristomium non lahiatum, pentagonum, (squilaterale, ore 
qmnqueralis, anus intra periprostium centralis, valvis clansur quinque- 
octo ; apertvrce genitales hince ; semita unica peripetala.'^ Leskia is a 
true Spatangoid, save the mouth and the vent; the latter, instead of 
being surrounded by a threefold circle of minute plates, the greater 
and outermost, has only 5, 7, or 8 great triangular outer plates, and 
an equal number of minute inner papillee. The peristome is not 
bilabiate with a prominent under -lip, nor is it formed principally by 
the ambulacral plates ; it is pentagonal, and bordered almost exclu- 
sively by the interambulacralia ; there is no buccal membrane covered 
with three to five series of irregular plates, decreasing inwards, but 
the mouth is closed up by five equal triangular plates, inserted on 
the five sides of the peristome. "No living Echinid has such a 
mouth ;" but the author thinks that the genus Toxaster of the " Neo- 
cromien Inferieur," whose peristome was pentangular, not labiate 
might possibly — though the configuration of its mouth somewhat 
more approaches to that of the true Spatangidm — have had a similar 
organization. 

In the Silurian Cystidea again, we find precisely the same structure 
as in the recent East Indian Sea-urchin, viz., in the commonly so- 
termed "ovarian pyramid," which, after the opinions of Gyllenhal, 
Wallenberg, Pander, Hisinger, de Koninck, and Billings, is really the 
mouth, whilst von Buch, with some inconsequence, makes it the mouth 
of Caryocrinus, but the genital outlet in the other Cystidea, and Joh. 
Miiller and Volborth sought the mouth in the centre of the converg- 
ing ambulacral furrows. The remarkable observations on Sphceronites 
pomum and Echinoy cheer ites aurantium, by means of which Prof. 
Loven draws the conclusion that Leshia is a Spatangoid with the 
mouth of a Cystidean, we will give with his own words. 

"Good specimens of Sphceronites pomum GylL, collected by Prof. 
Angelin, show its organization more distinctly than usual. He had 
observed that this animal had no stalk, but adhered immediately to 
rocks or other objects through a part of its lower surface, which is 
without pores, and surrounded by a ridge formed of the somewhat 
thickened, free, smooth border of the undermost plates. This sur- 



Loven — On Leskia Mirabilis. 181 

face of attachment is of a very variable form and extension in diffe- 
rent specimens, — round and but little excavated in some, oblong and 
deep in others, — depending upon the nature of the object to which 
it adhered. On the point opposite to this basal surface lies the 
apex with the ambulacral apparatus. In the middle a somewhat 
deepened area d, through which five delicate but distinct ambulacral 
furrows pass towards five arms, whose bases form a circle, which 
however is broken at i, one-fifth of its circumference. Where 
the furrows reach the arms, they will be seen to pass into an oblong 
hole e, which is the lumen of the broken furrow of the lost arm ; 
in every remaining arm-base you will see an indication of the 
branching of the arms and of the central channels of the branches. 
Close up to the ambulacral circle lies the '' pyramid" or mouth a, 
closed by its five valves of unequal dimensions, two of them are 
emarginate on one side in order to give space to the two adjoining 
outermost arms, which are less than the others, and, as it were, 
crippled, the right by its vicinity to an oral valve, the left by an 
apparatus h, that cannot be interpreted otherwise than as an ex- 
ternal genital organ. When it is tolerably well preserved, it is 
conical, with a rounded apex, without any terminal aperture ; for 
vestiges of valves I have sought in vain, but in two specimens I 
found the two pores indicated in the figure. From this organ a 
ridge c runs towards the next arm, suggesting the idea of the possi- 
ble existence of a '' madreporite." The centre of the brachial appa- 
ratus forms with the genital organ, and the oral orifice a compressed 
but only slightly inequilateral triangle. In EchinosphcBrites auran- 
tium the relative position of these parts is the same, but the triangle, 
which they form with each other, is much larger, longer, and more 
inequilateral, because the distances are greater, especially that of the 
mouth from the ambulacral apparatus, which is correctly described 
and delineated by Volborth and Joh. MuUer. Close to this is seen 
the other " orifice," viz., the external genital organ. All specimens 
that I have examined have this so-termed "orifice" in such a con- 
dition that it most likely is the remnant of a prominent broken part, 
and it must be assumed that in this species also it had a conical 
form, but remained mainly in the surrounding stone-matrix. Vol- 
borth's figm-e (Ueber die Eussischen Sphasroniten, x. ix. f. 9) appears 
to be correct, but gives no complete evidence as to the presence of 
the three valves." That the "pyramid," which in Leskia is the 
armature and covering of the mouth, is the same thing in Cystidea, 
is now quite certain ; in the last-named group it was, doubtless, also 
the vent. The mouth does not lie where J. Miiller and Volborth 
sought for it, viz., in the centre of the ambulacral furrows ; and the 
organ, interpreted as the vent by Volborth and von Buch, is more 
correctly regarded as an external sexual organ." 

It is not my intention to criticise the various interpretations 
of the morphology of Cystidea given by different authors, or 
to trespass on the space here allowed me by a detailed examina- 
tion of aU the questions entangled with them. But should I 
venture to express any humble opinion of my own on this important 



182 Notices of Memoirs — By Dr, C. Liitken. 

point in the morphology of Echinodermata, I must first confess that 
hitherto I have been very sceptical as to the theory advocated so very 
ingeniously by Mr. Billings and now upheld by Mr. Loven. The con- 
cordance between these two authorities is nevertheless not so great 
as would be supposed — that the ''pyramid" was the mouth of the 
Cystidea, and that this orifice accordingly would lie elsewhere than 
in the centre of the ambulacral system, where it lies in all living 
Echinoderms and (I may add, where it did lie, I have no doubt, also 
in the Palaeozoic Crinoids, where no superficial ambulacral channels 
are to be seen, but where they pursued their way on the inferior 
surface of the "vault" through the "ambulacral orifices" at the 
base of the arms, — as shown by Mr. Billings, with whose re- 
searches [see Decades Geol. Survey of Canada] I was, I regret, un- 
acquainted when I wrote my paper on Pentacrinus, etc.) I 
know no other exception to this rule, and would it not be a 
dangerous thing — not be done without very strong arguments — 
to give up the leading principle of Palaeontology, viz., that only from 
the organization of the living form can we learn to understand that of 
the extinct? Might we not thus too often run the risk of giving 
up ourselves to the delusions of fancy. When we remember how 
minute and concealed the mouth often is in recent Crinoids, we 
should not be puzzled at its being almost or quite invisible in fossils; 
and if we should search for the interpretation of an orifice, closed by 
a definite low number of triangular valves, will not several recent 
Bchinidce {Echinocidaris, Echinometra arhacia ; Leshta itself,) give 
us the answer, that such an aperture could (at least) be a vent ? Nor 
can I well conceive that an aperture should altogether fail to exist in 
the centre of the ambulacral system of Cystidea. How otherwise could 
the ambulacral vessels communicate with the interior ? And if such 
an orifice must be assumed (though it be often obliterated and hidden 
in the fossils), why should not this "apical" or "ambulacral 
orifice" be also the mouth as in Asteridce and recent Crinoids, and 
the valvular orifice be the vent, analogous to the "proboscis" of the 
Palaeolithic Crinoids^ or the "oral tube" of the living? The supe- 
riority of size of the presumed mouth is not, as Mr. Billings thinks, 
a very good argument. Has not the oral tube in many of our 
recent Crinoids {Anteden, Actinometra, Pentacrinus) the same pre- 
ponderance over the minute buccal orifice ? Nor has the repeated 
revision of the published descriptions of other Cystidea, accessible to 
me, convinced me of the correctness of a theory, according to which 
the mouth would, in many instances, lie very far from the arms, 
sometimes nearer to the base (the stalk or point of attachment) than 
to the apex of the calyx. The argument deduced in later times from 
the presumed existence of five similar peristomatic valves in the 
recent Pentacrini, I have elsewhere had the opportunity of refuting^; 
no such hard "clapets" are to be seen in P. Miilleri, and until their 

1 The analogy between the valvular aperture of Caryocrinus and the " proboscis" of 
Crinoids is also argued by Mr. Billings (Dec. No. p. 1 4. 

' Ora Vestindiens Peutacinen, p. 205 (Vidempel. Meddel. f. d. Naturhist Foreninff, 
1864). 



Loven — On Leskia Mirabilis, 



183 




Fig. 1. 




©, 



,® e©!^G 




Fig. 3. 





Fig. 4. 



Fig. 5. 



Fig. 1. Mouth, and adjoining parts of Leskia mirahilis, Gray. Fig. 2. Vent of the 
same. Figs. 3. and 4. The mouth of EcMnosphcerites auranimm, Gyll Fiff 5 
The apex of Sph^ronites pomum, Gyll. (« ) The mouth, {b.) The genital prScess". 
(c.) Its ndge (^.) The ambulacral area with its furrows. (..) The lumen of the 
furrows, ff.) The base of the five arms. 



184 Notices of Memoirs — By Prof. C. H. Hitchcock, 

existence is proved in other recent Pentacrini, I must doubt, or rather 
deny, their existence at all ! ^ On the other hand, I must confess that 
matters are considerably altered by these highly valuable investiga- 
tions of Prof. Loven, who, for the first time, supports this theory with 
strong (perhaps convincing) arguments. It is now no longer a mere 
hypothetical supposition — hitherto it was in reality no more — but a 
real scientific explanation, borne out by well-established facts and 
imdeniable analogies from living forms.^ To Dr. Gray we certainly 
owe the first intimation of this analogy between Leskia and Cystidea, 
but while the knowledge of that genus rested on a single examination, 
there might still linger some doubt whether its importance in this 
respect had not possibly been overrated. Science, therefore, must 
be highly indebted to Prof. Loven for his small but valuable memoir, 
and for the excellent observations laid down in it. The absolute 
denying of the existence of an apical orifice in that place where, in 
other Cystidea at least, such an orifice was always believed to 
exist, is particularly recommended to the attention of future 
investigators of Cystidea, as bearing upon the very heart of the 
question. Adhuc sub judice lissit ! 

[Note. — For a very able account of the internal structure and 
passages in Actinocrinus, Amphoracrinus, CyatJiocrinus, Bhodocrinus, 
Pentremites, and Codonaster, see Memoir, by John Eofe, Esq., F.G.S., 
in Geol. Mag., Vol. II. p. 245, Plate VIII. 1865.]— H. W. 



New American Fossil Fish from the Devonian. 

{Communicated by Professor C. H. Hitchcock, of Lafayette College, Geologist to 
the State of Maine, etc.) 

AT the late meeting of the American Association for the Advance- 
ment of Science, Professor J. S. Newberry, LL.D., described 
a new genus of fossil fishes. The specimens were obtained 'from 
the Devonian Black shales of Delaware, Ohio, by the Kev. H. 
Herzer, and named Dinichthys Herzeri, inasmuch as the animal 
deserved the same distinction among fishes as the Dinotherium and 
Dinornis among mammals and birds. Most of the bones obtained 
belong to the head, which was over three feet long by one and a half 
broad, and wonderfully strong and massive. All parts of the head 
were represented, and there were several individuals among the 
specimens. The cranium is composed of a number of plates firmly 
anchylosed together, and strengthened near the occiput by internal 
ribs or ridges nearly as large as one's arm. The external surface is 
covered with a very fine vermicular ornamentation. The most 

^ Prof. Loven told me himself that during his last stay in Paris he succeeded in 
getting access to the original specimen of Mr. Dushascaing, in the collection of the 
late Mr. Michelin. It did not show the five valves, because it had no peristome at all ! 

2 To these analogies might be added, that between the valves of C^stideee SLud those 
of the young (larval) Antedon. 



Newberry — On a new Devonian Fish, 



185 



marked peculiarity in the anatomical structure relates to the form 
and texture of the jaws and teeth, best understood by the annexed 
figures. 




Fip. 1. Anterior aspect of head of Dinichthys Herzeri, one-eighth nat. size. 




Fig. 2. Mandible of Dinichthys Herzeri, one-eighth nat. size. 

The head terminated anteriorly and above in two great incisors, 
representing the premaxillarj'-, behind which on either side are 
the maxillaries, broad, flattened, dense bones, along the lower 
edge of which is set one row of small robust teeth, formed by the 
consolidation and prolongation of the jaw-tissue. The mandibles are 
over two feet long by six inches deep, laterally flattened and very 
massive. The anterior extremity was turned up in a huge triangular 
tooth composed of dense ivory-like tissue, which locked in with 
the divergent incisors of the upper jaw. Behind this, in some 
specimens, is another triangular summit, and posterior to it a 
row of small teeth, corresponding with those of the maxillaries. 
Such was the power of this tremendous dental apparatus, that the 
bodies of our largest living fishes would be instantly pierced and 
crushed by it, if exposed to its action. Behind the head are large 
thick plates, one of them corresponding to the os medium dorsi of 
the Heterosteus of Pander, and being at least of equal size. These 
bones occur exclusively in concretions. 



VOL. V. — NO. XLIVJ. 



13 



186 Notices of Memoirs — By Prof. C. H. Hitchcock, 

III — .New Carboniferous Keptiles and Fishes from Ohio, 
Kentucky, and Illinois. 

(Communicated by Professor C. H. Hitchcock, of Lafayette College ; Geologist to 
to the State of Maine, etc.) 

AT the late meeting of the American Association for the advance- 
ment of Science, Professor J. S. Newberry exhibited and 
described specimens of reptiles and fishes from the Cannel 
stratum beneath the principal coal bed at Linton, Ohio ; fishes 
from the Coal Measures of Illinois, collected by the State Geologist; 
and fishes from bituminous shale in the Waverly group, 125 feet 
above its base at Vanceburg, Ky., collected by Dr. Patterson. Of 
these the first series included Banicejos Lyelli, Wyman, and others 
undescribed, partly related to Prof. Huxley's new genera Ophider- 
peton and Urocordylus. Twenty species of fish accompanied these 
reptiles, among which are eight species of Eurylepis, Newb., small 
Lepidoids allied to Palceoniscus, distinguished by having the scales 
of the sides much broader than long. The scales on several of the 
species are very highly ornamented. These specimens were gilded 
by iron pyrites. Some specimens of CoelacantJius — two species — 
indicated the presence of a supplementary caudal fin, as in Undina. 

This is an interesting fact, confirmatory of Huxley's view of the 
relations of Undina, Macropoma, and Coel acanthus. The numerous 
and very complete specimens of CoelacantJius, exhibited supply much 
that was wanting to a perfect knowledge of the anatomy of the genus. 
The bones of the head are similar in form to those oi Macropoma, highly 
ornamented with tubercles above and thread-like lines below. The 
jugular plates are double, and oblong-elliptical in outline, as in 
Undina and Macropoma. The position and form of the fins is the 
same as in Undina, but the anterior dorsal is stronger. The fins 
are supported on palmated interspinous bones, similar to those of 
the other genera of the family. The paired fins are slightly lobed ; 
the supplemental caudal has been referred to. The scales are orna- 
mented with curved and converging raised lines. In many specimens 
the otolites are distinctly visible. 

Besides the fishes found at Linton already enumerated, there are 
scales and teeth of two species of Rhizodus — one at least of which 
(jB. angustus) has teeth of two forms, the one large and flattened, the 
other smaller, more numerous, slender, striated, and conical, with a 
circular section throughout : two species of Diplodns, consisting of 
bony base and enamelled crown, the latter distinctly and beautifully 
serrated — so that there can scarcely be a question that they were 
teeth, and not as claimed by Mr. Atthey, of Newcastle, England, 
to be dermal tubercles. There are also examples of Palceoniscus 
scutigerus, Newb., one species of Pygopterus, one of Megalichihys 
represented by scales, and numerous species of placoid fishes of the 
genera Compsacanthus and Pleur acanthus. 

The fish remains from Illinois consisted of a splendid specimen of 
Edestes vorax, Leidy, from the coal at Belleville, opposite St. Louis, 
and of several individuals of a new species of Platysomus from Mason 



Newberry — New Reptiles and Wishes from the Coal. 187 

Creek. The Edesies is allied to a fine specimen from Indiana, figured 
in Owen's Palcieontology, p. 124, 2nd ed.,and there properly referred 
to the spine of a Plagiostome. Platysomus has not been found in 
America before. 

The fish remains from the Waverly sandstone are from a new 
horizon, having furnished a single species in Northern Ohio, Falmo- 
niscus Brainerdi. The new specimens consist of teeth of Cladodus 
and Orodus, with spines of Ctenacanthus, and the tail of one of these 
Selachians distinctly preserved. This is a great rarity, as the soft 
and even the cartilaginous parts of plagiostomous fishes are usually 
decomposed, leaving only the detached teeth, spines, and dermal 
tubercles. The only other similar cases known to the author, are the 
tail and fins of a Chondrosteus from the Lias of Lyme Kegis, and the 
preservation of the form of Thydina in the Solenhofen slates. These 
specimens are from the base of the Carboniferous series, and therefore 
much older than the European examples. This tail is very heterocercal. 
like the caudal fin of some living sharks, and indicates an animal 
seven or eight feet long. The author hopes to be able to gather from 
this collection the data for uniting many teeth and spines, now 
described as distinct genera, into the same species. 



S,E-V"IE"W^S. 



Reoherches Geologiques dans les Parties de la Savoie, du 

PlEMONT ET DE LA SuiSSE VOISINES DU MoNT-BlANC. AveC 

un Atlas de 32 Planches. Par Alphonse Favre, Professeur de 
Geologic a I'Academie de Geneve. Paris, Victor Masson, 1867. 

THIS work, by M. Alphonse Favre, upon the geological structure 
of the mountains and valleys surrounding Mont Blanc, consists 
of three volumes, containing in all 1,488 pages, and is the result of 
the labours of a large portion of the life of a praiseworthy follower 
of his distinguished countryman de Saussure, and is a full illustration 
of his previously published remarkable Geological Map of this 
region. By exhibiting numerous features and structural details in 
sections, and other illustrations of the physical relations of the rocks, 
and by bringing to bear on them those lights of palaeontology, which 
were unknown to de Saussure, and in which his contemporaries and 
countrymen Pictet and Loriol have been so distinguished, he has 
vastly extended and improved the original sketch by his great 
master. 

Any geologist, who, leaving for the first time the shores of Lake 
Leman, Taa.j have attempted to reduce to anything approaching 
classified order the various broken rock-masses which surround Mont 
Blanc, must have found, to his discomfiture, that they were composed 
of countless fragments of difterent sorts, thus presenting a confused 
assemblage, which seemed to defy methodical arrangement. But, 
with time and patience, and through a succession of researches in 
the eastern parts of the great chain where the natural formations. 



188 Reviews — Alph, Favres Geological Researches 

particularly the older, are more expanded, and have been less 
subjected to disturbances and change, the time has now come, when 
even this, the most complicated tract of the whole chain, is to a 
great extent laid open with clearness. 

The Alps, as a whole, have only in truth been brought into a true 
geological order of succession by a long series of patient investiga- 
tions, particularly during the last forty years, as carried out by a 
number of hard-working geologists, of all countries ; and M. Favre 
has now accomplished for his portion of the chain that which Pro- 
fessor Studer has more particularly elaborated for the great central 
or Swiss masses of the range. 

In the last century the chain of Mont Blanc, with its flanks, was 
viewed as of primitive age, and this error has been dispelled by the 
successive labours of numerous explorers. Among these Brochant 
led the way in 1808 in his able work on the Tarentaise, wherein he 
showed that a great part of the supposed primary rocks were of 
Neptunian or sedimentary origin, including rocks of Carboniferous 
and Liassic age ; and, long after M. Elie de Beaumont, extending his 
excellent Geological Map of France into Savoy, showed the vast 
extension of the Liassic deposits. 

In correlating the disjecta membra of the chain of the Alps as a 
whole with their true equivalents in less disturbed regions of the 
globe, our countrymen have also played a fair part. In 1820, Buckland, 
after a summer's tour, boldly dashed off his general views as to the 
great " Alpine Limestone," representing in its range most of the 
Secondary rocks ; and though necessarily very incomplete, these 
generalisations were at the time striking evidences of the power of 
that eminent geologist. ^ 

But of all the earlier English writers on the structure of the Alps, 
no one threw so much light on the Savoyard portion of the region 
as Bakewell. In his ''Travels in the Tarentaise" (1820-22), this 
author not only instituted comparisons with known British forma- 
tions, but he clearly showed that chemical changes took place on 
a stupendous scale by the transmutation of mountain masses of 
stratified limestone into gypsum and dolomites. 

In 1827, Murchison hit off an exact definition, which remains 
correct to the present day, by showing on the southern flanks 
of the Alps, north of Bassano, the existence of a regular order of 
succession from the massive Oolitic or Jurassic rocks of the chain 
through the Cretaceous, the latter being symmetrically flanked by 
the Nummulitic and younger Tertiary deposits of the north of Italy. 

In the meantime, struggling with considerable difficulties, Boue 
had been constructing maps and descriptions of large portions 
of the Austrian Alps, which, considering the want of good geo- 
graphical materials, did that indefatigable geologist infinite credit.^ 
Sedgwick and Murchison explored together a large portion of those 
same Austrian Alps in 1829, and were so far successful, whilst dis- 
puting (not always with justice) some of the conclusions of Boue, 

^ Annals of Philosophy. 

2 Boue was the first to publish a geological" map of Scotland, anno 1820. 



In the vicinity of Mont Blanc. 189 

as to reduce to symmetrical order a large tract of the Secondary 
rocks north of and around Salzburg, and to exhibit in regular order 
the succession of the Secondary and Tertiary rocks in their eastern- 
most extremity, where the Alps die away into the plains of Styria.' 

From such efforts, and particularly from the excellent researches 
of Leopold von Buch, Boue, Studer, and others which followed, the 
true order was gradually extended to the more complicated region 
of the west, in several parts of which, wliere complicated crystal- 
line rocks — whether igneous or metamorphic — most aboimd, other 
distinguished German geologists besides von Buch had been for 
many years occupied. 

Among the French geologists, no one had more distinguished 
himself tham M. Elie de Beaumont in elaborating the effects of the 
great intrusions of granitic and other igneous rocks in the Western 
Alps, and in explaining the abnormal position into which the 
original deposits had been thrown. In the same way von Buch, 
who wandered during many a year, on foot, through all the recesses 
of the Alps, has, in his maps and writings left behind him frequent 
proofs of the effects produced by granites and porphyries upon the 
sedimentary deposits which they have invaded.'^ 

But to no school of geologists who have been working out the 
original symmetry of the Eastern Alps have we been more indebted 
of late years than to the Austrians, who have succeeded in assigning 
to some of the great central calcareous masses of the chain their 
places in the geological series much more exactly than was pre- 
viously known, and to delineate them in detailed and well finished 
maps, published under the direction of the Imperial Eoyal Geological 
Institute, presided over by its veteran leader, Haidinger.^ The 
clear proofs of the existence of the Trias, and its calcareous centre, 
the Muschelkalk, though long ago indicated by von Buch, is one 
of the great recent trophies of those Austrian geologists. 

But passing from tliis rapid glance at the methods by which a 
general acquaintance with the structure of the whole chain has been 
attained, we return to the consideration of the mountains and valleys 
around Mont Blanc. It is this region, so broken and so complicated, 
and which seemed to baffle the industry of that accurate mineralogical 
geologist, Necker de Saussure, which M. Alphonse Favre has described ; 
and his task, we are bound to say, has been accomplished in a masterly 

1 The Geological Map of the Eastern Alps (Trans. Geol. Soc. 2nd Series, vol. iii- 
p. 35) which comprised the result of these and other researches, was executed by 
Murchison after the labour of three summers. It exhibited the real order of succes- 
sion then known (1831), from the axial and oldest rocks to the secondary and tertiary 
deposits on either flank of the chain. See 2nd ser., vol. iii., pi. 35, in the Trans. Geol. 
Soc, with description thereof. See Sedgwick's explanatory preamble. 

* See particularly the Maps of the Alps published by Martin Schropp & Co., Berlin? 
which are essentially the results of the labours of von Buch. 

3 To obtain a just appreciation of the value of the labours of the Austrian 
geologists, it is only necessary to inspect the sheet (No 5) of the remarkable general 
Map of the Austrian Monarchy, by Herr k. k. Director, Dr. Franz Bitter von Hauer, 
in which the various rocks of the Tyrolese, Milanese, and Venetian Alps are defined 
by 48 distinct colours and signs. 



190 Revieivs — Alph. Favre's Geological Researches 

manner.- As it was said of de Saussure, who first grappled with the 
physical obscurities of this region, that " he was one of the men privi- 
leged by Providence to trace the road to new conquests," so we may 
say of his countryman and successor, Alphonse Favre, that in follow- 
ing his great master he has wrested from this complex region many 
important revelations unknown to his predecessors. To take one 
striking example of his successes, nothing can be more creditable to 
him than the clear and skilful explanations and diagrams with which 
he has taken a leading part in clearing up the long mooted question 
as to whether or no the fossil plants of the old Carboniferous period, 
in Haute-Maurienne, and at Petit Coeur in Savoy, lived on to the 
age of the Lias : it being now generally admitted that the strata of 
these two widely different formations, having been accidentally col- 
located, have been so twisted up by convolutions as to appear to 
belong to one and the same geological mass.^ 

On the other hand, the candour with which the author acknow- 
ledges a mistake in his earlier researches, by which he placed a 
Secondary limestone above the Nummulitic rocks, is so ingenuous, 
that we quote the passage as a valuable reminder to all working 
geologists, who well know that during their career they will have 
to acknowledge many such an error. " Mais ce qui me console (says 
he) d'etre classe parmi ceux que les terrains des Alpes ont entraine 
a faire certaines confusions, c'est la nombreuse et bonne societe dans 
laquelle je me trouve" (vol. ii. p. 33). So numerous, indeed, are 
the points of confusion, that no historian of the geological succession 
in the Alps can perform his task rightly and completely, if he has 
only viewed the complicated region so well examined by M. 
Favre. In it there do not exist any recognizable Palaeozoic rocks 
of higher antiquity than the Carboniferous ; and of these, portions only 
of clearly defined zones are to be here and there detected among the 
crystalline and metamorphic masses of the broken ridges. It is a 
region, in short, without any recognizable fundamental rocks; 
the lowest and axial masses being disguised by heat and change. 
Hence it follows that if in the Central, and particularly in the Eastern 
and Central Alps, the disarranged strata had not been reduced to 
order, and the real Palaeozoic succession recognized, the geological 
history of the whole chain would have had no true beginning. In 
other words, had it not been already shown that in those Eastern 
Alps there existed Silurian, Devonian, and Carboniferous animal 
remains, the key to a true historical succession of the whole 
chain would not have been obtained. Yet, though the work in 
question deals with the most broken and complicated poi-tion of 
the chain, the manner in which M. Favre has unravelled this record 
does him infinite credit. 

M. Favre gives also a very complete summary of every contribution 

1 See also a just and highly favourable estimate of this work as given by Professor 
Studer, in Archives des Sciences Physiques et Naturelles, No. 121, Fevrier, 1868. 

2 In the opinion of the geologists of the Geological Society of France who visited 
this tract, the views of M. Favre were fully sustained ; and the area of observation 
considerably extended.— See Bull. Geol. Soc. de France, vol. xxii. p. 59, 1864-5. 



In the vicinity of Mont Blanc, 191 

of knowledge by other authors to his favourite portion of the chain, 
from the days of de Saussure downwards ; and all those who have 
contributed their notices among this multitude of observations have 
been carefully and honourably quoted.' Among English geologists, he 
cites Murchison, as having in company with M. Pillet discovered 
true fossiliferous Upper Chalk at Thones, east of the Lake of Annecy ; 
and he gives indeed a section published in the Quarterly Journal 
of the Geological Society, ^ which our countryman dwelt upon, 
as one of the several proofs to establish the generalisation, that 
Chalk with characteristic fossils and wholly void of Nummulites 
rested on a series of the Lower Cretaceous rocks, and was re- 
gularly superposed by masses of Nummulitic Limestone ; and 
followed by •' Macigno Alpin," or "Flyscli," which he also observed 
in more eastern ranges of the chain, as well as in the Apennines. 

In parts of the region north of Mont Blanc the Secondary rocks have 
been here and there developed (particularly at Mont Saleve), and M. 
Favre disentangles their various members from the breaks and con- 
tortions to which they have been subjected, and so assigns to each 
the fossil remains by which they are recognised, that we feel we are 
following a skilful pilot through a devious labyrinth. As regards 
these Western Alps, no organic remains have been found beneath 
the Lias except numerous plants of the palasozoic Carboniferous era. 
For, although M. Favre applies the term of *' Trias" to a great thick- 
ness of crystalline and sub-crystalline rocks which lie between 
the Lias and the Carboniferous, these strata have not as yet afforded 
any of those fossils which in the Eastern Alps so clearly characterize 
the Trias with its numerous Muschelkelk remains. 

The English reader will find the divisions of the strata, from the 
upper portion above the Oolitic series (" Oolite Corallienne"), de- 
scribed under the Cretaceous divisions of Valangian, Neocomian, 
Qrgonian, or Lower Greensand, their fossils being well defined and 
figured by M. Loriol and the author. It has been long since ascer- 
tained that these Cretaceous deposits, including those of Gosau, 
which abound so greatly in the more eastern parts of the Alps, and 
are particularly distinguished by large Nerineas, Tornatellse, the 
Diceras, and shells of a Cerithium form, belong really to the Creta- 
ceous grouj), though nearly forty years ago they were at first referred 
to a supra-Cretaceous age,^ — an opinion, however, which was long ago 
abandoned. In a word, we commend this work of M. Favre as entitled 
to a place of honour in all scientific libraries, if only to show the vast 
difficulties which have been overcome in bringing great masses of 

1 In proof of the assiduous labour with which M. Favre has ransacked every scrap 
of writing respecting this Alpine region, it may be stated that, in his history of the 
Carboniferous rocks, he refers, in one long chapter thereon, to eighty authorities who 
have published on the subject ; and, of English geologists, he cites the names of 
Bakewell, Buckland, Buckman, Bunbury, De la Beche, James Forbes, "W. Hamilton, 
L. Horner, Lyell, Murchison, Playfair, &c. 

2 Vol. v., p. 186, In this work Sir R. Murchison expresses his deep obligations to 
Canon Chamouset, of Chambery, as well as to M. Pillet, for the accurate knowledge 
he obtained in company with them. 

3 See Sedgwick and Murchison, Trans. Geol. Soc. 2nd Series, vol. iii. p. 301. 



192 Reviews — Alph. Favre's Geological Researches 

such varied lithological character into anything like a regular classifi- 
cation. 

Yet, after all, the author candidly indicates how much still 
remains to be done before every mass of the Western Alps can 
be assigned with precision to its normal equivalent in the undisturbed 
regions of the world. Thus, his inferences as to the age of the supposed 
oldest stratified rock, the Protogine of Mont Blanc, are of an enquiring 
rather than a conclusive character. Many pages are, indeed, devoted to 
the development of his theoretical views of granite having been formed 
in an aqueous manner, though, in adopting this view, he admits that 
granite was a decomposed subterranean lava ; and as sub-aerial lavas 
also contain water, we do not appreciate the value of this subtle dis- 
tinction. But apart from this theory, when he states his belief, that 
granites were formed in this wise during very early or ante-palaeozoic 
eras, his hypothesis seems untenable when we consider the conflict- 
ing evidences with which this troubled region abounds, and wherein 
no true sedimentary rock, as proved by infraposition and fossils, is 
older than the Carboniferous era. It is a region, we repeat, void 
of a recognizable base, — the Laurentian, Cambrian, Silurian, and 
Devonian rocks, and even the Carboniferous limestone, having here 
no representatives with fossil animal remains ; and believing that 
the granitiform and porphyritic rocks of the Alps are, geologically 
speaking, of no high antiquity, we demur to the assumption that 
they can be connected with earlier geological times. 

If we follow the author along his mountain walks among the 
highest Alps of Maurienne and the little Saint Bernard, and see 
how he recognizes the complete overthrow of formations of great 
dimensions, in so crystalline a state, we see that the distinction 
between what used to be known as igneous and aqueous rocks is 
in many places almost evanescent. For, whether we side with him 
or not in his belief in the sedimentary origin of many of these 
quasi- stratified granitiform masses, we have before us sufficient 
proofs of disturbance to account for the grand fan-shaped arrange- 
ments and convolutions involving great overthrows, which he 
describes, to say nothing of the stupendous rents and fractures 
which abound in this tract. 

Even when he is treating of his only really recognizable funda- 
mental formation in these Western Alps, — the strata containing 
old coal plants, — we see how this formation is irregularly followed 
by distinct superincumbent secondary formations in diff'erent parts 
of the chain. Thus, the so-called ''Trias" is nowhere characterized 
as in the Eastern Alps, by possessing its true central Muschelkalk 
fossils. On the contrary, it is composed of highly schistose and 
crystalline masses with gypsum and dolomitic limestone. And, 
as if to render the confusion greater, in a vast portion of this 
western chain, particularly in the Maurienne and Savoy, even 
this equivalent of the Trias is wanting ; and the Lias and Jurassic 
rocks, with their fossils, are not only placed at once in contact with 
the Carboniferous rocks, but the two are convoluted in so many 
rapid plications, that eminent geologists have been unable to 



In the vicinity of Mont Blanc, 193 

dissever them stratigraphically. Nay, we even there see the Num- 
mulitic rocks, which in parts of the chain are clearly superimposed 
upon fossiliferous Chalk, pass under all these older rocks, whether 
Secondary or Carboniferous ! 

Now, one of the great merits of M, Favre is, that he has patiently 
and diligently followed out many of such folds and inversions in 
the heart of these mountains, and has b^n able to assign to them 
their relative places ; but still there are many lofty portions of the 
chain respecting which great uncertainty still exists as to the relative 
age of some rocks which most geologists consider to be metamorphic. 

In conclusion, we recommend the work of M. Favre as a capital 
study for those nimble climbers of the higher parts of the chain, who, 
ignoring nearly everything but the superficial accumulations of snow, 
ice, and glaciers, go aloft to catch light and shadows, air-effects, and 
cloud-views. Without such preliminary study they can have little or 
no conception of the physical and mental toil which the geologist has 
undergone in unravelling the complicated strata of which the peaked, 
the gnarled, and the rounded mountain-masses are respectively formed 
— complications, indeed, repeated in breaks, twistings, and crumplings, 
most of which were successively brought about in ages long before a 
flake of snow fell upon the rising Alps. And upon this point, 
too, the glacierist, as well as the geologist, will find in the first 
volume of M. Favre's book many excellent and original data illus- 
trative of the more recent periods at which the glaciers have shot 
off much detrital matter, and of the relations of such debris to the 
existing valleys and river-courses. 

No one can doubt that the snows and glaciers of the Alps, in 
melting and moving since the earliest glacial period, have deepened 
valleys on highly inclined planes, have lowered peaks and abraded 
surfaces of considerable magnitude. But he who, exaggerating the 
power of these comparatively recent causes, says, in his atmospheric 
and glacierist pride, that they have carved out the great valleys and 
have determined the main outlines of the chain, overlooks the 
indubitable effects of the grand subterranean forces which truly 
gave in very early ages a leading impress to the broadly marked 
features of mountain and valley — features which, however since 
modified by atmospheric agencies, have never been obliterated, and 
which are as eternal as the snows and glaciers of the Alps are, in 
a broad geological sense, casual and ephemeral.^ 

In short, the glacierist who has not worked out the evidences of 
these great subterranean changes, and reasons upon present forms 
and outlines of nature, must first learn his lesson respecting internal 
and original structures, before he can pretend to reason on this broad 
and complicated question. To all such persons we commend the 

^ It is in the first volume of the work of M. Favre, that the reader will find how 
he eliminates from each other the various superficial deposits, beginning witb what he 
calls the accumulations of the plain and the deposits of the Rhone and its leading 
affluents. He then describes the Quaternary Deposits, consisting of recent alluvium, 
terrace deposits with remains of extinct animals, glacier detritus, and still older marine 
deposits, with lignite. 



194 Reviews — Alph. Favre's Geological Researches 

study of this work of M. Favre, and its numerous illustrative 
diagrams. For he shows clearly, that the gi*eat valleys and lake 
basins are greatly due to original geological impress. Adopting this 
view, he has ably refuted the theory, that the depression of the Lake 
of Geneva could have been duo to erosion by ice, that cavity having 
been a necessary and confluent depression accompanying the great 
contiguous upheaval of the central mountains, as indicated by de 
Saussure.^ 

Nothing indeed can more strongly support the original ^^ew of that 
great man, as worked out by Favre, that the main outlines of the 
Alps are due to subterranean influence, than the following aphorism 
or law of Studer, derived from a life-long study of his native country, 
Switzerland, and which M. Favre puts in these words : — 

"Toutes les fois que les couches en forme de C ont le dos toume 
aux Alpes, les couches anciennes sont a I'exterieur et les couches 
modernes a I'interieur, et reciproquement, toutes les fois que les 
couches en forme de C ont le dos toume en dehors des Alpes, les 
couches anciennes sont a I'interieur et les couches modernes a I'ex- 
terieur." (Vol. ii.) 

The question of the greater or less permanency of the older ex- 
ternal features of the earth, as due to subterranean geological action, 
has indeed been recently brought into discussion among British 
geologists by an appeal to the stratified crystalline rocks of the 
Central and Western Highlands of Scotland by the Duke of Argyll. 
On this point, however, it may at once be observed, that no two 
regions of the earth present greater differences in lithological and 
geological structure than the Highlands of Scotland and the Alps. 
In the former, the great and central mass consists of Lower Silurian 
rocks, for the most part crystallized, and occupying highly inclined 
and convoluted positions, they rest quite unconformably on the older 
Cambrian and Laurentian rocks of the west coast, the latter having, 
indeed, an entirely divergent direction to the others.^ Now all the 
old crystalline rocks of the great central region are uncovered by any 
Secondary or Tertiary rocks, or indeed by any trace of their former 
existence ; such deposits being only known to have occurred on the 
centre and western flanks of this primeval chain. In the Western 
Alps, on the contrary, as has been shown, no recognizable Palaeozoic 
rocks exist below the Carboniferous, and these are surmounted by a 
variety of Secondary and Tertiary deposits, some of which reach to 
the highest summits, and are often in a metamorphosed and crystal- 
line state. Now, whilst the geologist has to ferret out amidst such 
varied rocks, the movements from beneath, which have given to the 
Alps their main configuration, it is the rocky simplicity of the 
Central Highlands, and the character and appearance of the ancient 
rocks there rising everywhere to the surface, which have led the 
able author of the " Reign of Law" to express his opinion, that when 
those metamorphosed and crystalline Lower Silurian rocks assumed 
their main outlines, they were in a folded, broken, hardened, and 

1 See M. Favre's letter thereon to Sir R. Murcliison, Phil. Mag., March, 1865. 

2 See Siluria, 4th Edit. Frontispiece, Map, and pp. 24, 163. 



In the vicinity of Mont Blanc. 195 

crystalline form ; and that this aboriginal outline, remaining to a 
vast extent persistent to the present day, has given and still pre- 
serves to that country the chief features of its configuration : i.e., its 
grand fiords and lakes, its main valleys, and its mountain ridges. 

This memoir was prepared to oj)pose the ingenious views of 
Mr. Archibald Geikie, in his attractive and highly popular work, the 
" Scenery of Scotland viewed in connection with Physical Geology." 
In it Mr. Geikie points out, that, as the troughs or barrier- shaped 
strata often constitute the summits of lofty mountains, and that as the 
deep valleys are often the seat of great axial lines, so it follows that 
vast masses of once intervening and connecting strata must have been 
removed by erosion. This great erosion he attributes to long-con- 
tinued atmospheric agencies during countless ages, including the 
action of glaciers, and the melting of the great sheets of snow and ice 
which during the glacial period rendered Scotland a region like the 
modern Greenland. 

But, leaving the theoretical questions of Scottish Geology to be 
worked out on their own merits, we know, as regards the Alps, that 
Studer, Favre, and indeed all those geologists from the days of de 
Saussure who have best studied the chain, are of opinion, that most 
of the deep depressions and Alpine lakes (which are either at right 
angles to, or parallel to the general direction of the rocks) are mainly 
due to former subterranean movements, though doubtlessly much 
modified in subsequent ages by atmospheric agencies, and particularly 
by the action of glaciers, snow, ice, and waters descending upon steep 
declivities. 

When, therefore, we see how the consideration of the inner struc- 
ture of the Alps has been passed over by some casual visitors, who 
seek to account for much of the main outlines of the earth by external 
agencies, and who have gone so far as even to refer to ice action the 
excavation of these deep cavities and lake basins, which to practical 
native geologists and other able and observant thinkers are 
manifestly due to older geological forces, we fall back on the ex- 
clamation of one of \)i\.Q sturdiest veterans among Alpine explorers, 
the late Leopold von Buch, who, when the extreme glacier doctrines 
were coming into fashion, and were tending to obliterrate the study 
of all that he considered to be true Geology, fell on his knees, and 
exclaimed — 

"0 sancte de Saussure, ora pro nobis!" R. I. M. 



Geological Society of London. — February 5th, 1868. — 1. " On 
the Geological Structure of Argyllshire." By His Grace the Duke 
of Argyll, K.T., D.C.L., F.R.S., F.G.S., etc. 

The object of the paper was to set forth some of the author's 
reasons for not accepting the views propounded by Mr. Geikie in 
his " Scenery of Scotland viewed in connexion with Physical 
Geology." His Grace believes that, although the atmospheric 



196 Geological Society of London. 

agencies of waste have produced great modificatioDS of the surface, 
the form of the hills and valleys has in the main been determined 
by the action of subterranean forces. 

In illustration of his opposition to Mr. Geikie's theory, he de- 
scribed a supposed case of the formation of a valley by atmospheric 
agencies, observing that, if the crumplings of the strata have not 
affected the present surface, a subsequent submergence and a fresh 
unconformable deposition filling in all the inequalities must have 
ensued, and that these new deposits must have been again raised 
along different lines of elevation. Taking this new deposit to be 
the Old Eed Sandstone, the author asks how it was removed, and 
points out difficulties in the way of supposing the removal to have 
been either by submergence or by subaeriel agencies. 

His Grace then stated that Mr. Geikie admits that the agencies 
of erosion have been guided in their work by the prevailing strike 
of the strata, which strike is followed along the same line by the 
larger faults, and by the anticlinal and synclinal axes, — at least as 
regards the general trend. He then pointed out that in reality all 
the great physical features of Scotland take the same N.E. and 
S.W. direction. He therefore considered that Mr. Geikie had 
understated the case of the coincidence of certain physical features, 
and had entirely omitted all mention of others, such as the appear- 
ances of subsidence and dislocation to be observed in the Western 
Islands, and the relations existing between dislocated sedimentary 
strata and apparently intrusive rocks. 

In supporting his argument by special facts, the Duke of Argyll 
endeavoured to show that the whole valley-system of Argyllshire 
may be accounted for either by faults, foldings, subsidences, or anti- 
clinals, mentioning in particular that Loch Tyne occupies the bed of 
an enormous fault ; that Loch Awe lies along the line of a great 
subsidence of the metamorphic slates, and that the gorge of the 
Brander Pass lies along the line of a great fracture connected with 
the subterranean movements which brought up the granites of Ben 
Cruachan ; with many other instances of a like nature, in discussing 
which he especially demurred to Mr Geikie's theory that the trans- 
verse valleys and gorges have been formed by two streams, each 
working backwards towards its own source, until the ridge which 
divided them was finally destroyed. 

His Grace also remarked that the mineral condition of the granites 
at the time of the subterranean movements was such as would facili- 
tate the transmission of earthquake waves ; and the condition of the 
slates was such as necessitated fracture when those waves were pro- 
pagated beneath them. 

In conclusion, the author contested Mr. Geikie's statement of the 
symmetry of river- valleys and uniformity of mountain heights ; and 
contrasted the philosophy of the older geologists with that of the 
advocates of subaerial denudation. 



Correspondence — Dr. P. Martin Duncan. 197 



CYGLOPHYLLUM FUNGITi:S, Flem. sp. 

Sir, — In your report of tho Meeting of the Geological Society of 
Glasgow, December 12, 1867 (Geol. Mag. Vol. V. No. 3, p. 142), I 
find that Mr. John Young is made to assert that " Dr. Duncan's 
figures reveal no new points in the structure of this coral which were 
not already known, etc., etc." Mr. Young also appears to have 
stated that David Ure was the original discoverer of the genus in 
question, and that Professor M'Coy had clearly delineated the various 
parts constituting the internal organization of the coral. To these 
statements I must give my most unqualified contradiction. 

It can be readily seen in David Ure's good old book that he 
believed the curved horn-shaped coral in question was one of the 
''class Coralloides,''^ or "sub-marine plants," and that it grew with 
its broad calicular end downwards. He called the coral Fungites, 
but gave neither a generic nor a specific name to it. 

Fleming classified the coral in the genus Turhinolia, and gave it 
the specific name fungites. All subsequent generic names should be 
followed by Fleming's specific name. 

M'Coy described the coral, and a drawing of its anatomy appeared 
with the description in Sedgwick and M'Coy, Brit. Pal. Foss. 1855, 
plate 3C, figs. 5 and 5a. He named it Clisiophyllum prolapsum. He 
was neither justified in his genus nor in his change of the specific 
name. M'Coy neither drew nor saw what is so evident in the scores 
of sections which Mr. Thomson has prepared of the species of coral in 
question. M'Coy's drawings of Clisiophyllum show a solid lamellar 
columella in the axis of the corals he properly described as belonging 
to that genus, but there is no such structure in his Clisiophyllum 
prolapsum. 

There is a columella in the Fungites of Ure, the Turhinolia fungites 
of Fleming, the Clisiophyllum prolapsum of M'Coy, — it is not a solid 
lamella, but a series of ascending processes which pass from the base 
to the depression at the bottom of the calice, which is surrounded by 
the coronet of internal septa. 

Milne Edwards and Jules Haime separated the " fungites " from 
the genus Clisiophyllum, and their specimens were not sufficiently 
well preserved or cut to enable them to discover the arrangement of 
the septa and columellary processes within the endothecal tissue which 
separates the coral into inner and outer portions. 

Mr. Thomson and I claim these as new points, and considering 
that septal and columellary structures are of paramount importance in 
recent corals, we have a right to esteem them worthy of the conside- 
ration of all who have the slightest possible knowledge concerning 
the anatomy and physiology of the Zoantharia. 

P. Martin Duncan. 

Lee, S.E., March 13, 1868. 

THE TRIAS OF CHARNWOOD FOREST. 
Sir,— The paper in your last number, on Charnwood Forest,by the 



198 Correspondence — Mr, George Maw, 

late Professor Baden Powell, suggests my recording one or two facts 
relating to the disposition of the Red marls on the older rocks that I 
noticed when visiting the district with the British Association excur- 
sion in August, 1866. 

Professor Powell observes, " that there are several localities where 
the New Eed has undergone some disturbance since its deposition," 
and gives an engraving of the Swithland Slate Quarry in illustration, 
which does not, however, seem to support this view. In all the 
sections I examined, the dip appeared wholly independent of disturb- 
ance, and due to an irregular base line of deposit, an element which 
is often overlooked in estimating the extent of changes of inclination 
subsequent to deposition. The Red marls of Charnwood Forest dip 
away in every direction from the high ground of the older rocks 
towards the surrounding level plain ; but I was much struck with 
the fact that the direction and amount of inclination seemed to be 
less related to the entire mass of the high ground than to its details 
of contour. In the section of Swithland Old Pit, given at page 119, 
the two masses of Red marls are represented dipping towards a gully 
intersecting the slate. A subsequent movement of the slate is not, 
however, required to account for this, and an examination of the beds 
m situ conclusively show that the details of inclination are directly 
related to the original surface -contour of the fundamental rock, a 
point which is faithfully represented in diagram No. 2 of Professor 
Jukes' memoir.^ A similar arrangement is observable in a cutting 
of the Bristol and Exeter Railway near the Bourton Station,- where 
the Keuper beds rise and fall at considerable angles of inclination 
over some prominent bosses of Carboniferous Limestone, and had not 
the fundamental rock been visible, the sudden changes of dip might 
appear to have been the result of disturbance. 

Another noticeable feature in Charnwood Forest is the relation of 
the areal outline of the Red marls to the surface contour of the older 
rocks rising above them ; long winding tongues of the red beds run- 
ning up into the ancient valleys of the high ground, the contour of 
the exposed portions of which is entirely in harmony with that of 
the bottoms of the valleys buried beneath the remnants of the later 
deposit. This affords a good illustration of the extreme antiquity 
of the surface contour and hill-and-valley system of the Palaeozoic 
rocks; and whatever form of erosion may have determined this 
contour, it has evidently been very little modified by marine erosion 
during the submergences of the Trias and succeeding formations. 
In fact, the general surface contour of the high ground, and all the 
principal hills and valleys of Charnwood Forest were in existence 
before the period of the Trias, for remnants of the Red marls occupy 
the ancient lines of waterflow, and these do not appear to have been 
changed by subsequent disturbances. 

George Maw. 

Benthall Hall, Broseley, March 6th, 1868. 

' In Potter's History and Antiquities of Charnwood Forest. 

2 See Section, Fig. 2, page 443, Geological Magazine, Vol. III., October, 1866. 



Correspondence — Mr, John Plant. 109 

BADEN POWELL AND CHARNWOOD FOREST. 
Sir, — The posthumous paper in your March number, by Baden 
Powell, appears out of date. More than half of its material had ap- 
peared in print before it was written in 1859 ; and the few new 
points it contains have been told over and over again during the last 
decennary. But what I wanted especially to note was a correction 
of the opening statement in the article, '' That the Geology of Charn- 
wood Forest was first systematically investgated by Professors Sedg- 
wick, Whewell, and Airy in 1833." Your readers will find in the 
Annals of Philosophy, Jan., 1824, an elaborate memoir, with a good 
geological map and woodcuts, by William Phillips and S. Luck 
Kent, ''Observations on the Kocks of Mount Sorrel, Charnwood 
Forest, and Grooby." This memoir is 20 pages long, and excepting 
the antiquated nomenclature, is as sound in its principles, accurate 
in its details and classification of the rocks, as are any of the recent 
Memoirs of Charnwood Forest, the Geological Survey, Mr. Jukes, or 
the recently published memoir by Professor Ansted. 

From another remark in Mr. Baden Powell's paper, anyone would 
suppose that the district of Charnwood Forest had been a neglected 
field, whereas for many years past, and remarkably so of late, the 
local geologists of Leicester, of whom I am proud to be one, have 
explored every yard of its area, and are well acquainted with every 
geological feature to be found about its rocks. Their labours may 
not find a place in the Quarterly Journal of the London Geological 
Society, but they are to be found in the memoirs and transactions of 
several local societies. 

John Plant. 
Peel Park, Salford, 
5th February, 1868. 

CLASSIFICATION OF GRAPTOLITES. 

Sir, — I must ask you for leave to say a few words in reply to 
Dr. Nicholson's in your last. 

1. The Graptolites have been supposed to be related to the 
Ctenostomatous Polyzoa — the Ctenostomata have corneous polv- 
paries like the Graptolites. Dr. Nicholson dismisses the question of 
their Ctenostomatous affinity, because the Polyzoa " as a rule" have 
Calcareous tests ; a "-summary" process indeed. Dr. Nicholson has 
yet to make the acquaintance of the Ctenostomata, for the '' free 
and corneous Polyzoa," of whose existence he is "perfectly aware," 
are a novel group of real or imaginary animals very different from 
the fixed Polyzoa to which Busk gave the name. 

2. Dr. Nicholson changed his views after I pointed out, in the 
Geological Magazine, his errors, and his progress in knowledge 
followed step by step my corrections. Your readers will form their 
own estimate of that " honesty" which accepts these corrections and 
publishes them without acknowledgment. 

3. I ventured to suggest that somehow Dr. Nicholson had con- 
founded gonophore with gonotheca, but such an error was so gross 
and so fundamental, that I suggested it with diffidence. Now Dr. 



200 Correspondence — Mr. W, Carruthers. 

Nicholson says plainly that he used " gonophore instead of gono- 
theca, to signify the external bell-shaped ovarian vesicle of the 
Sertulariadas." He also quotes Greene ' in support of his posi- 
tion, and triumphantly adds that his quotation is but one of 
many similar statements ! Had he pursued his examination of 
Greene's Manual a little further, he would have found, at page 
47, that in the Sertulariadse "gonophores, protected by the gono- 
theca, are borne along the sides of the gonoblastidium." Ignorant 
of the difference between a ''reproductive body" and an "ovarian 
vesicle," that is, between a gonophore and a gonotheca, and conse- 
quently of all the remarkable phenomena connected with the de- 
velopment of the Hydrozoa, of which these terms are the exponents, 
Dr. Nicholson has discanted before learned societies and to the 
readers of scientific journals, on the relation of an obscure group of 
fossils to recent animals from these organs of reproduction ! I may 
as well here give the reason why I have come to the rescue of a set 
of animals in which I have long been greatly interested. More than 
two years ago, when Prof. Wyville Thompson, who had promised a 
monograph of them to the Palseontographical Society, pressed me to 
undertake it instead of him, I refused, because I had resolved to 
confine myself to botanical researches ; and to this resolution I 
would have adhered had I not been constrained to rescue my old 
friends from the hands of a man who, from the first, appeared to 
me to be, as he has now declared himself, imperfectly acquainted 
alike with the fossils and their living representatives. 

4, A perusal of the laws of scientific nomenclature (British 
Association or M. De Candolle's) will enlighten Dr. Nicholson as to 
his Pleurograpsus. 

5. It is not pleasant to be personal, but it is often necessary — 
scientific precision and truth require it. Dr. Nicholson has another 
method. In the first part of his letter in your last number, he says 
the error (introduced by Mr. Jenkins into the abstract of his 
paper?) in the generic character of Dichograpsus, "has been re- 
produced in a recent paper on Graptolites." Would it not have 
been better to have been personal here, and said, reproduced by Mr. 
Carruthers ? But what is the truth ? This erroneous character was 
published by me in June, 1867 (did Mr. Jenkins make by mistake 
his abstract from my paper?), in a paper which Dr. Nicholson has 
read, for he has quoted from it. If there is any plagiarism, it is 
Dr. Nicholson who has stolen from me. But if he prosecutes his 
enquiries a little further, he will find that this character was not 
published even then for the first time. 

And now, sir, I have done with Dr. Nicholson, and I trust he has 
for some years done with Graptolites. Let Dr. Nicholson lay aside 
his honours for a little, and become a scholar in natural science, and 
no one will more heartily welcome him as a worker when he has 
somewhat mastered his subject, than — Wm. Carruthers. 

^ Prof. Allman (whose terminology Greene adopts) and Prof, Huxley did me the 
favour to read and approve my proof. — W.C. 



THE 

GEOLOaiCAL MAGAZINE 



No. XLVII.— MAY, 1868. 

I. — On Saubosternon- Bainii, and Pristerodon McKati, Two New 

Fossil Lacertilian Eeptiles from South Africa. 

By Professor T. H. Huxley, LL.D., F.R.S. 

President of tlie Geological Society of London : Hunterian Professor of Comparative 
Anatomy in the Royal College of Surgeons, etc., etc. 

(PLATES XL, XII.) 

SOME time since Prof. T. Eupert Jones directed my attention to 
a curious fossil in the British Museum, obtained by Mr. Bain 
from Styl Krantz, Sniewe Berg, South Africa. The matrix is of the 
same nature as that in which the Dicynodonts are so commonly found, 
and exhibits the greater part of the skeleton, but unfortunately not the 
skull, of a Lacertilian reptile, not more than seven or eight inches in 
length. It is represented of the natural size in Plate XI., Fig. 1. The 
trunk is about two and a half inches long, and appears to have 
attained hardly more than one-third the length of the tail, which is 
bent round into three-quarters of a circle, and consists of vertebrae, 
which are \Qry stout near its root, but become attenuated at its 
termination {a). The centra of these vertebrse appear to have been 
slightly constricted in the middle, and are about one-tenth of an 
inch in length. The anterior caudal vertebrse present strong and long 
transverse processes. The dorsal vertebrae can hardly have been 
fewer than eighteen or twenty, and seem also to have possessed 
hour-glass shaped centre. They are for the most part provided with 
long curved ribs, the hindermost four or five pair of which become 
gradually shorter. One or two vertebrae in front of the sacrum may 
have been devoid of ribs. 

Both the fore and the hind limbs are in place, though but im- 
perfectly preserved The impression of the large semilunar coracoids 
(Figs. 1 and 2 6) which meet, and perhaps overlap in the middle line, 
is very distinct. But one of the most interesting features of the fossil, 
and that which best indicates its relation with the typical Lacertilia, is 
the great T-shaped, or rather crossbow shaped, episternum or inter- 
clavicle (Figs. 1 and 2, c), which in its general form and properties 
closely resembles that of the existing Monitors. The clavicles them- 
selves are not to be distinctly made out. The humerus is equal to 
about 7 vertebree in length, and possesses a cylindrical shaft, which 

YOL. v. — NO. XLYII. 14 



202 Huxley — New Fossil Reptiles, 

is moderately expanded at eacli end. The radius and ulna are 
rather shorter than the humerus. The manus (Fig. 2 d) has 
slender digits, some of which were certainly terminated by claws, 
and which seem to have been present in the full number of five. 
The impression of the pelvis is distinctly visible, though its details 
cannot be clearly made out. The femur is a long and strong bone, 
not notably dilated at either extremity. The tibia is stouter than 
the fibula ; both bones are considerably shorter than the femur. 
The total length of the leg without the foot is 1-8 inch ; that of the 
fore-limb without the manus is 1'4 inch. The foot, represented as 
twice the size of nature, in Fig. 3, seems to have been penta-dactyle, 
with slender digits, the largest of which could hardly have been 
shorter than the tibia. 

Our knowledge of the characters of the trunk and of the limbs of 
the Dicynodonts is very defective, but the limb-bones of this skeleton 
are so unlike any of the corresponding bones which are known 
among the Dicynodonts, that I think there can be little doubt that 
the fossil is not the trunk of Dicynodon. On the other hand, it is 
in many respects curiously like Telerpeton, and I am disposed to 
think that the little African reptile, which may be called Sauros- 
ternon Bainii, was really allied to that famous Lacertian. 

At the International Exhibition held at Paris last year, Mr. 
McKay, of British Kaffraria, exhibited a model of " East London 
and the Harbour Works at the Mouth of the Buffalo River, British 
Kaffraria, Cape of Good Hope," with some geological sections. The 
latter are thus described : — 

"EXPLANATION OF GEOLOGICAL SECTIONS. (Figs. 1 & 2.)" 

" A. — Is a Permian formation, most probably of the age equivalent to the Magnesian 
Limestone of England and Zeclistein of Germany. Its freshwater origin is in- 
ferred from the total absence of Marine remains, particularly shells -and the 
presence of multitudes of remains of reptiles capable of existing on land or 
freshwater — together with the remains of land-plants in the erect position in 
which they grew. 

D. — Is a wind-stratified Post-Tertiary formation which fringes the coast for a con- 
siderable distance (it has been traced from the Kowie to N;ital). but does not 
extent any distance inlnnd, generally under a mile. It is, in fact, nothing more 
than consolidated sand hills, which, in some pLices, attain a height of 200 feet 
and upwards. The hillocks of loose sand that skirt the coast at the present day 
are identical in composition, stratification, and organic remains. 

E. — Is a stiff, reddish, yellow clay, with a considerable proportion of calcareous 
matter ; pellets and nodular concretions of lime are dispersed throughout it. 
It occupies all the depressions in the surface of A, and, in consequence, is very 
irregular in thickness, ranging from 5 to 150 feet. No fossils have yet been 
found in it. 

F. — A thin layer of ironstone gravel, containing rolled fragments of silicified wood, 
agate, cornelian, chalcedony, etc. 

G. — A rich, dark, earthy clay, from 2 to 5 feet thick, with thin layers of existing 
marine shells sparingly dispersed in it These marine remains have been found 
at an elevation of 800 feet (" sic. in Mr, McKay's MS., at p. 204 he says 200 feet ") 
above the present sea level, so that the land must have been quiescently sub- 
merged to that depth within a very recent period. 

H. — This deposit owes its origin to an obstruction across the mouth of the river, 
which has penned back the water and converted the estuary into a temporary lake, 
about 20 feet above its present level— three distinct occurrences of this obstruction 



Huxley — New Fossil Reptiles. 



203 



are plainly seen. After carefully observing most of the mouths of the rivers on our 
coast, I am satisfied that they are all more or less liable to periodical obstructions 
of this description. 
, It is only in this deposit (H) that traces of man have been found. They consist 
of implements, fragments of native pottery and charred wood.^ It is only when 
the fossils are close to the underlying hard rock that the process of concretion and 
cementation has made any advance, otherwise they are loose in their bed, or are beached 
up in heaps of loose shells and rubbish in a direction against the sea, as in H, Fig. 1." 




Fig. 1. iiuls uibide Estuuiy at the mouth of the buttalo Kiver, bnii»u h.aliiaiia, (Jape of 
Good Hope. H. Bed of Shells = to TI. in Fia:. 2. 




Fig. 2. Order of Super-position of Deposits, Buttuio liiver. 

"LIST OF FOSSILS OBTAINED BY MR. McKAY, OF BRITISH 
KAFFRARIA." 

" Bed A. — All the animal remains of this group are presumed to be Reptilian. No. I. 
Section of Vertebrae. No. 2. Vertebrae and ribs. No. 3. Skull of Dimjnodwiy 
tusks directed forward, inward, and downward ; the mouth and temporal fossae 
analogous to the existing turtle. No. 4. Bones of the feet, ribs, etc. No. 5. 
Part of a Skull. No. 6 and 7. Vertebrae and ribs. No. 8. Jaw with teeth 
placed in a groove. No. 9. Upper and lower jaw with teeth, one of which is 
serrated. No. 10. Jaw with teeth in distinct sockets, large teeth to the front, 
and gradually diminishing in size towards the posterior part of the jaw; remark- 
able for the massiveness of the jaw in proportion to the size of the teeth. No. 11. 
Small jaw with a row of cylindrical teeth and four supplemental teeth compressed 
and serrated on the anterior edge only; some elements of the lower jnw. No. 12. 
Vertebral column of a small reptile ; some bones of the legs and sternum. No. 13. 
Skull with teeth in a groove. No. 14 and 15. Skulls. No. 17. Serrated tooth ; 
two other teeth of this description in my possession are deeply implanted ia 
distinct sockets in a massive jaw ; they are serrated on both edges — an at- 
tempt was made to clear the serration on the other edge of No. 17, but it was 
found too brittle, and it shivered with the lightest tap. No. 18. Tooth; the 
cast of the point of the tooth suggests indentation on the edge of a right angle, 
rather than projecting serrations ; it was associiited with No. 17. No. 19, 
Part of skull and lower jaw teeth, some of which are serrated. Concentrie 
ring-marks are visible in section. No. 20. Rib > No. 21. Tibia? No. 22. Ribs 
and bones of the feet or paddles } No. 23. Bones of the feet fragments of 
the jaw and teeth, etc. Lastly. Many plant impressions, ripple marks^ and cast 
of rain drops. 

^ Since the above was written, Mr. McKay has discovered a fragment of native 
pottery in a layer of existing shells in the bed G. 



204 Huxley — New Fossil Reptiles. 

Bed D, — Existing land shells, casts of existing marine shells, vertebrae of shark, 

claw of crustacean, bone of land animal, existing marine shells and fragments. 
Beds E, and F, are unfossiliferous. 
Bed G, contains existing marine shells 220 feet ("sec. in Mr. McKay's MS., at p. 202 

he says 800 feet' ) above the present sea-level. 
Bed H, yielded teeth and tusks of Hippopotamus; stone ring used by Bushmen. 

(They are wedged on to the pointed sticks as make-weights to assist in digging 

up roots.) Lastly. Fragments of native pottery." 

The specimen represented of the natural size in PI. XII. Fig. 1, 
is from Bed a, and is the fossil marked No. 9 in Mr. McKay's list. 
It is a shattered lacertilian skull having very much the general 
shape of that of Jthynchosaiirus, being very broad posteriorly owing 
to the large size of the supratemporal fossa (a), and tapering 
anteriorly. The extremity of the snout is broken off. The large 
orbits {h) looking almost directly upwards, lie in the anterior half of 
the cranium, and are separated by a relatively narrow interorbital 
space. What appears to be a parietal foramen is situated in the sagittal 
suture near the truncated occipital margin of the skull. The 
mandible is very much broken, but what remains of it shows that 
it was remarkably thick, and that it was provided with teeth, the 
best preserved of which is represented of twice the natural size in 
Fig. 1 a. Eight or nine such teeth can be counted in relation with 
the left ramus of the mandible between d and d. Each of these 
teeth is straight, flattened from side to side in the crown, but more 
cylindrical in the fang, and contains a pulp cavity, which extends 
nearly to its summit, and is wide in the crown of the tooth. The 
anterior edge of each tooth is like its surface, smooth and rounded, 
but the posterior is produced into relatively strong and long denti- 
culations. 

The ramus of a mandible of the same animal, is represented of 
twice the size of nature in Plate XII. Fig. 2. From the arrangement 
of the teeth in this and in the foregoing specimen, it appears that they 
were not disposed in distinct alveoli, but lay close together in a 
groove of the bony substance of the jaw. The symphysial end of 
the ramus (a) seems to have been devoid of teeth. 

The successional teeth are well seen in various stages of develop- 
ment at the bases of those which are fully formed. Most of the 
latter have been split, or ground down, so as to show their pulp 
cavities. I propose to name this new Lacertian Pristerodon McKayi. 

Fig. 3, PI. XII. is a figure, of the natural size, of another incom- 
plete mandible, similar in its stoutness, and in the apparent absence 
of teeth from the symphysial region, to the foregoing. But the 
transverse sections of the fangs of the teeth, which have been ex- 
posed, apparently by taking a slice for microscopic purposes, are 
oval, and show that the pulp-cavity is almost obliterated. The teeth 
increase in size from behind forwards, and a thin bony septum 
between the first and second gives rise to a complete alveolus for the 
first tooth. 

The inner side of the ramus gives off a singular slender bony 
process, which may correspond with the flat and slender plate of 



CrujlMuy L86d. 



Vol. V.FI. XI. 




VUf.Z ^ 





FUr. 3. 



A rnolintootil .-: ,Vt 



]r. rr, 






Gc.^lMa^.imd 



Vaivnxn. 




A . T Eollulf rieJ. e^ tijth. 



P-rh6 Uu-odjj-n. M^KoD/-b, Hizxl&y. 
A iVen/ Fossvb Puepal& -Ftottu SouuJiAfrua 



Wilson — On Contortions and Faults, 205 

bone wliicli appears to be given off from the inner side of the man- 
dible of Fristerodon, nearly opposite the lower d in Fig. 1, PI. XII. 

DESCRIPTION OF PLATES XI. and XII. 

Pl. XI. — Fig. 1. The impression of the ventral face of Saurosternon Bainii, of the 
natural size, a, the extremity of the tail ; b, the coraioid ; c, the 
interclavicle or epistema. 

2. A portion of the counterpart, d, the manus ; b, c, as before. 

3. The left foot ; from the counterpart twice the natural size. 

Pl. XII.— Fig. 1. The skull of Prisferodon McKayi, of the natural size. The greater 
part of the left half of the skull has split off, leaving the left ramus 
of the mandible {c) exposed, a, the right temporal fossa; i, the 
orbit ; d d^ the teeth. 
\a. A tooth, X 2. 

2. A detached ramus of a mandible of Pri&ierodon, viewed laterally, 

and apparently from the inner side. 

3. A similar mandible, viewed from above. 



II. — On the Cause of Contortions and Faults. 

By J. M. Wilson, M.A., F.G.S., etc. ; Fellow of St. John's College, Cambridge; 
Assistant Master at Rugby School. 

DURING the last few years, in lecturing on geology at Rugby 
School, I have frequently given an explanation of the causes 
that produce contortions and faults, which I find, to my surprise, 
is not given in the ordinary text books, and yet seems to me an 
extremely obvious explanation. 

The explanation given by Lyell (Elements, p. 64), is contained 
virtually in the diagram he gives (Fig. 1). I quote however a few 
words from his book. ''Suppose the mass of rock a, b, c (Fig. 1), 
to overlie an extensive chasm d, e, formed at the depth of several 
miles. Now, if this region be convulsed by earthquakes, the fissures 
/, g, and others at right angles to 
them, may sever the mass b from 
A and from c, so that it may 
move freely, and allow it to sink 
into the chasm." ^'^' "" 

It is clear from this that Lyell considers faults as caused by 
subsidence of detached portions of the crust of the earth ; and since 
a wedge-shaped block could not so subside, the faults must be either 
vertical or overhanging on one side of the detached portion ; that is 
faults would *' hade to the upthrow " as often as to the downthrow, 
which is not the case. 

Phillips, I believe, offers no explanation of faults, but points out 
the very general law that the plane of separation slopes tinder the 
depressed portion of the disrupted strata, expressed above by saying 
that faults " hade to the downthrow." 

Page does not discuss the question. 

Jukes discusses it at considerable length, and his explanation, in 
some respects, is like my own. He explains, however, the general 




206 



Wilson — On Contortions and Faults, 




law of the inclinatioTi of the plane of the fault as follows : — " Sup- 
pose til at in the diagram (Fig. 
2) we have a portion of the 
earth's crust, of which a b is 
he surface, and c d a plane 
icted on by some wide spread 
force of expansion tending to 
bulge upwards the part a, b, 
0, D. If, then, a fracture take 
place along the line e f, it is 
obvious that the expanding force will, on the side of a c, have the 
widest base c f to act upon, while it will have a proportionately- 
less mass to move." Jukes then proceeds to discuss the junction 
between two opposite faults, which produces what is often called 
a " trough," of which his explanation only differs in some details 
from my own ; only that my own is applied to all faults, and de- 
pends on no hypothetical causes whatever. 

Similarly when I read manuals with a view to see what account 
is given of contortions, I meet with nothing but general allusions to 
" forces of disturbance," " unequal densities and pressures," and no 
clear mechanical account of their origin. 

Lyell's account is that they may be due to lateral pressure, and 
two ways of producing lateral pressure are indicated ; one by the 
injection into fissures of molten, or the protrusion of solid rocks, and 
the other by unequal degrees of subsidence arising from various 
causes. 

Now, contortions and faults are, I think, readily explained when 
one recollects — 

(1) That depressions and elevations take place over large areas. 

(2) That the surface of the earth is curved. 

(3) That rocks are compressible by foldings. 

(4) That rocks are not extensible or elastic. 

(5) That at great depths rocks are somewhat plastic through heat. 

For, consider a portion of the earth's sur- 
face A, B, c, (Fig 3) and suppose it to be 
an area of subsidence, or to sink graduall}" 
to the position occupied by the dotted lines. 
It is clear that to do so it must be laterally 
compressed. Here is a source of power 
for producing contortion, viz., the prodi- 
gious weight of the mass, slowly sinking, 
and crumpling up into curves and folds 
that part of the area a, b, c which yields 
most to lateral pressure. 

Contortions then are the inevitable result 
of subsidence of a curved surface. 

Now, consider the re-elevation of a dis- 
trict. The rocks have to expand so as to ^'^s- »• 
occupy a larger area. How can this be accomplished ? Clearly by 




Wilson — On Contortions and Faults. 



207 




The piec>-s a, a, o, 0, are of the same 



cracks, passing riglit through the solid crust, taking place in a 
variety of directions, and all the pieces, which are broader at the 
surface than lower down, sinking further relatively to the rest. 

It will be seen at once by reference to a diagram, which I have 
made on an exaggerated scale (see Fig 4). If the mass a b is elevated 
so that it assumes the more curved i''?- 4. 

form c D, A B will crack; (a) will 
rise, and {d) will rise, but the in- 
creased space between (a) and (d) will 
be occupied by the sliding down of 
the pieces (6) and (c). Then since 
these faults always take place when 
the area is depressed, the rise will take 

place under the sea, and be extremely ti^eliom cT Dt^Ti t^JJ^f"^ 
slow, and the marine denudation will a to b, 

soon level the surface, and obliterate all trace of faults. It is clear 
that this explains the general law of faults given above ; and puts 
contortions and faults in connection with one another. Faults then 
are the inevitable result of the elevation of a curved surface. The 
only point that needs further examination is this, whether the cause 
assigned above is adequate to produce the observed amount of faults 
and contortions. 

I have examined this question mathematically, and the following 
are the results I have obtained on the supposition that a circular area 
of the earth's surface whose diameter subtends an angle of 2 ^ at the 
centre of the earth, is depressed, so as to maintain a spherical form, 
(of course a portion of a larger sphere) to a depth of {a) miles in 
the centre of the depressed region ; — that is on the supposition that 
the arcs a b and c d, as in the diagram, are both circular. The cal- 
culation only requires a little trigonometry, and may be relied on as 
true within a few yards. 

Table of Compression, in Yards. 



For an arc of 2 0, depressed 


;to a depth a ; radius = 4,000 miles. 




= 5° 


e=w 


= 20° 


= 40° 


o = I mile 


121 


211 


354 


800 


o = 2 miles 


189 


408 


745 


1625 


o = 4 miles 


355 


788 


1584 


3214 


o=8 miles 


598 


1527 


3213 


8539 


linear distance 

across depressed 

area 


345 miles 


690 miles 


1380 miles 


2760 miles 



208 Ruskin — Banded and Brecciated Concretions. 

The inspection of this table will shew that the known rising and 
sinking of large areas of the earth's surface is adequate to produce 
much compression and extensive faults. But this table can be made 
to yield some other important results. 

When the geological structure of a country is pretty well known, 
the amount of contortion, — i.e. the difference between the direct dis- 
tances of two distant points, (1) measured along a circular arc, (2) 
measured along strata, — may become approximately known. And if 
this contortion appears not to be due to the intrusion of local 
igneous rocks, and does appear to be due to depression, we get a 
means of calculating to what depth the strata sank when those con- 
tortions were being produced. 

And, again, it appears that the horizontal projection of the fault, 
or, in other words, the '' barren ground," is the measure of the 'power 
of a fault. Hence, if the vertical throw of a fault be /, and the in- 
clination of its plane to the vertical be 6, and the barren ground be 
therefore / tan ^, it appears that X (/ tan^), taken along any 
section, is a measure of the subsequent elevation. But X (/ tan 6) 
is an observable quantity, independent of hypotheses : hence we 
may be able to infer the amoimt of re-elevation, which ought to cor- 
respond approximately with the amount of depression obtained for 
the same section from the contortions. 

But apart from this application of my explanation of the origin 
of contortions and faults, which is not yet, I imagine, practicable, 
I should be glad to know the opinion of geologists about the ex- 
planation itself. 



III.-— On Banded and Brecciated Concretions. 

By John Ruskin, Esq., F.G.S. 

(PLATE XIII.) 

(Continued from the April Number, p. 161.) 

THE next group of agates which I have to describe belongs to the 
nested series ; but is distinguished from all other varieties of 
that series by having a pure chalcedonic surface (unaffected, except 
in the form of it, by the material of its gangue) ; and by uniformity 
of colour ; consisting only of white and transparent grey bands, 
wholly untinged by more splendid colours. But nearly all the agates 
of this group which now occur in the market have been dyed brown 
or black at Oberstein, to the complete destruction of their loveliest 
phenomena. 

With the true agates of this group must be associated some 
transitional examples, in which the surface is more or less entangled 
with, and degraded by, the material of the gangue, (the body of the 
stone then becoming susceptible of colouring by iron, or of chloritic 
arborescence from the exterior) ; and others, in which the mass is 
rudely egg-shaped, like a rolled pebble, and the crust is of a fine 



Ca'OL jWuj hS(Ki 


Vol.V HLX/// 

) w 








J. Raskin , deJ 



i.ALlen. inct 



FOLDED AGATES AND MURAL AGATES 



Ruskin — Banded and Brecciated Concretions, 



209 



pale brown agatescent jasper in multitudinous concretions, plainly- 
visible on the surface, like the convolutions of the brain of an 
animal. But in the typical examples of the whole series, no lines of 
concretion are visible on the surface ; it is knotted and pitted ; but 
not banded — it is of grey clear chalcedony, and the entire mass of 
the stone is often thrown into irregularly contorted folds, which are 
sometimes parallel to tlie interior bands, and from which I shall, 
for convenience sake, give the name to the whole group of " Folded 
Agates." 

I say '' sometimes parallel," because the folds of the interior beds 
are much more complex than those of the surface, and often are 
most notable when the exterior is undisturbed ; and they are 
specifically peculiar in two respects. First, they are formed out of 
beds which are in the greater part of their course accurately 
parallel, and arranged in gracefully sweeping continuous curves, 
while the bands of ordinary agates are broken into minor undulation, 
and run into irregular curves. Fig. 1 is the typical structure of 
common, and Fig. 2 of folded agate ; the line a h, in each figure, re- 
presenting the surface of the stone. 





Fig. 1. 

Secondly, These sweeping and beautifully parallel beds are at par- 
ticular points of their course suddenly and systematically contracted, 
and bent outwards, (outwards, that is to say, in nested agates — in- 
wards in stellar agates, but the stellar formation is very rare in this 
group) like flowing drapery raised by a rod beneath it ; and this ideal 
rod may either raise these sheets of drapery hanging over it, as clothes 
hang over a line ; or on the end of it, as the sides of a tent hang from 
its pole ; ^ with every variety of beautiful curvature, intermediate be- 
tween these two arrangements. The ideal rod is of course composed 
of the interior chalcedony or quartz ; and I once supposed the entire 
range of these phenomena to be dependent on the former subtle 
influx of the dissolved silica at the points where the apparent rods 
or tubes reached the exterior of the stone ; but I now believe rather 



^ In Plate XIII. Fig. 1 shows the clothes-line arrangement in pure surface-section, 
and Fig. 2 in perspective, seen through the transparent stone, the edges only of the 
pendant veils being at the surface. Of the tented arrangement I will give examples 
In succeeding plates, but they are not specifically different arrangements ; they are 
only accidental variations in the direction of the interrupting masses. 




210 RusJiin — Banded and Brecciated Concretions, 

that, taking Fig. 3 as a formal type of a perfect folded agate, tlie 

points a, b, c, etc., at the sides of the 
nest have been those of impeded secre- 
tion or deposit (if, which is not by any 
means clear to me, there has been suc- 
cessive deposit at all), and that the in- 
termediate curved beds are the increas- 
ing stalactitic masses. The right lines 
indicating flaws at the intersection of 
these masses, are essential in the typi- 
cal structure. The two upper figures 
in Plate XIII. will characteristically 
represent the phenomena j^rincipally 
resultant, though the complexity of 
these phenomena is so great that in 
Fig. 3. detail they can only be followed out 

by the reader with good specimens of the stones in his hand. 

Fig. 1 is from a very rare agate in my own collection, which 
unites the characters of the folded group with that of the nested 
agates which have level beds (the pure folded agates never, as far as 
I have seen, contain rectilinear tracts), and the folds, or tubes of 
arrest, in this stone are less regular in structure than in typical 
examples, and present somewhat the appearance of having been 
caused by contraction, the rent spaces being afterwards filled by the 
inner quartz. But I believe this appearance to be wholly deceptive. 
Whatever the cause of the interruptions may be, they are certainly 
not mere rents like those of septaria. The greater width of the 
white band at the top, which suggests the idea of large influx there, 
is a sectional deception ; this white band is of equal thickness every- 
where ; and, with all the others, seems entirely concentric, except 
when interrupted by the tubes, and by the changes in the direction 
of the films in its own substance which are connected with- them. 
Fig. 2 is from a piece of perfect folded agate, showing the symme- 
trical arrangement of its successive beds round the tubes, and their 
lovely dependent curves as they detach themselves. In some cases, 
however, the tubes appear isolated in the mass of the stone, or in- 
terrupt the beds in their own thickness ; but in whatever accidental 
relation to the secreted chalcedony, they assuredly indicate a peculiar 
state of its substance at the time of secretion ; and their nature, and 
the conditions under which they develope themselves, must be under- 
stood before we can hope to explain the more complex tubular form- 
ation of dendritic chalcedonies. 

And this investigation is rendered doubly difficult by the per- 
petual confusion in all agatescent bodies between the concretionary 
separation, and successive deposit of their beds. If these folded 
agates were, indeed, formed in successive beds, from without 
inwards, as it has been supposed, it should be possible some- 
times to trace the point of influx of material, and the sequence of 
the added bands from it, which I never yet have been able to do 
satisfactorily in a single instance in folded agates (and only with 
suspicion of the appearance of it, even in the brown coated and level 



Rusldn — Banded and Brecciated Concretions, 



211 



bedded stones in which it seems to be of ordinal}^ occurrence) : and 
also, the beds ought to present some of the irregularly accumulate 
aspect of common calcareous stalactite; and in the interior we 
ought to find sometimes vacancies left by the failure of supply. 
But on the contrary, folded agates are always full, so far as I have 
seen, except occasionally in the centres of their tubes, or in hollows 
of outer folds, but they are always closed in their centres (differing, 
observe, again essentially from common agate in this circumstance), 
and their beds are not only parallel, instead of irregularly heaped, 
but involved in the strangest way in reduplicate crystalline series. 
See the interior of the stone, Fig. 2, in Plate XIII. 

On the other hand, were they truly concrete, these beds ought to 
exhibit occasionally clear evidence of subordinate concretion in their 
mass. Thus in the true concrete jasperine agate, Fig. 4/ the beds 




which are simply concurrent on the right hand break up presently, 
and separate into flamy and shell-like groups, transverse to the 
general bedding, and at last bend round a knotted nucleus ; but 
nothing of this kind ever occurs in folded agates, though their veils 
of dependent film are sometimes covered with an exquisite dew of 
minute pisolitic concretions, making them look (under the lens) like 
a beautiful tissue of gossamer laden with dew, and connected with a 
peculiar complex basalt-like fracture : then finally, to finish the 
difficulty, these folded agates are connected by a series of scarcely 
distinguishable transitions with the group which we shall have next 
to examine, which seems to be in great part concretionary, but 
concretionary in right lines. The two lowest figures in Plate XIII. 
are outlines of two of the most singular conditions of it. Fig. 3, 
Plate XIII. is reduced in scale from a stone which I shall hereafter 
engrave of its real size, as its mode of association of agatescent with 
crystalline structure is, as far as I know, unique — and its proper 
discussion is connected with that of the modes of increase of crystals. 
Fig. 4, Plate XIII. is from an agate of almost equal rarity, though 
I have seen other examples of its structure, but never so decisive in 
character. This figure is slightly enlarged, being of a portion of a 
mass which has crystallized out of a breccia, in thin walls of linear 
brown agate enclosing opaque white agate, leaving internal spaces 
filled with quartz. 

The entire group to which these examples belong, consisting of 

^ Magnified abmit tlirpe timpja. 



212 



Bushin — Banded and Brecciated Concretions, 



walls, or tabular crystallizations, of agate, I shall name Mural agates ; 
and they are connected, on the one hand, with Folded agates, by a 
series in which tabular portions of the external matrix are torn off 
like pieces of broken slate, lifted up into the agatescent mass, and then 
encrusted with folds of chalcedony ; on the other hand, when the 
Mural fragments become curved, they are connected with a great 
jasperine group of the most curious interest, which I shall examine 
under the general term of Involute Agates, consisting of bands of a 
consistent structure, broken up (or fragmentarily secreted), Fig. 5, a, 
in fine specimens disposed in curves resembling the contour of a 
haliotis shell. Fig. 5, b, but in less developed examples forming broken 
vermicular concretions in a jasperine paste, Fig. 5, c. It is almost 

Fig. 5. 




A. B. C. 

impossible without microscopic examination to distinguish some of 
these shell-like concretions (of which the most delicate are white, 
closely crowded, and surrounded by milky chalcedony), from true 
organic remains ; and to my mind perhaps the most singular fact, of 
all that are connected with minor physical phenomena, is this 
apparent effort of the occult natural powers to deceive their investi- 
gator, by making one thing resemble another. There seems to be a 
mocking spirit in Nature which sometimes plays with its creatures, 
as in the orchis tribe of plants, or the mantis group of insects ; and 
sometimes deliberately connects two totally different systems of its 
work by deceptive resemblances, causing prolonged difficulty or error 
in the attempt to discriminate them. In this subject before us, for 
instance, the inorganic secretions of chert and flint are connected, by 
the most subtle resemblances, with those which have organic nuclei ; 
the filiform and foliated secretions of chlorite, and the flamelike and 
infinitely delicate mossy traceries of jasper, pass with the cunningest 
treason into the organisms of altered sponge and wood ; the pisolitic 
and radiated-crystalline agates confuse themselves with true corals ; 
the involute agates with shells ; the rolled breccias with slowly 
knotted secretions ; and all the phenomena of successive deposits, 
quite inextricably with those of segregation ! I imagine, however, 
that the reader must have had enough, for the present, of these mere 
statements of doubt, and as my next subject, mural agate, is a very 
difficult one, I shall delay the paper for some time ; but meanwhile, 
if any good chemist would set briefly down for me what is now 
positively known of the fluent and gelatinous states of silica, and 
silicate of iron, with respect to their modes of separation, when 
undisturbed, from other substances, it would be of the greatest 
service to me (and not, I should imagine,) irrelevant to the general 



Fisher — Notes on Clacton, 213 

purpose of this Magazine ; for all inquiries respecting metamorphic 
rocks must rest on such chemical data primarily) ; and, also, I 
should be grateful to any mineralogist who would give me some 
tenable clue, or beginning of clue, to the laws which affect the 
modes of crystalline increase ; that is to say, which determine 
whether a prism of quartz or calcito shall increase at the extremities 
or at the flanks, or consistently on both, or inconsistently at 
different parts of the prism ; and, especially, by what law stellar or 
or roseate aggregations take place, instead of confused ones, in 
groups of crystals ; and by what tendencies some minerals, fluor for 
instance, are limited in their expansions of the cubic or other com- 
mon form, while others, such as salt and the oxide of copper, are 
enabled to shoot unlimitedly into prismatic needles ; and others, like 
sulphide of iron, will form in solid crystals on the outside of calcite 
and in stellar acicular groups within it. If I can get some help in 
this chemical and microscopic part of the work, which I cannot do 
myself, I have hope of being able to give something like a service- 
able basis for future description of the two great groups of calcite 
and silica, and the modifications of iron which colour the con- 
cretions of marble in the one case, and of agate in the other ; and I 
should do this piece of work with, perhaps, more zeal and care than 
another person, owing to its connection with my own speciality of 
subject, by the use of these two earth-products in the arts, and the 
foundation of much of what is most beautiful in architecture, and 
perfect in gem-engraving, on the accidents of congelation which 
have veined the marble and the onyx. J. Ruskin. 

Denmark Hill, 22nd April, 1868. 

IV. — A Few Notes on Clagton, Essex. 
By the Rev. 0. Fisher, MA., F.G.S. 

THE following is taken from a MS. by the late Mr. John Brown, 
E.Gr.S., of Stan way, Essex, and given by him to Professor 
Henslow, who gave it to me. The actual measurements are not 
mentioned, but I believe the scale to be about an eighth of an inch 
to a foot. It is valuable as having evidently been made when the 
beds were better seen than usual. Moreover, the constant waste of 
the cliff alters the section continually. 

"1. Vegetable Soil 

2. Loam with interspersed flints, both rounded and angular, white 
quartz pebbles, and Quartz Sandstone in boulders 

3. Freshwater shells in red sand 



4. Peat, 



5. Marine and freshwater shells , 

6. Peat, with subordinate and interrupted beds of marine and fresh- 
water shells (tooth of water rat) 



Marine and freshwater shells 

Bones of the larger mammalia, generally found between the cliif 
and low-water-mark, freshwater shells, trunks of trees, nuts, and 

seeds, as we find in tbe upper beds : no marine fossil shells 

London clay at the j unction of low- water-mark " 



(^) 



>W 



1 

J 



214 



Fhher — Notes on Clacton, 



V ^ 



2 e 



To this I append a quotation from a 
paper by the same geologist in the 
Mag. Nat. Hist., vol. iv., p. 197, 18G0 :— 

"The hollow or basin occupied by 
this deposit" (I conclude he means the 
exposed section of it) " measures about 
600 yards in a north and south direction, 
and at low water it can be traced for 
about 80 yards eastward from the face 
of the cliff, and it doubtless extends 
much further under the sea, as the 
freshwater shells and bones of the fossil 
mammalia are seen lying in their la- 
custrine beds close up to low-water- 
mark." 

I never could find the bed (t?) exposed 
on the shore as Mr. Brown did. But 
specimens of the TJnio Utoralis, and of 
the black and white pebbles from the 
top of it, are by no means uncommon at 
low water exactly opposite (d) in the 
cliff. Even in the cliff the bed (d) is 
seldom now to be seen without digging 
for it, and then it can only be found ex- 
tending a very few feet. 

In Mr. Brown's section No. 2 is what 
I call " trail." 

The woodcut (Fig. 2) is copied from a 
sketch, made on the spot, of the manner 
in which the "trail" (a) cuts into (6), 
where it is five feet thick, above the 
peat (c) at a spot about 160 yards west 
of {d), in the diagram. For about 600 
j^ards to the west beyond the end of the 
low cliff' the shore at low water is oc- 
cupied by London clay ; and then com- 
mences a submarine forest with the 
stools of trees rooted in the London 
clay. Tt is covered with the usual Scro- 
hicularia clay, the Scrobicularice and 
other shells being of large size, and in 
that respect very unlike those in the 
older peaty deposit, which covers the 
Lower freshwater bed. I saw some 
small lagoons behind the present beach, 
where a deposit exceedingly like the old 
peat is now in course of formation. 
It seemed to show that the sandy layers in the old peat were 
caused by sand being blown into pools of brackish water. 



5,e 



9 ^ 



III 



te ^ to 






•i3 — ti; to N - 



■'* c * ;^ -= p. a> 
c- e JJ ? -S 



S to 



fef> === g^ =-2 ^ 
Jr, r= t: S - ** N g* » 
'^•^ n S -S ^ -r; to -^ 



^a-e 






.M;llllr 



Fisher — Notes on Clacton, 



215 



Just beyond the second groin going from East to West, a layer of 
muddy clay containing roots of herbaceous plants, immediately be- 
neath the shingle's foot, is overlaid by a laminated clay with indurated 
nodules in the' laminations, which appears to mo to oifer a curious 
instance of quasi cleavage. This laminated clay is full of " sliken- 
slide," and its peculiar condition seems to be due to some heavy 
weight, perhaps of a shingle beach, pressing it towards the sea, and 
by the pressure causing layers of it to become indurated (see Fig. 3). 



Fig. 2. 



tft^^^^jjMs. Wi;;.«>, 




Fig. 3. 



(a) Clay with rootlets. 

(6) Laminated clay with indurated nodules 

parallel to tlie laminations. 
The arrow shows the probable direction 

of the efficient part of the pressure. 



Some caution is necessary in accepting fossil bones as the pro- 
duce of the Clacton deposit. Fossil bones are frequently procured off 
the Essex coast in the process of dredging, and, being sold by the 
Clacton fishermen, are said to come from Clacton. There is no 
reason to suppose that some of them may not come from an extension 
of the deposit (d), and others probably from beds of the same age ; 
but their different mineral condition will at once show that they have 
not been obtained immediately from the bed beneath the cliff. The 
bones from thence, which Mr. Brown deposited in the British 
Museum, are black and fragile. Those which are dredged are 
reddish brown, ponderous and strong. This is the condition of most 
of the dredged bones which I have seen, whether from the Essex, 
Suffolk, or Norfolk coast. It would be worth while to enquire how 
their condition of mineralization becomes thus altered, as it appears 
to be, by the action of sea water. It seems to me probable that the 
peculiar condition of the rolled bones of the Crag-deposits, which 
have been derived from older beds, may be accounted for in the 
same manner. Bones are also obtained from the submarine forest at 
Clacton, which, unless I am very much mistaken, is of an age long 
posterior to the deposit (d). This case of the juxtaposition of 
mammaliferous beds of very different ages is similar to that de- 
scribed by Mr. Dawkins as occurring at Pagham, on the coast of 
Sussex.^ 

* Pleistocene Mammalia Palaeont. Vol. xviii., p. 25. 



216 Scudder — Fossil Insects of North America. 

V. — The Fossil Insects of North America. 

By Samuel II. Scudder, Curator of the Museum of the Boston Society of Natural 

History, U.S. 

(Concluded from the April Number, p. 177.) 

Some years ago, Dr. Dawson, who lias himself been very succesa- 
ful in the discovery of insect-remains, described and figured ^ frag- 
ments of a species of myriapod under the name of Xylohius sigillaria. 
The remains, many of which occurred in coprolites of reptiles, were ob- 
tained at the Joggins, in upright Sigillaria trees, between coal-groups 
fourteen and fifteen of division four in Dr. Dawson's detailed section 
of the Nova Scotia formations.'^ As his descriptions of the animal 
and its mode of occurrence^ are easily accessible to English geologists, 
it is needless to refer to them more explicitly. The coprolites, how- 
ever, yielded some true insect remains ; * these, as well as fragments 
of insects, not coprolitic,^ were kindly sent me for examination by 
Dr. Dawson. They consist almost entirely of crushed and indeter- 
minate masses of chitinous matter ; the few detached and connected 
abdominal segments which can be distinguished invariably show that 
the abdomen was slender and the insect of medium size. Beyond 
this, little can be said of them. I noticed, however, two remains of 
eyes ; one crushed, distorted, and ill-defined, the other, the beautiful 
fragment mentioned by Dr. Dawson,'^ whose original size it is diffi- 
cult to determine. The facets are large and regularly disposed, 
somewhat resembling the Perlidce ; but the proportion of the eye to 
the body varies so much in insects that it is impossible to judge of 
the size of the animal to which this fragment belonged. A few 
articulations of an antenna are seen on one of the stones ; they pro- 
bably belonged to a very small or very young cockroach. All the 
remains of insects appear to be neuropterous or orthopterous. I 
believe I have distinguished five different kinds. There were also 
two leeches belonging to distinct genera. 

Dr. Dawson states that he has seen a fossil fern (Cyclopteris 
\_Aneim{tes^ acadica) from the Coal measures of Nova Scotia which 
bore tracks like those made by mining insects.''' 

Eemains of insects, much more completely preserved than those 
which I have mentioned, have been found in the Carboniferous rocks 
of Morris, Illinos. The beds from which the fossils are derived lie 
near the base of the Illinois Coal-measures. In the locality at 

^ Quart. Journ. Geol. Soc. Lond,, vol. xvi. pp. 271-3; vol. xviii. p. 6; Can. Nat. 
vol. viii. pp. 280, 283, pi. vi. figs. 57-61 ; Air-breathers of the Coal Period, pp. 63, 
64, 67, pi. vi., figs. 57-61, Svo., Montreal, 1863 ; Acadian Geology, Suppl., p. 36, 
fig. 45, IBmo., Edinburgh, 1855-60. 

2 Quart. Journ. Geol. Soc. Lond., vol. xxii. p. 116. 

3 Quart. Journ. Geol Soc. Lond., vol. ix. pp. 58-63 ; vol. xvi. pp. 269-70 ; Acadian 
Geology, p. 161, Suppl. p. 33. 

* See also Quart. Journ. Geol. Soc. Lond., vol. xviii. p, 6. 

6 From Coal Groups 7 and 9 of div. 4 : Quart. Journ, Geol. Soc. Lond. vol. xxii. 
pp. 113, 114. 

6 Quart. Journ. Geol. Soc. Lend., vol. xviii. p. 6 ; Can. Nat. vol. viii. p. 276, pi. 
vi. fig. 56 ; Air-breathers of the Coal Period, p. 59, pi. vi. fig. 56. 

' Quart. Journ. Geol. Soc. Lond., vol. xviii. p. 5. 



Scudder — Fossil Insects of North America. 217 

Morris they form the overlying deposit, but a short distance beyond, 
at Murphysboro, the beds are capped by others and their strati- 
graphical position made clear. The following section given me by 
Mr. Lesquereux v^rill afford an idea of their relation to the surround- 



ing strata : — 




/ 
\ 

1 


The true coal as it occurs in Illinois 




Sandstone 


200 ft. 


Coal 


5 ft. 


Soft blue Shales with pebbles containing Insects, etc. 


40 ft. 


Coal (Morris coal) 


( 3-4 ft. at Morris 
\ 5 ft. at Murphysboro 


Shales 


40 ft. 


Millstone Grit-conglomerate 


6 ft. 



At Frog Bayou, in Arkansas, the millstone grit is much more 
extensively developed, and the insect shales lie directly beneath it. 

The fossils at Morris are enclosed in biscuit-shaped ironstone 
nodules. On weathered surfaces, these nodules show a tendency to 
lamination, but the interior has a homogeneous, compact structure of 
a greyish colour ; the enclosed fossil seems to have been the nucleus 
around which the concretionary action took place.^ The remains 
consist of reptiles, insects, amphipod crustaceans, worms, and plants. 
Several insects were found, two of which have been described by 
Professor Dana'^ under the names of Miamia Bronsoni and Heme- 
ristia occidentalis. In a letter written to Professor Dana,^ I gave 
my views of the zoological relations of these animals, and subse- 
quently published an extensive memoir,* discussing some questions 
which arose from their study. In both of these insects, the wings 
were all preserved, and, in one case, the greater portion of the body- 
also ; but as the wings were embedded in the concretions in their 
natural position in repose, overlapping one another, new difSculties 
were added to the determination of their affinities. A close examina- 
tion of this intricate network of crossed veins enabled me to assign 
to each wing its respective veins ; the body, also, of Miamia per- 
mitted restoration. Heretofore no naturalist had made use of the 
structure of the wings in distinguishing the families of Neurojytera 
from each other ; but, confident of success, I made careful compari- 
sons among the living types, and found that characters drawn from 
these parts were both important and reliable. I showed how a 
formula of the structure of the wing could be laid down for every 
family, and thus came to the conclusion that Miamia and Hemerisiia 
were types each of a new family of Neuroptera, synthetic in character, 

1 Meek and Worthen. Proc. Acad. Natural. Sc. Philad. 1865, pp. 41-2. 

2 Sill. Amer. Journ. Sc. and Arts [2] xxsvii. p. 34. 
3' Sill. Amer. Journ. Sc. and Arts [2] xl. p. 268. 

4 Memoirs Bost. Soc. Nat. Hist. vol. 1. pp. 173-92, pi. vi. 

VOL. V. — NO. XLVII. 15 



218 Scudder — Fossil Insects of North America. 

combining peculiarities both of Neuroptera proper and of Pseiido- 
neuroptera. I subsequently came to similar conclusions concerning 
some of the Devonian insects and the Haplophlehiiim from the Car- 
boniferous rocks of Cape Breton. In the case of Miamia and Beme- 
ristia, I have ventured to define and name the families to which they 
belong, calling them respectively Falceoplerina and Hemeristina. 
From the remains of the body we may judge that the habits of 
Palceopterina were similar to those of Sialina. 

Kemains of two other animals, found in the ironstone concretions 
at Morris, have been described by Messrs. Meek and Worthen.- 
One form was considered a Myriapod ; the other, the woolly cater- 
pillar of a moth. If the latter were truly a caterpillar, it must have 
belonged to one of the higher families {Arctiadce), and the discovery 
would be one of the most interesting facts in the recent history of 
fossil embryology. It must be confessed that the resemblance of 
Palceocampa anthrax to a caterpillar is very striking, but, judging 
from the descriptions and figures, I am inclined to refer both of these 
imperfectly preserved remains to the class of worms. The hinder 
half of the body of the so-called myriapod {AntJiracerpes typus) 
tapers to a point, and the extremity, which is furnished with a few 
setae, bears little resemblance to the form of myriapod. Neither 
head nor legs are represented on the plate. 

Passing upwards, we have next, in the Triassic rocks of the 
Connecticut Eiver, some questionable tracks, referred by Hitchcock 
to insects and myriapods : little attention has yet been paid to them. 

Eemains of insects, which I believe to be larvae of Coieoptera, 
have been found in slates similar to those in which the fossil fish of 
the Connecticut Eiver occur ; but Professor Marsh informs me that 
the two remains have never been found directly associated with 
each other. Professor Hitchcock has described and figured these 
larvae under the name of Mormolucoides articulatus,'^ stating that 
Professor Dana considered them neuropterous. Dr. Le Conte, 
having examined the figures alone, expressed an opinion that the 
animal was the larva of a neuropterous insect, belonging to the 
family of EpliemeridcB. Dr. Hitchcock then desired the name to be 
changed to Palepliemera mcedieva, by what just law of zoological 
nomenclature I do not know. I shall, therefore, in writing, retain 
the original name of Mormolucoides articidatus. 

Professor 0. C. Marsh has kindly lent me a slab containing from 
twenty to thirty specimens of this insect, and I have examined 
individuals in the Museum of the Boston Society of Natural History. 
So few of the insects have a single segment of the body perfectly 
preserved, that it is difficult to make out their real form ; enough 
can be seen, however, to warrant the following statements and 
descriptions : — 

The body is formed of fourteen segments ; the first two are rather 
smaller than the others. The first segment is quadrangular, and 

^ Geological Survey of Illinois, vol. ii. p. 409-10, pi. 32, figs. 1, la, 3. Proc. 
Acad. Nat. Sc. Pliilad., 1865, p. 51-3. 

2 Ichnology of Massachusetts, pp. 7, 8, pi. vii., figs. 3 and 4. 



Scudder — Fossil Insects of North America, 219 

twice as broad as \on^ ; the angles are well rounded ; the front is 
defeply excavated, and the two lobes thus formed have elevated bosses. 
The second segment is a little larger than the first, and is regular in 
form, twice as broad as long, and has rounded sides. The third and 
largest segment of the body is twice as broad as the second, but of 
the same form and proportions ; the rest are of a similar form, but 
grow very gradually smaller, and, toward the extremity of the 
abdomen, proportionally longer. The last segment is no broader 
than the second, and nearly square, with rounded angles : a dorsal 
mark, consisting of two impressed lines, lying parallel and close 
together, extends the whole length of the body. 

Where the dorsal surfaces are exposed, there are no signs of 
appendages, but, in a single case, the upper surface seems to be 
presented to view. Here, the anterior extremity is imperfect, but 
on either side of the first three segments which are preserved, slight 
elevations appear to be indications of legs. The inner edges of 
these elevations are bent at right angles, the angle being directed 
inward and rounded off, so as to make the elevations appear almost 
crescent- shaped ; on the outer side, the elevated portion slopes 
gradually away. The segments composing the body are widely 
separated from each other, and, in many cases, actually parted; 
they must have been of a horny, or, at least, a coriaceous texture, 
with a slighter connecting membrane. Fragments, consisting of 
one or two segments, are scattered about on the stones. 

The drawings given by Dr. Hitchcock are inaccurate, if the speci- 
mens before me belong, as I suppose, to his species. He has figured 
them with lateral appendages of a peculiar character. I believe these 
do not exist — but, that, in all cases, the sides of the segments are 
regularly and symmetrically curved. Unless they are examined with 
great care, one might easily believe in such a lateral prolongation of 
the segments, but this appearance is always owing either to the 
imperfect state of the specimens or to their incomplete exhibition 
upon the stone. It was chiefly on account of these appendages that 
Dr. Le Conte referred the insect to the Ephemerina. 

There is but one specimen on Professor Marsh's slab where the 
anterior segments are well defined ; even here, they have a deceptive 
anomalous appearance, similar to the large drawing in Dr. Hitchcock's 
last work. 

Judging from the form of the Mormolucoides, from its being pro- 
vided with feet on the thoracic segments alone ; and, from the fact, 
that all the segments were evidently formed of hard shells — I am 
convinced that the remains must be larvas of coleopterous or neurop- 
terous insects. The nature of the segments, indeed, would be in 
exact keeping with a myriopodal character, but the absence of any 
indication of legs upon the posterior segments, and the small and 
fixed number of the segments themselves, prevent our referring them 
to that group. The slight development of legs seems to preclude the 
possibility of their belonging to Neuroptera, and we are thus inclined 
to consider them coleopterous larvas. They certainly remind one of 
some Cehrionidce, but the only known larva of that group lives on the 



220 



Scudder — Fossil Insects of North America, 



roots of plants, and would not be likely to occur in such a deposit as 
that in wliich these remains were found. 

The only specimens of insects from the Tertiaries of North America 
were discovered, in 18G5, by Professor William Denton, in the valley 
of the White Eiver, Colorado, near the confines of Utah.^ This 
valley lies just west of the main chain of the Kocky Mountains, and, 
according to Professor Denton, the rocks all belong to the Tertiary 
age. The country in which they occur is a most remarkable one ; 
the whole surface is bare rock, eroded by water into ravines and 
canons, gorges and valleys, a thousand feet in depth.^ 

The following table gives Professor Denton's view of the super- 
position of the rocks ; the thickness of the several deposits is only 
estimated. The upper beds are found near the junction of the White 
and Green Eivers in Utah ; the lower ones, near the Parahlamoosh 
Kange, where they are covered by immense beds of lava. 



1 


Eed and white sandstones 


Seen, but not examined 


2000 ft. 


2 


Brown sandstones, passing occasionally 
into conglomerate and alternating 
with thin beds of blueish and cream- 
coloured shales, all dipping to the 
w€st at an angle of about 20*. Pro- 
bably of Miocene age. 


Turtles; fragments of large 
bones and teeth of mam- 
mals ; fossil wood of de- 
ciduous trees. Perpendi- 
cular veins of petroleum 
coal. In the lower shales 
Insects and leaves of de- 
ciduous trees. 


1200 ft. 


3 


Petroleum shales, varying in tint from 
a light-cream to inky blackness. One 
bed, 20 feet thick, resembles cannel 
coal. 


Innumerable remains of 
Insects and leaves of de- 
ciduous trees. 


1000 ft. 


4 


"White or light-brown sandstones. 
White shales, on which are ripple 
marks. Brown shales and shaiy 
sandstones. 




800 ft. 


5 


Thick white sandstones and brown 
shales. Thick brown sandstones. 


Brown sandstones, wea- 
thered into cavities. 


1000 ft. 


6 

7 


Sandstone, limestone, shales, blue, 
brown, and black underclays. Beds 
of coal or lignite. Brown sandstones 
and shales, very soft. Coal in se- 
veral beds, with underclays. "White 
sandstones, with alternating blue 
shales. 


Limestone contains conchs 
and small gasteropods. 
Two wide expansions of 
White Biver Valley have 
been made where the soft 
shales occur. 


2700 ft. 


Compact red sandstones. Wliite sand- 
stones. Red sandstones, shaly and 
micaceous. Thin fetid limestones. 


Fragments of shell in the 
limestone. 


1400 ft. 


8 


Yellow soft sandstone 




300 ft. 


9 


Gypsum 




200 ft. 



1 Proc. Bost. Soc. Nat. History, vol. x., pp. 305-6, vol. xi., pp. 117-8 ; American 
Naturalist, vol. i., p. 56 ; HoUister; The Mines of Colorado, pp. 378-87, 12rao. 
Springfield, 1867. a Hollister, Mines of Colorado, p. 383. 



Scudder — Fossil Insects of North America, 221 

I have examined specimens from Bod No. 3, above ; perhaps, the 
lower shales of No. 2, in which insect remains occur, belong pro2)erly 
to No. 3. The fossils were brought from two localities, called, by 
Professor Denton, Fossil Canon and Chagrin Valley ; they were 
about sixty miles apart, but the rocks in both cases were the same. 
From the specimens I have seen, I should judge that«the shales were 
deposited at the edge of a fresh-water lake. 

Ninety specimens, embracing about sixty-five species, were 
brought home ; many of the little slabs contain several species of 
insects, but the remains are often too fragmentary and imperfectly 
preserved for identification. Two-thirds of the species, and, at least, 
three-fourths of the specimens, are dipterous; some of these are 
stout, aquatic larvae, whose more advanced stages are not rej^resented 
on the stones. The perfect Biptera are mostly MijcetojpMlidce and 
TipuUdce ; there are also some small Coieoptera and a few Homoptera, 
Eymenoptera, Lepidoptera, and Phjsopoda. The Homoptera are repre- 
sented by species allied to Issus, Gypona, and Delphax; well 
preserved specimens of Myrmica and Formica represent the Hymen- 
optera. A poorly-preserved Moth, apparently a Noctuid, is the only 
member of the Lepidoptera, unless one of the larvae prove to belong 
to some genus resembling Limacodes. Perhaps the Physopod, 
belonging to a group which has never been found fossil, is of the 
greatest interest : it differs essentially from all of Heeger's illustra- 
tions of this group. The abdomen is scarcely larger than the thorax ; 
the veinless under wings are almost as long and — near the tip — quite 
as broad as the upper wings. Both the upper and lower veins of the 
upper wings are connected with the margin by cross-veins, which 
occur, at about one-third and two-thirds of the distance, from the 
base to the tip of the wing. The principal veins approach each other 
near the centre of the wing, and are connected by a cross-vein. The 
wing is heavily fringed with hairs, those on the under border — espe- 
cially near the tip — being about three times the length of those on 
the costal border ; there are a few hairs at the tip of the abdomen. 
Several specimens of this insect are admirably preserved : although 
its parts are so minute that the outline of the under wing can only 
be determined by the microscopic hairs upon its border, the insect 
can be completely restored from two or three individuals. I have 
proposed for it the name of Falceotlirips fossils. 

The specimens from the two localities differ so completely as to 
awaken the suspicion that the rocks of one locality may be older 
than those of the other. In both places, Mycetopliilidce and other 
Diptera are found, but, in Fossil Canon, the variety and abundance 
are proportionately greater. The Ant, the Moth, the Thrips, and 
nearly all the small Coleoptera are restricted to Fossil Canon, while 
the larvae come from Chagrhi Valley. 

Perhaps no general conclusion can be drawn from this small 
collection, particularly as there is a total absence of means of com- 
paring it with fossil insects of a similar age in this country ; yet, 
while it does not agree in the aggregation of species with any of 
the insect-beds of England or Southern Europe, nor with those of 



222 Notices of Memoirs — D, Forbes' 

the Amber fauna, there can be little doubt that it belongs to the 
Tertiary epoch. 

We close with a few statements relative to the eighty-seven species 
mentioned in the previous pages. Six of them are from the 
Devonian Formation ; fifteen from the Carboniferous ; one from the 
Trias ; and sixty-five from the Tertiaries. Ten are ColeojJtera : viz., 
one from the Trias and nine from the Tertiaries ; four are Orthoptera, 
all from the Carboniferous ; nine are Neuroptera, viz., six from the 
Devonian and three from the Carboniferous. Five more, either 
Orthoptera or Neuroptera, are from the Carboniferous. Three are 
Hyrnenoptera, forty-five are Diptera, six are Hemiptera, all from the 
Tertiaries. Three are Lepidoptera, viz., one doubtful from the 
Carboniferous and two from the Tertiaries, one of which is also 
doubtful. Two are Myriapoda, both from the Carboniferous, but one 
of doubtful character. No spiders have been found fossil in America. 

From this it appears that the Diptera, Hemiptera, Hyrnenoptera, 
and Lepidoptera (omitting the doubtful ones from Illinois) are re- 
stricted to the Tertiaries ; the Coleoptera, with one Triassic excep- 
tion, to the same ; the Orthoptera and Myriapoda to the Carboni- 
ferous ; while the Neuroptera are found in both the Devonian and 
Carboniferous formations. 

Boston, U.S., November 25th, 1867. 



nsroTiciES oip 3VI::ElIs^OII^s. 

— ♦ — 

I. — Mr. David Forbes' Eesearches in British Mineralogy. 

MK. FORBES has published in recent numbers of the "Philo- 
sophical Magazine" a series of papers, in which he 
proposes to record, from time to time, the results of his investi- 
gations in British Mineralogy. In these communications it is his 
intention, to use his own words, '' besides treating of the physical 
character and chemical composition of the minerals under con- 
sideration, to pay especial attention, whenever it is practicable, to 
their association, paragenesis, and mode of occurrence, as connected 
with the petrology and geology of their localities, in order thereby 
to elucidate, as far as possible, the origin and formation of the rock- 
masses, or mineral veins, in which they may happen to be im- 
bedded." Before proceeding to the task in question, he devotes 
some attention to the present position of this branch of science in 
the United Kingdom, and finds that, though the labours of British 
mineralogists in the first third of the present century gained for 
British science a position " of which the country might well be 
proud," the advances which have since been made are mainly due to 
the researches of Continental inquirers. This unsatisfactory state 
of things he ascribes to the superior attraction of palaeontology on 
the one hand, and organic chemistry on the other, and fears, more- 
over, that the British geologists of the present day often undervalue 
the importance of a knowledge of mineralogy for the successful pro- 



Researches in British Mineralogy. 223 

secution of petrological investigations. Speculations are made on the 
cliemical changes which our rock-masses have undergone before we 
are in possession of accurate data respecting the mineralogical cha- 
racter and chemical composition of the rocks themselves. " Only very- 
few chemical analyses of British rocks have been made," and it is 
humiliating to learn that, " in this respect, England stands far be- 
hind the rest of Europe ; France, Germany, Russia, and even the 
small kingdoms of Norway and Sweden are far in advance with 
regard to the knowledge of the chemical and mineralogical compo- 
sition of their rocks." Through the absence of exact information on 
this important subject, the nomenclature at present used by petrolo- 
gists " is altogether inadequate to the demands of the more advanced 
state of the other branches of geological inquiry ; in geological sur- 
veys and maps it is common to find eruptive rocks of totally different 
mineral and chemical composition and age confounded with one 
another, and, in other cases, to find rocks coloured and described by 
names that do not pertain to them. In fact, the present state of 
classification and nomenclature of the eruptive rocks is such that it 
becomes impossible to know with any certainty what exact rock may 
be intended or mapped under the names generally in use." The 
science of mineralogy, as expounded in text books, is too apt to be 
considered merely to treat of the physical, chemical, and crystal- 
lographic characters of mineral species, and to end here. "The 
study of their mode of occurrence, association, and paragenesis, as 
well as of their origin and the relations which they bear to the geo- 
logy of the matrix in which they are embedded, is one of the highest 
importance and interest to the mineralogist." These considerations are 
generally neglected, and it has become customary to regard the presence 
of minerals in rock masses as accidental, and to shirk the question of 
their origin. It is evident, however, their presence is due, not to 
chance, but to the operation of definite laws ; and to this important 
subject the author directed his attention. His researches have led 
him to certain general conclusions, which are given. " Excepting 
only the smaller number of species which make up the bulk of rock 
masses in general, it was found that most other minerals when oc- 
curring in eruptive rocks, even when met with in the most widely 
separated parts of the globe, present themselves under similar con- 
ditions, have the same associated minerals along with them ; and 
that the eruptive rocks in which they occur, whenever the age of 
their intrusion could be satisfactorily ascertained, frequently, if not 
always, corresponded in geological chronology." In the eruptive 
rocks by far the greater number of mineral species have been found ; 
and in all parts of the globe the same or very analogous minerals 
are, as a rule, found to accompany the outbursts of similar eruptive 
rocks. Far, therefore, from regarding the appearance of minerals in 
eruptive rock-masses as accidental or extraneous, the author holds 
that more extended and accurate investigation will demonstrate, that, 
in like manner as the occurrence of certain fossils or groups of 
fossils enables the geological age of a sedimentary bed to be deduced, 
so will the presence of certain minerals, or classes of minerals, serve 



224 Notices of Memoirs — D. Forbes^ 

as a means of identifying the contemporaneous intrusions and out- 
bursts of the eruptive rocks, which, at different geological epochs, 
have disturbed the earth's external crust." It was, likewise, observed 
that " whenever the same mineral is present in two or more rocks of 
different geological age, it is usually, if not invariably, characterised 
in each case by certain peculiarities, either in physical structure or 
chemical composition, which serve to distinguish it under the different 
circumstances of occurrence." This is shown to be true of felspar, 
mica, augite, garnet, apatite, hornblende, etc. In short the minerals 
generally regarded as accidental and extraneous, oftentimes form the 
real characteristic of the rock-masses containing them. 

The author's labours on this important question have been greatly 
retarded by the great scarcity of facts which were found available. 
This is principally due to the neglect of mineralogists to record 
in their description of minerals their mode of occurrence, their 
mineral association, and the nature and age of the rock in which 
they are imbedded, as well as to the want, already mentioned, of 
chemical analyses of many of even the most common British mineral 
species. Of the 306 British species and sub-species described in one 
of the most recently published manuals of mineralogy of the British 
Islands, 164: have not yet been examined ; and, it would scarcely 
be believed, that amongst these are included such minerals as horn- 
blende, augite, orthoclase, labradorite, chlorite, talc, garnet, tourmaline, 
olivine, epidote, serpentine, beryl, etc. Moreover, our present know- 
ledge of the composition of British rocks is of an equally unsatisfactory 
kind. " May it not now be fairly asked whether the natural infer- 
ence to be deduced from these facts is not, that it is high time for 
British mineralogists and geologists to set to work, in order to supply 
these deficiencies before occupying themselves in propounding vague 
theoretical explanations, to account for the origin and metamorphosis 
of rocks in the field ?" In the author's papers are given a descrip- 
tion and analyses of the following British minerals. 

Gold from the Glogau Quartz Lode, No. 2. — The lode occurs in the 
Lower Silurian Lingula beds, close to their junction with the Cam- 
brian strata of the Geological Survey ; it runs about 18° north of east, 
and dips at an angle of 88° to south, cutting through both fossili- 
ferous strata and the intruded diabases, which are described as green- 
stones in the Survey ; and it is, consequently, of later geological age 
than both these rocks, and is not improbably younger than the Silu- 
rian formation as a whole. The explorations appear to indicate that 
the lode is more auriferous at the parts where it cuts through the 
Lingula beds, with their accompanying diabases, than at greater depth 
where it traverses the Cambrian grits. Among the accessory minerals 
found in the lode are tetradymite, iron pyrites, chalco-pyrite, galena, 
chlorite, calcite, dolomite, chalybite, and heavy spar, which, as well 
as the gold, are distributed very irregularly in the quartz. When 
the quartz contains calcite, dolomite, and chalybite, or includes frag- 
ments of neighbouring clay-slate, it is regarded as likely to be more 
auriferous than when the lode consists of quartz only. When iso- 
lated fragments of the slate are found in the quartz of the lode, the 



Researches in British Mineralogy, 225 

gold and other metallic minerals are commonly found adhering to 
or crystallizing on their under surfaces, which may have arrested 
these minerals in the act of being carried into lode-fissure from 
below with the stream of liquid quartz. The specific gravity of one 
specimen of gold was found to be 17-26, and two analyses showed 
the per-centage composition of gold 90, silver 9*25, the remainder 
being quartz. These numbers closely agree with the formula Aug 
Ag. Another alloy, lighter in colour and probably richer in silver, 
is sometimes met with in the lode. 

Stream Gold from the Biver Mcmddach. — A specimen of the dust 
washed from the bed of the river near Gwynfyndd, some eight miles 
from Dolgelly, contained small, flattened, elongated spangles of gold, 
the largest having the size of a pin's head, accompanied by abund- 
ance of fine black sand, supposed to be magnetite, but found to be 
titanoferrite, together with some small particles of quartz, slate- 
rock, mica, iron pyrites, and galena. The gold was found to have 
a specific gravity of 15.79, and the following composition : gold 
84-89, silver 13-99, iron 0.34, and quartz 0-43. Several spangles 
had a peculiarly rich yellow colour due to a thin film of sesquioxide 
of iron adhering to their surface. 

Titanoferrite. — The basaltic or doloritic rocks of the South Staf- 
fordshire coal-field invariably contain a small amount of a heavy 
black metallic mineral, strongly attracted by the magnet, and 
generally regarded as magnetic oxide of iron, whilst analysis showed 
it to be titanoferrite. Removed from the pulverised rock by means 
of a magnet, it was found, on examination, tc have a specific gravity 
of 4'69, and a composition closely approximating to the formula 
Fcj O3 Ti O2. The associated minerals, distinguishable only in thin 
sections when viewed under the microscope, are a triclinic soda-lime 
felspar, augite, and a small quantity of what is probably seladonite, 
whilst pyrites, apatite, and a zeolitic mineral are likewise occa- 
sionally present. An examination of specimens of these basaltic 
rocks from each eruptive boss in Staffordshire, as well as others 
from the intrusive masses occurring in coal - pits, showed that 
titanoferrite is invariably present, and is consequently an essential 
constituent of the rock itself. It is, moreover, that variety of 
titanoferrite, which usually accompanies the eruptive rocks of 
Palasozoic age. The presence of titanium not only serves to charac- 
terise the basalts of this district, but likewise affords a means of 
detecting these rocks where altered by metamorphic action, and of 
referring tuffs, clays, etc., formed from them, to the original source. 
Two instances furnishing proofs of this are mentioned. 

Polytelite from the Foxdale Silver Lead Mine, Isle of Man. — This 
mineral has been found in quantity sufficient to make it an object of 
commercial consideration. The lode wherein it occurs cuts through 
both the Lower Silurian and the eruptive granite ; the latter 
appeared subsequent to the deposition to these beds, and is identical 
in its mineralogical character with the auriferous granites of other 
parts of the globe. The minerals associated with the polytelite are 
galena, chalcopyrite, iron pyrites, zincblende, quartz, dolomite, 



226 Notices of Memoirs — D. Forbes' 

chalybite, and calcite. The characters of the mineral itself are as 
follows : massive ; opaque ; lustre metallic ; colour brown -black ; 
streak black to brown-black ; fracture sub-conchoidal, uneven, and 
granular, brittle; powder black; hardness, 3*5, scratching calcite, 
but not fluor ; specific gravity, 4-97. Analysis led to the following 
numbers : sulphide of silver, 15'67 ; sulphide of antimony, 34"82 ; 
sulphide of copper (Cu S), 34*26; sulphide of iron, 7-57; sulphide 
of zinc, 7-18 ; and sulphide of lead, 1-66. These results differ but 
little from the composition of specimens of polytelite from other 
localities to which the formula 4 (Cuj, Ag, Fe, Zn, Pb) S, Sb Sg is 
attributed ; it appears not unlikely, however, that in such metallic 
sulpho-salts the copj^er may really be in the form Cu S. 

Polytelite from the Tjjddynglwadis Silver Lead Mine, N. Wales. — 
This mine lies in the valley of the river Mawddach, near Dolgelly, 
and is close to the junction of the Cambrian rocks with the Lower 
Silurian Lingula beds, the main lode cutting through the Menevian 
group with its associated diabases. The polytelite is disseminated 
in the lead ores of this mine, and was with difficulty isolated in 
sufficiently pure a condition for analysis. Its associated minerals 
are native gold, native silver, galena, chalcopyrite, blende, iron 
pyrite, arsenical pyrites and quartz. Assays showed the polytelite 
to contain 11-25 per cent, of silver. In the washing of the ores of 
this mine it had been noticed that the lighter slimes were the 
richer in the precious metals, which the author imagined to be 
due to the greater part of the silver occurring in the form of poly- 
telite (specific gravity 4-8), and not as a constituent of the galena 
(specific gravity, 7*7). He succeeded, by careful washing, in 
separating the metallic portion of the powdered ore into two layers, 
the lighter in which was most of the polytelite, containing 182 
ounces of silver per ton, and the denser, consisting of argentiferous 
galena, yielded 60 ounces of silver per ton. 

Sulphides of Iron and Nickel. — The sulphide of iron and nickel 
from the nickel mine, near Inverary Castle, Argyllshire, possessed 
the following characteristics : massive ; fracture between granular 
and semicrystalline ; brittle ; opaque ; lustre metallic ; colour, light 
bronze-brown ; hardness, 3*5 ; strongl}'- magnetic ; specific gravity, 
4*5. It was composed of 38*01 per cent, sulphur, 50*66 iron, and 
11*33 nickel ; and is probably to be regarded as composed of 
Millerite and pyrrhotine. Some specimens of nickeliferous pyrrho- 
tine from this mine are studded with brass-yellow spots resembling 
iron pyrites, and after the lapse of some years the double sulphide 
becomes disaggregated, whereby the separation of the yellow 
mineral can be effected. Its specific gravity was found to be 4*93, 
and its composition : sulj^hur 43*32, iron 45*73, nickel 1*99, cobalt 
1*24, copper, 1-18. The iron pyrites appears to have segregated out 
of the general mass, carrying with it the cobalt and copper, scarcely 
a trace of cobalt being found in the pyrrhotine ; and there appears 
to be a tendency on the part of cobalt to associate itself with bisul- 
phide of iron, whilst nickel appears to prefer uniting itself with the 
magnetic sulphide. A chemical examination of several hundred 



Researches in British Mineralogy, 227 

specimens of iron pyrites and maf^etic pyrites taken from mineral 
lodes and eruptive rocks, proved that nickel was very rarely found 
in iron pyrites, when unaccompanied by pyrrhotine, but that cobalt 
was very commonly present in small quantity, — and, on the other 
hand, that cobalt was equally seldom present in magnetic pyrites if 
unaccompanied by iron pyrites, — also that when both these metals 
were present in a specimen of pyrites, the nickel greatly prepon- 
derated when the pyrites in question was magnetic, whilst the 
reverse was found to be the case in the ordinary iron pyrites. A 
specimen of sulphide of iron and nickel from the Craigrnuir mine, 
near Inverary, was likewise examined. The lode in this district 
traverses metamorphic strata, and is disturbed by intersecting trap- 
pean dykes. The characters of this mineral agreed closely with 
those of the specimen already mentioned, its specific gravity was 
4-602, and its composition : sulphur 37-99, iron 50-87, nickel 10-01, 
and cobalt 1-02. 

Gersdorffite from the Craigrnuir Nickel Mine, near Inverary. — This 
mineral occurs in a small string or cross-course intersecting the main 
lode of sulphide of iron and nickel. The specimen examined was 
a compact aggregate of minute indistinct crystals along with quartz 
and a talcose mineral. In places, patches and strings of copper 
pyrites were visible, but little or no sulphide of iron and nickel 
occurred with it, although this last-mentioned mineral formed the 
mass of the lode. The characters of the mineral are as follow : 
crystallized ; opaque ; lustre metallic ; colour, white to greyish 
white, tarnishing to a greyish-brown tinge ; streak, black ; powder, 
blackish grey; fracture, granular; brittle; hardness, 3-75, rather 
below fluor spar; specific gravity of two specimens, 5-^b and 5-49. 
The percentages of the analyses accord with the formula Ni (S As) 2, 
and show the British mineral species to bear a resemblance to the 
crystallized specimens from Schladming in Styria. 



II. — The Bone-Caves of Brazil and their Animal Eemains. 
By Professor Eeinhardt. 

THIS distinguished author, well known to zoologists by his 
numerous and valuable contributions to the history of Mammals 
(especially Cefacea), Birds, Eeptiles, Fishes, etc., has favoured one 
of the popular scientific journals^ of his country with a detailed 
and very interesting account of ''The Bone-Caves of Brazil and their 
Animal Remains ;" a subject on which Professor Eeinhardt, through 
his repeated travels in that country, and his familiarity with its 
recent and Post Pliocene fauna,^ must be regarded as one of the first 
authorities. In the hope that one of the many popular scientific 
reviews and journals of England will give its readers the plea- 
sure of becoming acquainted with his memoir in extenso, through a 

^ Tidschrift for populare Fremstillinger af Naturrnidenskaben, udginet af C. Togh 
az C. Liitken, 1867. 

2 Dr. P. W. Lund's collections from the Brazilian Caves in the Museum of Copen- 
hagen are entrusted to the care of Prof. Eeinhardt. 



228 Notices of Memoirs — Eeinkardfs Bone-Caves of Brazil, 

translation, we shall here restrict ourselves to giving in the author's 
own words the general conclusions with which he sums up the most 
important results of his careful studies on the subject. 

" 1. During the Post Pliocene epochs, Brazil was inhabited by a 
veiy rich Mammalian Fauna, of which the recent one might almost 
be said to be a mere fraction or a crippled remnant, as many of its 
genera, even families and sub-orders, have vanished, and very few 
been added in more recent times. 

"2. During the whole Post Pliocene epoch the Brazilian Mam- 
malian Pauna had the same peculiar character which now distin- 
guishes the South American Fauna, compared with that of the Old 
World ; the extinct genera belonging to groups and families, that 
to this very day are peculiarly characteristic of South America. Only 
two of its genera, the one extinct (Mastodon), the other still living 
(the Horse), belong to families that in our epoch are limited to the 
Eastern Hemisphere. 

"3. All the Mammalian orders were not in the same degree richer 
in genera in former times than now. The Bruta, Ungulata, Pro- 
boscidea, and, lastly, the Ferse, have relatively suffered the greatest 
losses. Some orders, for instance the Chiroptera and Simiee, number 
perhaps even more genera now than formerly. 

"4. The Post Pliocene Mammalian Fauna of South America 
differed much more from the modern one, and was especially more 
rich in peculiar genera, now extinct, than the corresponding fauna of 
the Old World. 

" 5. The scantiness of great Mammalia — one might say the dwarf- 
like stamp impressed upon the South American Mammalian Fauna 
of our days, when compared with that of the Eastern Hemisphere, was 
much less observable, or rather did not exist in the prehistoric Fauna. 
The Post Pliocene Mastodonts, Macraucheni^, and Toxodonts 
of Brazil, its many gigantic Armadillos and Sloths could well rival 
the Elephants, Ehinoceros, and Hippopotami, which during the same 
period roamed the soil of Europe." X.A. 



I^:EA^I:E^ws. 



NouvELLES Eecherches sur les Animaux Vertebres dont on 

TROUVE LES OSSEMENTS ENFOUIS DANS LE SOL ET SUR LEUR COM- 
PARAISON AVEC RES ESPECES ACTUELLEMENT EXISTANTES. Par 

Paul Gervais. Ire. serie. Illustrated by 50 plates and numerous 
woodcuts. Arthur Bertrand, Paris, 1867. 4to. 

THIS work, of which we have the first five numbers before us, is 
announced to be completed in thirteen parts, each of 24 pp., 
accompanied by four lithographic plates and woodcuts. 

The first division of the work treats of the Antiquity of Man and 
the Quarternary Period 

After giving a short history of the opinions that have beeen ex- 
pressed since the attention of geologists was first turned to this 
subject, the author recounts some of the discoveries which led scien- 



Reviews — Gervais on the Cave-Fauna, 229 

tific men to suspect the co-existence of man with the larger, and long 
since extinct, Mammalia of the Pleistocene epoch. 

In the first chapter, M. Gervais discusses the value of the different 
proofs of the existence of prehistoric man in Western Europe, e.g. 
fossil human bones, flint and bone implements, many of the latter 
being made of the bones of extinct animals, that had evidently been 
cut when in a fresh state, and on some of which were drawings of 
the Mammoth, Keindeer, and other animals long since extinct, or 
which had migrated from these regions in prehistoric times, and 
whose remains are found associated in the Quaternary deposits and 
caves of France and England, etc. 

Next comes an account of the " Palafittes " or Swiss lake-habi- 
tations, the newest of which, our author thinks, approach very near 
to historic times, and do not date back more than 2000 years (just 
at the commencement of the Bronze Age), the earlier ones, how- 
ever, belonging to the Stone Age. 

In talking of the Bronze Age, a curious mistake occurs, for M. 
Gervais says the Phenicians came as far as Scotland to seek one of 
the elements of this alloy, which surely must be a misprint for 
Cornwall (Part 2, p. 29). 

Full descriptions of the implements and human animal remains, 
as well as a long list of the plants found in the Lake -habitations, are 
given. 

The second chapter is on the deposits of the Quaternary Period, 
and their division into four epochs, in all of which flint implements 
are found, but which are palseontologically distinguishable by means 
of the animal remains occurring in them. 

1st. The Epoch of Elephas meridionalis, which he considers indis- 
putable since the discovery of worked flint at St. Prest. E. meri- 
dionalis is considered in England to characterize an epoch antecedent 
to man's appearance in Western Europe. If found with human im- 
plements at St. Prest, we may yet hear of the discovery of flint 
implements in the Norfolk Forest bed. M. Gervais admits that it 
is difficult to separate this period from the 

2nd, The Epoch of Elephas primigenius ; having the Mammoth for 
its principal species, also the Great Bear, the Hyaena, and the Cave 
Lion, etc. 

3rd. The Epoch of the Domestic Beindeer. 

4th. The Epoch of tJie Lake-dwellings. 

Then follow descriptions of the Osseous Breccia of Montpellier, etc. 

Chapter III. contains minute descriptions of caverns which M. 
Gervais has himself explored. They are mostly situated near the 
centre of France and in Lower Languedoc. He commences with 
Eoca-Blanca, near Cabrieres, Herault, one of the most modern. 
Here several human skeletons have been found ; the skulls are of 
the hr achy cephalic type, and associated with them are bones of sheep, 
pigs, rabbits, and a small race of oxen. 

2nd. Cavern of Baillargues, near Castries (Herault). 

3rd. Pontil, near St. Pons (Herault), in which were found, along 
with a human frontal bone, a canine tooth of TJrsus arctos split 



230 Reviews — Our Scientijic and Popular Journals. 

longitudinally and pierced near the base ; tlie jaw of a beaver, 
various instruments formed from bones of rhinoceros {Bh. Merckii ?) 
ox (Bos prhnigenius), fox, badger, from teeth of horse, of stag's 
horn, and terra-cotta, which apparently belong to the age of 
the Swiss Lake-habitations ; handles made of horn for flint im- 
plements, and some stone implements. Five plates are devoted to 
the contents of this cavern, and the figures are of the natural size. 
Here were also found some instuments of the Bronze and even of the 
Iron Age, and a fibula of silver; but these latter had apparently 
fallen in at a superior opening. 

4th. Several caverns in the neighbourhood of Ganges (Herault). 
In which were found flint implements, bones of man, ox, and goat ; 
teeth of fox, pierced by man ; two valves of the common mussel, 
bones of Ursus spelceus, Cervus elapTius, and Capra cegagrus that had 
evidently been fractured by man. 

5th. Cavern of Bize (Aude). Bones of Eqims cahaUus, Bos primi- 
genius, Capra cegagrus, Antilope Christolii, Bupicapra, Cervus Behoulii, 
C. tarandus, Canis lupus, G. vulpes, Felis sevaloides, Ursus spelceus, 
Hyaena spelcea, embedded with human remains and implements made 
of stone and of the bone of many of the above animals, together 
with the following shells : — Pectunculus glycimeris, Pecten jacohceus, 
Mytilus edulis, Buccinum reticulatum, Natica mille-punctata, Turho neri- 
toideus, Clyclonassa neritcea, Cyprcea coccinella, some of which had 
been perforated by man. 

6. Caverns of Mialet, etc. (Gard), where occur bones of Felis 
antiqua, in addition to those mentioned before, and Antelope Mialeti. 

Chapter IV. contains remarks on Ehinoceros and a few other 
genera of Pleistocene mammals, having reference more especially on 
the identity of their species, and on what has been recorded about 
them by other palaeontologists. 

Chapter V. gives an account of the fossils of Algeria, and a com- 
parison of the Quaternary mammals with those of Western Europe, 
and their living representatives in Central Africa. 

In Chapter YI. the reader is furnished with an account of all the 
known mammals of the Quaternary period, and the localities where 
the remains of the rarer species have been met with. 



OUR SCIENTIFIC AND POPULAR JOURNALS. 

I. The Popular Science Eeview (No. 27) for April contains, in 
addition to much other interesting scientific matter, an excellent and 
most instructive article on " The Gems and Precious Stones of Great 
Britain." By Professor John Morris, F.G.S., of University College. 

After giving a brief historical account of the uses to which pre- 
cious stones are applied by Oriental races, and of the traditions con- 
nected with various species of gems, the author proceeds to describe 
those which occur in the British Islands, — e.g. the garnet, topaz, 
beryl or emerald, sapphire (?), and the varieties of amorphous and 
crystallized quartz, as rock-crystal, amethyst, cairngorm, agate, 
onyx, calccdouy, jasper, opal, etc. In Great Britain these are 



Reviews — Our Scientific and Popular Journals. 231 

generally found embedded in the rock-mass, whilst the valuable 
and most highly prized stones, which come to us from abroad, are 
rarely obtained from the original matrix, but are usually found as 
grains or pebbles in ancient or modern alluvial deposits, the more 
perfect and solid ones only having resisted the wear and tear to 
which they have been subjected since they were set free by the 
breaking up of their parent rocks. Hence the comparative aljund- 
ance of the precious stones in the river-valleys of India, Ceylon, 
Australia, and South America, which traverse the metamorphic 
strata in which these minerals were originally imbedded. 

Of the gems and precious stones found in Great Britain, by far 
the largest class are compounds and varieties of silica, which owe 
their beauty as gems, in many instances, to the presence of an in- 
finitesimal quantity of some metallic oxide, as manganese, iron, 
chromium, etc., thus producing those beautifully coloured stones, 
the emerald, amethyst, cairngorm, etc., so extensively used in 
jewelry. 

In speaking of the Beryl, at page 130, we observe a misprint, 
which might, if passed over, mislead the reader. It is there stated 
that " Beryl is harder than Topaz." On referring to the " Table 
of Physical Characters of Gems," given on page 133, however, we 
find their relative hardness correctly stated thus (placing the hardness 
of the Diamond at 10) : — Topaz = 8 ; Beryl = 7*5. 

This article will be found most instructive, both historically and 
mineralogically — the Chromolithographic plate which accompanies 
it is not, however, so good in its way as those to " Reynaud's 
Histoire Elementaire des Mineraux Usuels" (see Geol. Mag. Vol. 
IV. 1867, p. 555). 

II. The Quarterly Journal of Science (No. 28) for April, par- 
ticularly recommends itself to our notice by a most valuable 
paper by Professor Dr. G. Zaddach, of Konigsberg, on " Amber, 
its Origin and History, as illustrated by the Geology of Samland " 
(Prussia). The age of the " Glauconitic sand " deposit, which yields 
this interesting and valuable fossil Eesin, is of Eocene or Lower 
Oligocene age, according to Mr. C. Mayer, of Zurich ; but the 
associated fossils are marine Mollusca, Echinoderms, and Polyzoa ; 
and the Amber is usually, more or less, rounded and water- worn, 
the associated fossil-wood being generally only found in small pieces 
apparently half- decayed at the time of their deposit. Dr. Zaddach 
devoted himself therefore to the task of ascertaining the probable 
position of the old land-surface, upon which the Amber-pines grew, 
that furnished this rich deposit, yielding, on an average, ^-Ib. to lib. 
of Amber to every cubic foot of sand. Searching for and examining 
with care all the pebbles and fragments of rock which occur in the 
''' Amber-earth," and tracing these to the parent-rock, he shows that 
the Tertiary " Glauconitic sand " has been formed out of the waste 
of the Greensand where that deposit reposed on old Silurian rock 
and he traces the derivation of both the Silurian pebbles and Green- 
sand to the waste of the old high lands of Northern Europe, con- 



232 Revmvs — Our Scientific and Popular Journals. 

Bistinj^ of the crji'stalline rocks of Scandinavia and Finland and the 
Silurian, Devonian, and Cretaceous strata, once extending from 
Scandinavia over the area now occuj^ied by the northern part of 
the Baltic and its bays through Courland and Esthonia far away 
eastwards. 

The trees of this old northern land appear, nevertheless, to have 
enjoyed a temperate climate, elevated probably by a warm marine 
current from the tropics. Thus Camphor-trees, Willows, Beeches, 
Birches, and numerous Oaks occur, together with Pines and Firs, in 
great variety, and amongst them the Amber-pine. In order to account 
for the richness of the Amber deposit. Dr. Zaddach assumes that 
many thousands of this last-named tree must have perished, and 
the amber-gum accumulated in vast quantities in the soil previous to 
the submergence of the land. 

A detailed account of all the beds is given, including a description 
of the more modem Brown- Coal Formation, the trees of which 
nearly agree with the existing European flora. 

A good map of the North-west Coast of Samland, with numerous 
sections, and also a plate of Fossil Insects found in Amber (deter- 
mined by Mr. Frederick Smith, of the British Museum), together 
with a list of authors who have written on the subject, completes 
this most useful and valuable memoir. 

III. The Intellectual Observer having remained single for six 
years, has become tired of celibacy, and this being leap-year, has 
wedded the " Student," by which name it will be in future known. 
Mr. Jackson writes in No. I, February, on "The Screw-Pine" 
{Pandanus) and its allies. (For a good account of the fossil Pandanece 
see Mr. Carruthers' article in Geol. Mag. for April last, p. 153, PI. 
IX.) — Mr. Shirley Hibberd, about Ailantus silkworm culture ; — Mr. 
J. K. Lord on the Pocky Mountain Goat. — Mr. Thomas Wright (in 
Nos. 1, 2 and 3), on Womankind in all ages : he has not, at present, 
touched upon Pre-historic ladies, when he does, however, we shall 
take care to call attention to the fact. 

In No. 2, Mr. Jackson informs us that the fine old patriarch of the 
vegetable world, " The Dragon-tree" of Teneriffe, computed by some 
authorities to be six thousand years old, fell a victim to a furious 
gale which swept across the Island last autumn. Humboldt describes 
it as 45 feet in circumference a little above the root, and Sir George 
Staunton as 12 feet in diameter, 10 feet from the ground, and its 
height 70 to 75 feet. Fossil wood from the Iguanodon Quarry near 
Maidstone has been attributed to this genus {Braccena Benstedii, 
Konig.) 

In No. 3, Professor Church gives us an account of " Turacine." a 
new animal pigment containing copper obtained by him from the red 
feathers of the " Touraco," or ''plantain-eater." It is not a little 
singular that this red colour is instable in the wing of the living bird, 
and can readily be removed by washing the feather. Three birds 
— two species of Plantain-eaters and one Musophaga — have yielded 
this compound of copper. The birds are from the Cape, Natal, and 



Morris — Geological Excursion to Bathy ^c, 233 

the Gold Coast. There is also, among many others, an important and 
valuable paper by the Kev. W. Houghton, M.A., F.L.S., on Holoth- 
uria, or Sea-cucumbers, soft-bodied vermiform Echinoderms, much 
sought after as microscopic objects, on account of the beautiful cal- 
careous spicules which are found in the skin. Being soft-bodied, 
their occurrence in the fossil state is always doubtful, although some 
instances are on record. One of the plates is very nicely executed. 



I^:E:poI^TS jl.j<tid I^i^oo:B:BX)IJ^a-s. 



Geological Excuksion to Bath and its Neighboukhood. — The 
students attending the Geological class at University College, Lon- 
don, made an excursion to Bath with the view of acquiring some 
practical lessons in field geology. They were accompanied by 
Professor Morris, Mr. D. Forbes, Mr. Beale, Dr. Murie ; and were 
met at Bath by Mr. C. Moore, F.G.S., whose intimate knowledge 
of the Geology of Somersetshire materially assisted their researches, 
as that gentleman kindly accompanied them to all the most im- 
portant geological localities. 

Bath is well situated for geological exploration, as not only are 
there many well-exposed sections, but the physical features of the 
district afford striking evidence of the denuding agencies to which 
the whole area has been subjected, and from which has resulted — 
owing to the characters of the rocks — the picturesque scenery of 
the district. The sections around Bath afford good opportunities 
for studying the Lower Oolitic strata — i.e. the Lower, Middle, and 
Upper Lias, the Inferior Oolite, Fuller's earth, and the different 
beds of the Great Oolite, — all of them shewing the very difi'erent 
conditions under which they have been deposited. This is well 
marked in the Bath Oolite series, where the comparatively finer 
stone, known as the Bath freestone (an Oolitic rock largely worked 
and used for building both there and elsewhere) is well distin- 
guished from the upper coarse shelly limestone containing corals, 
sponges, and Bryozoa, and frequently presenting false-bedding due 
to ancient current action. It is to the alternation of these hard 
and soft strata that the terrace-like appearance of the vallej^s is 
due; while, at the same time, their alternate permeable and imper- 
meable nature are the sources of the water-supply of the neigh- 
bourhood, as seen in the springs bursting out at the top of the 
Fuller's earth and Liassic beds — an arrangement which W. Smith 
availed himself of, in lajdng out the canal system of the Oolitic 
districts — these clay beds presenting also, more or less, sloping 
banks and irregular ground. The bottom of the valleys near Bath 
are filled to some height with an old alluvium termed " Mammal 
drift," containing remains of the Mammoth {Elephas primigenius) 
and the Musk ox {Ovibos moschatus), etc. 

The railway now making from Bath to Mangotsfield, near Weston, 

VOL. v.— NO. XLVII. 16 



234 Morris — Geological Excursion to Bath, j-c. 

afforded the party some new and highly interesting sections; one 
about two miles out, exposed the Ehsetic strata, with so-called Gotham 
Marble, White Lias, and " Sun-bed," with few fossils, overlain by the 
Ammonites angidaius, and Bucldandi beds, containing many fossils, 
noticed by Mr. Moore,^ the section presenting two faults or displace- 
ment of the rocks. Not far distant is the Twerton Coal-pits sunk 
through the overlying but unconformable lower Secondary strata of 
no great thickness ; and it was interesting to observe close to the 
pit's mouth another fine stone quarry in the Am. Bucldandi beds 
overlying the probable equivalents of the Am. planorlis zone,^ the 
former containing the characteristic Lima gigantea, GryphcBa incurva, 
Nautilus lineatus, Fleurotomaria Angh'ca, etc., and consisting of thick- 
bedded limestones, with intercalated shaly bands, some containing 
Foraminifera. In the uppermost portion of the Am. Bucklandi beds 
of this pit is a thin band of brown indurated marl, indicating a 
persistent horizon at the top of the series throughout the district. It 
contains many plants and remains of fishes {Hyhodus, Acrodus, Lepi- 
dotus, etc.,) as well as Avicida ineqmvalvis and other shells. 

A section on the same railway near Saltford afforded a fine expo- 
sure of the Am. Bucklandi bed with the associated fossils, showing 
bands of tabular and septaroid limestone, the latter frequently 
containing large Ammonites, while fissures were lined with beau- 
tiful crystals of brown calcite, presenting both the dog-tooth and 
rhombohedral forms, as well as modified octohedrons of pyrites. 
The Ammonite is found here in the same condition as the large one 
originally obtained by Dr. Buckland from the neighbourhood, having 
lost the inner whorls, which enabled the Doctor to thrust his head 
and shoulders through, and thus he rode home, dubbed by his friends 
the Ammon Knight, encircled with the species which now bears his 
name (Sow. Min. Con. 2, p. 69). 

The party visited, on the railway above-mentioned, at Willsbridge, 
another fine section, showing the curved strata of the Eed Marl, 
Eha3tic beds, and Lower Lias faulted against a mass of Pennant rock, 
or sandstone, deeply ferruginous at the junction, but further on 
intercalated with carbonaceous layers and bands of red Hematite. 
The conditions of this section are very instructive, as at the south 
end is seen the Eed marl with greenish bands, and nodules of 
celestine (sulphate of strontian) superposed by a fair development 
of the Eh^tic series with the Avicula contorta zone, Estheria and 
Oythere shales and White Lias, with Modiola, overlain by the Am. 

1 Geol. Journal^ vol. xxiii. p. 497. 

2 The term zone is applied to a subdivision of Lias strata characterized by the 
abundance of a peculiar Ammonite and associated fauna, but which are not entirely 
restricted to that zone. The following are the subdivisions of the Lias, shewing the 
Ammonite zones : — 



Upper ( Am. Juremis 
Lias \ A. communis 
{A. spinatus 

Middle J ^- ^''^^^.^'•^■^^^"* 
T s -^' caprtcornus 

A. ibex 
[a. Jamesoni 



Lower 
Lias 



A. raricostatus 
A. oxynotus 
A. obticsus 

•^ A.. Turneri 
A. Bucldandi 
A. angulatus 

(^ A. planorbis 



Morris — Geological Excursion to Bath, ^c. 235 

Bucklandi beds with the characteristic fossils.^ These beds, as you 
ascend the hill sides above Bitton, are successively overlain by the 
Middle and Upper Lias, and the sands of the Inferior Oolite. 

Another day the party visited — after passing a narrow strip of 
Old Ked Sandstone at Spring Garden, north of Frome — the fine sec- 
tions of the Vallis, where, at Hapsford Mills, the upturned and 
denuded edge of the Carboniferous Limestone are immediately over- 
lain by a thick bed of conglomerate ; the rounded pebbles, many of 
limestone, being sometimes bored and occasionally having oysters 
attached to them. This bed is covered by more quietly deposited 
strata of marl and shale, with nodules containing Estherice ; further 
on a fault is observed bringing down the Inferior Oolite, beyond 
which the limestone contains a kind of mineral vein, which 
becomes far more numerous as you proceed up the valley, and 
more interesting from the fossil contents, consisting, (as shown 
by Mr. Moore,) of Liassic strata, partly filling the fissures, to the 
walls of which Lias fossils are adhering, associated with con- 
cretionary ferruginous bands of Sulphate of Barytes, some Galena 
and Blende. In this valley at the southern corner the Inferior 
Oolite is laid down upon the ancient Carboniferous Limestone sea- 
bottom, and has so accommodated itself to any inequalities in its 
surface as to make it exceedingly difficult to determine where the 
one formation begins, or the other ends. So intimately united are 
the unconformable deposits, that the same hand-specimen may show 
portions of each, with Lithodomi of Oolitic or any intervening age, 
still retained in their burrows in the surface of the Carboniferous 
Limestone.^ 

The Nunney and Holwell sections were afterwards visited, 
showing the numerous Liassic veins in the Carboniferous Limestone, 
of various thicknesses, and containing many organic remains. 
Beyond this is the Microlestes quarry on the Shepton Mallet road, — 
a dyke in the limestone which has yielded such a rich harvest of 
Khsetic remains, including the mammal teeth belonging to the same 
genus (Microlestes), which was first found in deposits of similar age 
near Stuttgard. Besides the mammals Mr. Moore carefully examined 
some tons weight of the vein, extracting therefrom many remains 
of Eeptilia (some new to England), Notliosaurus, Placodus, Psepho- 
derma, Iclitlujosanrus, Plesiosaurus, etc., and not less than 70,000 teeth 
of Lophod'iis, besides shells and corals, many of which are now ex- 
hibited in the Bath Museum. Above the hamlet of Holwell, on the 
Mars ton road, is a small section, in which the Carboniferous, Ehaetio, 
Lias, and Inferior Oolite are represented, the last bed being uncon- 
formable. 

The party concluded the day's excursion by a visit to a new 
trial sinking for coal on the estate of the Earl of Cork, near Iron 
Millbridge, which had reached the depth of eighty feet, in the 
Oxford-clay, showing the characteristic fossils, as Gryphea dilatattty 

^ See the section by Mr. Moore, Geol. Journ., vol. xxiii. p. 499. 
2 De la Beche, Mem. Geol. Survey, vol. i. p. 290 ; Moore, Geol. Journ. vol. xxiii. 
p. 488. 



236 3Io7iis— Geological Excursion to Bath, fc. 

Am. Jason, Nucula, Avicula espansa, and which had been thought to 
be of Liassic age. 

Another excursion included a visit to Eadstock, and the Mendips, 
passing along the table land of the Great Oolite, on Odd Down, the 
Fuller's earth was examined in a field cutting on the hill side, yielding 
many Rhynclionella varmns, and other fossils. At Eadstock, the 
White Lias and Lower Lias are fairly exposed, the zone of Spirifer 
Walcottu, with Pholadomya in their normal position was carefully 
examined, and it was interesting to observe that coal was won 
through these beds, owing, as is well known, to the comparative 
thinness of the Secondary strata in this area as compared with 
similar beds south of the Mendips, and their unconformity to the 
inclined and faulted Coal-measures below. Thus, according to Mr. 
C. Moore, the relative thickness in the two areas is as follows : ^ — 





"Without Coal basin. 


Within Coal basin. 




feet. 




feet. 


Triassic beds 


... 2000 




50 


Rheetic beds 


50 




50 


Lower Lias 


700 




2 


Middle and Upper Lias ... 


600 




42 


Inferior Oolite 


170 




25 



3420 169 

Many fossil plants were collected, and the party had the pleasure 
to examine the fine collection formed by Mr. J. McMurtrie, consisting 
of Lepidodendrce, Sigillaria, Calamites, Aster ophyllites, and the ferns 
Neuropteris and Pecopteris ; some specimens shewing the circinate 
vernation, others traces of fructification, but all in a state of preser- 
vation for which the Eadstock Coal-field is celebrated. 

Proceeding southward the Dolomitic conglomerate was seen near 
Stratton, and further on the outcropping of the Lower Coal-measures, 
the Millstone grit, and Carboniferous Limestone tilted up at a con- 
siderable angle ; beyond this is the Old Eed Sandstone, which there 
forms the crest of the Mendips, and at East End, near Stoke Lane, 
are portions of a dyke of considerable thickness, emerging from 
beneath the Old Eed Sandstone, occurring as bosses in the field, but, 
traced for some distance over the district, it is conglomeratic in 
places, and pronounced by Mr. D. Forbes to be Dolerite. 

This mass of igneous rock is considered by Mr. C. Moore to have 
been the cause of the elevation of many thousand feet of stratified 
rocks, and of the present anticlinal arrangement of the strata of the 
Mendips. Beside this, Mr. Moore inferred an old land-area, as 
originally suggested by Mr. Godwin-Austen, and that these hills 
in Ehaetic and Liassic times interposed a barrier, which, to a great 
extent, modified the physical features of the whole line of country, 
from Frome through a great part of South Wales, and shut out the 
Secondary deposits from the Coal-basin, within which unconforma- 
bility very generally prevails, and that the Secondary beds are very 
insignificant when compared with their equivalent deposits beyond.^ 

J. M. 

> Geol. Journ. vol. xxiii. p. 476. » Geol. Journ. vol. xxiii. p. 537. 



Geological Society of London, 237 

Geological Society of London. — I. February 26th, 1868. — 
Prof. T. H. Huxley, LL.D., F.K.S., President, in the Chair. 
The following communications were read : — 

1. " Notes on the formation of the Parallel Eoads of Glen Eoy." 
By C. Babbage, Esq., F.E.S. Communicated by the President. 

Accepting the theory that these roads were formed on the margin 
of a lake, the author discussed the mode in which this formation 
took place, objecting to the view of its having occurred through the 
piling up of pebbles by wave action, or the accumulation of blocks 
by rain washing them down the hill-side. 

Mr. Babbage expressed his opinion that the material of which 
the roads are formed was brought down by snow and ice slowly 
descending tlie hills until arrested on the margin of the frozen lake. 
On the melting of the snow and ice, it was tranquilly deposited with- 
out any further descent, and thus lay in a horizontal line. 

In conclusion the author adverted to the theory of the change of 
isothermal surfaces within the earth, an account of which he had 
published in the Society's ' Proceedings ' for 1834:, as affording the 
necessary explanation of the causes which had produced the changes 
of climate in the district of the Parallel Eoads. 

2. '' On the origin of smoothed, rounded, and hollowed surfaces of 
Limestone, and Granite." By D. Mackintosh, Esq., F.G.S. 

The author endeavoured to show that smoothed, rounded, hol- 
lowed, and regularly-perforated surfaces of rock (not glacial, nor 
mere developments of structure) have been produced, on the Men- 
dip Hills, by the action of waves charged with sand and stones ; 
and that deeply-grooved rock-surfaces, near Minera, may have 
been ground out by stones moved by waves with or without coast- 
ice. 

3. ''On a striking instance of apparent oblique lamination in 
Granite." By D. Mackintosh, Esq., F.G.S. 

In this paper the author drew attention to remarkable instances of 
apparent stratification and oblique lamination in the granite of the 
Hountor and other rocks of Dartmoor. They seemed to favour the 
aqueous origin of certain kinds of granite ; though this Mr. Mackin- 
tosh left an open question. 

4. " On the Encroachment of the Sea in the Bristol Channel." 
By D. Mackintosh, Esq., F.G.S. 

The object of this paper was to show how the sea denudes a sub- 
merged land valley by planing it down laterally, Stumps of trees 
are found under the sea at a distance of at least half a mile from the 
cliffs near Watchet, with a rocky sea-bottom between. The latter 
must have been left by the erosive action of the sea, which, to the 
east of Watchet, has removed the site of a village called Easenton, 
and encroached at least 200 yards in 150 years. 

5. '' On the two Plains of Hertfordshire and their Gravels." By 
T. MK. Hughes, Esq., M.A., F.G.S. 

The high ground near Hertford Heath, Brickendon, etc., forms the 
higher of the two plains which Mr. Hughes described ; out of it a 
great vaUey has been excavated, the bottom of which forms the lower 



238 Geological Society of London, 

plain ; and out of this again the valleys of the existing streams have 
been scooped, 

The gravels of the upper plain are a marine deposit, and indicate 
a marine denudation of great antiquity, followed by an emergence, 
during which the old valleys were scooped out of that plain. The 
gravels of these valley-plains were formed during a subsequent sub- 
mergence ; they contain bands of clay and loam passing into Boulder- 
clay, and are probably marine. This submergence continued until 
the Boulder-clay was deposited on the top of the higher-plain 
gravels ; and then succeeded a period of emergence, during which the 
present valleys were scooped out of the lower plain. 

II. March 11th, 1868.— "On the Structure of the Crag-beds of 
Norfolk and Suffolk, with some observations on their Organic 
remains. — Part I. Coralline Crag." By Joseph Prestwich, Esq., 
F.E.S., F.G.S., etc. 

The history of the division of the several Crag-deposits into three 
formations — the Mammaliferous, Red, and Coralline Crags — having 
been recounted, the author stated that for the last thirty years the 
evidence of their sequence had remained unaltered, the distinction 
between the Mammaliferous and Red Crags being still purely 
palseontological, not a single case of superposition having been dis- 
covered. Mr. Prestwich then proceeded to the special object of 
this paper, which was to describe more fully the physical structure 
of the several crags, and to determine, if possible, the exact relation 
which the Suffolk Crags bear to the Crag of Norfolk. 

Commencing with the Coralline Crag, the author stated that the 
well-known outlier at Sutton furnishes a base-line and the best clue 
to its structure and dimensions, showing also the depth to which it 
has been denuded and replaced by the Red Crag. The Coralline 
Crag is generally described as consisting of two divisions : — an upper 
one, formed chiefly of the remains of Bryozoa, and a lower one of 
light-coloured sands, with a profusion of shells ; and the author 
now gave their exact dimensions and his proposed subdivisions, as 
follows : — 

Character and Thickness. Localities. 



>^ 



U 



'^^ \h. Sand and comminuted shells, 6 ft. Sudbourne and Gedgrave. 

^ '^^ { y- Comminuted shells and remains of Bryozoa, Sutton, Sudbourne, Ged- 
g g f forming a soft Building-stone, 30 ft. grave, Iken, Aldboro'. 



f/. Comminuted shells, with numerous entire Sutton, Iken, Orford, High 

small shells, 5 ft. Gedgrave. 

Sands with numerous Bryozoa, and some Sutton, Broom Hill. 

small shells and Echini, 12 ft. 

Comminuted shells, large, entire, and double Sutton, Broom Hill, Sud- 

^ shells, and bands of limestone, 15 ft. bourne. 

e. Marly beds, with numerous well-preserved Sutton, Ramsholt. 

and double shells, 10 ft. 

b. Comminuted shells and Cetacean remains, 4 ft. Sutton. 

a. Phosphatic nodules and mammalian remains, Sutton. 
1 ft. 



Geological Society of London. 239 

Mr. Prestwich then stated the localities at which these sub-clivisions 
of the Coralline Crag are exposed, and proceeded to discuss the geo- 
graphical distribution of the existing species in the several zones, 
and the present range of the organic remains. He agreed in the 
opinion that the greater number of the Mammalian remains are ex- 
traneous fossils ; but regarded those of a whale as truly contem- 
poraneous, and probably also the teeth of the Rhinoceros and 3Ias- 
todon, while the bones that are more or less drilled he considered to 
be derived. The occurrence of a large block of porphyry in the 
basement-bed at Sutton was considered a proof that a considerable 
degree of winter cold had been attained at that period, as it would 
be difficult to account for its presence in that bed except by ice- 
action ; the author also enumerated the physical conditions which 
seem to be suggested by the mineral character and the structure of 
the several zones, inferring, from the peculiar mixture of southern 
forms of life with others of a more northern type, that at this early 
period the setting-in of conditions of considerable cold had com- 
menced. 

With the aid of Mr. Gwyn Jeffreys, the author had revised the 
list of Mollusca from the Coralline Crag, and he gave a Table in 
which the range of the species in space, depth, and time was given, 
and an analysis of their synonymy by Mr. Jeffrej^s. He also dis- 
cussed the relations of the Coralline Crag with its foreign equi- 
valents, agreeing in the conclusion that the Crag Noir is a stage 
older than it, while the destruction of beds of the age of some of the 
older Crags of Belgium have furnished many of its derived fossils. 
In conclusion the author described the distribution of sea and land 
at the period of the deposition of the Coralline Crag, as suggested 
by the affinities of the fossils of that deposit. 

ni. March 25th, 1868. — 1. " On some new species of Palaeozoic 
Crustacea from the Upper Silurian rocks of Lanarkshire, etc., and 
further Observations on the Structure of Pterygotus.'' By Henry 
Woodward, Esq., F.G.S., F.Z.S. 

The nature of the remains which have been referred by Mr. Salter 
to Pierygotns (but by the author to Eurypterus) punctatus was first 
discussed by the author, who came to the conclusion that the Lanark- 
shire specimens belong to a new s]3ecies — Eurypterus scorpioides, — 
while the chelate antennas and the detached lip -plate from Ludlow 
must have belonged to other species. 

Eurypterus scorpioides is the first of the new forms now described 
by Mr. Woodward, and is represented by a specimen exhibiting an 
almost entire individual, and certain other fragments. The punc- 
tate ornamentation of this species may be readily distinguished from 
the scale-like markings of Pterygotus and Slimonia. The second new 
iorm, Eurypterus obesus, is remarkable for the great obesity of the 
thoracic somites ; it is represented by the impression and counter- 
part of an entire specimen. Its small size suggested to the author 
the possibility of its being the young of some larger species. The 
third new species, Pterygotus raniceps, is at present known only by 



240 Geological Society of London. 

a single example ; its head is remarkable on account of its obtusely 
pointed triangular form and prominent marginal eyes. 

In conclusion the author made some observations on the structure 
of Pterycjolus, showing that it possessed a series of branchial plates, 
— leaf-like bodies presenting a highly vascular and delicate struc- 
ture, arranged in a linear series of from six to eight in each row, 
and appearing to have occupied a position beneath the thoracic plate 
on the ventral surface of the body, as seen in Limulus at the present 
day. He also suggested that Pterygotus perornatus and P. crassus are, 
possibly, both varieties of P. bilohus ; they are all possessed of a 
bilobed telson or tail-plate. 

2. " On the Coniston Group." By Professor R. Harkness, F.R.S., 
F.G.S., and Dr. H. A. Nicholson, F.G.S. 

The object of this communication v^^as to record the occurrence of 
a new and unique horizon, containing a rich Graptolite -fauna, in that 
portion of the Silurian series of the Lake-district termed the Conis- 
ton-flags by Professor Sedgwick. The authors also gave a detailed 
description of these flags, and pointed out their physical and palas- 
ontological relations with the Coniston Limestone below, and the 
Coniston Grits above them. 

The palgeontological relations of the Coniston Limestone and of 
the underlying green slates and porphyries have been previously 
shown to be those of the Bala and Caradoc group. The mudstones 
succeeding to the Coniston Limestone yield an entirely new fauna, 
including six species of Diplograpsus, all of ^which, with one ex- 
ception, are in Britain characteristic Upper Llandeilo forms ; and the 
evidence of the other species is in the same direction. In Ireland, 
however, many of these species have been obtained from strata of 
Caradoc age. The fossils of the Coniston Grits have very little 
affinity with those of the Kendal Flags, nor do they exhibit such a 
facies as would connect them with the lower members of the Upper 
Silurian series. Palaeontologically, therefore, this Coniston series 
must be looked upon as a continuous group of rocks, and the phy- 
sical evidence leads to the same conclusion. There is, thus, in the 
Lake-district, a greater development of Caradoc and Bala rocks 
than is to be found elsewhere in the British Islands, as we are now 
required to add a great thickness of strata, possessing, on the whole, 
a decidedly Lower Silurian fauna, but containing some new forms 
of life in its higher portions. 

3. " Death of Fishes on the coast of the Bay of Fundy." By Dr. 
A. Leith Adams, F.G.S., 22nd Regiment. 

On the 24:th of September, during a heavy gale from the west, 
impinging almost straight on to the entrance of the Lagoon, known 
as Anderson's Cove, enormous numbers of fish were observed floating 
dead upon the surface of the water, and thrown up in quantities by 
the waves. On the gale subsiding, the whole surface of the lagoon 
and its banks were covered with dead fish, to the depth of a foot in 
some places. It was evident that the shoal had been literally ground 
to pieces against the rocks by the force of the waves. In conclusion 
the author referred to the vast quantities of fossil fish found in the 



Geological Society of Edinburgh, 241 

Devonian and other strata, which suggested catastrophes allied to 
the above incident. 

4. "On Volcanoes in the New Hebrides and Banks Islands." By 
K. Atkins, Esq., of the Southern Cross." Communicated by J. 
Codrington, Esq., F.G.S. 

The author described the islands of Tanna, Lopevi, and Ambrym, 
in the New Hebrides, and Santa Maria and Great Banks Islands, 
among the Banks Island group, as being now active volcanoes, and 
gave an account of a visit to the Hot Springs of Great Banks Island. 
These springs deposit quantities of almost pure sulphur. 

Edinburgh Geological Society, 2nd April, 1868. — In the 
absence of Mr. Powrie, one of the Vice-Presidents of the Society, 
Dr. Page read a paper prepared by that gentleman, "■ On the Working 
together of Volcanic and Denuding Agencies in the Formation of the 
Scenery of Scotland," which was in opposition to the theory pro- 
pounded and advocated by Mr. A. Geikie, in his recent publication 
on the Scenery of Scotland, as also the theory recently advocated by 
the Duke of Argyll. It will be remembered that Mr. Geikie gives 
primary prominence to denudation, while the Duke of Argyll gives 
primary prominence to volcanic agencies alone, and catyclismal 
revolutions. Mr. Powrie exhibited a very elaborate section em- 
bracing the district from the Grampians over Strathmore, the Sid- 
laws to the Ochils, and particularly detailing the valley of the Tay. 
He clearly showed that a subsidence must have taken place in the 
valley of the Tay from the fact of two lines of faults, one on either 
side of the valley, with the upper Old Eed Sandstone in the valley 
lying unconformably to the Old Eed ; whereas Mr. Geikie's theory 
maintains that a hill formerly occupied the present valley of the 
Tay, while Mr. Powrie advocates not only denuding agencies, but 
also a subsidence of the valley, and that it is to volcanic agencies 
the direction of the denuding currents are mainly due. Mr. Powrie, 
from his great local knowledge of the district of the Tay and the 
Forfarshire Old Eed Sandstone, was enabled to give minute details 
of the various positions which thay occupy, as well as the numerous 
outbursts of trap injected through them. He further stated, in 
opposition to Mr. Geikie, that the valley of the Tay and the Carse 
of Gowrie must have been all occupied by the upper Old Eed 
Sandstone to the top of the Ochils, or that the upper Old Eed now 
occupying the valley of the Tay at a considerably lower level than 
where it crops out in the neighbouring districts, clearly shows a 
" downthrow" in the valley of the Tay. Mr. Powrie also exhibited 
upon his section the line of the hypothetical hill supposed to have 
been washed away or denuded from the valley of the Tay. — Dundee 
Advertiser. 

Geological Society of Glasgow, March 5th, 1868. — "Miscel- 
laneous Notes on Chemical Geology." By J. Wallace Young. 

1st. On the Analysis of Foliated Chlorite from St. Catherine's 
Loch, Fyne. Colour, blackish green; lustre, pearly; consists of 



242 Geological Society of Glasgow, 

long narrow folia3 cohering together, rendering the mineral almost 
fibrous in appearance, in thin leaves, nearly transparent. "When in 
a state of very fine subdivision it is entirely decomposed by sul- 
phuric acid. 

Sp. Gr. 2-781. 

Silicic Acid 33-55 

Alumina 15-00 

Ferrous Oxide 10-78 

Magnesia 2973 

AVater (by difference) 10-94 

100-00 
In one specimen the chlorite was associated with a ferriferous 
dolomite in rhomboidal crystals. Its composition was as follows : — 

Sp. Gr. 2-935. 

Carbonate of Lime 5300 

„ Iron 8-16 

„ Magnesia 39-00 

100-16 
Trace of Manganese. 

2nd. On the presence of Sulphide of Zinc in a crystalline car- 
bonate from a trap dyke at Fairly, Ayrshire, Mr. Wiinsch drew the 
attention of the author to some small brownish-black crystals 
enclosed in a carbonate of iron, lime, and magnesia. On applying 
suitable tests they were found to consist of sulphide of zinc and 
some sulphide of iron. No carbonate of zinc was present. A por- 
tion of the trap rock from the dyke itself was tested carefully for 
zinc, but none was found. 

3rd. On a deposit from a Chalybeate water. Described as con- 
sisting of hydrated ferric oxide, with a little clay and sand mechani- 
cally intermixed. No lime was present. The water itself contained 
carbonate of iron and sulphate of lime, but no carbonate of lime. 

4th. On Laumonite. 

5th. On some mineral cavities in trap rocks. The author ex- 
hibited and described many specimens, showing the deposition of 
quartz crystals on carbonate of lime ; also fluor spar and sulphate of 
baryta, on quartz and carbonate of lime. 



C0I^I^:E:s:P02s^IDE!^sT•c:K!. 



YACHTING ON THE COAST OF NORWAY. 

Sir, — I am making preparations for a trip to Stavanger, Bergen, 
and Trondhjun, starting after the middle of June. It has struck me 
that, believing myself a fair observer, though a very ignorant 
geologist, I might be of use to any more learned gentleman who 
might wish any marks of coast elevation in modern times observed, 
and also (being somewhat of a chemist) to mineralogists, so far as 
the time and opportunity of so limited a trip wiU allow. I shall 



Correspondence — Mr, Geo. W, Ormerod, 



243 



hopo to visit the further end of the Fjords, more especially of the 
Sagno Fjord. And, having had great experience in Glacier travel- 
ling, I shall spend some time, probably, about Fjerland, and the 
Justedal's Broeen. I shall be happy to do anything in that way 
also. I enclose ray card, and any gentleman who may have a 
distinct operation to propose will meet with my best attention to his 
communication. M. H. 

London, April 11, 1868. 



OEMEROD'S INDEX TO THE QUARTERLY JOURNAL AND TRANS- 
ACTIONS OF THE GEOLOGICAL SOCIETY. 

Sm, — I have kept up my interleaved copy of my Geological Index 
down to the end of last year,. 1867. Thinking that you might feel 
interested in a tabular view of the progress of Geology, which is 
shown by a comparison of the number of papers and authors included 
in the Index (occupying a space of 49 years) with those in the 
manuscript Supplement (occupying a space of 12 years), I send 
you a copy which I think is satisfactory as to the results. The 
great point is the increase in the number of authors : 288 fresJi 
names having appeared in the Quarterly Journal during the last 
twelve years, and these may be considered of course as only the 
creme of the Geologists. If the inclosed statistics are of any use to 
your Magazine, they are at your service. 



Tertiary & Recent. 


Titles of Papers 

in Index. 

1807 to 1855 

(inclusive). 

49 years. 


Titles of Papers 

in Supplement. 

1856 to 1867 

(inclusive). 

12 years. 


Authors of 

Papers 

in Index. 

1807 to 1855. 


Authors of 
Papers in Sup- 
plement. 
1856 to 1867. 


575 


436 


310 


f 31 Old authors. 
\ 273 New ditto. 


Secondary 


693 


434 


330 


/ 45 Old. 

\ 229 New. 




Palseozoic 


658 


397 


273 


1 47 Old. 
( 184 New. 




Metamorphic 

Volcanic 


190 
288 
180 


112 
170 
110 


104 
145 
101 


j 13 Old. 
t 54 New. 
1 21 Old. 

( 85 New. 
( 12 Old. 
\ 63 New. 


Plutonic 




Topographical .. ] 

Geology 

Miscellaneous... ; 


232 


109 


179 


/ 6 Old. 
\ 81 New. 


Mining, etc 


216 


144 


144 


f 13 Old. 

\ 83 New. 


Palaeontology ...\ 
General ] 


23 


16 


13 


r 1 Old. 

\ 11 New. 


Fauna 


493 
80 


353 
50 


162 
39 


( 29 Old. 
\ 102 New. 
8 Old. 
25 New. 


Flora 





244 Correspondence — Colonel George Greenwood, 



Districts and Localities described. 





Index. 


Supplement, 


Britisli Islands 


419 

255 

113 

36 

27 

59 

25 

8 


( 100 Old Localities. 

164 New ditto. 
/ 61 Old. 
( 161 New. 
/ 18 Old. 
1 26 New. 
/ 9 Old. 
1 16 New. 
/ 6 Old. 
\ 15 New. 
/ 10 Old. 
\ 12 New. 
/ 6 Old. 
\ 21 New. 
/ 2 Old. 
\ 4 New. 


Europe 


Asia 


Australia 


Africa 


America, North 


„ South 


„ Islands 





N.B. In this list a place is only entered once ; but divisions, such as " North 
Devon" and *' Devon," would be counted as separate localities. 

Authors. 

Number of authors in Index 536 

Number of new authors in the Supplement 288 

Number of old authors who have papers in the Supplement written on form- 
ations which they had not treated upon in Index 91 

The number of authors writing on old subjects has not been calculated. 

Chagford, Exeter. Geo. War^- OkmeroD. 



SUBMERGED FORESTS, AND RAISED SEA-BEACHES. 

Sir, — In the Quarterly Journal of the Geological Society for 
February, page 4, Mr. Wynne says that peat and timber trees 
are found beneath the Youghal Strand. In accounting for this 
he goes into the old error of the necessity of a '' subsidence of the 
land." Mr. Wynne says : " At some time (about the close of the 

Glacial period perhaps) the land became depressed — it 

may be generally — as such evidences are common round the shores of 
Ireland as well as parts of England, but whether generally or 
locally, the land here sank to a depth of more than 90, perhaps 100 
feet, or even more. Subsequently, to this depression of 90 or 100 
feet the land rose again." Mr. Wynne further says that, " On the 
landward side of the beach the low ground is covered with peat 

The water from the low boggy ground is conveyed through 

the beach by the usual contrivance of tidal floodgates or sluices, so 
that there is reason to believe that the peat on land and that beneath 
the bay are at the same level, and connected under the beach ; and 
that the sea, by throwing the beach up, has banked itself out from a 
considerable portion of the low ground." 

This is the precise description which I have given in Rain and 
Rivers of our English so-called " submerged forests." They are all 
choked up estuaries, and Mr. Wynne and every one else must see 



Corrrespondence — Colonel George Greenwood, 245 

that as the sea erodes the whole line of coast, the beach will travel 
landward, and the peat and roots of trees which it covered will be 
uncovered and submerged by the sea. But there needs no " subsi- 
dence" for this. On the contrary, the raised beach which Mr. 
Wynne mentions, and those near the English "■ submerged forests," 
prove exactly the reverse. These raised beaches prove a rising of 
the land. As I have said (page 123), the so-called " submerged 
forests" are simply the results of the most gradual operations of 
rain, rivers, and the sea. In former days the stream or the rain 
valley cut its estuary far deeper even than low-water-mark, and 
formed what is called an arm of the sea. In later days the sea 
throws up a bank of shingle across the mouth of the deep-cut 
estuary, completely dams itself out, and partially dams the streams 
in, though these often soak through the shingle at low- water so as 
never to rise near the height ' of high water. Thousands of such 
cases exist in England. These sea beaches thrown up by storms 
frequently stand not only very much higher than the high water of 
the sea which throws them up, but the land behind them is often 
much lower than the high water of the sea. And thus, according 
to circumstances, peat, pasture, or wood, grows heloio the high-ivater 
marh. The rapidity of the growth of alluvial deposit from ]3eriodi- 
cal inland floods is then much increased. For all the alluvial wash 
of the entire valley or water slope is here at once stopped short, 
none of it can percolate the shingle into the sea. Deposit is rapidly 
accumulated on deposit, and rooted trees are found under peat, in 
peat, and above peat, not only on the shore outside the shingle bank, 
but in cutting the sluices inside the shingle bank, and by degrees 
the land which was below water-mark may be raised by alluvial 
deposit far above high-water mark. When man appears on the 
scene, if fine alluvium plasters up the shingle enough to hold back 
the water, it is a common practice to dig a trench a few feet into 
the clean shingle. The water may then be seen to flow into the 
shingle in a stream. Or, if circumstances admit, a trench is cut 
completely across the shingle bank, and occasionally cleaned. Then 
come sluices and iron piping beneath the shingle bank. The land 
drainage is let out at low water, and the sea Z^ep^ out at high water. 
Millions of acres of our best pasturage far below high-water-mark 
are held on this tenure. But when the streams are embanked, and 
are let ofl' to the sea so perfectly as to prevent their natural annual 
overflow, annual denudation of the old alluvium will take place 
instead of deposit of new alluvium, and the land may again become 
denuded far below the usual tidal level," The chalk flints men- 
tioned by Mr. Wynne are quite en regie. That is (speaking literally) 
all erratics, including what is absurdly called ''Northern drift" 
have travelled on sea-shores. (See chapter on travelling of sea 
beach in Eain and Rivers.) 

At page 2 of the same geological journal, Mr. Tylor, while he 
considerately spares us "a gravel period," creates a bran new period 
of his own — a pluvial period. With this implement (notwithstand- 
ing that " the valley of the Somme had assumed its present form 



246 Correspondence — Mr, John Young, 

prior to the deposition of any of the gravel or ' loess' now to be seen 
there"), he floods the valley " eighty feet above the present level of 
the Somme." These prodigious bodies of water do not in the least 
erode the soft chalk sides, or the bed of the valley, but, on the con- 
trary, they deposit the gravel terraces as their high-water mark. 
Flints, therefore, in the pluvial period must have been lighter than 
water, and must have floated on the surface to their present posi- 
tion. In periods other than the pluvial one drift is driven along 
the beds of rivers and valleys. And these terraces of the Somme 
have been the beds of the river or valley, as I have had the honour 
to state in the Geological Magazine for May, 1867. 

Brook WOOD Park, Alresford. George Greenwood, Colonel. 



CYCLOPHYLLUM FUNGITES. 

Sir, — In the last number of the Geological Magazine, Dr. 
Duncan made some remarks upon a statement of mine which 
appeared in your Magazine for March, 1868. I beg now to offer a 
few words of explanation. 

Dr. Duncan writes, " Mr. Young also appears to have stated that 
David Ure was the original discoverer of the genus in question, and 
that Prof. M'Coy had clearly delineated the various jDarts consti- 
tuting the internal organization of this coral ; to these statements I 
must give my unqualified contradiction." 

In my remarks I only wished to imply that David Ure was the 
original discoverer of the species of coral upon which Dr. Duncan's 
new genus was founded, not the discoverer or author of the various 
generic and specific names that have since been applied to it. 

As to whether Prof. M'Coy has or has not delineated in his 
figures and description all the essential points in the internal organi- 
zation of this coral, or whether Dr. Duncan is warranted in estab- 
lishing new generic characters upon the points which he says he 
was the first to discover, this I will leave to the decision of those 
palseontologists who are better able than I am to decide in this 
matter. The parts of this coral upon which Dr. Duncan founds his 
generic distinctions, were not, I think, so entirely unknown to Prof. 
M'Coy, as Dr. Duncan's remarks would imply. With him, how- 
ever, they did not constitute points of generic distinction, but only 
served, as he states, to characterise a well-marked species. 

I was induced to make those remarks to which Dr. Duncan has 
seen fit to repl}^, from being present at a meeting of the Geological 
Society of Glasgow, on the 18th of April, 1867, when Mr. James 
Thomson exhibited a coral, which he asserted to be new to science 
(I will not say that he did this with Dr. Duncan's consent). I had 
not then seen Messrs. Duncan and Thomson's joint-paper on Cyclo- 
phjllum fimgites, but I stated in my remarks that I believed it was 
founded upon the species of coral first discovered by David Ure, 
and figured by him in his book as a Fungites in the year 1793, but 
which had subsequently received new generic and specific names 
from Fleming, M'Coy, and Milne-Edwards. 



Correspondence — Rev. E, }Yyatt-Edgell. 2il 

Since then Mr. Thomson has obtained the loan of lire's original 
specimen from the collection of the Eoj^al Society of Edinburgh, 
has had it cut and polished ; and has thus proved that Cyclophyllum 
fungites of Duncan and Thomson is lire's Fungites ; the point for 
which I have all along contended. John Young. 

HUNTERTAN MuSEUM, CoLLEGE, GLASGOW, 

Jpril 8l/t, 1868. 

FISH-REMAINS IN THE LOWER DEVONIAN OF SOUTH DEVON 
AND CORNWALL. 

Sir, — Mr. Salter, in going over my late son's collection, has made 
a somewhat important discovery, which he has requested me to 
communicate to you. 

There has been so much doubt thrown upon the specimens iden- 
tified with fish remains in Devonian rocks, whilst they are T^nown 
to swarm in the Old Eed sandstone, that every communication on 
the subject is of some importance. 

It will be remembered that many supposed remains of fish from 
the slate rocks of Polperro, in Cornwall, were identified by Professor 
M'Coy with the Sponges. On this new form of sponge he bestowed 
the name Steganodictyum, describing it as a reticular layer overlaid 
by a striated coat. Some specimens of this are in my late son's 
collection. But with them is a large and well preserved plate, six 
inches long, which evidently belongs to a species of Pteraspis. 

Of course, only the usual nuchal plate is preserved ; but the 
markings on this are so perfect as to render it almost impossible 
to mistake the nature of the fossil. The closely-set sinuous grooves, 
occasionally interrupted, and disposed in concentric fashion over the 
whole plate, are rather closer together than in the ordinary species 
of Pteraspis from the Cornstone rocks. The species is undoubtedly 
new to Britain, although Mr. Salter has not, at present, the means 
of comparing it with the one described by Eoemer from the Lower 
Devonian of Germany. 

The point of interest is, of course, the finding a Lower Old Eed 
Sandstone fish in Lower Devonian rocks in our own country. It 
also throws doubts upon the relationship of Steganodictyum to the 
sponges, inasmuch as this fossil shows cells like those of that 
genus immediately beneath the striated coat, whilst specimens of 
Steganodictyum, also in this collection, show the internal layer of the 
fish-plate with the cellular layer above it. 

I only wish to draw attention to this fact. Mr. Salter will pro- 
bably send you a fuller description than is contained in these few- 
notes ; but he thinks that no time should be lost in making the fact 
known. E. Wyatt-Edgell. 

2, Lansdowne Place, Ladbroke Square, W., 
nth April, 1868. 

Having — together with Mr. E. Eay Lankester — ^^examined the late 
Mr. Wyatt-Edgell's specimens of the so-called Steganodictyum Cormi- 
bicum and also the cephalic plate of Pteraspis, from Mudstone Bay, 
South Devon, and compared them with Eoemer's type-specimen of 



248 Fish-remains in South Devon^ <^x. 

Pteraspis (Archceoteuthis) Dunensis from the Lower Devonian of the 
Eifel (preserved in the British Museum), and vi^ith M'Coy's figures 
of the Cornish specimen ^ — we fully concur in Mr. Salter's identifi- 
cation of M'Coy's genus Steganodictymn with the Pieraspidian plate 
in Mr. Wj'^att-Edgeirs collection, and consider that they must both 
be referred to the genus Scaphaspis (see Brit. As. Kept. 1864, and 
Geol. Mag., 1864, Vol. I. p. 292) ; and, further, that the Cornish 
specimens cannot at present be separated specifically from Eoemer's 
Pteraspis (ArchcEoteutJiis) Dunensis. As M'Coy's specific name, Cornu- 
hicum, however, bears date 1851 (Ann. and Mag. Nat. Hist., 2nd ser., 
vol. viii.), and Eoemer's name, Dunensis, was given in 1855 (Palaeonto- 
graphica, Dunker and von Meyer, vol. iv. p. 72, tab. xiii.), the name 
to be adopted should be Scaphaspis Cornubicus. The late Dr. S. P. 
Woodward called attention to the ichthyic character of Eoemer's 
supposed Archceoteuthis in his Manual of Mollusca, 1856, p. 417. 

Henry Woodward. 
P.S. Since the above was written, Professor Huxley informs me 
that Mr. Leonard Lyell brought to him for examination (some six 
weeks ago) specimens of the so-called Steganodictyum of McCoy, from 
South Devon and Cornwall, from the cabinet of W. Pengelly, Esq., 
F.E.S., of Torquay, which he at once pronounced to be true cephalic 
plates of Pteraspis. H. W. 

1 See Sedgwick and M'Coy's Palaeozoic Fossils (Tab. 2a. fig. 1, 3). It is highly 
probable that Steganodictyum Carteri^ M'Coy, from the Devonian of Cornwall (Tab, 2a. 
fig. 4), is founded on a fragment of a cephalic plate of Ccphalaspis. 



Aerolitic Shower. — Poggendorff's Annalen (Band cxxxiii.) contains a 
notice of a recent great fall of Meteoric Stones, of which the following is a sum- 
mary : — On the 30th of January of the present year, a number of Stone Aerolites 
fell at Sielce and Gostkow, near Pultusk, in Poland. Many details of the fall are 
yet wanting ; but, according to the accounts which have already reached us, the phe- 
nomena accompanying it appear to have been of tbe usual kind. A large fire-ball 
was seen about seven o'clock in the evening, passing rapidly from the North- West to 
the South-East, with a constantly increasing brilliancy, and at last exploded with 
a great noise, scattering a shower of stones in the immediate vicinity of the above 
places. This fire-ball was visible in Silesia, Prussia, Posen, etc. Professor Eber- 
hard Fuggcr, of Stockerau, Austria, under the date of February 7th, gives the fol- 
lowing account of the meteor as seen at that place. It may be premised that the 
distance between Stockerau and Pultusk is nearly 400 miles as the crow flies. " On 
the 30th of January of this year, a brilliant meteor was observed here. About ten 
minutes before seven in the evening, a blue flaming ball showed itself, which ap- 
peared to come from the moon ; it travelled towards the South-East, becoming 
during its progress larger and more brilliant, a blue light at the same time spreading 
itself over the neighbourhood. The ball gradually disappeared behind the moun- 
tains on the right bank of the Danube, decreasing in size, and, after it had com- 
pletely disappeared, a sudden crack like thunder was heard. When the meteor was at 
its greatest size, it did not appear to be higher from the ground than double the height 
of a church-tower. This phenomenon lasted for fifteen seconds, and was visible at 
Eriinn and other places. A similar meteor was observed in Stockerau on the 21st of 
January of this year, at 7.40 p.m." A stone as large as a child's head is reported to 
liave fallen at Baden-Baden, at eleven o'clock on the same evening as those near 
Pultusk, some fragments of which are said to have been received by the Dantzic 
astronomer, Kayser. Several of the Sielce and Gostkow stones, ranging from a few 
ounces to 71bs. in w^eight, have been forwarded to the British Museum. The interior 
of these stones is of a bluish-grey colour, somewhat similar to those which fell at 
L'Aigle, in France, in April, 1803 ; and the crust is of a dull black and brown colour, 
and of varying thickness. T. D. 



THE 

GEOLOaiCAL MAGAZINE. 



No. XLVIII.— JUNE, 1868. 



I. — On Denudation now in Pkogress.^ 
By Archibald Geikie, F.R.S., Director of the Geological Survey of Scotland. 

THE extent to which a country suffers denudation at the present 
time is to be measured by the amount of mineral matter removed 
from its surface and carried into the sea. An attentive examination 
of this subject is calculated to throw some light on the vexed ques- 
tion of the origin of valleys and also on the value of geological 
time. Of the mineral substances received by the sea from the land, 
one portion, and by far the larger, is brought down by streams, the 
other is washed off by the waves of the sea itself. 

I. The material removed by streams is two-fold ; one part being 
chemically dissolved in the water, the other mechanically suspended 
or pushed along by the onward motion of the streams. The former, 
though in large measure derived from underground sources, is like- 
wise partly obtained from the surface. In some rivers the substances 
held in solution amount to a considerable proportion. The Thames, 
for example, carries to the sea every year about 450,000 tons of salts 
invisibly dissolved in its waters. But the material in mechanical 
suspension is of chief value in the present enquiry. The amount of 
such material annually transported to the sea by some of the larger 
rivers of the glol)e has been the subject of careful measurement and 
calculation. Much has been written of the vastness of the yearly - 
tribute of silt borne to the ocean by such streams as the Ganges and 
Mississippi. But, as was first pointed out by Mr. Tylor, " the 
mere consideration of the number of cubic feet of detritus annually 
removed from any tract of land by its rivers does not produce so 
striking an impression upon the mind as the statement of how much 
the mean surface level of the district in question would be reduced 
by such a removal."^ '\Vhen the annual discharge of sediment and the 

^ Abstract of part of a paper read before the Geological Society of Glasgow on 
26th March, and which will appear in a forthcoming part of the Transactions of that 
Society. 

2 Tylor, Phil. Mag., 4th series, v. 260 (1853). My attention was first called to 
this very obvious and instructive method of representing the results of denudation 
by some" remarks of Mr. Croll in the Phil. Mag. for February, 1867. Mr. Tylor's 
earlier publication was afterwards pointed out to me by Professor Ramsay. Mr. Croll, 
following up the line of argument suggested in his former paper, has gone into 
further detail upon this subject in a memoir published in the Phil. Mag. for this 
month (May), which will be of essential service to geology. 

VOL. V. — NO. XLVIII. 17 



250 A, Geikie — On Denudation now in Progress, 

area of the river-basin are both known, the one sum divided by the 

other gives the fraction by which the area drained by the river has 

its general level reduced in one year. For it is clear that if a river 

carries so many millions of cubic feet of sediment every year into 

the sea, the area of country drained by it must have lost that quantity 

of solid material, and if we could restore the sediment so as to 

spread it over the basin, the layer so laid down would represent the 

fraction of a foot by which the basin had been lowered during a year. 

Thus the Ganges has its drainage area lowered by ^-^^ of a foot per annum.^ 

Mississippi „ „ ^^ „ 

Hoang Ho „ „ ^^ „ 

l^lione „ „ i:^ „ 

Danube „ „ ^g „ 

The laborious investigations of Messrs. Humphreys and Abbot '^ 
have shewn that in the Avater of the Mississippi the amount of sedi- 
ment is 1^0 by weight. This is a much smaller quantity than that in 
many other rivers of the globe. Taking -it, however, as an approxi- 
mate mean for the rivers of this country, we find that 

The Thames lowers its drainage basin by ~^^ of a foot per annum.^ 

It is much to be desired that careful measurements should be made 
of the quantity of silt carried down by our British rivers. In the 
case of the Nith a series of measurements and deductions made by 
the engineer on the river led him to the conclusion that the quantity 
of detritus borne by that stream into the Solway Firth reaches every 
year an amount varying from 112,000 to 120,000 cubic yards.^' This 
is equal to the lowering of the surface of the basin of drainage by 
about —^ of a foot per annum. 

But besides the materials held in suspension there must also be 
taken into account the quantity of sand and gravel pushed along the 
bottom. In the case of the Mississippi this was estimated by the 
United States Survey at 750,000,000 cubic feet. In our own rivers 
it is probably on the whole proportionally greater. Indeed the 
amount of coarse detritus carried down even by small streams is almost 
incredible. Mr. Thomas Stevenson, the eminent harbour engineer, 
informs me that at Lybster on the Caithness Coast, where a harbour 
has been constructed at the mouth of a small stream, between 400 
and 500 cubic yards of gravel and sand are every year carried down 
by the stream. The area of drainage is estimated at about 4 square 
miles. A weir or dam has been constructed to protect the harbour 
from the inroad of the coarser sediment, and this is cleaned out regu- 
larly every summer. A great deal of fine silt must be swept out to 
sea, yet the portion of detritus caught by the weir, and annually 

1 These fractions represent the amount of solid rock removed from the drainage- 
basins, allowing 1'9 as the specific gravity of the silt, and 2*5 as that of average rock. 

2 Ecport oil the Physics and Hydraulics of the Mississippi River. 1861. 

3 Appendix C to Second Keport of Tidal Harbour Commission, 1847, p. 603. 



A. Ge'ikie — On Denudation now in Progress. 251 

removed, represents a yearly lowering of the surface of this littlo 
basin by i^o of a foot. 

Comparing the measm-ements which have been made of the pro- 
portion of sediment in different streams we shall probably not assume 
too high an average if we take that of the carefully elaborated Survey 
of the Mississippi. This gives an annual loss over the area of drain- 
age equal to gooo of a foot. If then a country is lowered by eooo of a 
foot in one year, should the existing causes continue to operate undis- 
turbed as now, it will be lowered 1 foot in 6000 years, 10 feet in 60,000 
years, 100 feet in 600,000 years, and 1000 feet in 6,000,000 years. 
The mean height of the Continents, according to Humboldt's calcula- 
tion,^ is in Europe 671, North America 748, South America 1151, and 
Asia 1132 English feet. Under such a rate of denudation therefore 
Europe must disappear in little more than four million of years, 
North America in about four millions and a half, South America and 
Asia in less then seven millions. These results do not pretend to be 
more than approximative, but they are of value inasmuch as they 
tend to shew that geological phenomena, even those of denudation, 
which are often appealed to as attesting the enormous duration of 
geological periods, may have been accomplished in much shorter in- 
tervals than have been claimed for them. The demands made by 
geologists for unlimited ages during which the history of the earth 
has been advancing are opposed by modern physics. It will as- 
suredly be necessary to revise the whole subject of geological time, 
and in the end to accept a much lower antiquity for our planet than 
has been on geological grounds assigned to it. 

The material carried to sea by rivers has been spoken of in the 
previous part of this paper as having been removed from the general 
area of drainage, which in consequence is thereby reduced in level. 
It is of importance to look at the subject from this point of view in 
order to obtain some adequate idea of the extent of the loss which 
the land is constantly undergoing before our eyes. But it is obvious 
that the material so removed does not come equally from the whole 
area of drainage. Very little may be obtained from the plains and 
watersheds ; a great deal from the declivities and valleys. It may 
not be easy to apportion its share of the loss to each part of a 
district, but the sum total of denudation is not affected thereby. 
If we allow too little for the loss of the table-lands, we increase the 
proportion of the loss sustained by the slopes and valleys, and vice 
versa. There can be no doubt that the erosion of the slopes and 
water-courses is very much greater than that of the more level 
grounds. Let it be assumed that the waste is nine times greater in 
the one case than the other (in all likelihood it is more) ; in other 
words, that while the plains and table -lands have been having one 
foot worn off their surface, the declivities and river-courses have 
lost nine feet. Let it be further assumed that one-tenth part of the 
surface of a country is occupied by its water-courses and glens, while 
the remaining nine-tenths are covered by the plains, wide valleys, 
or flat grounds. Now, according to the foregoing data, the mean 
^ Asie Centrale, tome i. 168. 



252 A. Geilde — Oti Denudation now in Progress. 

annual quantity of detritus carried to the sea is equal to the yearly 
loss of -\ of a foot from the general surface of the country. The 
valleys, therefore, are lowered by ~ of a foot, and the more open 
and flat land b}'- ^^ of a foot. At this rate it will take' 10,800 years 
before the level ground has had a foot pared off its surface, while in 
1200 years the valleys will have sunk a foot deeper into the frame- 
work of the land. By the continuance of this state of things a 
valley 1000 feet deep may be excavated in 1,200,000 years. We may 
take other proportions, but the facts remain, that the country loses 
a certain ascertainable fraction of a foot from its general surface per 
annum, and that the loss from the valleys and water-courses is much 
larger than that fraction, while the loss from the level grounds is 
mucli loss. 

It seems an inevitable conclusion that those geologists who point 
to deep valleys, gorges, lakes, and ravines, as parts of the primeval 
architecture of a country, referable to the upheavals of early geolo- 
gical time, ignore the influence of one whole department of natural 
forces. For it is evident that if denudfttion in past time has gone 
on with anything like the rapidity with which it marches now, the 
original irregularities of surface produced by such ancient subter- 
ranean movements must long ago have been utterly effaced. That 
the influence of these underground disturbances has often con- 
trolled the direction in which the denuding forces have worked, or 
are now working, is obvious enough; but it is equally clear that 
under the regime of rain, frost, ice, and rivers, there must have 
been valley-systems wherever a mass of land rose out of the sea, 
irrespective altogether of faults and earthquakes. No one who has 
ever studied rocks in the field is likely to overlook the existence of 
faults and other traces of underground movement. But he meets 
everywhere witn proofs of the removal of vast masses of rock from 
the surface, which no amount of such mo^'cments Vv'ill explain. At 
their present rate of excavation the '' gentle rain from heaven," and 
its concomitant powers of waste, will carve out deep and wide 
valleys in periods which, by most geologists, will be counted short 
indeed. And if an agency now in operation can do this, it seems as 
unnecessary as it is unphilosophical to resort to conjectural cataclysms 
and dislocations for which there is no evidence, save the very phe- 
nomena which tliey are invented to explain. 

In reference to the origin of the present configuration of the earth's 
surface, attention has recently been more specially drawn to the 
Highlands of Scotland as retaining in great measure the " aboriginal 
outline" impressed upon them by ancient upheavals and fractures. 
To this subject it may be jDroper to return on another occasion. In 
the meantime it may be remarked that those subterranean move- 
ments nmst have happened previous to the formation of the Old Ked 
Sandstone. If, then, the present outlines of the surface are, in the 
main, older than that formation, it is evident either that the time of 
the Old Ked Sandstone cannot be removed by any long period from 
our own day, otherwise these outlines would have been obliterated 
by atmospheric waste, acting even no faster than it is doing now ; 



A, Geikle — On Denudation now in Progress. 253 

or that the rate of denudation (and consequently of deposition) must 
have been in past time infinitely slower than at the present day. 
The former half of the alternative will be at once rejected ; the latter 
goes in the face of all received geological belief. 

In accordance with the views now exjircssed, existing lakes as a 
rule must be of comparatively modern origin. We see that the 
streams which enter them push j^early increasing deltas into the 
water. The rate at which the deltas grow shows that they cannot, 
in a geological sense, be very old. If the delta of the Khone has 
crept a mile and a half into the lake of Geneva during eight cen- 
turies, a thousand years must represent no insignificant fraction of 
the interval since the river began to push its detritus into the lake. 
Had the lake basin, therefore, been of ancient origin, it must neces- 
sarily have been long ago filled up with sediment ; and, once in that 
condition, no power of running water could re-excavate it so as to 
turn it into a lake again. If the immense mass of lakes scattered 
over the temperate and northern parts of our hemisphere be due in 
any large measure to underground forces, there must have been in 
recent geological times an amount of dislocation, upheaval, and de- 
pression, of which there is no other evidence, and which indeed is 
directly contradicted by the actual facts. "We are driven, therefore, 
to seek some explanation which will account for these rock basins 
on the admission that they are of recent date, and cannot be due to 
underground agency. The theory of Professor Ramsay — that they 
were scooped out by the ice of the Glacial period — harmonizes these 
postulates, and furnishes a most important element in the elucidation 
of the history of the earth's surface. 

II. — The detritus wasted from the land is carried away not only 
by streams, but in part also by the waves and currents of the sea. 
Yet if we consider the abrasion due directly to marine action, we shall 
be led to perceive that its extent is comparatively small. In what 
is called marine denudation, the part played by the sea is rather that 
of removing what has been loosened and decomposed by atmospheric 
agents than that of eroding the land by its own proper action. 
Indeed, when a broad view of the whole subject is taken, the amount 
of denudation which can be traced to the direct effects of the sea 
alone is seen to be altogether insignificant. Yet even if we grant 
to the action of the waves and tides all that is usually included 
under marine denudation, the sum total of waste along the sea- 
margin of the land is still trifling compared with that effected by 
the meteoric agents upon the interior. Islanders, as we are, familiar 
from infancy with the fury of the breakers which beat along our 
coast-line and strew it with wrecks, we are apt to attribute to the 
ocean too great a share in the work of wearing down the land. 
Even in an island like Britain the extent of surface exposed to the 
power of the waves is very small indeed when contrasted with that 
which is under the influence of atmospheric waste. And, of course, 
in the case of the continents the discrepancy is infinitely greater. 
In the general degradation of the land this is an advantage in favour 
of tte subaerial agents, which would not be counterbalanced, unless 



!2o4 A. GelJde — On Denudation noiv in Progress, 

tlie rate of waste by the sea were many thousands or millions of 
times greater than that of rains, frosts, and streams. But no such 
compensation exists. Let us suppose that the sea eats away a conti- 
nent at the rate of ten feet in a century — an estimate which probably 
attributes to the waves a very much higher rate of erosion than can 
as the average be claimed for them, — then a slice of about a mile in 
breadth will require about 52,800 years for its demolition, ten miles 
will be eaten away in 528,000 years, one hundred miles in 5,280,000 
years. But we have already seen that on a moderate computation 
such a continent as Europe will, at the present rate of subaerial 
waste, be worn away in about 4,000,000 years. Hence, before the 
sea could pare off more than a mere marginal strip of land between 
70 and 80 miles in breadth, the whole land would be washed into 
the ocean by atmospheric denudation.^ 

If therefore the elements have acted upon the surface of the land 
in past time with any approach to the proportions in which they are 
acting now, it is clear that the sea can have played but a secondary 
part in modelling the outlines of a continent. It may be objected, 
to this conclusion, that the traces of wide level tracts, known as 
plains of marine denudation, so commonly to be met with over the 
earth's surface, can only be attributed to sea-action, and prove the 
sea to have had no small share in the general task of planing down 
the land. These plains are, indeed, in all probability, referable to 
the action of the sea ; but if we reflect on the tendency of atmo- 
spheric waste, we must perceive that such plains are the natural 
and necessary result of that waste. In short, a " plain of marine 
denudation " is the sea-level, to which a mass of land has been 
reduced by rains, ice, and streams, — the line below which further 
degradation became impossible, because the land was thereafter 
protected by being covered by the sea. Undoubtedly the last 
touches in the long process of sculpturing were given by the waves 
and currents ; yet in the past history of our planet the influence of 
the ocean has been far more conservative than destructive. Beneath 
the reach of the waves the surface of the submerged land has 
escaped the demolition which sooner or later overtakes all that rises 
above them, and there too have been accumulating the sedimentary 
materials out of which the existing continents have been framed. 



n. — The Suffolk Bone-bed and the Diestien ob Black Crag 

IN England. 

By E. PtAY Lankester, Junior Student of Christ Church, Oxford. 

IN the following pages, I am anxious briefly to make known 
certain new facts bearing on the history of the Crags which 
I have recently ascertained, and also to make some observations on 
papers lately published relating to those beds. 

^ The action of meteoric agents and of the sea is independent of subterranean 
movements, and must go on whether a land is upheaved or depressed. These move- 
ments will in some cases favour subaerial denudation, in others marine denudation, 
as shewn in the paper of wliich the above is an abstract. But in taking a generalized 
view of the subject their influence may be disregarded. 



Lankester — On the Suffolk Bone-bed and the Black Crag. 2.55 

In the November number of this journal, my friend, Dr. A. von 
Koenen, of Marburg, does me the honour of criticizing the paper 
which I published herein during 1865. As to matters of fact. Dr. 
von Koenen and myself agree most closely, but he has taken excep- 
tion to my use of the terms Pliocene and Miocene. I now regret 
very much that I have ever used those terms at all ; and agree with 
Mr. Godwin-Austen that they may tend to misunderstanding and 
confusion. It is, however, I must submit, rather strange that a 
geologist who adopts such an innovation as '' Oligocene" should be 
severe on another as to the limitations of " Pliocene " and 
" Miocene." I hereby desire to abandon these terms altogether in 
speaking of the English and Belgian Crags, and by so doing I 
believe that I leave myself in complete accord with Dr. von Koenen 
as to the age of the Black Crag of Antwerp. It is a deposit which 
may be classed very naturally with the other Crags, but differs 
little from beds called Upper Miocene, agreeing with such 
especially in its Cetacean and Shark fauna. Dr. von Koenen 
also appears to have no high opinion of M. Nyst's concho- 
logical investigations, of which I availed myself in estimating the 
age of the Diestien and Scaldisien beds. In reply to this I must 
refer to my paper (Geol. Mag., 1865, p. 149), in which I gave the 
results of very careful analyses of the researches of Mr. Searles 
Wood and M. Nyst, corrected by the aid of my much-regretted 
friend Dr. S. P. Woodward. The per centage results which I 
arrived at — so far as they have any value (and I think they have 
considerable value) — are almost identical with those given by Mr. 
Prestwich, through Mr. Gwyn Jeffreys, in a paper recently read at 
the Geological Society. 

The paper by Mr. Prestwich just referred to, has the great value 
which all the work of so eminent an observer carries. Hence I 
feel some gratification in pointing out that he recognises the exist- 
ence of the so-called Coprolite bed at the base of both Coralline 
and Eed Crag, containing both terrestrial and marine mammalian 
remains and Plagiostomous fish-teeth. This fact I first announced 
in my paper already referred to. Mr. Prestwich also confirms me 
in my observation of the different mineral condition of the " Copro- 
lite bed " bones from that of those proper to the Crags. This fact 
I dwelt on at some length in a paper in the Quart. Journ. Geol. 
Society, 1865, p. 1423. Further, Mr. Prestwich agrees to my 
deductions from these facts, and a study of the palaeontological 
evidence, and he endorses my conclusion that the Cetacean and 
Shark remains of the Coprolite-bed are derived from a previous 
deposit of the age of the Systeme Diestien of Belgium.^ 

The existence in the Coprolite beds of a glauconitic sandy matrix 

1 In former papers I have spoken of the bed from which the Cetaceans originally 
come as of Middle Crag age. This is an error; the Middle Crag of Antwerp is pro- 
bably, as Mr. Godwin- Austen says, of Scaldisien age, with remaine Diestien forms 
in it. There is no doubt that the Antwerp Cetaceans and Sharks belong truly to the 
Diestien system, and hence it is to the derived Diesten fauna in the Middle Crag that 
our Coprolite fossils are related. 



25G Lanhester — On the Suffolk Bone-hed and the Black Crag. 

adherent to many of the Cetacean remains, and of sandstone nodules 
containing fossils of Diestien age is not noticed by Mr. Prestwich. 
I have emphatically alluded to this sandy matrix in both the papers 
on the Crags, which I have published. I have now to state that 
during a recent visit to Suffolk I have obtained some thirty species 
of Mollusca (perhaps more) from these sandstone blocks, and that 
they are, as far as I have yet had leisure to examine them, of 
Diestien age. I have Pectimcidi, an unusually large number of 
Isocardice, some of the form J. lunulata, Voluta Lamherti of the 
Diestien variety, differing notably from the Scaldisien, Eed, and 
Coralline Crag form in its more elongate spire, Pyrida sp., and 
many others. The Pyrida figured by Mr. Searles Wood from one 
of these nodules differs from all the normal Eed and Coralline 
Crag specimens so widely, that he gives it a distinct specific title. 
Mr. Wood appears to have had but few specimens from these 
nodules, and considered them of Coralline Crag age. The specimens 
are in the condition of casts, the shell being in almost every case 
dissolved away. They present a remarkable similarity in appearance 
to the fossils from the ferruginous sandstones of Lenham in Kent, 
which are reputed of Crag age. I had the pleasure of examining 
Mr. Prestwich's collection of these fossils with Dr. von Koenen 
some years since, and I think it very probable that their age, and 
that of the Suffolk sandstone nodules, is identical. That the latter 
are of Diestien age there can, I think, be little doubt ; for in addi- 
tion to the Mollusca we have the important evidence of the existence 
of the Cetacean remains in these rolled sandstones, and I have just 
obtained the largest Carcharodon tooth I have yet seen embedded in 
part in one of these sandstone nodules. 

With regard to the so-called Coprolite-bed, which is evidently a 
great beach or littoral accumulation (like all other bone-beds) which 
was formed, immediately before the Coralline Crag, from the detritus 
of the London Clay, the Diestien or Black Crag, and the fragments 
of subaerial and fresh-water accumulations (whence its Mastodon, 
Bhinoceros, Tapir, Hyoena, Sus, and Cervus teeth), I wish to point out 
the impropriety of the term "Coprolite-bed" (which is the local 
name, and which, I believe, Mr. Prestwich adopts), for there is 
probably not one coprolite in the whole of it. The phosjDhatic 
nodules are masses of London Clay, often with characteristic fossils, 
such as may now be seen rolled about on Suffolk beaches; and 
these — by a process of substitution, which is no vague theory but a 
recognised chemical fact — have received some 50 per cent, of 
phosphate of lime from the vast quantities of fossil bones with 
which they Avere associated on the sea-shore. This same history 
applies to other phosphatic deposits, Cambridge, Potton, etc., as I 
believe Mr. Walker has pointed out. This being the case I propose 
to substitute the term ''Suffolk Bone-bed" for ''Coprolite-bed," 
since it does not involve an erroneous theory, and the bed in question 
is truly a "bone-bed," and comparable to other great "bone-beds," 
such as that at the base of the Lias. 

I am able to offer an additional proof of the distinct character of 



Lankester — On the Suffolk Bone-hed and the Black Crag, 257 

the Suffolk Bonc-bcd, in its occurrcnco in a pit at Trimlcy on the 
Orwell, without any superimposed Crag, Red or Coralline. The 
section in this pit gave soil 1^ ft., clay with flints 4J ft., red sand 
(from which I obtained a tooth of Elephas meridionalis) 12 feet. 
Bone-bed IJ feet, consisting of phosphatic-clay nodules, sandstone 
nodules and slabs, bones, teeth, etc., with greyish white sand. 

The study of chemical geology does not receive in this country 
the attention which it merits. The discussions in this Magazine on 
the chemistry of the Prima} val earth, show who are the men to deal 
with such questions, but nothing appears to be done as to the pro- 
cesses of fossilization, a most important subject, which, if reduced to 
principles, would greatly aid students of Cainozoic geology.^ The 
mineral conditions of the vertebrate remains of the Suffolk Bone -bed 
is a case in point. The enamel crowns only (with rare exceptions) 
of the teeth of terrestrial mammalia are found in it. Some persons 
have been astonished at the very great rarity of bones corresponding 
to the teeth of the terrestrial mammals, whilst bones in the same 
mineral condition as the cetacean teeth and tusks of Trichecodon are 
by no means so rare. I believe the explanation of this is to be 
found in the fact that the bones of land animals came on to the 
Bone-bed beach either in a fresh condition or in a very different 
state of preservation from the Diestien Cetaceans. The sea very 
rapidly destroys fresh bones by a chemical as well as mechanical 
action : this fact was elicited last year at Dundee, in the discussion 
on Mr. Gwyn Jeffrey's dredging report, who recorded the occurrence 
of a ferret's bone dredged from a considerable depth : this was the 
only bone of a land animal which Mr. Jeffreys had ever dredged, 
great as his experience has been. Thus it is that the cement and 
dentine of the teeth as well as the bones of the terrestrial mammals 
of the Crag Bone-bed have been destroyed, whilst the durable 
stony enamel crowns remain intact. It is very probable that 
many of the remains of terrestrial mammals in the Crag Bone-bed 
were embedded in fresh-water deposits contemporaneous with 
Diestien beds, which I have alluded to in other papers, as deposits 
of late Miocene or early Pliocene age. A most remarkable thing is 
the supposed persistence of Mastodon Arvernev.sis from this early 
period to the epoch of the Forest-bed of Norfolk ; is it not a 
derived fossil there? The present coast-line of Essex, Suffolk, 
and Norfolk indicates and limits an area of alternate depres- 
sion and elevation which commenced as early as the London 
Clay period (for here we find splendid teeth of Corypliodon, etc.), 
and is even now continuing. On the clay lands of the early 
Eocene flourished the small mammalia, whose remains are embedded 
in the Kyson sands, much later the Mastodon, Tapir, Bhinoceros, 
Hycena antiqua, and others appeared on the scene.^ These were 

1 No Elephant occurs with the Mastodon in the Suffolk Bone-bed. The late Dr. 
Falconer was, I believe, misled on this point, by specimens from the Eed Sands above 
the Red Crag. 

2 Dr. Hugo Miiller, whose name is well known among chemists, and who has paid 
especial attention to this subject, has kindly promised to communicate an article to the 
Geological Magazine upon this very question, at a future day. — Edit. 



25S H. Woodward — New Fossil Crustacea. 

succeeded by Elephas and Hippopotamus, and by other Ehinoce- 
roses, with which perhaps the Mastodon still lingered on ; whilst 
these again in turn gave way to yet other species of Elephant and 
large mammalia, and to these succeeded the historic fauna. These 
changes in the terrestrial fauna are thus briefly alluded to, in order 
to draw the line between them and the changes of the marine fauna 
as indicated by the mollusca, etc. It is a fundamental law of distri- 
bution that contiguous marine and terrestrial faunas are rarely 
similarly affected by the same cause. Hence, whilst the sea may 
have undergone such changes as to convert its fauna from one of 
''Miocene" facies to one of sub-arctic facies, the same great 
mammals — all or only some — may have continued to hold the land. 

In conclusion, I have to record a new Cetacean from the Suffolk 
Bone-bed, indicated by a flattened foliaceous tooth with a dentate 
margin, probably belonging to the genus Squalodon. 1 have also 
further evidence of Hycena antiqua. 



III. — CONTKIBUTIONS TO BrITISH FoSSIL OrUSTACEA. 

By Henry Woodward, F.G.S., F.Z.S. 

[PLATE XIV.] 

j^ pYBGOMA CBETACEA, H. Woodw.— In my first Eeport on 
Fossil Crustacea (Brit. Assoc, for the Advancement of 
Science, 1865, Reports, p. 321), I called attention to the occurrence, 
in the Upper Chalk of Norwich, of a sessile Cirripede belonging to 
the genus Pyrgoma. This unique example — for which I proposed 
the name of Pyrgoma cretacea — was discovered by Mr. T. G. Bayfield, 
of Norwich, who forwarded the specimen to the British Museum 
where I had the good fortune to detect its character. As no other 
specimen of this new species has been met with, I have thought it 
advisable (although only an imperfect example) to place.it on record 
in the hope that better ones may be found. It is represented in the 
accompan3dng Plate XIV., Figs. 1 and 2, of the natural size. 

The genus Pyrgoma was proposed by Leach (Joum. de Physique, 
tome 85, 1817) for a minute form of Balanus obtained living, on the 
south coast of England and Ireland, Sicily, Madeira, St. Jago, and 
the Cape de Verde Islands ; generally found attached to the edge of 
the cup of a coral belonging to the genus Caryopliyllia. The shell 
is formed of a single piece ; the basis, cup-formed or sub-cylindrical; 
the scutal and tergal valves are articulated together.^ 

The only fossil species hitherto recorded belonging to the genus 
Pyrgoma, are the Pyrgoma undata, of Michelotti,^ from the Miocene 
Tertiary strata of northern Italy ; and the Pyrgoma anglicum (Sowerby), 
from the Coralline Crag of Suffolk, which Dr. Darwin considers to 
be identical with the recent British species.^ 

The single fossil example we possess consists of about two-thirds 

1 Darwin Foss. Cirripedia, Pal. Soc. Men., 1854, pp. 35, 36. 
' Bulletin Soc. Geol., torn. ix. p. 141. 
3 Darwin Foss. Cirripedia, p. 36. 



//. Woodward — New Fossil Crustacea. 259 

of the circnmference of the conical walls of the shell ; the opercular 
valves and base being absent. It would be impossible to speak 
positively of such a fragment, were it not for the steeply conical 
fonn and the rounded approximate, radiating ribs, which mark the 
surface (PI. XIV. Fig. 2a). Viewed from above the costse are more 
rounded and less prominent than in the Pyrgoma angliciim (Plate 
XIV. Fig. 3), from which it also differs in its larger size and the 
greater thickness of the shell-walls, and the obliquity of the cone. 

Diameter at base, 4^ lines; at apex, IJ line; height of shell, 5 
lines. 

The ribs are crossed, at regular intervals, by well-marked lines of 
growth, forming, with the costa3, a reticulated ornamentation on the 
surface of the shell-wall, there being seven rings of growth in the 
space of a line. 

The shell, if perfect, would probably have displayed about twenty- 
five or thirty vertical costas, and about thii*ty-five transverse rings. 
The interior of the shell is smooth, and the wall is nearly one line 
in thickness near its base. No sutures are visible, the parietes 
having, apparently, all coalesced in the adult, as is the case with the 
recent species of Pyrgoma. 

M. Bosquet, of Maestricht, has already figured and described a 
species of Verrm^a from the Uppermost Chalk.^ 

Dr. Darwin has also shown that the species common to our Eed 
and Coralline Crag, and to the Glacial deposits of Scotland, is 
identical with the living Verruca stromia of our British seas (Mon. 
Foss. Cirripedia, p. 42, T. 2, f. 9). 

We have now another sessile cirripede, embracing the same range 
in time — in the case of Pyrgoma, not parasitic upon shells (like 
Verruca), but fixed to the cup of a coral ; and it is interesting to find 
it associated with the same form of corals, both in the Chalk and in 
recent seas ; serving as an excellent illustration of the principle, so 
universal in Natural History, that whenever conditions are the same, 
similar associations of animals recur, even through periods of time, 
far beyond our powers to estimate. 

II. ' Necrocarcinus tricarinatus, Bell. — In Professor Bell's Mono- 
graph on the Crustacea of the Gault and Greensand (l^al^eonto- 
graphical Soc. Mon. 1862, p. 19,) he adopts the name Necrocarcinus 
for certain forms of Crustacea, from the Chalk-marl and Upper 
Greensand, figured and described by him, and referred (not, how- 
ever, without some doubt) to the family of Corystidce. To this 
genus I wish now to call attention, and especially to the species 
N. tricarinatus (ib. p. 21). The examples figured by Professor Bell 
are from the Upper Greensand of Cambridge and of Wiltshire. 
"The margin of tlie specimen described," writes the author, "is 
much broken, so that we are left to speculate in some measure 
upon the exact figure of the carapace ; but, following the line in- 
dicated by the portions which remain entire, it appears to be less 
uniformly rounded than in Necrocarcinus Woodwardii. 

1 Verhandelingen Geologische Beschrijving en Kaart van Nederland. Haarlem, 
- " -16. 



260 //. Woodwai'd — New Fossil Crustacea. 

Having lately obtained from the Gault of Folkestone the beautiful 
crustacean figured on Plate XIV. Fig. 4, I at first inclined to con- 
sider it a new species ; but after a very careful comparison of it 
with Professor Bell's N. tricarinaius, I am led to conclude that it 
is only a more perfectly preserved specimen of that species than 
has been hitherto met with. It is, however, extremely valuable, 
as serving not only to complete the necessarily im23erfect descrip- 
tion of the species, but also to demonstrate that, in all probability, 
its affinities are with the Portunidce, and not with the Corysiidce. 
But, on this point, however, we still need fuller evidence than that 
to be derived from the form of the carapace, of which, as yet, only 
the uj^per surface is known to us. 

Description. — The specimen figured on our Plate measures If inch in greatest 
breadth, and 1^ inch in length. The posterior margin is 8 lines in breadth and expands 
■with a nearly straight border laterally to the epibranchial spine, where it is If inch 
broad. The latero-anterior border is rounded and is marked by 4 spines, in addition 
to the epibranchial spine. The orbits have two fissures in their superior margin. The 
nuchal furrow is distinctly marked and is divided into two branches, laterally, en- 
closing the hepatic region. Behind the nuchal furrow and separating the urogastric 
from the epicardiac lobe is a short, strongly-marked transverse cardiac furrow, 3 lines 
in length, which indents the median ridge or carina, and is then bent forward and out- 
wards for about 2| lines. 

h\ decorticated or water-worn specimens (as in tliose figured by Professor Bell and 
on the right-hand side of the specimen figured in our Plate (Fig. 4), there is a curved 
sculptured line between the meso- and ni eta- branchial lobes strongly marked and re- 
sembling impressed letters. A distinct, but not very elevated, carina follows the median 
line, extending the Avhole lengtb of the gastric region, and is only interrupted by the 
cardiac furrow; whilst another less strongly marked granulated ridge marks each 
branchial region, extending longitudinally on the middle of the meta-branchial lobe. 
The epigastric and protogastric lobes are marked by tubercles of moderate size ; a 
somewhat larger and more prominent one is seen on each epibranchial, and three 
minute prominences mark the epicardiac lobe. 

After a more careful comparison of Professor Bell's Necrocarcinus 
Becliei and N. Woodioardii with N. tricarinatiis, one cannot but con- 
clude that the two former species are generically distinct from the 
latter — i.e., of course assuming that it is lawful to differentiate a fossil 
species of Crustacean upon the carapace alone, without a knowledge 
of the other parts. 

The generic name applied to the original species described by 
Deslongchamps in 1836 (Mem. Soc. Linn. Norm. V. p. 40, t. 1, 
fig. 7-9), was Orithyia Becliei. The generic name Orithjia ought, 
therefore, to be re-habilitated for Becliei and Woodwardii, restricting 
Necrocarcinus to the species tricarinatiis. 

Sir H. T. de la Beche has figured an example of 'Necrocarcinus tri- 
carinatiis from near Lyme Eegis, Dorset^ (probably from the true 
Gault). Professor Bell records and figures it from the Upper Green- 
sand of Cambridge and Wiltshire : the specimen in our plate is 
from the Gault of Folkestone. We have thus evidence of its oc- 
currence in four well-marked British localities. 

III. Paliimrina longipes, IMiinst. [Plate XIV. Fig. 5].— In Count 
Miinster's Beitriigo zur Petrefactenkunde, 1839, JBd. II. p. 36, he 
proposed the genus Palinurina for certain species of Macroura 

^ Trans. Geol. Soc, 2ud series, Vol. I. pi. iii. fig. 1, p. 42. 



//. Woochvard — Nc7v Fossil Crustacea. §61 

(having a general resemblance to the recent Palinurus) found in the 
Lithographic stone of Solcnhofen. 

In a paper by Mr. Charles Moore, F.G.S., published in the 
Proceedings of the Somersetshire Archaeological and Natural 
History Society, vol. xiii. (Taunton, November, 1867), I have 
recorded the occurrence, among many others, of two species of 
Palinicrina in the Upper Lias of Ilminster, identical with those 
occurring in the Solcnhofen slates described l)y Miinster — namely, 
Paliniirina pygmcea and P. lomgifes} I have now to rec(3rd the occur- 
rence of this last-named species in the Lower Lias of Lyme Regis, 
discovered by Mr. E. C. H. Day, F.G.S., late of Charmouth, and 
now of Columbia College, New York, U.S. 

Description. — This elegant little Crustacean measures 2 inches in length, whilst 
the large and rigid anteunsc are of equal extent with the entire body. The anten- 
nules, not clearly seen in the specimen (fig. ob.) are 8 lines in length, and are divided 
above the third joint into two multi-articulate sctic of equal length ; the outer pair of 
antennae have three large and scabrous basal joints, 1 line in breadth, and 1;^ in length, 
succeeded by stout multiarticulate setoe 20 lines in length, apparently but little 
flexible, as they are always found lying nearly in a straight line. 

The late Dr. Oppel has pointed out that the articuli of the antennas in the Solcn- 
hofen specimens are fringed with very minute hairs : ^ these cannot, of course, be de- 
tected in our Lias example. The five pairs of thoracic limbs are all monodactylous, 
the first pair being the stoutest and somewhat shorter than the succeeding : they are 
all scabrous like the bases of the antenna). The surface of the carapace and abdominal 
segments is finely granulated, the former having a row of rather larger granules ar- 
ranged in pairs down its centre. The abdominal segments decrease slightly towards 
the telson, the first being 4 lines and the fifth 3 lines in breadth, by rather more than 
a line in length. The tail-plates, whicli Avere broad and well adapted for swimming, 
are but imperfectly preserved in any of the specimens I have examined. 

Within the past few years an extremely large number of Crustacea 
have been met with in our Lias, common also to the Solcnhofen 
stone : as many as seven genera and eight species being apparently 
found in both. 

The })ersistence of such forms as Eryon, Eryma, Glyplioea, and 
Paltannna through the whole Oolitic series, seems clearly to de- 
monstrate that having escaped total extinction in the Lower Lias 
sea, they migrated from time to time to more favourable areas, and 
thus were enabled to live on during the periods of time represented 
by the long series of deposits, from the Lower Lias to the Litho- 
graphic stone, in which so many are found fossil.^ 
EXPLANATION OF PLATE XIV. 
Fig. L Fyrgoma crctucea, PI. Woodw., Upper Chalk, Norwich (exterior view) 
natural size. 

,, 2. Fyrgoma cretacea, interior view of the same; natural size. 

„ 2«. „ „ portion of the shell, much enlarged, to show costae. 

,, 3. Fyrgoma anglicum, Sby. (greatly magnified view), Cor. Crag, Sufi"olk. 

„ 4. Necrocarcinus tricarinahis, Bell, sp. Gault, Folkestone ; nat. size. 

,, 5. Falinurina longipes, Miinst., Lower Lias, Lyme Ecgis; nat. size. 

„ ba. Portion of one of the antenna magnified f (after Oppel). 

,, 5b. One of antennules magnified ^ (after Oppel). 

The above specimens are all preserved in the British Museum. 

' See also British Association Report for 1867, Third Eepor on the Structure and 
Classification of the Fossil Crustacea. 

- See Oppel's Palseontologische Mittheilungen, etc., Stuttgardt, 1852, p. 86, 
Taf. 24, fig. lb. ; see also our Plate XIV., fig. 5a. 

3 See Brit. Assoc. Report on Foss. Crustacea, 1867. p. 46. 



262 Davies — Phospkatic Deposits in Nassau. 

IV. — On tue Deposits of Phosphate of Lime recently dis- 
covered IN Nassau, North Germany. 

By D. C. Davies, Oswestry. 

THE little duchy of Nassau, so recently annexed to the kingdom 
of Prussia, has long been famous for its mineral wealth. It 
yields yearly about 350,000 tons of iron ore, principally Hematite, 
and about half that quantity of Manganese. Of its natural mineral 
water from Seltzers it exports above a million bottles annually. In 
its north-western corner are the Brown-Coal deposits of the Wester- 
wald ; and to these sources of wealth must now be added more 
valuable and extensive deposits of phosphate of lime, which, though 
not long since discovered, have already attracted the attention of the 
leading agricultural chemists of this country. This discovery has 
its scientific attractions, as well as its commercial advantages ; and, 
as I have lately had an opportunity of examining these deposits in 
detail, it may be of interest to the reader, if I record a few par- 
ticulars concerning them. 

The principal phosphoritic deposits of Nassau occupy an irregular 
area, bounded on the north-east by the town of Weilburg, on the 
north-west by the Westerwald, on the east by the Taunus Moun- 
tains, and on the south by the town of Dietz. South of this point, 
as well as north-east of Weilburg, there are traces of the occurrence 
of the deposit ; but, from the nature of the underlying rock, they 
will, I think, be found limited in their extent. Inside the eastern 
and southern boundaries of this district flows the river Lahn, which 
is made use of at various points along its course for the purpose of 
washing the Phosphorite from its surrounding clay, as well as for the 
carriage of the washed material to the junction of this river with 
the Rhine at Oberlahnstein. The basement rock of this district is 
porphyry, varying in colour from dark to light gray and green ; the 
green is thickly studded with cavities, containing calcareous matter, 
which, after long exposure to the atmosphere, decomposes and dis- 
appears. Upon this rock, in its many varieties, rests a succession of 
slaty and shaly beds (schiverstein) which are greatly contorted and 
twisted ; these again are overlaid by a great thickness of dark red 
sandstone beds, which, in places, contain deposits of Hematite. 
Over a large portion of the district these rocks are capped uncon- 
formably by a thick deposit of massive limestone (Dolomite), which 
ranges in colour from bluish gray to pink and bluish white. It is 
resting upon this limestone that the Phosphatic deposit is found ; 
the whole series being crowned with a covering of brown clay (Tohn) 
which sometimes assumes a shaly appearance, and which also, in its 
upper portion, occasionally contains numerous fragments of the 
adjacent rocks. 

These rocks have, by German geologists, been referred to the 
Devonian Group, an opinion which is strengthened by the similarity 
of the contour of the land to that of Devonshire. Some have 
even ventured to assign to each rock its exact place in the Devonian 
series ; but the difficulty of co-ordinating these rocks with those of 



Davies—Phosphatic Deposits in Nassau- 

particular groups or subdivisions in England is in- 
creased by the entire absence of fossils ; the only trace 
of one, observed by myself, being an ill-preserved 
fragment of coral in the red sandstone beds under the 
limestone. 

The general appearance of the country is that of a 

large upland plain, with gentle undulations, out of 

which protrude, here and there, as the bone work of 

the country, great porphyritic masses, like the rocks 

Phosphatic Deposits of Nassau. 

Fig. 2. 



263 




4 4. ^ 

Section at Staffel Nassau shewing the dislocation of the Limestone prior to ^ 

the deposition of the Phosphate of Lime. tg 

Fig. 3. 3 




4 4- 

Section at Cubach Nassau illustrative of the rounding of the edges of the 
Limestone prior to the deposition of the Phosphate of Lime. The larger black 
spots are concretions of Manganese. 



1. Porphyritic and Basaltic rocks generally crowned with a castle. 

2. Shaly and Slaty beds (Schiverstein), much contorted and disturbed. 

3. Red Sandstone beds. 

4. Limestone Dolomite. 

5. Deposit of Phosphate of Lime (Phosphorite). 

6. Clay (Tohn). 

of Weilbmg, Merenberg, and Hof Beslich. This up- 
land plain is also intersected by the valleys of the Lahn 
and its tributaries ; but as you look across it from a 
sufficiently elevated point, these valleys are scarcely 
discernible, so sharply for the most part are they dis- 
rupted in the older rocks, or worn in the newer de- 
posits. This smoothness of appearance is greatly 
helped by the way in which the inequalities in the 
older rocks are filled up by the deposit of Phosphorite 
and clay ; but when we probe through this exterior pad- 
ding, the inequalities in the surface of the rock become 



264 Davies — P/iosphatic Deposits in Nassau. 

very apparent, and present indications of having originated, first, 
with dislocations of the strata before the phosphate of lime was 
deposited (Fig. 2), and, secondly, with long continued aqueous and 
atmospheric agencies ; the first by means of currents scooping out 
grooves and miniature valleys, or by chemical action where the 
water lay still, wearing hollows in the limestone, and the latter 
slowly rounding the exposed edges of the beds (Fig. 3). 

The deposit occurs in the form of concretions, imbedded in a 
matrix of clay ; these concretions are most irregular in their shape, 
and vary in dimensions from the size of an apple to masses weigh- 
ing two or three tons. It would also beem as if the original 
concretions had, subsequently to their formation, been subjected to a 
good deal of attrition : this is indicated by the preponderance of 
small fragments, decreasing in size down to that of grains of sand. 
Where the deposit assumes this form it is known locally as 
Washstein. 

Besides this deposit of phosphate of lime resting upon the older 
rocks there are also deposits of Hematite and Manganese, which 
occur in just the same position, filling up the inequalities of the 
limestone. As far, however, as my observation went, these deposits 
are found in bulk around the outer margin of the phosphatic area. 
Smaller portions of these, however, either held in solution by the 
water in which all were deposited, or redistributed by currents, 
have become mixed up with the j)hospliorite (Fig. 3), and have also, 
in places, so permeated the latter as to reduce its per centage of 
phosphate of lime so low that its commercial value is considerably 
lessened. The Manganese and Hematite are also found in separate 
deposits within the phosphatic area. 

Along the northern boundary, where the deposits border on the 
development of the older rocks, we find the greatest admixture of 
these extraneous matters, and the per centage of phosphate of lime 
ranging below sixty per cent. ; but southward, towards Limburg, 
the deposit improves in quality, containing, in places, as much as 
ninety-two per cent, of phosphate of lime, and assuming the crystal- 
line form of Apatite. 

As might be expected from the mode of its occurrence, the 
deposit is most irregular in thickness, varying, even in the same 
mine, from six inches to as many feet. It appears to attain its 
greatest continuous thickness on a line ranging north-east and 
south-west, and thins out gradually to the north-west and south- 
east. To the north-west and west, the brown clay also becomes 
thinner, and is found covered with splintery gi'avel (Quartzgeschiebe), 
the detritus of neighbouring rocks. Hitlierto the discoveries of 
phosphorite have been made only where limestone is the underlying 
rock. With the limestone, generallj^ speaking, it appears to be co- 
extensive, its presence or absence, however, in particular places, 
will depend upon the presence or absence of deposits of iron ore or 
Manganese, as well as the possibility of its having suffered denu- 
dation in exposed places since its deposition. 

To the enquiry, whence came such an amount of phosphatic 



Davies — Phosphatic Deposits in Nassau, 265 

matter, several answers have been f^iven. It has been supposed to 
be derived from immense shoals of fish and other organisms, which 
crowded the shallows of this limestone sea, and whose remains were 
deposited in hollows and crevices of the rock. It has also been 
suggested that the phosphorite owes its origin to the action of car- 
bonic acid water springs, bringing up phosphoric acid, or phosphate 
in solution from the older strata below ; and, yet again, that the 
phosphate was dissolved out of the porphyritic rocks on the surface 
by the action of carbonic acid water ; and that the absence of fossils 
from the deposit clearly shows that it is not composed of the 
remains of organic life deposited upon the sea bed. 

In considering these suggestions it will, I think, be evident that 
the phosphatic matter was, in either case, derived originally from 
the older rocks, either by the action of springs from below, or by the 
decomposition of rocks on the surface ; for we have already seen 
how full of calcareous matter, in some shape or another, some of 
those older rocks are, and that they bear traces also of a considerable 
amount of decomposition. Then the matter might also be derived 
largely second hand from the remains of former organic life de- 
posited in the neighbouring subjacent rocks. The question then 
which remains to be decided is, whether this matter derived from 
the older rocks in various ways, and held in solution by the water, 
was deposited pure and simple, or whether it was not taken up first 
into organic forms, and afterwards deposited as the remains of these 
upon the ocean floor? No fossils are found in the deposit, but it is 
possible, it may be even probable, that, if there had been organic 
life, the structure of its remains would become destroyed by chemi- 
cal action, just as I have elsewhere shown that the distinctive 
structure of the organic remains, which so largely compose the bed 
of phosphate of lime which occurs in the Bala limestone of North 
Wales, has been almost completely destroyed.^ Indeed, such a sup- 
position appears to me more reasonable than that of a lifeless sea 
resting upon a limestone bed. Without saying therefore that all 
the phosphate of lime derived from the older rocks was absorbed 
into organic life we may suppose that there was life in the sea of 
that period, and that, in some measure, these phosphatic deposits are 
the remains of that life. 

To what geologic period do these deposits belong ? Two answers 
have been given to this question ; the one refers them to the age of 
the Lower Devonian beds, and regards them as the remains of 
Devonian fishes ; and the other assigns to them a Tertiary date. 
The latter supposition is, I think, the one most in accordance with 
the general features of the deposit. For, an immense period must 
have elapsed after the deposition of the limestone to admit of the 
extensive denudation of the surface, often through unbroken strata, 
which took place before the phosplioi;ijte began to be deposited ; a 
period of sufficient length, as it appears to me, to bring the depo- 
sition down to a much later period than that of the Devonian. 
And then if we consider the comparative softness of the deposit and 
I Geological Magazine, 1867. Vol. IV., p. 251. 

VOL. V. — NO. XLVIII. 18 



266 Leonard — Midden on Omey Island, 

its overlying claj', with the fact that, together, they do not attain a 
maximum thickness of eighty feet — oftener less than forty — we 
shall see how improbable it is that such deposits could resist all the 
geological changes, with their disturbing, abrading, denuding forces, 
from Devonian times until now. In the manner of its occurrence, 
as well as in its stratigraphical position, the deposit appears to me 
to be analogous to the deposits of white clay, which Mr. Maw has 
recently described as lying in pockets and hollows of the carboni- 
ferous limestone of North Wales, just below the mass of sands, 
gravels, and clays of the Glacial epoch.^ To that epoch I think the 
clay and gravel overlying the Nassau phosphorite must be referred, 
and from the way in Avhich this deposit is interlaced, dovetailed and 
mingled with the lower portion of the clay, I am led to regard it as 
a Tertiary deposit, whose formation immediately preceded the 
somewhat indefinite period which we term Glacial. 

It may be interesting to note that the absence of boulders of any 
considerable size, either foreign or local, from the clays and gravels 
of Nassau appear to confirm the opinion of the late Edward Forbes, 
that, at a point not far south of England, the severe climate of the 
north passed rapidly, even during the Glacial epoch, into one much 
warmer. 

The discovery of large stores of the raw material at a time when 
superphosphates of lime are so largely in demand for agricultural 
purposes, must be of great importance, and already considerable 
quantities of the Nassau phosphorite have been shipped to this country 
for use in the manufacture of artificial manures, — if, indeed, it be 
true that the lapse of time makes that artificial, which was as 
natural in its origin as the phosphates of yesterday. 



V. — Kitchen Midden on Omey Island, Co. Galwat. 
By H. Leonard, F.R.G.S.I., of the Geological Survey of Ireland. 

OMEY is a half-tide island off the coast of Galway. It is chiefly 
a Porphyritic Granite rock, on the north-west portion of which 
are wind-blown sands that are for ever changing their positions, the 
houses of the inhabitants being covered to such an extent by them, 
that, in order to reach the interior, they are compelled to descend 
through holes, like large rabbit-burrows. The oldest record we 
have in connection with the island is, that St. Fechin built an 
Abbejr there previous to a.d. 664. This abbey is said to be buried 
in the sands, but its exact site cannot be pointed out; however, 
there is a supposed fifteenth-century church, that is now sunk 
12 feet deep in the sand. 

Tlie Kitchen-Midden or shell-heap (the subject of this paper) is 
situated on the south shore of a small bay, which indents the western, 
shore of the island ; and opposite to which, on the north shore, is a 
very ancient well, dedicated to St. Fechin. The shell-heap is 50 

^ Geological Magazine, 1867. Vol. IV., pp. 241 and 299. 



Leonard — Midden on Omcy Island. 267 

yards lon^^, by 20 yards wide, and presents at the sea-cliff the fol- 
lowing section :— feet inches 

6. Sandy soil 3 

4. Bed of shells, calcined boulders with pieces of 

charcoal, bones, etc 3 

3. Brown sand 11 

2. Dark sandy soil, containing some Patella vulgata 5 

1. Fine white shell sand ... 9 

The principal shells composing it are : — 

Patella vulgata, limpet about '5 

LHorina litorea, periwinkle ,, '3 

Cardium edule, cockle „ "2 

which are in about the proportions marked to each ; " razor-shells " 
{Solen siliqua) were also observed, besides bones of sheep, pigs, and 
fowl ; there were also traces of fires, consisting of ashes, burnt stones, 
bones, and shells. At the present day the sea- weed gatherers may 
be seen cooking shell-fish, by placing them on a stone that they had 
previously heated to redness in a fire ; and many of the stones here 
found may have been similarly used, as they are usually flattish, 
roundish boulders from four to seven inches in diameter. 

The Midden appears to have extended further seaward, as now the 
deepest part is at the cliff, from which it gradually gets shallower, 
till it reaches its southern limits. As no implements of any kind 
were found here, the age of this shell-mound cannot be easily esti- 
mated. It may, perhaps, be of a comparatively recent origin, and 
in some way connected with the holy well previously mentioned, 
which is supposed to have miraculous properties, and is still visited 
by the credulous, who remain in its neighbourhood all night, while 
" performing their stations " at it. A little north of this heap and 
east of the holy well, is a thin surface heap of Patella vulgata and 
Solen siliqua, with bones, etc., many of the latter are broken, seem- 
ingly to obtain the marrow. 

My colleague, G. H. Kinahan, M.E.I.A., writing on this subject, 
says as follows : — '' I have remarked many shell-heaps or 
Kitchen-Middens near the shores of Gal way Bay, some of 
which may be ancient, wliile others are undoubtedly modern. 
Those on the headlands, enclosing the different small bays to 
the east and south, are nearly altogether of Ostrea edulis, — how- 
ever, there is one at the east end of Lough Atalia, formed altogether 
of Mytilus edulis, but this is quite modern only now being formed 
by the inhabitants of the east suburbs of Galway. The largest of 
the oyster-heaps seems to be that of Creggauns, the headland next 
south of that of Ardfry, the seat of the Lords Wallscourt. This 
heap is now only 210 feet long, 70 feet in its widest part, and 
about 8 feet deep, its base being two feet below high-water-mark 
of mean spring tides ; the principal shells in it are those of the 
Ostrea edulis, but in places there are quantities of Mytilus edulis, 
others also occur but none in remarkable quantities. An excavation 
was made partly across this heap by Dr. Buckland and myself, 
without finding any implements; but on the shore among the shells, 
were picked up two flake-like implements made of hard limestone. 



268 Meyer — On Cretaceous Brachiopoda, 

These seem to have been knives for flaying animals, but as stone 
knives have to a very recent period been used on the Islands of Arran 
for similar purposes, these cannot be relied on to prove the antiquity 
the Midden, more especially as there is a tradition that formerly the 
oysters were shelled at stations along this coast, previous to being 
preserved for foreign consumption ; and what gives a colour to 
this tradition is, that in the neighbourhood of the Kenmare Kiver, 
the same tradition is found in reference to the heaps of oyster-shells 
which occur there also. If this is the true history of these heaps, 
might not the ashes found in such quantities among the shells be 
the remains of the fires used in the preserving process. 

On the islands near the entrance to the Bay, the principal shells 
in the heaps are Patella vulgata and Liiorina litorea. On Gorumna, 
in the vicinity of the church called Ballynakill Abbey, there is a large 
heap composed of these shells, with some bones of the cow, sheep, 
pig, etc., and on the east shore of Greatman's Bay there is a remark- 
able Midden 50 feet in diameter, 15 feet high, and forming a flat-topped 
hillock, composed seemingly entirely of the shells of the limpet and 
periwinkle. On the Arran islands, heaps are very numerous, some near 
the old Pagan, and more near the early Christian dwellings, while 
others are in the vicinity of what may have been, comparatively 
speaking, modern erections ; among the latter, being one on the 
middle island, in which a coin with the date 1610 was found, among 
the more ancient, may be those near Dubhcaher [anglice black city), 
supposed to be the oldest settlement on the islands, and to have been 
inhabited previous to the Christian era ; but what is probably the 
most ancient, is one lately discovered by the Eev. W. Kilbride, 
Yicar of the Island, which has been buried for ages under the sand- 
hill on the south of Killany Bay — as I have not seen this, I cannot 
give you any information about it." 

From this it will be seen that the heaps are probably of all ages, 
some being of modern construction — more of medieval age — while 
others may be very ancient. In favour of the last supposition, it 
may be mentioned that W. Harte, Esq., F.E.G.S.I., has explored and 
described various very similar Kitchen-Middens on the coast of 
Donegal, in which the only implements found were made of stone. 
{See Dublin Quarterly Journal of Science, Vol. IV., p. 189 et seq.). 



VI. — Notes on Cretaceous Brachiopoda and on the Develop- 
ment OF the Loop, and Septum in Tekebratella. 

By C. J. A. Meyer, Esq. 

IN a paper on "Cretaceous Brachiopoda," published in the first 
volume of the Geological Magazine, page 249, I noticed the 
occurrence of a species of Waldheimia in the Lower Greensand of 
Surrey, under the name of Waldheimia Moutoniana, which at the 
time appeared to me to answer to the figure and description of 
Terebratula Moutoniana of D'Orbigny. 

The identification of this species has been, however, severely 



Meyer — On Cretaceous Brachiopoda. 269 

criticised by Dr. Schloenbach, of Salzgitter (Hanover)' who states 
that D'Orbigny's Terehratula Moutoniana possesses the short loop 
of a true Terehratula. 

Such being the case the so-called " Waldheimia Moutoniana'' 
figured by Mr. E. Eay Lankester in the " Greologist," vol. vi., 
pi. xxi., figs. 1-4, and subsequently by myself in the Geological 
Magazine (Vol. I., PL XII., Figs. 12-14), becomes a new species, 
for which I suggest the name of Waldheimia Morrisii. 

1 append the following description : — 

Waldheimia Morrisii, sp. nov. (Geol. Mag., Vol. I., PI. XII., 
Figs. 12-14).2 

Shell ovate or oblong-ovate, sliglitly tapering towards the beak. Valves convex, 
deepest towards the posterior portion of the shell. Beak slightly incurved and 
truncated by a moderately sized foramen. Beak-ridges sharply defined, producing a 
slightly flattened hinge -area. Foramen semicircular above, pointed below where 
completed by the two, almost triangular, plates of the deltidium. Larger valve 
almost regularly convex, more abruptly so near the beak. Dorsal valve less equally 
convex, much depressed at the sides, elevated in front, and sometimes exhibiting a 
narrow longitudinal depression near the frontal margin of the shell, as in Terebratula 
ovata, Sow. Loop much elongated, extending to near the front of the shell before 
becoming reflected. Septum short and but slightly elevated. 

Length 10, width 7, depth 4|, lines. 

This species differs from Waldheimia celtica, Morris, in the com- 
parative breadth of the valves, and still more conspicuously in the 
curvature of the shell-margin, which in Wald. celtica is always 
nearly straight. 

From Waldheimia tamarindus, Sow., its nearest 
ally in the Greensand of Shanklin, it differs not 
only in the size and proportion of its valves, but 
also in the shape of the reflected portion of the 
loop. 

From certain peculiarities observable in the 
loop of Waldheimia tamarindus, Sow., Dr. Schlo- 
enbach proposes (in the paper above referred to) 
to place that species under the section Megerlia, Loop of an old specimen of 
King. Yet after a long and careful examination ^Vaidf^- tamari?idus, sow. 
of the interiors of a considerable number of specimens of Waldh- 
tamarindus, I am unable to perceive that its loop ever approaches 
sufficiently to that of a Megerlia, to warrant the removal of the species 
out of the section in which it has been placed by Davidson. 

The arrangement of the loop and septum of Waldh. tamarindus (as 
seen in examples from the Lower Greensand of Shanklin), may be 
described as follows : — 

Loop elongated and recurved. The produced portions (lamelles ascendantes. Eug. 
Desl.) extend (both in young and old examples) to very near the front of the shell 
before becoming reflected. The reflected portions (lamelles recurrentes) return back 
to about the middle of the shell, and form an arched or rounded loop, not unlike the 
same portion of the loop in the recent Waidheimia cranium. — Miiller. 

In old specimens certain spinose projections occasionally make 
their appearance on the sides and on the extreme front of the loop — 

^ Zeitschr. d. deutschen geologischen Gesellschaft, 1866. 

2 The numbering of Plates XL and XII. in Vol. I. of the Geol. Mag. was acci- 
dentally reversed by the engraver. 




270 Mejjer — On Cretaceous Brachwpoda, 

as in Terehratula resvpinata, Sow., — and these, by projecting side- 
ways or towards the edges of the shell, give the loop a somewhat 
unusual appearance. See fig. ante p. 269. 

The septum of Waldh. tamarindus, except in young examples, is 
short and but little elevated, and remains always unattached to the 
loop. The inner surface of the shell is smooth, and never spinose, 
as in Megerlia lima, Dav., end in the recent M. truncata, Gmel. 

In this description th«re is nothing to suggest the double (?) 
attachment of the loop to the septum, which forms so marked a 
feature in the section Megerlia. But Dr. Schloenbach, if I under- 
stand him aright, has applied to the section Megerlia, the theory of 
development of the loop and septum, which was (some years since) 
suggested by Mr. Chas. Moore as applicable to the genus " Terehra- 
tella,'' D'Orb. (Geologist, vol. iii., pi. xiii., '• On the development of 
the loop in Terehratella''). And the question whether Waldh. 
tamarindus is or is not a Megerlia depends therefore mainly on the 
real mode of development of its loop and septum. 

In the figures given by Mr. C. Moore (see Geologist, vol. iii., 
pi. xiii., figs. 1-4) representing several stages in the development of 
the loop in the genus Terehratella, the loop is represented as being 
free or unattached to the septum in the three first stages of its 
growth, and attached only in the fourth or complete state. The 
septum — in the same figures — is also apparently absent or un- 
developed in the earlier stages in the growth of the loop. 

But this description, in so far as regards the absence of the septum 
and the free condition of the loop in its earlier stages, is so entirely 
at variance with my own observations amongst the Cretaceous species 
of Waldheimia and Terebratella, that I cannot but suspect some error 
of observation or delineation in the examples figured, arising 
perhaps from the minuteness of the specimens from which Mr. C. 
Moore's figures were obtained. 

Now I have mostly observed that the septum in the sections 
Waldheimia, Terebratella, and Megerlia, is comparatively much longer 
and more largely developed in the extreme young and half grown, 
than in the adult shell, — as for instance in Megerlia lima and Tere- 
hratella Menardi, and that it even reaches in some cases the whole 
length of the smaller valve, as in some half-grown examples of 
Terehratella trijida now before me. 

From these and many other examples which I could mention, it 
would appear that the growth of the septum is at first strictly co- 
extensive with the growth of the shell until the former has attained 
to nearly its greatest length, and that it increases afterwards only 
in height and thickness. And further that a septum is seldom if 
ever produced for the first time in a full-grown shell. 

The attachment of the loop to the septum in the young of Tere- 
hratella does not, unfortunately, so readily admit of proof owing to 
the difficulty of obtaining perfect specimens. 

In examining the interiors of various species of Terebratella, I 
have, however, frequently observed that the septum itself exhibited 
what appeared to be unmistakable evidence of the continuous 



Meyer — On Cretaceous Brachiopoda. 271 

attachment of the loop. This evidence consisted in the occurrence 
of a curved line or ridge extending on the sides of the septum from 
its origin beneath the hinge-plate to the point from vv^hence the 
transverse processes then proceeded for the attachment of the loop. 
And as such ridges are not observable in any species of Waldheimia 
with which I am acquainted, they may, I imagine, be regarded as 
the remains of former processes from the septum, indicative of the 
attachment of the loop from its earliest development. 

The condition of the loop and septum in some very young speci- 
mens of Terehratella Menardi, in my collection, fully tends to sup- 
port this evidence. 

In these examples the septum is much elevated, and extends to 
nearly the front of the smaller valve. The descending portions of 
the loop, which diverge from the hinge-plate in the usual way, are 
broadly attached to the septum near its extremity, and bending 
sharply rise in an almost inconspicuous ridge above the septum. 

From this stage of the loop its development would probably 
follow what appears to me to be the natural law of increase in the 
loops of Brachiopoda, namely, the gradual absorption of the inner 
edges of the loop, and the increase of its outer or upper edges by the 
secretion of fresh shelly-matter from a portion of the lining mem- 
brane of the shell. 

With regard, therefore, to the attachment or n(3n-attachment of 
the loop at different ages of the shell in the sections Waldheimia, 
Terehratella, etc., the rule appears to be that the loops are either 
constantly attached to the septum — as in Terehratella, Megerlia, etc., 
— or constantly free, as in Waldheimia. And although the excep- 
tion may hold good as regards the young of Terehratella Biiclcmanii, 
Moore, I am sure that such is not the case with regard to Wald. 
tamarindus, Sow. 

By grinding down or in other ways partially removing the matrix 
from the interiors of the valves, I have succeeded in obtaining 
dissections exhibiting the loops of most of our Cretaceous Brachio- 
poda, and amongst others of the following species, the loops of 
which have not, I believe, been as yet described. 

1. Terehratula ovata, Sow. Loop short and simple ; no mesial 
septum. 

2. Terehratula rugulosa, Morris. Loop short and simple ; no mesial 
septum. 

3. Terehratula squamosa, Mant. Loop short and simple ; no 
mesial septum. 

The discovery of the loops of these three species has given me 
much pleasure, as tending to prove the correctness of Mr. David- 
son's observations respecting the small generic value of surface- 
markings on the valves of Brachiopoda. 

4. Terehratida Carteri, Dav. Loop short and simple. 

6. Waldheimia Bouhei (?) D'Archiac. {Ter.faha (?) (Sow.)^ 
Loop much elongated and reflected. Frontal extremity of loop 

1 Figured in Geol. Mag., Vol. I., PL XII., Figs. 5-7. 



272 Keeping — Dhcovery of Gault at Upware, 

studded with irregular spines, as in Terehratula resupinata, Dav. 
Septum short and but little elevated. 

Of this somewhat doubtful species I have several examples from 
the Lower Greensand of Folkestone and Godalming. The Folke- 
stone specimens are filled with silex, and possess the loop in the 
most perfect state of preservation. It is interesting to observe that 
the loop in these specimens approaches as near to the front in the 
young and half gi'own as in the adult shell. 

6. Terehratella ohlonga, Sow. Loop elongated and reflected, 
doubly attached ; mesial septum (in the adult shell) reaching to 
nearly the middle of the smaller valve. 



VII. — ^Discovery of Gault with Phosphatic Stratum at Upware. 
By H. Keeping, Assistant Curator of Woodwardian Museum, Cambridge. 

HAVING frequently visited Upware during the past fourteen 
months, for the purpose of collecting from the Lower Green- 
sand, in which I have been very successful, having obtained for this 
Museum a beautiful and choice collection, I have had every oppor- 
tunity of observing the progress of the excavations, and of noting 
the relative position of the beds. 

When there in February last, I picked up a phosphatised specimen 
of Ammonites interruptus at a short distance from the cropping-out 
of the Coral-rag. This led me to believe that the Gault might be 
found ; accordingly, on the 24th of March last, I sunk a pit. After 
passing through about seven feet of clay I came to a phosphatic bed, 
from which I collected the following fossils, proving, I believe, the 
whole to be Gault : — 

Ammonites serratiis, Nucula ovata, 

Ammonites interruptus, Nucula pectinata, 

Baculites ,, Dentalium ellipticum, 

Belemnites minimus, Inoceramus concentricus. 

Belemnites attenuatns. 
The pit sunk was about ten feet in depth. The phosphatic-bed 
(see i, in section) from which the fossils were derived averages five 
inches in thickness. After jDassing through another foot of the non- 
fossiliferous Gault I entered the Lower Greensand {g), and on 
sinking two feet lower the rising of the water compelled me to desist. 
It will be seen from the section that the Kimmeridge Clay is 
unconformable to the Coral-rag ; and it would appear that, at the 
time of the deposition of* the Kimmeridge Clay, a quantity of its 
broken and often rounded fragments became inteiTuixed with it, so 
that in the vicinity of junction it actually presents the appearance 
of Boulder-drift. This was at first puzzling, but when the position 
of the bed was determined it was seen to be a natural consequence. 

The collection of fossils obtained is small, but, considering that it 
is the production of a pit of about a yard square, they are as nu- 
merous as we can expect ; the distinct species being eight, and there 
are many specimens. Although the Gault has been found in this 
country, few fossils have been met with in it, and I know of no 



Ileer — Miocene Flora of the Polar Regions. 



273 



other collection that will compare with this, neither is there, to my 
knowledge, any other locality within the same district which gives 
so good a sequence from the Coral-rag to the Gault. 

Pit sunk. E. 

1 




Section of Strata at Upware on the Cam. 
Coral Rag in situ. 
Coral Rag intermixed witli Kimmeridge Clay (the bed marked (6) extends as liigh up the 

denuded surface of a as the deposit marked h although not shown in the diagram.) 
Pure Kimmeridge Clay. 
Lower phosphatic bed of Lower Greensand, rich in fossils and often cemented so as to form 

hard conglomerates, and containing a large quantity of derived fossils. 
Lower Greensand, with few or no fossils. 
Upper phosphatic bed of Lower Greensand. 
Upper layer of Lower Greensand. 
Gault of about one foot in thickness. 
Phosphatic bed in Gault of five inches in thickness. 
Non-fossiliferous Gault, seven feet. 



l^OTZCES OIP 3yEE3VI:OII^S. 



I. — On the Miocene Flora of the Polar Regions. Two Lectures 
given at the Annual meeting of the Natural History Society of 
Switzerland on the 9th and 11th September, 1867, at Rheinfelden, 
by Professor Oswald Heer, of Ziirich. 

(Translated by John Edward Lee, F.S.A., F.G.S.) 
I. 

PEOFESSOR HEER has had the opportunity of examining a 
large number of fossil plants from the museums of Dublin, 
London, Copenhagen, and Stockholm, which have been discovered 
in the north of Canada (on the Mackenzie), in Banksland, in North 
Greenland, in Iceland, and in Spitzbergen. They reveal to us valu- 
able information both as to the diffusion of plants in the early ages 
of the world, and also as to the climate which prevailed at that time 
in the far north. This Arctic Miocene flora, so far as can be ascer- 
tained from these specimens, consists of 162 species :i 18 species 
belong to the cryptogamia, and amongst them we notice small fungi, 
which have formed spots and dots on the leaves of trees, just as the 
leaf-fungi do at the present day ; and 9 species of fine large plants 
of the fern tribe, with which the ground under the forests was pro- 
bably clothed. The phanerogamous plants consist of 31 species of 
trees allied to the fir tribe, 14 monocotyledons, and 99 dicotyledons. 
Judging from their analogy with the nearest living plants, there 

1 These species are described and drawn in the work of Professor Heer, Ueber die 
fossile Flora der Polarlande." Zurich ; Fr : Schulthess, 1867. 



274 Heer — Miocene Flora of the Polar Regions, 

were 78 kinds of trees, and 50 shrubs : consequently, at that period, 
128 species of woody plants had been diffused over the far north. 
Amongst the pine or fir tribe we find silver firs (Tannen), spruce 
firs (Fichten), and common or Scotch firs (Fohren) — most of which 
very nearly approach the American species. We may especially 
mention the Finus MacClurii, which looks uncommonly like the 
Pinus alba of Canada, aid of which the cones were discovered in 
Banksland by Mr. McClure and his companions. This tree, doubt- 
less, contributed no little to the features of the mountain forests of 
that country. Iceland, however, in the Miocene times, was the 
richest in species of pine, for the remains of seven different kinds 
have been discovered there — viz., species of silver fir, of spruce and 
of common fir. The Sequoice, however, were far more abundant 
than the pines ; and, in the Miocene times, it can be proved that 
they were very abundant in Europe, Asia, and America ; while at 
the present day this genus is confined to California. Only two living 
species are known (S. sempervirens and S. gigantea) — the last sur- 
vivors of this remarkable type of plants, which contains the greatest 
trees in the world. In the Miocene times four species lived in the 
polar regions; three of which, however, were spread over middle 
Europe. The Sequoia Langsdoffii is the chief tree of North Greenland ; 
and not only branches with leaves upon them, but even the flowers, 
the cones, and the seeds, have been discovered. In the Miocene 
age it lived also in North Canada and in Vancouver's Island ; and, on 
the other hand, it can be proved also to have existed in Germany, 
Switzerland, and Italy. It is uncommonly near to Sequoia semper- 
virens, and is only distinguished from it by the cones being some- 
what larger. The S. Sternhergi, which was very abundant in Ice- 
land, is, on the other hand, closely related to S. gigantea (the " Welling- 
tonia ") ; while the S. Couttsice, which is found at Disco and Atane- 
kerdluk, fills up the gap between S. Langsdorffii and S. Sternhergi. 
The trees allied to the cypress are largely represented ; and we find 
three genera, Taxodium, Thujopsis, and Glyptostrohus. The home of 
the two last is in Japan, while that of Taxodium is in North America, 
The Glyptostrohus Europceus had precisely the same range as the 
Sequoia Langsdorffii ; and the same may be said of Taxodium duhium ; 
of which twigs, leaves, and cones were found at Atanekerdluk, and 
its remains were found in Spitzbergen, even at Bell Sound (nearly 
78 degrees north lat.). The Thujopsis Europcea (a kind of evergreen) 
is much rarer, and yet very pretty branches of it were found in 
Northern Greenland, which agree with those found in amber, and at 
Armissan (Narbone). Amongst the Taxince may be especially men- 
tioned a Salishurea from Greenland, as this genus at present grows 
wild only in Japan. 

The number of foliaceous trees of the Arctic zone in Miocene times 
was so great, that only a few species can be specified here. Many of 
them are very similar to those of our own country ; as, for instance, 
the beech and the chestnut, which are found in North Greenland up 
to 70 degrees north lat. One kind of beech, Fagus Deucalionis, was 
very nearly related to our common sj^ecies : the leaves have the same 



Heer — Miocene Flora of the Polar Regions. 275 

form size, and nervation, but the edge in front is dentated. It was 
apparently diffused over the whole north, for it can be proved to 
have existed in Greenland, Iceland, and Spitzbergen. The species 
of oak are found in still greater variety : there were eight kinds in 
North Greenland ; most of them had large leaves, beautifully in- 
dented, and they bear the greatest resemblance to American species. 
One of them {Querciis Olafseni), which can be traced from Northern 
Canada to Greenland and Iceland, corresponds with the Q. Prinm of 
the United States. A plane tree also {PL aceroides) had spread over 
all these countries — nay, was found even in the Icefiord of Spitz- 
bergen. Numerically, however, the j^oplars were far more abundant 
than the beeches, the oaks, or the planes. Two species {Populus 
Bichardsoni and P. arctica), together with the Sequoia Langsdorffii, 
were amongst the commonest trees of the polar zone, and can be 
traced from the Mackenzie to Spitzbergen. It is a striking fact 
that very few remains of willows are found, while at the present 
day willows form one-fourth part of the ligneous plants of the Arctic 
zone. Birches were abundant in Iceland; and a tulip tree, and a 
maple with large berries {Acer otopteryx), also flourished there. 
Remains of the walnut tree ; of a coriaceous-leaved Magnolia ; and 
of a Primus (P. Scottii) came from Greenland : and a large-leaved 
lime-tree was found in Spitzbergen (Tilia Malmgreni) : its leaves 
were found at Kingsbay in 79 degrees N.Lat. 

These types of trees, which approach those of living species, are 
accompanied with others of a different kind, the determination of 
which is somewhat difficult. One species with remarkably large 
coriaceous leaves (the Daphiogene Kanii), belongs probably to the 
LauracecB, and four others {Mc Clintoclcia and Hakea) to the Proteacece. 
It is doubtful whether the last-named plants took the form of trees 
or shrubs ; the others, judging from the analogy of living forms 
allied to them, very probably were the shrub-growth of that age. 
To these may be added a species of hazel {Corylus M'Quarrii), which 
was spread over the whole of the north, and is found in Spitzbergen, 
even 78 degrees N. Lat. ; also an alder (Alnus Kefersteinii), 
which was diffused equally far and wide. From Greenland up to 
70 degrees N. Lat., we know of species of buckthorn (Bhamnus)^ 
Paliurus, Cornus, Cratcegus, Ilex, Andromeda, and Myrica. Climbing 
plants also were not wanting. A species of ivy (Hedera M'Clurii) 
was foimd on the Mackenzie and in Greenland : there were also 
found here the remains of two kinds of vines, and a third flourished 
in Iceland. All three correspond with American forms. 

It would not be difficult, from this list of species, to draw a picture 
of the vegetation in these high northern latitudes; it would show 
us a mass of foliage of various tints, made up both of pines and other 
forest trees — trees with great leaves of varied forms, their stems 
twined round with vines and ivy, and under their shade there are 
numerous shrubs, mixed with elegant ferns. 

How very different is the picture now presented to us in the polar 
regions ! At the present day an enormous glacier covers Northern 
Greenland; leaving only a narrow strip of coast free from ice in the 



2 76 Jleer — Miocene Flora of the Polar Regions. 

summer, and this glacier every year sends out into the ocean thousands 
of icebergs, which lower the temperature of the southern latitudes ; 
but at one period this very country was covered with a luxuriant 
jjrimieval forest, composed of a great variety of trees, such as we 
now find onl}' in the warmer parts of the temperate zone ! In fact 
we find Taxodics and plane-trees in Spitzbergen in 78 degrees N. Lat., 
nay even a lime-tree and a poplar in 79 degrees N. Lat., consequently 
only 11 degrees distant from the pole. The lime-trees, the Taxodice, 
and the plane-trees may here have reached their most northern 
limits ; but this was certainly not the case with the firs, and the two 
kinds of poplar, which were living in Spitzbergen ; for we know 
that at the present day firs and poplars go 15 degrees further north 
than plane-trees. There is no ground for doubting that it would be 
the same in the Miocene ages ; and if so, these trees will have 
reached the pole, provided land then existed there. The Miocene 
limits of trees were therefore very different from those of the present 
day. This was made very evident by a glance at a large map of the 
Arctic zone, exhibited by Professor Heer, on which he had laid down 
the limits of trees ; he pointed out that this boundary coincides with 
the July isothermal of 10 degrees centigrade (50 Fahr.) : this falls 
under the normal parallel of 67 degrees N. Lat., so that at present 
the normal limit of trees is but a short distance within the polar 
circle, while in the Miocene age it reached to the very pole. This 
indicates a great change in the climate, and this was proved more 
definitively by the lecturer from the evidence given by the fossil 
flora of Spitzbergen and Greenland. From the character of the 
specimens brought from Spitzbergen, he concluded that it must, in 
79 degrees N. Lat., have had at that time a mean annual temperature 
of 5 degrees cent. (41 Fahr.). He had formerly estimated that in 
those ages Switzerland must have had a mean temperature of 21 
degrees cent. (69.8 Fahr.), so that the difference between the two is 
16 degrees cent. (28.8 Fahr.), or a decrease in going northward of 
0.5 cent. (0.9 Fahr.) per degree. According to this calculation we 
should have in Spitzbergen, in 78 degrees N. Lat., an annual 
temperature of 5.5 cent. (41.9 Fahr.), and in Greenland, at 70 de- 
grees N. Lat. an annual temperature of 9.5 cent. (49.1 Fahr.) ; but 
in Iceland, and on the Mackenzie, in Q5 degrees N. Lat., the 
temperature of 11.5 cent, (about 53 Fahr.), which enables us to 
explain all the phenomena in the vegetable world just described.^ 
At present the difference of temperature between Switzerland (in 
47 degrees N. Lat., and calculated at the level of the sea) and 
Spitzbergen (in 78 N. Lat.) is 20.6 cent. (37.08 Fahr.), which 
gives a difference per degree of 0,66 cent. (1.188 Fahr). In the 
Miocene times, therefore, the warmth was more equally distributed, 
and the diminution of heat in advancing to the north was much 
more gradual, so that consequently the isothermal of zero (cent., 32 
Fahr.) fell under the pole, while at the present day it comes down to 
58 degrees N. Lat. 

Lastly, the lecturer controverted the opinion that these plants had 
^ This is fully sliown in tiie •' Fossilen Flora der Polarlander," by Prof. Heer, p. 72. 



Heer — Miocene Flora of the Polar Regions, 277 

been floated, or brought by water, from a great distance to the arctic 
zone. This cannot possibly have been the case, for the leaves are in 
beautiful preservation, and lie together in great masses : they are 
found in connection with great beds of coal ; and amongst the speci- 
mens there are flowers, fruits, and seeds (nay, even berries them- 
selves), and young, tender, and even unfolded beech leaves ; and 
moreover, insects are found with them. Any one who, with a 
sound, unprejudiced mind, looks over the great variety of speci- 
mens of plants so beautifully preserved as those which fill the rocks 
of Atanekerdluk, in Northern Greenland, must come to the conclusion 
that they came from the immediate neighbourhood : in addition to 
which, the fact that the Spitzbergen plants are found in a fresh- 
water formation is a decisive proof that they were not the waifs of 
the sea. 

II. 
Professor Heer having been asked how he could explain the great 
change of climate indicated by the Miocene flora, gave a second 
lecture on this particular subject. In the first place, he discussed the 
conditions of the globe itself, which here come into consideration. A 
change of the pole, in the way which has lately been brought for- 
ward by Mr. Evans, is opposed by the fact that both in the Arctic zone 
and in the more southern latitudes, the same phenomena are observable 
all round the globe. We nowhere find indications of the pole having 
been displaced ; and we cannot, therefore, ascribe the change of cli- 
mate to any such cause. Much greater weight seems due to the idea 
that the climatic changes have arisen from a new distribution of land 
and water on the earth's surface. At the present time the proportion 
of land to water is about as 1 to 2|-. The greater part of the land is 
in the northern hemisphere, more especially in that part of it which 
is beyond the tropics. The earth, therefore, at the present moment 
is in an abnormal condition : what we should consider as the normal 
condition being a proportionate distribution of land and water over 
every zone of the earth, by which the temperate and cold zones would 
enjoy a warmer climate than they do at present. But even if we 
could imagine such a favourable apportionment of land and water, 
we should still not find such conditions as would enable us to extend 
the flora before mentioned from 70 to 79 degrees N. Lat. If we 
were to place all the main land under the tropics, and only a few 
islands in the north, the latter would, indeed, have the highest pos- 
sible medium annual temperature, and the winters would relatively 
be very mild, but the summer heat between 70 and 80 degrees N.Lat. 
never could rise so high as to produce so rich a forest flora. Besides 
this, there was apparently in the Miocene age a great quantity of 
main land in the temperate zone of the northern hemis23here, and it 
must also have extended a considerable distance into the polar regions, 
as may be proved by the spread of the Miocene plants ; for many 
kinds of trees and shrubs may be traced from the Mackenzie through 
Greenland up to Spitzbergen. Had there been only some scattered 
islands in the arctic zone at that time, these plants would never have 
spread so far. 



278 Ilecr — Miocene Flora of the Polar Regions, 

Great stress was some time since laid on the internal heat of the 
globe, and it was thought that this might account for the higher 
temperature of the early ages of the world. But even if this may 
with some probability be thought to apply to the oldest periods, it 
cannot do so to the Miocene times, for they come so near to our own 
age, that we cannot venture to attribute to such a cause so great a 
difference of temperature. It is, therefore, not possible to explain 
this great change of climate from the conditions of our globe, at any 
rate from those which are at present known to us. 

We must, therefore, turn to cosmical conditions, and see whether 
we can find in them the solution of the enigma. We may take into 
consideration the changes in the position of the earth relative to the 
sun — in the intensity of the sun's rays, and in the temperature of the 
universe. 

With respect to the first, great stress has lately been laid on the 
periodical changes in the eccentricity of the earth's orbit. It is well 
known that this is not a circle, but that it forms an ellipse, in con- 
sequence of the influence of the larger planets. The form of this 
ellipse changes within certain limits in the course of thousands of 
years. At the present moment the earth's orbit is gradually ap- 
proaching the form of a circle, and in 23,900 years the eccentricity 
will have reached its minimum, and become most like a circle, but 
from that time it will gradually become more eccentric. The mean 
distance of the earth from the sun is 91,400,000 English miles ; the 
greatest eccentricity of the orbit is about 1-1 3th of this distance, 
while the smallest is l-360th. At the time of its greatest eccentricity 
the earth would be about W\ millions of miles further from the sun 
than when its orbit most nearly approaches a circle. At the present 
time the difference amounts to 3 millions of miles. We must further 
bear in mind, that at the present time the earth in the winter of 
the northern hemisphere is nearest the sun (in perihelion), and in 
Bummer it is furthest from it (in aphelion). But even this condition is 
subject to a periodical change, which runs its course in 21,000 years. 
In about 10,000 years hence the summer of the northern hemis- 
phere will coincide with the time when the earth is nearest the sun, 
and the winter with the time when it is furthest from it ; while, of 
course, these conditions will be reversed in the other hemisphere. It 
has therefore, been assumed that at those periods when the earth has 
reached its maximum eccentricity, and when it also is nearest to the 
sun in winter (or in perihelion), this hemisphere has had a shorter 
and warmer winter, but on the other hand a longer and cooler 
summer; while the southern hemisphere must at this period have 
had exactly the reverse, that is a longer and colder winter, and a 
warmer and shorter summer, because the greatest distance from the 
sun must coincide with the winter of this hemisphere. Mr. CroU 
supposes that during this longer and colder winter so much ice must 
have formed, that the short summer, though certainly warm, would 
not have been able to melt it, and that the glacial period was a 
consequence of these conditions. During this period a perpetual 
spring would have prevailed in the other hemisphere, for the long 



Ileer — Miocene Flora of the Polar Regions. 279 

summer was cooler, and the short winter on the other hand was 
warmer. The astronomer, Mr. Stones, has calculated that 850,000 
years ago the eccentricity of the earth's orbit was at its maximum, 
and the northern hemisphere had the winter in aphelion. At that 
time the length of the winter was increased by thirty-six days. Very 
much ice and snow must have accumulated in this period, and con- 
sequently Lyell is inclined to consider this as the Glacial age. On the 
other hand, 900,000 years ago the eccentricity was at its minimum,and 
consequently other data must be given for the conditions of climate. 

But with respect to all these speculations, we must bear in mind 
the insufficiency of our knowledge as to the effect which the distance 
travelled by the sun's rays from the sun to the earth has on their 
intensity. Lyell has very justly drawn attention to the fact, that, 
according to the calculations of Dove, the earth is warmer in July, 
when it is actually further from the sun, than in December, when it 
is nearest to it. This arises from the different distribution of land 
and water in the southern and northern hemispheres, so that the latter 
has a warmer summer than the former, although in the summer the 
sun is nearer to the south than the north. But even this shows, that 
the distribution of land and sea on the earth is of much greater im- 
portance, in a question of climate, than the greater or smaller 
eccentricity of the earth's orbit, which ought not therefore to have 
Buch an excessive influence ascribed to it. Still, it is an item by no 
means to be neglected, and one which, combined with varied dis- 
tributions of land and sea, must exercise a great influence. Sir 
Chas. Lyell has demonstrated this in a most masterly manner. 

A second cosmical agent for changes of climate may be looked for 
in the sun itself. With respect to the spots on the sun's disc, we 
know that perpetual changes are going on upon the surface of the 
sun, so that there is at least a possibility that the action of the sun's 
rays may not always have been the same. 

But, besides the sun, there are also in the universe millions of 
heavenly bodies, pouring out their lightening and warming rays into 
the firmament. It is, therefore, possible, that different places in this 
infinite universe may possess a diff'erent temperature, as has been 
pointed out by the mathematician Poisson, who reminds us that the 
number of stars is so great that they form, as it were, a continuous 
covering over us. 

Now, we know that the sun, together with its planets, is continu- 
ally changing its place in the universe ; and, probably, together with 
them, is circling round some one great fixed star at an immeasurable 
distance. If we consequently venture to suppose that the universe 
has not everywhere the same temperature, we should have the most 
simple explanation of the phenomena we have described. If the 
sun, with its planets, was, in the Miocene times, in a part of the 
universe possessing a higher temperature than that in which it now 
moves, this warmth would have been proportionabty shared by every 
part of the earth, and would more especially have had an influence 
on the temperate and polar zones, and have caused a proportionate 
increase of temperature. Then, again, in this year of our sun (if it 



280 Witchell — Denudation of the Cotteswolds, 

may be so expressed), there "would be an alternation of colder with 
wanner seasons; and the Miocene age may be compared with its 
summer, the Glacial age with its winter, and our present age with 
its spring. This orbit of our sun is, indeed, one of immeasurable 
length, and we cannot yet fully comprehend it. But there is a time 
coming when its extent will be calculated ; and races yet unborn 
will teach in their hand-books the course of the sun, just as we now 
do the courses of the planets. If we, as it were, become dizzy with 
surveying the vast period of ages here spread before us, we ought to 
consider how small is the measure we are accustomed to apply to it. 
A glance will show us this. There are many living things whose 
life is but a day long. Let us imagine for a moment that one of 
these beings were endowed with consciousness ; — or that the life of 
man lasted but for a day : now, an individual, born in winter, could 
only learn by tradition that the climate was once warmer, and that 
at some future time, after a long series of generations, a warmer 
period would again occur : and another individual, born in summer, 
could only learn by means of races long since passed away, that this 
warm weather would be followed by a long cold season, and that 
afterwards the warmth would again return. One of our years must 
to these beings of a day have seemed immeasurably long, as it would 
have included 365 generations. 

But the present age of the world is not even a day, — it is hardly a 
minute of the great orbit, or year of our sun ; and no mortal will be able 
to note its phases. We certainly cannot examine them with our bodily 
eyes ; but we can do so with our mental vision ; for, in spirit, we 
can look back into far gone ages, and recognise the connection of 
phenomena which have occurred in the course of thousands of years. 
The mental eye glances into the very earliest periods of time, and 
scans even the furthest regions of the universe. 

But however small man may be corporeally, when compared 
with the immensity of nature— however short may be his life on 
the shoreless sea of time ; yet, as to his mind, he is great ; for it is 
this which raises him above the vicissitudes of ages, and gives him 
a consciousness that, under his perishable body, he hides the germ of 
an endless life. 

II. — On the Denudation of the Cotteswolds. 

By E. Witchell, F.G.S. 

(Proceedings of the Cotteswold Naturalists' Field-club. 1867.) 

THIS paper is a valuable contribution to the advancement of that 
theory of denudation which seems to be steadily gaining ground, 
and which explains the formation of present irregularities of surface 
by the action of subaerial forces. The following are the chief points 
insisted on : — 

There is no evidence that the valleys of the Cotteswolds were cut 
out by the sea or by tidal rivers : the sea would tend rather to wear 
away inequalities. There is abundant evidence of denudation, but 
it is of subaerial denudation, helped by landslips. 

It has been held that tides acting along lines of fracture are essen- 



Rath^Neio Crystalline Form of Silica. 281 

tial to the formation of the Cotteswold valleys, and it is a fact that 
there are fractures in many of the valleys ; but this is not enough, 
the existence of the conditions needful for the action of tides along 
lines of fracture must be shown ; — the land must have been low 
enough for the tides to reach it, and the fractures must have been 
opened into fissures wide enough to admit large volumes of water, 
and long enough to account for the formation of the long valleys as 
they now exist. There is no evidence of these things. 

A close connection exists between combes and springs ; there are 
no combes without a spring, and when a combe forks there is a 
spring in each branch. It may be said that the excavation of combes 
by the sea would cause springs ; but in this case surely some of the 
combes should be without springs, as one can hardly suppose that 
the sea would make combes only where subterranean springs abounded. 
This connection of combes and springs makes it hard to account for 
the formation of the former except by means of the latter. 

The widening of the valleys is owing in great part to slips ; but 
this process is now somewhat checked by the streams having been 
made more or less artificial, and therefore hindered from carrying 
away fallen matter. The slips from the Fuller's Earth are very 
many ; there is hardly a combe cut into that formation and the over- 
lying Great Oolite without a slip, sometimes stationary at present, 
sometimes moving slowly ; indeed where Fuller's Earth occurs on an 
escarpment a great part of the slope is moving. The Inferior Oolite 
has so tumbled that it is not uncommon to find quarries of the Free- 
stone on the sands below, or on the Upper Lias. 

The ^slopes facing south or south-west are more denuded and less 
steep than others, because more exposed to rain. 

A very large amount of earth is carried away by springs and 
storm-waters ; frost too has a great effect on soft Oolitic rocks. 

In going up a valley one finds that the volume of the stream gets 
less, and so also does the amount of denudation, until the valley is a 
mere hollow, and at last vanishes. Then, within a few yards, the 
ground begins to slope in the opposite direction, and gradually takes 
the form of a valley like the former, but falling the other way. 

Sub-angular gravels, which cannot be looked on as marine, but 
only as subaerial and fluviatile, are found in the valleys at heights 
ranging from 200 to 700 feet : it is clear therefore that like con- 
ditions held during the whole period of the formation of the valleys, 
and that no such deposits could have taken place in valleys washed 
by tidal waters. — W. W. 

III. — Peeliminaby Notice of a New Crystalline Fokm of 

Silica. — By Professor G. von Path. 

[Poggendorff's Annalen Band CXXXIII.] 

THE two great groups of Silica, the crystalline (Quartz) and the 
amorphous (Opal), with the respective densities of 2*65 and 
2'2 — 2-3, appear likely to have a third and intermediate species 
added, which, crystallising in forms belonging to the rhombohedral 

VOL. V. — NO. XLVII. 19 



282 Revieivs — Lartet's and Christy s Reliquice. 

system, yet possesses tlie low specific gravity of 2*2 — 2-3 ; thus by 
its crystalline character being related to the species Quartz, and by 
its low density to the species Opal. The crystals, though belonging 
to the rhombohedral system, the author states, stand in no relation to 
any of the hitherto observed forms of Quartz. They are in hexa- 
gonal tables, never simple, but always in twins, mostly of three indi- 
viduals (Drillingen), from which character the author proposes the 
name Tridymite, and under this name the mineral will be fully 
described by him in the next part of his '' Mineralogische Mit- 
theilungen." The crystals are not pseudomorphous, as has been sug- 
gested, as by polarised light they behave as doubly refracting 
optically uniaxial bodies. The Tridymite is found in small but 
sharply defined crystals in cavities in a volcanic porphyry, accom- 
panied with iron-glance and acicular crystals of hornblende from the 
Cerro S. Cristobal, near Pachuca, Mexico. Should the further 
description tend to substantiate the correctness of Professor von 
Bath's observations, it is evident that some of the arguments put for- 
ward both by the supporters and opponents of the igneous theory of 
the origin of Quartz in modern volcanic lavas and granite, based on 
its density, will be materially afiected. The fuller particulars will 
be anxiously looked for. T. D. 



• 



EELIQUIiE AQUITANICiE ; BEING CONTRIBUTIONS TO THE ArCH^OLOGY 

AND Paleontology of Perigord and the adjoining Provinces 
OF Southern France. By Edouard Lartet and Henry Christy. 
Edited by Prof. T. Rupert Jones, F.G.S. Part Y. London : H. 
Bailliere. 4to. Part V. April, 1868. 

IN this part the description of the Geology of the Vezere is completed 
by a short account of the ossiferous caves and recesses. These 
" (whether or not, in some cases, enlarged artificial^) have been 
hollowed out by atmospheric agency, where the softer alternate with 
the harder bands of limestones, the latter often still forming more 
or less continuous ledges around the interior." 

With regard to the in-filling of the cavern of Le Moustier with 
red, sandy, micaceous alluvium, very similar to the brick-earth of 
the valley below, "it is not necessary to suppose that the cave was 
on a level with the flood-waters of the valley since Man inhabited 
it; for, as Mr. John Evans has suggested (Geol. Soc. Lond. June 
22, 1864), the sand may either have been blown in by the winds, 
or, possibly, it may have reached the cave from the top of the hill 
during the formation of a talus, removed for the most part, since that 
time, by the river having swept the foot of the cliff, from which it 
has now receded." 

Some such explanation as the above is absolutely requisite in 
cases where the valley is of very considerabh^ width, and the filling 
in of some of the caves on the east side of Gilmiltar, partly by wind- 
blown sand from Catalan Bay, and in part by a talus formed of dis- 






Reviews — Lartet's and Christy's Reliquice. 283 

integrated limestone from the rock above, confirms the correctness 
of Mr. Evans's suggestion. 

In narrow valleys, however, where the river passes between per- 
pendicular limestone cliffs, the rise of the waters during heavy rains, 
(especially if obstructed by fallen trees and other similar debris) 
would be extremely rapid, and one can readily conceive that in such 
cases fine sediment might bo washed into caves considerably above 
ordinary high- water-mark. 

A gentleman engaged upon the Geological Survey in Australia, 
mentions an interesting fact in illustration of the difference of level 
in a country where the rain-fall is considerable. At the time of his 
writing home he was encamped in a dry gully or watercourse, 
where, at the height of sixty feet above his head, the wreck of last 
year's floods was still hanging from the roots and branches, and 
clinging to the rocky walls of the cliff. 

An interesting comparison is instituted between certain of the 
implements found in the caves of Dordogne, and some now used by 
the North- American Indians. Much A^aluable information, and 
many illustrations (communicated by Mr. Alexander C. Anderson, 
of Vancouver's Island), are added, which tend to explain the uses 
of many weapons not heretofore understood. Many suggestions are 
also offered as to the nomadic habits of the aborigines, their methods 
of hunting, and general mode of life. 

In the last number of the Geological Magazine, for May, p. 599, 
quoting from M. Gervais' recent work, on the animals found asso- 
ciated with man in Western Europe, " The Epoch of the Domestic 
Keindeer" is spoken of. We are glad to find so experienced an 
authority as Mr. Anderson decidedly opposed to this view. He 
writes, ''there is nothing to authorise the supposition that they" 
(the Germani or the Aquitanians) "tamed the Eeindeer for domestic 
purposes, but only hunted it." It seems very doubtful whether 
they possessed any domesticated animals, save perhaps the dog. 
That the horse was wild, like the reindeer, and formed an object of 
the chase and an article of food, is abundantly proved by the 
numerous remains met with in some of the French caverns, espe- 
cially in that of Bruniquel. From the bones of the horse many of 
their best implements (e.g. needles) were manufactured. 

Much has been said and written of late, in favour of connecting 
the ancient inhabitants of Gaul with the modern Laps, Fins, and 
Esquimaux ; probably this has arisen from the theory, that the pre- 
historic people of the south migrated northwards in quest of the 
herds of reindeer which by reason of a change in the climate, or, 
the increase of their enemies, ceased to visit central and southern 
France as in earlier times. A certain similarity in their weapons dif the 
chase and other manufactured articles discovered in their retreats has 
also favoured this view. But Mr. Anderson justly observes that" Any 
theory, based upon the disappearance of the Eeindeer from southern 
latitudes, in connexion with the migration northward in remote ages 
of the past of the Esquimaux and other northern tribes, ought, I 
submit to be very cautiously entertained." Nor would it be 



284 Revkivs — American Journals. 

prudent, I think, to found too mucli upon the similarity of imple- 
ments now, or recently, in use among divers barbarous nations, and 
the interesting relics which have been discovered in Dordogne." 
Mr. Anderson adds his belief '* that under similar circumstances and 
conditions of things, isolated branches of the human race will arrive, 
in simple matters of domestic or offensive art, at nearly similar con- 
clusions, each independently of the other." In this belief Mr. Ander- 
son is supported by M. Troyon, Dr. Ferdinand Keller, and many 
other able investigators of pre-historic man in Europe, who have ex- 
pressed their views in nearly the same words. 

The Plates in the present part, which continue to be executed in 
the same admirable manner, are Plates xv. and xvi., flint flakes, 
well selected to illustrate varieties of forms. Plate xvii., four 
cutting or chopping hatchet-like implements of flint, from Le 
Moustier, similar in type to those of the old gravel of the Somme, 
etc. Plate xviii. is devoted to the illustration of flint scrapers and 
awls. The two remaining plates commence a series of " Sketches 
on the Vezere," the first being a view of Le Moustier, the second of 
Les Eyzies, near the Junction of the Beune and the Vezere. They 
are executed by W. Tipping, Esq., F.S.A. 



n. — American Scientific and Popular Journals. 

1. Silliman's American Journal of Science (2nd Series, No. 
130, p. 96) contains an interesting description of the Glaciers of 
Alaska, Eussian America, by Mr. William P. Blake. 

"In ascending the Stickeen Kiver" (writes Mr. Blake), "one 
glacier after another comes into view ; all of them upon the right 
bank of the stream, and descend from the inner slope of the (Blue) 
mountain range. There are four large glaciers, and several smaller 
ones visible within a distance of 60 or 70 miles from the mouth. 
The first glacier observed, fills a rocky gorge of rapid descent, about 
two miles from the river, and looks like an enormous cascade. The 
mountains are greatly eroded by it, for it is overhung by freshly- 
broken cliffs of rock evidently produced by the action of the glacier.'* 

" The second glacier is much larger and has less inclination. It 
sweeps grandly out into the valley from an opening between high 
mountains, from a source that is not visible. It ends at the level of 
the river in an irregular bluff of ice, a mile and a half, to two miles 
in length, and about 150 feet high. Two or more terminal moraines 
protect it from the direct action of the stream. What, at first sight, 
appeared to be a range of ordinary hills along the river, proved, on 
landing, to be an ancient terminal moraine, crescent-shaped, and 
covered with a forest. It extends the full length of the front of the 
glacier." Within this old moraine is a belt of marsh-land and ponds 
of water, and then commences the modern moraine, which is desti- 
tute of vegetation of any kind, and covered with huge blocks of 
granite, perched in every conceivable position upon the most slender 
ice-columns, and ready to be hurled down at any moment. The 
glacier itself seemed rent and torn and faulted by huge chasms and 



Eeviews — American Journals, 285 

crevasses, filled in some cases with mud and water, in others, higher 
up, with hard snow. The surface of the glacier was found to be 
broken up into irregular stair-like blocks with smooth sides, and so 
large that it was impossible for Mr. Blake's party to ascend them 
without ladders or tools to cut footholds with. His sketches of the 
bluffs of the great glacier are very striking, and his paper will form 
a valuable contribution to the history of glacial phenomena. 

In the same number, Mr. C. A. White gives a sketch of the 
Geology of South-Western Iowa, with a clear and concise summary 
at the end of the nature and succession of the rocks from the Lower 
Coal-measures to sandstones, believed to be of Cretaceous age. In 
No. 132 there is given an account of the " San Louis Park." an im- 
mense elliptical basin (in which the Eio Grande del Norte takes its 
rise), surrounded — save where penetrated by the Poncho and other 
passes — by the lofty Sierras of the Colorado Mountains. 

The Park contains a surface-area of 9,400 square miles, at an 
average elevation of 6,400 feet above the sea-level. Entirely around 
the edge of the plain and uniting it with the mountain foot, runs a 
smooth glacis, resembling a sea-beach. From this glacis rise con- 
tinuously all round the horizon the great mountains, elevating their 
heads above the line of perpetual snow. At 5 to 6,000 feet above the 
plain a level line marks the cessation of vegetation, above which 
naked granite and snow alone are seen. 

The centre of the plain is occupied by the San Louis Lake, sixty 
miles in length, fed by nineteen confluent streams, but without any 
outlet to its waters. Its water-surface expands over the Savannah 
during the melting of the snows upon the Sierras, and contracts when 
the season of evaporation returns. Seventeen lofty peaks mark the 
serrated rim of the park, the highest of which has an elevation of 
16,000 feet above the sea. 

The climate appears to be healthy in the extreme, and subject to 
but little variation. 

The flanks of the mountains are clothed with dense forests of pine, 
fir, spruce, hemlock, aspen, oak, cedar, pinon, and a variety of 
smaller fruit-trees and shrubs, interspersed with luxuriant mountain 
pastures of verdant and nutritious grasses. 

The mineral wealth of this region appears to be great, and only 
needs railway transport to render it equal if not superior to any in 
America. Already the Park is occupied by a population of 24,000 
Mexican-American settlers, and their numbers are augmenting 
rapidly. The details of the geology of this region will be received 
with great interest. As many able Americans have already visited 
and examined it, their reports may be shortly looked for. 

In No. 133, Mr. Edward Hungerford contributes a paper on 
Evidences of Glacial Action on the Green Mountain Summits in Ver- 
mont, whose highest elevation is 4,430 feet. 

2. In No. 11 of the American Naturalist, Dr. Jeffries Wyman 
gives an account of some Shell-mounds or Kefuse-heaps in the State 
of Maine. These agree in the most singular manner with the shell- 



286 Reports and Proceedings, 

mounds of Denmark, the Orkneys, Scotland, and Ireland, containing 
abundant remains of land-animals, and birds, as well as the bones of 
fishes and the shells of mollusca, together with the rude weapons of 
stone and bone left by the aborigines, many of which strongly remind 
us of the weapons brought by our Arctic explorers from the shores 
of Arctic America, and used by the Esquimaux of to-day. 

Dr. C. A. White gives an account of certain lake -like hollows and 
depressions found in Iowa, supposed to be of artificial origin, some of 
which are now dry, and some still occupied by sheets of water. 
They have obtained the name of "walled lakes" from the heaping 
up of the large boulders along the shore in the direction of the pre- 
vailing winds, and the washing away of all the finer portions of the 
glacial drift in which these lake-basins have been formed. Dr.White 
shows that the action has continued since the Glacial epoch, and is 
going on at the present day. He gives an interesting account of the 
ancient river-terraces, also cut through the glacial drift, which covers 
a large portion of Iowa. 

3. The Canadian Naturalist and Geologist, New Series, 
Yol. III., No. I., contains a useful comparison of the icebergs of 
Belle-Isle with the Glaciers of Mont Blanc, with reference to the 
Boulder-clay of Canada, by Principal Dawson, LL.D., F.R.S., 
F.G.S. No. 3. On the Geological Formation of Lake Superior, by 
Mr. Thomas Macfarlane. On a subdivision of the Acadian Carboni- 
ferous Limestones, by Mr. C. Fred. Hartt, A.M. 

Several of the papers published in this periodical have already 
been noticed in the pages of the Geological Magazine, and we 
shall take any early opportunity to notice the others, whenever space 
permits. 

:KE:poI^TS j^istid :PI^ooEEIDIIs^C3-s. 

Geological Society of London. — I. April 8th, 1868. 

The following communications were read : — 

1. "On the Affinities and probable Habits of the extinct Austra- 
lian Marsupial, Thylacoleo carnifex, Owen." By W. H. Flower, Esq., 
F.R.S., F.G.S., etc. 

Thylacoleo was first described by Prof. Owen in the Philosophical 
Transactions for 1859, from an imperfect skull, the characters of 
which led to the conclusion that it was " one of the fellest and 
most destructive of predatory beasts," having its nearest affinities 
among existing marsupials with Dasyurus ursinus, although the 
interval be still very great between them. In a subsequent descrip- 
tion of a more perfect skull, Prof. Owen's views of the affinities, 
though not of the habits and food of the animal, were modified. It 
was stated to be more nearly related to the Diprotodons, Nototheres, 
Koalas, Phalangers, and Kangaroos, but at the same time to exem- 
plify " the simplest and most effective dental machinery for preda- 
tory life and carnivorous diet known in the Mammalian class." 

The author of the present paper, while entirely concurring with 



Geological Society of London, 287 

Prof. Owen in his later views of the affinities of Thylacoleo, and 
pointing out in detail its relations, especially with the liat Kan- 
garoos (Hypsiprymniis), and the Phalangers (Phalangista), demurred 
to the soundness of the conclusion as to its predaceous habits. He 
remarked that, as the greater number, if not all, of the known 
animals of the group to which Thylacoleo undoubtedly belongs, are 
either vegetable or mixed feeders, the probabilities would be that 
this creature conformed with its congeners in this respect, unless it 
possessed any such striking adaptive modification of the normal 
typical dentition of the group as to lead to a directly opposite con- 
clusion. 

He then proceeded to discuss this question, showing that in its 
rodent-like incisors, rudimentary canines, and hypsiprymnoid pre- 
molars it presents no sufficient approximation to any of the true 
predaceous carnivores, either placental or marsupial, as in his 
opinion to justify the inference as to its habits, which is expressed 
in the name bestowed upon it. 

2. " On the Thickness of the Carboniferous Kocks of the Pendle 
Range of Hills, Lancashire." By E. Hull, Esq., B.A., E.E.S., 
F.G.S., of the Geological Survey of Scotland. 

This paper was supplementary to a former communication by the 
author, in which he endeavoured to prove the south-easterly attenua- 
tion of the Carboniferous sedimentary strata of the North of England, 
while the calcareous member (the Mountain-limestone) attained its 
greatest vertical development in Derbyshire, and thence thinned 
away northward and westward. The author now gave the results 
of his subsequent investigations while engaged in the survey of the 
Pendle range and the neighbourhood of Burnley and Blackburn, 
which have shown that the increase in the thickness of the sedimen- 
tary deposits is continued into that district, the aggregate thickness 
of the Coal-measures, the Millstone-grit, and the Yoredale series 
being in the Burnley district 18,635 feet, while in Leicestershire it 
has dwindled down to 3,100 feet. In discussing the question of the 
source of these sediments, the author came to the conclusion that 
they were derived from a primaeval Atlantis, — a view which he 
considered to be strengthened by the fact that the Carboniferous 
sedimentary strata of North America also swell out towards the 
north-east, and become attenuated towards the south and west. 

3. " Observations on the relative Ages of the leading physical 
Features and Lines of Elevation of the Carboniferous district of 
Lancashire and Yorkshire." By E. Hull, Esq., B.A., F.E.S., of 
the Geological Survey of Scotland. 

The author first described the Pendle Range as a great arch of 
Carboniferous rocks, bordered on the north and south by a succession 
of parallel (W.S.W. to E.N.E.) arches and troughs, to all of which 
he assigned a Pre-Permian age. He regarded them as belonging 
to the earliest of three consecutive periods of disturbance, to which 
all the principal flexures and faults of the district may be referred. 
The Pennine Chain, which runs nearly north and south, he believed 
to have been upheaved during a later period, namely, the close of 



288 Reports and Proceedings, 

the Peiinian, while the numerous north-west faults of the district 
under consideration he referred to the close of the Jurassic period. 
Mr. Hull described in detail the evidence upon which these conclu- 
sions rested, observing that, immediately upon the close of the 
Carboniferous period, the northern limits of the Lancashire and 
Yorkshire coal-fields were determined by the upheaval and denuda- 
tion of the beds along east and west lines, the coal-fields themselves 
retaining their original continuity across the region now formed of 
the Pennine Hills, from Skipton southwards. At the close of the Per- 
mian period these coal-fields were dissevered by the uprising of the 
area now formed of the Pennine range, by lines of upheaval ranging 
from north to south, nearly at right angles to the former, this fact 
being of itself an evidence of difference of age. In conclusion the 
author pointed out that the denudation of the rocks of the district 
may be referred to seven periods, beginning with the commence- 
ment of the Permian and ending with the Post-glacial ; he defined 
the duration and effect of each of these periods, and stated the 
evidence on which his conclusions rested. 

4. '' On a Saliferous deposit in St. Domingo. By M. D. Hatch, 
Esq. Communicated by Sir R. I. Murchison, Bart., K.C.B., F.R.S., 
r.G.S., etc. 

The author described a deposit of salt situated about 15 miles 
from the harbour of Barabona, and about half-way between it and 
the great salt lake of Emiquilla. 

n. April 22nd, 1868. 

The following communications were read : — 
1. "On the Disposition of Iron in Variegated Strata." By George 
Maw, Esq., F.G.S. 

The author considered the subject under the following heads ; — 

1. Literature. 

2. The states of Combination of Iron in the principal stratified 
rocks. 

3. The Primary Conditions of Iron in Red beds. 

4. The variegation of Red beds due to differences in the amount of 
colouring oxide. 

5. Discolouration and bleaching connected with joints. 

6. The variegation of the Keuper Marls. 

7. The influence of organic matter in inducing variegation. 

8. Variegation due to the decomposition of Bisulphide of Iron. 

9. Variegated Cambrian slates. 

10. The discolouration of Red beds by lime and magnesia. 

11. The ferruginous banding of yellow sandstones. 

12. The condition of the Iron in the bleached areas. 

13. Exceptional cases of secondary variegation. 

14. General summary and conclusions, viz. : — 

1st. That the assumed production of the colouring matter of red 
beds from the decomposition of Iron Pyrites, appears on several 
grounds untenable. 

2nd.. With reference to the action of fossil Carbonaceous matter 



Geological Society of London, 289 

in inducing the bleaching of red beds, the mere reduction of the 
red peroxide to a lower state of oxide of less colouring power will 
in none of the cases examined account for the fact of the variegation : 
an increased proportion of protoxide to peroxide in the bleached 
portions is rarely found, and a material increase in the amount of 
protoxide in the bleached portions never occurrs. 

3rd. The bleaching induced by the presence of organic matter, and 
nearly every form of variegation of red beds, consists in the actual 
passage of the oxide of iron from the discoloured areas, unaccompanied 
by any change of combination, excepting the invariable conversion 
of the anhydrous into the hydrated peroxide. 

4th. The re -arrangement of the iron in variegated beds is not 
through the agency of dissolution, for it is more frequent in beds 
coloured with the insoluble peroxide, than where the iron occurs as 
the more soluble protoxide. 

5th. The dispersion of the peroxide of iron has been in some cases 
incited under a variety of evident conditions independent of mere 
chemical reaction, and in other cases precisely similar changes of 
position of the colouring oxide seem to have taken place arbitrarily, 
unconnected with any apparent cause or condition ; and again, in 
some cases the fresh location of the moved peroxide of iron is 
evident, whilst in others the disposal of the iron removed from the 
bleached areas is difficult to account for. 

6th. This rearrangement of the colouring peroxide of iron is 
rarely accompanied by any other change of position or state of 
combination of the other constituents of the stratum, and appears 
to be wholly independent of its chemical constitution ; in short, the 
movement of the iron seems to be inexplicable on any simple 
chemical theory. 

7th. The motion has sometimes taken place centripetally, the 
peroxide being aggregated to a nucleus forming the centre of the 
area of discolouration, and sometimes centrifugally as a ring of re- 
deposited peroxide around the bleached patch. 

8th. Of the forms of variegation due to simple chemical change, 
unaccompanied by any movement of the iron, the most frequent is 
the partial conversion of the Carbonate of protoxide into the 
hydrated peroxide, and also of the red anhydrous into the yellow 
hydrated peroxide, and less commonly the secondary formation of the 
bisulphide ; also the several stages of decomposition of the bisul- 
phide occurring in mechanical association with the peroxide, in 
various strata ; and lastly, the infiltration of lime and magnesia into 
red beds. 

9th. Some of the more complicated forms of variegation of red 
beds appear to be the joint result of the phenomena of segregation, 
and changes of combination which may have proceeded simultane- 
ously or in succession. 

10th. The ferruginous banding of yellow sandstones appears to be 
the result of the segregation of the hydrous peroxide of iron into lines 
which are invariably adjacent to a bleached part of the stratum over 
which they have advanced, gathering up the peroxide of iron in 



290 Reports and Proceedings. 

their course, and leaving behind them an exhausted area ; this 
motion has sometimes taken place in the plain of stratification. 
Occasionally centrifugally advancing from a depleted area, more 
frequently centripetally towards a nucleus which it ultimately 
environs with a ferruginous crust. 

11th. The bleaching of the Cambrian slates is due to two distinct 
causes, viz., (a) the occurrence of light bands adjacent to inter- 
bedded dark green layers, to the actual departure of the greater paii; 
of the colouring oxide without any increase in the proportion of 
protoxide to peroxide, and appears analogous to the local bleaching 
of red beds, (h) The conversion of blue and purple slate to green 
in large fields of colour by the conversion of most of the peroxide of 
iron to protoxide, and to which the green discolouration adjacent to 
the dykes of intrusive diabase is analogous. 

2. "On the older Eocks of South Devon and East Cornwall." 
By Harvey B. Holl, M.D., F.G.S. 

The author divided the rocks of the district to which the com- 
munication referred into a Lower, Middle, and Upper South Devon 
Group, and stated that the lowest beds were brought up along a 
line of country extending from Dartmoor by Hingston Down to the 
Brown Willey granite, where they formed a broad anticlinal axis. 
These rocks are unfossiliferous, and may not be lower in the series 
than the base of the Ilfracombe group of North Devon, or the highest 
part of the group immediately below it, the latter being more pro- 
bably represented by some still lower beds of red and greenish grits 
brought up to the surface in the anticlinal axis of St. Breock's Down 
further to the west. 

The Middle South Devon Group comprises at its base the discon- 
tinuous calcareous range of the Looe Eiver, St. Germans, Brickfort- 
leigh, Ashburton, and Bickerton, above which is a mass of blue and 
claret-coloured slates, which separates it from the upper or Plymouth 
and Torbay Range. 

This calcareous and fossiliferous group is succeeded by higher beds 
of blue and claret-coloured argillaceous slates, followed by hard, red, 
micaceous schists, and purple and greenish grits, which constitute 
the author's Upper South Devon Group. These rocks are very 
sparingly fossiliferous, and probably correspond to the upper and 
Morthoe portions of the Ilfracombe series of North Devon. 

The uncomformable position of the Culm-measures is seen in the 
circumstance that they rest upon different parts of the underlying 
Devonian rocks ; sometimes on the limestones of the Torbay Range, 
sometimes on the slates, at others on the volcanic rocks. This un- 
conformability entirely separates the older rocks of South Devon 
from the Carboniferous System. 

The occurrence of the genus JPteraspis and probably Cephalaspis, 
with Phyllolepis concentricus and (?) Holoptychius, and other fish- 
remains, appeared to the author to go a good way towards identify- 
ing these Cornish and South Devon beds with the Old Red Sandstone 
of Scotland. These fossils range up to the very base of the Torbay 
limestones. 



Geological Society of Glasgow. 291 

The author referred the whole of the rocks treated of, with the 
exception of the purple and greenish grits of St. Breock's Down to 
the Middle Devonian System, and considered that if the lower or 
Linton rocks were to be met with at all on the south side of the 
Culm-trough, it would be in the high ground which forms the 
watershed of West Cornwall. 

In the concluding portion of the paper. Dr. Holl entered upon the 
palseontological relations of the different South Devon Groups, and 
especially those of the Petherwin beds. 

Geological Society of Glasgow, April 2nd, 1868. — The fol- 
lowing papers were read : — 

I. '* On the Post-Tertiary Beds of Scotland." By the Eev. Henry 
W. Crosskey and Mr. David Eobertson. 

This paper dwelt upon the necessity of a classification of the Post- 
Tertiary beds, both on physical grounds and with reference to their 
fossil contents. Five distinct classes of Post-Tertiary beds were in- 
dicated. (1) Clays indicating the extreme range of cold, and with 
the most intensely Arctic fauna. Among these may be placed the 
beds at Errol, Dalmuir, Paisley, Stevenston, Lochglip, Kilchattan, 
and others. At a new bed lately investigated, near Millport, the 
plates of an Echinus, new to science, have been found. The authors 
obtained the same plates from some old beds in Norway, but are not 
aware of its occurrence in any other localities. (2) Clays indicating 
a moderate depth of water, and largely Arctic, but not so intensely 
northern as the preceding. Many of these clays crop out at half 
tide at numerous places in the Frith of Clyde, and the upper parts 
of many of the clay-pits, which have, in their lower parts, the most 
arctic fauna, may be ranked in this class. (3) Clays and sands 
denoting an increase of warmth, which continued until, very possibly, 
even a higher temperature than at present prevails, was reached. A 
typical bed of this class occurs in the Kyles of Bute. (4) Clays and 
sands in which the fauna approaches very nearly to that now preva- 
lent — the only difference being in the proportion of various species. 
Examples of this class may be seen in the lower part of the section 
at Irvine Water and the Ostrea bed near the Bridge of Allan. (5) 
The more recent raised beaches — common along the whole coast. 
It is most important that a complete list of species should be drawn 
up for every separate locality, and the authors propose to insert some 
special catalogues they have prepared, in the next part of the Trans- 
actions of the Society. 

II. " On the Surface Geology of the District round Glasgow, as 
indicated by the Journals of certain Bores." By Mr. James Bennie. 
— The object of this paper was to communicate the results obtained 
by the study of the surface portions of certain bores lately made for 
minerals, in order that the attention of geologists might be directed 
to this mode of research, as capable of supplementing natural sections, 
which are often imperfect from not exhausting the surface deposits ; 
and also in directing inquiry into interesting localities, which, from 
the surface being flat, nothing could be known except by direct 
boring. 



292 Reports and Proceedings. 

Tlie journals of bores referred to had been collected exclusively by- 
Mr. James Croll, during the latter part of last summer, before leaving 
for Edinburgh to join the staff of the Geological Survey of Scotland. 
These might be arranged into three divisions. First, — those bores 
which i^rove that breaks occun'ed in the formation of the Boulder 
clay, during which great beds of such water-formed materials as 
sand, gravel, or mud were laid down upon true ice-made debris 
alternately several times in succession, showing thereby that the 
glacial epoch was not uniform in character or duration, but was 
broken by comparatively warm periods, during which water instead 
of ice determined the character of the deposits. Some of the facts 
which proved this were very remarkable. One bore at Larkhall had 
in section — brown till, 8 feet ; sand, gravel, and mud, 36 feet ; 
brown till and boulders, 17 feet; sand, 3^ feet; brown till and 
boulders, 26 feet; mud and sand, 31 feet; brown till and boulders, 
6 feet ; from which it is evident that the water periods were not 
short, when 36 feet in the first, and 31 feet in the third were de- 
posited during their continuance. Another bore in the Mains of 
Garscadden gives — first, boulder clay, 78 feet ; then follow various 
beds of sands, gravels, and clays, 127 feet ; then succeed enough of 
Boulder-clay at the bottom to give an inter-glacial character to the 
127 feet of aqueous sediment resting upon it. Another bore, in 
the farm of Millichen, gives a greater variety. In it there are, 
first — brown clay and stones, assumed to be Boulder-clay, 17 
feet; various beds of mud, sand, and gravel, 150 feet; brown clay 
aud stones, 30 feet ; gravel and sand, 6 feet ; a thin bed of Boulder- 
clay, 6J feet ; another great water period, represented by 66 feet of 
sandy mud, and then at bottom Boulder-clay, 82 feet ; — in all, 355 
feet, which is certainly a remarkable group of deposits. Another 
bore sunk close to West Millichen farm house is 200 feet in depth, 
and consists of five beds of Boulder-clay interlaced with four beds 
of sand, one of which is 45 and another 53 feet in thickness. Upon 
the evidence furnished by these bores, the inference might be justly 
drawn, that the glacial epoch was not uniformly glacial throughout, 
but was broken up by warmer periods, during which the ice became 
water, and instead of Boulder-clay, the undoubted debris of ice, sand, 
gravel, and mud, the forms which water-made drift assumes, was 
the only sediment possible. 

The next division of bores reveal the existence of a deep trough 
or hollow, stretching from the valley of the Clyde, near Bowling, 
through Garscadden, the Haughs of Balmore, the valley of Kelvin, 
and round by the south-eastern end of the Campsie hills, into the 
valley of the Forth, by Falkirk. The first indication of its exist- 
ence is very curious. At Duntocher, the surface sand was cut into 
by the workings of a pit, belonging to Mr. Dunn, at a depth of 306 
feet, whereupon the sand rushed into the pit with such rapidity 
that the miners with the greatest difiiculty escaped with their lives. 
This proves that the surface strata at Duntocher is 306 feet deep. 
The next intimation of its existence is from a bore made by Messrs. 
Merry and Cunninghame, on the farm of Drumry, half-a-mile west 



Geological Society of Glasgow, 293 

of Garscadden House. It is 298 feet in depth ; 264 feet consist of 
sand, gravel, and mud, with 33 feet of Boukler-clay at the bottom. 
As the surface of the ground at Drumry is 68 feet above the sea 
level, and the depth of the bore 298 feet, consequently if the surface 
deposits were all removed, the sea would stand at Drumry 230 feet 
in depth. The knoll upon which Garscadden House is built rises 
78 feet above this bore. It is probable, therefore, that the surface 
deposits under the house are 376 feet in depth. The next bore in 
the line of this great hollow is that at the Mains of Garscadden, 219 
feet in depth, from the details of which it is probable that this 
hollow had an existence early in the glacial epoch. The next deep 
bore in its course is at New Kilpatrick, 222 feet, most of which 
was sand and gravel. Near Kilmardinny House a bore was driven 
to the depth of 240 feet without reaching the rock. The next is the 
deep bore at Millichen. As the top of the bore is 134 feet above sea 
level, and the bore itself 355 feet in depth, this gives 221 feet as the 
actual depth of the bottom of this hollow below sea level. The 
only height in the neighbourhood of which we are certain is where 
the Eoman wall crosses the road at 214 feet above sea level, which 
consequently gives 435 feet as the probable depth of the surface- 
deposits under the Eoman wall. So we may be certain that the 
Eoman navvies who dug the ditch which now forms the only 
remains of the wall, were in no danger of touching the rock-head in 
their excavation, and that the supply of raw material for earthworks 
was here inexhaustible. The next bore is that at West Millichen 
already detailed, 200 feet, and the last definite bore — the re- 
maining bores being imperfect from not exhausting the surface, or 
unsuitable from not being driven where the hollow is deepest. The 
following are their situations and depths : — Summerston, 150 feet, 
without reaching the rock; Buchley, 127 feet; Torrance of Campsie, 
108 feet ; Springfield, near Kirkintilloch, 212 feet, but only 111 feet is 
certain surface; Inchbreck, 110 feet; Auchenreoch House, 62 feet; 
Gavell, 72 feet ; Dumbreck, 120 feet, without reaching the rock, but 
another bore near the same place reached it at 72 feet ; Dennyloan- 
head, 92 feet; Larbert Junction, 120 feet; Camelon, near Falkirk, 
104 feet; and, finally, at Skinflats, within a mile of Grangemouth, a 
bore was driven through the estuarine mud to a depth of 240 feet, 
without reaching the rock. As the surface of the ground at Skin- 
flats is only 17 feet above sea-level, the surface deposits must be 
more than 223 feet below sea-level. Such is the strange fact which 
these bores reveal — a great, deep hollow, fairly splitting Scotland 
in twain. 

The third series of bores indicate the depth and character of the 
bottom of that branch of the glacial sea which extended from Paisley 
over to Garscadden, a distance of fully five miles, in which space 
more than 50 bores demonstrate the geography of the glacial sea- 
bottom more effectively than if an Admiralty survey of it had been 
taken when it was yet recent, and the water in it. It is shown to 
have been very uneven, as much marked by heights and hollows as 
any boulder-hillocked region on dry laud. Nine of these bores, one 



294 



Correspondence — Mr, George Maw, 



at Candren, two at Walkingshaw, five at Blythswood, and one in the 
bed of the Clyde at North Barr House, went through Boulder-clay 
alone, by which we learn that, as the ground is flat, they were sunk 
in what are now subterranean hillocks, but which were once sub- 
marine islands or shoals in a sea, depositing mud around them. 
Seventeen bores — two at Candren, nine at Walkingshaw, one at 
Blythswood, three at the Barns of Clyde, and one at Blairdardie, 
went through sand and mud only, the silt of the glacial sea filling 
up the hollows between the submerged hillocks or shoals. The 
deepest of these bores are at Walkingshaw, one being 152 and 
another 159 feet deep ; and one, at Shiels, above Kenfrew, 144 feet 
deep, and the remainder from 80 to 100 feet deep. Nineteen bores 
have more or less Boulder-clay, sometimes only a few feet, at other 
times more than half. At Craigielee, near Paisley, and Gamieland, 
near Eenfrew, rocks come above ground, and these must have 
been sunken rocks at that time, against which, doubtless, many 
an ice-berg struck. From these facts it is clear that the bottom of 
the glacial sea was extremely imdulating, as much so as any modem 
land surface. Into the hollows of the mud of the glacial sea the 
washings of these very hillocks were deposited, and in them lived 
the boreal shells which have made this region so famous in Post- 
Tertiary geology. J. A. 



coi^e»:bs:fo3^x)E3^ce. 



I.— HORIZONTAL PRESSURE AND VERTICAL DISPLACEMENT. 

Sir, — In the March number of the Magazine I made a few ob- 
servations on the probable connection between the vertical force of 
gravitation in a sphere with the horizontal force that appears to 
have produced slaty cleavage. 

The converse of this proposition is well illustrated in the dis- 
tortion of an old brick wall at Shiffnal, in this county, represented 
in the accompanying engraving, in which the coping has risen from 




its vertical support and ranged itself into an arch, leaving a vacant 
space underneath. The mortar joints had evidently been expanded 
by frost, the length of the coping thereby increased, and the expan- 
sion being horizontally resisted, the increased length was compelled 
to expand itself as a curve. 

The case seems strictly analogous to what might take place in the 



Correspondence — Mr, W, Stephen Mitchell. 295 

crust of the earth, and seems to bear out the views of the late D. 
Sharp, on the direction of slaty cleavage. 

The applicability of this illustration was first suggested to me in 
a note from the Rev. 0. Fisher, referring to my recent letter in the 
Magazine, on " Gravitation and Plorizontal Compression," in which 
he observes, " I find that if you take into consideration a spherical 
shell, of moderate, say a few miles, thickness, and conceive it for a 
moment unsupported by the matter within, then the horizontal pres- 
sure upon any two sides of a cubical element of this shell will be 
equal to the weight of a column of rock of the same density and 
half the length of the earth's radius. This would be sufficient to 
crush any strata, and is, I believe, the force to which the elevation of 
mountains is due." 

If you also take into consideration the effects of even the slightest 
inequality of local horizontal expansion, due to heat, its resolution 
vertically, in an arched form (bulging), would account for the 
fullest amount of displacement observed in the earth's crust. Take 
a segment of, say, only a hundred miles ; an expansion of but j^ 
part of its length would produce a vertical elevation of several 
hundred feet at its centre. 

The late D. Sharp's observations (Quart. Journ. of the Geol. Soc, 
vol. iii., p. 74,) tend to show the relation between the dip of slaty 
cleavage to areas of elevation in its apparent radiation from the 
axis of upheaval. If the slightest abnormal expansion is super- 
added to the uniform horizontal pressure within a sphere due to 
gravitation, it appears probable that the direction of the force would 
determine the dip and direction of cleavage plains. 

As Mr. Fisher informs me he has recently communicated a paper 
on a kindred subject to the Cambridge Philosophical Society, I for- 
bear, till it appears in print, to do more than give the drawing of 
the displaced wall-coping in further illustration of the suggestion I 
threw out in the March number of the Magazine. George Maw. 

JBenthall Hall, Broseley. 
May 2nd, 1868. 



FOSSIL PALM-LEAF FEOM THE EOCENE OF THE ISLE OF WIGHT. 

Sm, — In Room I., Wall-case 6, of the Geological Gallery of the 
British Museum is a fossil Palm -leaf in a nodule to which the follow- 
ing label is attached : — " Flahellaria lamanonis, Brogn. Eocene, 
Isle of Wight. From Dr. Mantell's Coll"- fig'i- at p. 52 of Mantell's 
fossils of the Brit. Mus. 1851." The locality given in Dr. Mantell's 
book is White Cliff Bay. On the back of the specimen is written in 
pencil " Upper Bembridge or Lower Hempstead." 

Can any of your readers state the exact locality and bed from 
which this specimen came, and whether any other specimens have 
been found in White Cliff Bay ? 

May 14, 1868. W. Stephen Mitchell. 



29C Correspondence — Rev, TF. 8, Symonds, 

FISH REMAINS IN THE LOWER DEVONIAN OF SOUTH DEVON 
AND CORNWALL. 

Sir, — I have read with much interest the comnmnication of the 
Eev. E. Wyatt-Edgell in the Geological Magazine on a Pteras- 
pidian plate found by his son the late Lieut. Wyatt-Edgell, at Mud- 
stone Bay, South Devon. 

As I was the person who detected the Pteraspidian plates in the 
cabinet of Mr. Pengelly, at Torquay, and sent them by my friend 
Mr. Leonard Lyell, for examination by Prof, Huxley, perhaps I may 
be allowed to say that several years ago the icthyic character of these 
fossils was detected by Mr. Pengelly, who only laid the specimens 
aside, as supposed sponges, on the authority of Prof. McCoy. I beg 
leave, Sir, therefore to suggest that the Devonian Pteraspis dis- 
covered years ago by Mr. Pengelly be named after that gentleman, 
who has done so much for Devonian geology, and who but for 
McCoy's mistake would have long ago made known the existence of 
a Lower Old Eed fish in the Lower Devonian seas. 

W. S. Symonds. 
Pendock Rectory, Tewkesbury, 
12 May, 1868. 

Note. — Much as one would wish to see the new Pteraspidian fish- 
plate from Devon named after Mr. Pengelly, the discoverer, j^et, 
according to the laws of nomenclature, we are bound to retain for it 
the older of the two names by which it is already known. It must, 
we fear, remain as Pteraspis (or ScapJiaspis) Cornubicus, McCoy, sp. 
(See Geol. Mag. for May, p. 248). I believe, more than twenty 
years ago, that veteran geologist, Mr. Peach, announced the dis- 
covery of fish-remains in Cornwall, in the Trans. Eoyal Geological 
Society of Cornwall, being the identical fossil afterwards called a 
Sponge (steganodictyum) by McCoy, and now once more pronounced 
a Fish by Prof. Huxley. — Edit. 



Eemains of the Gigantic Irish Deer Cervus megaceros. — Our 
correspondent, Mr. G. Henry Kinahan, M.E.I. A., etc., of the Geo- 
logical Survey of Ireland, kindly writes to informs us that he has 
just heard from Mr. William Heneby (carpenter), Thomond Gate, 
Limerick, who has obtained a skeleton of the great Irish deer 
(Cervus megaceros), of which he is desirous to dispose to some 
Museum. 

Mr. Kinahan has recommended this collector to various persons, 
and he always appears to have given satisfaction. A good skeleton 
of Cervus megaceros is a prize not to be lost sight of. — Edit. 



THE 

GEOLOGICAL MAGAZINE. 



No. XLIX.— JULY, 1868. 



I. — On the Influence of the Gulf Stkeam. 

TTTE last number of the Geological Magazine contained a trans- 
lation (by Mr. J. E. Lee, F.S.A., F.G.S., of Caerleon) of two 
lectures by Dr. Oswald Heer, '' On the Miocene Flora of the Polar 
Eegions," in which the author gives the results of his investigation 
of the fossil plant-remains from the Tertiary deposits of the north 
of Canada, Banksland, North Greenland, Iceland, and Spitzbergen. 
His examination has led him to conclude that, amongst them, there 
were nine large plants of the fern tribe, 78 kinds of trees, and 
50 shrubs. Among these, the remains of the beech and .the chest- 
nut, like those of our own island, the silver fir, spruce fir, and 
Scotch fir, the white pine of Canada, the Sequoia of California, the 
cypress and SaUshuna of Japan, the oak of temperate N. America, 
the poplar, plane-tree, birch, tulip-tree, the walnut, lime-tree, and 
magnolia have left their remains where they had grown, attesting 
a once temperate climate in Tertiary times, where now fields of 
snow and ice (once believed to be eternal) cover the length and 
breadth of the land. 

Dr. Heer's researches have been carefully considered by the late 
President of the Geological Society of London (Warington W. 
Smyth, Esq., M.A., F.E.S.), in his anniversary address (21st Feby., 
1868), from which we extract the followins: : — 

''In endeavouring to find an explanation for these facts now 
placed so distinctly before us, Professor Heer has examined a long 
series of the hypotheses which have from time to time been ad- 
vanced. He declines to admit, for a moment, any supposition of the 
displacement of the poles, and objects to the older views as well as 
to the recently propounded theory of Mr. J. Evans, F.E.S., which 
seeks to show that modifications of portions of the earth's crust may 
be attended by an actual movement of that rigid envelope over its 
internal nucleus.^ 

" Far more important, in the opinion of the Swiss botanist, is the 
speculation so admirably reasoned out by Sir Charles Lyell, on the 
climatal changes which must be produced by a new distribution of 
sea and land. And yet, granting the most favourable circumstances, 
and assuming that, instead of the present irregular and unequal 
1 For abstract see Geol. Mag. 1866, Vol. III. p. 171. 

VOL. v.— NO. XLIX. 20 



298 On the Influence of the Gulf Stream. 

distribution of sea and land, we had the continents united near the 
equator, and only scattered islets left amid great oceans in the 
higher latitudes, the mean annual temperature would undoubtedly 
be raised in no small degree, but not sufficiently to admit of the 
growth of a rich vegetation between the parallels of 70 and 80 
degrees. The very fact, however, of the wide distribution of this 
luxuriant Miocene flora shows that a large area of land was then 
amassed in the temperate and polar zones, and consequently that 
such explanation is inadequate to account for the facts. 

*' Professor Heer, like many others, is much tempted by the 
ingenious inquiries of Mr. James Croll, on the results of the vary- 
ing eccentricity of the earth's elliptical orbit. The present tendency 
of its course is towards the form of a circle, and in 23,912 years it 
will have made its nearest approximation to that figure, and the ex- 
centricity will be at its minimum, or little above half-a-million of 
miles. At the present time the linear value of the eccentricity is 
three millions, and when the orbit attains to the opposite extreme 
of form, it is above fourteen millions of miles. At present, also, the 
earth is nearest to the sun during the winter of our Northern hemi- 
sphere, and furthest during our summer. But since, in the mean- 
while, the relative position of the line of the apsides and that of the 
solstices is affected by a movement of revolution occupying 21,000 
years for its completion, our northera summer will, in about 10,000 
years, coincide with the perihelion, and the winter with the 
aphelion. Now when this latter coincidence takes place at the 
time of maximum excentricity of the orbit, the hemisphere so 
affected must suifer an unusually high degree of cold ; the moisture 
in winter would be precipitated as snow, and vast masses would 
be accumulated which the summer's heat would be unable to melt. 

'' The other hemisphere would in the meanwhile enjoy a temperate 
climate, like a continual spring. It has been calculated that such a con- 
currence of these elements of position took place 850,000 years ago, 
giving thirty-six days of winter in excess, a mean temperature in 
the latitude of London of 126° F. for the hottest, and 7° for the 
coldest month, and when it appears probable that the Grlacial period 
was in force, although only 50,000 years earlier, when the excen- 
tricity was at a minimum, the climatal conditions must have been 
entirely reversed. 

" Whilst, however, Professor Heer leans to the opinion that some 
effect from these latter causes may have combined with that of geo- 
graphical distribution of land and sea to produce changes of climate, 
and that the latter is probably the more energetic, as it is also 
the most securely deduced source of action, he looks further for as- 
sistance, and suggests the passage of our solar system through 
regions of varying temperature. This hypothesis was examined in 
detail by Hopkins, in his admirable paper on the causes which may 
have produced changes in the earth's superficial temperature, more 
particularly with reference to its being assigned as an explanation 

^ 1 For a full discussion of the causes of vicissitudes of climates, vide Lyell's " Prin- 
ciples," lOtli edit. chap, xii, and xiii. 



On the Influence of the Gulf Stream. 299 

of the cold of the Glacial period, for which he proves it to be 
entirely insufficient. Mr. Hopkins showed at the same time, that 
more might be said in favour of a maximum than of a minimum tem- 
perature acquired in this way, but yet that, if our sun were to 
approach a star within the distance of the planet Neptune, a case in- 
compatible with the continued existence of the solar system in its 
present form, the stellar radiation would not send to the earth much 
more than a thousandth part of the heat which she derives from the 
sun. The inappreciable increase of temperature derivable from this 
source renders the hypothesis untenable so long as his reasoning re- 
mains unimpugned. 

'' In order to estimate fairly the changes which may have taken 
place, we must consider the several conditions on which the climate 
of a given locality is dependent, viz, : — 

1. Its altitude above the sea-level. 

2. Its geographical latitude. 

3. Its distribution of land- and sea-surfaces. 

4. Hygrometric condition of atmosphere, cloud-formation and 

rainfall. 

5. The currents of the air and sea. 

6. The internal heat of the globe. 

The effect of the latter, being at present valued at only —^ C, may 
be neglected in questions relating to recent periods, although it 
must, in all probability, have formed an important item at the time 
of the more remote geological events." 

The distribution of land- and sea-surfaoes — the hj^grometric con- 
dition of the atmosphere, cloud formation, and rainfall — and the 
currents of the sea and air, have such an immediate and intimate 
connexion with one another that they cannot be treated separately ; 
and their important influence upon the Flora of the Polar regions 
deserves to be specially noticed — the more so, as they have been 
considered by Dr. Heer as inadequate to account for so widely dis- 
tributed a flora in Miocene times. 

From our knowledge of Tertiary Plant-beds in other parts of the 
world, and of the extremely limited areas which they cover, as com- 
pared with the associated marine deposits (the Carboniferous period 
alone excepted), it seems unnecessary to demand for the Miocene 
Arctic Flora a large and continuous land-surface, or to assume that 
the whole Polar region enjoyed a luxuriant Flora at the same time in 
precisely similar latitudes. On the contrary, we have every reason 
to assume the reverse to have been the case. 

Take, for example, two parallels of latitude at the present day. 
Mr. J. F. Campbell (author of ''Frost and Fire") writes July 30, 
1864, " Off Little Belle-isle, air 48°, water 40° ; icebergs in sight 
when the temperature was taken, wind south. Passed near a small 
berg which rose 40 feet out of water. It must have been 400 feet 
thick and 1500 long. Passed many others of far larger size ; some 
were guessed at 200 feet high, and were certainly 150 feet above 
water." ^ This is in the same latitude as London ! 
^ A Short American Tramp, p. 66. 



300 On the Influence of the Gulf Stream, 

Mr. Kedfield^ states, that in 1831 the harbour of St. John's, New- 
foundland, was closed with ice as late as the month of June ; yet 
who ever heard of the port of Liverpool, on our side, though 2° 
farther north, being closed with ice, even in the depth of Winter ? 
(Maury.) 

Again, in Baffin's Bay, on the west coast of Greenland, the glaciers 
stretch out from the shore, and furnish repeated crops of mountainous 
masses of ice which float off into the ocean.^ The number and 
dimensions of these bergs is prodigious. Captain Sir John Koss saw 
several of them together in Baffin's Bay aground in water 1,500 feet 
deep! Many of them are driven down into Hudson's Baj'', and 
accumulating there, diffuse excessive cold over the neighbouring 
continent ; so that Captain Franklin reports, that at the mouth of 
Hayes' Eiver, which lies in the same latitude as the north of Prussia 
or the south of Scotland, ice is found everywhere in digging wells, 
in summer, at the depth of four feet ! ^ 

How comes it that there is this great disparity in the relative 
temperature of places lying in tlie same parallels of latitude ? The 
explanation is to be found in the prevalence of certain winds and 
oceanic currents, which cause the isothermal line of 32° F- to vary 
as much as 14° of latitude in passing from east to west, as shown by 
Professor Dove.* 

By far the most important of oceanic currents to us is the Gulf 
Stream. It is, says Captain Maury,^ " a river in the ocean : in the 
severest droughts it never fails, and in the mightiest floods it never 
overflows ; its banks and its bottom are of cold water, while its 
current is of warm ; it takes its rise in the Gulf of Mexico, and 
empties into Arctic seas. There is in the world no other such 
majestic flow of waters. Its current is more rapid than the Missis- 
sippi or the Amazon, and its volume more than a thousand times 
greater. Its waters, as far out from the Gulf as the Carolina coasts, 
are of indigo blue. They are so distinctly marked that their line of 
juncture with the common sea-water may be traced by the eye. 
Often one half of the vessel may be perceived floating in Gulf- 
stream-water while the other half is in common water of the sea, — 
so sharp is the line, and such the want of affinity between those 
waters, and such, too, the reluctance, so to speak, on the part of 
those of the Gulf-stream to mingle with the littoral waters of the 
sea." 

This stream is about 25 miles in breadth off Cape Florida, whence 
its width increases to 127 miles off Sandy Hook, whilst its depth 
diminishes from 1000 feet to 200 and under as it proceeds north- 
wards. 

From the American coast and ihe banks of Newfoundland it is 
diverted across the Atlantic, reaching the Azores in about 78 days, 

* Silliman's American Journal of Science, vol. xiv. p. 293. 

* Scoresby's Arctic Regions, vol. i., p. 208. 

' Lyell's Principles, 10th edition, vol. i., chap, xii., p. 245. 

* Lvell's Principles, vol. i., p. 239, 

* Physical Geography and Meteorology of the Sea, 8th edition, 1860, p. 23. 



On the Influence of the Gulf Stream. 301 

after flowing nearly 3000 geographical miles. Our own islands 
enjoy its warmth, and many a Spirula and lantJdna is cast by its 
waters on our western shores. 

Scoresby observed its influence in Spitzbergen, in the 79° of N. 
latitude, the Glaciers being all stopped abruptly on their descent to 
the sea by the remnant of heat which the ocean still derives from this 
source ; whilst Dr. Petermann has shown that the stream extends 
beyond Spitzbergen along the coast of Siberia to an open sea near 
the pole.^ 

Mr. Croll ~ has estimated the total quantity of water conveyed by 
the Gulf-stream to be equal to that of a stream 50 miles broad and 
1,000 feet in depth, flowing at the rate of four miles an hour, with 
a mean temperature of 65°.^ Before it returns from its northern 
journey he concludes it has cooled down at least 25°. Each cubic 
foot of water, therefore, has carried from the tropics upwards of 1,500 
units of heat, or 1,158,000 foot-pounds. According to the above 
estimate of the size and velocity of the stream, 5,575,680,000,000 
cubic feet of water are conveyed from the Gulf per hour, or 
133,816,320,000,000 cubic feet per day. 

Capt. Maury's and Sir John Herschel's estimates are still greater 
than Mr. Croll's, the calculation of the former giving 6,166,700,000,000 
cubic feet per hour, and the latter 7^359,900,000,000 cubic feet per 
hour. Sir John Herschel estimates the temperature at 86° F. 

Principal J. D. Forbes has calculated that the quantity of heat 
thrown into the Atlantic Ocean by the Gulf-stream on a winter's 
day would raise the temperature of the atmosphere which rests on 
France and Great Britain from the freezing point to summer's heat.* 
Mr. Croll has calculated the heat received by the earth from the sun 
at the equator at the time of the equinoxes as equal to 1,780,474 
foot-pounds per square foot of surface daily, and per square 
mile 40,636,750,000^000 foot-pounds daily. But this represents 
oiily 31.2 ] 870 part of the quantity of heat daily conveyed from the 
tropics by the Gulf-stream. 

At the very time the Gulf-stream is rushing in greatest volume 
through the Straits of Florida, and hastening to the north, there is a 
cold stream from Baffin's Bay, Labrador, and the coasts of the north, 
running to the south with equal velocity. This current is ever 
flowing inshore on the North American sea-board, and beneath the 
Gulf-stream, but does not mingle with its waters. 

It will be sufficient to remind our readers that the great cause of 
these currents is identical with that which produces the atmospheric 
circulation, and that it exercises an important modifying influence in 
each case. The currents of the waters of the ocean, however, cannot 
travel with the same freedom as those of the air, being constantly 
aff'ected by land-barriers, which deflect or impede their course. To 

^ Lyell Principles, p. 215. 

2 Trans. Geol. Soc, Glasgow, vol. ii. p. 177. 

3 liyell gives the temperature on the authority of Prof. Bache as 80°. 
* Travels in Norway, p. 202. 



302 On the Influence of the Gulf Stream, 

the diurnal rotation of our earth is attributed the great equatorial 
current, which traverses the Pacific in a vast stream nearl}'- 3,500 
miles broad. Amongst the Asiatic Islands it is broken up, and a 
part turns to the north-east, supplying the Aleutian Islanders v^^ith 
timber drifted from China and Japan, while the main stream passes 
on through the Indian Ocean, and finally round the Cape, and runs 
northward into the Atlantic. This current travels at a mean rate of 
ten or eleven miles in twenty-four hours ; but when forced through 
narrow channels it acquires a much greater velocity.^ 

Passing inside the Lagullas bank, the current is continued along 
the western coast of Africa in a northerly course until deflected by 
the Guinea coast, when it strikes across the Atlantic, impinging on 
the coast of South America, south of the Amazons, with whose waters 
it unites, and flowing on into the Carribean Sea, it receives a vast 
acceleration of temperature, and again departs on a mission to the 
north as our Gulf- stream. 

To us the Gulf- stream must always be an object of extreme 
interest. It brings us genial showers, borne by the south-westerly 
winds from the surface of its warm and steaming waters. It carries 
the temperature of summer, even in the dead of winter, as far north 
as the Grand Banks of Newfoundland, and there maintains it in the 
midst of the severest frosts. It is the presence of this warm water 
and a cold atmosphere in juxtaposition which gives rise to the 
''silver-fogs " of Newfoundland, one of the most beautiful phenomena 
to be seen anywhere among the treasures of the Frost-King. Every 
west wind that blows crosses this stream on its way to Europe, and 
carries with it a portion of this heat to temper there the northern 
winds of winter.^ It is the influence of this stream upon the climate 
that makes Erin the ''Emerald Isle of the Sea" — that clothes the 
shores of Albion in evergreen robes, and encourages the Myrtle 
and the Magnolia to flourish at Mount Edgcombe in the open air all 
the year — which carries West Indian seeds to the Scottish isles, 
wafts the floating pteropods of the tropics to the latitude of Iceland, 
and renders the fauna of Spitzbergen richer than any other Arctic 
realm. To the Gulf-stream we owe our greatness as a nation, and 
that superiority of climate of which we have just spoken ; for if 
the barrier of Panama were submerged, as it has been at a compara- 
tively late geological time, the equatorial currents would flow on to 
the Pacific, and the climate of England would become like that of 
Newfoundland or Labrador, — if not colder.^ 

Nor is it merely with regard to their influence on the climate 
of the Arctic and Ant-arctic regions that the equatorial current and 
the Gulf-stream deserve our consideration ; for they must in all 
ages have mainly influenced the migration of marine animals, and in 
no small degree assisted in the distribution of land plants and 
animals, probably playing an important part even in the dispersion 
of man himself. 

1 Dr. S. P. Woodward, in " Critic," I860, No. 12. 

2 Maury, p. .56. 

=» Dr. S. P. Woodward, in " Critic," 1860, No. 10. 



Davidson — Earliest British Brachiopoda. 303 

From the foregoing statements it will be seen that oven with tho 
small amount of the Gulf-stream directed towards our shores, how 
great is the benefit we derive from the warmth which its waters 
impart to our atmosphere throughout the year. If, by a slight altera- 
ation of the trend of the land, its main body (now to a great 
extent deflected back upon the N. W. coast of Africa) were compelled 
to pass northwards into the Arctic Ocean, how enormous would bo 
the influence it would exert on the climate of Norway, Spitzbergen, 
and Siberia! — Or, on the contrary'-, suppose the cold northern current 
to descend on our shores and the full force of the Gulf-stream to be 
poured upon the shores of Greenland and Labrador, unchecked by 
the banks of Newfoundland, and any projecting lands ; again, tho 
Glaciers of these ice-locked lands would recede to their highland 
retreats, and all the valleys would become clothed with verdure, 
and be capable of supporting the vegetation of the warmer temperate 
regions, now only found there in a fossil state. — H. W. 



II. — On the Earliest Forms of Brachiopoda hitherto dis- 
covered IN THE British Paleozoic Eocks. 

By Thomas Davidson, Esq., F.R. S., F.G.S., etc. 

[PLATES XV. «fe XVI.] 

THE study of the earliest fossiliferous rocks, as well as that of 
their animal remains, has been, and will be for a long time 
to come, a subject of very considerable interest, and one that has, 
especially during the last few years, attracted the keen attention 
of several experienced and conscientious observers. Many have 
been the observations assembled in connection with the direct 
order of superposition and relative age of the various rocks com- 
posing the Cambrian and Lowest Silurian deposits, as well as in 
seeking out all the data that could be obtained, so as to enable 
the palcBontologist to attempt a correct diagnosis of the very earliest 
known ancestors of many of our fossils. The discoveries effected by 
Sir W. Logan amongst the ' Laurentian ' rocks of North America (as 
stated by Sir E. I. Murchison) " constitute the foundation stones of 
all Palasozoic deposits in the crust of the globe wherever their forma- 
tions are known ;" and with what keen interest has not the Eozoon 
been welcomed and elaborated — the oldest animal known ! 

The important discoveries of Barrande amongst the ' Primordial 
rocks ' of Bohemia have also thrown considerable light upon the 
life of that remote period, and it is truly wonderful that these 
animal remains should have been preserved to us in so complete 
a manner after the countless ages that have elapsed since the time 
of their final extinction. The creative power seems to have been 
always in operation, and as one set of organisms had served their time 
and purpose, they were either gradually or more suddenly modified 
or replaced by others more suited to the period at which they 
were called into existence. Now, setting aside the Eozoon as the 



304 Davidson — Earliest British Brackiopoda, 

oldest animal form on record, it becomes most interesting to seek 
out the exact period at which the next animal, or series of animals, 
made their appearance in the waters of our globe. It will, there- 
fore be my object in this brief communication to investigate the 
earliest Brachiopoda that have been discovered up to the present 
time in the * Primordial rocks ' of Great Britain. I had hoped, it 
is true, that my friends, Messrs. J. W. Salter, H. Hicks, T. Belt, 
E. Williamson, J. Plant, and same others, who have devoted so much 
time to the study and elaboration of the Cambrian and Lowest 
Silurian rocks of North and South Wales, and who, during their 
lengthened investigations, had assembled so many specimens, would 
have likewise completely worked out the new species of Brachioj^oda 
they had discovered ; but as a desire was expressed that such should 
be done by myself, I will now endeavour to carry out their wishes, 
although the task involves a certain amount of difficulty, from the 
circumstance that several of the species are very minute and occur 
only under the condition of internal casts and more or less perfectly 
preserved external impressions. 

It would not be possible in the short space into which the present 
communication must be compressed, to even refer to the many very 
important geological or stratigraphical labours that have been pub- 
lished upon these primordial rocks and fossils by Sir E. I. Mur- 
chison, the Eev. A. Sedgwick, Prof. Eamsay, Messrs. Salter, Hicks, 
Belt, and several others ; ^ but with the kind assistance of the 
last two named gentlemen, an attempt has been made to tabulate the 
vertical range of strata, as well as of each of the species of Brachio- 
poda, so far as such was practicable, and I will consequently, with- 
out further preamble, proceed to describe the various forms that have 
come under my notice : — 

Grenus Lingulella, Salter, 1861. 

At page B5 of my Silurian Monograph will be found a full descrip- 
tion of this genus, so far as we are at present acquainted with its 
internal characters. I was, therefore, somewhat surprised while 
reading in the twenty-third volume of the Quarterly Journal of the 
Geological Society (p. 341), '' that I had shown a bad example by 
merging Lingulella into Lingula (though the one has a pedicle 
gi'oove and the other has not)." If I, therefore, revert to this, no 
doubt, unintentional mistaken statement, it is simply in order to re- 
iterate that I adopt Lingulella as a section in the great family 
Lingulidce, and, as far as my observations extend, that all the speci- 
mens of the genus hitherto discovered in the ancient Palaeozoic 
deposits of our British Islands would be referable to the three 
following species : — 

1. Lingulella Davisii, M'Coy. PI. XV. Fig. 13-15. 

This is the largest, but not the most ancient species of the genus 

^ My thanks are also due to Messrs. J. Plant, R. A. Eskrigge, G. H. Morton, D. 
Homfruy, and J. C. Barlow for the communication of their specimens ; but parti- 
cularly to Messrs. II. Hicks and T. Belt, who have presented me with a fine and 
extensive series of specimens collected by them in North and South Wales. 



Davidson — Earliest British Brachiopoda. 



305 



! 

I 

S 

s 

•< 

1 

•< 

s 
.i 

;< 

<:5 


i 

% 

tX) 

1 

S 

m 

H 
CM 












1 


- 














Llandeilo 
Flags. 

Lower. Upper 




1 




1 


















Arenig or 
Skiddaw 
Group. 

Lower 
Llandeilo. 

Lower. Upper 


n.. 












1 










'.::::; 


Tremadoc 
Group. 

(Salter.) 

Tremadoc 

Slates. 
(Murchi- 
son.) 


-^i 
















1 
























i 


11 


Dolgelly 
Group. 
(Belt.) 
Upper 

Lingula 
Flags. 


-• 


"i 1 














-• 






\ 




















Maentwrog 
Group. 
(Belt). 
Middle 
Lingula 
Flags. 






. 


















: 




















: 








n 

p: 
o 


Menevian 

Group. 

(Salter and 

Hicks.) 

Lower 

Lingula 

Flags. 






















'• 




\ \ 
















'• i_ 
















: 


Harlech 
Group. 

(Sedgwick). 

Upper 
Longmynd. 
(Murchison) 






















• : : 






































Llanberis 
Slates. 

Lower 
Longmynd. 
(Murchison) 




















• 




















, 






























; j 


















































The black lines indicate the 

range of the species at 

present known. 

Species. 


Lingulella ferruginea, Salter. 

,, Davisii, M'Coy ... 

Icevis, Salter 


"o 

J' 

s: 

1 




.id 
O 

1 




1 

1 


Discina pileolus. H icks 

Obolella Sagiitalis, Salter ... 

„ Belli, Dav 

,, maculata, Uicks 

? Salteri, Holl 

Kutorgina ciugulata, Billings 

„ =G. Phillipsii, Holl. 

Obolus } vhimbea. Salter 


„ y&x.plicata, Hicks.... 
Acrotreta } Nicholsoni, Dav.. 
Siphonotreta micula, M'Coy.. 
Crania divaricata, M'Coy ... 
Orthis lUcJcsii. Salter 


t 

-^ 
1 


1 

1 




o 


,, calligramma, Dal 

Leptcena sericea, Sow 

Strophomena compressa^ Sow. 

Meristella crassa, Sow 

Orthisina 


-< 









































































306 Davidson — Earliest British Brachiopoda. 

with which wo arc at present acquainted ; and as it has been fully 
described in my Silurian Monograph, all I would here repeat is that 
it seems to have existed during the larger portion of the Middle and 
Upper Lingula flags, and that it apparently disappeared at about the 
termination of the ' Trcmadoc period.' I am not, however, satisfied 
that the two incomplete specimens (PL XV. Fig. 9), found by Mr. 
Belt in the upper division of his ' Maentwrog Group,' do really be- 
long to the species under description. L. Davisii is very abundant 
at Garth, Portmadoc, at Whitesand Bay, St. Davids, and in several 
other localities. 

2. LiNGULELLA FERRUGiNEA., Salter. PL XV. Fig. 1-8. 

Lingulella unguiculus, Salter. Eeport of the British Association, 
(p. 285), 1865 = L. ferruginea and L. ferruginea var. ovalis, 
Salter. Quarterly Journal Geol. Soc. (Vol. xxiii. p. 340), 1867. 

This small species has been correctly described and illustrated by 
Mr. Salter, and is, as far as we are aware, the earliest Brachiopod 
hitherto discovered, for the specimens (PL XV. Fig. 2^-'^) were 
found by Mr. Hicks at the very base of the purple and red rocks of 
the Harlech Group of Sedgwick, which directly underlies the Mene- 
vian Group or Lowest Lingula flags, ^ and where it does not appear 

^ " The little specimen kindly examined and pronounced by you (Mr. Davidson) to 
be Linff. ferruginea was recently found by me at Portbclais Harbom-, near St. David's, 
in one of the lowest beds belonging to the purple and red Cambrian rocks, exposed in 
this neighbourhood — at the very base of a series looked upon as the equivalent of the 
Harlech Group of Sedgwick and of the Upper Longmynds of Murchison, and directly 
overlying olive green grits and shales like those of North Wales and Shropshire. 
Its position, therefore, is about 1200 feet lower in the series than the specimen 
described by Mr. Salter and myself in the Quarterly Journal of the Geol. Soc. 
(vol. xxiii.), which was found, as there stated, in one of the red beds of the 
upper part of the series ; and also about 900 feet lower than the fauna subse- 
quently discovered by me in the intermediate beds, consisting of new species of 
Conocoryphe, Faradoxides, Microdiscus, Theca, Agnostus, and Liscina. It is un- 
doubtedly the earliest Brachiopod hitherto found : and it furnishes one of the first 
unmistakable evidences, yet obtained (next to the minute Rliizopod F.ozoon), of so 
very early an existence of animal life upon our globe ; lob-worms and fucoids claim, 
no doubt, an equal antiquity, but they are not of so high a form of organization. The 
Harlech fauna includes, in addition to the above-mentioned species of Conocoryphe, 
Faradoxides^ etc., another trilobite {Palceopyge Ramsayi) found by Mr. Salter in the 
Longmynds ; also the well-known Oldhamia, at Bray Head, These, inclusive, com- 
prise all the fossils yet discovered in the enormous series intervening between the 
Laurentian Rocks and the Menevian group." — (H. Hicks). 

In the Menevian Group,' along with L. ferruginea in addition to the other 
Brachiopoda from the group to be described in this paper, the following fossils have 
been found, namely: Faradoxides Favidis ; F. Ilicksii ; F. aurora; Conocoryphe 
variolaris ; C. humerosa ; C. applanata ; C. hufo ; Microdiscm imnciatus ; Anopolenus 
Salteri ; A. Henrici ; Frinnys {Harpides) venulosa ; IIolocep)halina primordialis ; 
Agnostus Favidis ; A. Barrandii : A. Fskriggii ; Fcperditia solvemis ', L. vexata : 
Frotospongia fenestrata ; F.Jlabellu ; F. diffusa : Froiocystites, S'p.; Theca corrugata ; 
T. stillclto ; T. penult ima ; Stenotheca cornucopia ; Cyrtotheca hamula ; etc., etc. I 
may also here remind the reader that it is interesting to notice how important 
a.nd well-known this group has become within the last few years. In 1862 Mr. 
Salter succeeded in finding fragments of Faradoxides and another Trilobite Micro- 
discus in the rocks of St. David's, and these were the first indications obtained of the 
presence of this fauna. In the following year Mr. Hicks succeeded in discovering no 
fewer than forty new species in these beds; these now ibnu the great and well- 



Davidson — Earliest British Brachiopoda, 307 

to be very scarce, but the beds are mucli cleaved, and the colour 
is not in any way favourable to the exhibition of the characters 
of so thin a shell. L. ferruginea is a small shell, rarely much ex- 
ceeding two and a half lines in length by some two in width. In 
external shape it is ovate, oblong, widest about the middle, broadly 
rounded in front, sides nearly parallel for some distance, while the 
beak is obtusely pointed. The valves are also very slightly convex, 
and marked with concentric lines of growth. 

After an attentive comparison of the single example of the variety 
ovalis with a number of specimens of L. ferruginea from the ' Mene- 
vian Group,' I was quite at a loss to make out any distinctive features, 
and I find that Mr. Salter himself does not fail to observe that his 
variety is not to be distinguished from the other, ''except by the 
front of the front edge, which is rounded off and not squared at all." 
However, this last character cannot be considered of any importance, 
for I have specimens before me of a similar size of L. ferruginea, 
which have the front quite as much rounded off as is seen to be the 
case in the single example of the var. ovalis. There can also be no 
doubt as to the shell originally termed unguiculus (in 1865), being 
the same species as the L. ferruginea described in 1867. L. ferruginea, 
it is true, like most of its congeners, varies slightly in its shape in 
different examples ; some, therefore, have their front a little more 
rounded than others, and the posterior portion converges rather more 
in some individuals than it does in others. After a very minute study 
of a number of specimens submitted to my examination by Messrs. 
Hicks and Belt, it appeared to me that the shell under description 
made its first appearance in the lowest beds of the Harlech period, 
and continued to live during the whole of the 'Menevian' or 'Lower 
Lingula flags,' and was very probably, if not certainly still existing, 
during the period of the deposition of the Middle and Upper Lingula 
flags ; for several examples much resembling Salter's species were 
met with by Mr. Belt in his ' Dolgelly and other divisions (?).' This, 
however, must still remain an undecided question, for several speci- 
mens of L. Icepis can hardly be distinguished from L. ferruginea, and 
in this predicament we find the small specimen found by Mr. Hicks 
at Rhyw-felyn, near Mawddach, North Wales (PL XV. Fig. 7). L. 
ferruginea occurs in the ' Menevian ' rocks of St. Davids, as well as 
at Camlan, Tafern Helig, Waterfall Valley, near Maentwrog, and 
several other places in North Wales, also in the Harlech grits of 
Solva and St. David's. 

3. LiNGULELLA L^pis, Salter. PI. XV. Figs. 10-12. 

Memoirs of the Geological Survey of Great Britain (Vol. iii. 
pp. 334, fig. 11, 1866). — This species appears to slightly exceed 
L. ferruginea in its dimensions, and is perhaps wider in proportion to 

known fauna of the 'Menevian Gronp,' which has been proved subsequently to 
extend not only through much of the N.-West of Pembrokeshire, but also in 
various districts in North Wales, and always to contain the same species as those 
first found in the district. Mr. T. Belt's valuable researches on the 'Lingula 
Flags ' will be found recorded in Vols. IV. and V. of this Magazine. 



308 Davidson — Earliest British Brachiopoda, 

its length, but, in other respects, does closely approach in external 
shape to the shell last described. Thanks to the kindness of Mr. 
Homfray, I have been able to examine a very interesting series of 
specimens of this species which he had obtained from the * Lower 
Tremadoc ' at Penmorfa Church, near Portmadoc, in North Wales. 
It is, however, much to be regretted that the shell rarely presents its 
true or normal condition, having been much distorted during the 
process of fossilization. 

Genus Lingula, Bruguiere, 1789. 

Well-authenticated species of Lingula do not appear to have been 
discovered lower down than the 'Middle Lingula flags,' where the 
genus would be first represented by L. squamosa — it is true, a badly- 
made-out species — while L. pygmea, another uncertain species, was 
found in the * Upper Lingula flags.' In the ' Arenig or Skiddaw 
Group ' we have L. petalon, but it is chiefly in the ' Llandeilo flags ' 
that the genus begins to be represented by such shells as L. attenuata, 
L. brevis, L. granulata, L. Bamsayi, and one or two others. 

Lingula petalon, Hicks, M.S. PL XV. Fig. 16. 

Shell small, broadest about the middle, from whence it becomes 
rapidly obtusely rounded ; valves much flattened and marked by con- 
centric lines of growth ; length 5, width 4J lines. 

This shell was found for the first time in 1864, by Mr. Hicks, in 
the Upper and Lower Arenig or Skiddaw group, at Whitesand Bay, 
near St. David's ; also, subsequently, in the same formation in Eamsay 
Island, and Tremanhire, but in no other group. It much approaches 
in shape to some forms of L. attenuata, but this last-named shell is 
usually larger and more elongated. 

Genus Obolella, Billings. 

In 1861 Mr. Billings proposed the genus Obolella with the follow- 
ing diagnosis : " Shell oval, circular or sub-quadrate, convex, or 
plano-convex. Ventral valve with a false area, which is sometimes 
minute, and usually grooved for the passage of the peduncle. Dorsal 
valve either with or without an area. Muscular impressions in the 
ventral valve, four : one pair in front of the beak, near the middle or 
in the upper half of the shell, the other pair situated one on each 
side near the cardinal edge. Shell calcareous, surface concentrically 
striated, sometimes with thin expanded lamellose ridges. In general 
form these shells somewhat resemble Obolus, but the arrangement of 
the muscular impressions is different. In Obolus, the two central 
scars have their smaller extremities directed downwards, and con- 
verging towards each other ; but in this genus the arrangement is 
exactly the reverse." Such is Mr. Billings's diagnosis, but I fear it 
will require some little modification in its details, if it is to comprise 
0. chromatica (the tj^pe), 0. ? politay 0. desiderata, O. Sagittalis, 0. 
maculata, O. ? Salteri, and several other species. Unfortunately the 
American material in my possession is not sufficiently complete to 
enable me to determine the point in question ; the interior of one 




Davidson — Earliest British Brachiopoda, 309 

of the valves of 0. desiderata being the only one I have been able to 

examine, and of which I here append ^^ 

a figure. The interior of 0. polita will^^M ^^^^^||^. 2 

be found figured in the 16th Annual ^^^ .^KraBi:^^™^. 

Eeport of the Eegents of the University 

of the State of New York for 1863, and 

some complete illustrations of both 

valves of O. Sagittalis are here given. 

Having sent drawings of these last to 

Mr. Billings, he wrote back, ''Your 

figures show the four muscular scars 

of Ololella, but their proportions are 

quite different from those of 0. chro- 

matica, 0. desiderata, and 0. polita. In 

TTalTq ficmrps? of O 'nnliin tTiP mimonlar 1- Exterior of OJ. (^es/rfemfo, nat. size. 
Haii S ngures OI U. poma, me muscuiar ^^ internal cast of the same greatly 

scars agree with those of my species as magnified. 
nearly as two forms of the same genus usually do, but the two an- 
terior scars are vastly larger in proportion to the size of the shell, 
than they are in 0. SagittaUs.'' I cannot, however, find any hinge 
area in the last-named shell, nor groove for the passage of a pedicle, 
this being visible only so far as I can make it out in 0. ? polita. 

Obolella Sagittalis, Salter, M.S. PI. XV. Figs. 17-24. 

Named only in the Eeport of British Association (p. 285), 1865. 

Discina lahiosa, Salter, ditto. ditto. 

Shell small, rarely exceeding two and a half lines in length and 
breadth; almost circular, rather broader anteriorly, front broadly 
rounded, beak in the dorsal valve slightly obtusely pointed, posterior 
margin in the ventral valve nearly straight or slightly indented in 
the middle. Valves convex, and more or less deeply marked by con- 
centric lines or ridges of growth. In the interior of the dorsal valve 
two rather large, irregularly circular, projecting scars {a., PL XV. 
Fig. 19) are situated close to the posterior margin, and separated by 
a moderately elevated tongue-shaped ridge which extends to about 
two-thirds of the length of the valve {e), and on either side, at about 
half the length of the valve, are two smaller oval- shaped, divari- 
cating, slightly-prominent scars {h). (In the cast these projections 
form corresponding depressions, but they vary considerably in their 
minor details according to age and specimen.) In the interior of the 
ventral valve, two oval-shaped, obliquely-placed scars, smaller than 
the corresponding ones in the opposite valve, and more widely 
separated, lie also close to the posterior margin {a). A little 
lower down, two rather larger, but very slightly marked, scars may 
be noticed ; while between the four muscular impressions a project- 
ing A-shaped ridge, with most elevated portion (o) in the middle, 
lies between the first-named scars, and leaves in the cast a deepish 
angular depression which assumes, at first sight, resemblance to an 
apicial foramen. 

This well-marked species was named by Mr. Salter in 1865, but was 
not figured or described. It is tolerably abundant under the condition 
of internal casts, which are sometimes very sharply marked, so that, 



310 Davidson — Earliest British Brackiopoda, 

I trust. I have been able to define its internal characters in a suffi- 
ciently satisfactory manner. I was, moreover, able to demonstrate 
that the so-termed Discina lahiosa had been established on the internal 
cast of the ventral valve of the species under description. This I 
ascertained, bej^ond doubt, first from finding the casts of both valves 
of 0. Sagittalis abundantly spread over the same slabs; secondly, 
because the casts agreed exactly in their resi^ective dimensions ; and, 
thirdly, because, having, b}'- the aid of gutta percha, taken moulds from 
these casts attributed to B. lahiosa, it became evident that the hollow, 
supposed to be due to a foraminal aperture, was nothing more than a 
prominence in the interior of the shell, as we have already described as 
existing between the four muscular scars. Now, if we compare the ; 
interior of the dorsal valve with the corresponding one in Crania, we 
shall find in both the same large scars («), which in that genus 
have been attributed to the divaricator muscle (Hancock), whilst 
those marked (J) would have been produced by the occlusor or ad- 
ductor muscle, and if the animal possessed ' anterior occlusors,' they 
would, as in Lingula, occu2')y the sides of the projecting tongue- 
shaped ridge at the place marked (c). Here, therefore, as in Crania, 
the divaricator scars are larger than are the occlusor or adductor 
ones. In Oholiis the scars (b) are larger than those marked (a), and 
in addition to these on either of the lateral portions of the interior of 
the valve are two other scars, not visible here. There is also a total 
absence of hinge-area or groove for the passage of a peduncle, so 
constant in Oholus. Nor do we find any trace of that flattened 
internal margin which surrounds the valves in Crania. If we again 
compare the interior of the ventral valve with that of Crania, we 
should in both cases refer the scars (a) to the divaricator, while the 
feebly-marked ones (b) would be attributable to the occlusor. 

Position and locality. — From the researches of Messrs. Hicks, 
Salter, and Belt, this remarkable and characteristic s^^ecies appears to 
be moderately plentiful throughout nearly the whole of the ' Menevian 
group,' but it is still uncertain whether a minute, obscurely-marked 
specimen found by Mr. Hicks in the upper portion of the ' Harlech 
group,' and which underlies the ' Menevian,' may not belong to the 
species under description. A still more minute shell, found tolerably 
abundantly by Mr. Belt in the Lower Tremadoc beds of Craig-y- 
dinas in North Wales, if not totally distinct from the present sj)ecies, 
would at any rate constitute a well-marked variety, or even, perhaps, 
species ; which we will, at least, provisionally, retain under the dis- 
tinctive denomination of 0. Belti. 0. Sagittalis was obtained by 
Mr. Hicks for the first time at Porth-y-rhaw, and subsequently at 
Penpleidau, and several other places near St. David's, also by Mr. 
Homfray in the beds of the Menevian formation at the Rheider 
"Waterfall Valley and other places in North Wales. Mr. Belt obtained 
it also at Gwynfynydd and in several other localities in the neigh- 
bourhood of Dolgelly. 

Obolella Belti, Dav. PL XV. Figs. 25-27. 

Shell small, less than a line in length by about one line in breadth ; 
transversely oval, beak acuminated, front broadly rounded. Valves 



Lamdson — Earliest British Brachiopoda. 311 

moderately convex and marked by concentric lines of growth. 
Lower Trcmadoc, Craig-y-dinas, North Wales. The internal cha- 
racters agree pretty closely with those already described in 0. 
Sagittalis. 

Obolella maculata, Hicks, M.S. PL XVI. Figs. 1-3. 

Report Brit. Assoc, (p. 285), 1865. 

Shell small, transversely oval, valves moderately convex : four 
lines in length by five in breadth ; beak very obtusely acuminated, 
front broadly rounded, greatest breadth at about the middle of the 
shell ; surface smooth, marked only by fine concentric lines of 
growth. Interior incompletely known. 

It has unfortunately not been possible to offer a description of the 
internal characters of this interesting fossil. I have, however, at- 
tempted to draw what little was clearly observable of its interior. 
0. maculata differs considerably from 0. Sagittalis, both on account 
of its much larger dimensions and very transverse shape. The shell 
appears also to have been much thinner than that of the species last 
named, and is often found in a much compressed or flattened state in 
the rock in which it is imbedded. 0. maculata was found by Mr. 
Hicks to occur chiefly in the middle portion of the ' Menevian 
Group ' at Porth-y-rhaw, St. David's. Mr. Belt obtained it from the 
' Lower Menevian ' at Camlan, and in the lower portion of the group 
at Gwynfynydd in North. Wales. 

Obolella r Salteri, Holl. PL XVI. Figs. 8 and 9. 

With reference to the genus to which this apparently rare species 
should be referred, some uncertainty must still prevail, for we have 
not yet seen its interior. It has been stated to occur in the ' Upper 
Lingula flags ' in the Malvern district. Mr. Belt has also found 
some specimens which I cannot distinguish from 0. ? Salteri in the 
' Lower Tremadoc ' at Craig-y-dinas, in North Wales. There would 
be nothing improbable in this species having passed from the Ffes- 
tiniog group into the overlying ' Tremadoc ' one. 

Genus Obolus, Eichwald, 1829. 

Obolus ? plumbea, Salter. Var. ]olicata, Hicks, M.S. PL XVI. 
Figs. 6 and 7. 

While describing the exterior of Ohohs ? phimlea at p. 61 of my 
Silurian monograph, I felt very uncertain as to the propriety of 
locating it with Obolella ; since that period, through the kindness of 
Mr. Morton of Liverpool, I have been able to examine the interior 
of one of its valves (PL XVI. Fig. 5), and which leads me to infer 
that the shell under notice is more nearly related to Obolus than to 
Obolella?. 

After a lengthened study and comparison of a smaller form sent to 
me by Mr. Hicks under the designation of Ob. plicata, which occurs 
sparingly in the ' Lower Arenig or Skiddaw group ' at Tremanhire 
and Ramsay Islands, near St. David's, in South Wales, I could not 
divest myself of the idea that this last w^as nothing more than a 
smaller variety of the typical form which occurs in the 'Upper Arenig' 
and ' Lower Llandeilo ' rocks of North Wales. In external shape 



812 Davidson — Earliest British Brachiopoda, 

this variety ' plicata ' is slightly transversely oval, obtusely acumi- 
nated posteriorly, broadly rounded anteriorly, while the largest 
example I have been able to examine did not exceed four lines in 
length by five in width. The valves are slightly convex, and marked 
by numerous fine thread-like radiating bifurcating striee. No suffi- 
ciently perfect interior having been discovered, I cannot attempt to 
describe its internal characters, but I have drawn the obscurely- 
marked impressions observable on a single internal cast that has 
fallen under my notice. I must also here observe that Mr. Hicks 
admits the possibility of his 0. plicata being a small variety of 0. 
plumhea. 

Genus Kutoegina, Billings, 1861. 

The characters of this genus (?) have not yet been discovered or 
described, but the exterior presents some remarkable peculiarities. 

KuTORGiNA ciNGULATA, Billings. PI. XVI. Fig. 10. Geol. Survey 
of Canada. Pal. Fossils, Vol. i. p. 8, figs. 8, 9, 10= OboMa} 
Fhillipsii, Holl, etc. Dav. Sil. Mon., p. 62. PI. 17-19. 

While preparing the first portion of my Silurian Monograph, I 
felt very uncertain as to the genus and sjoecies to which the so-termed 
0. PhiUipsn should be referred ; since then, thanks to the kindness 
of Mr. Billings, I have been able to compare his Canadian type of 
Kutorgina cingidata with a similar sized example of 0. Phdlipsii, 
kindly presented to me by the Kev. W. S. Symonds. I was also 
able to show these specimens to Dr. Holl. and he at once agreed with 
me that his 0. Phdlipsii and the American shell belonged to a single 
species. Neither, however, were at all referable to the genus Obolella^ 
their long straight hinge-line precluding such a possibility. The 
term 0. P}dllip)sii must consequently be considered as a synonym, 
Billings's name claiming priority of publication. Dr. Holl informs 
me also that the Potsdam Sandstone and shale, in which the K. cin- 
gulata is said to occur, occupies (he thinks) as nearly as possible the 
position of our ''Lingula beds," and all along the Appallachian 
chain, rests like our Hollybush Sandstone, unconformably on old 
Metamorphic rocks, which resemble precisely, and occupy the same 
position as those of the Malverns. Dr. Holl suggests the upper 
position of the Middle Lingula flags as the stage at which Kutorgina 
cingulata would occur. 

DisciNA piLEOLus, Hicks, M.S. PI. XVI. Figs. 11 and 12. Eeport 
of Brit. Assoc, (p. 285), 1865. 

Shell very small, circular or slightly longitudinally oval, rather 
broader anteriorly, about two lines and a half in length and a little 
less in breadth. Dorsal valve conical, ventral valve slightly convex 
or depressed near the margin ; vertex in both always at a short dis- 
tance from the centre, as also the foramen (?) in the ventral valve. 
Surface marked with concentric lines, which are more strongly 
marked in the ventral one. Interior not known. Mr. Salter was 
the first to detect the presence of this genus in the ' Menevian group,' 
and the species under description subsequently received the designa- 
tion of 'pileolus ' from Mr. Hicks, for we have already stated that 
the so-termed D. lahiosa (Salter) was founded on the internal cast of 



Davidson — Earliest British Brachiopoda, 313 

the ventral valve of O. Sngittalis. D. pileolus wae found by Mr. 
Hicks to occur in the Middle (Sandstone) beds of the ' Menevian 
group ' at Porth-y-rhaw, Ninewells, and Solva Harbour, St. David's, 
where it is scarce and usually very imperfectly preserved. One 
specimen of a minute Discina (PL XVI. Fig. 1^^) appears to have 
been obtained by Mr. Hicks in one of the yellowish grey beds of the 
' Harlech group,' on the road leading from Solva to Whitechurch, 
St. Davids ; and if it should turn out to be the same as the shell 
under description, which it appears to resemble, it would be the 
oldest form of the genus known, and one of the earliest Brachio- 
poda on record. B. pileolus was also found by Mr. Belt in the ' Mene- 
vian ' stage at Camlan in North Wales. 

Genus Acrotreta, Kutorga, 1848. 

AcROTRETA ? NiCHOLsoNi, Dav. PL XYI. Figs. 14-16. 
Shell small, about two lines in length by about the same in 
breadth, almost circular, rather wider and broadly rounded an- 
teriorly, nearly straight posteriorly ; dorsal valve very slightly con- 
vex ; ventral valve conical, apex sub-central and truncated by a 
minute circular foramen, which is situated at a little more than one- 
third of the length of the valve. From the centre of the posterior 
margin a narrow groove or channel extends to the base of the fora- 
men, while on either side a small flattened triangular space or false 
area {?) is limited by an indented line. Surface of both valves 
marked with numerous concentric lines of growth. 

Although the species under description has not, as far as I am 
aware, been hitherto found in Wales, it will be desirable to introduce 
it here, as it is new to Great Britain, and another of those minute 
and curious forms that have been discovered subsequent to the publi- 
cation of the first portion of my Silurian Monograph. Several 
examples of this interesting little species were sent to me in Feb., 
1867, by Dr. H. A. Nicholson, their discoverer, under the designation 
of Siphonotreta micula, but I soon perceived that they could not be 
identified with that genus or species, and although 1 am by no means 
confident as to the propriety of locating it in Acrotreta, this last is 
the genus to which our Scottish shell seems to bear the closest 
resemblance. One valve being nearly flat, the other conical, with a 
minute perforation at its apex, the longitudinal groove or canal and 
false area, — all being external features peculiar to the Eussian genus. 
However, as we know nothing of the interior of Acrotreta, and very 
little of the Scottish shell, the true generic position of this species must 
be viewed as provisional. A. ? Nicholsoni occurs in black shales in 
the Upper Llandeilo ? of Dobb's Linn, near Moffat in Dumfriesshire, 
whilst Siphonotreta micula is found at Hart Fell, or Glenkiln Burn, near 
Moffat, in distinct beds. Siphonotreta micula is, strictly speaking, a 
' Llandeilo flag ' species, but Mr Hicks believes he has found it, or 
another undeterminable allied form, in the upper portion of the 
' Arenig group ' at Whitesand Bay, St. David's. 

Genus Orthis, Dalman, 1827. 

It will not be necessary here to enter into a lengthened account of 

VOL. V. — NO. XLVIII. 21 



314 Davidson — Earliest British Brachiopoda, 

the earliest species of the genus Orthis, since they will be very shortly 
minutely described and illustrated in the third portion of my Silurian 
Monograph now in the press. Orthis is one of the earliest genera of 
Brachiopoda at present known, for it is represented by a single 
species in the rocks of the Menevian period. It is followed up by a 
fresh species in the Upper Lingula flags, and by other two new 
forms in the Arenig, or Lowest Llandovery period. 

Orthis Hicksii, Salter, M.S. PL XVI. Figs. 17-19. 

Shell small, measuring about four lines in length by five in breadth, 
transversely oval, hinge-line shorter than the greatest breadth of the 
shell, cardinal angles rounded. Dorsal valve semicircular, mode- 
rately convex, slightly longitudinally depressed along the middle. 
Ventral valve convex, deeper than the opposite one. Area triangular, 
moderately wide. Surface of valves ornamented by about ten prin- 
cipal narrow radiating ribs, with wide interspaces between each pair, 
in the middle of which is situated a shorter' rib. 0. Hicksii is a 
scarce fossil, and very rarely found in a complete condition. It was 
discovered by Mr. Hicks in the Middle (Sandstone) beds of the 
Menevian Group, at Ninewells and Porth-y-rhaw, near St. David's, 
and is the oldest species of the genus on record. It was named 
after Mr. Hicks by Mr. Salter, but was not figured or described. It 
has not been found as yet in North Wales. 

Orthis lenticularis, Dal. sp. PI. XVI. Figs. 20-22. 

This small species has been described at some length by Mr. Salter, 
at p. 339 of vol. iii. of the Memoirs of the Geological Survey of Great 
Britain. It occurs in the Upper Lingula flags (Dolgelly group of 
Mr. Belt), at Ogof-ddu, Criccieth, near Portraadoc; Penmorfa 
Church, Tremadoc; at Gwerny-y-Barcud, Ehiwfelyn, and in several 
other Welsh localities. It is immensely abundant in some beds, but 
usually of very small dimensions, and very much distorted from the 
effects of cleavage, so that it is all but impossible to obtain a complete 
example. 

Orthis menapi^. Hicks, M.S. PI. XVI. Figs. 24-28. 

Shell truncate-orbicular, rather wider than long; hinge line a 
little shorter than the greatest width of shell. Dorsal valve semi- 
circular, slightly convex, with a longitudinal depression or sulcus. 
Ventral valve rather deeper than the opposite one, with a longi- 
tudinal ridge commencing at the extremity of the small incurved 
beak, and gradually widening as it nears the front. Area rather 
narrow. Surface of both valves covered by numerous fine bifurcat- 
ing striee. About seven lines in length by eight or nine in width. 

O.-menapice is a well-marked species, but is nearly alwaj's more or 
less out of shape from the effects of cleavage and fossilization. It 
was discovered for the first time hy Mr. Hicks at the base of the 
Arenig group, or Lowest Llandeilo, at Tremanbire, and subsequently 
at Llanveran, Ramsey Island, and Whitesand Bay, all near St. David's. 
The designation menapice, assigned it by Mr. Hicks, is the classical 
name for the earliest city mentioned in the St. David's district. It 
occurs in company with the following species, but is easily distin- 
guished from it by its shape, as well as by the number and strength 
of its striae. 



Davidson — Earliest British Brachiopoda. 315 

Orthis carausii, Salter, M.S. V\. XVI. Fig. 23. 

Sub-orbicular, rather wider than long ; hinge-line the same or a 
little less than the width of the shell. Slightly indented in front. 
Dorsal valve gently convex with a longitudinal depression along the 
middle. Ventral valve deeper than the opposite one ; beak small 
incurved. Area rather narrow. Surface of valves covered with 
about sixteen simple rounded ribs, and concave interspaces of about 
equal breadth. Length seven, width eighth, depth three lines. 

This important species was discovered in the Lower Arenig Kocks 
of St. David's by Mr. Hicks about the year 1864, the shell occur- 
ing in vast abundance in the condition of internal casts and external 
impressions in yellow sandstone at Tremanhire, and in an extraor- 
dinary state of distortion in darker shales at Llanveran, Whitesand 
Bay, and at Kamsey Island, St. David's. Indeed, so great is the state 
of distortion from the effects of cleavage that one example found by 
Mr. Homfray at Llanveran measured five lines in length by twenty- 
seven in width, while the width of the shell prior to fossilization 
would not liave exceeded seven or eight. In other cases the shell 
was similarly elongated or twisted to one or other side in the most 
irregular possible manner. 

With these few remarks I will conclude; the whole subject in 
connection with this paper will in due time be more fully elaborated 
in my large Silurian Monograph. 

EXPLANATION OF PLATES XV. & XVL— PLATE XV. 

Fig. 1. Lingulellaferruginea (var ovalis), Salter, from purple beds of the Harlech 
group, St. David's. Fig. la, magnified. 
2a, b. „ „ from Porthclais Harbour, near St. David's, from 

tbe lowest beds of the purple and red Cambrian 
rocks and the earliest Brachiopod hitherto dis- 
covered ; 2 and 2a, nat. size ; 2a, enlarged. 
3-8. „ „ 3 and 4 from the 'Menevian,' St. David's ; 4 nat. size, 

after Mr. Salter's original figures ; 5 from Penmorfa, 
Tremadoc (Upper Dolgelly group of Belt) ; 6 from 
Gwern-y-barcud (Upper Ffestiniog) ; 7 from Ehiw- 
felyn (Upper Dolgelly beds) ; 8 from Tremadoc or 
Arenig group at Waun-feddu, Dolgelly. With re- 
ference to Figs. 5 to 8, some uncertainly may still 
prevail, although they very probably belong to L. 
ferruginea. 
9. „ ? specimen referred to L. Davisii by Mr. Belt from 

above Dolgelly, in his Upper Maentwrog beds. 

10-12. ,, lepis, Salter, different forms from Penmorfa church Portma- 

doc, Lower-Tremadoc. 10a, b, tvsro of Mr, Salter's 
original figures. 

13-15. „ iJavwu, M'Coy. 13, perfect specimens from Upper Lingula 

flags near Portmadoc; 14, internal cast; 15, small 
specimen out of shape from Gwern-y-barcud, Upper 
Ffestiniog. 
16. Lingula petalon. Hicks. Arenig rocks, Whitesand Bay. 

17-24. Obolella Sagittalis, Salter. A series of interiors and internal casts of both 
valves, with figures greatly magnified, the small 
ones being of natural size, from the Menevian rocks 
of St. David's. Fig. 19, interior of dorsal valve; 
20, interior of ventral valve, Mawddach Waterfall, 
Dolgelly. 

25-57. „ Belti, Dav. 25a, 27a, and 26a, enlarged. Lower Tremadoc, 

Craig-y-dinas, North Wales, 



316 Dawkins — On the Age of the Mammoth. 

PLATE XVI. 
Fig. 1-3. Oholella maculata, Hicks, " Menevian Group," Portli-y-rhaw, St. David's, 
South Wales, and Gwynfynydd and Caralan, North 
Wales. \a, 2a, 3a, magnified. 

4. Obolus ? plumhea, Salter, exterior, Lower Llandeilo, Wellfield Builth. 

5. ,, ,, „ interior, from Shelve, enlarged. 

6. „ ,, var. plicata, Hicks, exterior, Tremunhire, St. David's, 

Lower Arenig Rocks, 

7. ,, ,, „ „ internal cast of same enlarged. 

8. Obolella ? Salteri, Holl. Malvern, from original specimens. 

9. „ „ .*• Lower Tremadoc, Craig-y-diiias, N. Wales. 

10. Kutorgina cingulata, Billings = 0i. Phillipsii, Holl. a large specimen. 

Malvern. 
11-12. Diseina pileolus, Hicks, '< Menevian," Porth-y-rhaw Valley, St. David's. 

11a, \2a, enlarged. 
13. ,, ? „ from the yellow fossiliferous beds in the Harlecli 

Group, St. Davids. 13a enlarged. 
14-16. Acrotreta? Nicholsoni, Dav. Upper Llandeilo, Dobb's Linn, Moffat. 

14a, \5a, 16a, enlarged. 
17-19. Orthis HicJcsii, Salter, "Menevian," Porth-y-rhaw, St. David's. 
20-22. „ lenticularis, Dal. Upper Lingula flags, Ogaf-ddu. 

23. „ Carausii, Salter, Arenig Eocks (Lowest Llandeilo) St. Davids. 
24-28. ,, menapice, Hicks, „ ,, ,, 



IIL — On the Value of the Evidence for the Existence of the 
Mammoth in Europe in Pre-glacial Times. 

By W. Boyd Dawkins, M.A., F.R.S., F.G.S. 

EUROPE during the Tertiary period was invaded hj successive 
races of animals driven from their head quarters by press of 
numbers or by famine, or allured by some modification of circum- 
stances that was specially adapted for their well-being, in precisely 
the same way as it was subsequently invaded by successive races of 
men. Eocene Mammals were followed by Miocene, and those again 
by Pliocene, Pliocene by the Pre-glacial division of the Pleistocene, 
and, finally, the latter by the Post-glacial or Quaternary, in obedi- 
ence to the same natural laws which compelled the Stone- to vanish 
away before the Bronze-folk, and the Kelt to yield to the Teuton. 
The parallel between the conquest of Europe hj the ancient mam- 
malia and that by man is most exact. In both cases the conquering 
race absorbed a greater or less proportion of the conquered. Thus the 
Hippopotamus major and Bhinoceros Jiemitachus of the Pliocenes of 
Italy lingered on in France and Germany in association with, or, 
as it were, in a kind of helotage to, the Post-glacial fauna, just as the 
Kelt still survives in the midst of his Teutonic conquerors in Britain. 
In both there is the same uncertainty as to the ancient head-quarters 
of each race, except the last one, from which the present inhabitants 
of Western Europe are descended. Professor Max Miiller has traced 
the Aryan race from Central Asia northwards and westwards 
to the very extremitj^ of Europe, eastwards and southwards through- 
out the length and breadth of India, Persia, and Ceylon, by the 
identity in the root-meaning of words throughout that vast area. 
M. Lartet,' in 1858, traced the Post-glacial Mammalia from the 
^ Comptes Eendus, torn. xlvi. 



Dawkins — On the Age of the Mammoth. 317 

plains of Northern Asia and Siberia westward as far as the Pyrenees, 
their southern boundary being formed by a line passing between the 
Alps and the Caspian. Subsequently, in 1859, the discovery of the 
remains of the Mammoth at Kome compelled him to extend its range 
at least as far south as the valley of the Tiber, where it lived while 
the masses of tufifa which composed the seven hills of the Eternal 
City were being poured forth from active volcanos. 

In the Post-glacial fauna the Mammoth occupies a very important 
position, on account of its great range and the fact that its large 
molars are those of all others the first to have attracted the attention 
of naturalists, as well as from the vast quantity of its remains whicli 
occur in a fossil state in Siberia. Any proposition therefore that 
affects it, affects also the whole question of the origin of the Post- 
glacial fauna. If it be proved that the animal existed in Europe in 
Pre-glacial times, then M. Lartet's admirable theory of the migra- 
tion ^ of the Quaternary fauna into Europe after the Glacial epoch 
falls to the ground, and the animal loses all classificatory value in 
the determination of Pre- from Post-glacial deposits. The late Dr. 
Falconer towards the close of his life held that it dwelt in Europe 
at the time of the deposition of the forest bed of the Norfolk shore ; 
and M. Lartet himself has been so convinced of the truth of his con- 
clusion, that he has lately published an essay, in which he quotes the 
animal as one of those few which survived the physical changes that 
intervened between the Pre- and Post-glacial epochs,^ If the animal 
lived here along with Elephas meridionalis, then it cannot be viewed 
as a fellow-immigrant with the Eeindeer. It is, therefore a point of 
very high importance to determine the value of the evidence on 
which Dr. Falconer founded his conclusion, which we are able to do 
by the late publication of all his data in the magnificent work con- 
taining his scientific essays, and the more valuable portions of his 
private notes.^ 

The only remains of the Mammoth that can by any possibility be 
ascribed to the Forest-bed are those in the possession of the Kev. S. 
W. King, F.G.S., the Eev. John Gunn, F.G.S., and in the Wood- 
wardian Museum at Cambridge. "With reference to the first of these 
Dr. Falconer writes as follows, page 164^ : — 

" I have also examined two specimens of the first true molar, upper 
jaw of Elephas primigenius, in the collection of the Kev. S. W. King, 
from the Norfolk coast section, near Cromer. The specimens were 
carefully compared with a molar from Ilford, in the valley of the 
Thames, belonging to Mr. Prestwich. 

"The specimen first to be noticed, marked No. 3, is labelled 
* Picked out of blue clay and black gravel on beach, solid level, after 
scouring from shoot of cliff, in March, 1860 (Anderson, Cromer).' 

" It is a very perfect example of an antepenultimate true molar, 
upper jaw right (t. m. 1) presenting the crown quite perfect. The 

^ Comptes Eendus, torn, xlvi., p. 409. 

2 Note sur Deux Tetes de Carnassiers Fossiles Ann. des Sc. Nat. 5 ser. torn viii. 

3 Palseontological Memoirs of the late Hugh Falconer. Edit, by Dr. Murchison. 
Vol. ii. 



318 Dawk'ms — On the Age of the Mammoth, 

crown is composed of twelve principal ridges, with front and back 
talons ; the nine anterior ridges are worn, the rest intact, and 
enveloped in cement. The most anterior ridge is confluent in its 
disc with the adjoining talon disc. The second disc is confluently 
transverse, somewhat irregularly reniform in its contour, the con- 
vexity being directed backwards. The third is composed of three 
semi-detached, oblong discs, the worn digitations not having become 
quite confluent. The four or five posterior ridges are but very 
slightly affected by wear. The ground surface of the crown is broad 
relatively to the length of the molar ; the ridges are high, thin, and 
closely compressed. The plates of enamel are decidedly thin, pre- 
senting no appearance of crimping or primary undulation, the only 
plicature shown being that produced by the confluence of the discs 
(that is, secondary undulations). In all these respects this molar 
bears a very close resemblance to Mr. Prestwich's Ilford specimen. 
The fangs are all broken off below, where, in the interstices, the 
matrix is distinctly seen, in some places penetrating into the hollow 
cores of the fangs. This matrix consists of a very ferruginous, fine 
sand, containing small pebbles, and closely agrees with the matrix 
of the Elephant-bed at Mundesley. There are also some patches of 
blue clay, resembling that of the laminated blue beds. There is no 
appearance of a disc of pressure behind, but this is intelligible from 
the semi-worn condition of the tooth. The fresh broken surfaces of 
the ivory of the fangs presents a dull cholocate, or pale sepia colour, 
like that of the Mammoth molars, from the 'Big-bone-lick' of 
America : it burns blac